LIGHT GUIDE STRUCTURE, BACKLIGHT MODULE, AND DISPLAY DEVICE

• US 20170131457A1
• Filed: 11/23/2015
• Published: 05/11/2017
• Est. Priority Date: 06/19/2015
• Status: Active Grant

• Current Assignee: BOE Technology Group Co., Ltd.
• Original Assignee: BOE Technology Group Co., Ltd.
• Inventors: ZHU, Ming, SUZUKI, Teruaki
• Granted Patent: US 9,897,741 B2
• Time in Patent Office: Days
• CPC Class Codes: G02B 6/005 provided by one optical element, or plurality thereof, placed on the light output side of the light guide
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02B 6/0055 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0056 for producing polarisation effects, e.g. by a surface with polarizing properties or by an additional polarizing elements
• CPC Class Codes: G02B 6/0065 Manufacturing aspects; Material aspects
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side
• CPC Class Codes: G02F 1/133638 Waveplates, i.e. plates with a retardation value of lambda/n

Abstract

A light guide structure (10), a backlight module (20) and a display device are disclosed, which can reduce loss of light in travelling and increase utilization rate of light. The light guide structure (10) including: a light guide plate (1) including a light-exiting surface (11) and a reflection surface (12) that are opposite to each other and a side surface (13) connecting the light-exiting surface (11) with the reflection surface (12), a material of the light guide plate (1) being an isotropic material; a reflection type brightness enhancement film (2) that is disposed at a side where the light-exiting surface (11) of the light guide plate (1) is located; a quarter wavelength plate (3) that is disposed between the light-exiting surface (11) of the light guide plate (1) and the reflection type brightness enhancement film (2), with an angle of 45 degree existing between a slow axis of the quarter wavelength plate (3) and a transmission axis of the reflection type brightness enhancement film (2); and a reflection film (4) that is disposed at a side where the reflection surface (12) of the light guide plate (1) is located.

Claims

1. A light guide structure comprising:

a light guide plate, comprising a light-exiting surface and a reflection surface that are opposite to each other and a side surface connecting the light-exiting surface with the reflection surface, and a material of the light guide plate being an isotropic material;

a reflection type brightness enhancement film, being disposed at a side where the light-exiting surface of the light guide plate is located;

a quarter wavelength plate, being disposed between the light-exiting surface of the light guide plate and the reflection type brightness enhancement film, with an angle of 45 degrees existing between a slow axis of the quarter wavelength plate and a transmission axis of the reflection type brightness enhancement film; and

a reflection film, being disposed at a side where the reflection surface of the light guide plate is located.

2. The light guide structure according to claim 1, further comprising a lower polarizer disposed above the reflection type brightness enhancement film, wherein a transmission axis of the lower polarizer is parallel to the transmission axis of the reflection type brightness enhancement film.

3. The light guide structure according to claim 2, wherein the lower polarizer is an absorption type polarizer.

4. The light guide structure according to claim 1, wherein the light guide plate is a glass light guide plate or a light guide plate of hard polymethyl methacrylate.

5. The light guide structure according to claim 1, wherein the reflection film is an enhancement mirror reflection film.

6. The light guide structure according to claim 1, wherein a thickness of the reflection film is in a range of 2 μ

m-5 μ

m.

7. The backlight module comprising the light guide structure according to claim 1 and a light source, wherein the light source is disposed at the side surface of the light guide plate.

8. The display device comprising a display panel and the backlight module according to claim 7, wherein the backlight module is disposed at a non-display side of the display panel.

9. The display device according to claim 8, further comprising an upper polarizer, wherein the upper polarizer is disposed at a display side of the display panel, and a transmission axis of the upper polarizer is parallel or perpendicular to the transmission axis of the reflection type brightness enhancement film.

10. The light guide structure according to claim 2, wherein the light guide plate is a glass light guide plate or a light guide plate of hard polymethyl methacrylate.

11. The light guide structure according to claim 2, wherein the reflection film is an enhancement mirror reflection film.

12. The light guide structure according to claim 2, wherein a thickness of the reflection film is in a range of 2 μ

m-5 μ

m.

13. The backlight module comprising the light guide structure according to claim 2 and a light source, wherein the light source is disposed at the side surface of the light guide plate.

14. The light guide structure according to claim 3, wherein the light guide plate is a glass light guide plate or a light guide plate of hard polymethyl methacrylate.

15. The light guide structure according to claim 3, wherein the reflection film is an enhancement mirror reflection film.

16. The light guide structure according to claim 3, wherein a thickness of the reflection film is in a range of 2 μ

m-5 μ

m.

17. The backlight module comprising the light guide structure according to claim 3 and a light source, wherein the light source is disposed at the side surface of the light guide plate.

18. The light guide structure according to claim 4, wherein the reflection film is an enhancement mirror reflection film.

19. The light guide structure according to claim 4, wherein a thickness of the reflection film is in a range of 2 μ

m-5 μ

m.

20. The backlight module comprising the light guide structure according to claim 4 and a light source, wherein the light source is disposed at the side surface of the light guide plate.