JP2011140154A - Electronic blackboard system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric blackboard system which can prevent such nuisance as interference or wire-tapping from occurring between adjacent rooms, without deteriorating the operability of an electronic pen. <P>SOLUTION: The electronic pen 2 comprises a luminescent part which emits a visible light, an operation detecting part which detects the operation of a user, a modulation part which can obtain a modulated signal by modulating information concerning the operation of the user detected by the operation detecting part according to a modulation system of visible light communications, and a lighting control unit which controls the lighting of the luminescent part based on the modulated signal obtained by the modulation part. A display device 3 includes a light detecting part which detects the visible light, a demodulation part which can make available information regarding the operation of the user by demodulating the visible light detected by the light detecting part in accordance with a demodulation system corresponding with the modulation system, an image forming part which forms an image based on information, regarding the operation of the user, which is obtained by the demodulation part, and an image display part which displays the image formed by the image forming part on a screen. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electronic blackboard system used in a classroom of a school, a meeting room of a company, or the like.

  In recent years, electronic blackboard systems using large display devices of 50 inches or more have been developed. Patent Document 1 discloses an electronic blackboard system including a plasma display device, a touch panel disposed on a screen of the plasma display device, and a personal computer that displays an image on the plasma display device. In this electronic blackboard system, the touch panel is a user operation on the screen (for example, a drawing operation such as moving a finger while touching the touch panel, or a selection that touches an icon to select a color or width of a line to be drawn. Motion), and information related to the detected user operation is transmitted to the personal computer. The personal computer generates an image based on the received user operation information and displays the generated image on the plasma display device. Thereby, the user's operation is reflected on the screen of the plasma display device in real time.

JP 2000-43484 A

  By the way, the touch panel has a problem that the quality of the screen deteriorates due to the adhesion of scratches and oils as it is used repeatedly. Therefore, it is conceivable to employ an electronic pen instead of the touch panel as means for detecting a user operation. The electronic pen has a function of detecting a drawing operation or a selection operation of a user and transmitting information related to the detected user operation to a personal computer. Here, when wireless communication is adopted as the information transmission means, there is a risk of interference between the adjacent rooms or eavesdropping when used in school classrooms or corporate meeting rooms. When wired communication is adopted, interference and wiretapping can be prevented, but the operability of the electronic pen is deteriorated.

  Accordingly, an object of the present invention is to provide an electronic blackboard system that can prevent interference and wiretapping between adjacent rooms without degrading the operability of the electronic pen.

  An electronic blackboard system according to the present invention is an electronic blackboard system including an electronic pen, a screen, and a display device, and the electronic pen includes a light emitting unit that emits visible light, and an operation that detects a user operation. A detection unit, a modulation unit that obtains a modulation signal by modulating information on a user operation detected by the operation detection unit based on a modulation method of visible light communication, and a modulation signal obtained by the modulation unit. And a lighting control unit that controls lighting of the light emitting unit based on the light detection unit that detects visible light, and the visible light detected by the light detection unit corresponds to the modulation method. A demodulator that obtains information related to the user's operation by demodulating based on a demodulation method to perform, and an image generator that generates an image based on the information related to the user's operation obtained by the demodulator If, and an image display unit for displaying the generated image on the screen by the image generating unit.

According to the said structure, visible light communication is employ | adopted as a transmission means of information. In visible light communication, it is not necessary to connect the electronic pen and the display device with wiring, so that the operability of the electronic pen is not degraded. Further, in visible light communication, the communicable range is limited to the range where visible light can reach, so that interference and wiretapping between adjacent rooms can be prevented.
The display device includes a projector device and an image processing device that is communicably connected to the projector device, and the light detection unit, the demodulation unit, and the image display unit are included in the projector device. The image generation unit may be included in the image processing apparatus.

  According to the above configuration, since the light detection unit is included in the projector device, visible light communication is performed between the electronic pen and the projector device. Usually, an object that blocks visible light is not disposed between the projector device and the screen. That is, during use of the electronic pen, there is nothing that blocks visible light between the electronic pen and the projector device. Therefore, it is possible to suppress the occurrence of communication errors in visible light communication.

The operation detection unit includes a drawing button, a position detection unit that detects a position of the pen tip on the screen, and a pen tip position detected by the position detection unit when the drawing button is pressed. It is good also as providing the information output part which outputs the information which shows as information regarding a user's operation.
In order for the image processing apparatus to generate an image based on a user operation, it is necessary to know that the drawing button has been pressed on the electronic pen and the position of the pen tip at that time. At this time, if the detection timing of pressing the drawing button deviates from the detection timing of the pen tip position, accurate drawing cannot be performed. According to the above configuration, both the drawing button and the position detection unit are included in the electronic pen. Therefore, compared with the case where they exist separately, the shift between the detection timing of pressing the drawing button and the detection timing of the pen tip position can be reduced, and drawing can be performed more accurately.

  Further, the screen is rectangular, a reflection member that reflects a signal is provided on each of two orthogonal sides of the screen, and the position detection unit includes a signal emission unit that emits a signal in two orthogonal directions, A signal detector that detects signals reflected from the two orthogonal directions, and a signal is detected by the signal detector after the signals are emitted by the signal emitting unit for each of the two orthogonal directions. It is good also as providing the conversion part which converts the measurement part which measures time until, and the time measured by the said measurement part into the information which shows the position of the pen point on the said screen.

According to the above configuration, the position of the pen tip on the screen can be detected with a relatively simple configuration.
The drawing button is provided at a pen tip of the electronic pen so that a pressing direction thereof is orthogonal or inclined to a longitudinal direction of the electronic pen, and the electronic pen is parallel to the pressing direction of the drawing button. A swaying member that can be swayed about the direction and whose center of gravity is offset from the shaft may be provided, and the signal emitting unit and the signal detecting unit may be fixed to the swaying member.

  According to the above configuration, since the drawing button is provided at the pen tip, the drawing button is pressed when the pen tip of the electronic pen is pressed against the screen. Therefore, it is possible to draw on the screen with a natural operation. In addition, in order to accurately detect the position of the pen tip, it is necessary to maintain the direction in which the signal is emitted by the signal emitting unit in a certain direction during use of the electronic pen. According to the above configuration, the posture of the swing member is maintained so that the line connecting the shaft and the center of gravity of the swing member is vertical. Since such a swing member is provided with the signal emitting unit and the signal detecting unit, the direction in which the signal is emitted by the signal emitting unit can be maintained in a certain direction.

The projector device and the image processing device may be communicable by power line carrier communication.
According to the above configuration, it is possible to pass information related to user operations without providing wiring other than the power line between the projector apparatus and the image processing apparatus.
In addition, the screen and the display device are integrated to form a liquid crystal display device, and the operation detection unit includes a drawing button, a position detection unit that detects the position of the pen tip on the screen, An information output unit that outputs information indicating the position of the pen tip detected by the position detection unit as information related to a user's operation when the drawing button is pressed may be provided.

  In order for the image processing apparatus to generate an image based on a user operation, it is necessary to know that the drawing button has been pressed on the electronic pen and the position of the pen tip at that time. At this time, if the detection timing of pressing the drawing button deviates from the detection timing of the pen tip position, accurate drawing cannot be performed. According to the above configuration, both the drawing button and the position detection unit are included in the electronic pen. Therefore, compared with the case where they exist separately, the shift between the detection timing of pressing the drawing button and the detection timing of the pen tip position can be reduced, and drawing can be performed more accurately.

  Further, the screen is rectangular, a reflection member that reflects a signal is provided on each of two orthogonal sides of the screen, and the position detection unit includes a signal emission unit that emits a signal in two orthogonal directions, A signal detector that detects signals reflected from the two orthogonal directions, and a signal is detected by the signal detector after the signals are emitted by the signal emitting unit for each of the two orthogonal directions. It is good also as including the measurement part which measures time until, and the conversion part which converts the time measured by the said measurement part into the information which shows the position of the pen point on the said screen.

According to the above configuration, the position of the pen tip on the screen can be detected with a relatively simple configuration.
The light emitting unit is provided at a pen tip of the electronic pen so that a light emitting direction thereof is orthogonal or inclined with respect to a longitudinal direction of the electronic pen, and the electronic pen has a light emitting direction of the light emitting unit. A swaying member that can swing about a parallel direction as an axis, a center of gravity deviating from the axis is provided, and the signal emitting unit and the signal detecting unit may be fixed to the swaying member. .

  According to the above configuration, since the drawing button is provided at the pen tip, the drawing button is pressed when the pen tip of the electronic pen is pressed against the screen. Therefore, it is possible to draw on the screen with a natural operation. In addition, in order to accurately detect the position of the pen tip, it is necessary to maintain the direction in which the signal is emitted by the signal emitting unit in a certain direction during use of the electronic pen. According to the above configuration, the posture of the swing member is maintained so that the line connecting the shaft and the center of gravity of the swing member is vertical. Since such a swing member is provided with the signal emitting unit and the signal detecting unit, the direction in which the signal is emitted by the signal emitting unit can be maintained in a certain direction.

The figure which shows the whole structure of the electronic blackboard system which concerns on 1st Embodiment of this invention. The figure for explaining the detection principle of the position of the electronic pen on the screen It is a figure which shows the structure of an electronic pen, (a) is a front view, (b) is a side view, (c) is a rear view, (d) is a partially enlarged front view cut out by a dashed line. Figure Functional block diagram of electronic pen Functional block diagram of display device Flow chart showing operation of electronic pen Flow chart showing operation of electronic pen The figure which illustrates the format of pen information It is a figure which shows the structure of the liquid crystal display which concerns on 2nd Embodiment of this invention, (a) is a front view, (b) is sectional drawing. It is a figure which shows the structure of an electronic pen, (a) is a front view, (b) is a side view, (c) is a rear view, (d) is a partially enlarged front view cut out by a dashed line. Figure The figure which shows the use condition of an electronic pen in the electronic blackboard system which concerns on 2nd Embodiment of this invention. Block diagram of liquid crystal display device The figure which shows the modification by which a position detection part is arrange | positioned around the screen

DESCRIPTION OF EMBODIMENTS Embodiments for carrying out the present invention will be described in detail with reference to the drawings.
[First Embodiment]
<Overall configuration>
FIG. 1 is a diagram showing an overall configuration of the electronic blackboard system according to the first embodiment of the present invention.
The electronic blackboard system 1 includes an electronic pen 2, a display device 3, and a screen 4. The display device 3 includes a projector device 5 and an image processing device 6. The projector device 5 is connected to a power line 7 via a PLC (Power Line Communications) adapter 8. The image processing device 6 is connected to the power line 7 via the PLC adapter 9. As a result, information related to the user operation can be transmitted from the projector device 5 to the image processing device 6. The projector device 5 and the image processing device 6 are connected via a video signal line 10. Thereby, an image signal can be transmitted from the image processing device 6 to the projector device 5.

  The electronic pen 2 is operated by the user on the screen 4 (for example, a drawing operation such as moving the pen tip while being pressed against the screen, or a selection operation of pressing a button for selecting the color or width of the line to be drawn). And a function of transmitting information relating to the detected user operation to the projector device 5. Visible light communication is adopted as a communication means between the electronic pen 2 and the projector device 5.

The screen 4 is a sheet, a plate, a wall or the like for projecting the image projected from the projector device 5.
The projector device 5 has a function of transmitting information related to a user operation received from the electronic pen 2 to the image processing device 6 and a function of projecting an image on the screen 4 based on an image signal received from the image processing device 6. Power line carrier communication is employed as a communication means from the projector device 5 to the image processing device 6.

The image processing device 6 has a function of generating an image signal based on information related to a user operation and transmitting the image signal to the projector device 5. As the image processing apparatus 6, a personal computer can be used.
FIG. 2 is a diagram for explaining the principle of detecting the position of the electronic pen on the screen.
The screen 4 is rectangular, and reflection members 11 and 12 that reflect signals are provided on two orthogonal sides. The reflecting member 11 has a long shape, and its longitudinal direction is arranged in parallel to the x-axis direction of the screen 4. The reflecting member 12 has a long shape, and its longitudinal direction is arranged in parallel to the y-axis direction of the screen 4. The “signal” includes a sound wave or electromagnetic wave signal. In the present embodiment, a signal of light that is a kind of electromagnetic wave, in particular, a laser beam with excellent straightness is employed.

The electronic pen 2 emits signals in two orthogonal directions (x-axis direction and y-axis direction), detects signals reflected from the two directions, and outputs signals from each direction to detection. The time is measured, and the position of the pen tip is detected based on the time. In order to use this detection method, a configuration is required in which the signal emission direction does not change even if the posture of the electronic pen 2 changes (see A and B in the figure). Below, the structure of the electronic pen 2 is demonstrated.
<Configuration of electronic pen>
3A and 3B are diagrams showing the structure of the electronic pen, wherein FIG. 3A is a front view, FIG. 3B is a side view, FIG. 3C is a rear view, and FIG. FIG.

  As shown in FIGS. 3A and 3B, a conical transparent cover 22 is disposed on the front surface of the body 21, and a drawing button 23 is disposed on the top of the transparent cover 22. The drawing button 23 is configured to be pressed in a direction orthogonal to the longitudinal direction of the body 21 (conical axial direction). This drawing button 23 corresponds to the pen tip of the electronic pen. Since the drawing button 23 is provided at the pen tip, the drawing button 23 is pressed when the pen tip of the electronic pen 2 is pressed against the screen.

  As shown in FIG. 3C, on the back of the body 21, a light emitting unit 24 that emits visible light, a pen color button 25 for selecting a pen color, and a pen width button 26 for selecting a pen width. Also, a clear button 27 for erasing the drawn line is arranged. The light emitting unit 24 is disposed at a position corresponding to the back surface of the pen tip. Moreover, since the light emission part 24 is light-emitting at the time of drawing, it can make it easy to understand the position of the electronic pen 2 on a screen. As the light source of the light emitting unit 24, for example, an LED (Light Emitting Diode) can be adopted, and as the emission color, for example, red, green, blue, yellow, white, or the like can be adopted. In this example, three types of red (R), blue (B), and yellow (Y) are prepared as the pen color buttons 25, and thin (1), medium (2), and thick are provided as the pen width buttons 26. Three types (3) are prepared.

  As shown in FIG. 3 (d), a swaying member 29 having a shaft 28 perpendicular to the longitudinal direction of the body 21 as a swaying shaft is disposed inside the transparent cover 22. Since the center of gravity of the swing member 29 is deviated from the swing axis, even if the posture of the electronic pen 2 fluctuates, the swing member 29 so that the line connecting the center of gravity of the swing member 29 and the swing axis is vertical. Is maintained. A laser 30, a laser detection unit 31, a laser 32, and a laser detection unit 33 are arranged on the swing member 29. The laser 30 is arranged to emit laser light in a direction (x-axis direction) orthogonal to a line connecting the center of gravity of the swing member 29 and the swing axis. The laser detector 31 is arranged so as to detect laser light reflected from the x-axis direction. The laser 32 is arranged to emit laser light in a direction (y-axis direction) parallel to a line connecting the center of gravity of the swing member 29 and the swing axis. The laser detector 33 is arranged so as to detect the laser beam reflected from the y-axis direction. With such a configuration, even if the posture of the electronic pen 2 changes, the emission direction of the laser light of the lasers 30 and 32 does not change.

FIG. 4 is a functional block diagram of the electronic pen.
The electronic pen 2 includes a user operation detection unit 110, a visible light communication modulation unit 120, a light emission control unit 130, and a light emission unit 24. The user operation detection unit 110 includes an x laser 30, an x laser detection unit 31, a y laser 32, a y laser detection unit 33, a drawing button 23, a pen color button 25, a pen width button 26, a clear button 27, and an x position detection unit 111. , A y position detection unit 112, a button press detection unit 113, and a pen information generation unit 114. The x laser 30 and the y laser 32 correspond to a signal emitting unit that emits signals in two orthogonal directions. The x laser detection unit 31 and the y laser detection unit 33 correspond to a signal detection unit that detects signals reflected from two orthogonal directions. Further, the x laser 30, the x laser detection unit 31, the y laser 32, the y laser detection unit 33, the x position detection unit 111, and the y position detection unit 112 correspond to a position detection unit that detects the position of the pen tip on the screen. To do.

  The x position detection unit 111 has a function of measuring the time from when the x laser 30 emits the laser light until the x laser detection unit 31 detects the laser light, and the measured time is the x of the pen tip on the screen. And a function of converting to a position in the axial direction. The time measurement can be performed, for example, by using an interference effect between the laser light emitted from the x laser 30 and the laser light detected by the x laser detection unit 31. The conversion of the position can be performed by preliminarily storing the relationship between time and position in a memory and specifying the position corresponding to the obtained time using the relationship stored in the memory.

  The y position detection unit 112 has a function of measuring the time from when the y laser 32 emits the laser light until the y laser detection unit 33 detects the laser light, and the measured time is the y of the pen tip on the screen. And a function of converting to a position in the axial direction. The time measurement function of the x-position detection unit 111 and the time measurement function of the y-position detection unit 112 are from the time when the laser beam is emitted from the laser to the time when the laser beam is detected by the laser detection unit in each of two orthogonal directions It corresponds to a measuring unit that measures time. In addition, the position conversion function of the x position detection unit 111 and the position conversion function of the y position detection unit 112 correspond to a conversion unit that converts the measured time into information indicating the position of the pen tip on the screen.

The button press detection unit 113 detects pressing of various buttons.
The pen information generation unit 114 generates pen information in a specific format from information related to user operations obtained from the x position detection unit 111, the y position detection unit 112, and the button press detection unit 113. The format of the pen information is illustrated in FIG. The pen information is composed of fields 41 to 45, in which the x coordinate is written in the field 41, the y coordinate in the field 42, the pen color in the field 43, the pen width in the field 44, and the presence / absence of clearing in the field 45.

The visible light communication modulation unit 120 obtains a modulated signal by modulating pen information based on a modulation method of visible light communication.
The light emission control unit 130 controls the lighting of the light emitting unit 24 based on the modulation signal.
<Configuration of display device>
Next, the configuration of the display device 3 will be described. FIG. 5 is a functional block diagram of the display device.

  The display device 3 includes a projector device 5 and an image processing device 6. The projector device 5 includes a light detection unit 151, a visible light communication demodulation unit 152, a PLC communication modulation unit 153, a lamp 154, a liquid crystal unit 155, a lens 156, an image signal input unit 157, and a liquid crystal control unit 158. The image processing apparatus 6 includes a PLC communication demodulation unit 161, a pen image generation unit 162, a background image storage unit 163, an image composition unit 164, and an image signal output unit 165.

The light detection unit 151 detects visible light emitted from the light emitting unit 24. As the light detection unit 151, for example, a photodiode can be employed.
The visible light communication demodulation unit 152 obtains pen information (information related to user operation) by demodulating the visible light detected by the light detection unit 151 based on the demodulation method of visible light communication.
The PLC communication modulation unit 153 obtains a modulation signal by modulating pen information based on the modulation method of power line carrier communication.

The PLC communication demodulation unit 161 obtains pen information (information related to user operation) by demodulating the modulation signal based on the demodulation method of power line carrier communication.
The pen image generation unit 162 generates a pen image based on a user operation by analyzing each field of the pen information.
The background image storage unit 163 stores a background image.

The image composition unit 164 synthesizes the base image stored in the base image storage unit 163 and the pen image generated by the pen image generation unit 162.
The image signal output unit 165 outputs an image signal of the composite image obtained by the image composition unit 164.
The lamp 154 illuminates the external screen 4 through the lens 156. A liquid crystal unit 155 is interposed in the optical path from the lamp 154 to the lens 156.

The image signal input unit 157 receives an image signal of a composite image.
The liquid crystal control unit 158 functions as an image display unit that displays an image on the screen, and controls the liquid crystal unit 155 based on the image signal of the composite image obtained by the image signal input unit 157, thereby displaying the composite image on the screen 4. To display.
<Operation of electronic pen>
Next, the operation of the electronic pen will be described. 6 and 7 are flowcharts showing the operation of the electronic pen.

The electronic pen initializes the memory when the power is turned on (step S1), and enters a standby state until any of the pen color button, pen width button, clear button, and drawing button is pressed by a user operation (step S2, S2). S4, S6, S8: No).
When any one of the pen color button, the pen width button, and the clear button is pressed in the standby state (steps S2, S4, S6: Yes), information indicating the pressed button is saved in the memory each time (step S2). S3, S5, S7).

When the drawing button is pressed in the standby state (step S8: Yes), the position of the electronic pen on the screen is detected (step S9). The detection of the position is as described above, and as a result, the x coordinate and the y coordinate are obtained.
Next, the electronic pen reads information indicating the pressed button from the memory (step S10), and generates the pen information by combining them with the position information obtained in step S9 (step S11). Transmit (step S12). The pen information is transmitted using visible light communication as described above.

  Next, the electronic pen waits for a certain period (step S13), and determines whether or not the drawing button is kept pressed (step S14). If the pressing of the drawing button is maintained (step S14: Yes), an exemplary operation from steps S9 to S13 is repeated. As a result, the pen information is transmitted at regular intervals while the drawing button is kept pressed. Thereby, a line can be drawn using an electronic pen. On the other hand, if pressing of the drawing button is not maintained (step S14: No), the process returns to step S2.

According to the structure of 1st Embodiment, since visible light communication is employ | adopted, it is not necessary to connect the electronic pen 2 and the display apparatus 3 with wiring, and the operativity of the electronic pen 2 is not degraded. Moreover, in visible light communication, the communicable range is limited only to the range where visible light can reach, so that interference and wiretapping between adjacent rooms can be prevented.
[Second Embodiment]
In the second embodiment, an electronic blackboard system using a liquid crystal display device will be described.

FIG. 9 is a diagram showing a configuration of a liquid crystal display according to the second embodiment of the present invention, in which (a) is a front view and (b) is a cross-sectional view.
The liquid crystal display device 50 includes a housing 51, reflecting members 52 and 53, protective glass 54, a liquid crystal panel 55, a light guide panel 56, a circuit board 57, a light emitting element 58, and a light detection unit 59.
In this embodiment, the protective glass 54 functions as a transmissive screen. The protective glass 54 is rectangular, and reflection members 52 and 53 that reflect signals are provided on two orthogonal sides. The configuration other than the protective glass 54 of the liquid crystal display device 50 functions as a display device that displays an image on a screen.

10A and 10B are diagrams showing the structure of the electronic pen, where FIG. 10A is a front view, FIG. 10B is a side view, FIG. 10C is a rear view, and FIG. FIG.
The electronic pen 70 includes a body 71, a transparent cover 72, a light emitting unit / drawing button 73, a pen color button 75, a pen width button 76, a clear button 77, a shaft 78, a swing member 79, a laser 80, a laser detection unit 81, and a laser. 82 and a laser detector 83. In this example, a light emitting unit / draw button 73 is provided on the front of the body 71 instead of the light emitting unit on the back of the body 71. Other configurations are the same as those in the first embodiment. The light emitting unit / drawing button 73 is a combination of a light emitting unit that emits visible light and a drawing button. The functions of the light emitting unit and the drawing button are the same as those described in the first embodiment.

FIG. 11 is a diagram illustrating a usage state of the electronic pen in the electronic blackboard system according to the second embodiment of the present invention. When the light emitting unit / drawing button 73 is pressed against the protective glass 54, the light emitting unit / drawing button 73 emits light to transmit information related to the user operation through visible light communication. The light detection unit 59 detects visible light that has passed through the liquid crystal panel 55 and the light guide panel 56.
FIG. 12 is a block diagram of the liquid crystal display device.

The liquid crystal display device 50 includes a light detection unit 59, a visible light communication demodulation unit 172, a pen image generation unit 173, a background image storage unit 174, an image composition unit 175, a backlight 176, a liquid crystal panel 55, and a liquid crystal control unit 178. The configuration other than the backlight 176 and the liquid crystal panel 55 is the same as that described in the first embodiment.
The backlight 176 includes a light guide panel 56, a circuit board 57, and a light emitting element 58, and illuminates the liquid crystal panel 55 from behind.

According to the configuration of the second embodiment, since visible light communication is adopted, it is not necessary to connect the electronic pen 70 and the liquid crystal display device 50 including the display device with wiring, and the operability of the electronic pen 70 is reduced. There is nothing. Moreover, in visible light communication, the communicable range is limited only to the range where visible light can reach, so that interference and wiretapping between adjacent rooms can be prevented.
As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to the said embodiment. For example, the following modifications can be given.
(1) In the embodiment, the position detection unit for detecting the position of the electronic pen on the screen is included in the electronic pen, but the present invention is not limited to this. For example, as shown in FIG. 13, the position detection unit 90 may be arranged around the screen 4. The position detection unit 90 includes a laser 91, a polygon mirror 92, a laser detection unit 93, and a light emitting unit 94. The laser 91 is disposed so as to emit laser light toward the polygon mirror 92. The polygon mirror 92 rotates and changes the reflection angle of the laser light with time. The laser detector 93 detects the laser light reflected from the electronic pen 2. The angle of the polygon mirror 92 when the laser detector 93 detects the reflected light from the electronic pen 2 and the time until the reflected light is detected by the laser detector 93 after the laser 91 emits the laser light. By measuring, the position of the electronic pen on the screen can be detected. The light emitting unit 94 transmits information indicating the position of the electronic pen by visible light communication.
(2) In the first embodiment, the projector device includes a light detection unit that detects visible light emitted from the light emitting unit of the electronic pen. However, the present invention is not limited to this. For example, it may be included in the image processing apparatus. However, the possibility that communication errors can be suppressed can be increased by including the projector device.
(3) In the embodiment, the position of the electronic pen is detected by measuring the time from the emission of the laser light to the detection, but the present invention is not limited to this. For example, a method may be used in which fine dots are printed on the screen and the position on the screen is detected by detecting the shape of the dots.
(4) In the embodiment, the swing member is employed as means for emitting laser light in a certain direction even when the posture of the electronic pen changes, but the present invention is not limited to this. For example, an example including an attitude sensor such as a three-dimensional acceleration sensor and an adjusting unit that adjusts the emitting direction of the laser light based on the attitude detected by the attitude sensor may be used.
(5) In the embodiment, the drawing button is provided on the pen tip and the drawing button is pressed by touching the screen. However, the present invention is not limited to this. For example, a drawing button may be provided on the back of the electronic pen and the user may press it with a finger.
(6) In the embodiment, the drawing button is pressed in a direction orthogonal to the longitudinal direction of the electronic pen, but the present invention is not limited to this. For example, the drawing button may be pressed in a direction inclined in the longitudinal direction.

  The present invention can be used, for example, in an electronic blackboard system used in a school classroom, a company conference room, or the like.

DESCRIPTION OF SYMBOLS 1 Electronic blackboard system 2 Electronic pen 3 Display apparatus 4 Screen 5 Projector apparatus 6 Image processing apparatus 7 Power line 8 PLC adapter 9 PLC adapter 10 Video signal line 11,12 Reflective member 21 Body 22 Transparent cover 23 Drawing button 24 Light emission part 25 Pen color Button 26 Pen width button 27 Clear button 28 Axis 29 Shaking member 30, 32 Laser 31, 33 Laser detector 41-45 Field 50 Liquid crystal display device 51 Housing 52, 53 Reflective member 54 Protective glass 55 Liquid crystal panel 56 Light guide panel 57 Circuit Board 58 Light Emitting Element 59 Light Detection Unit 70 Electronic Pen 71 Body 72 Transparent Cover 73 Light Emitting / Drawing Button 75 Pen Color Button 76 Pen Width Button 77 Clear Button 78 Axis 79 Shaking Member 80, 82 Laser 81, 83 Laser Detection unit 90 Position detection unit 91 Laser 92 Polygon mirror 93 Laser detection unit 94 Light emission unit 110 User operation detection unit 111 Position detection unit 112 Position detection unit 113 Button press detection unit 114 Pen information generation unit 120 Visible light communication modulation unit 130 Light emission control Unit 151 light detection unit 152 visible light communication demodulation unit 153 PLC communication modulation unit 154 lamp 155 liquid crystal unit 156 lens 157 image signal input unit 158 liquid crystal control unit 161 PLC communication demodulation unit 162 pen image generation unit 163 base image storage unit 164 image composition 165 Image signal output unit 172 Visible light communication demodulation unit 173 Pen image generation unit 174 Base image storage unit 175 Image composition unit 176 Backlight 178 Liquid crystal control unit

Claims (9)

An electronic blackboard system comprising an electronic pen, a screen, and a display device,
The electronic pen is
A light emitting unit that emits visible light;
An operation detection unit for detecting a user operation;
A modulation unit that obtains a modulation signal by modulating information on a user operation detected by the operation detection unit based on a modulation method of visible light communication;
A lighting control unit that controls lighting of the light emitting unit based on a modulation signal obtained by the modulation unit,
The display device
A light detection unit for detecting visible light;
A demodulator that obtains information about the user's operation by demodulating the visible light detected by the light detector based on a demodulation scheme corresponding to the modulation scheme;
An image generation unit that generates an image based on information on the user's operation obtained by the demodulation unit;
An electronic blackboard system, comprising: an image display unit configured to display an image generated by the image generation unit on the screen. The display device includes a projector device and an image processing device connected to be able to communicate with the projector device,
The light detection unit, the demodulation unit, and the image display unit are included in the projector device,
The electronic blackboard system according to claim 1, wherein the image generation unit is included in the image processing apparatus. The operation detection unit is
A draw button and
A position detector for detecting the position of the pen tip on the screen;
The information output part which outputs the information which shows the position of the pen tip detected by the position detection part as information about a user's operation when the drawing button is pushed down. The electronic blackboard system described. The screen is rectangular, and a reflecting member that reflects a signal is provided on each of two orthogonal sides of the screen,
The position detector is
A signal emitting unit that emits signals in two orthogonal directions;
A signal detection unit for detecting signals reflected from the two orthogonal directions;
For each of the two orthogonal directions, a measuring unit that measures a time from when a signal is emitted by the signal emitting unit until a signal is detected by the signal detecting unit,
The electronic blackboard system according to claim 3, further comprising: a conversion unit that converts time measured by the measurement unit into information indicating a pen tip position on the screen. The drawing button is provided on the pen tip of the electronic pen so that the pressing direction thereof is perpendicular or inclined to the longitudinal direction of the electronic pen,
The electronic pen is provided with a swinging member that can swing about a direction parallel to the pressing direction of the drawing button as an axis, and whose center of gravity is deviated from the axis.
The electronic blackboard system according to claim 4, wherein the signal emitting unit and the signal detecting unit are fixed to the swing member. The electronic blackboard system according to claim 2, wherein the projector device and the image processing device can communicate with each other by power line carrier communication. The screen and the display device are integrated to form a liquid crystal display device,
The operation detection unit is
A draw button and
A position detector for detecting the position of the pen tip on the screen;
The information output part which outputs the information which shows the position of the pen tip detected by the position detection part as information about a user's operation when the drawing button is pushed down. The electronic blackboard system described. The screen is rectangular, and a reflecting member that reflects a signal is provided on each of two orthogonal sides of the screen,
The position detector is
A signal emitting unit that emits signals in two orthogonal directions;
A signal detection unit for detecting signals reflected from the two orthogonal directions;
For each of the two orthogonal directions, a measuring unit that measures a time from when a signal is emitted by the signal emitting unit until a signal is detected by the signal detecting unit,
The electronic blackboard system according to claim 7, further comprising: a conversion unit that converts time measured by the measurement unit into information indicating a pen tip position on the screen. The light emitting unit is provided at the pen tip of the electronic pen so that the light emission direction is orthogonal or inclined to the longitudinal direction of the electronic pen,
The electronic pen can be swayed around a direction parallel to the light emitting direction of the light emitting unit, and a swaying member having a center of gravity shifted from the axis is provided.
The electronic blackboard system according to claim 8, wherein the signal emission unit and the signal detection unit are fixed to the swing member.

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