JP2020060915A - Electronic display terminal and electronic writing system - Google Patents

Abstract

To reduce the power consumption of an electronic pen and an electronic display terminal.SOLUTION: An electronic display terminal is an electronic display terminal for drawing writing information by an electronic pen 2, and includes a pen holding part for detachably holding the electronic pen, an attachment and detachment detection part 4 for detecting the attachment and detachment of the electronic pen to/from the pen holding part, and a terminal side communication part 51 for starting to communicate with the electronic pen in the case that the attachment and detachment detection part detects that the electronic pen is taken out of the pen holding part.SELECTED DRAWING: Figure 8

Description

  The present invention relates to an electronic display terminal and an electronic writing system.

  2. Description of the Related Art There is known an electronic whiteboard (hereinafter referred to as an electronic display terminal) in which a function of capturing information, a display function, a communication function and the like are added to a conventional whiteboard. The information written by the user on the electronic display terminal is accumulated as coordinate data and drawn on the display surface of the electronic display terminal. The user can write characters and figures on the display surface like the conventional whiteboard.

  An electronic pen may be provided as a tool for writing on the display surface. When the electronic pen has a function of communicating with the electronic display terminal, the functionality and operability of the electronic display terminal are improved. For example, when the electronic pen has a pen pressure detection function, data such as pen pressure detected by the electronic pen is transmitted to the electronic display terminal at predetermined time intervals. The electronic display terminal changes the thickness of a line to be drawn according to the writing pressure data received from the electronic pen. As a result, the user can obtain a feeling of use as if he / she is actually writing with a pen (see, for example, Patent Document 1).

  However, if communication is continuously performed between the electronic pen and the electronic display terminal, communication is performed between the electronic pen and the electronic display terminal even if the electronic pen is not used, and power consumption becomes large. May be wasted.

  The disclosed technology has been made in view of the above circumstances and has been made to solve the problem, and an object thereof is to reduce power consumption of an electronic pen and an electronic display terminal.

  The disclosed technology is an electronic display terminal that draws writing information with an electronic pen, and a pen holding unit that detachably holds the electronic pen, and an attachment / detachment detection unit that detects attachment / detachment of the electronic pen to / from the pen holding unit. And a terminal-side communication unit that starts communication with the electronic pen when the attachment / detachment detection unit detects that the electronic pen has been taken out of the pen holding unit.

  The power consumption of the electronic pen and the electronic display terminal can be reduced.

It is a figure which shows schematic structure of the electronic writing system which concerns on 1st Embodiment. It is a figure which shows the modification regarding arrangement | positioning of a pen tray. It is a figure which shows schematic structure of an electronic whiteboard. It is a figure which shows schematic structure of an electronic pen. FIG. 19 is a block diagram showing an example of a hardware configuration of a computer. It is a figure which shows an example of the functional block of an electronic pen. It is a figure which shows typically an example of the packet format of transmission data. It is a figure showing an example of a functional block of a computer. It is a figure which shows an example of the attitude | position of the electronic pen in a writing state. It is a figure which shows an example of the operation sequence of an electronic writing system. It is a figure which shows an example of the operation sequence of an electronic writing system. It is a figure which shows an example of the operation sequence of an electronic writing system. It is a figure which shows an example of the operation sequence of an electronic writing system. It is a figure which shows the other example of installation of an electronic whiteboard. It is a figure which shows schematic structure of the electronic whiteboard which has a posture sensor. It is a flow chart which shows an example of judgment processing of a writing state. It is a figure which shows schematic structure of the electronic pen which has an attachment / detachment detection part.

  Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings. In each drawing, the same components may be denoted by the same reference numerals and duplicate description may be omitted.

[First Embodiment]
The electronic writing system according to the first embodiment of the present invention will be described below.

<Schematic configuration>
FIG. 1 is a diagram showing a schematic configuration of an electronic writing system 400 according to the first embodiment. The electronic writing system 400 includes a plurality of electronic pens 2 and an electronic whiteboard 300 as an electronic display terminal. The electronic whiteboard 300 has a display 200 and a pen tray 3 connected to the display 200.

  The electronic pen 2 is a tool for writing on the display surface 201 of the display 200. The electronic pen 2 is configured to be able to establish a one-to-one communication relationship with the electronic whiteboard 300 by using a physical address.

  The pen tray 3 is a pen holding unit that detachably holds the electronic pen 2, and is configured to hold a plurality of electronic pens 2. The pen tray 3 has an attachment / detachment detector 4 that detects attachment / detachment of each electronic pen 2. The attachment / detachment detection unit 4 is configured by a contact sensor such as a switch that detects the contact of the electronic pen 2.

  The display 200 is an image display device such as a liquid crystal display, a plasma emission display, an organic EL display, an electrophoretic display, or an FED (Field Emission Display). In the present embodiment, the display 200 need not have a touch panel, but may have a touch panel.

  When writing on the display surface 201 of the display 200 with the electronic pen 2, one or more electronic pens 2 are taken out from the pen tray 3 by the user.

  Although the pen tray 3 is arranged on the side of the display 200 in FIG. 1, the arrangement position of the pen tray 3 can be changed appropriately. As shown in FIG. 2, the pen tray 3 may be arranged below the display 200.

  In the present embodiment, it is assumed that the electronic whiteboard 300 is installed so that the display surface 201 of the display 200 is substantially parallel to the vertical direction (gravitational acceleration direction).

  FIG. 3 is a diagram showing a schematic configuration of the electronic whiteboard 300. The electronic whiteboard 300 includes image pickup units 32a to 32d, retroreflectors 81a to 81d, and a computer 100 in order to detect the coordinates (positional information) of the electronic pen 2 on the display surface 201. Hereinafter, when it is not necessary to distinguish the image capturing units 32a to 32d, they are simply referred to as the image capturing unit 32. Similarly, when it is not necessary to distinguish the retroreflective plates 81a to 81d, they are simply referred to as the retroreflective plate 81.

  An image output device 70 such as a PC (Personal Computer) is connected to the computer 100. The computer 100 can display the image output by the image output device 70 on the display surface 201 of the display 200. However, the image output device 70 is not essential.

  The retroreflective plates 81 a to 81 d are arranged around the display 200.

  A predetermined program 119 is installed in the computer 100. The computer 100 executes the program 119 to detect the coordinates on the display surface 201 with which the electronic pen 2 is in contact, based on the image captured by the image capturing unit 32. The computer 100 draws a stroke (writing information) by the electronic pen 2 on the display surface 201 in real time based on the detected coordinates.

  The electronic pen 2, which will be described in detail later, detects writing pressure information and transmits it to the computer 100 at the time of writing when the electronic pen 2 contacts the display surface 201. The computer 100 changes the thickness of the line drawn on the display surface 201 according to the writing pressure information.

  Further, the computer 100 can display an operation menu on the display surface 201. The user can select various items from the menu displayed on the display surface 201 with the electronic pen 2. The menu has items for designating the line color, thickness, line type, etc., and the user can select these to select the desired line to be drawn.

  It should be noted that in addition to the menu related to drawing, the entire content drawn on the display surface 201 (hereinafter referred to as a page) is saved, the page is redisplayed, the page is turned, the page is printed, and the page is transmitted to the user's PC or the like. There is something about.

  As described above, even if the display 200 does not have the touch panel function, the user can perform various operations only by touching the display surface 201 with the electronic pen 2.

  A display having a touch panel function may be used instead of the coordinate detection system configured by the image pickup unit 32 and the retroreflective plate 81.

<Schematic configuration of electronic pen>
Next, a schematic configuration of the electronic pen 2 will be described. FIG. 4 is a diagram showing a schematic configuration. The electronic pen 2 includes a control unit 21, a wireless communication unit 22, a writing pressure sensor 23, a memory 24, a posture sensor 25, and a power supply unit 26.

  The control unit 21 is, for example, a microcomputer and realizes various functions by executing a program for the electronic pen.

  The wireless communication unit 22 is, for example, a Bluetooth (registered trademark) module, establishes a communication relationship with the electronic whiteboard 300, and performs packet communication by radio waves.

  The writing pressure sensor 23 is, for example, a pressure sensor, generates an electric potential according to the pressure (writing pressure) applied to the pen tip 5, and outputs it to the control unit 21 as writing pressure information.

  The posture sensor 25 is, for example, a uniaxial acceleration sensor, and outputs the detected value of acceleration to the control unit 21 as posture information. The acceleration detection direction S by the uniaxial acceleration sensor is, for example, the direction in which the pen tip 5 is directed (longitudinal direction of the electronic pen 2).

  The power supply unit 26 is, for example, a rechargeable battery, and supplies power to each unit of the electronic pen 2.

  The control unit 21 has an AD converter. The control unit 21 digitizes the writing pressure information received from the writing pressure sensor 23 and the posture information received from the posture sensor 25 by the AD converter and stores the digitized information in the memory 24. The memory 24 is a storage device including a RAM (Random Access Memory), a flash memory, and the like.

  Further, the control unit 21 detects the battery remaining amount of the power supply unit 26 and stores it in the memory 24. The memory 24 also stores identification information (ID) unique to the electronic pen 2.

  The control unit 21 performs a process of outputting various information stored in the memory 24 together with the ID to the wireless communication unit 22.

  The wireless communication unit 22 performs a process of transmitting a packet including various information received from the control unit 21 to the electronic whiteboard 300.

<Computer hardware configuration>
Next, the hardware configuration of the computer 100 will be described. FIG. 5 is a block diagram showing an example of the hardware configuration of the computer 100. The computer 100 includes a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, a RAM 103, an SSD (Solid State Drive) 104, a network controller 105, and an external storage controller 106.

  The computer 100 also includes an electronic pen controller 116, a sensor controller 114, a GPU (Graphics Processor Unit) 112, a capture device 111, and a display controller 113. The display controller 113 is connected to the GPU 112.

  The CPU 101 executes the program 119 for the electronic writing system to control the overall operation of the electronic writing system 400. The ROM 102 stores a program such as an IPL (Initial Program Loader) which is mainly executed by the CPU 101 when the electronic writing system 400 is activated. The RAM 103 is a working memory when the CPU 101 executes the program 119. The SSD 104 is a non-volatile memory in which the program 119 and various data are stored.

  The network controller 105 performs processing based on a communication protocol when the computer 100 communicates with another device via the network.

  The external storage controller 106 writes to or reads from the removable external memory 117 according to an instruction from the CPU 101. The external memory 117 is, for example, a flash memory such as a USB memory or an SD card.

  The electronic pen controller 116 wirelessly communicates with the wireless communication unit 22 of each electronic pen 2 and receives the ID, the writing pressure information, the posture information, the remaining battery level, and the like.

Imaging units 32a to 32d are connected to the sensor controller 114. The imaging units 32a to 32d are CMOS sensors or CCD sensors that acquire two-dimensional images. The image capturing units 32a to 32d may be linear image sensors that acquire a one-dimensional image.
The sensor controller 114 uses the images captured by the image capturing units 32a to 32d to detect coordinates by the triangulation method.

  Further, four light sources 31 are connected to the sensor controller 114. The light source 31 is arranged adjacent to the image pickup unit 32 or integrally with the image pickup unit 32, and illuminates the retroreflection plate 81. The light source 31 emits infrared light, for example, and the imaging unit 32 has sensitivity to infrared light and the like.

  Further, the sensor controller 114 is connected to the attachment / detachment detection unit 4 provided on the pen tray 3 described above.

  The capture device 111 captures the video output by the image output device 70 on the screen 71.

  The GPU 112 is a drawing-only processor that calculates the pixel value of each pixel of the display 200. The display controller 113 outputs the image created by the GPU 112 to the display 200.

  The program 119 for the electronic writing system may be distributed while being stored in the external memory 117, or may be distributed via the network controller 105 to the server of the manufacturer of the electronic writing system 400 or the server of the company to which the manufacturer is requested. May be downloaded from. The program 119 may be distributed in a distribution format or an execution format.

<Functional configuration>
Next, the functional configuration of the electronic writing system 400 will be described. FIG. 6 is a diagram showing an example of functional blocks of the electronic pen 2. The electronic pen 2 includes a writing pressure information generation unit 41, a writing pressure information storage unit 42, a pen side communication unit 43, a posture information generation unit 44, and an information storage unit 45.

  The writing pressure information generation unit 41 is realized by the control unit 21 and the writing pressure sensor 23 working together. The writing pressure information generation unit 41 detects writing pressure with the writing pressure sensor 23 at predetermined detection intervals d, generates writing pressure information Pr, and outputs the writing pressure information Pr to the writing pressure information storage unit 42.

  The writing pressure information storage unit 42 is realized by the control unit 21 and the memory 24 working together. The writing pressure information storage unit 42 stores (buffers) the writing pressure information Pr output from the writing pressure information generation unit 41 during a communication interval T described later. The writing pressure information storage unit 42 outputs the writing pressure information Pr (T) accumulated during the communication interval T to the pen-side communication unit 43 for each accumulation period T. The writing pressure information Pr (T) includes a number of writing pressure information Pr corresponding to the ratio of the communication interval T and the detection interval d.

  The pen-side communication unit 43 is realized by the control unit 21 and the wireless communication unit 22 working together. The pen-side communication unit 43 generates the transmission data Sd by storing the writing pressure information Pr (T) output from the writing pressure information storage unit 42 in, for example, a Bluetooth (registered trademark) packet format, and transmits the transmission data Sd. Is transmitted to the computer 100 of the electronic whiteboard 300 in one transmission.

  In addition, the pen-side communication unit 43 receives communication setting information including the above-mentioned communication interval T from the computer 100 of the electronic whiteboard 300.

  The posture information generation unit 44 is realized by the control unit 21 and the posture sensor 25 working together. The posture information generation unit 44 detects acceleration at predetermined time intervals by the acceleration sensor included in the posture sensor 25, generates posture information Ar, and outputs the posture information Ar to the information storage unit 45.

  The information storage unit 45 is built in the memory 24. The information storage unit 45 stores information such as the communication interval T, the remaining battery level Br, and the ID in addition to the posture information Ar. The writing pressure information storage unit 42 acquires the communication interval T from the information storage unit 45, and stores the writing pressure information Pr during the communication interval T.

  Further, the posture information Ar and the remaining battery level Br stored in the information storage unit 45 are output to the pen-side communication unit 43 together with the ID. The pen-side communication unit 43 adds the posture information Ar and the remaining battery level Br to the transmission data Sd when generating the transmission data Sd.

  FIG. 7 is a diagram schematically showing an example of the packet format of the transmission data Sd. The packet format of FIG. 7 is based on the standard of Bluetooth (registered trademark) LE as an example, and the transmission data mainly includes a preamble, an access address, a header, a length, a data part, and a CRC (Cyclic Redundancy Check). Have. The various information described above is stored in the data section.

  FIG. 8 is a diagram illustrating an example of functional blocks of the computer 100. The computer 100 includes a terminal side communication unit 51, a writing state determination unit 52, a communication interval determination unit 53, a coordinate calculation unit 54, and a drawing data generation unit 55.

  The terminal-side communication unit 51 is realized by the CPU 101 and the electronic pen controller 116 working together. The terminal side communication unit 51 communicates with the plurality of electronic pens 2 and receives the transmission data Sd from each electronic pen 2. The terminal-side communication unit 51 also outputs communication setting information including the communication interval T to the pen-side communication unit 43 of each electronic pen 2.

  The terminal-side communication unit 51 extracts the posture information Ar from the transmission data Sd received from each electronic pen 2 and outputs it to the writing state determination unit 52 together with the ID. The terminal-side communication unit 51 also extracts the writing pressure information Pr (T) from the transmission data Sd received from each electronic pen 2 and outputs it to the drawing data generation unit 55 together with the ID.

  The writing state determination unit 52 is realized by the CPU 101. The writing state determination unit 52 determines whether or not each electronic pen 2 is in the writing state based on the posture information Ar and the writing pressure information Pr acquired from each electronic pen 2. The writing state means a state in which the user writes on the display surface 201 of the display 200 using the electronic pen 2.

  Specifically, as shown in FIG. 9, when the electronic pen 2 is in the writing state, the acceleration detection direction S by the uniaxial acceleration sensor forming the posture sensor 25 is in a state substantially orthogonal to the vertical direction. The detected acceleration value included in the posture information Ar is a value close to 0G. The writing state determination unit 52 refers to the posture information Ar and the writing pressure information Pr acquired from each electronic pen 2, and when the detected acceleration value is equal to or less than a predetermined value and a writing pressure equal to or more than a certain value is detected. , It is determined that the electronic pen 2 is in the writing state. That is, the writing state determination unit 52 determines that the electronic pen 2 is in the writing state when the electronic pen 2 is in a predetermined posture and the pen tip 5 is in contact with the display surface 201.

  In addition, the writing state determination unit 52 determines the total number Nw of the electronic pens 2 in the writing state by determining whether or not each electronic pen 2 taken out from the pen tray 3 is in the writing state, and determines the communication interval. Output to the unit 53.

  The communication interval determination unit 53 is realized by the CPU 101. The communication interval determination unit 53 determines the communication interval T based on the total number Nw of the electronic pens 2 in the writing state, and outputs the communication interval T to the terminal-side communication unit 51. Specifically, the communication interval determination unit 53 increases the communication interval T as the total number Nw increases. For example, the communication interval determination unit 53 determines the communication interval T based on the relational expression “T = Nw × d”.

  The communication interval determination unit 53 also acquires the attachment / detachment information of each electronic pen 2 from the attachment / detachment detection unit 4 provided on the pen tray 3. The communication interval determination unit 53 outputs the communication interval T to the terminal-side communication unit 51 when detecting that the electronic pen 2 is taken out from the pen tray 3 based on the attachment / detachment information. The communication interval T in this case is set to an initial value T0 which is a value larger than the communication interval in the writing state.

  The coordinate calculation unit 54 is realized by cooperation between the CPU 101 and the image pickup unit 32. The coordinate calculation unit 54 calculates the coordinate Ps of the electronic pen 2 according to the principle of triangulation and outputs it to the drawing data generation unit 55. The coordinate calculation unit 54 repeats the calculation and output of the coordinates Ps in a predetermined cycle.

  The drawing data generation unit 55 is realized by the CPU 101. The drawing data generation unit 55 generates drawing data of a line connecting the coordinates output by the coordinate calculation unit 54 in time series. Then, the thickness of the line at this time is adjusted according to the writing pressure information Pr (T). For example, the thickness is calculated based on a relational expression of “thickness = coefficient × writing pressure × basic thickness”, and drawing data of a line that is thicker as the writing pressure is larger and thinner as the writing pressure is smaller is generated. The coefficient is a constant or variable for converting writing pressure into thickness.

  Note that the coordinates Ps and the writing pressure information Pr (T) are not necessarily received at the same timing, but in this embodiment, it is assumed that the coordinates are obtained and the writing pressure information is received with a negligible time difference. Further, the acquisition frequency of the coordinates Ps and the acquisition frequency of the writing pressure information Pr (T) are not always the same.

<Operation sequence>
Next, an operation sequence of the electronic writing system 400 will be described. 10 to 13 are diagrams showing an example of an operation sequence of the electronic writing system 400. 10 to 13 show three electronic pens 2 mounted on the pen tray 3 of the electronic whiteboard 300, which are distinguished from the electronic pens 2a, 2b, 2c.

  For example, as shown in FIG. 10, when the attachment / detachment detection unit 4 detects that the electronic pen 2a is taken out from the pen tray 3, the communication interval determination unit 53 outputs communication setting information including the communication interval T (= T0), It is transmitted to the electronic pen 2a. The electronic pen 2a receives this communication setting information and communicates with the electronic whiteboard 300 at a communication interval T. For example, the electronic pen 2a transmits the transmission data Sd including the posture information Ar, the writing pressure information Pr, and the remaining battery level Br to the electronic whiteboard 300 at each communication interval T. In this case, the writing pressure information storage unit 42 does not store the writing pressure information Pr.

  Next, the writing state determination unit 52 of the electronic whiteboard 300 determines whether each electronic pen 2 is in the writing state, based on the posture information Ar and the writing pressure information Pr received from each electronic pen 2. The total number Nw of the electronic pens 2 in the writing state is calculated.

  FIG. 11 shows an operation sequence when Nw = 1. As shown in FIG. 11, when only the electronic pen 2a is in the writing state, the communication interval determination unit 53 transmits the communication setting information including the communication interval T (= d) to the electronic pen 2a. The electronic pen 2a receives the communication setting information, and transmits the writing pressure information Pr (T) to the electronic whiteboard 300 at every communication interval T. In this case, since T = d, the writing pressure information storage unit 42 does not store the writing pressure information Pr, and the writing pressure information Pr (T) includes one writing pressure information Pr. The electronic whiteboard 300 receives the writing pressure information Pr (T) at each detection interval d and draws on the display surface 201 of the display 200.

  FIG. 12 shows an operation sequence when Nw = 2. As shown in FIG. 12, when the electronic pens 2a and 2b are in the writing state, the communication interval determination unit 53 transmits the communication setting information including the communication interval T (= 2d) to the electronic pens 2a and 2b, respectively. . Each of the electronic pens 2a and 2b receives the communication setting information, stores the writing pressure information Pr by the writing pressure information storage unit 42 during the communication interval T, and writes the writing pressure information Pr (T (T) on the electronic whiteboard 300 at each communication interval T. ) Is sent. Since T = 2d, the writing pressure information Pr (T) includes two writing pressure information Pr. The transmission timings of the electronic pens 2a and 2b are preferably shifted by the time T / Nw (T / 2 in the case of FIG. 12). As a result, the electronic whiteboard 300 receives the writing pressure information Pr (T) at each detection interval d.

  FIG. 13 shows an operation sequence when Nw = 3. As shown in FIG. 13, when the electronic pens 2a, 2b, 2c are in the writing state, the communication interval determination unit 53 sends the communication setting information including the communication interval T (= 3d) to the electronic pens 2a, 2b, 2c. To send to each. Each of the electronic pens 2a, 2b, 2c receives the communication setting information, stores the writing pressure information Pr by the writing pressure information storage unit 42 during the communication interval T, and writes the writing pressure information Pr on the electronic whiteboard 300 at each communication interval T. (T) is transmitted. Since T = 3d, the writing pressure information Pr (T) includes three writing pressure information Pr. It is preferable that the transmission timings of the electronic pens 2a, 2b, 2c be shifted by the time T / 3. In this case, the electronic whiteboard 300 receives the writing pressure information Pr (T) at each detection interval d.

  As described above, the electronic whiteboard 300 does not increase the reception frequency of the writing pressure information Pr (T) even if the total number Nw of the electronic pens 2 in the writing state increases, so that the transmission signals from the plurality of electronic pens 2 are transmitted. Interference, etc. are prevented.

<Effect>
According to the present embodiment, the terminal-side communication unit 51 of the electronic whiteboard 300 starts communication with the electronic pen 2 when the attachment / detachment detection unit 4 detects that the electronic pen 2 has been taken out from the pen tray 3. The power consumption of the electronic pen 2 and the electronic whiteboard 300 is reduced.

  Further, it is not possible to determine whether or not the electronic pen 2 is actually in the writing state only by taking out the electronic pen 2 from the pen tray 3, but in the present embodiment, the attitude information Ar and the writing pressure information Pr are used. Since the determination is performed based on the determination, it is possible to determine with high accuracy that the electronic pen 2 is in the writing state. Therefore, it is possible to prevent the state in which the electronic pen 2 is placed on the pen tray 3 or the state in which the user simply holds the electronic pen 2 from being erroneously determined as the writing state.

<Modification>
Next, various modifications of the above embodiment will be described.

  In the above embodiment, the electronic whiteboard 300 is installed so that the display surface 201 of the display 200 is substantially parallel to the vertical direction, but the installation direction is not limited to this.

  For example, as shown in FIG. 14, the electronic whiteboard 300 may be installed so that the display surface 201 of the display 200 is substantially perpendicular to the vertical direction. In this case, the detected acceleration value included in the posture information Ar is a value close to 1G. The writing state determination unit 52 refers to the posture information Ar and the writing pressure information Pr acquired from each electronic pen 2, and when the detected acceleration value is a predetermined value or more and a writing pressure of a certain value or more is detected, , It is determined that the electronic pen 2 is in the writing state.

  It is also preferable to provide an attitude sensor on the electronic whiteboard in order to automatically respond to the installation direction of the electronic whiteboard.

  FIG. 15 is a diagram showing a schematic configuration of an electronic whiteboard 300a having an attitude sensor 60. The attitude sensor 60 is composed of an acceleration sensor or the like, detects the attitude of the electronic whiteboard 300a, and outputs the detected value to the computer 100.

  The writing state determination unit 52 can detect whether the display surface 201 is parallel or perpendicular to the vertical direction based on the detection value of the attitude sensor 60. The writing state determination unit 52 determines whether or not the electronic pen 2 is in the writing state based on the relationship between the detected value of the posture sensor 60 and the detected value of acceleration included in the posture information Ar.

  In the above embodiment, the writing state determination unit 52 determines that the electronic pen 2 is in the writing state when the electronic pen 2 is in a predetermined posture and the pen tip 5 is in contact with the display surface 201. Although it is determined, it may be added as a condition that the posture of the electronic pen 2 has continued for a certain time or more.

  FIG. 16 is a flowchart showing an example of the writing state determination process. As illustrated in FIG. 16, when the writing state determination unit 52 acquires the posture information Ar (step S10), the writing state determination unit 52 determines the posture of the electronic pen 2 and determines whether or not the posture has changed (step S11). . When there is no change in the posture (step S11: No), the writing state determination part 52 determines whether or not a predetermined time or more has passed (step S12). The writing state determination part 52 returns a process to step S10, when the fixed time or more has not passed (step S12: No).

  The writing state determination unit 52 acquires the writing pressure information Pr (step S13) when the posture has not changed and a certain time or more has passed (step S12: Yes), and whether or not the writing pressure is a certain value or more. Is determined (step S14). When the writing pressure is equal to or higher than a certain value (step S14: Yes), the writing state determination unit 52 determines that the electronic pen 2 is in the writing state (step S15).

  The writing state determination unit 52 resets a time counter or the like when the posture has changed (step S11: Yes) and when the writing pressure is not equal to or higher than a certain value (step S14: No) (step S16). , The process returns to step S10.

  In this way, the writing state can be determined more accurately by making the determination of the writing state on the condition that the predetermined posture has continued for a certain period of time or more.

  Further, in the above embodiment, the attachment / detachment detection unit 4 for detecting attachment / detachment of the electronic pen 2 to / from the pen tray 3 is provided in the pen tray 3, but instead of this, the attachment / detachment detection unit may be provided in the electronic pen.

  FIG. 17 shows an electronic pen 90 having an attachment / detachment detector 91. The attachment / detachment detection unit 91 includes a contact sensor such as a switch that detects a contact of the electronic pen 90 with the pen tray 3. The attachment / detachment information by the attachment / detachment detection unit 91 is acquired by the control unit 21 and output to the computer 100 of the electronic whiteboard 300 via the wireless communication unit 22. The processing of the communication interval determination unit 53 based on the attachment / detachment information is the same as that in the above embodiment.

  Further, some or all of the functions of the electronic pen or the computer 100 described above may be realized not only by software but also by a dedicated hardware circuit (for example, a semiconductor integrated circuit).

  Further, in the above-described embodiment, the coordinates of the electronic pen are detected by the imaging units 32a to 32d and the retroreflectors 81a to 81d, but instead of this, by providing the image display device with the touch panel function, The coordinates may be detected.

  The present invention has been described above based on the respective embodiments, but the present invention is not limited to the requirements shown in the above embodiments. With respect to these points, the gist of the present invention can be modified within a range that does not impair the invention, and can be appropriately determined according to the application mode.

2, 2a to 2c Electronic pen 3 Pen tray 4 Attachment / detachment detection unit 5 Pen tip 22 Wireless communication unit 23 Writing pressure sensor 25 Attitude sensor 26 Power supply unit 31 Light source 32, 32a to 32d Imaging unit 41 Writing pressure information generation unit 42 Writing pressure information accumulation Part 43 Pen side communication part 44 Attitude information generation part 45 Information storage part 51 Terminal side communication part 52 Writing state determination part 53 Communication interval determination part 54 Coordinate calculation part 55 Drawing data generation part 60 Attitude sensor 70 Image output device 71 Screen 81, 81a-81d Retroreflector 90 Electronic pen 91 Attachment / detachment detection unit 200 Display 201 Display surface 300, 300a Electronic whiteboard 400 Electronic writing system

JP, 2016-122382, A

Claims (10)

An electronic display terminal for drawing writing information with an electronic pen,
A pen holding portion for holding the electronic pen detachably,
An attachment / detachment detection unit that detects attachment / detachment of the electronic pen with respect to the pen holding unit,
A terminal-side communication unit that starts communication with the electronic pen when the attachment / detachment detection unit detects that the electronic pen has been taken out of the pen holding unit;
An electronic display terminal having. An electronic writing system having an electronic pen and an electronic display terminal for drawing writing information by the electronic pen,
The electronic display terminal,
A pen holding portion for holding the electronic pen detachably,
An attachment / detachment detection unit that detects attachment / detachment of the electronic pen with respect to the pen holding unit,
A terminal-side communication unit that starts communication with the electronic pen when the attachment / detachment detection unit detects that the electronic pen has been taken out of the pen holding unit;
Electronic writing system having a. The electronic pen is
A pen side communication unit that communicates with the terminal side communication unit,
A writing pressure information generation unit that detects writing pressure and generates writing pressure information,
Have
The electronic writing system according to claim 2, wherein the pen-side communication unit transmits the writing pressure information to the terminal-side communication unit. The electronic pen includes a posture information generation unit that detects a posture and generates posture information,
The electronic writing system according to claim 3, wherein the pen-side communication unit transmits the attitude information to the terminal-side communication unit.   The electronic writing system according to claim 4, wherein the electronic display terminal includes a writing state determination unit that determines whether or not the electronic pen is in a writing state based on the posture information and the writing pressure information. The pen holder can hold a plurality of the electronic pens,
The electronic writing system according to claim 5, wherein the writing state determination unit determines the total number of the electronic pens in the writing state by determining whether each of the electronic pens is in the writing state. The electronic display terminal has a communication interval determination unit that determines a communication interval between the terminal-side communication unit and the pen-side communication unit based on the total number,
The electronic writing system according to claim 6, wherein the communication interval determination unit increases the communication interval as the total number increases. The electronic pen has a writing pressure information storage unit that stores the writing pressure information generated by the writing pressure information generation unit during the communication interval,
The electronic writing system according to claim 7, wherein the pen-side communication unit transmits the writing pressure information stored in the writing pressure information storage unit to the terminal-side communication unit at each communication interval.   The electronic writing system according to claim 4, wherein the posture information generation unit includes a uniaxial acceleration sensor, and the posture information includes a detected value of acceleration by the acceleration sensor.   The electronic writing system according to claim 3, wherein the electronic display terminal includes a drawing data generation unit that generates drawing data of a line having a thickness corresponding to the writing pressure, based on the writing pressure information.

Images