| 摘要 |
<P>PROBLEM TO BE SOLVED: To stabilize the image quality of an image read during normal document reading, and to suppress glare of a user during pre-scanning. <P>SOLUTION: Based on a lighting period signal pwm output by the TG 11a, the DUTY_CTL 21a outputs a lighting signal for controlling the lighting period of LEDs 3a-3c by PWM system to the DRV 23. Based on a current control signal cur_sig output by the TG 11a, the CUR_CTL 22a outputs a current set value for setting the current values being supplied to the LEDs 3a-3c by the current variable system to the DRV 23. Based on a lighting signal output by the DUTY_CTL 21a, the DRV 23 controls the lighting period of the LEDs 3a-3c, i.e., the lighting and unlighting. Furthermore, based on a current set value output by the CUR_CTL 22a, the DRV 23 controls the instantaneous value of the amount of light of the LEDs 3a-3c. <P>COPYRIGHT: (C)2013,JPO&INPIT |
