LIGHT SOURCE DEVICE AND LIQUID CRYSTAL DISPLAY DEVICE USING SUCH LIGHT SOURCE DEVICE

• US 20100231491A1
• Filed: 02/13/2007
• Published: 09/16/2010
• Est. Priority Date: 02/16/2006
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Mizuuchi, Kiminori, Yamamoto, Kazuhisa
• Granted Patent: US 8,451,398 B2
• Time in Patent Office: Days
• US Class Current: 345/87
• 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

1-20. -20. (canceled)

21. 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 a polarization of the collimated laser beams is approximately parallel to a surface of the waveguide plate.

22. The light source device according to claim 21, wherein the waveguide plate has a double refraction.

23. The light source device according to claim 21, wherein the reflection part has a concave surface structure, and the reflection part also has a function of a lens part for collimating the laser beams that are propagated through the waveguide plate.

24. The light source device according to claim 21, further comprising a lens part provided in the waveguide plate, which together with the reflection part collimates the laser beams that are propagated through the waveguide plate, and has a Fresnel lens structure.

25. The light source device according to claim 21, further comprising a lens part provided in the waveguide plate, which together with the reflection part collimates the laser beams that are propagated through the waveguide plate, and is a micro-lens.

26. The light source device according to claim 21, comprising a second reflection part.

27. The light source device according to claim 21, wherein the waveguide plate has a two-layer structure, and the laser beams emitted from the laser light source is guided through a waveguide plate of a first layer as a diffused light, and thereafter is converted to a collimated light with the reflection part, and is propagated through a waveguide plate of a second layer.

28. The light source device according to claim 21, further comprising a λ

/4 plate, wherein a polarizing direction of the laser beams emitted from the laser light source is vertical to the surface of the waveguide plate, and the laser beams are converted to polarized lights parallel to the surface of the waveguide plate, by the λ

/4 plate provided in the vicinity of the reflection plate.

29. The light source device according to claim 21, further comprising optical elements for modulating any one of polarization, deflection, and a focal point of the laser beams, wherein at least any one of the polarization, the deflection, and a phase of the laser beams is changed in time series.

30. The light source device according to claim 21, further comprising a rotary prism, wherein a direction of the laser beams is modulated.

31. The light source device according to claim 21, wherein the laser beams of the laser light source include a visible light of at least any one of red, green and blue.

32. The light source device according to claim 31, wherein at least any one of laser light sources of the laser beams having wavelengths corresponding to the red, green, and blue, has a plurality of light emitting points.

33. The light source device according to claim 32, wherein each laser beam emitted from the laser light source of the same color having the plurality of light emitting points has a different wavelength.

34. The light source device according to claim 33, wherein wavelengths of the laser beams emitted from the laser light source of the same color having the plurality of light emitting points are different from one another by at least 1 nm.

35. The light source device according to claim 21, wherein at least a part of the laser beams is totally reflected by at least a part of a side face of the waveguide plate.

36. The light source device according to claim 21, comprising at least:

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, and a beam direction of only green laser beam of the green laser light source is scanned.

37. The light source device according to claim 21, comprising:

at least 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 wavelength conversion laser, and a green laser beam of the green laser light source is propagated through the waveguide plate and thereafter collimated with the reflection part, and other laser beams are made incident on the waveguide plate from a plurality of incident parts.

38. The light source device according to claim 21, comprising:

at least 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, and a green laser beam of the green laser light source is incident on a first layer of the waveguide plate, and after guided through the waveguide plate of a first layer, converted to a collimated light with the reflection part, and guided through the waveguide plate of a second layer;

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 waveguide plate of the second layer; 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 waveguide plate of the second layer.

39. The light source device according to claim 21, wherein the laser light source includes a semiconductor laser of wide stripe, and is arranged so that a surface of the semiconductor laser and a surface of the waveguide plate are approximately vertical to each other.

40. A liquid crystal display device including:

a light source device according to claim 21;

a liquid crystal panel, and

a liquid crystal panel controller connected to the liquid crystal panel so as to receive/transmit an electrical signal from/to the liquid crystal panel, for controlling an operation of the liquid crystal panel in accordance with a signal inputted from outside.