Note: Descriptions are shown in the official language in which they were submitted.
WH-952 2198288
TITLE: SECURITY SYSTEM WITH AUDIBLE LINK
AND TWO-WAY COMMUNICATION
FIELD OF THE INVENTION
The present invention relates to security systems and
in particular is directed to a security system having a
control panel and a combination keypad and door sensor.
BACKGROUND OF THE INVENTION
One of the issues with respect to security systems is
the ease of installation of the system and the ability of the
system to function easily in many different configurations.
Most recently many security systems have used wireless
sensors which at least transmit signals to a control panel
using a radio frequency. Many of these systems use two-way
communication between the sensors and the control panel.
Two-way communication is very effective and reliable and the
control panel can also carry out investigations to determine
whether the sensors are active.
A more recent change in security systems is the
ability to have a monitoring station carry out two-way
communication with anyone located in the premises. It is now
common for the monitoring station to announce that an alarm
has been received and the police have been dispatched. A
microphone allows anyone within the premise to respond and
this microphone also allows the monitoring station to record
the audible activity within the monitored space.
Security systems continued to evolve and glass break
sensors are often provided in the security system. These
sensors listen for a sound of breaking glass and produce an
alarm when such a sound is detected.
The technology for effectively monitoring a given
space is now quite well developed and the challenge often is
being able to provide effective coverage at a reasonable
cost.
- 1 -
..r
2198288
SUl~lARY OF THE INVENTION
A security system according to the present invention,
comprised of a control panel and accommodation keypad and
door sensor. The control panel includes an arrangement
connected to a telephone system for communication with a
monitoring station. The control panel includes a microphone,
a single processing arrangement for the signal from the
microphone, a microprocessor and a sound generating
arrangement. A combination keypad and door sensor comprised
of polarity of keys for entering codes into the keypad for
arming and disarming the system, a microphone, a signal
processing means for the signal of the microphone, a
microprocessor and a sound generating arrangement. The
control panel and the combination keypad and sensor use the
sound generated in the microphones to form a high frequency
communication link there between. The sound generator of the
combination keypad and sensor produces a communication link
part of the signal and high frequency range and produces an
audible portion for the user indicating a requirement to
enter information by the keypad. The control panel and the
- ..
combination keypad and sensor interact to allow user to arm
and disarm the system
at the combination keypad and sensor and have the
instructions communicated to the control panel by the two-way
communication channel there between.
According to an aspect of the invention, the
combination keypad and sensor also use the microphone as part
of the sensing arrangement detecting other changes in the
space being monitored.
According to a further aspect in the invention, the
microphone and sound generating arrangement of the control
panel is used by the control panel as part of the two-way
communication channel with the monitoring station when an
alarm condition has been communicated to the monitoring
station.
- 2 -
'~-9,_52 2198288
A further aspect of the invention the control panel
also processes the signal of its microphone for signals
indicative of an alarm condition in the monitored space and
thereby acts as a further sensor of the system.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention are shown in
the drawings, wherein:
Figure 1 is a schematic of the security system;
Figure 2 is an overview of the operation of the
combination keypad and sensor; and
Figure 3 illustrates the operation of the control
panel.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The security system 2 shown in Figure 1 is
particularly suitable for small premises such as condominiums
and apartments. Typically these units have a single door 6
used for entering and leaving the premises. A combination
unit 8 can be provided on the door 6 or immediately adjacent
- ..
to door 6 which combination unit senses by the door sensing
arrangement 16 the opening and closing of the door. The
combination unit includes a microphone 10, a sound generator
12 and the keypad 14. This combination unit 8 is in two-way
communication with the control panel 20. The control panel
also includes a microphone 22, a sound generator 24, an
optional keypad 26 and a communication arrangement 28 which
communicates over the telephone lines to the monitoring
station 40. As in existing security systems, the control
panel upon detection of an alarm condition communicates to
the monitoring station 40. Some security systems allow the
monitoring station to use the sound generator of the control
panel to report that the police have been dispatched. In
addition, some of these control panels include a microphone
for allowing the monitoring station to listen for a reply to
- 3 -
WH_9~s2
2198288
any questions posed. In this way the monitoring station has
a two-way communication link with the space being protected.
The combination unit 8 can also be used for detecting
other events in the monitored space, such as detecting the
sound of breaking glass.
As shown in Figure 2, the combination unit 8 processes
the signal from the microphone 10 in two distinct manners.
If the combination unit is also a glass break detector then
detection for the glass break event is carried out by the
processing arrangement 13 at 11 using various filtering steps
to recognize a glass break event. If a glass break event is
detected, an audible alarm type signal 17 is produced by the
sound generator 12. In addition, the signal from microphone
10 is also processed for communications 39 from the control
panel 20. Communication detection is indicated as 15 within
the processing arrangement 13 The communication between the
combination unit 8 and the control panel 20 is at high
frequency near the upper audible range and therefore
communication detection 15 includes of a relatively precise
notch filter which limits the signal to a narrow high
- ,.
frequency band. The processing arrangement 13 analyzes this
portion of the signal for information from the control panel.
The processing arrangement 13 also receives input from
the keypad 14. Depending upon the various signals and the
status of the system, the processing arrangement causes the
sound generator 12 to produce two types of signals indicated
as alarm type signal 17 and the communication signal 19. The
alarm type signal 17 can indicate that the system is in alarm
or about to go into alarm if the proper arming or disarming
sequence is not finished. The communication signal 19 is a
high frequency signal for reception by the control panel 20.
The sound generator 12 has two distinct components. The
first component 21 generates the audible signal indicating
the status of the alarm system and the second component 23
produces the communication signal. Each of these components
- 4 -
218288
include a piezoelectric transducer. The signal 19 from
component 23 is a high frequency signal and forms part of the
audible link between the control panel and the combination
unit 8. Preferably the signal is in the range of about
20,000 kHz and may sound like a fuzzy noise to an occupant.
The benefit of this arrangement is that the microphones 10
and 22 are broadband microphones and the signals from the
microphones are suitably processed for use in the
communication link as well as use in a detection or alarm
function. It is also possible to use some common components
in the sound generation such as amplifiers, for generating
the high frequency communication signals and the lower
frequency alarm type signal. A further benefit of the
arrangement is that the control panel is provided with a
microphone which is also used by the monitoring station
during the two-way communication between the monitored space
and the monitoring station.
As shown in Figure 2, the combination unit also
includes a door status detector 25 which senses the position
of the door relative to the door frame. This device will
- ..
cause the combination unit 8 to report a pre-alarmed
condition to the control panel when the system is armed and
the door is open. The user will then have a certain period
of time to enter the proper code using the keypad 14. If the
proper code is entered within a specified period of time, the
signal is transmitted by the combination unit to the control
panel. The control panel upon receipt of the signal
terminates an alarm process. If the signal is not received
within a certain period of time, the control panel 20 reports
the alarm condition to the monitoring station 20.
The user in arming the system is forced through the
normal security system procedure, such as entering a code at
the keypad 14 and having the unit send a communication signal
to the control panel 20 indicating that the system is to be
armed. The control panel 20 can then transmit a confirmation
- 5 -
21 X8288
signal to the combination unit. The combination unit upon
receipt of the confirmation signal then goes through a arming
sequence allowing the user a certain period of time to leave
the premises and producing the prealarm audible signal.
Figure 3 shows an overview of the operations of the
control panel 20. The control panel 20 has the microphone 22
and the signal from this microphone is used to detect sound
energy in the space being monitored. The signal from the
microphone 22 is provided to the processing arrangement 31.
The microphone receives signals 17 and 19 and also receives
any other sound signals used as part of the two-way
communication with the monitoring station. The processing
arrangement 31 evaluates the signal from microphone 22 at 33
for an alarm event, such as a glass break event, intruder
detection, etc. The signal from the microphone 22 is also
evaluated at 35 for communication signals from the
combination unit 8 or the detecting arrangement. The
processing arrangement 31 also processes at 36 signals from
the monitoring station to be reproduced by the sound
generator 37 as part of the two-way communication with the
monitored space during an alarm condition. The signal from
the microphone is also provided to the monitoring station to
complete the live two-way communication.
The sound generator 37 controlled by processing
arrangement 31 can produce the alarm type signal 41, the
communication signal 39 and the voice signal 43 from the
monitoring station. Signal 39 is a high frequency signal at
or near the upper end of the audible range.
Sound generator 37 can use piezoelectric transducers
for generating signals 41 and 39 and can use a speaker for
producing signal 43.
The present system using audible type signals received
by microphones to provide two-way communication between a
sensor and a control panel is cost effective and,
surprisingly, is quite tolerant to ambient noise. In many
- 6 -
WH-9552
cases, the monitored space is relatively quiet when the
system is armed, as no one is present. Communication
reliability is achieved by using a high frequency narrow
bandwidth and repeating the signal several times for each
transmission.
Although various preferred embodiments of the present
invention have been described herein in detail, it will be
appreciated by those skilled in the art, that variations may
be made thereto without departing from the spirit of the
invention or the scope of the appended claims.