US 4,393,413 AGranted

Velocity error compensator for time base error corrections of periodic information signals

AssigneeSony Corporation

InventorShinji Kaneko

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Abstract

A velocity error compensator adapted for use in a time base corrector of the type which includes a main memory into which individual periods, such as horizontal line intervals, of information signals, such as video signals, are written at a write-in rate synchronized with the information signals, and from which the individual periods of information signals are read out at a reference read-out rate. The velocity error compensator includes a storage device for storing velocity error signals associated with corresponding ones of the periods of information signals. The velocity error signal associated with the period of information signals then read out from the main memory, and also the velocity error signals associated with the preceding and next-following periods of information signals are simultaneously read out from the storage device. These three velocity error signals are combined to produce a velocity error correction signal which is used to modulate the information signal read-out rate.

Claims17

Dependent claims

A velocity error compensator for use in a time base corrector of the type which corrects time base errors in periodic information signals having a main memory for storing plural periods of said information signals, write-in means for writing individual periods of said information signals into said main memory at a rate synchronized with said periodic information signals, and read-out means for reading out said individual periods of said information signals from said main memory at a reference read-out rate, said velocity error compensator comprising velocity error detecting means for detecting a velocity error in each period of said information signals and for producing a velocity error signal representative thereof;

velocity error storage means for storing the velocity error signals associated with a plurality of said periods of information signals;
velocity error read-out means for reading out from said velocity error storage means simultaneously the velocity error signal associated with the period of information signals then read out from said main memory and the velocity error signals associated with at lest the preceding and next-following periods of information signals read out from said main memory;
combining means for combining the simultaneously read out velocity error signals to produce a velocity error-correction signal as a function of the simultaneously read out velocity error signals, said combining means including means for producing a gradient signal representing the gradient between the velocity error signals associated with said preceding and next-following periods of information signals, means for adjusting an offset in said gradient signal, means for summing the offset-adjusted gradient signal and said velocity error signal associated with the period of information signals then read out from said main memory and means for integrating the summed signals to produce said velocity rror-correction signal;
and means for modulating said reference read-out rate in accordance with said velocity error-correction signal.

1 more element

A velocity error compensator for use in a time base corrector of the type adapted to correct time base errors in successive horizontal line intervals of a video signal having a main memory for storing plural lines of said video signals, write-in means for writing individual lines of said video signals into said main memory at a write-in rate synchronized with said video signals, and read-out means for reading out said individual lines of said video signals from said main memory at a reference read-out rate, said velocity error compensator comprising velocity error detecting means for detecting velocity errors in respective lines of said video signals and for producing velocity error signals representative thereof;

velocity error storage means for storing the velocity error signals associated with a plurality of said lines of video signals;
velocity rror read-out means for reading out from said velocity error storage means simultaneously the velocity error signals associated with the line of video signals then read out from said main memory and the preceding and next-following lines of video information read out from said main memory;
gradient signal generating means for generating a gradient signal representing the gradient between the velocity error signals associated with said preceding and next-following lines of video signals;
summing means for summing said gradient signal and said velocity error signal associated with said line of video signals then read out from said main memory to produce a velocity error correction signal;
integrating means for integrating said velocity error correction signal;
and means for modulating said reference read-out rate in accordance with the integrated velocity error correction signal.

3 more elements

Dependencies are inferred from the claim text.