Backlight unit including reflection member and display device including the same

• US 10,288,795 B2
• Filed: 08/04/2017
• Issued: 05/14/2019
• Est. Priority Date: 08/04/2016
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Kim, Raeyoung, Shin, Taeksun, Ha, Sangwoo
• Primary Examiner(s): Mai, Anh T
• Assistant Examiner(s): Farokhrooz, Fatima N
• Application Number:
  US15/669,081
• Publication Number:
  US 20180039010A1
• Time in Patent Office: 648 Days
• CPC Class Codes: G02B 6/0038 Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide
• CPC Class Codes: G02B 6/0055 Reflecting element, sheet or layer

Abstract

A backlight unit includes: a light source which generates light; a light guide plate which receives the light from the light source and guides the light to a display panel which displays an image with the light, the light guide plate including a light incident side surface to which the light from the light source is incident, and an opposing side surface which opposes said light incident side surface; and a reflection member disposed facing the opposing side surface of the light guide plate. Along a length of the opposing side surface of the light guide plate, the reflection member facing the opposing side surface includes at least two reflective portions having different reflectances from each other.

Claims

1. A backlight unit comprising:

a light source which generates light;

a light guide plate which receives the light from the light source and guides the light to a display panel which displays an image with the light,

the light guide plate comprising a light incident side surface to which the light from the light source is incident, and an opposing side surface which opposes said light incident side surface; and

a reflection member disposed facing the opposing side surface of the light guide plate, wherein along a length of the opposing side surface of the light guide plate, the reflection member facing the opposing side surface comprises;

a first portion at a central portion of the opposing side surface of the light guide plate; and

a second portion at an end portion of the opposing side surface of the light guide plate,

wherein the first portion has a reflectance less than a reflectance of the second portion, and reflectance of the reflection member gradually increases from the first portion thereof toward the second portion thereof.

2. The backlight unit as claimed in claim 1, wherein along the length of the opposing side surface of the light guide plate, a thickness of the reflection member gradually increases from the first portion thereof toward the second portion thereof, the thickness taken in a direction from the opposing side surface of the light guide plate to the reflection member.

3. The backlight unit as claimed in claim 1, wherein the opposing side surface of the light guide plate or a light incident surface of the reflection member comprises a reflection layer thereon.

4. The backlight unit as claimed in claim 1, further comprising a reflective adhesive layer between the opposing side surface of the light guide plate and a light incident surface of the reflection member,

wherein the reflective adhesive layer comprises a transparent adhesive material and a reflective material which is dispersed in the transparent adhesive material.

5. The backlight unit as claimed in claim 1, wherein the light guide plate further comprises:

an upper surface through which guided light exits the light guide plate toward the display panel, and

a lens pattern at the upper surface of the light guide plate.

6. The backlight unit as claimed in claim 3, wherein the reflection layer comprises at least one selected from silver (Ag), aluminum (Al), nickel (Ni), gold (Au), ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), platinum (Pt) and alloys thereof.

7. The backlight unit as claimed in claim 3, wherein along the length of the opposing side surface of the light guide plate, an area of the opposing side surface of the light guide plate or the light incident surface of the reflection member respectively corresponding to the reflection layer gradually increases from the first portion of the reflection member toward the second portion thereof.

8. The backlight unit as claimed in claim 4, wherein along the length of the opposing side surface of the light guide plate, a density of the reflective material of the reflective adhesive layer between the opposing side surface of the light guide plate and the light incident surface of the reflection member gradually increases from the first portion of the reflecting member toward the second portion thereof.

9. The backlight unit as claimed in claim 5, wherein the lens pattern at the upper surface of the light guide plate comprises a dome-shaped lens pattern extending from the light incident side surface of the light guide plate toward the opposing side 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;

a light guide plate which receives the light from the light source and guides the light to the display panel,

the light guide plate comprising a light incident side surface to which the light from the light source is incident, and an opposing side surface which opposes said light incident side surface; and

a reflection member disposed facing the opposing side surface of the light guide plate,

wherein along a length of the opposing side surface of the light guide plate, the reflection member facing the opposing side surface comprises;

a first portion at a central portion of the opposing side surface of the light guide plate; and

a second portion at an end portion of the opposing side surface of the light guide plate,

wherein the first portion has a reflectance less than a reflectance of the second portion, and a reflectance of the reflection member gradually increases from the first portion thereof toward the second portion thereof.

11. The display device as claimed in claim 10, wherein along the length of the opposing side surface of the light guide plate, a thickness of the reflection member gradually increases from the first portion thereof toward the second portion thereof, the thickness taken in a direction from the opposing side surface of the light guide plate to the reflection member.

12. The display device as claimed in claim 10, wherein

the reflection member facing the opposing side surface of the light guide comprises a discrete reflection layer provided in plurality on a light incident surface of the reflection member, the plurality of reflection layers being arranged spaced apart from each other along the length of the opposing side surface of the light guide plate, and

an area of the light incident surface of the reflection member respectively corresponding to the reflection layers gradually increases from the first portion of the reflection member toward the second portion thereof.

13. The display device as claimed in claim 10, wherein

the light guide plate further comprises an upper surface through which the guided light exits the light guide plate toward the display panel and a lower surface opposite to the upper surface,

further comprising a reflection sheet which is separate from the reflection member, the reflection sheet disposed between the lower surface of the light guide plate and the lower frame.

14. The display device as claimed in claim 10, wherein the light guide plate further comprises:

an upper surface through which the guided light exits the light guide plate toward the display panel, and

at the upper surface, a dome-shaped lens pattern provided in plurality arranged along the length of the opposing side surface of the light guide plate, each dome-shaped lens pattern extending from the light incident side surface of the light guide plate to the opposing side surface of the light guide plate.