Backlight module and control method, display screen and wearable device

Patent metadata

Field	Value
Publication number	US-10796646-B2
Application number	US-201816338712-A
Country	US
Kind code	B2
Filing date	Oct 22, 2018
Priority date	Feb 2, 2018
Publication date	Oct 6, 2020
Grant date	Oct 6, 2020

Abstract

A backlight module comprising a light source and a light guide plate. The light guide plate comprises a transparent substrate and a plurality of dimming units having a reflecting function. The light source is disposed on at least one side of said transparent substrate, and the plurality of dimming units is disposed on a lower surface of the transparent substrate for adjusting an emergent intensity of light, which is incident from the light source into the light guide plate, on an upper surface of said transparent substrate facing away from said dimming units. A method for controlling a backlight module and a display screen and wear device including the backlight module are also disclosed.

First claim

The invention claimed is:

1. A backlight module, comprising a light source and a light guide plate, wherein said light guide plate comprises a transparent substrate and a plurality of dimming units having a reflecting function, said light source is disposed on at least one side of said transparent substrate, and said plurality of dimming units is disposed on a lower surface of the transparent substrate and adjusts intensity of light incident from said light source into said light guide plate and emergent from an upper surface of said transparent substrate facing away from said dimming units,
wherein at least one of the dimming units comprises a squeezing unit and at least one elastic reflecting element located between said squeezing unit and a surface of said transparent substrate; said squeezing unit is configured to provide a pressure towards said elastic reflecting element, said elastic reflecting element is configured to produce an elastic deformation when the pressure is provided by said squeezing unit and change a contact area with said transparent substrate, and
wherein said elastic reflecting element is an elastic sphere having a reflecting surface, and two adjacent elastic reflecting elements have a space therebetween.

2. The backlight module according to claim 1 , wherein the dimming units are distributed in a matrix on said transparent substrate.

3. The backlight module according to claim 1 , wherein said squeezing unit comprises a squeezing plate in contact with said at least one elastic reflecting element and an electrically driven pressure head connected to said squeezing plate, wherein said electrically driven pressure head is configured to drive said squeezing plate to squeeze said elastic reflecting element.

4. The backlight module according to claim 3 , wherein said backlight module further comprises a pressure control unit connected to each electrically driven pressure head;
wherein said pressure control unit is configured to control a pressure of each electrically driven pressure head based on a dimming requirement.

5. The backlight module according to claim 4 , wherein said pressure control unit comprises:
a receiving unit connected to a grey scale correction unit and configured to receive a grey scale display voltage;
a voltage setting unit configured to set a control voltage parameter for each electrically driven pressure head according to said grey scale display voltage;
a pressure setting unit configured to set a pressure for each electrically driven pressure head according to the control voltage parameter for each electrically driven pressure head and to set a driving voltage for each electrically driven pressure head according to the pressure of each electrically driven pressure head.

6. The backlight module according to claim 5 , wherein said pressure setting unit comprises:
a storage module configured to store an initial pressure of each electrically driven pressure head; wherein the initial pressure of each electrically driven pressure head makes brightness of light incident into the transparent substrate homogeneous after being reflected by the elastic reflecting elements;
a pressure calculating module configured to obtain a relative pressure of each electrically driven pressure head according to a control voltage parameter of each electrically driven pressure head and to obtain a pressure of each electrically driven pressure head according to an initial pressure of each electrically driven pressure head and a relative pressure of the corresponding electrically driven pressure head.

7. The backlight module according to claim 3 , further comprising an elastic buffering plate disposed on a side of said squeezing plate in proximity to said elastic reflecting element, wherein a projection area of said elastic buffering plate on said transparent substrate covers a projection area of a squeezing face of said squeezing plate on said transparent substrate, and said elastic buffering plate has a reflecting function.

8. A display screen, comprising the backlight module according to claim 1 and a display panel for use in collaboration with said backlight module, wherein said display panel is disposed on a light exiting face of said backlight module.

9. The display screen according to claim 8 , wherein at least one of the dimming units is configured to adjust brightness of at least one pixel of said display panel for use in collaboration with said backlight module.

10. The display screen according to claim 8 , wherein at least one of the dimming units comprises a squeezing unit and at least one elastic reflecting element located between said squeezing unit and a surface of said transparent substrate; said squeezing unit is configured to provide a pressure towards said elastic reflecting element, said elastic reflecting element is configured to produce an elastic deformation when the pressure is provided by said squeezing unit and change a contact area with said transparent substrate.

11. The display screen according to claim 10 , wherein a coverage area of each elastic reflecting element on said transparent substrate is in a range of a total area of 150 pixels of the display panel.

12. A wear device, comprising the display screen according to claim 8 .

13. A method for controlling a backlight module according to claim 4 , comprises:
receiving a grey scale display voltage;
setting a control voltage parameter for each electrically driven pressure head according to said grey scale display voltage;
setting a pressure for each electrically driven pressure head according to the control voltage parameter for each electrically driven pressure head and setting a driving voltage for each electrically driven pressure head according to the pressure of each electrically driven pressure head.

14. The method for controlling a backlight module according to claim 13 , wherein,
prior to receiving a grey scale display voltage, said method for controlling a backlight module further comprises:
storing an initial pressure of each electrically driven pressure head, wherein the initial pressure of each electrically driven pressure head controls brightness of light incident into the transparent substrate to be homogeneous after being reflected by the elastic reflecting elements;
wherein setting a pressure for each electrically driven pressure head according to the control voltage parameter for each electrically driven pressure head comprises:
obtaining a relative pressure of each electrically driven pressure head according to the control voltage parameter of each electrically driven pressure head;
obtaining a pressure of each electrically driven pressure head according to the initial pressure of each electrically driven pressure head and the relative pressure of the corresponding electrically driven pressure head.

15. The backlight module according to claim 4 , further comprising an elastic buffering plate disposed on a side of said squeezing plate in proximity to said elastic reflecting element, wherein a projection area of said elastic buffering plate on said transparent substrate covers a projection area of a squeezing face of said squeezing plate on said transparent substrate, and said elastic buffering plate has a reflecting function.

16. The backlight module according to claim 5 , further comprising an elastic buffering plate disposed on a side of said squeezing plate in proximity to said elastic reflecting element, wherein a projection area of said elastic buffering plate on said transparent substrate covers a projection area of a squeezing face of said squeezing plate on said transpare

Assignees

• Fuzhou Boe Optoelectronics Tech Co Ltd
• Boe Technology Group Co Ltd

Inventors

• Zhao Hongyu
• Cui Ting
• Tu Xiaoyan
• Diao Kai

Classifications

• G02F1/133615

  Edge-illuminating devices, i.e. illuminating from the side · CPC title

• G02F1/133601

  for spatial active dimming · CPC title

• G02F1/133605

  including specially adapted reflectors · CPC title

• G02B6/35

  having switching means (by changing the optical properties of the medium G02F1/00) · CPC title

• G02B6/0055 Primary

  Reflecting element, sheet or layer · CPC title