CN114078361A

CN114078361A - Backlight module

Info

Publication number: CN114078361A
Application number: CN202010811320.0A
Authority: CN
Inventors: 方宗豹; 张恒; 周欣; 管浩远; 胡玉斌; 黄华; 司群英
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: 2020-08-13
Filing date: 2020-08-13
Publication date: 2022-02-22

Abstract

The invention relates to a backlight module, which comprises a substrate, a plurality of lamp beads arranged on the substrate, a diffusion sheet arranged above the lamp beads and used for diffusing light, and a reflection part used for reflecting light, wherein the diffusion sheet is provided with a light transmission area and a light reflection area distributed in the light transmission area, the light reflection area comprises a plurality of reflection net points formed by a reflective material, and the distribution density of the plurality of reflection net points close to the lamp beads is greater than that of the plurality of reflection net points far away from the lamp beads; the light that the lamp pearl that shines on it is sent is reflected to the reflection of light district for the even light-emitting of area source, the utilization efficiency that has improved light, reach the vivid effect of feeling of vision and the effect of higher dynamic range and contrast.

Description

Backlight module

Technical Field

The invention relates to a backlight module, and belongs to the technical field of display.

Background

A mini LED is an LED chip that is between the LED and the OLED in size of around 100 um. Compared with a side backlight LED, the LED backlight source has better high dynamic range, better contrast ratio and width range of images, meets the thinner requirement of a user, and has higher response speed; compared with OLED, the product has lower cost and longer service life. However, the mini LED adopts a direct type backlight, which may cause the phenomena of bright and dark fields at various positions of the picture, and thus the visual effect is poor, which affects the experience of the user.

Disclosure of Invention

The invention aims to provide a backlight module which can uniformly emit light from a surface light source and has high light utilization efficiency.

In order to achieve the purpose, the invention provides the following technical scheme: a backlight module comprises a substrate, a plurality of lamp beads arranged on the substrate, a diffusion sheet arranged above the lamp beads and used for diffusing light, and a reflection part used for reflecting light, wherein the diffusion sheet is provided with a light transmission area and a light reflection area distributed in the light transmission area, the light reflection area comprises a plurality of reflection dots formed by a reflective material, and the distribution density of the plurality of reflection dots close to the lamp beads is greater than that of the plurality of reflection dots far away from the lamp beads; the light reflecting area reflects the light emitted by the lamp beads irradiated on the light reflecting area to the reflecting part.

Furthermore, the reflecting part comprises a reflecting sheet arranged between the diffusion sheet and the substrate, and the reflecting sheet is provided with an opening corresponding to the lamp bead.

Further, the reflective material is one or a combination of several of reflective ink, metal silver and metal aluminum.

Furthermore, concave parts are formed on the surface of the diffusion sheet, and the reflective mesh points are formed by coating a reflective material in the concave parts.

Further, the concave part is a groove or a concave line.

Further, the diameter of concave part is 2 ~ 100um, and highly is 2 ~ 10 um.

Further, the lamp beads are mini LED lamps.

Further, the reflective sheet is made by coating a layer of reflective material on a transparent or semi-transparent material, wherein the transparent or semi-transparent material is one of glass, acrylic resin, polycarbonate, amorphous polyolefin and polyester.

Further, the reflection net points are formed on at least one surface of the diffusion sheet.

Further, the reflection mesh points have lower surfaces facing the substrate, and the diffusion sheet is formed on the lower surfaces.

The invention has the beneficial effects that: the light-transmitting area and the reflection area formed by the reflection net points are arranged on the diffusion sheet, the reflection part is arranged on the substrate, the reflection area reflects light to the reflection part, and the distribution density of the reflection net points close to the lamp beads is greater than that of the reflection net points far away from the lamp beads, so that the surface light source uniformly emits light, the utilization efficiency of the light is improved, the visual sense of reality effect is achieved, and the effect of higher dynamic range and contrast ratio is achieved.

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 backlight module according to an embodiment of the invention;

fig. 2 is a schematic view of the distribution of the reflective dots on the diffusion sheet in fig. 1.

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 the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the mechanism or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

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, a backlight module according to an embodiment of the present invention, specifically a direct-type backlight module, includes a substrate 1, a plurality of beads 2 mounted on the substrate 1, a diffusion sheet 4 disposed above the beads 2 for diffusing light, and a reflection portion for reflecting light.

In the embodiment, the lamp beads 2 are mini 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 achieved; on the other hand, the use of the mini LED lamp can also shorten the optical light mixing distance (OD) so as to reduce the thickness of the backlight module and achieve the aim of ultra-thinning. Indeed, in other embodiments, the lamp bead 2 may also be an LED, an OLED, or the like, which is not specifically limited herein and may be selected according to actual needs. In this embodiment, a plurality of mini LED lamp arrays are arranged on the substrate 1, and the spacing between adjacent mini LED lamps, the specific number of mini LED lamps, and the arrangement of mini LED lamps on the substrate 1 are not specifically limited herein, and can be selected according to actual needs.

The reflecting part comprises a reflecting sheet 3 arranged between a diffusion sheet 4 and a substrate 1, the reflecting sheet 3 is provided with openings 31 corresponding to the lamp beads 2, and each lamp bead 2 penetrates through the corresponding opening 31 to be exposed from the opening 31. The reflective sheet 3 is made by coating a layer of reflective material on a transparent or semi-transparent material, which 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 3 reflects light, and the light reflected by the reflector 3 is reflected to the diffusion sheet 4, so that light energy is fully utilized, and the uniformity of the whole light can be improved. The reflective portion further includes a reflective layer (not shown) formed on the substrate 1, and the reflective layer is formed by coating a reflective material on the substrate 1. In this embodiment, the reflective material is coated on the one side of the substrate 1 where the lamp beads 2 are installed, so as to reflect the light reflected by the diffusion sheet 4 and irradiated on the substrate 1, and further improve the uniformity of the whole light. Indeed, in other embodiments, the reflective part may not include the reflective sheet 3, or the reflective part may not include the reflective layer formed on the substrate 1.

Referring to fig. 2, the diffusion sheet 4 has a light-transmitting area 42 and a light-reflecting area 41 distributed in the light-transmitting area 42, the light-reflecting area 41 includes a plurality of reflective dots 43 formed by a reflective material, in this embodiment, the diffusion sheet 4 is made of a transparent material or a translucent material, and has a thickness of 0.5 to 1 mm, and the thickness of the diffusion sheet 4 is not limited herein. Since the light transmittance is inherent to the diffusion sheet 4, the diffusion sheet 4 has only the light-transmitting region 42 before the reflection dots 43 are formed on the surface of the diffusion sheet 4. Indeed, in other embodiments, the diffuser 4 may be made of a light reflecting material, so that the diffuser 4 only has the light reflecting region 41, and the light transmitting region 42 capable of transmitting light is formed on the surface of the diffuser 4 by photolithography. The diffusion sheet 4 has a lower surface (not shown) facing the substrate 1 and an upper surface (not shown) provided opposite to the lower surface, and the reflective dots 43 are formed on at least one surface of the diffusion sheet 4. In this embodiment, the reflective dots 43 are formed on the lower surface, and indeed, in other embodiments, the reflective dots 43 may be formed on the upper surface of the diffusion sheet 4, or the reflective dots 43 may be formed on both the upper and lower surfaces of the diffusion sheet 4. The lower surface of the diffusion sheet 4 is formed with concave portions (not shown), the diameter of the concave portions is 2-100 um, the height of the concave portions is 2-10 um, the specific size of the concave portions is not limited in particular, and the reflective material is coated on the concave portions of the diffusion sheet 4 to form reflective dots 43. Similarly, the reflective material is one of reflective ink, metallic silver and metallic aluminum, but the reflective material is not limited to this, and may be other reflective materials or a mixture of a plurality of reflective materials.

The light reflecting area 41 reflects the light emitted from the lamp beads 2 irradiated thereon to the reflecting portion. Specifically, the light emitted by the lamp beads 2 irradiates the diffusion sheet 4, a part of the light irradiates the light-transmitting area 42 and then directly penetrates through the diffusion sheet 4 to be emitted, a part of the light irradiating the reflection mesh points 43 is partially reflected to the reflection sheet 3 by the reflection mesh points 43, the light is reflected to the diffusion sheet 4 by the reflection sheet 3, and the light directly penetrates through the diffusion sheet 4 to be emitted or continuously reflected repeatedly according to different positions irradiating the diffusion sheet 4, so that the lamp beads 2 irradiate the light uniformly diffused through the diffusion sheet 4.

The diffusion sheet 4 of the backlight module of this embodiment utilizes the change of the distribution density of the reflective dots 43 to emit the light emitted from the lamp beads 2 after entering, and functions as a diffusion unit. Referring to fig. 2, the reflective dots 43 on the diffusion sheet 4 are distributed unevenly, and there are areas 52 with a higher distribution density of the reflective dots 43 and areas 51 with a lower distribution density. The distribution density of the plurality of reflection net points 43 close to the lamp beads 2 on the diffusion sheet 4 is greater than that of the plurality of reflection net points 43 far away from the lamp beads 2, so that when high light intensity close to the lamp beads 2 passes through the reflection net points 43 with higher concentration coefficients, the light transmission effect is poor, and the light diffusion effect is good; when keeping away from the low light intensity of lamp pearl 2 department and passing through the reflection site 43 of lower aggregation coefficient, light transmission is effectual, and light diffusion effect is poor to realize the even light-emitting on diffusion piece 4 surface, reach and eliminate the uneven effect of bright dark between lamp pearl 2. It should be noted that each area 52 with a higher distribution density of the reflection dots 43 on the diffusion sheet 4 corresponds to one lamp bead 2, and each area 51 with a lower distribution density of the reflection dots 43 corresponds to a middle area between two lamp beads 2, that is, a plurality of reflection dots 43 are located at positions on the diffusion sheet 4 corresponding to each lamp bead 2, and the distribution density of the reflection dots 43 decreases with increasing distance from the lamp beads.

In summary, the light-transmitting area and the reflection area formed by the reflection dots are arranged on the diffusion sheet, and the reflection part is arranged on the substrate, so that the reflection area reflects light to the reflection part, and the distribution density of the reflection dots close to the lamp beads is greater than that of the reflection dots far away from the lamp beads, so that the surface light source uniformly emits light, the utilization efficiency of the light is improved, the visual sense effect is achieved, and the dynamic range and the contrast effect are higher.

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 invention. 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. A backlight module comprises a substrate, a plurality of lamp beads arranged on the substrate, and a diffusion sheet arranged above the lamp beads and used for diffusing light, and a reflection part used for reflecting light, wherein the diffusion sheet is provided with a light transmission area and a light reflection area distributed in the light transmission area, the light reflection area comprises a plurality of reflection dots formed by a reflective material, and the distribution density of the plurality of reflection dots close to the lamp beads is greater than that of the plurality of reflection dots far away from the lamp beads; the light reflecting area reflects the light emitted by the lamp beads irradiated on the light reflecting area to the reflecting part.

2. The backlight module as claimed in claim 1, wherein the reflecting portion comprises a reflecting sheet disposed between the diffusion sheet and the substrate, and the reflecting sheet is provided with openings corresponding to the beads.

3. The backlight module as claimed in claim 1, wherein the reflective material is one or more of reflective ink, silver metal and aluminum metal.

4. The backlight module as claimed in claim 1, wherein the diffusion sheet has recesses formed on a surface thereof, and the reflective dots are formed by coating a reflective material in the recesses.

5. The backlight module according to claim 4, wherein the concave part is a groove or a concave line.

6. The backlight module as claimed in claim 4, wherein the recess has a diameter of 2-100 um and a height of 2-10 um.

7. The backlight module as claimed in claim 1, wherein the lamp beads are miniLED lamps.

8. The backlight module as claimed in claim 1, wherein the reflective sheet is made by coating a layer of reflective material on a transparent or semi-transparent material, and the transparent or semi-transparent material is one of glass, acryl resin, polycarbonate, amorphous polyolefin and polyester.

9. The backlight module as claimed in claim 1, wherein the reflective dots are formed on at least one surface of the diffusion sheet.

10. The backlight module as claimed in claim 9, wherein the diffusion sheet has a lower surface facing the substrate, and the reflective dots are formed on the lower surface.