US3851323A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for detecting the absence of a finger in a type carrier of a printer
Assignee: Bull SAS
•
Filing: 1973-05-22
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Granted: 1974-11-26
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Expires: 1993-05-22
Abstract
Abstract A device is provided for detecting the absence of a finger in a printer, comprising a mobile support provided with print-type support-fingers and with an equal number of synchronization marks, and a fixed detector of synchronization marks which sends a so-called synchronization pulse to a strike triggering member, whenever a mark is passing before it. The device is characterized in that it comprises a second fixed detector placed at the lever of the finger associated with the mark, which, during the displacement, passes before the first detector and delivers a pulse indicating the presence of a finger each time a finger is passing before it, and a two input recognition circuit, each input receiving respectively pulses delivered by the first and the second detector.
Inventors
- 👤 J Eltgen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:30
CPC Classifications
B; B41; B41J; B41J9/00; B41J9/14
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
192 words
A device for the detection of the displacement of a finger for a printer comprising a movable support in the form of an endless band carrying print-type-carrying fingers subject to deformation relative thereto and synchronization marks in equal number, each mark being associated with one finger, and a first fixed detector for the synchronization marks positioned close to the path followed by said synchronization marks; said first detector having means for sending a synchronization pulse whenever a synchronization mark passes before it; a second fixed detector positioned close to the path followed by the fingers and on the level of the finger associated with the mark that passes before the first detector, said second detector having means for emitting a pulse indicative of the presence of a finger whenever a finger passes before it, and a recognition circuit having two inputs for receiving the pulses emitted by the first and the second detector, respectively, said circuit having an output and means for verifying the correspondence between the pulses emitted by the two detectors and generating at said output a signal indicating the displacement of a finger whenever the correspondence is not established.
Claim 2
Independent Claim
192 words
A device for the detection of the displacement of a finger for a printer comprising a movable support in the form of an endless band carrying print-type-carrying fingers subject to deformation relative thereto and synchronization marks in equal number, each mark being associated with one finger, and a first fixed detector for the synchronization marks positioned close to the path followed by said synchronization marks; said first detector having means for sending a synchronization pulse whenever a synchronization mark passes before it; a second fixed detector positioned close to the path followed by the fingers and on the level of the finger associated with the mark that passes before the first detector, said second detector having means for emitting a pulse indicative of the presence of a finger whenever a finger passes before it, and a recognition circuit having two inputs for receiving the pulses emitted by the first and the second detector, respectively, said circuit having an output and means for verifying the correspondence between the pulses emitted by the two detectors and generating at said output a signal indicating the displacement of a finger whenever the correspondence is not established.
Claim 3
Dependent Claim
243 words
A device according to claim 1 in which the recognition circuit verifying means includes a first and a second monostable circuit in series, a front-recognition circuit, a flip-flop circuit having first and second inputs and an output Q and a comparison circuit having first and second inputs, the first monostable circuit having means for receiving the synchronization pulse and sending in response thereto a first pulse to the second monostable circuit and to the front-recognition circuit, the second monostable having means for delivering in response to the first pulse a window pulse to the first input of the comparison circuit, the front-recognition circuit having means for sending in response to that same first pulse a signal to the first input of said flip-flop circuit, means for delivering to the second input of said flip-flop circuit the pulse indicative of the presence of the finger, the flip-flop circuit being of a construction wherein the signal transmitted to the flip-flop circuit first input puts the flip-flop circuit in a first state of equilibrium and the pulse indicative of the presence of a finger puts the flip-flop circuit in the second state of equilibrium, means for transmitting the output signal received in the output Q of the flip-flop circuit to the second input of the comparison circuit; and said comparison circuit having means for verifying if said flip-flop circuit is not in its first state of equilibrium beyond the time interval defined by said window pulse.
Claim 4
Dependent Claim
28 words
A device according to claim 1 in which the first detector includes a magnetic pickup of variable reluctance and a circuit for the amplification and forming of signals.
Claim 5
Dependent Claim
28 words
A device according to claim 1, in which the second detector includes a magnetic pickup of variable reluctance and a circuit for the amplification and forming of signals.
Claim 6
Dependent Claim
33 words
A device according to claim 1, in which the second detector includes the optic-electric pick-up including a light emitter and a photosensitive detector and a circuit for the amplification and forming of signals.
Claim 7
Dependent Claim
18 words
A device according to claim 1, in which two pulleys of parallel rotational axes support the endless band.
References Cited (Backward Citations)
US3370286A
Cited
US3656426A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-25 | 1978-05-27 | 1978-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-25 | 1982-05-27 | 1982-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-25 | 1986-05-27 | 1986-11-26 | $7700.00 | Window Closed / Lapsed |