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:
Sep. 15, 2009
Filed:
Nov. 22, 2004
Robert R. Keller, Jr., Chicago, IL (US);
Keith Johnson, Orland Park, IL (US);
Robert C. Markwart, Rolling Meadows, IL (US);
Robert R. Keller, Jr., Chicago, IL (US);
Keith Johnson, Orland Park, IL (US);
Robert C. Markwart, Rolling Meadows, IL (US);
The Chamberlain Group, Inc., Elmhurst, IL (US);
Abstract
A system is disclosed including a transmitter and receiver for the communication of security codes which may be validated at the receiver to operate equipment. In one embodiment, the transmitter transmits a security code at two frequencies contemporaneously to the receiver which may receive both frequencies and resolve the security code therefrom. The receiver may lock onto one frequency to the exclusion of the other frequency when parts of a security code are detected. In another embodiment, the transmitter selectively transmits security codes at a default frequency which is selected because of a recorded count of prior apparent successful transmission.