JP2004004629A - Liquid crystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device which reduces the capacity of a memory for storing LUTs and performs natural quick display in consideration of additional conditions such as temperature. <P>SOLUTION: The liquid crystal display device includes an applied gradation value acquisition part which receives succeeding gradation data, preceding gradation data, and measurement data from a temperature sensor 8 and calculates gradation data required for gradation display as target gradation data by referring to a plurality of LUTs stored in an LUT memory 12 to perform interpolation operation. Interpolation operation according with the measurement data is performed in accordance with table interpolation values from the applied gradation value acquisition part to calculate the target gradation data. Thus, target gradation data (interpolated values) of high accuracy is obtained by interpolation operation using local coordinates in consideration of various additional conditions. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention generally relates to a liquid crystal display device, and more particularly to a liquid crystal display device used for a television or an OA (Office Automation) device, or used as a monitor for a CAD (Computer-Aided Design) system.
[0002]
[Prior art]
The liquid crystal display device has been recently becoming an image display device that surpasses a cathode ray tube because the performance such as viewing angle, contrast, color reproducibility, and response speed has been improved in recent years in addition to features of space saving and power saving. Therefore, application of the liquid crystal display device to a television, a monitor for OA (computer monitor), and the like is expected to continue to expand in the future.
[0003]
Normally, when a voltage is applied to the liquid crystal cell, the long axis direction (director) of the liquid crystal material (liquid crystal molecules) in the liquid crystal cell changes due to its dielectric anisotropy. Since the liquid crystal material has optical anisotropy, when the direction is changed, the polarization direction of light transmitted through the liquid crystal cell also changes. The amount of light transmitted through the liquid crystal cell is controlled by the applied voltage (applied voltage) applied to the liquid crystal cell with the action of a polarizing plate or the like provided in the liquid crystal cell. Thereby, the luminance of each pixel can be set to the gradation luminance desired to be displayed, and an image can be displayed.
[0004]
However, it takes a certain amount of time for the liquid crystal material to respond to a change in the applied voltage (the response speed of the liquid crystal material is slow). For example, in the case of TN (Twisted Nematic), IPS (In-Plane-Switching), or VA (Vertically Aligned) in a currently widely used liquid crystal display method (liquid crystal display mode), the response speed of the liquid crystal material is slow. 30 msec to 50 msec between gradations. Therefore, a response speed corresponding to 60 Hz (about 16.6 msec) of an NTSC (National Television System Committee) signal or 50 Hz (20.0 msec) of a PAL (Phase Alteration by Line) signal cannot be realized. Therefore, in order to meet the demand for further market expansion, higher performance is required.
[0005]
Therefore, conventionally, a liquid crystal display device with a high response speed has been developed by devising a liquid crystal material and a display driving method.
[0006]
For example, Japanese Unexamined Patent Publication No. Hei 10-39837 (Patent Document 1), which is a public patent publication of Japan, applies a voltage larger than a voltage difference corresponding to a gradation change so that a liquid crystal material is sharply changed. A liquid crystal display device using “overshoot driving” for moving to a target gradation is disclosed. In the overshoot drive, an applied gradation value to be applied to the liquid crystal material in association with a start gradation (current gradation) and a target gradation (desired gradation) (or an applied voltage value for realizing the applied gradation) ) Is prepared in advance, and a voltage is applied based on the look-up table (LUT).
[0007]
[Patent Document 1]
JP-A-10-39837 (publication date: February 13, 1998)
[0008]
[Problems to be solved by the invention]
However, in the configuration described in the above publication, it is desirable to create an LUT by previously obtaining an applied voltage value (applied voltage values of all gradations) corresponding to all patterns of gradation change. This leads to a problem that the capacity of the memory to be used becomes extremely large.
[0009]
Further, in the configuration of the above publication, there is also a problem that appropriate overshoot driving cannot be performed depending on additional conditions such as the temperature of the liquid crystal display device, and natural high-speed display cannot be performed.
[0010]
In other words, the response speed of the liquid crystal display device changes remarkably when the viscosity of the liquid crystal material changes due to a change in the temperature of the liquid crystal display device. In this case, the overshoot drive is not sufficiently effective due to a decrease in the response speed of the liquid crystal material, the response speed is not sufficiently high, and writing cannot be performed in time. On the other hand, when the temperature is high, the overshoot drive is too effective, so that the display becomes excessively emphasized in white and black, which impairs the display characteristics of the liquid crystal display device.
[0011]
As a countermeasure against this problem, a method is considered in which a plurality of LUTs are prepared in advance for each temperature, and the LUT to be used is automatically switched to an optimum LUT suitable for the temperature of the liquid crystal display device using a temperature sensor or the like. Can be However, considering the capacity of the memory for storing the LUT, it is practically difficult to prepare the LUT for all gradations and all temperatures.
[0012]
In addition, although only the temperature has been described here, factors that change the response speed of the liquid crystal display device include various factors other than the temperature, such as the cell thickness of the display panel and the video frequency. It is very difficult to provide an LUT for all conditions, even if the number of gradations is limited.
[0013]
The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to reduce the capacity of a memory for storing an LUT by using an interpolation operation. It is another object of the present invention to provide a liquid crystal display device capable of performing natural high-speed display by performing appropriate overshoot driving in consideration of additional conditions such as temperature.
[0014]
[Means for Solving the Problems]
In order to solve the above-described problems, the liquid crystal display device of the present invention has at least one look for storing a plurality of pre-grayscale values and post-grayscale values, and a corresponding grayscale voltage value applied to the liquid crystal display. An up-table, and an applied gray-level value acquiring unit that refers to at least one of the look-up tables and determines a gray-scale voltage value applied to the liquid crystal display to change the liquid crystal display from a previous gray level to a second gray level. And the corresponding applied gradation value is read out from at least one of the look-up tables in which the preceding gradation value and the subsequent gradation value are stored. It has a configuration determined by interpolation using a local coordinate system including a grayscale axis and a plurality of applied grayscale values corresponding to pre-grayscale values and rear grayscale values stored in the local coordinate system. Doing .
[0015]
According to the above invention, at least one look-up table is provided, and each look-up table includes a plurality of pre-grayscale values and post-grayscale values, and corresponding grayscale voltage values (the above-described grayscale voltage values applied to the liquid crystal display). (A gradation voltage value corresponding to the previous gradation value and the rear gradation value) are stored. When the gradation voltage value is determined and applied to the liquid crystal display by the applied gradation value acquiring means, the display is changed from the previous gradation (currently displayed gradation) to the second gradation (desired target gradation). change.
[0016]
When the display is changed based on the corresponding applied gradation value, the corresponding applied gradation value is read from at least one of the look-up tables in which the preceding gradation value and the rear gradation value are stored.
[0017]
If the corresponding applied gradation value is not stored in the look-up table, the applied gradation value acquisition means refers to at least one of the look-up tables to determine the gradation voltage value. At this time, the applied gradation values are divided into a local coordinate system including a previous gradation axis and a rear gradation axis, and a plurality of applied gradations corresponding to the previous gradation values and the rear gradation values stored in the local coordinate system. It is determined by interpolation performed using the key value.
[0018]
As described above, since the desired applied gradation value is obtained by interpolation based on the stored applied gradation values, the capacity of a memory or the like for storing the look-up table (LUT) can be reduced. In other words, the LUT can be created by thinning out the pre-gray scale and the post-gray scale, rather than all gray scales.
[0019]
Therefore, the liquid crystal display device of the present invention can calculate a high-accuracy applied gradation value without increasing the capacity of a memory or the like, for example, as compared with the conventional case where local coordinates are not used. As a result, by using the interpolation calculation, it is possible to reduce the capacity of the memory for storing the LUT as much as possible, and to perform the appropriate overshoot drive to perform natural high-speed display.
[0020]
In the liquid crystal display device, at least one of the look-up tables includes at least one additional condition look-up table provided in accordance with an additional condition for changing a response characteristic of the liquid crystal, and includes a look-up table from a pre-gray scale to a post-gray scale. The applied gradation value that changes the display to a gradation changes according to the additional condition, and the applied gradation value acquiring unit performs the interpolation calculation using at least one of the additional condition lookup tables. Is preferably performed.
[0021]
In this case, at least one LUT is prepared according to an additional condition for changing the response characteristic of the liquid crystal, and an applied gradation value can be obtained in consideration of the additional condition. In this case as well, the number of LUTs is reduced by thinning out not all additional conditions but additional conditions so that the capacity of a memory or the like for storing the LUT can be reduced.
[0022]
Therefore, compared to an interpolation value that does not use the local coordinates as in the related art and that does not take into account additional conditions such as temperature, a high-precision application is performed while taking into account the additional conditions without increasing the capacity of the memory or the like. The gradation value can be calculated. As a result, by using the interpolation calculation, the appropriate overshoot drive is performed while reducing the capacity of the memory for storing the LUT as much as possible and without being affected by additional conditions such as temperature. Natural high-speed display can be performed.
[0023]
In performing the interpolation operation using the local coordinate system, the applied gradation value acquiring unit may be configured to store the stored previous gradation value and the rear gradation value close to the previous gradation value and the rear gradation value to be displayed. Preferably, four combinations are selected, one of which is used as the origin of the local coordinate system, and the difference between the origin and another combination is used as a local variable.
[0024]
According to the above configuration, when setting the local coordinate system, first, four combinations close to the combination of the previous gradation and the subsequent gradation to be displayed by the interpolation calculation, for example, already stored in the LUT. Of the combinations of the preceding gradation and the later gradation, a combination close to the target combination gradation is displayed on a spatial axis defined by the preceding gradation and the later gradation. Then, a local coordinate system having one of the four combinations as the origin is set.
[0025]
It is preferable that the applied gradation value acquiring means performs an interpolation operation using a local coordinate system having an axis defined by the preceding gradation, the following gradation, and the additional condition (attached to the axis). . The additional condition includes temperature.
[0026]
In performing the interpolation operation using the local coordinate system, the applied gradation value acquiring unit uses two look-up tables close to the additional condition, and uses a preceding gradation value and a rear gradation value to be displayed. Four combinations of the stored pre-grayscale value and post-grayscale value that are close to the selected value, and one of these eight combinations is set as the origin of the local coordinate system having these eight combinations. It is preferable to use the difference between and the other combination as a local variable.
[0027]
According to the above configuration, when setting the local coordinate system, first, two LUTs that are close to the additional condition are selected, and in each LUT, the LUT of the pre-gray scale and the post-gray scale to be obtained by the interpolation calculation is selected. Four combinations close to the combination (target combination gradation) are selected. Therefore, since two LUTs are used, eight combinations are selected. Then, a local coordinate system having one of the eight combinations as the origin is set.
[0028]
In such a local coordinate system, for example, the local coordinate system to which the target combination tone belongs can be correctly specified, as compared with a local coordinate system defined using the values of the preceding tone, the later tone, and the additional conditions as they are. Therefore, the interpolation accuracy of the acquired applied gradation value (interpolation value) is improved.
[0029]
In performing the interpolation operation using the local coordinate system, the applied gradation value acquiring unit stores the stored previous gradation value and the rear gradation value that are close to the previous gradation value and the rear gradation value to be displayed. Preferably, one of the four combinations is selected, one of the combinations is used as the origin of the local coordinate system, and the difference between the origin and another combination is used as a local variable.
[0030]
According to the above configuration, when the local coordinate system is set, first, four combinations that are close to the combination (target combination gradation) of the previous gradation and the subsequent gradation to be acquired by the interpolation calculation, that is, Of the combinations of the preceding gradation and the later gradation stored in the LUT, a combination close to the target combination gradation to be displayed is displayed on a spatial axis defined by the preceding gradation and the later gradation. Then, a local coordinate system having one of the four combinations as the origin is set.
[0031]
In such a local coordinate system, for example, compared to a local coordinate system defined using the values of the preceding and subsequent gradations as they are, the local coordinates to which the target combination gradation belongs can be correctly specified. The interpolation accuracy of the gradation value (interpolation value) is improved.
[0032]
In the above liquid crystal display device, the space represented by the local coordinate system is divided into an area composed of n + 1 vertices having the stored combination of applied gradation values as vertices, and the number of coordinate axes of the local coordinate system is n (n is an integer of 2 or more), and the applied gradation value acquiring means preferably performs the interpolation in any divided area.
[0033]
According to the above configuration, for example, if the local coordinates are associated with coordinates (three-dimensional coordinates) having the second gradation, the previous gradation, and the additional condition as axes, four points correspond to the applied gradation values. Enclosing a point (target point) on the local coordinates. Then, in order to easily represent the target point represented by the three (n = 3) coordinate axes of the local coordinates by the interpolation formula used for the interpolation operation, four unknowns are required. Therefore, four (n + 1 = 3 + 1) grid points are required. That is, if an interpolation operation is to be performed by expressing the target point by, for example, a linear expression, it is sufficient if there are four grid points. Therefore, according to the above configuration, the interpolation operation can be performed by the interpolation formula using the linear expression, and the labor required for the calculation of the interpolation operation can be reduced (for example, the memory capacity is reduced).
[0034]
It is preferable that the applied gradation value acquisition unit further performs an interpolation operation using an intermediate point located on a side connecting the n + 1 vertices, in addition to the n + 1 vertices.
[0035]
According to the above configuration, the number of points that can be used in the interpolation formula increases. Therefore, for example, an interpolation operation using a polynomial such as a quadratic expression can be performed. Therefore, the interpolation accuracy can be improved as compared with the linear expression.
[0036]
According to another liquid crystal display device of the present invention, at least one look-up table storing a plurality of pre-grayscale values and post-grayscale values, and corresponding grayscale voltage values applied to the liquid crystal display, respectively, If the key value is not stored in the at least one look-up table, the at least one look-up table is referred to and applied to the liquid crystal display to change the liquid crystal display from a previous gray level to a subsequent gray level. An applied gradation value acquiring unit for determining a gradation voltage value.
[0037]
According to the above invention, at least one look-up table is provided, and each look-up table includes a plurality of pre-grayscale values and post-grayscale values, and corresponding grayscale voltage values applied to the liquid crystal display. Is stored. When the gradation voltage value is determined and applied to the liquid crystal display by the applied gradation value acquiring means, the display is changed from the previous gradation (currently displayed gradation) to the second gradation (desired target gradation). change.
[0038]
When the applied gradation value is stored in at least one of the look-up tables, the applied gradation value acquiring means reads the value. On the other hand, if it is not stored, the applied gradation value acquiring means refers to at least one of the look-up tables, and changes the gradation applied to the liquid crystal display to change the liquid crystal display from the previous gradation to the rear gradation. The adjustment voltage value is determined by interpolation.
[0039]
As described above, since the desired applied gradation value is obtained by interpolation based on the stored applied gradation values, the capacity of a memory or the like for storing the look-up table (LUT) can be reduced. In other words, the LUT can be created by thinning out the pre-gray scale and the post-gray scale, rather than all gray scales.
[0040]
Therefore, the liquid crystal display device of the present invention can calculate a high-accuracy applied gradation value without increasing the capacity of a memory or the like, for example, as compared with the conventional case where local coordinates are not used. As a result, by using the interpolation calculation, it is possible to reduce the capacity of the memory for storing the LUT as much as possible, and to perform the appropriate overshoot drive to perform natural high-speed display.
[0041]
It is preferable that the applied gradation value acquisition means performs an interpolation operation using local coordinates having the preceding gradation and the following gradation as axes.
[0042]
In the above-mentioned liquid crystal display device, at least one of the look-up tables is prepared according to at least one additional condition for changing a response characteristic of the liquid crystal, and prepared by thinning out at least one of the additional conditions. When there is no lookup table that satisfies the corresponding additional condition, the applied gradation value acquiring unit calculates a value obtained by performing an interpolation operation using the applied gradation value stored in at least one of the lookup tables. It is preferable to determine the applied gradation value.
[0043]
In this case, at least one LUT is prepared according to an additional condition for changing the response characteristic of the liquid crystal, and an applied gradation value can be obtained in consideration of the additional condition. In this case as well, the number of LUTs is reduced by thinning out not all additional conditions but additional conditions so that the capacity of a memory or the like for storing the LUT can be reduced.
[0044]
Therefore, compared to an interpolation value that does not use the local coordinates as in the related art and that does not take into account additional conditions such as temperature, a high-precision application is performed while taking into account the additional conditions without increasing the capacity of the memory or the like. The gradation value can be calculated. As a result, by using the interpolation calculation, the appropriate overshoot drive is performed while reducing the capacity of the memory for storing the LUT as much as possible and without being affected by additional conditions such as temperature. Natural high-speed display can be performed.
[0045]
According to the above configuration, for example, in the case of a local coordinate system associated with coordinates (three-dimensional coordinates) having the second gradation, the previous gradation, and the additional condition as axes, the applied gradation value is calculated at four points. The corresponding point on the local coordinates (target point) is enclosed. Then, in order to easily represent the target point represented by the three (n = 3) coordinate axes of the local coordinates by the interpolation formula used for the interpolation operation, four unknowns are required. Therefore, four (n + 1 = 3 + 1) grid points are required. That is, if an interpolation operation is to be performed by expressing the target point by, for example, a linear expression, it is sufficient if there are four grid points. Therefore, according to the above configuration, the interpolation calculation can be performed by the interpolation formula using the linear expression, and the labor required for the calculation of the interpolation calculation can be reduced (for example, the memory capacity is reduced).
[0046]
It is preferable that the applied gradation value acquisition unit further performs an interpolation operation using an intermediate point located on a side connecting the n + 1 vertices, in addition to the n + 1 vertices.
[0047]
According to the above configuration, the number of points that can be used in the interpolation formula increases. Therefore, for example, an interpolation operation using a polynomial such as a quadratic expression can be performed. As a result, the interpolation accuracy can be improved as compared with the linear expression.
[0048]
According to another embodiment of the present invention, there is provided a liquid crystal display device including at least one look-up table including a plurality of memory blocks, and each memory block stores a plurality of gradation voltage values. Each gray scale voltage value is applied to a liquid crystal display to change the liquid crystal display from a previous gray scale to a rear gray scale. Each of the gray scale voltage values is a pair of a previous gray scale voltage in a local coordinate space. The grayscale voltage value is applied to the liquid crystal display corresponding to the tonal value and the rear grayscale value, and further interpolates the grayscale voltage value so as to change the liquid crystal display from the currently displayed front grayscale to a desired rear grayscale. An applied gradation value acquisition unit, wherein in the local coordinate system, at least one look-up table including a gradation voltage value close to a currently displayed preceding gradation value and a desired succeeding gradation value. Kicking has a configuration in which the applied tone values by interpolation using the memory block is determined.
[0049]
According to the above invention, at least one lookup table is provided, and each lookup table includes a plurality of memory blocks. Each memory block stores a plurality of gradation voltage values. When each gradation voltage value is applied to the liquid crystal display, the display changes from the previous gradation (currently displayed gradation) to the second gradation (desired target gradation). Each gradation voltage value corresponds to a pair of a previous gradation value and a rear gradation value in the local coordinate space.
[0050]
The applied gradation value acquiring means interpolates a gradation voltage value applied to the liquid crystal display to change the liquid crystal display from a currently displayed gradation to a desired rear gradation. This interpolation is performed in the local coordinate system using a memory block in at least one look-up table that includes a gradation voltage value close to the currently displayed previous gradation value and the desired subsequent gradation value. A gradation value is determined.
[0051]
As described above, a desired applied gradation value (applied gradation value not stored in the memory block) can be obtained by interpolation based on the gradation voltage value already stored in the memory block. ) Can be reduced in memory and the like. In other words, the LUT can be created by thinning out the pre-gray scale and the post-gray scale, rather than all gray scales. In addition, the interpolation makes it possible to quickly and easily find an accurate applied gradation value related to the previous gradation value and the rear gradation value that are not stored in the memory.
Therefore, the liquid crystal display device of the present invention can quickly and easily calculate a high-accuracy applied gradation value without increasing the capacity of a memory or the like, for example, as compared with the conventional case where local coordinates are not used. . As a result, by using the interpolation calculation, it is possible to reduce the capacity of the memory for storing the LUT as much as possible, and to perform the appropriate overshoot drive to perform natural high-speed display.
[0052]
Preferably, the plurality of memory blocks further store variables that can be used to interpolate the grayscale voltage value. It is preferable that the applied gradation value acquiring means interpolates the gradation voltage value using a primary expression or a secondary expression.
[0053]
Preferably, the apparatus further comprises at least one additional condition lookup table, and each additional condition lookup table comprises a plurality of blocks corresponding to the additional condition.
[0054]
In this case, at least one LUT is prepared according to an additional condition for changing the response characteristic of the liquid crystal, and an applied gradation value can be obtained in consideration of the additional condition. In this case as well, the number of LUTs is reduced by thinning out not all additional conditions but additional conditions so that the capacity of a memory or the like for storing the LUT can be reduced.
[0055]
Therefore, compared to an interpolation value that does not use the local coordinates as in the related art and that does not take into account additional conditions such as temperature, a high-precision application is performed while taking into account the additional conditions without increasing the capacity of the memory or the like. The gradation value can be calculated. As a result, by using the interpolation calculation, the appropriate overshoot drive is performed while reducing the capacity of the memory for storing the LUT as much as possible and without being affected by additional conditions such as temperature. Natural high-speed display can be performed.
[0056]
It is preferable that the applied gradation value acquiring means interpolates a gradation voltage value using a memory block of at least two lookup tables.
[0057]
BEST MODE FOR CARRYING OUT THE INVENTION
[Embodiment 1]
An embodiment of the present invention will be described below with reference to FIGS. Note that the present invention is not limited to this.
[0058]
FIG. 2 is a block diagram illustrating a configuration of the liquid crystal display device (LCD 10) according to the present embodiment.
[0059]
The LCD 10 includes a liquid crystal panel 3, a common circuit 4, a gradation circuit 5, a digital / analog converter (DAC) 6, an LCD controller 1, a frame memory (FM) 2, a video processing controller (Video Processing Controller; VPC) 7, and a temperature sensor. 8 and a computer 9.
[0060]
The liquid crystal panel 3 includes a substrate (screen) on which pixels are formed. For example, a plurality of source bus lines 61 arranged parallel to each other in a vertical direction of the screen and a plurality of source bus lines 61 arranged parallel to each other in a horizontal direction of the screen. And a plurality of scanning lines 62.
[0061]
Note that the source bus line 61 and the scanning line 62 intersect, and a pixel 63 is formed corresponding to the intersection. In the pixel 63, a TFT 64, a liquid crystal cell 65, and a load capacitor 66 are arranged. The liquid crystal cell 65 is connected to a drain of the TFT 64 and a common electrode (common electrode) (not shown) common to all pixels.
[0062]
The common circuit 4 is a circuit that generates a common voltage used by the common electrode.
The gradation circuit 5 sets an applied voltage (applied voltage) from the gradation data (applied gradation value) sent from the LCD controller 1. Further, the gradation circuit 5 is provided outside the liquid crystal panel 3 and includes a source driver 67 and a gate driver 68. The source bus line 61 is connected to a source driver 67, and the scanning line 62 is connected to a gate driver 68.
[0063]
The DAC 6 is a circuit for generating a reference voltage in the gradation circuit 5. As shown in FIG. 1, the LCD controller 1 includes an interpolation operation element 11 such as an FPGA (Field-Programmable Gate Array) or a GA, and is a controller that controls the source driver 67 and the gate driver 68 described above. The details of the interpolation operation element 11 will be described later.
[0064]
As shown in FIG. 2, the LCD controller 1 sends, via a source bus line 61, gradation data (image data) for specifying an applied voltage to be written to each pixel to a source driver 67. In addition, a signal for instructing the scanning timing is given to the gate driver 68, and a signal for switching and outputting the applied voltage is sent to the source driver 67 in synchronization with the scanning timing. Further, the timing of the drive signal for the common electrode can be controlled. Note that the gradation data here is converted into digital data by the VPC 7.
[0065]
FM2 is a memory capable of storing gradation data for one frame. Therefore, for example, the FM2 can perform simultaneous processing of data input / output. Further, through the FM2, the grayscale data can be output with a delay of one frame with a simple configuration. The VPC 7 converts grayscale data into digital data as described above.
[0066]
The temperature sensor 8 measures (monitors) the temperature of the liquid crystal display device (location where the liquid crystal display device is installed). Of course, if other additional conditions are included, additional or alternative sensors (not shown) known to those skilled in the art may be used and / or substituted to determine the other additional conditions. is there. The other additional conditions include, but are not limited to, cell gap, cell thickness, and / or video frequency. The computer 9 transmits the temperature data (measurement data) from the temperature sensor 8 and the data corresponding to the cell thickness of the liquid crystal panel, the video frequency (frame frequency), and the like to the interpolation operation element 11 (the applied gradation value acquisition unit 13 described later). ) To the computer.
[0067]
In the LCD 10 having the above configuration, when one image (frame) is displayed on the liquid crystal panel 3, the gate driver 68 sequentially turns on the TFTs 64 connected to the respective scanning lines 62 for each scanning line 18 while simultaneously turning on the source. The driver 67 writes the applied voltage corresponding to the gradation data (applied gradation value) corresponding to each scanning line 62 to the pixel corresponding to each scanning line 62.
[0068]
The liquid crystal display device of the present embodiment is capable of performing an interpolation operation in consideration of additional conditions such as temperature, and obtaining a highly accurate interpolation value (target gradation data).
[0069]
This interpolation calculation is performed by the interpolation calculation element 11 described above. As shown in FIG. 1, the interpolation operation element 11 has a configuration including a look-up table memory (LUT memory) 12 and an applied gradation value acquisition unit (applied gradation value acquisition unit) 13.
The LUT memory 12 stores a look-up table (LUT).
[0070]
This LUT uses two values of the gradation data of the gradation of the previous frame (the value of the previous gradation) and the gradation data of the gradation of the current frame (the value of the subsequent gradation) as arguments, and uses the liquid crystal material ( This stores gradation data (applied gradation values) corresponding to an applied voltage to be applied to the liquid crystal layer.
[0071]
More specifically, as shown in FIGS. 3A and 3B, in the local coordinate space, the value of the previous gradation (previous gradation value) is on the vertical axis, and the value of the subsequent gradation (post-gradation value) Is shown on the horizontal axis. The above-mentioned pre-gray scale value and post-gray scale value are set between a finite number of gray scales, and are set for every 32 gray scales in FIGS. Note that the present invention is not limited to the case of setting every 32 gradations, and may be set every other number of gradations. Further, the setting of the preceding gradation value and the setting of the subsequent gradation value need not always be the same. Further, the above setting changes from, for example, every 32 gradations to every 64 gradations, or every 32 gradations to every 128 gradations (including every 64 gradations) in one LUT. Therefore, it is not necessary to use the same number of gradations. In addition, for convenience of explanation, the numerical values of the gradation value (previous gradation value / rear gradation value) and the gradation data (applied gradation value) are shown in parentheses ("").
[0072]
When the operating temperature range of the liquid crystal display device according to the present embodiment is, for example, 40 ° C. to 0 ° C., the LUT memory 12 stores the temperature range as shown in FIGS. Two LUTs, table 1 (FIG. 3A), which is an LUT for a high temperature range (40 ° C.), and table 2 (FIG. 3B), which is an LUT for a low temperature range (0 ° C.), are provided. ing.
[0073]
The applied gradation value acquisition unit 13 obtains a gradation value (previous gradation value) one frame before the FM2, a gradation value (subsequent gradation value) via the VPC 7, and a temperature from the temperature sensor 8 via the computer 9. It uses data (measurement data) and refers to the stored LUT to calculate (interpolate) gradation data (applied gradation values) not stored in the LUT.
[0074]
Here, in the liquid crystal display device of the present embodiment, interpolation calculation performed when displaying an image using overshoot driving, in particular, calculation of unstored LUT gradation data as target gradation data. Will be described in detail.
[0075]
The target gradation data (applied gradation value obtained by the interpolation calculation) is obtained by performing the following procedure. In the following description of the procedure, in order to facilitate understanding, at 20 ° C., a necessary interpolation value is set when the pre-grayscale value “55” is changed to the post-grayscale value “90”. The case of “calculation” will be described as a typical example.
[Procedure 1]
First, in one LUT (for example, Table 1), a first interpolation operation (interpolation operation) performed between a previous gradation value and a rear gradation value is performed.
[0076]
In Table 1, when the previous gradation value “55” is to be changed to the rear gradation value “90”, that is, the gradation value “55” of the previous frame is changed to the gradation value “90” of the current frame. When a necessary value (gray scale data; first interpolation value H) is to be obtained, the previous gray scale value “32 to 64” including the previous gray scale value “55” and the subsequent gray scale The coordinates as shown in FIG. 4 are introduced into the subsequent gradation values “64 to 96” including the value “90”.
[0077]
In the coordinates, the rear gradation value “64” and the previous gradation value “32” are set as the origin P21, and the axis in the same direction as the axis of the rear gradation value from the origin P21 is the rear gradation local axis ξ. A local coordinate system (matrix type) is set in which an axis in the same direction as the axis of the previous gradation value from the origin P21 is the previous gradation local axis η. Therefore, the value ((な る, η)) of the origin P21 is (0, 0) in the local coordinates composed of the local axis 後 of the later gradation and the local axis η of the previous gradation.
[0078]
When the area surrounded by the preceding gradation values “32 to 64” and the following gradation values “64 to 96” is represented by local coordinates (ξ, η), the points P21 (0, 0) and P22 (32, 0), a point P23 (32, 32), and a point P24 (0, 32).
[0079]
Here, an interpolation formula for calculating the first interpolation value H (table interpolation value) is defined. For example, if a linear expression related to (ξ, η) is defined as an interpolation expression, aξ + bη + c = H, and in order to find H, three unknowns of a · b · c must be found. Therefore, in order to obtain these three unknowns, at least three points are required.
[0080]
Then, when the case where the previous gradation value “55” is to be changed to the rear gradation value “90” as described above is displayed on FIG. 4, it is displayed as a point P31 (point P31 (post-gradation value, front gradation value, (Gradation value) = (90, 55)).
[0081]
In order to obtain the first interpolation value H of the point P31 by the interpolation calculation, at least three points must be used as described above. Therefore, in a region of four known gradation data (points P21 to P24), a region of three points including the point P31 is selected. In the case of the point P31, an area (area A) surrounded by the points P21, P22, and P23 corresponds.
[0082]
Then, in the above-mentioned area A, the interpolation formula (aξ + bη + c) is calculated using the post-gradation value / pre-gradation value of the known points P21 to P23 and the gradation data of the table 1 (LUT) corresponding to these points. = H), the following interpolation calculation is performed. That is, when a known point is used, the interpolation calculation is performed by substituting the gradation data corresponding to the base (the rear gradation value and the previous gradation value) of each point (ξ, η) from Table 1 into H. I do.
[0083]
Then
Point P21 → 0a + 0b + c = 92
Point P22 → 32a + 0b + c = 118
Point P23 → 32a + 32b + c = 105
And from these three equations,
a = 26/32, b = −13 / 32, and c = 92.
[0084]
As a result, the first interpolation value H of the point P31 ((ξ, η) = (26, 23)) is 103.8 from the following equation (interpolation equation (1)).
(26/32) × 26 + (− 13/32) × 23 + 92 ≒ 103.8 (1)
[Procedure 2]
Next, in the same manner as in the procedure 1, the second interpolation calculation is performed in the table 2 between the previous gradation value and the rear gradation value.
[0085]
That is, in Table 2, a value (second interpolated value I (table interpolated value)) necessary for changing the previous tone value “55” to the subsequent tone value “90” is obtained.
[0086]
Then
Point P21 → 0a + 0b + c = 142
Point P22 → 32a + 0b + c = 192
Point P23 → 32a + 32b + c = 123
And from these three equations,
a = 25/16, b = −69 / 32, and c = 142.
[0087]
As a result, the second interpolation value I of the point P31 ((ξ, η) = (26, 23)) is 133.0 from the following equation (interpolation equation (2)).
(25/16) × 26 + (− 69/32) × 23 + 142 ≒ 133.0 (2)
Note that the local coordinates when the second interpolation value I is obtained are areas of points P41 to P44 shown in FIG.
[0088]
[Procedure 3]
Next, at 20 ° C., which is an intermediate temperature between 40 ° C. and 0 ° C., a third interpolation operation such as linear interpolation is performed using the first interpolation value H and the second interpolation value I. (The third interpolation value J can be calculated).
[0089]
Therefore, the third interpolation value J (target gradation data) is obtained as 118.4 from the following equation.
(103.8 + 133.0) / 2 = 118.4 [(first interpolation value H + second interpolation value) / 2 = third interpolation value J]
In other words, in the case of “when the pre-grayscale value“ 55 ”is to be changed to the post-grayscale value“ 90 ”at 20 ° C.”, the gradation of “118” or “119” is obtained by going through the procedures 1 to 3. It can be seen that an applied voltage based on the data should be applied.
[0090]
Note that the interpolation method (third interpolation calculation) used in the procedure 3 is not limited to linear interpolation, but various interpolation methods that do not use local coordinates, such as interpolation using a polynomial such as a quadratic expression, are used. it can.
[0091]
As described above, in the liquid crystal display device of the present embodiment, the interpolation calculation using the local coordinates is performed in the procedures 1 and 2, and the interpolation calculation using the additional conditions such as the temperature is performed in the procedure 3. Thus, the final interpolation value, that is, the target gradation data (the third interpolation value J in the above case) is obtained.
[0092]
That is, in each of the procedures 1 and 2, the first and second interpolation calculations based on the rear gradation value and the previous gradation value are performed using separate tables (tables 1 and 2), and further, the first and second interpolation calculations are performed. The third interpolation calculation corresponding to the additional condition is performed using the result of the two interpolation calculations (the first interpolation value H and the second interpolation value I).
[0093]
Therefore, the third interpolation value J is a value corresponding to additional conditions such as temperature. Of course, other additional conditions besides temperature can be used. In addition, the values used to determine the third interpolation value J (the first interpolation value H and the second interpolation value I) are also accurately determined using the local coordinates. , High-precision interpolation values.
[0094]
In other words, the liquid crystal display device according to the present embodiment performs a continuous output process from a plurality of LUTs storing a finite number of output gradations between a plurality of gradations under a plurality of additional conditions such as temperature. The target applied gradation data that can realize the tone can be calculated, and when the display based on the target applied gradation data is performed, for example, the inputted gradation data can be more faithfully performed without causing the gradation unevenness or the like. Display can be reproduced.
[0095]
Further, the accuracy of the target applied gradation data is remarkably improved as compared with a conventional interpolation value that does not use local coordinates and does not consider additional conditions such as temperature.
[0096]
Further, since the target applied gradation data (applied gradation value) can be obtained without using the LUT for all gradations and all additional conditions, the LUT is stored relatively, for example, the memory capacity is reduced. it can.
[0097]
Further, at the intermediate temperature between the table 1 and the table 2, for example, a linear interpolation is performed between the table 1 and the table 2 so that an LUT between a finite number of gradations is created for the intermediate temperature. It can be said that the three overshoot tables can be properly used in low, medium and high temperature regions. In step 3, after calculating two target applied gradation data from the two LUTs, respective values were calculated according to the additional condition. However, the LUT corresponding to the additional condition was linearly interpolated from the two LUTs. , And target application gradation data can be calculated for the LUT according to the procedure 1.
[0098]
Note that the point P31 is included only in the area A in FIG. 4, but for example, the point P32, that is, “the previous gradation value“ 48 ”is changed to the rear gradation value“ 80 ”. In this case, the necessary first interpolation value H (gradation data) is calculated. ”In this case, the value is included in both the area A and the area B.
[0099]
In such a case, the fact that the calculation can be performed using an interpolation formula based on both regions will be described below.
[0100]
In procedure 3, only one additional condition for performing the interpolation calculation is set. However, even if there are two or more additional conditions, basically the same interpolation processing can be performed.
[Procedure 1 ']
As in the above procedure 1, an interpolation formula for calculating the first interpolation value H in Table 1 is defined. For example, if a linear expression related to (ξ, η) is defined as an interpolation expression, three points including the point P31 must be selected. Then, in the case of the point P32, an area surrounded by the points P21, P22, and P23 (area A) and an area surrounded by the points P21, P23, and P24 (area B) correspond.
[0101]
Then, in the case of the area A,
Point P21 → 0a + 0b + c = 92
Point P22 → 32a + 0b + c = 118
Point P23 → 32a + 32b + c = 105
And from these three equations,
a = 26/32, b = −13 / 32, and c = 92.
[0102]
As a result, the first interpolation value H at the point P32 ((ξ, η) = (16, 16)) is 98.5 from the following equation (interpolation equation (3)).
(26/32) × 16 + (− 13/32) × 16 + 92 = 98.5 (3)
In the case of the area B,
Point P21 → 0a + 0b + c = 92
Point P23 → 32a + 32b + c = 105
Point P24 → 0a + 32b + c = 64
And from these three equations,
a = 41/32, b = −28 / 32, and c = 92.
As a result, the first interpolation value H of the point P32 ((ξ, η) = (16, 16)) is 98.5 from the following equation (interpolation equation (4)).
(41/32) × 16 + (− 28/32) × 16 + 92 = 98.5 (4)
As described above, at 40 ° C., when the previous gradation value “48” is to be changed to the rear gradation value “80”, that is, when the point P32 can be surrounded by either the area A or the area B as the point P32. The first interpolation value H can be calculated by using the interpolation formula of either region (the interpolation formula (3) of the region A or the interpolation formula (4) of the region B).
[0103]
This is because even if the first interpolation value H is calculated from different interpolation formulas (interpolation formula (3) and interpolation formula (4)), the point P21- which is a boundary line between different regions (region A and region B). This is because the value is the same on the line of the point P23 (on the diagonal line) (because it has a contact point).
[0104]
Therefore, the continuity of the first interpolation value H between the regions is maintained (even if an interpolation formula for a different region is used, the interpolation value on the boundary of the region does not become discontinuous).
[0105]
That is, even if the target applied gradation data is calculated using an interpolation formula used in different regions, that is, two or more interpolation formulas, the target gradation data has the same value at the boundary of the regions. The range of choices will be expanded.
[0106]
In Table 2, even if the above procedure 1 'is performed, the continuity of the second interpolation value I between the respective regions is maintained as in the procedure 1'.
[0107]
In the first embodiment, local coordinates are provided in each LUT, and a first interpolation value H and a second interpolation value I are calculated. However, the present invention is not limited to this. This will be described in the following second embodiment, for example.
[Embodiment 2]
The following will describe another embodiment of the present invention. Members having the same functions as the members used in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.
[0108]
Specifically, an interpolation operation is performed using local coordinates that simultaneously use Tables 1 and 2. FIG. 5 shows local coordinates in this interpolation calculation, for example.
[0109]
As shown in FIG. 5, the local coordinates are, with respect to the coordinates composed of three axes of the rear gradation value, the previous gradation value and the temperature value, with respect to the rear gradation local axis ξ and the previous gradation local axis η. The coordinates are three-dimensional local coordinates to which an additional axis 示 す indicating the vertical direction is added.
[0110]
In the following description, in order to facilitate understanding, "at 30 ° C., the necessary interpolation value K (gray level) is used to change the former gray level value" 48 "to the latter gray level value" 80 ". Data) is described as an example.
[0111]
Here, the above-mentioned “calculates a necessary interpolation value K (target gradation data) at 30 ° C. when trying to change the pre-gradation value“ 48 ”to the post-gradation value“ 80 ”” 5, the point P33 is shown as a point P33, and this point P33 is located inside a hexahedron surrounded by points P21 to P24 indicating the table 1 and points P41 to P44 indicating the table 2.
[0112]
Then, an interpolation formula for calculating the interpolation value K is defined in the three-dimensional local coordinates. For example, if a linear expression related to (ξ, η, ζ) is defined as an interpolation formula, then aξ + bη + cζ + d = K. In order to find an interpolation value K, four unknowns of a · b · c · d must be found. No. Therefore, in order to obtain these four unknowns, at least four points are required.
[0113]
Therefore, in the area of the gradation data of the known eight points (points P21 to P24 and points P41 to P44), four areas including the point P33 are selected. In the case of the point P33, an area (first area) surrounded by the points P21, P23, P22, and P43 corresponds.
[0114]
Then, using the known point P21, the point P23, the point P22, and the point P43, the post-gradation value and the pre-gradation value, and the gradation data of Tables 1 and 2 corresponding to these points, an interpolation formula is used. From (aξ + bη + cζ + d = K), an interpolation operation is performed. As in the first embodiment, when a known point is used, K corresponds to (the later gradation value, the previous gradation value) at each temperature, which is the basis of each point (ξ, η, ζ). Interpolation is performed by substituting the obtained gradation data from Tables 1 and 2.
[0115]
Substituting each point into the interpolation formula gives the following:
Point P21 → 0a + 0b + 40c + d = 92
Point P23 → 32a + 32b + 40c + d = 105
Point P22 → 32a + 0b + 40c + d = 118
Point P43 → 32a + 32b + 0c + d = 123
And from these four equations,
a = 13/16, b = -3 / 32, c =-／, and d = 100.
[0116]
As a result, the interpolation value K of the point P33 ((ξ, η, ζ) = (16, 16, 30)) is 105.5 from the following equation.
(13/16) × 16 + (− 3/32) × 16 + (− 1/5) × 30 + 100 = 105.5
In other words, in the case of “at 30 ° C., the pre-grayscale value“ 48 ”is to be changed to the post-grayscale value“ 80 ””, the grayscale data (voltage data) of “105” or “106” is applied. It will be good.
[0117]
As described above, in the liquid crystal display device of the present embodiment, by the above procedure, the interpolation operation using the three-dimensional local coordinates including the local axis 後 of the later gradation, the local axis η of the previous gradation, and the additional axis 付 加 is performed. , The final interpolation value, that is, the target gradation data (the interpolation value K in the above case).
[0118]
Therefore, the interpolation value K is a higher-precision interpolation value than a conventional interpolation value that does not use local coordinates and does not consider additional conditions such as temperature. Further, the interpolation value K is a high-precision interpolation value as compared with an interpolation value that does not use the local coordinates and does not consider the additional condition.
[0119]
That is, the liquid crystal display device of the present embodiment stores a finite number of output gradations between a plurality of gradations under one or more of a plurality of additional conditions such as temperature. From a plurality of LUTs, it is possible to calculate target applied gradation data capable of realizing a continuous output gradation, and when performing display based on the target applied gradation data, for example, without causing gradation unevenness or the like, A display can be reproduced in which the input gradation data is reproduced more faithfully.
[0120]
Note that the point P33 is included only in the area surrounded by the points P21, P23, P22, and P43 in FIG. In the case of calculating the interpolation value K (gradation data) when trying to change “48” to the subsequent gradation value “80” ”, the point P34 is shown in FIG. Is located at the center of a hexahedron surrounded by points P21 to P24 indicating table 1 and points P41 to P44 indicating table 2. That is, it is included in the following six regions.
First area → Area surrounded by points P21, P23, P22, and P43
Second area → Area surrounded by points P21, P22, P42, and P43
Third area → Area surrounded by points P21, P42, P41, and P43
4th area → Area surrounded by points P21, P41, P44, and P43
Fifth area → Area surrounded by points P21, P44, P24, and P43
Sixth area → Area surrounded by points P21, P24, P23, and P43
In such a case, the interpolation value K can be calculated using an interpolation formula based on one of the six regions.
[0121]
For example, in the case of the first region, since the above-mentioned values of a = 13/16, b = -3 / 32, c =-／, and d = 100 may be used, the point P34 ((ξ, η, ζ ) = (16, 16, 20)), the interpolation value K is 107.5 from the following equation.
(13/16) × 16 + (− 3/32) × 16 + (− 1/5) × 20 + 100 = 107.5.
[0122]
For example, in the case of the third area,
Point P21 → 0a + 0b + 40c + d = 92
Point P42 → 32a + 0b + 0c + d = 192
Point P41 → 0a + 0b + 0c + d = 142
Point P43 → 32a + 32b + 0c + d = 123
And from these four equations,
a = -50 / 32, b = 31/32, c = -5 / 4, and d = 142.
[0123]
As a result, the interpolation value K of the point P34 ((ξ, η, ζ) = (16, 16, 20)) is 107.5 from the following equation.
(−50/32) × 16 + (31/32) × 16 + (− 5/4) × 20 + 142 = 107.5.
[0124]
In the other second area and the fourth to sixth areas, the interpolation calculation can be performed in the same manner as in the first and third areas, and the interpolation value K is 107.5.
[0125]
As described above, in the liquid crystal display device of the present embodiment, when the point P34 is surrounded by any of the first to sixth regions as in the above-described point P34, the interpolation formula of each of the regions is used. Thus, the interpolation value K may be calculated.
[0126]
This is because the interpolation values K obtained from the above-described interpolation formulas of the first to sixth regions have the same value. This is because different interpolation formulas in each area are continuous on a line (diagonal) between points P21 and P43, which are boundaries between different areas (first to sixth areas) (because of having a contact point). . As a result, the interpolated value K obtained in each region has the same value on the boundary line of each region, so that the continuity between the regions is maintained (by using the interpolation formula for different regions). Also, the interpolated values on the boundary of the area do not become discontinuous). That is, even if the target gradation data is calculated using one space, the target gradation data has the same value, and the range of selection of the interpolation formula is widened.
[0127]
In the first and second embodiments, a linear expression is used as an interpolation expression, but the present invention is not limited to this. For example, the interpolation value can be calculated by using a polynomial such as a quadratic equation. This example will be described in the following third embodiment.
[Embodiment 3]
The following will describe another embodiment of the present invention. Members having the same functions as the members used in Embodiments 1 and 2 are denoted by the same reference numerals, and description thereof is omitted.
[0128]
In the procedure 1 (first interpolation calculation) in the first embodiment, if a quadratic equation related to (ξ, η) is defined as an interpolation equation, the interpolation equation is aξ ² + Bη ² + Cξη + dξ + eη + f = H. Then, in order to obtain the first interpolation value H, six unknowns of a, b, c, d, e, and f must be obtained. Therefore, in order to obtain these six unknowns, at least six points are required in the local coordinates shown in FIG.
[0129]
In the above case, in order to obtain the first interpolation value H corresponding to the point P31, as in the procedure 1 of the first embodiment, three points including the point P31 in the area of the known four points (points P21 to P24) are used. An area of a point (area (area A) surrounded by points P21, P22, and P23) is selected. For the remaining three necessary points, for example, the intermediate points P51 to P53 obtained from the above known points by, for example, linear interpolation are used.
[0130]
Note that the intermediate point is not limited to one obtained by linear interpolation, but may be calculated by another interpolation operation. In order to improve the interpolation accuracy, it is preferable to obtain from the actual measurement. In addition, finding the intermediate point means grasping three numerical values of a rear gradation value, a previous gradation value, and gradation data. Therefore, for example, the intermediate point P51 located between the point P22 and the point P23 (for example, exactly at the center of the two points (points P22 and P23)) (the latter gradation value, the previous gradation value, and the gradation data) Is obtained by linear interpolation, (96, 48, 111.5) is obtained ((post-gradation local axis ξ, pre-gradation local axis η, gradation data) = (32, 16, 111.5) ).
[0131]
Then, from the points P21 to P23 and the intermediate points P51 to P53, the numerical values corresponding to (ξ, η) and H are substituted, and an equation corresponding to each point (points P21 to P23 and intermediate points P51 to P53) is obtained. Create
[0132]
For example, in the case of the point P23 ((ξ, η) = (32, 32)), 32 ² a + 32 ² b + (32 × 32c) + 32d + 32e + f = 105. Then, such a correspondence expression is created for each point, and (a, b, c, d, e, f) is obtained from those expressions. Then, the first interpolation value H can be obtained from the point P31 ((ξ, η) = (16, 16)) and the above (abcdcdeef).
[0133]
As described above, when a polynomial is used as the interpolation equation, the interpolation accuracy is further improved as compared with the first interpolation value H calculated from the linear equation. Similarly, in the procedure 2 of the first embodiment, when a polynomial is used as the interpolation equation, the interpolation accuracy is further improved as compared with the second interpolation value I calculated from the linear equation. Therefore, the third interpolated value J obtained from the first interpolated value H and the second interpolated value I obtained using these polynomials naturally becomes a more accurate interpolated value.
[0134]
Further, in the interpolation calculation in the second embodiment, if a quadratic expression relating to (ξ, η, ζ) is defined as an interpolation expression, the interpolation expression becomes aξ ² + Bη ² + Cζ ² + Dξη + eηζ + fζξ + gξ + hη + iζ + j = K. Then, in order to find the interpolation value K, it is necessary to find ten unknowns a, b, c, d, e, f, g, h, i, and j. Therefore, in order to obtain these ten unknowns, at least ten points are required in local coordinates as shown in FIG. Note that, in the above interpolation formula, the term of {η} composed of ξ · η · ζ is not required. This is because it is a cubic expression.
[0135]
In the above case, in order to obtain the interpolation value K corresponding to the point P33, as in the procedure of the second embodiment, the point P33 is set in the known eight points (points P21 to P24 and points P41 to P44). Select the four included areas. As the remaining necessary six points, for example, the intermediate points P51 to P56 obtained by linear interpolation or the like from the above-described known points are used in the same manner as the above-described intermediate points P51 to P53.
[0136]
Then, the values corresponding to (ξ, η, ζ) and K are substituted from the points P21 to P23 and the intermediate points P51 to P56 to correspond to each point (points P21 to P23 and intermediate points P51 to P56). Create an expression that
[0137]
For example, in the case of the point P23 ((ξ, η, ζ) = (32, 32, 40)), 32 ² a + 32 ² b + 40 ² c + (32 × 32 × d) + (32 × 40 × e) + (40 × 32 × f) + 32g + 32h + 40i + j = 105.
[0138]
Then, such a correspondence expression is created for each point, and (abc, d, e, f, g, h, j) is obtained from those expressions. Then, interpolation is performed from the point P33 ((ξ, η, ζ) = (16, 16, 30)) and the above (a, b, c, d, e, f, g, h, i, j). The value K can be determined.
[0139]
As described above, when a polynomial is used as the interpolation equation, the interpolation accuracy is further improved as compared with the interpolation value K calculated from the linear equation.
[0140]
In the first to third embodiments, the target gradation data (for example, the interpolation formula K) is obtained by using the interpolation formula according to the situation of the temperature change. However, the present invention is not limited to the temperature change.For example, according to the film thickness of the cell, the video frequency, etc., as described above, a plurality of tables are provided, and by using this using local coordinates, The target gradation data can be obtained.
[0141]
In addition, the region A (the region including the interpolation formula (1)) including the point P32 and the region B (the region including the interpolation formula (2)) in the first embodiment are defined by a diagonal line between the point P21 and the point P23. (See FIGS. 4, 5, and 7). This means that the interpolation formulas are continuous on the axis of symmetry. Also, the respective interpolation formulas included in the first to sixth regions including the point P34 in the third embodiment can be freely folded back with the diagonal line between the points P21 and P43 as the axis of symmetry (see FIGS. 5 and 8). ). Therefore, as in the case of the first embodiment, it can be said that the interpolation formulas are continuous.
[0142]
Further, the number of regions (for example, regions A and B and the first to sixth regions) in the first to third embodiments has no relation to the number of undetermined values. This is because, for example, a region including the regions A and B (all regions) can be divided by any known three points. That is, the number of areas in the entire area can be changed freely as long as the points are points other than the points P21 to P24 as long as they are known points. The above-mentioned known points may be obtained from the points P21 to P24 by, for example, linear interpolation.
[0143]
The interpolation formula used in FIG. 4 represents a straight line for two-dimensional coordinates, FIG. 5 shows a plane for three-dimensional coordinates, FIG. 6 shows an ellipse for two-dimensional coordinates, and FIG. 7 shows an ellipsoid for three-dimensional coordinates.
[0144]
It can also be said that a unit or a program for applying a voltage to the liquid crystal material of the liquid crystal panel is incorporated inside or outside the display controller.
[0145]
Further, the liquid crystal display device of the present embodiment performs gradation display by changing an applied voltage, and further performs overshoot driving to apply a voltage larger than a voltage difference corresponding to a gradation change. I have. In addition, the display device may switch the applied voltage between two or more temperature regions. Interpolation using local coordinates may be performed on output gradation values between a finite number of gradations or output gradations that change depending on additional conditions such as temperature. It should be noted that, in addition to the above-described temperature, similar expansion is possible for additional conditions such as a cell thickness and a video frequency.
[0146]
Further, in the liquid crystal display device of the present embodiment, in the liquid crystal display device, the pre-gray scale and the post-gray scale are defined by a gray-scale area expressed using local coordinates or an additional condition such as temperature. When the number of space axes is n with respect to the space coordinates, it can be said that the region is divided into regions having (n + 1) vertices and interpolation calculation is performed.
[0147]
According to this, under a plurality of additional conditions such as temperature, the liquid crystal display device can output a continuous output gradation from a plurality of LUTs storing a finite number of output gradations between a plurality of gradations. By using the calculation method for calculation, it is possible to provide a display method for performing natural high-speed display.
[0148]
Further, the liquid crystal display device of the present embodiment can be expressed as follows. The liquid crystal display device is a liquid crystal display device that performs gradation display by changing an applied voltage, and performs a front display and a rear display under a plurality of (two or more) additional conditions such as a temperature, a cell thickness, and a video frequency. Output grayscale is set for display grayscale, and is defined by additional conditions such as temperature, cell thickness, video frequency, and previous and subsequent grayscales when performing interpolation calculation of output grayscale. By performing an interpolation operation using local coordinates associated with the spatial axis to be performed, continuity of the interpolation is enhanced, and video noise generated due to an operation error is reduced.
[0149]
In this way, under additional conditions such as temperature, cell thickness, video frequency, etc., the output gradation is calculated using interpolation in a space defined by the additional conditions, the preceding display and the subsequent display gradation. By doing so, it is possible to reduce video noise generated due to arithmetic errors by reducing resources such as memories and gates in terms of hardware, and by increasing continuity of interpolation in terms of software.
[0150]
The liquid crystal display device is a liquid crystal display device that performs gradation display by changing an applied voltage, and includes a plurality (two or more) of temperatures, a plurality of (two or more) cells, and / or a plurality of (two or more). Under the additional conditions such as the video frequency of the output, the output gradation is set for the gradation of the previous display and the subsequent display, and when performing the interpolation calculation of the output gradation, a plurality of additional conditions are required. On the other hand, by performing an interpolation operation using local coordinates associated with the spatial axis defined by the gradations of the previous display and the subsequent display, the continuity of the interpolation is improved, and the image noise generated by the calculation error is reduced. It is characterized by.
[0151]
As described above, under additional conditions such as temperature, cell thickness, and video frequency, the output grayscale is calculated using interpolation in a space defined by the grayscales of the previous display and the subsequent display. In terms of hardware, resources such as memories and gates can be further reduced as compared with the above-described liquid crystal display device, and in terms of software, video noise caused by an arithmetic error can be reduced by increasing the continuity of interpolation.
[0152]
In addition, in the interpolation operation using the local coordinates, the liquid crystal display device divides the number of interpolation axes n (2 or more) into local regions having vertices of n + 1 and performs the interpolation operation, thereby obtaining an output floor. It is characterized by enhancing the continuity of the key and reducing the image noise generated by the calculation error.
[0153]
According to this, when performing a multidimensional interpolation operation on the interpolation axis n (two or more) using the local coordinates, it is possible to perform interpolation using a linear expression, so that resources such as memories and gates are reduced in terms of hardware. In terms of software, by increasing the continuity of interpolation, it is possible to reduce video noise generated due to an arithmetic error.
[0154]
In addition, in the interpolation operation using the local coordinates, the liquid crystal display device divides the number of interpolation axes n (2 or more) into local regions having n + 1 vertices, and calculates the value of the midpoint between the vertices and each side. , The continuity of the output gradation is increased, and the video noise generated by the calculation error is reduced.
[0155]
According to this, when performing a multi-dimensional interpolation operation on the interpolation axis n (two or more) using local coordinates, interpolation can be performed by a quadratic expression, so that resources such as memories and gates are reduced in terms of hardware. In terms of software, the continuity of interpolation is further improved, and video noise generated due to a calculation error can be reduced.
[0156]
Further, the liquid crystal display device of the present invention has pixels, and applies a gradation voltage (applied voltage) based on the gradation data (applied gradation value) to each pixel on a frame-by-frame basis. In a liquid crystal display device that performs display, a storage unit that stores sequentially inputted gradation data as gradation data of a frame to be displayed, delays the gradation data by one frame, and outputs the same as gradation data of the immediately preceding frame. A plurality of LUTs indicating the gradation data to be output specified by the gradation data of the frame to be displayed and the gradation data of the immediately preceding frame in accordance with additional conditions. A memory, an additional condition measuring unit for measuring the additional condition, the gradation data of the frame to be displayed, the gradation data of the frame to be output, and the floor of the immediately preceding frame from the storage unit. Receives the data and the measurement data of the additional condition, and performs an interpolation operation with reference to the plurality of LUTs to calculate gradation data necessary for gradation display as target gradation data. A gradation value acquisition unit, wherein the applied gradation value acquisition unit sets, for each LUT, a coordinate system in which the gradation data of the frame to be displayed and the gradation data of the immediately preceding frame are grid points, In the coordinate system, a local coordinate system including a grid point corresponding to the target gray scale data is set, and an interpolation operation using the local coordinate system is performed. And the target gradation data is calculated by performing an interpolation operation according to the measurement data using the table interpolation value for each LUT.
[0157]
In addition, the liquid crystal display device of the present invention includes a pixel, and performs a gradation display by applying a gradation voltage based on the gradation data to each pixel on a frame-by-frame basis. A storage unit that stores gradation data sequentially input as gradation data of a frame to be delayed, delays the gradation data by one frame, and outputs the data as gradation data of the immediately preceding frame; The LUT memory previously storing a plurality of LUTs indicating gradation data to be output specified by the gradation data and the gradation data of the immediately preceding frame according to the additional conditions, and measuring the additional conditions. Receiving the additional condition measurement unit, the gradation data of the frame to be displayed, the gradation data of the immediately preceding frame from the storage unit, and the measurement data of the additional condition, An interpolation gradation value acquisition unit that calculates gradation data necessary for gradation display as target gradation data by performing interpolation while referring to several LUTs, and the applied gradation value acquisition unit includes: In addition to setting a coordinate system in which the gradation data of the frame to be displayed, the gradation data of the immediately preceding frame, and the measurement data are grid points, a local coordinate system including a point corresponding to the target gradation data is set. The target gradation data is calculated by performing an interpolation operation using the local coordinate system.
[0158]
In another embodiment, for example, four (not limited to four) applied gradation values are applied to a group (plurality) of four front gradation values and rear gradation values represented by local coordinates. Various sets (sets) of (gradation values applied to the liquid crystal) may be stored in a plurality of memory blocks. Further, the variable values a, b, and c of the linear expression aξ + bη + c = H of the local coordinates (ξ, η) are determined, and these variable values are stored in one memory block together with the stored four applied gradation values. It may be stored inside. Of the four stored applied gradation values, three are used as "up" values (used to increase the previous gradation value to a higher subsequent gradation value) and are used in the primary equation. A, b, and c may be determined and stored, and / or three of the four stored applied tone values that are different from the above may be "down" values (previous). Used to reduce the tone value to a lower tone value below), and determine and store another set of a, b, and c in the linear equation. Good.
[0159]
Then, in order to appropriately interpolate the appropriate gradation value H actually applied to the liquid crystal so that the gradation display can be appropriately performed, the previous gradation value and the rear gradation value are stored in one block. The "up" or "down" a, b, and c variable values in the corresponding stored block are used for accurate interpolation to fall between the values. Thus, the exact interpolation for the appropriate applied tone value H is achieved by using the local coordinates (ξ, し た, ｃ) using a, b, and c in the stored linear equation of the corresponding block's local coordinate system. η) based on the previous gradation value and the rear gradation value. A non-limiting example is shown below.
[0160]
First, a plurality of sets of four applied grayscale values (grayscale values applied to the liquid crystal) for a group of four pre-grayscale values and post-grayscale values represented by local coordinates, For example, it is stored in a plurality of memory blocks of one lookup table. For example, in the ninth memory block corresponding to the group of four pre-gray scale values and the post-gray scale values in Table 1 of FIG. The applied gradation value 92 (corresponding to the preceding gradation value 32 and the subsequent gradation value 64), the applied gradation value 64 (the preceding gradation value 64 and the subsequent gradation value). And the applied gradation value 24 (corresponding to the preceding gradation value 64 and the succeeding gradation value 32) may be stored. Since these applied gradation values are known, the values of a, b, and c for the corresponding “up” and / or “down” of the linear expression aξ + bη + c = H of the local coordinates (ξ, η) are also specified. it can. Thus, they are stored in the ninth memory block along with the applied gradation values. That is, a, b, and c for “up” are a = 60/32, b = −28 / 32, and c = 32. Further, a, b, and c for “down” are a = 40/32, b = −10 / 32, and c = 32.
[0161]
In Table 1 of FIG. 3A, for example, there are a total of 64 memory blocks corresponding to four groups of the pre-gray scale value and the post-gray scale value. That is, in Table 1 of FIG. 3A, the 0th memory block (applied gradation values 0, 88, 32, and 0 are stored) to the 7th memory block (applied gradation values , 238, 255, 255, and 238),..., 56th memory block (stores applied gradation values 0, 8, 0, and 0) to 63rd memory block ( (Applied gradation values 224, 255, 255, and 220 are stored).
[0162]
In the above, the case where a total of 64 memory blocks exist in the table 1 of FIG. 3A has been described. However, the present invention is not limited to this, and four, eight, and sixteen memory blocks are provided. , Or 32 memory blocks may be present. In each of these cases, three of the applied gradation values stored in each memory block are used as “up” values, and A, b, and c may be determined and stored, and / or using three of the stored applied tone values different from the above as "down"values; Another set of a, b, and c in the linear equation may be determined and stored. The display accuracy can be changed according to the number of applied gradation values stored in each memory block. That is, by setting the number of applied gradations stored in each memory block according to the display accuracy, a desired display can be obtained.
[0163]
As described above, by performing interpolation using the stored values in the memory block, accurate applied gradation values relating to the previous gradation value and the rear gradation value not stored in the memory can be quickly and easily obtained. Can be obtained. For example, the values in the ninth memory block are used for the previous gradation value 48 and the rear gradation value 56 corresponding to the local coordinates (48, 56). This is because the previous tone value 48 falls between the previous tone values 32 and 64 stored in the ninth memory block, and the previous tone value 56 falls between the stored previous tone values 32 and 64. Because. Further, since the previous gradation value 48 is increased to the rear gradation value 56, the corresponding stored “up” a, b, and c values may be used for the ninth memory block. Good. By substituting these values into the linear expression aξ + bη + c = H of the local coordinates (48, 56), the accurate applied gradation value H 73 is determined quickly and efficiently.
[0164]
Note that the employed interpolation calculation is not limited to the linear interpolation calculation. According to various embodiments of the present invention, the various interpolation operations described in each of the various embodiments of the present invention (eg, interpolation operations using polynomials including quadratic expressions, etc.) This is applicable to a memory block reference mode (look-up aspect). This memory block reference is applicable when the interpolation formula is defined by a linear expression relating to local coordinates (ξ, η, ζ) satisfying aξ + bη + cζ + d = K. Further, for example, in order to obtain the interpolation values such as the applied gradation values I and J as described above, the interpolation including the temperature and other additional conditions can be similarly performed using the memory block.
[0165]
In this manner, the liquid crystal display device includes at least one memory including a plurality of memory blocks, each block storing a plurality of gray scale voltage values, and each gray scale voltage value is used to control the liquid crystal display (display) to a pre-gray scale. The voltage values are changed to the post-grayscale voltage values, and these voltage values can be developed in the liquid crystal display device corresponding to the pair of pre-grayscale values and the post-grayscale values in the local coordinate space. The liquid crystal display device further includes an applied grayscale value acquisition unit configured to interpolate the grayscale value and to change the liquid crystal display from a currently displayed grayscale to a desired target grayscale. ing. The applied grayscale value includes at least one grayscale voltage value near the currently displayed grayscale value (previous grayscale value) and a desired target grayscale value (second grayscale value) in local coordinates. It is determined by interpolation performed using a memory block. Further, the plurality of memory blocks store variables that can be used when interpolating the gradation values.
[0166]
The liquid crystal display device according to the present invention can also be expressed as follows. That is, as described above, the liquid crystal display device according to the present invention performs the gray scale display by changing the voltage applied to the liquid crystal, and performs the gray scale of the previous frame which is the gray scale of one frame before and the gray scale of the next frame. A liquid crystal display device in which an applied gradation value to be actually applied to a liquid crystal is set in association with a subsequent gradation, wherein the applied gradation value is stored while the gradations are thinned out. A plurality of look-up tables and a plurality of lookup tables, and when a corresponding applied gradation value is not stored, a value obtained by performing an interpolation operation based on the stored applied gradation value is applied to the plurality of lookup tables. And an applied gradation value acquiring means for acquiring as a gradation value.
[0167]
According to the above liquid crystal display device, gradation display is performed by changing the voltage applied to the liquid crystal. At this time, an applied gradation value that is actually applied to the liquid crystal is set in association with the gradation of one frame before and the gradation of the next frame.
[0168]
2. Description of the Related Art Conventionally, in a liquid crystal display device, "overshoot driving" for rapidly moving a liquid crystal material to a target gradation is used. In this overshoot drive, a look-up table in which an applied gradation value to be applied to the liquid crystal material is determined is prepared in advance, and the voltage is applied based on this. In this case, since the LUT is created by previously obtaining applied voltage values (applied voltage values of all gradations) corresponding to all patterns of gradation change, the capacity of a memory for storing the LUT becomes extremely large. Invites the problem of
[0169]
Therefore, in the liquid crystal display device of the present invention, the look-up table is prepared by thinning out gradations. Therefore, the memory capacity of the look-up table can be made much smaller than in the case where the applied voltage values of all gradations are obtained.
[0170]
Since the present liquid crystal display device further includes an applied gradation value acquiring unit, the applied gradation value acquiring unit refers to the plurality of lookup tables and does not store the corresponding applied gradation value. In this case, a value obtained by performing an interpolation operation based on the stored applied gradation value is obtained as the applied gradation value. Note that the applied gradation value acquiring means acquires the stored applied gradation value when the corresponding applied gradation value is stored.
[0171]
Further, it is preferable that the applied gradation value acquisition means performs an interpolation calculation using local coordinates having the preceding gradation and the following gradation as axes. In this case, since the local coordinates are used, the accuracy is improved accordingly.
[0172]
Further, the plurality of look-up tables are prepared according to additional conditions for changing the response characteristics of the liquid crystal, and prepared by thinning out the additional conditions. When there is no look-up table that meets the additional condition, it is preferable to obtain a value obtained by performing an interpolation operation based on the stored applied gradation value as the applied gradation value.
[0173]
In a conventional liquid crystal display device, appropriate overshoot driving cannot be performed depending on additional conditions such as temperature, and natural high-speed display cannot be performed. Therefore, according to the present liquid crystal display device, the look-up table is prepared according to the additional condition for changing the response characteristic of the liquid crystal, and is prepared by thinning out the additional condition.
[0174]
Although the additional condition is taken into account in this way, the additional condition is thinned out and prepared in the lookup table, so that an appropriate condition can be set according to the additional condition without significantly increasing the memory capacity. Overshoot drive can be performed, and natural high-speed display can be performed.
[0175]
The applied gradation value acquiring means refers to the plurality of lookup tables, and if there is no lookup table that meets the additional condition, the applied gradation value acquiring unit performs interpolation calculation based on the stored content. Obtained as a gradation value. When there is a look-up table that meets the additional condition, the applied gradation value acquiring means uses the applied gradation value obtained based on the contents stored in the look-up table. As described above, the liquid crystal display device of the present invention performs gradation display by changing the voltage applied to the liquid crystal, and performs the previous gradation, which is the gradation of one frame before, and the rear gradation, which is the gradation of the next frame. In a liquid crystal display device in which an applied gradation value to be actually applied to the liquid crystal is set in association with the above, a lookup table (in which the applied gradation value is stored in association with the previous gradation and the rear gradation). A plurality of LUTs are provided according to additional conditions that change the response characteristics of the liquid crystal, and application is performed with reference to the plurality of LUTs according to the additional conditions and the combination of the preceding gradation and the later gradation. When the applied gradation value corresponding to the additional condition and the combination is stored in the LUT as the gradation value, the value is obtained as it is, otherwise, the applied gradation value stored in the LUT is obtained. Application close to conditions and combinations An applied gradation value acquiring unit that acquires a value by performing an interpolation operation using the tonal value. It is characterized in that an interpolation operation is performed by using local coordinates attached to a spatial axis defined by and a later gradation.
[0176]
The liquid crystal display device normally performs gradation display by applying an applied voltage to a pixel based on an applied gradation value. Conventionally, in a liquid crystal display device, in order to speed up the response characteristics of the liquid crystal, for example, the gradation data of the pixel is changed from the previous gradation which is the gradation data of the previous frame to the gradation data of the next frame. When switching to gray scale, overshoot drive is used in which the applied voltage to the liquid crystal is made larger than the voltage difference corresponding to the difference between gray scale data.
[0177]
The applied gradation value indicating the applied voltage (the applied voltage based on the applied gradation value corresponding to the switching from the previous gradation to the rear gradation) according to the switching is associated with the previous gradation and the rear gradation. Then, it is stored in the LUT, and is found out from the LUT, and the applied voltage is applied to perform gradation display of the pixel.
[0178]
In the liquid crystal display device of the present invention, the LUT is created by thinning out the tones between the preceding and succeeding tones, instead of all the tones, so that the capacity of a memory or the like for storing the LUT can be kept small. In the case where the applied gradation value acquiring means stores the applied gradation value corresponding to the switching, that is, the applied gradation value directly corresponding to the combination of the preceding gradation and the subsequent gradation in the LUT, While the value is used, if the corresponding applied gradation value is not stored, the value of the applied gradation value of the combination close to the combination stored in the LUT is obtained by interpolation. ing.
[0179]
Further, in the liquid crystal display device of the present invention, a plurality of LUTs are prepared according to additional conditions for changing the response characteristics of the liquid crystal, such as temperature, and the applied gradation value taking into account the additional conditions is also determined. You can get it. Also in this case, if the additional condition is temperature, the number of LUTs is reduced by thinning out the temperature, instead of the total temperature, so that the capacity of a memory for storing the LUT can be reduced. If there is an LUT that satisfies the additional condition, the gradation value acquisition unit uses the applied gradation value obtained based on the value of the LUT. If there is no LUT that satisfies the additional condition, If the additional condition is close to the additional condition, that is, if the additional condition is temperature, a plurality of LUTs having a temperature close to that temperature are used, and interpolation is performed based on the applied gradation value obtained based on each LUT. , An applied gradation value corresponding to the additional condition is acquired.
[0180]
In particular, in the liquid crystal display device of the present invention, in obtaining an applied gradation value in which an additional condition is added to a plurality of combinations of the preceding gradation and the following gradation by performing the interpolation operation, the combination of the preceding gradation and the following gradation is used. Interpolation between them uses local coordinates associated with a spatial axis defined by the later gradation and the preceding gradation indicated in the LUT. As described above, when the local coordinates are used, the interpolation area can be set smaller than the case where the entire area is interpolated. For example, sufficient accuracy can be compensated even by simple interpolation such as linear interpolation, so that Since the interpolation accuracy between the combination of the key gradation and the subsequent gradation is improved, and the value obtained by the interpolation calculation between the combination of the preceding gradation and the subsequent gradation becomes more highly continuity closer to the actual measurement, additional conditions are required. For, even if the calculation is interpolated normally, it is possible to calculate the applied gradation value with high accuracy in consideration of the additional condition.
[0181]
As described above, in the above-described liquid crystal display device, even if an influence is caused by an additional condition such as a temperature, a cell thickness, and a video frequency (frame frequency), the applied gradation value according to the additional condition is obtained. That is, the interpolation value can be accurately obtained by the interpolation calculation. In particular, even when there is no LUT that meets the additional condition, the value used to obtain the final applied gradation value (applied gradation value (interpolated value) of each LUT) uses local coordinates. Therefore, the applied gradation value is a highly accurate interpolation value.
[0182]
Therefore, the liquid crystal display device of the present invention does not use, for example, local coordinates as in the related art, and can perform additional processing without increasing the capacity of a memory or the like as compared with an interpolated value that does not consider additional conditions such as temperature. It is possible to calculate the applied gradation value with high accuracy while considering the target conditions. As a result, by using the interpolation calculation, the appropriate overshoot drive is performed while reducing the capacity of the memory for storing the LUT as much as possible and without being affected by additional conditions such as temperature. Natural high-speed display can be performed.
[0183]
In addition, in the liquid crystal display device of the present invention, in addition to the above configuration, the applied gradation value acquiring means performs an interpolation operation using local coordinates, and performs a preceding gradation and a subsequent gradation stored in the LUT. From the combinations of tones, four combinations close to the combination of the preceding gradation and the subsequent gradation to be obtained by the interpolation calculation are selected, and one of the combinations is set as the origin of the local coordinate system. It is preferable that a difference from another combination be a local variable.
[0184]
According to the above configuration, when setting the local coordinates, first, four combinations close to the combination (target combination gradation) of the previous gradation and the subsequent gradation to be obtained by the interpolation calculation, for example, the LUT Among the combinations of the pre-gray scale and the post-gray scale stored in the first gray scale are displayed on the spatial axis defined by the pre-gray scale and the post-gray scale. Then, local coordinates are set with one of the four combinations as the origin.
[0185]
With such local coordinates, for example, the local coordinates to which the target combination tone belongs can be specified more correctly than the local coordinates defined using the values of the previous tone and the subsequent tone as they are, so that the The interpolation accuracy of the value (interpolated value) is improved.
[0186]
Further, as described above, the liquid crystal display device of the present invention performs the gray scale display by changing the voltage applied to the liquid crystal, and performs the previous gray scale which is the gray scale of one frame before and the gray scale of the next frame. In a liquid crystal display device in which an applied grayscale value to be actually applied to a liquid crystal is set in association with a grayscale, an LUT storing an applied grayscale value in association with a previous grayscale and a rear grayscale is used. A plurality of applied gradation values provided in accordance with an additional condition for changing a response characteristic of a liquid crystal, and referring to the plurality of LUTs, in accordance with the additional condition and a combination of a preceding gradation and a subsequent gradation. If the applied gradation value corresponding to the additional condition and combination is stored in the LUT, the value is obtained as it is, otherwise, the additional condition and combination stored in the LUT are obtained. Interpolation using applied gradation values close to And an applied gradation value acquiring unit for acquiring a value by calculating a local gradation associated with a spatial axis defined by a preceding gradation, a following gradation, and additional conditions. It is characterized in that an interpolation operation is performed using coordinates.
[0187]
According to the above configuration, if the applied gradation value of a desired combination is stored in the LUT, the value is output as it is, while if the corresponding applied gradation value is not in the LUT, the interpolation calculation is performed. Has become.
[0188]
In this interpolation calculation, the applied gradation value acquisition unit performs the calculation using LUTs stored in plurality according to additional conditions (for example, temperature and the like). In particular, in this interpolation calculation, local coordinates associated with a spatial axis defined by the rear gradation, the previous gradation, and the additional condition indicated in the LUT are used. For example, when there is an LUT that satisfies the additional condition, an applied gradation value (interpolated value) is acquired by using local coordinates corresponding to the LUT and using an interpolation operation such as linear interpolation.
[0189]
On the other hand, when there is no LUT that satisfies the additional condition, the application gradation value is obtained (interpolated value) by using a plurality of LUTs close to the additional condition.
[0190]
As described above, in the above-described liquid crystal display device, even if an influence is caused by an additional condition such as a temperature, a cell thickness, and a video frequency (frame frequency), the applied gradation value according to the additional condition is obtained. (Interpolated value) can be obtained with high accuracy by an interpolation operation using local coordinates.
[0191]
Therefore, for example, the liquid crystal display device of the present invention does not use local coordinates as in the related art, and performs high-precision application while taking into account additional conditions as compared with an interpolation value that does not take into account additional conditions such as temperature. The gradation value can be calculated. As a result, by using the interpolation calculation, the appropriate overshoot drive is performed while reducing the capacity of the memory for storing the LUT as much as possible and without being affected by additional conditions such as temperature. Natural high-speed display can be performed.
[0192]
In addition, in the liquid crystal display device of the present invention, in addition to the above configuration, the applied gradation value acquiring means uses two LUTs close to the additional condition when performing the interpolation operation using the local coordinates. From the combination of the previous gradation and the subsequent gradation stored in the LUT, four combinations close to the combination of the previous gradation and the next gradation to be acquired by the interpolation operation are selected, and these 8 combinations are selected. For a space composed of two combinations, one of the combinations is preferably set as the origin of the local coordinate system, and the difference between the origin and another combination is preferably set as a local variable.
[0193]
According to the above configuration, when setting the local coordinates, first, two LUTs close to the additional condition are selected, and in each LUT, the combination of the pre-gray scale and the post-gray scale to be obtained by the interpolation calculation Four combinations close to (target combination gradation) are selected. Therefore, since two LUTs are used, eight combinations are selected. Then, local coordinates are set with one of the eight combinations as the origin.
[0194]
With such local coordinates, for example, the local coordinates to which the target combination gradation belongs can be correctly specified as compared with the local coordinates defined using the values of the previous gradation, the rear gradation, and the additional condition as they are. The interpolation accuracy of the applied gradation value (interpolation value) is improved.
[0195]
Further, as described above, the liquid crystal display device of the present invention performs the gray scale display by changing the voltage applied to the liquid crystal, and performs the previous gray scale which is the gray scale of one frame before and the gray scale of the next frame. In a liquid crystal display device in which an applied grayscale value to be actually applied to a liquid crystal is set in association with a grayscale, an LUT in which an applied grayscale value is stored in association with a previous grayscale and a rear grayscale is provided. The LUT is referred to as the applied gradation value corresponding to the combination of the previous gradation and the rear gradation, and when the applied gradation value of the combination is stored in the LUT, the value is obtained as it is. If the applied gradation value of the combination is not stored in the LUT, an applied gradation is obtained by performing an interpolation operation using a plurality of applied gradation values close to the combination stored in the LUT. Value obtaining means for obtaining the applied gradation value. Stage, upon interpolation operation is characterized by using a local coordinate associated with space axes defined by the front gradation and rear gradation.
[0196]
According to the above configuration, the applied gradation value corresponding to the combination (target combination gradation) of the pre-gray scale and the post-gray scale to be acquired is calculated based on the spatial axis defined by the pre-gray scale and the post-gray scale. Is calculated (acquired) using the local coordinates attached to. Therefore, for example, the applied gradation value (interpolated value) is more accurate than the applied gradation value obtained by the interpolation operation not using the local coordinates.
[0197]
In addition, in the liquid crystal display device of the present invention, in addition to the above configuration, the applied gradation value acquiring means performs an interpolation operation using local coordinates, and performs a preceding gradation and a subsequent gradation stored in the LUT. From the combinations of tones, four combinations close to the combination of the preceding gradation and the subsequent gradation to be obtained by the interpolation calculation are selected, and one of the combinations is set as the origin of the local coordinate system. It is preferable that a difference from another combination be a local variable.
[0198]
According to the above configuration, when setting the local coordinates, first, four combinations close to the combination (target combination gradation) of the previous gradation and the subsequent gradation to be obtained by the interpolation calculation, that is, the LUT has already been set. Among the combinations of the pre-gray scale and the post-gray scale stored in the first gray scale are displayed on the spatial axis defined by the pre-gray scale and the post-gray scale. Then, local coordinates are set with one of the four combinations as the origin.
[0199]
With such local coordinates, for example, the local coordinates to which the target combination tone belongs can be specified more correctly than the local coordinates defined using the values of the previous tone and the subsequent tone as they are, so that the The interpolation accuracy of the value (interpolated value) is improved.
[0200]
In addition, in the liquid crystal display device of the present invention, in addition to the above configuration, when performing the interpolation operation using the local coordinates, the applied gradation value obtaining unit may perform the interpolation operation using the local coordinates by the number n (n is 2 or more) of the coordinate axes of the local coordinates. ), The space represented by the local coordinates is divided into regions consisting of n + 1 vertices whose vertices are known combinations of applied gradation values, and an interpolation operation is performed for each of the divided regions. Is preferred.
[0201]
According to the above configuration, for example, if the local coordinates are associated with coordinates (three-dimensional coordinates) having the second gradation, the previous gradation, and the additional condition as axes, four points correspond to the applied gradation values. Enclosing a point (target point) on the local coordinates. Then, in order to easily represent the target point represented by the three (n = 3) coordinate axes of the local coordinates by the interpolation formula used for the interpolation operation, four unknowns are required. Therefore, four (n + 1 = 3 + 1) grid points are required. That is, if an interpolation operation is to be performed by expressing the target point by, for example, a linear expression, it is sufficient if there are four grid points. Therefore, according to the above configuration, the interpolation operation can be performed by the interpolation formula using the linear expression, and the labor required for the calculation of the interpolation operation can be reduced (for example, the memory capacity is reduced).
[0202]
In addition, in the liquid crystal display device of the present invention, in addition to the above-described configuration, the applied gradation value acquiring unit is further located on the side where each of the n + 1 vertexes is connected, in addition to the above-described n + 1 vertices. It is preferable to perform the interpolation operation using the intermediate point.
[0203]
According to the above configuration, the number of points that can be used in the interpolation formula increases. Therefore, for example, an interpolation operation using a polynomial such as a quadratic expression can be performed. Therefore, the interpolation accuracy can be improved as compared with the linear expression.
[0204]
It should be noted that the present invention is not limited to the above-described embodiments, and various changes can be made within the scope of the claims, and the technical means disclosed in different embodiments can be appropriately combined. Embodiments included in the invention are also included in the technical means of the present invention.
[0205]
【The invention's effect】
As described above, the liquid crystal display device of the present invention includes at least one look-up table storing a plurality of pre-grayscale values and post-grayscale values, and corresponding grayscale voltage values applied to the liquid crystal display. Referring to at least one look-up table, and applying gradation value acquisition means for determining a gradation voltage value to be applied to the liquid crystal display to change the liquid crystal display from a previous gradation to a later gradation, The corresponding applied gradation value is read out from at least one of the look-up tables in which the preceding gradation value and the subsequent gradation value are stored, and the applied gradation value is represented by a front gradation axis and a rear gradation axis. And a configuration determined by interpolation using a plurality of applied gradation values corresponding to the pre-gradation value and the post-gradation value stored in the local coordinate system. .
[0206]
According to the above invention, at least one look-up table is provided, and each look-up table includes a plurality of pre-grayscale values and post-grayscale values, and corresponding grayscale voltage values (the above-described grayscale voltage values applied to the liquid crystal display). (A gradation voltage value corresponding to the previous gradation value and the rear gradation value) are stored. When the gradation voltage value is determined and applied to the liquid crystal display by the applied gradation value acquiring means, the display is changed from the previous gradation (currently displayed gradation) to the second gradation (desired target gradation). change.
[0207]
When the display is changed based on the corresponding applied gradation value, the corresponding applied gradation value is read from at least one of the look-up tables in which the preceding gradation value and the rear gradation value are stored.
[0208]
If the corresponding applied gradation value is not stored in the look-up table, the applied gradation value acquisition means refers to at least one of the look-up tables to determine the gradation voltage value. At this time, the applied gradation values are divided into a local coordinate system including a previous gradation axis and a rear gradation axis, and a plurality of applied gradations corresponding to the previous gradation values and the rear gradation values stored in the local coordinate system. It is determined by interpolation performed using the key value.
[0209]
As described above, since the desired applied gradation value is obtained by interpolation based on the stored applied gradation values, the capacity of a memory or the like for storing the look-up table (LUT) can be reduced. In other words, the LUT can be created by thinning out the pre-gray scale and the post-gray scale, rather than all gray scales.
[0210]
Therefore, the liquid crystal display device of the present invention can calculate a high-accuracy applied gradation value without increasing the capacity of a memory or the like, for example, as compared with the conventional case where local coordinates are not used. As a result, by using the interpolation calculation, there is an effect that the natural high-speed display can be performed by performing appropriate overshoot drive while minimizing the capacity of the memory for storing the LUT.
[0211]
In the liquid crystal display device, at least one of the look-up tables includes at least one additional condition look-up table provided in accordance with an additional condition for changing a response characteristic of the liquid crystal, and includes a look-up table from a pre-gray scale to a post-gray scale. The applied gradation value that changes the display to a gradation changes according to the additional condition, and the applied gradation value acquiring unit performs the interpolation calculation using at least one of the additional condition lookup tables. Is preferably performed.
[0212]
In this case, at least one LUT is prepared according to an additional condition for changing the response characteristic of the liquid crystal, and an applied gradation value can be obtained in consideration of the additional condition. In this case as well, the number of LUTs is reduced by thinning out not all additional conditions but additional conditions so that the capacity of a memory or the like for storing the LUT can be reduced.
[0213]
Therefore, compared to an interpolation value that does not use the local coordinates as in the related art and that does not take into account additional conditions such as temperature, a high-precision application is performed while taking into account the additional conditions without increasing the capacity of the memory or the like. The gradation value can be calculated. As a result, by using the interpolation operation, the appropriate overshoot drive is performed while reducing the capacity of the memory for storing the LUT as much as possible and without being affected by additional conditions such as temperature. The effect that natural high-speed display can be performed is also exhibited.
[0214]
In performing the interpolation operation using the local coordinate system, the applied gradation value acquiring unit may be configured to store the stored previous gradation value and the rear gradation value close to the previous gradation value and the rear gradation value to be displayed. Preferably, four combinations are selected, one of which is used as the origin of the local coordinate system, and the difference between the origin and another combination is used as a local variable.
[0215]
According to the above configuration, when setting the local coordinate system, first, four combinations close to the combination of the previous gradation and the subsequent gradation to be displayed by the interpolation calculation, for example, already stored in the LUT. Of the combinations of the preceding gradation and the later gradation, a combination close to the target combination gradation is displayed on a spatial axis defined by the preceding gradation and the later gradation. In addition, there is an effect that a local coordinate system having one combination as an origin can be set among the above four combinations.
[0216]
It is preferable that the applied gradation value acquiring means performs an interpolation operation using a local coordinate system having an axis defined by the preceding gradation, the following gradation, and the additional condition (attached to the axis). . The additional condition includes temperature.
[0219]
In performing the interpolation operation using the local coordinate system, the applied gradation value acquiring unit uses two look-up tables close to the additional condition, and uses a preceding gradation value and a rear gradation value to be displayed. Four combinations of the stored pre-grayscale value and post-grayscale value that are close to the selected value, and one of these eight combinations is set as the origin of the local coordinate system having these eight combinations. It is preferable to use the difference between and the other combination as a local variable.
[0218]
According to the above configuration, when setting the local coordinate system, first, two LUTs that are close to the additional condition are selected, and in each LUT, the LUT of the pre-gray scale and the post-gray scale to be obtained by the interpolation calculation is selected. Four combinations close to the combination (target combination gradation) are selected. Therefore, since two LUTs are used, eight combinations are selected. Then, a local coordinate system having one of the eight combinations as the origin is set.
[0219]
In such a local coordinate system, for example, the local coordinate system to which the target combination grayscale belongs can be correctly specified, as compared with a local coordinate system defined using the values of the preceding gradation, the subsequent gradation, and the additional condition as they are. Therefore, it is possible to improve the interpolation accuracy of the acquired applied gradation value (interpolated value).
[0220]
In performing the interpolation operation using the local coordinate system, the applied gradation value acquiring unit stores the stored previous gradation value and the rear gradation value that are close to the previous gradation value and the rear gradation value to be displayed. Preferably, one of the four combinations is selected, one of the combinations is used as the origin of the local coordinate system, and the difference between the origin and another combination is used as a local variable.
[0221]
According to the above configuration, when the local coordinate system is set, first, four combinations that are close to the combination (target combination gradation) of the previous gradation and the subsequent gradation to be acquired by the interpolation calculation, that is, Of the combinations of the preceding gradation and the later gradation stored in the LUT, a combination close to the target combination gradation to be displayed is displayed on a spatial axis defined by the preceding gradation and the later gradation. Then, a local coordinate system having one of the four combinations as the origin is set.
[0222]
In such a local coordinate system, for example, compared to a local coordinate system defined using the values of the preceding and subsequent gradations as they are, the local coordinates to which the target combination gradation belongs can be specified correctly. In addition, there is an effect that the interpolation accuracy of the gradation value (interpolation value) can be improved.
[0223]
In the above liquid crystal display device, the space represented by the local coordinate system is divided into an area composed of n + 1 vertices having the stored combination of applied gradation values as vertices, and the number of coordinate axes of the local coordinate system is n (n is an integer of 2 or more), and the applied gradation value acquiring means preferably performs the interpolation in any divided area.
[0224]
According to the above configuration, for example, if the local coordinates are associated with coordinates (three-dimensional coordinates) having the second gradation, the previous gradation, and the additional condition as axes, four points correspond to the applied gradation values. Enclosing a point (target point) on the local coordinates. Then, in order to easily represent the target point represented by the three (n = 3) coordinate axes of the local coordinates by the interpolation formula used for the interpolation operation, four unknowns are required. Therefore, four (n + 1 = 3 + 1) grid points are required. That is, if an interpolation operation is to be performed by expressing the target point by, for example, a linear expression, it is sufficient if there are four grid points. Therefore, according to the above configuration, the interpolation calculation can be performed by the interpolation formula using the linear expression, and the effect of reducing the labor required for the calculation of the interpolation calculation (for example, reducing the memory capacity and the like) is also achieved.
[0225]
It is preferable that the applied gradation value acquisition unit further performs an interpolation operation using an intermediate point located on a side connecting the n + 1 vertices, in addition to the n + 1 vertices.
[0226]
According to the above configuration, the number of points that can be used in the interpolation formula increases. Therefore, for example, an interpolation operation using a polynomial such as a quadratic expression can be performed. Therefore, an effect that the interpolation accuracy can be improved as compared with the linear expression is also exhibited.
[0227]
According to another liquid crystal display device of the present invention, at least one look-up table storing a plurality of pre-grayscale values and post-grayscale values, and corresponding grayscale voltage values applied to the liquid crystal display, respectively, If the key value is not stored in the at least one look-up table, the at least one look-up table is referred to and applied to the liquid crystal display to change the liquid crystal display from a previous gray level to a subsequent gray level. An applied gradation value acquiring unit for determining a gradation voltage value.
[0228]
According to the above invention, at least one look-up table is provided, and each look-up table includes a plurality of pre-grayscale values and post-grayscale values, and corresponding grayscale voltage values applied to the liquid crystal display. Is stored. When the gradation voltage value is determined and applied to the liquid crystal display by the applied gradation value acquiring means, the display is changed from the previous gradation (currently displayed gradation) to the second gradation (desired target gradation). change.
[0229]
When the applied gradation value is stored in at least one of the look-up tables, the applied gradation value acquiring means reads the value. On the other hand, if it is not stored, the applied gradation value acquiring means refers to at least one of the look-up tables, and changes the gradation applied to the liquid crystal display to change the liquid crystal display from the previous gradation to the rear gradation. The adjustment voltage value is determined by interpolation.
[0230]
As described above, since the desired applied gradation value is obtained by interpolation based on the stored applied gradation values, the capacity of a memory or the like for storing the look-up table (LUT) can be reduced. In other words, the LUT can be created by thinning out the pre-gray scale and the post-gray scale, rather than all gray scales.
[0231]
Therefore, the liquid crystal display device of the present invention can calculate a high-accuracy applied gradation value without increasing the capacity of a memory or the like, for example, as compared with the conventional case where local coordinates are not used. As a result, by using the interpolation calculation, there is an effect that the natural high-speed display can be performed by performing appropriate overshoot drive while minimizing the capacity of the memory for storing the LUT.
[0232]
It is preferable that the applied gradation value acquisition means performs an interpolation operation using local coordinates having the preceding gradation and the following gradation as axes.
[0233]
In the above-mentioned liquid crystal display device, at least one of the look-up tables is prepared according to at least one additional condition for changing a response characteristic of the liquid crystal, and prepared by thinning out at least one of the additional conditions. When there is no lookup table that satisfies the corresponding additional condition, the applied gradation value acquiring unit calculates a value obtained by performing an interpolation operation using the applied gradation value stored in at least one of the lookup tables. It is preferable to determine the applied gradation value.
[0234]
In this case, at least one LUT is prepared according to an additional condition for changing the response characteristic of the liquid crystal, and an applied gradation value can be obtained in consideration of the additional condition. In this case as well, the number of LUTs is reduced by thinning out not all additional conditions but additional conditions so that the capacity of a memory or the like for storing the LUT can be reduced.
[0235]
Therefore, compared to an interpolation value that does not use the local coordinates as in the related art and that does not take into account additional conditions such as temperature, a high-precision application is performed while taking into account the additional conditions without increasing the capacity of the memory or the like. The gradation value can be calculated. As a result, by using the interpolation operation, the appropriate overshoot drive is performed while reducing the capacity of the memory for storing the LUT as much as possible and without being affected by additional conditions such as temperature. The effect that natural high-speed display can be performed is also exhibited.
[0236]
According to the above configuration, for example, in the case of a local coordinate system associated with coordinates (three-dimensional coordinates) having the second gradation, the previous gradation, and the additional condition as axes, the applied gradation value is calculated at four points. The corresponding point on the local coordinates (target point) is enclosed. Then, in order to easily represent the target point represented by the three (n = 3) coordinate axes of the local coordinates by the interpolation formula used for the interpolation operation, four unknowns are required. Therefore, four (n + 1 = 3 + 1) grid points are required. That is, if an interpolation operation is to be performed by expressing the target point by, for example, a linear expression, it is sufficient if there are four grid points. Therefore, according to the above configuration, the interpolation calculation can be performed by the interpolation formula using the linear expression, and the effect of reducing the labor required for the calculation of the interpolation calculation (for example, reducing the memory capacity and the like) is also achieved.
[0237]
It is preferable that the applied gradation value acquisition unit further performs an interpolation operation using an intermediate point located on a side connecting the n + 1 vertices, in addition to the n + 1 vertices.
[0238]
According to the above configuration, the number of points that can be used in the interpolation formula increases. Therefore, for example, an interpolation operation using a polynomial such as a quadratic expression can be performed. As a result, an effect that the interpolation accuracy can be improved as compared with the linear expression is also obtained.
[0239]
According to another embodiment of the present invention, there is provided a liquid crystal display device including at least one look-up table including a plurality of memory blocks, and each memory block stores a plurality of gradation voltage values. Each gray scale voltage value is applied to a liquid crystal display to change the liquid crystal display from a previous gray scale to a rear gray scale. Each of the gray scale voltage values is a pair of a previous gray scale voltage in a local coordinate space. The grayscale voltage value is applied to the liquid crystal display corresponding to the tonal value and the rear grayscale value, and further interpolates the grayscale voltage value so as to change the liquid crystal display from the currently displayed front grayscale to a desired rear grayscale. An applied gradation value acquisition unit, wherein in the local coordinate system, at least one look-up table including a gradation voltage value close to a currently displayed preceding gradation value and a desired succeeding gradation value. Kicking has a configuration in which the applied tone values by interpolation using the memory block is determined.
[0240]
According to the above invention, at least one lookup table is provided, and each lookup table includes a plurality of memory blocks. Each memory block stores a plurality of gradation voltage values. When each gradation voltage value is applied to the liquid crystal display, the display changes from the previous gradation (currently displayed gradation) to the second gradation (desired target gradation). Each gradation voltage value corresponds to a pair of a previous gradation value and a rear gradation value in the local coordinate space.
[0241]
The applied gradation value acquiring means interpolates a gradation voltage value applied to the liquid crystal display to change the liquid crystal display from a currently displayed gradation to a desired rear gradation. This interpolation is performed in the local coordinate system using a memory block in at least one look-up table that includes a gradation voltage value close to the currently displayed previous gradation value and the desired subsequent gradation value. A gradation value is determined.
[0242]
As described above, a desired applied gradation value (applied gradation value not stored in the memory block) can be obtained by interpolation based on the gradation voltage value already stored in the memory block. ) Can be reduced in memory and the like. In other words, the LUT can be created by thinning out the pre-gray scale and the post-gray scale, rather than all gray scales. In addition, the interpolation makes it possible to quickly and easily find an accurate applied gradation value related to the previous gradation value and the rear gradation value that are not stored in the memory.
Therefore, the liquid crystal display device of the present invention can quickly and easily calculate a high-accuracy applied gradation value without increasing the capacity of a memory or the like, for example, as compared with the conventional case where local coordinates are not used. . As a result, by using the interpolation calculation, there is an effect that the natural high-speed display can be performed by performing appropriate overshoot drive while minimizing the capacity of the memory for storing the LUT.
[0243]
Preferably, the plurality of memory blocks further store variables that can be used to interpolate the grayscale voltage value. It is preferable that the applied gradation value acquiring means interpolates the gradation voltage value using a primary expression or a secondary expression.
[0244]
Preferably, the apparatus further comprises at least one additional condition lookup table, and each additional condition lookup table comprises a plurality of blocks corresponding to the additional condition.
[0245]
In this case, at least one LUT is prepared according to an additional condition for changing the response characteristic of the liquid crystal, and an applied gradation value can be obtained in consideration of the additional condition. In this case as well, the number of LUTs is reduced by thinning out not all additional conditions but additional conditions so that the capacity of a memory or the like for storing the LUT can be reduced.
[0246]
Therefore, compared to an interpolation value that does not use the local coordinates as in the related art and that does not take into account additional conditions such as temperature, a high-precision application is performed while taking into account the additional conditions without increasing the capacity of the memory or the like. The gradation value can be calculated. As a result, by using the interpolation operation, the appropriate overshoot drive is performed while reducing the capacity of the memory for storing the LUT as much as possible and without being affected by additional conditions such as temperature. The effect that natural high-speed display can be performed is also exhibited.
[0247]
It is preferable that the applied gradation value acquiring means interpolates a gradation voltage value using a memory block of at least two lookup tables.
[Brief description of the drawings]
FIG. 1 is a block diagram of a member that performs an interpolation operation in a liquid crystal display device according to an embodiment of the present invention.
FIG. 2 is a block diagram of a liquid crystal display device including a member for performing the interpolation operation.
FIG. 3A is a look-up table (Table 1) at 40 ° C., and FIG. 3B is a look-up table (Table 2) at 0 ° C.
FIG. 4 is a graph showing two-dimensional local coordinates used by the present liquid crystal display device.
FIG. 5 is a graph showing three-dimensional local coordinates used by the present liquid crystal display device.
FIG. 6 is a schematic diagram when a secondary interpolation formula is used in the local coordinates (two-dimensional local coordinates) in FIG. 4;
FIG. 7 is a schematic diagram when a secondary interpolation formula is used in the local coordinates (three-dimensional local coordinates) of FIG. 5;
[Explanation of symbols]
1 LCD controller
2 FM
3 LCD panel
5 gradation circuit
6 DAC
7 VPC
8 Temperature sensor
9 Computer
10 Liquid crystal display device
11 Interpolation element
12 LUT memory
13 Applied gradation value acquisition section (applied gradation value acquisition means)
局 所 Post-gradation local axis
η Previous gradation local axis
ζ Additional axis

Claims (20)

At least one look-up table for storing a plurality of pre-grayscale values and post-grayscale values, and corresponding grayscale voltage values applied to the liquid crystal display,
Referring to at least one of the look-up tables, comprising an applied gradation value acquisition unit that determines a gradation voltage value applied to the liquid crystal display to change the liquid crystal display from a previous gradation to a subsequent gradation.
The corresponding applied gradation value is read out from at least one of the look-up tables in which the preceding gradation value and the subsequent gradation value are stored, and the applied gradation value is represented by a front gradation axis and a rear gradation axis. And a liquid crystal display device determined by interpolation using a plurality of applied gradation values corresponding to the previous gradation value and the rear gradation value stored in the local coordinate system. At least one look-up table includes at least one additional condition look-up table provided according to an additional condition that changes a response characteristic of the liquid crystal,
The applied gradation value that changes the display from the previous gradation to the rear gradation changes according to the additional condition,
2. The liquid crystal display device according to claim 1, wherein the applied gradation value acquisition unit performs the interpolation operation using at least one additional condition lookup table. 3. In performing the interpolation operation using the local coordinate system, the applied gradation value acquiring unit may be configured to store the stored previous gradation value and the rear gradation value close to the previous gradation value and the rear gradation value to be displayed. The liquid crystal according to claim 2, wherein four combinations are selected, one of which is used as an origin of the local coordinate system, and a difference between the origin and another combination is used as a local variable. Display device. 3. The apparatus according to claim 2, wherein the applied gradation value acquiring means performs an interpolation calculation using a local coordinate system associated with an axis defined by the preceding gradation, the following gradation, and the additional condition. 3. The liquid crystal display device according to 1. The liquid crystal display device according to claim 2, wherein the additional condition is temperature. In performing the interpolation operation using the local coordinate system, the applied gradation value acquisition unit uses two look-up tables that are close to the additional condition to obtain a pre-gray scale value and a post-gray scale value to be displayed. Select four combinations of near and stored pre-grayscale values and post-grayscale values, and set one of the eight combinations as the origin of the local coordinate system having these eight combinations. The liquid crystal display device according to claim 4, wherein a difference from a combination of the above is used as a local variable. In performing the interpolation operation using the local coordinate system, the applied gradation value acquiring unit stores the stored previous gradation value and the rear gradation value that are close to the previous gradation value and the rear gradation value to be displayed. 2. The method according to claim 1, wherein four combinations are selected, one of the combinations is used as an origin of the local coordinate system, and a difference between the origin and another combination is used as a local variable. Liquid crystal display. The space represented by the local coordinate system is divided into an area composed of n + 1 vertices having the stored combination of applied gradation values as vertices, and the number of coordinate axes of the local coordinate system is n (n is 2 or more). The liquid crystal display device according to claim 1, wherein the applied gradation value acquisition means performs the interpolation in any divided area. 9. The apparatus according to claim 8, wherein the applied gradation value acquiring means further performs an interpolation operation using an intermediate point located on a side connecting each of the n + 1 vertices, in addition to the n + 1 vertices. 3. The liquid crystal display device according to 1. At least one look-up table for storing a plurality of pre-grayscale values and post-grayscale values, and corresponding grayscale voltage values applied to the liquid crystal display,
When the applied gradation value is not stored in at least one of the look-up tables, the applied gradation value is applied to the liquid crystal display in order to change the liquid crystal display from a previous gradation to a subsequent gradation by referring to the at least one look-up table. A liquid crystal display device comprising: an applied gradation value acquiring unit that determines a gradation voltage value to be applied. 11. The liquid crystal display device according to claim 10, wherein the applied gradation value acquisition unit performs an interpolation calculation using local coordinates having the first gradation and the second gradation as axes. At least one look-up table is prepared according to at least one additional condition that changes the response characteristic of the liquid crystal, and is prepared by thinning out at least one of the additional conditions.
When there is no look-up table that satisfies the additional condition, the applied gradation value acquisition unit calculates the value obtained by performing an interpolation operation using the applied gradation value stored in at least one of the look-up tables. 11. The liquid crystal display device according to claim 10, wherein the gradation value is determined. The space represented by the local coordinate system is divided into an area composed of n + 1 vertices having the stored combination of applied gradation values as vertices, and the number of coordinate axes of the local coordinate system is n (n is 2 or more). 3. The liquid crystal display device according to claim 2, wherein the applied gradation value acquisition unit performs the interpolation in any divided area. 14. The method according to claim 13, wherein the applied gradation value acquiring means further performs an interpolation operation using an intermediate point located on a side connecting each of the n + 1 vertices, in addition to the n + 1 vertices. 3. The liquid crystal display device according to 1. At least one look-up table including a plurality of memory blocks is provided, wherein each memory block stores a plurality of gradation voltage values, and each gradation voltage value is applied to a liquid crystal display to control the liquid crystal display. It is configured to change from the previous gradation to the later gradation, and each of the above-mentioned gradation voltage values corresponds to a pair of the preceding gradation value and the rear gradation value in the local coordinate space,
Further, there is provided an applied gradation value acquiring means which is applied to the liquid crystal display and interpolates a gradation voltage value so as to change the liquid crystal display from a previous gradation currently displayed to a desired rear gradation. In the coordinate system, an applied gray scale value is determined by interpolation using a memory block in at least one look-up table that includes a gray scale voltage value close to a currently displayed previous gray scale value and a desired rear gray scale value. Liquid crystal display. The liquid crystal display device according to claim 15, wherein the plurality of memory blocks further store a variable that can be used to interpolate the grayscale voltage value. 17. The liquid crystal display device according to claim 15, wherein the applied gradation value acquiring means interpolates the gradation voltage value using a linear equation. 17. The liquid crystal display device according to claim 15, wherein the applied gradation value acquiring means interpolates the gradation voltage value using a quadratic equation. 17. The liquid crystal according to claim 15, further comprising at least one additional condition lookup table, wherein each additional condition lookup table includes a plurality of blocks corresponding to the additional condition. Display device. 20. The liquid crystal display device according to claim 19, wherein said applied gradation value acquiring means interpolates a gradation voltage value using a memory block of at least two look-up tables.

Images