JP2006030761A - Image display apparatus and driving method thereof - Google Patents

Abstract

To reduce flicker in an image display device having a high dynamic range.
A driving method of an image display apparatus for displaying an image by modulating light from a light source by a first light modulation element and a second light modulation element based on display image data, the method comprising: Each pixel corresponding to the first light modulation element of the second light modulation element is driven by inverting the polarity of the first light modulation element by applying a predetermined drive signal based on the display image data to each pixel. The second light modulation element is driven by applying a drive signal having a voltage phase opposite to that of the drive signal applied to each pixel of the first light modulation element to the pixel.
[Selection] Figure 9

Description

  The present invention relates to an image display device and a driving method thereof.

In recent years, electronic image display devices such as LCD (Liquid Crystal Display), EL (Electro-luminescence) displays, plasma displays, CRTs (Cathode Ray Tubes), and projectors have been remarkably improved. A device having a performance almost comparable to that of a device is being realized. However, regarding the luminance dynamic range, the reproduction range is about 1 to 10 ² [nit], and the number of gradations is generally 8 bits. On the other hand, human vision has a range of luminance dynamic range that can be perceived at a time of about 10 ⁻² to 10 ⁴ [nit], and the luminance discrimination capability is 0.2 [nit]. It is said to be equivalent to 12 bits. When viewing the display image of the current image display device via such visual characteristics, the narrowness of the luminance dynamic range is conspicuous, and in addition, the gradation of the shadow part and highlight part is insufficient. You will feel unsatisfied with the reality and power.

  Further, in CG (Computer Graphics) used in movies, games, etc., display image data (hereinafter referred to as HDR (High Dynamic Range) display image data) has a luminance dynamic range and gradation characteristics close to human vision. The movement to pursue the reality of depiction is becoming mainstream. However, since the performance of the image display device that displays it is insufficient, there is a problem that the expressive power inherent in the CG content cannot be fully exhibited.

  Furthermore, in the next OS (Operating System), adoption of a 16-bit color space is planned, and the dynamic range and the number of gradations are dramatically increased as compared with the current 8-bit color space. Therefore, it is expected that the demand for realizing a high dynamic range and high gradation electronic image display device capable of utilizing the 16-bit color space will increase.

  Among image display devices, projection display devices (projectors) such as liquid crystal projectors and DLP (Digital Light Processing (trademark)) projectors are capable of displaying large screens and are effective in reproducing the reality and power of display images. Image display device. In this field, the following proposals have been made to solve the above problems.

  As an image display device with a high dynamic range, for example, there is a technique disclosed in Patent Document 1, and a light source, a second light modulation element that modulates luminance in the entire wavelength region of light, and a wavelength region of light. For each wavelength region of RGB three primary colors, a first light modulation element that modulates the luminance of the wavelength region, and modulates the light from the light source with the second light modulation element to form a desired luminance distribution, the optical image The light is imaged and color-modulated on the display surface of the first light modulation element, and the second-order modulated light is projected. Each pixel of the second light modulation element and the first light modulation element is separately controlled based on the first control value and the second control value determined from the HDR display image data. As the light modulation element, for example, a transmittance modulation element having a pixel structure or a segment structure whose transmittance can be controlled independently and capable of controlling a two-dimensional transmittance distribution is used. A typical example is a liquid crystal light valve. Further, a reflectance modulation element may be used instead of the transmittance modulation element, and a typical example thereof is a DMD (Digital Micromirror Device) element.

  Consider a case where a light modulation element having a dark display transmittance of 0.2% and a bright display transmittance of 60% is used. With a single light modulation element, the luminance dynamic range is 60 / 0.2 = 300. Since the image display apparatus corresponds to optically arranging light modulation elements having a luminance dynamic range of 300 in series, a luminance dynamic range of 300 × 300 = 90000 can be realized. The same idea holds for the number of gradations, and an 8-bit gradation light modulation element is optically arranged in series, whereby a gradation number exceeding 8 bits can be obtained.

By the way, in an image display apparatus using a liquid crystal panel as a modulation element, reduction of flicker caused by a residual DC component of a drive signal is required for improving image quality. In a conventional liquid crystal projector, for example, as shown in Patent Document 2, the residual DC component of the liquid crystal panel is removed by using a plurality of polarity inversion drivers in the drive signal control of the liquid crystal panel, thereby suppressing the occurrence of flicker. is doing.
Japanese Patent Laid-Open No. 2001-1000068 JP-A-8-122743

However, as can be seen from the description in Patent Document 2, a conventional technique for reducing flicker has been proposed in correspondence with a high dynamic range image display device including a first light modulation element and a second light modulation element. Not a thing.
In the future, in order to promote the widespread use of the high dynamic range image display apparatus including the first light modulation element and the second light modulation element as described above, flicker in such a high dynamic range image display apparatus is reduced. Technology is desired.

  The present invention has been made in view of the above-described problems, and an object thereof is to reduce flicker in an image display device having a high dynamic range.

  In order to achieve the above object, an image display device of the present invention is an image display device that displays an image by modulating light from a light source based on display image data, and is a first device that modulates light from the light source. A light modulation element; and a first drive means for driving the first light modulation element to reverse its polarity by applying a predetermined drive signal based on the display image data to each pixel of the first light modulation element; A second light modulation element that modulates light from the first light modulation element, and each pixel of the first light modulation element with respect to each pixel corresponding to the first light modulation element of the second light modulation element And a second driving means for driving the second light modulation element by applying a driving signal having a voltage phase opposite to that of the applied driving signal.

According to the image display device of the present invention having such characteristics, the drive signal and voltage applied to each pixel of the first modulation element with respect to each pixel corresponding to the first light modulation element of the second light modulation element. The second light modulation element is driven by applying a drive signal having an opposite phase.
For this reason, a reverse-phase DC component that cancels the residual DC component that causes flicker generated in the first modulation element is generated in the second modulation element, and as a result, flicker in the image displayed by the image display device is reduced. It becomes possible.

In the image display device of the present invention, the first drive means reverses the polarity of the first light modulation element so that the polarity reversal period of the first light modulation element becomes one frame period for displaying the image. A configuration of driving can be employed.
In the image display device of the present invention, the first driving unit drives the first light modulation element so that the polarity inversion period of the first light modulation element becomes one horizontal line period of the image, In addition, a configuration in which a drive signal having a voltage phase opposite to that of the previous frame is applied to each pixel of the first light modulation element in one frame period for displaying the image may be employed.
In the image display device of the present invention, the first driving unit drives the first light modulation element so that the polarity inversion period of the first light modulation element is one vertical line period of the image. In addition, a configuration in which a drive signal having a voltage phase opposite to that of the previous frame is applied to each pixel of the first light modulation element in one frame period for displaying the image may be employed.
In the image display device of the present invention, the first driving unit drives the first light modulation element so that the polarity inversion period of the first light modulation element is one pixel period, and the image A drive signal having a voltage phase opposite to that of the previous horizontal line in one horizontal line cycle is applied to each pixel of the first light modulation element, and further, having a voltage phase opposite to that in the previous frame in one frame cycle for displaying the image. A configuration in which a drive signal is applied to each pixel of the first light modulation element may be employed.
According to the image display apparatus of the present invention that employs such a configuration, the first light modulation element is driven to invert the polarity by the various configurations described above, and the drive signal and the voltage phase applied to the first light modulation element. The second modulation element to which the opposite drive signal is applied is also driven by reversing the polarity in the same manner as the first light modulation element. For this reason, the residual DC component of the output image via the first light modulation element and the second light modulation element can be removed.

In the image display device of the present invention, a configuration in which the same number of the first light modulation elements and the second light modulation elements are provided can be employed.
By adopting such a configuration, even if a plurality of first light modulation elements are provided, residual DC components that cause flicker generated in each first modulation element are eliminated by each second modulation element. It can be canceled out by the generated reverse phase DC component. Therefore, flicker can be more reliably reduced.

Next, the driving method of the image display device of the present invention is a driving method of an image display device that displays an image by modulating light from a light source by a first light modulation element and a second light modulation element based on display image data. Then, by applying a predetermined drive signal based on the display image data to each pixel of the first light modulation element, the first light modulation element is driven to reverse the polarity, and the second light modulation element The second light modulation element is driven by applying a drive signal having a voltage phase opposite to that of the drive signal applied to each pixel of the first light modulation element to each pixel corresponding to the first light modulation element. It is characterized by doing.
According to the driving method of the image display apparatus of the present invention having such characteristics, each pixel corresponding to the first light modulation element of the second light modulation element is applied to each pixel of the first light modulation element. The second light modulation element is driven by applying a drive signal having a voltage phase opposite to that of the drive signal.
For this reason, a reverse-phase DC component that cancels the residual DC component that causes flicker generated in the first modulation element is generated in the second modulation element, and as a result, flicker in the image displayed by the image display device is reduced. It becomes possible.

  Hereinafter, an embodiment of an image display device and a driving method thereof according to the present invention will be described with reference to the drawings. In the following drawings, the scale of each member is appropriately changed in order to make each member a recognizable size.

(First embodiment)
FIG. 1 is an example of an image display apparatus according to the present invention, and is a diagram illustrating a main optical configuration of a projector PJ1.
As shown in FIG. 1, the projector PJ 1 includes a light source 10, a uniform illumination system 20 that uniformizes the luminance distribution of light incident from the light source 10, and RGB three primary colors in a wavelength region of light incident from the uniform illumination system 20. The color modulation section 25 that modulates the brightness of each of the three light-transmitting liquid crystal light valves 60B, 60G, 60R as the first light modulating means and the three light-transmitting liquid crystal light valves 100B, 100G, 100R as the second light modulating means. And a projection lens 110 that projects light incident from the color modulation unit 25 onto a screen (not shown).

  The light source 10 includes a lamp 11 such as an ultrahigh pressure mercury lamp or a xenon lamp, and a reflector 12 that reflects and collects light emitted from the lamp 11.

  The uniform illumination system 20 includes two lens arrays 21 and 22 made of fly-eye lenses, a polarization conversion element 23, and a condenser lens 24. Then, the luminance distribution of the light from the light source 10 is made uniform by the two lens arrays 21 and 22, and the uniformed light is polarized by the polarization conversion element 23 in the polarization direction in which the color modulation unit can be incident, and the polarized light is condensed. The light is condensed by the lens 24 and emitted to the color modulation unit 25. The polarization conversion element 23 is composed of, for example, a PBS array and a half-wave plate, and converts random polarization into specific linear polarization.

  The color modulation unit 25 includes two dichroic mirrors 30 and 35 as light separating means, three mirrors (reflection mirrors 36, 45, and 46), and five field lenses (lens 41, relay lens 42, and collimating lens 50B). , 50G, 50R), three first liquid crystal light valves 60B, 60G, 60R, three second liquid crystal light valves 100B, 100G, 100R, and a cross dichroic prism 80.

  The dichroic mirrors 30 and 35 separate (split) the light (white light) from the light source 10 into RGB (primary) light of red (R), green (G), and blue (B). The dichroic mirror 30 is formed by forming a dichroic film having a property of reflecting B light and G light and transmitting R light on a glass plate or the like, and is included in the white light from the light source 10. Reflects light and G light and transmits R light. The dichroic mirror 35 is formed by reflecting a G light on a glass plate or the like and forming a dichroic film having a property of transmitting the B light. Of the G light and the B light transmitted through the dichroic mirror 30, the dichroic mirror 35 reflects the G light. It transmits to the collimating lens 50G, transmits blue light, and transmits it to the lens 41.

  The relay lens 42 transmits light in the vicinity of the lens 41 (light intensity distribution) to the vicinity of the collimating lens 50B, and the lens 41 has a function of causing light to enter the relay lens 42 efficiently. The B light incident on the lens 41 is transmitted to the first liquid crystal light valve 60B which is spatially separated, with its intensity distribution almost preserved and almost no light loss.

  The collimating lenses 50B, 50G, and 50R substantially parallelize each color light incident on the corresponding liquid crystal light valves 60B, 60G, and 60R to narrow the angle distribution of the incident light and improve the display characteristics of the liquid crystal light valves 60B, 60G, and 60R. It has a function to make it. The light of the three primary colors of RGB dispersed by the dichroic mirrors 30 and 35 passes through the above-described mirrors (reflection mirrors 36, 45, 46) and field lenses (lens 41, relay lens 42, collimating lenses 50B, 50G, 50R). Through the first liquid crystal light valves 60B, 60G and 60R.

  The first liquid crystal light valves 60B, 60G, and 60R include a glass substrate on which pixel electrodes and switching elements such as thin film transistors and thin film diodes for driving the pixel electrodes are formed in a matrix, and a glass on which a common electrode is formed over the entire surface. This is an active matrix liquid crystal display element in which a TN liquid crystal is sandwiched between a substrate and a polarizing plate is disposed on the outer surface.

  The first liquid crystal light valves 60B, 60G, and 60R have a normally white mode in which a white / light (transmission) state is applied when no voltage is applied, and a black / dark (non-transmission) state when a voltage is applied, or vice versa. It is driven in the Marie Black mode, and gradation between light and dark is analog controlled according to a given control value. The first liquid crystal light valve 60B optically modulates the incident B light based on the display image data, and emits modulated light including an optical image. The first liquid crystal light valve 60G optically modulates the incident G light based on display image data, and emits modulated light including an optical image. The first liquid crystal light valve 60R optically modulates the incident R light based on the display image data, and emits modulated light including an optical image.

  The second liquid crystal light valves 100B, 100G, and 100R are active matrix liquid crystal display elements whose optical synthesis positions coincide with those of the first liquid crystal light valves 60B, 60G, and 60R. As shown in FIG. The liquid crystal light valves 60B, 60G, 60R are arranged close to each other. That is, the projector PJ1 of this embodiment includes the same number of first liquid crystal light valves 60B, 60G, 60R and the same number of second liquid crystal light valves 100B, 100G, 100R. The arrangement order of the first liquid crystal light valves 60B, 60G, 60R and the second liquid crystal light valves 100B, 100G, 100R may be reversed.

  The second liquid crystal light valves 100B, 100G, and 100R also have a normally white mode in which a white / bright (transmission) state is applied when no voltage is applied, and a black / dark (non-transmission) state when a voltage is applied, or vice versa. It is driven in the Marie Black mode, and gradation between light and dark is analog controlled according to a given control value. The second liquid crystal light valve 100B optically modulates the B light incident from the first liquid crystal light valve 60B based on the display image data, and emits modulated light including an optical image. The second liquid crystal light valve 100G optically modulates the G light incident from the first liquid crystal light valve 60G based on display image data, and emits modulated light including an optical image. The second liquid crystal light valve 100R optically modulates the R light incident from the first liquid crystal light valve 60R based on the display image data, and emits modulated light including an optical image.

  Here, in the projector PJ1 of the present embodiment, as will be described in detail later, the second liquid crystal light valves 100B, 100G, and 100R corresponding to the respective pixels of the first liquid crystal light valves 60B, 60G, and 60R, A drive signal having a voltage phase opposite to that of the drive signal applied to each pixel of the one liquid crystal light valve 60B, 60G, 60R is applied. Therefore, a reverse-phase DC component that cancels out the residual DC component that causes flicker generated in the first liquid crystal light valves 60B, 60G, and 60R is generated in the second liquid crystal light valves 100B, 100G, and 100R. Flicker components contained in the modulated light including the optical images emitted from the second liquid crystal light valves 100B, 100G, and 100R are reduced.

  The cross dichroic prism 80 has a structure in which four right-angle prisms are bonded to each other, and a dielectric multilayer film (B light reflecting dichroic film 81) that reflects B light and a dielectric multilayer film that reflects R light are included therein. (R light reflecting dichroic film 82) is formed in an X-shaped cross section. Then, the G light from the second liquid crystal light valve 100G is transmitted, and the R light from the second liquid crystal light valve 100R and the B light from the second liquid crystal light valve 100B are bent to synthesize these three colors of light. Forming a color image.

  The projection lens 110 projects an optical image transmitted from the second liquid crystal light valves 100B, 100G, and 100R onto a screen (not shown) to display a color image.

  Next, the overall light transmission flow of the projector PJ1 will be described. The white light from the light source 10 is split into three primary colors of red (R), green (G), and blue (B) by the dichroic mirrors 30 and 35, and the lenses and mirrors including the collimating lenses 50B, 50G, and 50R. Through the first liquid crystal light valves 60B, 60G, 60R. Each color light incident on the first liquid crystal light valves 60B, 60G, and 60R is light-modulated based on external data corresponding to each wavelength region, and is emitted as modulated light including an optical image. The modulated lights from the first liquid crystal light valves 60B, 60G, 60R are incident on the second liquid crystal light valves 100B, 100G, 100R. Each modulated light incident on the second liquid crystal light valves 100B, 100G, and 100R is further optically modulated based on external data corresponding to each wavelength region, and emitted as modulated light including an optical image. Then, the modulated lights incident from the second liquid crystal light valves 100B, 100G, and 100R are respectively incident on the cross dichroic prism 80, where they are combined into one light, and emitted to the projection lens 110. Then, the projection lens 110 projects the combined light on a screen (not shown) to display a desired image.

  As described above, in the projector PJ1, two-stage image formation is performed via the two light modulation elements (the first liquid crystal light valves 60B, 60G, and 60R and the second liquid crystal light valves 100B, 100G, and 100R) arranged in series. The light from the light source 10 is modulated according to the process. As a result, the projector PJ1 becomes a projector with a high dynamic range that realizes expansion of the luminance dynamic range and increase of the number of gradations.

[Specific example of liquid crystal light valve modulation]
Next, specific examples of modulation of the first liquid crystal light valves 60B, 60G, 60R and the second liquid crystal light valves 100B, 100G, 100R based on the display image data will be described in detail.
In the projector PJ1 (see FIG. 1), the first liquid crystal light valves 60B, 60G, and 60R and the second liquid crystal light valves 100B, 100G, and 100R are driven by the drive signal generated from the display image data, thereby adjusting the luminance dynamic range. Realizes enlargement and increase in the number of gradations. The modulation control of the liquid crystal light valve is performed by a display control device (display control device 200) described below.

FIG. 2 is a block diagram showing a hardware configuration of the display control apparatus 200 (first driving means and second driving means).
As shown in FIG. 2, the display control apparatus 200 reads out from the CPU 170 that controls the calculation and the entire system based on the control program, the ROM 172 that stores the control program of the CPU 170 in a predetermined area, the ROM 172, and the like. It is composed of a RAM 174 for storing data and calculation results required in the calculation process of the CPU 170, and an I / F 178 that mediates input / output of data to / from an external device, and these are used for transferring data. The signal lines are connected to each other via a bus 179 so as to be able to exchange data.

  The I / F 178 includes external liquid crystal light valves 60B, 60G, and 60R, second liquid crystal light valves 100B, 100G, and 100R, a storage device 182 that stores data, tables, and the like as files, and an external device. A signal line for connecting to the network 199 is connected.

  The storage device 182 stores HDR display image data for driving the first liquid crystal light valves 60B, 60G, 60R and the second liquid crystal light valves 100B, 100G, 100R.

  The HDR display image data is image data capable of realizing a high luminance dynamic range that cannot be realized by a conventional image format such as sRGB, and stores pixel values indicating pixel luminance levels for all pixels of the image. In the present embodiment, the HDR display image data uses a format in which a pixel value indicating a luminance level for each of the RGB three primary colors is stored as a floating point value for one pixel. For example, values (1.2, 5.4, 2.3) are stored as pixel values of one pixel.

Here, the luminance level of the pixel p in the HDR display image data is Rp, the transmittance of the pixel corresponding to the pixel p of the second light modulation element is T1, and the transmittance of the pixel corresponding to the pixel p of the first light modulation element is When T2, the following expressions (1) and (2) are established.
Rp = Tp × Rs (1)
Tp = T1 × T2 × G (2)
However, in the above formulas (1) and (2), Rs is the luminance of the light source, G is the gain, and both are constants. Tp is a light modulation rate.

  For details of the method of generating HDR display image data, for example, publicly known document 3 “PEDebevec, J. Malik,“ Recovering High Dynamic Range Radiance Maps from Photographs ”, Proceedings of ACM SIGGRAPH97, pp.367-378 (1997). ) ”.

  Further, the storage device 182 stores a control value registration table in which the control values of the first liquid crystal light valves 60B, 60G, 60R are registered for each of the first liquid crystal light valves 60B, 60G, 60R.

  FIG. 3 is a diagram illustrating a data structure of a control value registration table 420R in which control values of the first liquid crystal light valve 60R are registered.

  In the control value registration table 420R, as shown in FIG. 3, one record is registered for each control value of the liquid crystal light valve 60R. Each record includes a field in which the control value of the first liquid crystal light valve 60R is registered and a field in which the transmittance of the first liquid crystal light valve 60R is registered.

  In the example of FIG. 3, “0” is registered as the control value and “0.004” is registered as the transmittance in the first row record. This indicates that when the control value “0” is output to the first liquid crystal light valve 60R, the transmittance of the first liquid crystal light valve 60R becomes 0.4%. FIG. 3 shows an example in which the number of gradations of the first liquid crystal light valve 60R is 4 bits (0 to 15 values), but actually corresponds to the number of gradations of the first liquid crystal light valve. Record to be registered. For example, when the number of gradations is 8 bits, 256 records are registered.

  The data structure of the control value registration table corresponding to the first liquid crystal light valves 60B and 60G is not particularly shown, but has the same data structure as the control value registration table 420R. However, it differs from the control value registration table 420R in that different transmittances are registered for the same control value.

  The storage device 182 stores a control value registration table 400 in which the control values of the second liquid crystal light valves 100B, 100G, and 100R are registered for each of the second liquid crystal light valves 100B, 100G, and 100R.

  FIG. 4 is a diagram illustrating a data structure of a control value registration table 400R in which control values of the second liquid crystal light valve 100R are registered.

  In the control value registration table 400R, as shown in FIG. 4, one record is registered for each control value of the second liquid crystal light valve 100R. Each record includes a field in which the control value of the second liquid crystal light valve 100R is registered and a field in which the transmittance of the second liquid crystal light valve 100R is registered.

  In the example of FIG. 4, “0” is registered as the control value and “0.003” is registered as the transmittance in the first row record. This indicates that when the control value “0” is output to the second liquid crystal light valve 100R, the transmittance of the second liquid crystal light valve 100R becomes 0.3%. FIG. 4 shows an example in which the number of gradations of the second liquid crystal light valve 100R is 4 bits (0 to 15 values). Corresponding record is registered. For example, when the number of gradations is 8 bits, 256 records are registered.

  The data structure of the control value registration table corresponding to the second liquid crystal light valves 100B and 100G is not particularly shown, but has the same data structure as the control value registration table 400R. However, it differs from the control value registration table 400R in that different transmittances are registered for the same control value.

  Next, the configuration of the CPU 170 and the processing executed by the CPU 170 (including the method for driving the image display apparatus of the present invention) will be described.

  The CPU 170 includes a microprocessing unit (MPU) or the like, starts a predetermined program stored in a predetermined area of the ROM 172, and executes display control processing shown in the flowchart of FIG. 5 according to the program. .

  FIG. 5 is a flowchart showing the display control process.

  The display control process determines the control values of the first liquid crystal light valves 60B, 60G, 60R and the second liquid crystal light valves 100B, 100G, 100R based on the HDR display image data, and is generated based on the determined control values. 5 is a process for driving the first liquid crystal light valves 60B, 60G, 60R and the second liquid crystal light valves 100B, 100G, 100R according to the drive signals, and when executed in the CPU 170, first, as shown in FIG. The process proceeds to S100.

  In step S100, the HDR display image data is read from the storage device 182.

  In step S102, the read HDR display image data is analyzed, and a histogram of pixel values, a maximum value, a minimum value, an average value, and the like of luminance levels are calculated. This analysis result is for use in automatic image correction such as brightening a dark scene, darkening a scene that is too bright, or coordinating intermediate contrast, or for tone mapping.

  Next, the process proceeds to step S104, and the brightness level of the HDR display image data is tone-mapped to the brightness dynamic range of the projector PJ1 based on the analysis result of step S102.

  FIG. 6 is a diagram for explaining tone mapping processing.

  As a result of analyzing the HDR display image data, it is assumed that the minimum value of the luminance level included in the HDR display image data is Smin and the maximum value is Smax. Further, it is assumed that the minimum value of the luminance dynamic range of the projector PJ1 is Dmin and the maximum value is Dmax. In the example of FIG. 6, since Smin is smaller than Dmin and Smax is larger than Dmax, HDR display image data cannot be appropriately displayed as it is. Therefore, normalization is performed so that the histogram of Smin to Smax falls within the range of Dmin to Dmax.

  Details of tone mapping are disclosed in, for example, publicly known document 2 “F. Drago, K. Myszkowski, T. Annen, N. Chiba,“ Adaptive Logarithmic Mapping For Displaying High Contrast Scenes ”, Eurographics 2003, (2003)”. Are listed.

  Next, the process proceeds to step S106, and the HDR image is resized (enlarged or reduced) in accordance with the resolution of the first liquid crystal light valves 60B, 60G, 60R. At this time, the HDR image is resized while maintaining the aspect ratio of the HDR image. Examples of the resizing method include an average value method, an intermediate value method, and a nearest neighbor method (nearest neighbor method).

  Next, the process proceeds to step S108, and based on the luminance level Rp of the pixel of the resized image and the luminance Rs of the light source 10, the light modulation rate Tp is calculated for each pixel of the resized image by the above equation (1).

  Next, the process proceeds to step S110, where an initial value (for example, 0.2) is given as the transmittance T2 of each pixel of the first liquid crystal light valves 60B, 60G, 60R, and the first liquid crystal light valves 60B, 60G, 60R The transmittance T2 of each pixel is determined.

  Next, the process proceeds to step S112, and based on the calculated light modulation rate Tp, the determined transmittance T2 and the gain G, the transmittance T1 of each of the second liquid crystal light valves 100B, 100G, and 100R according to the above equation (2). Is calculated.

  Next, the process proceeds to step S116, and for each image of the second liquid crystal light valve 100B, 100G, 100R, a control value corresponding to the transmittance T1 calculated for the image is registered in a control value registration table (for example, shown in FIG. 4). 400R), and the read control value is determined as the control value of the image. In the subsequent series of control values, the transmittance that most closely approximates the calculated transmittance T1 is searched from the control value registration table, and the control value corresponding to the transmittance found by the search is read. This search is performed using, for example, a binary search method, thereby realizing a high-speed search.

  Subsequently, the process proceeds to step S120, and for each line of the first liquid crystal light valves 60B, 60G, 60R, a control value corresponding to the transmittance T2 calculated for the line is set as a control value registration table (for example, shown in FIG. 3). 420R), and the read control value is determined as the control value of the image. In the subsequent series of control values, the transmittance closest to the calculated transmittance T2 is searched from the control value registration table, and the control value corresponding to the transmittance found by the search is read out. This search is also performed using, for example, a binary search method, thereby realizing a high-speed search.

  Next, the process proceeds to step S122, where a drive signal is generated based on the control values determined in steps S116 and S120, and the first liquid crystal light valves 60B, 60G, 60R and the second liquid crystal light valves 100B, 100G shown in FIG. , 100R, the series of processing is terminated and the original processing is restored. Here, in the projector PJ1 of the first embodiment, the CPU 170 generates a drive signal such that the polarity inversion period of the first liquid crystal light valves 60B, 60G, and 60R becomes one frame period for displaying an image. 1 Input to liquid crystal light valves 60B, 60G, 60R. Further, the CPU 170 generates a drive signal having a voltage phase opposite to that of the drive signal input to the first liquid crystal light valves 60B, 60G, and 60R, and inputs the drive signal to the second liquid crystal light valves 100B, 100G, and 100R (this book). Driving method of image display device of invention).

  FIG. 7 is a circuit diagram showing circuit configurations of the first liquid crystal light valves 60B, 60G, 60R and the second liquid crystal light valves 100B, 100G, 100R.

  As shown in this figure, each liquid crystal light valve includes an X driver 101 and a Y driver 102, and a plurality of pixel circuits 300 are arranged in a matrix. Here, the pixel circuit 300 includes a pixel transistor T0, a pixel capacitor C0 that holds a voltage corresponding to the drive signal input to the source of the pixel transistor T0, and a voltage held in the pixel capacitor C0 in the liquid crystal layer. The pixel electrode E0 to be applied is included.

  The output terminals X0 to Xn of the X driver 101 are driven to the source of the pixel transistor T0 of the pixel circuit 300 in each column via the data lines S0 to Sn provided corresponding to the columns of the pixel circuit 300, respectively. A data switching transistor ST for supplying a signal is connected. The data switching transistor ST is connected to a data input line 103 to which a drive signal is directly input. Further, the output terminals Y0 to Yn of the Y driver 102 are connected to the gates of the pixel transistors T0 of the pixel circuits 300 in the respective rows through the scanning lines G0 to Gn provided corresponding to the respective rows of the pixel circuits 300. Yes.

  Here, for example, when the output terminal Y0 is selected by the Y driver 102, a voltage is selectively applied to the gate of the pixel transistor T0 of the pixel circuit 300 corresponding to the row of the scanning line G0 and connected to the scanning line G0. The pixel transistor T0 thus turned on is turned on. Next, for example, when the output terminal X0 is selected by the X driver 101, the drive signal is sent to the row of the scanning line G0 selected by the Y driver 102 and the column of the data line S0 via the switching transistor ST. The pixel transistor T0 of the pixel circuit 300 corresponding to is turned on, and a voltage corresponding to the drive signal is applied and held in the pixel capacitor C0 and the pixel electrode E0 of the pixel circuit 300. As a result, the liquid crystal between the pixel electrode E0 and the common electrode (not shown) enters a display state.

  As described above, when a drive signal having a polarity reversal period equal to one frame period for displaying an image is input to the first liquid crystal light valves 60B, 60G, and 60R having such a circuit configuration, For example, as shown in the timing chart of FIG. 8A, the voltages of the pixels of the valves 60B, 60G, and 60R are held positive with respect to the reference voltage for 1F (frame), and the next 1F During this time, the voltage is held negative with respect to the reference voltage. Further, as described above, the driving signals that have the voltage phases opposite to those of the driving signals input to the first liquid crystal light valves 60B, 60G, and 60R in the second liquid crystal light valves 100B, 100G, and 100R having the same circuit configuration. Is input, the voltage of each pixel of the second liquid crystal light valves 100B, 100G, and 100R becomes negative with respect to the reference voltage for 1F (frame) as shown in the timing chart of FIG. 8B. And held positive for the reference voltage for the next 1F.

  That is, when the drive signals as described above are input to the first liquid crystal light valves 60B, 60G, 60R and the second liquid crystal light valves 100B, 100G, 100R, as shown in FIG. 9, during the first frame, Each pixel of the first liquid crystal light valves 60B, 60G, and 60R is held positive, and each pixel of the second liquid crystal light valve 100B, 100G, and 100R is held negative, and the first liquid crystal light valve between the second frames. Each pixel of 60B, 60G, 60R is held negative, and each pixel of the second liquid crystal light valve 100B, 100G, 100R is held positive. In this way, the first liquid crystal light valves 60B, 60G, and 60R and the second liquid crystal light valves 100B, 100G, and 100R are driven to cause flicker generated in the first liquid crystal light valves 60B, 60G, and 60R. A negative-phase DC component that cancels the residual DC component is generated in the second liquid crystal light valves 100B, 100G, and 100R. As a result, flicker in an image displayed by the projector PJ1 can be reduced.

  In the projector PJ1 of the first embodiment, the same number of first liquid crystal light valves 60B, 60G, 60R and the second liquid crystal light valves 100B, 100G, 100R are arranged. For this reason, the residual DC component that causes flicker generated in each of the first liquid crystal light valves 60B, 60G, and 60R is canceled by generating a DC component having a reverse phase in each of the second liquid crystal light valves 100B, 100G, and 100R. be able to. Therefore, flicker in the image can be surely reduced.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. In the description of the second embodiment, the description of the same parts as in the first embodiment will be omitted or simplified.

  In the second embodiment, in step S122 of FIG. 5, the CPU 170 displays an image so that the polarity inversion period of the first liquid crystal light valves 60B, 60G, and 60R is one horizontal line period of the image. A drive signal having a voltage phase opposite to that of the previous frame in the frame period is generated and input to the first liquid crystal light valves 60B, 60G, and 60R. Similarly to the first embodiment, the CPU 170 generates a drive signal whose voltage phase is opposite to that of the drive signal input to the first liquid crystal light valves 60B, 60G, and 60R, and the second liquid crystal light valve 100B. , 100G, 100R.

  The first liquid crystal light valves 60B, 60G, and 60R are input with drive signals that have one horizontal line period of the image and a voltage phase opposite to that of the previous frame in one frame period for displaying the image. Then, the voltages of the pixels connected to the scanning line G0 of the first liquid crystal light valves 60B, 60G, and 60R and the pixels connected to every other scanning line (such as G2) from the scanning line G0 are, for example, As shown in the timing chart of FIG. 10A, the voltage is held positive with respect to the reference voltage for 1F (frame) and is held negative with respect to the reference voltage for the next 1F. In addition, the voltages of the pixels connected to the scanning line G1 of the first liquid crystal light valves 60B, 60G, and 60R and the pixels connected to every other scanning line from the scanning line G1, for example, are shown in FIG. As shown in the timing chart, it is held negative with respect to the reference voltage for 1F (frame), and held positive with respect to the reference voltage for the next 1F.

  Further, when a driving signal having a voltage phase opposite to that of the driving signal input to the first liquid crystal light valves 60B, 60G, 60R is input to the second liquid crystal light valves 100B, 100G, 100R, the second liquid crystal light valve. The voltages of the pixels connected to the scanning line G0 of the valves 100B, 100G, and 100R and the pixels connected to every other scanning line (such as G2) from the scanning line G0 are, for example, the timing shown in FIG. As shown in the chart, it is held negative with respect to the reference voltage for 1F (frame), and held positive with respect to the reference voltage for the next 1F. Further, the voltages of the pixels connected to the scanning line G1 of the second liquid crystal light valves 100B, 100G, and 100R and the pixels connected to every other scanning line from the scanning line G1, for example, are shown in FIG. As shown in the timing chart, it is held positive with respect to the reference voltage for 1F (frame), and held negative with respect to the reference voltage for the next 1F.

  That is, when the driving signals as described above are input to the first liquid crystal light valves 60B, 60G, 60R and the second liquid crystal light valves 100B, 100G, 100R, as shown in FIG. 12, during the first frame, Each pixel of the first liquid crystal light valves 60B, 60G, and 60R is held in a state where the polarity is inverted every row, and each pixel of the second liquid crystal light valves 100B, 100G, and 100R has a polarity every row. Inverted and held in a state where the polarities of the pixels of the first liquid crystal light valves 60B, 60G, and 60R are reversed, and between the second frame, the pixels of the first liquid crystal light valves 60B, 60G, and 60R and the second liquid crystal. Each pixel of the light valves 100B, 100G, and 100R is held in a state in which the polarity is inverted with respect to the first frame. As described above, by driving the first liquid crystal light valves 60B, 60G, and 60R and the second liquid crystal light valves 100B, 100G, and 100R, the same effects as those in the first embodiment can be obtained. In the second embodiment, since the pixels of the first liquid crystal light valves 60B, 60G, and 60R and the second liquid crystal light valves 100B, 100G, and 100R are driven to invert the polarity for each row, the first liquid crystal Residual DC components in the light valves 60B, 60G, 60R and the second liquid crystal light valves 100B, 100G, 100R can be removed.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIGS. In the description of the third embodiment, the description of the same parts as those of the first embodiment will be omitted or simplified.

  In the third embodiment, in step S122 of FIG. 5, the CPU 170 displays an image so that the polarity inversion period of the first liquid crystal light valves 60B, 60G, and 60R is one vertical line period of the image. A drive signal having a voltage phase opposite to that of the previous frame in the frame period is generated and input to the first liquid crystal light valves 60B, 60G, and 60R. Similarly to the first embodiment, the CPU 170 generates a drive signal whose voltage phase is opposite to that of the drive signal input to the first liquid crystal light valves 60B, 60G, and 60R, and the second liquid crystal light valve 100B. , 100G, 100R.

  When such a driving method is employed, it is necessary to reverse the polarity of the driving signal in one vertical line cycle. For this reason, a circuit configuration similar to that in FIG. 7 can be used. In this case, however, the voltage amplitude of the drive signal increases and the phase inversion frequency increases. A circuit configuration including the input lines 104 and 105 is preferably used. More specifically, the data input line 104 is connected to the pixel circuits 300 in the odd columns, and the data line 105 is connected to the pixel circuits 300 in the even columns.

  In the first liquid crystal light valves 60B, 60G, 60R having such a circuit configuration, the polarity inversion period is one vertical line period of the image, and the reverse of the previous frame in one frame period for displaying the image. A drive signal having a voltage phase is input. Specifically, for example, a component having a high voltage phase in the driving signal is supplied to the data input line 104, and a component having a low voltage phase in the driving signal is supplied to the data input line 105. Then, after one frame, the voltage phase of the drive signal input to the data input lines 104 and 105 is inverted.

  In such a case, the voltages of the pixels connected to the data line S0 of the first liquid crystal light valves 60B, 60G, and 60R and the voltages of the pixels connected to every other data line (such as S2) from the data line S0. Is held positive with respect to the reference voltage for 1F (frame) and held negative with respect to the reference voltage for the next 1F, as shown in the timing chart of FIG. The The voltages of the pixels connected to the data line S1 of the first liquid crystal light valves 60B, 60G, and 60R and the pixels connected to every other scanning line from the data line S1 are, for example, as shown in FIG. As shown in the timing chart, it is held negative with respect to the reference voltage for 1F (frame), and held positive with respect to the reference voltage for the next 1F.

  Further, when a driving signal having a voltage phase opposite to that of the driving signal input to the first liquid crystal light valves 60B, 60G, 60R is input to the second liquid crystal light valves 100B, 100G, 100R, the second liquid crystal light valve. The voltage of each pixel connected to the data line S0 of the valves 100B, 100G, and 100R and every other data line (S2 etc.) from the data line S0 is, for example, the timing of FIG. As shown in the chart, it is held negative with respect to the reference voltage for 1F (frame), and held positive with respect to the reference voltage for the next 1F. Further, the voltages of the pixels connected to the data line S1 of the second liquid crystal light valves 100B, 100G, and 100R and the pixels connected to every other data line from the data line S1 are, for example, shown in FIG. As shown in the timing chart, it is held positive with respect to the reference voltage for 1F (frame), and held negative with respect to the reference voltage for the next 1F.

  That is, when the driving signals as described above are input to the first liquid crystal light valves 60B, 60G, 60R and the second liquid crystal light valves 100B, 100G, 100R, as shown in FIG. 16, during the first frame, Each pixel of the first liquid crystal light valves 60B, 60G, 60R is held in a state where the polarity is inverted for each column, and each pixel of the second liquid crystal light valves 100B, 100G, 100R has a polarity for each column. Inverted and held in a state where the polarities of the pixels of the first liquid crystal light valves 60B, 60G, and 60R are reversed, and between the second frame, the pixels of the first liquid crystal light valves 60B, 60G, and 60R and the second liquid crystal. Each pixel of the light valves 100B, 100G, and 100R is held in a state in which the polarity is inverted with respect to the first frame. As described above, by driving the first liquid crystal light valves 60B, 60G, and 60R and the second liquid crystal light valves 100B, 100G, and 100R, the same effects as those in the first embodiment can be obtained. In the third embodiment, since the pixels of the first liquid crystal light valves 60B, 60G, and 60R and the second liquid crystal light valves 100B, 100G, and 100R are reversely driven for each column, the first liquid crystal light valves Residual DC components in the light valves 60B, 60G, 60R and the second liquid crystal light valves 100B, 100G, 100R can be removed.

  By combining the second and third embodiments described above, as shown in FIG. 17, the first liquid crystal light valves 60B, 60G, 60R and the second liquid crystal light valves 100B, 100G, The polarity of 100R can be inverted. As described above, even when the polarities of the first liquid crystal light valves 60B, 60G, 60R and the second liquid crystal light valves 100B, 100G, 100R are inverted in one pixel cycle, the same effects as in the first to third embodiments are obtained. Can be played.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described with reference to FIG. In the description of the fourth embodiment, the description of the same parts as those of the first embodiment will be omitted or simplified.

FIG. 18 is a diagram showing a main optical configuration of a projector PJ2 that is the fourth embodiment of the present invention.
As shown in this figure, the projector PJ2 of the fourth embodiment has a configuration in which only one second liquid crystal light valve 100, which is a second modulation element, is arranged. The second liquid crystal light valve 100 is disposed between the relay lens 90 and the projection lens 110.
Here, the relay lens 90 projects the first modulated image light-modulated by the first liquid crystal light valve of each color in the color modulator 25 and the second modulated image light-modulated by the second liquid crystal light valve into the projection lens 110. The optical lens group is arranged so as to be optically conjugate with respect to the lens.

  In the projector PJ2 of the fourth embodiment having such a configuration, the brightness of the combined light combined in the cross dichroic prism 80 is modulated in the single second liquid crystal light valve 100. Therefore, also in the projector PJ2, the light from the light source 10 is modulated by the two-stage image forming process. As a result, the projector PJ2 is a projector with a high dynamic range that realizes expansion of the luminance dynamic range and increase of the number of gradations.

  Also in the projector PJ2 of the fourth embodiment, as in the first embodiment, for each pixel of the second liquid crystal light valve 100 corresponding to each pixel of the first liquid crystal light valves 60B, 60G, 60R, A drive signal having a voltage phase opposite to that of the drive signal applied to each pixel of the first liquid crystal light valves 60B, 60G, and 60R is applied. Therefore, a reverse-phase DC component that cancels out the residual DC component that causes flickers generated in the first liquid crystal light valves 60B, 60G, and 60R is generated in the second liquid crystal light valve 100, and as a result, the second liquid crystal light valve Flicker components included in the modulated light including the optical image emitted from the bulb 100 can be reduced.

In the first embodiment described above, the second liquid crystal light valves 100B, 100G, and 100R are arranged for the first liquid crystal light valves 60B, 60G, and 60R. The transmittance T2 of each pixel of the light valves 60B, 60G, and 60R is determined, and based on the light modulation factor Tp, the determined transmittance T2, and the gain G, each pixel of each of the second liquid crystal light valves 100B, 100G, and 100R is determined. The transmittance T1 was calculated. On the other hand, since the projector PJ2 of the fourth embodiment has only the single second liquid crystal light valve 100, the CPU 170 averages the transmittance T1 determined for each color light of RGB light. The transmittance obtained by the conversion is used as the transmittance of the second liquid crystal light valve 100.
In the present embodiment, the second liquid crystal light valve 100 is arranged between the relay lens 90 and the projection lens 110. However, the present invention is not limited to this, and for example, the second liquid crystal light valve 100 may be arranged between the dichroic mirror 30 and the uniform illumination system 20.

(Fifth embodiment)
Next, a fifth embodiment of the present invention will be described with reference to FIG. In the description of the fifth embodiment, the description of the same parts as those of the first embodiment will be omitted or simplified.

FIG. 19 is a diagram showing a main optical configuration of a projector PJ3 that is the fifth embodiment of the present invention.
As shown in this figure, in the projector PJ3 of the fifth embodiment, only one first liquid crystal light valve 60 as the first modulation element and one second liquid crystal light valve 100 as the second modulation element are arranged. It has a configuration. Then, in one of the first liquid crystal light valve 60 and the second liquid crystal light valve 100, color modulation is performed in addition to luminance modulation.

  Also in the projector PJ3 of the fifth embodiment having such a configuration, the light from the light source 10 is modulated by the two-stage image forming process. As a result, the projector PJ2 is a projector with a high dynamic range that realizes expansion of the luminance dynamic range and increase of the number of gradations.

  In the projector PJ3 of the fifth embodiment, the first liquid crystal light is applied to each pixel of the second liquid crystal light valve 100 corresponding to each pixel of the first liquid crystal light valve 60, as in the first embodiment. A drive signal having a voltage phase opposite to that of the drive signal applied to each pixel of the bulb 60 is applied. Therefore, a reverse-phase DC component that cancels out the residual DC component that causes flicker generated in the first liquid crystal light valve 60 is generated in the second liquid crystal light valve 100, and as a result, is emitted from the second liquid crystal light valve 100. The flicker component contained in the modulated light including the optical image thus formed can be reduced.

(Sixth embodiment)
Next, a sixth embodiment of the present invention will be described with reference to FIG. In the description of the sixth embodiment, the description of the same parts as those in the first embodiment will be omitted or simplified.

FIG. 20 is a diagram illustrating a main optical configuration of a liquid crystal display device 500 as a direct-view image display device.
As shown in FIG. 20, a direct-view type liquid crystal display device 500 includes a transmission type liquid crystal display panel 501 as a second light modulation element, and an illumination system 502 and an optical system such as a Fresnel lens 503 and a light diffusion layer 504 that illuminate the same. Consists of elements.

  The illumination system 502 includes a light source 10, a uniform illumination system 20, a liquid crystal light valve 60 as a first light modulation element, and a projection lens 110.

  The light beam emitted from the light source 10 enters the uniform illumination system 20 in which the two lens arrays 21 and 22, the polarization conversion element 23, and the condenser lens 24 are sequentially installed, and the light intensity distribution in the light beam cross section is made uniform. The polarization conversion element 23 is composed of, for example, a PBS array and a half-wave plate. The polarization conversion element 23 converts the light beam emitted from the light source 10 into an indefinite polarization state light beam that can be used in the subsequent optical system so that the vibration direction is aligned in one direction. Convert.

  The light beam emitted from the uniform illumination system 20 enters a liquid crystal light valve 60 serving as a first light modulation element, and undergoes first modulation. The light beam modulated by the liquid crystal light valve 60 is enlarged and projected onto the light incident surface of the liquid crystal display panel 501 by the projection lens 110 to illuminate the liquid crystal display panel 501. The emitted light beam from the illumination system 502 is a polarized light beam, and the plane of polarization thereof coincides with the transmission axis of the incident side polarizing plate of the liquid crystal display panel 501.

  A Fresnel lens 503 disposed in front of the liquid crystal display panel 501 substantially parallelizes the emitted light beam from the illumination system 502 and guides it to the liquid crystal display panel 501 to reduce unevenness in the brightness of the display image. A light diffusion layer 504 is disposed on the light incident surface of the liquid crystal display panel 501. The light diffusion layer 504 expands the viewing angle of the display image by diffusing the light flux emitted from the illumination system 502 and widening the light distribution.

  In the liquid crystal display device 500 having the above-described configuration, the liquid crystal display panel 501 as the second light modulation element is illuminated using the modulated light that forms the optical image (image) with the liquid crystal light valve 60 as the first light modulation element. A typical display image is formed on the liquid crystal display panel 501. That is, the light from the light source 10 is modulated by two-stage image formation processes via two light modulation elements (liquid crystal light valve 60 and liquid crystal display panel 161) arranged in series. As a result, in the liquid crystal display device 500 as well, the luminance dynamic range and the number of gradations can be increased as in the above embodiment.

  In the liquid crystal display device 500 of the sixth embodiment, each of the liquid crystal light valves 60 is associated with each pixel of the liquid crystal display panel 501 corresponding to each pixel of the liquid crystal light valve 60, as in the first embodiment. A drive signal having a voltage phase opposite to that of the drive signal applied to the pixel is applied. Therefore, a reverse-phase DC component that cancels out the residual DC component that causes flicker generated in the liquid crystal light valve 60 is generated in the second liquid crystal display panel 501, and as a result, in the image displayed on the liquid crystal display panel 501 Flicker components can be reduced.

  20 is an example of a configuration in which one liquid crystal light valve 60 is arranged in the illumination system 502. However, as with the projector PJ1 in the first embodiment described above, R (red), You may use the illumination system of a 3 board | plate system provided with a liquid crystal light valve for every color light from which G (green) and B (blue) differ. In this case, a color separation optical system as a light separation means composed of a dichroic mirror or the like is disposed between the uniform illumination system and the liquid crystal light valve, and R (red), G (green), and B (blue). The light path is separated for each different color light, and each color light beam modulated by the liquid crystal light valve for each color light is synthesized by a color synthesis optical system such as a cross dichroic prism disposed between the liquid crystal light valve and the projection lens. A light beam representing a color image is formed.

  As described above, the preferred embodiments of the image display device and the driving method thereof according to the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the above-described embodiments. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  For example, in the above embodiment, the liquid crystal light valves 60, 60B, 60G, 60R, 100B, 100G, 100R, 100 and the liquid crystal display panel 501 are configured using active matrix type liquid crystal display elements, but the present invention is not limited thereto. Alternatively, a passive matrix liquid crystal display element and a segment type liquid crystal display element can be used. The active matrix type liquid crystal display has an advantage that precise gradation display can be performed, and the passive matrix type liquid crystal display element and the segment type liquid crystal display element have an advantage that they can be manufactured at low cost.

  Further, in each of the above-described embodiments, the case where the control program stored in advance in the ROM 172 is executed when executing the processing shown in the flowchart of FIG. The program may be read from the storage medium storing the program into the RAM 174 and executed.

  Here, the storage medium is a semiconductor storage medium such as RAM or ROM, a magnetic storage type storage medium such as FD or HD, an optical reading type storage medium such as CD, CDV, LD, or DVD, or a magnetic storage type such as MO. / Optical reading type storage media, including any storage media that can be read by a computer regardless of electronic, magnetic, optical, or other reading methods.

  In each of the above embodiments, a single light source that emits white light is used as the light source 10 and the white light is split into RGB three primary colors. However, the present invention is not limited to this. Three light sources corresponding to the three primary colors, a light source that emits red light, a light source that emits blue light, and a light source that emits green light, and a means for spectrally separating white light may be removed. .

It is a figure which shows the main optical structures of the projector of 1st Embodiment of this invention. 3 is a block diagram illustrating a hardware configuration of a display control device 200. FIG. It is a figure which shows the data structure of a control value registration table. It is a figure which shows the data structure of a control value registration table. It is a flowchart figure which shows a display control process. It is a figure for demonstrating a tone mapping process. It is the figure which showed the circuit structure of the liquid crystal light valve. It is a figure for demonstrating the drive method of the projector in 1st Embodiment of this invention. It is a figure for demonstrating the drive method of the projector in 1st Embodiment of this invention. It is a figure for demonstrating the drive method of the projector in 2nd Embodiment of this invention. It is a figure for demonstrating the drive method of the projector in 2nd Embodiment of this invention. It is a figure for demonstrating the drive method of the projector in 2nd Embodiment of this invention. It is the figure which showed the other circuit structure of the liquid crystal light valve. It is a figure for demonstrating the drive method of the projector in 3rd Embodiment of this invention. It is a figure for demonstrating the drive method of the projector in 3rd Embodiment of this invention. It is a figure for demonstrating the drive method of the projector in 3rd Embodiment of this invention. It is a figure for demonstrating the drive method of another projector. It is a figure which shows the main optical structures of the projector of 4th Embodiment of this invention. It is a figure which shows the main optical structures of the projector of 5th Embodiment of this invention. It is a figure which shows the main optical structures of the liquid crystal display device of 6th Embodiment of this invention.

Explanation of symbols

PJ1, PJ2, PJ3 ... Projector (image display device), 500 ... Liquid crystal display device (image display device), 60, 60B, 60G, 60R ... First liquid crystal light valve (first light modulation element), 100, 100B, 100G, 100R: second liquid crystal light valve (second light modulation element), 200: display control device (first drive means, second drive means)

Claims (7)

An image display device that displays an image by modulating light from a light source based on display image data,
A first light modulation element for modulating light from the light source;
First drive means for driving the first light modulation element to invert polarity by applying a predetermined drive signal based on the display image data to each pixel of the first light modulation element;
A second light modulation element that modulates light from the first light modulation element;
The drive signal applied to each pixel of the first light modulation element is applied to each pixel corresponding to the first light modulation element of the second light modulation element by applying a drive signal having a voltage phase opposite to that of the first light modulation element. An image display device comprising: a second drive unit that drives the second light modulation element. 2. The first driving means drives the first light modulation element to invert the polarity so that the polarity inversion period of the first light modulation element becomes one frame period for displaying the image. Image display device. The first driving means drives the first light modulation element so that the polarity inversion period of the first light modulation element becomes one horizontal line period of the image, and at one frame period for displaying the image. 2. The image display device according to claim 1, wherein a drive signal having a voltage phase opposite to that of the previous frame is applied to each pixel of the first light modulation element. The first driving means drives the first light modulation element so that the polarity inversion period of the first light modulation element becomes one vertical line period of the image, and displays the image at one frame period. 2. The image display device according to claim 1, wherein a drive signal having a voltage phase opposite to that of the previous frame is applied to each pixel of the first light modulation element. The first driving means drives the first light modulation element so that the polarity inversion period of the first light modulation element becomes one pixel period, and reverses the previous horizontal line in one horizontal line period of the image. Is applied to each pixel of the first light modulation element, and a drive signal having a voltage phase opposite to that of the previous frame in one frame period for displaying the image is applied to each pixel of the first light modulation element. The image display device according to claim 1, wherein the image display device is applied to a pixel. The image display apparatus according to claim 1, wherein the same number of the first light modulation elements and the second light modulation elements are provided. A driving method of an image display device for displaying an image by modulating light from a light source by a first light modulation element and a second light modulation element based on display image data,
Applying a predetermined drive signal based on the display image data to each pixel of the first light modulation element, the first light modulation element is driven to reverse the polarity,
The drive signal applied to each pixel of the first light modulation element is applied to each pixel corresponding to the first light modulation element of the second light modulation element by applying a drive signal having a voltage phase opposite to that of the first light modulation element. A driving method of an image display device, wherein the second light modulation element is driven.

Images