Claims
- 1. A light source apparatus comprising:
- a discharge lamp;
- a spherical mirror; and
- a condenser lens consisting of a bi-aspherical single lens having a first surface of convex form facing the larger conjugate side and a second surface facing the smaller conjugate side and whose outermost circular zone is formed concave, said condenser lens satisfying the following conditions
- 0.42<r1/nf<0.45
- 18<.vertline.r2/nf .vertline.
- -0.39<K1<-0.25
- 0.11<.DELTA.2/f<0.14
- where f:
- f: focal length of the whole lens system
- n: refractive index of the lens
- r1: radius off center curvature of the first surface
- r2: radius of center curvature of the second surface
- K1: conic constant of the first surface
- .DELTA.2: axial difference between the aspherical face of the outermost circular zone within the effective diameter of the second surface and a reference spherical face having the radius of center curvature of r2, wherein the direction in which the outermost circular zone of the second surface is curving toward the smaller conjugate side is taken as positive, and
- wherein the center of curvature of said spherical mirror and the focal point on the second surface side of said condenser lens are substantially coincident with each other, the center of emission of said discharge lamp being located at the coinciding point.
- 2. A light source apparatus according to claim 1, wherein
- said discharge lamp is a xenon discharge lamp having a pair of discharge electrodes, a positive electrode and a negative electrode, and the discharge tip of the negative electrode of the xenon lamp is situated at the coinciding point.
- 3. A light source apparatus according to claim 1, wherein
- the numerical aperture (NA) of said condenser lens is 0.9 or larger.
- 4. A light source apparatus according to claim 2, wherein
- the numerical aperture (NA) of said condenser lens is 0.9 or larger.
- 5. A light source apparatus according to claim 1, wherein
- the first surface of said condenser lens is treated with an antireflective coating of single layer, and the second surface is treated with an infrared/ultraviolet reflective or infrared reflective coating consisting of multiple optical layers.
- 6. A light source apparatus according to claim 2, wherein
- the first surface of said condenser lens is treated with an antireflective coating of single layer, and the second surface is treated with an infrared/ultraviolet reflective or infrared reflective coating consisting of multiple optical layers.
- 7. A light source apparatus according to claim 1, wherein
- when the radius of curvature of said spherical mirror is denoted as r and the diameter of a light beam emergent from the first surface of said condenser lens is denoted as D1, the following relationship is satisfied
- r.gtoreq.D1/2.
- 8. A light source apparatus according to claim 2, wherein
- when the radius of curvature of said spherical mirror is denoted as r and the diameter of a light beam emergent from the first surface of said condenser lens is denoted as D1, the following relationship is satisfied
- r.gtoreq.D1/2.
- 9.
- 9. A light source apparatus comprising:
- a discharge lamp;
- a spherical mirror; and
- a condenser lens consisting of bi-aspherical single lens having a first surface of convex form facing the larger conjugate side and a second surface facing the smaller conjugate side and whose outermost circular zone is formed concave, said condenser lens satisfying the following conditions
- 0.4<r1/nf<0.6
- -0.5<r2/nf<-0.3
- -0.6<K1<-0.2
- -0.1<SG2/f<0.1
- where
- f: focal length of the whole lens system
- n: refractive index of the lens
- r1: radius of center curvature of the first surface
- r2: radius of center curvature of the second surface
- K1: conic constant of the first surface
- SG2: axial difference of the aspherical face of the outermost circular zone within the effective diameter of the second surface with respect to the center of the second surface, wherein the direction in which the outermost circular zone of the second surface is curving toward the smaller conjugate side is taken as positive, and
- wherein the center of curvature of said spherical mirror and focal point on the second surface side of said condenser lens are substantially coincident with each other, the center of emission of said discharge lamp being located at the coinciding point.
- 10. A light source apparatus according to claim 9, wherein
- said discharge lamp is a xenon discharge lamp having a pair of discharge electrodes, a positive electrode and a negative electrode, and the discharge tip of the negative electrode of the xenon lamp is situated at the coinciding point.
- 11. A light source apparatus according to claim 9, wherein
- the numerical aperture (NA) of said condenser lens is 0.9 or larger.
- 12. A light source apparatus according to claim 10, wherein
- the numerical aperture (NA) of said condenser lens is 0.9 or larger.
- 13. A light source apparatus according to claim 1, wherein
- the first surface of said condenser lens is treated with an antireflective coating of single layer, and the second surface is treated with an infrared/ultraviolet reflective or infrared reflective coating consisting of multiple optical layers.
- 14. A light source apparatus according to claim 2, wherein
- the first surface of said condenser lens is treated with an antireflective coating of single layer, and the second surface is treated with an infrared/ultraviolet reflective or infrared reflective coating consisting of multiple optical layers.
- 15. A light source apparatus according to claim 1, wherein
- when the radius of curvature of said spherical mirror is denoted as r and the diameter of a light beam emergent from the first surface of said condenser lens is denoted as D1, the following relationship is satisfied
- r.gtoreq.D1/2.
- 16. A light source apparatus according to claim 10, wherein
- when the radius of curvature of said spherical mirror is denoted as r and the diameter of a light beam emergent from the first surface of said condenser lens is denoted as D1, the following relationship is satisfied
- r.gtoreq.D1/2.
- 17.
- 17. A light source apparatus comprising:
- a light source for emitting light;
- a condenser lens assembly having an optical axis and formed of plural lens portions separated from each other by joints provided parallel to the optical axis, said plural lens portions collectively forming a desired continuous single condenser lens profile, substantial portions of the light emitted from said light source passing through a single one of said lens portions, said joints producing discontinuities in the condenser lens assembly to absorb thermal expansion and prevent cracking of the lens.
- 18. The apparatus of claim 17 wherein said lens assembly is formed of said plural lens portions to avoid use of a single lens susceptible to thermal stress cracking.
- 19. The apparatus of claim 17 wherein the light emitted by said light source is transmitted by said condenser lens generally along an optical axis;
- said condenser lens assembly being divided into condenser lens portions by one or more separating planes extending parallel to said optical axis.
- 20. The apparatus of claim 19 wherein the one or more separating planes are partially defined by said optical axis.
- 21. The light source apparatus of claim 17 wherein said light source is a linear emission lamp.
- 22. The light source apparatus of claim 21 wherein said linear emission lamp is oriented so that maximum emission is along said optical axis.
- 23. The light source apparatus of claim 22 further comprising a spherical reflector disposed opposite said light source from said condenser lens assembly.
- 24. The light source apparatus of claim 23 wherein said lamp is a discharge lamp.
Priority Claims (4)
Number |
Date |
Country |
Kind |
4-99653 |
Apr 1992 |
JPX |
|
4-113475 |
May 1992 |
JPX |
|
4-287671 |
Oct 1992 |
JPX |
|
4-313261 |
Nov 1992 |
JPX |
|
Parent Case Info
This application is a divisional of application Ser. No. 08/047,504 filed on Apr. 16, 1993, now U. S. Pat. No. 5,384,689, the entire contents of which are hereby incorporated by reference.
US Referenced Citations (11)
Foreign Referenced Citations (3)
Number |
Date |
Country |
142687 |
Feb 1989 |
JPX |
4427 |
Jan 1992 |
JPX |
0361939 |
Nov 1931 |
GBX |
Non-Patent Literature Citations (1)
Entry |
"Laser and Optics Guide II" Japan Melles Griot Inc., pp. 122-124, Jun. 1989. |
Divisions (1)
|
Number |
Date |
Country |
Parent |
47504 |
Apr 1993 |
|