JP4157577B2 - Coordinate input device - Google Patents

Description

  The present invention relates to an input device such as a mouse, a touch panel, or a pen input device used for operating a computer, and more particularly, to a coordinate input device capable of performing a pointing operation on both a display screen and a top surface of a desk.

  As a conventional technique, there is an optical digitizer disclosed in JP-A-11-3170. This is located above and to the left and right of the display screen, and detects the pointing position of a finger, pen, etc. by processing the imaging signals of two line cameras that image the surface along the display screen from the side. A peripheral frame is provided around the display screen to prevent unnecessary external light from entering the camera.

  When such a technique is applied to a display device of a personal computer used on a desk, the display screen can be pointed with a finger or a pen like a touch panel, so that a more intuitive operation is possible.

Japanese Patent Laid-Open No. 11-3170

  However, since the display screen is usually installed perpendicular to the desk surface, when performing long-time handwriting input such as inputting characters or pictures using a pen, touch the pen on the display screen. However, there is a problem that the workability is poor and the fatigue of the operator is increased.

  In addition, when touch input is performed on the display screen, if a finger or a pen is brought close to the display screen, the input is performed even if the screen is not actually touched. This is because a touch input is detected as soon as a finger or pen enters the image of a camera having a field of view in a surrounding frame having a certain width.

  In order to solve such operability problems, the present invention operates a computer while viewing a display screen of a display device connected to a computer and located on a desk, and operates an indicator such as a finger or a pen. In the coordinate input device for performing the above, the coordinate detection range of the pointing position of the pointing tool such as a finger or a pen is not only the display surface of the display screen but also at least both of the predetermined desktop coordinate detection area surface on the upper surface of the desk It is located in the vicinity of the extended surface of the display screen and above and to the left and right of the display screen so that both the side surface of the object touching an arbitrary place on the display screen and the desktop coordinate detection area surface are in the field of view. Based on the two cameras that capture the image that falls within the field of view and the image signals output from the two cameras, the indicated coordinate values of the pointing tool such as a finger or pen that are indicated within the coordinate detection range are calculated. , Computer A control circuit for input to the program, and so comprises a.

  In addition, in order to solve the touch detection problem that touch detection is performed without touching the display surface, a highly reflective member and a reflectivity are provided on three sides except the upper side around the display screen. A peripheral reflection frame installed so that the boundary line of these members falls within the field of view of the two cameras, and a display surface when an indicator such as a finger or a pen crosses the boundary line Touch control means for determining that there has been a touch input to is provided in the control circuit.

  Further, the pointing tool such as a pen includes a retroreflective member at the tip thereof, and each of the two cameras includes an illumination unit that illuminates a coordinate detection range in the vicinity of the imaging lens of the camera. It is preferable that the camera receives the reflected light reflected by the retroreflective member. The pointing device may have a pressure sensitive sensor.

  Further, such a coordinate input device can be provided with a display screen of a computer so as to have an integrated structure with two cameras.

  In any case, the control circuit can be configured to calculate the coordinate value as a unit independent of the computer body, and to input the calculated coordinate value to the computer, or to directly input the image signal of the camera to the computer. It is also possible to configure the control circuit using driver software and a computer operating on the computer so that the input can be performed.

  When a finger or pen touches the display screen, the two cameras above and below the display screen capture the image of the finger or pen in contact with the screen from the side and process this captured image signal with the control circuit. Since the angle between the camera and the straight line connecting the touch position is obtained for each two cameras with respect to the base line connecting the cameras, the control circuit performs triangulation calculation using this value to obtain the coordinate value, It acts to pass the coordinate value on the display screen of the touch position to the program operating on the computer.

  In addition, when a finger or pen is placed on a predetermined detection area on the desk, the control circuit performs processing from the captured image signals of the two cameras to obtain the coordinate value of the tip of the finger or pen. It works to pass the value to the program running on the computer.

  According to the above means, even when an operator starts an application program and touches the screen directly with a finger or a pen, the operator touches a predetermined area on the desk to perform the operation. Since menu selection, etc., can be performed directly on the screen, and when performing handwritten character recognition, etc., the pen operation is performed on the desk, so that smooth and comfortable operation with less fatigue is achieved. The effect that it can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a preferred embodiment of the coordinate input device of the present invention. A display device 1 connected to a computer is placed on a desk 10. The display screen 6 of the display device 1 is set substantially perpendicular to the upper surface of the desk 10. In the display device 1, cameras 2 are incorporated in two places on the upper left and right sides of the display screen 6. In FIG. 2, which is an enlarged view of the camera 2, the camera 2 includes an imaging lens 21 and an area image sensor 22. The imaging lens 21 is a wide-angle lens having an angle of view of about 90 degrees. The central axes of the fields of view of the two cameras are parallel to the display screen and directed diagonally to the display screen. An infrared light emitting diode 23 that emits infrared light is provided next to the imaging lens 21 to illuminate the periphery of the display screen 6 and the desk 10.

  As shown in FIG. 1, the display device 1 is provided with surrounding reflection frames 5 on three sides surrounding the display screen 6. As shown in FIG. 3, a narrow retroreflective tape 51 is attached to the peripheral reflection frame 5 closer to the display screen 6, and a nonreflective black tape 52 is attached in contact with the retroreflective tape 51. Yes. Retroreflective tape is a member that reflects light faithfully in the direction in which the light came. Since the reflected light of the sign illuminated by the headlight of the car is efficiently directed toward the driver, it is often used for traffic signs and the like. It is easy to obtain.

  A desk coordinate detection area 7 is located on the desk 10 from directly below the display screen 6 toward the front. A mark or the like indicating this area may be pasted on the desk 10 to make it clear, but it may be omitted.

  An image shown in each camera 2 is shown in FIG. 4A shows the case where the display screen 6 is touched with the finger 8, FIG. 4B shows the case where the display screen 6 is touched with the pen 4, and FIG. 4C shows the case where the pen 4 contacts the desktop coordinate detection area 7. It is an image of the case.

  FIG. 5 shows details of the pen 4 used in this embodiment. The pen point member 43 protrudes from the tip of the pen body 41 and is connected to the pressure sensor 42 inside the pen body 41, and the output signal of the pressure sensor 42 is connected to the control circuit 3 through a cable. A retroreflective tape 44 is wound around a portion near the tip of the pen body 41.

  First, the operation when the display screen 6 is touched with the finger 8 will be described. FIG. 4A shows an image captured by the camera when the display screen 6 is touched with the finger 8. Since the center of the field of view of the camera 2 is set to be the side of the surface of the display screen, the imaging area 99 inside is not used. Further, behind the finger image 93, an image of the surrounding reflection frame 5 with a bright black and white contrast is shown. A retroreflective tape 51 is provided inside the surrounding reflection frame 5, that is, at a position close to the display screen 6, and efficiently reflects the light of the infrared light emitting diode 23 provided near the camera 2 to generate a strong white signal. Is imaged. Accordingly, the finger image 93 is captured as a shadow of the retroreflective tape image 91.

  The imaging signals of the two cameras 2 are connected to the control circuit 3 as shown in FIG. 1, and the control circuit 3 uses the white and black boundary lines of the surrounding reflection frame 5, that is, the retroreflective tape image 91 and the black tape. An image of the boundary line with the image 92 is detected, and a horizontal pixel row slightly deviated from the boundary line image to the white side is extracted (S71 in FIG. 7). FIG. 6A shows a signal of this pixel column. Since this pixel row includes information on the place where the finger 8 and the display screen 6 are in contact, the control circuit 3 determines the angle with respect to each camera from the cut-off pixel positions of the left and right camera images as shown in FIG. Obtaining (S73), the coordinate value touched by the finger by triangulation calculation is obtained from each angle, and the coordinate value is sent to the computer (S74).

  Next, the operation of the control circuit 3 when the pen 4 touches the display screen 6 will be described. When the pen 4 touches the display screen 6, the image shown in FIG. Unlike the finger, the retroreflective tape 44 is wound around the tip of the pen, and since the reflected light is strong, it is imaged as a strong white signal, so it cannot be distinguished from the retroreflective tape image 91 of the surrounding reflection frame. However, since it is easy to distinguish from the black tape image 92 which is a non-reflective portion of the surrounding reflection frame, a horizontal pixel row slightly on the black side is extracted from the boundary line (S81 in FIG. 8). FIG. 6B shows signals of this pixel column. Since this pixel row includes information on the place where the pen 4 and the display screen 6 are in contact, the control circuit 3 determines the angle with respect to each camera from the peak pixel positions of the left and right camera images as shown in FIG. Determination (S83), the coordinate value touched by the pen 4 by triangulation calculation is determined from each angle, and the coordinate value is sent to the computer (S84).

  Next, the operation when the pen 4 is in contact with the desktop coordinate detection area 7 will be described. At this time, the image captured by the camera is as shown in FIG. Each camera 2 shows the entire desktop coordinate detection area 96, and an image 95 of the pen tip that falls within this area is shown. Since the camera 2 captures an image with respect to the pen tip 44 obliquely from above, the pen tip 44 does not become a shadow of a hand holding the pen in the normal use of the pen.

  The control circuit 3 first obtains the pixel with the highest detection level in the entire image as shown in the procedure of FIG. 9 (S92). Since the retroreflective tape 44 provided at the pen tip is illuminated by the infrared light emitting diode 23 of the camera 2 and returns the strongest reflected light to the camera 2, this pixel is the position of the pen tip. The control circuit 3 obtains the coordinate value of the pen tip from the predetermined pixel-coordinate conversion table using the location information of the pixel with the highest detection level in the imaging signal of one of the two cameras 2 (S93). The coordinate value is sent to the computer.

  The detection that the pen 4 has touched the desktop coordinate detection area 7 is detected because the output signal of the pressure sensor 42 connected to the pen tip member 43 is connected to the control circuit 3. Can easily know the touch of the pen.

  Note that the coordinate input device of the present invention is not limited to the illustrated examples described above, and it is needless to say that various modifications can be made without departing from the scope of the present invention.

  For example, in this embodiment, the display screen 6 is positioned perpendicular to the upper surface of the desk 10, but a certain degree of inclination is provided by performing simple calibration on the coordinate values of the desk coordinate detection area 7. Of course you can. Of course, the present invention is not limited to this embodiment, and can be realized as an attachment device in which the camera 2 is housed in a housing independent of the display device 1 and can be mounted on an arbitrary display device. Needless to say, the touch detection signal of the pen 4 can be removed by providing wireless transmission means inside the pen and wireless reception means in the control circuit without using a cable.

  As described above, according to the coordinate input device of the present invention, the field of view of the camera installed on the upper and left sides of the display screen is not limited to the side of the surface along the display screen, but also to a partial area on the desk By expanding, it becomes possible to detect the coordinates of the finger, pen, etc. on the desk, and the pointing operation on the desk is also possible, and the operability of the computer operated with the pen or finger is remarkably improved. There is an effect.

  A high-reflectance member and a low-reflectance member are provided in close contact with the vicinity of the display screen on three sides excluding the upper side around the display screen so that the boundary line between these members falls within the field of view of the two cameras. By using the boundary reflection frame installed as a reference and using the boundary line as a reference, the touch input can be stably detected near the display screen.

  In addition, a high-reflectance member and a low-reflectance member are in contact with the three sides of the display screen except for the upper side, and the boundary line between these members is placed in the field of view of the two cameras. By providing the surrounding reflection frame, there is an effect that both a highly reflective pen and a low reflective finger can be used for pointing on the display screen.

  A retroreflective member is provided at the tip of an indicator such as a pen, and illumination means for illuminating the entire coordinate detection area in the vicinity of the imaging lens of the camera is provided. By making the camera receive light, it is possible to recognize an indication tool such as a pen by simply searching for the pixel with the strongest brightness without performing complicated image processing, and it is an inexpensive and highly reliable input device. There is an effect that can be realized.

  By incorporating a display screen into such a coordinate input device, there is an effect that a compact coordinate input device or display device that is easy to install can be realized.

1 is a perspective view of a coordinate input device according to the present invention. It is an enlarged plan view of the camera used for the coordinate input device by this invention. It is an expansion perspective view of the surrounding reflection frame used for the coordinate input device by this invention. FIG. 4A is a diagram of a captured image captured by the left and right cameras, FIG. 4A is a diagram illustrating a captured image when a finger touches the display screen, and FIG. 4B is a diagram where the pen touches the display screen. FIG. 4C is a diagram illustrating the captured image when the pen touches the desktop coordinate detection area. It is an expansion permeation | transmission figure of the pen used for the coordinate input device by this invention. It is a figure explaining the signal strength of the horizontal pixel sequence which is a part of the picked-up image which the camera imaged, and Fig.6 (a) is the vicinity of the image of the boundary line of a surrounding reflective frame when a finger | toe touches a display screen. FIG. 6B is a diagram for explaining the signal intensity of the horizontal pixel row of the image of the retroreflective tape, and FIG. 6B shows the image of the black tape near the boundary line image of the surrounding reflection frame when the pen touches the display screen. It is a figure explaining the signal strength of a horizontal pixel row. It is a figure of a procedure explaining a coordinate detection procedure of a control circuit when a finger touches a display screen. It is a figure of the procedure explaining the coordinate detection procedure of a control circuit when a pen touches a display screen. It is a figure of the procedure explaining the coordinate detection procedure of a control circuit when a pen touches a desktop coordinate detection area.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Display apparatus 2 Camera 3 Control circuit 4 Pen 5 Surrounding reflection frame 6 Display screen 7 Desk coordinate detection area 8 Finger 10 Desk 21 Imaging lens 22 Area image sensor 23 Infrared light emitting diode 41 Pen body 42 Pressure sensor 43 Pen tip member 44 Pen tip, retroreflective tape 51 Retroreflective tape 52 Black tape 91 Retroreflective tape image 92 Black tape image 93 Finger image 94 Pen image 95 Retroreflective tape image 96 at the tip of the pen 96 Image of desktop coordinate detection area 99 Inner imaging area

Claims (3)

A coordinate input device for inputting coordinates indicated by a finger or a pointing tool such as a pen having a retroreflective member at the tip thereof, the coordinate input device comprising:
An inner retroreflective tape that is installed along the three peripheral sides of the display screen and is close to the display screen and an outer non-reflective tape that is far from the display screen are installed near the extended surface of the display screen of the display device. A pair of cameras each including a peripheral frame provided parallel to the longitudinal direction in the field of view;
An irradiating means provided in the vicinity of the imaging lens of the camera and irradiating light toward the peripheral frame;
Control means for calculating the indicated position coordinates of the pointing tool based on image signals output from the pair of cameras, wherein the control means is provided between the retroreflective tape and the non-reflective tape of the peripheral frame. Control means for calculating the indicated position coordinates of the pointing tool in the vicinity of either the retroreflective tape or the non-reflective tape of the boundary line with reference to the boundary line;
A coordinate input device comprising:   2. The coordinate input device according to claim 1, wherein the irradiating means is formed of a light emitting diode.   The coordinate input device according to claim 1, wherein the pair of cameras has an integrated structure with the display screen.