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:
Nov. 14, 1995
Filed:
Mar. 17, 1994
David Leaver, Keymer Hassocks, GB;
International Business Machines Corporation, Armonk, NY (US);
Abstract
A deflection apparatus for a raster scanned cathode ray tube display, the apparatus comprising: a ramp generator having a flyback circuit including a first inductor connected in series with a first transistor switch, the first transistor switch being responsive to a line drive signal to alternately open and close a current path through the first inductor between a first voltage level and a second voltage level lower than the first voltage level to generate a raster scan current signal in a deflection coil of the display, the amplitude of the raster scan current signal being determined as a function of the first voltage level and the frequency of the line drive switching signal, and a boost circuit connected to the flyback circuit, the boost circuit comprising a second inductor connected in series with a second transistor switch, the second transistor switch being responsive to a pulse signal synchronized to the line drive signal to alternately open and close a current path through the second inductor between the second voltage level and a third voltage level higher than the second voltage level to generate the first voltage level, the first voltage level being determined as a function of the third voltage level and the width of the pulses of the pulse signal; and a regulator connected to the flyback circuit and the boost circuit for varying the width of the pulses of the pulse signal as a function of the amplitude of the line scan signal to maintain a constant raster line width as the frequency of the line drive signal is varied.