CN215375836U

CN215375836U - Diffusion sheet and backlight module

Info

Publication number: CN215375836U
Application number: CN202120574543.XU
Authority: CN
Inventors: 方宗豹; 张恒; 司群英; 周云; 李成
Original assignee: Yancheng Weiwang Technology Co ltd; NICROTEK CO Ltd; Suzhou University
Current assignee: Yancheng Weiwang Technology Co ltd; NICROTEK CO Ltd; Suzhou University
Priority date: 2021-03-22
Filing date: 2021-03-22
Publication date: 2021-12-31
Anticipated expiration: 2031-03-22

Abstract

The utility model relates to a diffusion sheet, which comprises a color master batch diffusion sheet body and a plurality of microstructures formed on the surface of the color master batch diffusion sheet body, wherein the cross section of each microstructure is any one of a triangle, a rectangle or a semi-arc, the width of each microstructure is 10-100um, and the height of each microstructure is half of the width. The problem of diffusion piece light transmittance too high has been solved in the interpolation of masterbatch, and the diffusion piece light transmittance that obtains is moderate and has good shielding nature, and this diffusion piece is used in backlight unit, can even light-emitting, reach the effect of the lifelike sense of vision and the effect of higher dynamic range and contrast.

Description

Diffusion sheet and backlight module

Technical Field

The utility model relates to a diffusion sheet, and belongs to the technical field of display.

Background

The backlight module is one of the key components of the liquid crystal display panel, and has the functions of supplying sufficient light source with uniform brightness and distribution to normally display images, and the light emitting effect of the backlight module directly influences the visual effect of the liquid crystal display module.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a diffusion sheet with moderate transmittance and strong shielding property.

In order to achieve the purpose, the utility model provides the following technical scheme: the diffusion sheet comprises a color master batch diffusion sheet body and a plurality of microstructures formed on the surface of the color master batch diffusion sheet body, the cross sections of the microstructures are any one of triangular, rectangular or semi-arc shapes, the width of each microstructure is 10-100um, and the height of each microstructure is half of the width.

Further, the diffusion sheet is applied to a backlight module with an LED or a minLED.

Further, the color master batch in the color master batch diffusion sheet body is white color master batch or yellow color master batch.

Further, the color master batch diffusion sheet body and the microstructure are integrally formed.

Further, the diffusion sheet is prepared by an extruder.

Further, the surface of the roller set used for molding the color master batch diffusion sheet body of the extruder is provided with a preset structure for forming the microstructure.

The utility model also provides a backlight module which comprises the diffusion sheet, a substrate, a plurality of lamp beads arranged on the substrate and a reflection sheet positioned between the substrate and the diffusion sheet and used for reflecting light rays, wherein the diffusion sheet is arranged above the plurality of lamp beads and used for diffusing light rays.

The utility model has the beneficial effects that: the diffusion sheet provided by the utility model contains the color master batch, the micro structure is arranged on the diffusion sheet, the addition of the color master batch solves the problem of overhigh light transmittance of the diffusion sheet, the obtained diffusion sheet has moderate light transmittance and good shielding property, and the diffusion sheet can uniformly emit light, achieve the effect of visual vivid sense and the effect of higher dynamic range and contrast when being applied to a backlight module.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings.

Drawings

Fig. 1 is a schematic structural diagram of a diffusion sheet according to an embodiment of the utility model;

fig. 2 is a schematic structural diagram of a backlight module according to an embodiment of the utility model.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Referring to fig. 1, in a diffuser 1 according to an embodiment of the present invention, the diffuser 1 includes a color master batch diffuser body 11 and a plurality of microstructures 12 formed on a surface of the color master batch diffuser body 11, a cross section of each microstructure 12 is any one of a triangle, a rectangle or a semi-arc, a width of each microstructure 12 is 10-100um, and a height of each microstructure is half of the width.

The diffusion sheet 1 is mainly applied to a backlight module with an LED or a minLED, and the diffusion sheet 1 diffuses light emitted by the LED or the minLED so that the backlight module emits light uniformly.

Wherein, the masterbatch diffusion piece body 11 is obtained by containing masterbatch in the high molecular material. The diffusion sheet 1 is made of a polymer material, wherein the polymer material contains color master batches, and the polymer material used for making the diffusion sheet 1 is any one of PET, PC, and PMMA, but not limited thereto. The color master batch can be PET color master batch, PC color master batch, PMMA color master batch, etc., and the color master batch is white color master batch or yellow color master batch, wherein the color master batch is mainly white color master batch, but is not limited thereto, and can also be color master batch of other colors. The kind and color of the color master batch have no influence on the performance of the resulting diffusion sheet 1.

The thickness of the master batch diffusion sheet body 11 is 0.5-1mm, the shape of the master batch diffusion sheet body 11 can be a rectangular parallelepiped, and the thickness and the shape of the master batch diffusion sheet body 11 are not particularly limited herein. The microstructures 12 are formed by inward concave of the surface of the diffusion sheet body 11 or outward convex of the surface of the diffusion sheet body 11, and the microstructures 12 are semicircular grooves, semicircular convex blocks, circular concave rings, convex rings, cones and the like, which are not listed here. And the microstructures 12 may be formed on the upper surface, the lower surface, or both surfaces of the master batch diffusion sheet body 11.

In this embodiment, the color master batch diffusion sheet body 11 and the microstructure 12 are integrally formed, the diffusion sheet 1 is prepared by an extruder, the surface of the roller set for forming the color master batch diffusion sheet body 11 for the extruder has a preset structure for forming the microstructure 12, namely, when the diffusion sheet 1 is prepared by the extruder, the color master batch diffusion sheet body 11 and the microstructure 12 are simultaneously prepared, the process is reduced, the preparation time is saved, the problem of too high transmittance of the obtained diffusion sheet 1 is solved, and the diffusion sheet has higher optical performance.

The preparation process of the diffusion sheet comprises the following steps:

step one, providing color master batches and high polymer materials, and uniformly mixing and melting the color master batches and the high polymer materials;

extruding and calendering the molten material in an extruder, and adjusting the gap of a roller set to obtain a uniform diffusion sheet with corresponding thickness; the preset structure on the surface of the roller set forms a microstructure on the diffusion sheet;

and step three, cooling the diffusion sheet by a cooling roller to obtain the diffusion sheet.

In the prior art, the size of the microstructure obtained by an extruder is generally more than 100um, and the microstructure with larger size limits the application of the diffusion sheet, so that an ultrathin backlight module cannot be obtained. The size of the microstructure obtained by the utility model is 2-15um, so that the size of the microstructure is greatly reduced, and the obtained diffusion sheet can be applied to an ultrathin backlight module, thereby reducing the thickness of a product.

Referring to fig. 2, the present invention further provides a backlight module 100, wherein the backlight module 100 may be a side-light type backlight module or a direct type backlight module, and includes a substrate 2, a plurality of beads 3 mounted on the substrate 2, the diffusion sheet 1 disposed above the beads 3 for diffusing light, and a reflection sheet 4 disposed between the substrate 2 and the diffusion sheet 1 for reflecting light.

In the embodiment, the lamp beads 3 are mini LED lamps or LED lamps, and the mini LED lamps are small in chip structure, so that the Dimming partition numbers (Local Dimming Zones) are more detailed, a Higher Dynamic Range (HDR) is achieved, and the effect of higher contrast is realized; on the other hand, the use of the mini LED lamp can also shorten the optical light mixing distance (OD) to reduce the thickness of the backlight module 100, thereby achieving the purpose of ultra-thinning. In this embodiment, a plurality of mini LED lamp arrays or LED lamp arrays are arranged on the substrate 2, and the distance between adjacent mini LED lamps or LED lamps, the specific number of mini LED lamps or LED lamps, and the arrangement of the mini LED lamps or LED lamps on the substrate 2 are not specifically limited herein and may be selected according to actual needs.

The reflector 4 is provided with openings (not numbered) corresponding to the lamp beads 3, and each lamp bead 3 is exposed out of the corresponding opening. The reflective sheet 4 is made of a transparent or semi-transparent material coated with a layer of reflective material, wherein the transparent or semi-transparent material is one of glass, acrylic resin, polycarbonate, amorphous polyolefin and polyester, but not limited thereto. The reflective material may be one of reflective ink, metallic silver, and metallic aluminum, but is not limited thereto, and may be other reflective materials, or a mixture of reflective materials. The reflector 4 reflects light, and the light reflected by the reflector 4 is reflected to the diffusion sheet 1, so that light energy is fully utilized, and the uniformity of the whole light can be improved.

The distribution density or the distribution area of the microstructures 12 on the diffusion sheet 1 can be set according to the distance between the diffusion sheet 1 and the lamp beads 3, and when the diffusion sheet 1 is applied to the direct type backlight module 100, the distribution density or the distribution area of the microstructures 12 close to the lamp beads 3 is larger than that of the microstructures 12 far away from the lamp beads 3, so that light can be uniformly emitted from the surface of the diffusion sheet 1. When the diffusion sheet 1 is applied to the side-light type backlight module 100, the distribution density or the distribution area of the microstructures 12 close to the lamp beads 3 is smaller than that of the microstructures 12 far away from the lamp beads 3, so that light can be uniformly emitted from the surface of the diffusion sheet 1.

In conclusion, the diffusion sheet provided by the utility model contains the color master batch, the micro structure is arranged on the diffusion sheet, the problem of overhigh light transmittance of the diffusion sheet is solved due to the addition of the color master batch, the obtained diffusion sheet has moderate light transmittance and good shielding property, and the diffusion sheet can uniformly emit light, achieves the effect of visual fidelity and has higher dynamic range and contrast ratio when being applied to a backlight module.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the utility model. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. The diffusion sheet is characterized by comprising a color master batch diffusion sheet body and a plurality of microstructures formed on the surface of the color master batch diffusion sheet body, wherein the cross sections of the microstructures are any one of triangular, rectangular or semi-arc shapes, the widths of the microstructures are 10-100um, and the heights of the microstructures are half of the widths.

2. The diffusion sheet as claimed in claim 1, wherein the diffusion sheet is applied to a backlight module having an LED or a minLED.

3. The diffuser of claim 1, wherein the color master in the master batch diffuser body is a white or yellow color master.

4. The diffuser of claim 1, wherein the master batch diffuser body and the microstructures are integrally formed.

5. The diffuser of claim 4, wherein the diffuser is prepared by an extruder.

6. The diffuser of claim 5 wherein the surface of the roller set used to mold the masterbatch diffuser body has a predetermined structure that forms the microstructure.

7. A backlight module, comprising the diffuser of any one of claims 1-6, a substrate, a plurality of beads mounted on the substrate, and a reflector sheet positioned between the substrate and the diffuser for reflecting light, wherein the diffuser is disposed above the plurality of beads and for diffusing light.