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. 17, 1999
Filed:
Dec. 24, 1997
Applicant:
Inventor:
Michael R Praiswater, Albuquerque, NM (US);
Assignee:
Honeywell Inc., Minneapolis, MN (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H05B / ;
U.S. Cl.
CPC ...
315D / ; 3152 / ; 315219 ;
Abstract
A method and apparatus for dimming a lamp in a backlight system of a display device, e.g., liquid crystal display ('LCD'), with a brightness dimming ratio of 10,000:1, which is a factor of 10 better than conventional dimming devices. A switch is provided in an inverter circuit, which has reactive components, that drives the lamp. The is positioned in the inverter circuit such that, when it is closed, the energy stored within the reactive components of the inverter circuit is discharged to ground. In one embodiment, the signals from the power supply are pulse width modulated.