| 摘要 |
PROBLEM TO BE SOLVED: To provide an imaging device capable of suppressing the generation of a shadow even if a photographing lens aperture is closed. SOLUTION: A digital camera 100 as an imaging device is provided with: a photographing lens 50 on which light from a patient is made incident; an imaging element 10 for acquiring an image of the patient; and an optical low pass filter 20 arranged between the photographing lens 50 and the imaging element 10. The optical low pass filter 20 includes linear type phase diffraction gratings 21 wherein unit gratings composed of mutually adjoined recessed parts 21b with an equal width and projecting parts 21a with an equal width are periodically arranged at a grating pitch P. The optical path length difference of light whose phase changes in accordance with the linear type phase diffraction gratings 21 is equal toλ/2 when the standard wavelength to be used isλ. COPYRIGHT: (C)2008,JPO&INPIT
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