US 4,729,013 A · Time base error corrector

Abstract

A time base error corrector comprises a chrominance subcarrier phase corrector whereby the subcarrier phase of a video signal is controlled before being written in the buffer memory in such a way that when the video signal is read from the buffer memory on the basis of the reference video signal, the subcarrier phase of the read video signal may match that of the reference video signal. In the NTSC system, the succeeding line odd/even (O/E) identification is predicted on the basis of a content O/E of the preceding field identification and a content O/E of the preceding field top line identification, and a non-inverted return subcarrier signal is generated when the succeeding top line identification is determined to be odd but an inverted return subcarrier signal RSC is generated when determined to be even. In the PAL system, the succeeding line O/E odd/even and I/N inversion/non-inversion identifications are predicted to generate four different return subcarrier signals. The above control is effective when a VTR is servo-controlled in such a way that the reproduced video signal is written in the buffer memory in advance of the reference video signal in phase.

Claims6

Dependent claims

A time base error corrector for outputting an output video signal having no time base error by means for writing an input video signal in a buffer memory in response to a synchronizing signal included in the input video signal and by means for reading the written video signal from the buffer memory in response to a synchronizing signal included in a reference video signal, which comprises:

means for controlling phase of a chrominance subcarrier included in the input video signal, before the input video signal is written in the buffer memory, so that the phase of a chrominance subcarrier included in the read video signal matches that of a chrominance subcarrier included in the reference video signal when the video signal written in the buffer memory is read therefrom in response to the reference video signal, wherein in the case of a National Television System Committee (NTSC) color television system, said chrominance subcarrier phase controlling means is a return subcarrier generating means for generating a first return subcarrier signal RSC when a succeeding top line identification of a succeeding field, representative of the relative phase relationship between the burst signal and the synchronizing signal at a top horizontal line of said field, is determined to be an odd number but a second return subcarrier signal RSC when the succeeding top line identification is determined to be an even number both by predicting the succeeding top line odd/even (O/E) identification on the basis of an O/E content of a preceding field identification of a preceding field, representative of an odd and even number of the field, and an O/E content of the preceding field top line identification.

means for controlling phase of a chrominance subcarrier included in the input video signal, before the input video signal is written in the buffer memory, so that the phase of a chrominance subcarrier included in the read video signal matches that of a chrominance subcarrier included in the reference video signal when the video signal written in the buffer memory is read therefrom in response to the reference video signal, wherein in the case of phase alternation by a line color television system, said chrominance subcarrier phase controlling means is a return subcarrier generating means for generating a first return subcarrier signal S.sub.2 when two preceding top line identifications of preceding fields, representative of the relative phase relationship between the burst signal and the synchronizing signal at the top lines of said fields, are determined to be an odd number and a non-inversion mode, a second return subcarrier signal S.sub.3 90 degrees out of phase with respect to the first signal S.sub.2 when two preceding top line identifications are determined to be an even number and a non-inversion mode, a third return subcarrier signal S.sub.2 when the two preceding top line identifications are determined to be an odd number and an inversion mode, and a fourth return subcarrier signal S.sub.3 when to two preceding top line identifications are determined to be an even number and an inversion mode, all by predicting the succeeding top line odd/even (O/E) identification and the succeeding top line inversion/non-inversion (I/N) identification on the basis of an O/E content of the preceding field identification of a preceding field, representative of an odd or even number of the field, and the O/E and I/N contents of the preceding field top line identifications.

Dependencies are inferred from the claim text.

Time base error corrector

Life of this patent

Time base error corrector

Life of this patent

Abstract

Claims6