| 摘要 |
PURPOSE:To obtain correct exposure on a photoreceptor with respect to a change in macro-magnifications over a wide range by combining the control of the quantity of the light emitted by an exposure lamp and the control of the quantity of the light by a slit. CONSTITUTION:A microfilm 2 is projected onto a photosensitive drum 5 by a projecting lens 3. If only the quantity of light of a lamp 1 is regulated to control the exposure in accordance with a change in macro-magnifications in this case, there is the possibility of an unstable change in the sensitivity of the photosensitive naterial on the emitted light. Thereupon, a magnification setting instructiob signal is applied from a setting means 10 to a microcomputer 9, then a control signal is emitted to a slit driving means 7 and the lamp, by which both of the slit width and the quantity of light of the lamp are changed. Since the wavelength of the light emitted by the lamp does not change largely, unstability with the sensitivity of the photosensitive material on the drum is reduced. |
