Decentered 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 first prism and a second prism, each of said first prism and second prism being formed from a medium having a refractive index (n) larger than 1.3 (n>
1.3), said second prism being placed at a position on an image side of said first prism, in an optical path exiting said first prism and intersecting a plane where said object image is formed,wherein an intermediate image is not formed,said first prism having three optical surfaces said three optical surfaces comprising;
a first surface through which a light beam from an object enters said first prism;
a second surface that reflects the light beam entering through said first surface in said first prism;
said first surface further reflecting the light beam reflected by said second surface in said first prism; and
a third surface through which the light beam reflected by said first surface exits from said first prism;
wherein at least one of said first surface and said second surface has a curved surface having a power;
said curved surface having a rotationally asymmetric surface configuration that corrects aberrations due to decentration;
said second prism having at least one reflecting surface, said reflecting surface having a rotationally asymmetric surface configuration having a power and correcting aberrations due to decentration.
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 from an object enters the first prism, and a second surface that reflects the light beam entering through the first surface in the first prism. The first surface also reflects the light beam reflected by the second surface in the first prism. The first prism further has a third surface through which the light beam reflected by the first surface exits from the first prism. The first or second surface has a rotationally asymmetric surface configuration that gives a power to a light beam. The second prism has at least one reflecting surface that reflects a light beam in the second prism. The reflecting surface has a rotationally asymmetric surface configuration that gives a power to a light beam and corrects aberrations due to decentration.
64 Citations
23 Claims
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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:
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a first prism and a second prism, each of said first prism and second prism being formed from a medium having a refractive index (n) larger than 1.3 (n>
1.3), said second prism being placed at a position on an image side of said first prism, in an optical path exiting said first prism and intersecting a plane where said object image is formed,wherein an intermediate image is not formed, said first prism having three optical surfaces said three optical surfaces comprising; a first surface through which a light beam from an object enters said first prism; a second surface that reflects the light beam entering through said first surface in said first prism; said first surface further reflecting the light beam reflected by said second surface in said first prism; and a third surface through which the light beam reflected by said first surface exits from said first prism; wherein at least one of said first surface and said second surface has a curved surface having a power; said curved surface having a rotationally asymmetric surface configuration that corrects aberrations due to decentration; said second prism having at least one reflecting surface, said reflecting surface having a rotationally asymmetric surface configuration having a power and correcting aberrations due to decentration. - 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)
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Specification