| 摘要 |
<p>PURPOSE:To obtain the light receiving position of a semiconductor position detecting element accurately without the effect of the amount of light with respect to a material to be measured wherein the amount of incident light is dispersed. CONSTITUTION:A pair of I-V converting circuits 2 and 2' convert the outputs of a PSD 1 into the voltages. The outputs of a pair of the I-V converting circuits 2 and 2' are added in an adding circuit 3. The output of the adding circuit 3 is subtracted from a reference voltage 4 and integrated. The gains of the two outputs of the I-V converting circuits 2 and 2' are amplified with a pair of AGC circuit 6 and 6'. The two outputs of the AGC circuits 6 and 6' are normalized by (A-B)/(A+B). The input voltages into a normalizing circuit 7 can be controlled at the approximately constant level regardless of the dispersion of the amount of the incident light into the semiconductor position detecting element. Thus, the light receiving position can be accurately obtained.</p> |
