Back light device with diffusing sheet for a liquid crystal display apparatus
AssigneeDai Nippon Printing Co., Ltd.
InventorKeiji Kashima
Life of this patent
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Abstract
A back light device 10 comprises a light source 12, a lightconductor 14 for outputting light from the light source from its outputting surface 14B, a light diffusing sheet 16 for receiving diffused light from the lightconductor 14 and shifting the maximum intensity direction to the direction of the normal standing on the light outputting face 16B, a polarized beam splitting sheet 18 through which one polarized light component among the light from the light diffusing sheet 16 is transmitted and on which the other polarized light component is reflected.
Claims10
A back light device comprising:
- a light source;
- a lightconductor in a substantial plate form comprising a front face, a back face and side end faces,
- light radiated from the light source and made incident on the one of the side end faces being outputted as diffused light from the front face as a light outputting surface;
- at least one light diffusing sheet for receiving, on its face, the diffused light outputted from the light outputting surface of the lightconductor, and outputting, from the light outputting surface opposite to the face, shifting the maximum intensity direction of the diffused light toward the direction of the normal standing on the light outputting surface, and outputting the diffused light;
- a polarized beam splitting sheet which can receive the light from the light outputting surface of the light diffusing sheet, through which one polarized light component of the light is transmitted, and on which the other polarized light component is reflected;
- and
- a light reflecting sheet which is arranged on the back face of the lightconductor and is for reflecting the light into the lightconductor.
A liquid crystal display apparatus comprising a back light device, a liquid crystal panel arranged at the light outputting surface side of the polarized beam splitting sheet of the back light device, and the back light device comprising a light source a lightconductor in a substantial plate form comprising a front face, a back face and side end faces, light radiated from the light source and made incident on the one of the end side faces being outputted as diffused light from the front face as a light outputting surface, at least one light diffusing sheet for receiving, on its face, the diffused light outputted from the light outputting surface of the lightconductor, and outputting, from the light outputting surface opposite to the face, shifting the maximum intensity direction of the diffused light toward the direction of the normal standing on the light outputting surface, and outputting the diffused light a polarized beam splitting sheet which can receive the light from the light outputting surface of the light diffusing sheet, through which one polarized light component of the light is transmitted, and on which the other polarized light component is reflected, and a light reflecting sheet which is arranged on the back face of the lightconductor and is for reflecting the light into the lightconductor.
Dependencies are inferred from the claim text.