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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a data communication apparatus or system.
2. Related Background Art
A conventional system for causing an LCD (Liquid Crystal Display) element
to display a communication mode on a displaying means is known as a
typical data communication system.
However, it is impossible to determine a remaining image send time in a
conventional data communication system. If original sheets are set in and
sequentially sent by the data communication system, the remaining send
time may be roughly estimated by the number of remaining pages. However,
if image data stored in a memory is automatically simultaneously sent to a
plurality of destinations, the sender or operator cannot determine the
remaining image sent time.
In view of the above, the operator who has an original to be sent may
return from the location of the data communication system to his seat
since the system is sending another original although sending of this
other original will finish within one minute. The operator who has an
original to be sent next may have to wait near the data communication
system for a long period of time. In this manner, the data communication
system cannot be always used conveniently.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improvement in a
data communication system.
It is another object of the present invention to eliminate the conventional
drawbacks described above.
It is still another object of the present invention to signal a data
communication end timing during data communication to the operator.
It is still another object of the present invention to allow effective use
of a data communication system.
It is still another object of the present invention to display a time
required for data communication.
The above and other objects, features, and advantages of the present
invention will be apparent from the following preferred embodiments in
conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a data communication system according to a
first embodiment of the present invention;
FIGS. 2 and 3 are flow charts for explaining the operation of the first
embodiment;
FIG. 4 is a block diagram of a data communication system according to a
second embodiment of the present invention;
FIGS. 5A to 5H are tables for calculating the times required for sending
each page of a standard original under predetermined send conditions,
respectively;
FIG. 6 is a flow chart for explaining the control operation in the
transmitter according to the second embodiment;
FIG. 7 is a flow chart for explaining the control operation of the receiver
according to the second embodiment;
FIG. 8 is a block diagram of a data communication system according to a
third embodiment of the present invention;
FIG. 9 is a block diagram exemplifying a facsimile system as the third
embodiment; and
FIG. 10 is a flow chart for explaining the operation of the third
embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will be described in detail
with reference to the accompanying drawings.
A first embodiment will be described below. The first embodiment
exemplifies a facsimile system. The transmitter of the facsimile system
can perform packet sending, and the receiver thereof does not perform
packet reception but real-time reception.
FIG. 1 is a block diagram of the facsimile system of the first embodiment.
An NCU (Network Control Unit) 2 controls connections of a telephone
network to a circuit terminal and switching of connections to a data
transmission line so as to utilize the telephone network for data
communication. The NCU 2 also cooperates to hold a communication loop. A
telephone circuit or telephone line 2a is connected to the NCU 2. A
communication control telephone set 4 is connected to the NCU 2 through a
signal line 2b. The NCU 2 is controlled by a control circuit 32 such as
microcomputer through a signal line 32a. If the signal line 32a is set at
logic level "1", the NCU 2 connects the telephone circuit 2a to the
telephone set 4. However, if the signal line 32a is set at logic level
"0", the NCU 2 connects the circuit 2a to a hybrid circuit 6 through a
signal line 2c.
The hybrid circuit 6 separates a send signal from a receive signal. A
signal appearing on the signal line 2c is sent onto a signal line 6a. A
signal appearing on a signal line 18a is sent onto the signal line 2c.
Therefore, the input of the receiver is connected to the signal line 6a,
and the output of the transmitter is connected to the signal line 18a.
The transmitter will be described below.
The send signals are classified into a communication control procedure
signal and an image signal.
Each procedure signal complying with the CCITT (International Consulative
Committee for Telephone and Telegraph) recommendations is generated by the
control circuit 32. The procedure signal is modulated by a V21 modulator 8
complying with the CCITT Recommendation V21 through a signal line 32b. The
modulated procedure signal is input to an adder circuit 18 through a
signal line 8a and to the hybrid circuit 6 through the signal line 18a.
Original image information is read by a reader circuit 10 using a CCD line
sensor. The read data is encoded into a modified Huffman code by an
encoder circuit 12 through a signal line 10a. This code is directly input
to a memory circuit 14 and a V27ter or V29 modulator 16.
The modulator 16 selects one of the outputs from the encoder circuit 12 and
memory circuit 14 and performs differential phase modulation or orthogonal
modulation complying with the CCITT Recommendation V27ter or V29. Input
selection control is performed by the control circuit 32 through the
signal line 32c. More specifically, if the signal line 32c is set at logic
level "0", the modulator 16 receives the output from the encoding circuit
12 through the signal line 12a. However, if the signal line 32b is set at
logic level "1", the image data stored in the memory circuit 14 is
received by the modulator 16 through a signal line 14a.
The modulated result of the modulator 16 is input to the adder circuit 18
through the signal line 16a. The adder circuit 18 outputs a sum signal of
the image signal and the procedure signal through the hybrid circuit 6.
The receiver of the facsimile system is arranged as follows.
The procedure signal output from the hybrid circuit 6 is demodulated by a
demodulator 20 having the same system as that of the modulator 8. The
procedure signal demodulated as digital data is input to the control
circuit 32.
The image signal is demodulated by a demodulator 22 having the same system
as that of the modulator 16. The demodulated image signal is input to a
memory circuit 24 or a decoder circuit 26. The decoder circuit 26 performs
decoding on the basis of a decoding scheme corresponding to the encoding
scheme of the encoder circuit 12 and selects one of the direct input from
the demodulator 22 and the output from the memory circuit 24 to decode the
selected input. The input signal selection is performed in response to a
control signal supplied from the control circuit 32 through a signal line
32d. If the signal line 32d is set at logic level "0", the decoder circuit
26 receives the output from the demodulator 22 without modification
through the signal line 22a. However, if the signal line 32d is set at
logic level "1", the decoder circuit 26 receives the image data from the
memory circuit 24 through a signal line 24a.
The decoded image data is recorded at a recorder circuit 28 constituted by
a thermal printer or the like.
A display circuit 30 and a control unit 31 are connected to the control
circuit 32 so as to perform control operation to be described later.
The display circuit 30 comprises a liquid crystal display element and
displays the number of remaining sheets to be sent. The LCD display
circuit 30 is also used to display communication information.
The control unit 31 includes a keyboard panel having input keys such as
numerical keys, letter keys, a start/stop key, symbol keys and the like
and is used for known communication control (e.g., registration of
telephone numbers) in addition to control operations to be described
later. Letter key input data is supplied to the control circuit 32 through
the signal line 31a; numerical input data, through the signal line 31b;
and a start/stop or symbolic input data such as "#" and "*", through the
signal line 31c.
The data communication system having the arrangement described above will
be described with reference to flow charts in FIGS. 2 and 3. FIGS. 2 and 3
are respectively flow charts showing parts of send and receive control
procedures of the control circuit 32.
In the image send mode, in step S40, the control circuit 32 controls the
display circuit 30 through a signal line 32e to display "0" as the number
of sheets to be sent.
In order to display the number of remaining sheets in only the store mode,
the control circuit 32 determines in step S42 whether the store mode for
storing the read image data into a memory is selected. If YES in step S42,
the image send data obtained by causing the reader circuit 10 to read the
image information and the encoder circuit 12 to encode the image data from
the reader circuit 10 sequentially stored in the memory circuit 14. In
this case, the number of pages is stored in a predetermined counter by
utilizing an output from a known original sensor arranged in the reader
circuit 10 to read the image send information in units of pages or sheets.
When the image send data is completely stored in the memory circuit 14, the
flow returns to step S40. In this case, the flow jumps from step S42 to
step S46. The control circuit 32 determines in step S46 whether the data
send mode for sending data from the memory circuit 14 is selected. If YES
in step S46, the flow advances to step S48. In this step, the number of
sheets to be sent is displayed on the display circuit 30.
In steps S50 and S52, the pre-procedure and image data transmission are
performed in the same manner as in a known conventional scheme. In the
pre-procedure in step S50, data representing the number of sheets read by
a facsimile data field represented by a predetermined procedure signal,
e.g., an NSS (Non-Standard System) signal is sent to the destination
facsimile system. The destination facsimile system can know how many
sheets are sent thereto.
Step S52 represents one-page image transmission. Upon detection of an EOP
(End-Of-Page) signal, the flow advances to step S54. The control circuit
32 determines in step S54 whether the currently detected EOP signal is the
one for the last page sent to the destination facsimile system.
If NO in step S54, the flow advances to step S56. Every time one page is
sent, the number of sheets to be sent, which is set in the counter, is
decremented by one. The decremented number is displayed on the display
circuit 30.
If the image quality mode or the send mode is not changed, the flow returns
from step S56 to step S52. However, if the image quality mode or the send
mode is changed, the flow returns from step S56 to step S50.
If the control circuit 32 determines that the last page has been sent to
the destination facsimile system, the flow advances to step 58, and the
post-procedure is performed in the same manner as in a known
post-procedure. Thus, data send processing is ended.
The number of image information sheets to be sent, which data is stored in
the memory circuit 14, is displayed on the display circuit 30. The
operator can refer to the display content and can determine the end time
of the communication currently performed with the destination facsimile
system. Therefore, the operator can easily decide proper work procedures
to effectively use his time.
The receive mode will be described with reference to FIG. 3.
In the image receive mode, the control circuit 32 causes the display
circuit 30 to display "0" as the number of sheets to be sent to the self
facsimile system (the number of sheets to be received with respect to the
self facsimile system currently serving as a destination system) in step
S60 in the same manner as in step S40.
The control circuit 32 determines the pre-procedure in step S62, according
to the states of the start key and the communication protocol or
procedure, whether the receive mode is set. In step S64, the pre-procedure
is performed. In the case of the same facsimile system as that of this
embodiment, the number of sheets to be sent can be signalled as described
above. Data representing the number of sheets to be sent is stored in a
predetermined counter in step S64. In step S66, this data is displayed on
the display circuit 30.
Subsequently, the procedures in steps S68 to S76 are the same as those in
steps S50 to S58 except that the self facsimile system is not set in the
send mode but the receive mode. The count of the counter is decremented
for every transmission of one page, and the decremented count is displayed
on the display circuit 30.
In the image receive mode, the number of remaining sheets is displayed on
the display circuit 30, and the user can determine the end time of the
current communication, thereby obtaining the same effect as described
above. The above description has been made for the real-time receive mode.
However, in the store mode for temporarily storing image data, the number
of stored data can be detected. In this case, the number of remaining
sheets need not be displayed on the display circuit.
In the above description, the number of sheets to be sent is displayed to
signal the communication end timing to the operator. However, the number
of imge data stored in the memory circuits 14 and 24 may be displayed on
the display circuit 30. Alternatively, the time required for sending the
remaining sheets may be roughly calculated on the basis of the number of
remaining sheets and the number of image data as well as the processing
speed of the reader circuit 10 and a facsimile system to be communicated
with the self facsimile system. The calculated time may then be displayed
on the display circuit 30. In the above embodiment, the data representing
the number of sheets to be sent to the destination facsimile system is
sent thereto in the pre-procedure. However, the number of sheets may be
signalled every time one page is sent or received. This embodiment
exemplifies the facsimile system for converting image data to pixel
signals and sending the pixel signals. However, the present invention is
applicable to a system for sending character codes, decoding them to image
data, and recording the resultant image data.
According to the first embodiment as is apparent from the above
description, since an arrangement includes a means for signalling the end
timing of the current data communication to the operator, the operator can
determine the time when the current data communication is to be completed.
He can easily decide the work procedures to the end of the current data
communication. Therefore, the data communication system can be effectively
utilized and allows the operator to effectively use his own time.
The operation for displaying a time required for data transmission will be
described with reference to a second embodiment.
As in the first embodiment, assume that in the second embodiment, the
sending system is operated in the store send mode, and the receiving
system is not operated in the store receive mode but the normal real-time
receive mode.
The transmitter encodes original information and stores the resultant image
data in a memory, and at the same time, original size data is stored. For
actual data transmission, the send mode is performed in accordance with
the capacity of the receiving system. Normally, date is encoded with a
highest data compression rate.
In this embodiment, the original sizes are A4, B4, and A3; the send modes
are the G2, G3, standard, and fine modes; the encoding schemes are MH
(Modified Huffman) coding and MR (Modified READ) coding (for only G3); the
sending speeds are 2,400 bps, 4,800 bps, 7,200 bps, and 9,600 bps (for
only G3); and minimum send times are 0 msec, 10 msec, and 20 msec (for
only G3).
If original information is encoded and stored in a memory, the number of
sheets is counted. Upon initiation of facsimile transmission, a send mode,
an original size, a sending speed, and a minimum send time are determined
in the pre-procedure. Under these conditions, a reference time required
for sending one page of the standard original sheet is known. The
reference time is multiplied by the number of sheets to derive a total
send time.
The send time is displayed on the display circuit so that the operator can
know the end time of the current transmission. If the send time is added
to the current time, the operator can determine the end time in hours,
minutes, and seconds.
When the second page is to be sent upon sending of the first page, the send
mode, the original size, the sending speed, and the minimum send time are
checked again, and the time required for sending one page of the standard
original sheet under these conditions is then calculated. The calculated
time is multiplied by the number of remaining sheets, and the resultant
value is set again. A difference between the time required for sending one
page of the standard original sheet under predetermined conditions and the
time required for actually sending one page is absorbed (i.e., the errors
are not accumulated).
If the fallback or the like occurs and the sending speed is changed or the
send mode (the standard mode, the fine mode or the like) is changed, the
send time can be updated to allow display of accurate remaining time.
The receiver detects the number of sheets to be sent thereto in the
pre-procedure. The receiver checks the time required for sending one page
of the standard original sheet in units of pages under the sending
conditions in the same manner as in the transmission section. The
calculated time is multipled by the number of remaining sheets. The
resultant time is displayed and the operator can determine the end time of
the current transmission.
FIG. 4 is a block diagram of the second embodiment.
Referring to FIG. 4, in order to use the telephone network for data
communication, an NCU (Network Control Unit) 102 controls to connect a
terminal of a telephone circuit 102a, switches a connection of the
telephone circuit to a data transmission line, and holds a loop. More
specifically, the NCU 102 connects the telephone circuit 102a to a
telephone set 104 if a switching circuit from a control circuit 144 is set
at logic "0". However, if an exchange signal is set at logic "1", the NCU
102 connects the telephone circuit 102a to a facsimile system. The
telephone circuit 102a is normally connected to the telephone set 104.
The data communication system also includes a hybrid circuit 106 for
separating a send signal from a receive signal, a tonal signal generator
circuit 108 for generating various tonal signals, and a V21 modulator 110
for performing modulation on the basis of the known CCITT Recommendation
V21. The tonal signal generator circuit 108 generates 462 Hz, 1080 Hz,
1650 Hz, 1850 Hz, and 2100 Hz signals. If the control signal from the
control signal circuit 144 is set at logic "1", the tonal signal generator
circuit 108 generates one of the various tonal signals described above.
A reader circuit 112 sequentially reads one-line image signals from the
sending original along the main scanning direction. The reader circuit 112
comprises an image pickup device such as a CCD (Charge-Coupled Device),
and an optical system. An AM-PM-VSB modulator 114 performs AM-DM-VSB
(Amplitude Modulation-Phase Modulation-Vestigial Sideband Modulation).
An encoder circuit 116 encodes binary data to output MH or MR data.
The data communication system also includes a memory circuit 118, a V27ter
(differential phase modulation) or V29 (orthogonal modulation) modulator
120 for performing differential phase or orthogonal modulation based on
the CCITT Recommendation V27ter or V29, and an adder circuit 122. The
modulator 120 modulates one of the output signals from the encoder circuit
116 and the memory circuit 118 on the basis of the control signals from
the control circuit 144.
A tonal signal detector circuit 124 detects a tonal signal included in the
receive signal. If the tonal signal detector circuit 124 detects 426 Hz,
1080 Hz, 1650 Hz, 1850 Hz, and 2100 Hz tonal signals, values "1", "2",
"3", and "4" are output to the control circuit 144. However, if no tonal
signal is detected, the tonal signal detector circuit 124 supplies value
"5" to the control circuit 144.
The data communication system of the second embodiment further includes a
V21 demodulator 126 for performing modulation based on the CCITT
Recommendation V21, an AM-PM-VSB demodulator for performing AM-PM-VSB
modulation, a V27ter or V29 demodulator 130 for performing decoding based
on the CCITT Recommendation V27ter or V29, a decoder circuit 132 for
performing MH or MR decoding, a memory circuit 134, a recorder circuit
136, an operation unit 138, a remaining send time display circuit 140, and
a standard send time table 142.
The recorder circuit 136 receives signals from the memory circuit 134, the
decoder circuit 132 and the demodulator 128 in response to the control
signal from the control circuit 144 and records the monochromatic signal
in units of lines.
The operation unit 138 has letter (A to Z) keys, numerical (0 to 9) keys,
the * key, the # key, a start key, function keys, a memory key, and the
like. The remaining send time display circuit 140 receives the remaining
send time (required for completing the current transmission) and displays
this time.
The standard send time table 142 receives the original size (A4, B4, or
A3), the send mode (G2, G3, standard mode, or fine mode), the coding
method (MH or MR), the sending speed (2400, 4800, 7200, or 9600 bps), and
the minimum send time (0, 10, or 20 msec). Upon reception of a table
search instruction pulse, the standard send time table 142 calculates and
outputs time required for sending one page of the standard original sheet
on the basis of the stored data.
FIGS. 5A to 5H are tables showing times each required for sending one page
of the standard original.
The contents in FIGS. 5A to 5H are examples, and the tables are not limited
to these contents. The fine mode is used in place of the standard mode of
FIG. 5A, the original size B4 or A3 is used in place of A4 of FIG. 5A, and
the sending speed is changed to 9600 bps, as shown in FIGS. 5B to 5H.
The function of the control circuit 144 will be described in detail below.
The function of the control circuit 144 in the send mode will be first
described.
The transmitter encodes the original information when the store mode is set
to store the image data in a memory. The image data is stored, and the
number of sheets is counted. The original information is sent when the
data stored in the memory is transmitted. In this case, the time required
for sending one page of the standard original sheet under the conditions
predetermined in the pre-procedure is read out from the standard send time
table 142.
In the G3 send mode, a time obtained by adding the standard send time to a
procedure time (i.e., about 3 seconds) is multiplied by the number of
sheets, and the resultant send time is displayed. In the G2 send mode, a
time obtained by adding the standard send time (about 190 seconds) to a
procedure time (i.e., about 21 seconds) is multiplied by the number of
sheets to be sent. The send time is updated for every page. The operator
at the sending system can therefore easily know the time required for
sending the number of remaining sheets.
The function of the control circuit 144 in the receive mode will then be
described.
In the receive mode, the receiver detects the number of remaining sheets of
the currently sent original in the pre-procedure. The receiver calculates
the time required for sending one page of the standard original sheet
under the conditions determined in the pre-procedure in the same manner as
in the transmitter. The updated send time is read out from the standard
send time table 142. More specifically, the procedure time is added to the
standard send time, and the resultant time is multiplied by the number of
sheets. The time is updated for every one-page transmission. The operator
at the receiving system can easily determine the time required for sending
the remaining sheets.
The operation of the second embodiment will be described in detail below.
FIG. 6 is a flow chart for explaining the control operation of the control
circuit 144 (FIG. 4) in the sending system.
In the initial state, the telephone circuit 102a is connected to the
telephone set 104.
The remaining send time display circuit 140 receives data "0 hour:0
minute:0 second" and displays is (S150). The control circuit 144
determines in step S152 whether the store mode is selected, i.e., whether
a function key, the memory key, or the W key is depressed. If YES in step
152, data is stored in the memory (S154). In this case, the number of
sheets is also counted.
However, if NO in step S152, i.e., the control circuit 144 determines that
the store mode is not selected, the control circuit 144 determines in step
S156 whether the send mode is selected, i.e., a function key, the memory
key, or the R key is depressed. If NO in step S156, the flow returns to
step S150.
However, if the control circuit 144 determines that the send mode is
selected, the pre-procedure is performed. In this pre-procedure, the
telephone circuit 102a is connected to the facsimile system (S158). The
control circuit 144 checks the send mode, the image and send mode, the
original size, the original speed (for only G3), the encoding scheme (for
only G3), and the minimum send time (for only G3). The procedure time is
added to the send time required for sending one page of the standard
original sheet under the conditions, and the sum is multiplied by the
number of sheets, thereby calculating the remaining send time. The
remaining send time is displayed on the display circuit 140 (S160).
Thereafter, the post-procedure such as image transmission is performed
(S162). The operations in steps S158 to S162 are repeated up to the last
page (S164). In the post-procedure, the telephone circuit 102a is
connected to the telephone set 104 (S166).
When the flow returns from S164, the pre-procedure (S158) can be omitted
without a mode change. However, if the mode is changed, the operations
including the pre-procedure (S158) are repeated.
FIG. 7 is a flow chart for explaining the control operation of the control
circuit 144 (FIG. 4) in the receiving system.
In the initial state, the telephone circuit 102a is connected to the
telephone set 104.
The display circuit 140 receives data "0 hour:0 minute:0 second" and
displays it as the remaining send time (S170). If the receive mode is
selected (S172), the telephone circuit 102a is connected to the facsimile
system, and the pre-procedure is performed (S174). The receiver in the
receiving system recognizes the number of sheets on the basis of the NSS
(Non-Standard Signal) from the transmitter in the sending system.
The send mode, the image send mode, the original size, the sending speed
(for only G3), the encoding scheme (for only G3), and the minimum send
time (for only G3) are checked. The procedure time is added to the time
required for sending one page of the standard original under these
conditions, and the sum is multiplied with the number of sheets to obtain
the remaining send time. The remaining send time is displayed on the
display circuit 140 (S176).
Image transmission is then performed (S178), and the above operation is
repeated up to the last page (S180). Thereafter, the post-procedure is
performed to connect the telephone circuit 102a to the telephone set 104
(S182). If no mode change is detected in step S180, the above operation
without the pre-procedure (S174) is repeated. However, if a mode change is
detected, the above operation including the pre-procedure (S174) is
repeated.
As described above, when the operator at the receiving or sending facsimile
system wishes to send an original, the operator can determine the end time
of the current facsimile transmission if any. Therefore, if the operator
judges that the current facsimile transmission will be immediately ended,
it is convenient for the operator to wait near the facsimile system.
However, if he judges that the current facsimile transmission will not
finish soon, he gives up sending the original for the time being and can
work on another job. The utilization state of the system can be properly
judged by the operator.
In the above embodiment, the time required for sending one page of the
standard original sheet is calculated under the current conditions, and
the calculated time is multiplied with the number of remaining sheets to
obtain a total remaining send time. This operation (i.e., the arithmetic
operation) is performed by both the receiving and sending systems.
However, such an operation may be performed by only the sending system for
every one-page transmission, and the remaining send time may be sent from
the sending system to the receiving system.
If a plurality of sheets are to be sent, the numbers of pieces of
information of the respective sheets are often substantially identical.
Therefore, the time obtained by multiplying the number of remaining sheets
with the actual time required for sending one page may be assumed as a
total remaining send time.
If the sending system does not have a memory, the number of sheets to be
sent may be input at the sending system, and the time required for sending
the remaining sheets may be calculated on the basis of the received page
number data.
Furthermore, if the sending system has a memory, the number of data to be
sent may be calculated. A time obtained by dividing the number of data by
the sending speed is added to a time obtained by multiplying the procedure
time with the number of sheets to be sent. In this case, the sum may be
displayed as the remaining send time. The above calculation must be
performed for every one-page transmission to display the remaining send
time. Information sent from the sending system to the receiving system may
be the number of stored data or the remaining send time. In this case,
such information is preferably sent for every page.
The display time may be the read or write and time in place of the send
time. Alternatively, both the send and read times or the send and write
times may be displayed.
According to the second embodiment, the operator can efficiently utilize
the time during the data communication between the sending and receiving
facsimile systems.
A third embodiment will be described wherein a time required for data
communication is calculated on the basis of the number of data and the
communication speed.
The third embodiment will be described with reference to the accompanying
drawings.
FIG. 8 shows the schematic configuration of a data communication system
according to the third embodiment. The data communication system comprises
a discrimination means A for discriminating the number of image data to be
sent, a communication time calculating means B for calculating the
predetermined time for sending the image data at a predetermined
communication speed, and a display means C for displaying the
predetermined time.
FIG. 9 is a block diagram of a facsimile system of third embodiment. A
memory 202 stores data used for operation of a CPU (Central Processing
Unit) 210. A keyboard 203 designates whether the required time of the
image data is displayed. A display unit 204 displays the depression state
of the keyboard 203 and the time required for transmission. A
communication unit 205 interfaces a communication line 206 and the
facsimile system. The communication line 206 is defined as a circuit for
connecting the facsimile system and the public exchange.
The facsimile system also includes an original sheet reader (to be referred
to as a reader hereinafter) 207, a coding unit 208 for coding the image
data read by the reader 207, and an image memory 209 for temporarily
storing the image data coded by the coding unit 208.
The CPU 210 controls the reader 207, the keyboard 203, the display unit
204, the communication unit 205, and the coding unit 208 according to the
control procedures or protocol to be described later.
The control procedures for displaying the predetermined time required for
sending the image data will be described with reference to the flow chart
in FIG. 10.
The image read by the reader 207 is stored in the image memory 209 by using
the start or head address thereof as a variable X (step S202).
Thereafter, the reader 207 is driven to start reading the image (steps S203
and S204). The image read by the reader 207 is converted by the coding
unit 208 into a run-length code (step S205). The run-length code is stored
in the image memory (step S206).
The above operations (steps S204 to S207) are repeated until image data is
completely read.
The last or end address of the image memory 209 for storing the image data
is stored as a variable Y (step S208).
In step S209, the number of image data stored in the image memory is
calculated on the basis of the addresses X and Y of the image data. The
number of image data and the bit rate of the communication line 206 are
used to calculate a time required for transmission. The time is displayed
on the display unit 204 (step S210), and image data sending is started
(step S211).
In the above embodiment, the time required for sending the image data is
digitally displayed. However, bar code display may be utilized to decrease
it upon a lapse of the send time, thereby indicating the remaining send
time.
The present invention is applicable not only to the facsimile system but
also to any other data communication system such as a telex for performing
data communication.
According to the present invention, the number of data to be sent can be
calculated to signal the time required for communication to the operator,
thereby obtaining a convenient data communication | | |
