| 摘要 |
<P>PROBLEM TO BE SOLVED: To increase the light quantity of a light source of a scanner having a structure using light-emitting diodes. <P>SOLUTION: A plurality of chip-like light-emitting diodes (LEDs) 1 are fixed on the surface of a substrate P made of a thermally conductive material satisfactorily transmitting heat, a Peltier element 14 and a thermal conductor 15 are provided on the rear surface of this substrate, a heat exchange mechanism EX is provided for transmitting the heat of the thermal conductor 15 to an external fin 16 of a light source case by a liquid thermal medium to forcibly cool, and a control device is provided for controlling this heat exchange mechanism EX to perform control to increase a current to be supplied to the LEDs 1 for maintaining the temperature of the substrate P at less than a thermal destructive temperature of the LEDs 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
