The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 01, 1989
Filed:
Oct. 28, 1987
Werner Vogt, Remetschwil, CH;
Anton Schuhwerk, Geislingen, DE;
Interflex Satensysteme GmbH, Stuttgart, DE;
Abstract
A forgery-proof optoelectric card system is disclosed which includes a reader and code card comprising invisible light and dark codings forming at least one reading track. At least one reading head is provided which may comprise a photodiode as a ligh source and a phototransistor as a light receiver. The light codings having a first pass band to infrared light. Superimposed over selected ones of said light codings are filters having an attenuation band that is narrower than and lies within the pass band of the light codings. Additionally, a secondary light receiver responsive only to light lying within the attenuation band of the filter is provided.