Illumination system for a projection system

• US 6,877,882 B1
• Filed: 03/12/2003
• Issued: 04/12/2005
• Est. Priority Date: 03/12/2003
• Status: Expired due to Fees

• Current Assignee: Delta Electronics Incorporated
• Original Assignee: Delta Electronics Incorporated
• Inventors: Vatne, Rolf S., Haven, Thomas J.
• Primary Examiner(s): Husar, Stephen
• Assistant Examiner(s): Zeade, Bertrand
• Application Number:
  US10/387,787
• Time in Patent Office: 762 Days
• Field of Search: 362/308, 362/310, 362/268, 362/309, 362/331, 362/521, 362/298, 362/299, 353/31, 353/33, 353/34, 353/22, 359/599, 359/615, 359/813, 359/463
• US Class Current: 362/308
• CPC Class Codes: G03B 21/2026 Gas discharge type light sources, e.g. arcs
• CPC Class Codes: H04N 9/315 Modulator illumination systems general applications of lighting devices F21V; general optical systems G02B; lamp houses for projectors not peculiar to the presence of an electronic spatial light modulator G03B21/20

Abstract

An illumination system for illuminating an object includes a light source and a lens array system. The light source includes an illumination element emitting light rays and surrounded by a parabolic reflector. The lens array system includes a first lens array plate and a second lens array plate. The first lens array plate includes a matrix of lenslets where, in one embodiment, each lenslet has a shape matching the aspect ratio of the object to be illuminated. The second lens array plate includes a radial pattern of wedge shaped lenslets each corresponding to a lenslet in the first lens array plate. Each wedge shaped lenslet in the second lens array plate has dimensions that are selected to provide a radial and theta collection angles matching the maximum divergence angle of the light source and the maximum divergence angles of the corresponding lenslet in the first lens array plate.

Claims

1. An illumination system for illuminating an object, comprising:

a light source including an illumination element emitting light rays and surrounded by a parabolic reflector for directing the light rays;

a lens array system for collecting and focusing incident light rays from the light source, the lens array system comprising;

a first lens array plate comprising a plurality of lenslets arranged in a matrix configuration; and

a second lens array plate comprising a plurality of wedge shaped lenslets arranged in a radial pattern, each wedge shaped lenslet corresponding to a lenslet in the first lens array plate, the second lens array plate superimposing images of the first lens array plate on the object to be illuminated,

wherein each wedge shaped lenslet in the second lens array plate has dimensions that are selected to provide a radial and theta collection angles matching the maximum divergence angle of the light source and the maximum divergence angles of the corresponding lenslet in the first lens array plate.

2. The illumination system of claim 1, wherein the lens array system directs light to a light integrating device for illuminating the object, the light integrating device comprising a light collection aperture having a first collection cone angle;

and wherein the second lens array plate has dimensions selected to fit substantially all the transmitted light within the first collection cone angle of the light collection aperture.

3. The illumination system of claim 1 wherein each wedge shaped lenslet in the second lens array plate has a first dimension and a second dimension, the first dimension providing a collection angle in the radial direction matching the vertical maximum divergence angle of the corresponding lenslet in the first lens array plate and the second dimension providing a collection angle in the theta direction matching the horizontal maximum divergence angle of the corresponding lenslet in the first lens array plate.

4. The illumination system of claim 3, wherein each lenslet in the first lens array plate projects an image of the illumination element onto a corresponding lenslet in the second lens array plate, each wedge shaped lenslet in the second lens array plate disposed to collect substantially all of the light corresponding to the image of the illumination element.

5. The illumination system of claim 1 wherein the maximum divergence angle that can be collected by a lenslet in the first or the second lens array plate is given by:

(W/2)(1/fl)57.3 where W is a dimension of the lenslet and fl is the focal length of the lenslet.

6. The illumination system of claim 1 wherein, each of the lenslets in the first lens array plate has a shape matching the aspect ratio of the object to be illuminated.

7. The illumination system of claim 1, wherein the illumination element comprises an UHP lamp.

8. A projector system, comprising:

a light source including a first illumination element and a second illumination element each emitting light rays and each surrounded by a parabolic reflector for directing the light rays onto an optical axis;

a first and second lens array systems each for collecting and focusing incident light, the first lens array system coordinated with the first illumination element and the second lens array system coordinated with the second illumination system, each of the first and second lens array systems comprising;

a first lens array plate comprising a plurality of lenslets arranged in a matrix configuration; and

a second lens array plate comprising a plurality of wedge shaped lenslets arranged in a radial pattern, each wedge shaped lenslet corresponding to a lenslet in the first lens array plate, the second lens array plate superimposing images of the first lens array plate;

wherein each wedge shaped lenslet in the second lens array plate has dimensions that are selected to provide a radial collection angle and a theta collection angle matching the maximum divergence angle of the light source and the maximum divergence angles of the corresponding lenslet in the first lens array plate;

a light integrating device including an input aperture for receiving superimposed light from the second lens array plate of each of the first lens array system and the second lens array system;

a color separating device disposed to receive light from the light integrating device and generate light in three primary color components; and

a first, second and third DMD panels each receiving light in a respective one of the primary color components and modulating the incident light to generate image light in a respective one of the primary color components.

9. The projection system of claim 8, wherein the light integrating device has a first collection cone angle and wherein the second lens array plate in each of the first and second lens array systems has dimensions selected to fit substantially all the transmitted light within the first collection cone angle of the light integrating device.

10. The projection system of claim 8 wherein each wedge shaped lenslet in the second lens array plate has a first dimension and a second dimension, the first dimension providing a collection angle in the radial direction matching the vertical maximum divergence angle of the corresponding lenslet in the first lens array plate and the second dimension providing a collection angle in the theta direction matching the horizontal maximum divergence angle of the corresponding lenslet in the first lens array plate.

11. The projection system of claim 8 wherein the maximum divergence angle that can be collected by a lenslet in the first and second lens array plates is given by:

(W/2)(1/fl)57.3 where W is a dimension of the lenslet and fl is the focal length of the lenslet.

12. The projection system of claim 8 wherein each of the lenslets in the first lens array plate has a shape matching the aspect ratio of the first, second and third DMD panels.

13. The projection system of claim 8, further comprising:

a projection lens assembly for receiving and projecting superimposed image light from each of the first, second and third DMD panels.

14. The projection system of claim 8, wherein each of the first and second illumination elements comprises an UHP lamp.

15. The projection system of claim 8, further comprising a condenser lens disposed between the first and second lens array systems and the light integrating device, the condenser lens directing light from the first and second lens array systems to the input aperture of the light integrating device.

16. A projector system, comprising:

a light source including an illumination element emitting light rays and surrounded by a parabolic reflector for directing the light rays onto an optical axis;

a lens array system for collecting and focusing incident light, the lens array system comprising;

a first lens array plate comprising a plurality of lenslets arranged in a matrix configuration; and

a second lens array plate comprising a plurality of wedge shaped lenslets arranged in a radial pattern, each wedge shaped lenslet corresponding to a lenslet in the first lens array plate, the second lens array plate superimposing images of the first lens array plate;

wherein each wedge shaped lenslet in the second lens array plate has dimensions that are selected to provide a radial collection angle and a theta collection angle matching the maximum divergence angle of the light source and the maximum divergence angles of the corresponding lenslet in the first lens array plate;

a light integrating device including an input aperture for receiving superimposed light from the second lens array plate of the lens array system; and

a DMD panel receiving light from the light integrating device and modulating the light to generate image light.

17. The projection system of claim 16, further comprising:

a color separating device disposed to receive light from the light integrating device and sequentially generate light in three primary color components;

wherein the DMD panel receives light from the color separating device in the three primary color components and modulates the light to generate image light in the three primary color components.

18. The projection system of claim 16, wherein the light integrating device has a first collection cone angle and wherein the second lens array plate in each of the first and second lens array systems has dimensions selected to fit substantially all the transmitted light within the first collection cone angle of the light integrating device.

19. The projection system of claim 16, wherein each of the lenslets in the first lens array has a shape matching the aspect ratio of the DMD panel.

20. The projection system of claim 16 wherein the maximum divergence angle that can be collected by a lenslet in the first and second lens array plates is given by:

(W/2)(1/fl)57.3 where W is a dimension of the lenslet and fl is the focal length of the lenslet.

21. The projection system of claim 16, further comprising:

a projection lens assembly for receiving and projecting image light from the DMD panel.

22. The projection system of claim 16, further comprising a condenser lens disposed between the lens array system and the light integrating device, the condenser lens directing light from the first and second lens array systems to the input aperture of the light integrating device.