| 摘要 |
PROBLEM TO BE SOLVED: To overcome a problem in using the optical sensor for detecting a medium in an environment of remarkably reducing in the quantity of light of an optical sensor, where in adjusting time increases due to an enlargement of a width of voltage applied on a light emitting part of the optical sensor when adjusting the quantity of light. SOLUTION: This medium detecting device has the optical sensor composed of the light emitting part 2154 and a light receiving part 2155, and has a first means for determining the voltage applied on the light emitting part 2154 by using an arithmetic operation executed by a microcomputer 2108 when adjusting the quantity of light of the optical sensor, and a second means controlled by the microcomputer 2108 by a signal from an A/D converter 2107, emitting the light by gradually applying the voltage on the light emitting part 2154, and determining the voltage applied on the light emitting part 2154 according to the fact that output received by the light receiving part 2155 is a prescribed condition. |
