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US 6,272,285 B1Granted
Digital/analog compatible video tape recorder
AssigneeHitachi, Ltd.
InventorsHiroya Abe, Hideo Nishijima, Hiroyuki Torii, Kouji Kaniwa, Katsuyuki Watanabe, Toshio Nakamoto
Life of this patent
Estimating the term…
Abstract
A VTR compatible with the current analog VTR and capable of recording and reproducing digital signals, determines the presence or absence of recorded digital signals and selects an operating mode for recording and reproducing in accordance therewith.
Claims22
A helical scanning video tape recorder for recording video signals and audio video signals on a magnetic tape contained in a tape cassette using a rotary head and reproducing video signals and audio signals recorded on the magnetic tape using the rotary head said video tape recorder comprising:
- a pair of first magnetic heads mounted on the rotary drum diametrically opposite to each other;
- a pair of second magnetic heads mounted on the rotary drum diametrically opposite to each other;
- first signal recording processing means for converting a composite video signal into an FM luminance signal and a down-converted chrominance signal and for supplying the FM luminance signal and the down-converted chrominance signal to said pair of first magnetic heads;
- first signal reproducing processing means for processing signals read by said pair of first magnetic heads to produce a composite video signal;
- second signal recording processing means for modulating the frequency of an audio signal and for supplying the FM audio signal to said pair of second magnetic heads;
- second signal reproducing processing means for demodulating FM audio signals read by said pair of second magnetic heads;
- third signal recording processing means for converting a digital signal into a signal having a frequency in a frequency band higher than the frequency band of said audio signal and for supplying a converted signal to said pair of second magnetic heads;
- third signal reproducing processing means for demodulating a modulated digital signal read by said pair of second magnetic heads;
- detecting means for determining whether or not a signal read by said pair of second magnetic heads is a digital signal;
- control means for selecting an operating mode on the basis of the type of signal detected by said detecting means, wherein said control means controls the respective output signals of said second signal reproducing processing means and said third signal reproducing processing means on the basis of type of the signal detected by said detecting means;
- a receiving unit that receives data-compressed digital information and converts the data-compressed digital information into desired data-compressed signals;
- a decoding circuit that converts a digital signal into a video signal and an audio signal by data expansion;
- a first switch connected to the input side of said decoding circuit to transfer selectively either a digital signal provided by said third signal reproducing processing means or a digital signal provided by said receiving unit;
- a second switch to transfer selectively either a video signal provided by said decoding circuit or a video signal provided by said first signal reproducing processing means;
- and
- a third switch to transfer selectively either an audio signal provided by said second signal reproducing processing means or an audio signal provided by said decoding circuit,
- wherein said control means controls said first, said second and said third switches on the basis of a result of detection by said detecting means.
14 more elements
A helical scanning video tape recorder for recording video signals and audio signals on a magnetic tape contained in a tape cassette using a rotary head and for reproducing video signals and audio signals recorded on the magnetic tape using the rotary head, said video tape recorder comprising:
- a pair of first magnetic heads mounted on the rotary drum diametrically opposite to each other;
- first signal recording processing means for converting a video signal into an FM luminance signal and a down-converted chrominance signal;
- a first recording amplifier for transferring signals provided by said first signal recording processing means to said pair of first magnetic heads;
- a first reproducing head preamplifier connected receive signals read by said pair of first magnetic heads;
- first signal reproducing processing means for processing an output signal of said first reproducing head preamplifier to generate a video signal;
- a pair of second magnetic heads mounted on said rotary drum diametrically opposite to each other;
- second signal recording processing means for effecting frequency modulation of audio signals;
- a first low-pass filter for filtering a signal provided by said second signal recording processing means;
- third signal recording processing means for modulating a digital signal into a signal having a frequency in a frequency band higher than that of the FM signal;
- a second recording amplifier, comprising a wide-band amplifier capable of recording and reproducing modulated digital signals, for transferring a signal transmitted by said first low-pass filter or a signal provided by said third signal recording processing means to said pair of second magnetic heads;
- a second reproducing head preamplifier, comprising a wide-band amplifier capable of reproducing modulated digital signals, connected to receive signals read by said pair of second magnetic heads;
- a second low-pass filter for filtering a signal provided by said second reproducing head preamplifier;
- second signal reproducing processing means for demodulating an FM signal transmitted by said second low-pass filter;
- third signal reproducing processing means for demodulating a digital signal provided by said second reproducing head preamplifier;
- first tracking control means that carries out an automatic tracking control operation on the basis of a reproduced signal provided by said first or said second magnetic heads;
- second tracking control means that carries out an automatic tracking control operation on the basis of a reproduced signal provided by said pair of second magnetic heads;
- mode discriminating means for discriminating between a first reproducing mode in which a video signal produced by said first signal reproducing processing means and an audio signal demodulated by said second signal reproducing processing means are used as reproduced signals, and a second reproducing mode in which a digital signal demodulated by said third signal reproducing processing means is used as a reproduced signal on the basis of signals read by said pair of second magnetic heads;
- and
- switching means for selecting either the tracking control operation of said first tracking control means or that of said second tracking control means according to a signal provided by said mode discriminating means.
16 more elements
A helical scanning video tape recorder for recording video signals and audio signals on a magnetic tape contained in a tape cassette using a rotary head and for reproducing video signals and audio signals recorded on the magnetic tape using the rotary head, said video tape recorder comprising:
- a pair of first magnetic heads mounted on the rotary drum diametrically opposite to each other;
- a first signal recording processor which converts a video signal into an FM luminance signal and a down-converted chrominance signal;
- a first recording amplifier which transfers signals provided by said first signal recording processor to said pair of first magnetic heads;
- a first reproducing head preamplifier connected to receive signals read by said pair of first magnetic heads;
- a first signal reproducing processor which processes an output signal of said first reproducing head preamplifier to generate a video signal;
- a pair of second magnetic heads mounted on said rotary drum diametrically opposite to each other;
- a second signal recording processor which effects frequency modulation of audio signals;
- a first low-pass filter which filters a signal provided by said second signal recording processing means;
- a third signal recording processor which modulates a digital signal into a signal having a frequency in a frequency band higher than that of the FM signal;
- a second recording amplifier, comprising a wide-band amplifier capable of recording and reproducing modulated digital signals, for transferring a signal transmitted by said first low-pass filter or a signal provided by said third signal recording processor to said pair of second magnetic heads;
- a second reproducing head preamplifier, comprising a wide-band amplifier capable of reproducing modulated digital signals, connected to receive signals read by said pair of second magnetic heads;
- a second low-pass filter which filters a signal provided by said second reproducing head preamplifier;
- a second signal reproducing processor which demodulates an FM signal transmitted by said second low-pass filter;
- a third signal reproducing processor which demodulates a digital signal provided by said second reproducing head preamplifier;
- a first tracking controller that carries out an automatic tracking control operation on the basis of a reproduced signal provided by said first or said second magnetic heads;
- a second tracking controller that carries out an automatic tracking control operation on the basis of a reproduced signal provided by said pair of second magnetic heads;
- a mode discriminator which discriminates between a first reproducing mode in which a video signal produced by said first signal reproducing processor and an audio signal demodulated by said second signal reproducing processor are used as reproduced signals, and a second reproducing mode in which a digital signal demodulated by said third signal reproducing processor is used as a reproduced signal on the basis of signals read by said pair of second magnetic heads;
- and
- a switch which selects either the tracking control operation of said first tracking controller or that of said second tracking controller according to a signal provided by said mode discriminator.
16 more elements
A helical scanning tape apparatus for reproducing analog signals and digital signals on a magnetic tape using a rotary head, said tape apparatus comprising:
- an analog signal reproducing mode in which FM-modulated audio signals recorded on the tape by a pair of magnetic heads having a predetermined azimuth angle are reproduced;
- a digital signal reproducing mode in which modulated digital signals having a frequency band higher than the frequency band of said FM-modulated audio signals recorded on the tape by said pair of magnetic heads are reproduced;
- a tracking controller which carries out an automatic tracking control operation on the basis of signals reproduced by said pair of magnetic heads;
- a recording mode detector which detects a recording mode by determining whether the reproduced signals are FM-modulated audio signals or digital signals;
- and
- a controller which selects a reproducing mode according to the recording mode detected by said recording mode detector;
- wherein said controller effects control to operate said recording mode detector after said tracking controller has operated.
4 more elements
A helical scanning tape apparatus for reproducing analog signals and digital signals on a magnetic tape using a rotary head, said tape apparatus comprising:
- an analog signal reproducing mode in which analog signals recorded on the tape by a pair of magnetic heads are reproduced by said pair of magnetic heads;
- a digital signal reproducing mode in which digital signals recorded on the tape by a pair of magnetic heads are reproduced;
- a tracking controller which carries out an automatic tracking control operation on the basis of signals reproduced by said pair of magnetic heads;
- a recording mode detector which detects a recording mode by determining whether the reproduced signals are analog signals or digital signals;
- and
- a controller which selects a reproducing mode according to the recording mode detected by said recording mode detector;
- wherein said controller effects control to operate said recording mode detector after said tracking controller has operated.
4 more elements
A helical scanning video tape recorder for recording video signals and audio signals on a magnetic tape and reproducing video signals and audio signals recorded from the magnetic tape, said video tape recorder comprising:
- a pair of first magnetic heads having a first azimuth angle;
- a pair of second magnetic heads having a second azimuth angle;
- a pair of third magnetic heads having the second azimuth angle;
- an analog signal recoding mode in which a composite video signal is converted into an FM luminance signal and a down-converted chrominance signal and in which the FM luminance signal and the down-converted chrominance signal are recorded on the magnetic tape by said pair of first magnetic heads and the frequency of an audio signal is modulated and the FM audio signal is recorded on a deep layer of the magnetic tape by said pair of second magnetic heads;
- an analog signal reproducing mode in which signals read by said pair of first magnetic heads are processed to produce a composite video signal and in which FM audio signals read by said pair of second magnetic heads are demodulated;
- a digital signal recording mode in which a digital signal is converted into a signal having a frequency in a frequency band higher than the frequency of said audio signal and in which a converted signal is recorded on the magnetic tape by said pair of third magnetic heads;
- a digital signal reproducing mode in which a modulated digital signal read by said pair of third magnetic heads is demodulated;
- a first recording mode detector which detects a recording mode in accordance with a pitch of control signals recorded on the magnetic tape;
- a second recording mode detector which detects a recording mode on the basis of the reproduced signal read by said pair of first or second or third magnetic heads;
- a controller which changes over between said analog and digital reproducing mode according to the recording mode detected by said first and second recording mode detectors.
7 more elements
A helical scanning video tape recorder for recording video signals and audio signals on a magnetic tape and reproducing video signals and audio signals from the magnetic tape, said video tape recording comprising:
- a pair of first magnetic heads having a first azimuth angle;
- a pair of second magnetic heads having a second azimuth angle;
- a pair of third magnetic heads having the second azimuth angle;
- an analog signal recoding mode in which a composite video signal is converted into an FM luminance signal and a down-converted chrominance signal and in which the FM luminance signal and the down-converted chrominance signal are recorded on the magnetic tape by said pair of first magnetic heads and in which the frequency of an audio signal is modulated and the FM audio signal is recorded on a deep layer of the magnetic tape by said pair of second magnetic heads;
- an analog signal reproducing mode in which signals read by said pair of first magnetic heads are processed to produce a composite video signal and in which FM audio signals read by said pair of second magnetic heads are modulated;
- a digital signal recording mode in which a digital signal is converted into a signal having a frequency in a frequency band higher than the frequency of said audio signal and in which a converted signal is recorded on the magnetic tape by said pair-of third magnetic heads;
- a digital signal reproducing mode in which a modulated digital signal read by said pair of third magnetic heads is demodulated;
- a first tracking controller which carries out an automatic tracking control operation on the basis of signals read out by said pair of first magnetic heads or said pair of second magnetic heads;
- a second tracking controller which carries out an automatic tracking control operation on the basis of signals read out by said pair of third magnetic heads;
- a recording mode detector which detects a recording mode on the basis of the reproduced signal read by said pair of first or second or third magnetic heads;
- and
- a controller which selects a reproducing mode according to the recording mode detected by the recording mode detector.
9 more elements
Dependencies are inferred from the claim text.