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Dynamic Dynamic Focusing Circuit for High Resolution Display Monitor

IP.com Disclosure Number: IPCOM000057850D
Original Publication Date: 1988-Jul-01
Included in the Prior Art Database: 2005-Feb-15

Publishing Venue

IBM

Related People

Authors:
Ohsawa, T [+details]

Abstract

An object of this circuit is to be able to apply one more dynamic focusing correction on a current dynamic focusing circuit. A new method is referred to as DDF (Dynamic Dynamic Focusing) and a new Additional Dynamic Correction is referred to ADC. Recently on cathode ray tubes, a full square (FS) tube and a wide angle deflection (WAD) tube are being required to realize legible screen and compact size. But, because of the difference of the deflec- tion radius and the face plate radius, a mismatch of the focusing problem is caused. Focusing voltages should vary according to the distance from the center of deflection to a face plate where the beam lands. The optimum focusing voltages are almost directly proportional to aX2+bY2+cX2Y2 . (X is horizontal distance, and Y is vertical distance of the landing point from the center).