| 摘要 |
PURPOSE:To obtain a flat distribution of the quantity of light over the entire surface of a sensor block by turning on not only a light source facing a sensor block, but also light source block at both ends of the light source block. CONSTITUTION:When a clock waveform 1P-CLK is inputted from an input terminal 6, flip-flops FF1-FF3 are set by the rise of said waveform and Q output terminals are held at ''1'', so that a light source element driving circuit 7 turns on light sources D1-D3. Simultaneously, a sensor signal leading-out circuit (not shown in the figure) operates at the timing of a readout clock. Then, the flip-flop FF1 is reset at the rise of the clock waveform 1P-CLK, and the output Q of the FF4 is set to ''1'' at the rise of a 2PCLK on condition that the output Q of the FF1 is ''0'' and outputs Q of the FF2 and FF3 are both ''1'', so that the light sources D2, D3, and D4 are turned on. |
