Backlight module, display module, spliced display screen and display apparatus

Patent metadata

Field	Value
Publication number	US-12353085-B2
Application number	US-202218271232-A
Country	US
Kind code	B2
Filing date	May 31, 2022
Priority date	May 31, 2022
Publication date	Jul 8, 2025
Grant date	Jul 8, 2025

Abstract

A backlight module is provided to include a back plate, and a light source, a middle frame, a diffuser plate, an optical film layer sequentially arranged in a direction away from the back plate; a light outgoing surface of the light source faces the diffuser plate; orthographic projections of the optical film layer, the diffuser plate and the light source on the back plate overlap with each other; an orthographic projection of the middle frame on the back plate overlaps with a peripheral edge of the back plate; the middle frame is connected to the peripheral edge; the orthographic projection of the middle frame on the back plate does not overlap with that of the light source; the middle frame includes a body structure and a first support portion, which have a one-piece structure; the body structure is on a side of the diffuser plate close to the back plate.

First claim

What is claimed is:

1. A backlight module, comprising: a back plate, a light source, a middle frame, a diffuser plate and an optical film layer;
wherein the light source, the middle frame, the diffuser plate and the optical film layer are on the back plate and are sequentially arranged in a direction away from the back plate;
a light outgoing surface of the light source faces the diffuser plate; orthographic projections of the optical film layer, the diffuser plate and the light source on the back plate overlap with each other;
an orthographic projection of the middle frame on the back plate overlaps with a peripheral edge of the back plate; the middle frame is connected to the peripheral edge of the back plate;
the orthographic projection of the middle frame on the back plate does not overlap with the orthographic projection of the light source on the back plate;
the middle frame comprises a body structure and a first support portion, wherein the body structure and the first support portion are connected together to have a one-piece structure;
the body structure is on a side of the diffuser plate close to the back plate, and the body structure supports a peripheral edge of the diffuser plate;
the first support portion is arranged outside an edge end face of the diffuser plate and an edge end face of the optical film layer, and is used for supporting a peripheral edge of a display panel on a side of the optical film layer away from the back plate; and
the first support portion is made of a light-transmitting material;
the backlight module further comprises a groove in a light-transmitting material layer on an outer side surface of the middle frame away from the edge end face of the diffuser plate and the edge end face of the optical film layer;
the groove is recessed towards the edge end face of the diffuser plate;
the groove is configured such that the middle frame comprises an arc surface which is convex towards a side where the first support portion is located;
a second reflector is on the arc surface; and
the second reflector is capable of reflecting light irradiated onto the second reflector from the light source towards inside of the first support portion.

2. The backlight module according to claim 1 , wherein the body structure comprises a body portion and a second support portion, the body portion and the second support portion are sequentially arranged in the direction away from the back plate, and the body portion and the second support portion are connected together to have a one-piece structure;
the second support portion is in contact with a surface of the diffuser plate close to the back plate;
the second support portion extends in a direction close to the edge end face of the diffuser plate, and is connected to the first support portion; and
the second support portion is made of a light-transmitting material.

3. The backlight module according to claim 2 , wherein the body portion comprises a first surface and a second surface, the first surface is one surface of the body portion away from the diffuser plate; the second surface is the other surface than the first surface of the body portion; and
the first support portion and/or the second support portion further extends to cover at least the second surface of the body portion.

4. The backlight module according to claim 3 , further comprising a first reflector on the outer side surface of the middle frame away from the edge end face of the diffuser plate and the edge end face of the optical film layer, wherein the first reflector covers a light-transmitting material layer on the outer side surface of the middle frame; and
the first reflector is in contact with the light-transmitting material layer, and the first reflector is capable of reflecting light irradiated onto the first reflector from the light source into the light-transmitting material layer.

5. The backlight module according to claim 3 , wherein a dimension of the first support portion in a direction away from the edge end face of the diffuser plate is a thickness of the first support portion, which is 0.8 mm or more; and
a dimension of the second support portion in a direction away from the back plate is a thickness of the second support portion, which is in a range of 1.2 mm to 2 mm.

6. The backlight module according to claim 1 , wherein the groove is at a height where a surface of the body portion close to the diffuser plate is located.

7. The backlight module according to claim 1 , wherein the first support portion comprises a support surface which is in contact with the display panel and support the display panel;
the backlight module further comprises a third reflector on the outer side surface of the middle frame away from the edge end face of the diffuser plate and the edge end face of the optical film layer, and an orthographic projection of the third reflector on the outer side surface is between the support surface of the first support portion and the groove; and
the third reflector is in contact with the light-transmitting material layer, and is capable of reflecting the light irradiated onto the third reflector from the light source into the light-transmitting material layer.

8. The backlight module according to claim 7 , wherein a distance between an edge of the third reflector close to the support surface of the first support portion and the support surface of the first support portion along an arrangement direction of the back plate, the diffuser plate and the optical film layer is in a range of 1.5 mm to 2 mm; and
a distance between two edges of the third reflector sequentially arranged in a direction away from the support surface of the first support portion is in a range of 3 mm to 4 mm.

9. The backlight module according to claim 7 , further comprising a fourth reflector on the outer side surface of the middle frame away from the edge end face of the diffuser plate and the edge end face of the optical film layer; wherein the fourth reflector covers a region of the light-transmitting material layer except for where the third reflector is located and covers an opening of the groove;
the fourth reflector is in contact with the light-transmitting material layer, and the fourth reflector is capable of reflecting the light irradiated onto the fourth reflector from the light source into the light-transmitting material layer.

10. The backlight module according to claim 9 , wherein each of the second reflector and the fourth reflector has a reflectivity in a range of 80% to 90%, respectively;
the third reflector has a reflectivity in a range of 28% to 30%;
the third reflector has an absorptivity in a range of 70% to 72% for the light irradiated onto the third reflector from the light source;
the body portion is made of a metal or a metal alloy; and
the light-transmitting material comprises a transparent resin material.

11. The backlight module according to claim 1 , wherein the back plate comprises a bottom wall and a side wall,
the side wall surrounds a peripheral edge of the bottom wall, and is connected to the bottom wall to form a first accommodating space, the light source is in the first accommodating space and on the bottom wall; and
a part of the side wall on at least one side is recessed towards the first accommodating space to form a second accommodating space at a recessed surface away from the first accommodating space.

12. The backlight module according to claim 11 , further comprising a reflective layer on a side of the bottom wall of the back plate close to the diffuser plate;
wherein an orthographic projection of the reflective layer on the bottom wall of the back plate covers a region excep

Assignees

• Beijing Boe Display Tech Co
• Boe Technology Group Co Ltd

Inventors

• Bu Zhanchang
• Qu qingshan
• Sun Jixing
• Wang Bochang
• Shi Haijun

Classifications

• G02F1/133611

  including means for improving the brightness uniformity · CPC title

• G02F1/133608

  including particular frames or supporting means · CPC title

• G02F1/133606

  including a specially adapted diffusing, scattering or light controlling members · CPC title

• G02F1/133605 Primary

  including specially adapted reflectors · CPC title

• G02F1/13336 Primary

  Combining plural substrates to produce large-area displays, e.g. tiled displays · CPC title