| 摘要 |
PURPOSE:To prevent partial disorder of recording image quality by providing a copying control information processor which detects the photoreceiving of a photoelectric converting element and processes copying control information. CONSTITUTION:From a CPU to FET transistors (TR) FT1 and FT2, a switching signal is sent as a timing signal. Since a fluorescent lamp which is turned on at a high frequency is used as a light source 4, its luminance increases and decreases in every half cycle and its emitted light is detected bya photocell, whose output is observed through an oscilloscope. Consequently, the light is seen as if it pulsates, and luminance with a ripple similar to the frequency of high-frequency lighting is obtained. Therefore, zero-cross pulses of this frequency are applied to the CPU, which constitutes photodetection level detecting circuits 291-2913 for outputting switch signals when the luminance is maximum as shown in the figure, thereby obtaining invariably constant luminance. |
