| 摘要 |
PURPOSE:To attain color reproducing with stable and excellent picture quality by reading a color test chart so as to generate a reference color signal, applying a prescribed processing to this signal and correcting the color. CONSTITUTION:When a test mode switch 165 is turned on, a color test chart is read, and reference color signal separated into three red B, green G and red R are photo detected by image pickup elements 14, 16 and 18, respectively. Then, the color signal drives a semiconductor laser 21 via an image processing section 27. The copy image of the test chart formed by the laser light is read by a photo sensor 170 and its output signal is inputted to a main body control section 64. When an output difference among four phototransistors sensing the pattern different from the gradation of the sensor 170 is a prescribed value or over, it is decided that the gradation is sufficient and when the output difference is a prescribed value or below, the control section 64 selects a gamma memory by color of a gamma correcting unit and corrects the gradation. When the value is not corrected out, an alarm lamp 167 is lighted so as to raise alarm. |
