Title:
GAUSSIAN LENS
Document Type and Number:
Japanese Patent JPH01302311
Kind Code:
A
Abstract:
PURPOSE:To obtain the brightness of about F number 1.2, to extend the back focus, and to satisfactorily correct various aberrations by constituting a lens satisfying specific conditions. CONSTITUTION:Conditions of inequalities I-VIII are satisfied where (f), fB, Ri, Di, Ni, nui, L, and LB are the focal length of the whole of a lens system consisting of lenses G1-G8, the focal length of lenses on the image surface side of a stop S, the radius of curvature of the i-th lens face from the object side, the i-th lens thickness or air interval, the refractive index of the i-th less, the Abbe's number of this lens, the length from the first lens face to the image surface, and the back focus respectively. Thus, the brightness of F number 1.2 is obtained, and the back focus is extended, and aberrations are satisfactorily corrected.
Inventors:
ENDO HIROSHI
Application Number:
JP13412888A
Publication Date:
December 06, 1989
Filing Date:
May 31, 1988
Export Citation:
Assignee:
CANON KK
International Classes:
G02B9/64; G02B13/18; (IPC1-7): G02B9/64; G02B13/18
Attorney, Agent or Firm:
Takanashi Yukio