Backlight modules and display devices

A backlight module and a display device are disclosed. The backlight module includes: a back plate (1); a middle frame (3) disposed on the back plate (1); a light-emitting substrate (2) disposed on the back plate (1) and in the middle frame (3), the light-emitting substrate (2) including a first light-emitting area (203) and a second light-emitting area (204) surrounding the first light-emitting area (203), and the second light-emitting area (204) being close to an edge of the light-emitting substrate (2); a light compensation structure (100) close to the edge of the light-emitting substrate (2), the light compensation structure (100) including one or more light conversion materials. The backlight module and the display device can improve the display effect.

TECHNICAL FIELD

The present disclosure relates to the field of display technologies, in particular to backlight modules and display devices.

BACKGROUND

With the development of display technologies, display devices have attracted more and more attention.

A display device typically includes a backlight module and a display panel. The backlight module is used to provide a light source for the display panel. The display panel generally includes a lower polarizer, an array substrate, a liquid crystal layer, a color filter substrate and an upper polarizer that are sequentially disposed. Light emitted by the backlight module passes through the lower polarizer, the array substrate, the liquid crystal layer, the color filter substrate and the upper polarizer sequentially, thereby realizing display. However, the display effect of such display device is poor.

SUMMARY

The purpose of the present disclosure is to provide a backlight module and a display device, which can improve the display effect.

According to an aspect of the present disclosure, there is provided a backlight module, including:

a back plate;

a middle frame disposed on the back plate;

a light-emitting substrate disposed on the back plate and in the middle frame, the light-emitting substrate including a first light-emitting area and a second light-emitting area surrounding the first light-emitting area, and the second light-emitting area being close to an edge of the light-emitting substrate; and

a light compensation structure close to the edge of the light-emitting substrate, the light compensation structure including one or more light conversion materials.

Further, a surface of the light-emitting substrate facing away from the back plate is provided with a protective layer, an area of the protective layer corresponding to the second light-emitting area is doped with light conversion particles, and the area of the protective layer doped with the light conversion particles constitutes the light compensation structure.

Further, the light-emitting substrate has a light-emitting color of blue, and the light conversion particles include one or more yellow light conversion materials.

Further, the light-emitting substrate has a light-emitting color of blue, and the light conversion particles include one or more red light conversion materials and one or more green light conversion materials.

Further, light emitted from the first light-emitting area is blue light after passing through an area of the protective layer corresponding to the first light-emitting area, and the backlight module further includes a color conversion layer disposed on a side of the light-emitting substrate away from the back plate, where the color conversion layer includes one or more red light conversion materials and one or more green light conversion materials, or the color conversion layer includes one or more yellow light conversion materials.

Further, the backlight module further includes a color conversion layer disposed on a side of the light-emitting substrate away from the back plate, where the color conversion layer is a green quantum dot layer, and an area of the protective layer corresponding to the first light-emitting area is doped with one or more red light conversion materials.

Further, the protective layer includes a sealing adhesive.

a base disposed on the back plate; and

a plurality of light-emitting units disposed on a surface of the base facing away from the back plate,

where the protective layer includes a plurality of protective units, one protective unit of the plurality of protective units covers a light-emitting surface of one light-emitting unit of the plurality of light-emitting units and is in direct contact with the light-emitting surface of the light-emitting unit, and a surface of the protective unit facing away from the light-emitting unit is a curved surface.

Further, a doping concentration of the light conversion particles gradually decreases along a direction that an edge of the protective layer is close to an inside of the protective layer.

Further, the light compensation structure is disposed on an inner wall of the middle frame.

Further, the light compensation structure includes:

a plurality of light conversion units disposed on the inner wall of the middle frame.

Further, the inner wall of the middle frame provided with the plurality of light conversion units includes a first area and a second area with a same area, the first area is located on a side of the second area away from the light-emitting substrate, and a density of the light conversion units disposed in the first area is greater than a density of the light conversion units disposed in the second area.

Further, the inner wall of the middle frame provided with the plurality of light conversion units includes a first area and a second area, the first area is located on a side of the second area away from the light-emitting substrate, and a size of the light conversion units disposed in the first area is larger than a size of the light conversion units disposed in the second area.

Further, the middle frame includes a first frame segment and a second frame segment that are connected to each other, the first frame segment is disposed on the back plate, the second frame segment is disposed on a side of the first frame segment away from the back plate, an inner diameter of the second frame segment gradually increases along a direction away from the first frame segment, the first area is located on an inner wall of the second frame segment, and the second area is located on an inner wall of the first frame segment.

Further, the inner wall of the middle frame is provided with a reflector, and the plurality of light conversion units are disposed on the reflector.

Further, the light-emitting substrate has a light emission color of blue, and the plurality of light conversion units are yellow light conversion units.

Further, the one or more light conversion materials include one or more fluorescent materials or quantum dot materials.

According to an aspect of the present disclosure, there is provided a display device including the above-mentioned backlight module.

In the backlight module and the display device of the present disclosure, the second light-emitting area is close to the edge of the light-emitting substrate, the light compensating structure is close to the edge of the light-emitting substrate, and the light compensating structure includes one or more light conversion materials, so that the light compensating structure can emit light with one or more specific colors under the irradiation of the second light-emitting area. The light with the one or more specific colors emitted by the light compensation structure is mixed with the light emitted from the second light-emitting area, which can solve the problem of color shift caused by the light emitted from the second light-emitting area and passing through a gap between a dimming film and the middle frame, and improve the display effect.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Exemplary embodiments will be described in detail herein, examples of which are illustrated in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numerals in different drawings indicate the same or similar elements. The exemplary embodiments described below do not represent all embodiments consistent with the present disclosure. Rather, they are merely examples of device consistent with some aspects of the present disclosure, as recited in the appended claims.

In the related art, a backlight module of a display device includes a light-emitting substrate, a dimming film, and a middle frame. The dimming film and the light-emitting substrate are stacked, and the dimming film is located on a light-emitting side of the light-emitting substrate for modulating light emitted from the light-emitting substrate, such as color conversion. The middle frame surrounds the light-emitting substrate and the dimming film. However, the dimming film shrinks when the temperature is low, resulting in a gap between the dimming film and the middle frame, so that part of the light emitted from the light-emitting substrate passes through the gap between the dimming film and the middle frame, thereby forming a gradual color shift/color cast, which reduces the display effect of the display device.

An embodiment of the present disclosure provides a backlight module. The backlight module is applied to a display device. As shown inFIG.1,FIG.2andFIG.5, the backlight module includes a back plate1, a middle frame3, a light-emitting substrate2and a light compensation structure100.

The middle frame3is disposed on the back plate1. The light-emitting substrate2is disposed on the back plate1and located in the middle frame3. The light-emitting substrate2includes a first light-emitting area203and a second light-emitting area204surrounding the first light-emitting area203. The second light-emitting area204is close to an edge of the light-emitting substrate2. The light compensation structure100is close to the edge of the light-emitting substrate2, and the light compensation structure100includes one or more light conversion materials.

In the backlight module according to the embodiment of the present disclosure, the second light-emitting area204is located at the edge of the light-emitting substrate2, and the light compensation structure100is close to the edge of the light-emitting substrate2. The light compensation structure100includes one or more light conversion materials for converting the color of light emitted by the light-emitting substrate2, so that the light compensation structure100can emit light with one or more specific colors under the irradiation of the second light-emitting area204. The light with the one or more specific colors emitted by the light compensation structure100is mixed with light emitted from the second light-emitting area204, which can solve the problem of color shift caused by the light emitted from the second light-emitting area204and passing through a gap between a dimming film and the middle frame3, and improve the display effect.

The backlight module according to embodiments of the present disclosure will be described in detail below.

As shown inFIG.2, the back plate1is a support structure of the backlight module. A side of the back plate1is provided with a bearing surface. The middle frame3can be disposed on the bearing surface of the back plate1. As shown inFIG.5andFIG.6, the middle frame3may include a first frame segment301and a second frame segment302along a direction perpendicular to the back plate1. The first frame segment301and the second frame segment302are connected to each other. The first frame segment301can be disposed on the back plate1, and the second frame segment302can be disposed on a side of the first frame segment301away from the back plate1. An inner diameter of the second frame segment gradually increases along a direction away from the first frame segment301. A surface of an inner wall of the second frame segment302may be a smoothly curved surface. The first frame segment301has a uniform inner diameter in the direction perpendicular to the back plate1. The inner diameter of the second frame segment302may be larger than the inner diameter of the first frame segment301. In addition, the middle frame3may include a mold frame.

As shown inFIG.2andFIG.3, the light-emitting substrate2can be disposed on the bearing surface of the back plate1, that is, the light-emitting substrate2and the middle frame3are located on the same side of the back plate1. A light-emitting side of the light-emitting substrate2faces away from the back plate1. The light-emitting substrate2is located in the middle frame3, that is, the middle frame3surrounds the light-emitting substrate2. The light-emitting substrate2may include a base201and a plurality of light-emitting units202. The base201may be disposed on the bearing surface of the back plate1, and the plurality of light-emitting units202may be disposed on a surface of the base201facing away from the back plate1. The base201can be a circuit board to provide power for the plurality of light-emitting units202. Light-emitting colors of the plurality of light-emitting units202may be the same, for example, all of the light-emitting colors are green. The light-emitting units202may be light-emitting chips, such as mini light-emitting diodes (LEDs), etc. In addition, in a direction parallel to the back plate1, the light-emitting substrate2may include a first light-emitting area203and a second light-emitting area204. The first light-emitting area203may be in a block shape, the second light-emitting area204may be in a ring shape, and the second light-emitting area204may surround the first light-emitting area203. The second light-emitting area204is close to the edge of the light-emitting substrate2. An outer boundary of the first light-emitting area203in the block shape may coincide with an inner boundary of the second light-emitting area204, but this is not particularly limited by the embodiments of the present disclosure. Light emitted from the first light-emitting area203is light emitted from the light-emitting units202located in the first light-emitting area203, and the emitted light of the second light-emitting area204is light emitted from the light-emitting units202located in the second light-emitting area204. As shown inFIG.3andFIG.7, the light-emitting substrate2may be a lamp plate, or the light-emitting substrate2may be formed by splicing a plurality of lamp plates.

As shown inFIG.2, a surface of the light-emitting substrate2facing away from the back plate1is provided with a protective layer4. That is, the protective layer4covers the above-mentioned plurality of light-emitting units202and the base201to prevent the light-emitting units202from being damaged. For example, the protective layer4can include a sealing/packaging adhesive. As shown inFIG.10, the protective layer4may include a plurality of protective units401. One protective unit401covers a light-emitting surface of one light-emitting unit202and is in direct contact with the light-emitting surface of the light-emitting unit202. A surface of the protective unit401facing away from the light-emitting unit is a curved surface. An area of the protective layer4corresponding to the second light-emitting area204may be doped with light conversion particles5. That is, protective units401of the plurality of protective units401corresponding to the second light-emitting area204may be doped with the light conversion particles5. The light conversion particles5include the above-mentioned one or more light conversion materials. A light-emitting intensity of the light-emitting substrate2gradually decreases from an inside of the light-emitting substrate2to the edge of the light-emitting substrate2. A doping concentration of the light conversion particles5gradually decreases along a direction that an edge of the protective layer4is close to an inside of the protective layer4, that is, a direction from the edge of the protective layer4to the inside of the protective layer4. Taking the protective layer4including a plurality of protective units401as an example, the forming process of the protective layer4may include: forming the plurality of protective units401through an adhesive dispensing process on a side of the plurality of light-emitting units202away from the base201, where the light-emitting surfaces of the protective units401are curved surfaces, and one of the plurality of protective units401covers the light-emitting surface of one of the plurality of light-emitting units and is in direct contact with the light-emitting surface of the light-emitting unit. For the protective unit401doped with the light conversion particles5, the adhesive dispensing process may include: mixing a transparent colloidal material and the light conversion particles5, and forming the protective unit401through the adhesive dispensing process.

Taking the light-emitting substrate2including the base201and light-emitting chips and the protective layer4including a sealing adhesive as an example, the preparation method of the protective layer4may include: carrying out solder paste printing, die bonding, reflow soldering and cleaning on the base201, dripping the transparent sealing adhesive in the first light-emitting area of the light-emitting substrate2, dripping the sealing adhesive doped with the light conversion particles5in the second light-emitting area of the light-emitting substrate2, and finally carrying out baking and curing.

As shown inFIG.2andFIG.5, the backlight module according to the embodiments of the present disclosure may further include a dimming film. The dimming film is disposed on a side of the light-emitting substrate2away from the back plate1, and at least part of areas of the dimming film in a thickness direction is located in the middle frame3. The dimming film may include a color conversion layer6. The color conversion layer6is disposed on the side of the light-emitting substrate2away from the back plate1, that is, the color conversion layer6faces the light-emitting side of the light-emitting substrate2. The color conversion layer6is used for color conversion of the light emitted from the light-emitting substrate2. The dimming film may further include a prism sheet7. The prism sheet7may be disposed on a side of the color conversion layer6away from the light-emitting substrate2. The dimming film may further include a diffusion sheet9. The diffusion sheet9may be located on a side of the color conversion layer6close to the light-emitting substrate2.

In an embodiment of the present disclosure, as shown inFIG.2andFIG.4, the light-emitting substrate2has a light-emitting color of blue, that is, the light-emitting substrate2emits blue light. The light conversion particles5doped in the area of the protective layer4corresponding to the second light-emitting area204include one or more yellow light conversion materials, which emit yellow light under the irradiation of blue light, so that the area of the protective layer4corresponding to the second light-emitting area204emits yellow light under the irradiation of the blue light, and the yellow light and the blue light are mixed to form white light. The blue light emitted from the light-emitting substrate2is blue light after passing through the area of the protective layer4corresponding to the first light-emitting area203. That is, the area of the protective layer4corresponding to the first light-emitting area203is not doped with the light conversion particles5. The color conversion layer6includes one or more red light conversion materials and one or more green light conversion materials. The one or more red light conversion materials can emit red light under the irradiation of the blue light, and the one or more green light conversion materials can emit green light under the irradiation of the blue light, so that the color conversion layer6emits red light and green light under the irradiation of the blue light.

In another embodiment of the present disclosure, as shown inFIG.2andFIG.4, the light-emitting substrate2has a light-emitting color of blue. The light conversion particles5doped in the area of the protective layer4corresponding to the second light-emitting area204include one or more red light conversion materials and one or more green light conversion materials. The blue light emitted from the light-emitting substrate2is blue light after passing through the area of the protective layer4corresponding to the first light-emitting area203. The color conversion layer6includes one or more red light conversion materials and one or more green light conversion material.

In yet another embodiment of the present disclosure, as shown inFIG.2andFIG.4, the light-emitting substrate2has a light-emitting color of blue. The light conversion particles5doped in the area of the protective layer4corresponding to the second light-emitting area204include one or more yellow light conversion materials. The blue light emitted from the light-emitting substrate2is blue light after passing through the area of the protective layer4corresponding to the first light-emitting area203. The color conversion layer6includes one or more yellow light conversion materials.

In yet another embodiment of the present disclosure, as shown inFIG.2andFIG.4, the light-emitting substrate2has a light-emitting color of blue. The light conversion particles5doped in the area of the protective layer4corresponding to the second light-emitting area204include one or more red light conversion materials and one or more green light conversion materials. The blue light emitted from the light-emitting substrate2is blue light after passing through the area of the protective layer4corresponding to the first light-emitting area203. The color conversion layer6includes one or more yellow light conversion materials.

In other embodiments of the present disclosure, as shown inFIG.2andFIG.4, the light-emitting substrate2has a light-emitting color of blue. The light conversion particles5doped in the area of the protective layer4corresponding to the second light-emitting area204include one or more red light conversion materials and one or more green light conversion materials. An area of the protective layer4corresponding to the first light-emitting area203is doped with one or more red light conversion materials. The color conversion layer6is a green quantum dot layer, which can emit green light under the irradiation of the blue light.

As shown inFIG.2andFIG.5, the light compensation structure100can be disposed between the light-emitting substrate2and the color conversion layer6. That is, the light compensation structure100is located on the side of the light-emitting substrate2away from the back plate1, and the color conversion layer6is located on a side of the light compensation structure100away from the back plate1. An orthographic projection of the light compensation structure100on the back plate1does not coincide with an orthographic projection of the first light-emitting area203of the light-emitting substrate2on the back plate1. That is, in the direction parallel to the back plate1, the light compensation structure100is located to the side of the first light-emitting area203, and the second light-emitting area204is also located to the side of the first light-emitting area203, so that the light compensation structure100is located close to the second light-emitting area204, and the light emitted from the light compensation structure100is easily mixed with the light emitted from the second light-emitting area204. Further, the orthographic projection of the light compensation structure100on the back plate1surrounds the orthographic projection of the first light-emitting area203on the back plate1. The light compensation structure100includes one or more light conversion materials for converting the color of the light emitted by the light-emitting substrate2. The one or more light conversion materials include one or more fluorescent materials or quantum dot materials, or may also include one or more phosphorescent materials. The one or more fluorescent materials may be organic fluorescent materials, inorganic fluorescent materials or fluorescent dyes.

As shown inFIG.2andFIG.4, the light compensation structure100can be disposed on the light-emitting substrate2. Specifically, the area of the protective layer4corresponding to the second light-emitting area204is doped with the light conversion particles5, and the area of the protective layer4doped with the light conversion particles5constitutes the light compensation structure100. In addition, as shown inFIG.5andFIG.6, the light compensation structure100may be disposed on an inner wall of the middle frame3. The light compensation structure100disposed on the inner wall of the middle frame3may include a plurality of light conversion units10. The light conversion units10include the above-mentioned one or more light conversion materials. Taking the light emitted from the light-emitting substrate2being blue light as an example, the light conversion units10can be yellow light conversion units10, that is, the light conversion units10can emit yellow light under the irradiation of blue light. The plurality of light conversion units10may be distributed on the inner wall of the middle frame3at intervals. As shown inFIG.8, the inner wall of the middle frame3provided with the light conversion units10includes a first area303and a second area304with a same area/size. The first area303is located on a side of the second area304away from the light-emitting substrate2. A density of the light conversion units10disposed in the first area303is greater than that of the light conversion units10disposed in the second area304. That is, the number of the light conversion units10disposed in the first area303is greater than that of the light conversion units10disposed in the second area304. In other embodiments of the present disclosure, as shown inFIG.9, a size of the light conversion units10disposed in the first area303is larger than that of the light conversion units10disposed in the second area304. That is, a mass of the light conversion materials contained in the light conversion units10disposed in the first area303is greater than that of the light conversion materials contained in the light conversion units10disposed in the second area304. Taking the middle frame3including the first frame segment301and the second frame segment302connected to each other as an example, the first area303may be located on the inner wall of the second frame segment302, and the second area304may be located on an inner wall of the first frame segment301. Since the inner diameter of the second frame segment302is larger than the inner diameter of the first frame segment301, the intensity of the light emitted from the light-emitting substrate2to the second frame segment302is smaller than the intensity of the light emitted from the light-emitting substrate2to the first frame segment301. In addition, the inner wall of the middle frame3can also be provided with a reflector305, and the light conversion units10are disposed on the reflector305.

For example, as shown inFIG.5, the reflector305can be disposed on an upper part of the inner wall of the middle frame3flush with or higher than an upper surface of the base201and the upper surface of the base201. The reflector305can improve the brightness. In some embodiments, the reflector305can be disposed on the upper part of the inner wall of the middle frame3flush with or higher than the upper surface of the base201and the upper surface of the base201in a form of a whole sheet. In some embodiments, the reflector305can be separately disposed on the upper part of the inner wall of the middle frame3flush with or higher than the upper surface of the base201and the upper surface of the base201in a form of a plurality of sheets, then, for example, a reflector disposed on the upper part of the inner wall of the middle frame3flush with or higher than the upper surface of the base201can be connected with a reflector on the upper surface of the base201by such as pressing.

One or more embodiments of the present disclosure also provide a display device. The display device may include the backlight module described in any one of the above embodiments. In addition, as shown inFIG.1,FIG.2andFIG.5, the display device may further include a display panel8. Since the backlight module included in the display device according to the embodiments of the present disclosure is the same as the backlight module according to the above-mentioned embodiments of the backlight module, they have the same beneficial effects, and the details are not described herein again.

The above is only the exemplary embodiments of the present disclosure, and does not limit the present disclosure in any form. Although the present disclosure has been disclosed as above in the exemplary embodiments, it is not intended to limit the present disclosure. Any technical personnel familiar with the art, without departing from the scope of the technical solutions of the present disclosure, can make some changes or modifications to equivalent embodiments of equivalent changes by using the technical contents disclosed above. Any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present disclosure that do not depart from the contents of the technical solutions of the present disclosure still fall within the scope of the technical solutions of the present disclosure.