Victor Company of Japan, Limited

Shinsuke Ono

Takashi Shinozaki

Yoshichi Ohtake

Yoshichi Otake

Yuzuru Inoue

An optical low-pass filter is used in a television camera which has an optical system including an iris and a color stripe filter. The optical low-pass filter comprises a base plate, and a plurality of bi-prisms respectively formed on at least one surface of the base plate, and extending parallel with respect to one direction, where the plurality of bi-prisms are arranged at a pitch which is smaller than the diameter of a minimum aperture used of the iris.

Optical low-pass filter

A television camera has an optical system including an iris, a master lens, and a color stripe filter. The television camera further comprises an optical lowpass filter provided within an effective light path of an afocal system which reaches the master lens through the iris. The optical lowpass filter has a shape to partially produce an optical lowpass filter effect with respect to a part of a beam in the effective light path.

Television camera having an optical lowpass filter

The image of a subject imaged on the photoelectric conversion surface of a pickup tube of the color television camera is defocused in a given direction by a given amount to make a blur so that beat interference due to specific black and white pattern of the subject does not occur in the reproduced picture. In first and second embodiments of the present invention, at least one optical filter having specific characteristics is employed for defocusing the image, while in a third embodiment, an aperture stop is used to defocus the image by utilizing the aberration of the lens system of the color television camera. The aperture stop of the third embodiment may be used together with the optical filter(s) of the first and second embodiments.

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Yokosuka, Japan

Shinsuke Ono