US3819947A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photodynamic monitor for and process of detecting the momentary presence of an object between two points
Assignee: Sharp Corp
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Filing: 1972-12-26
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Granted: 1974-06-25
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Expires: 1992-12-26
Abstract
Abstract A photodynamic monitor or stop motion machine for detecting when a yarn has passed across a space and for automatically biasing a circuit to shut down a textile machine upon such an occurence. The stop motion machine has one or a plurality of transmitters for transmitting infrared light in time-spaced pulses across a tufting machine (or other textile machine) adjacent selected yarns, and one or more transducers which digitally compare the original signal with the received signal for biasing the fail safe control circuit when a programmed discontinuity is detected. Reflecting surfaces direct the light pulses along prescribed paths between one or more of the transmitters and transducers. The transmitter includes a pulse generator, generating pulses in the 2kHz range, each having a duration of 25 microseconds, and a current regulating amplifier which feeds these pulses to one or a plurality of infrared emitting diodes. The transducer includes one or more infrared sensing detectors, for receiving the infrared beams, each detector being also illuminated by an individually controlled lamp, the brighness of which is adjusted so as to extend the modulation transfer function characteristics of the detector, and thus, improve the high frequency response of the detector. The received signal of each sensing detector is sent through a detector amplifier to the reset circuit of a counter, into which counter the signal from the pulse generator is also sent. The counter and reset circuit includes a Nand Gate Schmitt trigger which detects any drop in amplitude of the signal and a comparator gate which transmits the pulse counter differential to a decoder programmed to trigger the fail safe circuit when a given number of successive pulses is received.
Inventors
- 👤 W Johnson
- 👤 D Davis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:23
CPC Classifications
D; D05; D05C; D05C15/00; D05C15/04; D05C15/08; D05C15/16; D05C15/18; D05D; D05D2305/00; D05D2305/32; D05D2305/34
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
146 words
Process of detecting the momentary presence of object between two points, comprising: a. generating a first electrical signal consisting of discrete time spaced successive electrical pulses; b. converting said first electrical signal into electromagnetic radiation pulses; c. directing said electromagnetic radiation pulses from one of said points toward the other of said points; d. receiving said electromagnetic radiation pulses at said other of said points; e. generating a second electrical signal consisting of discrete spaced successive electrical pulses corresponding to the received electromagnetic radiation pulses; f. comparing the pulses of said first electrical signal with the pulses of said second electrical signal for detecting a discontinuity of the pulses of said second electrical signal; g. counting the number of said detected discontinuities in a prescribed consecutive group; and h. generating a control signal in response to the detection of said prescribed number of said detected discontinuities.
Claim 2
Dependent Claim
146 words
Process of detecting the momentary presence of object between two points, comprising: a. generating a first electrical signal consisting of discrete time spaced successive electrical pulses; b. converting said first electrical signal into electromagnetic radiation pulses; c. directing said electromagnetic radiation pulses from one of said points toward the other of said points; d. receiving said electromagnetic radiation pulses at said other of said points; e. generating a second electrical signal consisting of discrete spaced successive electrical pulses corresponding to the received electromagnetic radiation pulses; f. comparing the pulses of said first electrical signal with the pulses of said second electrical signal for detecting a discontinuity of the pulses of said second electrical signal; g. counting the number of said detected discontinuities in a prescribed consecutive group; and h. generating a control signal in response to the detection of said prescribed number of said detected discontinuities.
Claim 3
Dependent Claim
15 words
The process defined in claim 1 wherein said electromagnetic radiation pulses are infrared light pulses.
Claim 4
Dependent Claim
27 words
The process defined in claim 1 wherein said object is one of a plurality of parallel yarns which moves out of its prescribed path adjacent said beam.
Claim 5
Dependent Claim
26 words
The process defined in claim 1 wherein the time spaced pulses have a frequency of approximately 2kHz and each has a duration of approximately 25 microseconds.
Claim 6
Dependent Claim
98 words
The process defined in claim 1 wherein said time spaced pulses each have approximately the same amplitude and said pulses of said second electrical signal normally have approximately the same amplitude and wherein the momentary presence of an object in said electromagnetic radiation pulses will cause a drop in amplitude of said electromagnetic pulses and a corresponding drop in amplitude of said second electrical signal, and wherein the step of detecting the discontinuity of pulses includes detecting a change in the ratio of amplitude between pulses of said first electrical signal and pulses of said second electrical signal.
Claim 7
Dependent Claim
32 words
The process defined in claim 1 wherein said electromagnetic radiation pulses are infrared pulses generated by an infrared emitting diode and wherein said electromagnetic radiation pulses are received by a photosensitive element.
Claim 8
Dependent Claim
96 words
Process of detecting an object momentarily passing between a first point and a second point, comprising: a. generating and directing, in a beam from said first point to said second point, a series of electromagnetic radiation pulses, each pulse being time spaced from each other, each pulse having approximately the same characteristic; b. receiving said series of pulses at said second point; c. counting, in the received series of pulses, the number of eliminated and altered pulses; and d. providing a signal in response to the counting of a prescribed number of altered and eliminated pulses.
Claim 9
Dependent Claim
96 words
Process of detecting an object momentarily passing between a first point and a second point, comprising: a. generating and directing, in a beam from said first point to said second point, a series of electromagnetic radiation pulses, each pulse being time spaced from each other, each pulse having approximately the same characteristic; b. receiving said series of pulses at said second point; c. counting, in the received series of pulses, the number of eliminated and altered pulses; and d. providing a signal in response to the counting of a prescribed number of altered and eliminated pulses.
Claim 10
Dependent Claim
41 words
The process defined in claim 7 wherein the step of counting the altered and eliminated pulses includes counting all pulses having an amplitude less than a threshold amplitude with respect to the general amplitude of the remaining pulses in that series.
Claim 11
Dependent Claim
47 words
The process defined in claim 8 wherein said step of counting the eliminated and altered pulses comprises comparing the generated series of pulses and the received series of pulses for ascertaining the number of received pulses having a difference in the amplitude from the remaining received pulses.
Claim 12
Dependent Claim
99 words
The process defined in claim 7 including: a. generating and directing from a third point a second beam similar to the first mentioned beam and in which a second series of electromagnetic radiation pulses are in phase with first mentioned series of pulses; b. receiving said second series of pulses at a fourth point; c. simultaneously comparing the received first mentioned series of pulses and the received second series of pulses with the first mentioned electromagnetic pulses; d. and wherein the step of counting includes detecting and counting the altered and eliminated from the received second series of pulses.
Claim 13
Dependent Claim
143 words
A photodynamic monitor comprising: A. a transmitter having a. a pulse generator for producing a generated first signal having spaced discrete first pulses; and b. a beam source controlled by said pulse generator for producing a beam of second discrete pulses of electromagnetic radiation in response to the generated first signal from said pulse generator, said beam being directed across a space to be monitored for being interrupted when an object passes across said beam; and B. a transducer having: a. a sensor for receiving said beam and for producing a second signal having spaced discrete third pulses in response to said second pulses of said beam; and b. means for digitally comparing simultaneously said first pulses and said third pulses, and for generating a third signal in response to a prescribed digital difference between said first pulses and the said third pulses.
Claim 14
Dependent Claim
143 words
A photodynamic monitor comprising: A. a transmitter having a. a pulse generator for producing a generated first signal having spaced discrete first pulses; and b. a beam source controlled by said pulse generator for producing a beam of second discrete pulses of electromagnetic radiation in response to the generated first signal from said pulse generator, said beam being directed across a space to be monitored for being interrupted when an object passes across said beam; and B. a transducer having: a. a sensor for receiving said beam and for producing a second signal having spaced discrete third pulses in response to said second pulses of said beam; and b. means for digitally comparing simultaneously said first pulses and said third pulses, and for generating a third signal in response to a prescribed digital difference between said first pulses and the said third pulses.
Claim 15
Dependent Claim
40 words
The photodynamic monitor defined in claim 11 wherein said source includes a plurality of light emitting diodes simultaneously driven by said pulse generator and wherein said sensor includes a plurality of photosensitive detectors respectively receiving the light from said diodes.
Claim 16
Dependent Claim
16 words
The photodynamic monitor defined in claim 12 wherein said light emitting diodes are disposed in series.
Claim 17
Dependent Claim
32 words
The photodynamic monitor defined in claim 13 wherein a capacitor is in the circuit with said diodes for being charged between adjacemt pulses and for discharging when said second pulses are generated.
Claim 18
Dependent Claim
48 words
The photodynamic monitor defined in claim 11 wherein said pulse generator includes a pair of free running multivibrators, each having a multivibrator and an RC circuit therefore, one of said multivibrators generating the pulse for said first pulses rate and the other generating the duration of each pulse.
Claim 19
Dependent Claim
40 words
The photodynamic monitor defined in claim 11 wherein said pulse generator includes: a. means for generating time spaced positive pulses; b. means for receiving and inverting said positive pulses; and c. a current control amplifier triggered by said inverted pulses.
Claim 20
Dependent Claim
20 words
The photodynamic monitor defined in claim 16 wherein said light source includes a light emitting diode driven by said amplifier.
Claim 21
Dependent Claim
27 words
The photodynamic monitor defined in claim 17 including a capacitor with said diode for filtering power supply pulses occurring as said diode is triggered by said amplifier.
Claim 22
Dependent Claim
118 words
In a photodynamic monitor, A. a transmitter including: a. means for generating a continuous train of electrical pulses according to a pulse pattern; b. a source of electromagnetic energy pulses, controlled by said means for producing a corresponding train of electromagnetic pulses according to said pulse pattern; and B. a transducer for receiving said electromagnetic pulses, and said transducer being electrically connected to said means for generating pulses for also receiving said electrical pulses, means in said transducer for detecting a change in the pulse pattern; and of said electromagnetic pulses from the pattern of said electrical pulses. C. means for shutting down a motor or other device in response to said detected change in the pulse pattern.
Claim 23
Dependent Claim
118 words
In a photodynamic monitor, A. a transmitter including: a. means for generating a continuous train of electrical pulses according to a pulse pattern; b. a source of electromagnetic energy pulses, controlled by said means for producing a corresponding train of electromagnetic pulses according to said pulse pattern; and B. a transducer for receiving said electromagnetic pulses, and said transducer being electrically connected to said means for generating pulses for also receiving said electrical pulses, means in said transducer for detecting a change in the pulse pattern; and of said electromagnetic pulses from the pattern of said electrical pulses. C. means for shutting down a motor or other device in response to said detected change in the pulse pattern.
Claim 24
Dependent Claim
41 words
The photodynamic monitor defined in claim 19 wherein said source includes a plurality of light emitting diodes simultaneously driven by said first mentioned means and wherein said sensor includes a plurality of photosensitive detectors respectively receiving the light from said diodes.
Claim 25
Dependent Claim
16 words
The photodynamic monitor defined in claim 19 wherein said light emitting diodes are disposed in series.
Claim 26
Dependent Claim
32 words
The photodynamic monitor defined in claim 19 wherein a capacitOr is in the circuit with said diodes for being charged between adjacent pulses and for discharging when said second pulses are generated.
Claim 27
Dependent Claim
49 words
The photodynamic monitor defined in claim 19 wherein said first mentioned means includes a pair of free running multivibrators, each having a multivibrator and an RC circuit therefore, one of said multivibrators generating the pulse for said first pulses rate and the other generating the duration of each pulse.
Claim 28
Dependent Claim
30 words
The photodynamic monitor defined in claim 19 wherein said first mentioned means includes: a. means for generating time spaced positive pulses; b. a current control amplifier controlled by said pulses.
Claim 29
Dependent Claim
19 words
The photodynamic monitor defined in claim 20 wherein said source includes a light emitting diode driven by said amplifier.
Claim 30
Dependent Claim
19 words
The photodynamic monitor defined in claim 11 wherein said transducer includes an operational amplifier for amplifying said second signal.
Claim 31
Dependent Claim
18 words
The photodynamic monitor defined in claim 11 wherein said sensor includes a photo-Darlington for generating said second pulses.
Claim 32
Dependent Claim
46 words
The photodynamic monitor defined in claim 11 wherein said sensor includes a photo-detector and a light source shining on said photodetector, said light source being of insufficient intensity to actuate said photodetector but being sufficient to permit said pulses of said beam to actuate said photo-detector.
Claim 33
Dependent Claim
70 words
The photodynamic monitor defined in claim 11 including a motor control circuit, a motor controlled by said motor control circuit, a relay having a normally open switch, said relay when energized closing said switch, said normally open switch being in motor control circuit for preventing energization of said motor when said switch is open, means for energizing said relay, and means for de-energizing said relay when said discontinuity is detected.
Claim 34
Dependent Claim
33 words
The photodynamic monitor defined in claim 11 including a motor control circuit and an electrical latch triggered by said means upon detection of said discontinuity, disabling said motor control circuit in response thereto.
Claim 35
Dependent Claim
66 words
The photodynamic monitor defined in claim 11 wherein said means includes a binary counter and a decoder for said binary counter, said binary counter receiving said first pulses and said third pulses and transmitting to said decoder discontinuity pulses corresponding to the discontinuity between the first and third pulses, said decoder counting a prescribed number of discontinuity pulses for triggering a control circuit in response thereto.
Claim 36
Dependent Claim
36 words
The photodynamic monitor defined in claim 31 wherein said means includes a latch circuit in said control circuit for providing a continuous signal in said control circuit in response to the triggering of said control circuit.
Claim 37
Dependent Claim
20 words
The photodynamic monitor defined in claim 11 including reflector means for reflecting said beam from said source to said sensor.
Claim 38
Dependent Claim
38 words
The photodynamic monitor defined in claim 33 wherein said reflector is disposed on one side of a yarn sheet and said sensor and said source are disposed adjacent each other on the other side of said warp sheet.
Claim 39
Dependent Claim
14 words
The photodynamic monitor defined in claim 34 wherein said reflector means includes a pentaprism.
Claim 40
Dependent Claim
45 words
The photodynamic monitor defined in claim 34 wherein said reflector means includes a semi-reflector mirror disposed in front of said source and through which said beam is directed and a reflector for directing said beam back against said semi-reflector mirror and thence into said source.
Claim 41
Dependent Claim
74 words
Process of utilizing a pulsed radiation beam comprising directing said beam onto the photosensitive portion of an electrical photosensitive detector and simultaneously therewith continuously biasing said photosensitive detector by directing a prescribed and substantially constant intensity light onto said photosensitive portion of said detector, said light being of an intensity sufficient to modify the modulation transfer function characteristics of said detector for enhancing the high frequency response of said detector to said pulsed beam.
Claim 42
Dependent Claim
74 words
Process of utilizing a pulsed radiation beam comprising directing said beam onto the photosensitive portion of an electrical photosensitive detector and simultaneously therewith continuously biasing said photosensitive detector by directing a prescribed and substantially constant intensity light onto said photosensitive portion of said detector, said light being of an intensity sufficient to modify the modulation transfer function characteristics of said detector for enhancing the high frequency response of said detector to said pulsed beam.
Claim 43
Dependent Claim
26 words
The process defined in claim 37 wherein the pulse duration of each pulse of said beam is less than that which would normally actuate said detector.
Claim 44
Dependent Claim
15 words
The process defined in claim 38 in which said duration is less than 300 microseconds.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-24 | 1977-12-24 | 1978-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-24 | 1981-12-24 | 1982-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-24 | 1985-12-24 | 1986-06-25 | $7700.00 | Window Closed / Lapsed |