| 摘要 |
PROBLEM TO BE SOLVED: To obtain an image reader where occurrence of moire can be reduced. SOLUTION: In the case that levels of read outputs of R, G, B channels of photo sensors while keeping R-LED, G-LED, B-LED lighted are in the order of Vb>Vr>Vg, a ratio of lighting time of the LEDs is in the order of DG> DR>DB. For example, when a blinking period of the LEDs is 100μs and a received luminous quantity of the photo sensor is desirably 70%, a ratio of the lighting time is selected to be 0.7 and a drive signal is controlled to repeat blinking with a lighting time of 70μs and a blackout time of 30μs in one period. When image reading is started, a control section moves a carriage in parallel with an original face and perpendicularly to an arrangement direction of light emitting diode elements while the blinking the light source for a prescribed period and at a ratio of the DR, DG, DB.
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