Backlight module and liquid crystal display device using same

Patent metadata

Field	Value
Publication number	US-9341894-B2
Application number	US-201414467862-A
Country	US
Kind code	B2
Filing date	Aug 25, 2014
Priority date	Aug 27, 2013
Publication date	May 17, 2016
Grant date	May 17, 2016

Abstract

A backlight module includes a number of laser units, a number of diffraction units, and a number of diverging units. Each laser unit includes three colored lasers arranged in a first straight line. The three lasers respectively emit red, green, and blue light. Each of the diffraction units includes three diffraction elements. The three diffraction elements are configured to diffract the light along the first straight line. Each of the diverging units is substantially an elongated semi-cylinder, and the longitudinal direction is along the first straight line. The diverging units diffract the three colors of light along a direction which is perpendicular to the direction of the first straight line.

First claim

What is claimed is:

1. A backlight module, comprising:
a laser unit, comprising:
a first laser light source emitting a red laser light;
a second laser light source emitting a green laser light;
a third laser light source emitting a blue laser light;
wherein the first laser light source, the second laser light source, and the third laser light source are arranged along a straight line in a first direction;

a diffraction unit corresponding to the laser unit, which is positioned at the output light path of the laser unit, the diffraction unit comprising
a first diffraction element that is corresponding to the first laser light source and is configured to diffract said red laser light from a point laser light source to a linear laser light source with a linear optical distribution;
a second diffraction element that is corresponding to the second laser light source and is configured to diffract said green laser light from a point laser light source to a linear laser light source with a linear optical distribution;
a third diffraction element that is corresponding to the third laser light source and is configured to diffract said blue laser light from a point laser light source to a linear laser light source with a linear optical distribution; and

a diverging unit, that is corresponding to the diffraction unit and is substantially an elongated semi-cylinder to match the liner optical field distribution, the longitudinal direction of the diverging unit is along the first direction and the diverging unit is configured to diverge the diffracted laser light along a second direction which is perpendicular to the first direction.

2. The backlight module according to claim 1 , wherein said backlight module further comprises:
a reflection unit, which is corresponding to the diffraction unit and positioned at a side of the diffraction unit far from the laser unit, and the reflection unit is configured to reflect the light emitted from said diffraction unit to said corresponding diverging unit.

3. The backlight module according to claim 1 , wherein said backlight module further comprises:
a bottom reflection sheet including a bottom surface and a reflection surface, wherein said bottom surface and said reflection surface are position at different sides of the reflection sheet, and wherein the bottom reflection sheet includes a plurality of elongated openings which are corresponding to a plurality of diverging units which are carried on said reflection surface to cover the elongate openings, and said bottom surface is positioned at the same side of said laser unit and said diffraction unit.

4. The backlight module according to claim 1 , wherein said backlight module further comprises:
a diffusion plate corresponding to the diverging unit, which is configured to uniformly diffuse the light emitted from the diverging unit.

5. A liquid crystal display device, comprising:
a backlight module, comprising:
a laser unit, comprising:
a first laser light source emitting a red laser light;
a second laser light source emitting a green laser light;
a third laser light source emitting a blue laser light;
wherein the first laser light source, the second laser light source, and the third laser light source are arranged along a straight line in a first direction;

a diffraction unit, that is corresponding to the laser unit and is positioned at an output light path of the laser unit, the diffraction unit comprising:
a first diffraction element that is corresponding to the first laser light source and is configured to diffract said red laser light from a point laser light source to a linear laser light source with a linear optical distribution;
a second diffraction element that is corresponding to the second laser light source and is configured to diffract the green laser light from a point laser light source to a linear laser light source with a linear optical distribution;
a third diffraction element that is corresponding to the third laser light source and is configured to diffract the blue laser light from a point laser light source to a linear laser light source with a linear optical field distribution; and

a diverging unit, that is corresponding to the diffraction unit and is substantially a elongated semi-cylinder to match the liner optical field distribution, the longitudinal direction of the diverging unit is along the first direction and the diverging unit is configured to diverge said diffracted laser light along a second direction which is perpendicular to the first direction; and

a liquid crystal display panel arranged to receive light emitted from said diverging unit, and a control system electronically coupled to said first laser, said second laser and said third laser for sequentially turning on and turning off said first laser, said second laser, and said third laser in an alternating or cyclical control order.

6. The liquid crystal display device according to claim 5 , wherein said backlight module further comprises:
a reflection unit, which is corresponding to the diffraction unit and positioned at a side of the diffraction unit far from the laser unit, the reflection unit is configured to reflect the light emitted from the diffraction unit to corresponding said diverging unit.

7. The liquid crystal display device according to claim 5 , wherein said backlight module further comprises:
a bottom reflection sheet including a bottom surface and a reflection surface, wherein said bottom surface and said reflection surface are position at different sides of the reflection sheet,
and wherein the bottom reflection sheet includes a plurality of elongated openings which are corresponding to a plurality of diverging units which are carried on said reflection surface to cover the elongate openings, and said bottom surface is positioned at the same side of said laser unit and said diffraction unit.

8. The liquid crystal display device according to claim 5 , wherein said backlight module further comprises:
a diffusion plate, that is corresponding to the diverging unit and is configured to uniformly diffuse the light emitted from the diverging unit.

9. The liquid crystal display device according to claim 5 , wherein said liquid crystal panel further comprises:
a plurality of pixel areas, each pixel area is corresponding to the diverging unit and includes a plurality of pixels, wherein each pixel defines a transmission rate of the light passing through the pixel.

10. The liquid crystal display device according to claim 5 , wherein said liquid crystal panel comprises:
an array substrate;
a counter substrate facing said array substrate; and
a liquid crystal layer sandwiched between said array substrate and said counter substrate.

11. A liquid crystal display device, comprising:
a liquid crystal display panel extending along a first direction and a second direction perpendicular to the first direction;
a backlight module arranged to backlight the liquid crystal display panel, the backlight module including a diverging unit elongated along the first direction and configured to receive a linear optical field distribution along the first direction and diverge the linear optical field distribution along the second direction to illuminate a region of the liquid crystal display panel with light diverged from the linear optical field distribution; a first laser light source emitting a red laser light, a second laser light source emitting a green laser light, a third laser light source emitting a blue laser light, a first diffraction element configured to diffract the red laser light from the first laser light source to a first linear laser light source with a linear optical field distributio

Assignees

• Hon Hai Prec Ind Co Ltd

Inventors

• Chen Po-Chou

Classifications

• G02F1/133606

  including a specially adapted diffusing, scattering or light controlling members · CPC title

• G02F1/133621 Primary

  providing coloured light (G02F1/133617, G02F1/133533 take precedence) · CPC title

• G02B6/0068

  Arrangements of plural sources, e.g. multi-colour light sources · CPC title

• G02F2001/133622

  Physics · mapped topic

• G02F1/133622

  Colour sequential illumination · CPC title