Iwatsu Electric Company Ltd.

Yoshio Horiguchi

Yousuke Igarashi

Masahiro Kogiso

Satoshi Hisabayoshi

In a copying machine of the type comprising an image projecting lens movable in a direction of an optical axis thereof for varying a magnifying power, a reflecting mirror interlocked with the lens for effecting focusing, and two groups of light sources for illuminating a manuscript, there is provided an exposure control system comprising variable resistors driven by the projecting lens, oscillators for generating pulse signals of frequencies varying in accordance with resistance variations of the variable resistors and with a variation in a source voltage, counters counting the number of the pulse signals in accordance with an exposure index, and switch means for lighting the light sources during intervals determined by an exposure index.

Growing community of inventors

Hachioji, Japan

Yoshio Horiguchi