Lenses for electronic imaging systems
First Claim
1. A lens system for forming an image of an object, said system having a focal length f0 and consisting in order from its object side to its image side of:
- (a) a first lens element having a focal length f1 and a thickness t1 ; and
(b) a second lens element having a focal length f2, said second lens element being spaced from the first lens element by a distance d12 ;
wherein;
space="preserve" listing-type="equation">f.sub.1 <
0;
space="preserve" listing-type="equation">|f.sub.1 |/f.sub.0 >
1.0;
space="preserve" listing-type="equation">t.sub.1 /f.sub.0 >
0.5;
space="preserve" listing-type="equation">f.sub.2 >
0; and
space="preserve" listing-type="equation">d.sub.12 /f.sub.0 >
0.25.
3 Assignments
0 Petitions
Accused Products
Abstract
A lens system for an electronic system has two lenses. The first lens (S1/S2) has a negative power, and the second lens (S4/S5 or S5/S6) has a positive power and is spaced from the first lens (S1/S2) by a distance of at least a quarter of the focal length of the lens system. In one embodiment (FIG. 3), the second lens (S4/S5) is a refractive-diffractive hybrid lens; in which case both the first and the second lenses (S1/S2 and S4/S5) can be composed of acrylic, and can have only spherical and conic surfaces. In other embodiments (FIG. 1, 2, 4), the first lens (S1/S2) has a higher dispersion than the than the second lens (S4/S5 or S5/S6); for example, the first lens (S1/S2) is composed of styrene, and the second lens (S4/S5 or S5/S6) is composed of acrylic. In this case, the first lens (S1/S2) can have a spherical surface and a general aspherical surface, and the second lens (S5/S6) can have conic surfaces (FIG. 1, 2); or both of the first and second lenses (S1/S2 and S4/S5) can have a spherical surface, and a conic surface (FIG. 4).
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Citations
33 Claims
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1. A lens system for forming an image of an object, said system having a focal length f0 and consisting in order from its object side to its image side of:
-
(a) a first lens element having a focal length f1 and a thickness t1 ; and (b) a second lens element having a focal length f2, said second lens element being spaced from the first lens element by a distance d12 ; wherein;
space="preserve" listing-type="equation">f.sub.1 <
0;
space="preserve" listing-type="equation">|f.sub.1 |/f.sub.0 >
1.0;
space="preserve" listing-type="equation">t.sub.1 /f.sub.0 >
0.5;
space="preserve" listing-type="equation">f.sub.2 >
0; and
space="preserve" listing-type="equation">d.sub.12 /f.sub.0 >
0.25. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 24, 25)
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18. A lens system for forming an image of an object, said system consisting in order from its object side to its image side of:
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(a) a negative first lens element having a spherical surface and a general aspherical surface; and (b) a positive second lens element having two conic surfaces. - View Dependent Claims (26, 27)
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19. A lens system for forming an image of an object, said system consisting in order from its object side to its image side of:
-
(a) a negative first lens element having a spherical surface and a conic surface; and (b) a positive second lens element having two conic surfaces. - View Dependent Claims (20, 28, 29)
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-
21. A lens system for forming an image of an object, said system consisting in order from its object side to its image side of:
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(a) a negative first lens element having a spherical surface and a conic surface; and (b) a positive second lens element having a spherical surface and a conic surface. - View Dependent Claims (30, 31)
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22. A lens system for forming an image of an object, said system having an entrance pupil whose diameter is DEP and consisting in order from its object side to its image side of:
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(a) a negative lens element having a diameter D1 ; and (b) a positive lens element having a diameter D2; wherein;
space="preserve" listing-type="equation">D.sub.1 /D.sub.EP >
2.5; and
space="preserve" listing-type="equation">D.sub.2 /D.sub.EP >
1.3. - View Dependent Claims (23, 32, 33)
-
Specification