| 摘要 |
PROBLEM TO BE SOLVED: To provide an image reader capable of appropriately and rapidly stabilizing the light quantity of a light source for irradiation of an original with reading light. SOLUTION: In the color image reader, the temperature of the tubular surface of a lamp 4 for irradiating the original with the reading light is detected by a thermistor 52, and the detected temperature of the lamp 4 is compared with target temperature by a temperature data comparison part 72. Based on the result of comparison, the lighting frequency of the lamp 4 is obtained by a frequency arithmetic operation part 73, and the lamp 4 is lit at the obtained lighting frequency by an inverter circuit 62 to rapidly stabilize the light quantity of the light source. Therefore, the output of a CCD which photoelectrically converts reflected light from an original with which the original is irradiated from the lamp 4 is easily and rapidly stabilized to the target output of the CCD, and the image quality of a read image is improved. COPYRIGHT: (C)2008,JPO&INPIT |
