Image-forming optical system using prism elements
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 first prism and a second prism, each of said first prism and second prism being formed from a prism medium, said second prism being placed on an image side of said first prism,wherein an intermediate image is not formed,said first prism having;
a first surface through which a light beam enters said first prism;
a second surface that reflects the light beam entering through said first surface in said first prism;
a third surface that reflects the light beam reflected by said second surface in said first prism; and
a fourth surface through which the light beam exits from said first prism;
wherein at least one of said second surface and said third surface 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;
said second prism having at least one reflecting surface that reflects a light beam in said second prism, said reflecting surface having a rotationally asymmetric surface configuration that gives a power to a light beam and corrects aberrations due to decentration;
wherein said first prism satisfies the following condition;
space="preserve" listing-type="equation">10°
<
θ
'"'"'<
90°
wherein θ
'"'"' is an angle formed between an axial principal ray entering the first surface of said first prism and an axial principal ray exiting from the fourth surface of said first prism.
2 Assignments
0 Petitions
Accused Products
Abstract
A high-performance image-forming optical system made compact and thin by folding an optical path using reflecting surfaces arranged to minimize the number of reflections. The image-forming optical system has a first prism placed on the object side and a second prism placed on the image side and does not form an intermediate image. The first prism has a first surface through which a light beam enters the first prism, a second surface reflecting the incident light beam in the prism, a third surface reflecting the reflected light beam in the prism, and a fourth surface through which the light beam exits from the prism. At least one of the second and third surfaces has a rotationally asymmetric curved surface configuration that gives a power to a light beam and corrects aberrations due to decentration. The second prism has at least one reflecting surface that reflects a light beam in the prism. The reflecting surface has a rotationally asymmetric surface configuration that gives a power to a light beam and corrects aberrations due to decentration.
63 Citations
26 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 first prism and a second prism, each of said first prism and second prism being formed from a prism medium, said second prism being placed on an image side of said first prism, wherein an intermediate image is not formed, said first prism having; a first surface through which a light beam enters said first prism; a second surface that reflects the light beam entering through said first surface in said first prism; a third surface that reflects the light beam reflected by said second surface in said first prism; and a fourth surface through which the light beam exits from said first prism; wherein at least one of said second surface and said third surface 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; said second prism having at least one reflecting surface that reflects a light beam in said second prism, said reflecting surface having a rotationally asymmetric surface configuration that gives a power to a light beam and corrects aberrations due to decentration; wherein said first prism satisfies the following condition;
space="preserve" listing-type="equation">10°
<
θ
'"'"'<
90°wherein θ
'"'"' is an angle formed between an axial principal ray entering the first surface of said first prism and an axial principal ray exiting from the fourth surface of said first prism. - 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)
-
Specification