JP2003241714A - Method for driving display device, and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a color breakup and a color rainbow are generated and the picture quality is lowered in the liquid crystal display device of a color sequential display system. <P>SOLUTION: In the liquid crystal display device of the color sequential display system, a sub-field for displaying a video having a neutral tint and sub-fields for displaying videos having primary colors which are not included in the neutral tint are made to be adjacent. Moreover, a sub-field for displaying a video having the neutral tint or an achromatic color is provided at the first portion or the last portion of one frame period. Furthermore, a ratio for distributing luminance to respective sub-fields is optimized. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display control technique in a color sequential display type display device, and is suitable for reducing color breakup that occurs when displaying a moving image and color rainbow that occurs when the line of sight is greatly diverted. Related technology.

[0002]

2. Description of the Related Art A color-sequential display system (field-sequential display) in which red, green, or blue images are displayed, and in conjunction with that, illumination according to the respective colors is radiated in any order from the entire surface or the back surface to perform color display. In a liquid crystal display device of (color type), S
As in ID2001 L-4 (pages 400 to 403), the moving direction and the moving amount of an image are detected, and 2 is set in one frame period based on the detected moving direction and moving amount.
The second and third images to be displayed are corrected in the display position in the moving direction and displayed. In addition, JP-A-8
In -101672, RGB signals (hereinafter R is red, G
Represents green and B represents blue), and an achromatic color signal is generated, and four video signals of red, green, blue, and white (achromatic color) are displayed.

[0003]

In a color display of a color sequential display system, an image in which any two or more of R, G and B are mixed is represented by a combination of R, G and B primary color subfields. Therefore, there is a problem in that when the image moves and the eyes of the observer follow it, the temporal deviation of the light emission timings of R, G, and B is perceived as a spatial deviation. On the other hand, if R only, G only, B only, etc.
Color cracking does not occur if the image is a single color.

In FIG. 18, when displaying by the conventional method,
The principle of color breakup that occurs when a certain white pattern moves is shown schematically. Since the white pattern is obtained by combining the images displayed in the RGB subfields,
When a white object is displayed on the screen, R, G, and B colors are sequentially displayed at the same position in one frame. Here, one frame period is composed of a plurality of subfields including at least three primary colors of R, G, and B, and is a minimum unit required to display one image.

When the white pattern moves from left to right on the screen, it shifts to the right for each frame as shown in FIG. 18 (a). In this case,
The video displayed in each subfield has a time lag. Also, as the line of sight of the observer moves smoothly as indicated by arrow T, the position to be observed is Δx.
It will be slightly behind the object as shown by. In other words, these are the causes, for example, FIG.
As shown in FIG. 5, colors such as B and C (cyan) are on the left side of the W (achromatic) object P, and R and M are on the right side.
Colors such as (magenta) appeared. This is a potential problem specific to field sequential displays.

Further, in the method proposed in SID2001 L-4, when the detection of the moving direction and the moving amount fails, or when the observer pays attention to which object in a pattern in which a plurality of objects are moving. However, there is a problem in that if the detection or correction fails, the color breakup may become severe.

Further, in the method of Japanese Patent Laid-Open No. 8-101672, in which an achromatic color signal is generated and used, an effect is recognized for a completely achromatic color portion, but even for a slightly colored portion. Is not so effective, and there is a problem in that the generated white image and the image of other colors may cause new color breakage, which may rather deteriorate the image display quality.

Alternatively, regardless of whether it is a still image or a moving image, when the line of sight is diverted from the screen, a so-called color rainbow phenomenon occurs in which the colors are perceived as being divided over the entire screen, which gives viewers an unpleasant feeling.

[0009]

In order to solve this problem, in the first invention of the present application, one frame period is divided into a plurality of subfields, and an image of any color is displayed in each of the subfields. In a method of displaying and obtaining a color image, an intermediate color image in which any two colors of red, green or blue are mixed is displayed in an arbitrary subfield,
Further, in at least one subfield adjacent to the subfield for displaying the intermediate color image, an image of a color not included in the intermediate color is displayed.

Further, in the second invention of the present application, one frame period is divided into a plurality of subfields, and in the method for displaying a color image by displaying an image of an arbitrary color in each of the subfields, an arbitrary color image is obtained. An image of an intermediate color in which any two colors of red, green, and blue are mixed is displayed in the subfield, and the intermediate color is included in at least one subfield adjacent to the subfield displaying the intermediate color. A non-colored image is displayed, and an achromatic image is displayed in at least one remaining subfield.

In the third invention of the present application, one frame period is divided into a plurality of subfields, and red, green, and
A subfield for displaying the three primary colors of blue,
In a field-sequential liquid crystal display device having at least one sub-field for displaying an image of an intermediate color, priority is given to luminance distribution when generating image signals of other colors from image signals corresponding to red, green and blue. The ranking is 1. A subfield that displays an image of neutral colors,
2. Subfields for displaying images of three primary colors of red, green, or blue are arranged in this order.

In the fourth invention of the present application, one frame period is divided into a plurality of subfields, and red, green,
In a field sequential liquid crystal display device having at least one subfield for displaying an image of three primary colors of blue, a subfield for displaying an intermediate color image, and a subfield for displaying an achromatic image, red, green,
When the video signals of other colors are generated from the video signal corresponding to blue, the priority order of the luminance distribution is 1. 1. A subfield that displays an achromatic image, 2. A subfield for displaying a video of a neutral color, Subfields for displaying images of three primary colors of red, green, or blue are arranged in this order.

Further, in the fifth invention of the present application, one frame period is divided into a plurality of subfields, and at least a subfield for displaying an achromatic image and a subfield for displaying an image of other colors are respectively provided. In one field sequential liquid crystal display device, an achromatic image is displayed in both a subfield displaying an achromatic image and a subfield displaying an image of other colors.

In the sixth invention of the present application, one frame period is divided into a plurality of subfields, and red, green,
In a field sequential liquid crystal display device having at least one subfield for displaying images of three primary colors of blue and at least one subfield for displaying images of intermediate colors or one for displaying achromatic images, the peak luminance of the image in each subfield The brightness of the backlight is adjusted according to the above.

Further, in the seventh invention of the present application, an upper limit is set to the backlight luminance in the subfield for displaying an image of an intermediate color or W (achromatic color), and this upper limit is further applied to the backlight in the subfield for displaying an image of the primary color. It is set to be lower than the brightness.

Further, in the eighth to fourteenth inventions of the present application, a display device of a color sequential display system is realized by the first to seventh inventions of the present application.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. 1 to 20. Further, although a normal video signal has been subjected to gamma correction processing, the processing described below is the video signal in which the inverse gamma correction processing is further applied to the signal subjected to the gamma correction processing, that is, the floor signal. It shall be performed for a signal in which the gradation and the luminance have a linear relationship. It is well known that when the display device has a non-linear characteristic, the gamma correction process needs to be performed again accordingly. Further, in the following description, the case where the video signal has a maximum of 255 gradations is taken as an example, but it should be added that the present invention is not limited to this.

(Embodiment of the First Invention) As described above with reference to FIG. 18 (b), although the observer's eyes follow the moving pattern of the color splitting, the color splitting occurs within one frame period. Since the display position of the image displayed in each subfield is the same, it is as if the display position of the image displayed in each subfield is slightly shifted in the moving direction of the pattern. It occurs when the observer recognizes it.

Further, as can be understood from FIG. 18 (b), a part of the image displayed in the first or last subfield within one frame period does not mix with other subfields, resulting in color breakup. The most prominent color among them.

If there is a white pattern and a pattern of another color adjacent to the white pattern, the color of the pattern adjacent to the white pattern is Y rather than the primary colors of R, G, and B.
Attention should be paid to the fact that the boundary between the two patterns is less noticeable in intermediate colors such as (yellow), C (cyan), and M (magenta).

That is, when the color of the pattern adjacent to the white pattern is closer to white, the boundary between the two is less noticeable. This state is schematically shown in FIGS. 19 (a) and 19 (b). In FIG. 19A, the square on the left side is the intermediate color,
The square on the right represents the white pattern. On the other hand, in FIG. 19B, the left square represents the primary color, and the right square represents the white pattern. Thus, FIG. 19 (a)
Makes the boundary between the two patterns less noticeable.

In view of these facts, in the first invention of the present application, the subfield for displaying the image of the intermediate color and the subfield for displaying the image of the primary color not included in the intermediate color are arranged adjacent to each other. As a result, even if the pattern moves, the arbitrary intermediate color and the primary color not included in the intermediate color are mixed to approach an achromatic color, and it is possible to reduce color breakup.

Further, the order of each subfield in one frame period was also devised. The color of the video displayed in the first or last subfield in one frame period, which is most noticeable when color breakup occurs,
Instead of the conventional three primary colors of R, G, and B, intermediate colors such as Y (yellow), C (cyan), and M (magenta) are used. Further, in at least one subfield adjacent to the subfield displaying the intermediate color, an image of a primary color not included in the intermediate color is displayed. As a result, when color breakup occurs, the image of the intermediate color and the image of the primary color displayed at a timing adjacent thereto are mixed to approach an achromatic color, and the color breakup can be reduced.

Further, by providing the sub-field for displaying the image of the intermediate color, each color component is dispersed in each sub-field, and thereby the brightness of each image in each sub-field becomes lower than in the conventional case, so that the color rainbow Is also effective in reducing

(Embodiment of the Second Invention) In the second invention of the present application, in addition to the first invention of the present application, a subfield for displaying an intermediate color image and a subfield for displaying a W (achromatic) image are provided. Further, subfields for displaying images of primary colors not included in the intermediate colors are arranged adjacent to each other.
As a result, even when the pattern moves, the intermediate color and the primary colors not included in the intermediate color are mixed to approach an achromatic color, and it is possible to reduce color breakup.

Regarding the order of the sub-fields in one frame period, the color of the image displayed in the first or last sub-field in one frame period is the most conspicuous when color breakup occurs, as in the first invention of the present application. Instead of the conventional three primary colors of R, G, and B
An intermediate color such as (yellow), C (cyan), and M (magenta) or W (achromatic color) was used. Further, an image of a primary color not included in the intermediate color is displayed in at least one subfield adjacent to the subfield displaying the intermediate color or W (achromatic color). As a result, when color breakup occurs, the image of the intermediate color and the image of the primary color displayed at a timing adjacent thereto are mixed to approach an achromatic color, and the color breakup can be reduced.

Further, by providing a subfield for displaying an image of an intermediate color or W (achromatic color), each color component is dispersed in each subfield, whereby the luminance of each image in each subfield is higher than in the conventional case. Since it decreases, it is also effective in reducing color rainbow.

Next, the first or second invention of the present application will be specifically described with reference to FIGS. 1 to 5. 1 to 5, "SF" represents a subfield.

In FIG. 1, one frame is divided into four subfields. Here, a Y (yellow) image is displayed in the first subfield SF1, and an image of the color component B not included in Y (yellow) is displayed in the adjacent subfield SF2. ing. As a result, color breakup of the pattern containing the Y (yellow) component can be reduced. When displaying W (achromatic color), the Y (yellow) subfield and the B subfield may be combined. By doing this, even if the pattern moves and color breakup occurs,
Y (yellow) and B are mixed in the edge portion, and color breakup is reduced.

FIG. 2 shows one frame divided into five subfields. A Y (yellow) image is displayed in SF1, and a B image is displayed in SF2 adjacent to SF1. In addition, a C (cyan) image is displayed in SF5, which is the last subfield of one frame period, and SF
The image of R is displayed on SF4 adjacent to 5. As a result, in addition to the case of FIG. 1, it is possible to reduce the color breakup of the pattern including the C (cyan) component.

FIG. 3 also shows that one frame is divided into five subfields. The difference from Fig. 2 is that it is W in SF5.
This is the point where the (achromatic) image is displayed. By providing the subfield of W (achromatic color), color breakup of the pattern including the (achromatic color) component can be reduced in addition to the case of FIG.

FIG. 4 shows one frame divided into six subfields. This is provided with an M (magenta) subfield in addition to FIG. As a result, it is possible to reduce color breakup of a pattern including a Y (yellow) component, a C (cyan) component, and an M (magenta) component.

FIG. 5 also shows that one frame is divided into six subfields. The difference from FIG. 4 is that the M (magenta) subfield is replaced with W (achromatic color). As a result, it is possible to reduce color breakup of a pattern including a Y (yellow) component, a C (cyan) component, and a W (achromatic color) component.

As described above, in the first or second invention of the present application, an image of an intermediate color or W (achromatic color) is displayed in the first or last subfield of one frame,
Further, in at least one subfield adjacent to this, by displaying an image of a color that is not included in the color of the image displayed in the first or last subfield, color breakup and color rainbow can be achieved according to the above-described principle. Can be reduced.

Of course, the first or second invention of the present application is not limited to the examples shown in FIGS. 1 to 5, and the number of subfields within one frame period and the colors emitted in each subfield. Other combinations may be used.

(Embodiment of the Third Invention) Next, the third embodiment of the present invention
A method of allocating luminance to each sub-field, which is the invention of the above, will be described. First, as an example, consider a case where Y (yellow) is displayed in a certain pixel in the subfield structure shown in FIG. Since the subfield structure shown in FIG. 1 has four subfields R, G, B, and Y (yellow) within one frame period, the R component included in Y (yellow) is the same as the R subfield and Y. It is possible to allocate to the (yellow) subfield. As a result of the study conducted by the inventor, it has been found that the effect of reducing color breakup is greater when the intermediate color Y (yellow) subfield is preferentially distributed than the primary color R subfield.

Alternatively, instead of allocating only to one of the Y (yellow) subfield and the R subfield, some allocation to both subfields is perceived when the line of sight is greatly missed. It has been found that the effect of reducing the color rainbow is great. Therefore, the primary color component (R in this example) in the color (Y (yellow) in this example) included in the intermediate color is distributed to each subfield depending on which one of the color breakup and the color rainbow is desired to be further reduced. Just determine the proportion. The distribution ratio may be changed arbitrarily.

As a concrete example, as shown in FIG. 6A, it is assumed that the RGB components of a pixel are {R, G, B} = {100, 160, 60}, respectively. A subfield structure like 2,
That is, consider a case of displaying with a subfield structure having Y (yellow) and C (cyan) subfields in addition to the RGB primary color subfields.

Before allocating color components to each subfield, it is necessary to prioritize each subfield first. For example, if you want to reduce color breakage more effectively, 1. Y, 2. C, 3. Priorities are assigned in the order of RGB primary color subfields. Then, the color components are distributed according to the priority order. This will be described with reference to FIG.

First, since the Y (yellow) component is a component common to R and G, it is 100. At this point, all R components are distributed to Y (yellow), so the rest is 0 and the G component is 1.
60-100 = 60.

Next, C (cyan) is 60 because it is a common component of G and B. At this point, both G and B are C
Since it is allocated to (cyan), all the rest are 0.

The result of the distribution is {R, G, B, Y (yellow), C (cyan)} =
It becomes {0,0,0,100,60}. As a result, in the conventional case, the light that was emitted at each of three times of R, G, and B was changed to Y (yellow).
Since light emission occurs only at two timings, C and C (cyan), the time lag of the light emission timing is reduced and color breakup is reduced. In addition, the power of light is the strongest in the subfields with high priority (Y, C in this example),
Since the power of light becomes weaker as the priority becomes lower, the color of the subfield having the higher priority becomes conspicuous, the color of the subfield having the lower priority becomes less conspicuous, and the color breakup becomes less conspicuous.

Alternatively, if it is desired to more preferentially reduce the color rainbow generated when the eyes are greatly deflected, the distribution ratio of the color component to each subfield may be changed. Color rainbow can be reduced by distributing color components to subfields containing the color components instead of preferentially distributing the color components to some subfield. Specifically, as shown in FIG. 6A, {R,
A pixel having G, B} = {100, 160, 60} will be described as an example with reference to FIG. 7.

First, paying attention to Y (yellow) and C (cyan), R component and G commonly included in Y (yellow)
Since the component is 100, for example, 50% of these are Y
(Yellow). Then R is 100-5
0 = 50, and G becomes 160-50 = 110.

Similarly, for C (cyan), C
Since the G component and the B component commonly included in (cyan) are 60, if 50% of these are also distributed to C (cyan), G becomes 110-30 = 80 and B becomes 60-30 = 30. .

Therefore, the result of distribution is {R, G, B, Y (yellow), C (cyan)} = {5
0,80,30,50,30}. As a result, the image is displayed in all subfields, and the light power of the image when attention is paid to each subfield is weaker than that in the case where the conventional RGB three subfields are used for display. Color rainbow is reduced. The distribution ratio of the color components to each subfield is not limited to this, and can be arbitrarily changed.

(Embodiment of Fourth Invention) Next, the fourth embodiment of the present invention
The invention will be described. The fourth invention of the present application is the third invention of the present application.
In addition to the above invention, an achromatic subfield is also provided so that the achromatic color subfield has the highest priority in luminance distribution priority. As described above, the distribution ratio of the color components other than the achromatic component may be selected according to whether color breakup is preferentially reduced or color rainbow is preferentially reduced.

Similarly, as shown in FIG. 6A, {R,
A pixel having G, B} = {100, 160, 60} will be described as an example with reference to FIG. Here, color breakup is preferentially reduced.

First, the W (achromatic) subfield is distributed. The component commonly contained in all R, G, B is 6
Since it is 0, W (achromatic color) is 60. At this point, the remaining R of each color component is 100-60 = 40 for R, 160-60 = 100 for G, and 60-60 = 0 for B.

Next, when the Y (yellow) component is distributed by the above-mentioned method, it becomes 40 because it becomes the common component of R and G, although W (achromatic color) is subtracted, and C (cyan) is obtained.
Is 0. Therefore, {R, G, B, Y (yellow), C (cyan), W (achromatic color)} = {0, 60, 0, 40, 0, 60}.

As described above, according to the third invention of the present application or the fourth invention of the present application, color breakup and color rainbow can be prevented by devising a method of distributing the color components to the intermediate color or W (achromatic color) subfield. It can be reduced.

As already described, color breakup is a phenomenon that occurs when the observer's eyes follow a moving pattern on the screen. Therefore, when the displayed image is a moving image,
The distribution ratio of the color components is set to a distribution ratio that preferentially reduces color breakup, and when the image to be displayed is a still image, the distribution ratio that preferentially reduces the color rainbow is set to the image. Therefore, the optimum display can be obtained, and the display quality is improved.

Further, the response speed of the current liquid crystal display device when displaying white → black → white is about 1.5 ms at the fastest, and considering the slew rate of the source driver and the writing capability of the TFT. One horizontal scanning period is at least about 2μ
s is required. Considering these, the number of subfields in one frame period seems to be limited to about six at the present time, so here, a combination of up to six subfields in one frame period is given as an example. In projector-type display devices other than liquid crystals, one frame period is generally divided into 12 or more subfields to reduce color breakup and color rainbow. According to the present invention, it is possible to reduce color breakup and color rainbow with a small number of subfields even in a liquid crystal display device in which it is difficult to increase the number of subfields within one frame period due to the reasons described above.

Further, since the points of the first to fourth inventions of the present application are in order with the color of the image displayed in each subfield in one frame period, it should be easily understood that it does not depend on the method of the display device. . That is, the present invention brings about the same effect as long as it is a field-sequential display device. For example, organic EL display device, plasma display panel (PDP), field emission display (FED), DMD
A display device (for example, a projector) using an element,
And so on.

(Embodiment of the Fifth Invention) In the above-mentioned color component distribution method, the color components of each subfield are R, G, and B.
The original value was added when each was added. However, in this case, most of the light emitted from the backlight is blocked by the liquid crystal shutters and discarded, resulting in a decrease in power use efficiency.

By the way, the maximum brightness and the contrast are the items showing the performance of a general display device. The larger these values are, the better the image quality of the display device is.

Therefore, in the present invention, the achromatic color component is distributed to each subfield so as to exceed the given video signal, so that the brightness of the achromatic color component included in the video is increased and the brightness of the display device is increased. It is intended to improve the contrast. In the following description, attention is paid to a certain pixel, but actually, the increase amount of the W (achromatic color) component may be determined over the entire screen in consideration of the luminance balance with other colors, the gamma characteristic, and the like.

As a concrete example, as shown in FIG. 6A, the RGB components of a pixel are {R, G, B} =
{100, 160, 60}, and one frame period is divided into six color subfields of R, G, B, Y, C, and W as shown in FIG. Then, according to the fifth invention of the present application, it is assumed that each subfield is allocated as follows.

{R, G, B, Y, C, W} = {0, 6
0,0,40,0,60} Here, focusing on the W (achromatic) subfield, 6
Only 0 is allocated. Now, considering the case where the maximum gradation is 255, it is possible to further allocate 255-60 = 195. Therefore, for example, when the distribution of white is extremely increased, {R, G, B, Y, C, W} = {0, 60, 0, 40,
0,255}. This state is shown in FIG.

Alternatively, focusing on each of the R, G, and B subfields, 195 can be allocated to these subfields. Therefore, {R, G, B, Y, C, W} = {195, 255, 19
5,40,0,255}. This is shown in FIG. 9 (b). Of course, a halftone subfield may also be used.

This is a very extreme example because attention is paid only to a certain pixel, but theoretically it is possible to increase the white peak luminance by such a method. As a result, it is possible to improve the maximum brightness and contrast of the display device while reducing color breakup and color rainbow.
Moreover, the power of the backlight is not wasted.

(Embodiment of Sixth Invention) In the above-described color component distribution method, the color components of each subfield are dispersed into a plurality of subfields including a halftone and a W (achromatic color) subfield. Therefore, the distribution amount of each subfield tends to decrease.

For example, the RGB component of a certain pixel as shown in FIG. 6A is converted into {R, G, B, Y, C, W} = {0, 60, 0, 40, as shown in FIG.
0,60}, then in this pixel R
Since the subfields of B and C are 0, R, B and C
It is not necessary to turn on the backlight in the subfield. However, in the conventional driving method, the backlight emits light in accordance with the peak luminance regardless of the open / close state of the liquid crystal shutter, and thus wastes power.

The same is true when the field of view is widened and the entire screen is considered. For example, if the maximum value of R on the entire screen is 120, as shown in FIG. 10A, the brightness corresponding to 120 is exceeded. Since the power of the R light corresponding to that amount is blocked by the shutter of the liquid crystal, the power is wastefully consumed.

Therefore, in the present invention, as shown in FIG. 10 (b), the backlight brightness is reduced to a necessary minimum in each subfield, and at the same time, the liquid crystal shutter is controlled accordingly, thereby reducing the backlight power. It is something that is done.

Specifically, 1. First, the peak value for each subfield in the entire screen is detected.

2. The backlight brightness is controlled to be the brightness corresponding to the peak value.

3. Adjust the LCD shutter opening according to the backlight brightness. It should be controlled.

Here, for the sake of simplicity, it is assumed that the transmittance of the liquid crystal is 100% at the gradation of 255. However, when actually adjusting the opening of the liquid crystal shutter, the transmittance of the liquid crystal display element is adjusted. It goes without saying that it is necessary to make a decision in consideration of the gamma characteristics, the gamma characteristic, the backlight brightness, and the like.

As described above, according to the sixth aspect of the present invention, by adjusting the backlight brightness according to the peak brightness of the image displayed in each subfield, the light emitted from the backlight can be displayed in the liquid crystal as much as possible. It is possible to prevent the shutter from blocking the light, so that the light from the backlight can be effectively used, and the power consumption of the liquid crystal display device can be reduced while maintaining the image quality.

(Embodiment 7 of the Invention)
The invention will be described. The sixth invention of the present application is a method of dimming the backlight luminance only when the peak value of the video signal of each subfield is not the maximum value that can be input. In this method, since the backlight brightness is adjusted while maintaining the distribution ratio of the color components, a good result is obtained in terms of image quality, but the peak value of the input video signal is the maximum value that can be input. In this case, the backlight also emits the maximum brightness, so if there is a video signal with the maximum value somewhere on the entire screen, the brightness of the backlight in that subfield will also be maximum, and the power saving effect will be obtained. I can't.

Therefore, in the seventh invention of the present application, an upper limit is set for the backlight luminance in the intermediate color subfield or W (achromatic color) subfield, and this upper limit is set as the backlight in the intermediate color subfield or W (achromatic color) subfield. By setting a value lower than the maximum brightness of, the power consumption is more actively reduced.

In the case of the subfield structure having the intermediate color or W (achromatic color) subfields according to the first to fourth inventions of the present application, each of the R, G and B light sources is divided into a plurality of subfields within one frame period. To emit light. For example, in FIG.
In the case of the subfield structure shown in Fig. 3, the R and G light sources are the Y (yellow) subfield and the primary colors (R, G), respectively.
It emits light in two subfields.

However, the liquid crystal shutter opens only for one sub-field period in one frame period, and the ratio of the time when the liquid crystal shutter is open to the light emission time of the light source is small, so that the power use efficiency decreases. I have a problem to say.

To be more specific, consider a case where Y (yellow) is displayed on a certain pixel in the subfield structure of FIG. Now, as shown in FIG. 11A, R component and G
Assume that the components are each 255. In this case, there are an unlimited number of combinations of allocation methods to each subfield, but here, 100% is assigned to the Y (yellow) subfield.
Two cases are considered: 0% is allocated to the R and G primary color subfields, and 50% is allocated to each of the Y (yellow) and R, G primary color subfields.

FIG. 11B shows the states of the liquid crystal shutter and the backlight when 100% is allocated to the Y (yellow) subfield and 0% is allocated to the primary color subfield, and FIG. 11C shows the Y (yellow). 50%, and 50% is allocated to the R and G primary color subfields.

First, in FIG. 11 (b), in SF1, R and G of the backlight emit light, and the liquid crystal shutter has 25
Open 5/255. The backlight emits light in SF3 and SF4, but the liquid crystal shutter does not open. B of SF2 is Y
(Yellow) does not include it, so I will not consider it here. Focusing on the R light source and the G light source, R is SF
1 and SF3, G emits light in SF1 and SF4. On the other hand, the liquid crystal shutter is open only in SF1, and is closed in SF3 and SF4. That is, although the backlight emits light in two subfield periods in one frame period, light can be extracted to the outside only in one subfield period.
Only 0% is taken out and 50% is discarded.

Next, FIG. 11C will be described. In FIG. 11 (c), R and G of the backlight emit light in SF1, and the liquid crystal shutter opens 127/255. SF
The backlight also emits light in 3 and SF4, but the liquid crystal shutter still opens 127/255. B of SF2 is not included in Y (yellow) and is ignored.
Focusing on the R light source and the G light source, R emits light with maximum brightness in SF1 and SF3, and G emits light with maximum brightness in SF1 and SF4. On the other hand, the liquid crystal shutters are SF1, SF3,
In all of SF4, only half, 127, is open. Also in this case, although the backlight emits the maximum brightness in the two sub-field periods in one frame period, 50% of the light can be extracted to the outside in each sub-field. Also 50%
Is throwing away.

The same can be said not only for the above two cases but also for any distribution ratio of color components.

By the way, in the subjective evaluation conducted by the inventor,
When expressing intermediate colors such as Y (yellow), C (cyan), and M (magenta), it was found that if the ratio of the luminance of the intermediate color and the primary color is up to intermediate color: primary color = 1: 1, it will be within the allowable limit. It was

Further, it was found that in the case of W (achromatic color), if the ratio of W (achromatic color) and the primary color was W (achromatic color): primary color = 7: 3, it was within the allowable limit.

Therefore, if the upper limit of the backlight luminance of the intermediate color subfield is set up to 50% in advance and the rest is supplemented by the primary color subfield,
It is possible to reduce the backlight power in the intermediate color subfield. Further, it is known from subjective evaluation that deterioration of image quality can be suppressed within an allowable limit.

Similarly, if the upper limit of the backlight luminance of the W (achromatic color) subfield is set up to 70% in advance and the rest is supplemented by the primary color subfield, the W (achromatic color) subfield will be supplemented. It is possible to reduce the backlight power in the field. However, as described above, when the backlight brightness is changed, the opening of the liquid crystal shutter must be adjusted in consideration of the backlight brightness and the gamma characteristic.

One point to note here is the relationship between the present invention and the fact that human visual sensitivity is insensitive to changes in brightness in a high brightness region. I mentioned earlier that the upper limit of the backlight brightness in the intermediate color subfield is set to 50% of the maximum brightness of the backlight and to 70% in the W (achromatic color) subfield. Sensitivity is insensitive to changes in brightness, so it is not necessary to strictly set it to 50%, plus 5
An error of about% is an allowable range.

As described above, according to the seventh aspect of the present invention, by setting an upper limit to the backlight luminance in the intermediate color or W (achromatic color) subfield in advance, the intermediate color or W
Since the liquid crystal shutter opening in the (achromatic) subfield can be used in a more open state, it is possible to improve the utilization efficiency of the light emitted from the backlight and reduce power consumption. Becomes Further, according to the present invention, even when the power-brightness characteristic of the backlight is not linear, even when the backlight has a characteristic that the light emission efficiency is lowered when the brightness is increased, the backlight can be used in a part where the efficiency of the backlight is high. Therefore, it is effective in reducing power consumption.

Here, the difference from the color distribution method described in the third or fourth invention of the present application will be described. Third application
Alternatively, in the fourth invention, the method of evenly distributing the color distribution ratio to the intermediate color subfield and the primary color subfield has been described. However, this is to always evenly distribute the intermediate color components, no matter what value. On the other hand, in the seventh invention of the present application, if it is less than or equal to the upper limit of the intermediate color subfield, all are allocated to the intermediate color subfield, which is different from the third or fourth invention of the present application.

This will be described with reference to FIG. 12 (a), (b), and (c) are all the third or fourth application of the present application.
Is a result of allocating color components according to the invention of. here,
Prioritizing the reduction of color rainbow, 50% is allocated to each of the intermediate color subfield and the primary color subfield.

In FIG. 12A, the original video signal is R, G
Since each of them is 255, it is shown that 127 are allocated to each of the intermediate color subfield and the primary color subfield.

In FIG. 12B, the original video signals are R, G
Since they are 128 respectively, it is shown that 64 are allocated to each of the intermediate color subfield and the primary color subfield.

FIG. 12C shows that since the original video signals are 64 for each of R and G, 32 are allocated to each of the intermediate color subfield and the primary color subfield.

As described above, in the third or fourth invention of the present application, the distribution ratio to the intermediate color subfield and the primary color subfield is always constant.

On the other hand, in the seventh invention of the present application, as long as the upper limit set for the intermediate color subfield is not exceeded, the distribution to the intermediate color subfield may be any amount, so that the distribution ratio shown in FIG. 13 may be used. Here, it is assumed that the upper limit of the luminance of the intermediate color subfield is set to 128, which is 50% of 255.

In the case of FIG. 13A, since the R and G components of the original video signal are 255 respectively, 128 are allocated to the intermediate color subfield and 127 are allocated to the primary color subfield.

In the case of FIG. 13B, since the R and G components of the original video signal are 128, respectively, they are within the upper limit of the intermediate color subfield. Therefore, 128 is allocated only to the intermediate color subfield and nothing is allocated to the primary color subfield.

The same applies to the case of FIG. 13C, and since the original video signal has 64 R and G components respectively, it is within the upper limit of the intermediate color subfield. Therefore, all 64 are allocated to the intermediate color subfield and nothing is allocated to the primary color subfield.

As described above, by setting the upper limit of luminance in the intermediate color subfield and preferentially distributing it to the intermediate color subfield, it is possible to distribute only the components exceeding the upper limit of the intermediate color subfield to the primary color subfield. Become. As a result, the backlight luminance in the intermediate color subfield is half that of the primary color subfield even at the maximum, so that the power consumption of the backlight can be reliably reduced. The value of 50% set as the upper limit of the luminance of the intermediate color subfield is a value proved to be within the allowable limit by the subjective evaluation result. Therefore, even if the luminance of the intermediate color subfield is reduced to 50% and the rest is supplemented by the primary color subfield, the observer does not feel uncomfortable.

Also, while the intermediate color has been described so far,
The same principle can be applied to W (achromatic color). According to the result of subjective evaluation by the inventor, W
In the case of (achromatic color), it was found that it is desirable to set the upper limit of the luminance in the W (achromatic color) subfield to 70% or more. At 50% or less, the effect of reducing color rainbow and color breakage was hardly seen.

In summary, according to the seventh aspect of the present invention, by setting the upper limit of the luminance of the intermediate color subfield or the W (achromatic color) subfield in advance,
It is possible to reduce the backlight brightness in the intermediate color subfield or W (achromatic color) subfield, and the liquid crystal shutter can be used at a higher aperture accordingly, so the backlight light is blocked. Since the amount to be discarded is reduced, utilization efficiency is improved and power consumption of the display device can be reduced.

Further, according to the present invention, even when a light source (for example, an LED) whose light emission efficiency of the backlight decreases on the high brightness side is used, the backlight is used in a region having a high light emission efficiency. It becomes possible to improve the efficiency of power usage.

Further, according to the result of the subjective evaluation, the upper limit of the luminance in the intermediate color subfield is set to a value of 50% or more and W
If the upper limit of the luminance in (achromatic color) is set to a value of 70% or more, the observer does not feel uncomfortable, and it is possible to reduce the power consumption of the display device at the same time without damaging the display product. Become.

Further, when combined with the sixth invention of the present application, the backlight luminance can be further lowered when the luminance of the intermediate color subfield is less than the upper limit as shown in FIG. Power consumption can be reduced.

(Embodiments 8 to 14 of the Invention) In FIG. 14, 701 is a video signal input terminal and 70
Reference numeral 2 is a storage means capable of storing a video signal, 703 is a calculation means for generating a video signal of another color from the input video signal, 704 is a controller for controlling the liquid crystal display device, and 705 is a backlight. Backlight control means 706, a source driver 706 for driving a source line of the liquid crystal display device, 707 a gate driver for driving a gate line of the liquid crystal display device, 708 a liquid crystal display element, 70
Reference numeral 9 is a backlight, and 710 is an external setting input terminal for the user to set the color distribution ratio from the outside.

The video signal input from the video signal input terminal 701 is temporarily stored in the video signal storage means 702.
Then, the calculation unit 703 reads out the video signal of an arbitrary pixel from the video signal storage unit 702. The calculation means 703 is
R according to a preset color distribution algorithm
Y (yellow) or C based on the GB video signal
An image signal of (cyan), M (magenta), or W (achromatic color) is generated. Then, the generated video signal is transferred to the controller 704. The color distribution algorithm is a method of distributing color components to each subfield, and is the same as already described with reference to FIGS. 6 to 8, and therefore its explanation is omitted here. Here, the external setting input terminal 710 is opened to the user so that it is possible to specify whether to preferentially reduce color breakup or color rainbow according to the user's preference. By doing so, it is possible to display a video that matches the needs of the user.

The controller 704 outputs a control signal to the source driver 706 and the gate driver 707 according to the video signal received from the arithmetic means 703, and also outputs a backlight control signal to the backlight control means 705. . Since the control of the source driver and the gate driver is the same as that of the conventional liquid crystal display device, detailed description will be omitted here.

The backlight control means 705 controls the backlight 7 based on the control signal received from the controller.
The backlight 709 emits a desired color by controlling 09.

Next, three specific examples of the method for adjusting the brightness of the backlight will be given. However, since the point of the present invention is to adjust the brightness of the backlight,
It is noted in advance that the configuration is not limited as long as this can be realized.

FIG. 15 shows a first circuit example used for the light source of the liquid crystal display device according to the eighth to fourteenth inventions of the present application.
601 is a power supply terminal, 602 is a buffer circuit, 603 is a smoothing capacitor, 604 is a red light source, 605 is a green light source,
606 is a blue light source, 607 is a switching element, and 608
Is a backlight control means for controlling the light emission timing of the light sources 604 to 606, and 610 is a variable resistor.

The variable resistor 610 is an adjusting unit for performing brightness correction when the light emitting period of the light source is changed, and for adjusting individual variations in LED voltage-luminance characteristics and white balance. By making red, green, and blue independent, independent reference voltages can be obtained. The reference voltage generated by the variable resistor 610 is input to the red, green, and blue buffer circuits 602. The buffer circuit 602 amplifies the input reference voltage and supplies power to the anode terminal of the LED. By connecting the smoothing capacitor 603 to the output section of the buffer circuit, the bias current of the buffer circuit can be minimized, and the power constantly consumed in the buffer circuit can be reduced. Further, it is possible to prevent the rising of the voltage supplied to the LED from being rounded.

A switching element 607 is connected to the cathode terminal of the LED. The switching element 607 closes and opens the circuit according to the control signal from the backlight control means 608, and the LED emits light when the circuit is closed. The backlight control unit 608 sends a control signal corresponding to the light emitting period of each light source to the switching element 607.

Further, the sixth application, the seventh application, the thirteenth application,
When adjusting the brightness of the backlight according to the fourteenth invention of the present application, ON / O is performed a plurality of times within one subfield period.
The FF signal is output to the switching element 607 to adjust the brightness.

Next, FIG. 16 shows a second circuit example used for the light source of the liquid crystal display device according to the eighth to fourteenth inventions of the present application. 1101 is a digital / analog converter (D
/ A converter), 1102 is an operational amplifier for supplying a constant current to the light sources 604 to 606, 604 is a red light source, 605 is a green light source, 606 is a blue light source, and 608 is 6
This is a backlight control means for controlling the light emission timing and brightness of 04 to 606.

The backlight control means outputs a digital signal corresponding to the brightness to the D / A converter 1101. The D / A converter 1101 converts the received digital signal into an analog voltage, and the operational amplifier 11
Output to 02. The operational amplifier 1102 adjusts the output voltage so that the input voltage and the terminal voltage of the resistor 1103 match. This makes it possible to adjust the brightness of each of the light sources 604 to 606 independently.

Alternatively, it may be configured as shown in FIG.
In FIG. 17, 1201 is a switching element for keeping the terminal voltage of the light sources 604 to 606 constant. To ensure that the terminal voltage of the resistor 1103 and the voltage input to the + input terminal of the operational amplifier 1102 are the same, the operational amplifier 110
2 controls the switching element 1201. With this configuration, the output current capacity of the operational amplifier can be suppressed to an amount necessary for driving the switching element 1201. Therefore, the operational amplifier responds at high speed, and as a result, the brightness of the light source can be controlled at high speed. is there.

[0114]

As described above, according to the first invention of the present application, an intermediate color is displayed in an arbitrary subfield, and at least one subfield adjacent thereto is included in the intermediate color. By displaying an image of a color that is not present, even if color breakage occurs, the intermediate color and a color that is not included in the intermediate color are mixed to reduce the color breakup. Further, by distributing the color components in each subfield, the luminance of the image displayed in each subfield is lowered, and the color rainbow can be reduced.

According to the second invention of the present application, the first invention of the present application
In addition to the invention described above, by displaying an achromatic image in at least one subfield within one frame period, similarly, even for a pattern including an achromatic component, color breakup and color rainbow The effect is that it can be reduced.

According to the third invention of the present application, one frame period is divided into a plurality of subfields, and red,
In a field-sequential liquid crystal display device having at least one subfield for displaying so-called three primary colors of green and blue, and at least one subfield for displaying an intermediate color image, video signals corresponding to red, green and blue. When the video signals of other colors are generated from 1 to 1, the priority of the luminance distribution is 1. 1. A subfield that displays an image of a neutral color, By making the order of subfields that display so-called three-primary-color images of red, green, or blue, the brightness of an intermediate-color image that is less noticeable than the primary colors when the color breakup occurs is that of the three-primary-color image. The brightness exceeds the brightness of 1, and there is an effect that color breakup and color rainbow can be reduced.

According to the fourth invention of the present application, the third invention of the present application
In addition to the invention described above, a subfield for displaying an achromatic image in one frame period is also provided, and the priority of luminance distribution when the image signals of other colors are generated from the image signals corresponding to red, green, and blue is set. 1. 1. A subfield that displays an achromatic image, A subfield that displays an image of neutral colors,
3. Color breakup and color rainbow can be further reduced by arranging red, green, or blue so-called subfields displaying an image of three primary colors.

According to the fifth invention of the present application, one frame period is divided into a plurality of subfields, and a subfield for displaying an achromatic image and a subfield for displaying an image of other colors are provided. In a field-sequential liquid crystal display device having at least one each, by displaying an achromatic image in both a subfield displaying an achromatic image and a subfield displaying an image of other colors, the peak The brightness can be increased, and the electric power can be effectively used.

According to the sixth aspect of the present invention, one frame period is divided into a plurality of subfields, and red,
In a field sequential liquid crystal display device having at least one subfield for displaying images of so-called three primary colors of green and blue and at least one subfield for displaying images of intermediate colors or one for displaying achromatic images By adjusting the backlight brightness according to the peak brightness of
It is possible to reduce power consumption while maintaining image quality.

Further, according to the seventh aspect of the present invention, an upper limit is set for the backlight luminance of the subfield displaying the intermediate color or achromatic image, and the upper limit is set to be higher than the maximum luminance of the backlight of the intermediate color or achromatic subfield. Also, by lowering it, the liquid crystal shutter can be used in a high opening state, and power consumption can be reduced. In addition, it can be used in a region where the light emission efficiency of the backlight is good.

Further, according to the eighth invention to the eleventh invention of the present application, the display device according to the first invention to the fifth invention of the present application can be realized, and the display device of the color sequential display system is realized. However, a display device capable of displaying with less color breakup and color rainbow can be obtained.

Further, according to the twelfth invention of the present application, it is possible to realize the display device according to the fifth invention of the present application, it is possible to increase the peak brightness, and it is possible to effectively use electric power in the color sequential system. A display type display device can be realized.

Further, according to the thirteenth invention of the present application, the display device according to the sixth invention of the present application can be realized, and the backlight luminance is adjusted according to the peak luminance of the screen in each subfield. By doing so, it is possible to realize a color-sequential display type display device capable of reducing power consumption while maintaining image quality.

According to the fourteenth invention of the present application, the display device according to the seventh invention of the present application can be realized, and a display device of a color sequential display system capable of reducing power consumption can be realized. .

By using the first to fourteenth inventions of the present application, it is possible to obtain a display device with less color breakup even in the color sequential display system. Therefore, it is possible to reduce the power consumption as compared with the prior art. Display method It can contribute to the spread of display devices, and will be friendly to the global environment and space environment.

[Brief description of drawings]

1 is a first invention, a second invention, or a third invention.
An explanatory diagram of a display color of an image in each subfield according to the fourth invention, the fifth invention, or the sixth invention.

FIG. 2 is the first invention, the second invention, or the third invention.
An explanatory diagram of a display color of an image in each subfield according to the fourth invention, the fifth invention, or the sixth invention.

FIG. 3 is the first invention, the second invention, or the third invention.
An explanatory diagram of a display color of an image in each subfield according to the fourth invention, the fifth invention, or the sixth invention.

FIG. 4 is a first invention, a second invention, or a third invention.
An explanatory diagram of a display color of an image in each subfield according to the fourth invention, the fifth invention, or the sixth invention.

FIG. 5 is the first invention, the second invention, or the third invention.
An explanatory diagram of a display color of an image in each subfield according to the fourth invention, the fifth invention, or the sixth invention.

FIG. 6 is an explanatory view showing an example of distribution ratios of color components in the case of preferentially reducing color breakup according to the first or third aspect of the present invention.

FIG. 7 is an explanatory diagram showing an example of a distribution ratio of color components in the case of preferentially reducing color rainbow according to the third or fourth aspect of the present invention.

FIG. 8 is an explanatory view showing an example of a distribution ratio of color components in the case of preferentially reducing color breakup according to the third or fourth aspect of the present invention.

FIG. 9 is an explanatory diagram showing an example of distribution ratios of color components when improving the luminance of the W (achromatic color) component according to the fifth aspect of the present invention.

FIG. 10 is an explanatory view showing a method for reducing the power consumption by optimizing the openings of the backlight and the liquid crystal shutter according to the sixth aspect of the present invention.

FIG. 11 is an explanatory diagram showing the openings of the backlight and the liquid crystal shutter.

FIG. 12 is an explanatory diagram showing a state of distribution of color components according to the third invention of the present application.

FIG. 13 is an explanatory diagram showing a state of distribution of color components according to the seventh invention of the present application.

FIG. 14 is a block diagram of a display device of a color sequential display system according to the seventh invention, the eighth invention, the ninth invention, the tenth invention, the eleventh invention, or the twelfth invention.

FIG. 15 is a circuit diagram of a light source unit of a display device of a color sequential display system according to the seventh invention, the eighth invention, the ninth invention, the tenth invention, the eleventh invention, or the twelfth invention.

FIG. 16 is a circuit diagram of a light source section of a display device of a color sequential display system according to the seventh invention, the eighth invention, the ninth invention, the tenth invention, the eleventh invention, or the twelfth invention.

FIG. 17 is a block diagram of a display device of a color sequential display system according to the seventh invention, the eighth invention, the ninth invention, the tenth invention, the eleventh invention, or the twelfth invention.

FIG. 18 is an explanatory diagram of the principle of color breakup.

FIG. 19 is a schematic diagram showing a state of a boundary portion when patterns of different colors are adjacent to each other.

FIG. 20 is an explanatory diagram of colors of images displayed in each subfield when Y (yellow) is displayed by a conventional method.

[Explanation of symbols]

601 Power terminal 602 buffer circuit 603 Smoothing capacitor 604 red light source 605 green light source 606 Blue light source 607 Switching element 608 Backlight control means 610 Variable resistance 701 Video signal input terminal 702 video signal storage means 703 calculation means 704 controller 705 Backlight control means 706 Source driver 707 gate driver 708 liquid crystal display element 709 Backlight 710 External setting input terminal 1101 Digital / Analog converter 1102 operational amplifier 1103 resistance 1201 switching element

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G02F 1/13357 G02F 1/13357 G09G 3/20 641 G09G 3/20 641E 642 642J 642L 650 650M 3/34 3 / 34 J H04N 9/30 H04N 9/30 F term (reference) 2H091 FA41Z FD22 FD24 GA13 LA15 LA19 2H093 NA15 NA16 NA33 NC24 NC43 NC54 NC59 ND06 ND07 ND17 ND24 NE06 5C006 AA01 AA14 AA22 AF01 AF44 AF85 AF61 AF53 AF53 AF53 AF53 AF53 AF53 AF53 BB16 BB29 BC06 BC12 BC16 BF02 BF14 BF15 BF25 BF34 BF36 BF37 BF38 BF41 BF49 EA01 EC11 FA24 FA29 FA47 FA56 GA02 GA03 5C060 AA07 BA04 BA08 BB13 BC01 BE05 BE10 DB01 DB13 HB05 HB07 HD07 JA00 5C080 AA05 AA06 AA07 AA08 AA10 AA17 BB05 CC03 DD02 DD06 DD26 EE19 EE29 EE30 FF02 FF03 FF11 GG08 GG12 HH09 HH13 HH17 JJ01 JJ02 JJ03 JJ05 KK43

Claims (26)

[Claims] 1. A method in which one frame period is divided into a plurality of subfields, and in which a color image is obtained by displaying an image of an arbitrary color in each of the subfields, red or green is generated in the arbitrary subfield. Alternatively, an image of an intermediate color in which any two colors of blue are mixed is displayed, and an image of a color not included in the intermediate color is displayed in at least one subfield adjacent to the subfield for displaying the image of the intermediate color. A method for driving a display device, comprising: 2. The driving method of the display device according to claim 1, wherein an image of an intermediate color is displayed in the first or last subfield in one frame period. 3. The color of the intermediate color image and the primary color image displayed in the adjacent sub-fields includes all three primary colors of red, green and blue lights. Driving method for display device. 4. A method in which one frame period is divided into a plurality of subfields, and a video image of an arbitrary color is displayed in each of the subfields to obtain a color image. In the subfield, red or green is displayed. Alternatively, an image of an intermediate color in which any two colors of blue are mixed is displayed, and an image of a color not included in the intermediate color is displayed in at least one subfield adjacent to the subfield displaying the intermediate color. And a method for driving a display device, wherein an achromatic image is displayed in at least one remaining subfield. 5. The color of the intermediate color image and the primary color image displayed in the adjacent sub-fields includes all three primary colors of red, green and blue lights. Driving method for display device. 6. One frame period is divided into a plurality of subfields, and a subfield for displaying an image of three primary colors of red, green, and blue and an image of an intermediate color are displayed within the one frame period. In a display device having at least one sub-field, each of the luminance distribution priorities for generating video signals of other colors from video signals corresponding to red, green, and blue is 1. 1. A subfield that displays an image of a neutral color, A driving method of a display device, characterized in that subfields for displaying an image of three primary colors of red, green, or blue light are in order. 7. One frame period is divided into a plurality of sub-fields, and a sub-field displaying an image of three primary colors of red, green and blue and a sub-field displaying an intermediate color image are included in the one frame period. In a display device having at least one subfield for displaying an achromatic image, the priority order of luminance distribution when generating image signals of other colors from image signals corresponding to red, green, and blue is 1. 1. A subfield that displays an achromatic image,
2. A subfield for displaying a video of a neutral color, A driving method of a display device, characterized in that subfields for displaying an image of three primary colors of red, green, or blue light are in order. 8. The luminance distribution ratio at the time of generating video signals of other colors from video signals corresponding to red, green and blue changes according to an image to be displayed.
Alternatively, the method of driving the display device according to claim 7. 9. One frame period is divided into a plurality of sub-fields, and a sub-field for displaying an intermediate color image or a sub-field for displaying an achromatic image and red and green within the one frame period. , At least one subfield for each of the three primary colors of blue
In a display device having two, a display device for displaying an image of an intermediate color or an achromatic color in both a subfield for displaying the intermediate color or an achromatic color and a subfield for displaying an image of the three primary colors. Driving method. 10. One frame period is divided into a plurality of subfields, and a subfield for displaying an image of three primary colors of red, green, and blue, and a subfield for displaying an image of an intermediate color or an achromatic image is displayed. In a display device having at least one sub-field, the backlight brightness is adjusted according to the peak brightness of the image in each sub-field. 11. One frame period is divided into a plurality of sub-fields, and a sub-field displaying an image of three primary colors of red, green and blue and a sub-field displaying an image of an intermediate color or an achromatic image is displayed. In a display device having at least one sub-field, an upper limit is set to the backlight luminance of a sub-field displaying an intermediate color or W (achromatic color) image. 12. A storage means capable of storing a video signal for one screen, a backlight control means for controlling a backlight, a computing means for arithmetically processing the video signal, and a liquid crystal display for displaying an image corresponding to the video signal. An element is provided, and one frame period is divided into a plurality of subfields, and the arithmetic means generates a video signal to be displayed in each subfield based on the video signal stored in the storage means, and the generation An image corresponding to the image signal is displayed on the liquid crystal display element, and the emission color of the backlight is controlled by the backlight control means in conjunction with the displayed image to obtain a color display. A subfield for displaying an image of an intermediate color in which any two colors of red, green or blue are mixed in the field, and further displaying an image of the intermediate color In at least one subfield adjacent display device and displaying the color of the image that are not included in the intermediate color. 13. The display device according to claim 12, wherein an image of an intermediate color is displayed in the first or last subfield in one frame period. 14. The color of an image displayed in the arbitrary subfield and at least one subfield adjacent to the arbitrary subfield includes all three primary colors of red, green and blue light. The display device according to claim 12, wherein: 15. A storage means capable of storing a video signal for one screen, a backlight control means for controlling a backlight, a computing means for arithmetically processing the video signal, and a liquid crystal display for displaying a video corresponding to the video signal. An element is provided, and one frame period is divided into a plurality of subfields, and the arithmetic means generates a video signal to be displayed in each subfield based on the video signal stored in the storage means,
In a display device for displaying an image corresponding to the generated image signal on a liquid crystal display element, and controlling a light emission color of a backlight by the backlight control means in conjunction with the displayed image to obtain a color display. An intermediate color image in which any two colors of red, green, and blue are mixed is displayed in an arbitrary subfield in the frame period, and further, in a subfield adjacent to the subfield displaying the intermediate color image, A display device, which displays an image of a color not included in the intermediate color and further displays an achromatic image in at least one remaining subfield. 16. The display device according to claim 15, wherein an image of an intermediate color is displayed in the first or last subfield in one frame period. 17. The color of the intermediate color image and the primary color image displayed in the adjacent sub-fields includes all three primary colors of red, green and blue lights. Display device. 18. A storage means capable of storing a video signal for one screen, a backlight control means for controlling a backlight, a computing means for arithmetically processing the video signal, and a liquid crystal display for displaying a video corresponding to the video signal. Equipped with elements, one frame period is divided into multiple subfields, red, green,
At least one subfield for displaying an image of the three primary colors of blue or at least one subfield for displaying an image of an intermediate color is provided, and the subfield is displayed in each subfield based on the video signal stored in the storage means by the computing means. A video signal is generated, a video corresponding to the generated video signal is displayed on a liquid crystal display element, and the light emission color of the backlight is controlled by the backlight control means in cooperation with the displayed video to obtain a color display. In the display device, when the video signals corresponding to red, green, and blue are used to generate video signals of other colors by the arithmetic processing, the priority order of the luminance distribution is 1. A subfield that displays an image of neutral colors,
2. A display device characterized in that subfields for displaying images of three primary colors of red, green, or blue are in order. 19. A storage means capable of storing a video signal for one screen, a backlight control means for controlling a backlight, a computing means for arithmetically processing the video signal, and a liquid crystal display for displaying a video corresponding to the video signal. Equipped with elements, one frame period is divided into multiple subfields, red, green,
At least one subfield for displaying an image of the three primary colors of blue, a subfield for displaying an intermediate color image, or a subfield for displaying an achromatic image, respectively,
A video signal to be displayed in each subfield is generated from the arithmetic means based on the video signal stored in the storage means, an image corresponding to the generated video signal is displayed on a liquid crystal display element, and the display is performed. When a video signal of other colors is generated from video signals corresponding to red, green, and blue in a display device that obtains a color display by controlling the light emission color of the backlight with the backlight control means in conjunction with the video The priority order of the brightness distribution is 1. 1. A subfield that displays an achromatic image, 2. A subfield for displaying a video of a neutral color, A display device characterized in that subfields for displaying images of three primary colors of red, green, or blue are in order. 20. A luminance distribution ratio at the time of generating video signals of other colors from video signals corresponding to red, green and blue,
20. The display device according to claim 18, wherein the display device changes according to an image to be displayed. 21. A storage means capable of storing a video signal for one screen, a backlight control means for controlling a backlight, a computing means for arithmetically processing the video signal, and a liquid crystal display for displaying a video according to the video signal. Equipped with elements, one frame period is divided into multiple subfields, red, green,
An image which has at least one subfield for displaying an image of the three primary colors of blue and at least one subfield for displaying an intermediate color image or a subfield for displaying an achromatic image, and which is further stored in the storage unit by the calculating unit. A video signal to be displayed in each subfield is generated based on the signal, a video corresponding to the generated video signal is displayed on a liquid crystal display element, and the emission color of the backlight is linked to the displayed video. In a display device which is controlled by the light control means to obtain color display, an intermediate color or achromatic image is displayed in both a subfield for displaying the intermediate color or achromatic color and a subfield for displaying the image of the three primary colors. A display device characterized by: 22. Storage means capable of storing a video signal for one screen, backlight control means for controlling a backlight, arithmetic means for arithmetically processing the video signal, and liquid crystal display for displaying an image corresponding to the video signal. Equipped with elements, one frame period is divided into multiple subfields, red, green,
An image having at least one subfield for displaying an image of the three primary colors of blue, an intermediate color image, or an achromatic image, and an image displayed in each subfield based on the image signal stored in the storage unit by the computing unit A signal is generated, an image corresponding to the generated image signal is displayed on a liquid crystal display element, and the emission color of the backlight is controlled by the backlight control means in conjunction with the displayed image to obtain a color display. In the device, depending on the peak brightness of the screen in each subfield,
A display device characterized by dimming the backlight brightness. 23. Storage means capable of storing a video signal for one screen, backlight control means for controlling a backlight, arithmetic means for arithmetically processing the video signal, and liquid crystal display for displaying an image according to the video signal. Equipped with elements, one frame period is divided into multiple subfields, red, green,
An image having at least one subfield for displaying an image of the three primary colors of blue, an intermediate color image, or an achromatic image, and an image displayed in each subfield based on the image signal stored in the storage unit by the computing unit A signal is generated, an image corresponding to the generated image signal is displayed on a liquid crystal display element, and the emission color of the backlight is controlled by the backlight control means in conjunction with the displayed image to obtain a color display. In the display device, an upper limit is set to the backlight brightness of a subfield displaying an intermediate color or W (achromatic color) image. 24. The backlight has a light source having at least two power supply terminals, an adjusting means for adjusting white balance, an amplifying means for amplifying a reference voltage, and turning on / off power supplied to the light source. A switching means for controlling and a backlight control means for controlling the switching means are provided, an output terminal of the adjusting means is connected to an input terminal of the amplifying means as a reference voltage, and an output terminal of the amplifying means is of the light source. The power supply terminal is connected to one side, the switching means is connected to the other power supply terminal of the light source, and the backlight control means is connected to the switching means. 12
The display device according to any one of claims 15 or 18 or claim 19 or claim 21 or claim 22 or claim 23. 25. The backlight includes a light source having at least two power supply terminals, a digital / analog converter (D / A converter), an operational amplifier, a current detecting element, and a backlight control means. The output terminal of the backlight control means is connected to the input terminal of the digital / analog converter, the output terminal of the digital / analog converter is connected to the non-inverting input terminal of the operational amplifier, and the output terminal of the operational amplifier is one of the light sources. 19. The power supply terminal of the light source, and the other power supply terminal of the light source is connected to the current detection element and the inverting input terminal of the operational amplifier. Or any one of claim 19 or claim 21 or claim 22 or claim 23 Display device according to. 26. The backlight has a light source having at least two power supply terminals, a digital / analog converter (D / A converter), an operational amplifier, a current detection element, a switching element, a power supply terminal, and a back light. A light control means, wherein the output terminal of the backlight control means is the digital / digital
An input terminal of an analog converter, an output terminal of the digital / analog converter is connected to a non-inverting input terminal of the operational amplifier, an output terminal of the operational amplifier is connected to the switching element, and one power supply terminal of the light source is connected. A power supply terminal is connected to the power supply terminal, a switching element is connected to the other power supply terminal of the light source, and a current detection element and an inverting input terminal of an operational amplifier are connected to the switching element. The display device according to any one of claims 12 or 15 or claim 18 or claim 19 or claim 21 or claim 22 or claim 23.