Projector

• US 20050134812A1
• Filed: 12/03/2004
• Published: 06/23/2005
• Est. Priority Date: 12/03/2003
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Akiyama, Koichi
• Granted Patent: US 7,185,991 B2
• Time in Patent Office: Days
• US Class Current: 353/102
• CPC Class Codes: G03B 21/14 Details
• CPC Class Codes: G03B 21/208 Homogenising, shaping of the illumination light

Abstract

A projector capable of obtaining a smooth motion picture display of high quality without significantly reducing the utilization efficiency of light includes a light source device, a first lens array, a second lens array, a superimposing lens, a liquid crystal display device, and a projective optical system. The superimposing lens includes an anamorphic optical system to shape illumination luminous fluxes from the second lens array into illumination luminous fluxes having a cross-sectional shape that illuminates all the image formation regions of the liquid crystal display device in one direction along an X-axis direction, and a part of the image formation regions in the other direction along a Y-axis direction. The projector further includes a scanning device to scan the illumination luminous fluxes shaped by the superimposing lens in synchronism with a field frequency of the liquid crystal display device along the other direction on the image formation region.

Claims

1. A projector, comprising:

a light source device to emit an illumination luminous flux substantially parallel to an illuminated region side;

a first lens array having a plurality of small lenses to separate the illumination luminous flux from the light source device into a plurality of partial luminous fluxes;

a second lens array having a plurality of small lenses corresponding to the plurality of small lenses of the first lens array;

a superimposing lens to superimpose respective partial luminous fluxes from the second lens array on an illuminated region;

an electro-optical modulator to modulate the luminous fluxes superimposed by the superimposing lens according to image information; and

a projective optical system to project the luminous fluxes modulated by the electro-optical modulator,

the superimposing lens including an anamorphic optical system to shape the illumination luminous fluxes from the second lens array into illumination luminous fluxes having a cross-sectional shape so as to illuminate all of image formation regions of the electro-optical modulator in one of longitudinal and transverse directions, and a part of the image formation regions in another direction thereof, and

the projector further including a scanning device to scan the illumination luminous fluxes shaped by the superimposing lens in synchronism with a field frequency of the electro-optical modulator along the other direction on the image formation region.

2. The projector according to claim 1,

the superimposing lens including a first cylindrical lens having a bus line along the other direction and a second cylindrical lens having a bus line along the one direction,

the first cylindrical lens including a first tandem optical system group including a plurality of tandem optical systems together with the plurality of small lenses of the second lens array,

the second cylindrical lens including a second tandem optical system group including a plurality of tandem optical systems together with the plurality of small lenses of the second lens array, and

the first tandem optical system group and the second tandem optical system group having different magnifications from each other.

3. The projector according to claim 2, the magnification of an image formation region of the first tandem optical system group being set greater than that of an image formation region of the second tandem optical system group.

4. The projector according to claim 2, the second cylindrical lens being provided to be rotated on an illumination optical axis as a pivot axis.

5. The projector according to claim 2, each of the first and second cylindrical lenses being a tablet.

6. The projector according to claim 1, the scanning device including a galvano-mirror or a polygon mirror.

7. The projector according to claim 1, the light source device including an ellipsoid reflector, an arc tube having a light emitting center in the vicinity of a first focus of the ellipsoid reflector, and a collimating lens for converting a luminous flux from the ellipsoid reflector into a substantially parallel luminous flux.

8. The projector according to claim 1, the light source device including a paraboloid reflector and an arc tube having a light emitting center in the vicinity of a focus of the paraboloid reflector.

9. The projector according to claim 7, the arc tube being provided with a reflecting device to reflect a light emitted to an illuminated region side from the arc tube toward the ellipsoid reflector or the paraboloid reflector.

10. The projector according to claim 1, a polarization converting element being provided between the second lens array and the superimposing lens, to convert the illumination luminous fluxes from the second lens array into illumination luminous fluxes, each having a polarization axis of a predetermined direction.