| 摘要 |
PURPOSE:To simplify a circuit by computing automatic or manual exposing quantity by means of digitized data and controlling impressing voltage on a light source. CONSTITUTION:When a manual exposing mode is set, a CPU 70 fetches the set position of a manual exposing setting knob 30c by digital data through an A/D converter 81. Moreover it operates a lamp impressing voltage set value to obtain proper exposing quantity and outputs it to a lamp regulator 71. The regulator 71 impresses voltage according to the set value on an exposing lamp 4. In automatic exposing mode, the CPU 70 fetches the output of a light detector 74 according to reflected light quantity from the original of the lamp 4 in the form of digital data and operates the lamp impressing voltage set value to obtain proper exposing quantity according to such as copy magnification. More over it outputs to the regulator 71 and impresses voltage according to the set value on the lamp 4. Consequently the scale of the analog control circuit can be reduced and its reliability is improved. |
