| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a photo sensor device capable of varying a driving current value of a light emitting element, allowing a binary output element available as a light receiving element by setting an appropriate driving current value of the light emitting element to an output signal level of the light receiving element, and lengthening a distance between the light emitting element and the light receiving element. <P>SOLUTION: Setting the driving current of the light emitting diode 14 to a minimum value "zero", the dark state of the output signal level of a phototransistor 16 obtained at this time is determined. After the output signal level is determined as the dark state, the driving current of the light emitting diode 14 is gradually increased (e.g. 256 stages/8 bits), the driving current value at the time of the level change of the output signal of the phototransistor 16 from the dark state to a bright state is detected, and the twice of the detected driving current value is set as a usual operating current value. The usual operating current value is set as the driving current value of the light emitting diode 14. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
