JP2012203462A - Computer device and program of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate automatic preparation of a new page in a system for drawing a drawing stroke inside a page with an electronic pen and erasing the drawing stroke with an electronic eraser.SOLUTION: By stroke drawing means, drawing strokes, specified corresponding to movement of an electronic pen to a writing medium on which a dot pattern is printed, are drawn inside a page of a processing object. By new page preparation means, a new page is prepared on condition that the amount of drawing strokes of erasure objects specified corresponding to movement of an electronic eraser to the writing medium is equal to or larger than a first prescribed amount among the drawing strokes drawn inside the page of the processing object.

Description

  The present invention relates to a computer apparatus and a program for automatically creating a new page in a system that draws a drawing stroke in a page with an electronic pen and erases the drawing stroke from the page with an electronic eraser.

  An electronic pen that digitizes written information has been developed. As a representative example, “Anot pen” developed by Swedish company Anoto is known. Anotopen is used with special paper on which a predetermined dot pattern is printed. In addition to the usual ink cartridge for writing characters, etc., the anotopen has a small camera for capturing the dot pattern printed on the dedicated paper and the position coordinates on the dedicated paper from the captured dot pattern. A processor for calculating and a data communication unit for transmitting the calculated position coordinates and the like to an external device are mounted. When the user writes characters on the special paper with an anotopen or puts a check mark on the image designed on the special paper, the small camera captures the dot pattern printed on the special paper as the pen moves. Then, the entry information such as characters and images written by the user is recognized from the continuous position coordinates calculated by the processor. Then, the entry information is transmitted from the Anotopen to a nearby personal computer, a mobile phone or other terminal device by the data communication unit (see, for example, Patent Document 1). Further, a rotation correction processing function for correcting the arrangement of dots on the image due to the angle of the electronic pen 1 facing the dot pattern is described in, for example, Patent Document 2 of the same company.

  Using such a system composed of an electronic pen, a computer, etc., there is a technique for entering a drawing stroke with an electronic pen and erasing the drawing stroke with an electronic eraser on a writing board on which a dot pattern is printed. , Patent Document 3 and Patent Document 4.

  Further, Patent Document 5 discloses a technique in which a terminal such as a personal computer is provided to each student when a class is conducted in a classroom, and the same teaching material is simultaneously distributed to each terminal.

Then, by applying the technology disclosed in Patent Document 4 to the system disclosed in Patent Document 3 or 4, the teacher enters a drawing stroke on the writing board with an electronic pen, and the written content is stored in each student's terminal. A class in the form of distribution is possible.
In such a class, the screen display of each student's terminal corresponds to a conventional paper-medium notebook page.

Japanese Patent No. 3874498 Special table 2003-529853 gazette Special table 2003-508831 gazette US Patent Application Publication No. 2009/309839 JP-A-5-113743

  In this form of lesson, if the teacher wishes to display a new page on the teacher's computer device or student's terminal, a new page is automatically created without explicit instruction from the teacher. This is convenient for both teachers and students.

  The present invention has been made in view of such a situation, and automatically draws a new page in a system in which a drawing stroke is drawn in a page by an electronic pen or the drawing stroke is erased from the page by an electronic eraser. The purpose is to create it automatically.

  A computer apparatus according to the present invention includes a stroke drawing unit that draws a drawing stroke specified according to movement of an electronic pen with respect to a writing medium on which a coded pattern is printed in a processing target page, and the processing target page. A new page is created on the condition that, among the drawing strokes drawn inside, the amount of drawing strokes to be erased specified according to the movement of the electronic eraser relative to the writing medium is equal to or greater than a first predetermined amount. And a new page creation means.

According to this configuration, the drawing stroke specified according to the movement of the electronic pen with respect to the writing medium on which the coded pattern is printed is drawn in the page to be processed by the stroke drawing means. Of the drawing strokes drawn in the page to be processed by the new page creation means, the amount of the drawing stroke to be erased specified according to the movement of the electronic eraser with respect to the writing medium is greater than or equal to a first predetermined amount. A new page is created on the condition that it exists.
As described above, it is possible to easily create a new page automatically in a system in which a drawing stroke is drawn in a page with an electronic pen or the drawing stroke is deleted with an electronic eraser. Further, it is convenient for the user to erase a predetermined amount without erasing all contents written on the writing medium with the electronic pen in order to create a new page.

The computer apparatus further includes stroke amount calculation means for calculating the total amount of the drawing stroke in the page to be processed, and the new page creation means has the total amount calculated by the stroke amount calculation means, The new page is created on the condition that the amount of the drawing stroke to be erased specified according to the movement of the electronic eraser is equal to or greater than the first predetermined amount for the state equal to or greater than the second predetermined amount. Good.
As a result, a new page is created as soon as the stroke is simply erased by the electronic eraser even though the amount of drawing stroke in the page to be processed is still small (less than the second predetermined amount). Can be prevented.

In the computer apparatus, the total amount is less than the second predetermined amount, or the amount of the drawing stroke to be erased is less than the first predetermined amount even if the total amount is equal to or greater than the second predetermined amount. On the condition that the drawing stroke to be erased is erased from the page to be processed, and after the drawing stroke is drawn by the stroke drawing means, or by the stroke erasing means, Overwriting storage means for overwriting and saving the contents of the page to be processed after the drawing stroke to be erased is erased, and the stroke amount calculating means is configured to store the page to be processed by the overwrite storage means. After the contents are overwritten and saved, the total amount may be calculated.
Thereby, the entire amount of the drawing stroke in the page to be processed is updated even after the drawing stroke is erased, so that a new page can be created at a more appropriate timing.

In the computer device, the stroke erasing unit may specify a movement area of an eraser portion of an electronic eraser with respect to the writing medium as an erasure area, and determine a drawing stroke to be erased based on the erasure area.
As described above, by using the erasing area when determining the drawing stroke to be erased, it is possible to determine the drawing stroke to be erased by various methods.
For example, any of the following methods (1) to (4) can be adopted.
(1) Drawing strokes that are entirely included in the erasing area (2) Drawing strokes that are partly included in the erasing area (3) The erasing area includes a predetermined proportion (for example, 50% or more) (4) The portion of the drawing stroke that is included in the erasure area If the method (4) is adopted, the entire drawing stroke included in the erasure area is not erased. Only the portion included in the erase area is erased.

In the computer device, the new page creation means may further include the new page on condition that a time when the amount of the drawing stroke to be erased is equal to or greater than the first predetermined amount is within a predetermined time. It is good to create.
When the amount of the drawing stroke to be erased exceeds the first predetermined amount within such a predetermined time, the user wants to erase all the current drawing strokes (want to draw a new drawing stroke on a new page). It can be estimated that this is desired. Therefore, by creating a new page in such a case, it becomes possible to quickly reflect the operation of the electronic eraser by the user.

In the computer device, the new page creation unit creates a new page on condition that an explicit instruction for creating a new page by a user is detected, and the processing target is included in the explicit instruction by the user. When an instruction to transfer the drawing stroke in the page to the new page is included, the drawing stroke may be displayed on the new page.
Thereby, the user can instruct creation of a new page without depending on the operation of the electronic eraser, and further, as a form of the new page, a form of taking over the drawing stroke in the processing target page, It is possible to arbitrarily select a form that does not take over (a clean form).

Further, the system includes the computer device and a terminal device, and the computer device is configured to transmit data to the terminal device so that a drawing stroke and a new page creation state in a processing target page are synchronized. Good.
Accordingly, the drawing stroke and the new page creation state in the processing target page are synchronized with the computer device that is processed in accordance with the writing of the stroke with the electronic pen on the writing medium and the deletion of the stroke with the electronic eraser. It is reflected in the device and is convenient for the user who uses the terminal device.

  A program according to the present invention is a program executed by a computer apparatus, and processes the drawing stroke specified by the movement of the electronic pen with respect to the writing medium on which the coded pattern is printed. Stroke drawing means for drawing in the target page, and among the drawing strokes drawn in the page to be processed, the amount of the drawing stroke to be erased specified according to the movement of the electronic eraser relative to the writing medium is the first. It is characterized by functioning as a new page creation means for creating a new page on condition that it is 1 predetermined amount or more.

  In the above program, the computer device is further caused to function as stroke amount calculation means for calculating the total amount of the drawing stroke in the processing target page, and the new page creation means is calculated by the stroke amount calculation means. On the condition that the amount of the drawing stroke to be erased specified according to the movement of the electronic eraser is not less than the first predetermined amount with respect to the state where the total amount is not less than the second predetermined amount. Create a new page.

  In the above program, the computer device may be configured such that, even if the total amount is less than the second predetermined amount or the total amount is equal to or greater than the second predetermined amount, the amount of the drawing stroke to be erased is the first amount. 1 On condition that the drawing stroke to be erased is less than a predetermined amount, a stroke erasing unit for erasing the drawing stroke to be erased from the page to be processed, and after the drawing stroke is drawn by the stroke drawing unit, or the stroke After the drawing stroke to be erased has been erased by the erasing means, it further functions as an overwrite saving means for overwriting and saving the contents of the page to be processed, and the stroke amount calculating means is configured to perform the processing by the overwrite saving means. After the content of the target page is overwritten and saved, the total amount may be calculated.

  In the above program, the stroke erasing means may specify a movement area of an eraser portion of an electronic eraser with respect to the writing medium as an erasure area, and determine a drawing stroke to be erased based on the erasure area.

  In the above program, the new page creating means may further create the new page on the condition that a time when the amount of the drawing stroke to be erased is equal to or greater than the first predetermined amount is within a predetermined time. Good.

  In the above program, the new page creation means creates a new page on the condition that an explicit instruction for creating a new page by a user is detected, and includes in the page to be processed in the explicit instruction by the user. When the instruction to transfer the drawing stroke to the new page is included, the drawing stroke may be displayed on the new page.

  The program may cause the computer apparatus to further include data transmission means for transmitting data to an external terminal device so that a drawing stroke in the page to be processed and a new page creation state are synchronized.

  The computer apparatus can be configured by installing and executing these programs on the computer apparatus.

  According to the present invention, a new page can be automatically created in a computer device in a system that draws a drawing stroke in a page with an electronic pen and erases the drawing stroke from the page with an electronic eraser. .

It is a system configuration figure of a display system in this embodiment. It is a figure which shows the cross section of the white board in this embodiment. It is explanatory drawing which shows the relationship between the arrangement | positioning of the dot in a dot pattern, and the value converted. (A) shows a dot pattern typically, and (b) is a figure showing an example of information corresponding to it. It is the schematic which shows the structure of an electronic pen. It is the schematic which shows the structure of an electronic eraser. It is a functional block diagram of a computer apparatus. It is a figure which shows typically the data structure of the definition information of coordinate area | region, and the definition information of the deletion of an electronic eraser. It is a conceptual diagram for demonstrating the erasure | elimination of the drawing stroke by an erasure | elimination area | region. It is a conceptual diagram for demonstrating the erasure | elimination of the drawing stroke by an erasure | elimination area | region. It is a flowchart which shows a stroke display processing flow. It is a figure which shows a mode that a new page is created. It is a figure which shows a mode that a new page is created. It is a flowchart which shows the stroke display processing flow of a modification.

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

[Display system configuration]
FIG. 1 shows a configuration of a display system according to the present embodiment. It is assumed that the display system according to the present embodiment is installed in a classroom where one teacher teaches one or more students. As shown in FIG. 1, a display system 10 according to the present embodiment includes an electronic pen 1, an electronic eraser 2, a white board 3, a computer device 4, and n terminals 5 used by each student. -1 to 5-n.

  The teacher advances the class by writing a drawing stroke with the electronic pen 1 on the whiteboard 3 or erasing the drawing stroke with the electronic eraser 2. The entry information from the electronic pen 1 and the erasure information from the electronic eraser 2 are wirelessly transmitted to the computer apparatus 4 by Bluetooth (registered trademark).

  The computer device 4 is configured by a personal computer or the like. The computer device 4 receives the entry information from the electronic pen 1 and the erasure information from the electronic eraser 2 and displays an image indicating the contents of the drawing strokes written on the whiteboard 3 on the display. Information indicating the contents is Wi-Fi (a certification mark by an industry group indicating that the wireless LAN standard conforms to the IEEE802.11 series. In this embodiment, a wireless LAN device with a Wi-Fi mark. Are also used to indicate a wireless communication system between the terminals 5-1 to 5-n.

  Each of the n terminals 5-1 to 5-n is configured by a smartphone and is provided to each of n students. Hereinafter, when it is not necessary to individually distinguish the terminals 5-1 to 5-n, these are collectively referred to simply as “terminal 5”. The terminal 5 receives and stores information from the computer device, and displays an image indicating the content of the drawing stroke written on the whiteboard 3 on the display based on the received information. Each terminal 5 may be a PDA or other portable terminal.

  Thus, the terminal 5 is used by the student as a substitute for a conventional paper medium notebook. Therefore, “page” corresponding to a notebook page of a paper medium is adopted as a unit of storage and display in the terminal 5. That is, the terminal 5 displays an image or stores information corresponding to the image in units of pages.

  In other words, the computer apparatus 4 performs control so that the terminal 5 can perform processing in units of pages. Specifically, the computer device 4 creates a new page when a predetermined condition is satisfied. Then, the computer device 4 draws a drawing stroke written on the whiteboard 3 on the page based on the information entered from the electronic pen 1 until the predetermined condition is satisfied next time, or the electronic eraser Based on the erasure information from 2, the drawing stroke is erased from the page. However, if the teacher erases a drawing stroke of a predetermined amount or more with the electronic eraser 2, it can be estimated that the teacher wants to create a new page. Therefore, the computer apparatus 4 adopts that the amount of the erased drawing stroke is equal to or larger than a predetermined amount as one of the predetermined conditions described above, and if the predetermined amount is larger than the predetermined amount, the predetermined condition is satisfied. Create new pages automatically.

  Furthermore, in the present embodiment, the fact that the teacher explicitly indicates the creation of a new page is also adopted as one of the predetermined conditions for creating a new page. In order for the teacher to give such an explicit instruction, a new page creation instruction area (no takeover) 31 and a new page creation instruction area (with takeover) 32 are arranged on the whiteboard 3. The new page creation instruction area 31 is an instruction to create a new page without handing over the drawing stroke in the page to the new page, that is, an instruction to create a new blank page with no drawing stroke. When the teacher performs, tap with the electronic pen 1 (tapping the whiteboard 3 with a pen tip portion 103 in FIG. 5 described later) is performed. The new page creation instruction area 32 is an instruction to create a new page by taking over the drawing stroke in the page as it is, that is, an instruction to create a new page in which the drawing stroke in the page is drawn as it is. When the teacher performs, the tap with the electronic pen 1 is made.

  FIG. 2 is a diagram showing a cross section of such a whiteboard 3. As shown in FIG. 2, each dot 51 constituting an Anoto dot pattern (coded pattern) is printed so as to overlap the entire surface of a white whiteboard substrate 52. Here, each dot 51 is printed with an ink containing carbon that absorbs infrared rays so that it can be read by the electronic pen 1. An EB cured resin protective layer 53 is formed of EB (Electron Beam) curable resin on the whiteboard substrate 52 on which the dot pattern of each dot 51 is superimposed and printed. The EB curable resin protective layer 53 protects each dot 51 printed on the whiteboard substrate 52 from friction by the electronic pen 1 or the electronic eraser 2, and prevents deterioration of the whiteboard 3 due to aging.

[Dot pattern]
Next, an Anoto dot pattern (coded pattern) formed on the whiteboard 3 will be described. FIG. 3 is a diagram illustrating the relationship between the dots of the dot pattern printed on the whiteboard 3 and the values to which the dots are converted. As shown in FIG. 3, each dot of the dot pattern is associated with a predetermined value depending on its position. That is, each dot is associated with a value of 0 to 3 depending on which direction the top, bottom, left, and right are shifted from the reference position of the grid (the intersection of the vertical and horizontal lines). The value of each dot can be further converted into a first bit value for the X coordinate and a second bit value for the Y coordinate. The position coordinates on the whiteboard 3 are determined by the combination of the information thus associated.

  FIG. 4A shows an arrangement of a certain dot pattern. As shown in FIG. 4A, 6 × 6 dots are arranged in a range of about 2 mm in length and width so that a unique pattern can be obtained regardless of where 6 × 6 dots are taken from any part on the whiteboard 3. ing. A dot pattern formed by these 36 dots holds position coordinates (for example, where on the whiteboard 3 the dot pattern is located). FIG. 4B is a diagram in which each dot shown in FIG. 4A is converted into a value associated with the regularity shown in FIG. 3 according to the shift direction from the reference position of the lattice. This conversion is performed by the electronic pen 1 that captures an image of a dot pattern.

[Electronic pen]
Next, the electronic pen 1 will be described. As shown in FIG. 5, the electronic pen 1 includes a marker pen 104, an LED 105, a CMOS camera 106, a pressure sensor 107, a processor 108 including a CPU, a memory 109 such as a ROM and a RAM, A communication unit 111 including a real-time clock 110, an antenna, and the like, and a battery 112 are provided. The tip of the marker pen 104 is a pen tip portion 103 that includes ink, and the user (teacher) brings the pen tip portion 103 of the electronic pen 1 into contact with the whiteboard 3 to draw a stroke of characters or the like ( (Handwritten stroke) is entered or tapped (tapping the whiteboard 3 with the pen tip 103). Here, first contact of the pen tip portion 103 of the electronic pen 1 with the whiteboard 3 is referred to as pen-down, and removal of the pen tip portion 103 from the contacted (contacted) state is referred to as pen-up. . A trajectory entered between the pen-down and pen-up of the electronic pen 1 is one drawing stroke, and characters, figures, and the like are made up of one or a plurality of drawing strokes. In addition, when the electronic pen 1 is pen-downed, the locus of substantially the same trajectory as the drawing stroke is displayed on the whiteboard 3 by the ink flowing out from the pen tip portion 103 onto the whiteboard 3.

  The battery 112 is for supplying electric power to each component in the electronic pen 1. For example, the battery 112 is configured to turn on / off the electronic pen 1 itself by attaching and detaching a cap (not shown) of the electronic pen 1. May be. The real time clock 110 transmits time information indicating the current time (time stamp) and supplies the time information to the processor 108. The pressure sensor 107 detects the pressure applied through the marker pen 104 from the pen tip portion 103 when the user writes or taps a character or mark on the whiteboard 3 with the electronic pen 1, that is, the writing pressure. Transmit to the processor 108.

  The processor 108 switches on / off the switches of the LED 105 and the CMOS camera 106 based on the writing pressure data supplied from the pressure sensor 107. That is, when the user writes a character or the like on the whiteboard 3 with the electronic pen 1, the pen pressure is applied to the pen tip portion 103, and when the pressure sensor 107 detects a writing pressure exceeding a predetermined value, the processor 108 Is started, the LED 105 and the CMOS camera 106 are operated. Then, the communication unit 111 associates pen-down information detected by the pressure sensor 107 with a pen ID described later, and transmits the information to the computer apparatus 4 as entry information. When the user finishes entering one drawing stroke and releases the electronic pen 1 from the whiteboard 3, the pressure sensor 107 detects pen-up by detecting that the writing pressure exceeding a predetermined value is not detected. Then, the communication unit 111 associates the pen-up information detected by the pressure sensor 107 with the pen ID, and transmits it to the computer apparatus 4 as entry information.

  The LED 105 and the CMOS camera 106 are attached near the pen tip portion 103 of the electronic pen 1, and an opening 102 is formed in a portion of the housing 101 that faces the LED 105 and the CMOS camera 106. The LED 105 illuminates infrared rays toward the vicinity of the pen tip portion 103 on the whiteboard 3. The area is slightly deviated from the position where the pen tip 103 contacts the whiteboard 3. The CMOS camera 106 is provided with an infrared filter that transmits infrared rays and blocks non-infrared rays. The CMOS camera 106 captures a dot pattern in an area illuminated by the LED 105 and processes image data of the dot pattern as a processor. 108. Here, since the ink material of dots reflects infrared rays, the infrared rays irradiated by the LED 105 are reflected by the dots. Therefore, the dot portion has a relatively large amount of infrared reflection, and the portion other than the dot has a relatively small amount of infrared reflection. By photographing with the CMOS camera 106, a dot area and other areas can be distinguished by providing a threshold value based on the difference in the amount of reflected infrared light. Note that the shooting area by the CMOS camera 106 is a range including a size of about 2 mm × about 2 mm as shown in FIG. 4A, and the shooting by the CMOS camera 106 is performed at regular intervals of about 50 to 100 times per second. Is called. Further, the CMOS camera 106 has a sufficient depth of field in order to photograph dots clearly.

  The processor 108 performs X and Y coordinates (simply “position coordinates” on the whiteboard 3 of the drawing stroke (handwriting) to be entered by the user from the dot pattern of the image data supplied by the CMOS camera 106 during the user entry. ", Also referred to as" coordinate information "). That is, the processor 108 converts the image data of the dot pattern as shown in FIG. 4A supplied by the CMOS camera 106 into the data array shown in FIG. The data is converted into a Y coordinate bit value, and X, Y coordinate data is calculated from the data array by a predetermined calculation method. The processor 108 has a rotation correction processing function for correcting the arrangement of dots on the image due to the angle of the electronic pen 1 facing the dot pattern. Then, the processor 108 associates the current time (time stamp: entered time information) transmitted from the real-time clock 110, the pen pressure data, and the X and Y coordinate data. Hereinafter, these associated data are collectively referred to as “coordinate attribute information”. Since the 6 × 6 dot pattern on the whiteboard 3 does not overlap in the whiteboard 3, when the user enters characters or the like with the electronic pen 1, the written position corresponds to any position on the whiteboard 3. This can be specified by coordinate calculation by the processor 108.

  The memory 109 stores property information such as a pen ID such as “pen01” for identifying the electronic pen 1, a pen manufacturer number, and a pen software version. Then, the communication unit 111 associates the pen ID with the coordinate attribute information (time information, writing pressure data, and X and Y coordinate data), and transmits the information to the computer device 4 as entry information. Transmission to the computer apparatus 4 by the communication unit 111 is performed immediately and sequentially by wireless transmission such as Bluetooth (registered trademark). Here, one or a plurality of entry information (coordinate attribute information) generated between the pen-down and pen-up of the electronic pen 1 and transmitted to the computer device 4 is stored as drawing stroke information by the computer device 4. The In other words, one drawing stroke is composed of one or a plurality of X, Y coordinates (coordinate points), and the computer apparatus 4 is configured by one or more composing one drawing stroke by pen down information and pen up information. Recognize pieces of coordinate attribute information. As described above, a set of coordinate attribute information generated by the electronic pen 1 when the user enters one drawing stroke is referred to as “drawing stroke information”. The pen tip 103 transmits the writing pressure to the pressure sensor 107 via the marker pen 104.

[Electronic Eraser]
Next, the electronic eraser 2 will be described. As shown in FIG. 6, the electronic eraser 2 detects the pressure applied to the case 201, the holder 213 formed to be removable from the case 201, the eraser unit 214 fixed to the holder 213, and the eraser unit 214. The pressure sensor 207 is provided. The electronic eraser 2 includes a communication unit 211 including an LED 205, a CMOS camera 206, a processor 208 including a CPU, a memory 209 such as a ROM and a RAM, a real-time clock 210, an antenna, and the like. And a battery 212.

  The eraser unit 214 of the electronic eraser 2 has the same configuration as the whiteboard eraser, and the user (teacher) draws the drawing stroke written by the electronic pen 1 by bringing the eraser unit 214 into contact with the whiteboard 3. (Handwriting stroke) More precisely, the ink is erased by wiping ink corresponding to the drawing stroke. Here, the first contact of the eraser unit 214 of the electronic eraser 2 with the whiteboard 3 is referred to as eraser down, and the removal of the eraser unit 214 from the contacted (contacted) state is referred to as eraser up. A continuous area erased by the eraser unit 214 between the eraser down and the eraser up of the electronic eraser 2 is called an erase area.

  The battery 212 is for supplying electric power to each component in the electronic eraser 2. For example, the power of the electronic eraser 2 itself is turned on / off by attaching / detaching a cap (not shown) of the electronic eraser 2. May be. The real time clock 210 transmits time information indicating the current time (time stamp) and supplies the time information to the processor 208. The pressure sensor 207 detects the pressure at the time of erasure given from the eraser unit 214 when the user erases characters and marks written on the whiteboard 3 by the electronic eraser 2, and transmits the value to the processor 208.

  The processor 208 switches on / off the LEDs 205 and the CMOS camera 206 based on the pressure data supplied from the pressure sensor 207. That is, when the user erases characters or the like on the whiteboard 3 with the electronic eraser 2, pressure is applied to the eraser unit 214, and when the pressure sensor 207 detects a pressure higher than a predetermined value, the processor 208 erases the character. The LED 205 and the CMOS camera 206 are activated. Then, the communication unit 211 associates eraser down information detected by the pressure sensor 207 with an eraser ID, which will be described later, and transmits it to the computer apparatus 4 as erasure information. Further, when the user finishes erasing one drawing stroke and releases the electronic eraser 2 from the whiteboard 3, the pressure sensor 207 detects an eraser up because a pressure equal to or greater than a predetermined value is not detected. Then, the communication unit 211 associates the eraser up information detected by the pressure sensor 207 with the eraser ID, and transmits it to the computer apparatus 4 as erasure information.

  The LED 205 and the CMOS camera 206 are attached near the front end of the housing 201 of the electronic eraser 2, and an opening 202 is formed in a portion of the housing 201 that faces the LED 205 and the CMOS camera 206. If the center point of the area captured by the CMOS camera 206 is the reference point A when the electronic eraser 2 is brought into contact with the whiteboard 2 vertically, the LED 205 illuminates infrared rays toward the reference point A on the whiteboard 3. To do. Here, only part B of the eraser unit 214 contacts the whiteboard 3 and erases the drawing stroke. In this manner, the portion B of the eraser unit 214 that actually erases the drawing stroke is hereinafter referred to as an erased portion B. That is, the erased portion B of the eraser portion 214 is a portion within a range from the position B11 inside the predetermined distance from the reference point A of the eraser portion 214 to the position B12 inside the predetermined distance of the other end portion. Further, the position B11 that is the boundary between the erased portion B and the other portion is separated from the reference point A. Hereinafter, the separation distance between the position B11 and the reference point A is referred to as a separation distance C. Note that the length of the erased portion B and the separation distance C are stored in the computer device 4 as electronic eraser information in association with the eraser ID. The CMOS camera 206 is provided with an infrared filter that transmits infrared rays and blocks non-infrared rays. The CMOS camera 206 captures a dot pattern in an area illuminated by the LED 205, and the image data of the dot pattern is processed by a processor. 208 is supplied. Here, since the ink material of dots reflects infrared rays, the infrared rays irradiated by the LED 205 are reflected by the dots. Therefore, the dot portion has a relatively large amount of infrared reflection, and the portion other than the dot has a relatively small amount of infrared reflection. By photographing with the CMOS camera 206, a threshold value is provided based on the difference in the amount of reflected infrared light, whereby the dot region and the other region can be distinguished. Note that the shooting area by the CMOS camera 206 is a range including a size of about 2 mm × about 2 mm as shown in FIG. 4A, and the shooting by the CMOS camera 206 is performed at regular intervals of about 50 to 100 times per second. Is called. The CMOS camera 206 has a sufficient depth of field in order to capture dots clearly.

  While the drawing stroke is erased by the user, the processor 208 determines the reference point A necessary for specifying the drawing stroke (erasing area) to be erased by the user from the dot pattern of the image data supplied by the CMOS camera 206. The X and Y coordinates on the whiteboard 3 are continuously calculated. That is, similarly to the processor 108 of the electronic pen 1, the processor 208 converts the dot pattern image data as shown in FIG. 4A supplied by the CMOS camera 206 into the data array shown in FIG. Then, the data is further converted into an X coordinate bit value and a Y coordinate bit value, and X and Y coordinate data are calculated from the data array by a predetermined calculation method. The processor 108 has a rotation correction processing function for correcting the arrangement of dots on the image due to the angle of the electronic pen 1 facing the dot pattern. Further, in order to specify the erase area, an angle of the electronic eraser 2 with respect to the whiteboard 3 (hereinafter referred to as “erase angle”) is required. Therefore, every time the processor 208 calculates the X and Y coordinate data, the processor 208 also calculates the erasure angle. Then, the processor 208 associates the current time (time stamp), pressure data, X, Y coordinate data, and erase angle transmitted from the real-time clock 210 as “deletion coordinate attribute information”. Since the 6 × 6 dot pattern on the whiteboard 3 does not overlap in the whiteboard 3, when the user erases characters or the like with the electronic eraser 2, which position on the whiteboard 3 the reference point A corresponds to Can be specified by coordinate calculation by the processor 208.

  The memory 209 stores property information such as an eraser ID “E1” for identifying the electronic eraser 2, an eraser manufacturer number, and an eraser software version. The communication unit 211 associates the eraser ID with the erasure coordinate attribute information (time information, pressure data, X and Y coordinate data, and erasure angle), and transmits the erasure information to the computer apparatus 4 as erasure information. Transmission to the computer apparatus 4 by the communication unit 211 is immediately and sequentially performed by wireless transmission such as Bluetooth (registered trademark). Here, one or more pieces of erasure information (erase coordinate attribute information) generated between the eraser down and the eraser up of the electronic eraser 2 and transmitted to the computer apparatus 4 are erase stroke information by the computer apparatus 4. Is remembered as In other words, one erasing stroke is composed of one or a plurality of X and Y coordinates (coordinate points), and the computer device 4 can identify one erasing stroke based on the eraser down information and the eraser up information. Alternatively, a plurality of erased coordinate attribute information is recognized. In this way, a set of erasing coordinate attribute information generated by the electronic eraser 2 in accordance with a single erasing operation by the user is referred to as “erasing stroke information”. The erase area is obtained by the computer device 4 from the erase stroke information, the erase angle corresponding to each coordinate point constituting the erase stroke, the length of the erase portion B of the electronic eraser 2, and the separation distance C. Further, the eraser unit 214 transmits the pressure at the time of erasure to the pressure sensor 207.

[Computer device]
Next, the computer apparatus 4 will be described. The computer device 4 includes, as hardware, an antenna device capable of data communication with the electronic pen 1 and the electronic eraser 2, a processor such as a CPU, a memory such as ROM and RAM, a personal computer including a display, a mouse, a keyboard, and the like. Is done. FIG. 7 is a functional block diagram of the computer apparatus 4. Functionally, the computer apparatus 4 includes an input unit 41, a reception unit 42, a storage unit 43, a processing unit 44, a display unit 45, and a transmission unit 46. Then, the computer device 4 performs a predetermined process based on the entry information received from the electronic pen 1 or the erasure information received from the electronic eraser 2.

  The input unit 41 is configured by a mouse, a keyboard, and the like, and inputs various information according to user operations and supplies the information to the processing unit 44. The receiving means 42 is constituted by an antenna receiving circuit or the like, and transmits the entry information from the electronic pen 1 or the erasure information from the electronic eraser 2 to the processing means 44. The transmission means 46 transmits the created new page data or overwritten and saved page data to each terminal 5. Note that the data transmission method to the terminal 5 may be wired or wireless, but in this embodiment, a wireless communication method using Wi-Fi is adopted. The display means 45 is constituted by a display or the like, and displays the contents instructed by the processing means 44 as an image.

  The storage means 43 is configured by a memory such as a hard disk, ROM, or RAM. The storage unit 43 stores the entry information received from the electronic pen 1 for each pen ID according to the processing instruction of the processing unit 44. In addition, the storage unit 43 stores the erasure information received from the electronic eraser 2 for each eraser ID in accordance with the processing instruction of the processing unit 44.

  Further, as shown in FIG. 8A, the storage unit 43 stores the data of the upper left corner coordinates (X1, Y1), the height H1, and the width W1 as the definition information of the coordinate area of the whiteboard 3. . The storage unit 43 stores each data of the upper left corner coordinates (X2, Y2), the height H2, and the width W2 as the definition information of the coordinate area of the new page creation instruction area (no takeover) 31. The storage means 43 stores the upper left corner coordinates (X3, Y3), height H3, and width W3 as definition information of the coordinate area of the new page creation instruction area (with takeover) 32.

  Further, as shown in FIG. 8B, the storage means 43 stores the association data of the length of the erased portion B for each eraser ID (E1 and E2) and the separation distance C between the position B11 and the reference point A. Are stored as electronic eraser information for calculating the erased area. Note that specific uses of the information illustrated in FIGS. 8A and 8B will be described later.

  9 and 10 are conceptual diagrams for explaining the erase of the drawing stroke by the electronic eraser 2. As shown in FIG. 9, when erasing the drawing stroke (ink indicating it) written on the whiteboard 3, the user (teacher) moves the electronic eraser 2 at an arbitrary position on the surface of the whiteboard 3. While the eraser is down and the eraser down state is maintained, the eraser unit 214 is moved to an arbitrary position along the surface of the whiteboard 3, and the eraser is raised at the arbitrary position. In this case, the locus of the erased portion B of the electronic eraser 2 becomes an erased area on the surface of the whiteboard 3.

Here, in this embodiment, as shown in FIG. 10, after the user erases down the electronic eraser 2, the user moves to an arbitrary position along the surface of the whiteboard 3 (in FIG. 10, near the upper end or the lower end of the whiteboard 3. ), And after the eraser up, the operation is recognized as a series by the computer device 4 when the eraser is downed and moved again within a predetermined time.
That is, when the computer device 4 detects the eraser up and then continuously detects the eraser down within a predetermined time, the computer device 4 recognizes it as a series of erase operations. Then, when determining the erase stroke amount, which will be described later, the computer device 4 performs the determination on the entire locus (erased region) of the erased portion B of the series of electronic erasers 2.

  Returning to FIG. 7, the processing means 44 will be described. The processing unit 44 mainly includes a stroke drawing unit 441, a new page creation unit 442, a stroke amount calculation unit 443, an erase stroke amount determination unit 444, a stroke deletion unit 445, an overwrite storage unit 446, and a data transmission unit 447. The The processing unit 44 executes various processes necessary for displaying the page on which the drawing stroke is drawn on each terminal 5 in accordance with the input by the user's electronic pen 1 or electronic eraser 2.

The stroke drawing unit 441 is configured to display a drawing stroke written on the whiteboard 3 with the electronic pen 1 based on the entry information transmitted from the electronic pen 1 and received by the receiving unit 42 in a corresponding position in the page to be processed. To draw.
Here, the processing target page refers to a page to be displayed on the computer device 4 and each terminal 5.
Further, at the stage where the drawing stroke is drawn on the page by the stroke drawing means 441, the drawing is not fixed and is not reflected in the display contents of the computer device 4 or each terminal 5. That is, at this stage, the drawn drawing stroke is not yet displayed on the computer device 4 or each terminal 5. The confirmation of drawing will be described later as part of the description of the overwrite storage unit 446.

The new page creation unit 442 creates a new page when a predetermined condition is satisfied. When a new page is created, the new page becomes a page to be processed thereafter, and the display contents of the computer device 4 and each terminal 5 are updated from the previously displayed page to the new page. Is done.
In the present embodiment, as one of the predetermined conditions for creating a new page, in a state where a drawing stroke of a predetermined amount or more exists on the page to be processed, out of the drawing strokes in the page, The condition that the amount of the drawing stroke is equal to or larger than a predetermined amount (the ratio of the erasure target with respect to the entire drawing stroke is equal to or larger than the predetermined proportion) is adopted. Note that whether or not the amount of drawing strokes to be erased is equal to or greater than a predetermined amount is determined by an erasure stroke amount determination means 444 described later. Further, by imposing the requirement that a drawing stroke of a predetermined amount or more exists on the page to be processed, a special effect (described in the process of step S111 in FIG. 11 described later) can be achieved. May be omitted as necessary, for example, when is unnecessary.
As another predetermined condition, a condition that a new page creation instruction area (no takeover) 31 and a new page creation instruction area (with takeover) 32 are tapped with the electronic pen 1 is also employed.

The stroke amount calculation means 443 calculates the amount (total amount) of drawing strokes in the processing target page.
Specifically, when the drawing stroke newly entered by the electronic pen 1 is recognized to be drawn in the page to be processed, the stroke amount calculation unit 443 adds the recognized drawing stroke amount to process the drawing stroke. Calculate (update) the total amount of drawing strokes in the target page. More specifically, the total length of drawing strokes existing in the processing target page, that is, the total stroke length is adopted as the amount of drawing strokes (total amount). Therefore, the stroke amount calculation unit 443 calculates the length of the recognized drawing stroke, and updates the total stroke length by adding it to the total stroke length so far.
On the other hand, when erasure is confirmed for the erasure target drawing stroke specified from the erasure area formed by the electronic eraser 2 in the processing target page, the stroke amount calculation unit 443 determines the amount of the drawing stroke for which erasure is confirmed. By subtracting, the total amount of drawing strokes in the processing target page is calculated (updated). More specifically, the stroke amount calculation unit 443 calculates the length of the drawing stroke for which erasure is confirmed, and updates the total stroke length by subtracting it from the total stroke length before erasure.
Note that it is not essential to employ the total stroke length as the amount of drawing strokes (total amount). For example, the total number of strokes in the page, that is, the total number of strokes may be employed.
Further, the recognition of the stroke and the confirmation of the erasure will be described later as part of the description of the overwrite storage unit 446.

  The erase stroke amount determination means 444 determines whether or not the amount of the drawing stroke to be erased is equal to or greater than a predetermined amount. If it is determined that the amount is equal to or greater than the predetermined amount, one of the predetermined conditions for creating a new page described above is satisfied, and therefore a new page is created by the new page creation unit 442. .

The stroke erasing means 445 uses the erasing information transmitted from the electronic pen 1 and received by the receiving means 42 to erase areas (see FIGS. 9 and 10) formed on the whiteboard 3 by the movement of the electronic eraser 2. Identify. Then, the stroke erasing unit 445 specifies the drawing stroke to be erased based on the erasing area and erases it from the page to be processed.
Here, when the stroke to be drawn is erased from the page by the stroke erasing means 445, the erasure is not confirmed and is not reflected in the display contents of the computer device 4 or each terminal 5. That is, at this stage, the drawing stroke to be erased is still displayed on the computer device 4 and each terminal 5. The confirmation of erasure will be described later as part of the description of the overwrite storage unit 446.

The overwrite storage unit 446 updates the contents after drawing or erasure when a new drawing stroke is drawn by the stroke drawing unit 441 or the drawing stroke is deleted by the stroke erasing unit 445 on the processing target page. The page data to be processed is overwritten and saved in a memory or the like. Hereinafter, the process of the overwrite storage unit 446 is expressed as being overwritten on a page. When the page is overwritten and saved, drawing or erasure is confirmed, and the content after the confirmation is reflected in the display content of the computer device 4 or each terminal 5. That is, at this stage, a newly drawn drawing stroke is displayed on the computer device 4 or each terminal 5, or an erased drawing stroke disappears from the display on the computer device 4 or each terminal 5. More specifically, the display content of the display unit 45 is updated based on the data of the page to be processed after confirmation, and the data is transmitted from the transmission unit 46 to each terminal 5. Each terminal 5 updates the display content based on the data.
The data transmission unit 447 transmits data of predetermined processing to each terminal 5 by the transmission unit 46 so that the state of each page in each terminal 5 is synchronized with the computer apparatus 4.

[Stroke display processing flow]
Next, a stroke display processing flow by the display system 10 using the electronic pen 1 and the electronic eraser 2 will be described with reference to FIG.

  First, the computer apparatus 4 receives the entry information transmitted from the electronic pen 1 and the erasure information transmitted from the electronic eraser 2 and stores them in the storage means 43 (S101).

  Next, the processing means 44 determines whether the received information is entry information or erasure information, depending on whether the received information includes a pen ID or an eraser ID (step S102). . When the processing unit 44 determines that the received information is entry information (step S102: entry information), the processing unit 44 determines whether the entry information is in the new page creation instruction area 31 or 32 (step S102). S103). Specifically, the processing unit 44 refers to the definition information of the coordinate areas of the whiteboard 3 and the new page creation instruction areas 31 and 32 shown in FIG. The coordinates obtained from the coordinate information of the received entry information (hereinafter referred to as “electronic pen coordinates”) are included in the coordinate area of the new page creation instruction area 31 or 32, or new page creation instruction areas 31 and 32. By determining whether it is included in the coordinate area in the other whiteboard 3, it is determined whether the entry information is in the new page creation instruction area 31 or 32 or in the whiteboard 3 other than that area To do.

When the processing means 44 determines that the entry information is in the area of the whiteboard 3 other than the new page creation instruction areas 31 and 32 (step S103: No), the stroke drawing means 441 of the processing means 44 determines from the entry information. A stroke drawing process of drawing the specified drawing stroke on the page to be processed is performed (step S104).
The overwriting storage unit 446 of the processing unit 44 overwrites and saves the drawing stroke in the storage unit 43 on the page (step S105).
Next, the stroke amount calculation unit 443 of the processing unit 44 obtains the stroke amount (overall amount) in the page, overwritten and saved in the process of step S105, here, the total stroke length (step S106).
In this way, the amount of the drawing stroke in the processing target page is updated by executing the processing of step S106. Then, in the processing of the computer apparatus 4 after the next time, a new page is created using such a drawing stroke amount as one of the predetermined conditions. Therefore, a new page can be created at a more appropriate timing.
Next, the data transmission unit 447 transmits the data of the page overwritten and saved in the process of step S105 to each terminal 5 (step S107). Thereby, the display content of each terminal 5 of the student is updated to the content of the overwritten and saved page. And the computer apparatus 4 complete | finishes a process.

  On the other hand, when the user (teacher) taps the electronic pen 1 in the new page creation instruction area 31 or 32, the processing unit 44 refers to the coordinate area definition information shown in FIG. It is determined that the electronic pen coordinates are included in the coordinate area of the new page creation instruction area 31 or 32 (step S103: Yes). In this case, the new page creation unit 442 creates a new page different from the current page as the page to be processed (step S108).

Next, if the electronic pen coordinates of the entry information are in the new page creation instruction area 32 that takes over the drawing stroke and creates a new page in step 103, the new page creation means 442 takes over the drawing stroke. Judgment is made (step S109: Yes), and these drawing strokes are transferred to a new page and overwritten and saved (step S110). That is, the data of the page at that time is duplicated and saved as a new page.
On the other hand, in step 103, the new page creation means 442, when the electronic pen coordinates of the entry information are in the new page creation instruction area 31 for creating a new page without taking over the drawing stroke, It is determined that the drawing stroke at the time is not transferred to the new page (step S109: NO), and a new page on which no drawing stroke is drawn becomes a new page.
In this way, when the process of step S109: NO or S110 ends, the data transmission unit 447 transmits data of a new page to each terminal 5 (step S107). Thereby, the display content of each terminal 5 of the student is updated to the content of the new page. And the computer apparatus 4 complete | finishes a process.

  Here, a new page created by the new page creation unit 442 will be described with reference to FIG. 1, FIG. 12, and FIG. When the new page creation instruction area (no takeover) 31 is tapped with the electronic pen 1 (step S109 in FIG. 11: NO), the computer apparatus 4 displays the processing target page in FIG. 12A. A new page (P-2) shown in FIG. 12B, which is different from the current page (P-1) shown, is created. The new page (P-2) is a new page without any drawing stroke information drawn on the current page (P-1) being taken over. In the process of step S107 in FIG. 11, the data of this completely new page (P-2) is transmitted to each terminal 5. Then, each student's terminal 5 displays a new page (P-2) shown in FIG. 12B based on the transmitted data.

On the other hand, when the new page creation instruction area (with takeover) 32 is tapped with the electronic pen 1 (in the case of YES in step S109 in FIG. 11), the computer apparatus 4 performs the processing target page in the process of step S110. Then, the contents of the current page (P-1) shown in FIG. 13A are duplicated to create a new page (P-2) shown in FIG. 13B. Since this new page (P-2) has inherited all the drawing stroke information drawn on the current page (P-1), it has the same contents as the drawing contents of the current page (P-1). It is the page of. In the process of step S107 of FIG. 11, the data of this new page (P-2) is transmitted to each terminal 5. Then, each student's terminal 5 displays a new page (P-2) shown in FIG. 13B based on the transmitted data.
The symbols (P-1) and (P-2) at the upper right of each page do not need to be displayed on each terminal 5 in particular. However, if the symbol is not displayed, the display content of each terminal 5 does not change even when the page is transferred when the drawing content is taken over. Therefore, each student who operates each terminal 5 has a new page. There is a risk that you may notice that you have moved to the page. Therefore, by displaying the symbols (P-1) and (P-2) at the upper right of each page on each terminal 5 and explicitly showing each student the current page to be processed, You can easily notice that the page has moved to a new page.

Next, returning to FIG. 11, the processing of the computer device 4 when the user (teacher) erases the drawing stroke written on the whiteboard 3 by the electronic eraser 2 will be described.
In this case, the electronic eraser 2 sequentially transmits erasure information to the computer device 4.
Specifically, when the eraser is down, the electronic eraser 2 generates erasure information that associates the eraser down information and the eraser ID, and transmits the erasure information to the computer apparatus 4. In addition, during the erase of the drawing stroke, the electronic eraser 2 coordinates information (X and Y coordinates of the reference point A in FIG. 6) calculated from the dot pattern photographed along the erase stroke, and the erase angle (with respect to the whiteboard 3). Erasure information in which coordinate attribute information including the angle), time information, and eraser ID are associated with each other is continuously generated repeatedly and sequentially transmitted to the computer apparatus 4. When the eraser is up, the electronic eraser 2 generates erasure information in which the eraser up information and the eraser ID are associated with each other and transmits them to the computer apparatus 4.
The processing unit 44 stores the erasure information sequentially transmitted in this manner in the storage unit 43. When the processing unit 44 recognizes that the erasure information including the new eraser down information is received within a predetermined time from the reception of the eraser up information, the processing unit 44 determines that a series of erasing operations by the user continues, Continue to receive and store erase information. On the other hand, if the erasure information is not received even after a predetermined time has elapsed since the reception of the eraser up information, the processing means 44 determines that the series of erasing operations has been completed, and proceeds to the processing of step S102.

When the processing unit 44 determines that the information is erasure information in step S102, the stroke amount calculation unit 443 of the processing unit 44 determines whether or not the amount of the drawing stroke in the processing target page is equal to or larger than a predetermined amount. (Step S111).
Specifically, the stroke amount calculating means 443 determines whether or not the drawing stroke amount obtained in the processing of step S106 or S116 in the previous processing of the computer apparatus 4 is greater than or equal to a predetermined amount.
Here, the predetermined amount of the drawing stroke is such that a new page is created even if the user erases the stroke at the initial stage when the user (teacher) starts writing the handwritten drawing stroke with the electronic pen 1 for the new page. Any amount that can be estimated to be unnecessary is sufficient. Here, since the stroke length is adopted as the stroke amount, for example, about 20 cm can be adopted as the predetermined amount. In addition, when the number of strokes is employ | adopted as an amount of strokes, about 20 stroke numbers can be employ | adopted as a predetermined amount, for example.
That is, when a new page is automatically created only when the user erases the electronic eraser 2, the user (teacher) enters a handwritten drawing stroke with the electronic pen 1 for the new page. In the initial stage, a new page is created even if the user simply uses the electronic eraser 2 to correct the stroke. That is, although the user does not want to create a new page at all, a new page is unnecessarily created. In this way, it is possible to prevent a new page from being created unnecessarily simply because the electronic eraser 2 is used even though the amount of the drawing stroke in the page to be processed is still small. In order to do so, the determination process of step S111 is provided.

That is, when the stroke amount calculation unit 443 determines that the amount of the drawing stroke in the page to be processed is less than the predetermined amount, at the initial stage when the user starts to enter the handwritten drawing stroke with the electronic pen 1 for the new page. Assuming that there is a possibility that the user will make corrections, it is determined NO in step S111 so that a new page is not created.
In this case, the stroke erasing unit 445 of the processing unit 44 specifies an erasing area (see FIGS. 9 and 10) specified from the erasing information acquired as a series of operations, and the drawing stroke to be erased from the erasing area. Then, the erasure area stroke erasure process is performed such that the erasure target drawing stroke is erased from the process target page (step S114).
Here, the method for determining the drawing stroke to be erased may be a method based on the erase region, and for example, any of the following types of methods (1) to (4) may be employed.
(1) Drawing strokes that are entirely included in the erasing area (2) Drawing strokes that are partly included in the erasing area (3) The erasing area includes a predetermined proportion (for example, 50% or more) (4) The portion of the drawing stroke that is included in the erasure area If the method (4) is adopted, the entire drawing stroke to be erased is not erased, but the erasure area Only the part contained in is deleted.
The overwrite storage unit 446 of the processing unit 44 overwrites and saves the contents after the erased drawing stroke is erased (step S115). That is, erasure of the drawing stroke to be erased by the stroke erasing process of the erasing area in step S114 is confirmed, and the data of the page to be processed is overwritten and saved in the storage means 43 with the content after the confirmation. Then, the determined content is displayed on the display means 45. That is, the drawing stroke to be erased disappears from the display content of the display means 45.
Next, the stroke amount calculation unit 443 of the processing unit 44 obtains the stroke amount (overall amount) in the page overwritten and saved in the process of step S115, here, the total stroke length (step S116).
In this way, the amount of the drawing stroke in the processing target page is updated in real time and accurately by executing the processing of step S116. Then, in the processing of the computer device 4 after the next time, a new page is created using such a drawing stroke amount (see steps S111, 112, and 113 described later). Therefore, a new page can be created at a more appropriate timing.
Next, the data transmission means 447 transmits the data of the page overwritten and saved in the process of step S116 to each terminal 5 (step S107). Thereby, the display content of each terminal 5 of the student is updated to the content of the overwritten and saved page. That is, the drawing stroke to be erased disappears from the display of each terminal 5. When this process ends, the computer apparatus 4 ends the process.

On the other hand, when the amount of the drawing stroke in the processing target page is equal to or larger than the predetermined amount, the stroke amount calculation unit 443 determines YES in step S111, and the following series of processing is executed. .
That is, the erasure stroke amount determination unit 444 determines whether or not a predetermined ratio or more of the entire drawing strokes currently drawn on the processing target page is included in the erasure area (step S112).
In other words, the erase stroke amount determination unit 444 determines whether or not the amount of drawing strokes to be erased is equal to or greater than a predetermined ratio with respect to the total amount of drawing strokes.
Here, in this embodiment, since the total stroke length is adopted as the entire amount of the drawing stroke, it is determined whether or not the stroke length of the drawing stroke to be erased is equal to or greater than a predetermined ratio with respect to the total stroke length. . The predetermined ratio is set to a ratio that is estimated to erase almost all the written contents in order to fill in new contents after the explanation of the contents entered by the user (teacher) is completed. % Can be adopted.
When the total number of strokes is adopted as the total amount of drawing strokes, it is determined whether or not the stroke amount of the drawing strokes to be erased is equal to or greater than a predetermined ratio with respect to the total stroke amount. The predetermined ratio in this case is not particularly limited, and for example, about 70% can be adopted.

  When the erasure stroke amount determination means 444 determines that the drawing stroke included in the erasure area, that is, the amount of drawing strokes to be erased, is less than a predetermined ratio with respect to the whole (step S112: NO), the process proceeds to step S114. Then, the subsequent processing is executed. That is, in this case, it is presumed that the user (teacher) does not want to write on a new page but wants to partially correct the drawing stroke on the whiteboard 3, and only the drawing stroke to be erased is estimated. Is erased, the state of the stroke after erasure is overwritten and saved, and the amount of the drawing stroke is obtained (steps S114, 115, 116).

On the other hand, when the erasing stroke amount determination means 444 determines that the drawing stroke included in the erasing area, that is, the amount of drawing strokes to be erased, is greater than or equal to a predetermined ratio (step S112: YES). The new page creation unit 442 creates a new page different from the current page as the page to be processed (step S113).
That is, when the amount of drawing strokes to be erased is equal to or larger than a predetermined ratio, the user (teacher) does not want to partially correct the drawing strokes on the whiteboard 3 but performs writing on a new page. Therefore, it is estimated that the drawing stroke is being erased entirely, so that the drawing stroke is not erased on the computer device 4, and a new new page as shown in FIG. Created automatically.
In this way, when the processing of step S113 is completed, the data transmission unit 447 transmits data of a completely new page to each terminal 5 (step S107). Thereby, the display content of each terminal 5 of the student is updated to the content of a completely new page. When this process ends, the computer apparatus 4 ends the process.

[Effects of this embodiment]
As described above, according to the present embodiment, the computer apparatus 4 includes the stroke drawing unit 441 and the new page creation unit 442.
The stroke drawing unit 441 draws a drawing stroke specified according to the movement of the electronic pen 1 with respect to the whiteboard 3 on which the dot pattern is printed in the page to be processed.
The new page creation unit 442 has a drawing stroke amount to be erased specified according to the movement of the electronic eraser 2 with respect to the whiteboard 3 among drawing strokes drawn in the processing target page being a predetermined amount or more. Create a new page on the condition.
As described above, it is possible to easily create a new page automatically in a system in which a drawing stroke is drawn in a page with an electronic pen or the drawing stroke is deleted with an electronic eraser. In addition, it is convenient for the user to create a new page by deleting only a predetermined amount without erasing all contents written on the writing medium with the electronic pen.

[Modification]
The present invention is not limited to the above embodiment.
For example, in the determination process in step S112 of FIG. 11 in the above embodiment, whether or not to create a new page when the amount of the drawing stroke in the page to be processed is equal to or larger than a predetermined amount (step S111: YES). This is a determination process. In contrast to this determination process, the above embodiment employs a determination method for determining whether or not a predetermined ratio or more of the entire drawing stroke currently drawn on the processing target page is included in the erasure area. However, the determination method is not particularly limited to this. The erasure stroke amount determination means 444 determines whether or not a predetermined ratio or more of the entire drawing strokes currently drawn on the processing target page is included in the erasure area, but the determination method is limited to this. Absent.

Specifically, as shown in the stroke display processing flow of the modification of FIG. 14, the determination process by the erasure stroke amount determination unit 444 in step S112 is performed when the amount of the drawing stroke in the processing target page is a predetermined amount or more. This is a determination process regarding whether or not to create a new page in (step S211: YES). For this determination process, it is possible to employ a determination method for determining whether or not the time during which a predetermined ratio or more of the entire drawing strokes currently drawn on the processing target page is included in the erasure area is within a predetermined time. .
Here, the predetermined time is usually set to a time required for the user to erase almost all the contents written on the whiteboard 3 with the intention of entering new contents. For example, an eraser down is performed. 10 seconds should be used.
In such a predetermined time, a predetermined ratio or more of the entire drawing stroke is included in the erasure area, that is, the user (teacher) erases the drawing stroke of a predetermined amount or more within the predetermined time. It can be presumed that this means that the user (teacher) wants to erase all the contents entered in the whiteboard 3 and enter new contents (desired to draw a new drawing stroke on a new page). Therefore, in such a case (step S212: YES), the new page creation unit 442 creates a new page reflecting the user's feelings.
On the other hand, the ratio of the drawing strokes included in the erasure area is less than the predetermined ratio even after the predetermined time has passed, that is, the user continues the erasing operation by moving the electronic eraser 2 beyond the predetermined time. Can be presumed to mean that the user does not intend to create a new page. Therefore, in such a case (step S212: NO), a normal erasing area stroke erasing process, that is, a process of erasing the drawing stroke within the range in which the user performs the erasing operation is executed.
The other processes in steps S201 to S211, S215, and S216 in FIG. 14 are basically the same as the processes in steps S101 to S111, S115, and S116 in FIG. Description is omitted.

In the above embodiment, the new page creation unit 442 indicates that the electronic pen 1 has been tapped in the new page creation instruction area 31 or 32 in the whiteboard 3, and an explicit instruction to create a new page is given by the user. Recognize that there was, and create a new page. However, the explicit instruction for creating a new page by the user is not limited to this.
For example, a user has performed a predetermined operation using the input unit 41 of the computer device 4, specifically, for example, a predetermined software button included in a GUI (Graphical User Interface) image displayed on the display unit 45. The pressing operation with the mouse (a part of the input means 41) can be adopted as an explicit instruction for creating a new page by the user.
In this case, the first operation and the second operation are prepared in advance as predetermined operations, and an instruction that the drawing stroke in the processing target page is not transferred to the new page is assigned to the first operation, and the second operation is performed. For the operation, an instruction to take over the drawing stroke in the processing target page to a new page can be assigned. For example, by including two software buttons in the GUI image, a pressing operation of one software button can be a first operation, and a pressing operation of the other software button can be a second operation.
In this case, when the first operation is performed, processing equivalent to the series of processing in step S108, step S109: No, and step 107 in FIG. 11 is executed. That is, when the current page (P-1) shown in FIG. 12A is the page to be processed, a completely new page (P-2) as shown in FIG. Is created.
On the other hand, when the second operation is performed, processing equivalent to the series of processing in step S108, step S109: Yes, step S110, and step 107 in FIG. 11 is executed. That is, when the current page (P-1) shown in FIG. 13A is the page to be processed, the drawing contents of the current page (P-1) are shown in FIG. 13B. A new page (P-2) having the same content as is created.

In short, the new page creation means 442 has a configuration capable of creating a new page on the condition that an explicit instruction for creating a new page has been given by the user. It suffices to include an instruction as to whether or not the drawing stroke in the target page is taken over by a new page.
In this case, the user can issue an explicit instruction to create a new page. Further, as a new page form, a form in which the drawing stroke in the page to be processed is taken over and a form in which no takeover is carried out (smoothly) Can be arbitrarily selected.

  In the above embodiment, the target using the electronic pen 1 and the electronic eraser 2 is the whiteboard 3. However, the present invention is not limited to this, and it may be any writing medium on which an Anoto dot pattern is printed. . Also, the coding pattern printed on the writing medium is not limited to the Anoto dot pattern.

DESCRIPTION OF SYMBOLS 1 ... Electronic pen 2 ... Electronic eraser 3 ... White board 4 ... Computer apparatus 5 ... Terminal 10 ... Display system 41 ... Input means 42 ... Reception means 43 ... Storage means 44 ... Processing means 46 ... Display means 47 ... Transmission means 441 ... Stroke Drawing means 442 ... New page creation means 443 ... Stroke amount calculation means 444 ... Erase stroke amount determination means 445 ... Stroke erase means 446 ... Overwrite storage means 447 ... Data transmission means

The LED 105 and the CMOS camera 106 are attached near the pen tip portion 103 of the electronic pen 1, and an opening 102 is formed in a portion of the housing 101 that faces the LED 105 and the CMOS camera 106. The LED 105 illuminates infrared rays toward the vicinity of the pen tip portion 103 on the whiteboard 3. The area is slightly deviated from the position where the pen tip 103 contacts the whiteboard 3. The CMOS camera 106 is provided with an infrared filter that transmits infrared rays and blocks non-infrared rays. The CMOS camera 106 captures a dot pattern in an area illuminated by the LED 105 and processes image data of the dot pattern as a processor. 108. Here, since the ink material of dots absorbs infrared rays, the infrared rays irradiated by the LED 105 are absorbed by the dots. Therefore, portions of the dots, the amount of reflected infrared rays rather relatively small, portions other than the dot is relatively not large, the amount of reflection of infrared radiation. By photographing with the CMOS camera 106, a dot area and other areas can be distinguished by providing a threshold value based on the difference in the amount of reflected infrared light. Note that the shooting area by the CMOS camera 106 is a range including a size of about 2 mm × about 2 mm as shown in FIG. 4A, and the shooting by the CMOS camera 106 is performed at regular intervals of about 50 to 100 times per second. Is called. Further, the CMOS camera 106 has a sufficient depth of field in order to photograph dots clearly.

Claims (14)

Stroke drawing means for drawing a drawing stroke specified according to the movement of the electronic pen with respect to the writing medium on which the coded pattern is printed, in a page to be processed;
Of the drawing strokes drawn in the page to be processed, on the condition that the amount of drawing strokes to be erased specified according to the movement of the electronic eraser relative to the writing medium is equal to or greater than a first predetermined amount, A computer device comprising: a new page creating means for creating a new page. Stroke amount calculating means for calculating the total amount of the drawing stroke in the page to be processed;
The new page creation unit is configured to determine a drawing stroke to be erased specified according to the movement of the electronic eraser with respect to a state where the total amount calculated by the stroke amount calculation unit is equal to or greater than a second predetermined amount. The computer apparatus according to claim 1, wherein the new page is created on the condition that the amount is equal to or greater than the first predetermined amount. The total amount is less than the second predetermined amount, or the amount of the drawing stroke to be erased is less than the first predetermined amount even if the total amount is not less than the second predetermined amount. In addition, stroke erasing means for erasing the drawing stroke to be erased from the page to be processed,
Overwriting storage means for overwriting and saving the contents of the page to be processed after the drawing stroke is drawn by the stroke drawing means or after the drawing stroke to be erased is erased by the stroke erasing means; Further comprising
The computer apparatus according to claim 2, wherein the stroke amount calculation unit calculates the total amount after the content of the processing target page is overwritten and stored by the overwrite storage unit.   4. The stroke erasing unit identifies a moving area of an eraser portion of an electronic eraser with respect to the writing medium as an erasing area, and determines a drawing stroke to be erased based on the erasing area. Computer equipment.   The new page creating means further creates the new page on the condition that the amount of the drawing stroke to be erased is equal to or greater than the first predetermined amount within a predetermined time. The computer apparatus as described in any one of Claims 1-4. The new page creating means creates a new page on condition that an explicit instruction for creating a new page by the user is detected,
When the explicit instruction by the user includes an instruction to take over the drawing stroke in the processing target page to the new page, the drawing stroke is displayed on the new page. The computer apparatus as described in any one of Claims 1-5. A system comprising the computer device according to any one of claims 1 to 6 and a terminal device,
The computer device transmits data to the terminal device so that a drawing stroke and a new page creation state in a page to be processed are synchronized. A program executed by a computer device,
Said computer device,
Stroke drawing means for drawing a drawing stroke specified according to the movement of the electronic pen with respect to the writing medium on which the coded pattern is printed, in a page to be processed;
Of the drawing strokes drawn in the page to be processed, on the condition that the amount of drawing strokes to be erased specified according to the movement of the electronic eraser relative to the writing medium is equal to or greater than a first predetermined amount, New page creation means to create a new page,
A program characterized by functioning as Further causing the computer device to function as stroke amount calculation means for calculating the total amount of the drawing stroke in the page to be processed;
The new page creation unit is configured to determine a drawing stroke to be erased specified according to the movement of the electronic eraser with respect to a state where the total amount calculated by the stroke amount calculation unit is equal to or greater than a second predetermined amount. The program according to claim 8, wherein the new page is created on condition that the amount is equal to or greater than the first predetermined amount. Said computer device,
The total amount is less than the second predetermined amount, or the amount of the drawing stroke to be erased is less than the first predetermined amount even if the total amount is not less than the second predetermined amount. In addition, stroke erasing means for erasing the drawing stroke to be erased from the page to be processed,
Overwriting storage means for overwriting and saving the contents of the page to be processed after the drawing stroke is drawn by the stroke drawing means or after the drawing stroke to be erased is erased by the stroke erasing means; To make it work,
The program according to claim 9, wherein the stroke amount calculation unit calculates the total amount after the content of the processing target page is overwritten and stored by the overwrite storage unit.   11. The stroke erasing unit identifies a moving area of an eraser portion of an electronic eraser with respect to the writing medium as an erasing area, and determines a drawing stroke to be erased based on the erasing area. Program.   The new page creating means further creates the new page on the condition that the amount of the drawing stroke to be erased is equal to or greater than the first predetermined amount within a predetermined time. The computer apparatus as described in any one of Claims 8-11. The new page creating means creates a new page on condition that an explicit instruction for creating a new page by the user is detected,
When the explicit instruction by the user includes an instruction to take over the drawing stroke in the processing target page to the new page, the drawing stroke is displayed on the new page. The program as described in any one of Claims 8-12.   14. The computer apparatus according to claim 8, further comprising data transmission means for transmitting data to an external terminal device so that a drawing stroke and a new page creation state in the page to be processed are synchronized. The program as described in any one of these.

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