GAUSSIAN LENS

Japanese Patent JPH01155310

A

PURPOSE:To obtain about 1.4 F-number brightness and to compensate aberrations at the time of photography excellently by employing the lens constitution of a Gaussian type as basic constitution and utilizing floating. CONSTITUTION:This lens has a 1st group with positive refracting power and a 2nd group with positive refracting power in order from its object side, the 1st group is composed of two lens groups, i.e., a 11th group and a 12th group arranged almost symmetrically across a stop as the basic constitution, and the 1st group is moved on the optical axis to perform focusing; and requirements are met as shown by inequalities, where F1 and F2 are the focal lengths of the 1st and 2nd groups, F is the focal length of the whole system, F12 is the focal length of the 12th group, (l) the overall length of the 1st group, R11B is the radius of curvature of the lens surface of the 11th group closest to the image plane side, and R12A is the radius of curvature of the lens surface of the 12th group closest to the object side. Consequently, the Gaussian lens is obtained which has an about 46 deg. photographic field angle while having aberrations compensated excellently over the entire image plane and having small aberrational variation at the time of focusing, and having 1.4 F-number brightness and long back-focal distance.

JPH05505043	INDUSTRIAL APPLICABILITY Apochromatic relay lens system suitable for use in a high-resolution telecine device.
WO/2021/127881	CAMERA OPTICAL LENS
WO/2022/139473	OPTICAL SYSTEM

YANO KOTARO

JP31554887A

June 19, 1989

December 14, 1987

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CANON KK

G02B9/64; (IPC1-7): G02B9/64

Takanashi Yukio

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