| 摘要 |
<p>The invention is directed to change a gain of the received light intensity at a stable rate, with respect to sensitivity adjustment manipulations. A photoelectric sensor amplifies a received light intensity signal generated through light projection processing and light receiving processing, and performs detection processing using the amplified received light intensity signal. The photoelectric sensor is provided with a device (a variable resistor) generating an adjustment command signal changing linearly with respect to sensitivity adjustment manipulations performed by a user. Further, the sensor is provided with an amplification processing part including a variable gain amplifier which is adapted such that the aforementioned adjustment command signal is inputted thereto. Further, the variable gain amplifier is adapted to convert the signal into a gain control signal changing exponentially with respect to sensitivity adjustment manipulations and, further, is adapted to perform amplification processing using a gain according to the gain control signal.</p> |
