Abstract: A power supply device is provided with the following: a rectifier circuit that rectifies an alternating voltage from an alternating current source; a booster circuit that boosts the voltage after rectification, and generates an input side voltage of a voltage conversion unit; the voltage conversion unit that outputs a voltage required for reducing the input side voltage and supplying the input side voltage to a light source; a voltage current detection unit that determines whether or not the light source is connected; and an output voltage control unit that, if it is determined that a first resistor and a second resistor, which are connected in parallel with respect to the light source, and the light source are not connected, controls the voltage of the first resistor so that the voltage is no more than a prescribed value.

Abstract: A power supply device is provided with the following: a rectifier circuit that rectifies an alternating voltage from an alternating current source; a booster circuit that boosts the voltage after rectification, and generates an input side voltage of a voltage conversion unit; the voltage conversion unit that outputs a voltage required for reducing the input side voltage and supplying the input side voltage to a light source; a voltage current detection unit that determines whether or not the light source is connected; and an output voltage control unit that, if it is determined that a first resistor and a second resistor, which are connected in parallel with respect to the light source, and the light source are not connected, controls the voltage of the first resistor so that the voltage is no more than a prescribed value.

Abstract: An optical modulation-type detection device has a noise detection mode having (i) an offset canceling (hereinafter referred to as “OC”) period in which (a) the light-reception signal pathway of a pulse signal converting section is cut off so that an offset of the pulse signal converting section is suppressed and (b) the light-reception signal pathway of the pulse signal converting section is reconnected while a state in which the offset is suppressed is being maintained, at an end of the OC period, and (ii) an asynchronous reception period in which whether or not asynchronous reception occurs is detected after the first period, and an object detection mode having a synchronous reception period in which whether or not synchronous reception occurs is detected after the asynchronous reception is not detected in the noise detection mode.

Abstract: An optical modulation-type detection device has a noise detection mode having (i) an offset canceling (hereinafter referred to as “OC”) period in which (a) the light-reception signal pathway of a pulse signal converting section is cut off so that an offset of the pulse signal converting section is suppressed and (b) the light-reception signal pathway of the pulse signal converting section is reconnected while a state in which the offset is suppressed is being maintained, at an end of the OC period, and (ii) an asynchronous reception period in which whether or not asynchronous reception occurs is detected after the first period, and an object detection mode having a synchronous reception period in which whether or not synchronous reception occurs is detected after the asynchronous reception is not detected in the noise detection mode.