BACKLIGHT UNIT AND DISPLAY DEVICE INCLUDING THE SAME

• US 20110096265A1
• Filed: 06/29/2010
• Published: 04/28/2011
• Est. Priority Date: 10/26/2009
• Status: Abandoned Application

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: SUMINOE, Shinji, OGATA, Nobuo, MURAKOSHI, Kenichi, HIROTA, Makoto, OHATA, Takafumi, HINENO, Mitsuru, HIRANO, Yasuaki, SEKIGUCHI, Yoshihisa
• Application Number:
  US12/825,603
• Publication Number:
  US 20110096265A1
• Time in Patent Office: Days
• US Class Current: 349/64
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133605 including specially adapted reflectors
• CPC Class Codes: G02F 1/133607 the light controlling member including light directing or refracting elements, e.g. prisms or lenses

Abstract

Provided is a backlight unit capable of increasing luminance and of reducing unevenness in luminance. The backlight unit includes: a light diffusing member provided to cover a light emitting element mounted on a surface of a substrate; and a first light reflective member having a hole portion opened larger in size than an outer shape of the light diffusing member, the first light reflective member being provided on the surface of the substrate while having the light diffusing member protrude from the hole portion. In addition, a second light reflective member is further provided on the surface of the substrate, and the second light reflective member covers at least a part of a region corresponding to a gap left between the light diffusing member and the hole portion of the first light reflective member.

Claims

1. A backlight unit, comprising:

a substrate;

a light emitting element mounted on a surface of the substrate;

a light diffusing member provided on the surface of the substrate so that the light emitting element is covered with the light diffusing member;

a first light reflective member having a hole portion opened larger in size than an outer shape of the light diffusing member, the first light reflective member being provided on the surface of the substrate while having the light diffusing member protrude from the hole portion so that the first light reflective member covers the surface of the substrate; and

a second light reflective member further provided on the surface of the substrate, the second light reflective member being a member different from the first light reflective member, wherein;

the light diffusing member and the hole portion of the first light reflective member have a gap left therebetween; and

the second light reflective member covers at least a part of a region of the surface of the substrate, the region corresponding to the gap.

2. A backlight unit according to claim 1, wherein the second light reflective member is formed of a material obtained by further adding a predetermined light reflective material to a white solder resist.

3. A backlight unit according to claim 1, wherein the second light reflective member extends from the region on the surface of the substrate, the region corresponding to the gap, to another region on the surface of the substrate, the another region overlapping an inner edge portion of the hole portion of the first light reflective member.

4. A backlight unit according to claim 1, wherein the second light reflective member has an opening portion formed therein, the opening portion being for exposing a region where the light diffusing member is installed on the surface of the substrate.

5. A backlight unit according to claim 4, wherein:

the light diffusing member has a fixing portion fixed onto the surface of the substrate; and

the opening portion of the second light reflective member has a shape formed along a shape of the fixing portion of the light diffusing member.

6. A backlight unit according to claim 1, wherein:

the light emitting element comprises a plurality of light emitting elements and the light diffusing member comprises a plurality of light diffusing members;

the plurality of light emitting elements are arranged two-dimensionally and mounted on the surface of at least one of the substrate, and the plurality of light diffusing members respectively covering the plurality of light emitting elements are provided on the surface of the at least one substrate; and

one of the first light reflective member has a plurality of the hole portion formed therein so that the surface of the at least one substrate is covered with the one first light reflective member.

7. A backlight unit according to claim 1, wherein the light diffusing member comprises an optical lens.

8. A backlight unit according to claim 1, wherein the first light reflective member comprises a reflective sheet.

9. A backlight unit according to claim 1, wherein the light emitting element comprises a white light emitting diode.

10. A display device, comprising:

a display panel; and

a backlight unit for illuminating the display panel, wherein;

the backlight unit includes;

a substrate;

a light emitting element mounted on a surface of the substrate;

a light diffusing member provided on the surface of the substrate so that the light emitting element is covered with the light diffusing member;

a first light reflective member having a hole portion opened larger in size than an outer shape of the light diffusing member, the first light reflective member being provided on the surface of the substrate while having the light diffusing member protrude from the hole portion so that the first light reflective member covers the surface of the substrate; and

a second light reflective member further provided on the surface of the substrate, the second light reflective member being a member different from the first light reflective member;

the light diffusing member and the hole portion of the first light reflective member have a gap left therebetween; and

the second light reflective member covers at least a part of a region of the surface of the substrate, the region corresponding to the gap.