JP6821998B2 - Electronic blackboard, program, method - Google Patents

Description

The present invention relates to electronic blackboards, programs and methods .

Electronic information board systems such as electronic whiteboards that display stroke images of characters, figures, symbols, etc. are used in companies, educational institutions, government agencies, and the like. The electronic information board system includes a display device provided with a touch panel and a computer device that controls the display device. The touch panel detects strokes drawn on the display device by the user. The computer device displays the stroke image formed by the stroke and erases the stroke image displayed on the path of the stroke.

Patent Document 1 describes a touch panel, an acquisition means for acquiring a contact area via the touch panel, a first determination means for determining whether or not the shape of the contact area satisfies a predetermined condition, and the touch panel. A display including a display control means for displaying an image at a position corresponding to a first contact region that does not satisfy the predetermined condition and erasing the image in the second contact region that satisfies the predetermined condition. The device is disclosed.

An image processing device such as an electronic information board system not only detects the movement of a finger or the like in contact with the touch panel and accepts operation inputs such as writing or erasing, but also detects the movement of a plurality of fingers and pinches out. , Or accepts input for gesture operations such as pinch-in. However, in the image processing apparatus, in order to switch between the writing / erasing process and the process based on the gesture operation, there arises a problem that the user needs to input the operation mode.

The electronic blackboard of the invention according to claim 1 is an electronic whiteboard that has a display and can be drawn by contact of an object with the display, and when the object and the display are in contact with each other, the object and the display When the size of the area in contact with the object is equal to or larger than the first threshold value, the change means for erasing the image in the range based on the contact position of the target from the image displayed on the display is provided by the change means. When the contact of the second target is detected while the process of erasing the image of the contact portion of the first target is being executed, the contact between the contact portion of the first target and the contact portion of the second target When the distance to the unit is equal to or less than a predetermined threshold value, the process of displaying an image on the display with respect to the contact portion of the second target and the contact position of the contact portion of the second target The process of erasing the image in the based range from the image displayed on the display is prohibited.

As described above, according to the present invention, in the image processing apparatus, it is possible to switch between the writing or erasing process and the process based on the gesture operation without causing the user to input the operation mode. Play.

FIG. 1 is an external view of an electronic blackboard according to an embodiment. FIG. 2 is a hardware configuration diagram of the electronic blackboard according to the embodiment. FIG. 3 is a functional block diagram of the electronic blackboard according to the embodiment. FIG. 4 is a conceptual diagram showing a screen of a display. FIG. 5 is a diagram showing an example of detecting an event by the event distribution unit. FIG. 6 is a state transition diagram showing an example of the transition of the operation mode. FIG. 7 is a flow chart showing an example of the mode determination process. FIG. 8 is a flow chart showing an example of the mode determination process. FIG. 9 is a flow chart showing an example of the mode determination process. FIG. 10 is a display example of the display. FIG. 11 is a flow chart showing a process of setting an erasure range in a modified example of the embodiment. FIG. 12 is a flow chart showing an example of the mode determination process. FIG. 13 is a diagram showing an example of an image erasing operation on the display.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<< Overall configuration of electronic blackboard >>
First, the overall configuration of the electronic blackboard 2 will be described with reference to FIG. 1 as an example of the electronic information board system. FIG. 1 is an external view of an electronic blackboard according to an embodiment. As shown in FIG. 1, the electronic blackboard 2 is based on the detection results of the contact sensor 215 that detects the contact of the detection target such as the hand H, the display 3 that outputs the image drawn by the hand H, and the contact sensor 215. Based on this, it has a CPU (Central Processing Unit) and the like, which will be described later, that perform processing related to the image displayed on the display 3.

The electronic information board system is not limited to the electronic blackboard, and may be, for example, a PC (Personal Computer), a tablet, a smartphone, a digital signage, a telestrator, or a game machine. Further, the electronic information board system may have a communication device and may be able to share the image drawn on the touch panel as content data with other communication terminals.

<Hardware configuration of electronic blackboard>
The hardware configuration of the electronic blackboard according to the embodiment will be described with reference to FIG. Note that FIG. 2 is a hardware configuration diagram of the electronic blackboard according to the embodiment.

As shown in FIG. 2, the electronic whiteboard 2 is a work of a CPU (Central Processing Unit) 201 that controls the operation of the entire electronic whiteboard 2, a ROM 202 that stores a program used to drive a CPU 201 such as an IPL, and a CPU 201. RAM 203 used as an area, SSD 204 for storing various data such as programs for electronic blackboards, network I / F 205 for controlling communication with communication network 9, and external storage controller 206 for controlling communication with USB memory 5. It has. Further, the electronic blackboard 2 displays video information as a still image or a moving image on the display of the camera 207 that captures the subject under the control of the CPU 201, the image pickup element I / F208 that controls the drive of the camera 207, and the notebook PC 6. It includes a capture device 211 to display, a GPU (Graphics Processing Unit) 212 that specializes in graphics, and a display controller 213 that controls and manages the screen display to output the output image from the GPU to the display 3. .. Further, the electronic blackboard 2 includes a sensor controller 214 that controls the processing of the contact sensor 215, and a contact sensor 215 that detects that the electronic pen 4 or the user's hand H or the like touches the display 3. In one embodiment, the contact sensor 215 inputs and detects the coordinates by the infrared blocking method. In the method of inputting the coordinates and detecting the coordinates, two light receiving / receiving devices installed at both upper ends of the display 3 emit a plurality of infrared rays in parallel with the display 3 and are provided around the display 3. This is a method of receiving light that is reflected by a reflective member and returns on the same optical path as the light path emitted by the light receiving element. The contact sensor 215 outputs an infrared ID (Identification) emitted by two light emitting / receiving devices blocked by the object to the sensor controller 214, and the sensor controller 214 identifies a coordinate position which is a contact position of the object. All the IDs shown below are examples of identification information.

The detection method of the contact sensor 215 is not limited to the infrared blocking method, but is a capacitance method that specifies a contact position by detecting a change in capacitance, and a contact position that is specified by a voltage change of two opposing resistance films. The resistance film method or the electromagnetic induction method that specifies the contact position by detecting the electromagnetic induction generated by the contact object coming into contact with the display unit may be used. Further, the contact sensor 215 may use a camera to determine the contact and specify the coordinate position.

Further, the electronic blackboard 2 includes an electronic pen controller 216. The electronic pen controller 216 determines whether or not there is a touch of the pen tip or a touch of the pen tail on the display 3 by communicating with the electronic pen 4. The electronic pen controller 216 may determine whether or not not only the pen tip and pen end of the electronic pen 4 but also the portion gripped by the user of the electronic pen 4 and other electronic pen portions are touched. ..

Further, the electronic whiteboard 2 has a sound input / output I / F 224 that processes sound signal input / output between the external microphone 222 and the external speaker 223 under the control of the CPU 101, and an operation button 225 that accepts user operations. And a power switch 226 for switching the power ON / OFF of the electronic whiteboard 2. Either the microphone 222 or the speaker 223 may be built in the electronic blackboard 2.

Further, the electronic blackboard 2 is provided with a bus line 230 such as an address bus or a data bus for electrically connecting the above-mentioned components to each other.

The program for the electronic blackboard may be recorded on a computer-readable recording medium such as a CD-ROM or a server on the network for distribution or download.

<< Functional configuration of the embodiment >>
FIG. 3 is a functional block diagram of the electronic blackboard according to the embodiment. The electronic blackboard 2 realizes each functional configuration shown in FIG. 3 by the hardware configuration and the program shown in FIG. Further, the electronic blackboard 2 has a storage unit 2000 constructed by SSD 204.

The coordinate detection unit 22 is realized by the contact sensor 215, detects contact with the display 3 to be detected such as the hand H, and outputs the coordinates and size of the contact unit HT1 and the contact unit HT2. FIG. 4 is a conceptual diagram showing the screen of the display 3. In one embodiment, the coordinates on the screen of the display 3 correspond to pixels. For example, the coordinates C0 of the upper left vertex of the screen are (0,0), and the lower right vertex of the screen is (1920,1080). The size of the contact portion HT1 is from the coordinate CR (for example, (11,11)) of the lower right vertex of the rectangle R formed by the tangent line of the contact portion HT1 to the vertex of the upper left CL of the rectangle (for example, (7,5)). It is the difference obtained by subtracting the coordinates (for example, (4, 6)).

The event distribution unit 25 is realized by a command from the CPU 201, distributes the event that the user's hand H touches on the display 3 into more detailed events, and sets the operation mode.

The event determination unit 251 of the event distribution unit 25 acquires the output of the coordinate detection unit 22 and detects the following events.
-Touchdown event: A detection target such as a hand H is pen-down (detected by the contact sensor 215).
-Touch move event: The coordinates of the detection target detected as a touchdown event move. Coordinates move means that the coordinates detected at time t _n and the coordinates detected at time t _{n + 1} are within a predetermined range (a predetermined distance at which a detection target such as a hand H can move between time t _n and time t _{n + 1} ). ).
-Touch-up event: The detection target determined to be a touch-down event or a touch-move event is pen-up (not detected by the contact sensor 215).
The event determination unit 251 assigns one identification number (hereinafter referred to as an ID) to the detection target between the time when the detection target is pen-down and the time when the detection target is pen-up.

The mode determination unit 252 of the event distribution unit 25 determines the operation mode based on the event detected by the event determination unit 251.

The timer 255 of the event distribution unit 25 is a time measuring means for measuring a fixed time. The timer 255 may measure the time by a program or may measure the time by hardware such as an IC. This fixed time is set assuming the time from the touch of the first finger to the touch of the second finger when the user touches the display 3 with two fingers for the gesture operation, for example. It is tens to hundreds of milliseconds. The time set in the timer 255 does not have to be constant, and the event determination unit 251 learns the time from the touch of the first finger to the touch of the second finger when the user makes a gesture operation. , The timer may be set to 255.

The time-out flag 253 is set to True in the storage unit 2000 when the timer 255 times out. The initial value of the timeout flag 253 is set to False when the electronic blackboard 2 is activated.

The gesture processing unit 27 executes processing corresponding to the gesture operation for the events that are realized by the instruction from the CPU 201 and are distributed to the operation mode "Gesture" by the event distribution unit 25.
The display processing unit 29 is realized by a command from the CPU 201, and executes a process for displaying an image on the display 3.

The stroke processing unit 32 executes a process corresponding to the operation mode for an event that is realized by a command from the CPU 201 and is distributed to the operation mode “EraseLarge, EraseSmall, Draw” by the event distribution unit 25. The result of the process corresponding to the operation mode is stored in the page data storage unit 300 as operation data.

The page data storage unit 300 is constructed as a part of the storage unit 2000 and stores page data as shown in Table 1. Table 1 is a conceptual diagram showing page data. The page data is data for one page (stroke array data (each stroke data) and media data) displayed on the display 3.

The page data includes a page data ID for identifying an arbitrary page, a start time indicating the time when the display of this page is started, and an end time indicating the time when the contents of the page are no longer rewritten by strokes or gestures. , The stroke array data ID for identifying the stroke array data generated by the stroke by the electronic pen 4 or the user's hand H, and the media data ID for identifying the media data are stored in association with each other. The stroke array data is data for displaying the stroke image on the display 3. The media data is data for displaying another image superimposed on the stroke image on the display 3.

In addition, the stroke array data shows detailed information as shown in Table 2. Table 2 is a conceptual diagram showing stroke array data. As shown in Table 2, one stroke array data is represented by a plurality of stroke data. Then, one stroke data includes a stroke data ID for identifying the stroke data, a start time indicating the writing start time of one stroke, an end time indicating the writing end time of one stroke, and a stroke color. The width of the stroke and the coordinate array data ID for identifying the array of passing points of the stroke are shown. For example, when the user draws the alphabet "S" with the electronic pen 4, it is written in one stroke, so that one stroke data ID and one letter alphabet [S] are shown. However, when the user draws the alphabet "T" with the electronic pen 4, it is written in two strokes, so that the alphabet "T" of one character is indicated by two stroke data IDs.

Further, this coordinate array data shows detailed information as shown in Table 3. Table 3 is a conceptual diagram showing coordinate array data. The coordinate array data includes one point (X coordinate value, Y coordinate value) on the display 3, the time (ms) of the difference from the start time of the stroke when passing through this one point, and the electronic pen at this one point. Each information of the pen pressure of 4 is shown. That is, a set of one point shown in Table 3 is shown by one coordinate array data shown in Table 2. For example, when the user draws the alphabet "S" with the electronic pen 4, it is written in one stroke, but since the user passes through a plurality of passing points by the time the drawing of the "S" is completed, the coordinate array data has these multiple passing points. Information is shown.

<< Processing of the embodiment >>
Subsequently, the process according to one embodiment will be described.

<Event detection>
FIG. 5 is a diagram showing an example of detecting an event by the event distribution unit 25. FIG. 5 shows the events detected first at the top and the events detected later at the bottom. Further, FIG. 5 shows the touchdown event in the left column, the touch move event in the center column, and the touch up event in the right column. Note that FIG. 5 shows an example in which the coordinate detection unit 22 detects two detection targets from the contact start time ts2 of the second detection target to the contact end time te1 of the first detection target. ing.

When the finger of the user's hand H touches the screen of the display 3, the coordinate detection unit 22 determines the coordinates of the contact portion HT1 between the hand H and the display 3, the size of the contact portion HT1, and the event occurrence time. Output to 251. The event determination unit 251 detects a touchdown event by inputting the coordinates of the contact unit HT1 and the like (step S1). When the event determination unit 251 detects the touchdown event, the event determination unit 251 generates the ID “1” of the contact unit HT1. The event determination unit 251 outputs to the mode determination unit 252 the coordinates of the contact unit HT1, the size of the contact unit HT1, the event occurrence time, the ID "1" generated in step S1, and the "TouchDown" indicating the event type. .. Table 4 shows an example of the information output by the event determination unit 251.

Subsequently, when the finger of the user's hand H moves while touching the screen of the display 3, the coordinate detection unit 22 moves the coordinates after the movement of the contact portion HT1, the size of the contact portion HT1, and the event occurrence time. Is output to the event determination unit 251. When the event determination unit 251 confirms that the distance between the previously input coordinates of the contact unit HT1 and the newly input coordinates is equal to or less than a predetermined threshold value, the event determination unit 251 detects a touch move event (step S2). The predetermined threshold value is a set value indicating the maximum distance that can be moved by a human stroke drawing operation. The event determination unit 251 outputs the coordinates of the contact unit HT1, the size of the contact unit HT1, the event occurrence time, the "TouchMove" indicating the event type, and the ID of the contact unit HT1 to the mode determination unit 252.
Subsequently, when a part of the user's hand moves further while touching the touch panel T, the event determination unit 251 detects a touch move event (step S3). The process at this time is the same as in step S2.

Subsequently, when another finger of the user's hand H touches the screen of the display 3, the coordinate detection unit 22 determines the coordinates, size, and event occurrence time of the contact portion HT2 between the other finger and the screen of the display 3. , Output to the event determination unit 251. When the event determination unit 251 confirms that the distance between the previously input coordinates of the contact unit HT1 and the newly input coordinates of the contact unit HT2 exceeds a predetermined threshold value, the event determination unit 251 detects a touchdown event (step S4). ). When the event determination unit 251 detects the touchdown event, the event determination unit 251 generates the ID “2” of the contact unit HT2. The event determination unit 251 outputs the coordinates of the contact unit HT2, the size of the contact unit HT2, the event occurrence time, the ID “2” generated in step S4, and the event type “TouchDown”.

Subsequently, when the finger of the user's hand H or another finger moves further while touching the screen of the display 3, the event determination unit 251 detects a touch move event (steps S5, 6, 7, 8). , 10). The process at this time is the same as in step S2. However, when the movement of the contact portion HT1 is detected, the event determination unit 251 outputs the ID "1", and when the movement of the contact portion HT2 is detected, the event determination unit 251 outputs the ID "2".

When the finger of the user's hand H is separated from the touch panel T and the contact portion HT1 is no longer detected, the coordinate detection unit 22 detects the touch-up event of the contact portion HT1 (step S9). The event determination unit 251 modes the coordinates of the contact unit HT1 last input from the coordinate detection unit 22, the contact unit HT1 size, the event occurrence time, the event type "TouchUp", and the contact unit HT1 ID "1". Output to the determination unit 252.

When the other finger of the user's hand H is separated from the touch panel T and the contact portion HT2 is no longer detected, the coordinate detection unit 22 detects the touch-up event of the contact portion HT2 (step S11). The event determination unit 251 inputs the coordinates of the contact unit HT2 last input from the coordinate detection unit 22, the size of the contact unit HT2, the event occurrence time, the "TouchUp" indicating the event type, and the ID "2" of the contact unit HT2. Output to the mode determination unit 252.

<Mode judgment>
Subsequently, the processing by the mode determination unit 252 will be described. FIG. 6 is a state transition diagram showing an example of the transition of the operation mode. As shown in the state transition diagram of FIG. 6, the operation mode changes depending on conditions such as an event or time. In FIG. 6, the operation mode “Draw, EraseSmall, EraseLarge” belongs to the operation mode “Input”. In the operation mode "Input", one operation request is input by one target. The operation mode "Draw" is a mode for displaying an image on a contact portion with an object. The operation mode "Erase Small" is a mode for erasing an image of a relatively small area in a contact portion with an object. The operation mode "Erase Large" is a mode for erasing an image in a relatively large area at a contact portion with an object. Note that erasing an image is a process for obscuring the displayed image. In this process, the electronic blackboard 2 may delete the image data for reproducing the image from the storage area of the electronic blackboard 2, or may prevent the image data from being output to the display 3 without deleting the image data. In the operation mode "Gesture", one operation request is input by two targets. The operation in the operation mode "Gesture" includes pinch-in, pinch-out, page turning, and the like. The operation mode "Unsettled" indicates a provisional operation mode that is set before the operation mode "Gesture, Input" is determined.

7 to 9 are flow charts showing an example of the mode determination process. The mode determination process according to the state transition rule of FIG. 6 will be described with reference to FIGS. 7 to 9.

(Touchdown event)
The mode determination unit 252 sets an operation mode indicating an operation by the target for each contact portion of the target. When the coordinates, size, ID, and event "TouchDown" of the contact unit HT1 are input from the event determination unit 251 to the mode determination unit 252 by the touchdown of the finger of the hand H (see step S1), the mode determination unit 252 , The operation mode corresponding to the contact portion HT1 is set to "Unsettled" (step S21). Further, the mode determination unit 252 stores the set operation mode "Unsettled" in the RAM 203 in association with the coordinates, size, ID, and event occurrence time sent from the event determination unit 251 (step S22).

The mode determination unit 252 starts the timer 255 after the event "TouchDown" occurs (step S23). The timer 255 started in step S23 operates until a certain time elapses and a timeout occurs, or the mode determination unit 252 stops the timer. The timer 255 sets the timeout flag 253 to "False" when it starts, and sets it to "True" when it stops.

After that, when the timer is operating, that is, when the timeout flag 253 is "False" and the event "TouchDown" due to the detection of the second target is input, the first target is processed later. , And one operation mode "Gesture" is set for the second target. Therefore, the mode determination process is not executed for the event generated by the second target.

(Touch move event)
Subsequently, the mode determination process when the touch move event is input from the event determination unit 251 to the mode determination unit 252 will be described with reference to FIG.

When the coordinates, size, ID, and event "TouchMove" of the contact unit HT1 are input from the event determination unit 251 to the mode determination unit 252 (see step S2 and the like), the process of FIG. 8 is started.

The mode determination unit 252 determines whether the size (for example, (5, 8)) of the contact unit HT1 sent from the event determination unit 251 is equal to or greater than the threshold value T1 (step S31). In one embodiment, the threshold value T1 is a size "3" assuming that three fingers are in contact with each other, and the threshold value T2 is a size "6" that is assumed to be in contact with the palm of a hand. When the width and height in the size of the contact portion HT1 are different, the mode determination unit 252 may compare the larger width and height with the threshold value T1.

When it is determined that the size of the contact portion HT1 is not equal to or larger than the threshold value T1 (NO in step S31), the mode determination unit 252 sets an event "TouchDown" due to the contact of the second target before the timer 255 times out. It is determined whether the event has been received from the event determination unit 251 (step S32).

If YES is determined in step S31, or NO is determined in step S32, the mode determination unit 252 sets the operation mode corresponding to the contact unit HT1 to “Input” (step S33).

If YES is determined in step S32, the mode determination unit 252 stops the timer 255 (step S34).
Further, the mode determination unit 252 sets the operation mode corresponding to the contact unit HT1 and the contact unit HT2 to “Gesture” (step S35). In this case, the mode determination unit 252 adds the operation mode "Gesture" to the coordinates, size, event occurrence time, and ID sent from the event determination unit 251 and transmits them to the gesture processing unit 27. Further, when the coordinates, size, event occurrence time, and ID information are stored in the RAM 203, the mode determination unit 252 transmits the stored information to the gesture processing unit 27 (step S36). As a result, when the operation mode is undecided, the information of the contact portion HT1 and the contact portion HT2 stored in the RAM 203 is transmitted to the gesture processing unit 27 together with the operation mode “Gesture”. After transmission, the mode determination unit 252 deletes the coordinates, size, event occurrence time, and ID information stored in the RAM 203.

The gesture processing unit 27 executes the processing of the operation mode "Gesture" based on the information sent from the mode determination unit 252. For example, when the coordinates sent from the mode determination unit 252 indicate that the distance between the two contact units HT1 and the contact unit HT2 becomes shorter with the passage of time, the gesture processing unit 27 displays a pinch-in request. It is transmitted to the processing unit 29. Alternatively, when the coordinates sent from the mode determination unit 252 indicate that the distance between the two contact portions HT1 and the contact portion HT2 increases with the passage of time, the gesture processing unit 27 requests pinch-out. It is transmitted to the display processing unit 29. The display processing unit 29 outputs the image data for display changed in response to the request from the gesture processing unit 27 to the display 3.

When the operation mode is set to "Input" in step S33, the mode determination unit 252 sets a more detailed operation mode from the operation modes "Draw, EraseSmall, EraseLarge".
First, the mode determination unit 252 determines whether the operation mode corresponding to the ID "1" sent from the event determination unit 251 together with the event "TouchMove" is "Draw" (step S41). When the operation mode corresponding to the contact portion HT1 is set to "Draw" in step S51 described later, the mode determination unit 252 stores the ID "1" of the contact portion HT1 and the operation mode "Draw" in the RAM 203 in association with each other. To do. If the operation mode "Draw" has already been set in the previous touch move event in the contact unit HT1, the mode determination unit 252 determines YES in step S41 with reference to the information in the RAM 203.

If YES is determined in step S41, the mode determination unit 252 adds the operation mode "Draw" to the coordinates, size, event occurrence time, and ID sent from the event determination unit 251 together with the event "TouchMove". Is transmitted to the stroke processing unit 32 (step S61). When the RAM 203 stores the coordinates, the size, the event occurrence time, and the ID information, the mode determination unit 252 transmits the stored information to the stroke processing unit 32. As a result, when the operation mode is undecided, the information of the contact portion HT1 stored in the RAM 203 is transmitted to the stroke processing unit 32 together with the operation mode “Draw”. After transmission, the mode determination unit 252 deletes the coordinates, size, event occurrence time, and ID information stored in the RAM 203.

The stroke processing unit 32 executes the processing of the operation mode "Draw" based on the information sent from the mode determination unit 252. In this process, the stroke processing unit 32 generates stroke array data corresponding to the coordinates sent from the mode determination unit 252 and stores it in the page data storage unit 300 (see Tables 1, 2, and 3). The display processing unit 29 outputs the image data of the handwritten image formed by the updated stroke arrangement data to the display 3. As a result, the handwritten image is displayed on the screen of the display 3 at the coordinates sent from the mode determination unit 252. FIG. 10A is a display example of the display in step S61.

If NO is determined in step S41, the mode determination unit 252 determines whether the operation mode corresponding to the ID "1" sent from the event determination unit 251 together with the event "TouchMove" is "Erase Large" (step). S42). When the operation mode corresponding to the contact portion HT1 is set to "EraseLarge" in the process of step S52 described later, the mode determination unit 252 associates the ID "1" of the contact portion HT1 and the operation mode "EraseLarge" with the RAM 203. Remember in. If the operation mode "Erase Large" has already been set in the previous touch move event in the contact unit HT1, the mode determination unit 252 determines YES in step S42 with reference to the information in the RAM 203.

If YES is determined in step S42, the mode determination unit 252 adds the coordinates, size, event occurrence time, and ID sent from the event determination unit 251 together with the event "TouchMove", and the operation mode "EraseLarge". Then, it is transmitted to the stroke processing unit 32 (step S62).

The stroke processing unit 32 executes the processing of the operation mode "Erase Large" based on the information sent from the mode determination unit 252. The stroke processing unit 32 deletes the stroke array data included in the range A2 (for example, 8 × 8 dots) centered on the coordinates sent from the mode determination unit 252 from the page data storage unit 300. The display processing unit 29 outputs the image data formed by the updated stroke array data to the display 3. As a result, the screen of the display 3 displays an image in which the handwritten image included in the range A2 is deleted. FIG. 10B is a display example of the display in step S62.

When NO is determined in step S42, the mode determination unit 252 has a size (for example, (6, 4)) sent from the event determination unit 251 together with the event "TouchMove" when the threshold value T2 (for example, 6) or more. It is determined whether or not there is (step S43). In one embodiment, when the width (eg, 6) and the height (eg, 4) in size are different, the mode determination unit 252 has a larger value of size (eg, 6) and a threshold T2 (eg, 6). May be compared.

If YES is determined in step S43, "Erase Large" is set as the operation mode corresponding to the contact portion HT1 (step S52). The set operation mode "Erase Large" is associated with the ID "1" of the contact unit HT1 and is stored in the RAM 203 by the mode determination unit 252. If the timer 255 has not timed out, the mode determination unit 252 stops the timer 255. Further, the mode determination unit 252 adds the operation mode "EraseLarge" to the coordinates, size, event occurrence time, and ID sent from the event determination unit 251 and transmits them to the stroke processing unit 32 (step S62). When the hand H or the like is brought into contact with the touch panel, it is assumed that the contact portion HT1 having a size less than the threshold value T2 is first formed, and then the contact portion HT1 having a size equal to or larger than the threshold value T2 is formed. In such a case, even if "Erase Small" is set as the operation mode corresponding to the contact portion HT1 when the size of the contact portion HT1 is initially less than the threshold value T2, the size of the contact portion HT1 is subsequently set to the threshold value. When T2 is exceeded, the mode determination unit 252 sets the operation mode “Erase Large”.

When the coordinates, size, event occurrence time, and ID information are stored in the RAM 203, the mode determination unit 252 transmits the stored information to the stroke processing unit 32. As a result, when the operation mode is undecided, each information of the contact portion HT1 stored in the RAM 203 is transmitted to the stroke processing unit 32 together with the operation mode “Erase Large”. The mode determination unit 252 deletes the transmitted coordinates, size, event occurrence time, and ID information from the RAM 203. The stroke processing unit 32 and the display processing unit 29 that have received the coordinates and the like to which the operation mode "EraseLarge" is added execute a process of erasing the handwritten image included in the range A2 as a process by the operation mode "EraseLarge".

If NO is determined in step S43, the mode determination unit 252 determines whether the operation mode corresponding to the ID "1" sent from the event determination unit 251 together with the event "TouchMove" is "EraseSmall" (step). S44). When the operation mode corresponding to the contact portion HT1 is set to "EraseSmall" in the process of step S53 described later, the mode determination unit 252 associates the ID "1" of the contact portion HT1 and the operation mode "EraseSmall" with the RAM 203. Remember in. If the operation mode "EraseSmall" has already been set in the previous touch move event in the contact portion HT1, the mode determination unit 252 determines YES in step S44 with reference to the information in the RAM 203.

If YES is determined in step S44, the mode determination unit 252 adds the coordinates, size, event occurrence time, and ID sent from the event determination unit 251 together with the event "TouchMove", and the operation mode "EraseSmall". Then, it is transmitted to the stroke processing unit 32 (step S63).

The stroke processing unit 32 executes the processing of the operation mode "Erase Small" based on the information sent from the mode determination unit 252. The stroke processing unit 32 deletes the stroke array data included in the range A1 (for example, 2 × 2 dots) centered on the coordinates sent from the mode determination unit 252 from the page data storage unit 300. The display processing unit 29 outputs the image data formed by the updated stroke array data to the display 3. As a result, the screen of the display 3 displays an image in which the handwritten image included in the range A1 is deleted. FIG. 10C is a display example of the display in step S63.

When NO is determined in step S44, the mode determination unit 252 has a size (for example, (3, 2)) sent from the event determination unit 251 together with the event "TouchMove" at a threshold value T1 (for example, 3) or more. It is determined whether or not there is (step S45). In one embodiment, when the width (eg, 3) and the height (eg, 2) in size are different, the mode determination unit 252 has a larger value of size (eg, 3) and a threshold T1 (eg, 3). You may compare with.

If YES is determined in step S45, "Erase Small" is set as the operation mode corresponding to the contact portion HT1 (step S53). The set operation mode "Erase Small" is associated with the ID "1" of the contact unit HT1 and is stored in the RAM 203 by the mode determination unit 252. If the timer 255 has not timed out, the mode determination unit 252 stops the timer 255. Further, the mode determination unit 252 adds the operation mode "EraseSmall" to the coordinates, size, event occurrence time, and ID sent from the event determination unit 251 and transmits them to the stroke processing unit 32 (step S63). When the RAM 203 stores the coordinates, the size, the event occurrence time, and the ID information, the mode determination unit 252 transmits the stored information to the stroke processing unit 32. As a result, when the operation mode is undecided, each information of the contact portion HT1 stored in the RAM 203 is transmitted to the stroke processing unit 32 together with the operation mode “Erase Small”. The mode determination unit 252 deletes the transmitted coordinates, size, event occurrence time, and ID information from the RAM 203. The stroke processing unit 32 and the display processing unit 29 that have received the coordinates and the like to which the operation mode "EraseSmall" is added execute the above processing for erasing the handwritten image included in the range A1 as the processing by the operation mode "EraseSmall". ..

If NO is determined in step S45, the operation mode "Draw" is set as the operation mode corresponding to the contact portion HT1 (step S51). The set operation mode "Draw" is associated with the ID "1" of the contact unit HT1 and is stored in the RAM 203 by the mode determination unit 252. If the timer 255 has not timed out, the mode determination unit 252 stops the timer 255. The mode determination unit 252 adds the operation mode "Draw" to the coordinates, size, event occurrence time, and ID sent from the event determination unit 251 and transmits the operation mode "Draw" to the stroke processing unit 32 (step S61). When the RAM 203 stores the coordinates, the size, the event occurrence time, and the ID information, the mode determination unit 252 transmits the stored information to the stroke processing unit 32. As a result, when the operation mode is undecided, each information of the contact portion HT1 stored in the RAM 203 is transmitted to the stroke processing unit 32 together with the operation mode “Draw”. The mode determination unit 252 deletes the transmitted coordinates, size, event occurrence time, and ID information from the RAM 203. The stroke processing unit 32 and the display processing unit 29 that have received the coordinates and the like to which the operation mode "Draw" is added execute a process of displaying a handwritten image as a process by the operation mode "Draw".

<<< Modification A of the embodiment >>>
Subsequently, the modified example A of the embodiment will be described as different from the above-described embodiment. FIG. 11 is a flow chart showing a process of setting the erasing range in the modified example A of the embodiment.

When the electronic blackboard 2 is activated, the mode determination unit 252 acquires model information from the display 3 (step S71). The model information may be model identification information, or may be information indicating the resolution of the screen of the display 3 or the reading method of the contact portion. Hereinafter, the case where the model information is the model identification information “1 or 2” will be described. In one embodiment, the model with the identification information "1" has a higher screen resolution than the model with the identification information "2".

The mode determination unit 252 determines whether the acquired model information is "1" (step S72). In the storage unit 2000, the default threshold value T1 and the threshold value T2 are "3,6", the custom threshold value T1 and the threshold value T2 are "2,4", and the default erasure range A1 and the range A2 are "2 × 2,8". "X8", "1.5 x 1.5, 6 x 6" is stored as the custom erase range A1 and range A2. When it is determined that the model information acquired in step S72 is "1", the mode determination unit 252 determines that the default values are used as the threshold value T1, the threshold value T2, and the erasure range A1 and the range A2. (Step S73). As a result, in step S52, step S94, step S62, and step S104, any one of the default threshold value T1 and the threshold value T2, and the default erasure range A1 and range A2 is used.

When it is determined that the model information acquired in step S72 is "2", the mode determination unit 252 determines that the threshold value T1, the threshold value T2, and the erasure range A1 and the range A2 are custom ones. (Step S73). As a result, in step S52, step S94, step S62, and step S104, any one of the custom threshold value T1, the threshold value T2, and the custom erasure range A1 and range A2 is used.

According to the modification A of the embodiment, the threshold value T1 and the threshold value T2 used for the determination, and the erasing range A1 and the range A2 can be arbitrarily set according to the resolution. Thereby, for example, when the resolution is high, the threshold value T1, the threshold value T2, and the range A1 and the range A2 can be set large to match the detection range and the erasure range of the contact portion with the mounting. In the modified example A of the embodiment, an example is shown in which the threshold value T1 and the threshold value T2 used for the size determination and the erasing range A1 and the range A2 are set according to the resolution. However, for example, the settings of the threshold value T1, the threshold value T2, and the range A1 and the range A2 may be changed according to the accuracy of the reading method of the contact portion.

<<< Modification B of the embodiment >>>
Subsequently, the modified example B of the embodiment will be described as different from the above-described embodiment.
When the coordinates are stored in the RAM 203 in step S22, the display processing unit 29 refers to the coordinates stored in the RAM 203 and causes the display processing unit 29 to display a provisional image at these coordinates.

Subsequently, after the operation mode "Gesture, EraseLarge, EraseSmall" is set in step S45, step S53, and step S63, when the coordinates stored in the RAM 203 are deleted, the display processing unit 29 displays a provisional image. Erase.

Even if the coordinates stored in the RAM 203 are deleted after the operation mode "Draw" is output in step S44, the display processing unit 29 deletes the provisional image of these coordinates. However, in this case, since the stroke processing unit 32 generates the stroke array data including the coordinates, the display processing unit 29 displays the image at the above coordinates based on the stroke array data.

<<< Modification C of the embodiment >>>
Subsequently, the modified example C of the embodiment will be described as different from the above-described embodiment. In the modified example C, the number of contact portions HT that can be simultaneously detected by the coordinate detection unit 22 is limited to, for example, five due to hardware or software restrictions. In the modified example C, the contact unit management table is stored in the storage unit 2000. Table 5 is a conceptual diagram showing a contact portion management table.

The contact portion management table is managed in association with the IDs of the five detectable contact portion HTs, the coordinates of the contact portion HT, and the operation mode corresponding to the contact portion HT. When the event determination unit 251 detects the event "TouchDown", the event determination unit 251 touches down from the IDs "2,3,4,5" recorded in the record whose coordinates are empty in the contact unit management table in Table 5. The ID corresponding to the contact portion HT generated in is selected. The event determination unit 251 records the coordinates of the contact unit HT in association with the selected ID in the contact unit management table.

The mode determination unit 252 records the operation mode determined for the contact unit HT in association with the ID of the contact unit HT in the contact unit management table. Each time the event determination unit 251 detects the event "TouchMove" in the contact unit HT, the event determination unit 251 updates the coordinates associated with the ID of the contact unit HT to the coordinates after the movement in the contact unit management table. When the event determination unit 251 detects the event "TouchUp" in the contact unit HT, the event determination unit 251 deletes the coordinates associated with the ID of the contact unit HT touched up in the contact unit management table and the operation mode.

In the electronic blackboard 2, when the user performs the operation of erasing the image, the user brings the relatively large area of the hand H into contact with the display 3 as compared with the case of writing. In this operation, when a plurality of points of the hand H come into contact with the display, each contact portion is detected by the coordinate detection unit 22 as another contact portion HT. While the number of contact unit HTs that can be simultaneously detected by the coordinate detection unit 22 is 5, when a plurality of contact unit HTs are detected by the hand H of one user, an operation of writing or erasing at the same time by five people. Cannot be executed. Alternatively, for example, the operation mode "EraseSmall" is assigned to one of the plurality of contact portions HT, and the operation mode "Draw" is assigned to the other, so that an operation different from the user's intention can be performed. It may be executed. Therefore, in the modified example C, the mode determination unit 252 determines the operation mode based on the distance between the contact portion HT1 due to the first touchdown and the contact portion HT2 due to the subsequent touchdown.

FIG. 12 is a flow chart showing an example of the mode determination process in the modified example C. The mode determination process in the modified example C will be described with reference to FIG. The process of FIG. 12 starts after the touchdown of the second point is detected in step S4 and the operation mode corresponding to the contact portion HT2 of the second point is determined to be “Input” in step S33. It is assumed that the hand H that has come into contact with the display 3 by the first touchdown has not been touched up at the time of the second touchdown. As a result, as shown in Table 5, the coordinates of the contact portion HT1 by the first touchdown and the operation mode corresponding to the contact portion HT1 are recorded in the contact portion management table.

First, the mode determination unit 252 determines whether the operation mode corresponding to the first contact portion HT1 is "Erase Large" or "Erase Small" (step S81). In this process, the mode determination unit 252 determines whether the operation mode corresponding to the ID of the first contact unit HT1 is "Erase Large" or "Erase Small" by referring to the contact unit management table.

If YES is determined in step S81, the mode determination unit 252 calculates the distance between the contact unit HT1 and the contact unit HT2. In this process, the mode determination unit 252 uses the coordinates recorded in the contact unit management table as the coordinates of the contact unit HT1 at the first point. Further, the mode determination unit 252 uses the coordinates of the second contact portion HT2 sent from the event determination unit 251 together with the event "TouchDown". The mode determination unit 252 may calculate the distance in any unit such as millimeters. In this case, the event determination unit 251 is expressed in an arbitrary unit by dividing the distance calculated from the coordinates of the contact unit HT1 and the contact unit HT2 by the pixel density (for example, dot / mm) of the display 3. Find the distance.

The method for calculating the distance between the contact portion HT1 and the contact portion HT2 may be a predetermined method and is not limited to the above method. When the process of erasing the image of the range A1 or the range A2 including the first contact portion HT1 is executed, the mode determination unit 252 determines the distance between the center of the range A1 or the range A2 and the contact portion HT2. May be calculated as the distance between the contact portion HT1 and the contact portion HT2.

The mode determination unit 252 determines whether the calculated distance between the contact portion HT1 and the contact portion HT2 is equal to or less than a predetermined threshold value D1 (step S82). The threshold value D1 is not particularly limited, but may be, for example, 75 mm, assuming that two places on the palm unintentionally come into contact with the display 3. FIG. 13 is a diagram showing an example of an image erasing operation on the display. When the contact portion HT2 is detected outside the circle D whose radius centered on the contact portion HT1 is the threshold value D1 as shown in (A) of FIG. 13, NO is determined in step S82. When the contact portion HT2 is detected inside the circle D whose radius centered on the contact portion HT1 is the threshold value D1 as shown in FIG. 13B, it is determined as YES in step S82.

If YES is determined in step S82, the mode determination unit 252 ends without executing processing such as writing and erasing corresponding to the second touchdown (step S104). That is, the mode determination unit 252 does not assign any of the operation modes "EraseLarge, EraseSmall, Draw" to the contact unit HT2. As a result, the processing of the operation mode "EraseLarge, EraseSmall, Draw" is not executed for the contact portion HT2 (see (B) in FIG. 13).

If NO is determined in step S81, or NO is determined in step S82, the mode determination unit 252 selects the operation mode corresponding to the second touchdown from "Erase Large, Erase Small, Draw". Performs processing according to the allocation and operation mode (steps S83 to S103). This process is the same as the process of step S43, step S52, and step S62, the process of step S45, step S53, and step S63, or the process of step S51 and step S61 in FIG. However, since the operation mode corresponding to the contact portion HT2 has not been determined in advance when the event "TouchDown" occurs, the processes of steps S41, S42, and S44 in FIG. 9 are not executed.

When the operation mode corresponding to the contact portion HT2 is selected from "Erase Large, Erase Small, Draw" in the processes of steps S83 to S103, the process selected by the mode determination unit 252 is executed ((A) of FIG. 13). reference).

<< Main effects of the embodiment >>
According to the image processing method of the above embodiment, the electronic blackboard 2 (an example of an image processing device) is displayed on the display 3 (an example of a display device) after the contact of the target is detected by the contact sensor 215 (an example of the detection device). Execute the process related to the displayed image. The event determination unit 251 (an example of the acquisition means) of the electronic blackboard 2 acquires information indicating the size of the target contact portion (an example of the acquisition process). The timer 255 (an example of the measuring means) of the electronic blackboard 2 measures the time after the contact of the first target is detected by the contact sensor 215 (an example of the measurement process). The mode determination unit 252 (an example of the changing means) of the electronic blackboard 2 detects the information indicating the size acquired by the event determination unit 251 and the second target by the time when the measurement by the timer 255 elapses. The image is displayed on the contact portion, the image of the contact portion is erased, or the image to be displayed is changed based on the gesture operation by the first target and the second target (an example of the change process). ). As a result, the electronic blackboard 2 can switch between the writing or erasing operation mode "Input" and the operation mode "Gesture" without causing the user to input the operation mode.

The mode determination unit 252 of the electronic blackboard 2 erases the image of the contact portion when the information indicating the size acquired by the event determination unit 251 is equal to or greater than the threshold value T1 (an example of the first threshold value). Thereby, for example, when an object forming a contact portion having a threshold value T1 or more such as a palm is brought into contact with the screen of the display 3, the electronic blackboard 2 can erase the image of the contact portion.

The mode determination unit 252 of the electronic blackboard 2 has a contact portion range A1 (an example of a second threshold value) when the information indicating the size acquired by the event determination unit 251 is equal to or greater than the threshold value T1 and does not reach the threshold value T2 (an example of the second threshold value). When the image included in the first range) is erased and the size information acquired by the event determination unit 251 is equal to or greater than the threshold value T2, the contact area A2 (an example of the second range) is set. Erase the included image. The area of range A2 is larger than the area of range A1. As a result, the erased area of the image can be changed according to the size of the contact portion.

When the event determination unit 251 acquires the information indicating the size indicating the size of the threshold value T1 or more and less than the threshold value T2, and then the information indicating the size indicating the threshold value T2 or more is received, the mode determination unit 252 of the electronic blackboard 2 sets the mode determination unit 252. The image included in the range A1 of the contact portion is erased, and then the image included in the range A2 of the contact portion is erased. As a result, when the size of the contact portion HT1 changes after contact, the electronic blackboard 2 can erase an image in an appropriate range according to the size.

In the mode determination unit 252 of the electronic blackboard 2, the information indicating the size acquired by the event determination unit 251 is smaller than the threshold value T1, and two are measured by the timer 255 until a certain time (an example of a predetermined time) elapses. When the target of the eyes is detected, the image to be displayed is changed based on the gesture operation by the first target and the second target. Further, in the mode determination unit 252 of the electronic blackboard 2, the information indicating the size acquired by the event determination unit 251 is smaller than the threshold value T1, and the second target is not detected until the measurement by the timer 255 elapses for a certain time. In some cases, the image is displayed on the contact portion. As a result, the electronic blackboard 2 can be divided into an operation of performing a plurality of handwritings by a plurality of targets and a gesture operation by a plurality of targets.

The RAM 203 (an example of the storage means) of the electronic blackboard 2 has the coordinates of the contact portion HT1 of the target detected by the contact sensor 215 before the operation mode “Draw, EraseLarge, EraseSmall, Gesture” is determined by the mode determination unit 252. Memorize the information indicating. The electronic blackboard 2 displays an image based on the information indicating the coordinates stored in the RAM 203. As a result, the electronic blackboard 2 can display a provisional image on the contact portion HT1 before the operation mode "Draw, EraseLarge, EraseSmall, Gesture" is set.

In the RAM 203 of the electronic blackboard 2, the mode determination unit 252 (an example of the deletion means) deletes the information indicating the coordinates stored in the RAM 203 after the operation mode “Draw, EraseLarge, EraseSmall, Gesture” is determined. As a result, the electronic blackboard 2 can stop displaying the provisional image.

The mode determination unit 252 of the electronic blackboard 2 acquires the model information of the display 3. The mode determination unit 252 of the electronic blackboard 2 sets a threshold value T1 and a threshold value T2 of the size of the contact portion and an erasure range A1 and a range A2 according to the acquired model information. As a result, the electronic blackboard 2 can set the threshold value and the range according to the model of the display 3.

When the operation mode "Erase Large" or "Erase Small" is being executed in the first contact portion HT1 (an example of the first contact portion) by the mode determination unit 252, the contact sensor 215 contacts the second point. When the contact of the contact portion HT2 is detected, the mode determination unit 252 calculates the distance between the contact portion HT1 and the contact portion HT2. When the calculated distance is larger than the threshold value D1 (third threshold value), the mode determination unit 252 executes any process of the operation mode "EraseLarge, EraseSmall, Draw". When the calculated distance is equal to or less than the threshold value D1, the mode determination unit 252 ends the process. As a result, when the number of contact portion HTs that can be simultaneously detected by the coordinate detection unit 22 is limited, a plurality of contact portion HTs can be detected by touching the display 3 at a plurality of places of the hand H by an erasing operation by one user. By doing so, it is possible to prevent the operation by other users from being restricted.

<< Supplement to the embodiment >>
The program for the electronic blackboard 2 may be recorded and distributed on a computer-readable recording medium by a file in an installable format or an executable format. Further, as another example of the above-mentioned recording medium, a CD-R (Compact Disc Recordable), a DVD (Digital Versatile Disk), a Blu-ray disc, and the like can be mentioned. Further, the above-mentioned recording medium or HD (Hard Disk) in which these programs are stored can be provided as a program product in Japan or abroad.

Further, the electronic blackboard 2 in the above embodiment may be constructed by a single device, or may be constructed by a plurality of devices arbitrarily assigned by dividing each part (function or means).

Each function of the embodiment described above can be realized by one or more processing circuits. Here, the "processing circuit" in the present specification is a processor programmed to execute each function by software such as a processor including an electronic circuit, or an ASIC designed to execute each function described above. It shall include devices such as (Application Specific Integrated Circuit) and conventional circuit modules.

2 Electronic touch panel 3 Display 4 Electronic pen 22 Coordinate detection unit 25 Event distribution unit 27 Gesture processing unit 29 Display processing unit 32 Stroke processing unit 251 Event judgment unit 252 Mode judgment unit 253 Timeout flag 255 Timer 300 page Data storage unit 2000 Storage unit H hand T touch panel HT contact part

JP-A-2010-224635

Claims (11)

An electronic blackboard that has a display and can be drawn by the contact of an object with the display.
When the object is in contact with the display
When the size of the area where the object and the display are in contact is equal to or larger than the first threshold value, there is a changing means for erasing the image in the range based on the contact position of the object from the image displayed on the display. ,
When the contact of the second target is detected while the process of erasing the image of the contact portion of the first target is being executed by the changing means.
When the distance between the contact portion of the first target and the contact portion of the second target is equal to or less than a predetermined threshold value, an image is displayed on the display with respect to the contact portion of the second target. An electronic blackboard that prohibits processing and processing of erasing an image in a range based on the contact position of the contact portion of the second object from the image displayed on the display. This is the case where the second target is contacted while the image of the contact portion of the first target is erased.
When the distance between the contact portion of the first target and the contact portion of the second target is larger than a predetermined threshold value,
A process of displaying an image on the display with respect to the contact portion of the second target, or a process of erasing an image in a range based on the contact position of the contact portion of the second target from the image displayed on the display. The electronic blackboard according to claim 1, to which any of the above is assigned. An acquisition means for acquiring information indicating the size of the contact portion of the target, and
The electronic blackboard according to claim 1 or 2, further comprising a display control means for displaying an image on the display based on the contact position of the target when the size of the contact area is less than the first threshold value. .. The above range is
The electronic blackboard according to claim 3, which is changed according to the size of the contact area. The display control means
When the size of the contacted region becomes the first size equal to or greater than the first threshold value and then becomes the second size equal to or greater than the second threshold value larger than the first threshold value.
The electron according to claim 4, wherein the image included in the first range according to the first size is erased, and then the image included in the second range corresponding to the second size is erased. blackboard. The electronic blackboard according to claim 5, wherein the image is a stroke image drawn on the display by the user. The acquisition means acquires the model information of the display and obtains the model information.
The electronic blackboard according to any one of claims 5 to 6, wherein the changing means sets the first threshold value and the second threshold value according to the model information acquired by the acquisition means. The changing means claims to set the first range according to the first size and the second range according to the second size according to the model information acquired by the acquisition means. Item 7. The electronic blackboard according to item 7. The electronic blackboard according to claim 7 or 8, wherein the model information is information indicating the resolution of the display. On an electronic blackboard that has a display and can be drawn by touching the display with a hand,
When the hand and the display are in contact
When the size of the area where the hand and the display are in contact is equal to or larger than the first threshold value, the computer is subjected to a process of erasing the image in the range based on the contact position of the hand from the image displayed on the display. Let it run
The processing is performed when the contact of the second target is detected while the process of erasing the image of the contact portion of the first target is being executed.
When the distance between the contact portion of the first target and the contact portion of the second target is equal to or less than a predetermined threshold value, an image is displayed on the display with respect to the contact portion of the second target. A program that prohibits processing and processing for erasing an image in a range based on the contact position of the contact portion of the second target from the image displayed on the display. A method using an electronic blackboard that has a display and can be drawn by touching the display with a hand.
When the hand and the display are in contact
When the size of the area where the hand and the display are in contact is equal to or larger than the first threshold value, there is a procedure for erasing the image of the range based on the contact position of the hand from the image displayed on the display.
The above procedure is performed when the contact of the second target is detected while the process of erasing the image of the contact portion of the first target is being executed.
When the distance between the contact portion of the first target and the contact portion of the second target is equal to or less than a predetermined threshold value, an image is displayed on the display with respect to the contact portion of the second target. A method of prohibiting a process and a process of erasing an image in a range based on the contact position of the contact portion of the second target from the image displayed on the display.

Images