Lens systems
First Claim
Patent Images
1. A lens system which includes an aperture stop and which comprises:
- (a) a first lens unit which comprises two meniscus element whose concave surfaces face each other and whose combined optical power is negative, the system'"'"'s aperture stop being located between the two meniscus elements; and
(b) a second lens unit which has a positive power, said lens system including at least one aspheric lens surface.
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Accused Products
Abstract
A lens system is provided which includes two lens units. The first lens unit includes two meniscus lenses whose concave surfaces face each other and the second lens unit has a positive power. The system can be configured to have a wide field of view and/or to be telecentric. In its basic form, a well-corrected lens having a relatively large aperture and field of view is achieved through the use of only three lens elements.
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Citations
47 Claims
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1. A lens system which includes an aperture stop and which comprises:
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(a) a first lens unit which comprises two meniscus element whose concave surfaces face each other and whose combined optical power is negative, the system'"'"'s aperture stop being located between the two meniscus elements; and (b) a second lens unit which has a positive power, said lens system including at least one aspheric lens surface. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A telecentric lens system which includes an aperture stop and a telecentric pupil, said system comprising:
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(a) a first lens unit which comprises two meniscus elements whose concave surfaces face each other; and (b) a second lens unit which has a positive power and which forms the telecentric pupil by imaging the aperture stop, said lens system including at least one aspheric lens surface. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A wide angle lens system which includes an aperture stop and which comprises:
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(a) a first lens unit which comprises two meniscus elements whose concave surfaces face each other, the system'"'"'s aperture stop being located between the two meniscus elements; and (b) a second lens unit which has a positive power;
said lens system including at least one aspheric lens surface and having a half angle field of view in the direction of the first lens unit of at least about 20 degrees. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29)
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30. A lens system which includes an aperture stop and which comprises:
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(a) a first lens unit which comprises two meniscus elements whose concave surfaces face each other and whose combined optical power is negative, the system'"'"'s aperture stop being located between the two meniscus elements and each of said meniscus elements having a weak optical power whose absolute value is less than the absolute value of the optical power of the lens system; and (b) a second lens unit which has a positive power. - View Dependent Claims (31, 32, 33, 34)
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35. A telecentric lens system which includes an aperture stop and a telecentric pupil, said system comprising:
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(a) a first lens unit which comprises two meniscus elements whose concave surfaces face each other, each of said meniscus elements having a weak optical power whose absolute value is less than the absolute value of the optical power of the lens system; and (b) a second lens unit which has a positive power and which forms the telecentric pupil by imaging the aperture stop. - View Dependent Claims (36, 37, 38, 39, 40, 41)
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42. A wide angle lens system which includes an aperture stop and which comprises:
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(a) a first lens unit which comprises two meniscus elements whose concave surfaces face each other, the system'"'"'s aperture stop being located between the two meniscus elements and each of said meniscus elements having a weak optical power whose absolute value is less than the absolute value of the optical power of the lens system; and (b) a second lens unit which has a positive power;
said lens system having a half angle field of view in the direction of the first lens unit of at least about 20 degrees. - View Dependent Claims (43, 44, 45, 46, 47)
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Specification