Optical measuring system
US4648718A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 22, 1985 |
| Grant date | Mar 10, 1987 |
| Priority date | — |
| Expiry date | Jul 22, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/08
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention provides an optical measuring apparatus in which an object to be measured is scanned by parallel measuring rays, the length of the object being measured from changes of intensity of the measuring rays. The received rays are utilized as start and stop signals from a counter for counting clock pulses. The measuring rays are emitted from a laser and reflected by a rotating mirror to scan the object. When the measuring rays are blocked by the object, the counting operation of the counter is initiated. As the rays again appear from behind the object, the counting operation is stopped. The number of clock pulses counted between the start and stop of the counting operation is used to measure the length of the object. Any error induced from deflection or scattering of the measuring rays at the end faces of the object or from the transparent part of the object can be avoided by providing a register for latching the output of the counter. The register latches the value in the counter on receiving either of a detection signal indicative of the finish end of the object or false detection signals. The final latched value corresponding to the finish end of the object is utilized.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.