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:
Jun. 26, 2001
Filed:
Jun. 14, 1999
Daniel James Winarski, Tucson, AZ (US);
Masaki Hasegawa, Kanagawa-ken, JP;
Kamal Emile Dimitri, Tucson, AZ (US);
Robert LaMar Bingham, Tucson, AZ (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A bar code reader for an automated storage library has a lens assembly with a pair of polarized liquid crystal lenses. Each lens has pair of parallel glass plates that are separated by upper and lower glass substrates. A series of polymer films are symmetrically spaced apart between the substrates. Both the substrates and the films are perpendicular to the glass plates. Electrodes are formed on the films and combine to form a semi-cylindrical stack of film. Liquid crystal fills the spaces between adjacent pairs of the films. The films are coated and/or treated by an alignment process to predispose the liquid crystals to a specific rotational direction. When a selected voltage is applied between adjacent ones of the electrodes, the liquid crystals are synchronously rotated to alter their refractive index to a desired value. Thus, when the layers of each lens are manipulated in unison, the bar code reader is able to quickly adjust its focal length to read bar codes at various distances.