WO2012004997A1 - Self-luminous video display device - Google Patents

Abstract

Provided is a self-luminous video display device, comprising: a self-luminous display panel that employs an extended primary color point, which is a primary color point that differs from a red primary color point, a green primary color point, and a blue primary color point, in an (x, y) chromaticity diagram, in addition to the red primary color point, green primary color point, and blue primary color point, in carrying out color reproduction; an input unit that receives video signal input; a display setting unit that sets the display mode of the self-luminous display panel to either a three-dimensional mode that displays the video signal as a three-dimensional image or a two-dimensional mode that displays the video signal as a two-dimensional image; and a color transform unit that generates, from the received video signal, an extended color signal that is represented using the red primary color point, the green primary color point, the blue primary color point, and the extended primary color point, according to the set display mode. When the three-dimensional mode is set, the color transform unit employs a first color transform protocol to generate the extended color signal, and when the two-dimensional mode is set, the color transform unit employs a second color transform protocol that differs from the first color transform protocol to generate the extended color signal.

Description

Self-luminous video display device

The present invention relates to a self-luminous video display device that performs color conversion on an input video signal composed of RGB primary color points and outputs the video signal to a self-luminous display.

With the recent development of video technology, 3D display devices have been developed to provide viewers with 3D perceived video (3D video). In many cases, such a 3D display device displays an image including a left-eye frame image for viewing with the left eye and a right-eye frame image for viewing with the right eye. The 3D display device transmits a synchronization signal synchronized with the display of the frame image of the video. The user wears a dedicated eyeglass device for viewing 3D video. The eyeglass device controls the visual field of the viewer's right eye and left eye based on the synchronization signal transmitted from the display device. For example, an eyeglass device including an electronic shutter closes the electronic shutter of the right eye of the eyeglass device so that the viewer's right eye cannot see the image while the display device displays the left eye frame image, and the viewer The electronic shutter of the left eye of the eyeglass device is opened so that the left eye can visually recognize the image. Further, while the display device displays the right eye frame image, the electronic shutter of the left eye of the spectacle device is closed so that the viewer's left eye cannot see the image, and the viewer's right eye can see the image. Thus, the electronic shutter of the right eye of the eyeglass device is opened. Thus, the viewer can visually recognize the image displayed on the display device in three dimensions.

In the three-dimensional image display as described above, the left eye frame image and the right eye frame image are expressed using the three primary colors of red, green, and blue, as in a normal two-dimensional image.

On the other hand, a technology related to a liquid crystal display has been developed that uses four primary colors in which yellow is added in addition to the three primary colors of red, green, and blue in two-dimensional image display and has a color reproduction range that is larger than the three primary colors. (See Patent Document 1 and Patent Document 2)

JP 2001-209047 A International Publication WO2007 / 148519

In a self-luminous video display device that emits light using a phosphor or the like like a PDP (plasma display panel) display, afterglow characteristics differ depending on the type of phosphor. Actually, the afterglow of the green phosphor is longer than the afterglow of the phosphors of other colors (red and blue). In particular, in a display that performs three-dimensional display in a time-sharing manner using a frame sequential method, a long afterglow of a green phosphor causes crosstalk.

In order to reduce crosstalk in three-dimensional display, a four-color display with a fourth color using a phosphor with little afterglow can be considered. In this case, it is conceivable to reduce crosstalk caused by the afterglow of green by color-converting the three-color signal into the four-color signal so that the amount of green used is reduced as much as possible.

However, reducing afterglow to reduce crosstalk has no significant effect on the display when performing normal two-dimensional display. However, there is a problem that the fourth color cannot be utilized, such as reducing the light emission efficiency and reducing the color reproducibility by reducing the crosstalk.

The present invention has been made to solve the above-described problem, and when color conversion is performed on an input video signal, color conversion suitable for each video characteristic of a 2D video and a 3D video is set. It is an object of the present invention to provide a self-luminous video display device capable of performing the above.

The self-luminous video display apparatus according to the present invention is not limited to the R primary color point, the G primary color point, and the B primary color point, but the R primary color point, the G primary color point, and the B primary color point on the (x, y) chromaticity diagram. A self-luminous display panel that performs color reproduction using extended primary color points that are different primary color points, an input unit that inputs a video signal, and a display mode of the self-luminous display panel are displayed as a three-dimensional video image. A display setting unit for setting a 3D mode or a 2D mode for displaying a video signal as a 2D video, and according to the set display mode, an R primary color point, a G primary color point, a B primary color point, and A color conversion unit that generates an extended color signal expressed using the extended primary color point. The color conversion unit generates an extended color signal using the first color conversion method when set to the three-dimensional mode, and a second different from the first color conversion method when set to the two-dimensional mode. The extended color signal is generated using the color conversion method.

In this way, the self-luminous video display device uses different color conversion methods to color the video signal when the display mode is set to the three-dimensional mode and when the display mode is set to the two-dimensional mode. Can be converted. Thereby, when displaying a video signal on a self-luminous panel, a video signal suitable for two-dimensional or three-dimensional video characteristics can be displayed.

The second self-luminous image display device according to the present invention includes an R primary color point, a G primary color point, and a B primary color on the (x, y) chromaticity diagram in addition to the R primary color point, the G primary color point, and the B primary color point. A self-luminous display panel that reproduces colors using an extended primary color point that is a primary color point different from the point, an input unit for inputting a video signal, a display mode of the self-luminous display panel, and a three-dimensional video signal A display setting unit for setting to a three-dimensional mode for displaying as a two-dimensional mode for displaying a video signal as a two-dimensional video. The self-luminous display panel displays the video signal according to the display mode set by the display setting unit. The combination pattern of primary color points to be emitted in the self-luminous display panel is different between the two-dimensional mode and the three-dimensional mode.

In this way, it is possible to set a combination pattern of primary color points (that is, color conversion) suitable for each video characteristic in the two-dimensional mode and the three-dimensional mode.

The self-luminous video display device of the present invention can perform color conversion using different color conversion methods depending on whether the display mode is set to the three-dimensional mode or the two-dimensional mode. Become. Therefore, when the input video signal is color-converted, it is possible to set the color conversion suitable for the video characteristics of the two-dimensional video and the three-dimensional video.

The figure which shows the specific structure of the PDP television 1 in this embodiment. The figure which represented the color reproduced using three primary color points of R, G, and B in this embodiment on the (x, y) chromaticity diagram Functional block diagram of the signal processing unit 102 in the present embodiment Flowchart up to conversion of video signal to extended color signal in this embodiment The figure which shows the example which reproduces 4 colors with the conversion characteristic of the said 1st conversion mode, using Y color as an extended color in this embodiment. The figure which shows the color gamut which can be reproduced in this embodiment The figure for demonstrating the modification of the color gamut expansion mode in this embodiment. The figure which shows arrangement | positioning of the fluorescent substance which comprises each color in the display part 105 in this embodiment. The figure for demonstrating the modification at the time of using C (cyan) primary color point instead of Y primary color point in this embodiment. The figure for demonstrating the modification at the time of using W (white) primary color point instead of Y primary color point in this embodiment.

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

1. Configuration of PDP Television FIG. 1 is a diagram showing a specific configuration of a PDP television that is an embodiment of the present invention. As shown in FIG. 1, the PDP television 1 is connected to a recorder device 2, an antenna 3, and an SD card 4. The PDP television 1 inputs video signals from the recorder device 2, the antenna 3 and the SD card 4. The PDP television 1 processes the input video signal and displays it as a video.

The PDP television 1 includes an input / output IF unit 101, a signal processing unit 102, a buffer memory 103, a flash memory 104, a display unit 105, and a tuner 106.

The input / output IF unit 101 is an interface that enables connection with the recorder device 2 and the SD card 4. The input / output IF unit 101 can exchange control signals and video signals with the signal processing unit 102. The input / output IF unit 101 transmits a signal received from the recorder device 2 or the SD card 4 to the signal processing unit 102. Further, the input / output IF unit 101 transmits the signal received from the signal processing unit 102 to the recorder device 2 or the SD card 4. The input / output IF unit 101 can be realized by, for example, an HDMI connector, an SD card slot, or the like. Further, the input / output IF unit 101 may be configured as a device having the function of the input / output IF unit 101 and the function of the recorder device 2. In FIG. 1, one block is illustrated as the input / output IF unit 101. However, a card slot for the SD card 4 and a connector for the recorder device 2 may be provided. In short, the signal processing unit 102 only needs to realize an interface with an external recording apparatus.

The signal processing unit 102 controls the operation of each unit of the PDP television 1. Further, the signal processing unit 102 may decode the video signal output from the input / output IF unit 101. Further, the signal processing unit 102 performs image processing on the video signal and converts it into a display signal that can be displayed on the display device. The signal processing unit 102 may be configured with a microcomputer or a hard-wired circuit.

The buffer memory 103 is used as a work memory when the signal processing unit 102 performs signal processing. The buffer memory 103 can be realized by a DRAM, for example.

The flash memory 104 records a program executed by the signal processing unit 102.

The display unit 105 displays an image based on the display signal output from the signal processing unit 102. The display unit 105 can be realized by, for example, a self-luminous surface device such as a plasma display panel (PDP). Further, in addition to the R primary color point, the G primary color point, and the B primary color point, the display unit 105 uses a primary color point different from the R primary color point, the G primary color point, and the B primary color point on the (x, y) chromaticity diagram. An image is displayed using a certain extended primary color point. Hereinafter, the color indicated by the extended primary color point is referred to as an “extended color”. In the following, for convenience of explanation, a configuration using one extended color will be described. However, the extended color is not limited to one color, and two or more extended colors may be used. As the extended color, for example, a yellow primary color point, a cyan primary color point, or a white primary color point can be considered.

The tuner 106 receives a broadcast wave via the antenna 3. The tuner 106 transmits a video signal having a specific frequency designated by the signal processing unit 102 to the signal processing unit 102. As a result, the signal processing unit 102 can process a video signal of a specific frequency included in the broadcast wave and display it on the display unit 105.

1-1. About Extended Colors Hereinafter, extended colors used by the PDP television 1 of the present embodiment will be described. A plasma display panel, which is a self-luminous display, discharges plasma for each pixel coated with RGB phosphors. Ultraviolet rays are generated by this plasma discharge, and the generated ultraviolet rays excite phosphors of RGB colors, so that phosphors of R (red), G (green), B (blue), that is, primary color points emit light. Afterglow occurs when each primary color phosphor emits light. Afterglow is light emission of the phosphor remaining after the generation of ultraviolet rays stops. The afterglow time is attributed to the material constituting the phosphor. That is, the afterglow time varies depending on the color of the phosphor.

Generally, among phosphors used in plasma display panels, the afterglow time of the B color phosphor is short and is 1 msec or less. On the other hand, the afterglow time of the G color phosphor is very long and is about 10 msec. The afterglow time of the R color phosphor is a time between the afterglow time of the B color phosphor and the afterglow time of the G color phosphor. Therefore, reducing the amount of light emitted by the G-color phosphor having a long afterglow time is effective for improving the afterglow characteristics of the plasma display panel and reducing crosstalk.

FIG. 2 is a (x, y) chromaticity diagram showing colors reproduced using the three primary color points of the R primary color point, the G primary color point, and the B primary color point. When the R color is expressed by (R, G, B) = (1, 0, 0), the G color is (0, 1, 0) and the B color is (0, 0, 1). The secondary colors Y (yellow), C (cyan), and M (magenta) are (1, 1, 0), (0, 1, 1), (1, 0, 1), respectively. become. The tertiary color W (white) is (1, 1, 1).

When attention is paid to the usage amount of the G primary color point that has the most influence on the afterglow time, the usage amount of the G primary color point becomes the maximum value 1 for the G color, Y color, W color, and C color.

In FIG. 2, the shaded shade represents the usage amount of the G primary color point. That is, the dark color region in FIG. 2 uses a large amount of the G primary color point, and the light color region uses a small amount of the G primary color point. Since the usage amount of the G primary color point in the region surrounded by GCWY takes the maximum value 1, the afterglow is the largest.

Here, consider W color = (1,1,1). In general, most of the colors representing the video signal are low-saturation colors, that is, colors near the W color. In the video signal, the usage amount of the G primary color point is high although the appearance frequency of the color near the W color is high. Actually, the use amount of the G primary color point is the maximum value 1 in the color near the W color. Therefore, in 3D display, crosstalk due to afterglow is likely to occur, resulting in poor quality of 3D display.

Therefore, the PDP television 1 of the present embodiment introduces primary color points (extended colors) different from the R primary color point, the G primary color point, and the B primary color point in order to reduce the usage amount of the G primary color point. When the PDP television 1 displays the video signal three-dimensionally, the PDP television 1 processes the video signal so as to reduce crosstalk. In addition, by adding an extended color, the display unit 105 may improve display performance other than afterglow reduction. Using this improvement in display performance, the PDP television 1 performs signal processing on the video signal so that the two-dimensional display performance is improved in the display unit 105 in the two-dimensional display of the video signal.

1-2. Signal Processing Unit Hereinafter, a specific configuration of the signal processing unit 102 will be described with reference to the drawings.

FIG. 3 is a functional block diagram of the signal processing unit 102. As illustrated in FIG. 3, the signal processing unit 102 includes an RGB conversion unit 201, an inverse gamma conversion unit 202, a mode acquisition unit 203, a four-color conversion unit 204, and a driver 205.

The RGB conversion unit 201 converts the video signal composed of the luminance signal Y and the color difference signals Cb, Cr input from the input / output IF unit 101 into an RGB signal composed of R color, G color, and B color. .

The inverse gamma conversion unit 202 performs inverse gamma conversion on the RGB signal output from the RGB conversion unit 201 and outputs the converted RGB signal to the four-color conversion unit 204.

The mode acquisition unit 203 sets the display mode of the PDP television 1 based on meta information such as header information of the video signal output from the RGB conversion unit 201. The display mode includes a two-dimensional mode and a three-dimensional mode. The two-dimensional mode is a mode in which a video signal is signal-processed as a two-dimensional signal and displayed on the display unit 105. The three-dimensional mode is a mode in which a video signal is signal-processed as a three-dimensional signal and displayed on the display unit 105. For example, when the video signal has several bits of flag information indicating a three-dimensional signal, the mode acquisition unit 203 sets a mode based on the flag information. That is, when the flag information is ON, the mode acquisition unit 203 detects that the display mode when reproducing the video signal is the three-dimensional mode. Conversely, when the flag information is OFF, the mode acquisition unit 203 detects that the display mode when reproducing the video signal is the two-dimensional mode.

When the mode acquisition unit 203 has a receiver function for receiving an operation signal corresponding to a user's operation via wireless such as infrared rays, the mode acquisition unit 203 determines the mode from the received operation signal. It doesn't matter. When the video signal and command information indicating whether or not the video signal is a three-dimensional signal are input from the recorder device 2, the display mode may be determined based on the command information. Further, for example, when the video signal has a video format unique to the 3D signal, such as a side-by-side 3D video format, the mode acquisition unit 203 analyzes the video signal and determines whether the video signal is a 3D signal 2. It is also possible to detect whether the signal is a dimension signal and determine the display mode from the detection result. The mode acquisition unit 203 outputs information indicating the display mode (hereinafter referred to as “mode information”) to the four-color conversion unit 204. The display unit 105 sets the display mode to the two-dimensional mode or the three-dimensional mode according to the mode information, and displays the video signal.

The 4-color conversion unit 204 converts the RGB signal output from the inverse gamma conversion unit 202 into an extended color signal using R, G, B, and extended colors. When converting to an extended color signal, the four-color conversion unit 204 changes the conversion method from the RGB signal to the extended color signal based on the mode information output from the mode acquisition unit 203. When determining that the three-dimensional mode is based on the mode information, the four-color conversion unit 204 converts the RGB signal in the first color conversion mode and generates an extended color signal (RGBCex). On the other hand, when determining that the two-dimensional mode is based on the mode information, the four-color conversion unit 204 converts the RGB signal in the second color conversion mode and generates an extended color signal (RGBCex). Details of the first color conversion mode and the second color conversion mode will be described later. The four-color conversion unit 204 outputs the generated extended color signal (RGBCex) to the driver 205.

The driver 205 converts the extended color signal output from the four-color conversion unit 204 into a display signal that can be displayed on the display unit 105.

2. Operation of PDP Television A video signal conversion operation in the PDP television 1 configured as described above will be described with reference to the drawings.

FIG. 4 is a flowchart until the video signal is converted into the extended color signal. Hereinafter, for convenience of explanation, it is assumed that a YCbCr video signal is input to the input / output IF unit 101 from the recorder device 2.

First, when a video signal is input from the input / output IF unit 101, the RGB conversion unit 201 converts the video signal into an RGB signal (S801). The converted RGB signal is output to the inverse gamma conversion unit 202.

When the RGB signal is input from the RGB conversion unit 201, the inverse gamma conversion unit 202 performs reverse gamma conversion on the RGB signal (S802). Then, the inverse gamma conversion unit 202 outputs the RGB signal obtained by the inverse gamma conversion to the four-color conversion unit 204.

Next, the mode acquisition unit 203 outputs mode information indicating whether the video signal is in the two-dimensional mode or the three-dimensional mode. (S803). Specifically, the mode acquisition unit 203 detects meta information added to the video signal input from the input / output IF unit 101. And the mode acquisition part 203 detects the flag information which shows whether it is a three-dimensional mode from the detected meta information. When the flag information is ON, mode information indicating the three-dimensional mode is output to the four-color conversion unit 204. Then, the process proceeds to step S804. On the other hand, when the flag information is OFF, mode information indicating the two-dimensional mode is output to the four-color conversion unit 204. In this case, the process proceeds to step S806.

When mode information indicating a three-dimensional mode is input from the mode acquisition unit 203, the four-color conversion unit 204 performs four-color conversion on the RGB signal subjected to inverse gamma conversion in the first color conversion mode to generate an extended color signal. To do. Then, the generated extended color signal is output to the driver 205 (S804). Note that the first color conversion mode is a color conversion mode for reducing crosstalk when a video signal is three-dimensionally displayed on the display unit 105. Details of the first color conversion mode will be described later.

When the extended color signal is input from the four-color conversion unit 204, the driver 205 generates a display signal that can be displayed on the display unit 105 based on the extended color signal (S805). Then, the driver 205 outputs the generated display signal to the display unit 105.

On the other hand, when mode information indicating the two-dimensional mode is input from the mode acquisition unit 203, the four-color conversion unit 204 performs four-color conversion on the RGB signal subjected to inverse gamma conversion in the second color conversion mode, and an extended color signal. Is generated (S806). Then, the generated extended color signal is output to the driver 205. Note that the second color conversion mode is a color conversion mode in which extended colors are used to improve display performance during two-dimensional display. Details of the second color conversion mode will be described later.

When a display signal is input from the driver 205, the display unit 105 displays an image that can be viewed by the viewer based on the display signal (S807).

In step S803, the mode acquisition unit 203 refers to the flag information and detects whether the mode is the three-dimensional mode. However, the mode acquisition unit 203 may detect whether or not the mode is the three-dimensional mode based on an operation signal transmitted by the user in advance. The mode acquisition unit 203 may detect whether or not the mode is the three-dimensional mode based on command information transmitted from the recorder device 2.

In step S806, as the second color conversion mode, the viewer may select one mode from the efficiency improvement mode, the color gamut expansion mode, and the luminance unevenness reduction mode.

As described above, the PDP television 1 of the present embodiment generates the display signal in the first color conversion mode when the video signal is displayed three-dimensionally, and the second signal when the video signal is displayed two-dimensionally. A display signal is generated in the color conversion mode. As described above, since the color conversion mode is switched between the case where the image is displayed two-dimensionally and the case where the image is displayed three-dimensionally, color reproduction using a color conversion mode suitable for each of the two-dimensional display and the three-dimensional display becomes possible. High-quality video playback can be realized in each display mode.

3. Color Conversion Mode Hereinafter, operations in the first color conversion mode and the second color conversion mode in the four-color conversion unit 204 will be described with reference to the drawings.

The four-color conversion unit 204 has a function of converting the RGB signal input from the inverse gamma conversion unit 202 into a color signal expressed by the four primary color points that the display unit 105 has. The four-color conversion unit 204 applies different color conversion methods depending on the display mode of the PDP television 1 (that is, the three-dimensional mode or the two-dimensional mode).

Hereinafter, for convenience of explanation, a case where the R primary color point, the G primary color point, the B primary color point, and the Y primary color point are used as the four primary color points will be described. The Y primary color point is a primary color point located between the G primary color point and the R primary color point for convenience of explanation. Further, the RGB signal output from the inverse gamma conversion unit 202 is converted into four colors by the four-color conversion unit 204, and the resulting color signal is defined as an R′G′B′Y signal.

3-1. First Color Conversion Mode The first color conversion mode is a color conversion mode for reducing crosstalk when a video signal is three-dimensionally displayed on the display unit 105. Specifically, the primary purpose of the first color conversion mode is to reduce crosstalk caused by the afterglow of the video signal displayed on the display unit 105.

Hereinafter, the characteristics of the first conversion mode will be described. Some Y color phosphors constituting the Y primary color point have a short afterglow time like the B color phosphors. Therefore, when such a Y-color phosphor with a short afterglow time is used as the phosphor of the display unit 105, a very short afterglow characteristic can be realized.

Therefore, in the first conversion mode, the use amount of the G primary color point is reduced by replacing the G primary color point with the Y primary color point. In this first conversion mode, for example, the four-color conversion unit 204 performs four-color conversion on the RGB signal based on the following conversion equations (1) to (4).

Y = min (R, G) (1)
R '= RY (2)
G ′ = G−Y (3)
B '= B (4)
The function min (R, G) in the expression (1) is a function that outputs the smaller value of the R and G values.

The conversion characteristics shown in equations (1) to (4) minimize the amount of G primary color point used for the required reproduction color. In the above example, the conversion characteristic that minimizes the usage amount of the G primary color point is shown. However, the conversion characteristic may be configured such that a part of the G primary color point is replaced with the Y primary color point.

FIG. 5 is a diagram showing color characteristics when performing four-color reproduction in the first conversion mode using the Y primary color point as an extended color. The shaded pattern in FIG. 5 indicates the amount of use of the G primary color point, as in FIG. For each color, a color symbol (R, G, B, Y, W, etc.), the R primary color point, the G primary color point, or the B primary color point usage level and the Y primary color point usage level are described. . For example, the Y primary color point is expressed as Y: 000-1. From this description, regarding the Y primary color point, it can be understood that the usage rate of the G primary color point, which was the usage rate 1 in the color characteristics shown in FIG. For the W color, W: 001-1 is indicated, and it can be understood that the usage rate of the G primary color point, which was the usage rate 1 in the color characteristics shown in FIG. In this way, by performing four-color reproduction using the Y primary color point as the extended color, the G primary color point usage rate can be reduced.

In the color characteristics as shown in FIG. 5, the color in which the usage amount of the G primary color point increases is a limited color between the G color and the C color (the color in the region 401 in FIG. 5). That is, in the color characteristics shown in FIG. 2, the use amount of the G primary color point is large in a wide range of colors surrounding GCWY. On the other hand, in the color characteristics shown in FIG. 5, the usage amount of the G primary color point is a limited color between the G color and the C color. Is reduced.

Further, the color in the region 402 shown in FIG. 5 (corresponding to the highly saturated G color) hardly exists in the object color of the natural image. Therefore, these colors are rarely required in a normal video. Therefore, even if the usage amount of the G primary color point in the region 401 increases, the influence on the entire color space is small. On the other hand, the normal video signal has a high appearance ratio of colors close to monochrome with low saturation, and therefore, the frequency of applying for the W color increases. Accordingly, the usage rate of the G primary color point being 0 in the reproduction of the W color advantageously works to reduce crosstalk in normal video display.

Therefore, when four-color conversion is performed in the first conversion mode, image quality deterioration due to crosstalk is greatly reduced, and image quality in three-dimensional display can be improved. In addition, since the obstruction factor of stereoscopic vision due to crosstalk is reduced, not only image quality but also easy-to-see 3D image quality can be realized.

3-1-1 Modified Example of First Conversion Mode A modified example of the first conversion mode that further enhances the effect of improving the image quality of three-dimensional display excluding the influence of crosstalk will be described. In the first conversion mode described above, there is a region (region 401 in FIG. 5) in which the usage amount of the G primary color point is large. In general, the color of this region is rarely input as a video signal in a natural image. However, the color of this area may be input in the case of CG, animation, an image of a luminous object such as a neon sign, or a test pattern image.

From the viewpoint of the image quality of the three-dimensional display, it is preferable for the user that the crosstalk is reduced even if the saturation of these colors is slightly reduced, rather than correctly reproducing the color of the region 401 in these videos. It may be perceived as better image quality. Whether or not the user who feels that the cross talk is reduced even if the color saturation is slightly reduced is perceived as better image quality for the user depends on the degree of afterglow of the G primary color point.

In this modification, in the improvement of the quality of 3D image display, it is more important to reduce the crosstalk of a color with a lot of crosstalk (a color located between the G color and the C color) than to reproduce a vivid color. In addition to the above-described four-color conversion in the first conversion mode, the following processing is further performed.

Therefore, in this modification, color conversion is performed to limit the color gamut from the color of the shaded area with the highest density in FIG. 5 (the color of the area on the left side of the straight line L) to the color on the right side of the straight line L. Such color conversion can be realized by a known technique such as color gamut conversion (Gamut conversion). The color gamut conversion can also be realized by a simple method of clipping a signal. As a result, the saturation of these colors slightly decreases, but the occurrence of crosstalk due to the color that can generate the most crosstalk can be reduced. Thereby, when a video signal is displayed as a 3D video, the quality of the 3D video can be improved.

3-2. Second Color Conversion Mode The first color conversion mode is a color conversion mode for reducing crosstalk when a video signal is three-dimensionally displayed on the display unit 105. On the other hand, the second color conversion mode is a color conversion mode in which extended colors are used to improve display performance during two-dimensional display. Hereinafter, the second color conversion mode will be described with reference to the drawings.

The second color conversion mode includes at least the following three modes as an improvement in display performance during two-dimensional display.
(1) Efficiency improvement mode: Conversion mode that improves luminous efficiency and reduces power consumption (2) Color gamut expansion mode: Conversion mode that increases color reproducibility by widening the color gamut (3) Brightness unevenness reduction mode: Display Conversion mode for reducing spatial luminance unevenness when a video signal is displayed on unit 105

Unlike the first color conversion mode, the second color conversion mode is not intended to reduce crosstalk by shortening the afterglow time. This is because in the two-dimensional display, the afterglow time of the phosphor has little influence on the image quality.

Hereinafter, the details of the above three conversion modes will be described with reference to the drawings.

3-2-1. Efficiency Improvement Mode Hereinafter, the efficiency improvement mode will be described. For convenience of explanation, consider the case where the Y primary color point is used as the extended color. When the Y primary color point is used, the afterglow time is shortened, but the luminous efficiency may be deteriorated.

In this case, as the second color conversion mode, it is desirable that the four-color conversion unit 204 refrain from using the Y primary color as much as possible. For example, a configuration of the four-color conversion unit 204 that reproduces a desired color using only the R, G, and B primary color points without using any Y primary color point can be considered. With this configuration, it is possible to reduce power consumption.

3-2-2. Color Gamut Expansion Mode Hereinafter, the color gamut expansion mode will be described. As an example of the color gamut expansion mode, it is conceivable to remove the restriction on the color gamut as described in the modification of the first color conversion mode.

In the first color conversion mode, the reproduction of the color gamut located to the left of the straight line L in FIG. 5 was limited in order to reduce the usage rate of the G primary color point and reduce the crosstalk. However, in the two-dimensional display in which the afterglow time of the phosphor has little influence on the image quality, the expansion of the color gamut is more effective for the image quality than the reduction of the afterglow.

Therefore, in the color gamut expansion mode, for example, the color gamut conversion performed in the modification of the first color conversion mode (that is, the color gamut located to the left of the straight line L in FIG. Color gamut conversion). Furthermore, it is possible to increase the saturation of the color in the area on the right side of the straight line L and convert it to the color in the area on the left side of the straight line L.

Further, when the Y primary color point on the straight line connecting the G primary color point and the R primary color point is used as the extended color, the chromaticity of the G primary color point is shifted to the left on the (x, y) chromaticity diagram than before. It is effective to change the phosphor to a G ′ primary color point having a chromaticity value. Since the phosphor constituting the G primary color point is a blend of a plurality of phosphors, the chromaticity value can be easily changed by changing the blending ratio. The color gamut that can be reproduced in this case is an area surrounded by a solid line shown in FIG. Instead of the color gamut between the Y color and the G color being slightly narrowed, the wide color gamut between the G ′ color and the B color is expanded. In addition, the area | region enclosed with the broken line of Fig.6 (a) shows the color gamut at the time of using the conventional primary color point.

Here, the significance of this color gamut expansion will be described with reference to FIG. The DCI color gamut, which is a wide color gamut color space used in digital cinema, corresponds to the color gamut on film and is represented by RGB. The feature is that the G primary color point is from the right, and red-yellow is rich. The RGB primary color points in FIG. 6B represent the DCI primary color points. On the other hand, the color gamut of AdobeRGB, which is a wide color gamut color space used in photographs, is represented by R-G'-B (the difference between B color and R color is small). This color space is characterized by a wide color reproduction range of an emerald (blue green) region that can represent a photograph. In any case, the bright green color that is the color of the region 501 shown in FIG. 6B does not exist in nature and does not exist as an object color. Therefore, it is not important when generating a color signal. Therefore, the RG'BY primary color point with Y color added as an extended color and G changed to G 'is a feature that is rich in red-yellow, which is a feature of the DCI gamut, and a wide feature, which is a feature of the AdobeRGB gamut. It also has an emerald color area. Therefore, it is possible to effectively perform color gamut expansion when an extended color is added.

Note that when the C color is used as the extended color, as shown in FIG. 6C, a C color having a chromaticity outside the straight line connecting GB can be realized. Therefore, as shown in FIG. 6C, a wide color gamut having both the features of the DCI color gamut and the AdobeRGB color gamut can be realized.

3-2-2-1. Modification Example of Color Gamut Expansion Mode A modification example of the color gamut expansion mode will be described. The first color conversion mode was intended to reduce crosstalk by reducing the amount of G primary color point used. At this time, it has been explained that the usage amount of the G primary color point can be reduced to 0 for the Y color and the W color. On the other hand, in the second color conversion mode used for two-dimensional display, the usage amount of the G primary color point is not reduced.

In this color conversion mode, the usage amounts of the G primary color point and the R primary color point are used for the color conversion characteristics in the first color conversion mode for colors in the color gamut of the GYR region centering on the Y color. It is characterized by being used in excess of the amount of use of the G ′ primary color point and R ′ primary color point obtained by the equations (2) and (3). This makes it possible to increase the luminance of the color gamut in the area 601 in FIG. This color gamut expansion effect will be described in more detail. FIG. 7B illustrates a state in which the hue direction (BWY direction) of the arrow 602 illustrated in FIG. 7A is viewed from the top including the luminance. Here, the Y primary color point and the Y primary color point by the R primary color point and the G primary color point are the same.

The B primary color point has low luminance, and the Y primary color point has high luminance. When the above color conversion mode is used, as shown in FIG. 7B, the color gamut of the Y color extends to the Y ′ color in the luminance direction. Of the expanded color gamut, the hatched area 603 can be effectively used for color reproduction. For example, the color of this hue is a color with high luminance such as yellow, skin color, orange, or bright yellow. When these colors are adjusted in the direction of increasing the luminance or the direction of increasing the saturation by color adjustment processing such as gradation correction or saturation expansion, the margin for the luminance is small, so that an arrow 604 in the figure indicates. Color is saturated. For example, when a person's face is exposed to light, the color is saturated and becomes yellow. However, if the color conversion mode allows the gamut of the region 603 to be sufficient for this color gamut, a brighter color than the W color can be reproduced with the flesh tone hue. Therefore, high-quality color expression is possible. The color gamut color is included in a region that can be expressed in the extended color space xvYCC, and can be input to an image obtained by photographing a yellow neon sign or the like. With the above color conversion mode, even when a yellow neon sign or the like is photographed, the color can be displayed without being saturated.

Note that Y = R + G is used here for the sake of simplicity. However, even if it is out of this relationship, the conversion is complicated, but it goes without saying that it functions similarly.

3-2-3. Brightness unevenness reduction mode Hereinafter, the brightness unevenness reduction mode will be described with reference to the drawings. FIG. 8 is a diagram showing an example of the arrangement of phosphors constituting each color in the display unit 105.

As shown in FIG. 8A, in the color arrangement of the phosphor of the display unit 105, it is desirable that the G primary color point and the Y primary color point at which the viewer can easily perceive the luminance are arranged at equal intervals. As a result, it is difficult to visually perceive uneven brightness, and a smooth video signal with less unevenness can be displayed on the display unit 105.

Here, let us consider a case where the usage amount of the G primary color point is reduced and the Y primary color point is used as much as possible (corresponding to the first color conversion mode). In this case, for the visually important W color, (R ′, G ′, B ′, Y) = (0, 0, 1, 1). In this case, the usage amount of the G primary color point having a high influence on the luminance is reduced. As a result, the influence on the luminance depends on the Y color, and the luminance frequency becomes a quarter of the sub-pixel frequency, as indicated by the hatching in FIG.

Also, consider the case where reproduction is performed using only RGB signals without using the Y primary color point (an example of the second color conversion mode). In this case, in the visually important W color display, (R ′, G ′, B ′, Y) = (1, 1, 1, 0). In this case, the amount of Y color that has a great influence on luminance is reduced. As a result, the influence on the luminance depends on the G color, and as indicated by the hatching in FIG. 8B, the luminance frequency is a quarter of the sub-pixel frequency.

In the above two cases, the luminance band is a quarter of the subpixel frequency. Therefore, in reproduction of W color, which is important for image quality, the expected brightness unevenness reduction effect by the arrangement of FIG. 8A or FIG. 8B is low, and white stripes are easily noticeable.

From the above points, in the luminance unevenness reduction mode (an example of the second color conversion mode), conversion is performed so that the usage amounts of the G color and the Y color are kept substantially equal. Such a conversion is represented by the following equation, for example.

Y = min (R, G / 2) (5)
R '= RY (6)
G ′ = G−Y (7)
B '= B (8)

When this luminance unevenness reduction mode is used, in the visually important W color display, (R ′, G ′, B ′, Y) = (1/2, 1/2, 1, 1/2) Become. Therefore, as shown in FIG. 8C, the Y and G colors that have a high influence on the luminance emit light in equal amounts. As a result, the luminance frequency can be increased to twice the frequency that is half of the sub-pixel frequency, and a high-quality two-dimensional image with little unevenness is displayed.

Also, a technology is known that can use sub-pixels to represent pixels that are a group of 3 primary color points or 4 primary color points. This technique aims to realize luminance resolution exceeding the resolution.

According to this technology, a video signal having a resolution higher than the resolution that can be expressed by a pixel is input, and the luminance component of the video signal is allowed to pass a luminance component having a frequency about twice the pixel frequency, and the color difference component is The band is limited to less than the pixel frequency, and it is converted into an RGB signal and displayed. Since this technique requires a set of three colors for color representation, the color representation is limited to a representation below the pixel frequency. However, for luminance expression, R, G, and B are treated as independent, and an expression with a resolution exceeding the pixel frequency is realized.

However, when this technology is actually applied to an RGB stripe display with three primary colors, as described above, although the G pixel has high luminance expressivity, the R pixel and B pixel have low luminance expressivity. Streaks or color blurs occurred, and it was difficult to improve the resolution as desired.

On the other hand, the subpixel processing technique is applied to the display using the extended color (here, the Y primary color point) shown in FIG. 8C, and the luminance unevenness reduction mode equations (5) to (8) are applied. Apply color conversion. As a result, G and Y pixels with high luminance representation capability exist in the pixels represented by the four primary color points, so that the luminance resolution can be doubled well, and vertical stripes and color blurs are also compared. Reduction.

As described above, the luminance unevenness reduction mode in the two-dimensional display has high affinity with the subpixel processing technology. Therefore, since the three primary color points are increased to the four primary color points, it is possible to compensate for the resolution being reduced to 3/4 by the subpixel processing technique without increasing the pixel density.

As described above, the four-color conversion characteristics in the “efficiency improvement mode”, “color gamut expansion mode”, and “brightness unevenness reduction mode” are specifically described as the “second color conversion mode” used in the two-dimensional display. did. However, the “second color conversion mode” is not limited to the color conversion described above. For example, in order to visually recognize a three-dimensionally displayed image, there is a case where glasses (hereinafter referred to as “three-dimensional glasses”) for independently viewing a right-eye image and a left-eye image are used. . In this case, color reproduction and gradation reproduction are changed by the three-dimensional glasses. Therefore, in a display device optimized for three-dimensional display, characteristics such as white balance characteristics, color conversion characteristics, and gradation characteristics in the two-dimensional display mode are different from those in the case of three-dimensional display. Therefore, it is also effective to convert these characteristics in the second color conversion mode.

Also, as described above, the first color conversion mode is used during 3D display, and the second color conversion mode is used during 2D display. For this reason, the combination of primary color points used differs between the three-dimensional display and the two-dimensional display even when the same video signal is input. That is, the light emission pattern is different. Specifically, the usage amount of the G primary color point is smaller in the three-dimensional display than in the two-dimensional display.

4). 4. Effects according to extended colors 4-1. When the C primary color point is used as the extended color FIG. 9 shows a modification when the C (cyan) primary color point is used instead of the Y primary color point. Again, for simplicity of explanation, it is assumed that the C primary color point has a chromaticity value equivalent to the chromaticity value obtained by the G primary color point + B primary color point.

As shown in FIG. 9, when the C primary color point is used, the usage amount of the G primary color point can be reduced as compared with the case where the three primary color points of RGB are used. Therefore, when the C primary color point with little afterglow is used, a high-quality three-dimensional image with little crosstalk can be displayed. Also, the point where the important W color crosstalk is reduced is the same as the case where the Y primary color point is used.

On the other hand, in the two-dimensional display, the color gamut of bright colors of C hue can be expanded.

Further, since the C color is also a color having a high contribution to the luminance, the luminance unevenness is the same as described above.

4-2. When W Primary Color Point is Used as Extended Color FIG. 10 shows a modification in which the W (white) primary color point is used instead of the Y primary color point. Again, for simplicity of explanation, the W primary color point has a chromaticity value similar to the chromaticity value obtained from the R primary color point + G primary color point + B primary color point.

As shown in FIG. 10, when the W primary color point is used, the usage amount of the G primary color point is slightly increased as compared with the case where the Y primary color point or the C primary color point is used. Compared to the case, the usage amount of the G primary color point can be reduced. Therefore, it is possible to display a high-quality three-dimensional image with less crosstalk as compared with the case of displaying three primary color points constituting an RGB signal. Also, the point where the important W color crosstalk is small is the same as the case where the Y primary color point is used.

Also, by using the W primary color point, the brightness of the W color can be expanded in two-dimensional display. Further, since the W color is also a color having a high contribution to luminance, the above-described luminance unevenness is the same as described above. Further, since the achromatic color can be expressed by only W pixels, there is a possibility that the power efficiency can be further increased.

<Correspondence between this embodiment and the present invention>
The PDP television 1 is an example of the self-luminous video display device of the present invention. The input / output IF unit 101 is an example of the input unit of the present invention. The four-color conversion unit 102 is an example of the color conversion unit of the present invention. The display unit (PDP) 105 is an example of the self-luminous panel of the present invention.

5. Summary In addition to the R primary color point, the G primary color point, and the B primary color point, the PDP television 1 in the present embodiment includes the R primary color point, the G primary color point, and the B primary color point on the (x, y) chromaticity diagram. Is a display unit (PDP) 105 that performs color reproduction using extended primary color points of different primary color points, an input / output IF unit 101 that inputs a video signal, and a display mode of the display unit (PDP) 105, and the video signal is 3 A mode acquisition unit 203 for setting a 3D mode for displaying as a 2D video or a 2D mode for displaying a video signal as a 2D video, and an R primary color point and a G primary color from the input video signal according to the set display mode. And a four-color conversion unit 204 that generates an extended color signal expressed using the points, the B primary color points, and the extended primary color points. The four-color conversion unit 102 generates an extended color signal using the first color conversion method when set to the three-dimensional mode, and is different from the first color conversion method when set to the two-dimensional mode. An extended color signal is generated using the second color conversion method.

In this way, the PDP television 1 can appropriately change the method of generating the extended color signal depending on whether the input video signal is a two-dimensional signal or a three-dimensional signal. As a result, even when switching from the three-dimensional mode to the two-dimensional mode, it is possible to provide high-quality video in each display mode.

The first color conversion mode in the present embodiment is a signal expressed by the G primary color point so that the signal value expressed by the G primary color point among the signal values expressed by the respective primary color points constituting the video signal becomes smaller. A part of the value is expressed by a primary color point different from the G primary color point.

In this way, when the four-color conversion unit 204 is set to the three-dimensional mode, when the video signal is converted into the extended color signal, the usage amount of the G primary color point can be reduced. Therefore, even when there are many G primary color points in the video signal, it is possible to reduce the influence of crosstalk.

More specifically, in the first color conversion mode, the G primary color point is set such that the signal value expressed by the G primary color point among the signal values expressed by the primary color points constituting the video signal is the minimum value. A part of the signal value to be expressed is expressed by a primary color point different from the G primary color point.

In this way, when the video signal is color-converted in the three-dimensional mode, the usage amount of the G primary color point can be minimized.

Further, when the first color conversion mode and the second color conversion mode are applied to the same video signal in the four-color conversion unit 204, the G primary colors included in the extended color signal generated in the first color conversion mode The signal value of the point is set to be equal to or less than the signal value of the G primary color point included in the extended color signal generated in the second color conversion mode.

In this way, the usage amount of the G primary color point in the 3D mode can be set to be equal to or less than the usage amount in the 2D mode. As a result, it is possible to display the 3D video as a video signal with reduced crosstalk or the same performance, rather than simply displaying the extended color signal used in the 2D video display. Further, when displaying a two-dimensional image, priority can be given to light emission efficiency and color reproducibility compared to the case of displaying a three-dimensional image.

Also, the mode acquisition unit 203 sets the display mode to the three-dimensional mode or the two-dimensional mode based on the header information of the video signal.

In this way, the mode acquisition unit 203 can determine whether the video signal is a three-dimensional signal or a two-dimensional signal only by detecting meta information of the video signal. As a result, the four-color conversion unit 204 can set a color conversion mode to be applied to the RGB signal without analyzing the RGB signal.

Also, the mode acquisition unit 203 of the PDP television 1 receives an operation signal generated according to a user operation. The mode acquisition unit 203 may set the display mode to the three-dimensional mode or the two-dimensional mode based on the received operation signal.

In this way, the mode acquisition unit 203 can determine whether the video signal is a three-dimensional signal or a two-dimensional signal only by detecting the input operation signal. Thus, the determination can be made without analyzing the header information of the video signal in the mode acquisition unit 203.

In addition to the R primary color point, the G primary color point, and the B primary color point, the PDP television 1 in the present embodiment is different from the R primary color point, the G primary color point, and the B primary color point on the (x, y) chromaticity diagram. A display unit (PDP) 105 that performs color reproduction using an extended primary color point that is a primary color point, an input / output IF unit 101 that inputs a video signal, a display mode of the display unit (PDP) 105, and a three-dimensional video signal. A mode acquisition unit 203 configured to set a three-dimensional mode for displaying as a video or a two-dimensional mode for displaying a video signal as a two-dimensional video. A display unit (PDP) 105 displays a video signal in accordance with the display mode set by the mode acquisition unit 203. The combination pattern of primary color points to be emitted in the display unit (PDP) 105 is different between the two-dimensional mode and the three-dimensional mode.

In this way, it is possible to set a combination pattern of primary color points (that is, color conversion) suitable for each video characteristic in the two-dimensional mode and the three-dimensional mode.

6). Other Embodiments Although one embodiment has been described above, the present invention is not limited to this.

For example, in the first embodiment, the example in which the idea of the present invention is applied to the PDP television 1 including the display unit 105 has been described. However, the idea of the present invention can also be applied to an apparatus that performs color conversion processing that does not include the display unit 105.

The color conversion function realized by the PDP television 1 of the first embodiment may be realized by hardware such as an integrated circuit, a program (software), and a computer (hardware) that executes the program. It can also be realized by a combination of the above.

Such a program can be distributed via a recording medium such as a CD-ROM (Compact Disc-Read Only Memory) or a communication network such as the Internet.

Further, the integrated circuit can be realized as an LSI which is a typical integrated circuit. In this case, the LSI may be composed of one chip or a plurality of chips. For example, the functional blocks other than the memory may be configured by a one-chip LSI. An integrated circuit is also referred to as an IC, a system LSI, a super LSI, or an ultra LSI depending on the degree of integration.

The integrated circuit is not limited to an LSI, and may be realized by a dedicated circuit or a general-purpose processor. An FPGA (Field Programmable Gate Array) that can be programmed after manufacturing the LSI or a circuit cell inside the LSI. You may use a reconfigurable processor that can reconfigure the connection and settings.

Furthermore, if integrated circuit technology that replaces LSI emerges in the future due to advances in semiconductor technology or other technologies derived from it, it will naturally be possible to integrate functional blocks that implement the above functions using that technology. May be. For example, it is considered possible to apply biotechnology.

In addition, in the case of integration into an integrated circuit, only the unit for storing data among the functional blocks may not be included in the configuration of one chip but may be configured separately.

The idea of the present invention is not limited to a PDP (plasma display) television, but can be applied to any self-luminous display device having afterglow characteristics.

The self-luminous video display device according to the present invention can be applied to a PDP television or the like because it can perform color conversion processing of video signals so that the user can comfortably view 3D video.

DESCRIPTION OF SYMBOLS 1 PDP television 2 Recorder apparatus 3 Antenna 4 SD card 101 Input / output IF unit 102 Signal processing unit 103 Buffer memory 104 Flash memory 105 PDP
106 Tuner 201 RGB Conversion Unit 202 Inverse Gamma Conversion Unit 203 Mode Acquisition Unit 204 Four Color Conversion Unit 205 Driver

Claims (7)

In addition to the R primary color point, the G primary color point, and the B primary color point, an extended primary color point that is a primary color point different from the R primary color point, the G primary color point, and the B primary color point on the (x, y) chromaticity diagram. A self-luminous display panel that reproduces colors using,
An input unit for inputting a video signal;
A display setting unit for setting the display mode of the self-luminous display panel to a three-dimensional mode for displaying the video signal as a three-dimensional video or a two-dimensional mode for displaying the video signal as a two-dimensional video;
A color conversion unit that generates an extended color signal expressed using the R primary color point, the G primary color point, the B primary color point, and the extended primary color point from the input video signal according to the set display mode;
With
When the color conversion unit is set to a three-dimensional mode, the color conversion unit generates the extended color signal using a first color conversion method. When the color conversion unit is set to a two-dimensional mode, the first color conversion method is Generating the extended color signal using a different second color conversion method;
Self-luminous video display device. In the first color conversion method, a signal expressed by the G primary color point so that a signal value expressed by the G primary color point among signal values expressed by the primary color points constituting the video signal becomes smaller. The self-luminous video display device according to claim 1, which is a color conversion method in which a part of a value is expressed by a primary color point different from the G primary color point. The first color conversion method is expressed by the G primary color point so that the signal value expressed by the G primary color point is the smallest among the signal values expressed by the primary color points constituting the video signal. The self-luminous video display device according to claim 2, which is a color conversion method in which a part of the signal value to be expressed is expressed by a primary color point different from the G primary color point. When the first color conversion method and the second color conversion method are applied to the same video signal in the signal processing unit, the extended color signal generated by the first color conversion method has G 2. The self-luminous video display device according to claim 1, wherein a signal value of a primary color point is equal to or less than a signal value of a G primary color point included in the extended color signal generated by the second color conversion method. The self-luminous video display device according to claim 1, wherein the display setting unit sets the display mode to the three-dimensional mode or the two-dimensional mode based on header information of the video signal. A receiver that receives an operation signal generated in response to a user operation;
The self-luminous video display device according to claim 1, wherein the display setting unit sets the three-dimensional mode or the two-dimensional mode based on an operation signal received by the receiving unit. In addition to the R primary color point, the G primary color point, and the B primary color point, an extended primary color point that is a primary color point different from the R primary color point, the G primary color point, and the B primary color point on the (x, y) chromaticity diagram. A self-luminous display panel that reproduces colors using,
An input unit for inputting a video signal;
A display setting unit for setting a display mode of the self-luminous display panel to a three-dimensional mode for displaying the video signal as a three-dimensional video or a two-dimensional mode for displaying the video signal as a two-dimensional video;
The self-luminous display panel displays a video signal according to a display mode set by the display setting unit,
The combination pattern of primary color points that emit light in the self-luminous display panel is different between the two-dimensional mode and the three-dimensional mode.
Self-luminous video display device.

Images