Light guide plate, and backlight unit and display device including the same

• US 10,267,975 B2
• Filed: 07/31/2017
• Issued: 04/23/2019
• Est. Priority Date: 08/02/2016
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Chong, Joonggun, Choi, Jehong, Park, Chanjae
• Primary Examiner(s): Liu, Shan
• Application Number:
  US15/664,050
• Publication Number:
  US 20180039009A1
• Time in Patent Office: 631 Days
• Field of Search: 349 65, 359385, 385129
• CPC Class Codes: G02B 6/00 Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
• CPC Class Codes: G02B 6/0043 provided on the surface of the light guide
• CPC Class Codes: G02B 6/0055 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0065 Manufacturing aspects; Material aspects
• CPC Class Codes: G02F 1/133607 the light controlling member including light directing or refracting elements, e.g. prisms or lenses
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G02F 2201/123 pixel

Abstract

A backlight unit and a display device includes a light source which generates light used by a display panel to display an image; and a light guide plate which receives the light from the light source and emits the light through a light emission surface thereof. The light guide plate includes: a base layer; a light transmitting layer on the base layer and defining the light emission surface of the light guide plate; and a light transmitting particle provided in plurality between the base layer and the light transmitting layer. The light transmitting particle has a refractive index higher than a refractive index of the light transmitting layer.

Claims

1. A backlight unit comprising:

a light source which generates light used by a display panel of a display device to display an image; and

a light guide plate which receives the light from the light source and emits the light toward the display panel of the display device,

wherein the light guide plate comprises;

a light emission surface through which the emitted light exits from the light guide plate toward the display panel of the display device;

a base layer;

a light transmitting layer on the base layer, the light transmitting layer defining the light emission surface of the light guide plate; and

a light transmitting particle provided in plurality between the base layer and the light transmitting layer, all of the light transmitting particles directly contacting a flat surface of the base layer, among which a same light transmitting particle forms an interface with both the base layer and the light transmitting layer defining the light emission surface of the light guide plate,

wherein the light transmitting layer defining the light emission surface of the light guide plate and with which the same light transmitting particle forms the interface has a refractive index lower than each of;

a refractive index of the same light transmitting particle forming the interface with both the base layer and the light transmitting layer defining the light emission surface of the light guide plate, and

a refractive index of the base layer with which the same light transmitting particle forms the interface.

2. The backlight unit as claimed in claim 1, wherein

the refractive index of the light transmitting particle ranges from about 1.4 to about 2.0, and

the refractive index of the light transmitting layer ranges from about 1.1 to about 1.3.

3. The backlight unit as claimed in claim 1, wherein the light transmitting particle of the light guide plate has a bead shape.

4. The backlight unit as claimed in claim 3, wherein the light transmitting particle of the light guide plate has a diameter ranging from about 10 micrometers to about 20 micrometers.

5. The backlight unit as claimed in claim 1, wherein the base layer of the light guide plate comprises glass.

6. The backlight unit as claimed in claim 1, wherein

the base layer further comprises an adhesive layer,

the same light transmitting particle forms the interface with both the adhesive layer of the base layer and the light transmitting layer defining the light emission surface of the light guide plate, and

the light transmitting layer defining the light emission surface of the light guide plate and with which the same light transmitting particle forms the interface has the refractive index lower than each of:

the refractive index of the same light transmitting particle forming the interface with both the adhesive layer of the base layer and the light transmitting layer defining the light emission surface of the light guide plate, and

the refractive index of the adhesive layer of the base layer with which the same light transmitting particle forms the interface.

7. The backlight unit as claimed in claim 1, wherein the light emission surface of the light guide plate comprises a concavo-convex pattern defined by the light transmitting layer.

8. The backlight unit as claimed in claim 7, wherein the light transmitting layer comprises a photosensitive organic material.

9. The backlight unit as claimed in claim 1, further comprising a reflecting member on a rear surface of the light guide plate, the rear surface opposing the light emission surface of the light guide plate.

10. A display device comprising:

a display panel which displays an image with light;

a light source which generates the light; and

a light guide plate which receives the light from the light source and emits the light toward the display panel,

wherein the light guide plate comprises;

a light emission surface through which the emitted light exits from the light guide plate toward the display panel;

a base layer;

a light transmitting layer on the base layer, the light transmitting layer defining the light emission surface of the light guide plate; and

a light transmitting particle provided in plurality between the base layer and the light transmitting layer, all of the light transmitting particles directly contacting a flat surface of the base layer, among which a same light transmitting particle forms an interface with both the base layer and the light transmitting layer defining the light emission surface of the light guide plate,

wherein the light transmitting layer defining the light emission surface of the light guide plate and with which the same light transmitting particle forms the interface has a refractive index lower than each of;

a refractive index of the same light transmitting particle forming the interface with both the base layer and the light transmitting layer defining the light emission surface of the light guide plate, and

a refractive index of the base layer with which the same light transmitting particle forms the interface.