Method and device for generating a signal dependent on the distance of an object in an object space
US4040739A · kind A · utility
Inventor
Key dates
| Filing date | Mar 15, 1976 |
| Grant date | Aug 9, 1977 |
| Priority date | — |
| Expiry date | Mar 15, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01C3/32
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A light beam passes through a physical pattern of opaque and transparent areas and is projected into space to an image plane. Upon an object appearing at the image plane the pattern is reflected back to the physical pattern as a second pattern image. The optical system is such that, in part, this second pattern image is a reversal of the pattern. The physical pattern is on a rotating drum to produce relative motion between the second pattern image and the pattern. Light from the second pattern image which passes through the pattern is received by a photoelectric cell to generate a signal. By having the pattern in the form of a spiral and the width of the pattern correspond to the width of the light beam at the point where it intersects the beam, various distances can be detected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.