Light amount measuring apparatus
AssigneeOki Semiconductor Co., Ltd.
InventorTadashi Chiba
Life of this patent
Estimating the term…
Abstract
A light amount measuring apparatus including a light amount measuring circuit and a power supply for supplying power to the light amount measuring circuit; wherein the light amount measuring circuit includes a light receiving device for receiving light and outputting an electric signal corresponding to light amount of the received light; a first switch for switching between electrical connection and disconnection between the light receiving device and the power supply; and a drive controller for controlling the first switch so that the first switch electrically connects the light receiving device to the power supply when the light receiving device is set to an activated state and electrically disconnects the light receiving device from the power supply when the light receiving device is set to a deactivated state.
Claims7
A light amount measuring apparatus comprising:
- a light amount measuring circuit;
- and
- a power supply for supplying power to the light amount measuring circuit;
- wherein the light amount measuring circuit includes:
- a light receiving device for receiving light and outputting an electric signal at an output node of light receiving device, the electric signal corresponding to a light amount of the received light;
- a first switch for switching between electrical connection and disconnection of the light receiving device and the power supply;
- and
- a drive controller for controlling the first switch so that the first switch electrically connects the light receiving device to the power supply when the light receiving device is set to an activated state and electrically disconnects the light receiving device from the power supply when the light receiving device is set to a deactivated state.
A light amount measuring apparatus comprising:
- a light amount measuring circuit;
- and
- a power supply for supplying power to the light amount measuring circuit;
- wherein the light amount measuring circuit includes:
- a light receiving device for receiving light and outputting an electric signal at an output node of light receiving device, the electric signal corresponding to a light amount of the received light;
- an amplifier circuit for amplifying the electric signal output by the light receiving device;
- a first switch for switching between electrical connection and disconnection of the light receiving device and the power supply;
- a drive controller for controlling the first switch so that the first switch electrically connects the light receiving device to the power supply when the light receiving device is set to an activated state and electrically disconnects the light receiving device from the power supply when the light receiving device is set to a deactivated state, the drive controller additionally activating the amplifier circuit when the light receiving device is set to the activated state and deactivating the amplifier circuit when the light receiving device is set to the deactivated state, and
- a second switch for switching between electrical connection and disconnection of the output node of the light receiving device and a ground, and
- wherein the drive controller controls the second switch so that the second switch electrically disconnects the output node of the light receiving device from the ground when the light receiving device is set to the activated state and electrically connects the output node of the light receiving device to the ground when the light receiving device is set to the deactivated state.
Dependencies are inferred from the claim text.