WO2012124007A1

WO2012124007A1 - Display device and display method

Info

Publication number: WO2012124007A1
Application number: PCT/JP2011/006928
Authority: WO
Inventors: 芳規和泉
Original assignee: パナソニック株式会社
Priority date: 2011-03-16
Filing date: 2011-12-12
Publication date: 2012-09-20

Abstract

The purpose of the present invention is to provide a display device, whereby a relative luminance difference between luminance of an image displayed by a four-color display unit and luminance of an image assumed to be displayed by a display unit not including a white sub-pixel can be visually recognized, and to provide a display method. A display device of the present invention is provided with: a four-color display unit (11), which includes red, green, blue and white sub-pixels (21-24); a signal processing unit (14), which generates red, green, blue and white output control signals on the basis of image signals, and outputs the output control signals to the four-color display unit; and a region setting unit (13), which sets a first display region (111) and a second display region (112). The signal processing unit (14) attenuates, from signal levels that correspond to the image signals, the signal levels of the red, green, blue and white output control signals (Ro1, Go1, Bo1, Wo1) of each of the sub-pixels that correspond to the first display region (111) and/or the signal levels of the red, green, blue and white output control signals (Ro2, Go2, Bo2, Wo2) of each of the sub-pixels that correspond to the second display region (112).

Description

Display device and display method

The present invention relates to a display device including a display unit such as a liquid crystal display or a plasma display panel, and a display method.

In a display device including a red sub-pixel, a green sub-pixel, a blue sub-pixel, and a white sub-pixel, a four-color display region using a red sub-pixel, a green sub-pixel, a blue sub-pixel, and a white sub-pixel as a video display region And a display device that sets a three-color display region using only a red subpixel, a green subpixel, and a blue subpixel has been proposed (see, for example, Patent Document 1). In the device described in Patent Document 1, four-color conversion is not performed in the three-color display region using only the red subpixel, the green subpixel, and the blue subpixel, or the control signal for the white subpixel is simply set to zero. It is not used for display.

However, in the apparatus described in Patent Document 1, the difference in signal processing between the three-color display area and the four-color display area is only that the control signal for the white subpixel is set to zero in the three-color display area. It has become. Therefore, the luminance of the image displayed by the four-color display unit including the red sub-pixel, the green sub-pixel, the blue sub-pixel, and the white sub-pixel, and the four-color display unit includes the red sub-pixel, the green sub-pixel, and the blue sub-pixel. It is impossible to visually recognize a relative luminance difference from the luminance displayed when it is assumed that only the sub-pixel is included and the white sub-pixel is not included.

JP 2002-149116 A

The present invention solves the above-described problem. The luminance of an image displayed by a four-color display unit, and the four-color display unit includes only a red subpixel, a green subpixel, and a blue subpixel. It is an object of the present invention to provide a display device and a display method capable of visually recognizing a relative luminance difference from the luminance displayed when it is assumed that no pixel is included.

A display device according to the present invention is input with a four-color display unit having a plurality of pixels including a red sub-pixel, a green sub-pixel, a blue sub-pixel, and a white sub-pixel that display red, green, blue, and white, respectively. From the video signal for each pixel, a red output control signal, a green output control signal, a blue output control signal for controlling display luminance of the red subpixel, the green subpixel, the blue subpixel, and the white subpixel, respectively, and A signal processing unit that generates a white output control signal and outputs the white color output control signal to the four-color type display unit; and the display area of the four-color type display unit includes the plurality of pixels of the four-color type display unit, A first display area for displaying an image with a first luminance corresponding to the luminance when it is assumed that only the green subpixel and the blue subpixel are included and the white subpixel is not included. And a region setting unit for setting a second display region for displaying an image with a second luminance corresponding to the first luminance, and the signal processing unit is configured to correspond to the first display region. Signal levels of the red output control signal, the green output control signal, the blue output control signal, and the white output control signal of the sub-pixel, and the red output control signal of the sub-pixel corresponding to the second display area, At least one of the green output control signal, the blue output control signal, and the white output control signal is attenuated from a signal level corresponding to the video signal.

A display method according to the present invention includes a four-color display unit having a plurality of pixels including a red subpixel, a green subpixel, a blue subpixel, and a white subpixel that display red, green, blue, and white, respectively. A red output control signal for controlling display luminance of each of the red sub-pixel, the green sub-pixel, the blue sub-pixel, and the white sub-pixel from the input video signal for each pixel. A signal processing step of generating a green output control signal, a blue output control signal, and a white output control signal and outputting them to the four-color display unit; and the four-color display unit as a display area of the four-color display unit Luminance when assuming that the plurality of pixels include only the red sub-pixel, the green sub-pixel, and the blue sub-pixel but not the white sub-pixel. A region setting step for setting a first display region for displaying an image with a corresponding first luminance and a second display region for displaying an image with a second luminance corresponding to the first luminance; The signal processing step includes signal levels of the red output control signal, the green output control signal, the blue output control signal, and the white output control signal of each of the sub-pixels corresponding to the first display area, and the second Corresponding to the video signal at least one of the red output control signal, the green output control signal, the blue output control signal, and the white output control signal of each sub-pixel corresponding to the display area. Attenuate from signal level.

The block diagram which shows the structure of the display apparatus of 1st Embodiment of this invention. The figure explaining the signal produced | generated by the conversion part. The figure explaining the brightness | luminance displayed on a 1st display area and a 2nd display area in 1st Embodiment. The figure which shows the display screen of a display part. The block diagram which shows the structure of the display apparatus of 2nd Embodiment of this invention. The block diagram which shows the structure of the display apparatus of 3rd Embodiment of this invention. The figure explaining the brightness | luminance displayed on a 1st display area and a 2nd display area in 3rd Embodiment. The figure which shows the display screen of a display part.

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

(First embodiment)
FIG. 1 is a block diagram showing the configuration of the display device according to the first embodiment of the present invention. As shown in FIG. 1, the display device includes a display unit 11, a mode setting unit 12, a region setting unit 13, and a signal processing unit 14. The signal processing unit 14 includes a storage unit 15, a conversion unit 16, and a correction unit 17.

The display unit 11 includes pixels arranged in a matrix. Each pixel has a red sub-pixel 21 that displays red, a green sub-pixel 22 that displays green, a blue sub-pixel 23 that displays blue, and a white sub-pixel 24 that displays white. That is, the display unit 11 constitutes a four-color display unit. As the display unit 11, various displays such as a liquid crystal display, a plasma display panel, and an organic EL (electroluminescence) display can be adopted.

The mode setting unit 12 sets an operation mode. The luminance of the image displayed on the display unit 11 that is a four-color display unit, and each pixel of the display unit 11 includes a red subpixel, a green subpixel, and a blue color. A mode for demonstrating the comparison with the brightness of the image displayed when only the sub-pixel is included and the white sub-pixel is not included (hereinafter referred to as “demo mode”), and a normal mode that is not the demo mode Set. The mode setting unit 12 is composed of, for example, operation keys that can be operated by a specific operator, and outputs a control signal S1 having a level corresponding to the setting mode to the conversion unit 16 and the correction unit 17. In this embodiment, for example, the mode setting unit 12 outputs a high-level control signal S1 when the demo mode is set, and outputs a low-level control signal S1 when the normal mode is set.

The area setting unit 13 sets a first display area 111 and a second display area 112 as display areas of the display unit 11. For example, the area setting unit 13 sets the first and

second display areas

111 and 112 based on the vertical synchronization signal and the horizontal synchronization signal included in the input video signal. The region setting unit 13 outputs a control signal S2 indicating the first and

second display regions

111 and 112 to the conversion unit 16 and the correction unit 17. The region setting unit 13 outputs the control signal S2 to the conversion unit 16 and the correction unit 17 for each pixel. In this embodiment, for example, the region setting unit 13 outputs a high-level control signal S2 to the pixels corresponding to the first display region 111, and outputs a low-level control signal S2 to the pixels corresponding to the second display region 112. To do. In the following description, when the red sub-pixel 21, the green sub-pixel 22, the blue sub-pixel 23, and the white sub-pixel 24 are integrally represented, they are simply referred to as pixels.

In the demo mode, the signal processing unit 14 displays the luminance displayed when it is assumed that each pixel of the display unit 11 includes only the red subpixel, the green subpixel, and the blue subpixel and does not include the white subpixel. The video is displayed on the first display area 111 with the corresponding first luminance, and the video is displayed on the second display area 112 with the second luminance corresponding to the first luminance. Hereinafter, the display unit when it is assumed that each pixel of the display unit 11 includes only the red subpixel, the green subpixel, and the blue subpixel and does not include the white subpixel is referred to as a “virtual display unit”.

The storage unit 15 of the signal processing unit 14 includes, for example, a hard disk or a flash memory, and stores a luminance ratio k and a luminance reduction rate p1 obtained in advance. The luminance ratio k is obtained, for example, as follows. That is, first, all the white sub-pixels 24 of the display unit 11 are displayed with the maximum light amount, and the luminance Wcd is measured. Subsequently, all the red sub-pixels 21, green sub-pixels 22, and blue sub-pixels 23 of the display unit 11 are displayed with the maximum light amount, and the luminance (Rcd + Gcd + Bcd) is measured. The luminance ratio k is a quotient obtained by dividing the former by the latter. That is, the luminance ratio k is
k = Wcd / (Rcd + Gcd + Bcd) (1)
Sought by. Then, the brightness ratio k thus obtained in advance is stored in the storage unit 15.

The luminance reduction rate p1 represents a reduction rate of the size of each sub-pixel in the display unit 11 with respect to the size of each sub-pixel in the virtual display unit. Compared with the virtual display unit when each pixel of the display unit 11 includes only the red subpixel, the green subpixel, and the blue subpixel and does not include the white subpixel, the red subpixel of the display unit 11 21, the sizes of the green sub-pixel 22 and the blue sub-pixel 23 are reduced by the amount of the white sub-pixel 24. Therefore, the maximum luminance that can be displayed by the red subpixel 21, the green subpixel 22, and the blue subpixel 23 is decreased by the size reduction. In this embodiment, for example, the red subpixel 21, the green subpixel 22, the blue subpixel 23, and the white subpixel 24 in the display unit 11 are the same size. In this case, the size of each sub-pixel of the display unit 11 is 75% of the size of each sub-pixel of the virtual display unit when the above assumption is made. Therefore, in this embodiment, p1 = 0.75 is stored in the storage unit 15.

The conversion unit 16 converts the input video signals Ri, Gi, Bi using, for example, a known method using the luminance ratio k, and the red subpixel 21, the green subpixel 22, the blue subpixel 23, and the white subpixel 24. A red color conversion signal R2, a green color conversion signal G2, a blue color conversion signal B2, and a white color conversion signal W2 used for display control are generated.

FIG. 2 is a diagram illustrating a signal generated by the conversion unit 16. Section (A) in FIG. 2 shows an example of the input video signals Ri, Gi, Bi. Section (B) of FIG. 2 shows an example of the increase signals R1, G1, and B1. Section (C) in FIG. 2 shows an example of the conversion signals R2, G2, B2, and W2. An example of a signal generation method performed by the conversion unit 16 will be described with reference to FIG.

The conversion unit 16 generates the increased signals R1, G1, and B1 increased by (1 + k) times the input video signals Ri, Gi, and Bi according to the equation (2).

R1 = (1 + k) × Ri,
G1 = (1 + k) × Gi,
B1 = (1 + k) × Bi (2)

The conversion unit 16 generates, for example, increase signals R1, G1, and B1 shown in the section (B) of FIG. 2 from the input video signals Ri, Gi, and Bi shown in the section (A) of FIG.

In FIG. 2, “1” indicates the maximum value of displayable luminance, that is, the maximum value of the gradation range that can be displayed by the red subpixel 21, the green subpixel 22, and the blue subpixel 23. When expressed in bits, it corresponds to “255”. In other words, in this embodiment, the signals of the respective colors are shown by normalizing the maximum displayable luminance value to “1”. The increase signals R 1, G 1, and B 1 are obtained by increasing the luminance level that can be displayed by the red sub-pixel 21, the green sub-pixel 22, and the blue sub-pixel 23 by obtaining the effect of increasing the luminance by the white sub-pixel 24. Represents.

The conversion unit 16 generates a white conversion signal W2 used for display control of the white sub-pixel 24 from the increase signals R1, G1, and B1 according to Expression (3).

W2 = min (R1 / k, G1 / k, B1 / k, 1) (3)

That is, the conversion unit 16 exceeds the maximum luminance value when any of R1 / k, G1 / k, and B1 / k obtained by dividing the increase signals R1, G1, and B1 by k, respectively, does not exceed the maximum luminance value. The smallest minimum R1 / k, G1 / k, and B1 / k are set as the white conversion signal W2. On the other hand, when any of R1 / k, G1 / k, and B1 / k exceeds the maximum luminance value, the conversion unit 16 sets the maximum luminance value, that is, “1” as the white color conversion signal W2.

The conversion unit 16 generates red, green, and blue conversion signals R2, G2, and B2 according to Equation (4).

R2 = R1−k × W2,
G2 = G1-k × W2,
B2 = B1−k × W2 (4)

In the expression (4), when k <1, it is possible to suppress the red conversion signal R2, the green conversion signal G2, and the blue conversion signal B2 from becoming too dark as compared with the case where the white conversion signal W2 is subtracted as it is. Can do. The method of generating the red color conversion signal R2, the green color conversion signal G2, the blue color conversion signal B2, and the white color conversion signal W2 by the conversion unit 16 is not limited to the above, and other known methods can be used.

Returning to FIG. 1, when the control signal S1 representing the normal mode is output from the mode setting unit 12, the conversion unit 16 converts the red conversion signal R2, the green conversion signal G2, and the blue conversion signal B2 as described above. And a white color conversion signal W 2 is generated and output to the correction unit 17. In addition, when the control signal S1 representing the demo mode is output from the mode setting unit 12, the conversion unit 16 performs different processing depending on the control signal S2 from the region setting unit 13 as described below. Execute.

For the input video signal of a pixel whose control signal S2 from the region setting unit 13 is a high level signal (that is, a pixel corresponding to the first display region 111), the conversion unit 16 converts the red conversion signal R2 according to Expression (5). The green color conversion signal G2, the blue color conversion signal B2, and the white color conversion signal W2 are generated and output to the correction unit 17.

R2 = Ri,
G2 = Gi,
B2 = Bi,
W2 = 0 (5)

That is, the conversion unit 16 does not perform the conversion using the above equations (2) to (4) for the pixels corresponding to the first display area 111, and uses the input video signals Ri, Gi, Bi as they are as the red conversion signal R2. , Green conversion signal G2, blue conversion signal B2, white conversion signal W2 as zero, and output to correction unit 17. The red color conversion signal R2, the green color conversion signal G2, the blue color conversion signal B2, and the white color conversion signal W2 in Equation (5) are respectively the first red color conversion signal, the first green color conversion signal, the first blue color conversion signal, and the first white color conversion. Corresponds to the signal.

For the input video signal of the pixel whose control signal S2 from the region setting unit 13 is a low level signal (that is, the pixel corresponding to the second display region 112), the conversion unit 16 applies the above equations (2) to (4). Are converted to generate a red color conversion signal R2, a green color conversion signal G2, a blue color conversion signal B2, and a white color conversion signal W2, and output them to the correction unit 17. The red color conversion signal R2, the green color conversion signal G2, the blue color conversion signal B2, and the white color conversion signal W2 in the equations (4) and (3) are respectively the second red color conversion signal, the second green color conversion signal, and the second blue color conversion signal. , Corresponding to the second white color conversion signal.

When the control signal S1 indicating the normal mode is output from the mode setting unit 12, the correction unit 17 receives the red conversion signal R2, the green conversion signal G2, the blue conversion signal B2, and the white conversion input from the conversion unit 16. The signal W2 is used as it is, a red output control signal Ro, a green output control signal Go, a blue output control signal Bo for controlling the display luminance of the red subpixel 21, the green subpixel 22, the blue subpixel 23 and the white subpixel 24, respectively. The white output control signal Wo is output to the display unit 11. In the following, when output control signals are distinguished between the first display area 111 and the second display area 112, they are referred to as a red output control signal Ro1, a red output control signal Ro2, and the like. And a red output control signal Ro.

When the control signal S1 indicating the demo mode is output from the mode setting unit 12, the correction unit 17 performs different processing according to the control signal S2 from the region setting unit 13, as described below. To do.

For the pixel whose control signal S2 from the region setting unit 13 is a high level signal (that is, the pixel corresponding to the first display region 111), the correction unit 17 receives the red conversion signal R2 and the green conversion signal input from the conversion unit 16. G2, the blue color conversion signal B2, and the white color conversion signal W2 are directly used as the red output control signal Ro1, the green color output control signal Go1, the blue color output control signal Bo1, and the white color output control signal Wo1 in the first display area 111 of the display unit 11. Output. That is, as described using the above formula (5), the white output control signal Wo1 = 0, and the white sub-pixel 24 does not contribute to video display in the first display area 111.

For the pixel whose control signal S2 from the region setting unit 13 is a low level signal (that is, the pixel corresponding to the second display region 112), the correcting unit 17 uses the red output control signal Ro2 and the green output control signal according to Expression (6). Go2, blue output control signal Bo2, and white output control signal Wo2 are generated and output to the second display area 112 of the display unit 11.

Ro2 = p1 × R2,
Go2 = p1 × G2,
Bo2 = p1 × B2,
Wo2 = p1 × W2 (6)

That is, for the pixel corresponding to the second display region 112, the correction unit 17 multiplies the red color conversion signal R2, the green color conversion signal G2, the blue color conversion signal B2, and the white color conversion signal W2 by the luminance reduction rate p1, respectively. The signal level is attenuated to generate a red output control signal Ro2, a green output control signal Go2, a blue output control signal Bo2, and a white output control signal Wo2.

FIG. 3 is a diagram for explaining the luminance displayed in the first display area 111 and the second display area 112 in the first embodiment. Section (A) in FIG. 3 is a diagram schematically illustrating the color gamut of the virtual display unit. Section (B) in FIG. 3 is a diagram schematically showing a color gamut when the display unit 11 does not cause the white sub-pixel 24 to emit light. Section (C) in FIG. 3 is a diagram schematically illustrating the color gamut of the display unit 11. Section (D) of FIG. 3 is a diagram schematically showing a color gamut when the signal level of section (C) of FIG. 3 is multiplied by p1 (in this embodiment, for example, p1 = 0.75). FIG. 4 is a diagram showing the display screen 110 of the display unit 11. The brightness displayed in the first display area 111 and the second display area 112 in the first embodiment will be described with reference to FIGS. 3 and 4.

As can be seen by comparing the section (A) of FIG. 3 and the section (C) of FIG. 3, the red subpixel R, the green subpixel G, and the blue subpixel of the display unit 11 shown in the section (C) of FIG. The size of B is reduced by the amount of white subpixel W compared to the size of red subpixel R, green subpixel G, and blue subpixel B of the virtual display section shown in section (A) of FIG. Yes.

Suppose that the maximum luminance Lmax that can be displayed in the color gamut of the virtual display section shown in section (A) of FIG. Here, for convenience of explanation, Lmax = 1. As shown in section (B) of FIG. 3, Lmax = 1 cannot be realized when the display unit 11 does not cause the white subpixel 24 to emit light. As described above, the sizes of the red sub-pixel R, the green sub-pixel G, and the blue sub-pixel B of the display unit 11 are respectively the red sub-pixel R, the green sub-pixel G, and the blue sub-pixel of the virtual display unit. Since the white subpixel W is smaller than the size of B, the maximum luminance that can be displayed only by the red subpixel R, the green subpixel G, and the blue subpixel B of the display unit 11 is reduced. It is. In this embodiment, since the luminance reduction rate p1 = 0.75, the maximum luminance Lmax that can be displayed when the display unit 11 does not cause the white subpixel 24 to emit light is Lmax = 0.75.

On the other hand, as shown in the section (C) of FIG. 3, the color gamut of the display unit 11 is small in size of the red subpixel R, the green subpixel G, and the blue subpixel B in the R, G, and B directions. The color gamut of the virtual display section shown in the section (A) of FIG. 3 is smaller by the amount (that is, the luminance reduction rate p1). However, the maximum luminance value Lmax that can be displayed in the section (C) of FIG. 3 is increased by the amount of the white sub-pixel W (that is, the luminance ratio k) compared to the section (A) of FIG. . The luminance ratio k in the above equation (1) is, for example, k = 0.6 in FIG. At this time, since p1 = 0.75, the luminance increase rate p2 of the maximum luminance that can be displayed by the display unit 11 with respect to the maximum luminance that can be displayed by the virtual display unit is
p2 = (1 + k) × p1
= 1.6 × 0.75 = 1.2 (7)
It becomes. That is, as shown in section (C) of FIG. 3, the maximum luminance Lmax that can be displayed in the color gamut of the display unit 11 is Lmax = 1.2.

In order to compare the luminance of the video displayed by the virtual display unit with the luminance of the video displayed by the display unit 11, the luminance of the color gamut shown in the section (A) of FIG. It is necessary to compare the luminance of the color gamut shown in section (C). That is, it is necessary to compare Lmax = 1 (virtual display portion) and Lmax = 1.2 (display portion 11). However, as described above, the display unit 11 cannot realize the color gamut shown in the section (A) of FIG.

Therefore, in this embodiment, as shown in section (D) of FIG. 3, the signal level is attenuated by the luminance decrease of section (B) of FIG. 3 relative to section (A) of FIG. The brightness is reduced. That is, the maximum luminance Lmax that can be displayed in the color gamut shown in the section (D) of FIG.
Lmax = 1.2 × p1 = 1.2 × 0.75 = 0.9
It becomes. In this embodiment, instead of comparing the luminance of the color gamut shown in section (A) of FIG. 3 with the luminance of the color gamut shown in section (C) of FIG. The luminance of the color gamut shown in B) is compared with the luminance of the color gamut shown in section (D) of FIG. Thereby, the luminance of the video displayed by the virtual display unit and the luminance of the video displayed by the display unit 11 can be correctly compared.

In the demo mode, as shown in FIG. 4, the area setting unit 13 divides the display screen 110 of the display unit 11 and sets a first display area 111 and a second display area 112. Then, the signal processing unit 14 displays an image based on the color gamut shown in the section (B) of FIG. 3 in the first display area 111, that is, an image having the maximum luminance Lmax = 0.75. Further, the signal processing unit 14 displays an image based on the color gamut shown in the section (D) of FIG. 3 in the second display region 112, that is, an image having the maximum luminance Lmax = 0.9. As shown in FIG. 4, it is possible to visually recognize the relative luminance difference between the luminance of the video displayed on the virtual display unit and the luminance of the video displayed on the display unit 11. In FIG. 4, for convenience of explanation, the second display area 112 that is roughly hatched is higher in luminance than the first display area 111 that is densely hatched. In FIG. 4, by changing the hatching direction, the first display area 111 displays an image without using the white sub-pixel 24, and the second display area 112 displays an image using the white sub-pixel 24. It represents that. The maximum luminance Lmax = 0.75 shown in the section (B) of FIG. 3 corresponds to the first luminance, and the maximum luminance Lmax = 0.9 shown in the section (D) of FIG. 3 corresponds to the second luminance.

As described above, according to the first embodiment, the red subpixel, the green subpixel, and the blue subpixel of the display unit 11 with respect to the sizes of the red subpixel, the green subpixel, and the blue subpixel of the virtual display unit. In consideration of the luminance reduction rate representing the size reduction rate, the video of the first display area 111 and the video of the second display area 112 are generated. That is, the image of the first display area 111 is displayed without causing the white sub-pixel 24 to emit light among the pixels corresponding to the first display area 111. Further, the video level of the video signal of the pixel corresponding to the second display area 112 is attenuated by the luminance reduction rate p1 with respect to the input video signal level, and the video in the second display area 112 is displayed. Therefore, it is possible to correctly compare the luminance of the video displayed by the virtual display unit and the luminance of the video displayed by the display unit 11 while using the display unit 11 that is a four-color display unit. Further, it is possible to visually recognize a relative luminance difference between the luminance of the video displayed on the virtual display unit and the luminance of the video displayed on the display unit 11.

(Second Embodiment)
FIG. 5 is a block diagram showing a configuration of a display device according to the second embodiment of the present invention. In the second embodiment, the same reference numerals are assigned to the same elements as in the first embodiment. The display device of the second embodiment shown in FIG. 5 includes the conversion unit 161 instead of the conversion unit 16 in the display device of the first embodiment shown in FIG. 1, and the correction unit 171 instead of the correction unit 17. Prepare. Moreover, in 2nd Embodiment, the position of the conversion part and the correction | amendment part is replaced with respect to 1st Embodiment. Hereinafter, the second embodiment will be described focusing on differences from the first embodiment.

When the control signal S1 indicating the normal mode is output from the mode setting unit 12, the correction unit 171 outputs the input video signals Ri, Gi, Bi to the conversion unit 161 as they are. Further, when the control signal S1 representing the demo mode is output from the mode setting unit 12, the correction unit 171 performs different processing depending on the control signal S2 from the region setting unit 13, as will be described below. Execute.

For the pixel when the control signal S2 from the region setting unit 13 is a high level signal (that is, the pixel corresponding to the first display region 111), the correction unit 171 converts the input video signals Ri, Gi, Bi as they are. 161 to output. In addition, the correction unit 171 determines the red correction signal Ric1 and the green color for the pixel when the control signal S2 from the region setting unit 13 is a low level signal (that is, the pixel corresponding to the second display region 112) according to Expression (8). The correction signal Gic1 and the blue correction signal Bic1 are generated and output to the conversion unit 161.

Ric1 = p1 × Ri,
Gic1 = p1 × Gi,
Bic1 = p1 × Bi (8)

That is, the correction unit 171 attenuates the signal level by multiplying the input video signals Ri, Gi, Bi of the pixels corresponding to the second display region 112 by the luminance reduction rate p1, respectively, and thereby red correction signal Ric1, green A correction signal Gic1 and a blue correction signal Bic1 are generated.

When the control signal S1 indicating the normal mode is output from the mode setting unit 12, the conversion unit 161 operates in exactly the same way as the conversion unit 16 of the first embodiment, and the above equations (2) to ( 4), a red color conversion signal R2, a green color conversion signal G2, a blue color conversion signal B2, and a white color conversion signal W2 are generated. The converter 161 generates the red color conversion signal R2, the green color conversion signal G2, the blue color conversion signal B2, and the white color conversion signal W2 as they are, and the red color output control signal Ro, the green color output control signal Go, the blue color output control signal Bo, and the white color output control. The signal Wo is output to the display unit 11. In addition, when the control signal S1 representing the demo mode is output from the mode setting unit 12, the conversion unit 161 performs different processing depending on the control signal S2 from the region setting unit 13, as described below. Execute.

The conversion unit 161 is exactly the same as the conversion unit 16 of the first embodiment for pixels when the control signal S2 from the region setting unit 13 is a high-level signal (that is, pixels corresponding to the first display region 111). In operation, the red color conversion signal R2, the green color conversion signal G2, the blue color conversion signal B2, and the white color conversion signal W2 are generated according to the above equations (2) to (4). The converter 161 uses the generated red conversion signal R2, green conversion signal G2, and blue conversion signal B2 as the red output control signal Ro1, green output control signal Go1, and blue output control signal Bo1 as they are for the first display on the display unit 11. Output to area 111. Further, the conversion unit 161 sets the white output control signal Wo1 to zero and does not cause the white subpixel 24 to emit light.

In addition, the conversion unit 161 replaces the input video signals Ri, Gi, and Bi for pixels when the control signal S2 from the region setting unit 13 is a low level signal (that is, pixels corresponding to the second display region 112). , Except that the red correction signal Ric1, the green correction signal Gic1 and the blue correction signal Bic1 input from the correction unit 171 operate in the same manner as the conversion unit 16 of the first embodiment, and the red conversion signal Rc2, green A conversion signal Gc2 and a blue color conversion signal Bc2 are generated.

That is, the conversion unit 161 generates the increase signals Rc1, Gc1, and Bc1 according to the equation (9) similarly to the equation (2).

Rc1 = (1 + k) × Ric1,
Gc1 = (1 + k) × Gic1,
Bc1 = (1 + k) × Bic1 (9)

Also, the conversion unit 161 generates the white color conversion signal Wc2 according to the equation (10), similarly to the above equation (3).

Wc2 = min (Rc1 / k, Gc1 / k, Bc1 / k, 1) ... (10)

Also, the conversion unit 161 generates the red color conversion signal Rc2, the green color conversion signal Gc2, and the blue color conversion signal Bc2 according to the equation (11) as in the above equation (4).

Rc2 = Rc1-k × Wc2,
Gc2 = Gc1-k × Wc2,
Bc2 = Bc1−k × Wc2 (11)

Also, the conversion unit 161 generates a red output control signal Ro2, a green output control signal Go2, a blue output control signal Bo2, and a white output control signal Wo2 according to Expression (12).

Ro2 = Rc2,
Go2 = Gc2,
Bo2 = Bc2,
Wo2 = Wc2 (12)

That is, in the second embodiment, since the correction unit 171 has already multiplied the luminance reduction rate p1 by the input video signals Ri, Gi, Bi to attenuate the signal level, the pixels corresponding to the second display area 112 , The red color conversion signal Rc2, the green color conversion signal Gc2, the blue color conversion signal Bc2 and the white color conversion signal Wc2 are directly used as the red output control signal Ro2, the green color output control signal Go2, the blue color output control signal Bo2 and the white color output control signal Wo2.

As described above, according to the second embodiment, as in the first embodiment, the red sub-pixel of the display unit 11 with respect to the sizes of the red sub-pixel, the green sub-pixel, and the blue sub-pixel of the virtual display unit. The video of the first display area 111 and the video of the second display area 112 are generated in consideration of the luminance reduction rate indicating the reduction rate of the size of the green subpixel and the blue subpixel. That is, the signal processing unit 14 generates and displays the video of the first display area 111 based on the input video signal without causing the white subpixel 24 to emit light. Further, the signal processing unit 14 attenuates the signal level by multiplying the input video signal of the pixel corresponding to the second display area 112 by the luminance reduction rate, and generates and displays the video of the second display area 112. ing. Therefore, it is possible to correctly compare the luminance of the video displayed by the virtual display unit and the luminance of the video displayed by the display unit 11 while using the display unit 11 that is a four-color display unit. Further, it is possible to visually recognize a relative luminance difference between the luminance of the video displayed on the virtual display unit and the luminance of the video displayed on the display unit 11.

(Third embodiment)
FIG. 6 is a block diagram showing the configuration of the display device according to the third embodiment of the present invention. In 3rd Embodiment, the same code | symbol is assigned with respect to the element similar to 1st Embodiment. The display device according to the third embodiment shown in FIG. 6 includes the storage unit 151 instead of the storage unit 15 and the conversion unit 162 instead of the conversion unit 16 in the display device of the first embodiment shown in FIG. And a correction unit 172 is provided instead of the correction unit 17. Moreover, in 3rd Embodiment, the position of the conversion part and the correction | amendment part is replaced with respect to 1st Embodiment. In the third embodiment, the control signal S1 of the mode setting unit 12 and the control signal S2 of the region setting unit 13 are not output to the conversion unit 162 but are output only to the correction unit 172. Hereinafter, the third embodiment will be described focusing on differences from the first embodiment.

The storage unit 151 stores the luminance ratio k. In addition, the storage unit 151 stores the luminance increase rate p <b> 2 described using the above equation (7). In the third embodiment, p2 = 1.2 as in the first embodiment.

When the control signal S1 representing the normal mode is output from the mode setting unit 12, the correction unit 172 outputs the input video signals Ri, Gi, Bi to the conversion unit 162 as they are. Further, when the control signal S1 representing the demo mode is output from the mode setting unit 12, the correction unit 172 performs different processing depending on the control signal S2 from the region setting unit 13, as will be described below. Execute.

For the pixel when the control signal S2 from the region setting unit 13 is a low-level signal (that is, the pixel corresponding to the second display region 112), the correction unit 172 uses the equation (13) from the input video signals Ri, Gi, Bi. ), A red correction signal Ric2, a green correction signal Gic2, and a blue correction signal Bic2 are generated and output to the converter 162.

Ric2 = Ri,
Gic2 = Gi,
Bic2 = Bi (13)

That is, the correction unit 172 outputs the input video signals Ri, Gi, Bi to the conversion unit 162 as they are as the red correction signal Ric2, the green correction signal Gic2, and the blue correction signal Bic2 without being attenuated.

In addition, the correction unit 172 uses the input video signals Ri, Gi, Bi for the pixels when the control signal S2 from the region setting unit 13 is a high level signal (that is, the pixels corresponding to the first display region 111). The red correction signal Ric2, the green correction signal Gic2, and the blue correction signal Bic2 are generated by (14) and output to the conversion unit 162.

Ric2 = (1 / p2) × Ri,
Gic2 = (1 / p2) × Gi,
Bic2 = (1 / p2) × Bi (14)

That is, as will be described later with reference to FIG. 7, the correction unit 172 has a signal level so that the luminance of the video displayed in the first display area 111 corresponds to the luminance of the video displayed by the virtual display unit. Gain processing that attenuates is performed.

The conversion unit 162 performs normal signal conversion processing regardless of whether the control signal S1 output from the mode setting unit 12 is a signal indicating the normal mode or a signal indicating the demo mode. That is, when the control signal S1 indicating the normal mode is output from the mode setting unit 12, the conversion unit 162 uses the input video signals Ri, Gi, Bi input from the correction unit 172, and the above equation ( 2) to 4), a red color conversion signal R2, a green color conversion signal G2, a blue color conversion signal B2 and a white color conversion signal W2 are generated. The generated conversion signals are directly used as a red output control signal Ro, a green output control signal Go, and a blue color. The output control signal Bo and the white output control signal Wo are output to the display unit 11.

When the control signal S1 representing the demo mode is output from the mode setting unit 12, the conversion unit 162 replaces the input video signals Ri, Gi, Bi with the red correction signal Ric2, the green correction signal Gic2, and the blue color. Other than using the correction signal Bic2, the operation is exactly the same as the conversion unit 16 of the first embodiment, and the red color conversion signal R2, the green color conversion signal G2, the blue color conversion signal B2, and the white color conversion signal W2 are generated.

That is, the conversion unit 162 generates the increase signals R1, G1, and B1 according to the equation (15) similarly to the equation (2).

R1 = (1 + k) × Ric2,
G1 = (1 + k) × Gic2,
B1 = (1 + k) × Bic2 (15)

Further, the conversion unit 162 generates the white color conversion signal W2 according to the equation (16), similarly to the equation (3).

W2 = min (R1 / k, G1 / k, B1 / k, 1) ... (16)

Also, the conversion unit 162 generates red, green, and blue conversion signals R2, G2, and B2 according to the equation (17), similarly to the equation (4).

R2 = Rc1-k × W2,
G2 = Gc1-k × W2,
B2 = Bc1−k × W2 (17)

Further, the conversion unit 162 converts the red output control signal Ro, the green output control signal Go, and the blue color with respect to all the pixels of the display unit 11, that is, the pixels corresponding to the first and

second display regions

111 and 112 according to the equation (18). An output control signal Bo and a white output control signal Wo are generated and output to the display unit 11.

Ro = R2,
Go = G2,
Bo = B2,
Wo = W2 (18)

That is, the conversion unit 162 uses the generated conversion signals as they are as the red output control signal Ro, the green output control signal Go, the blue output control signal Bo, and the white output control signal Wo.

Thus, in the third embodiment, an image is displayed using the white sub-pixel 24 also in the first display area 111. In the third embodiment, since the correction unit 172 performs gain processing for attenuating the signal level only for the video signal of the pixel corresponding to the first display region 111, the conversion unit 162 Regardless of the

second display areas

111 and 112, a signal output from the correction unit 172 is used to generate a red output control signal Ro, a green output control signal Go, a blue output control signal Bo, and a white output control signal Wo. To the display unit 11.

FIG. 7 is a diagram for explaining the luminance displayed in the first display area 111 and the second display area 112 in the third embodiment. Section (A) in FIG. 7 is a diagram schematically illustrating the color gamut of the virtual display unit. Section (B) in FIG. 7 is a diagram schematically illustrating a color gamut when the display unit 11 does not cause the white sub-pixel 24 to emit light. Section (C) in FIG. 7 is a diagram schematically illustrating the color gamut of the display unit 11. Section (D) in FIG. 7 is a diagram schematically showing a color gamut when the signal level of section (C) in FIG. 7 is (1 / p2) times (in this embodiment, for example, p2 = 1.2). is there. FIG. 8 is a diagram showing the display screen 110 of the display unit 11. The brightness displayed in the first display area 111 and the second display area 112 in the third embodiment will be described with reference to FIGS.

The drawings shown in sections (A), (B), and (C) of FIG. 7 are exactly the same as those shown in sections (A), (B), and (C) of FIG. Is omitted. As described in the first embodiment, in order to compare the luminance of the video displayed by the virtual display unit with the luminance of the video displayed by the display unit 11, section (A) in FIG. It is necessary to compare the brightness of the color gamut shown in FIG. 7 with the brightness of the color gamut shown in section (C) of FIG. That is, it is necessary to compare Lmax = 1 (virtual display portion) and Lmax = 1.2 (display portion 11). However, as described above, the display unit 11 which is a four-color display unit cannot realize the color gamut shown in the section (A) of FIG.

Therefore, in the third embodiment, as shown in section (D) of FIG. 7, the display shown in section (C) of FIG. 7 with respect to the luminance of the virtual display unit shown in section (A) of FIG. The brightness is reduced from the brightness shown in the section (C) of FIG. As a result, the luminance equal to the luminance shown in the section (A) of FIG. 7 is realized. That is, the maximum luminance Lmax that can be displayed in the color gamut shown in the section (D) of FIG.
Lmax = p2 × (1 / p2) = 1
It becomes. In this third embodiment, instead of comparing the luminance of the color gamut shown in section (A) of FIG. 7 with the luminance of the color gamut shown in section (C) of FIG. The brightness of the color gamut shown in section (D) is compared with the brightness of the color gamut shown in section (C) of FIG. Thereby, the luminance of the video displayed by the virtual display unit and the luminance of the video displayed by the display unit 11 can be correctly compared.

In the demo mode, as shown in FIG. 8, the area setting unit 13 divides the display screen 110 of the display unit 11 and sets a first display area 111 and a second display area 112. Then, the signal processing unit 14 displays an image based on the color gamut shown in the section (D) of FIG. 7 in the first display area 111, that is, an image having the maximum luminance Lmax = 1. In addition, the signal processing unit 14 displays an image based on the color gamut shown in the section (C) of FIG. 7 in the second display region 112, that is, an image having the maximum luminance Lmax = 1.2. As shown in FIG. 8, it is possible to visually recognize the relative luminance difference between the luminance of the video displayed on the virtual display unit and the luminance of the video displayed on the display unit 11. In FIG. 8, for convenience of explanation, the second display area 112 that is roughly hatched is higher in luminance than the first display area 111 that is densely hatched. In FIG. 8, the hatching directions are the same to indicate that the first display area 111 and the second display area 112 display images using the white sub-pixels 24. The maximum luminance Lmax = 1 shown in the section (D) of FIG. 7 corresponds to the first luminance, and the maximum luminance Lmax = 1.2 shown in the section (C) of FIG. 7 corresponds to the second luminance.

As described above, according to the third embodiment, the first display area 111 is considered in consideration of the luminance increase rate of the maximum luminance that can be displayed by the display unit 11 with respect to the maximum luminance that can be displayed by the virtual display unit. And the video of the second display area 112 are generated. That is, a video is displayed on the first display area 111 by attenuating the signal level of the video signal of the pixel corresponding to the first display area 111 by the luminance increase rate with respect to the input video signal level. In the second display area 112, the video based on the input video signal is displayed as it is. Therefore, it is possible to correctly compare the luminance of the video displayed by the virtual display unit and the luminance of the video displayed by the display unit 11 while using the display unit 11 that is a four-color display unit. Further, it is possible to visually recognize a relative luminance difference between the luminance of the video displayed on the virtual display unit and the luminance of the video displayed on the display unit 11.

In the third embodiment, an image based on the color gamut shown in the section (C) of FIG. 7 is displayed in the second display area 112 shown in FIG. In other words, in the second display area 112, an image having the original brightness of the display unit 11 can be displayed. Therefore, in this respect, the third embodiment is preferable to the first and second embodiments.

In the third embodiment, the converter 162 performs normal signal conversion processing regardless of whether the control signal S1 output from the mode setting unit 12 is a signal indicating the normal mode or a signal indicating the demo mode. The control signal S1 of the mode setting unit 12 and the control signal S2 of the region setting unit 13 are not output to the conversion unit 162 but are output only to the correction unit 172. Therefore, the configuration can be simplified as compared with the first and second embodiments.

(Other)
In each of the embodiments described above, the area setting unit 13 divides the display screen 110 of the display unit 11 in half, for example, as shown in FIG. 4 or FIG. Although set, it is not limited to this. For example, a setting key 18 may be provided as indicated by a broken line in FIGS. The setting key 18 designates the positions and sizes of the first display area 111 and the second display area 112 by an external operation by an operator or the like, for example. The area setting unit 13 sets the first and

second display areas

111 and 112 having the position and size designated by the setting key 18. By providing the setting key 18, for example, the first display area 111 can be displayed in a small window in the second display area 112.

In each of the above embodiments, the area setting unit 13 always generates and outputs the control signal S2 indicating the first and

second display areas

111 and 112, but is not limited thereto. For example, as indicated by broken lines in FIGS. 1, 5, and 6, the mode setting unit 12 outputs a control signal S1 indicating the setting mode to the region setting unit 13, and the region setting unit 13 Only when the control signal S1 indicating the mode is input, the control signal S2 indicating the first and

second display areas

111 and 112 may be generated and output.

In each of the above embodiments, the three primary color signals Ri, Gi, Bi are used as the input video signal. However, for example, signals input from the outside are not limited. That is, for example, when a video signal other than the three primary color signals such as NTSC is input from the outside, the three primary color signals Ri, Gi, Bi are separated from the input video signal and used as the input video signal. That's fine.

In the first and second embodiments, the luminance reduction rate p1 stored in the storage unit 15 is set to p1 = 0.75, but is not limited thereto. For example, when the sizes of the red subpixel 21, the green subpixel 22, the blue subpixel 23, and the white subpixel 24 in the display unit 11 are not the same, each of the red subpixel, the green subpixel, and the blue subpixel instead. In addition, the luminance reduction rate for each sub-pixel of the virtual display unit may be obtained. Further alternatively, when one of the red sub-pixel, the green sub-pixel, and the blue sub-pixel is a specific color sub-pixel, the size reduction rate of the display unit 11 with respect to the virtual display unit in the specific color sub-pixel May be applied to sub-pixels of other colors. Thereby, even when the sizes of the sub-pixels are not the same, it is possible to simplify the configuration such as calculation. In other words, in the first and second embodiments, since the sizes of the sub-pixels are the same, the same luminance reduction rate p1 can be obtained regardless of which color sub-pixel is the specific color sub-pixel. become.

The specific embodiments described above mainly include inventions having the following configurations.

A display device according to the present invention is input with a four-color display unit having a plurality of pixels including a red sub-pixel, a green sub-pixel, a blue sub-pixel, and a white sub-pixel that display red, green, blue, and white, respectively. From the video signal for each pixel, a red output control signal, a green output control signal, a blue output control signal for controlling display luminance of the red subpixel, the green subpixel, the blue subpixel, and the white subpixel, respectively, and A signal processing unit that generates a white output control signal and outputs the white color output control signal to the four-color display unit; and a display region of the four-color display unit, the plurality of pixels of the four-color display unit are the red sub-pixels, A first display area for displaying an image with a first luminance corresponding to the luminance when it is assumed that only the green subpixel and the blue subpixel are included and the white subpixel is not included. And a region setting unit for setting a second display region for displaying an image with a second luminance corresponding to the first luminance, and the signal processing unit is configured to correspond to the first display region. Signal levels of the red output control signal, the green output control signal, the blue output control signal, and the white output control signal of the sub-pixel, and the red output control signal of the sub-pixel corresponding to the second display area, At least one of the green output control signal, the blue output control signal, and the white output control signal is attenuated from a signal level corresponding to the video signal.

According to this configuration, the four-color display unit has a plurality of pixels including a red sub-pixel, a green sub-pixel, a blue sub-pixel, and a white sub-pixel that display red, green, blue, and white, respectively. The signal processing unit, from the input video signal for each pixel, a red output control signal, a green output control signal, and a blue output control that respectively control the display luminance of the red subpixel, the green subpixel, the blue subpixel, and the white subpixel. A signal and a white output control signal are generated and output to the four-color display unit. The region setting unit assumes that a plurality of pixels of the four-color display unit includes only a red sub-pixel, a green sub-pixel, and a blue sub-pixel and does not include a white sub-pixel as a display region of the four-color display unit. A first display area for displaying an image with a first luminance corresponding to the luminance at the time and a second display area for displaying an image with a second luminance corresponding to the first luminance are set. The signal processing unit includes signal levels of the red output control signal, the green output control signal, the blue output control signal, and the white output control signal of each sub pixel corresponding to the first display area, and each sub pixel corresponding to the second display area. At least one of the red output control signal, the green output control signal, the blue output control signal, and the white output control signal is attenuated from the signal level corresponding to the video signal.

When it is assumed that a plurality of pixels of the four-color display unit includes only a red sub-pixel, a green sub-pixel, and a blue sub-pixel and does not include a white sub-pixel, the red sub-pixel, green included in the virtual display unit The size of the sub-pixel and the blue sub-pixel is the same as the size of the red sub-pixel, the green sub-pixel, and the blue sub-pixel that are actually included in the four-color display unit, because the white sub-pixel is not included. It should be bigger. Therefore, it is not possible to display an image with a brightness that can be displayed by the virtual display unit when the above assumption is made. Therefore, in the above configuration, the signal processing unit includes the signal level of each output control signal of each subpixel corresponding to the first display area and the signal level of each output control signal of each subpixel corresponding to the second display area. Is attenuated from the signal level corresponding to the video signal. Thus, the video is displayed on the first display area with the first luminance corresponding to the luminance when the above assumption is made, and the video is displayed on the second display area with the second luminance corresponding to the first luminance. That is, the first luminance is set to a luminance lower than the luminance corresponding to the video signal, or the second luminance is set to a luminance lower than the luminance corresponding to the video signal. As a result, it is assumed that the luminance that can be displayed by the four-color display unit and that the plurality of pixels of the four-color display unit include only the red subpixel, the green subpixel, and the blue subpixel and do not include the white subpixel. It is possible to visually recognize a relative luminance difference from the luminance that can be displayed by the virtual display unit.

In the above display device, the signal processing unit includes the red output control signal, the green output control signal, and the green subpixel corresponding to the first display area, the green subpixel, and the blue subpixel. The signal level of the blue output control signal is set to a signal level corresponding to the video signal, the signal level of the white output control signal of the white sub-pixel corresponding to the first display area is set to zero, and the second display area It is preferable to attenuate signal levels of the red output control signal, the green output control signal, the blue output control signal, and the white output control signal of each of the sub-pixels corresponding to the video signal from the signal level corresponding to the video signal. .

According to this configuration, the signal processing unit determines the signal levels of the red output control signal, the green output control signal, and the blue output control signal of the red subpixel, the green subpixel, and the blue subpixel corresponding to the first display area as the video signal. And the signal level of the white output control signal of the white sub-pixel corresponding to the first display area is set to zero. At this time, in the first display region, the white sub-pixel does not contribute to the display, and the video is displayed only by the red sub-pixel, the green sub-pixel, and the blue sub-pixel. However, as described above, an image cannot be displayed in the first display area with the brightness when the above assumption is made. Therefore, in this configuration, the signal processing unit corresponds to the video signal with the signal levels of the red output control signal, the green output control signal, the blue output control signal, and the white output control signal of each sub-pixel corresponding to the second display area. Attenuate from signal level. As a result, the second luminance, which is the luminance of the video displayed in the second display area, can be reduced to a value corresponding to the first luminance displayed in the first display area. As a result, it is assumed that the luminance that can be displayed by the four-color display unit and that the plurality of pixels of the four-color display unit include only the red subpixel, the green subpixel, and the blue subpixel and do not include the white subpixel. It is possible to visually recognize a relative luminance difference from the luminance that can be displayed by the virtual display unit.

Further, in the above display device, when the signal processing unit uses a sub-pixel of one color among the red sub-pixel, the green sub-pixel, and the blue sub-pixel as a specific color sub-pixel, the four-color display A quotient obtained by dividing the size of the specific color sub-pixel of the unit by the size of the specific color sub-pixel when the assumption is made, and a storage unit in which the luminance reduction rate is stored; The signal levels of the red output control signal, the green output control signal, the blue output control signal, and the white output control signal of each of the sub-pixels corresponding to the second display region are set with respect to the signal level corresponding to the video signal. Thus, it is preferable to attenuate the luminance reduction rate stored in the storage unit.

According to this configuration, when the storage unit included in the signal processing unit uses one of the red subpixel, the green subpixel, and the blue subpixel as a specific color subpixel, the four-color display unit A quotient obtained by dividing the size of the specific color sub-pixel by the size of the specific color sub-pixel when the above assumption is made is stored as the luminance reduction rate. The signal processing unit sets the signal levels of the red output control signal, the green output control signal, the blue output control signal, and the white output control signal of each sub-pixel corresponding to the second display area to the signal level corresponding to the video signal. Attenuation is attenuated by the luminance decrease rate stored in the storage unit. Therefore, the second luminance of the video displayed in the second display area can be accurately reduced to a value corresponding to the first luminance displayed in the first display area. As a result, it is assumed that the luminance that can be displayed by the four-color display unit and that the plurality of pixels of the four-color display unit include only the red subpixel, the green subpixel, and the blue subpixel and do not include the white subpixel. The relative luminance difference from the luminance that can be displayed by the virtual display unit can be reliably recognized.

In the display device, the signal processing unit may further convert a red input signal, a green input signal, and a blue input signal obtained from the video signal of the pixel corresponding to the first display region to a first red conversion signal. A first green color conversion signal and a first blue color conversion signal, a first white color conversion signal is set to zero, and the video signal of the pixel corresponding to the second display area is converted to obtain a second red color conversion A conversion unit that generates a signal, a second green conversion signal, a second blue conversion signal, and a second white conversion signal, the first red conversion signal generated by the conversion unit, the first green conversion signal, and the first The blue color conversion signal and the first white color conversion signal are used as the red output control signal, the green color output control signal, the blue color output control signal, and the white color output control signal as the first table of the four-color display unit. Output the brightness reduction rate stored in the storage unit and output to the area, the second red color conversion signal, the second green color conversion signal, the second blue color conversion signal, and the Each product obtained by multiplying the second white conversion signal is used as the red output control signal, the green output control signal, the blue output control signal, and the white output control signal, respectively. It is preferable that the correction | amendment part output to an area | region is included.

According to this configuration, the signal processing unit further includes a conversion unit and a correction unit. The conversion unit converts the red input signal, the green input signal, and the blue input signal obtained from the video signal of the pixel corresponding to the first display area into the first red conversion signal, the first green conversion signal, and the first blue conversion signal. The first white color conversion signal is set to zero. The conversion unit also converts the video signal of the pixel corresponding to the second display area to generate a second red conversion signal, a second green conversion signal, a second blue conversion signal, and a second white conversion signal. The correction unit converts the first red conversion signal, the first green conversion signal, the first blue conversion signal, and the first white conversion signal generated by the conversion unit into a red output control signal, a green output control signal, a blue output control signal, and a white color. An output control signal is output to the first display area of the four-color display unit. In addition, the correction unit multiplies the luminance reduction rate stored in the storage unit by the second red conversion signal, the second green conversion signal, the second blue conversion signal, and the second white conversion signal generated by the conversion unit, respectively. Each product is output to the second display area of the four-color display unit as a red output control signal, a green output control signal, a blue output control signal, and a white output control signal.

Therefore, the correction unit controls the output of each color to be output to the second display area so that the second luminance displayed in the second display area becomes a value corresponding to the first luminance displayed in the first display area. The signal is attenuated. As a result, it is assumed that the luminance that can be displayed by the four-color display unit and that the plurality of pixels of the four-color display unit include only the red subpixel, the green subpixel, and the blue subpixel and do not include the white subpixel. The relative luminance difference from the luminance that can be displayed by the virtual display unit can be reliably recognized.

In the display device described above, the signal processing unit further multiplies the video signal of the pixel corresponding to the second display area by the luminance reduction rate stored in the storage unit, thereby correcting red color. A correction unit for generating a signal, a green correction signal, and a blue correction signal; and converting the video signal of the pixel corresponding to the first display region to convert the red output control signal, the green output control signal, and the blue output control The white color output control signal is generated as zero and output to the first display area of the four-color display unit, and the red color correction signal and the green color correction signal generated by the correction unit And the blue correction signal are converted to generate the red output control signal, the green output control signal, the blue output control signal, and the white output control signal, respectively. Preferably includes a conversion unit to be output to the second display area of the display unit.

According to this configuration, the signal processing unit further includes a correction unit and a conversion unit. The correction unit multiplies the luminance reduction rate stored in the storage unit by the video signal of the pixel corresponding to the second display area, and generates a red correction signal, a green correction signal, and a blue correction signal. The conversion unit converts the video signal of the pixel corresponding to the first display region to generate a red output control signal, a green output control signal, and a blue output control signal, and generates a white output control signal as zero to generate a four-color type. Output to the first display area of the display unit. The conversion unit converts the red correction signal, the green correction signal, and the blue correction signal generated by the correction unit to generate a red output control signal, a green output control signal, a blue output control signal, and a white output control signal, respectively. Output to the second display area of the four-color display.

Thus, the correction unit multiplies the video signal of the pixel corresponding to the second display area by the luminance reduction rate to generate a red correction signal, a green correction signal, and a blue correction signal. The conversion unit generates a red output control signal, a green output control signal, a blue output control signal, and a white output control signal based on the red correction signal, the green correction signal, and the blue correction signal. Therefore, the correction unit controls the output of each color to be output to the second display area so that the second luminance displayed in the second display area becomes a value corresponding to the first luminance displayed in the first display area. The signal is attenuated. As a result, it is assumed that the luminance that can be displayed by the four-color display unit and that the plurality of pixels of the four-color display unit include only the red subpixel, the green subpixel, and the blue subpixel and do not include the white subpixel. The relative luminance difference from the luminance that can be displayed by the virtual display unit can be reliably recognized.

In the display device, the signal processing unit may be configured to output the red output control signal, the green output control signal, the blue output control signal, and the white output control signal of each of the sub-pixels corresponding to the first display area. And the red output control signal, the green output control signal, the blue output control signal of each of the sub-pixels corresponding to the second display area, and the signal level corresponding to the video signal are attenuated from the signal level corresponding to the video signal. It is preferable that the signal level of the white output control signal is a signal level corresponding to the video signal.

According to this configuration, the signal processing unit corresponds to the video signal with the signal levels of the red output control signal, the green output control signal, the blue output control signal, and the white output control signal of each sub-pixel corresponding to the first display area. Attenuate from signal level. Further, the signal processing unit sets the signal levels of the red output control signal, the green output control signal, the blue output control signal, and the white output control signal of each sub-pixel corresponding to the second display area to the signal level corresponding to the video signal. To do. Here, since the effect of increasing the luminance by the white sub-pixel is obtained in the four-color display unit, the maximum luminance that can be displayed by the four-color display unit is higher than the maximum luminance that can be displayed by the virtual display unit. . Therefore, in the above configuration, the signal processing unit converts the signal levels of the red output control signal, the green output control signal, the blue output control signal, and the white output control signal of each sub-pixel corresponding to the first display area into the video signal. Attenuate from corresponding signal level. Thereby, the 1st brightness | luminance of the image | video displayed on a 1st display area can be reduced to the value corresponding to the maximum brightness | luminance which said virtual display part can display. On the other hand, the signal processing unit sets the signal levels of the red output control signal, the green output control signal, the blue output control signal, and the white output control signal of each sub-pixel corresponding to the second display area as signal levels corresponding to the video signal. Therefore, the second luminance of the video displayed in the second display area is a value corresponding to the maximum luminance that can be displayed by the four-color display unit. As a result, it is assumed that the luminance that can be displayed by the four-color display unit and that the plurality of pixels of the four-color display unit include only the red subpixel, the green subpixel, and the blue subpixel and do not include the white subpixel. It is possible to visually recognize a relative luminance difference from the luminance that can be displayed by the virtual display unit.

In the above display device, the signal processing unit can display the maximum brightness that can be displayed when the four-color display unit makes the assumption, and can be displayed when the four-color display unit does not make the assumption. The quotient obtained by dividing the maximum luminance includes a storage unit that stores the luminance increase rate, and the signal processing unit includes the red output control signal and the green output control for each of the sub-pixels corresponding to the first display area. It is preferable that the signal level of the signal, the blue output control signal, and the white output control signal is attenuated by the luminance increase rate stored in the storage unit with respect to the signal level corresponding to the video signal.

According to this configuration, the signal processing unit includes the storage unit. The storage unit increases the luminance by dividing the maximum luminance that can be displayed when the four-color display unit makes the above assumption by dividing the maximum luminance that can be displayed when the four-color display unit does not make the above assumption. Remember as a rate. The signal processing unit sets the signal levels of the red output control signal, the green output control signal, the blue output control signal, and the white output control signal of each sub-pixel corresponding to the first display area with respect to the signal level corresponding to the video signal. Attenuate by the luminance increase rate stored in the storage unit. Therefore, the first luminance of the video displayed in the first display area is a value corresponding to the maximum luminance that can be displayed by the virtual display unit. As a result, it is assumed that the luminance that can be displayed by the four-color display unit and that the plurality of pixels of the four-color display unit include only the red subpixel, the green subpixel, and the blue subpixel and do not include the white subpixel. It is possible to visually recognize a relative luminance difference from the luminance that can be displayed by the virtual display unit.

In the above display device, the signal processing unit further divides the video signal of the pixel corresponding to the first display area by the luminance increase rate stored in the storage unit, thereby obtaining a red color. A red input signal, a green input signal, and a blue input signal, which are generated from the video signal of the pixel corresponding to the second display area, are generated by generating a correction signal, a green correction signal, and a blue correction signal. A correction unit for generating the green color correction signal and the blue color correction signal, and converting the red color correction signal, the green color correction signal, and the blue color correction signal generated by the correction unit into the red color output control signal and the green color output signal. It is preferable to include a conversion unit that generates a control signal, the blue output control signal, and the white output control signal and outputs the generated signal to the four-color display unit.

According to this configuration, the signal processing unit further includes a correction unit and a conversion unit. The correction unit divides the video signal of the pixel corresponding to the first display area by the luminance increase rate stored in the storage unit to generate a red correction signal, a green correction signal, and a blue correction signal. The correction unit uses the red input signal, the green input signal, and the blue input signal obtained from the video signal of the pixel corresponding to the second display area as a red correction signal, a green correction signal, and a blue correction signal. The conversion unit converts the red correction signal, the green correction signal, and the blue correction signal generated by the correction unit to generate a red output control signal, a green output control signal, a blue output control signal, and a white output control signal. Output to the color display.

Therefore, since the video signal of the pixel corresponding to the first display region is divided by the luminance increase rate, the first luminance displayed in the first display region is the maximum luminance that can be displayed by the virtual display unit. Corresponding value. On the other hand, the correction unit uses the red input signal, the green input signal, and the blue input signal obtained from the video signal of the pixel corresponding to the second display area as the red correction signal, the green correction signal, and the blue correction signal. The second luminance of the video displayed in the display area is a value corresponding to the maximum luminance that can be displayed by the four-color display unit. As a result, it is assumed that the luminance that can be displayed by the four-color display unit and that the plurality of pixels of the four-color display unit include only the red subpixel, the green subpixel, and the blue subpixel and do not include the white subpixel. It is possible to visually recognize a relative luminance difference from the luminance that can be displayed by the virtual display unit.

According to this configuration, in the signal processing step, the red output control signal for controlling the display luminance of the red subpixel, the green subpixel, the blue subpixel, and the white subpixel, and the green output from the input video signal for each pixel. A control signal, a blue output control signal, and a white output control signal are generated and output to the four-color display unit. In the region setting step, it is assumed that a plurality of pixels of the four-color display unit includes only a red sub-pixel, a green sub-pixel, and a blue sub-pixel and does not include a white sub-pixel as a display region of the four-color display A first display area for displaying an image with a first luminance corresponding to the luminance at the time and a second display area for displaying an image with a second luminance corresponding to the first luminance are set. The signal processing step includes the signal levels of the red output control signal, the green output control signal, the blue output control signal, and the white output control signal of each sub pixel corresponding to the first display area, and each sub pixel corresponding to the second display area. At least one of the red output control signal, the green output control signal, the blue output control signal, and the white output control signal is attenuated from the signal level corresponding to the video signal.

When it is assumed that a plurality of pixels of the four-color display unit includes only a red sub-pixel, a green sub-pixel, and a blue sub-pixel and does not include a white sub-pixel, the red sub-pixel, green included in the virtual display unit The size of the sub-pixel and the blue sub-pixel is the same as the size of the red sub-pixel, the green sub-pixel, and the blue sub-pixel that are actually included in the four-color display unit, because the white sub-pixel is not included. It should be bigger. Therefore, it is not possible to display an image with a brightness that can be displayed by the virtual display unit when the above assumption is made. Therefore, in the above configuration, the signal processing step includes the signal level of each output control signal of each sub-pixel corresponding to the first display area and the signal level of each output control signal of each sub-pixel corresponding to the second display area. Is attenuated from the signal level corresponding to the video signal. Thus, the video is displayed on the first display area with the first luminance corresponding to the luminance when the above assumption is made, and the video is displayed on the second display area with the second luminance corresponding to the first luminance. That is, the first luminance is set to a luminance lower than the luminance corresponding to the video signal, or the second luminance is set to a luminance lower than the luminance corresponding to the video signal. As a result, it is assumed that the luminance that can be displayed by the four-color display unit and that the plurality of pixels of the four-color display unit include only the red subpixel, the green subpixel, and the blue subpixel and do not include the white subpixel. It is possible to visually recognize a relative luminance difference from the luminance that can be displayed by the virtual display unit.

According to the present invention, at least one of the signal level of each output control signal of each sub-pixel corresponding to the first display area and the signal level of each output control signal of each sub-pixel corresponding to the second display area Is attenuated from the signal level corresponding to the video signal. Thus, the first luminance of the video displayed in the first display area is set to a luminance lower than the luminance corresponding to the video signal, or the second luminance of the video displayed in the second display area is used as the video signal. The luminance is lower than the corresponding luminance. As a result, it is assumed that the luminance that can be displayed by the four-color display unit and that the plurality of pixels of the four-color display unit include only the red subpixel, the green subpixel, and the blue subpixel and do not include the white subpixel. It is possible to visually recognize a relative luminance difference from the luminance that can be displayed by the virtual display unit.

The display device and the display method according to the present invention are useful as an apparatus and a method for suitably displaying a color image on various displays such as a liquid crystal display, a plasma display panel, and an organic EL display.

Claims

A four-color display unit having a plurality of pixels including a red sub-pixel, a green sub-pixel, a blue sub-pixel, and a white sub-pixel for displaying red, green, blue, and white, respectively;
A red output control signal, a green output control signal, and a blue output control for controlling display brightness of the red subpixel, the green subpixel, the blue subpixel, and the white subpixel, respectively, from the input video signal for each pixel. A signal processing unit that generates a signal and a white output control signal and outputs the signal to the four-color display unit;
Assuming that, as the display area of the four-color display unit, the plurality of pixels of the four-color display unit include only the red sub-pixel, the green sub-pixel, and the blue sub-pixel and do not include the white sub-pixel. An area for setting a first display area for displaying an image with a first brightness corresponding to the brightness when the image is displayed and a second display area for displaying an image with a second brightness corresponding to the first brightness A setting unit,
The signal processing unit includes signal levels of the red output control signal, the green output control signal, the blue output control signal, and the white output control signal of each sub-pixel corresponding to the first display area, and the second Corresponding to the video signal at least one of the red output control signal, the green output control signal, the blue output control signal, and the white output control signal of each sub-pixel corresponding to the display area. A display device, wherein the signal level is attenuated from the signal level.
The signal processing unit
Signal levels of the red output control signal, the green output control signal, and the blue output control signal of the red subpixel, the green subpixel, and the blue subpixel corresponding to the first display region correspond to the video signal. A signal level, the signal level of the white output control signal of the white sub-pixel corresponding to the first display area is set to zero, and
The signal levels of the red output control signal, the green output control signal, the blue output control signal, and the white output control signal of each of the sub-pixels corresponding to the second display region are determined from the signal levels corresponding to the video signal. The display device according to claim 1, wherein the display device is attenuated.
When the signal processing unit uses a sub-pixel of one color among the red sub-pixel, the green sub-pixel, and the blue sub-pixel as a specific color sub-pixel, the signal processing unit A quotient obtained by dividing the size by the size of the specific color sub-pixel when the assumption is made includes a storage unit in which the luminance reduction rate is stored,
The signal processing unit determines signal levels of the red output control signal, the green output control signal, the blue output control signal, and the white output control signal of the sub-pixels corresponding to the second display area, The display device according to claim 2, wherein the signal level corresponding to is attenuated by the luminance reduction rate stored in the storage unit.
The signal processing unit further includes:
A red input signal, a green input signal and a blue input signal obtained from the video signal of the pixel corresponding to the first display area are set as a first red conversion signal, a first green conversion signal and a first blue conversion signal, A first white color conversion signal is set to zero, and the video signal of the pixel corresponding to the second display area is converted to obtain a second red color conversion signal, a second green color conversion signal, a second blue color conversion signal, and a second color signal. A conversion unit for generating a white conversion signal;
The first red conversion signal, the first green conversion signal, the first blue conversion signal, and the first white conversion signal generated by the conversion unit are converted into the red output control signal, the green output control signal, and the blue output. The luminance reduction rate output to the first display area of the four-color display unit as the control signal and the white output control signal and stored in the storage unit is generated by the conversion unit. 2 red conversion signal, the second green conversion signal, the second blue conversion signal, and the second white conversion signal respectively multiplied by the respective products, the red output control signal, the green output control signal, and the blue output control, respectively. The display device according to claim 3, further comprising: a correction unit that outputs the signal and the white output control signal to the second display area of the four-color display unit.
The signal processing unit further includes:
A correction unit that multiplies the video signal of the pixel corresponding to the second display area by the luminance reduction rate stored in the storage unit to generate a red correction signal, a green correction signal, and a blue correction signal;
Converting the video signal of the pixel corresponding to the first display area to generate the red output control signal, the green output control signal, and the blue output control signal, and generating the white output control signal as zero; Output to the first display area of the four-color display unit, and convert the red correction signal, the green correction signal, and the blue correction signal generated by the correction unit, respectively, and the red output control signal, The display device according to claim 3, further comprising: a conversion unit that generates the green output control signal, the blue output control signal, and the white output control signal and outputs the generated signal to the second display region of the four-color display unit.
The signal processing unit
The signal levels of the red output control signal, the green output control signal, the blue output control signal, and the white output control signal of each of the sub-pixels corresponding to the first display area are determined from the signal levels corresponding to the video signal. Attenuate, and
The signal levels of the red output control signal, the green output control signal, the blue output control signal, and the white output control signal of each of the sub-pixels corresponding to the second display region are set to a signal level corresponding to the video signal. The display device according to claim 1.
The signal processing unit has a maximum luminance that can be displayed when the four-color display unit makes the assumption, and a quotient obtained by dividing the maximum luminance that can be displayed when the four-color display unit does not make the assumption, Including a storage unit stored as a luminance increase rate,
The signal processing unit
The signal levels of the red output control signal, the green output control signal, the blue output control signal, and the white output control signal of each of the sub-pixels corresponding to the first display area are set to signal levels corresponding to the video signal. On the other hand, the display device according to claim 6, wherein the display unit attenuates the luminance increase rate stored in the storage unit.
The signal processing unit further includes:
Dividing the video signal of the pixel corresponding to the first display area by the luminance increase rate stored in the storage unit to generate a red correction signal, a green correction signal, and a blue correction signal; and A correction unit that uses the red input signal, the green input signal, and the blue input signal obtained from the video signal of the pixel corresponding to the second display region as the red correction signal, the green correction signal, and the blue correction signal;
The red correction signal, the green correction signal, and the blue correction signal generated by the correction unit are converted to generate the red output control signal, the green output control signal, the blue output control signal, and the white output control signal. The display device according to claim 7, further comprising a conversion unit that outputs to the four-color display unit.
A display method used in a display device including a four-color display unit having a plurality of pixels including a red sub-pixel, a green sub-pixel, a blue sub-pixel, and a white sub-pixel that display red, green, blue, and white, respectively. ,
A red output control signal, a green output control signal, and a blue output control for controlling display brightness of the red subpixel, the green subpixel, the blue subpixel, and the white subpixel, respectively, from the input video signal for each pixel. A signal processing step of generating a signal and a white output control signal and outputting the generated signal to the four-color display unit;
Assuming that, as the display area of the four-color display unit, the plurality of pixels of the four-color display unit include only the red sub-pixel, the green sub-pixel, and the blue sub-pixel and do not include the white sub-pixel. An area for setting a first display area for displaying an image with a first brightness corresponding to the brightness when the image is displayed and a second display area for displaying an image with a second brightness corresponding to the first brightness Including a setting step,
The signal processing step includes signal levels of the red output control signal, the green output control signal, the blue output control signal, and the white output control signal of each of the sub-pixels corresponding to the first display area, and the second Corresponding to the video signal at least one of the red output control signal, the green output control signal, the blue output control signal, and the white output control signal of each sub-pixel corresponding to the display area. A display method, wherein the signal level is attenuated from the signal level.