Light source device and liquid crystal display device using such light source device

• US 8,451,398 B2
• Filed: 02/13/2007
• Issued: 05/28/2013
• Est. Priority Date: 02/16/2006
• Status: Expired due to Fees

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Mizuuchi, Kiminori, Yamamoto, Kazuhisa
• Primary Examiner(s): Briggs, Nathanael R
• Application Number:
  US12/279,611
• Publication Number:
  US 20100231491A1
• Time in Patent Office: 2,296 Days
• Field of Search: 362/611, 362/561, 349/61
• US Class Current: 349/61
• CPC Class Codes: G02B 6/0056 for producing polarisation effects, e.g. by a surface with polarizing properties or by an additional polarizing elements
• CPC Class Codes: G02F 1/13362 providing polarized light, e.g. by converting a polarisation component into another one
• CPC Class Codes: G02F 1/133621 providing coloured light G02F1/133617, G02F1/133533 take precedence
• CPC Class Codes: G02F 1/133622 Colour sequential illumination

Abstract

A light source device with high use efficiency is provided. By using a laser light source of a single polarization, uniformization of light quantity and uniformization of polarization are simultaneously realized, in a two-dimensional planar illumination utilizing reflection and collimating. Thus, it is possible to realize the two-dimensional planar illumination with polarization aligned, and therefore the use efficiency of light can be significantly improved, when combined with switching utilizing the polarization of a liquid crystal panel, etc.

Claims

1. A light source device, comprising:

a laser light source of a single polarization;

a waveguide plate;

a reflection part provided on an end portion of the waveguide plate; and

a lens part provided in the waveguide plate,

wherein laser beams from the laser light source are propagated through the waveguide plate, and thereafter collimated with the reflection part, and polarization directions of the collimated laser beams are parallel to each other, and

wherein the waveguide plate has a two-layer structure, and the laser beams emitted from the laser light source are guided through a first layer of the waveguide plate as a diffused light, and thereafter are converted to a collimated light with the reflection part, and are propagated through a second layer of the waveguide plate.

2. A light source device, comprising:

a laser light source of a single polarization;

a waveguide plate;

a reflection part provided on an end portion of the waveguide plate; and

a lens part provided in the waveguide plate,

wherein laser beams from the laser light source are propagated through the waveguide plate, and thereafter collimated with the reflection part, and polarization directions of the collimated laser beams are parallel to each other,

wherein the device comprises a red laser light source, a blue laser light source, and a green laser light source,

wherein the green laser light source is composed of a light source of a wavelength conversion laser, the waveguide plate has a two-layer structure including a first layer and a second layer, and a green laser beam of the green laser light source is incident on a first layer of the waveguide plate, and thereafter guided through the first layer of the waveguide plate, converted to a collimated light with the reflection part, and guided through the second layer of the waveguide plate,

wherein a red laser beam of the red laser light source and a blue laser beam of the blue laser light source are incident from an end face of the second layer of the waveguide plate, and

the red laser beam of the red laser light source, the blue laser beam of the blue laser light source, and a green laser beam of the green laser light source are emitted from a surface of the second layer of the waveguide plate.