Alternate frame shift color video display technique

Claim 2

Apparatus for continuously displaying on an NTSC television monitor a single video frame NTSC colour signal stored in a video signal source, characterized by delay means adapted to delay said NTSC colour signal by a predetermined time interval and video signal switching means controllable to alternately switch to an output said NTSC colour signal output by one of said video source and said delay means.

Claim 3

Apparatus as claimed in claim 1, said predetermined time interval being equivalent to one-half the period of the colour sub-carrier frequency of said NTSC signal, and said video signal switching means being two video signal inputs, receiving said NTSC colour signal one from said video store and the other from said delay means and having an output.

Claim 4

Apparatus as claimed in claim 2, said video signal switching means controlled to alternately connect one of said two inputs to said output in response to logic means responsive to said video source.

Claim 5

Apparatus as claimed in claim 3, said logic means responsive to vertical drive and frame identifier pulses from a video timebase generator in said video source.

Claim 6

Apparatus as claimed in claim 4 said wider signal switching means being a switching video amplifier further comprising a control input responsive to said logic means.

Claim 7

Apparatus as claimed in claims 3, 4 or 5, said video source having analog video signal storage means and wherein the output of said video signal switching means is an output of said apparatus adapted to drive a base-band television monitor.

Claim 8

A signal processing method for continuously displaying on an NTSC television monitor a stored single frame NTSC colour signal, characterized by the step of delaying every alternate retrieved frame by a time interval substantially equivalent to one-half the period of the colour sub-carrier frequency in said stored single frame NTSC colour signal prior to application of said every alternate retrieved frame to said NTSC television monitor, the other retrieved frames being applied to the monitor undelayed but processed through a substantially identical signal path not including said delaying step.

Claim 9

A signal processing method for continuously displaying on an NTSC television monitor a stored single frame NTSC colour signal, characterized by the step of delaying every alternate retrieved frame by a time interval substantially equivalent to one-half the period of the colour sub-carrier frequency in said stored single frame NTSC colour signal prior to application of said every alternate retrieved frame to said NTSC television monitor, the other retrieved frames being applied to the monitor undelayed but processed through a substantially identical signal path not including said delaying step.

Claim 10

The method as defined in claim 7, said step of delaying being preceded by a step of converting said stored single frame NTSC colour signal to an analog format.

Claim 11

The method as defined in claim 8, said step of delaying being accomplished by splitting said colour signal into two paths, one delayed and the other undelayed, and switching alternately between the two paths.

Claim 12

The method as defined in claim 9, said switching following the incidence of a frame start signal.