Backlight module

• US 10,139,677 B2
• Filed: 05/01/2015
• Issued: 11/27/2018
• Est. Priority Date: 08/20/2008
• Status: Active Grant

• Current Assignee: Maxell, Ltd.
• Original Assignee: Funai Electric Co., Ltd. (Funai Electric Holdings Company Limited)
• Inventors: Kawada, Kazuaki
• Primary Examiner(s): Han, Jason Moon
• Application Number:
  US14/702,104
• Publication Number:
  US 20150234231A1
• Time in Patent Office: 1,306 Days
• Field of Search: 362 971- 972, 362632-634, 349 58
• CPC Class Codes: F21V 7/04 Optical design
• CPC Class Codes: G02F 1/133605 including specially adapted reflectors
• CPC Class Codes: G02F 1/133608 including particular frames or supporting means

Abstract

A backlight module includes at least one light source, a light reflecting member, and a cabinet. The light reflecting member includes a center reflecting part, and four peripheral reflecting parts. The center reflecting part and the peripheral reflecting parts are integrally formed as a one-piece, unitary member. The peripheral reflecting parts are slanted with respect to the center reflecting part, respectively, while the light reflecting member is attached to the cabinet.

Claims

1. A backlight module comprising:

at least one light source that emits light;

a light reflecting member arranged to reflect the light emitted from the light source, the light reflecting member including

a center reflecting part with a rectangular shape having two first opposite side portions and two second opposite side portions,

four peripheral reflecting parts each having a trapezoidal shape with a lower base and an upper base that is longer than the lower base, the lower bases being connected to the first and second opposite side portions of the center reflecting part, respectively, the peripheral reflecting parts extending from the first and second opposite side portions of the center reflecting part, respectively,

extension parts extending from the upper bases of the peripheral reflecting parts, respectively, with the light reflecting member being integrally formed as a one-piece, unitary member;

an optical sheet disposed on the light reflecting member; and

a cabinet including a bottom part, two first side parts and two second side parts, the first and second side parts extending frontward from peripheral portions of the bottom part, respectively, with the first and second side parts defining an interior of the cabinet therebetween and including first and second peripheral edges, respectively, that define an opening of the cabinet,

while the light reflecting member is attached to the cabinet, the center reflecting part and the peripheral reflecting parts being disposed within the interior of the cabinet, the peripheral reflecting parts being slanted with respect to the center reflecting part, respectively, and the peripheral reflecting parts extending in an opening direction of the cabinet and outward from the first and second opposite side portions of the center reflecting part, respectively,

the extension parts being supported on the first and second side parts,

the optical sheet directly contacting with the extension parts in a direction perpendicular to the center reflecting part at a location outside the interior of the cabinet on an opposite side of the opening with respect to the bottom part of the cabinet,

side end portions of an adjacent pair of the peripheral reflecting parts abutting against each other to form a corner section of the light reflecting member at a corner portion of the center reflecting part while the light reflecting member is attached to the cabinet, and

the side end portions of the adjacent pair of the peripheral reflecting parts defining an abutment interface while the light reflecting member is attached to the cabinet, the abutment interface extending from the corner portion of the center reflecting part in a direction that intersects with a diagonal of the center reflecting part that extends through the corner portion of the center reflecting part as viewed in the direction perpendicular to the center reflecting part.

2. The backlight module according to claim 1, wherein

the extension parts are arranged parallel to the center reflecting part of the light reflecting member while the light reflecting member is attached to the cabinet.

3. The backlight module according to claim 2, wherein

the light reflecting member has a first depth measured between the center reflecting part and the extension parts in a direction perpendicular to the center reflecting part while the light reflecting member is attached to the cabinet, and

the cabinet has a second depth measured between an inner surface of the bottom part and a top surface of one of the first and second side parts in a direction perpendicular to the inner surface of the bottom part, with the second depth of the cabinet being larger than the first depth of the light reflecting member, the center reflecting part of the light reflecting member being spaced apart from the inner surface of the bottom part while the light reflecting member is attached to the cabinet.

4. The backlight module according to claim 3, wherein

while the light reflecting member is attached to the cabinet, an inner edge of one of the extension parts is aligned with an inner edge of the top surface of one of the first and second side parts on which the one of the extension parts is disposed as viewed in the direction perpendicular to the center reflecting part.

5. The backlight module according to claim 1, wherein

the optical sheet is disposed on the light reflecting member, the optical sheet at least partially overlapping with the extension parts of the light reflecting member as viewed in a direction perpendicular to the center reflecting part while the light reflecting member is attached to the cabinet.

6. The backlight module according to claim 1, wherein

while the light reflecting member is attached to the cabinet, the extension parts are disposed on the first and second side parts, respectively.

7. The backlight module according to claim 1, wherein

the extension parts are disposed along entire lengths of the upper bases of the at least one opposite pair of the peripheral reflecting parts, respectively.

8. The backlight module according to claim 7, wherein

the extension parts have a rectangular shape.

9. The backlight module according to claim 7, wherein

the extension parts have a first width measured in a widthwise direction perpendicular to a lengthwise direction of the extension parts, and

either the first side parts or the second side parts on which the extension parts are disposed have a second width measured in the widthwise direction, with the second width being larger than the first width.

10. The backlight module according to claim 1, wherein

the light reflecting member further includes a tongue part that extends from one of the side end portions of the adjacent pair of the peripheral reflecting parts towards the other of the side end portions of the adjacent pair of the peripheral reflecting parts, and

the tongue part of the light reflecting member at least partially overlaps with the other of the side end portions of the adjacent pair of the peripheral reflecting parts while the light reflecting member is attached to the cabinet.

11. The backlight module according to claim 1, wherein

the peripheral reflecting parts of the light reflecting member each have an isosceles trapezoidal shape as the trapezoidal shape.

12. The backlight module according to claim 1, wherein

one of the first and second side parts of the cabinet extends perpendicularly frontward with respect to the bottom part, the one of the first and second side parts of the cabinet and corresponding one of the peripheral reflecting parts that is adjacently opposite the one of the first and second side parts of the cabinet define a spacing therebetween while the light reflecting member is attached to the cabinet.

13. The backlight module according to claim 1, wherein

at least one of the first and second side parts of the cabinet has an outer surface that is perpendicular to the bottom part of the cabinet.

14. The backlight module according to claim 1, wherein

angles defined between the center reflecting part and a pair of the peripheral reflecting parts are equal to each other.

15. The backlight module according to claim 14, wherein

angles defined between the bottom part and either the first side parts or the second side parts are equal to each other.

16. The backlight module according to claim 1, wherein

the first opposite side portions of the center reflecting part are longer than the second opposite side portions of the center reflecting part, respectively.

17. The backlight module according to claim 16, further comprising

a plurality of light sources arranged with respect to the cabinet, the light sources being connected to a plurality of electric connectors, respectively, the electric connectors being arranged closer to one of the second side parts of the cabinet than the other of the second side parts of the cabinet.

18. The backlight module according to claim 17, wherein

the light sources are symmetrically arranged relative to the cabinet with respect to a horizontal center plane of the backlight module.

19. The backlight module according to claim 18, wherein

the light reflecting member further has a plurality of openings located on the center reflecting part, the light sources being supported with respect to the cabinet via light source supports that are disposed through the openings of the light reflecting member.

20. The backlight module according to claim 19, wherein

the light reflecting member further has a plurality of through holes with continuous periphery, the light sources being connected to the electric connectors through the through holes, respectively, the through holes being at least partially located on one of the second peripheral reflecting parts that is adjacently opposite the one of the second side parts of the cabinet while the light reflecting member is attached to the cabinet.

21. The backlight module according to claim 1, wherein

the corner portion of the center reflecting part is located between the adjacent pair of the peripheral reflecting parts,

the light reflecting member further includes a tongue part that extends from one of the side end portions of the adjacent pair of the peripheral reflecting parts towards the other of the side end portions of the adjacent pair of the peripheral reflecting parts, and

the tongue part of the light reflecting member at least partially overlaps with the other of the side end portions of the adjacent pair of the peripheral reflecting parts while the light reflecting member is attached to the cabinet.

22. The backlight module according to claim 1, wherein

while the light reflecting member is attached to the cabinet, the extension parts are disposed on the first and second side parts, respectively, and

each of the extension parts having the same width in a widthwise direction thereof that is perpendicular to corresponding one of the upper bases.

23. A display device comprising:

a liquid crystal cell;

at least one light source that emits light;

a light reflecting member arranged to reflect the light emitted from the light source toward the liquid crystal cell, the light reflecting member including

a center reflecting part with a rectangular shape having two first opposite side portions and two second opposite side portions, and

four peripheral reflecting parts each having a trapezoidal shape with a lower base and an upper base that is longer than the lower base, the lower bases being connected to the first and second opposite side portions of the center reflecting part, respectively, the peripheral reflecting parts extending from the first and second opposite side portions of the center reflecting part, respectively,

extension parts extending from the upper bases of the peripheral reflecting parts, respectively, with the light reflecting member being integrally formed as a one-piece, unitary member;

an optical sheet disposed on the light reflecting member; and

a cabinet including a bottom part, two first side parts and two second side parts, the first and second side parts extending frontward from peripheral portions of the bottom part, respectively, with the first and second side parts defining an interior of the cabinet therebetween and including first and second peripheral edges, respectively, that define an opening of the cabinet,

while the light reflecting member is attached to the cabinet, the center reflecting part and the peripheral reflecting parts being disposed within the interior of the cabinet, the peripheral reflecting parts being slanted with respect to the center reflecting part, respectively, and the peripheral reflecting parts extending in an opening direction of the cabinet and outward from the first and second opposite side portions of the center reflecting part, respectively,

the extension parts being supported on the first and second side parts, and

the optical sheet directly contacting with the extension parts in a direction perpendicular to the center reflecting part at a location outside the interior of the cabinet on an opposite side of the opening with respect to the bottom part of the cabinet,

side end portions of an adjacent pair of the peripheral reflecting parts abutting against each other to form a corner section of the light reflecting member at a corner portion of the center reflecting part while the light reflecting member is attached to the cabinet, and

the side end portions of the adjacent pair of the peripheral reflecting parts defining an abutment interface while the light reflecting member is attached to the cabinet, the abutment interface extending from the corner portion of the center reflecting part in a direction that intersects with a diagonal of the center reflecting part that extends through the corner portion of the center reflecting part as viewed in the direction perpendicular to the center reflecting part.