Optical system and visual display apparatus
First Claim
1. An optical system comprising:
- a partial optical system having at least two semitransparent surfaces which are disposed so that each semitransparent surface transmits light rays at least once and reflects them at least once;
a refracting optical element having refractive power; and
wherein a semitransparent surface of said partial optical system which is closer to a pupil plane is a flat surface, and a semitransparent surface of said partial optical system which is closer to an image plane is a concave surface, and wherein said refracting optical element is disposed at the pupil plane or image plane side of said partial optical system with an air spacing provided therebetween, said refracting optical element having a focal length which satisfies the following condition;
space="preserve" listing-type="equation">f.sub.a >
0where fa is a focal length of said refracting optical element.
1 Assignment
0 Petitions
Accused Products
Abstract
An optical system which is usable as either an ocular optical system or an imaging optical system, and which is satisfactorily corrected for both field curvature and comatic aberration for a field angle of up to about 120° and for a pupil diameter of up to about 15 millimeters. The optical system includes a partial optical system (10) having a flat semitransparent surface (1) which is closer to a pupil plane (E), and a concave semitransparent surface (2) which is closer to an image plane (I). A refracting optical element (4) is disposed at the pupil plane (E) or image plane (I) side of the partial optical system (10) with an air spacing provided therebetween. Alternatively, the refracting optical element (4) may be cemented to the partial optical system (10). The refracting optical element (4) has a focal length fa which satisfies the condition of fa >0.
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Citations
11 Claims
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1. An optical system comprising:
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a partial optical system having at least two semitransparent surfaces which are disposed so that each semitransparent surface transmits light rays at least once and reflects them at least once; a refracting optical element having refractive power; and wherein a semitransparent surface of said partial optical system which is closer to a pupil plane is a flat surface, and a semitransparent surface of said partial optical system which is closer to an image plane is a concave surface, and wherein said refracting optical element is disposed at the pupil plane or image plane side of said partial optical system with an air spacing provided therebetween, said refracting optical element having a focal length which satisfies the following condition;
space="preserve" listing-type="equation">f.sub.a >
0where fa is a focal length of said refracting optical element. - View Dependent Claims (2, 3, 4, 8, 9, 10, 11)
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5. An optical system comprising:
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a partial optical system having at least two semitransparent surfaces which are disposed so that each semitransparent surface transmits light rays at least once and reflects them at least once; a refracting optical element having refractive power; and wherein said refracting optical element having refractive power is cemented to a side of said partial optical system which is closer to a pupil plane or an image plane, and wherein the following condition is satisfied;
space="preserve" listing-type="equation">0.1<
f.sub.2 /f.sub.a <
3where fa is a focal length of said refracting optical element, and f2 is a focal length of said partial optical system. - View Dependent Claims (6, 7)
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Specification