Electronic endoscope system
First Claim
1. An endoscope system comprising:
- an endoscope having a solid-state imaging device and an objective optical system that converges an object image on said solid-state imaging device, said objective optical system including an optical phase modulation member that exhibits a response of 0.2 or more derived from an optical transfer function relative to up to a spatial frequency on said solid-state imaging device determined based on the Nyquist theorem, that is, a Nyquist frequency, over a wider range of distances than a depth of field offered by an objective optical system not including the optical phase modulation member; and
a signal processing unit that processes an image signal produced by said endoscope so as to produce a video signal.
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Abstract
An endoscope system in accordance with the present invention consists mainly of: an endoscope having a solid-state imaging device and an objective optical system that converges an object image on said solid-state imaging device; and a signal processing unit that processes an image signal produced by the endoscope so as to produce a video signal. The objective optical system includes an optical phase modulation member. The optical phase modulation member exhibits a response of 0.2 or more derived from an optical transfer function relative to up to a spatial frequency on the solid-state imaging device determined based on the Nyquist theorem, that is, a Nyquist frequency, over a wider range of distances than a depth of field offered by an objective optical system not having the optical phase modulation member.
61 Citations
20 Claims
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1. An endoscope system comprising:
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an endoscope having a solid-state imaging device and an objective optical system that converges an object image on said solid-state imaging device, said objective optical system including an optical phase modulation member that exhibits a response of 0.2 or more derived from an optical transfer function relative to up to a spatial frequency on said solid-state imaging device determined based on the Nyquist theorem, that is, a Nyquist frequency, over a wider range of distances than a depth of field offered by an objective optical system not including the optical phase modulation member; and
a signal processing unit that processes an image signal produced by said endoscope so as to produce a video signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An endoscope system comprising:
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an endoscope having a solid-state imaging device and an objective optical system that converges an object image on said solid-state imaging device, said objective optical system including an optical phase modulation member that exhibits a response of 0.2 or more derived from an optical transfer function relative to up to a spatial frequency on said solid-state imaging device determined based on the Nyquist theorem, that is, a Nyquist frequency, over a wider range of distances than a depth of field offered by an objective optical system not including the optical phase modulation member; and
a signal processing unit that processes an image signal produced by said endoscope so as to produce a video signal, said signal processing unit including an image processor that enhances components of the video signal, which is produced based on the image signal produced by said endoscope, falling within a specific frequency band. - View Dependent Claims (10, 11, 12, 13, 14)
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15. An endoscope system comprising:
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an endoscope having a solid-state imaging device and an objective optical system that converges an object image on said solid-state imaging device, said objective optical system including an optical phase modulation member that exhibits a response of 0.2 or more derived from an optical transfer function relative to up to a spatial frequency on said solid-state imaging device determined based on the Nyquist theorem, that is, a Nyquist frequency, over a wider range of distances than a depth of field offered by an objective optical system not having the optical phase modulation member; and
a signal processing unit that processes an image signal produced by said endoscope so as to produce a video signal, said signal processing unit including a hue image processor that performs different kinds of image processing on red, green, and blue video signals produced based on the image signal produced by said endoscope. - View Dependent Claims (16, 17)
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18. An endoscope system comprising:
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an endoscope having a solid-state imaging device and an objective optical system that converges an object image on said solid-state imaging device, said objective optical system including an optical phase modulation means that transforms the phase of light, and exhibiting a response of 0.2 or more derived from an optical transfer function relative to up to a spatial frequency on said solid-state imaging device determined based on the Nyquist theorem, that is, a Nyquist frequency; and
a signal processing unit that processes an image signal produced by said endoscope so as to produce a video signal.
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19. An endoscope system in which an optical image picked up by an objective optical system is converged on a solid-state imaging device and a plurality of endoscopes is employed, wherein:
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at least one endoscope has an objective optical system that includes an optical phase modulation member;
said optical phase modulation member acts so that a variation of an optical transfer function dependent on a distance to an object will be smaller than that of an optical transfer function characterizing an objective optical system not having said optical phase modulation member; and
the same image processing is adapted to both the endoscope having said optical phase modulation member and an endoscope not having said optical phase modulation member. - View Dependent Claims (20)
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Specification