| 摘要 |
PURPOSE:To shorten the period of a read scan by using a CCD image sensor as a charge storage type photoelectric converting element and also by taking a scan for erasing charge accumulated in the element by residual light from a light source. CONSTITUTION:Fluorescent lamp 1 is applied with a driving voltage from fluorescent-lamp lighting power source 7 for time TA. Then, the time from the start of the lighting of fluorescent lamp 1 until light emitting intensity becomes zero is denoted as TB. Next, CCD image sensor 14 is made to take a scan for reading signal charge accumulated for time TA from the point in time when the driving voltage to fluorescent lamp 1 becomes zero, thereby obtaining a color-separated picture signal. Next, a scan for reading signal charge accumulated in sensor 14 is carried out by the residual light of fluorescent lamp to discharge sensor 14 completely. Then, the picture signal obtained by this scan is inhibited from being output. From when the read scan of sensor 14 is started, switch 8 is changed over and fluorescent lamp 2 is applied with the driving voltage from electric power source 7 for the same operation. Next, original 3 is sent up to the next scanning line within the residual- light time of a fluorescent lamp 2. |
