| 摘要 |
PURPOSE:To improve the quality of copies by detecting the position of an original placed on an original platen and driving automatically an original moving device to move the original to a correct position if the position is not correct. CONSTITUTION:The surface of an original pressing plate 133 in the side facing an original platen 132 is made black, and the reflected optical image from an original 131 is focused through a lens 138 by a CCD sensor 140, and the variable density of the picture is read, and the output is amplified by an amplifier 141 and is converted to a digital value by an A/D converter 142. This digital value is compared with a standard value and is corrected by a correcting circuit 143, and the picture is bindarized to white or black by a binarizing circuit 144. When the original 131 is placed on the original platen 132, thereflected optical image is read along the Y axis by picture elements of the CCD sensor 140, and coordinates of the position of the first change from black to white and the position of the last change from white to black are obtained for every line in the Y-axis direction by scanning in the X-axis direction. A CPU performs operations on a basis of position detection signals, and a turning angle signal ST, a signal SX of the extent of movement in the X axis direction, a signal SY of the extent of movement in the Y axis direction, and home position detection singals SHX and SHY for correction are supplied to a controller 230.
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