Edge detector in optical measuring instrument
US4557602A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 4, 1983 |
| Grant date | Dec 10, 1985 |
| Priority date | — |
| Expiry date | Apr 4, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/028
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An edge detector in an optical measuring instrument, for detecting a transmitted light or reflected light to directly or indirectly measure dimensions of an object being measured, comprising: PA0 a sensor including four light receiving elements provided on a plane substantially in parallel with a plane of relative movement between the sensor and said object being measured, whereby at least two sets of phase shift signals are generated in accordance with brightness and darkness generated during said relative movement; a first and a second operational means for calculating differences between the sets of said phase shift signals; a third operational means for calculating a difference between output signals emitted from said first and second operational means and a fourth operational means for calculating a sum of said output signals; and a detecting means for emitting a crossing signal when an output signal from said third operational means is on a reference level, and when an output signal from said fourth operational means is above said reference level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.