Patent EP0254511A2 successfully refreshed from Google Patents.
EP0254511A2
Expired / Lapsed
EP
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Apparatus for reproducing signals recorded on a tape
Assignee: Panasonic Holdings Corp
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Filing: 1987-07-20
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Granted: —
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Expires: 2007-07-20
Abstract
Abstract Disclosed herein is an apparatus for reproducing signals recorded in slanting tracks on a recording tape including a tape position information recorded at a specified area on each track. The apparatus has a tape speed setting circuit capable of setting a plurality of tape speeds, and a cylinder speed setting circuit for setting such a rotational speed of a rotary cylinder that the track direction speed component of a reproducing head mounted on the rotary cylinder is kept constant. A tape running control circuit controls a reel drive circuit so that the tape runs at a speed set by the tape speed setting circuit. A cylinder control circuit controls the rotary cylinder so that the rotary cylinder rotates at a speed set by the cylinder speed setting circuit. In a transition state from a normal reproduction mode to a high speed search mode, the tape speed setting circuit changes the tape speed in step-wise so that the deviation of the track direction speed component of the head in each step of tape speed change is within a range in which the tape position information is correctly read.
Inventors
- 👤 Kazuo Arai
- 👤 Kiyoshi Ota
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 00:59
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/02; G11B5/09; G11B15/00; G11B15/18; G11B15/46; G11B15/467; G11B15/4671; G11B15/1808; G11B15/1875; G11B5/008; G11B5/00813; G11B5/00847; G11B5/0086
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
285 words
An apparatus for reproducing signals recorded in slanting tracks on a recording tape including a tape position information recorded at a specified area on each track, comprising: a rotary cylinder mounting thereon a reproducing head; a cylinder rotation detector for producing a periodic signal corresponding to a rotational speed of said rotary cylinder; two reels on which said tape is wound for running said tape; two reel rotation detectors for producing periodic signals corresponding to rotational speeds of said two reels, respectively; a reel drive means for driving either one of said two reels to run said tape; a tape speed setting means capable of setting a plurality of tape speeds and outputting a signal indicative of one of the settable plurality of tape speeds; a tape running control means for outputting a drive signal to said reel drive means according to the output signals from said two reel rotation detectors and the output signal from said tape speed setting means so that said tape runs at the speed set by said tape speed setting means; a cylinder speed setting means for setting such a rotational speed of said rotary cylinder that a track direction speed component of said head is kept constant according to the output signal from said tape speed setting means and outputting a signal indicative of the set rotational speed; a cylinder control means for controlling said rotary cylinder according to the output signal from said cylinder rotation detector and the output signal from said cylinder speed setting means so that said rotary cylinder rotates at the speed set by said cylinder speed setting means; and a signal processing circuit for reading information picked up by said head from said tape.
Claim 2
Independent Claim
285 words
An apparatus for reproducing signals recorded in slanting tracks on a recording tape including a tape position information recorded at a specified area on each track, comprising: a rotary cylinder mounting thereon a reproducing head; a cylinder rotation detector for producing a periodic signal corresponding to a rotational speed of said rotary cylinder; two reels on which said tape is wound for running said tape; two reel rotation detectors for producing periodic signals corresponding to rotational speeds of said two reels, respectively; a reel drive means for driving either one of said two reels to run said tape; a tape speed setting means capable of setting a plurality of tape speeds and outputting a signal indicative of one of the settable plurality of tape speeds; a tape running control means for outputting a drive signal to said reel drive means according to the output signals from said two reel rotation detectors and the output signal from said tape speed setting means so that said tape runs at the speed set by said tape speed setting means; a cylinder speed setting means for setting such a rotational speed of said rotary cylinder that a track direction speed component of said head is kept constant according to the output signal from said tape speed setting means and outputting a signal indicative of the set rotational speed; a cylinder control means for controlling said rotary cylinder according to the output signal from said cylinder rotation detector and the output signal from said cylinder speed setting means so that said rotary cylinder rotates at the speed set by said cylinder speed setting means; and a signal processing circuit for reading information picked up by said head from said tape.
Claim 3
Dependent Claim
62 words
An apparatus according to claim 6, wherein said tape running control means comprises: two period-to-voltage conversion means for converting periods of the respective periodic output signals from said two reel rotation detectors to two voltage signals according to the output signal from said tape speed setting means; and an adding means for adding the two voltage signals to obtain said drive signal.
Claim 4
Dependent Claim
173 words
An apparatus according to claim 2, wherein each of said period-to-voltage conversion means comprises: a clock signal generating means for generating a plurality of clock signals having different frequencies from one another and outputting one of the plurality of clock signals according to the output signal from said tape speed setting means; a counter for counting clocks of the output clock signal from said clock signal generating means; a latch circuit for latching a count output of said counter at intervals of time corresponding to the period of the periodic output signal from corresponding one of said two reel rotation detectors; a latch pulse generating circuit for generating a latch pulse for said latch circuit from the periodic output signal from the corresponding one of said two reel rotation detectors; a reset pulse generating circuit for generating a reset pulse from said latch pulse for resetting said counter; and a DA converter for converting a latched output of said latch circuit to an analog signal which is one of said two voltage signals.
Claim 5
Dependent Claim
236 words
An apparatus according to claim 1, wherein said cylinder speed setting means comprises: a memory storing therein a plurality of rotational speed data corresponding to a plurality of rotational speeds of said rotary cylinder for keeping the track direction speed component of said head constant; and an address setting circuit for outputting an address for said memory according to the output signal from said tape speed setting means so that said memory outputs one of said plurality of rotational speed data, and said cylinder control means comprises: a clock signal generator for generating a clock signal; a presettable counter which presets the output rotational speed data from said cylinder speed setting means and counts clocks of the clock signal from said clock signal generator; a latch circuit for latching a count output of said counter at intervals of time corresponding to the period of the periodic output signal from said cylinder rotation detector; a latch pulse generating circuit for generating a latch pulse for said latch circuit from the periodic output signal from said cylinder rotation detector; a preset pulse generating circuit for generating a preset pulse from said latch pulse for presetting the rotational speed data from said cylinder speed setting means to said counter; a DA converter for converting a latched output of said latch circuit into an analog signal; and a drive circuit for driving said rotary cylinder according to said analog signal.
Claim 6
Dependent Claim
73 words
An apparatus according to claim 1, wherein, during a transition state in which the tape speed is changed from one speed to another, said tape speed setting means changes the tape speed in step-wise so that a deviation of the track direction speed component of said tape in each step of change of the tape speed is within a range in which said signal processing circuit can correctly read said tape position information.
Claim 7
Independent Claim
310 words
An apparatus for reproducing signals recorded in slanting tracks on a recording tape including a tape position information recorded at a specified area on each track, comprising: a rotary cylinder mounting thereon a reproducing head; a cylinder rotation detector for producing a periodic signal corresponding to a rotational speed of said rotary cylinder; two reels on which said tape is wound for running said tape; two reel rotation detectors for producing periodic signals corresponding to rotational speeds of said two reels, respectively; a signal processing circuit for processing signals picked up by said head from said tape; a reel drive means for driving either one of said two reels to run said tape; a tape speed setting means capable of setting a plurality of tape speeds and outputting a signal indicative of one of the settable plurality of tape speeds, a period target value calculating means for producing a period target value from an output signal from said signal processing circuit; a tape running control means for outputting a drive signal to said reel drive means according to the output signals from said two reel rotaiton detectors, the output signal from said tape speed setting means and said period target value so that said tape runs at the speed set by said tape speed setting means; a cylinder speed setting means for setting such a rotational speed of said rotary cylinder that a track direction speed component of said head is kept constant according to the output signal from said tape speed setting means and outputting a signal indicative of the set rotational speed; and a cylinder control means for controlling said rotary cylinder according to the output signal from said cylinder rotation detector and the output signal from said cylinder speed setting means so that said rotary cylinder rotates at the speed set by said cylinder speed setting means.
Claim 8
Independent Claim
310 words
An apparatus for reproducing signals recorded in slanting tracks on a recording tape including a tape position information recorded at a specified area on each track, comprising: a rotary cylinder mounting thereon a reproducing head; a cylinder rotation detector for producing a periodic signal corresponding to a rotational speed of said rotary cylinder; two reels on which said tape is wound for running said tape; two reel rotation detectors for producing periodic signals corresponding to rotational speeds of said two reels, respectively; a signal processing circuit for processing signals picked up by said head from said tape; a reel drive means for driving either one of said two reels to run said tape; a tape speed setting means capable of setting a plurality of tape speeds and outputting a signal indicative of one of the settable plurality of tape speeds, a period target value calculating means for producing a period target value from an output signal from said signal processing circuit; a tape running control means for outputting a drive signal to said reel drive means according to the output signals from said two reel rotaiton detectors, the output signal from said tape speed setting means and said period target value so that said tape runs at the speed set by said tape speed setting means; a cylinder speed setting means for setting such a rotational speed of said rotary cylinder that a track direction speed component of said head is kept constant according to the output signal from said tape speed setting means and outputting a signal indicative of the set rotational speed; and a cylinder control means for controlling said rotary cylinder according to the output signal from said cylinder rotation detector and the output signal from said cylinder speed setting means so that said rotary cylinder rotates at the speed set by said cylinder speed setting means.
Claim 9
Dependent Claim
212 words
An apparatus according to claim 6, wherein said tape running control means comprises: a clock signal generating means for generating a plurality of clock signals and outputting one of the plurality of clock signals according to the output signal from said tape speed setting means; a first presettable counter which presets said period target value and counts clocks of the output clock signal from said clock signal generating means during a first interval corresponding to the period of the periodic output signal from one of said two reel rotation detectors; a first latch circuit for latching a count output of said first presettable counter at the end of said first interval; a second presettable counter which presets said period target value and counts clocks of the output clock signal from said clock signal generating means during a second interval corresponding to the period of the periodic output signal from the other of said two reel rotation detectors; a second latch circuit for latching a count output of said second presettable counter at the end of said second interval; an adder for adding latched outputs of said first and second latch circuits; and a DA converter for converting an added output of said adder to an analog signal which is said drive signal.
Claim 10
Dependent Claim
76 words
An apparatus according to claim 6, wherein said signal processing circuit has: a PLL circuit for producing an oscillation signal synchronized with a signal picked up by said head from said tape; and a PLL operating point detecting circuit for detecting a difference of the number of waves of the oscillation signal from a predetermined number of waves and outputting a difference value indicative of said difference as said output signal of said signal processing circuit.
Claim 11
Dependent Claim
89 words
An apparatus according to claim 8, wherein said period target value calculating means comprises: a first memory and a first adder, said first adder adding said difference value outputted from said signal processing circuit with a value stored in said first memory, an added output value of said first adder being written into said first memory; a second memory storing a predetermined fixed value; and a second adder for adding the added output value of said first adder with said predetermined fixed value to obtain said period target value.
References Cited (Backward Citations)
No citation records indexed.
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