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US 7,247,834 B2Granted
Photoelectric sensor for detecting presence/absence of object
AssigneeHosiden Corporation
InventorKouji Fujita
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AssigneeHosiden Corporation
InventorKouji Fujita
Estimating the term…
An object of the present invention is to enable the detection of the presence/absence of an object over a plurality of detection areas without using a plurality of light-receiving devices and light-emitting devices. A sensor detects the presence/absence of an object in a detection area where a light-emitting area of a light-emitting device and a light-receiving area of a light-receiving device are overlapped with each other, and includes: a power supply unit that outputs a driving current I of the light-emitting device such that its current value is variable; a control unit that has the function of controlling the power supply unit to change in magnitude of the driving current I of the light-emitting device, and determining the presence/absence of an object based on an output from the light-receiving device to output the result of determination as a detection signal; and an output signal 50 that converts the detection signal into an analog signal to output the converted signal as a signal α.
A photoelectric sensor for detecting the presence/absence of an object in a plurality of detection areas where a plurality of light-emitting areas of a light-emitting device and a single light-receiving area of a light-receiving device are overlapped with each other, the photoelectric sensor comprising:
A photoelectric sensor for detecting the presence/absence of an object in a detection area where a light-emitting area of a light-emitting device and a light-receiving area of a light-receiving device are overlapped with each other, the photoelectric sensor being configured to allow the light-emitting device to emit light, compare an output level of the light-receiving device with a plurality of reference values different from one another, and output the result of comparison as a digital or analog detection signal in order to detect the presence/absence of the object over a plurality of detection areas, wherein in order to produce the detection signals based on the output levels of the light-receiving device, said plurality of reference values are repeatedly changed in a predetermined pattern and compared with the output level and the results of comparison are outputted in sequence.
Dependencies are inferred from the claim text.