Patent · US Expired

Apparatus for detecting edge of semitransparent plane substance

US4559452A · kind A · utility

97Cited by
6References
10Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 27, 1983
Grant dateDec 17, 1985
Priority date
Expiry dateMay 27, 2003

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG07D7/17
  • WIPO fieldControl
  • WIPO sectorInstruments

Abstract

An apparatus for detecting an edge of a semitransparent plane substance provided with a light source array including a plurality of light sources and a photosensor array including a plurality of photosensors. A selection circuit selects a pair of one of the light sources and one of the photosensors, respectively, and a comparator circuit compares the outputs of each of the photosensors in each pair when no detected substance exists between the light source array and the photosensor array, and the corresponding outputs when a substance exists between the light source array and the photosensor array, so that the edge portion of the substance can be detected.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.