Projector

• US 8,113,664 B2
• Filed: 11/18/2008
• Issued: 02/14/2012
• Est. Priority Date: 03/11/2008
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Nagarekawa, Satoru, Morikuni, Eiji, Minefuji, Nobutaka, Okoshi, Masayuki
• Primary Examiner(s): Dowling, William C
• Assistant Examiner(s): Howard, Ryan
• Application Number:
  US12/273,196
• Publication Number:
  US 20090231555A1
• Time in Patent Office: 1,183 Days
• Field of Search: 353/98, 353/99, 353/102, 353/37, 353/81, 353/78, 359/850, 359/857, 348/756
• US Class Current: 353/78
• CPC Class Codes: G03B 21/28 Reflectors in projection beam in illumination beam G03B21/2066

Abstract

In a projection optical system comprising: two lens groups, and a curved plane mirror, wherein the projection optical system including two story structure, and having bend means for bending at least two times the light incident from an electro-optic modulator.

Claims

1. A projector comprising:

an illumination system that emits an illumination light flux;

an electro-optic modulator that modulates the light from the illumination system in accordance with image information; and

a projection system that projects the light modulated by the electro-optic modulator, wherein the projection system includes

a first lens group including a plurality of lenses, the lens optical axis of the plurality of lenses shifted from the central axis of an image formation area of the electro-optic modulator in a first direction,

a second lens group including a plurality of lenses, the second lens group disposed on the light-exiting side of the first lens group,

a curved mirror disposed on the light-exiting side of the second lens group, and

a reflective light guiding system disposed along the optical path between the first lens group and the curved mirror, the reflective light guiding system reflecting the light from the first lens group in a predetermined direction containing a second direction that is opposite the first direction as a vector component and guiding the light to the curved mirror, and

wherein the reflective light guiding system includes;

a first reflection element disposed between the first lens group and the second lens group, the first reflection element reflecting the light from the first lens group in the second direction,

a second reflection element disposed between the first reflection element and the second lens group in such a way that a normal to the reflection plane of the second reflection element is perpendicular to a normal to the reflection plane of the first reflection element, and

a third reflection element disposed between the second reflection element and the second lens group, the third reflection element reflecting the light from the second reflection element toward the second lens group, each of the reflection elements having a flat reflection plane.

2. The projector according to claim 1,

wherein the optical axis of the first lens group does not intersect the optical axis of the curved mirror.

3. The projector according to claim 2,

wherein two of the optical axis of the first lens group, the optical axis of the second lens group, and the optical axis of the curved mirror are present in the same plane, and

the one remaining optical axis is not present in the plane.

4. The projector according to claim 1,

wherein the reflective light guiding system is configured as a unit structure in which at least two of the first, second and third reflection elements are integrated.

5. The projector according to claim 1,

wherein each of the first lens group and the second lens group is configured as a unit structure in which the plurality of lenses are integrated.

6. The projector according to claim 1,

wherein each of the reflection elements in the reflective light guiding system is a reflection mirror or a reflection prism.

7. The projector according to claim 1,

wherein the curved mirror is a concave mirror.