JP2001282190A - Liquid crystal display device, medium and information aggregate - Google Patents

Abstract

(57) [Summary] [Problem] In a conventional liquid crystal display device, chromaticity cannot be easily adjusted. A conversion means for converting an n-bit digital signal of at least one of red, blue and green into a (n + α) -bit (α is a natural number) digital signal, and a liquid crystal display means for displaying the n-bit digital signal on a liquid crystal display And a control means for controlling the digital signal converted by the conversion means to display the digital signal on the liquid crystal display means, further comprising n bits of at least one of red, blue, and green. Conversion tables (outputs 0 to 3) for converting each value into each value represented by (n + α) bits
And the value represented by (n + α) bits from 0 to (2 ⁿ −
The conversion means performs conversion using any one of the plurality of conversion tables, and the control means performs control using the correspondence table.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active matrix type liquid crystal display device, in particular, a high quality TFT (Thin Film) used for a display of a computer or the like.
m Transistor: a thin-film transistor active matrix type liquid crystal display device.

[0002]

2. Description of the Related Art Conventional liquid crystal modules, especially TFT liquid crystal display devices, have been mainly used for small AVs and notebook personal computers. It is being used. Along with this, video sources that display natural images and moving images have increased from conventional character-based displays.

Conventionally, CRT (Cathode-ray tube: cathode ray tube) has been widely and generally used as a display device in this field. However, the characteristics of a liquid crystal module, such as thin and light, low power consumption, and eye friendliness, are utilized. LCD modules are gradually penetrating the market.

[0004]

For example, when designing a television, both the CRT and the liquid crystal module are display devices, and are treated as one component that controls display. Therefore, when an attempt is made to replace a CRT with a liquid crystal module, all functions are compared and evaluated.

At this time, adjustment of chromaticity (color) becomes an issue. In a CRT, the light sources of RGB (red, green, and blue) are originally independent. Therefore, if the light amount is adjusted for each of the RGB, the chromaticity, that is, the white balance can be easily adjusted.

However, in the case of the liquid crystal module, since the light source of the fluorescent tube (white color) is originally separated by RGB color filters, there is no means for adjusting the respective light amounts of RGB. The mechanism of adjusting with an input signal is a method that is not very advantageous because it reduces the dynamic range.

Further, considering the current market, CRT
And LCD modules are treated as a single display device, so CRTs are manufactured by CRT manufacturers, and liquid crystals are manufactured by LCD manufacturers. TVs, computers and display monitor manufacturers that use them are CRT manufacturers.
And there seems to be a desire to use the liquid crystal module as a compatible component.

However, when a CRT is used, CR
Although the function of controlling chromaticity is provided in the circuit section for controlling T, in the case of a liquid crystal module, controlling the chromaticity by an external circuit cannot be easily realized.

The present invention provides a liquid crystal display device capable of adjusting chromaticity in consideration of the problem that chromaticity cannot be easily adjusted in a conventional liquid crystal display device. It is the purpose.

[0010]

Means for Solving the Problems The first invention (claim 1)
Means for converting an n-bit digital signal of at least one of red, blue and green into a (n + α) -bit (α is a natural number) digital signal, and a liquid crystal display for displaying the n-bit digital signal on a liquid crystal display And a control means for controlling the digital signal converted by the conversion means to be displayed on the liquid crystal display means, further comprising n of at least one of the red, blue and green colors. A plurality of conversion tables for converting each value represented by bits into each value represented by (n + α) bits;
The value represented by (n + α) bits is changed from 0 to (2 ⁿ -1)
A conversion table that corresponds to any one of the numbers. The conversion unit performs the conversion using one of the conversion tables, and the control unit performs the control using the conversion table. A liquid crystal display device.

According to a second aspect of the present invention (corresponding to claim 2), the conversion table has a plurality of colors corresponding to the conversion table on a side darker than the standard and / or on a side brighter than the standard. The liquid crystal display device according to the first aspect of the present invention, comprising:

According to a third aspect of the present invention (corresponding to claim 3), when the liquid crystal display means performs liquid crystal display, the second control means for changing the luminances of all the red, blue and green colors at substantially the same rate is further provided. A liquid crystal display device according to the first or second aspect of the present invention, comprising:

According to a fourth aspect of the present invention (corresponding to claim 4), the second control means changes the luminances of all the colors substantially at the same rate based on a conversion table used by the conversion means. A liquid crystal display device according to the third aspect of the present invention, which is characterized in that:

A fifth invention (corresponding to claim 5) is characterized in that the control means performs the control using a frame rate control method or an error diffusion method (dithering method). A liquid crystal display device according to any one of the first to fourth aspects of the present invention.

According to a sixth aspect of the present invention (corresponding to claim 6), the first aspect
A medium that carries a program and / or data for causing a computer to execute all or a part of the functions of all or part of the liquid crystal display device according to any one of the fifth to fifth aspects of the present invention. This is a medium that can be processed by a computer.

According to a seventh aspect of the present invention (corresponding to claim 7), the first aspect
An information set, which is a program and / or data for causing a computer to execute all or a part of functions of all or a part of the liquid crystal display device according to any one of the first to fifth aspects of the present invention. Body.

As described above, in the liquid crystal display device of the present invention, the chromaticity adjustment is completed in the liquid crystal module body by using a plurality of conversion tables, and the dynamic range such as the luminance and color purity of the liquid crystal is reduced. The adjustment can be performed without any need, and the application using the liquid crystal module does not need to consider the chromaticity variation.

The liquid crystal display device of the present invention will be described in detail. In this system, the input signal of the liquid crystal is digital, and after performing timing processing and the like by a controller, the signal is converted into an analog signal by a liquid crystal driver IC, and It is assumed that a liquid crystal module is configured to be supplied to a panel.

When converting signals from digital to analog, the chromaticity can be adjusted by adjusting the red, green, and blue signal amplitudes, but conventionally, a digital input liquid crystal having an adjustment function is used. No driver IC exists. this is,
To control the red, blue, and green characteristics,
There are too many reference potentials to be input and I
It can be estimated that the cost cannot be denied as C.

On the other hand, since the present system performs digital signal conversion, it can be dealt with only by changing the internal circuit of the controller already mounted, and can be dealt with without adding an external circuit.

More specifically, if the liquid crystal module is equipped with an n-bit input interface and an n-bit liquid crystal driver IC, the controller performs frame rate control and n-bit + α bit expansion such as an error diffusion method. Let's do it. Since the number of bits actually used is n bits, it is only necessary to output 2 n gray scales, so that 2 n of the required characteristics from 2 (n + α) gray scale levels is required. The output level of the power can be selected.

The above control is considered to be sufficient for red, blue and green, which are hardly affected by the luminance characteristic, of red, blue and green. Changing the characteristics of green causes a large change in luminance, so it is not suitable for changing only the chromaticity. However, changing the characteristics of red and blue alone will inevitably change the brightness,
It is also possible to add an external circuit for correcting this.

Since the above chromaticity characteristic is changed by selecting from a conversion table determined in advance, if a parameter for correcting an expected change in luminance at that time is obtained, a chromaticity parameter can be obtained. Can be changed independently.

[0024]

Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1 FIG. 2 is a block diagram of a liquid crystal module (liquid crystal display) according to Embodiment 1 of the present invention.

Reference numeral 201 denotes an input connector of a liquid crystal module,
202 is a data signal, and 203 is a power supply. A controller IC 204 performs timing control and data conversion of an input signal, and a DCDC converter 208 generates a power supply voltage required for each circuit block.

The signal output from the controller IC 204 and the power generated by the DCDC converter 208 are supplied to a source driver IC 205 and a gate driver IC 207. Outputs of the gate driver IC 207 and the source driver IC 205 are supplied to a liquid crystal panel 210. Reference numeral 211 denotes a 6-bit dip switch connected to the controller IC 204.

The data signal input to the input connector 201 is a signal of a total of 18 bits of 6 bits each for red, blue and green. In the present embodiment, the input data signal of the source driver IC 205 is also a 6-bit input for each color. Normally, the input signal has 64 (2 6) gradations per color, but the controller IC 204 expands it by 2 bits. The extension is performed based on any of a plurality of conversion tables in FIG. 1 described later.

By the way, in order to display the digital value represented by 8 bits extended by 2 bits on the liquid crystal panel 210 in 6 bits, that is, 64 gradations, the digital value represented by 8 bits is converted from 0 to 63. It is necessary to correspond to one of the numbers. Any of the numbers need not be an integer. It only needs to be a real number. Thus, the controller IC 204 has a correspondence table for associating the digital value represented by 8 bits with any number from 0 to 63.

Then, the controller IC 204 sets the digital value represented by 8 bits to 0 according to the correspondence table.
To 63 are displayed on the liquid crystal panel 210. This is a technique that is also performed by a video controller IC of a computer, for example, a frame rate control or an error diffusion method is used.

In the frame rate control, for example, a signal between the third and fourth gradations is displayed by repeatedly displaying a signal of the third gradation and a signal of the fourth gradation every frame. It is possible to output. The error diffusion method is a method of expressing an intermediate gradation as a whole by controlling pixels at the top, bottom, left and right, and is sometimes called a dithering method. In this embodiment, by using these methods, the controller IC 204 has a display capability equivalent to 8 bits.

FIG. 3 is a block diagram showing the inside of the controller IC 204. In FIG. 3, reference numeral 301 denotes a red data input bus line, 302 denotes a green data input bus line,
Reference numeral 303 denotes a blue data input bus line,
Has a bit bus width. The data input from these is converted into 8 bits by a data conversion block 304. This situation is simply converted by the conversion table of FIG.

When converting 6 bits to 8 bits, a DIP switch 305 determines which conversion table is to be selected from among a plurality of conversion tables. In the present embodiment, it is possible to select 2 bits for each color.

Here, the conversion table of FIG. 1 will be described. In the conversion table, any data from 0 to 255 is assigned to data input from 0 to 63 which is 6-bit data. Which data is to be assigned can be selected by the DIP switch 305. In this embodiment, since each color is 2 bits, when substantially converting to a standard color (“output 0” in FIG. 1),
When converting to the darker side than the standard, there are a total of four types of tables, including three types (“output 1”, “output 2”, and “output 3” in FIG. 1).

Although this table shows linear characteristics, it is needless to say that an arbitrary curve can be set according to the characteristics of the device. By the way, in FIG. 1, the input level 0 is the lowest luminance black,
63 is the highest luminance level, so when converted to 8 bits, “output 0” is close to the input characteristics,
As “output 1”, “output 2”, and “output 3” are obtained, the luminance decreases.

Returning to FIG. 2 again, the dip switch 2
When red is set to "output 0", green is set to "output 1", and blue is set to "output 1", it is possible to have a reddish chromaticity characteristic as a whole, and conversely a lamp or a color filter. When the redness of the characteristic is not enough, it is possible to correct the chromaticity by making such a setting. The data converted into 8 bits by the conversion table is 30 bits.
It is converted into a 6-bit bus line by 6 pseudo bit extension circuits. Although the data width is 6 bits, the bits are pseudo-expanded by the frame rate control and the error diffusion method described above to provide a gradation display capability equivalent to 8 bits.

As described above, the liquid crystal module (liquid crystal display device) according to the first embodiment has a plurality of conversion tables for converting each value represented by 6 bits into a value represented by 8 bits. (“Output 1” to “Output 4” in FIG. 1), and converts each value represented by 6 bits into a value represented by 8 bits using any of the conversion tables. Therefore, chromaticity conversion of a specific color can be performed.

In the first embodiment, the controller IC 204 is used as an example of the conversion means and the control means of the present invention, and the liquid crystal panel 2 is used as an example of the liquid crystal display means.
10, respectively.

In the first embodiment, “6” is replaced by “α” as an example of “n” described in the claims of the present invention.
As an example, “2” is used, but “n” and “α” are not limited to “6” and “2”, respectively.

(Embodiment 2) FIG. 4 shows a block diagram of a liquid crystal module (liquid crystal display device) according to Embodiment 2 of the present invention.

401 is an input connector of the liquid crystal module,
402 is a data signal, and 403 is a power supply. Reference numeral 404 denotes a controller IC that performs timing control and data conversion of an input signal, and reference numeral 408 denotes a DCDC converter that generates a power supply voltage required for each circuit block.

The signal output from the controller IC 404 and the power generated by the DCDC converter 408 are supplied to a source driver IC 405 and a gate driver IC 407. Outputs of the gate driver IC 407 and the source driver IC 405 are supplied to a liquid crystal panel 410. The DIP switch 411 is connected not only to the controller IC 404 but also to the DCDC converter 408.

In the first embodiment, the DIP switch 21
Although 1 could change the chromaticity by using the 8-bit value converted by the controller IC 204, the luminance may be different from the original value by changing the chromaticity. In order to correct this, by controlling the voltage serving as a luminance parameter, the luminance is constant, and only the chromaticity can be adjusted.

That is, the DCDC converter 408 changes the luminance of all the red, blue and green colors by substantially the same ratio by controlling the applied voltage. The control of the applied voltage may be performed based on a conversion table used by the controller IC 404.

In the second embodiment, the controller IC 404 is used as an example of the second control means of the present invention.

All or some of the components of the liquid crystal module (liquid crystal display device) according to the first and second embodiments may be hardware, or may have the same function as the hardware. It may be software having a function.

Further, it carries a program and / or data for causing a computer to execute all or some of the functions of all or some of the components of the liquid crystal module (liquid crystal display device) according to the first and second embodiments. Media that can be processed by a computer also belong to the present invention.

The medium includes a recording medium such as a ROM, a transmission medium such as the Internet, and a transmission medium such as light, radio waves, and sound waves. The carried medium includes, for example, a recording medium on which a program and / or data is recorded, a transmission medium for transmitting the program and / or data, and the like.

Therefore, when the medium is a recording medium,
The recording medium records a program and / or data for causing a computer to execute all or some of the functions of all or some of the components of the liquid crystal module (liquid crystal display device) of each of the embodiments described above. The medium may be a recording medium readable by a computer, and the program and / or the read data may execute the function in cooperation with the computer.

It should be noted that processing by a computer means that
For example, in the case of a recording medium such as a ROM, it means that the program can be read by a computer.
Or it means that the data can be handled by a computer as a result of the transmission.

Furthermore, it is a program and / or data for causing a computer to execute all or some of the functions of all or some of the components of the liquid crystal module (liquid crystal display device) of each of the above-described embodiments. The characteristic information aggregate also belongs to the present invention.

The information aggregate includes, for example, software such as programs and / or data.

The data in the medium and the information aggregate described above includes a data structure, a data format, a data type, and the like.

[Detailed Description of the Invention]

[0055]

As described above, according to the present invention,
Chromaticity adjustment, which has been difficult than in the past, can be performed inside the liquid crystal module only by expanding the internal circuit of the controller.

[Brief description of the drawings]

FIG. 1 is a diagram showing a conversion table according to Embodiment 1 of the present invention.

FIG. 2 is a block diagram of a liquid crystal module according to Embodiment 1 of the present invention.

FIG. 3 is a diagram illustrating a controller I in the liquid crystal module of FIG. 2;
Block diagram of the inside of C204

FIG. 4 is a block diagram of a liquid crystal module according to Embodiment 2 of the present invention.

[Explanation of symbols]

 Reference Signs List 201 Input connector of liquid crystal module 202 Data signal 203 Power supply 204 Controller IC 205 Source driver IC 207 Gate driver IC 208 DCDC converter 210 Liquid crystal panel 211 Dip switch 301 Red data input bus line 302 Green data input bus line 303 Blue data input Bus line 304 Data conversion block 305 Dip switch 306 Pseudo bit expansion circuit 401 Input connector 402 Data signal 403 Power supply 404 Controller IC 405 Source driver IC 407 Gate driver IC 408 DCDC converter 410 Liquid crystal panel 411 Dip switch

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G09G 3/20 650 G09G 3/20 650M F term (Reference) 2H093 NA16 NA43 NA53 NA55 NA64 NC05 NC13 NC14 NC34 NC50 NC66 5C006 AA01 AA02 AA13 AA14 AA22 AC02 AF52 AF84 BC03 BC05 BC12 BF50 EB06 EC02 EC05 FA56 5C080 AA10 BB05 CC03 DD30 EE29 EE30 FF09 GG08 JJ02 JJ05 KK43 KK43

Claims (7)

[Claims] 1. A conversion means for converting an n-bit digital signal of at least one of red, blue and green into a (n + α) -bit (α is a natural number) digital signal, and a liquid crystal display for displaying the n-bit digital signal on a liquid crystal And a control means for controlling the digital signal converted by the conversion means to be displayed on the liquid crystal display means, further comprising: n of at least one of the red, blue and green colors A plurality of conversion tables for converting each value represented by bits into each value represented by (n + α) bits, and a value represented by (n + α) bits from 0 to (2 ⁿ -1)
And a correspondence table that corresponds to one of the numbers. The conversion unit performs the conversion using one of the plurality of conversion tables, and the control unit performs the control using the correspondence table. A liquid crystal display device. 2. The apparatus according to claim 1, wherein a plurality of the conversion tables are provided on the side where the luminance of the color corresponding to the conversion table is darker than the standard and / or on the side where the luminance of the color is higher than the standard. 2. The liquid crystal display device according to 1. 3. When the liquid crystal display means performs liquid crystal display,
3. The liquid crystal display device according to claim 1, further comprising a second control unit that changes luminances of all colors of red, blue, and green at substantially the same rate. 4. The liquid crystal display according to claim 3, wherein the second control means changes the luminances of all the colors substantially at the same rate based on a conversion table used by the conversion means. apparatus. 5. The liquid crystal display device according to claim 1, wherein the control unit performs the control using a frame rate control method or an error diffusion method (dithering method). . 6. A medium carrying a program and / or data for causing a computer to execute all or a part of functions of all or a part of the liquid crystal display device according to claim 1. A medium which can be processed by a computer. 7. A program and / or data for causing a computer to execute all or a part of functions of all or a part of the liquid crystal display device according to any one of claims 1 to 5. Information aggregate to be.