JP2006308685A - Display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve resolution in a display apparatus equipped with a self light emitting type display of an RGBW system, when a white video including high frequency components is displayed. <P>SOLUTION: The display apparatus equipped with the self light emitting display of the RGBW system, comprises; an RGB-RGBW converting circuit in which an RGB-RGBW converting ratio is variable; a decision means for deciding whether or not it is a region in which the white video including high frequency components is displayed for each prescribed unit region, based on an RGB input signal entered to the RGB-RGBW converting circuit; and a control means for controlling the RGB-RGBW converting ratio when the RGB input signal is converted to the RGBW signal for each unit region by the RGB-RGBW converting circuit. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a display device including a self-luminous display such as an organic EL display, an inorganic EL display, and a plasma display.

  A self-luminous display such as an organic EL display has features such as thinness, light weight, and low power consumption, and its application is expanding. However, in applications such as mobile phones and digital still cameras, there is a high demand for further lower power consumption.

  An RGB organic EL display in which R, G, and B color filters are attached to a white light emitting material has already been developed. An RGB organic EL display includes an organic EL element for each RGB unit pixel. In the RGB organic EL display, since a part of the light is absorbed by the color filter when the light passes through the color filter, the light use efficiency is deteriorated. This low light utilization efficiency hinders a reduction in power consumption.

  Therefore, the applicant of the present invention is an RGBW organic EL in which one pixel is composed of four unit pixels of RGBW, the RGB unit pixel is provided with a color filter, and the W unit pixel is not provided with a color filter. A signal processing circuit for an organic EL display, which is a signal processing circuit for a display (self-luminous display) and can reduce power consumption, has already been developed and applied. An RGBW organic EL display includes an organic EL element for each RGBW unit pixel.

  A signal processing circuit of a self-luminous display already developed by the applicant will be described. The signal processing circuit of the self-luminous display already developed by the present applicant is intended for a self-luminous display such as an organic EL display in which a color filter is attached to a white light-emitting material. In this way, in the self-luminous display, as shown in FIG. 1, one pixel is composed of four unit pixels, and three unit colors, for example, R (red), G (green), B A color filter for displaying (blue) is arranged. The remaining one unit pixel is dedicated to white (W) display without a color filter.

  In such an RGBW arrangement, the unit pixel dedicated to white display does not have a color filter, so the light utilization efficiency is very high. Therefore, for example, when displaying 100% white, instead of displaying 100% white by emitting unit pixels for RGB display, it is possible to display 100% white by emitting unit pixels dedicated to white display. Thus, the power consumption can be greatly reduced.

  However, in reality, the white chromaticity obtained by the white light emitting material is often not the target white chromaticity, and the white luminescence of the unit pixel dedicated for white display is not suitable for RGB display. It is necessary to add light emission from the unit pixel.

  Therefore, when the white chromaticity obtained by the white light emitting material is different from the target white chromaticity, the RGB input signal has the same luminance and chromaticity corresponding to the input signal, and low power consumption can be achieved. A signal processing technique was developed for conversion to RGBW signals.

[1] Description of Configuration of Display Device FIG. 2 shows a configuration of the display device.
A digital RGB input signal is input to the RGB-RGBW signal conversion circuit 1. The RGB-RGBW signal conversion circuit 1 converts an RGB input signal into an RGBW signal. The RGBW signal obtained by the RGB-RGBW signal conversion circuit 1 is converted into an analog RGBW signal by the D / A conversion circuit 2. The RGBW signal obtained by the D / A conversion circuit 2 is sent to the organic EL display 3 in which one pixel is composed of four RGBW unit pixels.

[2] Explanation of basic concept of RGB-RGBW signal conversion An RGB input signal as shown in FIG. 3 is assumed. For convenience of explanation, it is assumed that gamma correction has not been applied to the RGB input signal in advance. In addition, RGB brightness that realizes target white brightness and chromaticity using only RGB is set in advance as RGB white-side reference brightness (white-side reference voltage for RGB of the D / A conversion circuit 2). To do. The white reference luminance of W is adjusted to be the target luminance (W luminance determined in step S4 in FIG. 9 described later) when only W is displayed.

In this example, the RGB input signal value is represented by 8 bits, and R = 200, G = 100, and B = 170. Since the minimum value of the RGB input signal value is 100, the RGB input signal value is set to the minimum value (min (RGB)) as shown in FIG. 4 and the remaining value (input) as shown in FIG. Signal-min (RGB)). In the case of FIG. 4, it is equivalent to the target white W _t (100) when the RGB input signal values are all 100.

If the RGBW signal values for expressing the target white W _t (255) when the RGB input signal values are all 255 are signal values (77, 0, 204, 255) as shown in FIG. The RGBW signal values for realizing the target white W _t (100) when the RGB input signal values are all 100 are as shown in FIG. Note that the RGB values other than W in the RGBW signal value for expressing the target white W _t (255) become smaller as the white chromaticity obtained by the white light emitting material approaches the target white chromaticity. .

  Signal values as shown in FIG. 6 can be obtained from RGB luminance values and RGBW luminance values for realizing the target white. Let RGBR signal values for realizing the target white when the RGB input signal values are all 255 be (R1, G1, B1, W1). The RGB luminance values for realizing the target white luminance and chromaticity are (LR1, LG1, LB1), and the RGBW luminance values for realizing the target white luminance and chromaticity are (LR2, LG2, LB2, LW2). Then, the RGBW signal values for realizing the target white when the RGB input signal values are all 255 are (R1 = 255 × LR2 / LR1, G1 = 255 × LG2 / LG1, B1 = 255 × LB2 / LB1, W1 = 255). In particular, W can be defined only by the RGBW display system, and is uniquely 255. Note that how to obtain the RGB brightness value and the RGBW brightness value for realizing the target white brightness and chromaticity will be described later.

  R, G, B, and W of FIG. 7 are calculated | required by following Formula (1).

R = 77 × 100/255 = 30
G = 0 × 100/255 = 0
B = 204 × 100/255 = 80
W = 255 × 100/255 = 100 (1)

  Therefore, the RGB values in FIG. 4 are replaced with the RGBW values in FIG. Therefore, the RGB values shown in FIG. 3 are converted into the RGBW values shown in FIG. 8 by adding the RGB values of FIG. 5 and the RGBW values of FIG.

  R, G, B, and W of FIG. 8 are calculated | required by following Formula (2).

R = 100 + 30 = 130
G = 0 + 0 = 0
B = 70 + 80 = 150
W = 0 + 100 = 100 (2)

  RGB white side reference luminance (RGB luminance value for realizing target white luminance and chromaticity), RGBW luminance value for expressing target white luminance and chromaticity, and RGB input signal value are all 255 The RGBW signal value for realizing the target white in this case is obtained in advance by panel adjustment processing.

[3] Description of the first RGB-RGBW signal conversion process

  FIG. 9 shows a panel adjustment processing procedure.

The brightness L _Wt and chromaticity coordinates (x _Wt , y _Wt ) of the target white W _t are set (step S1).

Next, the RGBW chromaticity of the organic EL display 3 is measured (step S2). For example, when measuring the chromaticity of R, only the unit pixel for R display of the organic EL display 3 is caused to emit light, and the chromaticity is measured by an optical measuring instrument. The measured RGBW chromaticity coordinates are (x _R , y _R ), (x _G , y _G ), (x _B , y _B ), and (x _W , y _W ), respectively.

Next, RGB luminance values at the time of white balance (WB) adjustment by RGB are calculated (step S3). That is, the RGB luminance values L _R (corresponding to the above LR1), L _G (above described) when expressing the luminance L _Wt and chromaticity (x _Wt , y _Wt ) of the target white W _t by three colors of RGB. L B1 (corresponding to LG1) and L _B (corresponding to LB1) are calculated. The luminance values L _R, L _G, L _B is determined from the following equation (3).

However, a _{z R = 1-x R -y} R, z G = 1-x G -y G, z B = 1-x B -y B, z Wt = 1-x Wt -y Wt.

Next, RGBW luminance values at the time of white balance (WB) adjustment by RGBW are calculated (step S4). That is, the 4 colors of RGBW, (corresponding to the LR2) luminance values L _R of RGBW in representing the target white W _t luminance L _Wt and chromaticity _{(x Wt, y Wt),} L G ( the LG 2 (corresponding to LG2), L _B (corresponding to LB2), and L _W (corresponding to LW2) are calculated.

RGBW chromaticity coordinates (x _R , y _R ), (x _G , y _G ), (x _B , y _B ), (x _W , y _W ) and target white W _t chromaticity coordinates (x _Wt , Y _Wt ) have a relationship as shown in FIG. 10, the chromaticity of the target white W _t can be expressed by only three colors of RBW. The 3 colors of RBW, brightness L _Wt and chromaticity (x _Wt, y _Wt) of the target white W _t (corresponding to the LR2) luminance values L _R of RBW in representing the equivalent to L _B (above LB2 ), L _W (corresponding to LW2) is obtained from the following equation (4). In this case, the L _G corresponding to the LG2 is 0.

However, a _{z R = 1-x R -y} R, z W = 1-x W -y W, z B = 1-x B -y B, z Wt = 1-x Wt -y Wt.

  Next, RGBW white-side reference luminance is calculated using the calculation result of step S3 (step S5).

If RGB input signal value is represented by 8 bits, white-side reference luminance of RGB, when input as RGB signals (255, 255, 255), the luminance of the white W _t of the emission luminance and emission color target L _Wt and chromaticity (x _Wt , y _Wt ) are adjusted. That is, when (255, 255, 255) is input as the RGB signal, the RGB white-side reference luminance is set such that the RGB luminances are the luminance values L _R , L _G , and L _B calculated in step S3. Is adjusted. When the RGB white side reference luminance is adjusted in this way, when the input RGB signals have the same value, the emission color always has the target white chromaticity. Note that the white-side reference luminance of W is adjusted to be the target luminance (the luminance value L _{W of} W determined in step S4 in FIG. 9) when only W is displayed.

Note that the RGBW signal value for realizing the target white W _t (255) when the RGB input signal values are all 255 is the luminance value L _R (corresponding to LR1) calculated in step S3 of the panel adjustment process. , L _G (corresponding to LG1), L _B (corresponding to LB1), and the luminance value L _R (corresponding to LR2) calculated in step S4, L _G (corresponding to LG2) , L _B (corresponding to LB2) and L _W (corresponding to LW2).

  FIG. 11 shows a procedure of signal conversion processing for converting an RGB input signal into an RGBW signal.

  First, the minimum value (min (RGB)) in the RGB input signal is determined (step S11). In the example of FIG. 3, min (RGB) = 100.

  Next, min (RGB) is subtracted from each RGB input signal (step S12). In the example of FIG. 3, as shown in FIG. 5, the subtraction results for RGB are 100, 0, and 70, respectively.

Next, min (RGB) is converted into an RGBW signal using the RGBW signal value for expressing the target white W _t (255) when the RGB input signal values are all 255 (step S13). If the RGBW signal value for expressing the target white W _t (255) is a signal value as shown in FIG. 6, in the example of FIG. 3, the RGBW signal signal value corresponding to min (RGB). Is as shown in FIG.

  Next, the RGBW signal corresponding to the RGB input signal is calculated by adding the signal value of the RGBW signal obtained in step S13 to the subtraction value {RGB-min (RGB)} calculated in step S12 ( Step S14). In the example of FIG. 3, the RGBW signal corresponding to the RGB input signal is as shown in FIG.

[4] Explanation of second RGB-RGBW signal conversion processing

  When the target white chromaticity can be expressed by only three colors of RBW, when the minimum value in the RGB input signal is the G signal, the processing of steps S11 to S14 in FIG. The RGBW signal in which one signal (G signal) of the RGB signal is 0 is obtained by the -RGBW conversion routine.

  Similarly, in the case where the target white chromaticity can be expressed by only three colors of RGW, even when the minimum value in the RGB input signal is the B signal, steps S11 to S14 in FIG. Through the processing (RGB-RGBW conversion routine), an RGBW signal in which one signal (B signal) of the RGB signals becomes 0 is obtained. Further, when the target white chromaticity can be expressed by only three colors of GBW, the processing in steps S11 to S14 in FIG. 11 is also performed when the minimum value in the RGB input signal is the R signal. By the (RGB-RGBW conversion routine), an RGBW signal in which one signal (R signal) of the RGB signal becomes 0 is obtained.

  However, when the target white chromaticity can be expressed by only three colors of RBW and the minimum value in the RGB input signal is a signal of a color other than the G signal, the target white chromaticity is When it is possible to express only by three colors of RGW, when the minimum value in the RGB input signal is a signal of a color other than the B signal, the target white chromaticity is expressed by only three colors of GBW. If the minimum value in the RGB input signal is a signal of a color other than the R signal when possible, the processing in steps S11 to S14 in FIG. 11 (RGB-RGBW conversion routine) is performed only once. Then, one signal in the RGB signal in the obtained RGBW signal does not become zero.

  That is, depending on the conditions, one signal in the RGB signal in the obtained RGBW signal does not become 0 only by performing the RGB-RGBW conversion routine once.

  When the RGB input signal is converted to the RGBW signal so that one signal in the RGBW signal in the RGBW signal becomes 0, the size of the W signal increases, the light emission efficiency increases, and the power consumption can be reduced. .

  Therefore, in the second RGB-RGBW signal conversion process, a signal conversion method is proposed in which an RGBW signal is obtained such that one signal in the RGB signal becomes 0 regardless of the conditions.

  FIG. 12 shows a procedure of second RGB-RGBW signal conversion processing for converting an RGB input signal into an RGBW signal.

Assume that the RGBW signal values for expressing the target white W _t (255) when the RGB input signal values are all 255 are signal values as shown in FIG.

  First, the minimum value (min (RGB)) in the RGB input signal is determined (step S21). As shown in FIG. 13, if the RGB input signal values are R = 200, G = 170, and B = 100, min (RGB) = 100 as shown in FIG.

  Next, min (RGB) is subtracted from each RGB input signal (step S22). In the example of FIG. 13, the subtraction results for RGB are 100, 70, and 0, respectively, as shown in FIG. That is, the RGB input signal is decomposed into the RGB signal value of FIG. 14 and the RGB signal value of FIG.

Next, min (RGB) is converted into an RGBW signal using the RGBW signal value for expressing the target white W _t (255) when the RGB input signal values are all 255 (step S23). If the RGBW signal value for realizing the target white W _t (255) is a signal value as shown in FIG. 6, in the example of FIG. 13, the signal value of the RGBW signal corresponding to min (RGB) is 16 (same as FIG. 7).

  Next, the RGBW signal corresponding to the RGB input signal is calculated by adding the signal value of the RGBW signal obtained in step S23 to the subtraction value {RGB-min (RGB)} obtained in step S22. (Step S24). In the example of FIG. 13, the RGBW signal corresponding to the RGB input signal is as shown in FIG.

  R, G, B, and W of FIG. 17 are calculated | required by following Formula (5).

R = 100 + 30 = 130
G = 70 + 0 = 70
B = 0 + 80 = 80
W = 0 + 100 = 100 (5)

  Next, it is determined whether or not the minimum value of the RGB signal in the obtained RGBW signal is 0 (step S25). When the minimum value of the RGB signal in the obtained RGBW signal is 0, the signal conversion process is terminated. That is, the RGBW signal obtained in step S24 is an RGBW output signal.

  If the minimum value of the RGB signal in the obtained RGBW signal is not 0, the obtained RGBW signal is regarded as an input RGBW signal, and the processing (RGB-RGBW conversion routine) performed in steps S21 to S24 is performed. Similar processing is performed again.

That is, when the minimum value of the RGB signal in the RGBW signal is not 0, the obtained RGBW signal is used as the R ₁ G ₁ B ₁ W ₁ input signal as shown in FIG. Then, the minimum value (min (R ₁ G ₁ B ₁ )) in the R ₁ G ₁ B ₁ input signal is determined (step S26). As shown in FIG. 18, assuming that R ₁ G ₁ B ₁ W ₁ input signals are R = 130, G = 70, B = 80, and W = 100, as shown in FIG. 20, min (R ₁ G ₁ B ₁ ) = 70.

Next, min (R ₁ G ₁ B ₁ ) is subtracted from each R ₁ G ₁ B ₁ input signal (step S27). In the example of FIG. 18, as shown in FIG. 19, the subtraction results for RGB are 60, 0, and 10, respectively. That, R ₁ G ₁ B ₁ input signal, the R ₁ G ₁ B ₁ signal values of FIG. 19, is decomposed into R ₁ G ₁ B ₁ signal values of FIG 20.

Next, min (R ₁ G ₁ B ₁ ) is converted into an RGBW signal using the RGBW signal value for expressing the target white W _t (255) when the RGB input signal values are all 255. (Step S28). If the RGBW signal value for realizing the target white W _t (255) is a signal value as shown in FIG. 6, in the example of FIG. 20, the RGBW signal corresponding to min (R ₁ G ₁ B ₁ ). The signal values are as shown in FIG.

  R, G, B, and W in FIG. 21 are obtained by the following equation (6).

R = 77 × 70/255 = 21
G = 0 × 70/255 = 0
B = 204 × 70/255 = 56
W = 255 × 70/255 = 70 (6)

Then, by adding the RGB signal values in the RGBW signals obtained in step S28 to the subtraction value calculated in step _{S27 {R 1 G 1 B 1} -min (R 1 G 1 B 1)} with obtaining the RGB signals, obtaining the W signal by adding the W signal values in RGBW signal obtained in step S28 to W ₁ in R ₁ G ₁ B ₁ W ₁ input signal (step S29). In this way, an RGBW signal is obtained.

  In the above example, the RGBW signal is as shown in FIG. R, G, B, and W of FIG. 22 are calculated | required by following Formula (7).

R = 60 + 21 = 81
G = 0 + 0 = 0
B = 10 + 56 = 66
W = 100 + 70 = 170 (7)

  Next, it is determined whether or not the minimum value of the RGB signal in the RGBW signal obtained in step S29 is 0 (step S30). When the minimum value of the RGB signal in the obtained RGBW signal is 0, the signal conversion process is terminated.

When the minimum value of the RGB signal in the obtained RGBW signal is not 0, the process returns to step S26. That is, the RGB-RGBW conversion routine is repeatedly performed until the minimum value of the RGB signal in the obtained RGBW signal becomes zero.
[5] Explanation of third RGB-RGBW signal conversion processing

  As described in the first RGB-RGBW signal conversion process, depending on the conditions, a signal that is set to 0 by subtracting min (RGB) is converted into 1 by a subsequent conversion from min (RGB) to RGBW signal. May have the above values. In such a case, the RGB-RGBW conversion routine is repeatedly performed as described in the second RGB-RGBW signal conversion process.

  In the third RGB-RGBW signal conversion process, a signal conversion method is proposed in which an RGBW signal in which at least one of the RGB signals is 0 is obtained regardless of the conditions by executing the RGB-RGBW conversion routine once. To do.

  Focusing on one signal in the RGB signals, the process of signal conversion will be described. When the signal of interest is always handled as min (RGB), and about 0.8% of the converted W signal is fed back to the signal by converting min (RGB) to an RGBW signal. Assuming that, for example, if the initial value is 50, the signal of interest changes according to the number of executions of the RGB-RGBW conversion routine as shown in the following equation (8).

  50 → 40 → 32 → 25.6 → 20.5 → 16.4 → 13.1 ... → 0 (8)

  In this case, the W signal is a value obtained by adding all the numerical values of the above equation (8), and can be obtained as the sum of an infinite geometric series having an initial term of 50 and a common ratio of 0.8. When −1 <common ratio <1, the sum of the infinite geometric series can be simplified as the following equation (9).

  Sum of infinite geometric series = first term / (1-common ratio) (9)

  Therefore, when the infinite geometric series is expressed by the above equation (8), the sum of the infinite geometric series is 50 / (1-0.8) = 250.

  In an actual system, the sum of the infinite geometric series as described above is calculated for each RGB signal, and the RGB-RGBW conversion routine is executed once, with the minimum one being min (RGB). As a result, one of the RGB signals in the obtained RGBW signal is 0, and the other two are 0 or more.

  The case where the RGB input signal values are R = 255, G = 255, and B = 50 will be described as an example.

Assuming a case where the RGBW signal value for expressing the target white W _t (255) when the RGB input signal values are all 255 is as shown in FIG. 6, conversion of min (RGB) to RGBW signal is performed. Therefore, the RGB signal feedback rate is 0.3 (= R in FIG. 6 / W in FIG. 6 = 77/255), 0 (= G in FIG. 6 / W in FIG. 6), 0.8 (= in FIG. 6). B / W in FIG. 6 = 204/255).

  If the sum of the infinite geometric series corresponding to R, G, and B is ΣR, ΣG, and ΣB, ΣR, ΣG, and ΣB are expressed by the following equation (10).

ΣR = 255 / (1-0.3) = 364
ΣG = 255 / (1-0) = 255
ΣB = 50 / (1-0.8) = 250 (10)

  Since the minimum value is 250, when 250 is subtracted from the RGB input signal value, the subtraction result is expressed by the following equation (11).

R = 255-250 = 5
G = 255-250 = 5
B = 50−250 = −200 (11)

  On the other hand, when min (RGB) (= 250) is converted into an RGBW signal, the following equation (12) is obtained.

R = 250 × 0.3 = 75
G = 255 × 0 = 0
B = 50 × 0.8 = 200
W = 250 (12)

  Therefore, the RGBW output signal is represented by the following equation (13).

R = 5 + 75 = 80
G = 5 + 0 = 5
B = −200 + 200 = 0
W = 250 (13)

  FIG. 23 shows a third RGB-RGBW signal conversion process procedure for converting an RGB input signal into an RGBW signal.

The feedback rate of the RGB signal is calculated using the RGBW signal value for expressing the target white W _t (255) when the RGB input signal values are all 255 (step S41). If the RGBW signal value for realizing the target white W _t (255) is a signal value as shown in FIG. 6, the feedback rate of the RGB signal is 0.3 (= 77/255), 0, 0. .8 (= 204/255).

  Next, for each RGB input signal, an infinite geometric series sum ΣR, ΣG, ΣB is calculated with the RGB input signal value as the first term and the feedback rate calculated in step S41 as a common ratio (step S42).

  Next, the minimum value of the sum ΣR, ΣG, ΣB of the infinite geometric series calculated for each RGB input signal is subtracted from the RGB input signal as min (RGB) (step S43).

Next, min (RGB) is converted into an RGBW signal using the RGBW signal value for expressing the target white W _t (255) when the RGB input signal values are all 255 (step S44).

Next, the RGBW signal corresponding to the RGB input signal is obtained by adding the signal value of the RGBW signal obtained in step S44 to the subtraction value {RGB-min (RGB)} obtained in step S43 ( Step S45).
JP 11-295717 A

  In the third RGB-RGBW signal conversion process shown in FIG. 23, 100% of min (RGB) is converted into an RGBW signal. That is, the RGB-RGBW conversion rate (W usage rate) was always 100%.

  If the pixel array of the RGBW-type self-luminous display is a pixel array (striped array) as shown in FIG. 24, the white chromaticity obtained by the white light-emitting material is very close to the target white chromaticity. Assume. When displaying an image including a high frequency component, an image including an edge portion, or a white image including a high frequency component (for example, white characters) on the RGBW self-luminous display having such a pixel arrangement, as shown in FIG. If only the W unit pixel is used, the video with reduced continuity is lost.

  In this case, when the RGB-RGBW conversion rate (W usage rate) is set to a value lower than 100%, the applicant of the present application causes not only the W unit pixel but also the RGB unit pixel to emit light as shown in FIG. I was able to conceive and improve the resolution.

  Further, the applicant of the present application has an RGB-RGBW conversion rate (W usage rate) of 100%, and displays a white unit pixel when displaying an image including a high-frequency component, an image including an edge portion, or a white image including a high-frequency component. The present inventors have conceived that the resolution can be improved by reducing the RGB-RGBW conversion rate (W usage rate) even when other RGB pixels emit light slightly.

  An object of the present invention is to provide a display device that can improve resolution when displaying a white image including a high-frequency component in a display device including an RGBW self-luminous display.

  According to the first aspect of the present invention, there is provided an RGB-RGBW conversion circuit that converts an RGB signal into an RGBW signal, and an RGBW type self-luminous display that displays an image based on the RGBW signal obtained by the RGB-RGBW conversion circuit. The display device includes an RGB-RGBW conversion circuit having a variable RGB-RGBW conversion rate, and an image including a high-frequency component for each predetermined unit area is displayed based on an RGB input signal input to the RGB-RGBW conversion circuit. An RGB-RGBW conversion rate when the RGB input signal is converted into an RGBW signal by the RGB-RGBW conversion circuit based on a determination unit for determining whether the region is a region to be processed and a determination result for each unit region by the determination unit It is characterized by comprising a control means for controlling each unit area.

  According to a second aspect of the present invention, in the invention according to the first aspect, the control means determines an RGB-RGBW conversion rate for a unit area determined by the determination means to display an image including a high frequency component. Is set to a value lower than the RGB-RGBW conversion rate used for the unit area determined not to display an image including a high-frequency component.

  According to a third aspect of the present invention, there is provided an RGB-RGBW conversion circuit that converts an RGB signal into an RGBW signal, and an RGBW self-luminous display that displays an image based on the RGBW signal obtained by the RGB-RGBW conversion circuit. In an equipped display device, an RGB-RGBW conversion circuit having a variable RGB-RGBW conversion rate, and an RGB input signal input to the RGB-RGBW conversion circuit determine whether or not each predetermined unit area is an edge portion. Control for controlling the RGB-RGBW conversion rate for each unit region when the RGB-RGBW conversion circuit converts the RGB input signal into the RGBW signal based on the determination unit and the determination result for each unit region by the determination unit Means are provided.

  According to a fourth aspect of the present invention, in the invention according to the third aspect, the control means determines the RGB-RGBW conversion rate at the edge portion for the unit area determined as the edge portion by the determination means. It is characterized in that it is set to a value lower than the RGB-RGBW conversion rate used for a unit area that is not determined to be present.

  According to a fifth aspect of the present invention, there is provided an RGB-RGBW conversion circuit that converts an RGB signal into an RGBW signal, and an RGBW self-luminous display that displays an image based on the RGBW signal obtained by the RGB-RGBW conversion circuit. An RGB-RGBW conversion circuit having a variable RGB-RGBW conversion rate, and a white image including a high-frequency component for each predetermined unit area is displayed based on an RGB input signal input to the RGB-RGBW conversion circuit. RGB-RGBW conversion when the RGB input signal is converted into an RGBW signal by the RGB-RGBW conversion circuit based on a determination unit for determining whether or not the region is to be processed and a determination result for each unit region by the determination unit Control means for controlling the rate for each unit area is provided.

  According to a sixth aspect of the invention, in the fifth aspect of the invention, the control means performs RGB-RGBW conversion for the unit area determined by the determination means to display a white image including a high frequency component. The rate is set to a value lower than the RGB-RGBW conversion rate used for a unit area determined that a white image including a high-frequency component is not displayed.

  The invention described in claim 7 includes an RGB-RGBW conversion circuit that converts an RGB signal into an RGBW signal, and an RGBW self-luminous display that displays an image based on the RGBW signal obtained by the RGB-RGBW conversion circuit. An RGB-RGBW conversion circuit having a variable RGB-RGBW conversion rate, a display color is determined for each predetermined unit area based on an RGB input signal input to the RGB-RGBW conversion circuit, and an edge portion And an RGB-RGBW conversion rate when the RGB input signal is converted into an RGBW signal by the RGB-RGBW conversion circuit based on a determination result for each unit area by the determination unit. It is characterized by comprising a control means for controlling each unit area.

  The invention according to claim 8 is the invention according to claim 7, wherein the determination means satisfies a condition that, for each unit region, all of the RGB input signals are larger than a predetermined threshold and are edge portions. For the unit area determined by the determining means to satisfy the condition that all of the RGB input signals are larger than a predetermined threshold and are edge portions, the control means The RGBW conversion rate is set to a value lower than the RGB-RGBW conversion rate used for the unit area determined not to satisfy the condition.

  The invention according to claim 9 includes an RGB-RGBW conversion circuit that converts an RGB signal into an RGBW signal, and an RGBW self-luminous display that displays an image based on the RGBW signal obtained by the RGB-RGBW conversion circuit. In the display device, the RGB-RGBW conversion circuit having a variable RGB-RGBW conversion rate, and the color intensity is determined for each predetermined unit area based on the RGB input signal input to the RGB-RGBW conversion circuit. An RGB-RGBW conversion rate when the RGB input signal is converted into an RGBW signal by the RGB-RGBW conversion circuit based on a determination unit for determining a high frequency component, and a determination result for each unit region by the determination unit. It is characterized by comprising control means for controlling each time.

  According to a tenth aspect of the present invention, in the invention according to the ninth aspect, when the RGB input signal is Rin, Gin, Bin, the determination means is | Rin−Gin |, | Gin−Bin | And a means for calculating the maximum value of | Bin−Rin | as the color density, and a W signal obtained by RGB-RGBW conversion when the RGB-RGBW conversion rate is assumed to be 100% for each unit area. Means for calculating and calculating a high frequency component included in the calculated W signal, wherein the control means is based on the color density and the high frequency component calculated for each unit area by the determination means. An RGB-RGBW conversion rate when the RGB input signal is converted into an RGBW signal by an RGBW conversion circuit is controlled for each unit region.

  According to an eleventh aspect of the present invention, in the invention according to the tenth aspect, the control means is configured such that the smaller the color density calculated by the determination means and the higher the high frequency component calculated by the determination means, The RGB-RGBW conversion rate is controlled so that the RGB-RGBW conversion rate becomes small.

  According to the present invention, when a white image including a high-frequency component is displayed in a display device including an RGBW self-luminous display, the resolution can be improved.

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

[1] Description of RGB-RGBW Conversion Circuit First, the RGB-RGBW conversion circuit used in the first embodiment will be described. The RGB-RGBW conversion circuit used in the first embodiment converts an RGB signal into an RGBW signal by a process substantially similar to the third RGB-RGBW conversion process described with reference to FIG. However, the difference is that the W usage rate (RGB-RGBW conversion rate) can be controlled.

  FIG. 27 shows a procedure of RGB-RGBW signal conversion processing by the RGB-RGBW conversion circuit used in the first embodiment.

First, the feedback rate of the RGB signal is calculated using the RGBW signal value for expressing the target white W _t (255) when the RGB input signal values are all 255 (step S51). If the RGBW signal value for realizing the target white W _t (255) is a signal value as shown in FIG. 6, the feedback rate of the RGB signal is 0.3 (= 77/255), 0, 0. .8 (= 204/255).

  Next, for each RGB input signal, an infinite geometric series sum ΣR, ΣG, ΣB is calculated with the RGB input signal value as the first term and the feedback rate calculated in step S51 as a common ratio (step S52).

  Next, the minimum value of the sum ΣR, ΣG, and ΣB of the infinite geometric series calculated for each RGB input signal is set to min (RGB), the set W usage rate is set to α, and α × from the RGB input signal is set to α × Min (RGB) is subtracted (step S53).

Next, α × min (RGB) is converted into an RGBW signal using the RGBW signal value for expressing the target white W _t (255) when the RGB input signal values are all 255 (step S54). ).

  Next, the RGBW signal corresponding to the RGB input signal is obtained by adding the signal value of the RGBW signal obtained in step S54 to the subtraction value {RGB−α × min (RGB)} obtained in step S53. Obtained (step S55).

[2] Description of Configuration of Display Device FIG. 28 shows a configuration of the display device.

  The digital RGB signals Rin, Gin, Bin are sent to the W usage rate determination unit 20 and also sent to the RGB-RGBW signal conversion circuit 1 via the line memories (LM) 11, 12, 13. The W usage rate determination unit 20 determines the W usage rate α for each pixel based on the RGB signals Rin, Gin, Bin, and gives the calculated W usage rate α to the RGB-RGBW signal conversion circuit 1.

  The RGB-RGBW signal conversion circuit 1 converts the RGB signals Rin, Gin, Bin into RGBW signals Rout, Gout, Bout, Wout in units of pixels using the W usage rate α for each pixel given by the W usage rate determination unit 20. Convert. The RGBW signals Rout, Gout, Bout, Wout obtained by the RGB-RGBW signal conversion circuit 1 are converted into analog RGBW signals by the D / A conversion circuit 2. The RGBW signal obtained by the D / A conversion circuit 2 is sent to the organic EL display 3 in which one pixel is composed of four RGBW unit pixels.

  The vertical synchronization signal Vsync and the horizontal synchronization signal Hsync of the RGB signals Rin, Gin, Bin are sent to the W usage rate determination unit 20 and the timing generation circuit 4. The timing generation circuit 4 generates a timing signal and sends it to the D / A conversion circuit 2 and the organic EL display 3.

  FIG. 29 shows the configuration of the W usage rate determination unit 20.

  Based on the RGB signals Rin, Gin, Bin, the W usage rate determination unit 20 determines, for each pixel, whether or not the video corresponding to the pixel is a white video including a high-frequency component, and a white including the high-frequency component. If it is not a video, the W usage rate α corresponding to the pixel is set to WGain1 (for example, 100%), and if it is a white video including a high frequency component, the W usage rate α corresponding to the pixel is set to WGain1. Set to a lower WGain2 (eg 70%).

  In the first embodiment, all of the RGB signals Rin, Gin, and Bin are pixels that are larger than the predetermined threshold value β, and the pixels in the edge portion are determined to be pixels that display a white image including a high-frequency component. I have to.

  The RGB signals Rin, Gin, Bin are sent to the signal comparison unit (display color determination means) 30. A predetermined threshold β is set in the signal comparison unit 30. For each pixel, the signal comparison unit 30 determines whether or not all of the RGB signals Rin, Gin, and Bin satisfy a condition that it is greater than a predetermined threshold value β. If this condition is satisfied, the comparison result signal “1” is determined. "" Is output, and if this condition is not satisfied, the comparison result signal "0" is output.

  The comparison result signal output from the signal comparison unit 30 is sent to the edge detection unit 50 and also sent to a first LM (line memory) 41 for delaying by one horizontal period. The comparison result signal held in the first LM (line memory) 41 is delayed by one horizontal period, then sent to the edge detection unit 50, and at the same time, the second LM for delaying by one horizontal period (Line memory) 42. The comparison result signal held in the second LM (line memory) 42 is delayed by one horizontal period and then sent to the edge detector 50.

  The edge detection unit 50 includes first to sixth flip-flops (FF) 51 to 56 and an edge determination unit 57 for delaying by one pixel period.

  The comparison result signal input from the signal comparison unit 30 to the edge detection unit 50 is sent to the edge determination unit 57 as it is and also sent to the first FF 51. The comparison result signal held in the first FF 51 is output after being delayed by one pixel period, sent to the edge determination unit 57, and sent to the second FF 52. The comparison result signal held in the second FF 52 is output after being delayed by one pixel period and sent to the edge determination unit 57.

  The comparison result signal input from the first LM (line memory) 41 to the edge detection unit 50 is sent to the edge determination unit 57 and also sent to the third FF 53. The comparison result signal held in the third FF 53 is output after being delayed by one pixel period, and is sent to the edge determination unit 57 and also sent to the fourth FF 54. The comparison result signal held in the fourth FF 54 is output after being delayed by one pixel period and sent to the edge determination unit 57.

  The comparison result signal input from the second LM 42 to the edge detection unit 50 is sent to the edge determination unit 57 and to the fifth FF 55. The comparison result signal held in the fifth FF 55 is output after being delayed by one pixel period, sent to the edge determination unit 57 and sent to the sixth FF 56. The comparison result signal held in the sixth FF 56 is output after being delayed by one pixel period and sent to the edge determination unit 57.

  As a result, as shown in FIG. 30, the edge determination unit 57 receives comparison result signals corresponding to 3 pixels (horizontal direction) × 3 (vertical direction) 9 pixels a to i. The edge determination unit 57 determines whether or not the target pixel is in the edge portion based on the comparison result signal corresponding to 9 pixels of 3 × 3 with the center pixel e as the target pixel.

  If any of the following conditions (1), (2), and (3) is satisfied, it is determined that the target pixel is not in the edge portion. If all of these conditions are not satisfied, the target pixel is in the edge portion. It is determined that

(1) The comparison result signal corresponding to the target pixel is “0” (see FIG. 31A).
(2) All the comparison result signals corresponding to the target pixel and the surrounding eight pixels are “1” (see FIG. 31B).
(3) The comparison result signal corresponding to the target pixel is “1” and the comparison result signal of only one of the four corner pixels among the eight peripheral pixels is “0” (FIG. 31). (See (c))

  The edge determination unit 57 outputs the determination result signal “1” when it is determined that the target pixel is in the edge portion, and the determination result signal “0” when it is determined that the target pixel is not in the edge portion. Is output.

  The determination result signal output from the edge determination unit 57 is sent to the selector 60 as a selection control signal. The selector 60 receives WGain1 (for example, 100%) and WGain2 (for example, 70%). When a determination result signal of “0” is sent, the selector 60 selects WGain1 as the W usage rate α corresponding to the pixel of interest and sets it in the RGB-RGBW signal conversion circuit 1 to determine “1”. When a result signal is sent, WGain2 is selected as the W usage rate α corresponding to the target pixel and set in the RGB-RGBW signal conversion circuit 1.

  As a result, the RGB-RGBW signal conversion circuit 1 performs RGB-RGBW signal conversion processing for pixels other than white images including high-frequency components with WGain1 (for example, 100%) as the W usage rate α. An RGB-RGBW signal conversion process is performed on a pixel of a white image including a component with WGain2 (for example, 70%) lower than WGain1 as a W usage rate α. Therefore, the resolution is improved when displaying a white image including a high-frequency component.

  The RGB-RGBW signal conversion circuit used in the second embodiment is the same as the RGB-RGBW signal conversion circuit used in the first embodiment. That is, as the RGB-RGBW signal conversion circuit used in the second embodiment, a circuit that performs RGB-RGBW signal conversion processing according to the procedure shown in FIG. 27 is used.

  The overall configuration of the display device is the same as the configuration shown in FIG. 28, but the configuration of the W usage rate determination unit 20 is different from that of the first embodiment.

  FIG. 32 shows the configuration of the W usage rate determination unit 20.

  The W usage rate determination unit 20 assumes that, for each pixel, the color density indicating whether the color is close to white or not, and the W usage rate is 100% based on the RGB signals Rin, Gin, Bin. The high frequency component of the W signal is calculated, and the W usage rate α is calculated based on the calculated color density and high frequency component.

  That is, the W usage rate α is calculated such that the W usage rate α decreases as the color density is lighter (closer to white) and as the high frequency component increases. This is because the darker the color is and the higher the high-frequency component is, the higher the possibility that the image is a white image containing the high-frequency component.

  The RGB signals Rin, Gin, Bin are sent to the W signal calculation unit 90 and also sent to the color density determination unit 80 via the line memories (LM) 71, 72, 73.

  The color density determination unit 80 calculates the color density for each pixel, and includes FFs (flip-flops) 81, 82, 83, subtractors 84, 85, 86, and a maximum value detection unit 87. Yes.

  The RGB signals Rin, Gin, Bin held in the LMs 71, 72, 73 are respectively delayed by one horizontal period and then sent to the FFs 81, 82, 83. The subtractor 84 calculates the absolute value | Rin−Gin | of the difference between the signal Rin output from the FF (flip flop) 81 and the signal Gin output from the FF (flip flop) 82, and the calculation result is It is sent to the maximum value detector 87. In the subtractor 85, an absolute value | Gin−Bin | of a difference between the signal Gin output from the FF (flip flop) 82 and the signal Bin output from the FF (flip flop) 83 is calculated. It is sent to the maximum value detector 87. In the subtractor 86, the absolute value | Bin−Rin | of the difference between the signal Bin output from the FF (flip flop) 83 and the signal Rin output from the FF (flip flop) 81 is calculated. It is sent to the maximum value detector 87.

  In the maximum value detection unit 87, the maximum value of the subtraction results (| Rin−Gin |, | Gin−Bin |, | Bin−Rin |) sent from the subtractors 84, 85, 86 for each pixel is used as a color. It is calculated as the density of. That is, the color intensity is expressed by the following equation (14).

  Color density = Max (| Rin−Gin |, | Gin−Bin |, | Bin−Rin |) (14)

  The color intensity calculated for each pixel by the maximum value detection unit 87 is sent to the W usage rate calculation unit 120.

  The W signal calculation unit 90 calculates a W signal after RGB-RGBW signal conversion when it is assumed that the W usage rate is 100% for each pixel. When the RGB feedback rate calculated by the same method as in step S51 of FIG. 27 is Rf, Gf, and Bf, the W signal Wsig after RGB-RGBW conversion when the W usage rate is assumed to be 100% is It is represented by the following formula (15).

  Wsig = Min {Rin / (1-Rf), Gin / (1-Gf), Bin / (1-Bf)} (15)

  The W signal calculation unit 90 includes multipliers 91, 92, 93 and a minimum value detection unit 94. The multiplier 91 multiplies the signal Rin by 1 / (1-Rf), and sends the multiplication result to the minimum value detection unit 94. The multiplier 92 multiplies the signal Gin by 1 / (1-Gf), and sends the multiplication result to the minimum value detector 94. The multiplier 93 multiplies the signal Bin by 1 / (1-Bf), and sends the multiplication result to the minimum value detection unit 94.

  The minimum value detection unit 94 performs the RGB-RGBW conversion after assuming that the minimum value of the multiplication results sent from the multipliers 91, 92, 93 for each pixel is 100%. Calculated as W signal Wsig.

  The signal Wsig calculated for each pixel by the minimum value detection unit 94 is sent to the high frequency component detection unit 110 and also sent to a first LM (line memory) 101 for delaying by one horizontal period. The signal Wsig held in the first LM (line memory) 101 is delayed by one horizontal period and then sent to the high frequency component detection unit 110, and at the same time, a second LM for delaying by one horizontal period (Line memory) 102. The signal Wsig held in the second LM (line memory) 102 is delayed by one horizontal period and then sent to the high frequency component detection unit 110.

  The high frequency component detection unit 110 includes first to fourth flip-flops (FF) 111 to 114 for delaying by one pixel period, a horizontal high-pass filter (H-HPF) 115, and a vertical high-pass filter (V−). HPF) 116 is provided.

  The signal Wsig input from the minimum value detection unit 94 to the high frequency component detection unit 110 is sent to the first FF 111. The signal Wsig held in the first FF 111 is output after being delayed by one pixel period and sent to the V-HPF 116.

  The signal Wsig input from the first LM (line memory) 101 to the high-frequency component extraction unit 110 is sent to the H-HPF 115 and also sent to the second FF 112. The signal Wsig held in the second FF 112 is output after being delayed by one pixel period, and sent to the H-HPF 115, the V-HPF 116, and the third FF 113. The signal Wsig held in the third FF 113 is output after being delayed by one pixel period and sent to the H-HPF 115.

  The signal Wsig input from the second LM (line memory) 102 to the high frequency component extraction unit 110 is sent to the fourth FF 114. The signal Wsig held in the fourth FF 114 is output after being delayed by one pixel period and sent to the V-HPF 116.

  That is, a signal Wsig corresponding to three pixels in the vertical direction of three consecutive horizontal lines is sent to the V-HPF 116, and a signal corresponding to three pixels in the horizontal direction of each horizontal line is sent to the H-HPF 115. Wsig is sent.

  The V-HPF 116 filters the input signal Wsig corresponding to the three pixels in the vertical direction using the filter coefficient shown in FIG. 33, so that the high frequency in the vertical direction of the center pixel of interest among these three pixels. Calculate the components.

  The H-HPF 115 filters the input signal Wsig corresponding to the three pixels in the horizontal direction by using the filter coefficient shown in FIG. 34, so that the high frequency signal in the horizontal direction of the center pixel of interest among these three pixels. Calculate the components.

  The high-frequency component in the vertical direction of the target pixel calculated by the V-HPF 116 and the high-frequency component in the horizontal direction of the target pixel calculated by the H-HPF 115 are sent to the W usage rate calculation unit 120.

  Based on the vertical high-frequency component, the horizontal high-frequency component, and the color density of the target pixel, the W usage rate calculating unit 120 increases the color density as the vertical high-frequency component and the horizontal high-frequency component increase. The W usage rate α is calculated so that the W usage rate α decreases as the thickness decreases.

  For example, the determination value X is calculated by the following equation (16), where Hv is the high frequency component in the vertical direction with respect to the pixel of interest, Hh is the high frequency component in the horizontal direction, and I is the color density.

  X = Hv · Hh / I (16)

  Then, the W usage rate α corresponding to the calculated determination value X is calculated based on a table representing the relationship of the W usage rate α corresponding to the predetermined determination value X. FIG. 35 is a graph showing the contents of a table representing the relationship of the W usage rate α corresponding to the determination value X.

  The determination value X may be calculated by the following equation (17).

  X = (Hv + Hh) / I (16)

  The W usage rate α calculated by the W usage rate calculation unit 120 is given to the RGB-RGBW signal conversion circuit 1. When the determination value X is compared with a predetermined threshold value and the determination value X is less than or equal to the threshold value, the W usage rate α is set to WGain1 (for example, 100%). The W usage rate α may be set to WGain2 (for example, 70%) smaller than WGain1.

  In the second embodiment, the color individuality determination unit 80 may be omitted. In this case, the W usage rate α is controlled based on the vertical high-frequency component of the target pixel calculated by the V-HPF 116 and the horizontal high-frequency component of the target pixel calculated by the H-HPF 115.

  Note that, based on the RGB input signals Rin, Gin, Bin, it is determined whether or not the image includes a high-frequency component for each pixel. Based on the determination result, the RGB-RGBW signal conversion circuit 1 performs RGB input. You may make it control W utilization rate (alpha) at the time of converting signal Rin, Gin, Bin into an RGBW signal for every pixel. In this case, the W usage rate α for a pixel determined to display an image including a high frequency component is higher than the W usage rate α used for a pixel determined not to display an image including a high frequency component. Set to a low value.

  Further, based on the RGB input signals Rin, Gin, Bin, it is determined whether or not each pixel is an edge portion. Based on the determination result, the RGB-RGBW signal conversion circuit 1 converts the RGB input signals Rin, Gin, Bin to RGBW. You may make it control W utilization rate (alpha) at the time of converting into a signal for every pixel. In this case, the W usage rate α for the pixel determined to be the edge portion is set to a value lower than the W usage rate α used for the pixel determined not to be the edge portion.

  The above embodiment can be applied to a panel having a delta arrangement in addition to a panel having a stripe arrangement as shown in FIGS.

It is a schematic diagram which shows the example by which 1 pixel is comprised by four units of R, G, B, and W. It is a block diagram which shows the structure of a display apparatus. It is a schematic diagram which shows an example of an RGB input signal. It is a schematic diagram which shows min (RGB). It is a schematic diagram which shows input signal-min (RGB). Showing the signal ratio of the RGBW for representing W _t (255) are schematic views. Showing the signal ratio of the RGBW for realizing W _t (100) are schematic views. It is a schematic diagram which shows the RGBW value calculated | required by adding the RGB value of FIG. 5, and the RGBW value of FIG. It is a flowchart which shows a panel adjustment process procedure. RGBW chromaticity coordinates (x _R , y _R ), (x _G , y _G ), (x _B , y _B ), (x _W , y _W ) and target white W _t chromaticity coordinates (x _Wt , Y _Wt ). It is a flowchart which shows the procedure of the signal conversion process for converting an RGB input signal into an RGBW signal. It is a flowchart which shows the other example of the signal conversion process for converting an RGB input signal into an RGBW signal. It is a schematic diagram which shows an example of an RGB input signal. It is a schematic diagram which shows RGB input signal-min (RGB). It is a schematic diagram which shows min (RGB). It is a schematic diagram which shows the RGBW signal corresponding to min (RGB). It is a schematic diagram which shows the RGBW value calculated | required by adding the RGB value of FIG. 14, and the RGBW value of FIG. The resulting RGBW signals in the case where the R ₁ G ₁ B ₁ W ₁ input signal is a schematic diagram showing the R ₁ G ₁ B ₁ W ₁ input signal. R ₁ G ₁ B ₁ input signal _{-min (R 1 G 1 B 1} ) is a schematic view showing a. It is a schematic diagram showing the _{min (R 1 G 1 B 1} ). It is a schematic diagram showing an RGBW signal corresponding to the _{min (R 1 G 1 B 1} ). By adding the R ₁ G ₁ B ₁ W ₁ value of R ₁ G ₁ B ₁ value and 21 in FIG. 19 is a schematic diagram showing the obtained RGBW values. It is a flowchart which shows the further another example of the signal conversion process for converting an RGB input signal into an RGBW signal. It is a schematic diagram which shows an example of the pixel arrangement | sequence of a RGBW system self-light-emitting display. FIG. 25 is a schematic diagram illustrating a display example when only a W unit pixel is used when displaying a white image (for example, white characters) including a high-frequency component on a self-luminous display having a pixel arrangement as illustrated in FIG. 24. . FIG. 26 is a schematic diagram illustrating a display example when RGB-RGBW signal conversion is performed with an RGB-RGBW conversion rate (W usage rate) set to a value lower than 100% for an input video similar to FIG. 25. . 3 is a flowchart illustrating a procedure of signal conversion processing by an RGB-RGBW conversion circuit used in the first embodiment. 1 is a block diagram illustrating a configuration of a display device according to Example 1. FIG. It is a block diagram which shows the structure of the W utilization rate determination part 20 by Example 1. FIG. It is a schematic diagram which shows 9 pixels of 3 (horizontal direction) * 3 (vertical direction) centering on an attention pixel. It is a schematic diagram which shows an example when it determines with a focused pixel not being in an edge part. It is a block diagram which shows the structure of the W utilization rate determination part 20 by Example 2. FIG. It is a schematic diagram which shows the filter coefficient used by V-HPF116. It is a schematic diagram which shows the filter coefficient used by H-HPF115. 4 is a graph showing the contents of a table used in a W usage rate calculation unit 120.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 RGB-RGBW signal conversion circuit 2 D / A conversion circuit 3 Organic EL display 20 W utilization rate determination part 30 Signal comparison part (display color determination means)
50 edge detection unit 57 edge determination unit 60 selector 80 color density determination unit 90 W signal calculation unit 110 high frequency component detection unit 120 W usage rate calculation unit

Claims (11)

In a display device including an RGB-RGBW conversion circuit that converts an RGB signal into an RGBW signal and an RGBW-type self-luminous display that displays an image based on the RGBW signal obtained by the RGB-RGBW conversion circuit,
RGB-RGBW conversion circuit with variable RGB-RGBW conversion rate,
Based on the RGB input signal input to the RGB-RGBW conversion circuit, determination means for determining whether or not an image including a high frequency component is displayed for each predetermined unit area, and for each unit area by the determination means Control means for controlling the RGB-RGBW conversion rate for each unit area when converting the RGB input signal into the RGBW signal by the RGB-RGBW conversion circuit based on the determination result;
A display device comprising: The control means determines the RGB-RGBW conversion rate for the unit area determined not to display the image including the high frequency component for the unit area determined by the determination means to display the image including the high frequency component. The display device according to claim 1, wherein the display device is set to a value lower than an RGB-RGBW conversion rate used for the display. In a display device including an RGB-RGBW conversion circuit that converts an RGB signal into an RGBW signal and an RGBW-type self-luminous display that displays an image based on the RGBW signal obtained by the RGB-RGBW conversion circuit,
RGB-RGBW conversion circuit with variable RGB-RGBW conversion rate,
Based on the RGB input signal input to the RGB-RGBW conversion circuit, determination means for determining whether or not each predetermined unit area is an edge portion, and based on the determination result for each unit area by the determination means, the RGB A control means for controlling the RGB-RGBW conversion rate for each unit area when the RGB input signal is converted into an RGBW signal by the RGBW conversion circuit;
A display device comprising: The control means uses the RGB-RGBW conversion rate for the unit area determined to be an edge part by the determination means, and the RGB-RGBW conversion rate used for the unit area not determined to be the edge part. The display device according to claim 3, wherein the display device is set to a lower value. In a display device including an RGB-RGBW conversion circuit that converts an RGB signal into an RGBW signal and an RGBW-type self-luminous display that displays an image based on the RGBW signal obtained by the RGB-RGBW conversion circuit,
RGB-RGBW conversion circuit with variable RGB-RGBW conversion rate,
Based on RGB input signals input to the RGB-RGBW conversion circuit, determination means for determining whether a white image including a high frequency component is displayed for each predetermined unit area, and for each unit area by the determination means Control means for controlling the RGB-RGBW conversion rate for each unit area when the RGB input signal is converted into the RGBW signal by the RGB-RGBW conversion circuit based on the determination result of
A display device comprising: The control means determines the RGB-RGBW conversion rate for the unit area determined by the determining means to display a white image including a high-frequency component, and the unit area determined not to display a white image including a high-frequency component. The display device according to claim 5, wherein the display device is set to a value lower than an RGB-RGBW conversion rate used for the display. In a display device including an RGB-RGBW conversion circuit that converts an RGB signal into an RGBW signal and an RGBW-type self-luminous display that displays an image based on the RGBW signal obtained by the RGB-RGBW conversion circuit,
RGB-RGBW conversion circuit with variable RGB-RGBW conversion rate,
Based on an RGB input signal input to the RGB-RGBW conversion circuit, a determination unit that determines a display color for each predetermined unit region and determines whether or not it is an edge portion, and a unit region by the determination unit for each unit region Control means for controlling the RGB-RGBW conversion rate for each unit area when converting the RGB input signal into the RGBW signal by the RGB-RGBW conversion circuit based on the determination result;
A display device comprising: The determination means determines whether or not all of the RGB input signals are larger than a predetermined threshold and are edge portions for each unit area, and the control means performs RGB determination by the determination means. For a unit region that is determined to satisfy the condition that all of the input signals are larger than a predetermined threshold and are edge portions, the RGB-RGBW conversion rate is changed to a unit region that is determined not to satisfy the condition. The display device according to claim 7, wherein the display device is set to a value lower than an RGB-RGBW conversion rate used for the display. In a display device including an RGB-RGBW conversion circuit that converts an RGB signal into an RGBW signal and an RGBW-type self-luminous display that displays an image based on the RGBW signal obtained by the RGB-RGBW conversion circuit,
RGB-RGBW conversion circuit with variable RGB-RGBW conversion rate,
Based on the RGB input signal input to the RGB-RGBW conversion circuit, the determination means for determining the color intensity for each predetermined unit area and the high frequency component, and the determination result for each unit area by the determination means Based on the control means for controlling the RGB-RGBW conversion rate for each unit region when converting the RGB input signal to RGBW signal by the RGB-RGBW conversion circuit,
A display device comprising: If the RGB input signal is Rin, Gin, Bin, the determination means calculates the maximum value of | Rin−Gin |, | Gin−Bin |, and | Bin−Rin | as the color intensity for each unit area. And a means for calculating a W signal obtained by RGB-RGBW conversion when an RGB-RGBW conversion rate is assumed to be 100% for each unit area, and calculating a high-frequency component included in the calculated W signal. The control means converts the RGB input signal into the RGBW signal by the RGB-RGBW conversion circuit based on the color density and the high frequency component calculated for each unit area by the determination means. The display device according to claim 9, wherein the RGBW conversion rate is controlled for each unit area. The control unit controls the RGB-RGBW conversion rate so that the smaller the color density calculated by the determination unit and the higher the high frequency component calculated by the determination unit, the smaller the RGB-RGBW conversion rate. The display device according to claim 10, wherein:

Images