Optical measuring device having d.c. component elimination
AssigneeDenso Corporation
InventorsTetsuya Nakashima, Yasuji Inobe, Seiji Nagakusa, Teiyuu Kimura
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Abstract
An optical measuring device includes a sensor which emits light flashes toward a subject of detection with a light emitting element which is supplied with electric power from a rechargeable battery for a certain duration at certain intervals and receives reflected light from the subject with a light sensitive element. A subtractor subtracts a d.c. component from a sensed signal provided by the light sensitive element, thereby extracting a variation component. The subtractor has its output signal amplified with an amplifier, with the output thereof being A/D-converted with an A/D converter.
Claims11
An optical measuring device comprising:
- a sensor having a light emitting element which emits light flashes to a subject of detection by being supplied with electric power from a battery for a prescribed duration at prescribed intervals and a light sensitive element which receives reflected light from the subject;
- a subtractor which subtracts a d.c. component from a sensed signal provided by the light sensitive element, thereby extracting a variation component;
- an amplifier which amplifies an output signal of the subtractor;
- and
- an A/D converter which implements an A/D conversion for an output signal of the amplifier.
Dependencies are inferred from the claim text.