Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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The invention relates to a method for blocking the
transmission of identifying information of a calling party
on a telephone network. The invention also relates to an
apparatus for carrying out the method.
Telephone companies presently provide Caller ID
service whereby to identify, to a party receiving a
telephone call, the telephone number of the calling party
With this service, the telephone number of the calling party
is transmitted, along with the ringing signal and, if the
receiving party has a special receiving device for this
purpose, the number of the calling party will be displayed
on this special device.
There are times when it is inconvenient to a
calling party to have his phone number disclosed to the
receiving party. For example, the calling party may be
calling from an unlisted telephone number which he does not
wish to disclose to the receiving party. For this reason,
the telephone companies providing the above services have
received complaints and they therefore now provide a further
service whereby, on action of the calling party, the
transmission of the identifying information will be blocked.
This action, which can be taken by any telephone
subscriber, consists of first registering with the telephone
company. Thereafter, before dialing any telephone number,
the caller would dial a predetermined code, for example,
*67.
The predetermined code is transmitted to a
computer of the telephone company which then blocks the
transmission of the identifying information.
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One of the problems with this solution is that it
is inconvenient to continually dial the predetermined code
before dialing any telephone number. In addition, it is
possible that a calling party will forget to dial the
predetermined code whereupon his telephone number will be
transmitted.
It is therefore an object of the invention to
provide a device which eliminates the necessity for the
calling party to dial the predetermined code.
It is also an object of the invention to provide a
method which eliminates the necessity for the calling party
to dial the predetermined code.
It is a more specific object of the invention to
provide an apparatus which automatically dials the
predetermined code before the calling party dials the
telephone number of the receiving party.
It is a further object of the invention to provide
a telephone so modified as to perform the functions of the
above-described device.
It is a further object of the invention to provide
a method wherein the predetermined code is automatically
dialed before the calling party dials the telephone number
of the receiving party.
In accordance with the broad principles of the
invention, the apparatus includes a means for detecting an
off-hook condition and, upon detection of the off-hook
condition, initiates an automatic dialer which automatically
dials the predetermined code.
Also, in accordance with the broad principles of
the invention, an off-hook detector detects an off-hook
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condition and, upon detection of the off-hook condition,
initiates an automatic dialer to automatically dial the
predetermined code before the calling party dials the
telephone number of the receiving party.
In accordance with a particular embodiment of the
invention there is provided a method for blocking the
transmission of identifying information of a calling party
on a telephone network, comprising:
detecting an off-hook condition on the telephone
line of said calling party;
providing an initiating signal on detecting said
off-hook condition;
said initiating signal causing automatic dialing
of a predetermined code, said dialed predetermined code
being applied to said telephone line of said calling party
to thereby block the transmission of identifying information
concerning said calling party;
said predetermined code being automatically dialed
before the calling party dials the telephone number of a
receiving party;
said predetermined code being transmitted to a
computer of the telephone company which then blocks the
transmission of the identifying information;
the speed of the automatic dialer being high
enough so that the action of the automatic dialer is
essentially transparent to said calling party;
said predetermined code being automatically dialed
each time said off-hook condition is detected on the
telephone line of said calling party.
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In accordance with a further particular embodiment
of the invention there is provided apparatus for blocking
the transmission of identifying information of a calling
party on a telephone network, comprising:
off-hook detector means having an input and an
output, said input of said off-hook detector means being
connected to the telephone line of said calling party to
detect an off-hook condition on said telephone line of said
calling party and to provide an initiating signal on
0 detection of said off-hook conditioni
automatic dialing means having an input and an
output, said automatic dialing means input being connected
to said off-hook detector means output and said automatic
dialing means output being connected to said telephone line
of said calling party;
so that, upon receipt of said initiating signal
from said off-hook detector means, said automatic dialing
means dials a predetermined code and applies it to said
telephone line of said calling party to thereby block the
transmission of identifying information concerning said
calling party;
said predetermined code being automatically dialed
before the calling party dials the telephone number of a
receiving party;
said predetermined code being transmitted to a
computer of the telephone company which then blocks the
transmission of the identifying information;
the speed of the automatic dialer being high
enough so that the action of the automatic dialer is
essentially transparent to said calling party;
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said predetermined code being automatically dialed
each time said off-hook condition is detected on the
telephone line of said calling party.
In accordance with a further particular embodiment
of the invention there is provided improvements in a
telephone which include an off-hook switch, said
improvements comprisingi
electronic circuit means having an input connected
to said off-hook switch;
an automatic dialer having an input connected to
the output of said electronic circuit means;
said automatic dialer being set to dial a
predetermined code;
so that, when the electronic circuit means senses
the actuation of the off-hook switch, it initiates the
dialing of the predetermined code by the automatic dialer.
In accordance with a further particular embodiment
of the invention there is provided improvements in a
telephone including an off-hook switch, said improvements
comprising;
a microprocessor having an input connected to said
off-hook switch;
said microprocessor being programmed to
automatically dial a predetermined code on sensing the
actuation of the off-hook switch.
The invention will be better understood by an
examination of the following description, together with the
accompanying drawings, in which:
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FIGURE 1 illustrates a telephone arrangement in
which the inventive apparatus is
connected;
FIGURE 2 is a schematic blocked diagram of the
inventive apparatus; and
FIGURE 3 illustrates schematically a telephone
modified to block the transmission of
identifying information of that
particular telephone.
Referring to Figure 1, a telephone line 1,
consisting of wires la and lb, is connected to a plurality
of sockets 3, 5 and 7, mounted on walls 9, 11 and 13
respectively in a household. Telephones 15 and 17 are
connected, via lines 19 and 21 respectively, to plugs 23 and
respectively which are plugged into sockets 5 and 7
respectively whereupon the telephones 15 and 17 are
connected to the telephone line 1. Although Figure
illustrates a situation in which a single line services a
plurality of telephones, the invention is equally applicable
when the telephone line services only a single telephone as
will be discussed below.
The apparatus in accordance with the invention is
illustrated generally at 27 in Figure 1 and includes a plug
29, which mates with the socket 3, as well as a socket 31
which is similar to the socket 3.
In Figure 2, the apparatus comprises an off-hook
detector 32 which, in one embodiment, can comprise a voltage
comparator 33 having an input terminal and a reference input
which is fed with a reference voltage 35. As is known, when
the line changes from an on-hook to an off-hook condition,
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there is a change in voltage - usually a decrease in
voltage, across the line. This change is detected by
comparator 33 which compares the voltage on the line with a
reference voltage. Other arrangements could be used to
detect the off-hook condition as well known in the art.
The output of the off-hook detector 32 is fed to
an automa.tic dialer. When an off-hook condition is detected
by the off-hook detector, an initiating signal is
transmitted to the automatic dialer whereupon the automatic
dialer will dial the predetermined code to block the
transmission of the identifying information of the calling
party. This predetermined code is applied to the telephone
line 1.
The automatic dialer dials at a high enough speed
so that the action of the apparatus 27 (Fig. 1) is
essentially transparent to the calling party. Accordingly,
the predetermined code is automatically dialed each time the
receiver of the telephone is lifted to place the telephone
line in an off-hook condition. Thus, the calling party does
not have to go through the inconvenience of dialing the
predetermined code each time, nor is it possible for the
calling party to dial the number and forget to predial the
predetermined code.
Returning to Figure 1, when the telephone line is
servicing only a single telephone, then that telephone would
be plugged into socket 31 of the apparatus 27. In fact,
this would be possible even when the line 1 is servicing a
plurality of telephone lines. This eliminates the
possibility that a socket will have to be used solely for
0 the apparatus 27. That is, in accordance with the
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invention, both the inventive apparatus 27 and a telephone
can be plugged into the same socket 3
In the illustrated embodiment, the apparatus 27
has been described as a separate unit. It is also within
the scope of the invention to incorporate the elements of
device 27 in the telephone instrument (15 or 17) so that it
forms a part of the instrument.
The inventive apparatus could, of course, be used
to block other information of the calling party than the
telephone number of the calling party.
Referring now to Figure 3, a telephone,
illustrated generally at 100, includes electronic circuitry
101 having one input connected to off-hook switch 103. An
output of the circuitry 101 is connected to dialer
arrangement 105.
When the receiver is lifted off the hook, the off-
hook switch 103 is activated and the off-hook switch
activation is detected by the circuitry 101. Upon detection
of the off-hook condition, a signal is sent to the dialer
105 to dial a predetermined code.
Although the Figure 3 embodiment as described
herein is directed to a telephone having an off-hook switch
103, and although the step of detecting the off-hook
condition in the Figure 3 embodiment is described as
monitoring the off-hook switch 103 until its activation is
detected, it will of course be apparent that the off-hook
condition can be detected in other ways, for example, see
above in the present application. In addition, there are
many other methods well known in the art for detecting the
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off-hook condition, and any one of these could be used in
implementing the invention of the Figure 3 embodiment.
As will be obvious, the circuitry 101 can comprise
a microprocessor which would also include the dialer 105.
The microprocessor 101 would then dial the predetermined
code, for example, *67, in execution of software
instructions.
Although a particular embodiment has been
described, this was for the purpose of illustrating, but not
limiting, the invention. Various modifications, which will
come readily to the mind of one skilled in the art, are
within the scope of the invention as defined in the appended
claims.
