US 5,345,076 A · Optically trimmed sensor for reducing influence of differential node losses

Abstract

A technique is disclosed for optically trimming a sensor (10) to account for manufacturing variations in the losses of the sensor. As a result, the sensor can be used interchangeably, without requiring adjustment of the processing system (12) the sensor is used with. More particularly, in one embodiment, variably transmissive optical filters 72 and 74 are positioned inside the sensor to effectively alter or standardize the losses of the sensor. Various other arrangements, including the use of variably reflective mirrors, wavelength selective elements, blocking elements, and path adjustment elements, are also described in which the characteristics of the sensor's optical paths are altered.

Claims27

Dependent claims

A sensor for transmitting an optical beam as part of the production of an output indicative of a parameter said sensor is exposed to, said sensor comprising:

transmission means for defining at least a first and a second optical transmission path for the optical beam within said sensor, said first and second optical transmission paths exposing the optical beam to differential losses that may influence the output of said sensor;
and
optical filter means, positionable in any of the first and the second optical transmission paths defined by said transmission means, for altering the optical characteristics of the optical transmission path in which the optical filter means is positioned to reduce the influence that the differential losses might have on the output of said sensor.

A sensor for processing an input beam of radiation received along an input path to produce an indication of the position of a sensed object relative to a reference object, the input beam including a first component having a first wavelength and a second component having a second wavelength, said sensor comprising:

filter means for separating the input beam into the first and second components;
modulation means for modulating the first component of the input beam with information relating to the position of the sensed object relative to the reference object and producing first and second modulated output beams of radiation;
separation means for separating the second component of the input beam into first and second reference output beams of radiation;
and
adjustment means for trimming at least one of the first modulated output beam, second modulated output beam, first reference beam and second reference beams of radiation.

2 more elements

Dependencies are inferred from the claim text.

Optically trimmed sensor for reducing influence of differential node losses

Life of this patent

Optically trimmed sensor for reducing influence of differential node losses

Life of this patent

Abstract

Claims27