摘要 |
PROBLEM TO BE SOLVED: To embody the rapid optimization of the light quantity of the light emitted in a light emitting part of a pattern detecting means with simple constitution. SOLUTION: Patterns 130 for light quantity control consisting of a single color (C in Figure) having a size of a prescribed value or above along a sub- scanning direction are formed separately from pattern 132 for image position detection for detecting and regulating the positions of respective color toner images are formed on an intermediate transfer belt 30 formed with the toner images of respective colors Y, M, C, and Bk by plural image forming sections The light quantity of the IR light emitted from LEDs and reflected by the patterns 130 for light quantity control is detected by photodiodes and the LED drive current value for regulating the light quantity of the light emitted by the LEDs when detecting the patterns 132 for image position detection to an optimum value is determined in each of image detecting sections 90A, 90B and 90C. |