| 摘要 |
PURPOSE:To invariably obtain a proper amount of exposure at each magnification level by providing a means which finely adjusts the amount of exposure in a wide range from unmagnification to enlargement. CONSTITUTION:A reference voltage setting circuit 212 is constituted of a DC amplifier 207, a limiting circuit 208, an automatic exposure circuit 209, an exposure voltage setting circuit 210, and an automatic/manual change-over switch 211, and controlled by a main processing group 71. The main processing group 71 outputs a control signal; with respect to the voltage impressed to an exposing lamp 4 for copying magnification, it adjusts exposure according to unmagnification, enlargement, or reduction and the optimum amount of exposure under an arbitrary magnification ranging from unmagnification to enlargement is finely adjusted in an adjusting mode, so that the exposing lamp 4 is controlled in such a way that it is on the folding line made by connecting four or more points. This provides an exposure voltage which is more approximate to the proper amount of exposure under the copying magnification. |
