JPH08265473A - Telewriting equipment - Google Patents

Abstract

PURPOSE: To attain the complete coincidence of level relation for writing type plotting among respective stations without generating any difference among the display contents of respective stations by executing plotting in the order of plotting generation time based upon plotting time data. CONSTITUTION: When plotting input operation is generated in a station itself, a plotting information preparing means 2 fetches the output from a clock means 5 as plotting data in a specified plotting unit, and prepares plotting information by adding plotting time data to the plotting data. A concept of plotting occurrence time is introduced as a reference for determining the order of plotting in each telewriting equipment (each station) and each station executes plotting in the order of plotting occurrence time. When plotting based upon the plotting occurrence time order is not executed in each station, replotting based upon the plotting occurrence time order is executed. Namely, each station executes plotting based upon the plotting occurrence time order regardless of the plotting of its own station or the plotting of the other stations. Thus the display contents of respective stations match perfectly with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telewriting device which communicates drawing data to be displayed on a shared screen with a telewriting device of another station to hold a teleconference.
In particular, it relates to a technique for eliminating display inconsistency in the telewriting devices of all stations.

[0002]

2. Description of the Related Art In this type of remote conference system,
Each station prepares a telewriting device (electronic blackboard device) including a display device capable of handwriting input including writing and erasing with an electronic pen or the like, and these telewriting devices are connected via a communication line. Then, by transmitting and receiving drawing data between the stations, the display device of each station functions as a shared screen so that the drawing data received from other stations is reflected on the display in addition to the drawing at the station.

However, in such a teleconferencing system, the writing process at one station and the erasing process at another station are
When they are performed on the same area of the display device and at almost the same time, a difference occurs in the display contents of these two stations. The difference in display content here does not refer to a temporary difference in display content that occurs before the time required for data communication elapses, but refers to a permanent one.

That is, as shown in FIG. 16, the erasing process is performed in the A station at a certain time, and the writing process is performed in the B station at the same time as the erasing area in the A station. Suppose it was done. As a result, the erasing process is reflected on the display at the station A, and the writing process is reflected on the display at the station B.

Thereafter, station A receives information indicating the writing process at station B, and this is reflected in the display. Also, B
The station also receives the information indicating the erasing process of the station A, and this is reflected on the display.

As a result, in the stations A and B, a difference in display contents as shown in FIG. 16 occurs.

Therefore, in Japanese Patent Laid-Open No. 4-217158, only one drawing execution right called a token exchanged between a plurality of terminals (electronic blackboard devices) is prepared, and a terminal having the token. A technique is disclosed that allows drawing only to only one terminal and avoids a situation where a plurality of terminals simultaneously draws.

However, in this conventional method, it is necessary to take an extra procedure for acquiring a token each time drawing is performed, and there is a problem that control becomes complicated. In addition, in this conventional method, not only erase-type drawing but also write-type drawing that does not cause a difference in display is prohibited in terminals that have not acquired tokens, so operability and conference efficiency are improved. Is very bad.

Therefore, in Japanese Patent Laid-Open No. 4-217158, when a different token is prepared for each terminal and the erase operation is performed, the token is requested to another terminal, and when the erase or write is completed. If there is a token other than the own terminal in the terminal, exchange the tokens such that it is returned to the corresponding terminal, write operation is allowed in the terminal that owns at least one token, and all tokens By permitting the erase operation only on the terminal that owns, it is possible to use write-type drawing simultaneously.

[0010]

However, in this prior art, (1) the procedure for acquiring the drawing permission right called the token is still required at each terminal, and the control becomes complicated. (2) Erase at a certain terminal Other terminals cannot execute the drawing process while drawing the type. (3) There is a problem that the vertical relationship on the display screen of the writing type drawing is different among the terminals.

The present invention has been made in view of such a situation, and it is easy to perform display control without causing any difference in display contents between stations even when simultaneous writing and erasing operations are performed in each station. It is an object of the present invention to provide a telewriting device which is realized by such a control procedure and in which the vertical relation of writing-type drawing is matched between the stations.

[0012]

According to the present invention, a shared screen (4) capable of drawing including writing and erasing is provided, and the shared screen (4) should be displayed with another telewriting device. In a telewriting device that communicates drawing data, a timekeeping means (5) for timekeeping and, when a drawing input operation occurs, the output of the timekeeping means (5) is fetched in predetermined drawing units as drawing time data, Drawing information creating means (2) for creating drawing information in which drawing time data is added to drawing data in the predetermined drawing unit, transmission processing means (6) for transmitting the drawing information to another telewriting device, and the like. Reception control means (8) for receiving the drawing information from the telewriting device, and the drawing information and the reception control means (8) created by the drawing information creating means (2). A storage unit (9) for storing the drawing information received by the drawing unit, and a drawing information management unit for managing and storing the drawing information stored in the storage unit (9) in order of time indicated by the drawing time data included in each drawing information. (2)
And controlling the display of the drawing data on the shared screen (4) according to the management by the drawing information management means (2), and drawing when the drawing information management means (2) manages the drawing time data order. When the information is exchanged, the shared screen (4) is provided with display control means (3) for redrawing the drawing data in the time sequence indicated by the drawing time data.

[0013]

According to the present invention, the concept of drawing occurrence time is introduced as a criterion for determining the drawing order in each telewriting device (each station), and each station executes drawing in the order of the time when drawing occurs. In each station, when drawing is not executed in the drawing occurrence time order, redrawing is executed in the drawing occurrence time order.

That is, since each station executes the drawing in the order of the drawing occurrence time regardless of the drawing in the own station or the drawing in the other station, the drawing contents in each station are completely the same.

Each station operates as follows.

When a drawing input operation occurs in the drawing station, the drawing information creating means takes in the output of the time measuring means as drawing time data in a predetermined drawing unit and adds the drawing time data to the drawing data. Create in a predetermined drawing unit. The created drawing information is transmitted to another station by the transmission processing means.

The drawing information created by another station is also received by the reception processing means.

The drawing information of the own station created by the drawing information creating means and the drawing information of another station received by the reception processing means are registered and stored in a storage means having a storage format such as a storage table and managed. However, the management at this time is performed by the drawing information management means in the order of the drawing time data included in each drawing information.

On the other hand, the drawing information management means outputs the drawing data in the drawing information to the display control means in the order of the drawing time data to execute the drawing display in the order of the drawing time data, and at the same time, to draw the drawing time data in the storage means. When the drawing information is exchanged during the management of the drawing information in order, that is, the drawing information already registered in the storage means is more than the time indicated by the drawing time data of the drawing information to be registered this time in the storage means. If the time indicated by the included drawing time data is older, the drawing control unit re-outputs the drawing data in the correct drawing time data order so that the drawing is performed again in the correct time order. To

The drawing time data is set to the second, 1/1
By taking a smaller unit such as 0 second, 1/100 second, millisecond, ..., Nanosecond, it is possible to avoid drawing that is determined to be at exactly the same time.

[0021]

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

FIG. 1 is a block diagram of a remote conference system.
The configuration of the first embodiment of the telewriting device of one station is shown. The telewriting devices of other stations connected to this telewriting device via the communication network 10 have the same configuration. .

In FIG. 1, the information input means 1 is, for example, a digitizer (pen and tablet) for handwriting input, a keyboard and a mouse, and the input operation information is input to the drawing information management means 2. In this case, the information input means 1 can perform writing-type drawing and erasing-type drawing.

The display 4 is a display device such as liquid crystal or CRT. The drawing processing means 3 displays the display 3 according to the drawing data input from the drawing information management means.
Is driven to display drawing data on the display 3.

According to the present invention, an input surface and a display surface are separate such as a tablet and a display, an input surface and a display surface are overlapped like a pressure sensitive system, and an input is performed like a rear projector and an infrared pen. It can be applied to any of the same surface and display surface.

The clock means 5 clocks the time and inputs the time data to the drawing information management means 2. Drawing information management means 2
When the input operation information is input from the information input means 1,
That is, when some drawing is performed on the display 4, the time data of the clock means 5 is fetched as the drawing time data corresponding to the drawing. In addition to the drawing time data, the drawing information management means 2 draws the drawing data indicating the input operation content of the information input means 1, the drawing mode (identification of writing-type drawing or erasing-type drawing), and drawing identification. A drawing event (drawing information) including information (drawing ID) as shown in FIG. 2 is created.

The drawing represented by one drawing event means the start of drawing input such as pen down and mouse button pressing (hereinafter referred to as drawing start) to the end of drawing input such as pen up and mouse release (hereinafter referred to as drawing start). (Hereafter, called drawing end)
The series of drawing contents up to the above may be used as a basic unit, or the series of drawing contents divided per unit time may be used as a basic unit.

The drawing ID in the drawing event shown in FIG. 2 is composed of a code part for identifying each station and a serial number part for indicating the time sequence of each drawing input in one station. For example, FIG. 3 shows an example of registered contents of the drawing information management table 9 in which drawing events are registered and stored. Among the drawing IDs shown in FIG. 3, “B-1” is shown.
Indicates the first drawing input at station B, and "A-1"
Indicates the first drawing input at station A, "B-2"
Indicates the second drawing input at station B. By adopting such a drawing ID, all drawing inputs in each station can be expressed as different drawing IDs, and the discrimination processing of drawing of the own station and drawing of another station becomes easy.

Next, the drawing event sending means 6 sends the drawing event of its own station created by the drawing information management means 2 to another station via the communication control means 7 and the communication network 10. The drawing event receiving means 8 receives drawing events from other stations via the communication network 10 and the communication control means 7. The communication control means 7 executes transmission / reception processing with other stations and access to resources on the network.

The drawing information management means 2 draws the drawing mode and drawing data (see FIG. 2) necessary for the actual drawing process among the drawing events relating to its own station created by itself in response to the operation input from the information input means 1. ) And the drawing mode and the drawing data of the drawing events from the other stations input from the drawing event receiving means 8 are sequentially output to the drawing processing means 3 so that the displays corresponding to these drawing events are displayed on the display 4. In performing the display control, the drawing information management table 9 is used to execute the drawing event management in time order.

In order to execute the management of the drawing events in time order, the drawing information management table 9 manages the drawing events of its own station and other stations in time order by the management of the drawing information management means 2. They are registered in the order of included drawing time data, and an example of the registered contents is shown in FIG.

That is, the drawing information management means 2 displays on the display 4 the drawing corresponding to the drawing event in the order of the drawing occurrence time, that is, the drawing time data included in the drawing event regardless of the drawing in the own station and the drawing in the other station. To run. Then, the drawing information management unit 2 causes redrawing in the drawing time data order when the drawing is not executed in the drawing time data order.

The outline will be described below.

Regarding the drawing at the own station, the information input means 1
A drawing event corresponding to each drawing input from is created in order by the drawing information management means 2, and these are registered in the drawing information management table 9 in order of time. When the drawing event of the own station is registered in the drawing information management table 9, if the drawing event registered immediately before is that of the own station, this drawing event is not displayed without referring to the drawing time data. The condition is registered in the required column of the drawing information management table 9, and the drawing corresponding to this drawing event is executed on the display 4.

However, when the drawing event of the own station is registered in the drawing information management table 9, if the drawing event registered immediately before is that of another station, the drawing event of the other station registered immediately before is registered. When the drawing time data in the drawing event is compared with the drawing time data in the drawing event, and if the drawing corresponding to the drawing event is performed as it is, it is determined whether a time contradiction occurs. Note that the drawing event registered in the drawing information management table 9 indicates that the display corresponding to the registered drawing event is being executed on the display 4.

If no temporal contradiction has occurred as a result of the above determination, the drawing event is registered in the required column of the drawing information management table 9 and drawing corresponding to this drawing event is executed on the display 4. . However, if there is a temporal contradiction in the above determination, the drawing events are rearranged in the drawing information management table 9 in the drawing time data order so that there is no temporal contradiction, and
The current display on the display 4 is invalidated, and the display corresponding to the drawing event is re-executed on the display 4 according to the rearranged order.

On the other hand, when a drawing event is input from another station, the drawing information managing means 2 executes the inquiry of the drawing time data described above each time the drawing event is input, and the display is executed according to the inquiry result. The display control of 4 is determined. That is, the drawing information management means 2 performs normal display and registration control when the inquiry result does not have a time contradiction, and when the inquiry result has a time contradiction, the drawing information management means 2 described above. Rearrangement of drawing events in the drawing information management table 9 and redrawing on the display 4 are executed.

FIG. 4 shows an example of the registered contents of the drawing information management table 9 when the station A receives a drawing event from another station (station B), and in this case, it is included in the drawing event received this time. The time indicated by the drawing time data that is displayed is the time advanced from the time indicated by the drawing time data included in all the drawing events stored in the drawing information management table. Does not occur. Therefore, in the drawing event received from the other station this time, the drawing corresponding to the drawing event is directly executed on the display 4, and the drawing event is registered in the next column of the drawing information management table 9.

However, as shown in FIG. 5, the time indicated by the drawing time data included in the drawing event received from the other station this time is stored in the drawing information management table 1.
When the time is on the past side of the time indicated by the drawing time data included in the plurality of drawing events, the time contradiction is detected by the inquiry of the drawing time data described above. Therefore, in this case, the drawing events are rearranged such that the drawing event received this time is inserted into the time-inconsistent column in the drawing information management table 9.
The redrawing process is executed according to the contents of the rearranged drawing information management table.

Next, various operations of the drawing information management means 2 will be described in more detail with reference to FIGS.

First, the detailed procedure from the input operation by the information input means 1 to the creation of the drawing event by the drawing information management means 2 will be described with reference to FIGS.

6 to 8 show the case where the mouse is selected as the information input means 1. Further, the drawing information management means 2 may directly receive the input signal from the information input means 1, but FIG.
In the procedure of FIG. 8, the drawing information management means 2 receives the input signal of the information input means 1 as an event via the window system.

FIG. 6 shows the operation of the drawing information management means 2 in response to a mouse pressing event output from the window system when a mouse button is clicked.
Indicates the operation of the drawing information management means 2 in response to a mouse drag operation event output from the window system when the mouse is dragged. FIG. 8 shows the window corresponding to this when the mouse button is released. The operation of the drawing information management means 2 in response to a mouse release operation event output from the system is shown.

First, the mouse pressing event will be described with reference to FIG.

When the drawing information managing means 2 receives a mouse pressing event including the designated coordinates of the mouse from the window system (step 100 in FIG. 4), the coordinates are stored in the buffer A and the buffer B in the drawing information managing means 2. (Steps 110, 120). The buffer A functions to store the starting point coordinates when the mouse operation is an erasing type drawing. The buffer B also functions to update and store the drawing start point (or drawing end point) of the drawing data in each drawing event when the mouse operation is writing-type drawing. That is, in this case, as described above, the drawing event has a basic unit that is obtained by dividing a series of drawing contents from the drawing start point to the drawing end point per unit time.

Next, the drawing information management means 2 sets a drawing flag indicating that drawing is in progress (step 130), and further creates a drawing ID corresponding to the current drawing (step 14).
0). That is, as described above, the drawing ID is composed of a code part for identifying each station and a serial number part indicating the temporal order of drawing input in one station. The process of incrementing the number of +1 is executed. Then, the drawing information management means 2 temporarily stores the created drawing ID in the buffer C built in the drawing information management means 2. The buffer C functions as a buffer that stores the drawing ID.

Next, the mouse drag event will be described with reference to FIG.

The drawing information management means 2 receives a mouse drag operation event including the designated coordinates of the mouse and the drawing mode (information for distinguishing between writing type writing and erasing type drawing) from the window system (step 20).
0), it is checked whether or not the currently drawing flag is set (step 210). When the drawing flag is set, the drawing information management means 2 checks the drawing mode in the mouse drag operation event input from the window system (step 220), and when it is the writing mode (step 230), the buffer. The mouse coordinates stored in B are used as the drawing start points, the mouse coordinates included in the mouse drag operation event input from the window system this time are used as the drawing end points, and the drawing consisting of these drawing start points and drawing end points is drawn. Data is created (steps 240 and 250).

Next, the drawing information management means 2 updates the stored contents of the buffer B with the mouse coordinates included in the current mouse drag operation event (step 260).

Next, the drawing information management means 2 loads the drawing ID stored in the buffer C (step 270), increments the serial number portion of the loaded drawing ID by +1 and increments it by +1. The contents stored in the buffer C are updated with the drawing ID including the number (step 280).

Next, the drawing information management means 2 receives the current time data from the time measuring means 5 (step 290), and uses the drawing ID, the drawing mode, the drawing time data and the drawing data as shown in FIG. A drawing event configured is created (step 300), and the created drawing event is sent to the window system (step 310).

The window system which has received the drawing event outputs the drawing event to the drawing event transmitting means 6 to transmit the drawing event to another station.

Next, the mouse release operation event will be described with reference to FIG.

The drawing information management means 2 receives the mouse release operation event including the designated coordinates of the mouse and the drawing mode from the window system (step 40).
0), it is checked whether or not the currently drawing flag is set (step 410). If the drawing flag is set, the drawing information management means 2 checks the drawing mode in the mouse release operation event input from the window system (step 420), and if it is the writing mode (step 430), the buffer. The mouse coordinates stored in B are used as the drawing start point (step 44).
0) Then, the mouse coordinates included in the mouse drag operation event input from the window system this time are set as the drawing end points (step 450), and drawing data composed of these drawing start points and drawing end points is created.

Next, the drawing information management means 2 initializes the buffer A and the buffer B (step 48).
0), the drawing ID stored in the buffer C is loaded (step 490), the number of the serial number part of the loaded drawing ID is incremented by 1, and the contents stored in the buffer C by the drawing ID including the incremented number. Is updated (step 500).

Next, the drawing information management means 2 includes the timekeeping means 5
Receives the current time data from (step 510),
As shown in FIG. 2, a drawing event composed of the drawing ID, the drawing mode (writing type drawing is designated in this case), the drawing time data and the drawing data is created (step 520) and the drawing flag is set. (Step 530), the created drawing event is sent to the window system (step 540).

On the other hand, when it is determined in the previous step 430 that the drawing mode included in the mouse release event input from the window system is the erase mode, the drawing information management means 2 stores it in the buffer A. The saved mouse coordinates are used as the starting point for erasable drawing (step 4
60), further, the mouse coordinates included in the mouse drag operation event input from the window system this time are set as the end points of the erase-type drawing (step 470), and the drawing data constituted by these start and end points of the erase-type drawing are set. create.

The operation of the subsequent steps 480 to 540 is the same as that of the above-mentioned writing type drawing, and finally the drawing ID, the drawing mode (in this case, the erasing type drawing is designated), the drawing time data. And a drawing event consisting of drawing data is dispatched to the window system.

Upon receipt of the drawing event, the window system outputs the drawing event to the drawing event transmitting means 6 to send the drawing event to another station.

Next, the details of the management control of the drawing information management table by the drawing information management means 2 and the drawing control for the display 1 when the drawing event of the own station or another station is received according to the flowcharts shown in FIGS. explain.

According to the procedures shown in FIGS. 9 and 10, the drawing information management means 2 receives drawing events of its own station and other stations via the window system. That is, in this case, when the window system receives the drawing event of its own station created by the drawing information managing means 2, the window system outputs this to the drawing event transmitting means 6 and also the drawing event of the own station. I / O control for the drawing event returned to the drawing information 2 and drawing control for outputting the drawing event received from the other station via the drawing information receiving means 8 to the drawing information managing means 2 are performed.

First, the drawing information management means 2, which has received a drawing event concerning its own station or another station from the window system, extracts the drawing ID, the drawing mode, the drawing time data, and the drawing data from the drawing event (steps 600 to 640). ). Next, the drawing information management means 2 checks the registered number of drawing events stored in the drawing information management table 9 and stores this in the variable A (step 65).
0). This variable A functions as a variable parameter for updating and storing the number of registered drawing events at each point in the drawing information management table 9.

Next, the drawing information management means 2 checks whether or not the variable A is 0 to determine whether or not there is a drawing event already registered in the drawing information management table 9 (step 660). When this determination result is A = 0,
That is, if there is no drawing event already registered (this time is the first drawing), the drawing information management table 9
The drawing event input this time is registered in the A + 1 line, that is, the first line column (step 670), and the drawing mode and drawing data of the input drawing event of this time are output to the drawing processing means 3. Drawing corresponding to the drawing event this time is executed on the display 4 (step 680).

That is, the procedure of steps 660 to 680 shows the procedure when the drawing event at its own station or at another station first occurs, and at this time, the drawing corresponding to this first drawing event is unconditionally performed. Display 4
To run. The drawing event at this time is registered in the first row of the drawing information management table 9.

Next, in the judgment processing of the previous step 660,
If the variable A is not 0, that is, the current drawing event is 2
In the case of the drawing after the first drawing, the drawing information management means 2 checks the drawing ID in the drawing event to determine whether the event belongs to its own station or another station (step 690).

When it is determined that the drawing event this time belongs to the own station, the drawing information management means 2 checks the drawing ID in the A line column in the drawing information management table 9 to check the A line column. It is determined whether the drawing event of (1) is for its own station or for another station (steps 700, 710).
Then, if it is determined by this determination that the drawing ID in the A-th row is that of the own station, the drawing information management table 9
The drawing event input this time is registered in the column of the A + 1 line of (step 720), and the drawing mode and drawing data of the input drawing event of this time are output to the drawing processing means 3 to be the drawing event of this time. The corresponding drawing is executed on the display 4 (step 730).

That is, in the procedure of steps 710 to 730, if both the drawing event of this time and the drawing event registered immediately before belong to the own station, the inquiry of the drawing time data described above is not performed. The drawing event of this time is unconditionally drawn, and the drawing event of this time is registered in the column of line A + 1 of the drawing information management table 9. Of course, this drawing event at the own station is transmitted to another station via the drawing event transmitting means 7.

Next, if it is determined in step 690 that the drawing event is from another station, or if it is determined in step 710 that the immediately preceding drawing event is from another station, the procedure is as follows. The process proceeds to step 740.

At step 740, the drawing information management means 2
Initializes the variable B to a predetermined initial value. The variable B
Will become clear in the description below, the drawing event registered at the oldest time among the drawing events already registered in the drawing information management table and having a time contradiction compared to this drawing event is It represents the registered line number, and the fact that this variable B is the initial value means that there is no registered drawing event with a time contradiction.

After the variable B is initialized in step 740, the drawing information management means 2 determines whether or not the current variable value A is 0 or less. The drawing time data of the drawing event in the eye column is extracted (step 760) and compared with the drawing time data of the current drawing event (step 770).

If it is determined by this comparison that the time indicated by the time data of the drawing event on the A-th row is older than the time indicated by the drawing time data of the current drawing event, the current drawing event It is assumed that there is no time contradiction even if is drawn as it is, and the procedure moves to step 800.

In step 800, the drawing information management means 2 determines whether or not the variable B is in the initial state. After initializing the variable B in step 740, if the determination in step 770 is NO for the first time via steps 750 and 760, the variable B is determined in step 800.
Cannot be other than the initial value, and in such a case, the determination in step 800 is YES and the procedure moves to step 840.

In step 840, the drawing event input this time is registered in the A + 1 line of the drawing information management table 9, and the drawing mode and drawing data of the input drawing event of this time are input to the drawing processing means 3. It is output and the drawing corresponding to the drawing event this time is executed on the display 4 (step 850).

That is, steps 740-770, 80
The procedure via 0, 840, 850 is the case where the drawing event of this time is from another station and there is no time contradiction in this drawing event, or the drawing event of this time is that of the own station and is immediately before. It corresponds to the case where the drawing event registered in is of another station and there is no time contradiction in this drawing event. In such a case, the drawing event of this time is drawn as it is and It operates so as to register the drawing event in the column of the (A + 1) th row of the drawing information management table 9.

However, if the time indicated by the time data of the drawing event in the A-th row is later than the time indicated by the drawing time data of the current drawing event in the determination in step 770, the current drawing is performed. If you draw the event as it is, a time contradiction will occur, so first,
The value of variable B is updated with the value of variable A (step 77).
0). Next, the value of the variable A is decremented by -1, and the above-described steps 760 and 7 are performed according to the value of the decremented variable A.
The processing of 70 is executed again. That is, the time data of the drawing event in the column A-1 is compared with the drawing time data of the current drawing event, and the procedure proceeds to step 800 or step 780 depending on the comparison result.

Then, such processing is performed in step 770.
Until there is no time contradiction or the variable A becomes 0
By repeatedly executing until the following, the drawing event registered at the oldest time among the drawing events already registered in the drawing information management table that have a time contradiction compared to this drawing event The registered line number is found and stored in the variable B.

That is, step 750 to step 79
In the procedure of 0, the process of comparing the time data of the drawing event registered in the drawing information management table 9 with the time data of the current drawing event is the latest in the drawing events registered in the drawing information management table 9. By tracing back one by one from the above, the line number in which the drawing event registered at the oldest time among those having a time contradiction is registered is found.

Next, in step 800, the variable B
Is determined to be the initial state. In the determination in step 800, the procedure when the variable B is in the initial state has been described above, and therefore the procedure when the variable B is not in the initial state will be described here.

That is, the variable B is determined in step 800.
Is not in the initial state, the drawing information management means 2 registers each information of the drawing event of this time in the B line column of the drawing information management table 9 and the drawing event previously registered in the B line and thereafter. A registration process is performed to shift the lines one by one to the backward line (step 810).

Next, the drawing information management means 2 invalidates (clears) the drawing currently displayed on the display 4 (step 820) and sets the first drawing event in accordance with the new registration contents of the drawing information management table 9. The drawing mode and drawing data of the read drawing events are sequentially read out from the row column in the order of registration, and redrawing according to the new registered contents of the drawing information management table 9 is performed on the display 4 by sequentially outputting the drawing mode and drawing data. It is executed (step 830).

Thus, steps 740-790, 8
The procedure via 00 to 830 is performed when the drawing event of this time is from another station and there is a time contradiction in this drawing event, or when the drawing event of this time is of its own station and is registered immediately before. It corresponds to the case where the drawn event of another station is temporally inconsistent with the drawn event of another station. In such a case, the drawn event received this time is set to the time in the drawing information management table 9. The drawing events are rearranged such that the drawing events are inserted into a column that does not have a contradiction, and the rearranged drawing information management table 9
The redrawing process according to the contents of is executed.

As described above, according to the control procedure shown in FIGS. 9 and 10, when the drawing event of this time is from another station, or when the drawing event of this time is from its own station and is registered immediately before. The drawing event is controlled based on the inquiry of drawing time data only when the drawn event is from another station, and the drawing event is displayed unconditionally in cases other than the above, so it is always drawn. Efficient display control can be achieved as compared with the control for executing the data inquiry.

FIG. 11 shows a concrete example of drawing control by the apparatus of the above embodiment.

In this case, the first drawing event A-1 occurs at the station A at 12:00:00. This first
The drawing event for the second time is drawn by the station A and is sent to the station B. In station B, drawing event A of station A received
-1 is the first drawing, so this drawing event A
The drawing event A-1 is unconditionally executed and the drawing event A-1 is registered in the drawing information management table 9.

Next, in station A, the second drawing event A-2 occurs at 12:00:22. The second drawing event A-2 is drawn by the station A and transmitted to the station B.

Here, in the B station, the time before the second drawing event of the A station is received, 12: 00: 2.
The first drawing event B-1 at station B occurs in 3 seconds. In station B, the drawing event A-1 registered immediately before this first drawing event B-1 is from another station, so the drawing time data of these drawing events are queried. Since no temporal contradiction occurs in the inquiry in this case, the display corresponding to the first drawing event B-1 at this station B is executed, and this drawing event B-1 is displayed in the drawing information management table 9 The drawing event A-1 is registered in the next column. Then, this drawing event B-1 is transmitted to the A station.

Next, station B receives the second drawing event A-2 of station A in this state. The station B inquires the drawing time data of the drawing event A-2 and the drawing time data of the already registered drawing events B-1 and A-1. In this case, there is a temporal contradiction between the drawing event A-2 this time and the registered drawing event B-1.
In station B, the registered contents of the drawing information table 9 are rearranged in the correct time order, and redrawing is executed in the rearranged order.

After that, the station A receives the drawing event B-1 from the station B, performs the inquiry processing similar to the above, and then displays the drawing event B-1.

As a result, the final display states of the A station and B station are completely the same.

Next, a second embodiment of the present invention will be described.

That is, in the first embodiment described above, when the drawing event of the own station is displayed, it is determined whether the immediately preceding drawing is the own station or another station, and further, the immediately preceding drawing belongs to another station. In some cases, the judgment is made based on the drawing time data, and after this judgment, the actual display or redisplay is executed based on these judgment results. However, in the second embodiment, the drawing event of the own station is executed. With respect to the above, when a drawing input occurs, immediately, unconditionally, the display corresponding to the drawing input is executed, then the above determination is performed, and the redisplay based on the determination result is executed. As a result, in the second embodiment, even when a processing device having a slow processing speed is used for the determination process, the drawing input of the own station is immediately displayed, which makes the operator of the own station feel uncomfortable. There is nothing to give. Note that the processing relating to the drawing event of another station is not particularly changed in the second embodiment.

In order to perform such an operation, in the second embodiment, the drawing information management means 2 in FIG. 1 draws some input data when the input operation information is input from the information input means 1. When an input is made, a display based on the input operation information is immediately executed on the display 4, and after this display, time data is taken in from the time measuring means 5, a drawing event is created, and the drawing event is based on the time order. The judgment and the redisplay based on the judgment are executed.

12 to 15 show the operation of the drawing information management means 2 in the second embodiment. FIG. 12 shows the operation when a mouse drag operation event is received from the window system (first embodiment). (Corresponding to Figure 7 of the example),
FIG. 13 shows the operation when received from the mouse release operation event window system (corresponding to FIG. 8 of the first embodiment), and FIG. 14 shows the first half of the control procedure for managing drawing events (first execution). (Corresponding to FIG. 9 of the example),
FIG. 15 shows the latter half of the control procedure relating to the management of drawing events (corresponding to FIG. 10 of the first embodiment).

That is, FIG. 12 shows a step 255 between the steps 250 and 260 in the flowchart of FIG.
FIG. 13 shows the flow chart in FIG. 8 in which step 465 is inserted between steps 450 and 480 and step 475 is inserted between steps 470 and 480 in FIG. Step 675 is inserted between steps 670 and 680 of the flowchart and step 730 is deleted, and FIG. 15 is such that step 845 is inserted between steps 840 and 850 of the flowchart of FIG. The operation when the mouse pressing event shown in FIG. 6 occurs is not particularly changed in the second embodiment.

Specific differences between the second embodiment and the first embodiment will be described below with reference to FIGS. 12 to 15.

That is, in the second embodiment, by inserting the step 255 for displaying the line from the drawing start point to the drawing end point on the display 4 between the steps 250 and 260 of FIG. 12, Each time a write-type mouse drag operation event is input from the window system, a display corresponding to this mouse drag operation event is immediately executed on the display 4, and FIG.
By inserting a step 465 of displaying a line from the drawing start point to the drawing end point on the display 4 between steps 450 and 480, the writing type mouse release operation event is input from the window system, The display corresponding to this mouse release operation event is immediately executed on the display 4.

Further, in the second embodiment, a step 475 for displaying the erasing type drawing based on the drawing start point and the drawing end point on the display 4 is inserted between the steps 470 and 480 of FIG. By doing so, when an erasing type mouse release operation event is input from the window system, that is, immediately when an erasing type drawing input is performed at the local station, the display erasing process corresponding to this erasing type drawing input is executed. I am trying.

As described above, in the second embodiment, with respect to the drawing input of the own station, when the operation event related to the drawing input is input, the actual display corresponding to the operation event is immediately executed. Therefore, in the second embodiment,
When the drawing event is received from the window system shown in FIGS. 14 and 15, the display operation regarding the drawing event of the own station has already been completed.

Therefore, in the drawing event management procedure shown in FIGS. 14 and 15, step 67 in FIG.
Step 675 is inserted between 0 and 680 and step 730 is deleted, and steps 840 and 8 of FIG.
By inserting the step 845 between the drawing event and the drawing event 50, the drawing display process regarding the drawing event of the own station is deleted from the procedure at the time of managing the drawing event. That is, in the second embodiment, when the drawing events shown in FIGS. 14 and 15 are managed, only the drawing process related to the drawing event from the other station is performed, and the drawing event of the own station is redrawn. The drawing display processing is performed only on the.

As described above, in the second embodiment, for the drawing event of its own station, when the drawing input occurs, the display is immediately and unconditionally executed, and thereafter, the judgment is made in the order of time and the Redisplay based on the judgment result.

Next, a third embodiment of the present invention will be described.

In the third embodiment, when redisplaying when a time contradiction occurs, when the display is invalidated (cleared) and redrawing is performed in time order, all areas of the display screen are displayed. The invalidation and redrawing are not performed, but the invalidation and redrawing are executed only for a minimum partial area, so that the redisplay processing time is shortened.

That is, in the third embodiment, the drawing information management means 2 of each station draws strokes of each input drawing (from the drawing start point to the drawing end point) for each drawing input.
2 is calculated by calculating an existing area (for example, a rectangular area having a stroke as a diagonal line), and FIG.
Insert it in each drawing event shown in.

Then, when re-displaying is performed, first, the existing area of each drawing in which the drawing time data has a temporal contradiction is extracted. Next, a drawing in which a part or the whole area overlaps the extracted area is selected from among the drawings in which the drawing time data has no temporal contradiction, and the existing area of the selected drawing is also extracted. Further, a drawing in which a part or the whole area overlaps the extracted range is selected from the drawings having no time contradiction in the drawing time data, and the existing area of the selected drawing is also extracted. Less than,
Until there are no overlapping drawings in the extracted existing area,
The same extraction process is repeated.

Then, the invalidation and redrawing processing is executed only for all the extraction areas obtained by such processing.

As described above, in the third embodiment, at the time of re-display, re-display is not performed for all the areas of the display screen, but re-display is performed only for a minimum partial area. The processing time for redisplay is shortened.

In the embodiment, the drawing information management means fetches the time output of the time measuring means when the drawing input occurs in order to obtain the drawing time data. Each time an input occurs, the time data at that time may be output to the drawing information management means 2.

Also, in the embodiment, the drawing information management means 2
Although various events such as a drawing event are exchanged via the window system, the events may be exchanged with each required circuit without passing through the window system.

[0109]

As described above, according to the present invention,
Drawing information with drawing time data indicating the drawing input occurrence time added to the drawing data is sent and received between each station, and each station draws the drawing occurrence time based on the drawing time data regardless of whether it is drawing in its own station or drawing in another station. Since the drawing is executed in order, even if the writing and erasing processes are performed at almost the same time at each station, the contents displayed on each station can be displayed without any complicated control procedure for acquiring the drawing execution right. It is possible to prevent the difference from occurring and to completely match the vertical relationship of the writing-type drawing between the stations.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing signals included in a drawing event.

FIG. 3 is a diagram exemplifying the storage contents of a drawing information management table.

FIG. 4 is a view exemplifying a case where drawing events are not replaced in the drawing information management table.

FIG. 5 is a diagram exemplifying replacement of drawing events in a drawing information management table.

FIG. 6 is a flowchart showing an operation example of the drawing information management means when a mouse pressing event occurs in the first or second embodiment of the present invention.

FIG. 7 is a flowchart showing an operation example of drawing information management means when a mouse drag operation event occurs in the first embodiment of the present invention.

FIG. 8 is a flowchart showing an operation example of drawing information management means when a mouse release operation event occurs in the first embodiment of the present invention.

FIG. 9 is a flowchart showing the first half of the control procedure relating to the management of drawing events by the drawing information management means in the first embodiment of the present invention.

FIG. 10 is a flowchart showing the latter half of the control procedure relating to the management of drawing events by the drawing information management means in the first embodiment of the present invention.

FIG. 11 is a diagram showing changes in display contents of two stations according to the control procedure of the present invention.

FIG. 12 is a flowchart showing an operation example of drawing information management means when a mouse drag operation event occurs according to the second embodiment of the present invention.

FIG. 13 is a flowchart showing an operation example of drawing information management means when a mouse release operation event occurs according to the second embodiment of the present invention.

FIG. 14 is a flowchart showing the first half of the control procedure relating to the management of drawing events by the drawing information management means in the second embodiment of the present invention.

FIG. 15 is a flowchart showing the latter half of the control procedure relating to the management of drawing events by the drawing information management means in the second embodiment of the present invention.

FIG. 16 is a diagram showing a transition of display contents of two stations according to a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Information input means 2 ... Drawing information management means 3 ... Drawing processing means 4 ... Display 5 ... Timing means 6 ... Drawing event transmission means 7 ... Communication processing means 8 ... Drawing event receiving means 9 ... Drawing information management table 10 ... Communication network

Claims (1)

[Claims] 1. A telewriting device that has a shared screen capable of drawing including writing and erasing and communicates drawing data to be displayed on the shared screen with another telewriting device, and measures time. Timing means and when a drawing input operation occurs, the output of the timing means is fetched as drawing time data in a predetermined drawing unit, and drawing information in which the drawing time data is added to the drawing data is created in the predetermined drawing unit. Drawing information creating means, transmission processing means for sending the drawing information to another telewriting device, reception control means for receiving the drawing information from another telewriting device, and drawing information creating means Storage means for storing the drawing information and the drawing information received by the reception control means, and the drawing stored in the storage means Drawing information management means for managing and storing information in order of time indicated by drawing time data included in each drawing information, and control for displaying the drawing data on the shared screen according to management by the drawing information management means, and drawing information management A display control unit that causes the shared screen to redraw the drawing data according to the time order indicated by the drawing time data when the drawing information is exchanged during the management of the drawing time data order by the means. Telewriting device characterized by.