Reimaging optical system and endoscope using the same
First Claim
1. A reimaging optical system adapted to re-form an image by an image guide on a solid-state imaging device having a diagonal length of 6.5 mm or longer, characterized by satisfying the following condition:
-
0.6<
(D×
β
)/V
(1)where D is a diameter of said image guide, β
is an optical transverse magnification of said reimaging optical system, and V in mm is a minor axis direction length of an imaging area of said solid-state imaging device.
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Accused Products
Abstract
The invention relates to an reimaging optical system that has a sufficiently enhanced magnification and better performance, and an endoscope using the same. The reimaging optical system 3 is adapted to re-form an image by an image guide 6 on a solid-state imaging device 4 having a diagonal length of 6.5 mm or longer, and satisfies the following condition.
0.6<(D×|β|)/V (1).
Here D is the diameter of the image guide 6, β is the optical transverse magnification of the reimaging optical system 3, and V in mm is the minor axis direction length of an imaging area of the solid-state imaging device 4.
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Citations
8 Claims
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1. A reimaging optical system adapted to re-form an image by an image guide on a solid-state imaging device having a diagonal length of 6.5 mm or longer, characterized by satisfying the following condition:
-
0.6<
(D×
β
)/V
(1)where D is a diameter of said image guide, β
is an optical transverse magnification of said reimaging optical system, and V in mm is a minor axis direction length of an imaging area of said solid-state imaging device.- View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
where fF is a focal length of the front unit, and F is a focal length of the whole reimaging optical system.
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3. The reimaging optical system according to claim 2, characterized in that said front unit comprises a first lens group including at least one positive single lens and a second lens group including a cemented lens of a positive lens and a negative lens, and satisfies the following condition:
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0.9<
f2F/F
(3)where f2F is a focal length of the positive lens in the second lens group.
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4. The reimaging optical system according to claim 1, characterized by comprising a front unit, a stop and a rear unit, and satisfying the following condition:
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6<
fB/fF
(2)where fF is a focal length of the front unit, and fB is focal length of the rear unit.
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5. The reimaging optical system according to claim 1, characterized in that an optical low-pass filter is located of an image side of said image guide.
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6. An endoscope, characterized by comprising an objective lens located at an end of the endoscope, an image guide for guiding an object image formed by said objective lens, and a reimaging optical system adapted to re-form the object image guided by said image guide onto a solid-state imaging device having a diagonal length of 6.5 mm or longer, wherein the reimaging optical system according to claim 1 is used as said reimaging optical system.
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7. The endoscope according to claim 6, characterized by further comprising an illumination means that includes a white light emitting diode without recourse to any color correction filter.
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8. The endoscope according to claim 6, characterized by further comprising a display means for displaying an image based on electric signals from said solid-state imaging device.
Specification