Security system operated by changes in light at specified locations

Claim 2

A security system for the detection of moving targets comprising: a plurality of sensors focused in inner and outer patterns, the said patterns creating inner and outer zones of intrustion; a sequence unit having first and second inputs and an output, said first and second inputs coupled to outputs of said sensors and said sequence unit being operable for producing an output after an input from said outer zone sensor and an input from said inner zone sensor after a predetermined delay.

Claim 3

The security system of claim 1 and further including: a lockout unit, said lockout unit having an input and an output coupled to an inhibit input of said sequence unit; and at least one lockout sensor disposed in proximity to said inner and outer sensors for sensing ambient conditions surrounding said zones of intrusion.

Claim 4

The security system of claim 1 and further including: a circuit coupled to a first group of said inner and outer zone sensors operable for yielding an output signal of one polarity; and a second group of sensors coupled to a second circuit means for yielding an output of another polarity with an identical variation in light condition within the inner and outer zones of intrusion.

Claim 5

The security system of claim 1 wherein: said inner and outer zones of intrusion comprise substantially coaxial cones.

Claim 6

The security system of claim 1 and including: first and second fire detecting sensors each having an output; and first and second threshold detectors having inputs coupled to the outputs of first and second fire sensors, respectively, said first and second threshold detectors being set for different levels of detection.

Claim 7

The security system of claim 5 and further including: a second sequence unit having first and second inputs coupled to the outputs of said first and second threshold detectors, said sequence unit being programmed for yielding an output after receiving first and second inputs in a predetermined time sequence; and a second lockout means having an input coupled to at least one said lockout sensor and an output coupled to an inhibit input of said sequence unit.

Claim 8

A security system for detecting moving intruders, including in combination: an A-series of sensor means for detecting changes in the illumination of a predetermined field of surveillance and for giving an intrusion signal, a B-series of similar sensor means having a significantly smaller field of surveillance entirely within that of the sensor means of said A-series and for giving an intrusion signal, a sequence unit connected to said A-series and having first and second circuits, each including a relay with latching means and relay-operated switches and timing means for retaining the latching of said relay for a predetermined time interval, the time interval for said first circuit being for a relatively brief time and that for said second circuit being for a longer time, an intrusion signal from said A-series activating both said first and second circuits, and an alarm output terminal connected by said sequence unit to said B-series through said relay switches when and only when said first circuit has been ''''on'''' and its time interval has expired and said second circuit is still ''''on'''' during its time interval, whereby said alarm output terminal is energized only when an A-series intrusion signal is followed by a B-series intrusion signal no sooner than after the expiry of the time interval of said first circuit but during the time interval of said second circuit.

Claim 9

A security system for detecting moving intruders, including in combination: an A-series of sensor means for detecting changes in the illumination of a predetermined field of surveillance and for giving an intrusion signal, a B-series of similar sensor means having a significantly smaller field of surveillance entirely within that of the sensor means of said A-series and for giving an intrusion signal, a sequence unit connected to said A-series and having first and second circuits, each including a relay with latching means and relay-operated switches and timing means for retaining the latching of said relay for a predetermined time interval, the time interval for said first circuit being for a relatively brief time and that for said second circuit being for a longer time, an intrusion signal from said A-series activating both said first and second circuits, and an alarm output terminal connected by said sequence unit to said B-series through said relay switches when and only when said first circuit has been ''''on'''' and its time interval has expired and said second circuit is still ''''on'''' during its time interval, whereby said alarm output terminal is energized only when an A-series intrusion signal is followed by a B-series intrusion signal no sooner than after the expiry of the time interval of said first circuit but during the time interval of said second circuit.

Claim 10

The security system of claim 7 having a C-series of sensor means like those of said A-series but having a field of surveillance relating to ambient light rather than a zone to be protected from intrusion, a lockout unit connected to said C-series and to said sequence unit and having a third circuit like said first and second circuits and having a time interval shorter than that of said first circuit and means energized by a signal from said C-series for disabling a simultaneous intrusion signal from said A-series.

Claim 11

The security system of claim 8 having a D-series of sensor means similar to the A-series, threshold amplifier means connected to said D-series for activation only when a predetermined threshold illumination change has been signaled by said D-series, alarm means activated by said threshold amplifier means for indicating the presence of fire or explosion conditions, a second lockout unit connected to said C-series and like the other said lockout unit for enabling a simultaneous signal for said D-series.

Claim 12

The security system of claim 7 having a D-series of sensor means like those of said A-series, threshold amplifier means connected to said D-series for activation only when a predetermined threshold illumination change is signaled by said D-series, and alarm means activated by said threshold amplifier means.

Claim 13

The security system of claim 10 having another sequence unit for comparing the signals of two spaced-apart sensor means of said D-series, and giving an ''''explosion'''' signal if the two sensor means give simultaneous signals and a ''''fire'''' signal if the sensor means gives its signal a few seconds later than the other said sensor means.

Claim 14

A security system for detecting moving intruders, including in combination an A-series of sensor means for detecting changes in the illumination of a predetermined field of surveillance and for giving an intrusion signal, a B-series of similar sensor means having a significantly smaller field of surveillance entirely within that of the sensor means of said A-series and for giving an intrusion signal, a sequence unit connected to said A-series and to said B-series and having first and second circuits, each including a relay with latching means an relay-operated switch and timing means for retaining the latching of said relay for a time interval, the time interval for said first circuit being for a relatively brief time anD that for said second circuit being for a longer time, an intrusion signal from either said A-series or said B-series activating both said first and second circuits, and an alarm output terminal connected by said sequence unit to said A-series and said B-series through said relay switches when and only when said first circuit has been ''''on'''' and its time interval has expired and said second circuit is still ''''on'''' during its time interval, whereby said alarm output terminal is energized only when either an A-series or a B-series intrusion signal is followed by another intrusion signal from said A or B series no sooner than after the expiry of the time interval of said first circuit but during the time interval of said second circuit.

Claim 15

A security system for detecting moving intruders, including in combination an A-series of sensor means for detecting changes in the illumination of a predetermined field of surveillance and for giving an intrusion signal, a B-series of similar sensor means having a significantly smaller field of surveillance entirely within that of the sensor means of said A-series and for giving an intrusion signal, a sequence unit connected to said A-series and to said B-series and having first and second circuits, each including a relay with latching means an relay-operated switch and timing means for retaining the latching of said relay for a time interval, the time interval for said first circuit being for a relatively brief time anD that for said second circuit being for a longer time, an intrusion signal from either said A-series or said B-series activating both said first and second circuits, and an alarm output terminal connected by said sequence unit to said A-series and said B-series through said relay switches when and only when said first circuit has been ''''on'''' and its time interval has expired and said second circuit is still ''''on'''' during its time interval, whereby said alarm output terminal is energized only when either an A-series or a B-series intrusion signal is followed by another intrusion signal from said A or B series no sooner than after the expiry of the time interval of said first circuit but during the time interval of said second circuit.

Claim 16

The security system of claim 12 having a C-series of sensor means like those of said A-series but having field of surveillance relating to ambient light rather than a zone to be protected from intrusion, a lockout unit connected to said C-series and to said sequence unit and having a third circuit like said first and second circuits and having a time interval shorter than that of said first circuit and means energized by a signal from said C-series for disabling a simultaneous intrusion signal from said A-series.

Claim 17

The security system of claim 13 having a D-series of sensor means similar to the A-series, threshold amplifier means connected to said D-series for activation only when a predetermined threshold illumination change has been signaled by said D-series, alarm means activated by said threshold amplifier means for indicating the presence of fire or explosion conditions, a second lockout unit connected to said C-series and like the other said lockout unit for enabling a simultaneous signal for said D-series.

Claim 18

The security system of claim 12 having a D-series of sensor means like those of said A-series, threshold amplifier means connected to said D-series for activation only when a predetermined threshold illumination change is signaled by said D-series, and alarm means activated by said threshold amplifier means.

Claim 19

The security system of claim 15 having another sequence unit for comparing the signals of two spaced-apart sensor means of said D-series, and giving an ''''explosion'''' signal if the two sensor means give simultaneous signals and a ''''fire'''' signal if the sensor means gives its signal a few seconds later than the other said sensor means.

Claim 20

A security system for detecting moving intruders, including in combination an A-series of photoconductive sensor means for detecting changes in the illumination of a predetermined field of surveillance and for giving an electrical intrusion signal, first mode selector means connected to said A-series for determining whether said intrusion signal is to give positive or negative polarity for a light increase, first signal amplifying means connected to from said first mode selector means, a B-series of photoconductive sensor means having a significantly smaller field of surveillance entirely within that of the sensor means of said A-series and for giving an intrusion signal, second mode selector means, like said first mode selector means, connected to said B-series, second signal amplifying means connected to said second mode selector means, a sequence unit connected to said first and second amplifier means and having first and second circuits, each including a latching relay with switches and timing means for retaining the latching of said relay for a predetermined time interval, the time interval for said first circuit being for a relatively brief time and that for said second circuit being for a longer time, an intrusion signal from said amplifying means activating both said first and second circuits, and an alarm output terminal connected by said sequence unit to at least one said amplifying means through said relaY switches when and only when said first circuit has been ''''on'''' and its time interval has expired and said second circuit is still ''''on'''' during its time interval.

Claim 21

A security system for detecting moving intruders, including in combination an A-series of photoconductive sensor means for detecting changes in the illumination of a predetermined field of surveillance and for giving an electrical intrusion signal, first mode selector means connected to said A-series for determining whether said intrusion signal is to give positive or negative polarity for a light increase, first signal amplifying means connected to from said first mode selector means, a B-series of photoconductive sensor means having a significantly smaller field of surveillance entirely within that of the sensor means of said A-series and for giving an intrusion signal, second mode selector means, like said first mode selector means, connected to said B-series, second signal amplifying means connected to said second mode selector means, a sequence unit connected to said first and second amplifier means and having first and second circuits, each including a latching relay with switches and timing means for retaining the latching of said relay for a predetermined time interval, the time interval for said first circuit being for a relatively brief time and that for said second circuit being for a longer time, an intrusion signal from said amplifying means activating both said first and second circuits, and an alarm output terminal connected by said sequence unit to at least one said amplifying means through said relaY switches when and only when said first circuit has been ''''on'''' and its time interval has expired and said second circuit is still ''''on'''' during its time interval.

Claim 22

The security system of claim 17 having a C-series of sensor means like those of said A-series but having field surveillance relating to ambient light rather than a zone to be protected from intrusion, a lockout unit connected to said C-series and to said sequence unit and having a third circuit like said first and second circuits and having a time interval shorter than that of said first circuit and means energized by a signal from said C-series for disabling a simultaneous intrusion signal from said A-series.

Claim 23

The security system of claim 17 wherein said amplifying means is in series with a gain resistor and is in parallel with a fixed resistor and a photoconductive sensor surveying ambient light and thereby decreasing its resistance and lowering gain of the amplifying means as ambient light increases and increasing the gain of said amplifying means as the ambient light gets darker.