Note: Descriptions are shown in the official language in which they were submitted.
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PUBLIC TELEPHONE HAVING PORTABLE COMPUTER INTERFACE
FUNCTION AND METHOD FOR CONTROLLING THE SAME
TECHNICAL FIELD
The present invention relates in general to a public
telephone and a method for controlling the same, and more
parti~~ularly to a public telephone having a portable
computer interface function which is capable of
interfacing a portable personal computer (PC) to a
computer communication network, and a method for
10 controlling the same.
BACKGROUND ART
Generally, a public telephone is a terminal of a
communication system having a basic function which allows
the user to perform voice communication with the other
15 party over a telecommunication network in duplex and real
time for a valid period of time if he inserts a magnetic
card, IC card, credit card or coins into the telephone.
The public telephone converts an audio signal of a voice
frequency into an electrical signal, transmits the
20 converted electrical signal through a telephone line and
receives an electrical signal from the other party through
the telephone line, thereby enabling voice communication
between separate locations.
With reference to Fig. 1, there is shown in block
25 form the construction of a conventional public telephone.
As shown in this drawing, the public telephone comprises
a hook switch 1 for opening or closing a speech path to
an office line connected to an exchange, a card reader 2
for reading money amount information or credit information
30 from a card inserted thereinto, a card verifier 3 for
checking a password of the card inserted into the card
reader 2 to determine whether the inserted card is valid,
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a coin sorter 4 for sorting coins dropped into a coin
slot (see the reference numeral 22 in Fig. 2), an
accumulated sum signal generator 5 for generating an
accumulated sum signal as a result of the coin sorting by
5 the coin sorter 4, a keypad input unit 6 for generating '
key signals in response to number and function keys being
operated by the user, a dual tone multifrequency (DTMF)
signal generator 7 for generating a DTMF signal in
response to the key signals generated by the keypad input
10 unit 6, and a controller 8 being initialized in response
to an output signal from the hook switch 1. The
controller 8 analyzes and processes input information to
control the entire operation of the telephone. A
character display unit 9 displays a use guidance character
15 message under the control of the controller 8. An office
line interface unit 10 performs an interface operation
with an office line under the control of the controller
8 to enable the use of the telephone by the user. A
handset 12 converts an audio signal from the user into an
20 electrical signal to be transmitted through the office
line interface unit 10 or an electrical signal received
through the office line interface unit 10 into an audio
signal to be sent to the user. A speaking circuit 11
amplifies the electrical signal from the handset 12, to
25 be transmitted through the office line interface unit 10,
and transfers it to the office line interface unit. 10 or
amplifies the electrical signal received through the
office line interface unit 10 and transfers it to the
handset 12. The speaking circuit 11 also transmits and
30 receives data for a telephone call through the office
line interface unit 10. A power supply circuit 13 is
adapted to supply or block power to the above components
in the telephone. Switches such as a flash switch (see
the reference numeral 27 in Fig. 2) and an emergency call
35 switch (see the reference numeral 29 in Fig. 2) may
further be provided in the telephone to control the
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speech path to the offi.CE line. The public telephone may
further comprise separate function switches such as a card
replacement switch (not shown) for indicating that the
existing card has been replaced with a new one.
5 As well known in the art, when the handset 12 (21 in
Fig. 2) is lifted or hung up by the user, the hook switch
1 enters an off-hook state or on-hook state to close or
open the speech path.
The operation of the conventional public telephone
10 with the above-mentioned construction will hereinafter be
described.
First, if the handset 12 is lifted up by the user,
the hook switch 1 enters the off-hook state. The
controller 8 recognizes the off-hook state of the nook
15 switch 1 and controls the character display unit 9 to
display a character message, "insert card or coins", on
a character display panel (see the reference numeral 23
in Fig. 2). If the user inserts a card into a card slot
(see the reference numeral 25 in Fig. 2) under the above
20 condition, the card reader 2 reads information recorded
on the inserted card. The card verifier 3 determines
whether the inserted card is valid and sends the
determined result to the controller 8. When the inserted
card is invalid, the controller 8 controls the character
25 display unit 9 to display a character message, "card is
invalid", on the character display panel in order to
inform the user that the inserted card is not available.
In the case where the inserted card is valid, the
controller 8 controls the DTMF signal generator 7 to
30 generate an audio signal indicative of a dialing enable
state and, also, the character display unit 9 to display
a character message, "dial telephone number", on the
character display panel. At this time, the keypad input
unit 6 is connected to the office line through the DTMF
35 signal generator 7 and speaking circuit 11 under the
control of the controller 8.
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If the user confirms the telephone number dial
message and dials a telephone number on a keypad (see the
reference numeral 24 in Fig. 2), the controller 8
controls the DTMF signal generator 7 to generate a DTMF
5 signal corresponding to the dialed telephone number and -
send the generated DTMF signal to the speaking circuit
11. The speaking circuit ll transmits the DTMF signal
from the DTMF signal generator 7 to the exchange through
the office line and, in turn, the exchange sends the
10 transmitted DTMF signal to the other telephone. When the
other telephone enters the off-hook state in response to
the sent DTMF signal, the speaking circuits 11 of the
public and other telephones are electrically connected
through the office line, thereby causing audio signals
15 thereof to be amplified and transmitted to each other's
handsets 22. As a result; bothway voice communication is
effected between the public and other telephones. At
this time, a charging signal based on the lapse of
telephone call time is received through the office line
20 and transferred to the controller 8 via the_ office line
interface unit 10. If the telephone call is performed on
the basis of a registered money amount-type telephone
card, the controller 8 controls the card reader 2 to
subtract a value corresponding to the received charging
25 signal from the amount of money registered in the card.
In the case where the telephone call is performed on the
basis of coins, the controller 8 subtracts the value
corresponding to the received charging signal from the sum
that the accumulated sum signal generator 5 accumulates
30 as a result of the coin sorting by the coin sorter 4.
Then, the controller 8 displays the current remainder
through the character display unit 9. On the other hand,
in the case where the used card is not the registered
money amount-type telephone card, but an accumulating
35 charged money-type card such as a credit card, the
controller 8 accumulates the value corresponding to the
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received charging signal and displays the accumulated
result through the character display unit 9.
When the remainder falls below a predetermined value
with the lapse of telephone call time under the condition
5 that the .telephone call is performed on the basis of the
telephone card or coins, the controller 8 gives an alarm
to the user through the handset 12 to inform him that a
telephone call enable period of time has expired. Unless
the user inserts additional coins or replaces the current
10 card with a new one before a predetermined period of time
has elapsed from the alarm generation, the controller 8
opens the speech path between the handset and the office
line.
On the other hand, recently, with computers becoming
15 popularized, a great amount of information has been
exchanged via information communication networks such as
the Internet within/beyond the country boundaries suitably
to an information-intensive age, and electronic commercial
transactions through the information communication
20 networks axe on an increasing trend. Further, portable
computers, which persons can carry and use conveniently
regardless of time and place, have widely been spread.
However, the utilization of the information
communication networks through portable computers has
25 conventionally been very inactive in contrast with the
increases in the information communication network using
rate and portable computer spreading rate. This results
from the fact that, differently from general computers,
the portable computers are often used outside the room,
30 in which there are installed few public telephone circuits
connectable to the information communication networks.
For this reason, persons have been extremely limited in
the opportunity to access the information communication
networks using the portable computers.
35 In order to overcome the above problem, there have
been recently proposed and practically used cellular
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phones having computer connection terminals connectable to
computers. However,
it is very poor economy to access the information
communication networks by radio using such a cellular.
phone to utilize information therefrom, because computer -'
communication generally requires a communication period of
time relatively longer than a telephone call period of
time and radio communication has a charging system
relatively more expensive than that in wire communication.
DISCLOSURE OF THE INVENTION
Therefore, the present invention has been made in
view of the above problems, and it is an object of the
present invention to provide a public telephone having a
portable computer interface function capable of
interfacing a portable personal computer (PC) to a
computer communication network and a method for
controlling the same, in which the portable PC can
readily be connected to the computer communication network
in any place where no telephone wire is installed and
information from the computer communication network can
be utilized at lower cost, resulting in a convenience to
the user.
In accordance with one aspect of the present
invention, the above and other objects can be accomplished
by a provision of a public telephone comprising a hook
switch for entering an on-hook state or an off-hook state
according to an operation of a handset by the user; a
card reader for reading information recorded on a card,
the card being inserted into a card slot after the public
telephone is connected to an office line: a card verifier
for checking the information read by the card reader to
determine whether the card is valid; a keypad input unit
for generating key signals in response to number and
function keys on a keypad being operated by the user
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under the condition that the card verifier determines that
the card is valid; a DTMF signal generator for generating
a DTMF signal in response to the key signals generated by
the keypad input unit; a controller being initialized in
5 response to the off-hook state of the hook switch, the-'
controller combining and analyzing output signals from
peripheral devices and controlling the entire operation
of the public telephone in accordance with the analyzed
result; a character display unit for outputting a guidance
10 character message about the use of the public telephone
to the user under the control of the controller; an
office line interface unit for performing an interface
operation with the office line under the control of the
controller; a speaking circuit connected to the office
15 line interface unit for amplifying a signal to be
transmitted through the office line interface unit and a
signal received through the office line interface unit and
selectively outputting the amplified signals to the
handset, a modem connector and the DTMF signal generator
20 under the control of the controller; the handset
converting an electrical signal amplified and transferred
by the speaking circuit into an audio signal, outputting
the resultant voice to the user and converting an audio
signal from the user into an electrical signal to be
25 amplified and transmitted to the office line by the
speaking circuit; a PC communication switch for starting
a PC communication mode; and the modem connector
connecting the speaking circuit to a modem of a PC under
the control of the controller if the PC communication
30 switch is turned on.
Preferably, the PC communication switch may control
the connection of the speaking circuit to the office line
interface unit under the condition that the card verifier
determines that the card is valid.
35 Further, preferably, a flash switch may further be
provided to initialize the card verifier, keypad input
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unit, DTMF signal generator, character display unit,
office line interface unit, speaking circuit and handset
under the control of the controller under the condition
that the hook switch is at the off-hook state.
Further, preferably, the flash switch may release the-'
connection between the speaking circuit and the office
line interface unit to initialize the PC communication
switch with its off state under the condition that the PC
communication switch is turned on.
In accordance with another aspect of the present
invention, there is provided a public telephone having a
portable computer interface function, comprising a hook
switch for opening or closing a speech path to an office
line; a coin sorter for sorting coins dropped into a coin
slot after the public telephone is connected to the
office line; an accumulated sum signal generator for
generating an accumulated sum signal as a result of the
coin sorting by the coin sorter; a keypad input unit for
generating key signals in response to number and function
keys on a keypad being operated by the user under the
condition that the sum accumulated by the accumulated sum
signal generator is above a predetermined value; a DTMF
signal generator for generating a DTMF signal in response
to the key signals generated by the keypad input unit; a
controller being initialized in response to an off-hook
state of the hook switch, the controller combining and
analyzing output signals from peripheral devices and
controlling the entire operation of the public telephone
in accordance with the analyzed result; a character
display unit for outputting a guidance character message
about the use of the public telephone to the user under
the control of the controller; an office line interface
unit for performing an interface operation with the office
line under the control of the controller; a speaking
circuit connected to the office line interface unit for
amplifying a signal to be transmitted through the office
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line interface unit and a signal received through the
office line interface unit; a handset for converting an
electrical signa l amplified and transferred by the
speaking circuit into an audio signal, outputting the
5 resultant voice to the user and converting an audio-'
signal from the user into an electrical signal to be
amplified and transmitted to the office line by the
speaking circuit; a PC communication switch for
controlling the connection of the speaking circuit to the
10 office line interface unit under the condition that the
hook switch is at an on-hook state; and a modem connector
for connecting the speaking circuit to a modem of a PC.
In accordance with yet another aspect of the present
invention, there is provided a method for controlling a
15 public telephone having a portable computer interface
function, comprising the steps of a) initializing all data
if a PC communication switch is turned on and then
starting a PC communication mode; b) connecting a modem
of a PC to a modem connector and determining whether a
20 card inserted into a card slot is valid; c) connecting
the modem of the PC to an office line if it is determined
at the step b) that the inserted card is valid; d)
transmitting and receiving data to/from a computer
communication network through the modem of the PC and
25 office line; e) receiving a charging signal based on the
lapse of telephone call time through the office line and
subtracting a value corresponding to the received charging
signal from the amount of money registered in the card or
accumulating the value corresponding to the received
30 charging signal; and f) releasing the connection between
the modem of the PC and the office line if the remainder
in the card falls below a predetermined value at the step
e), a flash switch is operated at the step d) or the
modem of the PC is turned off by the user.
35 Preferably, the step a) may be performed under the
condition that a hook switch is at an on-hook state.
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Further, preferably, the method may further comprise
the step of g) returning to the step a) if the flash
switch is again operated after the PC communication mode
is ended.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, ,features and advantages
of the present invention will be more clearly understood
from the following detailed description taken in
conjunction with the accompanying drawings, in which:
Fig. 1 is a block diagram showing the construction
of a conventional public telephone;
Fig. 2 is a front view of a public telephone with a
portable computer interface function in accordance with
the present invention;
I5 Fig. 3 is a block diagram showing the construction
of the public telephone with the portable computer
interface function in accordance with the preferred
embodiment of the present invention; and
Fig. 9 is a flowchart illustrating a method for
controlling the public telephone with the portable
computer interface function in accordance with the
preferred embodiment of the present invention.
BEST MODES FOR CARRYING OUT THE INVENTION
Fig. 2 is a .front view of a public telephone with a
portable computer interface function in accordance with
the present invention, wherein a telephone card and coins
can selectively be used. As shown in this drawing,
laterally mounted on a left upper portion of a case 100
is a hook switch 20 on which a handset 21 is hung up.
A coin slot 22 is formed on a right upper rear portion of
the case 100 and a character display panel 23 is
installed in a left upper front portion of the case 100.
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A keypad 24 is installed under the character display
panel 23 and has a plurality of number and function keys
arranged on its surface. A card slot 25 is formed on a
right lower front portion of the case 100 and a PC
5 communication connection terminal 26 is installed in a-"
left lower front portion of the case 100 to be externally
exposed. A flash switch 27, PC communication switch 28
and emergency call switch 29 are installed sequentially
from the top over the card slot 25.
10 Fig. 3 is a block diagram showing an internal system
construction of the public telephone with the portable
computer interface function in accordance with the
preferred embodiment of the present invention. As shown
in this drawing, the public telephone comprises the hook
15 switch 20, a card reader 30, a card verifier 31, a coin
sorter 32, an accumulated sum signal generator 33, a
keypad input unit 34, a DTMF signal generator 35, a
controller 36, a character display unit 37, an office
line interface unit 38, a speaking circuit 39, the
20 handset 21 and a power supply circuit 41. The public
telephone further comprises a modem connector 42 for
connecting a PC to the speaking circuit 39. The PC
communication switch 28 is adapted to artificially control
connection between the speaking circuit 39 and the modem
25 connector 42.
The hook switch 20 enters an off-hook state or on--
hook state according to an operation of the handset 21 by
the user to close or open a speech path between the
public telephone and an office line. That is, if the
30 handset 21 is lifted up by the user, the hook switch 20
enters the off-hook state to close the speech path to the
office line.
The card reader 30 includes the card slot (25 in
Fig. 2). The card reader 30 is adapted to read money
35 amount information or credit information from a card
inserted into the card slot 25 and transfer the read
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information to the card verifier 31.
The card verifier 31 checks a password of the
inserted card. Then, the card verifier 31 checks the
money amount information or credit information read by the
5 card reader 30 to determine whether the inserted card is-
valid and transfers the determined result to the
controller 36.
The coin sorter 32 mechanically sorts coins dropped
into the coin slot (22 in Fig. 2) according to their
10 types. The accumulated sum signal generator 33 calculates
the surn of dropped money as a result of the coin sorting
by the coin sorter 32 and sends the calculated result as
an electrical signal to the controller 36.
The keypad input unit 34 sequentially generates key
15 signals in response to the number and function keys on
the keypad {24 in Fig. 2) being operated by the user and
sends the generated key signals to the controller 36.
The DTMF signal generator 35 generates a DTMF signal
in response to the key signals from the keypad input unit
20 34 under control of the controller 36 and outputs the
generated DTMF signal to the speaking circuit 39.
The controller 3C is adapted to control the entire
operation of the telephone on the basis of output signals
from the peripheral devices. Namely, the controller 36
25 is initialized in response to an output signal from the
hook switch 20. The controller 36 then analyzes output
information from the peripheral devices and controls the
entire operation of the telephone in accordance with the
analyzed result.
30 The character display unit 37 is a liquid crystal
display (T~CD) device. The character display unit 37 is
adapted to output a guidance character message about the
use of the public telephone to the user under the control
of the controller 35 so that it can be viewed by the
35 user.
The office line interface unit 38 interfaces the
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speaking circuit 39 to the office line or separates them
from each other under the control of the controller 36.
As a result, the office line interface unit 38 acts to
connect the public telephone to a public telephone network
or separate them from each other.
The speaking circuit 39 is a communication circuit
for connection between the handset 21 and the office line
interface unit 38. The speaking circuit 39 amplifies an
electrical signal received through the office line
10 interface unit 38 in response to an office line interface
signal from the controller 36 and transfers the amplified
signal to the handset 21. Further, the speaking circuit
39 amplifies an electrical signal from the handset 21 and
transmits the amplified signal to the office line through
the office line interface unit 38.
The handset 21 converts the electrical signal
amplified and transferred by the. speaking circuit 39 into
an audio signal and outputs the resultant voice to the
user. Further, the handset 21 converts an audio signal
20 from the user into the electrical signal to be amplified
and transmitted to the office line by the speaking
circuit 39.
The flash switch (27 in Fig. 2) functions to re
connect the public telephone to the office line when the
25 card is determined to be still valid as a- result of the
card verification or the remainder is determined to be
present as a result of the coin verification after a
telephone call is completed. Further, the flash switch
27 acts to compulsorily release the connection between the
30 speaking circuit 39 and the modem connector 42.
The emergency call switch (29 in Fig. 2) functions
to apply an emergency call signal to the controller 36 to
connect the public telephone to a telephone line for a
notice of an emergency state such as, for example, a
35 notice of fire regardless of insertion of a card or
coins.
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A card replacement switch (not shown) applies a card
replacement signal to the controller 36 when a new card
is inserted into the card slot because a previously
inserted card is invalid. Upon receiving the card
5 replacement signal from the card replacement switch, the-'
controller 36 initializes the card reader 30 and card
verifier 31 to re-verify the new card.
The modem connector 42 enables transmission/reception
of data between the office line and the PC. To this end,
10 the modem connector 42 includes the terminal 26 for
connection between the speaking circuit 39 and the PC.
The modem connector 42 further includes a
transmission/reception separator (not shown) for
separating a transmission signal and a reception signal
15 from each other, a DC feeder (not shown) for feeding DC
current to a modem (not shown) of the PC, and a DC
detector (not shown) for detecting an on or off state of
the modem of the PC. Upon detecting the off state of the
modem, the DC detector releases the interface between the
20 office line interface unit 38 and the office line.
In a similar manner to the emergency call switch 29,
the PC communication switch 28 is a compulsory connection
switch for artificially controlling the connection between
the speaking circuit 39 and the modem connector 42
25 irrespective of the operation state of the hook switch
20.
The operation of the public telephone with the above-
mentioned construction in accordance with the preferred
embodiment of the present invention will hereinafter be
30 described in detail with reference to Figs. 2 to 4.
First, if the handset 21 is lifted up by the user,
the hook switch 20 enters the off-hook state to start a
general telephone call mode where voice information can
be exchanged between the user and the other party. The
35 general telephone call mode is performed in the same
manner as that in the conventional public telephone as
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stated previously with reference to Fig. 1. Therefore,
a description of the general telephone call mode will be
omitted and a detailed description will be given of only
a PC communication mode which is the kernel of the
5 present invention. -'
In order to utilize the present public telephone for
PC communication, the user first has to operate the PC
communication switch 28 to change the internal system of
the public telephone to the PC communication mode under
10 the condition that the handset 21 is hung up on the hook
switch 20. Then, the user connects a modem connection
terminal (serial port) of the PC to the PC communication
connection terminal 26 of the public telephone according
to a character message displayed by the character display
15 unit 37 and inserts a valid card into the card slot 25 or
drops coins into the coin slat 22. As a result, the PC
modem is connected to the office line .so that it can be,
in turn, connected to a computer communication network.
Then, the internal system of the public telephone is
20 operated as shown in Fig. 4.
Fig. 4 is a flowchart illustrating a method for
controlling the public telephone with the portable
computer interface function in accordance with the
preferred embodiment of the present invention.
25 First, if the PC communication switch 28 is turned
on according to a user's operation (PC communication mode
start step), the controller 36 determines through the
speaking circuit 39 whether the PC modem has been
connected to the modem connector 42. If it is determined
30 that the PC modem has not been connected to the modem
connector 42, the controller 36 controls the character
display unit 37 to display a character message, "connect
modem", on the character display panel 23. In the case
where the PC modem has been connected to the modem
35 connector 42, the controller 36 controls the character
display unit 37 to display a character message, "insert
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card or coins", on the character display panel 23. Then,
if the user inserts a card into the card slot 25 or drops
coins into the coin slot 22, the card reader 30 and card
verifier 31 or the coin sorter 32 determines whether the
5 inserted card or the dropped coins are valid (card or-
coin verification step) . If the inserted card or the
dropped coins are determined to be valid, the character
display unit 37 displays, on the character display panel
23, a PC communication service enable message indicating
10 that the PC modem has been connected to the office line
(PC communication connection step). As a result, the
user is able to connect the PC to the computer
communication network through the office line from that
time (PC communication step).
15 If the transmission/reception of data through the PC
are completed, the user pushes the flash switch 27 to
artificially open the speech path to the office line (PC
communication end step). In this case, the flash switch
27 performs the opposite function to that in the general
20 telephone call mode. Namely, the flash switch 27
releases the connection between the public telephone and
the office line in the PC communication mode, whereas it
re-establishes the connection between the public telephone
and the office line in the general telephone call mode.
25 The PC communication mode is ended by the artificial
method of operating the flash switch 27 as mentioned
above. On the other hand, the PC communication mode may
compulsorily be ended by the controller 36. That is, in
a similar manner to the telephone call mode, in the PC
30 communication mode, a charging step is performed in
parallel with the PC communication step to reduce the
registered amount of money while the PC communication step
proceeds. As a result, if the remainder falls below a
predetermined value during the PC communication step, the
35 PC communication mode is compulsorily ended by the
controller 36.
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If the connection to the office line is released,
the controller 36 controls the character display unit 37
to display a character message "release modem connection"
on the character display panel 23. When the user
5 releases the modem connection, the entire operation of the-'
public telephone is completed and the system thereof is
then initialized.
On the other hand, in the case where the PC modem is
not connected to the modem connector 42 within a
10 predetermined period of time or the inserted card or the
dropped coins are not valid after the PC communication
mode start step is performed, the controller 36 does not
establish the connection to the office line, displays a
service disable message through the character display unit
15 37 and then initializes the entire system.
In the above manner, the public telephone of the
present invention can be utilized for the PC communication
mode where the portable PC is connected to the computer
communication network through the telephone line to
20 transmit and receive data, as well as for the general
telephone call mode where voice information is transmitted
and received.
INDUSTRIAL APPLICABILITY
As apparent from the above description, according to
25 the present invention, the portable PC can readily be
connected to the computer communication network in any
place where no telephone wire is installed and information
from the computer communication network can be utilized
at lower cost. Therefore, the present invention has the
30 effect of significantly enhancing a convenience to the
user.
Although the preferred embodiments of the present
invention have been disclosed for illustrative purposes,
those skilled in the art will appreciate that various
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modifications, additions and substitutions are possible,
without departing from the scope and spirit of the
invention as disclosed in the accompanying claims.
