| 摘要 |
PURPOSE:To improve the copy productivity by correcting only one color among plural colors with a reflected luminous quantity from a reference white color board in the case of reading an original and correcting luminous quantity fluctuation through the multiplication of a prescribed correction value with other colors. CONSTITUTION:An analog gain at A/D conversion is matched (AGC) during warm-up before copy operation by an output of a CCD color sensor 8 reading a reference white color board 9. The AGC is implemented only to a green channel (G) severest in the characteristic of the visual sensitivity and the setting value is stored in a RAM. In the case of continuous copy, an output of the sensor 8 before the AGC input is corrected or the AGC setting is revised based on the processing of (G setting value X green/blue or green/red correction coefficient) with respect to blue and red channels. Thus, the digital read gradation number is constant for blue, green, red colors, the density fluctuation is suppressed, and one restoration of the read position of the board 9 is enough for one copy and the productivity is improved. |
