Communication apparatus selectively operable in voice-communication or in image-communication

The communication apparatus is provided with a timer for time counting a predetermined time interval and in the case where a control signal was detected witin a predetermined time interval, the automatic reception is done in the facsimile mode and image information is received. In the case where the control signal could not be detected within the predetermined time interval, the communication is done in telephone mode and the voice-communication is performed. Further, with such a constitution, the facsimile mode and the telephone mode are automatically switched, thereby enabling the image reception or voice-communication to be executed in correspondence upon a communication apparatus on the distant side.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a communication apparatus which can 
automatically select image communication in the facsimile mode or voice 
communication in the telephone mode in response to a communication 
apparatus on the distant side. 
2. Description of the Prior Art 
As a conventional apparatus of this type, there is known a facsimile 
apparatus having the automatic reception mode in which an image is 
automatically transmitted and received in response to a ringing tone 
signal from a facsimile apparatus on the calling side. 
Generally, a facsimile apparatus having the automatic 
transmitting/receiving function is also provided with the manual reception 
mode in which the outgoing call or incoming call is performed using an 
attached telephone set and thereafter the line is switched to the 
facsimile apparatus and the image communication is executed. In many 
cases, this automatic-manual switching is performed by a change-over 
switch provided on an operating panel or the like. 
Ordinarily, when the facsimile apparatus is set into the manual mode, a 
telephone set installed in the facsimile apparatus can be used similarly 
to an ordinary telephone, and even a call from a public telephone or the 
like can be received. However, in the case of receiving an original, the 
operator has to mediate between the transmission and reception sides. 
Namely, after picking up the handset, the operator has to switch the line 
to the side of the facsimile apparatus by operating a reception button or 
a switch. 
On the other hand, in the case of the auto reception mode, an image 
transmitted from the facsimile apparatus can be automatically received. 
However, in such a case, the ordinary communication function of the 
telephone set connected to the facsimile apparatus will have been lost, 
causing the drawback that it is impossible to receive a communication by 
an outgoing call from a public telephone or the like. 
FIG. 1 shows the operation of the facsimile apparatus which has been set 
into the auto reception mode in the case where it has been called from an 
ordinary telephone set. This diagram shows the operation of the facsimile 
apparatus of the G type (group 2) which meets CCITT (International 
Telegraph and Telephone Consultative Committee) Recommendation T3. 
As shown in the diagram, for an outgoing call from an ordinary telephone 
set, the apparatus which has been set into the auto reception mode first 
transmits a CED signal 1. This CED signal 1 is a called station 
identifying signal representing that the called station is the non-voice 
communication terminal. Subsequently, the facsimile apparatus transmits a 
GI2 signal 2. This GI2 signal 2 is a group 2 identification signal 
indicating that the apparatus can perform the communication on the basis 
of the G2 equipment recommendation method and at least one sheet of 
original can be received. 
Thereafter, the facsimile apparatus waits for a GC2 signal as an 
identifying signal on the transmitting side corresponding to the GI2 
signal 2. However, in the case of an outgoing call from an ordinary 
telephone set, the GC2 signal obviously will not be transmitted. 
Therefore, the facsimile apparatus on the receiving side repeats the 
retransmission of the GI2 signal 2 every three seconds during a 
predetermined initial identification time interval (ordinarily, for 35 
seconds from the first GI2 signal 2, namely, this interval corresponds to 
about seven transmissions of the GI2 signal 2). If the GC2 signal cannot 
be received in spite of this repetitive transmission, the facsimile 
apparatus will have disconnected the line as an error end. 
The conventional auto reception is as described above. For instance, the 
user who has only one telephone line contracted uses the telephone set as 
an ordinary telephone set as well, so that it is undesirable that the 
apparatus is always set into the auto reception mode. Consequently, the 
auto reception mode is a function useless to such a user. In addition, 
even for such a user, the apparatus is usually set into the auto reception 
mode at night in the case of communication with foreign countries. If the 
user forgets to switch the apparatus from the manual mode to the auto 
mode, the apparatus will not have functioned as the facsimile apparatus in 
the place where nobody is present at night. Therefore, in a conventional 
facsimile apparatus, even if both the manual and auto modes are provided, 
its proper use is troublesome and this results in the user often 
installing another telephone only for use in the facsimile apparatus. That 
would make the burden too heavy for the user. 
In consideration of the above point, technology has been provided whereby 
means for identifying a voice on the calling side is provided and the 
switching of the line is controlled by the voice from the calling side. 
However, since such an apparatus uses a voice recognizing apparatus, the 
whole apparatus becomes complicated and this results in an increase in 
cost and causes the burden for the operator on the calling side to be 
increased. 
The above-mentioned drawback is a common problem for communication 
apparatuses which perform predetermined communications on the basis of a 
predetermined protocol by use of telephone lines. 
SUMMARY OF THE INVENTION 
It is a first object of the present invention to enable the receiver side 
to be automatically set into the respective reception mode corresponding 
to a distant apparatus both in the case where a communication apparatus on 
the distant side is a facsimile apparatus and where image information is 
received, and in the case where a communication apparatus on the distant 
side is a telephone set and where voice communication is received. 
A second object of the invention is to enable image information to be 
immediately received in the case where a communication apparatus on the 
distant side is a facsimile apparatus. 
A third object of the invention is to enable voice communication to be 
performed by calling an operator after the lapse of a predetermined time 
interval in the case where a communication apparatus on the distant side 
is a telephone set. Awarding to the present invention, these objects are 
attained by providing a receiving apparatus in which, in response to 
detection of establishment of a communications link with a distant 
apparatus, an image reception mode signal is sent, and if a response to 
that signal, which response includes a signal representing an image 
transmission mode of the distant apparatus, is detected within a 
predetermined time, image signal reception is enabled. If the wanted 
response from the distant apparatus is no detected within that time, a 
calling signal is generated to call an operator. This arrangement makes 
possible efficient and convenient use of the receiving apparatus in both a 
facsimile and a voice mode, even if, for example, the user has only a 
single telephone line. 
The objects features and advantages of the invention will be more fully 
appreciated from a consideration of the following detailed description of 
the preferred embodiment, taken together with the accompanying drawings, 
in which like reference characters refer to the elements throughout.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The present invention will be described in detail hereinbelow with respect 
to an embodiment shown in the diagrams. In the following description, an 
example of a G2 facsimile apparatus in conformity to CCITT Recommendation 
T3 will be explained in detail. 
FIG. 2 shows a block diagram of one embodiment of a facsimile apparatus 
according to the present invention. 
FIG. 2, a reference numeral 10 indicates a network control unit 
(hereinbelow, referred to as an NCU). In order to use a telephone network 
for data communication and the like, the NCU 10 is connected to a terminal 
of a line 10a and controls the connection of a telelphone network, or 
switches to a data communication path, or holds a loop. In this invention, 
an output signal of a control unit 21 is inputted to the NCU 10 through a 
signal lead 21a and the NCU 10 is constituted in such a manner that it 
operates so as to connect the line 10a to the side of a telephone set 11, 
i.e., to a signal lead 10b of the telephone set 11 when a logical level of 
that output signal is "0" and to switch the line 10a to the side of the 
facsimile apparatus subsequent to a signal lead 10c when the logical level 
is "1". However, the line 10a is connected to the signal lead 10b on the 
side of the telephone set 11 in the ordinary state. 
The signal lead 10b is connected to a ringing tone signal detector 12 for 
detecting the presence and absence of a ringing tone signal sent in 
response to an outgoing call from the distant side. In the case where the 
telephone number on this side was dialed from the telephone set on the 
distant side, this ringing tone signal is sent after the exchanger has 
confirmed that the telephone on this side is not busy. When the ringing 
tone signal detector 12 detects a ringing tone signal, it generates a 
command pulse to a signal lead 12a. 
In the diagram, only important components in the transmitting system for 
procedure signals of the facsimile apparatus as shown. Namely, a CED 
signal sender 13 and a GI2 signal sender 14 are shown. The CED signal 
sender 13 outputs the above-mentioned CED signal to a signal lead 13a when 
a command pulse is generated from the control unit 21 to a signal lead 
21b, while the GI2 signal sender 14 generates the above-mentioned GI2 
signal to a signal lead 14a when a command signal is generated from the 
control unit 21 to a signal lead 21c. 
These procedure signals to be transmitted are added by an adder 15 and then 
the added signal is sent to a hybrid circuit 16 through a signal lead 15a. 
After it has been separated into a transmission signal and a reception 
signal by the hybrid circuit 16, they are sent to line 10a through the NCU 
10. Upon completion of the transmission of the above procedure signals, 
the CED signal sender 13 and the GI2 signal sender 14 generate command 
pulses to a signal lead 13b and a signal lead 14b, respectively. 
On the other hand, a GC2 signal detector 17 is shown as the receiving 
system for the procedure signals. The reception signal separated by the 
hybrid circuit 16 is inputted to the GC2 signal detector 17 through a 
signal lead 16a. When the GC2 signal detector 17 detects the GC2 signal 
transmitted from the distant side, it outputs a command pulse to a signal 
lead 17a. 
In addition, the facsimile apparatus of the invention is provided with a 
timer 18. This timer circuit 18 is started by the control unit 21 through 
a signal lead 21d immediately after the CED signal has been sent in 
response to the calling in the state whereby the apparatus was set into 
the auto reception mode. Thereafter, the timer 18 generates a command 
pulse to a signal lead 18a after the elapse of a constant time period 
(twenty seconds in this embodiment). In this embodiment, it is assumed 
that the distant side is determined to be a voice-communication terminal 
instead of a facsimile apparatus in the case where the GC2 signal cannot 
be received within that time interval. 
Further, the facsimile apparatus of this embodiment is equipped with an 
operator calling circuit 19. When the signal level on a signal lead 21e is 
set to "1" by the control unit 21, the operator calling circuit 19 
generates an artificial bell sound or the like, thereby calling the 
operator. 
In order to allow the operator to respond and communicate for the calling 
by the operator calling circuit 19, the facsimile apparatus of this 
embodiment is provided with a telephone set button on an operating panel 
or the like (not shown). A telephone set key depression detector 20 is 
provided to detect the depression of this telephone set button. When the 
telephone set button has been depressed, the telephone set key depression 
detector 20 generates a command pulse to a signal lead 20a. A button which 
is used for a publicly known polling function or the like may be used as 
the above telephone set button. 
The signals on the signal leads 12a, 13b, 14b, 17a, 18a, and 20a are 
inputted to the control unit 21, and the control unit 21 performs the 
following controls through the signal leads 21a, 21b, 21c, and 21d and is 
constituted by a microcomputer or the like. 
Namely, when a ringing tone signal is detected by the ringing tone signal 
detector 12, the control unit 21 controls the CED signal sender 13 so as 
to send the CED signal onto the line. Subsequently, after the elapse of 80 
milliseconds, the GI2 signal is sent onto the line by the GI2 signal 
sender 14 and the apparatus waits for the GC2 signal from the distant 
side. 
In the case where the GC2 signal has been detected by the GC2 signal 
detector 17, the operation similar to that in the conventional auto 
reception mode is performed and the image receiving operation is executed. 
When the GC2 signal from the distant side is to not be detected, the GI2 
signal is sent every three seconds similarly to the case of the 
conventional apparatus and the apparatus waits for the operation for the 
GC2 signal. In the case where the GC2 signal cannot be detected in spite 
of the repetitive transmission of the GI2 signal for 20 seconds, it is 
considered that the calling side is a voice-communication terminal such as 
a public telephone or the like. Therefore, the operator is called by 
controlling the operator calling circuit 19. During the interval when this 
calling is being done as well, the GI2 signal is sent at the 
above-mentioned predetermined interval by the GI2 signal sender 14 during 
the initial identification time interval mentioned in conjunction of a 
conventional example. When the GC2 signal is received during this 
interval, the calling by the operator calling circuit 19 is stopped and 
the apparatus enters the ordinary image communication mode. 
When the operator responds by the telephone set button within the initial 
identification time interval, the line 10a is connected to the side of the 
telephone set 11, thereby making the communication possible. When the 
operator does not respond within the initial identification time interval, 
the GI2 signal and the operator calling by the operator calling circuit 19 
are stopped and the apparatus returns to the standby mode. 
The operation of the control unit mentioned above will be explained further 
in detail with reference to flowcharts of FIGS. 3A and 3B. It is assumed 
that the portions designated by the same reference numerals in FIGS. 3A 
and 3B are connected to the other portions indicated by the same numerals, 
respectively. The procedures shown here may be stored as a program in an 
ROM (read only memory) or the like. 
In step S30 in FIG. 3A, the control unit outputs a signal level "0" onto 
the signal lead 21a. Thus, the line 10a is connected to the side of the 
telephone set 11 by the NCU 10. 
Next, in step S31, a signal level "0" is outputted onto the signal lead 
21e, thereby stopping the calling of the operator calling circuit 19. 
Then, in step S32, the state of the output signal lead 12a of the ringing 
tone signal detector 12 is checked to see if a command pulse is issued 
onto the signal lead 12a or not. Namely, the apparatus waits for the 
transmission of the ringing tone signal from the distant side. 
In the case where the ringing tone signal is transmitted and the pulse is 
issued onto the signal lead 12a, the processing advances the step S33 and 
a signal level "1" is outputted onto the signal lead 21a, thereby 
connecting the line 10a to the facsimile apparatus main body subsequent to 
the signal lead 10c. 
Next, in step S34, the control unit 21 issues a command pulse onto the 
signal lead 21b, thereby allowing the CED signal sender 13 to generate the 
CED signal. This CED signal is transmitted to the distant side through the 
line 10a along the above-mentioned path. Next, in step S35, the state of 
the signal lead 13b is checked and the apparatus waits for the completion 
of the transmission of the CED signal. 
When a command pulse is issued onto the signal lead 13b after the 
completion of the transmission of the CED signal, step S36 follows and the 
apparatus waits for the elapse of a predetermined time interval of 80 
milliseconds. Subsequently, in step S37, the count time of a timer A 
provided in the control unit 21 or the like is set at 35 seconds 
corresponding to the initial identification time interval. Further in step 
S38, a command pulse is issued onto the signal lead 21d, thereby starting 
the timer 18 which has been set at 20 seconds. 
Next, in step S39, the time counting of the timer A is checked to see if it 
has finished or not. This discrimination is performed by checking whether 
a command pulse was issued onto the signal line 18a or not. In the case 
where the time counting of the timer A has finished, namely, when the 
initial identification time interval has finished, the processing advances 
to step S40. Steps S40 and S41 are the routine to carry out the same 
operations as those in steps S30 and S31. Namely, the line 10a is 
connected to the side of the telephone set and the calling of the operator 
calling circuit 19 is stopped and the apparatus is returned to the initial 
standby mode. 
On the other hand, in the case where the initial identification time 
interval has not ended yet, step S42 follows and a command pulse is issued 
onto the signal line 21c, thereby allowing the GI2 signal sender 14 to 
transmit the GI2 signal. 
Subsequently, in step S43, the state of the signal lead 14b is checked and 
the apparatus waits for the transmission of the signal similarly to the 
case of the CED signal. When the command pulse has issued onto the signal 
lead 14b, i.e., when the transmission of the GI2 signal has finished, the 
processing advances to step S46. If not, step S44 follows. 
In step S44, it is checked whether a command pulse was issued onto the 
signal lead 18a or not, namely, whether twenty seconds have passed or not 
after the starting of transmission of the GI2 signal. When the command 
pulse has issued onto the signal lead 18a, i.e., when 20 seconds passed 
after the starting of transmission of the GI2 signal, step S45 follows. On 
the contrary, when a command pulse is not issued onto the signal lead 18a, 
step S43 follows. 
In step S45, a signal level "1" is outputted onto the signal lead 21e, 
namely, the operator is called by the operator calling circuit 19. 
Thereafter, the processing advances to step S60 which will be mentioned 
later. 
In step S46, a timer B provided in the control unit 21 or the like is set 
at three seconds and this timer is started. 
Next, in step S47, it is checked whether or not a command pulse has issued 
onto the signal lead 17a, i.e. whether the GC2 signal from the facsimile 
apparatus on the distant side has detected or not. When the GC2 signal has 
detected, the well known image receiving operation is executed in step 
S48. When the GC2 signal has not been received, step S49 follows. 
In step S49, the timer B started in step S46 is checked to see if its time 
is over or not. In the case that the time is over, the processing returns 
to step S39. Therefore, in the loop of steps S39 to S49, the GI2 signal is 
sent every three seconds and in the case where the GC2 signal on the 
distant side has detected in step S47, the image reception in the ordinary 
auto reception mode is carried out in step S48. In place of the image 
reception shown in step S48, the auto transmission by what is called a 
polling may be executed as an optional function. 
In step S50, it is checked whether a command pulse has issued onto the 
signal lead 18a or not, namely, whether 20 seconds passed after the 
starting of transmission of the GI2 signal or not. When 20 seconds have 
passed, step S51 follows. When 20 seconds have not passed yet, the 
processing is returned to step S47. 
The processing advances to step S51 in the case where the GC2 signal on the 
distant side has not been received for 20 seconds, namely, the distant 
side is considered to be an ordinary voice-communication terminal. 
Therefore, a signal level "1" is outputted onto the signal lead 21e and 
the operator is called by the operator calling circuit 19. 
Next, in step S52, it is checked whether a command pulse has been issued 
onto the signal lead 20a or not, namely, whether the telephone set button 
has been depressed by the operator or not. When the operator has responded 
to the calling of the operator calling circuit 19 by use of the telephone 
set button, step S53 follows. If not, the processing will advance to step 
S56. 
In the case where the operator responded to the calling, in step S53, a 
signal level "0" is outputted onto the signal lead 21a and the line 10a is 
connected to the side of the telephone set 11 by the NCU 10. Then, in step 
S54, a signal level "0" is outputted onto the signal lead 21e and the 
calling by the operator calling circuit 19 is stopped. Thereafter, the 
communication is made possible by the pick-up of the handset of the 
telephone set 11 by the operator in step S55. 
On the other hand, when a response of the operator is not obtained in step 
S52, it is checked to see if a command pulse was issued onto the signal 
lead 17a or not in step S56. Namely, it is detected to see if the GC2 
signal transmitted from the facsimile apparatus on the distant side was 
detected or not. When the GC2 signal has been detected, step S48 follows 
and the image communication is performed as mentioned above. However, when 
it cannot be detected, step S57 follows. 
In step S57, the timer B which has been set at three seconds is checked to 
see if its time is over or not. When three seconds have not passed yet, 
the processing is returned to step S52 and the operation for waiting for 
the response of the operator or for reception of the GC2 signal is 
repeated. When three seconds have passed, step S58 follows. 
In step S58, the timer A which has been set at the initial identification 
time interval of 35 seconds is checked to see if its time is over or not. 
When the initial identification time interval has finished, the processing 
advances to step S40 and after initialization, the apparatus returns to 
the standby mode. When 35 seconds have not passed yet, the processing 
advances to step S59. 
The processing advances to step S59 within the initial identification time 
interval and in the case where three seconds have passed from the 
transmission of the GI2 signal. Therefore, a command pulse is issued onto 
the signal lead 21c and the GI2 signal is sent. Next, in step S60, it is 
checked to see if a command pulse was issued onto the signal lead 14b or 
not, i.e., the apparatus waits for the end of transmission of the GI2 
signal. As long as the transmission of the GI2 signal has not finished 
yet, step S61 is executed and step S60 is repeated. In step S61, the state 
of the output signal lead 20a of the telephone set key depression detector 
20 is checked to see if the operator was called or not. When the operator 
has responded, the processing then advances to step S53. 
When the end of transmission of the GI2 signal is confirmed in step S60, 
step S62 follows, where the timer B is reset at three seconds and is 
started. Then, the processing is returned to step S52 and the 
above-mentioned loop is again executed. In this loop, the GI2 signal is 
sent every three seconds for the initial identification time interval 
after the elapse of the first twenty seconds and the operator is called. 
In this state, the apparatus waits for the GC2 signal on the distant side 
or the response of the operator. 
According to the above embodiment, the following operations can be 
realized. Namely, in the case where the GC2 signal cannot be received even 
when the CED signal is sent and the GI2 signal is repeatedly transmitted 
for 20 seconds, the operator is called by an artificial bell sound or the 
like, and during this interval, the GI2 signal is transmitted and the 
apparatus waits for the GC2 signal or a response of the operator for the 
initial identification time of 35 seconds. With such an arrangement, even 
when the apparatus has been set into the auto reception mode, it is 
possible to process both the outgoing call for the purpose of 
communication from an ordinary telephone set and the outgoing call for the 
purpose of image communication from a facsimile apparatus without causing 
a problem. For an outgoing call from an ordinary telephone set, the 
operator is called by the operator calling circuit. At this time, when the 
operator responds by means of the telephone set button or the like, the 
line is connected to the telephone set, so that the communication can be 
done similarly to an ordinary telephone set. On the other hand, when the 
apparatus receives an outgoing call from a facsimile apparatus, the 
automatic communication can be performed similarly to a conventional one. 
Therefore, the annoying switching operation is unnecessary and the manual 
mode function can be also omitted. Further, a shown in FIG. 2, the present 
ivention can be implemented using only conventional well known members and 
can be simply and cheaply constituted. 
Although an example of the facsimile apparatus in the G2 mode has been 
described in the foregoing embodiment, the constitution of the invention 
can be obviously also applied to equipment in another mode or a multi-use 
apparatus in a plurality of modes. For example, in the case of G3 
equipment, a DIS signal may be sent in place of the GI2 signal and a DCS 
signal may be detected in place of detecting the GC2 signal. In addition, 
the set time of the timer shown in the above embodiment is not limited to 
the above time but it can be freely set within a range based on CCITT 
Recommandation or other specifications. Or, the operator may variably set 
it. Also, the timers shown in the above embodiment may be obviously 
constituted by software. 
As will be apparent from the above description, according to the present 
invention, in a communication apparatus which is connected to a terminal 
of a telephone line together with a telephone set and starts predetermined 
communication when a predetermined control signal has been exchanged 
between the terminal on the distant side and the terminal on this side, 
this apparatus is provided with time-counting means for time counting a 
predetermined time, means for detecting the above-mentioned predetermined 
control signal from the terminal on the distant side, and means for 
calling an operator, wherein the operator calling means is made operative 
in the case where the predetermined control signal from the terminal on 
the distant side could not detected by the detecting means for the time 
interval set in the time-counting means. As a result it is possible to 
provide an excellent communication apparatus which can receive an outgoing 
call from an ordinary telephone set without causing a problem and can 
perform the automatic communication equivalent to the conventional one by 
a simple and cheap constitution without requiring the annoying switching 
operation. Consequently, according to the apparatus of the present 
invention, even a user who has only one telephone line contracted can 
efficiently use the line and the operation is simple and the burden for 
the user can be reduced.