EP0098727A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Improvements in helical scan recording and playback systems
Assignee: Dolby Laboratories Licensing Corp
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Filing: 1983-06-28
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Granted: —
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Expires: 2003-06-28
Abstract
Abstract A helical scan magnetic recording and reproducing system is of the type where time compressed audio signals are recorded in extensions of the video tracks. In orderto avoid a time delay of the reproduced audio relative to its original relationship to the video, additional audio playback heads (S1, S2) are located on the helical scanner so as to read the audio information sufficiently in advance of the video heads (P1, P2) to allow restoration of the original audio/video synchronism. The audio is recovered by a switch (26), de-interleaving circuit (28) - and time expansion circuits (30, 32). The arrangement allows full flexibility in audio editing even when the recorded audio signals are digitally encoded and interleaved. In order to avoid a time delay of the reproduced audio relative to the video when played back, additional audio recording heads are located on the helical scanner so as to record the audio information on tracks that when played back are reproduced sufficiently in advance of the video to allow restoration of the original audio/ video synchronism. The arrangement can thus can be employed to produce prerecorded tapes having time advanced audio such that synchronous audio/video is reproduced on conventional playback reproducing systems.
Inventors
- 👤 Craig C. Todd
- 👤 Kenneth J. Gundry
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 12:21
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/00007; G11B20/10; G11B20/10527; G11B20/18; G11B20/1806; G11B27/00; G11B27/02; G11B27/022; G11B27/029; G11B27/031; G11B27/036; G11B5/00; G11B5/008; G11B5/00813; G11B5/00847; G11B5/0086; G11B5/48; G11B5/52; G11B5/53; G11B5/531; H; H04; H04N; H04N5/00; H04N5/76; H04N5/91; H04N5/92; H04N5/9201; H04N5/9202; H04N5/9203; H04N5/928; G11B2220/00; G11B2220/90
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
148 words
A helical scan playback system for playing a magnetic medium on which a plurality of rotating magnetic heads has recorded signals in a series of sequential discontinuous tracks, the signals including at least one signal compressed along the time axis, comprising means including a rotating assembly carrying a plurality of playback heads scanning said tracks for playing back signals, said means playing back said at least one time compressed signal from tracks spaced apart from tracks from which said other signal or signals is or are played back such that said at least one time compressed signal is advanced in time with respect to said other signal or signals by virtue of being reproduced earlier than the track in which said other signal or signals were simultaneously recorded, and signal processing means receiving said signals, said means including means for expanding said at least one time compressed signal.
Claim 2
Dependent Claim
148 words
A helical scan playback system for playing a magnetic medium on which a plurality of rotating magnetic heads has recorded signals in a series of sequential discontinuous tracks, the signals including at least one signal compressed along the time axis, comprising means including a rotating assembly carrying a plurality of playback heads scanning said tracks for playing back signals, said means playing back said at least one time compressed signal from tracks spaced apart from tracks from which said other signal or signals is or are played back such that said at least one time compressed signal is advanced in time with respect to said other signal or signals by virtue of being reproduced earlier than the track in which said other signal or signals were simultaneously recorded, and signal processing means receiving said signals, said means including means for expanding said at least one time compressed signal.
Claim 3
Dependent Claim
69 words
A helical scan playback system according to claim 1 wherein said plurality of playback heads includes first and second pairs of playback heads, the pairs of playback heads carried by said rotating assembly offset with respect to each other such that one pair of heads reads at least portions of tracks earlier in time than when the other pair of heads reads at least portions of the same tracks.
Claim 4
Dependent Claim
35 words
A helical scan playback system according to claim 2 wherein the system is also for recording and one pair of said playback heads are the same as said magnetic heads used for recording said signal.
Claim 5
Dependent Claim
47 words
A helical scan record and playback system according to claim 3 further comprising means for re- recording in the same position on the tracks at least a portion of said at least one time compressed signal played back by the pair of heads reading earlier in time.
Claim 6
Dependent Claim
43 words
A helical scan playback system according to claim 2 wherein the offset of said pairs of playback heads is at least substantially equal to the offset required to restore the relative timing of the signals prior to their application to the recording system.
Claim 7
Dependent Claim
34 words
A helical scan playback system according to claim 2 wherein said signals are the audio and video portions of a television signal and the audio portion is the signal compressed along the time axis.
Claim 8
Dependent Claim
40 words
A helical scan playback system according to claim 6 wherein the offset of said pairs of playback heads is at least substantially equal to the offset required to restore.the synchronism of the audio and video portions of the television signal.
Claim 9
Independent Claim
118 words
A method of playing a magnetic medium on which a plurality of rotating magnetic heads has recorded signals in a series of sequential discontinuous tracks, the signals including at least one signal compressed along the time axis, comprising playing back said at least one time compressed signal from tracks spaced apart from tracks from which said other signal or signals is or are played back such that said at least one time compressed signal is advanced in time with respect to said other signal or signals by virtue of being reproduced earlier than the track in which said other signal or signals were simultaneously recorded, and processing said signals, including expanding said at least one time compressed signal.
Claim 10
Independent Claim
118 words
A method of playing a magnetic medium on which a plurality of rotating magnetic heads has recorded signals in a series of sequential discontinuous tracks, the signals including at least one signal compressed along the time axis, comprising playing back said at least one time compressed signal from tracks spaced apart from tracks from which said other signal or signals is or are played back such that said at least one time compressed signal is advanced in time with respect to said other signal or signals by virtue of being reproduced earlier than the track in which said other signal or signals were simultaneously recorded, and processing said signals, including expanding said at least one time compressed signal.
Claim 11
Dependent Claim
37 words
A playback method according to claim 8 wherein said time advance is at least substantially equal to the time advance required to restore the relative timing of the signals prior to their application to the recording system.
Claim 12
Dependent Claim
32 words
A playback method according to claim 9 wherein said signals are the audio and video portions of a television signal and the audio portion is the signal compressed along the time axis.
Claim 13
Dependent Claim
35 words
A playback method according to claim 10 wherein said time advance is at least substantially equal to the time advance required to restore the synchronism of the audio and video portions of the television signal.
Claim 14
Dependent Claim
173 words
A helical scan recording system for recording a plurality of signals on a magnetic medium in a series of sequential discontinuous tracks, comprising signal processing means receiving said signals, said means including means for compressing at least one of said signals along the time axis, and recording means receiving the signals from said signal processing means including said at least one time compressed signal, said recording means including a rotating assembly carrying a plurality of recording heads scanning said tracks for recording signals along said tracks, said means recording said at least one time compressed signal on tracks spaced apart from tracks on which said other signal or signals is or are simultaneously recorded such that when the magnetic medium is played back said at least one time compressed signal is advanced in time with respect to said other signal or signals received by the recording means by virtue of being recorded in a track that is played back earlier than the track in which said other signal or signals were simultaneously recorded.
Claim 15
Dependent Claim
173 words
A helical scan recording system for recording a plurality of signals on a magnetic medium in a series of sequential discontinuous tracks, comprising signal processing means receiving said signals, said means including means for compressing at least one of said signals along the time axis, and recording means receiving the signals from said signal processing means including said at least one time compressed signal, said recording means including a rotating assembly carrying a plurality of recording heads scanning said tracks for recording signals along said tracks, said means recording said at least one time compressed signal on tracks spaced apart from tracks on which said other signal or signals is or are simultaneously recorded such that when the magnetic medium is played back said at least one time compressed signal is advanced in time with respect to said other signal or signals received by the recording means by virtue of being recorded in a track that is played back earlier than the track in which said other signal or signals were simultaneously recorded.
Claim 16
Dependent Claim
69 words
A helical scan recording system according to claim 12 wherein said plurality of recording heads includes first and second pairs of recording heads, the pairs of recording heads carried by said rotating assembly offset with respect to each other such that one pair of heads records at least portions of tracks earlier in time than when the other pair of heads records at least portions of the same tracks.
Claim 17
Dependent Claim
38 words
A helical scan playback system according to claim 13 wherein the offset of said pairs of recording heads is at least substantially equal to the offset required to restore the relative timing of the signals when played back.
Claim 18
Dependent Claim
34 words
A helical scan playback system according to claim 13 wherein said signals are the audio and video portions of a television signal and the audio portion is the signal compressed along the time axis.
Claim 19
Dependent Claim
41 words
A helical scan playback system according to claim 15 wherein the offset of said pairs of recording heads is at least substantially equal to the offset required to restore the synchronism of the audio and video portions of the television signal.
Claim 20
Independent Claim
114 words
A method of recording signals in a series of sequential discontinuous tracks on a magnetic medium using a plurality of rotating magnetic heads, the signals including at least one signal compressed along the time axis, comprising recording said at least one time compressed signal on tracks spaced apart from tracks from which said other signal or signals is or are recorded such that said at least one time compressed signal is advanced in time with respect to said other signal or signals by virtue of being reproduced earlier than the track in which said other signal or signals were simultaneously recorded, and processing said signals, including expanding said at least one time compressed signal.
Claim 21
Independent Claim
114 words
A method of recording signals in a series of sequential discontinuous tracks on a magnetic medium using a plurality of rotating magnetic heads, the signals including at least one signal compressed along the time axis, comprising recording said at least one time compressed signal on tracks spaced apart from tracks from which said other signal or signals is or are recorded such that said at least one time compressed signal is advanced in time with respect to said other signal or signals by virtue of being reproduced earlier than the track in which said other signal or signals were simultaneously recorded, and processing said signals, including expanding said at least one time compressed signal.
Claim 22
Dependent Claim
37 words
A recording method according to claim 17 wherein said time advance is at least substantially equal to the time advance required to restore the relative timing of the signals prior to their application to the recording system.
Claim 23
Dependent Claim
32 words
A recording method according to claim 18 wherein said signals are the audio and video portions of a television signal and the audio portion is the signal compressed along the time axis.
Claim 24
Dependent Claim
35 words
A recording method according to claim 19 wherein said time advance is at least substantially equal to the time advance required to restore the synchronism of the audio and video portions of the television signal.
Claim 25
Dependent Claim
37 words
A recorded video tape having a plurality of adjacent tracks which bear video information and time compressed audio information, the time compressed audio information in each track being advanced in time with respect to the video information.
Claim 26
Dependent Claim
37 words
A recorded video tape having a plurality of adjacent tracks which bear video information and time compressed audio information, the time compressed audio information in each track being advanced in time with respect to the video information.
References Cited (Backward Citations)
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