| 摘要 |
<p>PURPOSE:To improve the linearity of a detecting output variation characteristic against a position variation of a detecting body by constituting a negative feedback control system of a transmitting element, a receiving element and a control circuit. CONSTITUTION:When a detecting body 1 moves and approaches a transmitting element 2 and a receiving element 3, a transmitting wave reflected by the detecting body 1 and received by the receiving element 3 increases, and a receiving output of the receiving element 3 increases. This receiving output is supplied to a control circuit 4. The control circuit 4 controls an input signal supplied to the transmitting element 2 in the direction in which its transmitting output decreases. By this negative feedback control operation, a detecting output which is varied roughly linearly against a variation of a relative distance of the detecting body 1 is obtained.</p> |
