US3735372A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Seven or nine channel readout with adjustable threshold
Assignee: DECISION DATA Inc A CORP OF
•
Filing: 1971-07-02
•
Granted: 1973-05-22
•
Expires: 1991-07-02
Abstract
Abstract A circuit for reading digital information recorded on magnetic tape. Nine transducers are arranged to sense information recorded on nine-channel magnetic tape and seven other transducers are arranged to sense data recorded on seven-channel magnetic tape. The circuit includes means for selecting the outputs of either the first or the second group of transducers so that data from either seven or nine-channel magnetic tape may be read. The input signal obtained from each transducer in the appropriate selected group is fed to a pair of subcircuits, one of the pair providing a signal in response to each negative pulse in the input signal at that pulses''s peak and the other subcircuit providing a signal in response to each positive pulse in the input signal at that pulses''s peak. Each of these subcircuits contains a threshold circuit which indicates each pulse that is greater (higher or lower) than a predetermined threshold and the output of the threshold circuit is gated with the output of a peak-detecting circuit so subcircuit each subcircuit provides a signal at the peak of each pulse which is greater than a predetermined threshold. The outputs of both subcircuits are fed to an output circuit which provides a signal in response to receiving a pulseindicating signal from either of the subcircuits. The circuit includes means for adjusting the threshold level of the threshold circuits so that the sensitivity of the circuit may be adjusted. Preferably, the threshold adjustment may be made to a 100 percent threshold level to aid in tuning the circuit.
Inventors
- 👤 E Coccagna
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:52
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/10009
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
263 words
A circuit for Reading information from a digital magnetic recording medium comprising: transducer means for converting said information into an input signal comprising a train of positive and negative pulses corresponding to said information; a first circuit comprising positive threshold means for receiving said input signal and providing a signal in response to each positive pulse in said input signal above a predetermined positive pulse in said input signal above a predetermined positive threshold level, positive peak-detecting means for receiving said input signal and providing a signal in response to the peak of each positive pulse in said input signal, positive gating means for receiving said signals from said positive threshold and positive peak-detecting means, said gating means providing a first signal in response to receiving both said signals; a second circuit comprising negative threshold means for receiving said input signal and providing a signal in response to each negative pulse in said input signal below a predetermined negative threshold level, negative peak-detecting means for receiving said input signal and providing a signal in response to the peak of each negative pulse in said input signal, negative gating means for receiving said signals from said negative threshold and negative peak-detecting means, said negative gating means providing a second signal in response to receiving both said signals; output circuit means for receiving said first and second signals from said first and second circuits, said output circuit means providing an output signal in response to either of said signals; and means, operating on said positive and negative threshold means, for selectively adjusting their threshold levels.
Claim 2
Dependent Claim
263 words
A circuit for Reading information from a digital magnetic recording medium comprising: transducer means for converting said information into an input signal comprising a train of positive and negative pulses corresponding to said information; a first circuit comprising positive threshold means for receiving said input signal and providing a signal in response to each positive pulse in said input signal above a predetermined positive pulse in said input signal above a predetermined positive threshold level, positive peak-detecting means for receiving said input signal and providing a signal in response to the peak of each positive pulse in said input signal, positive gating means for receiving said signals from said positive threshold and positive peak-detecting means, said gating means providing a first signal in response to receiving both said signals; a second circuit comprising negative threshold means for receiving said input signal and providing a signal in response to each negative pulse in said input signal below a predetermined negative threshold level, negative peak-detecting means for receiving said input signal and providing a signal in response to the peak of each negative pulse in said input signal, negative gating means for receiving said signals from said negative threshold and negative peak-detecting means, said negative gating means providing a second signal in response to receiving both said signals; output circuit means for receiving said first and second signals from said first and second circuits, said output circuit means providing an output signal in response to either of said signals; and means, operating on said positive and negative threshold means, for selectively adjusting their threshold levels.
Claim 3
Dependent Claim
31 words
The circuit as recited in claim 1 and further including means, operating on said transducer means, for selectively adjusting the amplitude of the positive and negative pulses in said input signal.
Claim 4
Dependent Claim
47 words
The circuit as recited in claim 1 wherein said positive peak-detecting means comprises: a differentiating circuit for differentiating said input signal; and a circuit for receiving the output of said differentiating circuit and providing a signal in response to said output crossing zero from positive to negative.
Claim 5
Dependent Claim
47 words
The circuit as recited in claim 3 wherein said negative peak-detecting means comprises: a differentiating circuit for differentiating said input signal; and a circuit for receiving the output of said differentiating circuit and providing a signal in response to said output crossing zero from negative to positive.
Claim 6
Dependent Claim
69 words
The circuit as recited in claim 1 and further including means, responsive to each output signal from said output circuit, for maintaining one of said peak-detecting means in a state providing its output signal for a predetermined period of time, said peak detecting means being within the first or second circuit which provides the first or second signal to which said output circuit responds to provide said output signal.
Claim 7
Dependent Claim
178 words
In a circuit for detecting digital data recorded on a magnetic record medium, the combination comprising: transducer means relatively movable with respect to said record medium for generating an input signal comprising a train of input pulses corresponding to said recorded data; threshold means for receiving said input pulses and providing an output signal in response to each input pulse which is greater than an operating threshold level, said threshold means including adjustment means for temporarily setting said threshold level such that said output signals are generated only in response to input pulses which are greater than a reference level which is higher than and bears a predetermined relationship to said operating threshold level; and tuning means cooperating with said transducer means for selectively varying the amplitude of said input signal, said tuning means being operable in conjunction with said adjustment means for setting the maximum amplitude of said input Pulses to a level substantially equal to said reference level whereby the relationship of said operating threshold level to the amplitude of said input pulses is precisely established.
Claim 8
Dependent Claim
178 words
In a circuit for detecting digital data recorded on a magnetic record medium, the combination comprising: transducer means relatively movable with respect to said record medium for generating an input signal comprising a train of input pulses corresponding to said recorded data; threshold means for receiving said input pulses and providing an output signal in response to each input pulse which is greater than an operating threshold level, said threshold means including adjustment means for temporarily setting said threshold level such that said output signals are generated only in response to input pulses which are greater than a reference level which is higher than and bears a predetermined relationship to said operating threshold level; and tuning means cooperating with said transducer means for selectively varying the amplitude of said input signal, said tuning means being operable in conjunction with said adjustment means for setting the maximum amplitude of said input Pulses to a level substantially equal to said reference level whereby the relationship of said operating threshold level to the amplitude of said input pulses is precisely established.
Claim 9
Dependent Claim
58 words
The circuit set forth in claim 6 further comprising: peak-detecting means for receiving said input pulses and providing a signal in response to the peak of each said pulse; and gating means for receiving said signals from said threshold means and said peak-detecting means and for providing a final output signal in response to receiving both said signals.
Claim 10
Dependent Claim
85 words
The circuit set forth in claim 6 wherein: said threshold means includes means for shaping said output signals such that each has a width proportional to the length of time that its respective input pulse exceeds the threshold level; and said adjustment means includes means operable in response to actuation of said tuning means for indicating the setting of said tuning means which produces output signals of minimum width whereupon said condition of substantial equality between said input pulses and said reference level is established.
References Cited (Backward Citations)
US3152322A
Cited
US3164815A
Cited
US3404391A
Cited
US3377584A
Cited
US3413625A
Cited
US3593334A
Cited
US3597751A
Cited
US3623040A
Cited
US3631424A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-21 | 1976-11-20 | 1977-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-21 | 1980-11-20 | 1981-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-21 | 1984-11-20 | 1985-05-22 | $7700.00 | Window Closed / Lapsed |