WO2010073393A1

WO2010073393A1 - Liquid crystal display device, liquid crystal display element driving circuit, color image generation method, and liquid crystal display element driving method

Info

Publication number: WO2010073393A1
Application number: PCT/JP2008/073816
Authority: WO
Inventors: 中西　秀一; 加藤　厚志; 飯坂　英仁; 宏行保坂; 拓北川
Original assignee: Ｎｅｃディスプレイソリューションズ株式会社; セイコーエプソン株式会社
Priority date: 2008-12-26
Filing date: 2008-12-26
Publication date: 2010-07-01
Also published as: JPWO2010073393A1; JP5376678B2

Abstract

A liquid crystal display device comprises: a plurality of correction means (3R1, 3G1, 3B1) for, when receiving corresponding image signals corresponding one-on-one to a plurality of image signals corresponding to a plurality of colors and corresponding to themselves among the plurality of image signals, outputting correction signals in which the corresponding image signals are corrected; an output control means for outputting, one by one in sequence, the correction signals outputted from the respective plurality of correction means (3R1, 3G1, 3B1); an irradiation means for, every time when the correction signals are outputted from the output control means, emitting light of colors corresponding to image signals from which the correction signals have been generated; and a liquid crystal display element for, every time when the correction signals are outputted from the output control means, modulating and outputting the light emitted from the irradiation means according to the correction signals. The plurality of correction means (3R1, 3G1, 3B1) output, as the correction signals, correction image signals in which the corresponding image signals are corrected based on the upper bits of the other image signals.

Description

Liquid crystal display device, liquid crystal display element drive circuit, color image generation method, and liquid crystal display element drive method

The present invention relates to a liquid crystal display device, a liquid crystal display element driving circuit, a color image generation method, and a liquid crystal display element driving method.

As one of the color display methods in a liquid crystal display device such as a projector or a direct-view display, the FSC (Field Sequential Color) method is known.

In the FSC method, light of different colors is sequentially irradiated to one monochrome liquid crystal display element, and the display image of the liquid crystal display element corresponds to the color of the irradiation light in synchronization with the switching of light (color). Switch to image.

The following describes the FSC method.

In the FSC system, one frame period constituting one screen is divided into a plurality of color field periods according to the color of the irradiation light.

For each color field, an image corresponding to the color of the color field is formed on one monochrome liquid crystal display element, and light having the color of the color field is irradiated to the liquid crystal display element.

The light irradiated to the liquid crystal display element is modulated and output by an image formed on the liquid crystal display element.

In the FSC method, since the field switching timing is shorter than the period of one frame, a plurality of modulated lights sequentially output from the liquid crystal display element are recognized as one color image by human eyes.

In the FSC system, it is necessary to switch the display image of the liquid crystal display element for each field that is a period shorter than one frame. For this reason, a quick response is required for the liquid crystal display element.

Many liquid crystal display devices have the following characteristics.
[1] The liquid crystal display element has a slow optical response (change in light transmittance).
[2] The response characteristic of the light transmittance is different between a change from black to white and a change from white to black.
[3] The response characteristic of the light transmittance varies depending on the wavelength.

Feature [1] deteriorates video quality.

Also, the feature [1] is that the FSC method often deteriorates the image quality even for a still image. In the FSC system, even if it is a still image, the image quality deteriorates when the level of the voltage applied to the same pixel is different in multiple color fields, that is, when a non-achromatic color is displayed. It is.

In addition, the feature [1] is that, in the FSC system, the gradation reproducibility is deteriorated when displaying a single primary color, and the color tone is deviated from the original color when displaying a mixed color and a chromatic color. Cause a phenomenon.

FIG. 1 is an explanatory diagram for explaining a malfunction phenomenon in the FSC method due to the feature [1].

In FIG. 1, one frame (Frame) has three colors including a field R (Field-R: red field), a field G (Field-G: green field), and a field B (Field-B: blue field). It is divided into fields.

The image data is image information (video information) corresponding to each of the R color (red), G color (green), and B color (blue) that can be associated with the pixels of the liquid crystal display element. It is the data shown.

LCD light transmittance indicates the light transmittance of the liquid crystal display element.

R-color LED light source lighting control, G-color LED light source lighting control, and G-color LED light source lighting control emit an R-color light LED (Light Emitting Diode) and a G-color light. This is light emission control of each color LED using a light source (light source constituting a lighting device) including an LED capable of emitting light of B color and an LED capable of emitting light of B color.

FIG. 1 shows an example in which a normally white liquid crystal display element (structure that displays white when no electric field is applied) is used as the liquid crystal display element (LCD).

Example (1) in FIG. 1 is an operation example when displaying a blue image on the entire surface. An example (2) in FIG. 1 is an operation example in the case of displaying a full-color cyan image.

As shown in FIG. 1, since the light transmittance response of the liquid crystal is slow, the following malfunction occurs.

Primary color is dark (example (1) due to low light transmittance of LCD when B color LED is lit). Although a in Example (1) and b in Example (2) have the same set gradation level of 100 [%], the light transmittance is different. Further, b in Example (2) and c in Example (2) have the same set gradation level 100 [%], but the light transmittance is different.

The defect caused by the feature [1] shown in the example (1) and the example (2) is that the light transmittance depends on the liquid crystal state of the previous field, that is, the liquid crystal state of the previous field changes to the liquid crystal state of the next field. It is also due to the influence.

Next, feature [2] is due to the fact that the response characteristics of the liquid crystal differ depending on the applied electric field.

For example, in the case of a TN (Twisted Nematic) mode liquid crystal, when the applied electric field is increased to change the direction of the liquid crystal and when the applied electric field is weakened to change the direction of the liquid crystal due to the viscoelasticity of the liquid crystal, the latter is Liquid crystal response characteristics are slow.

Therefore, when the liquid crystal display element has a normally white structure, the change from black to white is slower than the change from white to black. For this reason, when the liquid crystal display element has a normally white structure, the moving image quality deteriorates particularly when a dark image changes to a bright image. On the other hand, when the liquid crystal display element has a normally black structure, the moving image quality deteriorates particularly when the light image changes to a dark image.

Also, feature [2] also deteriorates the quality of still images in the FSC system.

For example, in the FSC system, when the liquid crystal display element is normally white, the primary color is not bright, and when the liquid crystal display element is normally black, the complementary color of the primary color is whitish. In addition, in the FSC system, when displaying mixed colors and chromatic colors, it becomes difficult to reproduce depending on the display color.

Liquid crystal display elements include TN mode, IPS (In-Plane Switching) mode, VA (Vertical Aligned) mode, and OCB (Optically Compensated Bend) mode. In either case, the direction of the liquid crystal (director) is changed by the applied electric field to control the degree of birefringence, and the polarization state of the light passing through the liquid crystal can be changed.

The degree of change in the polarization state depends on the wavelength of light. Therefore, feature [3] occurs. Feature [3] is a factor that further deteriorates the color reproducibility.

The liquid crystal display device controls the liquid crystal for each pixel. In many cases, the circuit for controlling the pixels has a matrix structure, and sequentially controls each pixel. Therefore, when attention is paid to a certain pixel, the pixel is accessed only during a part of a predetermined period. During the partial period, a voltage V for controlling the liquid crystal is applied to the pixel.

The pixel has a capacitive component C. Therefore, by applying the control voltage V to the pixel, the charge Q corresponding to the control voltage V is supplied to the pixel electrode.

Generally, the following equation holds.

Q = C × V. . . Formula [1]
The pixel capacitance C has a property of changing depending on the orientation (director) of the liquid crystal of the pixel.

If the voltage continues to be applied until the change in the liquid crystal orientation has settled, charge is supplied when the capacitance changes.

However, when the change in the orientation of the liquid crystal does not converge within the period when the pixel is accessed, the capacitance changes due to the change in the orientation of the liquid crystal after the supply of charges is interrupted. Therefore, the voltage applied to the liquid crystal in the pixel changes from the voltage applied at the time of access.

A so-called overdrive method is known as a method for solving the problem that a desired charge amount cannot be supplied by one access (see Patent Document 1).

Overdrive applies the desired amount of charge by applying an excessive voltage to the pixel that is different from the voltage when the director is in the desired director state, depending on which state the director is changed from to which state. This is a method of supplying the pixel.

In addition, overdrive also has an aspect of improving the slow response due to the viscoelasticity of the liquid crystal, that is, the defect caused by the feature [1].

Patent Document 2 describes a liquid crystal display device in which a color image is generated by the FSC method, and a level correction circuit provided for each color corrects a video signal of a color corresponding to the own circuit.

This level correction circuit corrects the video signal of the color corresponding to itself in order to correct the response characteristic of the light transmittance depending on the wavelength, that is, the feature [3].

Specifically, the liquid crystal display device described in Patent Document 2 includes level correction circuits 32R, 32G, and 32B. The level correction circuit 32R receives the red video signal and corrects the red video signal according to the red response characteristic. The level correction circuit 32G receives the green video signal and corrects the green video signal according to the green response characteristic. The level correction circuit 32B receives the blue video signal and corrects the blue video signal according to the blue response characteristic.

Patent Document 3 describes a liquid crystal display device that generates a color image by the FSC method and performs a kind of overdrive.

This liquid crystal display device corrects R image data using G and B image data from which part of the data has not been deleted, and uses B and R image data from which part of the data has not been deleted. G image data is corrected, and B image data is corrected using R and G image data from which part of the data is not deleted.
JP 2002-351409 A JP 2002-148484 A JP 2006-227458 A

Patent Document 1 does not mention that overdrive is used in an FSC liquid crystal display device.

When an overdrive such as that disclosed in Patent Document 1 is applied to an FSC type liquid crystal display device, attention is paid to a certain pixel, so that the color displayed by the pixel is not one. Overdrive is performed according to the state transition of the liquid crystal director at the time of switching.

Therefore, when applying overdrive in an FSC liquid crystal display device, it is necessary to use a video signal of another color in order to correct a video signal of a certain color.

For this reason, the level correction circuit described in Patent Document 2, specifically, a level correction circuit that accepts only a video signal of a color corresponding to its own circuit and corrects the video signal of that color is an FSC type liquid crystal display device. Then, it cannot be used as a correction circuit for overdrive.

The liquid crystal display device described in Patent Document 3 generates a color image by the FSC method, and corrects image data of each color by using image data of other colors from which part of the data is not deleted. Yes.

However, since the liquid crystal display device described in Patent Document 3 corrects image data of one color using image data of another color from which part of the data has not been deleted, the amount of data used for correction There was a problem that there were many.

In

Patent Documents

1 and 2, a technology that is a premise for causing the above problem, specifically, a color image is generated by the FSC method, and image data of one color is transferred to another color. A technique for correcting using image data is not described.

For this reason, in the techniques described in

Patent Documents

1 and 2, as a matter of course, the above problem, specifically, image data of one color is replaced with image data of another color from which part of the data is not deleted. The problem that a large amount of data is used for correction has not been solved.
An object of the present invention is to provide a liquid crystal display device, a liquid crystal display element driving circuit, a color image generation method, and a liquid crystal display element driving method capable of solving the above-described problems.

When the liquid crystal display device of the present invention has a one-to-one correspondence with a plurality of video signals corresponding to a plurality of colors and receives a corresponding video signal corresponding to itself among the plurality of video signals, A plurality of correction means for outputting a correction signal obtained by correcting the signal, an output control means for sequentially outputting the correction signals output from each of the plurality of correction means, and the correction from the output control means. Each time a signal is output, an irradiation unit that emits light of a color corresponding to the video signal that is the source of the correction signal, and each time the correction signal is output from the output control unit, the irradiation unit emits light. A liquid crystal display element that modulates the output light according to the correction signal and outputs the modulated light, and at least one of the plurality of correction means includes the corresponding video signal and a correction signal obtained by correcting the corresponding video signal. Straight Or, immediately after receiving a part of another video signal that is the basis of another correction signal output from the output control means, the corresponding video signal is corrected based on a part of the other video signal. The corrected video signal is output as the correction signal.

The drive circuit for a liquid crystal display element of the present invention is a drive circuit for a liquid crystal display element that, when receiving a drive signal, modulates and outputs light of a color corresponding to the drive signal in accordance with the drive signal. A plurality of video signals corresponding to the one-to-one correspondence, and when a corresponding video signal corresponding to itself is received among the plurality of video signals, a correction signal obtained by correcting the corresponding video signal is output. A plurality of correction means, and output control means for outputting the correction signals output from each of the plurality of correction means to the liquid crystal display element as the drive signals one by one in order. At least one of the corresponding video signal and a part of another video signal that is a source of another correction signal output from the output control unit immediately before or after the correction signal obtained by correcting the corresponding video signal. When When receiving the, the corrected video signal corrected on the basis of the corresponding image signal to a part of the other video signal is output as the correction signal.

The color image generation method of the present invention is a color image generation method performed by an FSC-type liquid crystal display device that displays a color image by sequentially displaying a plurality of color images corresponding to a plurality of video signals, When each of the plurality of correction units corresponding to the plurality of video signals on a one-to-one basis receives a corresponding video signal corresponding to itself among the plurality of video signals, a correction signal obtained by correcting the corresponding video signal is output. The correction signals are sequentially output one by one, and each time the correction signals are sequentially output one by one, light of a color corresponding to the video signal that is the source of the correction signal is emitted, Each time a correction signal is output one by one in sequence, the light is modulated and output according to the correction signal, and at least one of the plurality of correction means includes the corresponding video signal and the corresponding video signal. To correct When receiving a part of another video signal that is the source of another correction signal output immediately before or after the correction signal, the corresponding video signal is corrected based on a part of the other video signal. A corrected video signal is output as the correction signal.

The liquid crystal display element driving method of the present invention is a method for driving a liquid crystal display element that, when receiving a driving signal, modulates and outputs light of a color corresponding to the driving signal in accordance with the driving signal, When each of the plurality of correction means corresponding to the plurality of video signals corresponding to the one receives a corresponding video signal corresponding to itself among the plurality of video signals, a correction signal obtained by correcting the corresponding video signal The correction signals are output one by one in order, and at least one of the plurality of correction means is output immediately before or after the corresponding video signal and the correction signal obtained by correcting the corresponding video signal. When a part of another video signal that is the basis of another correction signal is received, a corrected video signal obtained by correcting the corresponding video signal based on a part of the other video signal is output as the correction signal. Do

According to the present invention, it is possible to reduce the amount of data used when generating a correction signal of a video signal corresponding to a plurality of colors in order to perform overdrive by the FSC method, thereby reducing the circuit scale. Can do.

It is explanatory drawing for demonstrating the malfunction phenomenon in a FSC system. 1 is a block diagram illustrating a liquid crystal display device 1 according to a first embodiment of the present invention. 3 is a block diagram illustrating an example of a color correction unit 3. FIG. FIG. 6 is a block diagram showing a color correction unit 3A, which is another example of the color correction unit 3 shown in FIG. It is the block diagram which showed the color correction part 3B which is another example of the color correction part 3 shown in FIG. FIG. 11 is a block diagram showing a color correction unit 3C, which is still another example of the color correction unit 3 shown in FIG. It is the block diagram which showed liquid crystal display device 1A of the 2nd Embodiment of this invention. It is the block diagram which showed the principal part of the 3rd Embodiment of this invention. It is the block diagram which showed the principal part of the 4th Embodiment of this invention. It is the block diagram which showed the principal part of the 5th Embodiment of this invention.

Explanation of symbols

1, 1A Liquid crystal display device 2 Liquid

crystal display element

3, 3A, 3B, 3C, 31, 32, 33, 34 Color correction unit 3R1, 3R2, 3R3, 3R4, 3R5, 3R6 R color correction LUT storage unit 3G1, 3G2, 3G3 3G4, 3G5, 3G6 G color correction LUT storage unit 3B1, 3B2, 3B3, 3B4, 3B5, 3B6 B color correction LUT storage unit 3M4 M color correction LUT storage unit 3Y4 Y color correction LUT storage unit 34a Frame buffer 4 Data rearrangement 4a Frame memory 4b Memory control unit 5 Irradiation unit 5a, 5aA Illumination unit 5b Timing control unit 6 Output control unit 7 VT characteristic correction unit 8 Color conversion unit

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 2 is a block diagram showing the liquid crystal display device 1 according to the first embodiment of the present invention.

2, the liquid crystal display device 1 includes a liquid crystal display element 2, a color correction unit 3, a data rearrangement unit 4, and an irradiation unit 5. The data rearrangement unit 4 includes a frame memory 4a and a memory control unit 4b. The irradiation unit 5 includes an illumination unit 5a and a timing control unit 5b.

The liquid crystal display device 1 receives a plurality of video signals corresponding to each of a plurality of colors on a one-to-one basis (hereinafter simply referred to as “a plurality of video signals”).

The liquid crystal display device 1 is an FSC liquid crystal display device that displays a color image by sequentially displaying a plurality of color images corresponding to a plurality of video signals.

The liquid crystal display element 2 has a plurality of pixels. When the liquid crystal display element 2 receives the drive signal, the liquid crystal display element 2 uses a plurality of pixels, modulates the light applied to the liquid crystal display element 2 according to the drive signal, and outputs light for forming an image.

When the liquid crystal display device 1 is a projector (projection display device), the light modulated and output by the liquid crystal display element 2 is magnified by a projection optical system (not shown) and is applied to a screen (not shown). Projected. When the liquid crystal display device 1 is a direct view display device, the light modulated and output by the liquid crystal display element 2 reaches the eyes of the user.

The color correction unit 3 inputs video signals of a plurality of colors synchronized with a timing signal indicating the synchronization timing of the input frame, and outputs a plurality of correction signals corresponding to the plurality of colors on a one-to-one basis.

In the present embodiment, the color correction unit 3 receives a plurality of video signals each time a timing signal generated every frame period is received, and a plurality of correction signals corresponding one-to-one to the plurality of video signals. Is output.

In the present embodiment, the color correction unit 3 includes, as a plurality of video signals, an R color video signal (video signal (R)) corresponding to red and a G color video signal (video signal (G)) corresponding to green. And a B color video signal (video signal (B)) corresponding to blue.

Each of the R color video signal, G color video signal, and B color video signal is an 8-bit signal. Note that the number of bits of each of the R color video signal, the G color video signal, and the B color video signal is not limited to 8 bits and can be changed as appropriate.

The color correction unit 3 outputs an R color correction signal corresponding to red, a G color correction signal corresponding to green, and a B color correction signal corresponding to blue as a plurality of correction signals. The color correction unit 3 generates an R color correction signal based on the R color video signal, generates a G color correction signal based on the G color video signal, and generates a B color correction signal based on the B color video signal. Is generated.

Each of the R color correction signal, G color correction signal, and B color correction signal is a 10-bit signal. The number of bits of each of the R color correction signal, the G color correction signal, and the B color correction signal is not limited to 10 bits, and can be changed as appropriate.

The function of the color correction unit 3 is based on the application of overdrive in the FSC system and the applied voltage based on the VT characteristic representing the relationship between the applied voltage (drive voltage) and the light transmittance in the liquid crystal display element 2. (Drive voltage) is corrected.

In the present embodiment, the number of output bits of the color correction unit 3 is smaller than the number of input bits of the color correction unit 3 in order to prevent the gradation reproducibility from being deteriorated while performing correction based on nonlinear VT characteristics. There are also many.

The data rearrangement unit 4 can be generally called output control means.

The data rearrangement unit 4 outputs the plurality of correction signals output from the color correction unit 3 to the liquid crystal display element 2 one by one as a drive signal.

In this embodiment, the data rearrangement unit 4 uses the R color correction signal, the G color correction signal, and the B color correction signal as drive signals in the order of the R color correction signal, the G color correction signal, and the B color correction signal. Output to the liquid crystal display element 2. This order can be changed as appropriate.

The frame memory 4a is used as a buffer for rearranging a plurality of correction signals functioning as video signals.

The memory control unit 4b rearranges the plurality of correction signals output from the color correction unit 3 in the order of output to the liquid crystal display element 2 on the frame memory 4a.

In this embodiment, the memory control unit 4b performs the R color correction signal, the G color correction signal, and the B color correction signal in the order of the R color correction signal, the G color correction signal, and the B color correction signal on the frame memory 4a. Rearrange.

The memory control unit 4b outputs the R color correction signal, the G color correction signal, and the B color correction signal on the frame memory 4a to the liquid crystal display element 2 as drive signals one by one in the arrangement order. .

The irradiation unit 5 can be generally called irradiation means.

The irradiating unit 5 becomes a source of the correction signal output to the liquid crystal display element 2 every time one of the plurality of correction signals output from the color correction unit 3 is output to the liquid crystal display element 2 as a drive signal. The liquid crystal display element 2 is irradiated with light of a color corresponding to the received video signal. However, the irradiation unit 5 adjusts the light irradiation timing (period and phase) in consideration of the response of the light transmittance after the drive signal is output to the liquid crystal display element 2.

The illumination unit 5a includes an R color LED that emits red light, a G color LED that emits green light, and a B color LED that emits blue light.

The timing control unit 5b receives a timing signal indicating the synchronization timing of the input frame (hereinafter referred to as “input frame synchronization timing”), and outputs the synchronization timing of the output field (hereinafter referred to as “color frame period”). A timing signal indicating "output field synchronization timing" is generated. In the present embodiment, the input frame synchronization timing and the output field synchronization timing are synchronized, but they may be asynchronous.

In the data rearrangement unit 4, the memory control unit 4 b receives the two types (not shown) of timing signals (a timing signal indicating the input frame synchronization timing and a timing signal indicating the output field synchronization timing) from the timing control unit 5 b. Writing to the frame memory 4a is controlled in synchronization with the frame synchronization timing, and reading from the frame memory 4a is controlled in synchronization with the output field synchronization timing. Then, the memory control unit 4b applies the R color correction signal, the G color correction signal, and the B color correction signal on the frame memory 4a to the liquid crystal display element 2 as drive signals one by one in the arrangement order. Output.

The liquid crystal display element 2 sequentially receives the R color correction signal, the G color correction signal, and the B color correction signal sequentially output from the data rearrangement unit 4 in synchronization with the output field synchronization timing by the timing signal from the timing control unit 5b. input. Then, the liquid crystal display element 2 sequentially controls the liquid crystal orientation (director) of each pixel in accordance with each color correction signal for each color, modulates each color light sequentially irradiated for each color, and outputs an image of each color. Are sequentially generated.

The illumination unit 5a lights up the R color LED, the G color LED, and the B color LED one by one in this order in synchronization with the output field synchronization timing by the timing signal from the timing control unit 5b.

Therefore, in this embodiment, the liquid crystal display device 1 operates as follows.

When the liquid crystal display element 2 is forming an image corresponding to the R color correction signal, the illumination unit 5a turns on the R color LED and irradiates the liquid crystal display element 2 with the R color light.

Thereafter, when the liquid crystal display element 2 is forming an image corresponding to the G color correction signal, the illumination unit 5a turns on the G color LED and irradiates the liquid crystal display element 2 with the G color light.

Thereafter, when the liquid crystal display element 2 forms an image corresponding to the B color correction signal, the illumination unit 5a turns on the B color LED and irradiates the liquid crystal display element 2 with B color light.

FIG. 3 is a block diagram illustrating an example of the color correction unit 3.

In FIG. 3, the color correction unit 3 has an input bit number of 24 bits and an output bit number of 30 bits (RGB each 10 bits).

The color correction unit 3 includes an R color correction LUT (Look-up Table) storage unit 3R1, a G color correction LUT storage unit 3G1, and a B color correction LUT storage unit 3B1.

Each of the R color correction LUT storage unit 3R1, the G color correction LUT storage unit 3G1, and the B color correction LUT storage unit 3B1 can be generally referred to as correction means or storage means. For this reason, the color correction unit 3 includes a plurality of correction means (storage means).

In this embodiment, each of the R color correction LUT storage unit 3R1, the G color correction LUT storage unit 3G1, and the B color correction LUT storage unit 3B1 has an input bit number of 12 bits and an output bit number of 10 bits.

The R color correction LUT storage unit 3R1 corresponds to the R color video signal on a one-to-one basis.

When the R color correction LUT storage unit 3R1 receives an R color video signal (corresponding video signal) corresponding to itself and at least a part of the B color video signal (other video signals) among the plurality of video signals. The R color correction signal obtained by correcting the R color video signal based on at least a part of the B color video signal is output.

The B color video signal is a video signal that is the source of the B color correction signal (other correction signal) output from the data rearrangement unit 4 immediately before the R color correction signal obtained by correcting the R color video signal. is there.

In this embodiment, the R color correction LUT storage unit 3R1 inputs the upper 4 bits of the B color video signal and all 8 bits of the R color video signal, and outputs a 10 bit R color correction signal.

For example, the R color correction LUT storage unit 3R1 corrects the upper 4 bits of the B color video signal, all 8 bits of the R color video signal, and all 8 bits of the R color video signal based on the upper 4 bits of the B color video signal. The LUT that stores the corrected video signal in association with each other is stored.

When the R color correction LUT storage unit 3R1 receives the upper 4 bits of the B color video signal and all 8 bits of the R color video signal, the R color correction associated with the upper 4 bits of the B color video signal and the 8 bits of the R color video signal. The video signal is output as an R color correction signal.

Here, an example of the setting method of the R color correction video signal will be described.

The color reproducibility depends on how quickly the liquid crystal director shifts to a desired state, but since the change of the liquid crystal director is slow, it also affects how the state immediately before the liquid crystal director is controlled.

Therefore, the R color reproducibility can be improved by using the B color video signal of the previous field related to the state of the liquid crystal director immediately before the R color.

For example, when setting the R color correction video signal in the situation where the gradation level of the B color video signal is 10% and the gradation level of the R color video signal is 50%, the gradation level of the R color correction video signal is Based on the gradation level of 10% of the B color video signal, if it is set to 70%, which is excessively higher than the gradation level of 50% of the R color video signal, the state of the liquid crystal director can be brought closer to the desired state more quickly. it can.

Therefore, when the gradation level of the B color video signal is 10% and the gradation level of the R color video signal is 50%, the R color corrected video signal with the gradation level set to 70% is output. As described above, if the R color correction LUT storage unit 3R1 is set, overdrive can be applied in the FSC method.

Also, for example, when setting the R color correction video signal when the gradation level of the B color video signal is 90% and the gradation level of the R color video signal is 50%, the gradation level of the R color correction video signal is set. Is set to 45%, which is an excessive level from the gradation level of 50% of the R color video signal when viewed from the gradation level of the B color video signal of 90%, and the liquid crystal director state is changed to a desired state faster. You can get closer.

Therefore, when the gradation level of the B color video signal is 90% and the gradation level of the R color video signal is 50%, the R color corrected video signal with the gradation level set to 45% is output. As described above, if the R color correction LUT storage unit 3R1 is set, overdrive can be applied in the FSC method.

In the case of a normally white liquid crystal display element, the response of light transmittance is faster when changing from white to black than when changing from black (small gradation level) to white (high gradation level). Since the response speed varies depending on the history of the liquid crystal state, the degree of overdrive is adjusted in consideration of this.

In the present embodiment, overdrive is performed by correcting the gradation level of the R color video signal based on the relationship between the gradation level of the B color video signal and the gradation level of the R color video signal. The R color correction video signal is set, and the R color correction video signal is stored in the R color correction LUT storage unit 3R1.

Note that reducing the number of bits of the video signal of the color of the previous field at the time of correction is one feature of the present embodiment. This feature is obtained in consideration of the phenomenon that the accuracy of the influence of the video signal of the previous field color is coarser than the accuracy of the influence of the self-color video signal.

For this reason, the number of bits of the video signal of the color of the previous field can be reduced at the time of correction, and the amount of information necessary for correction can be reduced.

The G color correction LUT storage unit 3G1 corresponds to the G color video signal on a one-to-one basis.

For the detailed description of the G color correction LUT storage unit 3G1, in the above description of the R color correction LUT storage unit 3R1, “R color correction LUT storage unit 3R1” is replaced with “G color correction LUT storage unit 3G1”. , Read the corresponding video signal from "R color video signal" to "G color video signal", read the other video signal from "B color video signal" to "R color video signal", and change "R color correction signal" to " This can be done by replacing it with “G color correction signal” and replacing “R color correction video signal” with “G color correction video signal”.

The B color correction LUT storage unit 3B1 corresponds to the B color video signal on a one-to-one basis.

For the detailed description of the B color correction LUT storage unit 3B1, in the above description of the R color correction LUT storage unit 3R1, “R color correction LUT storage unit 3R1” is replaced with “B color correction LUT storage unit 3B1”. , Read the corresponding video signal from "R color video signal" to "B color video signal", read the other video signal from "B color video signal" to "G color video signal", and change "R color correction signal" to " This can be done by replacing it with “B color correction signal” and replacing “R color correction video signal” with “B color correction video signal”.

When each of the LUT storage units 3R1, 3G1, and 3B1 is configured using a RAM (Random Access Memory), the total 12 bits of the input video signal is the RAM address, and the data in the RAM is the corrected video signal 10 bits. To do.

By storing the corrected video signal in the RAM, it is possible to output a correction signal that is a corresponding video signal corrected according to the input video signal.

In the example shown in FIG. 3, the memory size of the color correction unit 3 is (2 ^ 12) × 10 bits × 3 = 120 kbit (note that 1 kbit = (2 ^ 10) bits), which can be reduced to a practical size. .

On the other hand, for example, when three LUT storage units are not provided in the color correction unit 3, specifically, when the color correction unit 3 is a memory having an input of 24 bits and an output of 30 bits, the color correction unit The memory size of 3 is (2 ^ 24) × 30 bits = 480 Mbit (note that 1 Mbit = (2 ^ 20) bits), which is considerably larger than the example shown in FIG.

Next, the operation will be described.

In the color correction unit 3, the R color correction LUT storage unit 3R1 receives the upper 4 bits of the B color video signal and all 8 bits of the R color video signal in synchronization with the timing signal indicating the input frame synchronization timing, and receives the B color video signal. The R color correction video signal associated with the upper 4 bits and the 8 bits of the R color video signal are output to the memory control unit 4b as the R color correction signal.

The G color correction LUT storage unit 3G1 receives the upper 4 bits of the R color video signal and all 8 bits of the G color video signal in synchronization with the timing signal indicating the input frame synchronization timing, and receives the upper 4 bits of the R color video signal. The G color correction video signal associated with all 8 bits of the G color video signal is output to the memory control unit 4b as the G color correction signal.

The B color correction LUT storage unit 3B1 receives the upper 4 bits of the G color video signal and all 8 bits of the B color video signal in synchronization with the timing signal indicating the input frame synchronization timing, and receives the upper 4 bits of the G color video signal. The B color correction video signal associated with all 8 bits of the B color video signal is output to the memory control unit 4b as the B color correction signal.

When the memory control unit 4b receives the R color correction signal, the G color correction signal, and the B color correction signal, the memory control unit 4b converts the R color correction signal, the G color correction signal, and the B color correction signal into the R color on the frame memory 4a. The correction signal, the G color correction signal, and the B color correction signal are rearranged in this order.

On the other hand, the timing control unit 5b receives a timing signal indicating the input frame synchronization timing, generates a timing signal indicating the output field synchronization timing obtained by dividing one frame period into three color field periods, and the data rearrangement unit 4 To the liquid crystal display element 2 and the illumination unit 5a.

In the data rearrangement unit 4, the memory control unit 4b uses the two types of timing signals (a timing signal indicating the input frame synchronization timing and a timing signal indicating the output field synchronization timing) from the timing control unit 5b to change the input frame synchronization timing. The writing to the frame memory 4a is controlled in synchronization, and the reading from the frame memory 4a is controlled in synchronization with the output field synchronization timing. Then, the R color correction signal, the G color correction signal, and the B color correction signal on the frame memory 4a are output to the liquid crystal display element 2 as drive signals one by one in the arrangement order.

The liquid crystal display element 2 receives the R color correction signal, the G color correction signal, and the B color correction signal sequentially output from the data rearrangement unit 4 in synchronization with the output field synchronization timing by the timing signal from the timing control unit 5b. To do. Then, the liquid crystal display element 2 sequentially controls the liquid crystal orientation (director) of each pixel in accordance with each color correction signal for each color, modulates each color light sequentially irradiated for each color, and outputs an image of each color. Are sequentially generated.

For this reason, in the present embodiment, when the liquid crystal display element 2 forms an image corresponding to the R color correction signal, the illumination unit 5a lights the R color LED, and the liquid crystal display element 2 is illuminated with the R color light. When the liquid crystal display element 2 forms an image corresponding to the G color correction signal, the illumination unit 5a lights the G color LED and irradiates the liquid crystal display element 2 with the G color light. When the element 2 is forming an image corresponding to the B color correction signal, the illumination unit 5a turns on the B color LED and irradiates the liquid crystal display element 2 with the B color light.

In this embodiment, each of the R color correction LUT storage unit 3R1, the G color correction LUT storage unit 3G1, and the B color correction LUT storage unit 3B1 includes a corresponding video signal corresponding to itself and a correction signal obtained by correcting the corresponding video signal. When at least a part of the other video signal that is the source of the other correction signal output from the data rearrangement unit 4 immediately before or after is received, the corresponding video signal is converted into at least a part of the other video signal. A correction signal corrected based on the output is output.

For this reason, it becomes possible to output correction signals that function as drive signals for overdrive in parallel. Therefore, when generating a correction signal to perform overdrive by the FSC method, it is possible to shorten the time from receiving a video signal corresponding to a plurality of colors until outputting a plurality of correction signals. .

The liquid crystal display element 2 receives the correction signals one by one in order, and forms an image according to the received correction signal.

For this reason, overdrive can be realized in an FSC liquid crystal display device. By realizing overdrive, it becomes possible to improve the quality of moving images, the improvement of gradation reproduction of a single primary color, and the color reproduction of mixed colors and chromatic colors in an FSC liquid crystal display device.

In the present embodiment, at least one of the R color correction LUT storage unit 3R1, the G color correction LUT storage unit 3G1, and the B color correction LUT storage unit 3B1 includes a corresponding video signal and a part of another video signal (predetermined data). Is received, the correction signal (corrected video signal) obtained by correcting the corresponding video signal based on a part of the other video signal is output.

For this reason, the number of bits of other video signals can be reduced and the amount of data used for correction can be reduced compared to the case where other video signals from which data has not been deleted are input.

In the present embodiment, each of the R color correction LUT storage unit 3R1, the G color correction LUT storage unit 3G1, and the B color correction LUT storage unit 3B1 receives the corresponding video signal, a part of the other video signal, and the corresponding video signal. The corrected video signal corrected based on a part of the video signal is stored in association with each other, and when the corresponding video signal and a part of the other video signal are received, the corresponding video signal and a part of the other video signal are stored. The associated corrected video signal is output as a correction signal.

In this case, each of the R color correction LUT storage unit 3R1, the G color correction LUT storage unit 3G1, and the B color correction LUT storage unit 3B1 receives not all of the other video signals but a part of the other video signals. .

For this reason, the number of bits of other video signals can be reduced compared to the case where all other video signals are input, and the R color correction LUT storage unit 3R1, the G color correction LUT storage unit 3G1, and the B color correction LUT are stored. Each memory size of the unit 3B1 can be reduced. Therefore, the circuit scale of the liquid crystal display device 1 can be reduced.

In the present embodiment, the color correction unit 3 is not limited to the configuration shown in FIG. For example, the color correcting unit 3A shown in FIG.

FIG. 4 is a block diagram showing a color correction unit 3A, which is another example of the color correction unit 3 shown in FIG.

4, the color correction unit 3A has an input bit number of 24 bits and an output bit number of 30 bits (RGB each 10 bits).

The color correction unit 3A includes an R color correction LUT storage unit 3R2, a G color correction LUT storage unit 3G2, and a B color correction LUT storage unit 3B2.

Each of the R color correction LUT storage unit 3R2, the G color correction LUT storage unit 3G2, and the B color correction LUT storage unit 3B2 can be generally referred to as correction means or storage means. For this reason, the color correction unit 3A has a plurality of correction means (storage means).

The R color correction LUT storage unit 3R2, the G color correction LUT storage unit 3G2, and the B color correction LUT storage unit 3B2 each have an input bit number of 11 bits and an output bit number of 10 bits.

The R color correction LUT storage unit 3R2 has a one-to-one correspondence with the R color video signal.

When the R color correction LUT storage unit 3R2 receives an R color video signal corresponding to itself and at least a part of the G color video signal among the plurality of video signals, the R color correction LUT storage unit 3R2 converts the R color video signal into the G color video signal. An R color correction signal corrected based on at least a part is output.

The G color video signal is a video signal that is the source of the G color correction signal (other correction signal) output from the data rearrangement unit 4 immediately after the R color correction signal obtained by correcting the R color video signal. is there.

The R color correction LUT storage unit 3R2 inputs the upper 3 bits of the G color video signal and all 8 bits of the R color video signal, and outputs a 10 bit R color correction signal.

For example, the R color correction LUT storage unit 3R2 corrects the upper 3 bits of the G color video signal, all 8 bits of the R color video signal, and all 8 bits of the R color video signal based on the upper 3 bits of the G color video signal. The LUT that stores the corrected video signal in association with each other is stored.

When the R color correction LUT storage unit 3R2 receives the upper 3 bits of the G color video signal and all 8 bits of the R color video signal, the R color correction associated with the upper 3 bits of the G color video signal and all 8 bits of the R color video signal. The video signal is output as an R color correction signal.

Here, an example of a method for setting the R color correction video signal in the R color correction LUT storage unit 3R2 will be described.

Since the change of the liquid crystal director is slow, the state of the liquid crystal director in its own field affects the color reproducibility of the next field.

Therefore, the G color reproducibility can be improved by correcting the R color video signal using the G color video signal of the next field.

For example, when setting the R color correction video signal in the situation where the gradation level of the R color video signal is 50% and the gradation level of the G color video signal is 90%, the gradation level of the R color correction video signal is If the level is 70% close to the next color (G color), the state of the liquid crystal director of the next color can be brought closer to the desired state more quickly.

Therefore, when the gradation level of the R color video signal is 50% and the gradation level of the G color video signal is 90%, the R color corrected video signal with the gradation level set to 70% is output. As described above, if the R color correction LUT storage unit 3R1 is set, overdrive can be applied in the FSC method.

For example, when setting the R color correction video signal in the situation where the gradation level of the R color video signal is 50% and the gradation level of the G color video signal is 10%, the gradation level of the R color correction video signal is If the level is 45% close to the next color (G color), the state of the liquid crystal director of the next color can be brought closer to the desired state more quickly.

Therefore, when the gradation level of the R color video signal is 50% and the gradation level of the G color video signal is 10%, the R color corrected video signal with the gradation level set to 45% is output. As described above, if the R color correction LUT storage unit 3R1 is set, overdrive can be applied in the FSC method.

In the case of the color correction unit 3A, overdrive is executed by correcting the gradation level of the R color video signal based on the relationship between the gradation level of the G color video signal and the gradation level of the R color video signal. The R color correction video signal is set and stored in the R color correction LUT storage unit 3R1.

Note that the accuracy of the influence of the video signal of the next field color is coarser than the accuracy of the influence of the self-color video signal. For this reason, at the time of correction, the number of bits of the video signal of the color of the next field can be reduced. Therefore, the amount of information necessary for correction can be reduced.

The G color correction LUT storage unit 3G2 has a one-to-one correspondence with the G color video signal.

For the detailed description of the G color correction LUT storage unit 3G2, in the description of the R color correction LUT storage unit 3R2, the “R color correction LUT storage unit 3R2” is replaced with “G color correction LUT storage unit 3G2”. , Read the corresponding video signal from "R color video signal" to "G color video signal", read the other video signal from "G color video signal" to "B color video signal", and change "R color correction signal" to " This can be done by replacing it with “G color correction signal” and replacing “R color correction video signal” with “G color correction video signal”.

The B color correction LUT storage unit 3B2 has a one-to-one correspondence with the B color video signal.

For the detailed description of the B color correction LUT storage unit 3B2, in the description of the R color correction LUT storage unit 3R2, the “R color correction LUT storage unit 3R2” is replaced with “B color correction LUT storage unit 3B2”. , Read the corresponding video signal from "R color video signal" to "B color video signal", read the other video signal from "G color video signal" to "R color video signal", and change "R color correction signal" to " This can be done by replacing it with “B color correction signal” and replacing “R color correction video signal” with “B color correction video signal”.

When each LUT storage unit 3R2, 3G2, and 3B3 is configured using a RAM, a total of 11 bits of the input video signal is used as the RAM address, and the RAM data is output as the corrected video signal 10 bits.

In the example shown in FIG. 4, the memory size of the color correction unit 3A is (2 ^ 11) × 10 bits × 3 = 60 kbit, which can be reduced to a practical size.

Note that the configuration shown in FIG. 3, specifically, the color correction unit 3 that corrects the video signal of the own color using the video signal of the color of the previous field has a gradation level of the own color of 100% or 0%. In this case, the slow response of the liquid crystal cannot be improved.

On the other hand, in the configuration shown in FIG. 4, specifically, the color correction unit 3A that corrects the video signal of the own color using the video signal of the color of the next field, the gradation level of the color of the next field is 100% or Even in the case of 0%, the slow response of the liquid crystal can be improved.

Each of the R color correction LUT storage unit 3R2, the G color correction LUT storage unit 3G2, and the B color correction LUT storage unit 3B2 immediately before or immediately after the corresponding video signal corresponding to itself and the correction signal obtained by correcting the corresponding video signal. When at least a part of another video signal that is a source of another correction signal output from the data rearrangement unit 4 is received, the corresponding video signal is corrected based on at least a part of the other video signal. Output a signal.

In addition, each of the R color correction LUT storage unit 3R2, the G color correction LUT storage unit 3G2, and the B color correction LUT storage unit 3B2 is not all of the other video signals, but part of other video signals (predetermined portion of data). The other video signal from which is deleted is input.

Therefore, the number of bits of other video signals can be reduced as compared with the case where all other video signals are input, and the R color correction LUT storage unit 3R2, the G color correction LUT storage unit 3G2, and the B color correction LUT are stored. Each memory size of the unit 3B2 can be reduced. Therefore, the circuit scale of the liquid crystal display device 1 can be reduced.

FIG. 5 is a block diagram showing a color correction unit 3B, which is still another example of the color correction unit 3 shown in FIG.

The configuration shown in FIG. 5 is a combination of the configurations shown in FIGS.

In FIG. 5, the color correction unit 3B has an input bit number of 24 bits and an output bit number of 30 bits (RGB each 10 bits).

The color correction unit 3B includes an R color correction LUT storage unit 3R3, a G color correction LUT storage unit 3G3, and a B color correction LUT storage unit 3B3.

Each of the R color correction LUT storage unit 3R3, the G color correction LUT storage unit 3G3, and the B color correction LUT storage unit 3B3 can be generally referred to as correction means or storage means. Therefore, the color correction unit 3B has a plurality of correction means (storage means).

The R color correction LUT storage unit 3R3, the G color correction LUT storage unit 3G3, and the B color correction LUT storage unit 3B3 each have an input bit number of 15 bits and an output bit number of 10 bits.

The R color correction LUT storage unit 3R3 corresponds to the R color video signal on a one-to-one basis.

When the R color correction LUT storage unit 3R3 receives an R color video signal corresponding to itself, a part of the B color video signal, and a part of the G color video signal among the plurality of video signals, An R color correction signal obtained by correcting the video signal based on a part of the B color video signal and a part of the G color video signal is output.

In this embodiment, the R color correction LUT storage unit 3R3 inputs the upper 4 bits of the B color video signal, the entire 8 bits of the R color video signal, and the upper 3 bits of the G color video signal, and inputs 10 bits of R color. Output a correction signal.

For example, the R color correction LUT storage unit 3R3 includes the upper 4 bits of the B color video signal, the upper 8 bits of the R color video signal, the upper 3 bits of the G color video signal, and the upper 8 bits of the R color video signal. A LUT that stores the R color video correction signal corrected based on the 4 bits and the upper 3 bits of the G color video signal in association with each other is stored.

Upon receiving the upper 4 bits of the B color video signal, all 8 bits of the R color video signal, and the upper 3 bits of the G color video signal, the R color correction LUT storage unit 3R3 receives the upper 4 bits of the B color video signal and all of the R color video signal. The R color correction video signal associated with the 8 bits and the upper 3 bits of the G color video signal is output as an R color correction signal.

The R color video correction signal in the R color correction LUT storage unit 3R3 is created by correcting the R color video signal by referring to the B color video signal of the previous field and the G color video signal of the next field. The

The R color video correction signal in the R color correction LUT storage unit 3R3 is created by correcting the R color video signal by referring to the B color video signal of the previous field and the G color video signal of the previous field. May be.

The G color correction LUT storage unit 3G3 has a one-to-one correspondence with the G color video signal.

For the detailed description of the G color correction LUT storage unit 3G3, in the description of the R color correction LUT storage unit 3R3 described above, “R color correction LUT storage unit 3R3” is replaced with “G color correction LUT storage unit 3G3”. The corresponding video signal is read from “R color video signal” to “G color video signal”, and other video signals are read from “B color video signal” and “G color video signal” to “R color video signal” and “B color”. It can be performed by replacing “video signal”, “R color correction signal” with “G color correction signal”, and “R color correction video signal” with “G color correction video signal”.

The B color correction LUT storage unit 3B3 corresponds to the B color video signal on a one-to-one basis.

For the detailed description of the B color correction LUT storage unit 3B3, in the description of the R color correction LUT storage unit 3R3 described above, “R color correction LUT storage unit 3R3” is replaced with “B color correction LUT storage unit 3B3”. The corresponding video signal is read from “R color video signal” to “B color video signal”, and other video signals are read from “B color video signal” and “G color video signal” to “G color video signal” and “R color”. This can be performed by replacing “video signal”, “R color correction signal” with “B color correction signal”, and “R color correction video signal” with “B color correction video signal”.

When each of the LUT storage units 3R3, 3G3, and 3B3 is configured using a RAM, the total 15 bits of the input video signal is used as the RAM address, and the RAM data is output as the corrected video signal 10 bits.

In the example shown in FIG. 5, the memory size of the color correction unit 3B is (2 15) × 10 bits × 3 = 960 kbits, which can be reduced to a practical size.

Each of the R color correction LUT storage unit 3R3, the G color correction LUT storage unit 3G3, and the B color correction LUT storage unit 3B3 arranges data immediately before the corresponding video signal corresponding to itself and the correction signal obtained by correcting the corresponding video signal. Another correction signal output from the data rearrangement unit 4 immediately after the correction signal obtained by correcting the corresponding video signal and a part of the other correction signal output from the replacement unit 4 When a part of the other video signal that is the source of the video signal is received, a correction signal obtained by correcting the corresponding video signal based on a part of the other video signal is output.

Further, each of the R color correction LUT storage unit 3R3, the G color correction LUT storage unit 3G3, and the B color correction LUT storage unit 3B3 receives not all of the other video signals but a part of the other video signals.

For this reason, the number of bits of other video signals can be reduced compared to the case where all other video signals are input, and the R color correction LUT storage unit 3R3, the G color correction LUT storage unit 3G3, and the B color correction LUT storage. Each memory size of the unit 3B3 can be reduced. Therefore, the circuit scale of the liquid crystal display device 1 can be reduced.

FIG. 6 is a block diagram showing a color correction unit 3C, which is still another example of the color correction unit 3 shown in FIG. In FIG. 6, the same components as those shown in FIG. 4 or FIG.

The color correction unit 3C is obtained by changing the configuration of the correction LUT storage unit for each color.

The liquid crystal display element 2 has wavelength dependency in light transmittance. When the liquid crystal layer is thinned in order to improve the response delay due to the viscoelasticity of the liquid crystal, the transmittance on the long wavelength side (R color side) is generally lowered in the same liquid crystal director state. Therefore, the temporal response characteristic of the transmittance also has wavelength dependency.

In the color correction unit 3C, the configuration of the correction LUT storage unit is changed for each color in consideration of the temporal response characteristic and wavelength dependency of the transmittance.

In other words, each of the R color correction LUT storage unit 3R3, the G color correction LUT storage unit 3G1, and the B color correction LUT storage unit 3B2 in the color correction unit 3C has a difference in response characteristics for each color in the liquid crystal display element 2. Based on this, a part of the other video signal is set.

In FIG. 6, the color correction unit 3C has an input bit number of 24 bits and an output bit number of 30 bits (RGB each 10 bits).

The color correction unit 3C includes an R color correction LUT storage unit 3R3, a G color correction LUT storage unit 3G1, and a B color correction LUT storage unit 3B2.

The R color correction LUT storage unit 3R3 inputs the upper 4 bits of the B color video signal, all 8 bits of the R color video signal, and the upper 3 bits of the G color video signal, and outputs a 10-bit R color correction signal.

That is, in the R color correction LUT storage unit 3R3, in order to improve the color reproducibility of the R color whose transmittance response is slower than that of the other colors (G color and B color), the B color video signal of the previous field is displayed in advance. A signal obtained by correcting the R color video signal using the G color video signal of the field is used as the R color correction signal.

The G color correction LUT storage unit 3G1 inputs the upper 4 bits of the R color video signal and all 8 bits of the G color video signal, and outputs a 10 bit G color correction signal.

That is, the G color correction LUT storage unit 3G1 uses the R color video signal of the previous field in order to improve the color reproducibility of the G color having the medium transmittance response among the R color, the G color, and the B color. A signal obtained by correcting the G color video signal is used as the G color correction signal.

The B color correction LUT storage unit 3B2 outputs the B color correction video signal by using all 8 bits of the B color video signal and the upper 3 bits of the R color video signal as inputs.

That is, the B color correction LUT storage unit 3B2 uses the R color video signal of the next field in order to improve the color reproducibility of the R color having a slower transmittance response than the other colors (G color and B color). A signal obtained by correcting the B color video signal is used as the B color correction signal.

In this case, each of the R color correction LUT storage unit 3R3, the G color correction LUT storage unit 3G1, and the B color correction LUT storage unit 3B2 in the color correction unit 3C has a response characteristic for each color in the liquid crystal display element 2. Based on the difference, a part of the video signal (other video signal) used for correcting the corresponding video signal is set.

Therefore, color reproducibility can be effectively improved while reducing the memory size.

In the example shown in FIG. 6, the memory size of the color correction unit 3C is ((2 ^ 15) + (2 ^ 12) + (2 ^ 11)) × 10 bit = 380 kbit (note that 1 kbit = (2 ^ 10 ) bit), and the size can be made smaller than the example shown in FIG.

[Second Embodiment]
FIG. 7 is a block diagram showing a liquid crystal display device 1A according to the second embodiment of the present invention. In FIG. 7, the same components as those shown in FIG.

Compared with the liquid crystal display device 1 shown in FIG. 2, the liquid crystal display device 1 </ b> A has a VT characteristic correction unit 7 added, and the number of output bits is 8 bits for each RGB instead of the color correction unit 3. The color correction unit 31 is used, and the number of output bits of the data rearrangement unit 4 is changed to 8 bits for each RGB.

In the liquid crystal display device 1A, the color correction unit 3 shown in FIG. 3 (however, the number of output bits is 24 bits) is used as the color correction unit 31. The color correction unit 31 is not limited to the color correction unit 3 shown in FIG. For example, as the color correction unit 31, the color correction unit 3A shown in FIG. 4 (where the number of output bits is 24 bits), the color correction unit 3B shown in FIG. 5 (where the number of output bits is 24 bits), or FIG. The illustrated color correction unit 3C (however, the number of output bits is 24 bits) may be used.

The data rearrangement unit 4 and the VT characteristic correction unit 7 are included in the output control unit 6.

The output control unit 6 can generally be called output control means or output correction control means.

The output control unit 6 includes correction signals (number of output bits: 8 bits) output from each of the R color correction LUT storage unit 3R1, the G color correction LUT storage unit 3G1, and the B color correction LUT storage unit 3B1 in the color correction unit 31. Is received, the correction signal is corrected in accordance with the relationship between the drive voltage of the liquid crystal display element 2 and the light transmittance (VT characteristic), and a characteristic correction signal is output.

The output control unit 6 outputs the characteristic correction signals to the liquid crystal display element 2 as drive signals one by one instead of the correction signal.

When the data rearrangement unit 4 receives each 8-bit correction signal (R color correction signal, G color correction signal, B color correction signal) output from the color correction unit 31, the data rearrangement unit 4 sequentially outputs the correction signals one by one. , Output to the VT characteristic correction unit 7.

Each time the 8-bit correction signal is received, the VT characteristic correction unit 7 corrects the correction signal in accordance with the relationship between the drive voltage of the liquid crystal display element 2 and the light transmittance (VT characteristic). The characteristic correction signal is output to the liquid crystal display element 2 as a drive signal.

In the liquid crystal display device 1 shown in FIG. 2, the color correction unit 3 has a role of improving color reproducibility and gradation reproducibility in the FSC method, that is, a role of performing correction for overdrive in the FSC method, It plays the role of correcting the applied voltage (drive voltage) based on the VT characteristic representing the relationship between the applied voltage (drive voltage) of the liquid crystal display element 2 and the light transmittance.

On the other hand, in the liquid crystal display device 1A shown in FIG. 7, the color correction unit 31 has a role of improving color reproducibility and gradation reproducibility in the FSC method, that is, a role of performing correction for overdrive in the FSC method. The VT characteristic correction unit 7 plays a role of correcting the applied voltage (drive voltage) based on the non-linear VT characteristic.

Therefore, the number of output bits of the color correction unit 31 can be reduced from 30 bits to 24 bits. In this case, the memory size of the LUT in the color correction unit 31 can be set to 8/10 that of the color correction unit 3, and the size of the frame memory 4a in the liquid crystal display device 1A can be set in the liquid crystal display device 1. 8/10 of the frame memory 4a.

On the other hand, in the liquid crystal display device 1A, the number of circuits increases due to the addition of the VT characteristic correction unit 7. When the VT characteristic correction unit 7 is realized using an LUT, the memory size is (2 ^ 8) × 10 bits = 2.5 kbit.

Here, a change in memory size by using both the color correction unit 31 and the VT characteristic correction unit 7 will be described.

When the color correction unit 3 shown in FIG. 3 (however, the number of output bits is 24 bits) is applied to the color correction unit 31, the total memory size of the color correction unit 31 and the VT characteristic correction unit 7 is 120 kbit. × 8/10 + 2.5 kbit = 98.5 kbit, which is smaller than the memory size 120 kbit of the color correction unit 3 (the number of output bits is 30 bits) shown in FIG.

When the color correction unit 3A shown in FIG. 4 (however, the number of output bits is 24 bits) is applied to the color correction unit 31, the total memory size of the color correction unit 31 and the VT characteristic correction unit 7 is 60 kbit. × 8/10 + 2.5 kbit = 50.5 kbit, which is smaller than the memory size of 60 kbit of the color correction unit 3A (where the number of output bits is 30 bits) shown in FIG.

When the color correction unit 3B shown in FIG. 5 (the number of output bits is 24 bits) is applied to the color correction unit 31, the total memory size of the color correction unit 31 and the VT characteristic correction unit 7 is 960 kbits. X8 / 10 + 2.5 kbit = 770.5 kbit, which is smaller than the memory size 960 kbit of the color correction unit 3B (however, the number of output bits is 30 bits) shown in FIG.

When the color correction unit 3C shown in FIG. 6 (however, the number of output bits is 24 bits) is applied to the color correction unit 31, the total memory size of the color correction unit 31 and the VT characteristic correction unit 7 is 380 kbit. X8 / 10 + 2.5 kbit = 306.5 kbit, which is smaller than the memory size 380 kbit of the color correction unit 3C (however, the number of output bits is 30 bits) shown in FIG.

It should be noted here that the VT characteristic correction unit 7 affects the liquid crystal display device using the juxtaposed (parallel) additive color mixture or the color display method using the simultaneous additive color mixture, and the FSC method. This is different from the case of the liquid crystal display device.

A liquid crystal display device of a color display system using juxtaposed (parallel) additive color mixture is a pixel that performs color display by arranging sub-pixels (sub-pixels) having R, G, and B color filters in close proximity. A liquid crystal display device having a plurality of liquid crystal displays.

In addition, a liquid crystal display device of a color display system using simultaneous additive color mixing has three liquid crystal display elements that separately modulate each of R, G, and B colors, and the modulated image light of each color is received. This is a liquid crystal display device that displays images in an overlapping manner. This type of projection type liquid crystal display device such as a projector is common and is called a so-called three-plate type.

Here, how the VT characteristic correction unit 7 affects will be described.

When paying attention to a certain pixel, in the former, specifically, a liquid crystal display device of a color display system using juxtaposed (parallel) additive color mixture or simultaneous additive color mixture, the pixel always displays the same color.

Therefore, when displaying a still image, the state of the liquid crystal director converges over time. Therefore, the characteristic correction signal possessed by the VT characteristic correction unit 7 can be uniquely created for each color.

On the other hand, in the latter case, specifically, in the FSC type liquid crystal display device, the color displayed by the pixel is not one, and the state of the liquid crystal director often does not converge even when displaying a still image. .

Therefore, the characteristic correction signal possessed by the VT characteristic correction unit 7 cannot be easily created uniquely using only the own color video signal. Therefore, it is proper to include a VT characteristic correction function in the color correction unit 31 that receives video signals of a plurality of colors.

In spite of this situation, the present embodiment provides a method for effectively operating the function of correcting the VT characteristic while the function of correcting the non-linear VT characteristic is separated from the color correction unit 31. To do.

In the case of the FSC system, in many display images, the state of the liquid crystal director does not converge, but there is also an image in which the state of the liquid crystal director converges. That is, when the gradation levels of the R, G, and B colors are equal to each other, that is, an achromatic image.

Therefore, by using a video signal having achromatic image data, the state of the liquid crystal director converges, so that the characteristic correction signal of the VT characteristic correction unit 7 can be uniquely created. When the characteristic correction signal of the VT characteristic correction unit 7 is created uniquely, the video signal having achromatic image data bypasses the color correction unit 31.

Further, when creating the characteristic correction signal used in the VT characteristic correction unit 7, it is avoided to use an image that is a driving condition unique to the FSC method, so that juxtaposed (parallel) additive color mixing or simultaneous additive color mixing is performed. A correction data creation method for VT characteristics in the used color display method can be used, and the adjustment process can be simplified.

As described above, a non-linear VT characteristic correction function representing the relationship between the applied voltage of the liquid crystal display element 2 and the light transmittance is assigned to the VT characteristic correction unit 7 separate from the color correction unit 31. By doing so, the characteristics of the color correction unit 31 can be made closer to linear. Therefore, the number of output bits of the color correction unit 31 can be reduced.

A plurality of VT characteristic correction units 7 may be provided for each color, and the VT characteristic correction unit 7 to be used may be switched depending on the color to be displayed.

The correction data in this case may be generated by using a video signal of an achromatic image, constantly illuminating the liquid crystal display element with monochromatic light, and measuring the VT characteristics. By doing so, the color dependence of the transmittance characteristic of the liquid crystal display element 2 can be corrected more accurately.

[Third Embodiment]
In the third embodiment of the present invention, for example, the color correction unit 32 shown in FIG. 8 is used as the color correction unit 3 of the liquid crystal display device 1 shown in FIG. The color conversion unit 8 is provided.

Note that, in the third embodiment of the present invention, for example, the color correction unit 32 shown in FIG. 8 is used as the color correction unit 31 of the liquid crystal display device 1A shown in FIG. A color conversion unit 8 may be provided in the preceding stage.

In FIG. 8, the color conversion unit 8 in the previous stage of the color correction unit 32 can be generally referred to as generation means.

The color conversion unit 8 extracts five images corresponding to M (magenta), R, G, B, and Y (yellow) from three image signals of R, G, and B, respectively. Signals, specifically, an M color video signal, an R color video signal, a G color video signal, a B color video signal, and a Y color video signal are generated.

In this embodiment, it is assumed that there are five color fields in the FSC method, and the order is M, R, G, B, Y.

When the color correction unit 32 receives a plurality of video signals, the color correction unit 32 outputs a plurality of correction signals corresponding to the plurality of colors on a one-to-one basis.

The color correction unit 32 receives an M color video signal, an R color video signal, a G color video signal, a B color video signal, and a Y color video signal as a plurality of video signals.

Each of the M color video signal, the R color video signal, the G color video signal, the B color video signal, and the Y color video signal is an 8-bit signal. Note that the number of bits of each of the R color video signal, the G color video signal, the B color video signal, and the Y color video signal is not limited to 8 bits and can be changed as appropriate.

In addition, the color correction unit 32 uses a plurality of correction signals as an M color correction signal corresponding to magenta, an R color correction signal, a G color correction signal, a B color correction signal, and a Y color correction corresponding to yellow. Signal.

The color correction unit 32 generates an M color correction signal based on the M color video signal, generates an R color correction signal based on the R color video signal, and generates a G color correction signal based on the G color video signal. And a B color correction signal is generated based on the B color video signal, and a Y color correction signal is generated based on the Y color video signal.

In this embodiment, the data rearrangement unit 4 converts the M color correction signal, the R color correction signal, the G color correction signal, the B color correction signal, and the Y color correction signal into an M color correction signal, an R color correction signal, and a G color correction signal. The color correction signal, the B color correction signal, and the Y color correction signal are output to the liquid crystal display element 2 as drive signals in the order. This order can be changed as appropriate.

In the present embodiment, the illumination unit 5a irradiates the liquid crystal display element 2 with light of each color of M color, R color, G color, B color, and Y color.

When using multiple LEDs that individually emit R, G, and B light as the light source that is an element of the illumination unit 5a, it is only necessary to light the R and B LEDs simultaneously for M light. For the Y-color light, the R-color and G-color LEDs may be turned on simultaneously.

If C (cyan) light is required, the G and B LEDs can be turned on simultaneously. If W (white) light is required, the R, G, and B colors can be used. Just turn on the colored LEDs at the same time.

The color correction unit 32 includes an M color correction LUT storage unit 3M4, an R color correction LUT storage unit 3R4, a G color correction LUT storage unit 3G4, a B color correction LUT storage unit 3B4, and a Y color correction LUT storage unit 3Y4. ,including.

Each of the M color correction LUT storage unit 3M4, the R color correction LUT storage unit 3R4, the G color correction LUT storage unit 3G4, the B color correction LUT storage unit 3B4, and the Y color correction LUT storage unit 3Y4 generally includes correction means or It can be called storage means. Therefore, the color correction unit 32 has a plurality of correction means (storage means).

The M color correction LUT storage unit 3M4 has a one-to-one correspondence with the M color video signal.

The M color correction LUT storage unit 3M4 is an M color video signal corresponding to itself, a part of the Y color video signal, a part of the B color video signal, and one of the R color video signals. The M color correction signal obtained by correcting the M color video signal based on a part of the Y color video signal, a part of the B color video signal, and a part of the R color video signal is output.

The Y color video signal is a video signal based on the Y color correction signal (other correction signal) output from the data rearrangement unit 4 immediately before the M color correction signal obtained by correcting the M color video signal.

The B color video signal is a video signal based on the B color correction signal (other correction signal) output from the data rearrangement unit 4 immediately before the Y color correction signal obtained by correcting the Y color video signal.

The R color video signal is a video signal that is the source of the R color correction signal (other correction signal) output from the data rearrangement unit 4 immediately after the M color correction signal obtained by correcting the M color video signal.

In this embodiment, the M color correction LUT storage unit 3M4 includes the upper 2 bits of the B color video signal, the upper 4 bits of the Y color video signal, all 8 bits of the M color video signal, and the upper 3 bits of the R color video signal. To output the M color correction signal.

For example, the M color correction LUT storage unit 3M4 includes the upper 2 bits of the B color video signal, the upper 4 bits of the Y color video signal, all 8 bits of the M color video signal, the upper 3 bits of the R color video signal, and all of the M color video signal. An LUT that stores 8 bits of the M color corrected video signal corrected based on the upper 2 bits of the B color video signal, the upper 4 bits of the Y color video signal, and the upper 3 bits of the R color video signal in association with each other is stored.

When the M color correction LUT storage unit 3M4 receives the upper 2 bits of the B color video signal, the upper 4 bits of the Y color video signal, all 8 bits of the M color video signal, and the upper 3 bits of the R color video signal, The M color correction video signal associated with the upper 2 bits, the upper 4 bits of the Y color video signal, all 8 bits of the M color video signal, and the upper 3 bits of the R color video signal is output as an M color correction signal.

The M color correction LUT storage unit 3M4 corrects the M color video signal by referring to the B color video signal of the previous field, the Y color video signal of the previous field, and the R color video signal of the next field.

The R color correction LUT storage unit 3R4 corresponds to the R color video signal on a one-to-one basis.

For the detailed description of the R color correction LUT storage unit 3R4, “M color correction LUT storage unit 3M4” in the description of the M color correction LUT storage unit 3M4 described above is replaced with “R color correction LUT storage unit 3R4”. , Read the corresponding video signal from "M color video signal" to "R color video signal", and other video signals from "Y color video signal" and "R color video signal" to "M color video signal" and "G color" "Video signal" is read, "B color video signal" is read as "Y color video signal", "M color correction signal" is read as "R color correction signal", and "M color correction video signal" is read as "R color correction" This can be done by replacing it with “video signal”.

The G color correction LUT storage unit 3G4 has a one-to-one correspondence with the G color video signal.

For the detailed description of the G color correction LUT storage unit 3G4, “M color correction LUT storage unit 3M4” in the description of the M color correction LUT storage unit 3M4 described above is replaced with “G color correction LUT storage unit 3G4”. The corresponding video signal is read from “M color video signal” to “G color video signal”, and other video signals are read from “Y color video signal” and “R color video signal” to “R color video signal” and “B color”. "Video signal", "B color video signal" read "M color video signal", "M color correction signal" read "G color correction signal", "M color correction video signal" "G color correction" This can be done by replacing it with “video signal”.

The B color correction LUT storage unit 3B4 has a one-to-one correspondence with the B color video signal.

For the detailed description of the B color correction LUT storage unit 3B4, “M color correction LUT storage unit 3M4” in the description of the M color correction LUT storage unit 3M4 described above is replaced with “B color correction LUT storage unit 3M4”. , Read the corresponding video signal from “M color video signal” to “B color video signal”, and other video signals from “Y color video signal” and “R color video signal” to “G color video signal” and “Y color” "Video signal" is read, "B color video signal" is read as "R color video signal", "M color correction signal" is read as "B color correction signal", and "M color correction video signal" is read as "B color correction" This can be done by replacing it with “video signal”.

The Y color correction LUT storage unit 3Y4 has a one-to-one correspondence with the Y color video signal.

For the detailed description of the Y color correction LUT storage unit 3Y4, “M color correction LUT storage unit 3M4” in the description of the M color correction LUT storage unit 3M4 described above is replaced with “Y color correction LUT storage unit 3Y4”. The corresponding video signal is read from “M color video signal” to “Y color video signal”, and the other video signals are changed from “Y color video signal” and “R color video signal” to “B color video signal” and “M color”. "Video signal", "B color video signal" read "G color video signal", "M color correction signal" read "Y color correction signal", "M color correction video signal" "Y color correction" This can be done by replacing it with “video signal”.

According to this embodiment, the color conversion unit 8 generates five video signals from the three video signals, and the color correction unit 32 corrects each of the five video signals.

For this reason, overdrive can be applied even in the case of the FSC system having multicolor fields of three or more colors.

[Fourth Embodiment]
In the fourth embodiment of the present invention, for example, the color correction unit 33 shown in FIG. 9 is used as the color correction unit 3 of the liquid crystal display device 1 shown in FIG.

In the fourth embodiment of the present invention, for example, the color correction unit 33 shown in FIG. 9 may be used as the color correction unit 31 of the liquid crystal display device 1A shown in FIG.

In this embodiment, it is assumed that the order of the color fields in the FSC system is B, G, R.

Therefore, the data rearrangement unit 4 displays the B color correction signal, the G color correction signal, and the R color correction signal as a drive signal in the order of the B color correction signal, the G color correction signal, and the R color correction signal. Output to element 2. This order can be changed as appropriate.

The feature of the present embodiment is that the correction signal is used for correcting the color of the next field, and that the reference of the correction signal used for the correction does not become an infinite loop, and also extends across frames. That is, the color video signal is not referred to.

The color correction unit 33 includes a B color correction LUT storage unit 3B5, a G color correction LUT storage unit 3G5, and an R color correction LUT storage unit 3R5.

The B color correction LUT storage unit 3B5 can generally be referred to as correction means or storage means.

The B color correction LUT storage unit 3B5 has a one-to-one correspondence with the B color video signal.

The B color correction LUT storage unit 3B5 corrects the B color video signal so that the G color reproducibility of the next field is improved.

The B color correction LUT storage unit 3B5 inputs all 8 bits of the B color video signal and the upper 3 bits of the G color video signal, and outputs a B color correction signal.

For example, the B color correction LUT storage unit 3B5 corrects all 8 bits of the B color video signal, the upper 3 bits of the G color video signal, and all 8 bits of the B color video signal based on the upper 3 bits of the G color video signal. The LUT that stores the corrected video signal in association with each other is stored.

When the B color correction LUT storage unit 3B5 receives all 8 bits of the B color video signal and the upper 3 bits of the G color video signal, the B color correction associated with all 8 bits of the B color video signal and the upper 3 bits of the G color video signal. The video signal is output as a B color correction signal.

The G color correction LUT storage unit 3G5 can generally be referred to as correction means, storage means, or video signal correction means.

The G color correction LUT storage unit 3G5 has a one-to-one correspondence with the G color video signal.

The G color correction LUT storage unit 3G5 refers to the B color correction signal of the previous field to improve the G color reproducibility, and refers to the R color video signal of the next field to improve the R color reproducibility. The G color video signal is corrected so as to improve.

The G color correction LUT storage unit 3G5 inputs the upper 4 bits of the B color correction signal, all 8 bits of the G color video signal, and the upper 3 bits of the R color video signal, and outputs the G color correction signal.

For example, the G color correction LUT storage unit 3G5 includes the upper 4 bits of the B color correction signal, all 8 bits of the G color video signal, the upper 3 bits of the R color video signal, and all 8 bits of the G color video signal. A LUT that stores 4 bits and the G color corrected video signal corrected based on the upper 3 bits of the R color video signal in association with each other is stored.

Upon receiving the upper 4 bits of the B color correction signal, all 8 bits of the G color video signal, and the upper 3 bits of the R color video signal, the G color correction LUT storage unit 3G5 receives the upper 4 bits of the B color correction signal and all of the G color video signal. A G color correction video signal associated with 8 bits and the upper 3 bits of the R color video signal is output as a G color correction signal.

The R color correction LUT storage unit 3R5 can generally be referred to as correction means, storage means, or video signal correction means.

The R color correction LUT storage unit 3R5 has a one-to-one correspondence with the R color video signal.

The R color correction LUT storage unit 3R5 corrects the R color video signal so that the reproducibility of the R color is improved with reference to the G color correction signal of the previous field.

The R color correction LUT storage unit 3R5 inputs the upper 4 bits of the G color correction signal and all 8 bits of the R color video signal, and outputs an R color correction signal.

For example, the R color correction LUT storage unit 3R5 corrects the upper 4 bits of the G color correction signal, all 8 bits of the R color video signal, and all 8 bits of the R color video signal based on the upper 4 bits of the G color correction signal. The LUT that stores the corrected video signal in association with each other is stored.

When the R color correction LUT storage unit 3R5 receives the upper 4 bits of the G color correction signal and all 8 bits of the R color video signal, the R color correction associated with the upper 4 bits of the G color correction signal and all 8 bits of the R color video signal. The video signal is output as an R color correction signal.

According to the present embodiment, each of the G color correction LUT storage unit 3G5 and the R color correction LUT storage unit 3R5 uses the correction signal for correcting the color of the next field. Can improve sex.

In addition, since the reference of the correction signal used for correction is made not to be an infinite loop, it can be avoided that the output from each correction LUT storage unit does not converge.

When the order of the color field in the FSC system is B, G, and R, if the B color correction LUT storage unit 3B5 refers to the R color video signal of the previous field, it refers to the video signal of the previous frame. become.

When displaying a still image, there is no problem because the video signal of the previous frame is the same as the video signal of the own frame, but when displaying a moving image, the video signal is often different, so correct correction is necessary. Become.

In this embodiment, each of the B color correction LUT storage unit 3B5, the G color correction LUT storage unit 3G5, and the R color correction LUT storage unit 3R5 does not refer to a video signal of a color across frames. For this reason, the color reproducibility and gradation reproducibility when displaying a moving image can be improved.

In this embodiment, the color fields in the FSC system are B, G, and R colors, but the color fields in the FSC system are Y, B, G, R, and M colors. The color conversion unit 8 shown in FIG. 8 is provided in front of the color correction unit 33, and the color correction unit 33 may further include an M color correction LUT storage unit 3M4 and a Y color correction LUT storage unit 3Y4.

[Fifth Embodiment]
In the fifth embodiment of the present invention, for example, the color correction unit 34 shown in FIG. 10 is used as the color correction unit 3 of the liquid crystal display device 1 shown in FIG.

Note that, in the fifth embodiment of the present invention, for example, the color correction unit 34 shown in FIG. 10 may be used as the color correction unit 31 of the liquid crystal display device 1A shown in FIG.

The feature of this embodiment is that the correction signal is used for the correction of the color of the next field, the reference of the correction signal used for the correction does not become an infinite loop, and When referring to the data, it means that the frame buffer is used, and the data of the next frame is not referred to.

The color correction unit 34 includes a frame buffer 34a, a B color correction LUT storage unit 3B6, a G color correction LUT storage unit 3G6, and an R color correction LUT storage unit 3R6.

The frame buffer 34a can be generally referred to as storage means.

When one frame is updated, the frame buffer 34a is a video signal that is the source of the correction signal that is finally output from the data rearrangement unit 4 among a plurality of video signals that constitute one frame before the update. In the case of the embodiment, the R color video signal) is stored.

The frame buffer 34a stores a correction signal (R color correction signal in this embodiment) output last from the data rearrangement unit 4 among a plurality of video signals constituting one frame before update. Also good.

The B color correction LUT storage unit 3B6 can be generally referred to as correction means, storage means, or color video signal correction means.

The B color correction LUT storage unit 3B6 has a one-to-one correspondence with the B color video signal.

The B color correction LUT storage unit 3B6 refers to the R color video signal of the previous field (previous frame) or the R color correction signal of the same frame to improve the reproducibility of the B color, and the G color of the next field The B color video signal is corrected so that the G color reproducibility is improved by referring to the video signal.

The B color correction LUT storage unit 3B6 inputs the upper 4 bits of the R color video signal one frame before in the frame buffer 34a, all 8 bits of the B color video signal, and the upper 3 bits of the G color video signal. Outputs a B color correction signal.

For example, the B color correction LUT storage unit 3B6 includes the upper 4 bits of the R color video signal one frame before, all 8 bits of the B color video signal, the upper 3 bits of the G color video signal, and all 8 bits of the B color video signal in one frame. An LUT for storing the B color corrected video signal corrected based on the upper 4 bits of the previous R color video signal and the upper 3 bits of the G color video signal in association with each other is stored.

When the B color correction LUT storage unit 3B6 receives the upper 4 bits of the R color video signal of the previous frame, all 8 bits of the B color video signal, and the upper 3 bits of the G color video signal, the higher level of the R color video signal of the previous frame The B color correction video signal associated with 4 bits and all 8 bits of the B color video signal and the upper 3 bits of the G color video signal is output as a B color correction signal.

The G color correction LUT storage unit 3G6 has the same configuration as the G color correction LUT storage unit 3G5 shown in FIG.

The R color correction LUT storage unit 3R6 can generally be referred to as correction means, storage means, or video signal correction means.

The R color correction LUT storage unit 3R6 has a one-to-one correspondence with the R color video signal.

The R color correction LUT storage unit 3R6 corrects the R color correction signal so that the reproducibility of the R color is improved with reference to the B color correction signal of the previous field and the G color correction signal of the previous field.

The R color correction LUT storage unit 3R6 inputs the upper 3 bits of the B color correction signal, the upper 4 bits of the G color correction signal, and all 8 bits of the R color video signal, and outputs an R color correction signal.

For example, the R color correction LUT storage unit 3R6 includes the upper 3 bits of the B color correction signal, the upper 4 bits of the G color correction signal, all 8 bits of the R color video signal, and all 8 bits of the R color video signal. An LUT that stores 3 bits and the R color corrected video signal corrected based on the upper 4 bits of the G color correction signal in association with each other is stored.

When receiving the upper 3 bits of the B color correction signal, the upper 4 bits of the G color correction signal, and all 8 bits of the R color video signal, the R color correction LUT storage unit 3R5 receives the upper 3 bits of the B color correction signal and the higher order of the G color correction signal. An R color correction video signal associated with 4 bits and all 8 bits of the R color video signal is output as an R color correction signal.

In the present embodiment, the corrected color video signal, that is, the correction signal is used for correcting the color of the next field, so that color reproducibility or gradation reproducibility can be improved.

Also, since the reference is not infinite loop, it is possible to avoid the output from each correction LUT storage unit from converging.

In the present embodiment, when referring to the previous field data in the previous frame, the B color correction LUT storage unit 3B6 refers to the video signal or the correction signal in the frame buffer 34a, and the previous field color data in the current frame. Since it is not referred to (actually, the color data of the field one after another), it is possible to improve color reproducibility and gradation reproducibility when the image of the previous frame and the image of the current frame are greatly different.

In this embodiment, data for one field in the previous frame is buffered and referenced. However, more fields of data may be buffered and referenced. By doing so, color reproducibility and gradation reproducibility can be improved more accurately.

In this embodiment, the color fields in the FSC system are B, G, and R colors, but the color fields in the FSC system are Y, B, G, R, and M colors. The color conversion unit 8 shown in FIG. 8 is provided in front of the color correction unit 34, and the color correction unit 34 may further include an M color correction LUT storage unit 3M4 and a Y color correction LUT storage unit 3Y4.

[Other embodiments]
In each of the above embodiments, the specific number of bits has been described. However, the number of bits to be reduced in each correction LUT storage unit can be changed independently based on the trade-off relationship between the accuracy of correction and the memory size (0 bits). Or more than 1 bit).

Further, based on the trade-off relationship between the accuracy of correction and the memory size, for example, at least one of a plurality of correction LUT storage units (for example, the correction LUT storage unit corresponding to the slowest red color) is exceeded. A correction signal for driving is output, and another correction LUT storage unit does not output a correction signal for overdrive (for example, a correction LUT that outputs a correction signal corrected based on the VT characteristic) Storage unit).

In each of the embodiments described above, each color correction LUT storage unit is provided separately, but one color correction LUT storage unit may be shared in time division for several colors. Also in this case, a plurality of color correction LUT storage units are provided. In this case, the memory size can be reduced.

In each of the above embodiments, each correction LUT storage unit has been described so as to realize color correction only by the LUT. However, each correction LUT storage unit may perform color correction by combining the LUT and the calculation. For example, each correction LUT storage unit may correct the upper bits of the video signal using an LUT and correct the lower bits of the video signal using interpolation.

Further, instead of the correction LUT storage unit, a color correction calculation unit that generates a correction signal by calculation may be used. In this case, each color correction calculation unit functions as a correction unit and corresponds to each video signal one to one.

Each of the above embodiments can be applied to the liquid crystal display element 2 having a normally white configuration or a normally black configuration.

In addition, a person skilled in the art can easily conceive a method of reversing the polarity of the electric field applied to the liquid crystal for preventing image sticking by combining a well-known technique and the inventions of the present application.

As mentioned above, although this invention was demonstrated with reference to each embodiment, this invention is not limited to the said embodiment. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

Claims

When a plurality of video signals corresponding to a plurality of colors correspond one-to-one, and when a corresponding video signal corresponding to one of the plurality of video signals is received, a correction signal obtained by correcting the corresponding video signal is output. A plurality of correction means;
Output control means for sequentially outputting the correction signals output from each of the plurality of correction means, one by one;
Each time the correction signal is output from the output control means, an irradiation means for emitting light of a color corresponding to the video signal that is the source of the correction signal;
A liquid crystal display element that modulates and outputs the light emitted from the irradiation unit according to the correction signal each time the correction signal is output from the output control unit;
At least one of the plurality of correction means may be a source of the corresponding video signal and another correction signal output from the output control means immediately before or immediately after the correction signal obtained by correcting the corresponding video signal. When receiving a part of the video signal, the liquid crystal display device outputs a corrected video signal obtained by correcting the corresponding video signal based on a part of the other video signal as the correction signal.
At least one of the plurality of correction means stores the corresponding video signal and a part of the other video signal and the corrected video signal in association with each other, and stores the corresponding video signal and the other video. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is storage means for outputting the corrected video signal as the correction signal when a part of the signal is received.
The at least one of the plurality of correction means is configured such that a part of the other video signal is set based on a difference in response characteristics for each color in the liquid crystal display element. Item 2. A liquid crystal display device according to item 2.
At least one of the plurality of correction means accepts a part of the correction signal obtained by correcting the other video signal by the other correction means instead of the part of the other video signal, and the correspondence 4. The video signal correcting means according to claim 1, wherein when the video signal is received, the video signal correcting means outputs a correction signal obtained by correcting the corresponding video signal based on a part of the correction signal. 5. The liquid crystal display device described.
The plurality of video signals constitute one frame,
When the one frame is updated, it becomes the source of the correction signal that is finally output from the output control unit among the plurality of correction signals corresponding to each of the plurality of video signals constituting one frame before the update. Storage means for storing the received video signal,
Of the plurality of correction means, a video signal that is a source of a correction signal that is first output from the output control means among a plurality of correction signals corresponding to each of the plurality of video signals constituting the one frame. The one-to-one correction unit accepts a part of the video signal in the storage unit as a part of the other video signal, and receives the corresponding video signal and stores the corresponding video signal. 5. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is a color video signal correction unit that outputs a correction signal corrected based on a part of the video signal in the unit.
When the output control means receives the correction signal output from each of the plurality of correction means, the correction signal is corrected according to the relationship between the applied voltage and the light transmittance of the liquid crystal display element, The output correction control means for outputting a characteristic correction signal and outputting the characteristic correction signal one by one in place of the correction signal, according to any one of claims 1 to 5. The liquid crystal display device described.
The liquid crystal display device according to claim 6, wherein the characteristic correction signal is created using a video signal for forming an achromatic image.
The liquid crystal display device according to any one of claims 1 to 7, further comprising generating means for generating the plurality of video signals from a number of video signals different from the plurality of video signals.
A drive circuit for a liquid crystal display element that, upon receiving a drive signal, modulates and outputs light of a color corresponding to the drive signal according to the drive signal;
When a plurality of video signals corresponding to a plurality of colors correspond one-to-one, and when a corresponding video signal corresponding to one of the plurality of video signals is received, a correction signal obtained by correcting the corresponding video signal is output. A plurality of correction means;
Output control means for outputting correction signals output from each of the plurality of correction means to the liquid crystal display element as the drive signals one by one in order,
At least one of the plurality of correction means may be a source of the corresponding video signal and another correction signal output from the output control means immediately before or immediately after the correction signal obtained by correcting the corresponding video signal. When a part of the video signal is received, a drive circuit for a liquid crystal display element that outputs a corrected video signal obtained by correcting the corresponding video signal based on a part of the other video signal as the correction signal.
At least one of the plurality of correction means stores the corresponding video signal and a part of the other video signal and the corrected video signal in association with each other, and stores the corresponding video signal and the other video. 10. The driving circuit for a liquid crystal display element according to claim 9, which is storage means for outputting the corrected video signal as the correction signal when a part of the signal is received.
A color image generation method performed by an FSC liquid crystal display device that displays a color image by sequentially displaying a plurality of color images corresponding to a plurality of video signals,
When each of the plurality of correction units corresponding to the plurality of video signals on a one-to-one basis receives a corresponding video signal corresponding to itself among the plurality of video signals, a correction signal obtained by correcting the corresponding video signal is output. And
The correction signals are output one by one in order,
Each time the correction signals are output one by one, light of a color corresponding to the video signal that is the source of the correction signal is emitted,
Each time the correction signals are sequentially output one by one, the light is modulated and output according to the correction signal,
At least one of the plurality of correction means includes the corresponding video signal and a part of another video signal that is a source of another correction signal output immediately before or immediately after the correction signal obtained by correcting the corresponding video signal. , A color image generation method of outputting a corrected video signal obtained by correcting the corresponding video signal based on a part of the other video signal as the correction signal.
At least one of the plurality of correction means stores the corresponding video signal and a part of the other video signal and the corrected video signal in association with each other, and stores the corresponding video signal and the other video. 12. The color image generation method according to claim 11, wherein when a part of the signal is received, the corrected video signal is output as the correction signal.
A method of driving a liquid crystal display element that, when receiving a drive signal, modulates and outputs light of a color corresponding to the drive signal according to the drive signal,
When each of a plurality of correction means corresponding to a plurality of video signals corresponding to a plurality of colors receives a corresponding video signal corresponding to itself among the plurality of video signals, the corresponding video signal is corrected. Output the corrected signal,
The correction signals are output one by one in order,
At least one of the plurality of correction means includes the corresponding video signal and a part of another video signal that is a source of another correction signal output immediately before or immediately after the correction signal obtained by correcting the corresponding video signal. , A liquid crystal display element driving method of outputting a corrected video signal obtained by correcting the corresponding video signal based on a part of the other video signal as the correction signal.
At least one of the plurality of correction means stores the corresponding video signal and a part of the other video signal and the corrected video signal in association with each other, and stores the corresponding video signal and the other video. 14. The method of driving a liquid crystal display element according to claim 13, wherein when a part of the signal is received, the corrected video signal is output as the correction signal.