Electro-optical measuring system
US4427296A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 3, 1981 |
| Grant date | Jan 24, 1984 |
| Priority date | — |
| Expiry date | Sep 3, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/105
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An electro-optical measuring system is described wherein a laser or light beam is precisely translated in a straight line perpendicular to the direction of propagation of the beam at a uniform, repeatable speed to define a time-varying sensing field whose energy is picked up by a photosensor which yields an output signal. An object whose dimension is to be measured is inserted in the field whereby the output signal of the photosensor takes the form of a pulse whose leading edge is developed by the traversal of the beam across one edge of the object, thereby blocking passage of the energy to the photosensor. The trailing edge is developed by the traversal of the beam across the opposite edge of the object thereby restoring the energy to the photosensor. The width or time duration of the pulse is a measure of the distance between the two edges. Measurements of exceptional precision are obtained by a circulation reducer in the light path of the translated beam to substantially eliminate convection currents in the air, further precision is obtained by using group delay equalization in the edge sensing signal processing to reduce systematic errors due to variations in edge pulse width, …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.