Timebase stabilization and correction system for electron beam apparatus

Claim 3

The system of claim 1 wherein: said means for introducing a pilot signal introduces a plurality of pilot signals from the medium at selected frequencies; said reference signal generating means in addition to the reference signals further provides a plurality of pilot reference signals and a plurality of quadrature reference signals corresponding to the plurality of pilot reference signals; said first means includes a multiplier coupled to a selected one of the pilot reference signals and to the corresponding pilot reference signal from the medium to generate said in-phase output signal indicative of the accuracy and direction of the scanning beam; said third means defines a plurality of channels equal to the plurality of pilot signals from the medium, wherein each channel of the third means receives a respective pilot signal from the medium of selected frequency, a quadrature reference signal corresponding to the respective pilot signal from the medium, and selected reference signals, and each provides pairs of the quadrature initiated output signals therefrom indicative of the playback raster size and centering errors; said second means defines a similar plurality of channels wherein each channel receives a respective pair of the quadrature initiated output signals from said third means and is further adapted to provide a plurality of pairs of said reproduce raster size and centering control error signals; and said system further including adder means for combining the respective plurality of size control error signals and the plurality of centering control error signals and for selectively applying same to said sweep generating apparatus to control the scanning electron beam.

Claim 4

The system of claim 1 wherein the first means includes first multiplier means coupled to receive the pilot reference signal and said pilot signal from the medium to provide the in-phase output signal, and the third means includes second multiplier means for receiving said pilot signal from the medium and said quadrature reference signal to provide an initial quadrature output signal corresponding to a multiplication of the pilot signal from the medium and the quadrature reference signal.

Claim 5

The system of claim 3 wherein the third means further includes third multiplier means for receiving the initial quadrature output signal from the second multiplier means and a reference signal from said plurality generated by the reference signal generating means to provide the quadrature initiated output signal corresponding to the size control error signal, and fourth multiplier means for receiving the initial quadrature output signal from the second multiplier means and another reference signal from said plurality generated by the reference signal generating means to provide the quadrature initiated output signal corresponding to the centering control error signal.

Claim 6

The system of claim 1 wherein the first means includes first multiplier means coupled to receive the pilot reference signal and said pilot signal from the medium to provIde the in-phase output signal, and fifth multiplier means for receiving said quadrature reference signal and others of said plurality of reference signals from said reference signal generating means to provide initial quadrature output signals in the form of initial size and centering quadrature output signals corresponding to a multiplication of the quadrature reference signal and respective ones of the reference signals.

Claim 7

The system of claim 5 wherein the third means further includes sixth multiplier means for receiving the initial size quadrature output signal from the fifth multiplier means and the pilot signal from the medium to provide the quadrature initiated output signal corresponding to the size control error signal, and seventh multiplier means for receiving the initial centering quadrature output signal from the fifth multiplier means and the pilot signal from the medium to provide the quadrature initiated output signal corresponding to the centering control error signal.

Claim 8

The system of claim 1 wherein the reference signal generating means includes an oscillator means for generating a primary reference signal, a line rate reference signal, a 1/n line rate reference signal where 1/n is a selected fraction of the line rate frequency, and further includes phase shifting means operatively coupled to the oscillator means to selectively phase shift the primary reference signal to provide the quadrature reference signal.

Claim 9

The system of claim 7 wherein the oscillator means further comprises a crystal oscillator, and the signal generating means further includes a plurality of dividers selectively coupled to the crystal oscillator to provide said line rate reference signal and said 1/n line rate reference signal, said phase shifting means being operatively coupled to the crystal oscillator to phase shift said primary reference signal to provide the quadrature reference signal.

Claim 10

The system of claim 8 wherein said first means further includes a multiplier coupled to said primary reference signal and to said pilot signal from the medium to generate said in-phase output signal indicative of the accuracy and direction of the scanning beam, and the third means includes a quadrature multiplier coupled to said quadrature reference signal from the phase shifting means and to said pilot signal from the medium to generate an initial quadrature output signal, wherein said third means further includes a size error multiplier coupled to the initial quadrature output signal and to said line rate reference signal to generate the quadrature initiated output signal indicative of the playback raster size error, and a centering error multiplier coupled to the initial quadrature output signal and to said 1/n line rate reference signal to generate the quadrature initiated output signal indicative of the playback raster centering error.

Claim 11

The system of claim 8 wherein said first means further includes a multiplier coupled to said primary reference signal and to said pilot signal from the medium to generate said in-phase output signal indicative of the accuracy and direction of the scanning beam, and the third means includes a pair of quadrature multipliers each coupled to the quadrature reference signal from the phase shifting means, the first of said pair of quadrature multipliers also being coupled to said line rate reference signal to generate an initial size quadrature output signal, and the second of said pair of quadrature multipliers being coupled to said 1/n line rate reference signal to generate an initial centering quadrature output signal, wherein the initial size and centering quadrature output signals are indicative respectively of the playback raster size and centering errors, wherein the third means further includes a size error multiplier coupled to the initial size quadrature output signal and to said pilot signal from the medium to generate the quadrature initiated output signal indicative of The playback raster size error, and a centering error multiplier coupled to the initial centering quadrature output signal and to said pilot signal from the medium to generate the quadrature initiated output signal indicative of the playback raster centering error.