Optical comb filter
 An optical comb filter has a plurality of optical comb filter elements disposed successively in the advancing direction of light. The optical comb filter characteristics attenuate and remove specific space frequencies which do not have mutual relationships of odd-number multiples and frequencies of the specific space frequencies. At least one phase plate is interposed between neighboring optical comb filter elements in front and rear positions with respect to the light advancing direction. The phase plate converts a light exiting from the front filter element into a light which is divided in the rear filter element into normal light and abnormal light, exiting with mutually equal light quantity. The normal and abnormal light enters, as incident light, the rear filter element. 
Victor Company of Japan, Ltd.
G G H
G02B G02B H04N
inventional inventional inventional
Shintaro Koichiro Itsuo Kenichi Sumio Tadayoshi
Nakagaki Motoyama Takanashi Miyazaki Yokokawa Miyoshi