WO2020211597A1

WO2020211597A1 - Backlight module and display device

Info

Publication number: WO2020211597A1
Application number: PCT/CN2020/080698
Authority: WO
Inventors: 李泽龙; 王代青; 强科文; 季洪雷
Original assignee: 深圳Tcl新技术有限公司
Priority date: 2019-04-17
Filing date: 2020-03-23
Publication date: 2020-10-22
Also published as: CN209765224U

Abstract

Disclosed are a backlight module and a display device, comprising: a bracket (1), a receiving groove (2) arranged on the bracket (1), and an LED chip (3) arranged at the bottom of the receiving groove (2). The receiving groove (2) is also provided with packaging glue (4); the bottom surface of the packaging glue (4) covers the light emitting surface of the LED chip (3); the top surface of the packaging glue (4) is spherical and protrudes relative to the top surface of the bracket (1), which not only increases the exit angle of incident light on the spherical surface of the packaging glue (4) from the LED chip (3), but also plays the role of condensation on the LED chip (3) by decreasing the angle of incident light on the spherical surface of the packaging glue (4) from the LED chip (3) and relative to the packaging glue (4), thereby reducing total reflected light and decreasing light loss, improving the brightness of light emitted by the LED chip (3), reducing the number of LED chips (3) used, and achieving the purpose of effectively controlling the cost of backlight display.

Description

Backlight module and display device

priority

The PCT patent application requires that the application date is April 17, 2019, and the application number is 201920522298.0 Chinese patent priority. This patent application combines the technical solutions of the above patents.

Technical field

The present disclosure relates to the technical field of display devices, and in particular to a backlight module and a display device.

Background technique

At present, the backlight structure of LCD TVs is mainly divided into two forms: edge-type backlight and direct-type backlight. The traditional direct-type backlight uses LED as the light source, and the light field of the LED is distributed through the lens to expand the light-emitting angle. And the purpose of homogenizing the light field. As a high-efficiency, long-life photoelectric device, LED is currently widely used in backlight modules such as TVs and mobile phones. In TV applications, the LED light input methods are divided into two types: side-type and direct-type backlight. The mixing distance is a key indicator for evaluating a direct-type machine, and its meaning refers to the distance between the reflector and the lower surface of the diffuser. An important parameter of the direct backlight is the pitch value, that is, the distance between the LED and the LED. As shown in Figure 1, the traditional backlight structure includes an LED bracket 100, the LED bracket 100 has a groove, the LED chip 200 is installed in the groove 300, and the groove 300 is provided with glue. The top surface of the glue is flat to make the LED light The angle is about 120 degrees. Relative to the LED chip 200, a ray represents a small angle of light, b ray represents a larger angle of light, c ray represents a large angle of light, a ray, b ray and c ray If the traditional LED is directly applied to the ultra-multi-partition ultra-thin light mixing distance direct-down design, the light-emitting angle is small, the spacing value cannot be extended, and the total reflected light is too much, and the light is lost. The brightness is low, 65 inches may require tens of thousands or even hundreds of thousands of lamp beads, which greatly increases the cost.

Therefore, the existing technology needs to be improved and developed.

Public content

The technical problem to be solved by the present disclosure is to provide a backlight module and a display device in view of the above-mentioned defects of the prior art, aiming to improve the light-emitting angle and light-emitting brightness of the LED, so as to increase the pitch value and reduce the cost.

The technical solutions adopted by the present disclosure to solve the technical problems are as follows:

A backlight module includes a support, a receiving groove arranged on the support, and an LED chip arranged at the bottom of the receiving groove, wherein the receiving groove is also provided with packaging glue, The bottom surface covers the light emitting surface of the LED chip, and the top surface of the packaging glue is spherical and protrudes relative to the top surface of the bracket.

In the backlight module, the bracket is a transparent bracket.

In the backlight module, reflective particles are arranged in the bracket.

In the backlight module, the packaging glue is injection-molded silica gel.

In the backlight module, the edge of the top surface of the encapsulant is in contact with the bracket.

In the backlight module, the width of the bottom of the receiving groove is smaller than the width of the opening.

The backlight module further includes a PCB board on which a reflective layer is arranged, and the bracket and the reflective layer are arranged on the same side of the PCB board.

In the backlight module, the reflective layer is used to reflect the light emitted from the bracket toward the opening direction of the receiving groove.

In the backlight module, the reflective layer is a white ink layer.

The backlight module further includes an optical film, a quantum dot film, and a diffuser plate. The optical film, the quantum dot film, the diffuser plate and the bracket are along a direction close to the PCB board. Set in order.

In the backlight module, red quantum dots and green quantum dots are arranged in the quantum dot film.

The backlight module, wherein the red quantum dots and the green quantum dots both include III-V group compounds, II-VI group compounds, all-inorganic perovskite cesium lead halide quantum dots and organic-inorganic hybrid calcium One or more of titanium ore materials.

In the backlight module, the optical film includes one or more of a diffuser, a brightness enhancement film, and a microscope.

In the backlight module, the optical film includes a diffusion sheet, a brightness enhancement sheet and a microscope, and the diffusion sheet, the brightness enhancement sheet and the microscope are sequentially stacked.

A display device includes any one of the aforementioned backlight modules.

Beneficial effects: In the present disclosure, the encapsulant covers the light-emitting surface of the LED chip in the form of a lens, and the surface of the encapsulant beyond the bracket is set as a spherical surface, so that the LED chip can be incident on the The emission angle of the light from the spherical surface of the packaging glue increases, which can also condense the light of the LED chip, and the relative incident angle between the incident light emitted from the LED chip to the spherical top surface of the packaging glue and the packaging glue is changed. It is small, reducing total reflected light and reducing light loss, thereby improving the brightness of the LED chip. Through the improvement of the light-emitting angle and the light-emitting brightness of the LED chip, the ultra-multi-zone backlight is realized, while the number of the LED chips used is reduced, and the purpose of effectively controlling the cost of the backlight display is achieved.

Description of the drawings

FIG. 1 is a schematic diagram of the backlight structure in the prior art;

Figure 2 is a schematic diagram of the structure of the stent in the present disclosure;

3 is a schematic diagram of the LED chip, the packaging glue, and the bracket packaging in the first embodiment of the present disclosure;

4 is a schematic diagram of the LED chip, the packaging glue and the bracket packaging in the second embodiment of the present disclosure;

FIG. 5 is a schematic diagram of the distribution of the bracket on the PCB board in the present disclosure;

FIG. 6 is a schematic diagram of the structure of the backlight module in the present disclosure.

detailed description

In order to make the objectives, technical solutions, and advantages of the present disclosure clearer and clearer, the present disclosure will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present disclosure, but not used to limit the present disclosure.

Please also refer to Figure 2-Figure 6. The present disclosure provides a backlight module, as shown in FIG. 2, FIG. 3 and FIG. 4, which includes a bracket 1, a receiving groove 2 arranged on the bracket 1, and an LED chip arranged at the bottom of the receiving groove 2 3; The accommodating groove 2 is formed recessed downward from the top surface of the bracket 1, and the encapsulating glue 4 is also provided in the accommodating groove 2, and the encapsulating glue 4 removes the LED chip 3 from the accommodating groove 2 The outer area is filled so that the bottom surface of the encapsulant 4 can cover the light-emitting surface of the LED chip 3, and the top surface of the encapsulant 4 protrudes relative to the top surface of the bracket 1, that is, the encapsulant 4 The top surface of is located outside the containing groove 2; further, the top surface of the packaging glue 4 is spherical.

In the present disclosure, the encapsulant 4 covers the light-emitting surface of the LED chip 3 in the form of a lens, and the surface of the encapsulant 4 beyond the support 1 is set as a spherical surface, so that the LED chip 3 can be incident on The light emitting angle of the spherical surface of the encapsulant 4 is increased, and the LED chip 3 can be condensed. The incident light emitted from the LED chip 3 to the spherical top surface of the encapsulant 4 is consistent with the The relative incident angle of the encapsulant 4 becomes smaller, which reduces total reflected light and reduces light loss, thereby improving the brightness of the LED chip 3. Through the improvement of the light-emitting angle and the light-emitting brightness of the LED chip 3, the ultra-multi-zone backlight is realized while reducing the number of the LED chips 3 used, so as to achieve the purpose of effectively controlling the cost of the backlight display.

The LED chip 3 is a blue GaN chip, and the wavelength of light emitted by the LED chip 3 is 430 nm to 470 nm. The bracket 1 controls the dimensions of the LED chip 3 and the packaging glue 4 through the receiving groove 2, protects the LED chip 3 and the packaging glue 4, and performs corresponding optical functions.

In the first embodiment of the present disclosure, the bracket 1 is a transparent bracket, specifically as shown in FIG. 3. In FIG. 3, a1, b1, and c1 are schematic diagrams of typical light paths emitted by the LED chip 3 respectively. 3. The exit angle of a1 light, the exit angle of b1 light, and the exit angle of c1 light increase sequentially. a1 light represents a small angle light, which passes through the encapsulant 4, and due to the light-gathering effect of the encapsulant 4, the brightness of the central area on the top surface of the encapsulant 4 is increased; b1 light represents a larger angle light, which is relatively The plane design of the top surface of the conventional glue in FIG. 1 makes the relative incident angle of b1 light and the encapsulant 4 smaller, that is, the total reflected light is reduced, thereby reducing light loss and greatly improving the brightness of the LED chip 3 ; C1 light represents a large-angle light, because the transparent bracket is used, the c1 light can be directly emitted from the transparent bracket, and the light-emitting angle of the LED chip 3 is increased to about 150° relative to the prior art.

In the second embodiment of the present disclosure, as shown in FIG. 4, the support 1 is a non-transparent support, and reflective particles are arranged in the non-transparent support. In Fig. 4, a2, b2, and c2 are schematic diagrams of typical light paths emitted by the LED chip 3 respectively. Relative to the spherical surface of the encapsulant 4, the exit angle of a2 light, the exit angle of b2 light, and the exit angle of c2 light are in sequence Increase, and the light path of a2 light is the same as that of a1 light, and the light path of b2 light is the same as that of b1 light. The light-emitting brightness of the LED chip 3 is effectively improved by the a2 light and b2 light. The exit angle of the c2 light is the same as the exit angle of the c1 light, which is a large-angle light. The c2 light is reflected after irradiating the inner wall of the containing groove 2, thereby reducing the absorption loss caused by the absorption of the light by the non-transparent bracket and Because of the large-angle transmission loss, the brightness gain of the LED chip 3 in this embodiment is higher than the brightness gain of the LED chip 3 in the first embodiment; at the same time, compared with the existing conventional LED in FIG. The design of the spherical surface of the encapsulant 4 reduces the total reflection of the large-angle light irradiated on the spherical surface of the encapsulant 4 and increases the brightness of the light. Compared with the conventional LED in Fig. 1, the brightness is increased by more than 15%, and the light angle is slightly increased. To 125°.

In the present disclosure, the material of the bracket 1 can be selected as required. When the backlight module requires a large angle and a large spacing, the transparent bracket described in Embodiment 1 is used; when the backlight module requires higher brightness, When the light-emitting angle is slightly larger than that of the conventional LED, the non-transparent support with the reflective particles in the second embodiment is used.

The packaging glue 4 fills the area of the containing groove 2 except the LED chip 3, and further, the edge of the spherical top surface of the packaging glue 4 is in contact with the bracket, so that it is directed toward the containing The light at the opening of the slot 2 needs to pass through the spherical top surface of the encapsulant 4 to exit.

The shape of the bracket 1 can be 1608 common bracket shape, 2835 common bracket shape or 3030 common bracket shape, so that the existing common bracket shape can be used directly when the bracket 1 is made, without the need to re-manufacture the mold, and further reduce the production cost .

The receiving groove 2 is in the shape of a truncated cone, the bottom width of the receiving groove 2 is smaller than the opening width, and the LED chip 3 is located at the bottom. Since the bottom width of the receiving groove 2 is small, the bottom thickness of the support 1 is large, thereby enhancing the support strength of the support 1 and ensuring that the LED chip 3 and the packaging glue 4 are in the receiving groove 2 The stability of the setting and the strength of the containing tank 2 are ensured.

Since the opening direction width of the receiving groove 2 is greater than the bottom width, and the packaging glue 4 is located on the side of the LED chip 3 facing the opening of the receiving groove 2, the packaging glue 4 can cover the The light-emitting surface of the LED chip 3 ensures that the light-emitting angle of the LED chip 3 is increased.

The encapsulation glue 4 is injection-molded silica gel, which has high viscosity and is easy to be shaped. The spherical top surface of the encapsulation glue 4 can be achieved by controlling the amount of the injection-molded silica gel and using a glue dispensing process to ensure the backlight The uniformity of the overall optical visual effect of the module.

The backlight module further includes a PCB board 5 and a reflective layer. The bracket 1 and the reflective layer are both arranged on the PCB board 5, and the bracket 1 and the reflective layer are located on the PCB board 5. On the same side, the LED chip 3 is electrically connected to the PCB board 5. The reflective layer can be a sprayed white ink layer or a commonly used reflective film; the reflective layer can reflect the light emitted from the support 1 toward the opening direction of the receiving groove 2, so as to make full use of the LED The chip 3 emits light. As shown in Figure 5, the brackets 1 are arranged in an array on the PCB board 5. In a preferred embodiment, the distance X between two adjacent rows of brackets 1 is 8mm, and the distance between two adjacent rows of brackets 1 The spacing Y is 8 mm; specifically, the row spacing and column spacing of the bracket 1 arranged on the PCB board 5 can be adjusted according to the size of the PCB board 5 and the size of the bracket 1.

The PCB board 5 in the present disclosure may be an aluminum-based board or a BT board or an FR4 board; in the present invention, solder paste is used to solder the bracket 1 on the PCB board 5, when the solder paste commonly used in traditional surface assembly technology is used The temperature of reflow soldering is preferably 250°C or higher; when the transparent bracket is used, considering the temperature resistance of the transparent bracket, the surface assembly technology preferably uses low-temperature solder paste, and the temperature of reflow soldering is preferably set to 170°C~ 200°C.

As shown in FIG. 6, the backlight module further includes an optical film 8, a quantum dot film 7, and a diffusion plate 6. The optical film 8, the quantum dot film 7, the diffusion plate 6 and the The brackets 1 are sequentially arranged along the direction close to the PCB board 5. The quantum dot film 7 is used to improve the color gamut of the backlight module; the distance between the reflective layer and the diffuser 6 is 3 mm to 8 mm, preferably 8 mm.

In the present disclosure, the quantum dot film 7 is provided with red quantum dots and green quantum dots, and both the red quantum dots and the green quantum dots include III-V group compounds, II-VI group compounds, and all-inorganic perovskite One or more of cesium lead halide quantum dots and organic-inorganic hybrid perovskite materials. Specifically, the III-V group compounds include CdSe, CdTe, CaSe, MgTe, SrSe, ZnSe, ZnTe, SrTe, MgSe, CaTe, BaSe, BaTe, ZnS, CaS, MgS, SrS, BaS, and CdS; the II -Group VI compounds include GaAs, InN, GaN, GaP, InP and InAs; the all-inorganic perovskite cesium lead halide quantum dots include CsPbX ₃ (where X = Cl, Br, I); the organic-inorganic hybrid The perovskite material includes CH ₃ NH ₃ PbX ₃ (where X=Cl, Br, I).

The size of the red quantum dots is preferably 4 nm to 9 nm, and the peak wavelength of red light excited by them is 620 nm to 650 nm; the size of the green quantum dots is preferably 2 nm to 6 nm, and the peak wavelength of green light excited by them is 510 nm to 550 nm.

The optical film 8 includes one or more of a diffuser, a brightness enhancement film, and a microlens. When the optical film 8 includes a diffuser, a brightness enhancement film, a microlens, and a brightness enhancement film, , Only one polyethylene terephthalate substrate is used, and a variety of diffusers, brightness enhancement films, and microlenses are sequentially stacked on the polyethylene terephthalate substrate, thereby The number of polyethylene terephthalate substrates is reduced, the thickness of the optical film 8 is made smaller, and the wrinkle resistance of the optical film 8 is improved.

The present disclosure also provides a display device, which includes the above-mentioned backlight module.

In summary, the present disclosure provides a backlight module and a display device, which include a bracket, a receiving slot provided on the bracket, and an LED chip provided at the bottom of the receiving slot, and the receiving slot is also An encapsulation glue is provided, the bottom surface of the encapsulation glue covers the light emitting surface of the LED chip, and the top surface of the encapsulation glue is spherical and protrudes relative to the top surface of the bracket. In the present disclosure, the encapsulation glue covers the light-emitting surface of the LED chip in the form of a lens, and the surface of the encapsulation glue that extends beyond the bracket is set as a spherical surface, so that the LED chip can be incident on the encapsulation glue ball The emergence angle of the surface light is increased, and the LED chip can be condensed. The relative incident angle of the incident light emitted from the LED chip to the spherical top surface of the encapsulant and the encapsulant becomes smaller, reducing The totally reflected light reduces light loss, thereby improving the brightness of the LED chip. Through the improvement of the light-emitting angle and the light-emitting brightness of the LED chip, the ultra-multi-zone backlight is realized, while the number of the LED chips used is reduced, and the purpose of effectively controlling the cost of the backlight display is achieved.

It should be understood that the application of the present disclosure is not limited to the above examples, and those of ordinary skill in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the protection scope of the appended claims of the present disclosure.

Claims

A backlight module includes a support, a receiving groove arranged on the support, and an LED chip arranged at the bottom of the receiving groove, wherein the receiving groove is also provided with packaging glue, The bottom surface covers the light emitting surface of the LED chip, and the top surface of the packaging glue is spherical and protrudes relative to the top surface of the bracket.
The backlight module of claim 1, wherein the bracket is a transparent bracket.
The backlight module of claim 1, wherein reflective particles are arranged in the bracket.
The backlight module of claim 1, wherein the encapsulant is injection molded silicone.
The backlight module of claim 1, wherein the edge of the top surface of the encapsulant is in contact with the bracket.
The backlight module of claim 1, wherein the width of the bottom of the receiving groove is smaller than the width of the opening.
The backlight module according to claim 1, further comprising a PCB board on which a reflective layer is provided, and the bracket and the reflective layer are provided on the same side of the PCB board.
8. The backlight module of claim 7, wherein the reflective layer is used to reflect the light emitted from the bracket toward the opening direction of the receiving groove.
8. The backlight module of claim 7, wherein the reflective layer is a white ink layer.
The backlight module according to claim 7, further comprising an optical film, a quantum dot film and a diffuser, the optical film, the quantum dot film, the diffuser and the support are close to The directions of the PCB boards are set in sequence.
10. The backlight module of claim 10, wherein the quantum dot film is provided with red quantum dots and green quantum dots.
11. The backlight module of claim 11, wherein the red quantum dots and the green quantum dots both comprise III-V group compounds, II-VI group compounds, all-inorganic perovskite cesium lead halide quantum dots and organic- One or more of inorganic hybrid perovskite materials.
10. The backlight module of claim 10, wherein the optical film comprises one or more of a diffuser, a brightness enhancement film, and a microscope.
15. The backlight module of claim 13, wherein the optical film comprises a diffuser, a brightness enhancement film and a microscope, and the diffuser, the brightness enhancement film and the microscope are sequentially stacked.
A display device, wherein it comprises the backlight module according to any one of claims 1-14.