Backlight Module and LCD Device

• US 20130128190A1
• Filed: 12/05/2011
• Published: 05/23/2013
• Est. Priority Date: 11/23/2011
• Status: Active Grant

• Current Assignee: Shenzhen China Star Optoelectronics Technology Co., Ltd. (TCL Technology Group Corp.)
• Original Assignee: Shenzhen China Star Optoelectronics Technology Co., Ltd. (TCL Technology Group Corp.)
• Inventors: Huang, Jian-Fa
• Granted Patent: US 9,007,547 B2
• Time in Patent Office: Days
• US Class Current: 349/65
• CPC Class Codes: G02B 6/0011 the light guides being planar or of plate-like form
• CPC Class Codes: G02B 6/0031 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0085 Means for removing heat created by the light source from the package heat extraction or cooling elements for semiconductor light sources in general H01L33/64
• CPC Class Codes: G02B 6/0091 of the light source relative to the light guide G02B6/0021 takes precedence
• CPC Class Codes: G09F 13/18 Edge-illuminated signs

Abstract

A backlight module is disclosed, which comprises a light guide plate, a point light source and a substrate. The light guide plate comprises a top surface and a bottom surface opposite to each other and a side surface located between the top surface and the bottom surface. The point light source is disposed on the substrate. The backlight module further comprises a backplate, a front frame and a first reflective unit. The backplate is adapted to accommodate the light guide plate. The front frame is disposed adjacent to the top surface of the light guide plate. The point light source is disposed adjacent to the side surface. A bisector line of a light emitting range of the point light source is directed towards a plane in which the top surface or the bottom surface of the light guide plate is located. The first reflective unit is adapted to reflect light emitted from the point light source into the light guide plate. A liquid crystal display (LCD) device comprising the backlight module is further provided in the present disclosure. The backlight module and the LCD device of the present disclosure feature a narrow frame and can dissipate heat easily.

Claims

1. A backlight module, comprising a light guide plate, a point light source and a substrate, the light guide plate comprising a top surface and a bottom surface opposite to each other and a side surface located between the top surface and the bottom surface, and the point light source being disposed on the substrate, wherein the backlight module further comprises a backplate, a front frame and a first reflective unit, the substrate makes direct contact with the backplate, the backplate is adapted to accommodate the light guide plate, the front frame is disposed adjacent to the top surface of the light guide plate, the point light source is disposed adjacent to the side surface, a bisector line of a light emitting range of the point light source is directed towards a plane in which the top surface of the light guide plate is located, the bisector line is parallel to or includes an acute angle with a plane in which the side surface of the light guide plate is located, the first reflective unit is adapted to reflect light emitted from the point light source into the light guide plate, a reflective surface of the first reflective unit is a parabolic surface, and the point light source is disposed at a focus of the parabolic surface.

2. The backlight module of claim 1, wherein a top portion of the first reflective unit is located between the bottom surface of the light guide plate and a bisector plane of the light guide plate, and the bisector plane of the light guide plate is parallel to the top surface of the light guide plate and located at a half thickness of the light guide plate.

3. The backlight module of claim 1, further comprising a second reflective unit disposed around side edges of the point light source below the light emitting range.

4. A backlight module, comprising a light guide plate, a point light source and a substrate, the light guide plate comprising a top surface and a bottom surface opposite to each other and a side surface located between the top surface and the bottom surface, and the point light source being disposed on the substrate, wherein the backlight module further comprises a backplate, a front frame and a first reflective unit, the backplate is adapted to accommodate the light guide plate, the front frame is disposed adjacent to the top surface of the light guide plate, the point light source is disposed adjacent to the side surface, a bisector line of a light emitting range of the point light source is directed towards a plane in which the top surface or the bottom surface of the light guide plate is located, and the first reflective unit is adapted to reflect light emitted from the point light source into the light guide plate.

5. The backlight module of claim 4, wherein the bisector line of the light emitting range of the point light source is parallel to or includes an acute angle with a plane in which the side surface of the light guide plate is located.

6. The backlight module of claim 4, wherein the substrate makes direct contact with the backplate when the bisector line of the light emitting range of the point light source is directed towards the plane in which the top surface of the light guide plate is located.

7. The backlight module of claim 4, wherein a top portion of the first reflective unit is located between the bottom surface of the light guide plate and a bisector plane of the light guide plate when the bisector line of the light emitting range of the point light source is directed towards the plane in which the top surface of the light guide plate is located, and the bisector plane of the light guide plate is parallel to the top surface of the light guide plate and located at a half thickness of the light guide plate.

8. The backlight module of claim 4, wherein the backlight module comprises a second reflective unit when the bisector line of the light emitting range of the point light source is directed towards the plane in which the top surface of the light guide plate is located, and the second reflective unit is disposed around side edges of the point light source below the light emitting range.

9. The backlight module of claim 4, wherein a reflective surface of the first reflective unit is a parabolic surface, and the point light source is disposed at a focus of the parabolic surface.

10. The backlight module of claim 4, wherein the substrate makes direct contact with the front frame when the bisector line of the light emitting range of the point light source is directed towards the plane in which the bottom surface of the light guide plate is located.

11. The backlight module of claim 4, wherein the substrate comprises a printed circuit board (PCB) and an aluminum extruded piece in contact with each other, and the point light source and the aluminum extruded piece are located at two opposite sides of the PCB respectively.

12. The backlight module of claim 4, wherein when the bisector line of the light emitting range of the point light source is directed towards the plane in which the top surface of the light guide plate is located and includes an acute angle with the plane in which the bottom surface of the light guide plate is located, a sum of an inclination angle of the point light source with respect to the bottom surface of the light guide plate and an inclination angle of the reflective surface of the first reflective unit with respect to the bottom surface of the light guide plate is 90°

.

13. The backlight module of claim 12, wherein the point light source is disposed corresponding to a lower end of the side surface of the light guide plate.

14. The backlight module of claim 13, wherein the bisector line of the light emitting range of the point light source includes an angle of 45°

with the side surface of the light guide plate.

15. A liquid crystal display (LCD) device, comprising a backlight module, the backlight module comprising a light guide plate, a point light source and a substrate, the light guide plate comprising a top surface and a bottom surface opposite to each other and a side surface located between the top surface and the bottom surface, and the point light source being disposed on the substrate, wherein the backlight module further comprises a backplate, a front frame and a first reflective unit, the backplate is adapted to accommodate the light guide plate, the front frame is disposed adjacent to the top surface of the light guide plate, the point light source is disposed adjacent to the side surface, a bisector line of a light emitting range of the point light source is directed towards a plane in which the top surface or the bottom surface of the light guide plate is located, and the first reflective unit is adapted to reflect light emitted from the point light source into the light guide plate.