Patent · US Expired

Marked card reader employing afocal spatial filtering

US6299066A · kind A · utility

4Cited by
26References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 9, 2000
Grant dateOct 9, 2001
Priority date—
Expiry dateMar 9, 2020

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG05B2219/2633
  • WIPO fieldControl
  • WIPO sectorInstruments

Abstract

A marked card reader having a lensless optical detection system with fixed angle illumination and detection, the sensitivity of which is independent of the frequency response associated therewith. The optical detection system includes a radiation source to produce radiation and a radiation detector. A target plane is positioned so that the radiation source directs radiation toward the target plane. The detection source is positioned to sense radiation reflected from the target plane. An optically opaque body is positioned between the optical detector and the radiation source to prevent incident radiation from be sensed by the optical detector.

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