| 摘要 |
PROBLEM TO BE SOLVED: To provide a light reception circuit that can detect only an abrupt change in the quantity of light with high sensitivity, and is low in current consumption, low in cost and small in size.SOLUTION: The light reception circuit includes: a photoelectric conversion element for causing a current depending on a quantity of incident light to flow to a node; a voltage detection circuit for outputting a detection signal when a voltage of the node becomes equal to or higher than a first voltage; a reset circuit for, when the detection signal of the voltage detection circuit is input, causing the current of the photoelectric conversion element to flow to a GND terminal such that the voltage of the node becomes a second voltage lower than the first voltage, and when the detection signal is no longer input, holding the state; and a voltage rise detection circuit for detecting a fluctuation in the voltage of the node and outputting a detection result. |
