Optical apparatus and image projection apparatus having multiple reflective light modulators and multiple dichroic surface that separate light into multiple color lights and combines them

Patent metadata

Field	Value
Publication number	US-10015455-B2
Application number	US-201514941958-A
Country	US
Kind code	B2
Filing date	Nov 16, 2015
Priority date	Nov 26, 2014
Publication date	Jul 3, 2018
Grant date	Jul 3, 2018

Abstract

The optical apparatus includes multiple reflective light modulators, an illumination optical system and multiple dichroic surfaces separating a light flux from the illumination optical system into multiple color lights to introduce them to the light modulators and combining the multiple color lights reflected by the light modulators. The optical system includes a condenser lens disposed between an area in which light source images are formed and the multiple reflective light modulators. The light modulators are arranged such that their long sides are parallel to a first section, and a condition of f/D 1 >f/D 2 is satisfied where f represents a focal length of the condenser lens, D 1 and D 2 represent maximum effective widths of the areas in which the light source images are formed in the first section and in a second section parallel to an optical axis and orthogonal to the first section.

First claim

What is claimed is:

1. An optical apparatus comprising:
multiple reflective light modulators each having a light modulation surface that is rectangular;
an illumination optical system configured to illuminate the multiple reflective light modulators with a light flux from a light source;
a first optical element having a first dichroic surface and a second dichroic surface configured to separate the light flux from the illumination optical system into multiple color lights, introduce the multiple color lights to the multiple reflective light modulators, and combine the multiple color lights reflected by the multiple reflective light modulators; and
a second optical element configured to guide the multiple color lights combined by the first dichroic surface and the second dichroic surface to a projection optical system,
wherein the illumination optical system includes:
at least one third optical element configured to uniformly illuminate the light modulation surface with light from the light source; and
a condenser lens disposed between an area where a light source image is formed, other than at an incident surface of the at least one third optical element and the multiple reflective light modulators,

wherein a long side direction of the light modulation surface is parallel to a first plane and a short side direction of the light modulation surface is parallel to a second plane,
wherein the first plane is parallel to a normal of the first dichroic surface and a normal of the second dichroic surface,
wherein the second plane is orthogonal to the first plane and parallel to an optical axis of the illumination optical system, and
wherein the following condition is satisfied:
f/D 1> f/D 2,
where f represents a focal length of the condenser lens, D 1 represents a maximum effective width of the area where the light source images are formed in the first plane, and D 2 represents a maximum effective width of the area where the light source images are formed in the second plane.

2. The optical apparatus according to claim 1 , wherein the maximum effective width of the area where the light source image is formed in the first and second planes is a full width at half maximum.

3. The optical apparatus according to claim 1 , wherein the illumination optical system is telecentric on a side of the multiple reflective light modulators.

4. The optical apparatus according to claim 1 , wherein the first and second dichroic surfaces are arranged to mutually intersect with each other.

5. The optical apparatus according to claim 1 , wherein the first and second dichroic surfaces are arranged to not mutually intersect with each other.

6. The optical apparatus according to claim 1 , wherein:
the at least one third optical element comprises a first fly-eye lens including multiple lens cells and a second fly-eye lens including multiple lens cells corresponding to the multiple lens cells of the first fly-eye lens, and
each of the first and second fly-eye lenses is an eccentric fly-eye lens whose each eccentric lens cell is eccentric in a direction to be closer to or farther from the optical axis with respect to a center of that eccentric lens cell.

7. The optical apparatus according to claim 1 , wherein the at least one third optical element comprises a rod integrator having a shape where a size of a plane orthogonal to the optical axis varies from an entrance surface to an exit surface.

8. The optical apparatus according to claim 1 , wherein the multiple reflective light modulators are reflective liquid crystal panels.

9. The optical apparatus according to claim 1 , wherein the multiple reflective light modulators are mirror light modulators including multiple mirrors whose orientations are variable.

10. The optical apparatus according to claim 1 , wherein the at least one third optical element comprises multiple fly-eye lenses or a rod integrator.

11. The optical apparatus according to claim 1 , wherein the second optical element comprises a polarization beam splitter or an internal total reflective prism.

12. An image projection apparatus comprising:
a light source; and
an optical apparatus configured to project light from the light source, through a projection optical system, to display a projected image,
wherein the optical apparatus comprises:
multiple reflective light modulators each having a light modulating surface that is rectangular;
an illumination optical system configured to illuminate the multiple reflective light modulators with a light flux from the light source;
a first optical element having a first dichroic surface and a second dichroic surface configured to separate the light flux from the illumination optical system into multiple color lights, introduce the multiple color lights to the multiple reflective light modulators, and combine the multiple color lights reflected by the multiple reflective light modulators; and
a second optical element configured to guide the multiple color lights combined by the first dichroic surface and the second dichroic surface to the projection optical system,
wherein the illumination optical system includes:
at least one third optical element configured to uniformly illuminate the light modulation surface with light from the light source; and
a condenser lens disposed between an area where a light source image is formed, other than at an incident surface of the at least one third optical element and the multiple reflective light modulators,

wherein a long side direction of the light modulation surface is parallel to a first plane and a short side direction of the light modulation surface is parallel to a second plane,
wherein the first plane is parallel to a normal of the first dichroic surface and a normal of the second dichroic surface,
wherein the second plane is orthogonal to the first plane and parallel to an optical axis of the illumination optical system, and
wherein the following condition is satisfied:
f/D 1> f/D 2,
where f represents a focal length of the condenser lens, D 1 represents a maximum effective width of the area where the light source images are formed in the first plane, and D 2 represents a maximum effective width of the area where the light source images are formed in the second plane.

Assignees

• Canon Kk

Inventors

• Kawasumi Takehito

Classifications

• H04N9/3105

  for displaying all colours simultaneously, e.g. by using two or more electronic spatial light modulators (simultaneous projection in colour photography G03B33/10; beam splitting or combining systems per se G02B27/10) · CPC title

• G03B33/04

  by four or more separation records · CPC title

• H04N9/3158 Primary

  for controlling the spectrum · CPC title

• G02B27/149

  using crossed beamsplitting surfaces, e.g. cross-dichroic cubes or X-cubes · CPC title

• G03B21/2066

  Reflectors in illumination beam (in projection beam G03B21/28) · CPC title