JP3220273B2 - Control method of telewriting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method of a telewriting device having a telephone call function and a function of executing a handwriting input operation with a partner terminal while referring to a common screen.

[0002]

2. Description of the Related Art Conventionally, a telewriting device having a function of performing a handwriting input operation with respect to a partner terminal while referring to a common screen with a partner terminal has conventionally been a user of two terminals performing communication. After discussing the start of the telewriting function by telephone call, each terminal is operated to activate the telewriting communication function.

[0003]

However, such a conventional apparatus has the following disadvantages.

[0004] That is, in this case, the user of each terminal rarely operates and inputs the start of the telewriting communication function at the same time, and one terminal starts the telewriting communication function before the other terminal. You.
For this reason, for example, the user of the terminal that has started the telewriting communication function first has to wait unnecessarily until the telewriting communication function effectively functions between the two actual terminals. It is not preferable for operation of the communication terminal.

The present invention has been made in view of such circumstances, and has as its object to provide a control method of a telewriting device that allows a user to clearly know the start of communication.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a method for controlling a telewriting device having a function of performing a handwriting input operation with a partner terminal while referring to a common screen. The originating terminal transmits initial screen display information indicating the start of communication to the partner terminal at the start of communication.

Further, in a method of controlling a telewriting device having a call function and a function of executing a handwriting input operation with each other while referring to a common screen with a partner terminal, the destination terminal includes: Initial screen display information indicating the start of communication is transmitted to the partner terminal.

Further, in a control method of a telewriting device having a call function and a function of executing a handwriting input operation with each other while referring to a common screen with a partner terminal, the calling terminal includes: Sending the calling party initial screen display information indicating the start of communication to the partner terminal, and the receiving terminal receives the calling party initial screen display information from the calling terminal,
The destination-side initial screen display information indicating the start of communication is transmitted to the partner terminal.

[0009]

Therefore, at the start of communication, the initial screen sent from the partner terminal is displayed, so that the user operating the terminal can clearly know the communication start timing.

[0010]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows a still picture conference apparatus according to one embodiment of the present invention. In addition, this still image conference device
ISDN is used as a transmission path.

In FIG. 1, a still image conference apparatus 1 includes a call function, a facsimile communication function for transmitting and receiving conference materials, a telewriting communication function for appropriately drawing still images such as conference materials, and proceedings. Main unit 2 for realizing a still image conference function for document and document storage function for storing document information such as conference materials, scanner device 3 for reading a document image at a predetermined resolution,
Further, it is constituted by a page printer 4 for recording and outputting various documents at a predetermined resolution. Note that the scanner device 3 can read and input a book document and can continuously read and input a sheet document.

The main unit 2 includes, for example, 1280
A liquid crystal display 5 having a display dot configuration of × 960 (〜1728 × 1208) is provided, and the liquid crystal display 5 is provided with a touch panel device 6 capable of designating an arbitrary point on the display screen. ing. The operation of the touch panel device 6 is performed by the touch pen 7. Further, the main unit 2 is provided with a handset 8 for talking and a slot for a floppy disk device 9 for storing various data such as document information. The microphone / speaker 10 is used for talking in a hands-free state.

Further, in the still image conference apparatus 1, all functions are operated using the touch panel device 6. Therefore,
As a human-machine interface function for the operation, a so-called multi-window operation environment is provided.

FIG. 2 shows a configuration example of the still image conference apparatus 1 shown in FIG.

In FIG. 1, a CPU (central processing unit) 1
Reference numeral 1 denotes a control process of each unit of the still image conference apparatus 1 and a call storage function, a facsimile communication function, a telewriting communication function, a still image conference function, and a document storage function for storing document information such as conference materials. A ROM (Read Only Memory) 12 is for performing control processing, and includes a control program executed by the CPU 11,
The RAM 13 stores data such as various parameters necessary for executing the control program, and a RAM (random access memory) 13 forms a work area of the CPU 11.

The timer device 14 realizes various timer functions, and the clock device 15 outputs current time information.
Numeral 6 is for storing various information unique to the still image conference apparatus 1. The clock device 15 and the SRAM 16
Are backed up by a battery 17.

DMA (Direct Memory Access)
The control device 18 controls the CPU 1 without the intervention of the CPU 11.
This is for exchanging data at high speed between one peripheral device, and the interrupt control device 19 is for controlling the output of a large number of interrupt signals to the CPU 11.

The printer interface 20 is for connecting the page printer 4 to record and output an image (document), and the scanner interface 21 is for connecting the scanner device 3 to read and input a document image. And the floppy disk interface device 22
This is for connecting the floppy disk device 9 and storing / reading / erasing data on a recording medium.

The magnetic disk drive 23 is for storing a large amount of various types of document information and the like. The magnetic disk interface 3 is connected to the magnetic disk drive 23 to store / read / read data from / to the magnetic disk drive 23. It is for erasing.

The communication control device 25 is connected to the ISDN, and has a call control function on a D channel (signal channel), a call function on a B channel (information channel), a facsimile communication function, a telewriting communication function, and a still image. This is for performing a communication control function of a lower layer of the conference function. The handset 8 and the microphone / speaker 10 are connected to the communication control device 25.

The touch panel control device 26 determines the input coordinate position of the touch panel device 6 at that time based on the output signal of the touch panel device 6, and outputs the input coordinate signal. The input coordinate signal is a signal of a coordinate system unique to the touch panel device 6.
The display control device 27 is for controlling the display screen of the liquid crystal display 5.

These CPU 11, ROM 12, RAM
13, timer device 14, clock device 15, SRAM 16,
The DMA controller 18, the interrupt controller 19, the printer interface 20, the scanner interface 21, the floppy disk interface 22, the magnetic disk interface 24, the communication controller 25, the touch panel controller 26, and the display controller 27 are each a system bus. The data transmission between these components is mainly performed via the system bus 29. Also, a hook signal HS indicating the hook state of the handset 8 is transmitted to the CPU 1 via the system bus 20.
1 has been entered.

FIG. 3 shows an example of the communication control unit 25.

In FIG. 1, an ISDN interface circuit 31 is connected to the ISDN and has a function of processing the signal of the layer 1 of the ISDN and a function of integrating / separating the signal of the D channel and the two signals of the B channel. , D-channel signals are exchanged with the D-channel transmission control device 32 and the ISDN interface circuit 31
Communicates with the multiplexer / demultiplexer 33 for two B channel signals.

The LAPD channel transmission control device 32
This is for realizing the signal processing function of layer 2 of the channel. The multiplexing / demultiplexing device 33 multiplexes data of a plurality of media such as voice and general-purpose data exchanged using the B channel, and complies with CCITT Recommendation H.264. In addition to forming frame data specified in H.221 and sending it to the line side, it separates data of a plurality of media multiplexed with the received frame data. The multiplexing / demultiplexing device 33 converts the audio data into audio CODE.
It exchanges data with the C device 34 and exchanges two-channel general-purpose data with the LAPB controllers 35 and 36.
The multiplexing / demultiplexing device 33 is described in Recommendation H.264. When the function of H.221 is not used, the two B channels separated by the ISDN interface circuit 31 are connected to two LA channels.
It acts as a selector that connects to the PB controllers 35, 36 in any manner.

The audio CODEC device 34 is an ISDN B
This is for performing signal conversion processing of analog signal / digital data for transmitting an analog audio signal using a channel.

Group 3 facsimile modem device 37
Is for realizing the modem function of group 3 facsimile, and is a low-speed modem function (V.21 modem) for exchanging transmission procedure signals and a high-speed modem function (F-modem function mainly for exchanging image information) V.33 modem, V.29 modem, V.27ter modem, etc.).

The switch 38 is provided for the audio CODEC device 34
To the handset 8, the microphone / speaker 10, or the group 3 facsimile modem device 48. The operations of the switch 38 and the multiplexer / demultiplexer 33 are controlled by the CPU 11.

FIG. 4 shows an example of the display control device 27.

In the figure, a GDC (Graphic Device Controller) 41 controls the contents of the display screen of the liquid crystal display 5, and develops character code data into graphic character data (font data). Various images such as placement on bitmap data, image scaling, inverting dot colors, drawing figures such as straight lines, circles, ellipses and rectangles, setting display attributes such as line type of drawn figures, and masking figures It has a processing function and also controls the display timing of a liquid crystal display (LCD) display control device 42.

The GDC 41 has a VRAM (video R
AM) 43 is used as a work area, and the bitmap data of the display image obtained by the processing result is stored in the VRAM 43. Also, font RO
M44 stores graphic character data corresponding to each character code data.

The encoding / decoding device 45 encodes and compresses the image signal and decodes the coded image information into the original image signal. The encoding / decoding device 45 performs a group 3 facsimile mode encoding / decoding process. And a group 4 facsimile mode encoding / decoding processing function. Also,
The encoding / decoding device 45 uses the VRAM 43 as a work area.

As described above, the VRAM 43 is stored in the GDC 41
And the encoding / decoding device 45, the memory required by the display control device 27 can be reduced. Naturally, memory exclusive conflict control is performed so that the GDC 33 and the encoding / decoding device 35 do not access the same address of the VRAM 33 at the same time.

The liquid crystal display display control device 32 is a VRAM
The display data is extracted from a predetermined display screen area 33 and output to the liquid crystal display 5 for display.

The GDC 41, VRAM 43, font ROM 44, and encoding / decoding device 45 are connected to an internal bus 46, and exchange of data between these elements is mainly performed through the internal bus 46. Have been.

Now, in the still picture conference apparatus, in the B channel, the ITU-T H.264 standard is used. 221 (a national standard corresponding to CCITT recommendation H.221) is used to exchange data in a multi-frame format.

As shown in FIG. 5, one multi-frame MFL is composed of eight sub-multi-frames SMF1 to SMF.
8 in each sub-multiframe SMF1 to SMF1.
The SMF 8 is composed of two frames each. That is, one multi-frame MFL is composed of 16 frames FLM0 to FLM15.

Each of the frames FLM0 to FLM15
Is composed of 80 octets of data, as shown in FIG. 6, and the respective bit positions in which these octets are arranged in bit order constitute subchannels SCH1 to SCH8.

The eighth bit of the first to eighth octets is a frame synchronization signal (Frame Ali).
The 8th bit of the 9th to 16th octets constitutes a bit rate allocation signal (Bit rate Allocation).
(Signal) BAS. That is, the sub-channel SCH8 is allocated to the eighth bit of the 17th octet to the 80th octet, and this portion is allocated to the application channel AC (Application Channel).
el). Also, the sub-channel SC
In the seventeenth to twenty-fourth octets of H8, data of an encryption channel for exchanging key information for encrypting data and the like may be set (optional).

As described above, the frame synchronization signal FAS
Are arranged in one frame FLM0 to FLM15, and the bit allocation is configured in units of a multi-frame MFL as shown in FIG.

That is, even frames FLM0, FLM
2,..., FLM14, second to eighth octets, followed by odd frames FLM1, FLM3,.
A horizontal synchronizing signal composed of an 8-bit data pattern “00110111” is arranged in the FLM 15, and a first octet of the odd-numbered frames FLM 1, FLM 3,..., FLM 11 has a vertical synchronization composed of a 6-bit data pattern “001011”. A synchronization signal is provided.

By detecting the horizontal synchronizing signal and the vertical synchronizing signal, the synchronization of one multi-frame MFL can be detected.

The 0th frame, the 2nd frame, the 4th frame
Bits N1, N2, N3, N4, and N5 of the first octet of the frame, the sixth frame, and the eighth frame are used to indicate a multiframe number. Of these, bit N5 is used to indicate whether a multi-frame number is used. As described above, since the data used for the multi-frame number is 4 bits, the multi-frame number changes in a descending order with values from 0 to 15, and the same multi-frame number appears every 16 multi-frames.

The tenth frame, the twelfth frame,
And the bit L of the first octet of the thirteenth frame
1, L2 and L3 are used to display connection numbers indicating the order of connection of the B channels carrying the frame among the B channels currently used. Also, bit R of the first octet of the fifteenth frame is reserved (reserved) for future recommendations,
Its value is set to 0.

The bit TEA of the first octet of the fourteenth frame is used to indicate that data cannot be transmitted due to an internal failure of the data terminal device.

The odd frames FLM1, FLM3,
.., Bit A of the third octet of FLM 15 is used to indicate whether frame synchronization or multi-frame synchronization has been established, or whether synchronization has been lost.

The odd frames FLM1, FLM3,
,..., The fifth octet, the sixth octet, the seventh octet, and the eighth octet of the FLM 15
C2, C3 and C4 are used to indicate a CRC (Cyclic Redundancy Check) code which is referred to for data error detection (ie, channel quality detection) of two consecutive frames (ie, sub-multiframes). The bit E of the fourth octet of the odd frames FLM1, FLM3,..., FM15 is used to indicate that a transmission error has been detected on the receiving side.

Further, as shown in FIG. 8, the bit rate assignment signal BAS includes the even frames FLM0, FLM2,
, FLM14, 8-bit data representing a capability BAS or a BAS command is arranged, and subsequent odd-numbered frames FLM1, FLM3,.
A double error correction code for error correcting the value of the capability BAS or BAS command transmitted in the immediately preceding frame is arranged.

The transmission of the data of the multi-frame MFL is performed in the order of the frame numbers, and each of the frames FLM0 to FLM15 is transmitted in the octet order from the first octet to the 80th octet as shown in FIG. Octets are transmitted with the first bit first.

That is, each frame FLM0
In the FLM 15, the first bit of the first octet is transmitted first, and the eighth bit of the 80th octet is transmitted last.

FIG. 10 shows an example of a data transmission procedure executed by the still image conference apparatus 1 using the B channel.
In this case, the communication mode is point-to-point.

First, in order for the calling terminal to call the destination terminal, the "transmission capability" information element has unrestricted digital information, the "calling number" information element has its own ISDN address, and the "calling number" information element has The ISDN address of the destination terminal, and the H.264 information in the "lower layer compatibility" information element. 221 function, sends a call setup message SETUP in which the still image conference function is set in the “higher layer compatibility” information element, and
Call setting operations are performed between the calling terminal and the ISDN and between the destination terminal and the ISDN, respectively.
N and B channels are respectively established between the destination terminal and the ISDN, thereby establishing a communication path between the calling terminal and the called terminal.

The frame synchronization is performed while exchanging the frame data in which the PCM audio data is set on the established B channel (mode initialization). When the frame synchronization and the multi-frame synchronization are established (multi-frame synchronization detection), the mutual operation is started. Capability BAS data and command B
AS data is exchanged, and a transmission mode to be used at that time is determined (transmission mode determination). At this time, 56K
The transmission mode of the audio data of bps and the (general purpose) data of 6.4 Kbps is set. The data of the C & I mode other than the audio data, for example, the data of the C & I function, the telewriting communication function, and the bulk transfer function are exchanged using the general-purpose data channel.

Next, a BAS command designating the selected transmission mode is transmitted from the calling terminal to the called terminal, and the transmission mode of the calling terminal and the called terminal is switched (mode switching). Then, parameters common to the device functions, such as an encryption mode, are set (setting of common parameters), general data is set to be used in MLP (multilayer protocol) (MLP setting), and static data to be used is set. The video conference mode is set, and data transmission in the C & I mode is performed.

When the data transmission in the C & I mode is completed, the MLP is disconnected, the communication operation is terminated, and after the transmission mode is switched to mode 0F, the D channel is disconnected / released, and a series of stationary operations is performed. The video conference communication operation ends.

In C & I mode data transmission, the following conference operation is performed.

First, a conference mode is selected from the following four modes.

(A) Chair mode in which the chair designates the next operator.

(B) Operator designation mode in which the operator designates the next operator.

(C) A participant nomination mode in which an operation request is registered in a waiting list.

(D) Free mode in which the operation right (token) is not set.

Next, "conference start request", "attendance confirmation",
The proceedings such as “call request”, “meeting information retrieval request”, and “meeting state display request” proceed, and the telewriting application is activated to shift to a meeting referring to common meeting materials.

In this telewriting application, “requesting, revoking, abandoning (right) operation right”,
"Operation right transfer request", "document list request", "document retrieval request", "document storage request", "document deletion request", and "document recording request" are appropriately performed.

Further, a "leaving / participation request" and a "leaving permission request" are appropriately made, and when a "end request for conference" is issued, the data transmission in the C & I mode ends.

In this case, a case has been described where conference communication is performed using one B channel, but conference communication can be performed using two B channels. In this case, video information can be exchanged using a video input / output port that is optionally provided in the multiplexer / demultiplexer 33.

FIG. 11 shows a layer 5 (session layer) in data transmission in the C & I mode according to this embodiment.
2 shows an example of a part of the transmission procedure.

When the application of the calling terminal (telewriting application or C & I application) outputs a “connection request” to layer 5, layer 5 transmits signal CN (CoNect) _SPDU (Ses).
When the terminal CN receives the signal CN_SPDU, the layer 5 of the destination terminal outputs a “connection instruction” to the application. At this time, data indicating that the full-duplex communication is to be executed and data indicating that the communication procedure according to the present embodiment is to be executed are set in the signal CN_SPDU.

Thus, when the application of the called terminal outputs a “connection acknowledgment” to layer 5 in order to start communication with the partner terminal, layer 5 of the called terminal transmits signal AC (Accept) _SPDU to layer 5. Out, and upon receiving this signal AC_SPDU, Layer 5 of the calling terminal
Notify the application of "connection confirmation".

Next, when the application of the calling terminal outputs a “telewriting transmission start request” to layer 5 to execute telewriting communication started by a user's instruction operation, layer 5 transmits signal AS (Act).
activity Start) _SPDU, and upon receiving the signal AS_SPDU, the layer 5 of the destination terminal
Notify the application of a "communication start instruction".

Next, the application of the calling terminal forms calling-side initial screen display information for displaying and outputting a predetermined calling-side initial screen, for example, as shown in FIG.
With the source-side initial screen display information set in a predetermined transmission buffer area, a “drawing data transmission request” is
Output to As a result, the layer 5 becomes
(Private use) is used to send outgoing side initial screen display information set in the transmission buffer area to the destination terminal.

Upon receiving the DT_SPDU (for private use), the layer 5 of the destination terminal sets the contents of the calling-side initial screen display information included in the layer 5 to a predetermined reception buffer area, "Drawing data reception instruction" is output. Thereby, the application of the receiving terminal captures the calling-side initial screen display information in the reception buffer area, and displays and outputs the information on the screen of the own terminal.

At the same time, upon receiving the calling-side initial screen display information, the application of the called terminal receives the calling-side initial screen display information as shown in FIG.
In the state where the receiving side initial screen display information for displaying and outputting the predetermined receiving side initial screen as shown in the above, and the receiving side initial screen display information is set in a predetermined transmission buffer area,
The “drawing data transmission request” is output to the layer 5. Thus, layer 5 uses DT_SPDU (for private use)
Sends the destination initial screen display information set in the transmission buffer area to the calling terminal.

The layer 5 of the calling terminal that has received the DT_SPDU (for private use) sets the contents of the called-side initial screen display information included in the DT_SPDU in a predetermined reception buffer area, and sends an “ "Drawing data reception instruction" is output. As a result, the application of the calling terminal captures the receiving-side initial screen display information in the reception buffer area, and outputs the information on the screen of the own terminal.

When the display of the receiving-side initial screen is executed in this way, the application of the calling terminal executes the display for a predetermined time or starts the operation of the telewriting application when the user performs a touch input.

Further, the application of the destination terminal displays the initial screen of the calling side, and then displays the screen for a predetermined time, or starts the operation of the telewriting application when the user performs a touch input.

As described above, in the present embodiment, at the start of the telewriting application, the calling terminal sends the calling-side initial screen display information to the called terminal, and the user of the called terminal starts the telewriting application. At the same time, the destination terminal sends destination-side initial screen display information to the calling terminal to notify the user of the calling terminal that the start of the telewriting application has been accepted. The user and the user of the destination terminal can appropriately know the start of telewriting communication, and smooth telewriting communication can be performed.

FIG. 13 shows an example of processing executed by the calling terminal at the start of telewriting communication.

First, when the start of telewriting communication is input from the user (step 101), the above-mentioned calling-side initial screen display information is formed, and this calling-side initial screen display information is transmitted to the destination terminal (step 102). ), And waits until receiving-side initial screen display information is received from the receiving terminal (process 103).

When the receiving-side initial screen display information is received, a screen corresponding to the receiving-side initial screen display information is displayed on the liquid crystal display 5 (step 104). Then, in this state, it waits until a predetermined time has elapsed or until a touch input from the user is detected (NO loop of determinations 105 and 106).

The result of decision 105 or 106 is YE
At S, the called-side initial screen display information displayed at that time is deleted (step 107), and the telewriting application is started (step 108).

FIG. 14 shows an example of processing executed by the destination terminal at the start of telewriting communication.

First, when the user inputs a start of telewriting communication (step 201), a predetermined telewriting application initial screen is displayed (step 20).
2) In this state, wait until the calling side initial screen display information is received from the calling side or a predetermined time has elapsed (NO loop of determinations 203 and 204).

Receiving the caller-side initial screen display information, judgment 2
When the result of step 03 is YES, the above-mentioned called-side initial screen display information is formed, and the called-side initial screen display information is sent to the calling terminal (step 205). Then, a screen corresponding to the received caller-side initial screen display information is displayed on the liquid crystal display 5 (process 206), and in this state, a predetermined time has elapsed or a touch input from the user is detected. (NO loop of judgments 207 and 208).

If the result of judgment 207 or 208 is YE
At S, the calling-side initial screen display information displayed at that time is deleted (step 209), and the telewriting application is started (step 210).

When the result of the determination 204 is YES, the process shifts to step 210 to start the telewriting application.

By the way, in this embodiment, FIG.
As shown in (b), the image of the frame surrounding the screen, the graphic characters representing the contents of the message, and the graphic image constitute the initial screen of the calling side and the initial screen of the called side. There is no limit. Further, the contents of the calling-side initial screen display information and the receiving-side initial screen display information are data capable of displaying the respective screens, and appropriate information can be used.

The present invention can be similarly applied to a still picture conference apparatus having a configuration other than that shown in FIG. Further, the present invention can be similarly applied to a telewriting device.

[0089]

As described above, according to the present invention,
At the start of communication, the initial screen sent from the partner terminal is displayed, so that the user operating the terminal can clearly know the communication start timing, and the telewriting communication can proceed smoothly. obtain.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a still image conference apparatus according to one embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration example of the apparatus of FIG.

FIG. 3 is a block diagram illustrating an example of a communication control device.

FIG. 4 is a block diagram illustrating an example of a display control device.

FIG. 5 is a schematic diagram showing an example of a frame configuration of a multi-frame.

FIG. 6 is a schematic diagram showing an example of a signal configuration of one frame.

FIG. 7 is a schematic diagram showing an example of a frame adjustment signal.

FIG. 8 is a schematic diagram showing an example of a bit allocation signal.

FIG. 9 is a schematic diagram for explaining a signal transmission order.

FIG. 10 is a time chart showing an example of a transmission procedure executed by the apparatus shown in FIG. 1;

FIG. 11: Layer 5 immediately after starting telewriting
6 is a time chart showing an example of the transmission procedure of FIG.

FIG. 12 is a schematic diagram showing an example of a calling side initial screen and a called side initial screen.

FIG. 13 is a flowchart showing a processing example of a calling terminal at the start of telewriting.

FIG. 14 is a flowchart showing a processing example of a destination terminal at the start of telewriting.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G06F 13/00 H04M 3/42-3/58 H04M 11/00-11/10 H04N 1/00 H04N 1 / 32-1/36 H04N 1/42-1/44 H04N 7/10 H04N 7/14-7/173 H04N 7/20-7/22

Claims (3)

(57) [Claims] 1. A method for controlling a telewriting device having a call function and a function of executing a handwriting input operation with each other while referring to a common screen with a partner terminal, wherein the calling terminal includes: A method for controlling a telewriting device, comprising transmitting initial screen display information indicating the start of communication to a partner terminal. 2. A method for controlling a telewriting device having a call function and a function of executing a handwriting input operation with each other while referring to a common screen with a counterpart terminal, A method for controlling a telewriting device, comprising transmitting initial screen display information indicating the start of communication to a partner terminal. 3. A control method of a telewriting device having a call function and a function of executing a handwriting input operation with each other while referring to a common screen with a partner terminal, wherein the calling terminal includes: Sending-side initial screen display information indicating the start of communication is transmitted to the partner terminal. Upon receiving the calling-side initial screen display information from the calling terminal, the destination terminal sends destination-side initial screen display information indicating the start of communication to the partner terminal. A method for controlling a telewriting device.