Projector and image projection method

1. A projector, comprising:

a plurality of image-forming elements that are each provided with an image-forming surface including a plurality of micromirrors;

a plurality of reflecting elements that are provided so as to reflect respective plurality of image beams that are formed by said plurality of image-forming elements;

a beam-combining element into which said plurality of image beams are irradiated by said plurality of reflecting elements and that emits a combined image beam in which said plurality of image beams are combined such that directions of propagation of said plurality of image beams coincide; and

a projection unit that projects said combined image beam that is emitted by said beam-combining element,

wherein, of said plurality of image forming elements, at least two image-forming elements are arranged such that said image-forming surface of each image-forming element is located in a same plane,

wherein said plurality of image-forming elements include first to third digital micromirror devices, and

wherein said beam-combining element includes:

an emission surface;

a first incident surface into which an image beam of a first color is irradiated from said first digital micromirror device;

a second incident surface into which an image beam of a second color is irradiated from said second digital micromirror device;

a third incident surface into which an image beam of a third color is irradiated from said third digital micromirror device;

a first dichroic film that is configured to transmit an image beam of said first color that is irradiated from said first incident surface and emit the image beam from said emission surface, reflect an image beam of said second color that is irradiated from said second incident surface and emit the image beam from said emission surface, and transmit an image beam of said third color that is irradiated from said third incident surface; and

a second dichroic film that is configured to transmit an image beam of said first color that is irradiated from said first incident surface and emit the image beam from said emission surface, reflect an image beam of said third color that is irradiated from said third incident surface and emit the image beam from said emission surface, and transmit an image beam of said second color that is irradiated from said second incident surface.

2. The projector as set forth in claim 1 , wherein said plurality of image-forming elements are arranged such that the image-forming surface of each image-forming element is parallel to a predetermined plane.

3. The projector as set forth in claim 2 , wherein said beam-combining element comprises a cross-dichroic prism, and

wherein said predetermined plane comprises at least one of an upper surface and a base surface of said cross-dichroic prism.

4. The projector as set forth in claim 1 , wherein said beam-combining element includes a plurality of incident surfaces into which said plurality of image beams are irradiated, respectively and an emission surface for emitting said combined image beam, and

wherein said plurality of image-forming elements are arranged such that the image-forming surface of each image-forming element is perpendicular to said plurality of incident surfaces.

5. The projector as set forth in claim 1 , wherein the image beam of said first color comprises a green image beam, the image beam of said second color comprises a red image beam, and the image beam of said third color comprises a blue image beam.

6. The projector as set forth in claim 1 , wherein the long sides of said second image-forming surface are parallel to the long sides of said third image-forming surface, and the long sides of said first image-forming surface are perpendicular to the long sides of said second or third image-forming surface.

7. The projector as set forth in claim 1 , wherein said plurality of reflecting elements include total reflection prisms.

8. The projector as set forth in claim 7 , wherein said total reflection prisms are provided with first to third surfaces and a total reflection surface and are configured such that light that is irradiated from said first surface is transmitted through said total reflection surface and emitted from said second surface in the direction of said image-forming surface of a corresponding image-forming element, an image beam from the image-forming surface is irradiated from said second surface, and the irradiated image beam is reflected by said total reflection surface and emitted from said third surface in the direction of said beam-combining element.

9. The projector as set forth in claim 1 , wherein said image-forming surfaces of said plurality of image forming elements are positioned on the same plane and oriented in a same direction.

10. The projector as set forth in claim 1 , wherein all of said image-forming surfaces of said plurality of image forming elements are located in the same plane.

11. The projector as set forth in claim 1 , wherein said first digital micromirror device includes a first image-forming surface that is perpendicular to said first incident surface, long sides of the first image-forming surface being parallel to said first incident surface.

12. The projector as set forth in claim 11 , wherein said second digital micromirror device includes a second image-forming surface that is perpendicular to said second incident surface, long sides of the second image-forming surface being parallel to said second incident surface.

13. The projector as set forth in claim 12 , wherein said third digital micromirror device includes a third image-forming surface that is perpendicular to said third incident surface.

14. A projector comprising:

a plurality of image-forming elements that are each provided with an image-forming surface including a plurality of micromirrors;

a plurality of reflecting elements that are provided so as to reflect a plurality of image beams that are formed by said plurality of image-forming elements;

a cross-dichroic prism into which said plurality of image beams are irradiated by said plurality of reflecting elements and that emits a combined image beam in which said plurality of image beams are combined such that directions of propagation of said plurality of image beams coincide; and

a projection element that projects said combined image beam that is emitted from said cross-dichroic prism,

wherein, of said plurality of image-forming elements, at least two image-forming elements are arranged such that said image-forming surface of each image-forming element is positioned parallel to a plane that is perpendicular to a dichroic film of said cross-dichroic prism,

wherein said plurality of image-forming elements include first to third digital micromirror devices, and

wherein said cross-dichroic prism includes:

an emission surface;

a first incident surface into which an image beam of a first color is irradiated from said first digital micromirror device;

a second incident surface into which an image beam of a second color is irradiated from said second digital micromirror device;

a third incident surface into which an image beam of a third color is irradiated from said third digital micromirror device;

a first dichroic film that is configured to transmit an image beam of said first color that is irradiated from said first incident surface and emit the image beam from said emission surface, reflect an image beam of said second color that is irradiated from said second incident surface and emit the image beam from said emission surface, and transmit an image beam of said third color that is irradiated from said third incident surface; and

a second dichroic film that is configured to transmit an image beam of said first color that is irradiated from said first incident surface and emit the image beam from said emission surface, reflect an image beam of said third color that is irradiated from said third incident surface and emit the image beam from said emission surface, and transmit an image beam of said second color that is irradiated from said second incident surface.

15. The projector as set forth in claim 14 , wherein all of said image-forming surfaces of said plurality of image forming elements are located in a same plane.

16. The projector as set forth in claim 14 , wherein said first digital micromirror device includes a first image-forming surface that is perpendicular to said first incident surface, long sides of the first image-forming surface being parallel to said first incident surface.

17. The projector as set forth in claim 16 , wherein said second digital micromirror device includes a second image-forming surface that is perpendicular to said second incident surface, long sides of the second image-forming surface being parallel to said second incident surface.

18. The projector as set forth in claim 17 , wherein said third digital micromirror device includes a third image-forming surface that is perpendicular to said third incident surface, long sides of the third image-forming surface being parallel to said third incident surface.

19. An image projection method that uses a plurality of image-forming elements that are each equipped with an image-forming surface including a plurality of micromirrors to project, by a projection unit, an image beam that is formed on said image-forming surfaces, said image projection method comprising:

arranging, of said plurality of image-forming elements, at least two image-forming elements such that the image-forming surface of each image-forming element is positioned on a same plane;

by a plurality of reflecting elements, reflecting each of a plurality of image beams that are formed by said plurality of image-forming elements;

irradiating said plurality of image beams into a beam-combining element by said plurality of reflecting elements;

by said beam-combining element, combining said plurality of image beams such that directions of propagation of each image beam coincide; and

by said projection unit, projecting the combined image beam,

wherein said plurality of image-forming elements include first to third digital micromirror devices, and

wherein said beam-combining element includes:

an emission surface;

a first incident surface into which an image beam of a first color is irradiated from said first digital micromirror device;

a second incident surface into which an image beam of a second color is irradiated from said second digital micromirror device;

a third incident surface into which an image beam of a third color is irradiated from said third digital micromirror device;

a first dichroic film that is configured to transmit an image beam of said first color that is irradiated from said first incident surface and emit the image beam from said emission surface, reflect an image beam of said second color that is irradiated from said second incident surface and emit the image beam from said emission surface, and transmit an image beam of said third color that is irradiated from said third incident surface; and

a second dichroic film that is configured to transmit an image beam of said first color that is irradiated from said first incident surface and emit the image beam from said emission surface, reflect an image beam of said third color that is irradiated from said third incident surface and emit the image beam from said emission surface, and transmit an image beam of said second color that is irradiated from said second incident surface.