Photocell distance measurement
US4917488A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 17, 1989 |
| Grant date | Apr 17, 1990 |
| Priority date | — |
| Expiry date | Jan 17, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S11/12
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus and method for measuring the distance between CRT image display and a photocell spaced apart from the CRT, including apparatus to selectively illuminate a point and a line on the image screen, and apparatus which provides a distance measurement according to the ratio of the received light for the point and the line image, respectively. The present invention provides a highly accurate, non-contacting apparatus and method for measuring distance and is inherently independent of many sources of distance measurement error. Moreover, approximations in the technique are available which provide measurement accuracy to a predetermined level. The resulting apparatus, when mounted in an optical system, provides for the accurate adjustment of the optical system parameters and components.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.