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. 18, 2012
Filed:
Sep. 24, 2008
Applicant:
Patrick M. Campbell, St. Paul, MN (US);
Inventor:
Patrick M. Campbell, St. Paul, MN (US);
Assignee:
3M Innovative Properties Company, Saint Paul, MN (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G09G 5/10 (2006.01);
U.S. Cl.
CPC ...
Abstract
A unipolar gray scale drive scheme for passive matrix displays, more specifically, cholesteric liquid crystal displays, capable of creating any number of desired levels of gray scale. The drive scheme is single stage and can use either an amplitude modulation or a pulse width modulation column voltage signal in combination with a selecting row voltage signal to drive a pixel receiving the two intersecting signals to a desired level of gray scale.