JP2018156381A - Electronic blackboard system, brushstroke strength linearization method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic blackboard system for miniaturizing an electronic pen capable of detecting brushstroke strength, and to provide a brushstroke strength linearization method and a program.SOLUTION: An electronic blackboard system includes an electronic pen, and an electronic blackboard including a display part for displaying a line drawn by the electronic pen. The electronic pen includes: a pressure sensor for detecting brushstroke strength of the electronic pen and outputting voltage for expressing the brushstroke strength as brushstroke strength data; and a transmission part for transmitting brushstroke strength data outputted from the pressure sensor to the electronic blackboard. The electronic blackboard includes: a reception part for receiving brushstroke strength data from the electronic pen; a conversion part for converting the received brushstroke strength data to brushstroke strength data that change linearly as the brushstroke strength increases; and a change part for changing thickness of a line displayed on the display part, based on the brushstroke strength data that change linearly.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electronic blackboard system, a writing pressure linearization method, and a program.

  In recent years, an electronic blackboard system including an electronic pen and an electronic blackboard that displays an image such as a line drawn by the electronic pen has been widespread. The electronic blackboard system displays various information such as materials displayed on the electronic blackboard by moving it with the finger in contact with the electronic blackboard, or displays it on the electronic blackboard with an electronic pen. Since it can be easily written in various information such as recorded materials, it has begun to spread rapidly.

  There are two types of electronic pens: passive and active. A passive electronic pen does not incorporate a battery or the like, and is simply a pen that substitutes a user's finger. On the other hand, an active electronic pen has a battery or the like incorporated in the electronic pen, and detects that the electronic pen is in contact with the electronic blackboard or that the electronic pen is not in contact with the electronic blackboard. The pen pressure of the electronic pen can be detected by a sensor.

  By the way, in the electronic blackboard system that optically detects the contact of the electronic pen or the user's finger with the electronic blackboard, the passive electronic pen or the user's finger contacts the electronic blackboard with the electronic pen or the user's finger contact with the electronic blackboard. Since it detects before contacting, it is difficult to draw an image with respect to an electronic blackboard. However, by using the active electronic pen to notify the electronic blackboard of the detection result of the contact of the electronic pen with the electronic blackboard, it is possible to reduce the difficulty of drawing an image on the electronic blackboard.

  In addition, the electronic blackboard system incorporates a pressure sensor that detects the writing pressure with respect to the electronic pen so that the thickness of the line drawn by the electronic pen can be dynamically changed according to the writing pressure. In addition, a technique for more faithfully displaying “Tome”, “Hane”, and “Halai” when a character is drawn with an electronic pen on an electronic blackboard has been developed.

  However, in an electronic blackboard system having an electronic pen with a built-in pressure sensor, hardware (circuit board) for linearly thickening the lines displayed on the electronic blackboard as the writing pressure increases becomes electronic. By mounting on a pen, it is possible to reproduce “Tome” or the like when a character is drawn with the electronic pen on the electronic blackboard. For this reason, the number of components mounted on the electronic pen increases, the size of the circuit board mounted on the electronic pen increases, and it is difficult to reduce the size of the electronic pen.

  The present invention has been made in view of the above, and it is an object of the present invention to provide an electronic blackboard system, a pen pressure linearization method, and a program that can reduce the size of an electronic pen that can detect pen pressure.

  In order to solve the above-described problems and achieve the object, the present invention is an electronic blackboard system including an electronic pen and an electronic blackboard having a display unit for displaying a line drawn by the electronic pen. The electronic pen detects a writing pressure of the electronic pen and outputs a voltage representing the writing pressure as writing pressure data, a transmitting unit that transmits writing pressure data output from the pressure sensor to the electronic blackboard, Is provided. The electronic blackboard includes a receiving unit that receives pen pressure data from an electronic pen, a conversion unit that converts the received pen pressure data into pen pressure data that changes linearly as the pen pressure increases, and a pen pressure that changes linearly. And a changing unit that changes the thickness of the line displayed on the display unit based on the data.

  According to the present invention, it is possible to reduce the size of an electronic pen capable of detecting writing pressure.

FIG. 1 is a block diagram showing an example of the configuration of the electronic blackboard system according to the present embodiment. FIG. 2 is a block diagram illustrating an example of a functional configuration of the electronic blackboard included in the electronic blackboard system according to the present embodiment. FIG. 3 is a diagram illustrating an example of the configuration of the electronic pen included in the electronic blackboard system according to the present embodiment. FIG. 4 is a diagram illustrating an example of a writing pressure detection result in the electronic pen included in the electronic blackboard system according to the present embodiment. FIG. 5 is a diagram for explaining an example of A / D conversion processing performed on the pen pressure data in the electronic pen included in the electronic blackboard system according to the present embodiment. FIG. 6 is a diagram for explaining an example of linear conversion processing by the electronic blackboard of the electronic blackboard system according to the present embodiment. FIG. 7 is a diagram for explaining an example of linear conversion processing by the electronic blackboard of the electronic blackboard system according to the present embodiment.

  Exemplary embodiments of an electronic blackboard system, a writing pressure linearization method, and a program will be described below in detail with reference to the accompanying drawings.

  FIG. 1 is a block diagram showing an example of the configuration of the electronic blackboard system according to the present embodiment. As shown in FIG. 1, the electronic blackboard system according to the present embodiment can display an image such as an electronic pen 1 having a writing pressure detection function for detecting writing pressure and lines drawn by the electronic pen 1. The electronic blackboard 2.

  The electronic blackboard 2 is a so-called interactive whiteboard that can communicate with the electronic pen 1. In the present embodiment, the electronic blackboard 2 includes a display unit 201, a pen signal receiving unit 202, a controller 203, and a network I / F 204. The network I / F 204 is an interface that enables wireless communication with the electronic pen 1. The pen signal receiving unit 202 receives pen pressure data indicating the detection result of the pen pressure of the electronic pen 1 from the electronic pen 1 via the network I / F 204.

  The display unit 201 includes a display unit 205 that displays a line drawn by the electronic pen 1, and a touch panel 206 that can detect a touch operation (contact) with the electronic pen 1 on the display unit 205. The touch panel 206 includes a touch panel driver 207, a touch panel controller 208, an infrared LED 209, and a camera 210. The touch panel driver 207 is a driver that enables the controller 203 to control the touch panel 206.

  The infrared LED 209 is provided around the display unit 205 and emits infrared light on the screen of the display unit 205. The camera 210 detects the shielding of infrared rays by the electronic pen 1 when the electronic pen 1 comes into contact with the display unit 205. A touch panel controller 208 controls the entire touch panel 206. Specifically, the touch panel controller 208 obtains the position (contact position) of the touch operation on the display unit 205 by the electronic pen 1 by triangulation based on the detection result of the infrared light shielding by the camera 210.

  The controller 203 includes a CPU (Central Processing Unit) 211 that controls the entire electronic blackboard 2, a ROM (Read Only Memory) 212 that stores various programs such as a whiteboard application and a video conference application executed by the CPU 211, and a CPU 211. Have a RAM (Random Access Memory) 213 that functions as a work area when executing various programs stored in the ROM 212.

  The electronic pen 1 detects a writing pressure of the electronic pen 1 and outputs a voltage representing the writing pressure as writing pressure data, and digitally outputs analog writing pressure data output from the pressure sensor 101. A microcomputer 102 (hereinafter referred to as a microcomputer 102) that executes A / D conversion processing for converting the writing pressure data into a value, and a wireless module that transmits the writing pressure data to the electronic blackboard 2 by wireless communication or the like 103 (an example of a transmission unit). In the present embodiment, the microcomputer 102 transmits the writing pressure data subjected to the A / D conversion process to the electronic blackboard 2, but the writing pressure data output from the pressure sensor 101 is used as it is (that is, A / D). You may transmit to the electronic blackboard 2 without performing a conversion process.

  Next, an example of a functional configuration of the electronic blackboard 2 included in the electronic blackboard system according to the present embodiment will be described with reference to FIG. FIG. 2 is a block diagram illustrating an example of a functional configuration of the electronic blackboard included in the electronic blackboard system according to the present embodiment.

  In the present embodiment, a processor such as the CPU 211 executes a whiteboard application stored in a storage medium such as the ROM 212, thereby realizing the display control unit 211a, the conversion unit 211b, and the change unit 211c. The display control unit 211 a causes the display unit 205 to display an image such as a line drawn by the electronic pen 1 by the camera 210. In the present embodiment, the display control unit 211a obtains the movement locus of the contact position with respect to the display unit 205 by the electronic pen 1 based on the detection result of the infrared light shielding, and draws the obtained movement locus by the electronic pen 1. The displayed line is displayed on the display unit 205.

  The conversion unit 211b performs linear correction processing for converting the writing pressure data received by the pen signal receiving unit 202 into writing pressure data that changes linearly as the writing pressure increases. In the present embodiment, the pen pressure data received by the pen signal receiving unit 202 is converted into pen pressure data that increases linearly as the pen pressure increases. Thereby, it is not necessary to perform the linear correction process in the electronic pen 1, and the number of components to be mounted on the electronic pen 1 can be reduced, so that the electronic pen can be downsized. The changing unit 211c changes the thickness of the line displayed on the display unit 205 based on the writing pressure data that changes linearly. In the present embodiment, the changing unit 211c increases the thickness of the line displayed on the display unit 205 as the writing pressure data that changes linearly increases.

  Next, an example of writing pressure data output processing in the electronic pen 1 included in the electronic blackboard system according to the present embodiment will be described with reference to FIGS. 3 and 4. FIG. 3 is a diagram illustrating an example of the configuration of the electronic pen included in the electronic blackboard system according to the present embodiment. FIG. 4 is a diagram illustrating an example of a writing pressure detection result in the electronic pen included in the electronic blackboard system according to the present embodiment. In FIG. 4, the vertical axis represents the voltage (writing pressure data) output from the pressure sensor 101, and the horizontal axis represents the writing pressure of the electronic pen 1.

  In the present embodiment, the pressure sensor 101 is connected in series with a resistor R as shown in FIG. The pressure sensor 101 basically operates in the same manner as the resistance element Rx, and the resistance value decreases as the writing pressure of the electronic pen 1 increases. The microcomputer 102 is connected between the pressure sensor 101 (resistive element Rx) and the resistor R, and applies the voltage Vx (voltage V × (R / (R + Rx)) applied to the resistor R to the brush of the electronic pen 1. In this case, the voltage Vx is a voltage between the power supply and GND, and in this case, the voltage Vx detected by the microcomputer 102 is an electronic pen as shown in FIG. As the writing pressure of 1 increases, the amount of change gradually decreases and changes nonlinearly.

  Therefore, in the electronic blackboard system according to the present embodiment, the conversion unit 211b of the electronic blackboard 2 converts the writing pressure data received by the pen signal receiving unit 202 into writing pressure data that changes linearly as the writing pressure increases. As a result, a line having a thickness corresponding to the writing pressure can be displayed on the display unit 205.

  Next, an example of A / D conversion processing executed on writing pressure data in the electronic pen included in the electronic blackboard system according to the present embodiment will be described with reference to FIG. FIG. 5 is a diagram for explaining an example of A / D conversion processing performed on the pen pressure data in the electronic pen included in the electronic blackboard system according to the present embodiment.

  When the analog voltage (writing pressure data) output from the pressure sensor 101 is converted into a digital voltage in the microcomputer 102, the resolution depends on the resolution of the A / D conversion process in the microcomputer 102. For example, when the resolution of the A / D conversion processing of the microcomputer 102 is 12 bits, the writing pressure can be expressed in 4096 steps, and the wireless module 103 of the electronic pen 1 can output 12 bits of writing pressure data indicating the writing pressure in 4096 steps. Send to the electronic blackboard 2.

  However, the bit rate of communication between the electronic pen 1 and the electronic blackboard 2 is preferably 100 pps or more, and in that case, 12 bits × 100 pps = 150 bytes / s. In addition to the pen pressure data, the electronic pen 1 transmits to the electronic blackboard 2 ID information for distinguishing the electronic pen 1 and control data necessary for wireless communication such as Bluetooth (registered trademark). This may lead to a delay in displaying a line drawn by the electronic pen 1.

  By the way, when considering the number of bits necessary for writing pressure data, if the pitch interval of a general display is 0.1 to 1.0 mm, if the writing pressure can be expressed in about 200 steps, Since the thickness of the line can be changed up to ˜20.00 mm, it is sufficient that about 8-bit writing pressure data can be transmitted to the electronic blackboard 2.

  Therefore, in the present embodiment, the microcomputer 102 performs A / D conversion processing on the analog value pen pressure data output from the pressure sensor 101 into 12 bit (an example of the first bit number) digital value pen pressure data. Thereafter, the microcomputer 102 converts the 12-bit writing pressure data into 8 bits (an example of the second bit number) smaller than 12 bits. Then, the wireless module 103 transmits the writing pressure data converted into 8 bits to the electronic blackboard 2. Thereby, since the data amount of the writing pressure data from the electronic pen 1 to the electronic blackboard 2 can be reduced, it is possible to reduce the possibility of a delay in displaying a line drawn by the electronic pen 1.

  Next, an example of linear correction processing by the conversion unit 211b of the electronic blackboard 2 of the electronic blackboard system according to the present embodiment will be described using FIG. 6 and FIG. 6 and 7 are diagrams for explaining an example of linear conversion processing by the electronic blackboard of the electronic blackboard system according to the present embodiment. In FIG. 6, the vertical axis represents the voltage (writing pressure data) output from the pressure sensor 101, and the horizontal axis represents the writing pressure of the electronic pen 1.

  The pen pressure data received by the pen signal receiving unit 202 is non-linear data as shown by the solid line in FIG. 6, and the amount of change decreases as the pen pressure increases. Further, as shown in FIG. 7, when the thickness of a line displayed on the display unit 205 is changed according to a change in writing pressure data for which linear correction processing is not performed, the thickness of the line displayed on the display unit 205 is changed. Moreover, as the writing pressure increases, the amount of change decreases. Therefore, it becomes difficult to change the line thickness after a certain amount of writing pressure is applied.

  Therefore, in the present embodiment, as shown by the broken line in FIG. 6, the conversion unit 211b has the pen pressure data received from the electronic pen 1 equal to or higher than a preset threshold value by the least square method or the like. A linear correction process for converting the writing pressure data to linearly increase as the pressure increases is executed. Thereby, as shown in FIG. 7, when the thickness of the line displayed on the display unit 205 is changed in accordance with the change of the writing pressure data, the thickness of the line displayed on the display unit 205 also increases as the writing pressure increases. Can be changed linearly. Thereby, even after the user of the electronic pen 1 applies a certain amount of writing pressure, it becomes easy to change the thickness of the line. be able to.

  As described above, according to the electronic blackboard system according to the present embodiment, the electronic pen performs linear correction processing for converting the writing pressure data output from the pressure sensor 101 into writing pressure data that changes linearly as the writing pressure increases. 1 is eliminated, and the number of components to be mounted on the electronic pen 1 can be reduced, so that the electronic pen can be downsized.

  Note that the program executed on the electronic blackboard 2 of the present embodiment is provided by being incorporated in advance in the ROM 212 or the like, but is a CD-ROM, flexible disk (FD) in an installable or executable format file. Further, the recording medium may be provided by being recorded on a computer-readable recording medium such as a CD-R or a DVD (Digital Versatile Disk).

  Furthermore, the program executed on the electronic blackboard 2 of the present embodiment may be configured to be stored by being stored on a computer connected to a network such as the Internet and downloaded via the network. Further, the program executed on the electronic blackboard 2 of the present embodiment may be configured to be provided or distributed via a network such as the Internet.

  The program executed on the electronic blackboard 2 according to the present embodiment has a module configuration including the above-described units (the display control unit 211a, the conversion unit 211b, and the change unit 211c). The actual hardware includes the CPU 211 described above. By reading a program from the ROM 212 and executing it, the above-described units are loaded onto the main storage device, and a display control unit 211a, a conversion unit 211b, and a change unit 211c are generated on the main storage device.

DESCRIPTION OF SYMBOLS 1 Electronic pen 2 Electronic blackboard 101 Pressure sensor 102 Microcomputer 103 Wireless module 201 Display part 202 Pen signal receiving part 203 Controller 204 Network I / F
205 Display Unit 206 Touch Panel 207 Touch Panel Driver 208 Touch Panel Controller 209 Infrared LED
210 Camera 211 CPU
211a Display control unit 211b Conversion unit 211c Change unit 212 ROM
213 RAM

Japanese Patent Laid-Open No. 05-11915

Claims (4)

An electronic blackboard system comprising an electronic pen and an electronic blackboard having a display unit for displaying a line drawn by the electronic pen,
The electronic pen is
A pressure sensor that detects the writing pressure of the electronic pen and outputs a voltage representing the detected writing pressure as writing pressure data;
A transmission unit that transmits the pen pressure data output from the pressure sensor to the electronic blackboard,
The electronic blackboard
A receiving unit for receiving the writing pressure data from the electronic pen;
A converter that converts the received pen pressure data into the pen pressure data that linearly changes as the pen pressure increases;
Based on the writing pressure data that changes linearly, a changing unit that changes the thickness of the line displayed on the display unit;
Electronic blackboard system equipped with. The writing pressure data obtained by A / D converting the writing pressure data of an analog value into the writing pressure data of a digital value of a first bit number and A / D converting to the first bit number is converted into the first bit number. A controller for converting the number of bits into a smaller second bit number;
The electronic blackboard system according to claim 1, wherein the transmission unit transmits the writing pressure data converted into the second number of bits to the electronic blackboard. Display lines drawn with an electronic pen,
From the electronic pen, the voltage indicating the detection result of the writing pressure by the pressure sensor is received as writing pressure data,
The received pen pressure data is converted into the pen pressure data that changes linearly as the pen pressure increases,
Based on the writing pressure data that changes linearly, change the thickness of the line displayed on the display unit,
A pressure-pressure linearization method including: Computer
A display control unit for displaying a line drawn by the electronic pen on the display unit;
From the electronic pen, a receiving unit that receives a voltage indicating a detection result of the writing pressure by the pressure sensor as writing pressure data;
A converter that converts the received pen pressure data into the pen pressure data that linearly changes as the pen pressure increases;
Based on the writing pressure data that changes linearly, a changing unit that changes the thickness of the line displayed on the display unit;
Program to function as.

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