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:
Mar. 06, 2001
Filed:
Jul. 23, 1999
Dennis P. O'Neill, Monte Sereno, CA (US);
Linear Technology Corporation, Milpitas, CA (US);
Abstract
This invention provides apparatus and methods for causing a fluorescent lamp drive circuit to provide a continuous drive signal over a first (high) range of lamp intensity, and a pulse width modulated (PWM) drive signal over a second (low) range of lamp intensity, with a smooth transition between continuous and PWM drive that is unnoticeable to the user. This invention also provides fluorescent lamp circuits that include lamp intensity control circuitry, fluorescent lamp drive circuitry and a fluorescent lamp, the lamp intensity control circuitry providing control signals that cause the fluorescent lamp drive circuit to provide a continuous drive signal over a first (high) range of lamp intensity, and a PWM drive signal over a second (low) range of lamp intensity, with a smooth transition between continuous and PWM drive that is unnoticeable to the user.