Patent ID: 8907717

Claim:
A light receiving circuit, comprising: a photoelectric conversion element for causing a current corresponding to an amount of incident light to flow; a MOS transistor including a source connected to the photoelectric conversion element and a drain connected to a node, for causing the current of the photoelectric conversion element to flow to the node while maintaining a voltage of the source to a first voltage; a reset circuit for causing a current to flow from the node to a GND terminal so that a voltage of the node becomes a second voltage lower than the first voltage; a control circuit for outputting a reset signal to the reset circuit; and a voltage increase detection circuit for detecting a fluctuation in the voltage of the node and outputting a detection result, the reset circuit being configured to cause, when the reset signal of the control circuit is input, the current to flow from the node to the GND terminal so that the voltage of the node becomes the second voltage, and to hold this state when the reset signal is no longer input.