Color phase matching system for magnetic video tape recordings

Abstract

Color burst phase matching is achieved in magnetic video tape recording by coding the recording tape to identify alternate video frames to provide a synthetic color phase reference, comparing this synthetic color phase reference with a system frame reference and, based upon the comparison, controlling the tape speed or position relative to the system frame reference when required to achieve the proper color phase relationship.

I claim: 
     
       1. A color frame system for use with a video tape recorder/reproducer for providing color burst phase matching comprising: a. means for .Iadd.sequentially .Iaddend.identifying .[.alternate frames.]. .Iadd.each individual frame .Iaddend.of video recorded on the recording tape;   b. means for detecting the .[.alternate-.]. .Iadd.sequential individual .Iaddend.frame identifications to generate alternate-frame identification signals .Iadd.from the sequential individual frame identifications .Iaddend.to distinguish alternate frames recorded on the tape;   c. means synchronized with a stable signal source for generating frame reference signals at a frequency to provide means for distinguishing alternate video frames in time relative to said stable signal source;   d. means for comparing said alternate-frame identification signals and said frame reference signals; and   e. means .[.responive.]. .Iadd.responsive .Iaddend. to said comparison means to control the tape speed and/or position for correcting the recording tape frame position relative to said frame reference signal if required for proper color burst phase match.   
     
     
       2. A color frame system as in claim 1 wherein said tape speed and/or position control means comprises means for altering the recording tape frame position one frame relative to said frame reference signal. 
     
     
       3. A color frame system as in claim 2 wherein said frame reference generating means provides a 15 Hz signal. 
     
     
       4. A color frame system as in claim 3 wherein said .[.alternate.]. .Iadd.sequential individual .Iaddend.frame identification means comprises the SMPTE time code, and wherein alternate frames are identified odd and even in accordance with the least significant digit thereof. 
     
     
       5. A color frame system as in claim 1 wherein said frame reference generating means provides a 15 Hz signal. 
     
     
       6. A color frame system as in claim 1 wherein said .[.alternate.]. .Iadd.sequential individual .Iaddend.frame .[.identificatin.]. .Iadd.identification .Iaddend.means comprises the SMPTE time code, and wherein alternate frames are identified odd and even in accordance with the least significant digit thereof. 
     
     
       7. In a magnetic tape editing system having a record video tape recorder, at least one playback video tape recorder synchronized with said record video tape recorder and whose color burst phase is automatically maintained in phase with a stable color reference signal, .[.and.]. a system for providing proper color burst phase matching of video segments recorded upon said record video tape recorder comprising: a. means for identifying alternate frames of video recorded on the recording tape;   b. means for determining the alternate-frame identification of the video frame which will occur at a projected time when video information signals are to begin to be recorded upon said record tape;   c. means synchronized with a stable signal source for generating frame reference signals at a frequency to provide means for distinguishing alternate video frames in time relative to said stable signal source;   d. means for determining the state of said frame reference signals which is scheduled to occur at the projected time video information signals are to begin to be recorded upon said record tape;   e. means for comparing the scheduled frame reference state with the determined alternate-frame identification at the projected beginning of the record of video information signals; and   f. means responsive to said comparison means to alter in time the actual start of record if required for proper color burst match.   
     
     
       8. A magnetic tape editing system as in claim 7 wherein said means for altering the start of record alters the start time by one frame. 
     
     
       9. A magnetic tape editing system as in claim 7 wherein said means for altering the start of record delays the start time by one frame. 
     
     
       10. A magnetic tape system as in claim 9 wherein said frame reference generating means provides a 15 Hz signal. 
     
     
       11. A magnetic tape editing system as in claim 10 wherein said alternate frame identification means comprises the SMPTE time code, and wherein alternate frames are identified odd and even in accordance with the least significant digit thereof. 
     
     
       12. A magnetic tape system as in claim 7 wherein said frame reference generating means provides a 15 Hz signal. 
     
     
       13. A magnetic tape editing system as in claim 7 wherein said alternate frame identification means comprises the SMPTE time code, and wherein alternate frames are identified odd and even in accordance with the least significant digit thereof. 
     
     
       14. A method for use with a video tape recorder/reproducer for providing proper color burst phase matching comprising the steps of: a. identifying .[.alternate.]. .Iadd.sequentially each individual .Iaddend..[.frame.]. .Iadd.frames .Iaddend. of video recorded on the recording tapes;   b. detecting the .[.alternate.]. .Iadd.sequential, individual .Iaddend.frame identifications and generating alternate-frame identification signals .Iadd.from said sequential individual frame identifications .Iaddend.to distinguish alternate frames recorded on the tape;   c. generating a frame reference signal synchronized with a stable signal source at a frequency for distinguishing alternate video frames in time relative to said stable signal source;   d. comparing said alternate-frame identification signals and said frame reference signals; and   e. controlling the tape speed and/or position for correcting the recording tape frame position relative to said frame reference signal after said comparison step if required for proper color burst phase match.   
     
     
       15. In a video tape recording system, means for .[.insuring.]. .Iadd.ensuring .Iaddend.proper color phase matching comprising: .Iadd. means for sequentially identifying each individual frame of video recorded on the recording tape;   means for detecting the sequential, individual frame identifications and for generating alternate frame identification signals from the sequential individual frame identifications to provide a synthetic color phase reference; .Iaddend.   .[.  means for coding each video recording to identify alternate video frames to provide a synthetic color phase reference signal;.].   means for comparing the color phase of a video segment to be recorded with the synthetic phase reference; and   means responsive to said comparison means to control the tape speed or position for correcting the recording tape frame position relative to the color phase of the video segment to be recorded when required .Iadd.to obtain phase matching between the phase of the video segment to be recorded and the synthetic phase reference. .Iaddend.   
     
     
       16. A video tape recording system as in claim 15 wherein the color phase of the video segment to be recorded is locked to a system color phase reference signal.