JP2001067183A - Coordinate input/detection device and electronic blackboard system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coordinate input/detection device capable of easily switching color information and improving user's working efficiency. SOLUTION: When a pointing object A such as a pen is inserted into a coordinate input area 3 formed on the inside of a casing 2, an image is obtained by photographing the area 3 in the inserted state of the object A, only the subject image of the object A is extracted on the basis of the photographed image and a reference image stored in a reference image storing means, coordinate information pointed out by the object A is detected on the basis of image forming positions of the extracted subject image of the object A on respective color image pickup elements 5 is detected, and the color information of the extracted subject image of the object A is detected. Since the color information can be easily switched only by changing the color of the object A, user' s working efficiency can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a coordinate input / detection device and an electronic blackboard system using the coordinate input / detection device.

[0002]

2. Description of the Related Art Conventionally, handwritten information written on a writing surface such as a whiteboard or a writing sheet by using a writing instrument is read by a dedicated scanner and output to recording paper by a dedicated printer. Blackboard devices are known. On the other hand, in recent years, an electronic blackboard system in which a coordinate input / detection device is arranged on a writing surface of an electronic blackboard so that information written by hand on the writing surface can be input to a computer in real time has been developed. Provided.

For example, a software board manufactured by Microfield Graphics, Inc. (Microfield Graphics, Inc.) is configured by arranging a coordinate input / detection device on a whiteboard. This is a device that makes it possible to capture visual data such as pictures into a computer in real time. In an electronic blackboard system configured using this software board, visual data captured by the software board is input to a computer and displayed on a CRT (Cathode Ray Tube), or displayed on a large screen using a liquid crystal projector. It is possible to output to recording paper by a printer. Further, it is also possible to project a screen of a computer to which the software board is connected on the software board with a liquid crystal projector and to operate the computer on the software board.

[0004] Further, a display device for displaying characters and images, a coordinate input / detection device having a coordinate input surface (touch panel surface) provided on the display surface of the display device, and an input device for inputting from the coordinate input / detection device. There is provided an electronic blackboard system including a control device for performing display control of a display device based on the display device and a display surface and a writing surface of the electronic blackboard using the display device and the coordinate input / detection device.

[0005] For example, a Smart 2000 manufactured by SMART Technologies Inc. uses a liquid crystal projector connected to a computer to project characters, pictures, figures, and graphics onto the panel. The process of taking in handwritten information into a computer is performed using a coordinate input / detection device (writing surface) provided on the display surface of the projection surface (display surface). Then, the handwritten information and the image information are combined in the computer, and can be displayed again in real time via the liquid crystal projector.

[0006] In such an electronic blackboard system, an image input using the coordinate input / detection device can be displayed as an overwrite image on an image on the screen displayed by the display device. It is widely used in presentations, educational sites, etc., and its use effect is highly evaluated. The electronic blackboard system is also used as an electronic conference system by incorporating a communication function such as voice and image into the electronic blackboard system and connecting remote locations with a communication line.

In recent years, various types of coordinate input / detection devices used in the electronic blackboard system have been considered in accordance with differences in input methods. However, when considering a method suitable for applying to the above-described electronic blackboard system, it is possible to perform input without having a physical surface such as a coordinate input surface (touch panel surface). Input / detection devices are considered promising. As described above, a coordinate input / detection device having no physical surface such as a coordinate input surface (touch panel surface) has excellent visibility even when used by being mounted on the surface of a display device. This is because upsizing is relatively easy.

[0008]

By the way, as a method of switching colors of characters and pictures in the conventional electronic blackboard system, for example, a dedicated input pen and a pen place are provided for each color, and the user can select the number of colors of the pen. There is a first method in which the color is switched by detecting whether or not the user has lifted the camera with a sensor in a pen storage area.

As another color switching method, a plurality of buttons for performing various operations are arranged on a display device by a function of electronic blackboard software which is application software incorporated in a control device of the electronic blackboard system. There is a second method in which a toolbar is displayed, and the color is switched by operating the user to each button assigned to the displayed toolbar. In addition, the buttons assigned to the toolbar include a plurality of pen buttons that allow you to select a drawing mode that allows you to write by hand by specifying the color of characters and pictures, as well as erase characters and pictures written by hand. Also included is an eraser button that allows you to select an erase mode that can be used.

However, according to the first method, there is a problem that the type of color is limited by physical conditions such as the number of input pens and the size of a pen storage space. In addition, when switching colors, the input pen of the color used up to that point must be placed in the pen storage area, and then the input pen of another color must be lifted.

On the other hand, the second method is excellent in that the number of types of colors can be increased by arranging pen buttons and eraser buttons for each color on the toolbar, but the number of buttons on the toolbar is large. There is a problem that the color selection operation becomes more complicated as the number of colors increases. Also, because of the button operation, it is easy to forget to return from the erase mode to the drawing mode, and the problem of erroneously erasing characters, lines, etc. frequently occurs.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a coordinate input / detection device in which color information can be easily switched to improve user's work efficiency.

An object of the present invention is to provide a coordinate input / detection device capable of outputting desired color information with a simple configuration.

An object of the present invention is to provide an electronic blackboard system capable of improving the operability of the system.

An object of the present invention is to provide an electronic blackboard system for preventing occurrence of forgetting to return from the erase mode to the drawing mode.

[0016]

According to a first aspect of the present invention, there is provided a coordinate input / detection device for inserting a pointing object which is formed inside a housing and has a predetermined color. A coordinate input area for receiving the input object, image input means having a plurality of color image sensors arranged at predetermined intervals on the housing to capture the entire coordinate input area, and the pointing object being present in the coordinate input area. A reference image storage unit for storing a reference image captured by the image input unit in a state where the pointing object is not inserted, and a subject image of the pointing object inserted from the photographed image of the pointing object inserted into the coordinate input area by the image input unit. Image extracting means for extracting only an image based on the reference image stored in the reference image storing means, and an image forming position on each color image sensor of the subject image extracted by the image extracting means. Coordinate information detecting means for detecting coordinate information specified by the pointing object inserted based on the image information; and detecting color information of the inserted pointing object based on the subject image extracted by the image extracting means. And color information detecting means.

Therefore, when a pointing object such as a pen is inserted into the coordinate input area formed inside the housing, the image input means obtains a photographed image of the coordinate input area with the pointing object inserted. Then, based on the captured image and the reference image stored in the reference image storage means, an image of only the subject image of the pointing object is extracted by the image extraction means. The coordinate detecting means detects coordinate information indicating the pointing object based on the image formation position of the extracted object image of the pointing object on each color image sensor, and the color information detecting means detects the object of the extracted pointing object. Image color information is detected. Thus, the color information can be switched only by changing the color of the pointing object.

According to a second aspect of the present invention, in the coordinate input / detection device according to the first aspect, at least a portion of the pointing object inserted into the coordinate input area is given a predetermined color.

Therefore, it is possible to output the color information desired by the user based on at least the predetermined color added to the portion inserted into the coordinate input area, thereby facilitating the creation of the pointing object.

According to a third aspect of the present invention, there is provided an electronic blackboard system, wherein a display device for displaying a drawing, and the coordinate input area are provided on a display surface of the display device, and the color information and the coordinate information are displayed. 3. The coordinate input / detection device according to claim 1 or 2, wherein drawing information based on the color information is used as the drawing at a coordinate position of the display device based on the coordinate information detected by the coordinate input / detection device. And a control device having display control means for displaying.

Therefore, by arranging the coordinate input area of the coordinate input / detection device according to claim 1 on the display surface of the display device, the visibility of the display device can be improved and special means can be provided. By switching the color information only by changing the color of the pointing object without providing, it is easy to switch the color of the drawing information in the display control means, thereby improving the operability of the system.

According to a fourth aspect of the present invention, in the electronic blackboard system according to the third aspect, the display control means is configured to execute the coordinate input / detection when the specific color information is detected by the coordinate input / detection device. The drawing already displayed at the coordinate position of the display device based on the coordinate information detected by the device is deleted.

Therefore, in the same manner as, for example, erasing a character described with a pencil with an eraser, the color of the pointing object is changed to a specific color and inserted into the coordinate input area, and a predetermined coordinate position of the display device is set. Can be erased by tracing a drawing already displayed on the screen, it is possible to prevent the user from forgetting to return from the erasing mode to the drawing mode without providing any special means.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. In the electronic blackboard system of the present embodiment, the coordinate input / detection device is mounted on the display surface of a large-sized plasma display panel (Plasma Display Panel) connected to a computer such as a personal computer. It is configured by connecting to a computer.

FIG. 1 is a front view schematically showing the configuration of a coordinate input / detection device 1 used in an electronic blackboard system. Plasma display panel P as a display device
The coordinate input / detection device 1 mounted on the display surface (display surface) d of the DP corresponds to the size of the display surface d in a space for performing coordinate input such as inputting characters or figures by handwriting. A housing 2 that defines a range of a certain coordinate input area 3 is provided.

An image input device 4 (left camera 4a, right camera 4b) functioning as image input means for outputting a photographed image as an electric signal is provided at both upper ends of the coordinate input area 3 of the housing 2. L are provided. The left camera 4a and the right camera 4b are electronic cameras, each having a two-dimensional image sensor (two-dimensional image sensor) 5 for color and an imaging optical lens 6 with a distance f therebetween. I have. The two-dimensional image sensor 5 is a two-dimensional color image sensor formed by arranging a large number of CCDs (Charge Coupled Devices) in a matrix, and performs R data and G data by photoelectrically converting a subject image. , B data as analog image signals.
Although not shown, the image input device 4 includes R data, G data output from the two-dimensional image sensor 5,
Each analog image signal of B data is converted into R data, G data,
An A / D converter for converting B data into digital image signals is also provided. Furthermore, the left camera 4a and the right camera 4b are installed such that their optical axes are parallel to the display surface d of the plasma display panel PDP and substantially coincide with the surface of the display surface d of the plasma display panel PDP. Have been. This prevents the display surface d of the plasma display panel PDP from being reflected on the left camera 4a and the right camera 4b.

On the other hand, at a peripheral portion excluding the upper portion of the coordinate input area 3 and at a position covering the entire field of view without obstructing the angle of view of the image input device 4 (the left camera 4a and the right camera 4b),
The background plate 7 is arranged. Here, FIG. 2 is a front view partially showing the background plate 7. As shown in FIG. 2, the background plate 7 is provided with a reference pattern P for facilitating extraction of a difference image described later. The reference pattern P in the present embodiment is a pattern in which a light and shade color arrangement is formed in a horizontal stripe shape. In addition, as the reference pattern P, for example, a pattern in which shades of light and shade are arranged in a vertical stripe shape, a color pattern used in chroma key technology, and the like can be considered.

In addition, a left camera 4a and a right camera 4b
, A light shielding plate B for limiting an imaging area is attached. Here, FIG. 3 is a front view schematically showing the light shielding plate B, and FIG. 4 is a sectional view partially showing the configuration of the coordinate input / detection device 1. As shown in FIG. 3, the light shielding plate B has a vertically long notch B1. Then, as shown in FIG. 4, the light shielding plate B is provided on the front surface of the imaging optical lens 6 of the left camera 4a and the right camera 4b, and limits the imageable area to be substantially the same as the coordinate input area 3. Are located in This narrows the field of view and reduces the occurrence of noise due to disturbance light or the like.

Next, the electrical connection of each part built in the coordinate input / detection device 1 will be described with reference to FIG. As shown in FIG. 5, each block other than the image input device 4 forms a controller 8. The controller 8 includes a bus 9 for connecting each unit including the image input device 4.
A CPU 10 for centrally controlling each unit, a ROM 11 for previously storing fixed data such as a control program, and a RAM 12 for rewritably storing variable data.
A timer T, an image processing unit 13 for executing distortion correction, gamma correction, binarization processing, etc., a differentiator 14 functioning as image extracting means, and an XYZ function functioning as coordinate information detecting means
An arithmetic unit 15 and an EEPROM 1 as a nonvolatile memory
6 and a controller 8 as a control device, a computer P
An interface (I / F) 17 for connecting to C;
It has. The RAM 12 has a coordinate memory 12.
a is provided. Further, the EEPROM 16 is provided with a reference image memory 16a functioning as reference image storage means. The reference image memory 16a stores a predetermined image such as a photographed image 18 (see FIG. 9) in an initial state at the time of starting the apparatus as a reference image 19 (see FIG. 9).

Next, the processing executed by the controller 8 according to the control program stored in the ROM 11 will be described. Here, FIG. 6 is a front view showing an example in which one point of the coordinate input area 3 is pointed by the pointing object A, FIG. 7 is a front view showing a part thereof in an enlarged manner, and FIG. FIG. 7 is an explanatory diagram schematically showing a coordinate detection processing procedure based on an electric signal. As shown in FIG. 6, a pointing object A such as a user's finger or a pen is inserted into the coordinate input area 3 of the coordinate input / detection device 1 and the pointing object A is used to insert a suitable object on the display surface d of the plasma display panel PDP. When pointing or touching the position (x, y, z), the image input device 4 (the left camera 4
a, an image of the background plate 7 and the pointing object A is formed on the two-dimensional image sensor 5 of the right camera 4b) via the imaging optical lens 6.

As shown in FIG. 8, the image of the background plate 7 and the pointing object A formed on the two-dimensional image sensor 5 is output to the image processing unit 13 as a digital image signal which is an electric signal. After undergoing predetermined processing in the image processing unit 13, it is output as a photographed image 18. Thus, the photographed image 18 output via the two-dimensional image sensor 5 of each of the left camera 4a and the right camera 4b
And the reference image 19 stored in the reference image memory 16a
Are input and accumulated in the differentiators 14 and the respective difference images 20 are detected.

FIG. 9 is an explanatory diagram showing an example of the reference image 19, and FIG. 10 is an explanatory diagram showing an example of the photographed image 18. As shown in FIG. 9, the reference image 19 is a digital image signal of a photographed image or the like in an initial state when the apparatus is started, and only the reference pattern P of the background plate 7 is photographed, as shown in FIG. , The captured image 18 has the reference image 1
The pointing object A is photographed in addition to the image 9. Accordingly, the difference image 20 is an image (silhouette image) of only the subject image of the pointing object A when the pointing object A is inserted into the coordinate input area 3. And
These difference images 20 are input to the XYZ calculator 15, and the position coordinates (x, y, z) of the pointing object A are detected.

Next, the process of detecting the position coordinates (x, y) by the XYZ calculator 15 will be described. As shown in FIG. 7, the distance h from the center 5a of the two-dimensional image sensor 5 to the imaging center point of the difference image (silhouette image of the pointing object A) 20 is determined by the center line of the two-dimensional image sensor 5, It depends on the angle θ formed by the line connecting the object A and the imaging center point h, and this angle θ is calculated as θ = arctan (h / f).

The image input device 4 (left camera 4a)
Is obtained as β = α−θ... By using the mounting angle α of the image input device 4. As a result, the angle β1 between the left camera 4a and the pointing object A, and the angle β1 between the right camera 4b and the pointing object A
Are calculated respectively.

As described above, the position coordinates (x,
y) is calculated and detected according to the principle of triangulation as x = Ltanβ2 / (tanβ1 + tanβ2)... y = xtanβ1.

Next, detection of the position coordinates (z) by the XYZ calculator 15 will be described. Here, FIG. 11 is a side view showing an example in which one point of the coordinate input area 3 is pointed by the pointing object A. As shown in FIG. 11, the position coordinate (z) indicates the distance between the tip of the pointing object A and the display surface d of the plasma display panel PDP (the optical axis of the image input device 4). However, depending on the distance D (see FIG. 7) from the image input device 4 to the pointing object A,
Z imaged on the two-dimensional image sensor 5 of the image input device 4
The distance between the imaging center point of the direction difference image (silhouette image of the pointing object A) 20 and the center 5a of the two-dimensional image sensor 5 is different. Here, FIG. 12 is an explanatory diagram showing the relationship between the imaging center point of the difference image 20 in the Z direction formed on the two-dimensional image sensor 5 and the distance D. As shown in FIG. 12, when the pointing object A is inserted at a position at a height Z from the display surface d of the plasma display panel PDP, the image input device 4 transfers the pointing object A to the pointing object A (here, the pointing object A1). In the case where the reaching distance is D1, an image is formed at a distance k1 from the center 5a of the two-dimensional image sensor 5, and the distance from the image input device 4 to the pointing object A (here, the pointing object A2) is D2. In this case, an image is formed at a position at a distance k2 from the center 5a of the two-dimensional image sensor 5. That is, even if the same pointing object A is at the same height Z from the display surface d of the plasma display panel PDP (the optical axis of the image input device 4), the image forming position is determined by the distance D from the image input device 4 to the pointing object A. It can be seen that k is different. Therefore, the position coordinates (z) of the pointing object A are
Based on the distance D calculated based on the position coordinates (x, y) and the angle θ of the pointing object A, z is calculated as z = D (k / f). In this manner, by detecting the position coordinates (z) of the pointing object A, it becomes easy to detect pen-up / pen-down, double-click, and the like during drawing. The above-mentioned formulas are stored in the ROM 11 in advance as a part of the control program.

The coordinate information indicating the position coordinates (x, y, z) of the pointing object A detected as described above is temporarily stored in the coordinate memory 12a.

In addition, the controller 8 executes the detection of the color of the difference image (the silhouette image of the pointing object A) 20 in the image processing section 13 functioning as the color information detecting means. Here, the color of the difference image 20 is determined from the size, ratio, and the like of each digital image signal of R data, G data, and B data that has been subjected to image processing such as distortion correction in the image processing unit 13. When detecting the color of the difference image 20, the controller 8 stores the color information corresponding to the color in the coordinate memory 12a together with the coordinate information. Therefore, the pointing object A
It is preferable to apply a pen or the like rather than a finger in that various colors can be given. For example, black, red, blue,
A plurality of drawing pens 33 (see FIG. 14) of a plurality of colors such as yellow and green are prepared in advance, and the user can obtain desired color information by selecting a desired drawing pen 33 from the drawing pens 33. become.

The coordinate information and color information of the pointing object A thus detected are sequentially input to the computer PC via the interface (I / F) 17.

Subsequently, a computer PC as a control device
Will be described. Here, FIG.
FIG. 3 is a block diagram showing electrical connections of various units built in the ASIC. As shown in FIG. 13, the computer PC controls a CPU 21 for controlling the entire system, a ROM 22 storing a startup program and the like, a RAM 23 used as a work area of the CPU 21, and inputs characters, numerical values, various instructions, and the like. 24, a mouse 25 for moving a cursor, selecting a range, and the like, and a hard disk 2
6, a graphics board 27 connected to the plasma display panel PDP for controlling display of an image on the plasma display panel PDP, and an interface (I /
F) 28 and a bus 29 for connecting the above-described units.

The hard disk 26 has an operating system (OS) 30,
A device driver 3 for operating the coordinate input / detection device 1 on the computer PC via the controller 8
1. Various application programs 32 such as drawing software, word processor software, spreadsheet software, and presentation software are stored.

The various application programs 32
OS that starts when the power to the computer PC is turned on
It is executed by the CPU 21 under the control of 30.
For example, when the drawing software is started by a predetermined operation of the keyboard 24 and the mouse 25, the graphics
Plasma display panel PDP via board 27
Displays a predetermined image based on the drawing software. Further, the device driver 31 is also activated together with the OS 30, and becomes ready to receive data input from the coordinate input / detection device 1. When the user inserts the pointing object A into the coordinate input area 3 of the coordinate input / detection device 1 and draws a character or a figure in a state where the drawing software is activated, the coordinate information and the color information correspond to the pointing object A. The image data is input to the computer PC as image data based on the description, and is displayed as an overwrite image on an image on the screen displayed on the plasma display panel PDP, for example. here,
The function of the display control means is executed. More specifically, the CPU 21 of the computer PC converts the input color information into RA
In the conversion table (not shown) of the drawing software developed in M23, drawing information for drawing a line or a character by converting into a color corresponding to the color information is generated, and the input coordinate information Video memory provided on the graphics board 27 in accordance with the position coordinates based on
(Not shown). Thereafter, the graphics board 27 transmits the drawing information written in the video memory to the plasma display panel PDP as an image signal, so that the same characters as the characters written by the user are displayed on the plasma display panel PDP. Will be. That is, since the computer PC recognizes the coordinate input / detection device 1 as a pointing device such as the mouse 25, the computer PC performs the same processing as writing characters using the mouse 25 on drawing software. Will be When generating drawing information for drawing a line or a character in a color based on the color information, specific color information (including a pattern (an optically identifiable pattern such as a barcode or a stripe)) is included. It is also possible to specify an erase mode indicating the function of the eraser and an erase mode indicating in the conversion table.

Here, description of characters and the like will be specifically described. Here, a pen-shaped drawing pen 33 as shown in FIG. The drawing pen 33 is painted in two colors near the center thereof. The first portion 33a having a pen tip is black, and the remaining second portion 33b is white. Also,
In this embodiment, when the color of the drawing pen 33 is white, the application program 3 treats the drawing pen 33 as erasing with an eraser without considering it as drawing in white.
It shall be stipulated in 2. First, a case where the first portion 33a of the drawing pen 33 is used will be described. Try to write letters and lines by hand on a blackboard or whiteboard,
By writing characters and lines on the display surface d of the plasma display panel PDP using the first portion 33a of the drawing pen 33, corresponding characters and lines can be displayed on the plasma display panel PDP. here,
FIG. 15 is an explanatory diagram showing a state in which the result of writing characters and lines by hand is displayed on the plasma display panel PDP. Since the first portion 33a of the drawing pen 33 is painted black, the written characters and lines are displayed in black as shown in FIG.

Next, the case where the second portion 33b of the drawing pen 33 is used will be described. Second part 3 of drawing pen 33
3b, a character or line displayed on the plasma display panel PDP is traced by a procedure similar to that for erasing a handwritten character or line to be erased with an eraser, and the traced portion is replaced by a real eraser. Will be erased. Here, FIG. 16 is an explanatory diagram showing a state in which the handwritten characters and lines shown in FIG. 15 have been deleted. Since the second portion 33b of the drawing pen 33 is painted white, the traced portion is erased and displayed as shown in FIG. As a result, the color of the drawing pen 33 is changed to a specific color, inserted into the coordinate input area 3, and displayed on the plasma display panel PDP, as in the case of erasing a character written with a pencil, for example, with an eraser. The character or line can be erased by tracing the character or line that has been set, so that it is possible to prevent the user from forgetting to return from the erase mode to the drawing mode without providing any special means.

The pointing object A which can output color information desired by the user with a simple configuration such as the drawing pen 33 described above, in which at least a part inserted into the coordinate input area 3 is given a predetermined color. It is possible to create.

Here, when the pointing object A such as a pen is inserted into the coordinate input area 3 formed inside the housing 2, the coordinate input area 3 is photographed with the pointing object A inserted. After obtaining an image, the captured image and the reference image memory 1
An image of only the subject image of the pointing object A is extracted based on the reference image stored in the reference object 6a, and the pointing object A is extracted based on the image forming position of each of the extracted subject images of the pointing object A on each color image sensor 5. And the color information of the extracted subject image of the pointing object A is detected. Thus, only by changing the color of the pointing object A,
Since the color information can be easily switched, the work efficiency of the user is improved, and the operability of the system is improved.

In this embodiment, two electronic cameras (the left camera 4a and the right camera 4b) are used as the image input device 4. However, the number of electronic cameras is not limited to two.
It is good if it is more than the unit.

Further, in the present embodiment, the coordinate input / detection device 1 is mounted on the plasma display panel PDP. However, the present invention is not limited to this.
(Liquid Crystal Display), RP (rear projection projector), or other types of display devices.

[0049]

According to the coordinate input / detection device according to the first aspect of the present invention, a case having a predetermined shape and an insertion of a pointing object formed inside the case and having a predetermined color are received. Image input means having a coordinate input area, a plurality of color image sensors arranged at predetermined intervals in the housing, and imaging the entire coordinate input area, and a state where the pointing object does not exist in the coordinate input area A reference image storage unit for storing a reference image captured by the image input unit; and a subject image of the pointing object only from the captured image of the pointing object inserted in the coordinate input area captured by the image input unit. Image extracting means for extracting an image based on the reference image stored in the reference image storing means; and an image extracting means for extracting an image of the subject image extracted by the image extracting means based on an image forming position on each color image sensor. Coordinate information detecting means for detecting coordinate information specified by the pointing object inserted by the user, and color information for detecting color information of the pointing object inserted based on the subject image extracted by the image extracting means When a pointing object such as a pen is inserted into a coordinate input area formed inside the housing, a captured image of the coordinate input area in a state where the pointing object is inserted is obtained, Based on the captured image and the reference image stored in the reference image storage means, an image of only the subject image of the pointing object is extracted, and the extracted subject image of the pointing object is extracted based on the image forming position on each color image sensor. By simply detecting the coordinate information pointed to by the pointing object and detecting the color information of the extracted object image of the pointing object, the color information can be easily switched simply by changing the color of the pointing object. It is possible to obtain, it is possible to improve work efficiency.

According to the second aspect of the present invention, in the coordinate input / detection device according to the first aspect, the pointing object is given a predetermined color at least at a portion inserted into the coordinate input area. Since the color information desired by the user can be output based on at least the predetermined color added to the insertion part in the coordinate input area, the pointing object can be easily created, and the desired color can be easily configured. Information can be output.

According to the electronic blackboard system of the third aspect of the present invention, a display device for displaying a drawing and the coordinate input area are provided on a display surface of the display device, and the color information and the coordinate information are provided. The coordinate input / detection device according to claim 1 or 2, further comprising: drawing information based on the color information at a coordinate position of the display device based on the coordinate information detected by the coordinate input / detection device. And a control device having display control means for displaying the image as a drawing, wherein the coordinate input area of the coordinate input / detection device according to claim 1 or 2 is arranged on a display surface of the display device, so that the visibility of the display device is improved. The color information can be switched only by changing the color of the pointing object without providing any special means. Give a it can be facilitated, thereby improving the operability of the system.

According to a fourth aspect of the present invention, in the electronic blackboard system according to the third aspect, the display control means comprises:
When the specific color information is detected by the coordinate input / detection device, the drawing already displayed at the coordinate position of the display device based on the coordinate information detected by the coordinate input / detection device is deleted. By changing the color of the pointing object to a specific color and inserting it into the coordinate input area as in the case of erasing a character described with a pencil with an eraser, for example, the drawing already displayed on the display device , The drawing can be erased, so that it is possible to prevent the user from forgetting to return from the erasing mode to the drawing mode without providing any special means.

[Brief description of the drawings]

FIG. 1 is a front view schematically showing a configuration of a coordinate input / detection device used in an electronic blackboard system according to an embodiment of the present invention.

FIG. 2 is a front view partially showing a background plate.

FIG. 3 is a front view schematically showing a light shielding plate.

FIG. 4 is a sectional view partially showing the configuration of a coordinate input / detection device.

FIG. 5 is a block diagram showing an electrical connection of each unit built in the coordinate input / detection device.

FIG. 6 is a front view showing an example in which a pointing object points to one point of a coordinate input area.

FIG. 7 is an enlarged front view showing a part thereof.

FIG. 8 is an explanatory diagram schematically illustrating a coordinate detection processing procedure based on an electric signal output from a two-dimensional image sensor.

FIG. 9 is an explanatory diagram illustrating an example of a reference image.

FIG. 10 is an explanatory diagram illustrating an example of a captured image.

FIG. 11 is a side view showing an example in which a pointing object points to one point of a coordinate input area.

FIG. 12 is an explanatory diagram illustrating a relationship between an imaging center point and a distance of a difference image in the Z direction formed on a two-dimensional image sensor.

FIG. 13 is a block diagram showing an electrical connection of each unit built in the computer.

FIG. 14 is a side view schematically showing a drawing pen.

FIG. 15 is an explanatory diagram showing a state in which the result of writing characters and lines by hand is displayed on the plasma display panel.

FIG. 16 is an explanatory diagram showing a state in which the handwritten characters and lines shown in FIG. 15 have been deleted.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 coordinate input / detection device 2 housing 3 coordinate input area 4 image input means 5 color image sensor 13 color information detection means 14 image extraction means 15 coordinate information detection means 16 a reference image storage means 18 photographed image 19 reference image 20 subject image only Image 33, A pointing object PC control device PDP display device d display surface

Claims (4)

[Claims] 1. A housing having a predetermined shape, a coordinate input area formed inside the housing and receiving insertion of a pointing object having a predetermined color, and arranged at a predetermined interval in the housing. An image input unit having a plurality of color image pickup devices and imaging the entire coordinate input area; and a reference image storing a reference image captured by the image input unit in a state where the pointing object does not exist in the coordinate input area. A storage unit, based on the reference image stored in the reference image storage unit, an image of only a subject image of the pointing object from a captured image obtained by capturing the pointing object inserted into the coordinate input area by the image input unit; Means for extracting the object image extracted by the image extracting means, and a position indicated by the pointing object inserted based on an image forming position on each color image sensor of the subject image extracted by the image extracting means. Coordinate input / detection device comprising: a coordinate information detection means for detecting information, and a color information detecting unit that detects color information of the inserted the pointing object based on the extracted subject image by the image extracting unit. 2. The coordinate input / detection device according to claim 1, wherein the pointing object is given a predetermined color at least at a portion inserted into the coordinate input area. 3. A display device for displaying a drawing, wherein the coordinate input area is provided on a display surface of the display device, and the color information and the coordinate information are detected.
The coordinate input / detection device described above, and display control means for displaying drawing information based on the color information as the drawing at a coordinate position of the display device based on the coordinate information detected by the coordinate input / detection device. An electronic blackboard system including a control device. 4. The display control means, when the specific color information is detected by the coordinate input / detection device, a coordinate position of the display device based on the coordinate information detected by the coordinate input / detection device. 4. The electronic blackboard system according to claim 3, wherein the drawing already displayed on the electronic blackboard is deleted.