Image-forming optical system
First Claim
1. An image-forming optical system having a positive refracting power as a whole for forming an object image, said image-forming optical system comprising:
- a prism member formed from a medium having a refractive index (n) larger than 1 (n>
1), wherein said prism member is a single cemented or integrally molded prism, said prism having;
a first transmitting surface through which a light beam enters said prism;
first, second and third reflecting surfaces that reflect the light beam in said prism; and
a second transmitting surface through which the light beam exits from said prism, wherein said second reflecting surface and said third reflecting surface are arranged so that when an axial principal ray is projected onto a plane defined by the axial principal ray incident on said second reflecting surface and the axial principal ray reflected from said second reflecting surface, a path of the axial principal ray in said prism is folded in a triangular shape, and the axial principal ray incident on said second reflecting surface and the axial principal ray reflected from said third reflecting surface form intersecting optical paths, wherein at least one of said first, second and third reflecting surfaces has a curved surface configuration that gives a power to a light beam, said curved surface configuration having a rotationally asymmetric surface configuration that corrects aberrations due to decentration, and wherein said prism member has, in order in which light passes from an object side thereof, the first transmitting surface, the second reflecting surface, the third reflecting surface, the first reflecting surface, and the second transmitting surface so as to form an optical path in order mentioned.
2 Assignments
0 Petitions
Accused Products
Abstract
An image-forming optical system including a compact and high-performance prism optical system. The image-forming optical system has a prism member formed from a medium having a refractive index larger than 1. The prism member has a first transmitting surface, first to third reflecting surfaces, and a second transmitting surface. The second and third reflecting surfaces are arranged so that the path of the axial principal ray in the prism is folded in a triangular shape, and the axial principal ray incident on the second reflecting surface and the axial principal ray reflected from the third reflecting surface form intersecting optical paths. At least one of the first to third reflecting surfaces has a curved surface configuration that gives a power to a light beam. The curved surface configuration has a rotationally asymmetric surface configuration that corrects aberrations due to decentration.
68 Citations
27 Claims
-
1. An image-forming optical system having a positive refracting power as a whole for forming an object image, said image-forming optical system comprising:
-
a prism member formed from a medium having a refractive index (n) larger than 1 (n>
1),wherein said prism member is a single cemented or integrally molded prism, said prism having;
a first transmitting surface through which a light beam enters said prism;
first, second and third reflecting surfaces that reflect the light beam in said prism; and
a second transmitting surface through which the light beam exits from said prism, wherein said second reflecting surface and said third reflecting surface are arranged so that when an axial principal ray is projected onto a plane defined by the axial principal ray incident on said second reflecting surface and the axial principal ray reflected from said second reflecting surface, a path of the axial principal ray in said prism is folded in a triangular shape, and the axial principal ray incident on said second reflecting surface and the axial principal ray reflected from said third reflecting surface form intersecting optical paths, wherein at least one of said first, second and third reflecting surfaces has a curved surface configuration that gives a power to a light beam, said curved surface configuration having a rotationally asymmetric surface configuration that corrects aberrations due to decentration, and wherein said prism member has, in order in which light passes from an object side thereof, the first transmitting surface, the second reflecting surface, the third reflecting surface, the first reflecting surface, and the second transmitting surface so as to form an optical path in order mentioned. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
-
-
21. An image-forming optical system according to claim 20, wherein both said second reflecting surface and said third reflecting surface satisfy the following condition:
-
22. A finder optical system comprising:
-
said image-forming optical system according to any one of claims 2 to 19, said image-forming optical system being provided as a finder objective optical system;
an image-inverting optical system for erecting an object image formed by said finder objective optical system; and
an ocular optical system.
-
-
23. A camera apparatus comprising:
-
said finder optical system according to claim 22; and
an objective optical system for photography provided in parallel to said finder optical system.
-
-
24. An image pickup optical system comprising:
-
said image-forming optical system according to any one of claims 2 to 19; and
an image pickup device placed in an image plane formed by said image-forming optical system.
-
-
25. A camera apparatus comprising:
-
said image-forming optical system according to any one of claims 2 to 19, said image-forming optical system being provided as an objective optical system for photography; and
a finder optical system placed in one of an optical path separate from an optical path of said objective optical system for photography and an optical path split from the optical path of said objective optical system for photography.
-
-
26. An electronic camera apparatus comprising:
-
said image-forming optical system according to any one of claims 2 to 19;
an image pickup device placed in an image plane formed by said image-forming optical system;
a recording medium for recording image information received by said image pickup device; and
an image display device that receives image information from one of said recording medium and said image pickup device to form an image for observation.
-
-
27. An endoscope system comprising:
-
an observation system having said image-forming optical system according to any one of claims 2 to 19 and an image transmitting member for transmitting an image formed by said image-forming optical system along a longitudinal axis; and
an illumination system having an illuminating light source and an illuminating light transmitting member for transmitting illuminating light from said illuminating light source along said longitudinal axis.
-
Specification