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:
Jul. 14, 1998
Filed:
Jul. 24, 1996
Robert Albert Boie, Westfield, NJ (US);
William Turin, East Brunswick, NJ (US);
Lucent Technologies Inc., Murray Hill, NJ (US);
Abstract
Disclosed is a system and method for reading and decoding distorted data, e.g., bar code label or other symbology data, by fitting a scanned signal model j(t, .theta.), using a Deterministic Expectation-Maximization (DEM) algorithm, to the measured or detected data signal y(t). The DEM algorithm, which is a novel variation of the conventional Expectation-Maximization (EM) algorithm, enables the system and method according to the invention to determine the values of a plurality of parameters .theta. defining the scanned signal model j(t, .theta.) as it is being fitted to the measured data signal y(t). Based on these values, characteristic information such as data elements or symbols encoded within the image data are generated using conventional signal processing techniques. The use of the DEM algorithm advantageously deblurs the signal by reducing the effects of intersymbol interference. In an alternative embodiment, the DEM algorithm is supplemented by a conventional zero crossings decoding technique. In this manner, the zero crossings technique is used to obtain initial parameter estimates for the DEM algorithm in determining the parameters .theta. of the scanned signal model j(t, .theta.).