Capsule endoscope and observation system that uses it

Abstract

A capsule endoscope body is provided with a spatial frequency characteristic converter which causes the optical transfer function of the imaging system of the capsule endoscope to remain essentially constant within some range of in-focus position. The depth of field of images obtained from the capsule endoscope body is increased by signal processing in order to undue the effects of the spatial frequency characteristic converter. Also, signal processing to reduce variations in image quality due to manufacturing tolerances can be provided within the capsule endoscope body. It is preferred, however, that the signal processing be performed within a receiver which is separate from the capsule endoscope body or, ideally, within a personal computer that receives image data signals from the receiver via cable or wireless communications, processes these image signals, and outputs corrected image signals to a display device.

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