| 摘要 |
PURPOSE:To maintain good image performance by providing plural discrete adjusting means which set exposure controlling electric powers in corrspondence respectively to the combinations of image magnifications and image densities and an overall adjusting means which adjusts each controlling electric power overall. CONSTITUTION:The high level outputs of a microcomputer 12 are transmitted respectively via inverters to variable resistors VR2, VR3, VR4, VR5, VR6, VR7, VR8, VR9, so that the voltages corresponding to the set values of the respective variable resistors are applied to a lamp 5 by a dimming circuit 13. The optimum image exposure is obtained by adjusting the resistors VR1-VR9 discretely. For example, when a photographic fog comes to be produced in the images, it is corrected by adjusting only the variable resistor VR10 for overall adjustment, whereby the good image performance free from photographic fogs is maintained. |
