Backlight module, display apparatus, anti-peep display apparatus and driving method therefor

Patent metadata

Field	Value
Publication number	US-12449686-B2
Application number	US-202318681615-A
Country	US
Kind code	B2
Filing date	Jan 19, 2023
Priority date	Jan 19, 2023
Publication date	Oct 21, 2025
Grant date	Oct 21, 2025

Abstract

A backlight module includes a light guide plate having a bottom surface, a light exit surface, and a light incident surface a substrate located on a side of the bottom surface away from the light exit surface; first light-emitting devices located on a side of the substrate proximate to the bottom surface second light-emitting devices disposed opposite to the light incident surface; and a prism sheet located on a side of the light guide plate away from the substrate. The first light-emitting devices are configured to emit first light, so that the first light passes through the light guide plate and the prism sheet to become light of a first viewing angle. The prism sheet is configured to cooperate with the light guide plate to modulate second light emitted by the second light-emitting devices into light of a second viewing angle which is smaller than the first viewing angle.

First claim

What is claimed is:

1. A backlight module, comprising:
a light guide plate having a bottom surface and a light exit surface that are disposed oppositely, and a light incident surface connecting the bottom surface and the light exit surface;
a substrate located on a side of the bottom surface away from the light exit surface;
a plurality of first light-emitting devices located on a side of the substrate proximate to the bottom surface; the substrate being configured to control operating states of the plurality of first light-emitting devices;
a plurality of second light-emitting devices disposed opposite to the light incident surface; and
a prism sheet located on a side of the light guide plate away from the substrate; wherein
the plurality of first light-emitting devices are configured to emit first light, so that the first light passes through the light guide plate and the prism sheet to become light of a first viewing angle; and
the prism sheet is configured to cooperate with the light guide plate to modulate second light emitted by the plurality of second light-emitting devices into light of a second viewing angle, and the first viewing angle is larger than the second viewing angle; and
the substrate includes a plurality of driving circuits; and a driving circuit is electrically connected to at least one first light-emitting device; the substrate further includes a plurality of scan signal lines, a plurality of data signal lines and a plurality of second voltage lines;
the driving circuit includes a first transistor, a second transistor and a storage capacitor; wherein a control electrode of the first transistor is electrically connected to a scan signal line, a first electrode of the first transistor is electrically connected to a data signal line, and a second electrode of the first transistor is electrically connected to a first electrode of the storage capacitor; a control electrode of the second transistor is electrically connected to the first electrode of the storage capacitor, a first electrode of the second transistor is electrically connected to a first electrode of a first light-emitting device, and a second electrode of the second transistor is grounded; a second electrode of the first light-emitting device is electrically connected to a second voltage line; and a second electrode of the storage capacitor is grounded.

2. A backlight module, comprising:
a light guide plate having a bottom surface and a light exit surface that are disposed oppositely, and a light incident surface connecting the bottom surface and the light exit surface;
a substrate located on a side of the bottom surface away from the light exit surface;
a plurality of first light-emitting devices located on a side of the substrate proximate to the bottom surface; the substrate being configured to control operating states of the plurality of first light-emitting devices;
a plurality of second light-emitting devices disposed opposite to the light incident surface; and
a prism sheet located on a side of the light guide plate away from the substrate; wherein
the plurality of first light-emitting devices are configured to emit first light, so that the first light passes through the light guide plate and the prism sheet to become light of a first viewing angle; and
the prism sheet is configured to cooperate with the light guide plate to modulate second light emitted by the plurality of second light-emitting devices into light of a second viewing angle, and the first viewing angle is larger than the second viewing angle;
wherein the substrate includes a plurality of chips, and a chip of the plurality of chips is electrically connected to at least one first light-emitting device;
the substrate further includes a plurality of first pad groups each electrically connected to a first light-emitting device and a plurality of second pad groups each electrically connected to the chip;
each first pad group includes at least two adjacent pads, and each second pad group includes at least four adjacent pads; and
a pad of the second pad group is electrically connected to a pad of at least one first pad group.

3. The backlight module according to claim 1 , wherein the substrate further includes a plurality of first voltage lines and a plurality of first connection lines; a first voltage line is electrically connected to a pad of at least one first pad group; and a first connection line is electrically connected to the pad of the second pad group and a pad of a first pad group; and/or
in a case where the chip is electrically connected to multiple first light-emitting devices, the substrate further includes a plurality of second connection lines; and a second connection line is electrically connected to pads of two adjacent first pad groups; and/or
the substrate further includes a plurality of address signal lines, a plurality of power supply voltage signal lines and a plurality of common voltage signal lines; and multiple pads of the second pad group are electrically connected to a common voltage signal line, a power supply voltage signal line and an address signal line, respectively.

4. The backlight module according to claim 2 , wherein the first light-emitting device has a top surface and a first side surface surrounding the top surface and connected to the top surface, wherein
a light intensity of light emitted from the top surface of the first light-emitting device is smaller than a light intensity of light emitted from the first side surface of the first light- emitting device.

5. The backlight module according to claim 4 , wherein the first light-emitting device includes:
a first lamp bead; and
a transflective film covering a top surface of the first lamp bead; or
the first light-emitting device includes:
a second lamp bead; and
a lens, wherein the lens covers a top surface of the second lamp bead; a surface of the lens away from the substrate is a smooth curved surface, and the smooth curved surface includes a first portion and a second portion surrounding the first portion; the first portion is concave toward a direction approaching the substrate, and the second portion is convex toward a direction away from the substrate.

6. The backlight module according to claim 2 , wherein the light guide plate further has a second side surface; the second side surface connects the bottom surface and the light exit surface, and is opposite to the light incident surface;
an included angle between the bottom surface and the second side surface is an obtuse angle, and an included angle between the bottom surface and the light exit surface is a first acute angle.

7. The backlight module according to claim 2 , wherein the light guide plate includes a light guide body and a plurality of microstructures located on a side of the light guide body proximate to the substrate; and
the plurality of microstructures are configured to increase exit angle of the second light, so that the exit angle of the second light reaches a preset exit angle range.

8. The backlight module according to claim 7 , wherein the microstructures each have a reflective surface, and the reflective surface is configured to reflect the second light incident on the reflective surface.

9. The backlight module according to claim 8 , wherein the microstructures each further have a third side surface connected to the reflective surface;
an included angle between the third side surface and the light exit surface is a second acute angle, an included angle between the reflective surface and the light exit surface is a third acute angle, and the second acute angle is greater than the third acute angle; an included angle between the third side surface and the reflective surface is an obtuse angle; a

Assignees

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

Inventors

• Qi yongle
• Han Rui
• Cui Dong
• Yu Jie
• Yoon Daekeun
• Ma Qing
• Zhang Zhipeng
• Chi Weining
• Leng Shouyang
• Li Wenyang
• Zhai Yue
• Wang Fengping
• Yang Yue

Classifications

• G02F1/133612

  Electrical details · CPC title

• G02B6/0036

  2-D arrangement of prisms, protrusions, indentations or roughened surfaces · CPC title

• G02B6/0055

  Reflecting element, sheet or layer · CPC title

• G02F1/133605

  including specially adapted reflectors · CPC title

• G02F1/133524

  Light-guides, e.g. fibre-optic bundles, louvered or jalousie light-guides · CPC title