US3751667A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radiation path continuity transducer of high pass frequency
Assignee: Individual
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Filing: 1971-08-10
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Granted: 1973-08-07
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Expires: 1991-08-10
Abstract
Abstract A signal is generated at a frequency substantially higher than powerline frequency and used to modulate a radiation emitting device. A radiation responsive device detects the modulated radiation together with any ambient radiation from other sources. AC coupling removes any unmodulated component from the output of the radiation responsive device, and high pass filtering greatly attenuates any components of the signal at the first harmonic of power line frequency and lower. Those frequencies which are substantially higher than powerline first harmonic are amplified and detected, and are utilized to signal whether or not the modulated radiation path is or is not interrupted. Provisions are disclosed to decrease the possibility that ambient radiation, not from the specially modulated source, will saturate the detector and amplifier system.
Inventors
- 👤 G Quittner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:34
CPC Classifications
G; G01; G01D; G01D5/00; G01D5/26; G01D5/32; G01D5/34; G01D5/342; G01V; G01V8/00; G01V8/10; G01V8/12; G06; G06M; G06M1/00; G06M1/08; G06M1/10; G06M1/108
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
94 words
In a radiation responsive system, the combination of, radiation responsive means, source means to emit radiation along an interruptable path to said radiation responsive means, means for modulating the radiation source means at a modulation frequency in a high pass frequency band higher than power line frequency, and utilization means including high frequency pass filter means connected to said radiation responsive means for selecting and responding only to the frequencies of said high pass frequency band to indicate the presence or absence of a continuous radiation path between said radiation emitting and responsive means.
Claim 2
Dependent Claim
94 words
In a radiation responsive system, the combination of, radiation responsive means, source means to emit radiation along an interruptable path to said radiation responsive means, means for modulating the radiation source means at a modulation frequency in a high pass frequency band higher than power line frequency, and utilization means including high frequency pass filter means connected to said radiation responsive means for selecting and responding only to the frequencies of said high pass frequency band to indicate the presence or absence of a continuous radiation path between said radiation emitting and responsive means.
Claim 3
Dependent Claim
41 words
A responsive system as set forth in claim 1, wherein said radiation responsive means is further characterized as being a photosensitive transistor connected as an emitter follower, whose base is electrically biased through a high impedance to a source of current.
Claim 4
Dependent Claim
21 words
A responsive system as set forth in claim 1, wherein said modulating means modulates the emission from said radiation emitting means.
Claim 5
Dependent Claim
37 words
A responsive system as set forth in claim 1, including means to interrupt the path between said emitting and responsive means whereby said utilization means indicates the presence or absence of said interrupting means in said path.
Claim 6
Dependent Claim
27 words
A responsive system as set forth in claim 1, wherein said utilization means includes high frequency pass filter means preceding any amplification means in said utilization means.
Claim 7
Dependent Claim
33 words
A responsive system as set forth in claim 1, wherein said utilization means includes load means having an increasingly lower impedance with increasing frequency to be responsive to the higher frequency modulation frequency.
Claim 8
Dependent Claim
32 words
A responsive system as set forth in claim 6, wherein said load means includes capacitor means passing the signal output of said utilization means to have a decreased impedance with increasing frequency.
Claim 9
Dependent Claim
62 words
A responsive system as set forth in claim 7, including means to amplify the output from said capacitor means, means to rectify the output from said amplifier means, and low pass filter means connected to the output of said rectifying means to indicate by a higher or lower voltage Value of direct current the presence or absence of a continuous radiation path.
Claim 10
Dependent Claim
35 words
A responsive system as set forth in claim 8, including a switching transistor connected to the output of said low pass filter, and means connecting the output of said switching transistor to control a load.
Claim 11
Dependent Claim
21 words
A responsive system as set forth in claim 1, wherein said modulating means is separate from any interruptions along said path.
Claim 12
Dependent Claim
113 words
A radiation responsive system, comprising, in combination, a source of modulation signal having a frequency substantially higher than the first harmonic of line frequency, a modulatable radiation source, modulating means to said modulating signal and connected to modulate said modulatable radiation source, radiation responsive means, an interruptable radiation path between said radiation source and said radiation responsive means, means for selectively amplifying only signals substantially higher in frequency than the first harmonic of line frequency and connected to said radiation responsive means, and means for detecting and utilizing the amplitude of said higher in frequency than the first harmonic of line frequency signals to detect the interrupted or uninterrupted condition of said path.
Claim 13
Dependent Claim
113 words
A radiation responsive system, comprising, in combination, a source of modulation signal having a frequency substantially higher than the first harmonic of line frequency, a modulatable radiation source, modulating means to said modulating signal and connected to modulate said modulatable radiation source, radiation responsive means, an interruptable radiation path between said radiation source and said radiation responsive means, means for selectively amplifying only signals substantially higher in frequency than the first harmonic of line frequency and connected to said radiation responsive means, and means for detecting and utilizing the amplitude of said higher in frequency than the first harmonic of line frequency signals to detect the interrupted or uninterrupted condition of said path.
Claim 14
Dependent Claim
36 words
A radiation responsive system as set forth in claim 11, wherein said selective amplifying means attenuates all signals lower in frequency than said modulating frequency at a rate of 6 db per octave change of frequency.
Claim 15
Dependent Claim
36 words
A radiation responsive system as set forth in claim 11, wherein said selective amplifying means attenuates all signals lower in frequency than said modulating frequency at a rate of 12 db per octave change of frequency.
Claim 16
Dependent Claim
29 words
A radiation responsive system as set forth in claim 11, wherein said modulation signal has a frequency at least five octaves higher than the first harmonic of line frequency.
Claim 17
Dependent Claim
21 words
A radiation responsive system as set forth in claim 11, wherein said modulation signal is a source of relatively constant frequency.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-06 | 1977-02-05 | 1977-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-06 | 1981-02-05 | 1981-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-06 | 1985-02-05 | 1985-08-07 | $7700.00 | Window Closed / Lapsed |