Light source device for television

Abstract

In order to solve the problems that a traditional television light source cannot achieve color temperature adjustment of a liquid crystal television, and the contrast ratio and the brightness uniformity are limited, the invention provides a light source device for the television, which comprises a three-color LED light source array, a scattering layer, a brightness enhancement film, a color gray scale mask array and a lens array, the three-color LED light source can be used for color temperature control and contrast enhancement; the coupling structure of the color gray scale mask array and the lens array can be used for enabling the emergent light intensity of the liquid crystal panel in all directions to be kept consistent, so that the brightness uniformity is enhanced. Finally, the contrast ratio, the color temperature and the brightness uniformity of the display can be actively and accurately controlled, so that the display effect is optimized.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of display, more particularly, the present application relates to a light source device for television. BACKGROUND

[0002] In liquid crystal television, contrast ratio, color temperature and brightness uniformity are key technical indicators of image display quality. The traditional television light source usually contains white light LED light source array, scattering layer, light enhancement film and the like. The above simple structure is difficult to actively and accurately control the contrast ratio, color temperature and brightness uniformity of the display, thereby limiting the image display performance of the liquid crystal television. In order to realize the optimization of the above parameters, the present application enhances the light source and proposes a light source device for television. The light source device for television is provided with independently controllable three-color LED light sources for color temperature control and contrast ratio enhancement, and color gray scale mask array and lens array for brightness uniformity enhancement. SUMMARY

[0003] In order to solve the problem that the traditional television light source cannot realize color temperature adjustment of the liquid crystal television and has limited contrast ratio and brightness uniformity, the present application proposes a light source device for television.

[0004] The light source device for television contains three-color LED light source array, scattering layer, light enhancement film, color gray scale mask array and lens array; the three-color LED light source array, scattering layer, light enhancement film, color gray scale mask array and lens array are placed in order from back to front; the liquid crystal display panel is placed in front of the light source device for television.

[0005] The three-color LED light source array is arranged by a plurality of three-color LED light sources. The three-color LED light source contains white light source, red light source and blue light source, and in any one three-color LED light source, the white light source, the red light source and the blue light source are placed adjacent to each other; the white light source provides main light energy for display; the red and blue light sources are used for color temperature adjustment; the light brightness of all three-color LED light sources is independently controlled; the light brightness of the white light source, the red light source and the blue light source in the same three-color LED light source is independently controlled.

[0006] The control rule follows: when the brightness of a certain area of the liquid crystal display panel image is dark, the brightness of the white light source in the three-color LED light source behind the area is reduced; when the brightness of a certain area of the liquid crystal display panel image is high, the brightness of the white light source in the three-color LED light source behind the area is increased; when the color temperature of a certain area of the liquid crystal display panel image needs to be cold, the red light source of the three-color LED light source behind the area is turned off and the brightness of the blue light source is increased; when the color temperature of a certain area of the liquid crystal display panel image needs to be warm, the blue light source of the three-color LED light source behind the area is turned off and the brightness of the red light source is increased.

[0007] The lens array is arranged by several lenses; the color gray mask array is arranged by several color gray masks; the lens and the color gray mask correspond to each other; and the light in any region of the color gray mask can be projected directionally by the corresponding lens.

[0008] The light transmittance of different regions of the color gray mask is different, and the light transmittance is related to the light transmittance of the liquid crystal display panel and the spatial directional intensity of the light source. Assuming that the red light transmittance of any first region of the color gray mask is Trm1, the green light transmittance is Tgm1, and the blue light transmittance is Tbm1; the light passing through the first region is projected directionally by the corresponding lens to a first spatial direction; assuming that the red light transmittance of the liquid crystal display panel in the first spatial direction is Trd1, the green light transmittance is Tgd1, and the blue light transmittance is Tbd1 under the same pixel gray scale; assuming that the red light intensity of the three-color LED light source array in the first spatial direction is Qr1, the green light intensity is Qg1, and the blue light intensity is Qb1 through the scattering layer, the light enhancement film and the lens array; assuming that the red light transmittance of any second region of the color gray mask is Trm2, the green light transmittance is Tgm2, and the blue light transmittance is Tbm2; the light passing through the second region is projected directionally by the corresponding lens to a second spatial direction; assuming that the red light transmittance of the liquid crystal display panel in the second spatial direction is Trd2, the green light transmittance is Tgd2, and the blue light transmittance is Tbd2 under the same gray scale; assuming that the red light intensity of the three-color LED light source array in the second spatial direction is Qr2, the green light intensity is Qg2, and the blue light intensity is Qb2 through the scattering layer, the light enhancement film and the lens array. Then the light transmittance of any first region and any second region of the color gray mask should satisfy: Trm1*Trd1*Qr1=Trm2*Trd2*Qr2, Tgm1*Tgd1*Qg1=Tgm2*Tgd2*Qg2, and Tbm1*Tbd1*Qb1=Tbm2*Tbd2*Qb2.

[0009] Preferably, the distance from the color gray mask to the lens is equal to the focal length of the lens, so as to enhance the consistency of the light direction of the same region of the color gray mask. When the distance from the color gray mask to the lens is not equal to the focal length of the lens, the present application can also play a role in improving the brightness uniformity, but the greater the difference between the distance and the focal length of the lens, the worse the brightness uniformity.

[0010] The working principle of the present application is as follows:

[0011] (1) Contrast enhancement principle In the conventional mode, the backlight of the liquid crystal television is always on, and the liquid crystal display panel usually has light leakage. Therefore, in the display area with pixel value of 0, there is still light, which results in low contrast. In the present application, the brightness of all the three-color LED light sources is independently controlled. When the brightness of a certain area of the liquid crystal display panel image is dark, the brightness of the white light source in the three-color LED light source behind the area is reduced, so that the light leakage is reduced. When the brightness of a certain area of the liquid crystal display panel image is high, the brightness of the white light source in the three-color LED light source behind the area is increased, so that the illumination of the pixels in the area is realized. Based on the above process, the contrast of the bright area and the dark area of the image can be improved.

[0012] (2) Color temperature control principle In the conventional mode, the color temperature of the liquid crystal television is realized by processing the digital image. In the present application, the three-color LED light source contains a red light source and a blue light source, which can adjust the color temperature by adjusting the brightness of the red light source and the blue light source. In a certain area of an image, the color temperature needs to be warm, so the blue light source of the three-color LED light source behind the area is turned off and the brightness of the red light source is increased, so that the color of the area is warm. In another area of the image, the color temperature needs to be cold, so the red light source of the three-color LED light source behind the area is turned off and the brightness of the blue light source is increased, so that the color of the area is cold. Based on the above process, the color temperature of the same image can be adjusted in different areas.

[0013] (3) Brightness uniformity improvement principle Generally, the light brightness of liquid crystal display panel is not uniform in different exit directions, the larger the angle between the exit light and the normal line of the screen, the smaller the light exit, and the above characteristics result in uneven image brightness. In the present application, the problem of non-uniform light brightness in different exit directions is solved by using color gray mask and lens coupling. Taking red light as an example, if the intensity of the backlight source structure in any first direction is Qr1, the transmittance of the liquid crystal display panel in the direction is Trd1, then the actual light exit intensity is Qr1×Trd1, after introducing the color gray mask, the light emitted along the arbitrary first direction is regulated by the arbitrary first region, the light transmittance of the arbitrary first region is Trm1, then Trm1 can adjust the intensity of the final emitted light, finally, the light intensity emitted along the first direction is Trm1×Trd1×Qr1. Further, for the light emitted in any second direction, the present application sets the second region light transmittance Trm2 in the corresponding second region of the color gray mask, and the light intensity emitted along the second direction is Trm2×Trd2×Qr2. In the traditional mode, Trd1×Qr1 is not equal to Trd2×Qr2, resulting in uneven picture brightness, but in the present application, Trd1 and Trm2 are introduced, and Trm1×Trd1×Qr1=Trm2×Trd2×Qr2 is set, so that the intensity of light emitted in any direction is the same, thereby finally improving the brightness uniformity.

[0014] In summary, the present application can regulate the white light source in the three-color LED light source regionally, thereby improving the image contrast regionally; further, the present application can regulate the red and blue light sources in the three-color LED light source regionally, thereby changing the image color temperature regionally; finally, the present application can make the intensity of light emitted in any direction the same through color gray mask and lens coupling, thereby improving the brightness uniformity. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the present application.

[0016] Figure 2 It is a schematic diagram of the three-color LED light source of the present application.

[0017] Figure 3 It is a schematic diagram of high-contrast image display of the present application.

[0018] Figure 4 It is a control schematic diagram of the three-color LED light source for displaying high-contrast image of the present application.

[0019] Figure 5 It is a working principle schematic diagram of the color gray mask of the present application.

[0020] Figure 6 It is an effect schematic diagram of improving brightness uniformity of the present application.

[0021] Figure: 100 - light source array; 110 - three-color LED light source; 111 - red light source; 112 - white light source; 113 - blue light source; 210 - scattering layer; 220 - brightness enhancement film; 300 - color gray scale mask array; 310 - color gray scale mask; 311 - region A; 312 - region B; 313 - region C; 314 - region D; 315 - region E; 400 - lens array; 410 - lens; 500 - liquid crystal display panel; 501 - arbitrary first pixel; 502 - arbitrary second pixel; 601 - liquid crystal display panel image; 610 - image dark area; 620 - image bright area; 120 - dark state three-color LED light source; 130 - bright state three-color LED light source.

[0022] It should be understood that the above-mentioned figures are only schematic and not drawn to scale. DETAILED DESCRIPTION

[0023] Figure 1 A light source device for television is provided for the present embodiment.

[0024] The light source device for television comprises a three-color LED light source array 100, a scattering layer 210, a brightness enhancement film 220, a color gray scale mask array 300, and a lens array 400; the three-color LED light source array 100, the scattering layer 210, the brightness enhancement film 220, the color gray scale mask array 300, and the lens array 400 are placed in order from back to front; a liquid crystal display panel 500 is placed in front of the light source device for television.

[0025] Please refer to Figure 2 The three-color LED light source array 100 is arranged by a plurality of three-color LED light sources 110. The three-color LED light source 110 comprises a white light source 112, a red light source 111, and a blue light source 113; in any one three-color LED light source 110, the white light source 112, the red light source 111, and the blue light source 113 are placed adjacently and centrally; the white light source 112 provides main light energy for display; the red light source 111 and the blue light source 113 are used for color temperature adjustment; the brightness of all three-color LED light sources 110 is independently controlled; in the same three-color LED light source 110, the brightness of the white light source 112, the red light source 111, and the blue light source 113 is independently controlled.

[0026] Please refer to Figure 3 and Figure 4The control rule of the three-color LED light source 110 is as follows: when the brightness of a certain area of the liquid crystal display panel image 601 is dark, a dark area 610 is formed, at this time, the brightness of the white light source 112 in the three-color LED light source 110 behind the area is reduced, a dark-state three-color LED light source 120 is formed; when the brightness of a certain area of the liquid crystal display panel image 601 is high, the brightness of the white light source 112 in the three-color LED light source 110 behind the area is increased, a bright-state three-color LED light source 130 is formed; when the color temperature of a certain area of the liquid crystal display panel image 601 needs to be cold, the red light source 111 behind the area is turned off and the brightness of the blue light source 113 is increased; when the color temperature of a certain area of the liquid crystal display panel image 601 needs to be warm, the blue light source 113 behind the area is turned off and the brightness of the red light source 111 is increased.

[0027] Please refer to Figure 1 and Figure 5 The lens array 400 is arranged by a plurality of lenses 410; the color gray scale mask array 300 is arranged by a plurality of color gray scale masks 310; the lens 410 and the color gray scale mask 310 correspond to each other; the light passing through any area of the color gray scale mask 310 can be projected directionally through the corresponding lens 410.

[0028] Please refer to Figure 5 Different areas of the color gray scale mask 310 are provided with different light transmittances, and the light transmittance is related to the light transmittance of the liquid crystal display panel 500 and the spatial directional intensity of the light source.

[0029] Assume that the red light transmittance of any first area on the color grayscale mask 310 is Trm1, the green light transmittance is Tgm1, and the blue light transmittance is Tbm1; assume that the light passing through the first area is directed by the corresponding lens 410 to the first spatial direction; assume that under the same pixel grayscale, the red light transmittance of the liquid crystal display panel 500 in the first spatial direction is Trd1, the green light transmittance is Tgd1, and the blue light transmittance is Tbd1; assume that the red light intensity of the three-color LED light source array in the first spatial direction through the scattering layer 210, the brightness enhancement film 220 and the lens array 400 is Qr1, the green light intensity is Qg1, and the blue light intensity is Qb 1; suppose that the red light transmittance, green light transmittance, and blue light transmittance of any second area on the color grayscale mask 310 are Trm2, Tgm2, and Tbm2; suppose that the light passing through the second area is projected in a direction to the second spatial direction by the corresponding lens 410; suppose that under the same grayscale, the red light transmittance, green light transmittance, and blue light brightness of the liquid crystal display panel 500 in the second spatial direction are Trd2, Tgd2, and Tbd2; suppose that the red light intensity, green light intensity, and blue light intensity of the three-color LED light source array in the second spatial direction through the scattering layer 210, the brightness enhancement film 220, and the lens array 400 are Qr2, Qg2, and Qb2. The light transmittance of any first area and any second area on the color grayscale mask 310 should satisfy: Trm1×Trd1×Qr1=Trm2×Trd2×Qr2, Tgm1×Tgd1×Qg1=Tgm2×Tgd2×Qg2 and Tbm1×Tbd1×Qb1=Tbm2×Tbd2×Qb2.

[0030] Specifically, Figure 5 For example, color grayscale mask 310 has region A 311, region B 312, region C 313, region D 314, and region E 315. Light passing through region A 311 is projected by lens 410 and propagates along the α direction; light passing through region B 312 is projected by lens 410 and propagates along the β direction; light passing through region C 313 is projected by lens 410 and propagates along the γ direction; light passing through region D 314 is projected by lens 410 and propagates along the δ direction; and light passing through region E 315 is projected by lens 410 and propagates along the ε direction. When the grayscale of the liquid crystal display panel 500 is set to 255, the red light transmittance in the α, β, γ, δ and ε directions is 0.22, 0.24, 0.28, 0.24 and 0.22 respectively; the green light transmittance is 0.21, 0.25, 0.29, 0.25 and 0.21 respectively; and the blue light transmittance is 0.22, 0.24, 0.26, 0.24 and 0.22 respectively. The red light intensity of the three-color LED light source array in the α, β, γ, δ and ε directions through the scattering layer 210, the brightness enhancement film 220 and the lens array 400 is 1200, 1220, 1240, 1220 and 1200 respectively (unit: cd / m 2) respectively; green light intensity is 1210, 1230, 1250, 1230 and 1210 (unit: cd / m 2 ) respectively; blue light intensity is 1205, 1225, 1245, 1225 and 1205 (unit: cd / m 2 ) respectively. At this time, the red light transmittance of the area A 311, the area B 312, the area C 313, the area D 314 and the area E 315 is 0.947, 0.854, 0.72, 0.854 and 0.947 respectively, and the intensity of the red light along the alpha, beta, gamma, delta and epsilon directions is 250 cd / m 2 ) respectively. At this time, the green light transmittance of the area A 311, the area B 312, the area C 313, the area D 314 and the area E 315 is 0.984, 0.813, 0.69, 0.813 and 0.984 respectively, and the intensity of the green light along the alpha, beta, gamma, delta and epsilon directions is 250 cd / m 2 ) respectively. At this time, the blue light transmittance of the area A 311, the area B 312, the area C 313, the area D 314 and the area E 315 is 0.943, 0.85, 0.772, 0.85 and 0.943 respectively, and the intensity of the blue light along the alpha, beta, gamma, delta and epsilon directions is 250 cd / m 2 At this time, for any two areas, Trm1xTrd1xQr1=Trm2xTrd2xQr2, Tgm1xTgd1xQg1=Tgm2xTgd2xQg2 and Tbm1xTbd1xQb1= Tbm2xTbd2xQb2.

[0031] Please refer to Figure 6 When the human eye is located at a left position opposite the display, the left part of the pixel light is emitted to the human eye in the gamma direction, and the right part of the pixel light is emitted to the human eye in the alpha direction. In the traditional mode, because the light emission rate of the gamma direction opposite the screen is high, the image brightness on the left side of the screen is high, and the image brightness on the right side of the screen is low. In the present application, because the color gray mask 310 is used, the intensities of the light in the alpha, beta, gamma, delta and epsilon directions are equal, so the brightness on the left and right sides of the screen is the same.

[0032] Further, the distance from the color gray mask 310 to the lens 410 is equal to the focal length of the lens 410. At this time, for any first pixel 501 and any second pixel 502, the directions of the projection light beams of the same pixel area are consistent. Please refer to Figure 5 The projection light corresponding to the area A 311 propagates in the alpha direction after passing through any first pixel 501 and any second pixel 502.

[0033] The working principle of the present application is as follows:

[0034] (1) Contrast enhancement principle Please refer to Figure 3 and Figure 4 In the conventional mode, the backlight of the liquid crystal television is always on, and the liquid crystal display panel 500 will have light leakage, so in the display area where the pixel value is 0, there is still light, which leads to low contrast. In the present application, the brightness of all three-color LED light sources 110 is independently controlled. When the brightness of a certain area of the liquid crystal display panel image 601 is dark, the brightness of the white light source 112 in the three-color LED light source 110 behind the area is reduced, so that the light leakage is reduced. When the brightness of a certain area of the liquid crystal display panel image 601 is high, the brightness of the white light source 112 in the three-color LED light source 110 behind the area is increased, so as to realize the illumination of the pixels in the area. Based on the above process, the present application can improve the contrast of bright and dark areas of the image.

[0035] (2) Color temperature control principle Please refer to Figure 2 In the conventional mode, the color temperature of the liquid crystal television is realized by processing the digital image, while in the present application, the three-color LED light source 110 contains a red light source 111 and a blue light source 113, which can adjust the color temperature by adjusting the brightness of the red light source 111 and the blue light source 113. In a certain area of an image, the color temperature needs to be warm, so the blue light source 113 of the three-color LED light source 110 behind the area is turned off and the brightness of the red light source 111 is increased, so that the color in the area is warm. In another part of the image, the color temperature needs to be cold, so the red light source 111 of the three-color LED light source 110 behind the area is turned off and the brightness of the blue light source 113 is increased, so that the color in the area is cold. Based on the above process, the present application can adjust the color temperature in different areas of the same image.

[0036] (3) Brightness uniformity improvement principle Please refer to Figure 5 and Figure 6, the brightness of the liquid crystal display panel 500 is not uniform in different directions, the larger the angle between the outgoing light and the normal of the screen, the smaller the light emission, and the above characteristics result in uneven image brightness. In the present application, the color gray mask 310 and the lens 410 are coupled to solve the problem of non-uniform brightness in different directions. Taking red light as an example, if the intensity of the backlight source structure in any first direction is Qr1, the transmittance of the liquid crystal display panel 500 in the direction is Trd1, then the actual light emission intensity is Qr1xTrd1. After introducing the color gray mask 310, the light emitted along the arbitrary first direction is regulated by the arbitrary first region, and the light transmittance of the arbitrary first region is Trm1, so that Trm1 can adjust the intensity of the final emitted light. Finally, the light intensity emitted along the first direction is Trm1xTrd1xQr1. Further, for the light emitted in any second direction, the present application sets the second region light transmittance Trm2 in the corresponding second region of the color gray mask 310, and the final light intensity emitted along the second direction is Trm2xTrd2xQr2. In the traditional mode, Trd1xQr1 is not equal to Trd2xQr2, resulting in uneven picture brightness, but in the present application, Trd1 and Trm2 are introduced, and Trm1xTrd1xQr1=Trm2xTrd2xQr2 is set, so that the intensity of light emission in any direction is the same, thereby finally improving the brightness uniformity.

[0037] In summary, the present application can regulate the white light source 112 in the three-color LED light source 110 regionally, thereby improving the image contrast regionally. Further, the present application can regulate the red light source 111 and the blue light source 113 in the three-color LED light source 110 regionally, thereby changing the image color temperature regionally. Finally, the present application can make the intensity of light emission in any direction the same by coupling the color gray mask 310 and the lens 410, thereby improving the brightness uniformity.

Claims

1. A light source device for a television, characterized in that: The television light source device comprises a three-color LED light source array, a scattering layer, a brightness enhancement film, a color grayscale mask array, and a lens array; the three-color LED light source array, the scattering layer, the brightness enhancement film, the color grayscale mask array, and the lens array are arranged in sequence from back to front; and the liquid crystal display panel is placed in front of the television light source device; A three-color LED light source array is composed of several three-color LED light sources arranged in an array. The three-color LED light sources include white, red, and blue light sources. Within any three-color LED light source, the white, red, and blue light sources are placed adjacent to each other. The white light source provides the main light energy for display; the red and blue light sources are used for color temperature adjustment. The brightness of all three-color LED light sources is independently controlled. Within the same three-color LED light source, the brightness of the white, red, and blue light sources can be independently controlled. The control rules follow: when the brightness of a certain area of ​​the LCD panel image is dark, the brightness of the white light source in the three-color LED light source behind the area is reduced; when the brightness of a certain area of ​​the LCD panel image is high, the brightness of the white light source in the three-color LED light source behind the area is increased; when the LCD panel image requires a cooler color temperature in a certain area, the three-color LED light source behind the area turns off the red light source and increases the brightness of the blue light source; when the LCD panel image requires a warmer color temperature in a certain area, the three-color LED light source behind the area turns off the blue light source and increases the brightness of the red light source; The lens array is composed of a number of lenses arranged in an array; the color grayscale mask array is composed of a number of color grayscale masks arranged in an array; the lenses and color grayscale masks correspond one to one; light passing through any area on the color grayscale mask can be directed through the corresponding lens; Different areas on the color grayscale mask are set with different light transmittances. The light transmittances are related to the light transmittances of the liquid crystal display panel and the spatial direction intensity of the light source. Assume that the red light transmittance of any first area on the color grayscale mask is Trm1, the green light transmittance is Tgm1, and the blue light transmittance is Tbm1; assume that the light passing through the first area is projected in a direction to the first spatial direction by the corresponding lens; assume that under the same pixel grayscale, the red light transmittance of the liquid crystal display panel in the first spatial direction is Trd1, the green light transmittance is Tgd1, and the blue light transmittance is Tbd1; assume that the red light intensity of the three-color LED light source array in the first spatial direction through the scattering layer, the brightness enhancement film and the lens array is Qr1, the green light intensity is Qg1, and the blue light intensity is Qb1; assume that the red light transmittance of any second area on the color grayscale mask is T rm2, green light transmittance is Tgm2, blue light transmittance is Tbm2; suppose that the light passing through the second area is projected in a direction to the second spatial direction by the lens corresponding thereto; suppose that under the same grayscale, the red light transmittance of the liquid crystal display panel in the second spatial direction is Trd2, the green light transmittance is Tgd2, and the blue light brightness is Tbd2; suppose that the red light intensity of the three-color LED light source array through the scattering layer, the brightness enhancement film and the lens array in the second spatial direction is Qr2, the green light intensity is Qg2, and the blue light intensity is Qb2; then the light transmittance of any first area and any second area on the color grayscale mask should satisfy: Trm1×Trd1×Qr1=Trm2×Trd2×Qr2, Tgm1×Tgd1×Qg1=Tgm2×Tgd2×Qg2 and Tbm1×Tbd1×Qb1= Tbm2×Tbd2×Qb2.

2. A television light source device according to claim 1, characterized in that: The distance from the color grayscale mask to the lens is equal to the focal length of the lens.

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