Line flicker reduction by adaptive adjustment of vertical deflection in TV receivers

A system that reduces edge busyness in 50 Hz and 60 Hz systems without the need for full field memory or for 32 kHz line deflection is described. Instead, the vertical deflection of the receiver is adaptively adjusted as required, using only a small 4 bit field buffer and some line delays. The system may also be used with field repetition in receivers using field memory and 32 kHz line deflection. The line flicker reduction system has been incorporated in a prototype of a 100 Hz field repetition receiver. The system has shown good performance, and tests with critical moving patterns have shown no visible artifacts