US3928843A
Expired / Lapsed
US
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Dual channel infrared intrusion alarm system
Assignee: Optical Coating Laboratory Inc
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Filing: 1974-06-24
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Granted: 1975-12-23
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Expires: 1994-06-24
Abstract
Abstract An infrared intrusion alarm system utilizes two sensing elements and two signal processing channels arranged such that an intruder produces signals of opposite polarities in the two channels. An alarm signal is delivered only in the event that the two signals of opposite polarities are present simultaneously. Disturbances, such as component noise, which affect only one channel cannot give rise to an alarm, nor can power supply disturbances which produce signals of the same polarity in both channels.
Inventors
- 👤 James Cole Sprout
- 👤 Herbert L Berman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:08
CPC Classifications
G; G01; G01J; G01J5/00; G01J5/10; G01J5/20; G08; G08B; G08B13/00; G08B13/18; G08B13/189; G08B13/19; Y; Y10; Y10S; Y10S250/00; Y10S250/01
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
119 words
In an intrusion alarm system: first and second sensing elements having electrical resistances dependent upon the level of infrared energy impinging thereon, a resistive element connected in series with each of the sensing elements and a voltage source, first amplifier means for providing an output signal corresponding to the signal developed across the first sensing element, second amplifier means for providing an output signal corresponding to the signal developed across the resistive element in series with the second sensing element, first and second level detector means for producing signals when the output signals from the amplifier means reach predetermined levels, and gate means for providing an alarm signal upon conjoint receipt of the signals from the level detector means.
Claim 2
Dependent Claim
119 words
In an intrusion alarm system: first and second sensing elements having electrical resistances dependent upon the level of infrared energy impinging thereon, a resistive element connected in series with each of the sensing elements and a voltage source, first amplifier means for providing an output signal corresponding to the signal developed across the first sensing element, second amplifier means for providing an output signal corresponding to the signal developed across the resistive element in series with the second sensing element, first and second level detector means for producing signals when the output signals from the amplifier means reach predetermined levels, and gate means for providing an alarm signal upon conjoint receipt of the signals from the level detector means.
Claim 3
Dependent Claim
24 words
The alarm system of claim 1 wherein the amplifier means comprise amplifiers having a frequency response in the range of 0.2 to 2 Hz.
Claim 4
Dependent Claim
78 words
The alarm system of claim 1 wherein the sensing elements comprise flakes of thermistor material disposed side-by-side on a support comprising a cup-shaped case, a plurality of axially extending leads spaced in quadrature and passing through openings in the base of the case, and insulative material in the case holding the leads in predetermined positions, the flakes of thermistor material being mounted on adjacent ones of the leads outside the case adjacent to the base and spaced therefrom.
Claim 5
Dependent Claim
75 words
In an intrusion alarm system first and second sensing elements responsive to infrared energy from the body of an intruder, means for directing energy from a field of view simultaneously to both of the sensing elements, first and second amplifier means for providing output signals in response to infrared energy impinging upon the sensing elements, and means for providing an alarm signal upon conjoint receipt of the output signals from both of the amplifier means.
Claim 6
Dependent Claim
75 words
In an intrusion alarm system first and second sensing elements responsive to infrared energy from the body of an intruder, means for directing energy from a field of view simultaneously to both of the sensing elements, first and second amplifier means for providing output signals in response to infrared energy impinging upon the sensing elements, and means for providing an alarm signal upon conjoint receipt of the output signals from both of the amplifier means.
Claim 7
Dependent Claim
26 words
The alarm system of claim 4 wherein output signals of opposite polarities are provided in response to the infrared energy impinging simultaneously upon the sensing elements.
Claim 8
Dependent Claim
27 words
The alarm system of claim 4 wherein the amplifier means each include a tuned amplifier having a frequency response in the range of 0.2 to 2 Hz.
Claim 9
Dependent Claim
78 words
The alarm system of claim 4 wherein the sensing elements have resistances which vary in accordance with the level of infrared energy impinging thereon, each of the sensing elements being connected electrically in series with a resistive element and a source of voltage, the first amplifier means being responsive to signals developed across the first sensing element and the second amplifier means being responsive to signals developed across the resistive element in series with the second sensing element.
Claim 10
Dependent Claim
52 words
The alarm system of claim 4 wherein the means for providing an alarm signal comprises first and second level detectors for providing signals when the output signals from the amplifier means reach predetermined levels and gate means for providing an alarm signal upon conjoint receipt of the signals from the level detectors.
Claim 11
Dependent Claim
20 words
The alarm system of claim 4 wherein the sensing elements comprise flakes of thermistor material disposed side-by-side on a support.
Claim 12
Dependent Claim
70 words
The alarm system of claim 9 wherein the support comprises a cup-shaped case, a plurality of leads extending axially of the case, said leads being spaced in quadrature and passing through openingS in the base of the case, and insulative material inside the case holding the leads in predetermined positions, the flakes of thermistor material being mounted on the leads outside the case adjacent to the base and spaced therefrom.
Claim 13
Dependent Claim
100 words
In an intrusion alarm system: a detector assembly comprising a cup-shaped case, axially extending leads spaced in quadrature and passing through openings in the base of the case, insulative material in the case holding the leads in predetermined positions, and a pair of infrared sensing elements mounted side-by-side on adjacent ones of the leads outside the case adjacent to the base and spaced therefrom; first and second amplifier means for producing output signals in response to infrared energy impinging upon the sensing elements; and means for providing an alarm signal upon conjoint receipt of the output signals from the amplifiers.
Claim 14
Dependent Claim
100 words
In an intrusion alarm system: a detector assembly comprising a cup-shaped case, axially extending leads spaced in quadrature and passing through openings in the base of the case, insulative material in the case holding the leads in predetermined positions, and a pair of infrared sensing elements mounted side-by-side on adjacent ones of the leads outside the case adjacent to the base and spaced therefrom; first and second amplifier means for producing output signals in response to infrared energy impinging upon the sensing elements; and means for providing an alarm signal upon conjoint receipt of the output signals from the amplifiers.
Claim 15
Dependent Claim
25 words
The alarm system of claim 11 wherein output signals of opposite polarities are provided in response to the infrared energy impinging on the sensing elements.
Claim 16
Dependent Claim
124 words
In an intrusion alarm system: an axially extending housing, first and second infrared sensing elements mounted side-by-side toward one end of the housing and facing inwardly of the housing, means within the housing for directing infrared energy from a plurality of spaced-apart fields of view outside the housing to the sensing elements, the sensing elements being positioned side-by-side in a direction normal to the axis of the housing and normal to the direction in which the fields of view are spaced, first and second amplifier means within the housing for providing output signals in response to infrared energy impinging on the sensing elements, and means within the housing for providing an alarm signal upon conjoint receipt of the output signals from the amplifier means.
Claim 17
Dependent Claim
124 words
In an intrusion alarm system: an axially extending housing, first and second infrared sensing elements mounted side-by-side toward one end of the housing and facing inwardly of the housing, means within the housing for directing infrared energy from a plurality of spaced-apart fields of view outside the housing to the sensing elements, the sensing elements being positioned side-by-side in a direction normal to the axis of the housing and normal to the direction in which the fields of view are spaced, first and second amplifier means within the housing for providing output signals in response to infrared energy impinging on the sensing elements, and means within the housing for providing an alarm signal upon conjoint receipt of the output signals from the amplifier means.
Claim 18
Dependent Claim
30 words
The alarm system of claim 13 wherein the amplifier means are adapted to produce output signals of opposite polarities in response to the infrared energy impinging on the sensing elements.
Claim 19
Dependent Claim
70 words
A detector for a dual channel infrared intrusion alarm system comprising: a cup-shaped case, axially extending leads spaced in quadrature and passing through openings in the base of the case, a body of electrically insulative material in the case holding the leads in predetermined positions, and a pair of infrared sensing elements mounted side-by-side on adjacent ones of the leads outside the case proximate to the base and spaced therefrom.
Claim 20
Dependent Claim
70 words
A detector for a dual channel infrared intrusion alarm system comprising: a cup-shaped case, axially extending leads spaced in quadrature and passing through openings in the base of the case, a body of electrically insulative material in the case holding the leads in predetermined positions, and a pair of infrared sensing elements mounted side-by-side on adjacent ones of the leads outside the case proximate to the base and spaced therefrom.
Claim 21
Dependent Claim
15 words
The detector of claim 15 wherein the sensing elements comprise flakes of a thermistor material.
Claim 22
Dependent Claim
111 words
In an intrusion alarm system: an axially extending housing, first and second infrared sensing elements mounted side-by-side toward one end of the housing and facing inwardly of the housing, a plurality of reflective surfaces disposed horizontally of each other for directing infrared energy from horizontally spaced apart fields of view outside the housing to the sensing elements, the sensing elements being positioned side-by-side and vertically of each other, first and second amplifier means within the housing for providing output signals in response to infrared energy impinging on the sensing elements, and means within the housing for providing an alarm signal upon conjoint receipt of the output signals from the amplifier means.
Claim 23
Dependent Claim
111 words
In an intrusion alarm system: an axially extending housing, first and second infrared sensing elements mounted side-by-side toward one end of the housing and facing inwardly of the housing, a plurality of reflective surfaces disposed horizontally of each other for directing infrared energy from horizontally spaced apart fields of view outside the housing to the sensing elements, the sensing elements being positioned side-by-side and vertically of each other, first and second amplifier means within the housing for providing output signals in response to infrared energy impinging on the sensing elements, and means within the housing for providing an alarm signal upon conjoint receipt of the output signals from the amplifier means.
Claim 24
Dependent Claim
81 words
In an intrusion alarm system: first and second sensing elements arrangend to provide signals of opposite polarities in response to infrared energy from the body of an intruder, means for directing energy from a field of view simultaneously to both of the sensing elements, first and second amplifier means for providing output signals in response to the signals of opposite polarities, and means for providing an alarm signal upon conjoint receipt of the output signals from both of the amplifier means.
Claim 25
Dependent Claim
81 words
In an intrusion alarm system: first and second sensing elements arrangend to provide signals of opposite polarities in response to infrared energy from the body of an intruder, means for directing energy from a field of view simultaneously to both of the sensing elements, first and second amplifier means for providing output signals in response to the signals of opposite polarities, and means for providing an alarm signal upon conjoint receipt of the output signals from both of the amplifier means.
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) | 1978-12-22 | 1979-06-23 | 1979-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-22 | 1983-06-23 | 1983-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-22 | 1987-06-23 | 1987-12-23 | $7700.00 | Window Closed / Lapsed |