Backlight for liquid crystal display device having a reflector being coated with a gradation color layer composed by yellow graduating to blue

1. A backlight module, comprising:

a light source;

a waveguide including an light inlet surface facing the light source, and an light emitting surface being adjacent to the light inlet surface, and a bottom surface opposite to the light emitting surface;

a reflector disposed under the bottom surface of the waveguide;

an optical film disposed above the light emitting surface of the waveguide;

wherein the reflector is coated with a gradation color layer composed by yellow graduating to blue, wherein the percentage of the blue pigment proportionally increases as it is distant to the light source; and

wherein the bottom surface of the waveguide includes a printing pattern comprising a plurality of dots spaced from each other and each formed of a mixture of ink and pigments that comprise at least one of a blue pigment and a yellow pigment so that the percentage of the pigments within the dots of the printing pattern changes proportionally with respect to the distance with respect to the light source;

wherein the percentage of the blue pigment within the dots of the printing pattern increases proportionally when the distance to the light source increases; and alternatively, the percentage of the yellow pigment within the dots of the printing pattern decreases proportionally when the distance to the light source decreases.

2. A liquid crystal display device, comprising:

a liquid crystal display panel;

a backlight module, including:

a light source;

a waveguide including an light inlet surface facing the light source, and an light emitting surface being adjacent to the light inlet surface, and a bottom surface opposite to the light emitting surface;

a reflector disposed under the bottom surface of the waveguide;

an optical film disposed above the light emitting surface of the waveguide; and

wherein the reflector is coated with a gradation color layer composed by yellow graduating to blue;

wherein the gradation color layer includes a blue pigment, and the percentage of the blue pigment proportionally increases as it is distant to the light source;

wherein the bottom surface of the waveguide includes spaced dot-like patterns each formed of a mixture composed of ink and color pigments that comprise at least one of blue pigment and a yellow pigment, and a percentage of the pigments within the dot-like patterns changes proportionally with respect to the distance with respect to the light source; and

wherein the percentage of the blue pigment proportionally increases as it is distant to the light source; and alternatively, the percentage of the yellow pigment proportionally decreases as it is distant to the light source.

3. The liquid crystal display device as recited in claim 2 , wherein the bottom surface of the waveguide includes ink printing patterns and color compensation patterns, wherein when the pigment is the blue fluorescent pigments, the he percentage of the blue pigment within the printing pattern increases proportionally when the distance to the light source increases; when the pigment is the yellow fluorescent pigments the percentage of the blue pigment within the printing pattern decreases proportionally when the distance to the light source decreases.

4. The liquid crystal display device as recited in claim 3 , wherein dots of the printing pattern remain unchanged.

5. The backlight module as recited in claim 3 , wherein the printing patterns and the color compensation patterns are single layer configuration, the printing patterns and the color compensation patterns are alternatively arranged across the bottom surface of the waveguide.

6. The backlight module as recited in claim 3 , wherein the printing patterns and the color compensation patterns are stacked into two layers, and the color compensation patterns is arranged on a first layer of the bottom surface of the waveguide, and the ink printing patterns is located on a second layer of the bottom surface of the waveguide.

7. The backlight module as recited in claim 3 , wherein the printing patterns and the color compensation patterns are stacked into two layers, the ink printing patterns is located on a first layer of the bottom surface of the waveguide, and the color compensation patterns is arranged on a second layer of the bottom surface of the waveguide.