US 5,329,367 A · Horizontal blanking

Abstract

In a horizontal deflection system, an nf.sub.H timing signal is generated synchronously with an f.sub.H horizontal synchronizing component in a video signal, where nf.sub.H is a higher frequency than f.sub.H. A first circuit is responsive to the nf.sub.H timing signal for generating an nf.sub.H scan synchronizing signal synchronously with the nfH timing signal. A horizontal deflection stage is operable at nf.sub.H and responsive to the nf.sub.H scan synchronizing signal. A second circuit is responsive to the same nf.sub.H timing signal for generating horizontal blanking pulses. The nf.sub.H timing signal can be generated by a first phase locked loop and a frequency divider. The first circuit responsive to the nf.sub.H timing signal can comprise a second phase locked loop. The second circuit responsive to the nfH timing signal can comprise a driver/inverter. The horizontal blanking pulses are combined with vertical blanking pulses to form a composite blanking signal.

Claims16

Dependent claims

An apparatus, comprising:

a first phase locked loop operable at a horizontal synchronizing frequency f.sub.H and synchronized to a horizontal synchronizing component of a video signal;
an f.sub.H to nf.sub.H converter for deriving an nf.sub.H timing signal from at least one output of said first phase loop, where n is an integer;
a second phase locked loop, synchronized with said nf.sub.H timing signal, for generating an nf.sub.H scan synchronizing signal for synchronizing a deflection stage operating at nf.sub.H ;
and,
means responsive to said nf.sub.H timing signal and operable to generate a blanking signal for disabling an electron beam during horizontal retrace intervals of said deflection stage.

2 more elements

Dependencies are inferred from the claim text.

Horizontal blanking

Life of this patent

Horizontal blanking

Life of this patent

Abstract

Claims16