JP2011109287A - Image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide color expression without having an uncomfortable feeling since chromaticity of each of skin color being memory color, sky blue (cyan) and green is shifted as an area on a chromaticity diagram expressed by three RGB primary colors is very large, in an image display device capable of expressing a wide gamut. <P>SOLUTION: By a memory color determination part 53, a skin color correction gain generation part 54, and a memory color correction part 55, a color of which the chromaticity comes close to a six-axis primary color chromaticity side is displayed as an optimum memory color by increasing a white component to an original color without having an uncomfortable feeling. Similarly, a sky blue memory color is also determined by the memory color determination part 53, and the white component increased in an addition part 52 is subjected to correction for bringing the chromaticity coming close to a primary color close to a white side by a multiplier 55d by correction data being wide gamut display from a microcomputer to be replaced based on the memory color determination result to provide an output video signal. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image display device for displaying an image without a sense of incongruity based on a human memory color in image display on a wide color gamut display.

  Conventionally, images may be displayed with a projector using an ultra-high pressure mercury lamp, but the created chart is displayed on a personal computer screen due to insufficient brightness of the projector or the effects of room lighting or a screen. In many cases, it is difficult to express with color visibility such as Therefore, in recent years, efforts have been made to improve color visibility using an LED light source capable of expressing a wide color gamut. On the other hand, efforts have been made to improve color visibility by reducing white components of RGB input video signals including white components and conversely increasing complementary color components and primary color components. Furthermore, in order to recognize the surrounding lighting environment, photometry is performed with an optical sensor, input video signals are converted with a look-up table, and output is performed to improve optimal visibility. Is disclosed (see Patent Document 1).

  In addition, a technology is disclosed in which two color correction tables for faithful color reproduction and a table for brightness-priority color correction are prepared, and color correction is performed using the brightness-priority table when inputting to a personal computer ( Patent Document 2).

JP 2005-184586 A JP 2002-290759 A

  However, in an image display device that can represent a wide color gamut, the area on the chromaticity diagram represented by the three primary colors of RGB is very large, so the skin colors, sky (cyan), and green, which are memory colors, also shift in chromaticity. As a result, the color expression was uncomfortable.

  In the invention described in Patent Document 1, a white component is detected in order to improve color visibility. As the white component is increased, the complementary color component and the primary color component are increased. However, excessive color processing was performed, resulting in poor video quality.

  Furthermore, in the invention described in Patent Document 2, it is disclosed that there is a brightness-priority color correction table in addition to the color correction table for performing faithful color reproduction. In order to maintain the same lightness as the input level in the signal that has become darker, the color correction table in which the white component is added is displayed. As a result, as the white component is added, the color becomes an achromatic color, and there is a problem that the visibility of the color deteriorates.

  The image display device of the first aspect of the present invention is based on color component detection means for detecting a color component of a red (hereinafter R) green (hereinafter G) blue (hereinafter B) video signal, and the detected color component, A memory color determining means for determining the presence or absence of a memory color, and based on the results of the color gamut determining means for displaying and the means for detecting the minimum value of the RGB video signal, the memory color determining means has a memory color. Then, a means for correcting the signal level of the determined RGB video signal is provided.

  The color component detection means in the image display device of the second aspect of the present invention divides the six color components of the primary color component and the complementary color component according to the difference between RGB and determines the memory colors of skin color, cyan and green.

  In the image display device of the third aspect of the present invention, the skin color detection means performs processing in a hue region in which the values of the RG signal and the RB signal are both positive numbers.

  According to a fourth aspect of the present invention, there is provided a correction gain generating means for increasing the correction gain of the RGB signals as the display color gamut of the color gamut determining means for display is wider.

  According to a fifth aspect of the present invention, the correction gain of the correction gain generation means is increased as the white component of the RGB video signal is larger and the display color gamut of the color gamut determination means to be displayed is wider.

  According to the first aspect of the present invention, it is possible to determine whether or not the input video signal is a color in the memory color area, and to display a memory color that is optimal and has no sense of discomfort according to the color gamut that can be displayed. Further, since the minimum value of the RGB video signal, that is, the white component can be detected and correction control can be performed according to the amount of the white component, it has the effect of preventing the deterioration of the video quality due to the overcorrection of skin color and sky blue.

  According to the second aspect of the present invention, each color can be detected independently and a memory color can be determined.

  According to the third aspect of the present invention, it is possible to perform the correction process without generating a pseudo contour of the color in a wide hue range including the skin color.

  According to the fourth aspect of the present invention, it is possible to prevent the image quality of the memory color from deteriorating as the color gamut to be displayed is wider.

  According to the fifth aspect of the present invention, it is possible to prevent the image quality of the memory color from becoming worse as the RGB video signal has a wider color gamut to be displayed and has more white components.

1 is a block diagram showing a color conversion circuit according to Embodiment 1 and Embodiment 2 of the present invention. The block diagram which shows the 6-axis detection part of Embodiment 1 and Embodiment 2 of this invention The block diagram which shows the memory color determination part of Embodiment 1 and Embodiment 2 of this invention The block diagram which shows the MIN detection part of Embodiment 1 and Embodiment 2 of this invention The block diagram which shows the memory color correction | amendment part of Embodiment 1 and Embodiment 2 of this invention The block diagram which shows the addition part of the memory color correction part of Embodiment 1 and Embodiment 2 of this invention The figure which shows the color component signal level of Embodiment 1 and Embodiment 2 of this invention. Detailed block diagram showing projectors according to the first and second embodiments of the present invention 1 is an external view of a projector according to a first embodiment of the present invention. FIG. 7 is a diagram of a display system using the projector according to the second embodiment of the present invention.

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

(Embodiment 1)
First, the image display apparatus according to the first embodiment of the present invention will be described with reference to FIG.

  FIG. 9 is an external view of a projector that is an image display device. In the figure, a projector 100 processes an input video signal and presses a POWER button 150 to output an enlarged projection video from the projection lens 190 using an internal LED light source module (not shown). As an input, it has a video input 170 and an RGB input 160 terminal, and each is connected to a video signal output device (not shown) such as an external personal computer. In addition, a mouse port 130 such as a USB is provided, and the mouse 201 is connected to operate as a setting state of the projector 100 or a pointer that can move on the screen. This also realizes the same function with the operation button 140.

  Next, a detailed block diagram of the projector 100 is shown in FIG. The VIDEO terminal 11 is a terminal for inputting an NTSC composite video signal.

  The S-VIDEO terminal 12 is a terminal for inputting an S video signal.

  The RGB / YPbPr terminal 13 is a terminal for inputting an RGB signal or a YPbPr signal.

  The input selector 21 is a selector for selecting one of the composite video signal input from the VIDEO terminal 11 and the S video signal input from the S-VIDEO terminal 12.

  The Y / C separation circuit 23 is a circuit for separating the composite video signal input from the color decoder 22 into a Y signal and a C signal.

  The color decoder 22 is a decoder for color-decoding a Y / C separated signal or an inputted Y / C signal into a YPbPr signal.

  The matrix circuit 24 is a circuit for performing matrix processing when converting a YPbPr signal input from the RGB / YPbPr terminal 13 into an RGB signal.

  The input selector 25 is a selector for selecting one of the RGB signals input from the RGB / YPbPr terminal 13 and the RGB signals generated by the matrix circuit 24.

  The input selector 26 is a selector for selecting any one of the YPbPr signal generated by the color decoder 22 and the RGB signal input by the input selector 25. The selected analog video signal is A Input to / D converter 30.

  The A / D converter 30 is a converter for A / D converting the analog signal selected by the input selector 26 into an 8-bit digital signal.

  The resizing circuit 40 resizes the digital signal A / D-converted by the A / D converter 30 in accordance with the number of pixels of a liquid crystal display (LCD) panel 91 to 93, and superimposes the on-screen. Circuit.

  The color conversion circuit 50 is a color conversion circuit for correcting the stored color of the RGB data output from the resizing circuit 40 to a predetermined color.

  The main microcomputer 70 performs all kinds of control of the entire apparatus such as power supply (not shown) control, fan (not shown) control, temperature control, and input switching control, and also sends data to the color conversion circuit 50 based on data from the external interface 71. Is transferred or freeze control is performed on the resizing circuit 40. A predetermined current value is set in the LED light source module 200. Further, an RGB primary color chromaticity table 72 for defining a wide color gamut of the LED light source module 200 is provided on the EEPROM, and the color conversion circuit 50 is controlled using a correction gain for memory color correction based on the chromaticity data.

  The digital phase expansion circuits 81 to 83 are circuits for phase expansion of the digital signal color-corrected by the color conversion circuit 50 in consideration of the operation speed of the drive drivers (not shown) of the LCD panels 91 to 93.

  A panel driving integrated circuit (Integrated Circuit (IC)) 90 is a circuit for driving the LCD panels 91 to 93.

  The LCD panels 91 to 93 are panels for color-displaying digital signals color-corrected by the color conversion circuit 50 and phase-developed by the digital phase development circuits 81 to 83.

  Further, a detailed block diagram of the color conversion circuit 50 shown in FIG. 8 is shown in FIG.

  The RGB signal output from the resizing circuit 40 is detected by the six-axis detection unit 56 for the colors RGBY (Yellow) C (Cyan) M (Magenta), and the memory color determination unit 53 based on the result detects the skin color, sky blue, and green. I do. Further, the MIN detection unit 51 detects a white component that is the minimum value of RGB. Further, the correction gain is also transferred to the memory color correction unit 55 based on the values of the RGB primary color chromaticity table 72 from the microcomputer, the memory color correction amount is determined based on the results of the memory color determination unit 53 and the MIN detection unit 51, and color conversion is performed. Will do.

  As shown in the block diagram of FIG. 3, the memory color determination unit 53 performs skin color detection for determining whether the input signal is a skin color hue from the RG and RB signals based on the result of the six-axis detection unit 56, and cyan. Detection for determining whether the hue is sky blue from the (Cs) and blue (Bs) signals and green (Gs) color detection are performed.

  FIG. 5 shows the memory color correction unit 55. When the memory color correction unit 55 performs mixing processing on the signal added by the addition unit 52 and the input signal of the color conversion circuit 50, the minimum value determination unit 532 shown in the lower part of FIG. The correction amount is multiplied by the determined skin color correction coefficient, and further, the optimum memory color correction is performed with the gain data based on the primary color chromaticity table 72 from the microcomputer and output.

  FIG. 2 is a block diagram showing the 6-axis detection unit 56. The RGB signal is obtained by calculating the difference between RG, RB, GR, GB, BR, and BG at 561, respectively. For example, Ys (Yellow component) can be obtained by selecting a value having a smaller difference amount between RB and GB. Similarly, by selecting a small value from each difference amount, each component of RGBYCM is obtained.

  FIG. 6 is a block diagram showing the adder 52. The RGBYCM signal components are multiplied by the levels of the MIN detector 51 in the multipliers 59a to 59f, and finally the RGB signals are added to the adder 52. Determine the amount to add.

  FIG. 4 is a block diagram showing the MIN detection unit 51, and the smallest signal level is obtained by performing two comparisons 511 and 512 among the input RGB signals.

  The operation of the image display apparatus of the present invention in the projector 100 as described above will be described.

  The RGB signal of the personal computer input from the RGB / YPbPr terminal 13 is A / D converted and resized, and then input to the color conversion circuit 50. The input RGB signal is composed of a white component, a complementary color component, and a primary color component as shown in the color component signal level diagram of FIG. Such a video signal is first detected by the six-axis detection unit 56 shown in FIG. 2 with six difference results (RG, RB, GR, GB, BR, BG) and its difference. It can be separated into primary colors and complementary colors according to the comparison result. In the case of FIG. 7, since R: 200, G: 150, and B: 50 in 8-bit 256 gradations, the RB component is 150 and the GB component is 100, and the yellow component (Ys) is determined from the two comparison results. Becomes 100. Moreover, it becomes the RG component 50 and the RB component 150, and 50 can be detected as a red component (Rs) from the comparison result. Next, as shown in FIG. 4, a minimum value (MIN) signal can be obtained by selecting a smaller one in the comparison of each RGB in the MIN detection unit 51. This is the white component 50 shown in FIG.

  Next, as shown in FIG. 3, a green signal as a memory color is determined from the results (Ys, Cs, Ms, Rs, Gs, Bs) of the six-axis detection. Also, the cyan signal and blue signal comparator 533 determines the sky blue memory color signal required when there are many cyan signals. Furthermore, when the signal components of these two signals are positive data amounts using the RB and RG signals as detection results of the six-axis detection unit 56, that is, when a logical product is established, an AND circuit 531 becomes “1”, and the RGB input signal is determined to be the flesh color hue range. Finally, the logical sum circuit 535 determines the memory color. Further, the white component is detected by the MIN circuit 532, and the skin color correction coefficient amount is determined. At this time, the larger the white component, the larger the skin color correction coefficient. In this embodiment, the white component 50 and the correction coefficient are 1.1 times. When the white component is 100 or more, the ratio is 1.2 times or more. Conversely, when the white component is 30 or less, the ratio is 1.05 times.

  As described above, in this embodiment, the color quality of the RGB signal input to the memory color correction unit 55 in FIG. 1 is deteriorated in the wide color gamut display for the six-axis colors as shown in FIG. Therefore, the color correction without any sense of incongruity is performed by suppressing the color enhancement by increasing the white component.

  Further, blending processing by multiplication and addition of 55a, 55b, and 55c in FIG. 5 is performed using the skin color correction coefficient obtained earlier, and the ratio of the original RGB input signal is lower as the skin color correction coefficient is larger. Process. Further, a correction for bringing the chromaticity approaching the primary color closer to the white side by the multiplier 55d based on the correction data indicating that the display is a wide color gamut display from the microcomputer is performed in the range of 1.05 times to 1.2 times, and the memory color Based on the determination result, an output video signal is obtained by replacing the corrected signal.

  In this way, in the skin color region signal, the chromaticity is shifted to the 6-axis primary color chromaticity side by the memory color determination unit 53, the skin color correction gain generation unit 54, and the memory color correction unit 55 as shown in FIGS. It is possible to increase the white component to display the approaching color to the original uncomfortable color and display it as the optimum memory color. Similarly, the sky color is also determined by the memory color determination unit 53 and the increased white component of the addition unit 52 is emphasized by the correction data indicating that it is a wide color gamut display from the microcomputer, so that the sky color becomes darker. It is possible to perform color correction by increasing the optimum white for such a signal. And the effect which can maintain the image quality without a sense of incongruity can be exhibited.

(Embodiment 2)
An image display apparatus according to Embodiment 2 of the present invention will be described with reference to FIG.

  FIG. 10 shows an image display apparatus, that is, a display system using the projector 100. An image of the personal computer 61 connected to the RGB input terminal 160 in FIG. 9 is projected on the screen 110 by the projector 100. At this time, the remote controller 60 controls each function with respect to the projector 100. The optical sensor 94 is attached in the direction of the screen 110 and measures illuminance. As is clear from FIG. 8, the optical sensor 94 is input to the main microcomputer 70.

  The image display apparatus 100 in the present embodiment is almost the same as that in the first embodiment, but the difference is the processing contents of the color conversion circuit 50.

  The RGB signal input to the color conversion circuit 50 is discriminated between a primary color component and a complementary color component by the six-axis detection unit 56, and a white component is detected by the MIN detection unit 51. The adder 52 adds (subtracts) a minus component corresponding to the amount of the white component to determine the degree of color enhancement. At this time, the main microcomputer 70 determines whether to directly multiply the MIN signal (white component) to be multiplied with each 6-axis color component for determining the subtraction amount or to multiply the white component by -0.5 to 0.5 times. decide. The main microcomputer 70 senses the illuminance around the projector 100 with the optical sensor 94. If the ambient illuminance is high, the projector 100 is being used in a bright visual environment. After multiplying by five, multiplication is performed (59a, 59b, 59c, 59d, 59e, 59f), and then the addition unit 52 performs subtraction processing to enhance color. Subsequently, the RGB signal is multiplied by the skin color correction coefficient 1.05 times as the memory color by the multipliers 55c and 55d, and further multiplied by the correction coefficient 1.05 times for the wide color gamut display. These correction signals are added to the adder 55a, and are selected and output by the selector 551 only when the signal is determined as the memory color. On the other hand, when it is found from the level of the optical sensor 94 that the projector 100 is used in a dark visual environment, the main microcomputer 70 multiplies the MIN signal by 0.5 (59a, 59b, 59c, 59d). , 59e, 59f) A white component is added so as to prevent deterioration in image quality on a wide color gamut display. In addition, as shown in the first embodiment, the skin color hue color is corrected by the memory color correction unit 55 so as not to be overcorrected even when doubling in a bright visual environment. Get.

  As described above, in the memory color signal component, the memory color determination unit 53, the skin color correction gain generation unit 54, and the memory color correction unit 55 as shown in FIGS. The color can be controlled without any discomfort and the visibility can be improved.

  Further, by measuring the ambient illuminance using an optical sensor and performing optimum color enhancement, the memory color can be displayed with optimum color reproducibility on a wide color gamut display without overcorrection.

  The display device of the present invention described above has been described as a projector, but is not limited to a projector, and can be realized by a display such as an LED backlight liquid crystal display.

  Further, the processing of the present invention may be realized by software, and is not limited to the image display device, and it goes without saying that the display method itself is also effective.

  The image display apparatus according to the present invention has an effect of being able to display an image without a sense of incongruity based on a human memory color in an image display of a wide color gamut display of an LED light source with respect to an RGB input signal of a personal computer or the like. Suitable for applications such as digital signage installed for a long period of time, taking advantage of the long life of LED light sources.

DESCRIPTION OF SYMBOLS 11 VIDEO terminal 12 S-VIDEO terminal 13 RGB / YPbPr terminal 21 Input selector 22 Color decoder 23 Y / C separation circuit 24 Matrix circuit 25 Input selector 26 Input selector 30 A / D converter 40 Resize circuit 50 Color conversion circuit 51 MIN detection part 52 Addition Unit 53 Memory Color Determination Unit 54 Skin Color Correction Gain Generation Unit 55 Memory Color Correction Unit 56 6-Axis Detection Unit 60 Remote Controller 61 Personal Computer 70 Main Microcomputer 71 External Interface 72 Primary Color Chromaticity Table 81-83 Digital Phase Expansion Circuit 90 Panel Drive IC
91-93 LCD panel 94 Optical sensor 100 Projector 110 Screen 130 Mouse port 140 Operation button 150 POWER button 160 RGB input terminal 170 Video input terminal 190 Projection lens 200 LED light source module

Claims (5)

  Color component detection means for detecting a color component of a red (hereinafter R) green (hereinafter G) blue (hereinafter B) video signal, and memory color determination means for determining the presence or absence of a memory color based on the detected color component And determining the signal level of the RGB video signal determined to have a memory color by the memory color determination unit based on the results of the color gamut determining unit to display and the unit for detecting the minimum value of the RGB video signal. An image display device having means for correcting.   2. The image display device according to claim 1, wherein the color component detecting means divides the six color components of the primary color component and the complementary color component according to the differences of RGB and determines the skin color, cyan, and green memory colors.   3. The image display device according to claim 1, wherein the skin color determining means is defined by a hue region in which both the values of the RG signal and the RB signal are positive numbers.   2. The image display apparatus according to claim 1, further comprising correction gain generating means for increasing the correction gain of the RGB signals as the display color gamut of the color gamut determining means for displaying is wider.   5. The image display apparatus according to claim 4, wherein the correction gain of the correction gain generation means is increased as the white component of the RGB video signal is large and the display color gamut of the display color gamut determination means is wider.

Images