EP0117455A1
Expired / Lapsed
EP
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Multiplex magnetic recording and reproduction system
Assignee: Hitachi Ltd
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Filing: 1984-02-02
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Granted: —
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Expires: 2004-02-02
Abstract
Abstract In a video tape recorder of the helical scan type, a pair of rotary magnetic heads (9a, 9b) for the audio signal are provided in addition to the rotary video heads (8a, 8b) so that the audio signal is recorded on the same slant track as of the video signal on a multiplex basis. The audio head pair is provided with azimuth angles (+6 1 , -θ 1 ) of opposite polarities from each other and different in value from those of the video head pair, (+θ 2 , -θ 2 ). The system has the first operation mode of the standard tape speed and the second operation mode in which the tape is fed at a speed, for example, 1/3 the standard tape speed. The audio and video head pairs are disposed on lines intersecting at right angles with an offset of + T 1 provided in the axial direction of rotation between the two magnetic head pairs, where T 1 is the track pitch of the recording track formed on the tape in the second operation mode. The system produces overlapping tracks for the audio and video signals on the magnetic tape. In the first operation mode, the recording track is formed by a combination of magnetic heads providing an increased difference of azimuth angles between the audio and video heads, while in the second operation mode, the track is formed by a combination of magnetic heads providing a decreased difference of azimuth angles between the audio and video heads.
Inventors
- 👤 Kuniaki Miura
- 👤 Yoshinori Okada
- 👤 Isao Fukushima
- 👤 Teizo Tamura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 08:23
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/18; H; H04; H04N; H04N9/00; H04N9/79; H04N9/80; H04N9/802; G11B15/02; G11B15/12; G11B15/125; G11B15/1808; G11B15/1875; G11B20/00; G11B20/22; G11B5/00; G11B5/008; G11B5/00813; G11B5/00878; G11B5/48; G11B5/52; G11B5/53; G11B5/531; G11B5/534; H04N5/00; H04N5/76; H04N5/78; H04N5/782; H04N5/7824; H04N5/7826; H04N5/78263; H04N9/7921; H04N9/82; H04N9/83; H04N9/835; H04N9/8355; G11B15/46; G11B15/467; G11B15/4673
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
325 words
A magnetic recording and reproduction system of a helical scan type capable of recording and reproducing a plurality of information signals with a rotary magnetic head unit and operable selectively in a first operation mode in which a magnetic recording medium is transported at a standard speed for recording and reproducing operation and a second operation mode in which the magnetic recording medium is transported at a lower speed so as to obtain a longer recording and reproducing time than in said first operation mode using a same length of recording medium, comprising: a pair of first rotary magnetic heads (9a, 9b) having different azimuth angles of gaps (91) and disposed with an angular spacing of about 180 degrees from each other, said first rotary magnetic head pair being supplied with a first information signal in recording; and a pair of second rotary magnetic heads (8a, 8b, 27a, 27b) having azimuth angles of gaps (81) different from each other and from said first rotary magnetic heads and disposed with an angular spacing of about 180 degrees from each other, said second rotary magnetic head pair being supplied with a second information signal having different major frequency components from those of said first information signal, said first and second rotary magnetic head pairs being disposed in the axial direction of rotation with an offset (d) therebetween such that a pattern of record produced by said first rotary magnetic head is at least partly overlaid by a pattern of record produced in recording by said second rotary magnetic head, and, in said first operation mode, a large difference of azimuth angles of the first and second heads is produced on the substantially overlapping scanning tracks of said first and second rotary magnetic heads, and, in said second operation mode, a small difference of azimuth angles of the first and second heads is produced on the substantially overlapping scanning tracks of said first and second rotary magnetic heads.
Claim 2
Dependent Claim
325 words
A magnetic recording and reproduction system of a helical scan type capable of recording and reproducing a plurality of information signals with a rotary magnetic head unit and operable selectively in a first operation mode in which a magnetic recording medium is transported at a standard speed for recording and reproducing operation and a second operation mode in which the magnetic recording medium is transported at a lower speed so as to obtain a longer recording and reproducing time than in said first operation mode using a same length of recording medium, comprising: a pair of first rotary magnetic heads (9a, 9b) having different azimuth angles of gaps (91) and disposed with an angular spacing of about 180 degrees from each other, said first rotary magnetic head pair being supplied with a first information signal in recording; and a pair of second rotary magnetic heads (8a, 8b, 27a, 27b) having azimuth angles of gaps (81) different from each other and from said first rotary magnetic heads and disposed with an angular spacing of about 180 degrees from each other, said second rotary magnetic head pair being supplied with a second information signal having different major frequency components from those of said first information signal, said first and second rotary magnetic head pairs being disposed in the axial direction of rotation with an offset (d) therebetween such that a pattern of record produced by said first rotary magnetic head is at least partly overlaid by a pattern of record produced in recording by said second rotary magnetic head, and, in said first operation mode, a large difference of azimuth angles of the first and second heads is produced on the substantially overlapping scanning tracks of said first and second rotary magnetic heads, and, in said second operation mode, a small difference of azimuth angles of the first and second heads is produced on the substantially overlapping scanning tracks of said first and second rotary magnetic heads.
Claim 3
Dependent Claim
100 words
A magnetic recording and reproduction system according to claim 1, wherein said first rotary magnetic head pair have azimuth angles of gaps of +θ 1 and -8 I , and said second rotary magnetic head pair have azimuth angles of gaps of +6 2 and -8 2 different in value from said θ 1 , both rotary magnetic head pairs being disposed such that said first and second rotary magnetic head pairs have opposite polarities of directions of azimuth angles in said first operation mode and have a common polarity of directions of azimuth angles in said second operation mode.
Claim 4
Dependent Claim
61 words
A magnetic recording and reproduction system according to claim 1, wherein said first and second rotary magnetic head pairs have effective gap widths larger than a track pitch (T l ) of a magnetic recording medium in said second operation mode, and said offset between said first and second rotary magnetic head pairs has a value larger than said track pitch.
Claim 5
Dependent Claim
61 words
A magnetic recording and reproduction system according to claim 2, wherein said first and second rotary magnetic head pairs have effective gap widths larger than a track pitch (T l ) of a magnetic recording medium in said second operation mode, and said offset between said first and second rotary magnetic head pairs has a value larger than said track pitch.
Claim 6
Dependent Claim
72 words
A magnetic recording and reproduction system according to claim 1, wherein said first rotary magnetic head pair is used to record or reproduce a frequency-modulated audio signal, and said second rotary magnetic head pair is used to record or reproduce a frequency-modulated liminance signal in a video signal and a carrier chrominance, signal with its carrier frequency being converted to have a frequency band below the frequency band of said luminance signal.
Claim 7
Dependent Claim
72 words
A magnetic recording and reproduction system according to claim 2, wherein said first rotary magnetic head pair is used to record or reproduce a frequency-modulated audio signal, and said second rotary magnetic head pair is used to record or reproduce a frequency-modulated luminance signal in a video signal and a carrier chrominance signal with its carrier frequency being converted to have a frequency band below the frequency band of said luminance signal.
Claim 8
Dependent Claim
96 words
A magnetic recording and reproduction system according to claim 1, wherein said second operation mode is set to have a tape speed one third that of said first operation mode, and said first and second rotary magnetic head pairs are disposed to have said offset d therebetween in the axial direction of rotation satisfying relation d≈T 1 · + T 1 , where Ø is an angular spacing (measured in degrees) in the planar arrangement of said first and second rotary magnetic head pairs and T 1 is a track pitch in said second operation mode.
Claim 9
Dependent Claim
92 words
A magnetic recording and reproduction system according to claim 2, wherein said second operation mode is set to have a tape speed one third that of said first operation mode, and said first and second rotary magnetic head pairs are disposed to have said offset d therebetween in the axial direction of rotation satisfying relation d≈T 1 · , where is an angular spacing (measured in degrees) in the planar arrangement of said first and second rotary magnetic head pairs and T l is a track pitch in said second operation mode.
Claim 10
Dependent Claim
201 words
A magnetic recording and reproduction system according to claim 1 further comprising a pair of third rotary magnetic heads having a same azimuth angle as that of said second rotary magnetic head pair, said first rotary magnetic head pair being used for recording or reproducing an audio signal, said second rotary magnetic head pair being disposed with an angular spacing of Ø 1 from said first rotary magnetic head pair and used to record or reproduce a video signal in said second operation mode, said third rotary magnetic recording head pair being disposed with an angular spacing of Ø 2 from said first rotary magnetic head pair and used to record or reproduce a video signal in said first operation mode, said first and second magnetic head pairs being provided therebetween with an offset d l satisfying equation d 1 ≧ T 1 · , where T 1 is a track pitch of the magnetic tape in said second operation mode, said first and third magnetic head pairs being provided therebetween with an offset d 2 satisfying equation d 2 ≧ T 2 · , where T 2 is a track pitch of the magnetic tape in said first operation mode.
Claim 11
Dependent Claim
201 words
A magnetic recording and reproduction system according to claim 2 further comprising a pair of third rotary magnetic heads having a same azimuth angle as that of said second rotary magnetic head pair, said first rotary magnetic head pair being used for recording or reproducing an audio signal, said second rotary magnetic head pair being disposed with an angular spacing of Ø 1 from said first rotary magnetic head pair and used to record or reproduce a video signal in said second operation mode, said third rotary magnetic recording head pair being disposed with an angular spacing of Ø 2 from said first rotary magnetic head pair and used to record or reproduce a video signal in said first operation mode, said first and second magnetic head pairs being provided therebetween with an offset d 1 satisfying equation d 1 ≧ T 1 · , where T 1 is a track pitch of the magnetic tape in said second operation mode, said first and third magnetic head pairs being provided therebetween with an offset d 2 satisfying equation d 2 ≧ T 2 · , where T 2 is a track pitch of the magnetic tape in said first operation mode.
Claim 12
Dependent Claim
27 words
A magnetic recording and reproduction system according to claim 9, wherein said offset d 1 satisfies relation d 1 ≈T 1 · 180 + T 1 .
Claim 13
Dependent Claim
22 words
A magnetic recording and reproduction system according to claim 10, wherein said offset d 1 satisfies relation 1 , T 1 .
Claim 14
Dependent Claim
195 words
A magnetic recording and reproduction system according to claim 1 further comprising a pair of third rotary magnetic heads having a same azimuth angle as that of said second rotary magnetic head pair, said first rotary magnetic head pair being used for recording or reproducing an audio signal, said second rotary magnetic head pair being disposed with an angular spacing of Ø from said first rotary magnetic head pair and used to record or reproduce a video signal in said second operation mode, said third rotary magnetic recording head pair being disposed in adjacent to said second rotary magnetic head pair and used to record or reproduce a video signal in said first operation mode, said first and second magnetic head pairs being provided therebetween with an offset d 1 satisfying equation d 1 ≧ T 1 · , where T 1 is a track pitch of the magnetic tape in said second operation mode, said first and third magnetic head pairs being provided therebetween with an offset d 2 satisfying equation d 2 ≧ T 2 · , where T 2 is a track pitch of the magnetic tape in said first operation mode.
Claim 15
Dependent Claim
197 words
A magnetic recording and reproduction system according to claim 2, wherein further comprising a pair of third rotary magnetic heads having a same azimuth angle as that of said second rotary magnetic head pair, said first rotary magnetic head pair being used for recording or reproducing an audio signal, said second rotary magnetic head pair being disposed with an angular spacing of Ø from said first rotary magnetic head pair and used to record or reproduce a video signal in said second operation mode, said third rotary magnetic recording head pair being disposed in adjacent to said second rotary magnetic head pair and used to record or reproduce a video signal in said first operation mode, said first and second magnetic head pairs being provided therebetween with an offset d 1 satisfying equation d 1 ≧ T 1 · , where T 1 is a track pitch of the magnetic tape in said second operation mode, said first and third magnetic head pairs being provided therebetween with an offset d 2 satisfying equa- tion d 2 ≧ T 2 · , where T 2 is a track pitch of the magnetic tape in said first operation mode.
Claim 16
Dependent Claim
25 words
A magnetic recording and reproduction system according to claim 13, wherein said offset d 1 satisfies relation d T 1 · + 2T 1 .
Claim 17
Dependent Claim
27 words
A magnetic recording and reproduction system according to claim 14, wherein said offset d 1 satisfies relation d 1 ≈ T 1 · + 2T 1 .
References Cited (Backward Citations)
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