OPTICAL MULTIPLEXING APPARATUS AND PROJECTOR

• US 20120236212A1
• Filed: 10/12/2011
• Published: 09/20/2012
• Est. Priority Date: 10/19/2010
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Inventors: Itoh, Tatsuo, Mizushima, Tetsuro
• Granted Patent: US 9,188,709 B2
• Time in Patent Office: Days
• US Class Current: 348/744
• CPC Class Codes: G02B 27/123 The splitting element being a lens or a system of lenses, including arrays and surfaces with refractive power
• CPC Class Codes: G02B 3/005 arranged along a single direction only, e.g. lenticular sheets G02B3/0043 takes precedence
• CPC Class Codes: G02B 3/0056 arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085
• CPC Class Codes: G02B 3/0068 arranged in a single integral body or plate, e.g. laminates or hybrid structures with other optical elements G02B5/1885, G02B17/002, G02B30/27 take precedence
• CPC Class Codes: G03B 21/2013 Plural light sources
• CPC Class Codes: G03B 21/208 Homogenising, shaping of the illumination light

Abstract

An object of the present invention is to provide an optical multiplexing apparatus and a projector that keep an optical system small, and easily adjust a number of light source units. The optical multiplexing apparatus has: a light source section that uses light source units to emit collimated beams; a first lens portion that converges the collimated beams which enter at different incident angles from each other to define converging positions; and a second lens portion that has focal points that correspond to the converging positions, respectively, wherein the first and second lens portions form an optical reduction system, and an optical axis of the second lens portion, which is directed to the corresponding focal point to one of the converging positions, extends along anther optical axis of the second lens position, which is directed to the corresponding focal point to another of the converging positions.

Claims

1. An optical multiplexing apparatus, comprising:

a light source section which uses light source units to emit collimated beams;

a first lens portion which focuses the incident collimated beams at different incident angles from each other to define convergent positions; and

a second lens portion which has focal points that correspond to the convergent positions, respectively, wherein

the first and second lens portions form an optical reduction system, and

an optical axis of the second lens portion, which is directed to the corresponding focal point to one of the convergent positions, extends along another optical axis of the second lens portion, which is directed to the corresponding focal point to another of the convergent positions.

2. The optical multiplexing apparatus according to claim 1, wherein

the light source units include a first light source unit which emits the collimated beam so that the collimated beam travels along an optical axis of the first lens portion.

3. The optical multiplexing apparatus according to claim 1, wherein

the light source units include light source units which are symmetrically arranged with respect to an optical axis of the first lens portion.

4. The optical multiplexing apparatus according to claim 1, wherein

the first lens portion includes a first cylindrical lens array which splits and focuses the collimated beams so as to create split beams, and

the second lens portion includes a second cylindrical lens array which collimates the split beams to create collimated beams.

5. The optical multiplexing apparatus according to claim 1, wherein

the first lens portion includes a first micro-lens array which splits and focuses the collimated beams so as to create split beams, and

the second lens portion includes a second micro-lens array which collimates the split beams to create collimated beams.

6. The optical multiplexing apparatus according to claim 1, wherein

a reduction ratio of the optical reduction system is no more than an inverse number of a quantity of the light source units included in the light source section.

7. The optical multiplexing apparatus according to claim 1, wherein

the second lens portion is a concave lens.

8. The optical multiplexing apparatus according to claim 1, wherein

the second lens portion is formed on a substrate on which the first lens portion is formed,

the substrate includes a first surface, on which the first lens portion is formed, and a second surface opposite to the first surface, and

the second lens portion is formed on the second surface.

9. The optical multiplexing apparatus according to claim 1, wherein

the optical axis of the second lens portion is shifted from an optical axis of the first lens portion by f sin θ

.

10. The optical multiplexing apparatus according to claim 2, wherein

the light source units include a second light source unit which emits the collimated beam that travels in an inclined direction from the optical axis of the first lens portion.

11. A projector, comprising:

a signal processor which processes a video signal for displaying an image to generate a control signal;

the optical multiplexing apparatus according to claim 1;

a spatial light modulator which modulates light from the optical multiplexing apparatus in response to the control signal to create image light; and

an optical system configured to form the image by means of the image light.