CN113467129B

CN113467129B - Optical plate and display device comprising same

Info

Publication number: CN113467129B
Application number: CN202110742342.0A
Authority: CN
Inventors: 罗飞
Original assignee: Najing Technology Corp Ltd
Current assignee: Najing Technology Corp Ltd
Priority date: 2021-06-30
Filing date: 2021-06-30
Publication date: 2023-09-26
Anticipated expiration: 2041-06-30
Also published as: CN113467129A

Abstract

The present disclosure provides an optical plate and a display device. The inside of the optical plate is provided with a plurality of reflecting pieces perpendicular to the bottom surface of the optical plate, each reflecting piece is arranged in a regular array, each reflecting piece separates the optical plate to form a plurality of optical areas, and the optical plate is used for optically connecting a plurality of backlight light sources controlled in a partitioning mode. The light blocking effect of the reflecting piece of the optical plate forms a plurality of optical areas, realizes secondary partition of the backlight light source, reduces light leakage, and improves the contrast ratio of the image edge.

Description

Optical plate and display device comprising same

Technical Field

The present disclosure relates to the field of backlight display, and more particularly, to an optical plate and a display device including the same.

Background

The liquid crystal display is limited by the pixel light leakage phenomenon, and is compared with the novel display technology, the contrast ratio is already a short plate, so that a partition backlight method is gradually developed in the liquid crystal display technology, the backlight source LEDs are regulated and controlled in a partition mode, the backlight with different brightness is respectively regulated and controlled in a high gray level area and a low gray level area, the pixel light leakage phenomenon can be improved to a certain extent, and the display contrast ratio is improved. However, the display effect of the backlight partition control technology varies in positive correlation with the number of partitions, and the more partitions, the more difficult the realization of the technology and the higher the cost, and therefore, a more effective solution is needed.

Disclosure of Invention

The disclosure provides an optical plate and a display device comprising the same, which can effectively reduce the pixel light leakage phenomenon of the display device caused by insufficient backlight regulation and control and improve the contrast ratio.

In order to achieve the above object, according to a first aspect of the present disclosure, there is provided an optical plate, in which a plurality of reflection members perpendicular to a bottom surface of the optical plate are disposed, each of the reflection members is regularly arranged in an array, each of the reflection members partitions the optical plate into a plurality of optical areas, and the optical plate is used for optically connecting a plurality of area-controlled backlight light sources.

Further, the thickness of each reflecting member is 0.5mm or less, preferably 0.25mm or less.

Further, the reflectance of each reflecting member is not less than 50%, preferably not less than 80%.

Further, the orthographic projection of each optical area is rectangular, and one or more of the lateral lengths of each optical area are provided; when the lateral lengths of the respective optical regions are plural, the optical regions of the same lateral length are not adjacent to each other.

Further, the shape of the orthographic projection of each optical area is the same, and the area of the orthographic projection is preferably the same.

Further, the main body of the optical plate is a resin material, and the optical plate further comprises a quantum dot material dispersed in the resin material.

Further, the reflectivity of the reflecting member gradually decreases in a direction away from the backlight source.

Further, the optical plate includes a matrix of a resin material, the refractive index of the matrix gradually decreasing in a direction away from the backlight light source.

Further, the optical plate includes a matrix of a resin material and diffusion particles dispersed in the matrix, the concentration of the diffusion particles gradually decreasing in a direction away from the backlight light source.

Further, the optical plate includes a plurality of diffusion layers stacked, and the refractive index of the matrix of the diffusion layers of each layer gradually decreases in a direction away from the backlight source.

Further, the optical plate comprises two diffusion layers, the transverse length of the partition of the backlight light source is L, and the thickness of the optical plate is d; the refractive index of the matrix of the diffusion layer closest to the backlight source is n ₁ The refractive index of the matrix of the diffusion layer furthest from the backlight source is n ₂ And n is ₁ >n ₂ ，1＜n ₁ /n ₂ ＜2，L≥d。

Further, the method comprises the steps of,

according to a second aspect of the present disclosure, there is provided a display device, including a plurality of backlight light sources controlled by a partition and a display layer including a plurality of pixel points, and further including any one of the above optical plates, wherein a forward projection area of one partition of the backlight light sources is larger than a forward projection area of any one of the optical areas; when the display device is operated, light of the backlight source passes through the optical plate to the display layer, and the pattern is displayed through the display layer.

Further, the thickness of each reflecting member is 1 pixel or less, preferably 0.5 pixel or less, and more preferably 0.1 pixel or less.

Further, the front projection of each optical area is rectangular, and the lateral length of each partition of the backlight light source is larger than that of each optical area.

Further, the front projection of each reflector does not cover the dividing line of the partition of each backlight source.

Further, the display device is a direct type display device, and the optical plate is a diffusion plate; or the display device is a side-in display device, and the optical plate is a light guide plate.

By applying the technical scheme, due to the light blocking effect of the reflecting piece of the optical plate, a plurality of optical areas are formed, the secondary partition of the backlight light source is realized, and light leakage is reduced, so that the contrast ratio of the image edge is improved. The display device adopting the optical plate has higher display contrast.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure, illustrate and explain the exemplary embodiments of the disclosure and together with the description serve to explain the disclosure, and do not constitute an undue limitation on the disclosure. In the drawings:

fig. 1 shows a schematic cross-sectional structure and display effect of a direct type display device of the prior art.

Fig. 2 is a schematic diagram showing a cross-sectional structure and a display effect of another direct type display device according to the prior art.

Fig. 3 is a schematic diagram showing a cross-sectional structure and a display effect of a direct type display device according to an embodiment.

Fig. 4 is a schematic view showing the structures of a partition optical plate and a partition backlight light source of a direct type display device according to an embodiment.

Fig. 5 shows a schematic top view of a zoned optical plate of a side-entry display device according to an embodiment.

Fig. 6a shows a schematic top view of a partitioned optical plate according to an embodiment, and fig. 6b shows a schematic side view of a partitioned optical plate according to an embodiment.

FIG. 7 illustrates a schematic top view of a zoned optical plate of one embodiment.

FIG. 8 illustrates a schematic top view of a zoned optical plate of one embodiment.

Fig. 9 shows a schematic cross-sectional structure of a display device of an embodiment in which the refractive index of the optical plate is decreased.

Fig. 10 shows a schematic cross-sectional structure of a display device of an embodiment in which the refractive index of the optical plate is decreased.

Fig. 11 shows an image to be displayed of the display device of embodiment 1.

Fig. 12 shows a backlight partition size diagram of the display device of embodiment 1.

Fig. 13 shows an optical simulation display effect diagram of embodiment 1.

Fig. 14 shows an optical simulation display effect diagram of comparative example 1.

Fig. 15 shows an optical simulation display effect diagram of comparative example 2.

Reference numerals: 1. a display layer; 2A, a traditional optical plate; 2B, partitioning an optical plate; 3A, non-partitioned backlight source; 3B, partitioning a backlight source; z1, a light leakage area; z2, the image display area is set.

Abbreviations description: BL is the backlight source.

Detailed Description

It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the application. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It should be noted that the terms "comprises" and "comprising," and any variations thereof, in the description and claims of the present disclosure are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed or inherent to such process, method, article, or apparatus.

Exemplary embodiments of the technical solution provided according to the present disclosure will be described in more detail below. These exemplary embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. It should be appreciated that these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of these exemplary embodiments to those skilled in the art.

In the prior art liquid crystal display device, the conventional optical plate is made of an acrylic or other optical plastic material. As shown in fig. 1, if the backlight source is not used for the partition control, the light leakage is serious, so that pixels which do not need to be displayed also have light emission, and further the image edge is blurred. As shown in fig. 2, if the backlight source is used to control the on/off and brightness of the backlight source in a partitioned manner, because the optical plate can perform optical path transmission, besides the set image display area, the display layer right above the BL1 and BL4 backlight sources also receives the light (see arrow direction, refer to light ray direction) of the BL2 and BL3 backlight sources, and the design of fig. 2 has improved display effect compared with that of fig. 1, but still has a light leakage phenomenon of partial pixels, which causes blurring of the edges of the image to be displayed and reduces contrast ratio.

According to a first aspect of the present disclosure, there is provided an optical plate in which a plurality of reflection members perpendicular to a bottom surface of the optical plate are provided, each of the reflection members being arranged in a regular array, each of the reflection members dividing the optical plate into a plurality of optical areas, the optical plate being for optically connecting a plurality of divisionally controlled backlight light sources. The light blocking effect of the reflecting piece is utilized to form a plurality of optical areas, so that secondary partition of the backlight light source is realized, light leakage is reduced, and the contrast ratio of the image edge is improved.

The shape of the orthographic projection of the optical area is not limited, and is related to the array arrangement of the reflecting members. In some embodiments, the orthographic projection shape of the optical area is triangular, rectangular, pentagonal, hexagonal, octagonal, circular, or the like. In some preferred embodiments, the front projection shape of the optical zone is the same as the front projection shape of the backlight source zone. In some preferred embodiments, the orthographic projection shape of the optical area is the same as the pixel shape of the display device comprising the optical plate. In some embodiments, the reflective elements are one or both of laterally aligned and longitudinally aligned. In some embodiments, the regular array arrangement of reflectors may be arranged with reference to an array of pixels. In some embodiments, the forward projected areas of the respective optical zones are not exactly the same.

In some embodiments, the zoning situation of the optical plate is seen in fig. 6-8. If the partition distribution is thicker (large area), the effect of reducing the light leakage is smaller than that of the partition distribution which is thinner (small area).

In some embodiments, the reflector may be prepared within the optical plate by, but not limited to, the following methods: (1) Dividing the initial optical plate into a plurality of small plates, and splicing the small plates with the reflecting piece to prepare the optical plate, wherein the splicing can be adhesion; (2) When the optical plate is prepared by adopting an extrusion process, the reflecting piece is embedded into the optical plate matrix for synchronous solidification in the process of melting the extruded optical plate matrix; (3) And cutting the initial optical plate according to the reflection distribution position, and injecting the reflector colloid into the initial optical plate to realize solidification.

In some embodiments, each reflector has a thickness of 0.5mm or less, preferably 0.25mm or less. The presence of the thickness of the reflector reduces light emission and blocks light emission from the pixel, so that a thin reflector is preferable. The "thickness" herein refers to the width of the reflector cross-section.

In some embodiments, the material of each reflective element is metal, metal compound, glass, highly reflective inorganic coating, or colloid containing high concentration of scattering particles, such as titanium dioxide, silicon dioxide, etc., and can be selected by those skilled in the art according to the reflection effect.

In some embodiments, the reflectivity of each reflector is no less than 50%, preferably no less than 80%. The higher the reflectivity is, the better the light blocking effect is effectively realized.

In some embodiments, the orthographic projection of each of the optical zones is rectangular, and the lateral length of each optical zone is one or more; when the lateral lengths of the respective optical regions are plural, the optical regions of the same lateral length are not adjacent to each other. The term "lateral length" as used in this disclosure refers to the lateral length when in cross-section, such as "L" of FIG. 10.

In some embodiments, the shape of the orthographic projection of each optical zone is the same, preferably the area of the orthographic projection is the same.

In some embodiments, the individual optical zones are symmetrically distributed in the distribution of the optical plate. Therefore, when the light-leaking type LED display device is used for the display device, a symmetrically displayed picture can be displayed, namely, a picture with consistent light-leaking degree can be obtained, and the light-leaking type LED display device is more attractive.

In some embodiments, the body of the optical plate is a resin material, and the optical plate further includes a quantum dot material dispersed in the resin material. The quantum dot material may function as light conversion. The optical plate is not a quantum dot color film as understood by those skilled in the art. In some embodiments, the optical plate includes a mixed red quantum dot material and green quantum dot material.

In some embodiments, the reflectivity of the reflector decreases progressively in a direction away from the backlight source. The reflecting piece can make the light and shade transition of the image edge light leakage more uniform. Such reflectors may be realized by a controlled gradual decrease of the concentration of the reflective material in the longitudinal direction of the gel. The term "gradual" as used herein includes decreasing the difference and decreasing the difference.

In some embodiments, the optical plate includes a matrix of resin material having a refractive index that gradually decreases in a direction away from the backlight source. For example, in fig. 9, the light is concentrated toward the middle, and the effect of reducing the size of the partition of the original backlight light source is achieved, that is, the effect of increasing the partition is achieved. To achieve this design, a variety of resin materials of different refractive indices are required.

In some embodiments, the optical plate includes a matrix of a resin material and diffusion particles dispersed in the matrix, the concentration of the diffusion particles gradually decreasing in a direction away from the backlight light source. Those skilled in the art can select a diffusion particle of an appropriate particle diameter and kind depending on the optical characteristics to be achieved by the optical sheet. The diffusion particles scatter light, and the light of the backlight light source is divided into secondary areas after the light is scattered, so that the backlight energy of each area of the optical plate is more uniform.

In some embodiments, the optical plate includes a plurality of stacked diffusion layers, the refractive index of the matrix of the diffusion layers of each layer decreasing in a direction away from the backlight source. The diffusion layer refers to a resin layer containing diffusion particles.

In some embodiments, as shown in fig. 10, the optical plate includes two diffusion layers, where the lateral lengths of the sections of the backlight source are all L, and the thickness of the optical plate is d; the refractive index of the matrix of the diffusion layer closest to the backlight source is n ₁ The refractive index of the matrix of the diffusion layer furthest from the backlight source is n ₂ And n is ₁ >n ₂ ， 1＜n ₁ /n ₂ Less than 2, L is more than or equal to d. Therefore, the light is effectively limited in a small partition range after passing through the optical plate, and the light entering from one side edge of a partition of a backlight source can just exit from the other side edge of the optical plate. The effect of uniform overall light emission and local light collection is realized.

In some embodiments, 1 < n ₁ /n ₂ < 1.5. Thereby ensuring that the transmittance and diffusion effect of the optical plate are within preferred ranges.

In some embodiments of the present application, in some embodiments,

to achieve the above effects of the optical plate, those skilled in the art can design in conjunction with optical simulation software.

According to a second aspect of the present disclosure, there is provided a display device including a plurality of backlight light sources controlled by a partition, and a display layer including a plurality of pixel points, and further including any one of the optical plates, an area of one partition of the backlight light sources being larger than an area of any one of the optical areas; when the display device is operated, light of the backlight source passes through the optical plate to the display layer, and the pattern is displayed through the display layer. Fig. 3 is a schematic structural diagram of a display device, and comparing the display effects of fig. 3 and fig. 2, it can be seen that the image display area set by Z2 is a white area, the areas other than the area of Z2 are non-display areas, and if Z1 is not pure black, light leakage is represented, and the black of the light leakage area of Z1 in fig. 3 is deepened compared with the black of the light leakage area of Z1 in fig. 2, which means that light leakage is reduced, that is, the blurring degree of the displayed image edge area is reduced, and contrast is improved.

In some embodiments, each reflector has a thickness of 1 pixel or less, preferably 0.5 pixels or less, and more preferably 0.1 pixels or less. The dot pitch of the pixel dots can be calculated according to the overall display size and resolution of the display device. The presence of the reflecting member reduces the emission of light and blocks the emission of light from each pixel, so that the thickness thereof is preferably not affected by the thickness of light rays of pixels perceived by naked eyes.

In some embodiments, the orthographic projection of each of the optical zones is rectangular, and the lateral length of the partition of each backlight source is greater than the lateral length of each optical zone.

In some embodiments, the orthographic projection of each reflector does not cover the dividing line of the partition of each backlight source. So that the reflector of the optical plate separates more light from the backlight source to form more secondary backlight partitions.

In some embodiments, the display device is a direct type display device, and the optical plate is a diffusion plate; or the display device is a side-in display device, and the optical plate is a light guide plate.

In some embodiments, the forward projected areas of the partitions of the individual backlight sources are not exactly the same.

Hereinafter, the embodiments are described in more detail with reference to specific examples. However, they are illustrative examples of the present disclosure, and the present disclosure is not limited thereto.

Example 1

Direct type display device

The simulation is carried out by optical software: the selected display area is 100mm by 160mm. The display image was set as a hollowed-out pattern as shown in fig. 11, and the visible light transmittance (or light leakage rate) of the display layer was set to 10%.

As shown in fig. 12, a backlight source of 100mm×160mm is divided into 9 rectangular backlight partitions of 24.9mm×39.9mm and 16 rectangular backlight partitions of the remaining size. For the convenience of simulation, the partition interval is set to be 0.2mm (namely the line width of the parting line in software).

A diffusion plate with the thickness of 100mm multiplied by 160mm is divided into a plurality of rectangles with the size of 8.3mm multiplied by 13.3mm, the thickness of a reflecting piece is 0.2mm (namely the line width in software), the visible light transmittance of the diffusion plate is 50%, and the haze is 98%.

The simulation results are shown in fig. 13. The abscissa is the dimension (mm), and the following is the same.

Comparative example 1

Direct type display device

Other properties of the diffusion plate were the same as those of example 1 except that the diffusion plate and the backlight source were not partitioned. The simulation results are shown in fig. 14.

Comparative example 2

Direct type display device

The backlight partitioning situation is the same as in embodiment 1.

The other properties of the diffuser plate were the same as those of example 1, except that the diffuser plate was not partitioned. The simulation results are shown in fig. 15.

It should be noted that, because the resolution of the software and the display is limited, the applicant simultaneously lightens the brightness of the image of the simulation result by 10% to obtain fig. 13 to 15, so as to conveniently check the difference of the simulation result. From the simulation display results, the simulation result edge of example 1 has no obvious gray scale, the simulation result edge of comparative example 2 has a certain gray scale, and the simulation result edge of comparative example 1 has a obvious gray scale. The above results confirm that example 1 has an effect of improving contrast.

The foregoing description of the preferred embodiments of the present disclosure is provided only and not intended to limit the disclosure so that various modifications and changes may be made to the present disclosure by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. The display device is characterized by comprising a plurality of backlight light sources controlled in a partition mode and a display layer comprising a plurality of pixel points, and further comprising an optical plate, wherein a plurality of reflecting pieces perpendicular to the bottom surface of the optical plate are arranged in the optical plate, the reflecting pieces are regularly arrayed, the reflecting pieces divide the optical plate into a plurality of optical areas, the optical plate is used for being optically connected with the backlight light sources controlled in the partition mode, and the orthographic projection area of one partition of the backlight light sources is larger than the orthographic projection area of any one of the optical areas; when the display device is operated, light of the backlight source passes through the optical plate to the display layer, and a pattern is displayed through the display layer.

2. The display device according to claim 1, wherein a thickness of each of the reflecting members is 0.5mm or less.

3. The display device according to claim 2, wherein a thickness of each of the reflecting members is 0.25mm or less.

4. The display device according to claim 1, wherein a reflectance of each of the reflecting members is not less than 50%.

5. The display device according to claim 4, wherein a reflectance of each of the reflecting members is not less than 80%.

6. The display device of claim 1, wherein the orthographic projection of each of the optical zones is rectangular, and one or more of the lateral lengths of each of the optical zones; when the lateral lengths of the respective optical regions are plural, the optical regions of the same lateral length are not adjacent to each other.

7. The display device of claim 1, wherein the shape of the orthographic projection of each of the optical regions is the same.

8. The display device of claim 7, wherein the area of the orthographic projection of each of the optical regions is the same.

9. The display device according to claim 1, wherein the main body of the optical plate is a resin material, the optical plate further comprising a quantum dot material dispersed in the resin material.

10. The display device according to claim 1, wherein the reflectance of the reflecting member gradually decreases in a direction away from the backlight light source.

11. The display device according to claim 1, wherein the optical plate includes a matrix of a resin material, the refractive index of the matrix gradually decreasing in a direction away from the backlight light source.

12. The display device according to claim 1, wherein the optical plate includes a matrix of a resin material and diffusion particles dispersed in the matrix, the concentration of the diffusion particles gradually decreasing in a direction away from the backlight light source.

13. The display device according to claim 1, wherein the optical plate includes a plurality of stacked diffusion layers, and a refractive index of a matrix of the diffusion layers of each layer gradually decreases in a direction away from the backlight light source.

14. The display device according to claim 13, wherein the optical plate includes two diffusion layers, and a lateral length of a partition of the backlight source is L, and a thickness of the optical plate is d; the refractive index of the matrix of the diffusion layer closest to the backlight source is n ₁ The refractive index of the matrix of the diffusion layer furthest from the backlight source is n ₂ And n is ₁ >n ₂ ，

15. The display device of claim 14, wherein the display device comprises a display device,

16. the display device according to claim 1, wherein a thickness of each of the reflecting members is 1 pixel or less.

17. The display device according to claim 1, wherein a thickness of each of the reflecting members is 0.5 pixel points or less.

18. The display device according to claim 1, wherein a thickness of each of the reflecting members is 0.1 pixel or less.

19. The display device of claim 1, wherein the front projection of each of the optical zones is rectangular, and the lateral length of each of the partitions of the backlight source is greater than the lateral length of each of the optical zones.

20. The display device of claim 1, wherein the front projection of each of the reflectors does not cover a dividing line of the partition of each of the backlight sources.

21. The display device according to claim 1, wherein the display device is a direct type display device, and the optical plate is a diffusion plate; or the display device is a side-in display device, and the optical plate is a light guide plate.