Browse Prior Art Database

HIGH ORDER HORIZONTAL POSITION CORRECTION

IP.com Disclosure Number: IPCOM000008715D
Original Publication Date: 1998-Jun-01
Included in the Prior Art Database: 2002-Jul-04
Document File: 2 page(s) / 66K

Publishing Venue

Motorola

Related People

K. H. Lam: AUTHOR [+3]

Abstract

For large screen monitors, there is a requirement to have high order horizontal position correction and E/W correction, but there is currently no 1. C. available on the market which provides these corrections.

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MOTOROLA Technical Developments

HIGH ORDER HORIZONTAL POSITION CORRECTION

by K. H. Lam, P. K. Dunn and K. 6. Nip

INTRODUCTION

  For large screen monitors, there is a requirement to have high order horizontal position correction and E/W correction, but there is currently no 1. C. available on the market which provides these corrections.

The traditional approach is shown in Figure 1, in which waveform generation utilizing a ramp

generator and a multiplier was implemented to provide the horizontal position correction and the E/W correction was achieved by generating a ramp (ax) and parabola (bXi) for parallelogram, bow, and pin-cushion correction (ax + bXi). To have higher order correction (cX3, dX'...), more multipliers would be required, which involves complicated design methodology with consequent increases in both time and cost.

        -/ x 45 RAMP GENERATOR CAIN CONTROL ADDER - OUTPUT ax + b?

PARAUELOG

AM CONTROL

"SYNC __

j-q=E

bXZ

1

Fig. 1

NEW CIRCUIT high order equation (ax + bX* + cX' + . ..) can be programmed by modifying the 2N latch contents. in

  Figure 2 shows a block diagram of a new circuit which the number of bits of the counter N, is set in which a high frequency oscillator that operates to, for example, 5. This value could be increased at 2% the vertical frequency was implemented to or decreased to fit the requirements of different synchronize with the vertical sync by a phase lock monitors. As a result, a high order waveform can be loop so as to provide...