CN-118567146-B - Optical cavity assembly suitable for partition color mixing

CN118567146BCN 118567146 BCN118567146 BCN 118567146BCN-118567146-B

Abstract

The invention provides an optical cavity assembly suitable for partition color mixing, which comprises diffusion sheets, wherein black matrix arrays with equal size and interval are regularly arranged on the diffusion sheets, three primary color adjustable light sources in a backlight partition and the diffusion sheets with black matrixes form an optical cavity structure without a physical grid and capable of restraining light spot shapes, wherein the optical cavities are in one-to-one correspondence with the backlight partition, the sizes of black matrix units on the diffusion sheets are consistent with the sizes of the backlight partition, and the distance h between the diffusion sheets and the light sources in the optical cavity structure, the shapes, the structures and specific parameters of the black matrix units are regulated and determined by evaluating the light emitting effect of the diffusion sheets. By the technical scheme, uniformity of color and brightness in the backlight partitions can be improved, and light color and brightness crosstalk between the backlight partitions can be reduced.

Inventors

XU SHENG
GUO TAILIANG
WU WENLIN
XIAO XIANGZHI
FAN JING
LIN XINYU
Lan Weichen
Gao Hehuan
YE YUN
CHEN ENGUO

Assignees

福州大学

Dates

Publication Date: 20260505
Application Date: 20240604

Claims (6)

1. The optical cavity component suitable for partition color mixing is characterized by comprising diffusion sheets, wherein black matrix arrays with equal size and interval are regularly arranged on the diffusion sheets, three primary color adjustable light sources in a backlight partition and the diffusion sheets with black matrixes form an optical cavity structure without a physical grid and capable of restraining the shape of light spots, wherein the optical cavities are in one-to-one correspondence with the backlight partition, and the size of black matrix units on the diffusion sheets is consistent with the size of the backlight partition; the key structural parameters of the optical cavity formed by the diffusion sheet, the black matrix and the RGB mini-LED light source corresponding to the liquid crystal backlight partition meet the following expression: Wherein, the For the distance between the diffusion sheet and the RGB mini-LED light source, L is the length of the backlight partition, d is the line width of the black matrix unit, For the thickness of the diffusion sheet, For the lambertian limiting angle of an RGB mini-LED light source, The refraction angle of the light after entering the diffusion sheet; Distance lower limit between diffusion sheet integrated with black matrix unit and RGB mini-LED light source The lower limit implementation condition of the distance between the diffusion sheet and the RGB mini-LED light source is that the circular illumination area of the light emergent surface of the diffusion sheet circumscribes the backlight sub-partition, and the light overflowing the backlight sub-partition is just absorbed and shielded by the black matrix units distributed on the diffusion sheet at the moment The determination is made according to the following expression: when the liquid crystal panel determines that the line width d of the black matrix units distributed on the diffusion sheet is consistent with the line width of the black matrix between the liquid crystal pixels, if the backlight light source is also determined, the lower limit h1 of the distance between the diffusion sheet and the RGB mini-LED light source is determined by the length L of the backlight partition and the thickness of the diffusion sheet Influence of the presence of a specific substance, wherein, The value interval of the (C) is 0.001mm-1 mm; The black matrix unit is designed on the surface of the light inlet surface, the surface of the light outlet surface of the diffusion sheet or embedded into the diffusion sheet according to the size of the backlight partition; wherein, when the black matrix unit is designed on the surface of the light emitting surface of the diffusion sheet, the line width d of the black matrix unit is determined according to the following expression: When the black matrix unit is designed on the light incident surface of the diffusion sheet, the thickness of the diffusion sheet is set in the formula set =0, The line width of the black matrix cell is determined according to the following expression: 。
2. An optical cavity assembly suitable for zone color mixing according to claim 1, wherein the upper distance limit between the diffusion sheet of the integrated black matrix unit and the RGB mini-LED light source Determining method of upper limit of distance between diffusion sheet and RGB mini-LED light source The determination is made according to the following expression: When the liquid crystal panel determines that the line width d of the black matrix units distributed on the diffusion sheet is consistent with the line width of the black matrix between the liquid crystal pixels, at this time, if the backlight light source is also determined, the upper limit of the distance between the diffusion sheet and the RGB mini-LED light source Only by the size L of the backlight partition.
3. An optical cavity module for zoned color matching according to claim 1, wherein the line width of the black matrix unit on the surface of the diffusion sheet has a value interval of [ [ , ]; Wherein, the line width of the black matrix unit takes the lower limit of the value The determination is made according to the following expression: line width value upper limit of black matrix unit The determination is made according to the following expression: 。
4. An optical cavity assembly according to claim 1, wherein when the liquid crystal pixel unit is not rectangular, the black matrix unit is changed to a honeycomb or circular shape accordingly; 1) When the black matrix unit is in the shape of a honeycomb polygon, the width d thereof is determined according to the following expression: Wherein h is the distance between the diffusion sheet and the RGB mini-LED light source, For the lambertian limiting angle of an RGB mini-LED light source, As the refractive angle of the light after entering the diffusion sheet, A diffusion sheet thickness, 2) a black matrix unit having a circular shape, the width d of which is determined according to the following expression: Wherein h is the distance between the diffusion sheet and the RGB mini-LED light source, For the lambertian limiting angle of an RGB mini-LED light source, As the refractive angle of the light after entering the diffusion sheet, For diffuser thickness, R is the radius of the circular backlight partition.
5. An optical cavity assembly according to claim 1, wherein the cross-talk evaluation index of the low color cross-talk diffuser structure of the integrated black matrix unit Radiant flux defined as the circular illumination area of the diffuser Radiant flux zoned with backlight The difference of (2) is the radiant flux of the circular illumination area of the diffusion sheet Percent of (v), and The value interval is 0, ]; When the black matrix unit is designed on the light incident surface of the diffusion sheet, The determination is made according to the following set of expressions: Wherein, the RGB mini-LED light source is regarded as a lambertian radiation source, For the radiation intensity described in the spherical coordinate system, For the radiation intensity in the direction of the surface normal of the RGB mini-LED light source, For the lambertian limiting angle of an RGB mini-LED light source, For the included angle between the surface normal of the RGB mini-LED light source and the light passing through the edge of the backlight partition, h The distance d is the line width of the black matrix unit, and L is the length of the backlight partition.
6. The optical cavity assembly suitable for partition color mixing according to claim 1, wherein a circular cup-shaped reflective optical structure is added at the bottom of a light source in the optical cavity, and light emitted by the light source to the periphery is collected and is upwardly polymerized to emit light, so that the light utilization rate of backlight partition is effectively improved; wherein the height y and base radius x of the circular cup-shaped reflective optical structure are determined according to the following set of expressions: Wherein, the For the distance between the diffusion sheet and the RGB mini-LED light source, L is the length of the backlight partition, d is the line width of the black matrix unit, For the lambertian limiting angle of an RGB mini-LED light source, The optical path is an incident angle of an optical path, wherein the value interval of d is (0 mm-10 mm), and the value interval of L is (0 mm-1000 mm).

Description

Optical cavity assembly suitable for partition color mixing Technical Field The invention relates to the technical field of display optics, in particular to an optical cavity assembly suitable for partition color mixing. Background Conventional lcd backlighting systems employ a set of global backlights to illuminate the entire screen. However, this design has some limitations in displaying bright and dark details, which can lead to loss of dark details and reduced contrast. Backlight zonal tinting is a backlight adjustment technique applied in liquid crystal displays. This technique divides the backlight into a plurality of independent areas, each of which can individually adjust backlight brightness and color. By flexibly controlling these backlight partitions, higher contrast, a wider color gamut, and finer color representation can be achieved. The backlight partition toning technique can accurately adjust the backlight brightness of each partition according to the picture content. When only a part of areas in the picture need to display bright details, other areas can keep low backlight brightness and even completely turn off, so that higher contrast and deeper dark details are provided, and the quality of the image is further enhanced. The technical challenges in implementing a backlit zoned tinted lc panel are primarily to design fine backlight zones and corresponding drive circuits, as well as to provide a more efficient backlight source. By precisely controlling the backlight intensity and color output of each partition, bright areas and dark details can be displayed on the same screen at the same time, and the quality and viewing experience of images are improved. The existing partition color mixing technology based on liquid crystal backlight needs to realize dimming and color mixing simultaneously in each backlight partition, and add a metal physical grid between the partitions to prevent the light with different colors and intensities from cross-talk between the partitions. This requires precise alignment of the liquid crystal pixels with respect to the position of the segmented spacer grid, any minor deviations affecting the display. In addition, the selection of a partitioned isolation grid, the difficulty of processing, and the cost are challenges facing the technology. The selection of suitable spacer grid materials requires consideration of optical properties, stability, and manufacturing costs, and existing processing methods tend to be complex and expensive. Disclosure of Invention Accordingly, the present invention is directed to an optical cavity assembly suitable for partition color mixing, which improves uniformity of color and brightness in backlight partitions, and reduces crosstalk of light color and brightness between backlight partitions. The technical scheme is that the optical cavity component suitable for partition color mixing comprises diffusion sheets, wherein black matrix arrays with equal size and interval are regularly arranged on the diffusion sheets, three primary color adjustable light sources in a backlight partition and the diffusion sheets with black matrixes form an optical cavity structure without a physical grid and capable of restraining light spot shapes, the optical cavities are in one-to-one correspondence with the backlight partition, the size of black matrix units on the diffusion sheets is consistent with that of the backlight partition, and the distance h between the diffusion sheets and the light sources in the optical cavity structure, the shape, the structure and specific parameters of the black matrix units are regulated and determined by evaluating the light emitting effect of the diffusion sheets. In a preferred embodiment, the key structural parameters of the optical cavity formed by the diffusion sheet, the black matrix and the RGB mini-LED light source corresponding to the liquid crystal backlight partition satisfy the following expression: wherein h is the distance between the diffusion sheet and the RGB mini-LED light source, L is the length of the backlight partition, d is the width of the black matrix unit, a is the thickness of the diffusion sheet, θ is the lambertian limit angle of the RGB mini-LED light source, and θ' is the refraction angle of light after entering the diffusion sheet. In a preferred embodiment, the method for determining the lower limit h 1 of the distance between the diffusion sheet of the black matrix unit and the RGB mini-LED light source is integrated, wherein the lower limit h 1 of the distance between the diffusion sheet and the RGB mini-LED light source is determined according to the following expression: When the liquid crystal panel determines that the line width d of the black matrix units distributed on the diffusion sheet is consistent with the line width of the black matrix among the liquid crystal pixels, if the backlight light source is also determined, the lower limit h1 of the distance between the diffusi