Claims
- 1. A reduction projection optical system comprising:
- a first lens unit having a positive refraction power for converting a light beam from a first plane on which an object is mounted into a substantially collimated light beam;
- a polarization beam splitter for transmitting the light beam from said first lens unit, said polarization beam splitter including a polarization split plane which transmits a p-polarized light beam and reflects an s-polarized light beam;
- a second lens unit arranged in the light path of said light beam from said first lens unit transmitted through said polarization beam splitter, said second lens unit having a negative refraction power for diverging the transmitted light beam;
- a concave reflection mirror for converging the light beam diverged by said second lens unit and directing it back to said polarization beam splitter;
- a quarter wavelength plate arranged between said .[.polarizing.]. .Iadd.polarization .Iaddend.beam splitter and said concave reflection mirror, for converting the p-polarized light beam from said polarization beam splitter into an s-polarized light beam that is directed back to said polarization beam splitter after reflection on the concave reflection mirror; and
- a third lens unit having a positive refraction power for converging the light beam reflected by said concave reflection mirror and directed back to the polarization beam .[.splitting.]. .Iadd.splitter .Iaddend.to form a reduced image of the first plane onto a second plane;
- wherein said polarization split plane of said polarization beam splitter is disposed in such a manner that an angle of incidence and an angle of reflection of an on-axis light beam reflected by said polarization beam splitter with respect to said polarization split plane of the beam splitter are larger than 45 degrees.
- 2. A reduction projection optical system according to claim 1 wherein said polarization beam splitter includes a beam splitter cube having a plurality of prisms and a polarization split plane formed between the prisms, and an angle between peripheral light from an on-axis object point directed from said beam splitter cube to said third lens unit and an optical axis of the optical system does not exceed 7 degrees in the prism.
- 3. A reduction projection optical system according to claim 1 wherein said polarization beam splitter includes a beam splitter cube having a plurality of prisms and a polarization split plane formed between the prisms, and an angle between peripheral light from an off-axis object point directed from said beam splitter cube to said third lens unit and an optical axis of the optical system does not exceed 5 degrees.
- 4. A reduction projection optical system according to claim 1 wherein a power Pr of said concave reflection mirror and a negative refraction power Pn of said second lens unit meet a requirement of
- 1.5.vertline.Pn.vertline.<Pr<4.0.vertline.Pn.vertline..
- 5. A reduction projection optical system according to claim 1 wherein a radius of curvature of said concave reflection mirror is between 15 times and 25 times a diameter of an effective area of the image of the object formed on said second plane.
- 6. A reduction projection optical system according to claim 1 wherein said quarter wavelength plate is made of rock crystal and has a thickness no larger than 200 .mu.m.
- 7. A reduction projection optical system according to claim 1 wherein said quarter wavelength plate is arranged between said polarization beam splitter and said second lens unit.
- 8. A reduction projection optical system according to claim 1, wherein said polarization beam splitter includes a beam splitter cube that has two prisms forming said polarization split plane .[.therebewteen.]. .Iadd.therebetween .Iaddend.and an auxiliary prism having an exit surface from which the s-polarized light beam directed back to said polarization beam splitter is emitted, said exit surface being normal to an optical axis of the emitted light beam to maintain symmetry of the light path.
- 9. A reduction projection optical system according to claim 8, wherein said angle between the optical axis of the light path directed from said first plane to said concave reflection mirror and the normal line to said polarization split plane is no larger than 55 degrees.
- 10. A reduction projection optical system comprising:
- a first lens unit having a positive refraction power for converting a light beam from a first plane on which an object is mounted into a substantially collimated light beam;
- a polarization beam splitter for splitting the light beam from said first lens unit in accordance with a polarization state;
- a second lens unit having a negative refraction power arranged in the light path of a light beam split by said polarization beam splitter for diverging the split light beam;
- a concave reflection mirror for converging the light beam from said second lens unit and directing it back to said polarization beam splitter through said second lens unit,
- said concave reflection mirror meeting a requirement of:
- 1.5.vertline.Pn.vertline.<Pr<4.0.vertline.Pn.vertline.
- where Pr is a power of said concave reflection mirror and Pn is a negative refraction power of said second lens unit, and
- a third lens unit having a positive refraction power for converging the light beam converged by said concave reflection mirror and directed back to said polarization beam splitter to form a reduced image of the object on said first plane onto a second plane.
- 11. A reduction projection optical system according to claim 10, wherein said polarization beam splitter transmits the light beam directed from said first plane to said concave reflection mirror, and reflects the light beam converged by said concave reflection mirror and directed back to said polarization beam splitter.
- 12. A reduction projection optical system according to claim 10, wherein said polarization beam splitter has a polarization split plane, and an angle between an optical axis of a light path directed from said first plane to said concave reflection mirror and a normal line to said polarization split plane is no smaller than 45 degrees.
- 13. A reduction projection optical system comprising:
- a first lens unit having a positive refraction power for converting a light beam from a first plane on which an object is mounted into a substantially collimated light beam;
- a polarization beam splitter for splitting the light beam from said first lens unit into a reflected light beam and a transmitted light beam in accordance with a polarization state, said polarization beam splitter having a polarization split plane which transmits a p-polarized light beam and reflects an s-polarized light beam and which is of multi-layer film structure having a substantially linear phase change characteristic to .[.the.]. .Iadd.an .Iaddend.incident angle;
- a second lens unit arranged in the light path of a light beam split by said polarization beam splitter and having a negative refraction power for diverging the split light beam;
- a concave reflection mirror for converging the light beam diverged by said second lens unit and directing it back to said polarization beam splitter;
- a quarter wavelength plate arranged between said .[.polarizing.]. .Iadd.polarization .Iaddend.beam splitter and said concave reflection mirror, for converting the p-polarized light beam from said polarization beam splitter into an s-polarized light beam that is directed back to said polarization beam splitter after reflection on the concave reflection mirror, and a third lens unit having a positive refraction power for converging the light beam reflected by said concave reflection mirror and directed back to the polarization beam splitter to form a reduced image of the first plane onto a second plane;
- wherein said polarization split plane of said polarization beam splitter has such a phase change characteristic to the incident angle that a phase change Tp of a p-polarized light beam transmitted through said polarization split plane is represented by a gently sloping straight line and a phase change Rs of a reflected s-polarized light beam is represented by a substantially horizontal straight line.
- 14. A reduction projection optical system according to claim 13, wherein said polarization split plane of said polarization beam splitter is disposed in such a manner that an angle between an optical axis of a light path directed from said first plane to said concave reflection mirror and a normal line to said polarization split plane is no smaller than 45 degrees.
- 15. A reduction projection optical system according to claim 14, wherein a radius of curvature of said concave reflection mirror is between 19 times and 25 times a diameter of an effective area of the image of the object formed on said second plane.
- 16. A reduction projection optical system according to claim 14, wherein said angle between the optical axis of the light path directed from said first plane to said concave reflection mirror and the normal line to said polarization split plane is no larger than 55 degrees.
- 17. A reduction projection optical system according to claim 16, wherein a power Pr of said concave reflection mirror and a negative refraction power Pn of said second lens unit satisfy a condition of
- 1.5.vertline.Pn.vertline.<Pr<4.0.vertline.Pn.vertline..
- 18. A reduction projection optical system comprising:
- a first lens unit having a positive refraction power for converting a light beam from a first plane on which an object is mounted into a substantially collimated light beam;
- a polarization beam splitter for splitting the light beam from said first lens unit, said polarization beam splitter including a polarization split plane which transmits a p-polarized light beam and reflects an s-polarized light beam;
- a second lens unit arranged in the light path of a light beam from said .[.fist.]. .Iadd.first .Iaddend.lens unit transmitted through said polarization beam splitter, said second lens unit having a negative refraction power for diverging the transmitted light beam;
- a concave reflection mirror for converging the light beam diverged by said second lens unit and directing it back to said polarization beam splitter;
- a quarter wavelength plate arranged between said .[.polarizing.]. .Iadd.polarization .Iaddend.beam splitter and said concave reflection mirror, for converting the p-polarized light beam from said polarization beam splitter into an s-polarized light beam that is directed back to said polarization beam splitter after reflection on the concave reflection mirror; and
- a third lens unit having a positive refraction power for converging the light beam converged by said concave reflection mirror and directed back to the polarization beam splitter to form a reduced image of the first plane onto a second plane;
- wherein said polarization split plane of said polarization beam splitter is disposed in such a manner that an angle between an optical axis of a light path directed from said concave reflection mirror to said polarization split plane and a normal line of said polarization split plane at a concave reflection mirror side of said split .[.lane.]. .Iadd.plane .Iaddend.is larger than 45 degrees.
- 19. A reduction projection optical system according to claim 18, wherein said polarization beam splitter has a beam splitter cube which includes two prisms forming said polarization split plane .[.therebewteen.]. .Iadd.therebetween .Iaddend.and an exit surface from which the s-polarized light beam reflected on said polarization split plane is emitted, said exit surface of said beam splitter cube being normal to an optical axis of .[.said.]. .Iadd.the .Iaddend.reflected light path in said polarization beam .[.slitter.]. .Iadd.splitter .Iaddend.to maintain the symmetry of the light path.
- 20. A reduction projection optical system according to claim 19, wherein a power Pr of said concave reflection mirror and a negative refraction power Pn of said second lens unit satisfy a condition of:
- 1.5.vertline.Pn.vertline.<Pr<4.0.vertline.Pn.vertline..
- 21. A reduction projection optical system comprising:
- a first .[.lend.]. .Iadd.lens .Iaddend.unit having a positive refraction power for converging a light beam from a first plane into a substantially collimated light beam;
- a beam splitter for splitting a light beam path from said first lens unit into a reflected light beam path and a transmitted light beam path;
- a second lens unit having a negative refraction power arranged in one of .[.said.]. .Iadd.the .Iaddend.two light beam paths split by said beam splitter for diverging a light beam emitted from said beam splitter;
- a concave reflection mirror for converging the diverged light beam from said second lens unit and directing it back to said beam splitter, and a third lens unit having a positive refraction power for converging the light beam converged by said concave reflection mirror and directed back to the beam splitter to form a reduced image of the first plane onto a second plane,
- wherein a power Pr of said concave reflection mirror and a negative refraction power Pn of said second lens unit satisfy a condition of
- .[.1.5.vertline.Pn.vertline.<4.0.vertline.Pn.vertline..]. .Iadd.1.5 .vertline.Pn.vertline.<Pr<4.0 .vertline.Pn.vertline...Iaddend.
- 22. A reduction projection optical system according to claim 21, wherein a radius of said concave reflection mirror is between 15 times and 25 times the diameter of the image circle of said reduced image on said second plane.
- 23. A reduction projection optical system according to claim 22, wherein a radius of said concave reflection mirror is no smaller than 19 times the diameter of the image circle of said reduced image on said second plane.
- 24. A reduction projection optical system according to claim 21, wherein said beam splitter comprises a polarization beam splitter for splitting the light beam path from said first lens unit into said reflected light beam path and said transmitted light beam path in accordance with a polarization state of the light beam from said first lens unit.
- 25. A reduction projection optical system according to claim 24, further comprising a quarter wavelength plate disposed between said .[.polarizing.]. .Iadd.polarization .Iaddend.beam splitter and said concave reflection mirror, for converting a polarized light beam from said polarization beam splitter into a different polarized light beam directed back to said polarization beam splitter after reflection on the concave reflection mirror.
- 26. A reduction projection optical system comprising:
- a first lens unit having a positive refraction power for converting a light beam from a first plane into a substantially collimated light beam;
- a beam splitter for splitting a light beam path from said first lens unit into a reflected light beam path and a transmitted light beam path;
- a second lens unit having a negative refraction power arranged in one of .[.said.]. .Iadd.the .Iaddend.two light beam paths split by said beam splitter for diverging a light beam emitted from said beam splitter,
- a concave reflection mirror for converging the diverged light beam from said second lens unit and directing it back to said beam splitter, and
- a third lens unit having a positive refraction power for converging the light beam converged by said concave reflection mirror and directed back to the beam splitter to form a reduced image of the first plane onto a second plane;
- wherein a radius of said concave reflection mirror is between 15 times and 25 times the diameter of the image circle of said reduced image on said second plane.
- 27. A reduction projection optical system according to claim 26, wherein a radius of said concave reflection mirror is no smaller than 19 times the diameter of the image circle of said reduced image on said second plane.
- 28. A reduction projection optical system comprising:
- a first lens unit having a positive refraction power for converting a light beam from a first plane into a substantially collimated light beam;
- a polarization beam splitter for splitting a light beam path from said first lens unit into a reflected light beam path and a transmitted light beam path in accordance with a polarization state of .[.alight.]. .Iadd.a light .Iaddend.beam from said first lens unit;
- a second lens unit having a negative refraction power arranged in one of .[.said.]. .Iadd.the .Iaddend.two light beam paths split by said polarization beam splitter for diverging a light beam emitted from said polarization beam splitter;
- a concave reflection mirror for converging the diverged light beam from said second lens unit and directing it back to said beam splitter, and
- a third lens unit having a positive refraction power for converging the light beam converged by said concave reflection mirror and directed back to the polarization beam splitter to form a reduced image of the first plane onto a second plane; and
- a quarter wavelength plate arranged between said .[.polarizing.]. .Iadd.polarization .Iaddend.beam splitter and said concave reflection mirror, for converting the p-polarized light beam from said polarization beam splitter into an s-polarized light beam directed back to said polarization beam splitter after reflection on the concave reflection mirror, wherein said quarter wavelength plate is made of rock crystal and has a thickness of no greater than 200 .mu.m.
- 29. A reduction projection optical system according to claim 28, wherein said quarter wavelength plate is positioned between said polarization beam splitter and said second lens unit.
- 30. A reduction projection optical system for projecting a reduced image of an object on a first plane onto a second plane comprising:
- a first lens unit having a positive refraction power for converting a light beam from a first plane into a substantially collimated light beam;
- a polarization beam splitter for splitting a light beam path from said first lens unit into a reflected light beam path and a transmitted light beam path in accordance with a polarization state of .[.alight.]. .Iadd.a light .Iaddend.beam from said first lens unit;
- a second lens unit having a negative refraction power arranged in one of .[.said.]. .Iadd.the .Iaddend.two light beam paths split by said polarization beam splitter for diverging a light beam emitted from said polarization beam splitter;
- a concave reflection mirror for converging the diverged light beam from said second lens unit and directing it back to said beam splitter; and
- a third lens unit having a positive refraction power for converging the light beam converged by said concave reflection mirror and directed back to the polarization beam splitter to form a reduced image of the first plane onto a second plane; and
- a quarter wavelength plate arranged between said .[.polarizing.]. .Iadd.polarization .Iaddend.beam splitter and said concave reflection mirror, for converting the p-polarized light beam from said polarization beam splitter into an s-polarized light beam directed back to said polarization beam splitter after reflection on the concave reflection mirror;
- wherein an angle between peripheral light from an on-axis object point directed from said beam splitter to said third lens unit and an optical axis of the optical system does not exceed 7 degrees.
- 31. A reduction projection optical system according to claim 30, wherein said polarization beam splitter includes a beam splitter cube having a plurality of prisms and a polarization split plane formed between the prisms, and an angle between peripheral light from an on-axis object point directed from said beam splitter cube to said third lens unit and an optical axis of the optical system does not exceed 7 degrees in said prisms. .Iadd.
- 32. A catadioptric optical reduction system comprising:
- a first optical unit including refractive elements made from at least two different materials;
- a polarization beam splitter;
- a quarter wavelength plate;
- a second optical unit including a concave reflection mirror; and
- a third optical unit including refractive elements made from at least two different materials;
- arranged such that light rays entering the system pass through said first optical unit, said polarization beam splitter and said quarter wavelength plate, are reflected by said concave reflection mirror in said second optical unit back to said quarter wavelength plate, reach said polarization beam splitter, and then pass through said third optical unit..Iaddend..Iadd.
- 33. A catadioptric optical reduction system for projecting an image of a first plane onto a second plane, comprising:
- a first optical unit including refractive elements made from at least two different materials;
- a polarization beam splitter;
- a quarter wavelength plate;
- a second optical unit including a concave reflection mirror and a refractive element; and
- a third optical unit including refractive elements made from at least two different materials;
- arranged such that light rays from said first plane entering the system pass through said first optical unit, through said polarization beam splitter, through said quarter wavelength plate, and through the refractive element in said second optical unit, are reflected by the concave reflection mirror in said second optical unit back to said quarter wavelength plate, reach said polarization beam splitter, and pass through said third optical unit to said second plane..Iaddend.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2-83468 |
Mar 1990 |
JPX |
|
Parent Case Info
This is a continuation of application Ser. No. 727,307 filed Jul. 10, 1991, which is a continuation of application Ser. No. 509,741 filed Apr. 17, 1990, both now abandoned.
US Referenced Citations (19)
Continuations (2)
|
Number |
Date |
Country |
Parent |
727307 |
Jul 1991 |
|
Parent |
509741 |
Apr 1990 |
|
Reissues (1)
|
Number |
Date |
Country |
Parent |
950765 |
Sep 1992 |
|