发明名称 Variable magnification apparatus having illumination compensating ability
摘要 Apparatus herein disclosed comprises a photographing system having an optical system of variable magnification and an illumination system having a light source for photographing and a light source for observing. In the apparatus, the existing photographing magnification of the optical system is detected and the quantity of light incident upon a film or a finder visual field is controlled depending upon the detected magnification so as to obtain an optimum exposure to the film of the photographing system or to maintain the brightness of the visual field constant. To attain the control of quantity of light, light passing through the illumination system or light passing through the optical system is gradually reduced with widening of the angle of field. Alternatively, intensity of light emitted from the light source for observing or light emitting time of the light source for photographing is altered depending upon the detected magnification.
申请公布号 US4265518(A) 申请公布日期 1981.05.05
申请号 US19780919149 申请日期 1978.06.26
申请人 CANON KABUSHIKI KAISHA 发明人 MATSUMURA, ISAO
分类号 A61B3/14;G03B7/16;G03B15/00;G03B15/14;G03B41/00;(IPC1-7):A61B3/14 主分类号 A61B3/14
代理机构 代理人
主权项
地址