Illuminating optical device

• US 4,918,583 A
• Filed: 04/19/1989
• Issued: 04/17/1990
• Est. Priority Date: 04/25/1988
• Status: Expired due to Term

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Matsumoto, Koichi, Kudo, Yuji
• Primary Examiner(s): Lazarus, Ira S.
• Assistant Examiner(s): Hagarman, Sue
• Application Number:
  US07/340,444
• Time in Patent Office: 363 Days
• Field of Search: 362/32, 362/268, 362/259, 350/6.6, 350/167, 350/574, 350/576
• US Class Current: 366/268
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0047 for use with a light source G02B19/009, G02B19/0095 take precedence; details of lighting devices in general F21V; non-semiconductor lasers having optical devices external to the laser cavity H01S3/005
• CPC Class Codes: G02B 27/0955 Lenses lenses per se G02B3/00
• CPC Class Codes: G02B 27/0994 Fibers, light pipes optical fibers per se G02B6/02
• CPC Class Codes: G02B 3/005 arranged along a single direction only, e.g. lenticular sheets G02B3/0043 takes precedence
• CPC Class Codes: G03F 7/70058 Mask illumination systems

Abstract

An illuminating optical device having an optical integrator capable of receiving a light flux from a light source and substantially forming a plane light source comprising a plurality of light source images and uniformly illuminating an object includes a square-pillar-like internal reflection type integrator having a plurality of reflecting surfaces capable of reflecting the light flux from the light source and forming a plurality of virtual images of the light source on a plane near the entrance surface thereof, a fly-eye type integrator comprising a plurality of lens elements receiving the light flux from the light source and capable of forming a plurality of light source images on a plane, the lens elements being juxtaposed in proximity to one another, and relay lens means provided between the two integrators so that the exit surface of one of the two integrators which is adjacent to the light source and the entrance surface of the other integrator which is adjacent to the object are substantially conjugate with each other.

Claims

1. An illuminating optical device having an optical integrator capable of receiving a light flux from a light source and substantially forming a plane light source comprising a plurality of light source images and uniformly illuminating an object, including:

a square-pillar-like internal reflection type integrator having a plurality of reflecting surfaces capable of reflecting the light flux from said light source and forming a plurality of virtual images of said light source on a plane near the entrance surface thereof;

a fly-eye type integrator comprising a plurality of lens elements receiving the light flux from said light source and capable of forming a plurality of light source images on a plane, said lens elements being juxtaposed in proximity to one another; and

relay lens means provided between said two integrators so that the exit surface of one of said two integrators which is adjacent to the light source and the entrance surface of the other integrator which is adjacent to the object are substantially conjugate with each other.

2. An illuminating optical device according to claim 1, wherein said two integrators are disposed so that further the entrance surface of said one integrator and the exit surface of said other integrator are substantially conjugate with each other with respect to said relay lens means and said lens elements of said fly-eye type integrator.

3. An illuminating optical device according to claim 2, wherein said internal reflection type integrator is disposed on the light source side, and said relay lens means is designed to direct the light flux emerging from the exit surface of said internal reflection type integrator to said plurality of lens elements of said fly-eye type integrator.

4. An illuminating optical device according to claim 3, further including a condenser lens provided between said fly-eye type integrator and said object and wherein the entrance surface of said fly-eye type integrator is formed at a position substantially conjugate with the exit surface of said internal reflection type integrator with respect to said relay lens means and conjugate with said object with respect to said condenser lens and said lens elements of said fly-eye type integrator.

5. An illuminating optical device according to claim 2, wherein said fly-eye type integrator is disposed on the light source side, and said relay lens means is designed to direct the light flux emerging from the exit surface of said fly-eye type integrator to the entrance surface of said internal reflection type integrator.

6. An illuminating optical device according to claim 3, further including a positive lens provided between said internal reflection type integrator and said object for converging the light flux emerging from the exit surface of said internal reflection type integrator, and a condenser lens for enlarging the light flux converted by said positive lens and wherein said internal reflection type integrator is constructed so that the exit surface thereof lies at a position conjugate with said object with respect to said positive lens and said condenser lens.

7. An illuminating optical device for uniformly illuminating an object, including:

an illuminating light source;

a fly-eye type integrator comprising a plurality of lens elements parallel-disposed in proximity to one another and capable of receiving an illuminating light flux from said illuminating light source and forming a plane light source comprising a plurality of light source images;

a square-pillar-like internal reflection type integrator comprising a plurality of reflecting surfaces capable of reflecting the illuminating light flux from said illuminating light source and forming a plane light source comprising a plurality of light source images;

a relay lens provided on the illuminating optical path between said fly-eye type integrator and said internal reflection type integrator so that the focus position by the illuminating light flux passing through said fly-eye type integrator and the entrance surface of said internal reflection type integrator are substantially conjugate with each other; and

projecting optical means for projecting the illuminating light flux from the plane light source comprising the plurality of light source images formed by said fly-eye type integrator and said internal reflection type integrator onto said object.

8. An illuminating optical device according to claim 7, wherein the exit surface of said internal reflection type integrator and the entrance surface of said fly-eye type integrator are formed at positions substantially conjugate with respect to said relay lens.

9. An illuminating optical device according to claim 7, further including condensing means for converging the illuminating light from said illuminating light source and wherein the entrance surface of said internal reflection type integrator is provided near the condensing point of said illuminating light converged by said condensing means, and the entrance surface of said fly-eye type integrator is formed at a position substantially conjugate with the exit surface of said internal reflection type integrator with respect to said relay lens.

10. An illuminating optical device according to claim 9, wherein said projecting optical means includes a field lens provided in proximity to the exit surface of said fly-eye type integrator and a condenser lens for projecting the illuminating light passed through said field lens onto said object, and the entrance surface of said fly-eye type integrator is disposed at a position conjugate with said object with respect to said projecting optical means.

11. An illuminating optical device according to claim 7, further including collimator optical means for converting the illuminating light from said illuminating light source into a parallel light flux and wherein said fly-eye type integrator is provided on the optical path of said parallel light flux from said collimator optical means, and said entrance surface of said internal reflection type integrator is formed at a position substantially conjugate with the exit surface of said fly-eye type integrator with respect to said relay lens.

12. An illuminating optical device according to claim 11, wherein said projecting optical means includes a positive lens for converging the illuminating light emerging from the exit surface of said internal reflection type integrator and a condenser lens for projecting said illuminating light converged by said positive lens onto said object, and the exit surface of said internal reflection type integrator is disposed at a position conjugate with said object with respect to said projecting optical means.

13. An illuminating optical device according to claim 11, wherein said lens elements constituting said fly-eye type integrator are formed so as to have an inter-surface spacing shorter than the focal length of said lens elements.

14. An illuminating optical device for uniformly illuminating an object, including:

illuminating light source means emitting a collimated light flux;

a fly-eye type integrator comprising a plurality of lens elements parallel-disposed in proximity to one another and capable of receiving said light flux and forming a plane light source comprising a plurality of light source images in a space outside said lens elements;

a relay lens provided on the optical path of the illuminating light passed through said fly-eye type integrator;

an internal reflection type integrator formed into a square-pillar-like shape with a plurality of reflecting surfaces and capable of causing said plurality of light source images formed by said fly-eye type integrator to be reflected by said plurality of reflecting surfaces and further forming them into a plane light source comprising a number of light source images; and

projecting optical means for projecting the illuminating light flux from the plane light source comprising said number of light source images formed by said fly-eye type integrator and said internal reflection type integrator onto said object.

15. An illuminating optical device according to claim 14, wherein said lens elements constituting said fly-eye type integrator are plano-convex lenses having their convex surfaces facing the incident light side, the inter-surface spacing of said plano-convex lenses is shorter than the rearward focal length of said plano-convex lenses and the rearward focus position of said plano-convex lens is disposed at a position conjugate with the entrance surface of said internal reflection type integrator with respect to said relay lens.

16. An illuminating optical device according to claim 14, wherein said lens elements constituting said fly-eye type integrator are plano-concave lenses having their concave surfaces facing the emergent light side, said plurality of light source images are formed as virtual images at the forward focus position of said plano-concave lenses and the forward focus position of said plano-concave lenses is disposed at a position conjugate with the entrance surface of said internal reflection type integrator with respect to said relay lens.

17. An illuminating optical device according to claim 14, wherein said projecting optical means includes a positive lens for converging the illuminating light emerging from the exit surface of said internal reflection type integrator and a condenser lens for enlarging said illuminating light converged by said positive lens and projecting said converged illuminating light onto said object, and the exit surface of said internal reflection type integrator is disposed at a position conjugate with said object with respect to said projecting optical means.