Light-operated proximity detector with linear output

Patent · Tue May 07 04:00:00 EDT 1985

OSTI ID:6458696

Simpson, M L; McNeilly, D R

A light-operated proximity detector is described in which reflected light intensity from a surface whose proximity to the detector is to be gauged is translated directly into a signal proportional to the distance of the detector from the surface. A phototransistor is used to sense the reflected light and is connected in a detector circuit which maintains the phototransistor in a saturated state. A negative feedback arrangement using an operational amplifier connected between the collector and emitter of the transistor provides an output at the output of the amplifier which is linearly proportional to the proximity of the surface to the detector containing the transistor. This direct proportional conversion is true even though the light intensity is varying with the proximity in proportion to the square of the inverse of the distance. The detector may be used for measuring the distance remotely from any target surface.

• Assignee: The United States of America as represented by the United States Department of Energy
• Patent Number(s): US 4516020
• OSTI ID: 6458696
• Country of Publication: United States
• Language: English

Related Subjects

440300* -- Miscellaneous Instruments-- (-1989)
47 OTHER INSTRUMENTATION
AMPLIFIERS
ELECTROMAGNETIC RADIATION
ELECTRONIC EQUIPMENT
EQUIPMENT
FEEDBACK
MEASURING INSTRUMENTS
PHOTOTRANSISTORS
RADIATION DETECTORS
RADIATIONS
REMOTE SENSING
SEMICONDUCTOR DEVICES
SIGNALS
SOLAR EQUIPMENT
SPECTRALLY SELECTIVE SURFACES
SURFACES
TRANSISTORS
VISIBLE RADIATION