发明名称 Auxiliary light source for camera having automatic focusing device
摘要 An auxiliary light source for a camera having an automatic focusing device as an adapter attachable to a shoe part of the camera and which inhibits light measuring action during an auxiliary light emitting action for always obtaining accurate light measurement. The arrangement solves the following problems. In a camera of this type, the output of an automatic focusing sensor becomes too low for automatic focusing when automatic focusing is to be carried out under low light conditions. Systems contrived by the prior art to solve this problem have an auxiliary light source disposed within the camera for illuminating an object to be photographed during automatic focusing. However, since the auxiliary light source device is included within the camera, the auxiliary light is not effectively utilizable when a large lens such as a telephoto lens is used, since the auxiliary light is eclipsed by the lens barrel. Furthermore, when a light measuring circuit is operated during illumination by an auxiliary light, the light measurement output obtained for control would be affected by the illumination light making accurate light measurement almost unobtainable.
申请公布号 US4693582(A) 申请公布日期 1987.09.15
申请号 US19860858544 申请日期 1986.04.29
申请人 CANON KABUSHIKI KAISHA 发明人 KAWAMURA, MASAHARU;HIRAMATSU, AKIRA
分类号 G02B7/36;(IPC1-7):G03B3/00;G03B7/00 主分类号 G02B7/36
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