Patent · US Expired

Apparatus for discriminating sheets

US4352988A · kind A · utility

197Cited by
3References
10Claims
0Family size

Assignee

Inventor

Key dates

Filing dateNov 14, 1980
Grant dateOct 5, 1982
Priority date
Expiry dateNov 14, 2000

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG07D7/12
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A sheet discriminating apparatus comprises, in addition to a first detecting system for detecting light transmitted through a sheet and a second detecting system for detecting light reflected by the front surface of the sheet, a third detecting system for detecting light reflected by the rear surface of the sheet. The light doses sensed by these detecting systems are integrated by respective integrators for a predetermined period of time, and the outputs obtained from the integrators are coupled to an adder and added together therein. The sum output of the adder and a reference signal generator are compared with each other in a comparator, and the determination as to whether the sheet in question is adequate for re-use or not is effected on the basis of the result of the comparison.

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