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Description  |
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STATEMENT OF THE INVENTION
This invention relates to completely automatically operating pager systems
wherein radiant transmissions of limited content messages in coded form
are forwarded to selected subscribers from a central station, and the
corresponding messages are displayed on the video panel of a portable
receiver carried by the subscriber. This invention also relates to
improvements in such pager receivers having memories for prestoring such
messages, automatic entry of the codes, selective retrieval of messages,
and other features.
BACKGROUND
In an earlier U.S. Pat. No. 4,197,526, there is provided an automatically
operating pager system wherein a transmitting station automatically
receives and transmits limited content coded signals from callers, and
automatically sends out corresponding messages to remotely located
receivers. The pager receivers includes a video display panel for
displaying the limited content messages, and a memory for storing the
messages for later retrieval and display at the discretion and at the
convenience of the user. The page receiver provides for automatic storage
of any of a plurality of such received messages, such as call-back
telephone numbers, and selective manual or automatic retrieval and video
display of such plural messages at the convenience of the user, as well as
an audible alert of a paging call, automatic time delayed storage, and
other features.
SUMMARY OF THE INVENTION
According to the present invention, the transmitter station may comprise a
central broadcast station and serve a much greater number of subscribers,
at greater distance from the station. It also provides completely
automatic operation in paging such subscribers and transmitting messages
thereto in response to a much greater number of callers. In a preferred
embodiment, each of the callers is automatically instructed to not only
inform the central station of the limited message to be sent by dialing or
otherwise digitally transmitting the alpha-numeric message on the calling
telephone, but is also automatically instructed to digitally identify the
desired subscriber, such as by digitally sending the subscriber's
telephone number to the central station. At such station the subscriber's
page code address is automatically looked-up and determined from the
received subscriber's telephone number and this page code address is
transmitted to activate the selected subscriber's portable page receiver.
Additionally at such transmitter station, a message address code
corresponding to a call-back number is automatically located, and this
address code is also automatically transmitted to the page receiver.
The portable page receiver is provided with a memory containing a series of
such limited content messages, such as a plurality of call-back telephone
numbers, and each number is stored at a different address in the receiver
memory. Therefore upon receiving the transmitted message address code from
the central transmitter, the selected limited content message is
automatically retrieved from the memory and automatically displayed on the
video panel of the receiver in real-time when the transmission is
received, or is remembered and retrievable at a later time at the
convenience or availability of the subscriber.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a functional block diagram showing the automatic operation of the
Central Station and transmitter for receiving calls and transmitting
limited content messages to selected ones of many pager receivers.
FIG. 2 is a functional block diagram illustrating details of a preferred
pager receiver.
FIG. 3 is a functional block diagram illustrating a modification for
receiving an entire limited content message.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
Referring to FIG. 1, the overall system comprises a common Central Station
12, or stations, that is adapted to receive at random telephone calls from
one or many callers 10 who wish to have paged selected ones of the many
subscribers to the system. Depending upon the scope of the system,
including the number of subscribers, the Central Station is provided with
many incoming telephone circuits 11 that can receive calls sequentially or
simultaneously from outside callers. At the station 12, there is provided
a sufficient number of automatic telephone answering devices 13,
connectable to the various phone circuits 12, to accomodate a reasonable
number of simultaneously received incoming calls. The telephone answering
devices 13 are of conventional construction, and contain prerecorded
messages briefly informing the caller about the nature and interactive
operation of the system. According to a preferred mode of operation, the
caller is first instructed to dial, touch tone, or otherwise send the
telephone number of the selected party to be paged, and this seven digit
digital number is received and recorded as a digital series of pulses or
tones on a magnetic recorder 14 associated with that answering device 13.
Following this initial automatic reception of a selected subscriber's
phone number, the caller is then automatically instructed by prerecorded
message from telephone answering device 13 to then dial, touch tone or
send a desired call-back telephone number, or limited message, that the
caller wishes to be transmitted to the subscriber. This second seven-digit
call-back number, or limited message, is also recorded at the central
station at a magnetic recorder 15, that may be combined with recorder 14.
Thus the Central Station operation is completely automatic in nature,
using prerecorded instructions to each caller, and having the caller then
identify the subscriber or called party to be reached by dialing an
identifying digital number, and also dialing a second digital number
corresponding to a limited content message to be transmitted to that
subscriber, e.g., the person carrying the remote portable page receiver.
As will be described, each portable page receiver is activated or selected
by the transmitter station automatically sending a unique digital
identifying code. The number of digits required for such identify code
corresponds to the number of subscribers to the system. Thus if the number
of subscribers is only 100 or less, a three digit or three place code (if
in the decimal system) is sufficient. For 1000 subscribers or less, a four
place decimal address code is sufficient to uniquely identify each
subscriber by a different transmitted code number. The Central Station
assigns a different subscriber address code to each different page
receiver, and at the Central Station is provided a memory 16 for storing
each subscriber's own seven digit telephone number together with an
assigned three, four, or five (or other) digit subscriber address code
number.
Upon the Central Stations receiving a call for a page, and upon receiving
and recording the subscriber's telephone number from the calling party,
the Central Station automatically correlates the received and recorded
telephone number from recorder 15 with its stored memory of all subscriber
telephone numbers, and automatically locates the unique subscriber address
code number. Having automatically located the subscriber address code, a
pulse code corresponding thereto is directed to modulate radio transmitter
17 and the modulated radio transmission is radiated to the remote pager
receiver to activate the selected receiver.
In a similar manner, the dialed call-back telephone number or limited
message, that has been received from the caller and magnetically recorded
in recorder 15 is directed to a comparator 18. The comparator 18 includes
an extensive memory bank that contains for each subscriber, a list of
pre-stored call-back telephone numbers, or other limited messages,
together with a unique address code number associated with each said
call-back telephone number. The identifying subscriber address code number
that is conveyed over 21 to modulate the transmitter 17 and activate the
selected remote page receiver, is also directed over to a mass memory 20
to select that portion of the mass memory storage 20 that has been
previously allocated to that particular subscriber. Having located that
subscriber's section of the mass memory 20, the recorded call-back
telephone number, or other message, received from the caller is then
compared or correlated with the pre-stored phone numbers or limited
messages that have been pre-inserted into the memory 20, and in the event
a correlation is obtained, a message address code corresponding to such
message is located and directed over 22 to modulate the radio transmitter
17 for propagating the derived message address code to the remote
subscriber.
Thus, in automatic response to the calling party first dialing the
subscriber's phone number, followed by dialing a call-back phone number,
or other message, the Central Station looks-up the subscriber's paging
address code and automatically transmits this code to activate the
selected one of the page receivers. Additionally, the Central station
responds to the caller's dialing a call-back number, or other limited
message, to look up in its mass memory 20 whether that phone number or
message has been pre-stored by that subscriber, and, if so, a pre-assigned
unique message code is sent out by transmitter 17 to the activated
subscriber's page receiver.
The page receiver, shown in FIG. 2, contains a video display panel 43, for
displaying a limited message in alphanumeric form, an audio beeper 38,
and/or a flashing light 38a, both or either for signaling when a message
has been received from the remote transmitter station.
Referring to FIG. 2, the incoming code received from the transmitter
station 17 is initially detected and demodulated at 35, and then compared
at 36 with the unique subscriber code that has been assigned to that
particular pager receiver. In the event of coincidence, an AND circuit 37
is energized, signaling that the pager receiver is to respond to a
message. Upon subsequently receiving, detecting and demodulating the
message code from the transmitter over line 35a, the AND circuit initially
energizes the audible beeper 38 and/or the flashing light 38a to signal
the user that a message is being received.
As will be recalled, the received limited message is in the form of but a
few numerical digits, sequentially transmitted from the transmitter
station. This received digital code is directed from the AND circuit 37 to
an address counter 40 over line 58 where the received pulses are summed to
select a corresponding numerical address in a message memory 41. In a
preferred embodiment, the message memory 41 is a small size, electronic
chip circuit, such as a bubble memory, or other available on-the-shelf
circuit, into which has been pre-entered and prestored a series of about
one hundred different seven digit call-back telephone numbers, or a
corresponding number of other limited content messages, each of which is
individually addressable and retrievable by a different address code
number. The address counter 40 therefore receives the pulses summing a two
digit code number from the transmitter station 17, and in response
thereto, addresses that corresponding address or section of the message
memory 40 to retrieve a pre-stored seven digit message at that selected
address. The retrieved seven digit message is read-out by the circuit 42
and applied to the video display panel 43, to visually display the
retrieved seven digit call-back telephone number, or other limited
message.
Thus, the pager receiver is initially activated for operation by first
receiving its unique subscriber address code number; and upon subsequently
receiving a two-digit message code, it signals the user of an incoming
message by the beeper or flashing light, and it then retrieves a
pre-stored seven digit message from its message memory 41 corresponding to
the message code and displays that retrieved message on its video display
panel 43.
In the event that the overall system accomodates a total of one thousand
subscribers, with each receiver storing up to one hundred call-back
telephone numbers or other limited messages, a total of only five digits
are required to be transmitted from the transmitter station in order to
communicate a message of seven digits in length [such as a call-back
telephone number], not including, of course, synchronization or other
signals that may be required for control purposes.
Returning to FIG. 2, the incoming message code is also directed to an
address memory 44 where that two digit message code is remembered or
stored, and the initial pulse of that message code is further directed to
a fixed time delay circuit 45 to commence a fixed time delay of one minute
or other short time interval. At the conclusion of that fixed time delay,
the circuit 45 produces an erase pulse over line 46 to reset the address
counter 40, erase the video display 43 by resetting the readout circuit
42, to turn off the beeper 38 and/or the flashing light indicator 38a, and
to energize the AND circuit 47. The result of all of these actions is to
reset the receiver to a condition for receiving and displaying a
subsequent message from the transmitter station, but to "remember" the
previously received message code that has been stored in the address
memory 44, as described above. Therefore in the event that the user is
otherwise occupied and does not respond to the received message on the
display panel 43, the content of that message, [in the form of its
received two digit message code] is stored or remembered in the message
memory 44 and may be subsequently retrieved, as will be described.
However, in the event that the user has received and noted the display of
the call-back telephone number or other limited message, the user may
depress an acknowledge button switch 48 on the keyboard of the pager
receiver. This energizes a latch circuit 49 that, in turn, energizes the
AND circuit 47. Upon the subsequent generation of the time delayed reset
and erase pulse by the time delay circuit 46, and AND circuit 47 is
activated to energize the erase circuit 50, thereby to erase the
previously stored address code in the address memory 44.
In the event that the user is not available, of for other reason is unable
or unwilling to respond, the audio beeper 38 and/or flashing light 38a may
be manually disconnected and the receiver may be completely ignored by the
user and operate in an automatic manner. In such event as each succeeding
message code is received from the transmitter station, the corresponding
message is displayed on the video panel 43, and then automatically erased
after a fixed time as described above, but the message code is also stored
in the address code memory 44. When the user is available, or desires to
respond to the previously received messages, the user can manually
interrogate the address memory 44 by successively depressing a keyboard
switch 52 to retrieve, and transfer each stored code address from memory
44 to the address counter 40 to, in turn, retrieve and display the
call-back numbers on the video display panel 43.
Alternatively, there is provided an automatically operating play-back
circuit that is initiated by a different keyboard switch 59 to
automatically retrieve from memory 44 and successively display each of
previously received messages from the transmitter station. This is
performed by providing a low frequency clock 54 and time delay circuit 55
for automatically operating the interrogate circuit 53 for the address
memory 44. Upon depressing the automatic play-back switch 59, the clock 54
and time delay 55 automatically and successively pulse the interrogate
circuit 53 to retrieve, in time succession, each previously stored address
code in memory 44 and play-back each code over line 56, in time delayed
fashion, to the address counter 40 for successively displaying each
corresponding received message in the message memory 41. It will be
appreciated by those skilled in the art, that the interrogate circuit 53
provides for automatic resetting and erasure of the receiver after each
message is retrieved and displayed as discussed above.
As previously described in U.S. Pat. No. 4,197,526, the user of the pager
receiver may acknowledge receiving each message from the transmitting
station, to, in turn, inform the original caller that the message has been
received and noted. This is performed by the use of the keyboard switch 60
for energizing a miniature single frequency acknowledgement transmitter 61
that is incorporated as part of the receiver.
Manual operation of the switch 60 energizes the portable transmitter 61 to
send an acknowledgement transmission back to the central transmitter
station where it is received by receiver 23 (FIG. 1) and employed to
energize a prerecorded playback message at 13 to the Calling party,
informing the Calling party that the page message has been received. It
will be appreciated that the acknowledgement switch 60 may be the same
keyboard switch as switch 48 that is used to erase the message code from
address memory 44, as described above. However, it is often desired that
the Calling party be informed that the message has been received, while at
the same time retaining the message code in the memory 44. Consequently,
where it is desired to provide both functions independent of one another,
the use of separate switches 48 and 60 is preferred.
In the event that it is desired to automatically acknowledge receiving and
storing each limited content message without any action on the part of the
user of the receiver, this can be performed by coupling the
acknowledgement transmitter 61 for energization automatically upon entry
of each received code address into the memory 44. Referring to FIG. 2,
there may be provided an additional keyboard switch 63 and self-resetting
auto latch circuit 62, for coupling the acknowledgement transmitter 61 to
the AND circuit 37 over line 64. As will be recalled, the AND circuit 37
sequentially conveys the received pulses representing the message code to
be stored in the Address memory 44. Therefore when switch 63 is closed,
the initial pulse of any received message code is also directed to trigger
the self-resetting latch 62 to, in turn, provide a fixed time modulation
of the transmitter 61, thereby to send out an acknowledgement signal in an
automatic fashion. As each message code is received and stored, an
acknowledgement signal is automatically transmitted by the receiver back
to the transmitting station of FIG. 1.
As will be appreciated by those skilled in the art, the entire pager
receiver, with the sole exception of the address memory 44, is reset after
each message code is received from the transmitter. This may be performed
either automatically in response to operation of a time delay circuit, or
manually by depressing a keyboard switch. As will be noted it is preferred
that all of the various functions of resetting, erasing, acknowledging,
and others, are preferably performed by the use of separate circuits that
are each individually activated by closure of a different keyboard switch.
This provides the user with greater versatility, enabling the user to
program the receiver for either manual or automatic operation in various
modes.
It is intended and desired that the electronic pager receiver be small,
compact, and easily portable to be carried by the user. The advances in
the storage capacity of very small electronic memories 41, has increased
so rapidly in recent years that the receiver may now be easily provided
with a memory 41 having a sufficient storage capacity for prestoring many
limited content messages. In addition to the user's storing a number of
different call-back telephone numbers, other limited content messages are
intended to be stored. For example, in the event that the Calling party
dials a call-back number that is not one of those numbers that has been
previously stored in the message memory 41, this fact is automatically
determined at the transmitter station and a corresponding message code
address is sent to the pager receiver having it retrieve and display a
message such as "other" or the like, to inform the user to call back the
Central station transmitter to receive a message or a number that is not
in storage. Alternatively, the retrieval of a pre-stored message such as
"other" may be employed to condition other portions of the pager receiver
to receive, display, and/or store an entire limited message sent by the
transmitter station.
Referring to FIG. 3, for a functional illustration of this auxiliary
mode-of-operation, for transmitting and displaying an entire message, the
reception of a message code address, such as "other", is directed to a
series of AND circuits 70 to enable these circuits for subsequent
transmission of a complete coded message from the transmitter station. The
digital words or numbers subsequently transmitted in sequential pulse form
from the transmitter station and received over line 35a are then entered
and stored in a bank of shift registers 71, 72, and 73 and are
subsequently read-out and displayed on the video panel 42. In this manner,
limited messages that are not pre-stored in the message memory 41 may be
transmitted in their entirety to the pager receiver and visually displayed
on panel 43.
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Description  |
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