Detector for bidirectional movement of an extensible member in an electronic digital scale
US4150282A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 26, 1977 |
| Grant date | Apr 17, 1979 |
| Priority date | — |
| Expiry date | Oct 26, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B3/1069
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An extensible tape member is provided to extend along an object to be measured, and to permit a detection plate to rotate in unison with the pulling in and out movement of the extensible member. A pair of photo-electric elements is positioned with respect to the detection plate for developing detection signals in accordance with rotation of the detection plate. The detection signals are developed as a function of an amount of the extension of the tape member and the direction of the tape extension. The detection signals derived from the pair of the elements have a phase difference with respect to each other so as to determine whether the extensible tape member is being pulled out or in the housing of the digital scale, that is, the direction of the extension of the tape member. The detection signals are introduced into a logic circuit for developing control signals which are supplied to a display driver. The driver excites a display which provides an indication of distance information responsive to measured length.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.