Edge detecting device in optical measuring instrument
US4652765A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 25, 1985 |
| Grant date | Mar 24, 1987 |
| Priority date | — |
| Expiry date | Nov 25, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/028
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An edge detecting device in an optical measuring instrument for detecting a transmission or a reflected light to directly or indirectly measure a dimension of an object to be measured, the detecting device comprises: a sensor including two light receiving elements disposed on a moving plane of a relative movement between the object to be measured and the two light receiving elements so as to produce phase shift signals in response to a bright or a dark portion during the relative movement; a difference calculator connected to sensor output terminals in the sensor, for calculating a difference between the phase shift signals; a region signal generator for comparing a differential output signal of the difference calculator with reference signals of high level and low level, producing hold signals when the differential output signal is present between the high level and the low level, holding one sensor signal out of the sensor output signals, and outputting a signal in a specific region including a cross point between a reference level signal and the phase shift signals when the output signal is present between the high hold signal and the low hold signal thus held; and detector for …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.