JP2014199633A - Coordinate detection device, coordinate detection system, coordinate detection method, and coordinate detection program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the coordinate detection accuracy of a pointing device.SOLUTION: A plurality of circles or ellipses which have such sizes that the entire shape of the circles or ellipses can be specified even when they are partially shielded by an operator, are displayed on an operation surface 5 with a visible light laser source of a pointing device 1. An image of the operation surface 5 is captured by an imaging unit 3, and an apex angle α of a cone and an inclination angle θ of the pointing device are detected from diameters of the circles or longer diameters and shorter diameters of the ellipses, which are reflected in the obtained captured image, and coordinates of the pointing device 1 on the operation surface 5 are computed from the apex angle α and the inclination angle θ of the pointing device 1. The circles or ellipses on the operation surface 5 can be distinctly drawn with laser light having a sufficient amount of light by the visible light laser source. Circles or ellipses suitable for coordinate computation can be selected from the plurality of circles or ellipses to be used for coordinate computation. Thus, the coordinate detection accuracy can be improved.

Description

  The present invention relates to a coordinate detection device, a coordinate detection system, a coordinate detection method, and a coordinate detection program.

  Patent Document 1 (Japanese Patent Laid-Open No. 2012-53603) discloses an information display system that can detect the locus of a device even when the pointing device becomes a shadow of a person and cannot be captured by a camera. The information display system includes a plurality of rectangular slits and a light emitting unit at the tip of the pointing device. When the light emitting unit emits light, radiant light spreading radially around the tip of the pointing device is irradiated onto the operation surface via each slit. The camera captures an area including radiation on the operation surface. The radiated light detection unit detects radiated light from the captured image. And an estimation part estimates the position of the front-end | tip part of a pointing device from the detected emitted light.

  In Patent Document 2 (Japanese Patent No. 39755892), a laser interference fringe is generated from the tip of a pointing device using a lens, and the interference fringe is detected by a sensor to detect the three-dimensional coordinates of the pointing device. A position measurement system is disclosed.

  However, the information display system of Patent Document 1 needs to use a light source having a low directivity and spreading in order to project a radial pattern on the operation surface from the pointing device. Since this light source has low directivity, it is a light source with a small amount of light for one point compared to a light source with directivity such as laser light. For this reason, the information display system of Patent Document 1 has a problem that the light that forms the projected pattern is weak at a portion away from the pointing device, and this interferes with accurate coordinate detection due to disturbance of sunlight or the like. there were.

  Moreover, the information display system of patent document 1 images the pattern irradiated on an operation surface through each slit, and detects a coordinate. For this reason, the information display system of Patent Document 1 has a problem in that accurate coordinate detection is hindered when the pattern irradiated on the operation surface is shielded by the body of the operator of the pointing device over a large area. there were.

  Since the position measurement system of Patent Document 2 draws an ellipse with interference fringes, there is a problem that when drawing an ellipse of a large size, the light intensity becomes insufficient and it becomes difficult to draw the ellipse clearly. . In addition, since the position measurement system of Patent Document 2 draws an ellipse with interference fringes, there is a problem that the outline of the ellipse becomes ambiguous and the accuracy of coordinate detection decreases.

  It is an object of the present invention to provide a coordinate detection device, a coordinate detection system, a coordinate detection method, and a coordinate detection program capable of detecting coordinates with high accuracy.

  In order to solve the above-described problems and achieve the object, the present invention provides a pointing device based on an image obtained by imaging an operation surface operated by a pointing device that projects a plurality of circles or ellipses that are coaxial and have different sizes. A detection unit that detects one or more circles or ellipses used to calculate coordinates on the operation surface; and a coordinate calculation unit that calculates coordinates on the operation surface of the pointing device from the detected one or more circles or ellipses. It is characterized by.

  According to the present invention, there is an effect that accurate coordinate detection can be performed.

FIG. 1 is a system configuration diagram of the coordinate detection system according to the first embodiment. FIG. 2 is a block diagram of the coordinate detection system according to the first embodiment. FIG. 3 is a cross-sectional view of the pointing device used in the coordinate detection system according to the first embodiment cut along the longitudinal direction. FIG. 4 is a cross-sectional view of a mirror provided in the pointing device used in the coordinate detection system of the first embodiment. FIG. 5 is a diagram illustrating a locus of a circle drawn on the operation surface by the pointing device when the angle of the pointing device with respect to the operation surface is vertical (90 degrees). FIG. 6 is a view of an operator who performs an operation with the angle of the pointing device with respect to the operation surface being vertical (90 degrees) as viewed from behind. FIG. 7 is a diagram illustrating a locus of a circle drawn on the operation surface by the pointing device when the angle of the pointing device with respect to the operation surface is 75 degrees. FIG. 8 is a view of the operator who performs the operation with the angle of the pointing device with respect to the operation surface being 75 degrees as viewed from behind. FIG. 9 is a view of an operator who performs an operation with the angle of the pointing device with respect to the operation surface being 60 degrees as viewed from behind. FIG. 10 is a view of the operator who performs the operation with the angle of the pointing device with respect to the operation surface being 45 degrees as viewed from behind. FIG. 11 is a diagram illustrating a locus of a circle drawn on the operation surface by the pointing device when the angle of the pointing device with respect to the operation surface is vertical. FIG. 12 is a hardware configuration diagram of the information processing apparatus. FIG. 13 is a functional block diagram of the CPU when operating according to the coordinate detection program. FIG. 14 is a flowchart showing a flow of coordinate detection operation performed by the information processing apparatus. FIG. 15 is a flowchart showing the flow of detailed coordinate calculation operation of the CPU. FIG. 16 is a diagram for explaining the apex angle of the cone and the inclination angle of the pointing device. FIG. 17 is a diagram illustrating the two-dimensional image data (x, y) of the ellipse captured by the imaging unit in the xy coordinates. FIG. 18 is a diagram showing an ellipse having no inclination in the xy coordinates. FIG. 19A is a diagram for explaining the calculation of the coordinates of the pointing device. FIG. 19B is a diagram for explaining the calculation of the coordinates of the pointing device. FIG. 20A is another diagram for explaining the calculation of the coordinates of the pointing device. FIG. 20B is another diagram for explaining the calculation of the coordinates of the pointing device. FIG. 20C is another diagram for explaining the calculation of the coordinates of the pointing device. FIG. 20D is another diagram for explaining the calculation of the coordinates of the pointing device. FIG. 21 is a diagram of the geometric relationship between the laser beam emitted from the pointing device and the operation surface, as viewed from the side. FIG. 22 is a diagram for explaining a table showing the apex angle of the cone and the tilt angle of the pointing device corresponding to the length of the major axis of the circle. FIG. 23 is a diagram for explaining a table showing the apex angle of the cone and the tilt angle of the pointing device corresponding to the length of the minor axis of the circle. FIG. 24 is a diagram illustrating a mirror of the mirror unit that projects a small circle on the operation surface. FIG. 25 is a cross-sectional view of the pointing device used in the coordinate detection system according to the second embodiment, cut along the longitudinal direction. FIG. 26 is a diagram for explaining a pointing device used in the coordinate detection system of the second embodiment in which information is given to the line length of a circle drawn on the operation surface. FIG. 27 is a diagram for explaining a pointing device used in the coordinate detection system of the second embodiment in which information is given to the line length of a circle drawn on the operation surface. FIG. 28 is a diagram for explaining a pointing device used in the coordinate detection system of the second embodiment in which information is given to the thickness of a circle drawn on the operation surface.

  Hereinafter, embodiments of a coordinate detection device, a coordinate detection system, a coordinate detection method, and a coordinate detection program will be described in detail with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is a system configuration diagram of the coordinate detection system according to the first embodiment. The coordinate detection system shown in FIG. 1 has a pointing device 1 and a coordinate detection device 2. The coordinate detection device 2 includes an imaging unit 3 and an information processing device 4.

  FIG. 2 is a block diagram of the coordinate detection system according to the first embodiment. As shown in FIG. 2, the pointing device 1 includes a switch 11, a light emitting unit 12, and a control unit 13. FIG. 3 is a cross-sectional view of the pointing device 1 cut along the longitudinal direction. As shown in FIG. 3, the switch 11 is connected to the distal end portion 21 of the pointing device 1 through a spring member 23. The spring member 23 biases the distal end portion 21 in a direction in which the distal end portion 21 is separated from the housing 22.

  When the operator presses the distal end portion 21 of the pointing device 1 against the operation surface 5, the distal end portion 21 moves toward the housing 22 against the urging force of the spring member 23, and the switch 11 is turned on. The switch 11 is kept on while the tip 21 is pressed against the operation surface 5. The switch 11 is turned off when the distal end portion 21 is separated from the operation surface 5. Note that the urging force of the spring member 23 may be slightly increased so that the switch 11 does not turn on unless the operator intentionally pushes the tip 21. By doing in this way, even if the front-end | tip part 21 touches the operation surface 5 lightly, although the operator does not intend, the trouble that the switch 11 will be in an ON state can be prevented.

  Further, the switch 11 may be operated as follows. When the operator first presses the distal end portion 21 of the pointing device 1 against the operation surface 5, the switch 11 is turned on. If the tip 21 is again pressed against the operation surface 5 while the switch 11 is on, the switch 11 is turned off. That is, the switch 11 may be turned on / off every time the distal end portion 21 of the pointing device 1 is pressed.

  The light emitting unit 12 includes an invisible light source 14 and a mirror unit 15. The invisible laser light source 14 emits laser light having a wavelength that cannot be seen by humans. The invisible light source 14 emits a high level of laser light that has high directivity and does not affect the human body.

  The mirror unit 15 includes a mirror 16 and a motor unit 17. As shown in FIG. 3, the mirror 16 is rotationally driven by the motor unit 17. As will be described later, the mirror unit 15 is detachable from the housing 22 of the pointing device 1. As the mirror unit 15, there are provided a plurality of types of mirror units having different sizes of circles or ellipses to be drawn (hereinafter, the description of a circle or an ellipse may be simply abbreviated as a circle). The operator selects a mirror unit corresponding to the size of the circle to be drawn, and attaches it to the pointing device 1 for use.

  FIG. 4 shows a cross-sectional view of the mirror 16. In the example shown in FIG. 4, the mirror 16 includes a first mirror 30 to a fourth mirror 33. The first mirror 30 is a half mirror that reflects, for example, 20% of the laser light emitted from the invisible laser light source 14 and transmits the remaining 80% of the laser light. It has the optical characteristics to do. The second mirror 31 is a half mirror that reflects, for example, 30% of the laser light transmitted through the first mirror 30, and transmits the remaining 70% of the laser light. Has optical properties.

  The third mirror 32 is a half mirror that reflects, for example, 40% of the laser light transmitted through the second mirror 31, and transmits the remaining 60% of the laser light. Has optical properties. The fourth mirror 33 is a total reflection mirror and reflects all the laser light transmitted through the third mirror 32.

  Further, the reflection angles of the first mirror 30 to the fourth mirror 33 are set to different reflection angles as shown by dotted lines in FIG. As will be described later, in the coordinate detection system according to the first embodiment, a plurality of circles that are coaxial and have different sizes are drawn on the operation surface 5 by the pointing device 1. As an example, in the coordinate detection system of the first embodiment, the pointing device 1 draws first to fourth circles that are coaxial and have different sizes on the operation surface 5. The first circle is the smallest circle located on the innermost side, and the second circle is adjacent to the first circle and is larger than the first circle. In addition, the third circle is adjacent to the second circle, the circle larger than the second circle, and the fourth circle is the largest circle located on the outermost side.

  The reflection angle of the first mirror 30 is set to a reflection angle at which the fourth circle located on the outermost side can be drawn. The reflection angle of the second mirror 31 is set to a reflection angle at which a third circle, which is a smaller circle than the fourth circle, can be drawn. The reflection angle of the third mirror 32 is set to a reflection angle at which a second circle, which is a smaller circle than the third circle, can be drawn. The reflection angle of the fourth mirror 33 is set to a reflection angle at which the first circle, which is the smallest circle located on the innermost side, can be drawn. Such a configuration of the mirror 16 is an example. For this reason, a half mirror having a desired transmittance may be used as the half mirror, and a desired number of half mirrors may be provided. Furthermore, the reflection angle of the half mirror and the total reflection mirror may be set to a desired reflection angle.

  When the mirror 16 is rotationally driven by the motor unit 17, each laser beam reflected by the first mirror 30 to the fourth mirror 33 draws a circular locus on the operation surface 5. FIG. 5 is a diagram illustrating a locus of a circle drawn on the operation surface 5 by the pointing device 1 when the angle of the pointing device 1 with respect to the operation surface 5 is vertical (90 degrees). FIG. 6 is a view of the operator who performs the operation with the angle of the pointing device 1 with respect to the operation surface 5 being vertical (90 degrees) as seen from behind. In FIG. 5, the first circle 35 located on the innermost side is a locus drawn by the laser light reflected by the fourth mirror 33 of the mirror 16. The second circle 36 adjacent to the first circle 35 is a locus drawn by the laser light reflected by the third mirror 32 of the mirror 16. A third circle 37 adjacent to the second circle 36 is a locus drawn by the laser light reflected by the second mirror 31 of the mirror 16. The fourth circle 38 which is the maximum circle is a locus drawn by the laser light reflected by the first mirror 30 of the mirror 16. In this example, since the angle of the pointing device 1 with respect to the operation surface 5 is vertical (90 degrees), the trajectory of each circle 35 to 38 drawn on the operation surface 5 is a perfect circle as shown in FIG. The trajectory.

  FIG. 7 is a diagram illustrating a locus of a circle drawn on the operation surface 5 by the pointing device 1 when the angle of the pointing device 1 with respect to the operation surface 5 is 75 degrees. FIG. 8 is a view of an operator who performs an operation with the angle of the pointing device 1 with respect to the operation surface 5 being 75 degrees as viewed from behind. In the case of this example, since the angle of the pointing device 1 with respect to the operation surface 5 is 75 degrees, the trajectories of the circles 35 to 38 drawn on the operation surface 5 are elliptical as shown in FIGS. It becomes a trajectory.

  FIG. 9 is a view of an operator who performs an operation with the angle of the pointing device 1 with respect to the operation surface 5 being 60 degrees as viewed from behind. FIG. 10 is a view of an operator who performs an operation with the angle of the pointing device 1 with respect to the operation surface 5 being 45 degrees as viewed from behind. 6, 8, 9, and 10, as the angle of the pointing device 1 with respect to the operation surface 5 becomes an acute angle, the pointing device 1 draws a large elliptical locus on the operation surface 5. It becomes like this.

  That is, when the angle of the pointing device 1 with respect to the operation surface 5 is vertical, as shown in FIG. 6, from the back of the operator, the innermost first circle 35 is shielded by the operator's body. It is difficult to image one circle 35 by the imaging unit 3. Further, when the angle of the pointing device 1 with respect to the operation surface 5 is 75 degrees, as shown in FIG. 8, the trajectories of the first to third circles 35 to 37 are ellipses having a trajectory larger than the operator's body. Therefore, it is possible to take an image with the imaging unit 3 even from behind the operator. However, since the trajectory of the fourth circle 38 is an ellipse having a trajectory larger than that of the operation surface 5, the imaging unit 3 captures a trajectory like a parabola instead of an ellipse.

  When the angle of the pointing device 1 with respect to the operation surface 5 is 60 degrees, the trajectories of the first to fourth circles 35 to 38 are ellipses larger than the operator's body as shown in FIG. Therefore, it is possible to take an image with the imaging unit 3 even from behind the operator. However, since the trajectories of the second to fourth circles 36 to 38 other than the first circle 35 are ellipses having a trajectory larger than the operation surface 5, the imaging unit 3 has a trajectory like a parabola instead of an ellipse. Is imaged. Similarly, when the angle of the pointing device 1 with respect to the operation surface 5 is 45 degrees, the locus of the first to fourth circles 35 to 38 is an ellipse having a locus larger than the operator's body as shown in FIG. Therefore, the imaging unit 3 can capture images even from behind the operator. However, in this case as well, the trajectories of the second to fourth circles 36 to 38 other than the first circle 35 are ellipses having a trajectory larger than that of the operation surface 5, and therefore the imaging unit 3 is not an ellipse but a parabola. A trajectory like this is imaged. Thus, the locus of the ellipse drawn on the operation surface 5 changes according to the inclination angle of the pointing device 1 with respect to the operation surface 5.

  FIG. 11 is a diagram illustrating a locus of a circle drawn on the operation surface 5 by the pointing device 1 when the angle of the pointing device 1 with respect to the operation surface 5 is vertical. As shown in FIG. 11, the intervals between adjacent circles of the first to fourth circles 35 to 38 drawn by the pointing device 1 are set to different intervals. That is, the interval between the first circle 35 and the second circle 36 is set to the shortest interval. The interval between the third circle 37 and the fourth circle 38 is set to the longest interval. In addition, the interval between the second circle 36 and the third circle 37 is set to a substantially intermediate interval between the shortest interval and the longest interval.

  That is, the interval between adjacent circles of the first to fourth circles 35 to 38 is set so that the inner interval is “dense” and the interval is “sparse” toward the outer side. Such a difference in spacing between the circles 35 to 38 is realized by the reflection angles of the first to fourth mirrors 30 to 33 of the mirror 16. In other words, the reflection angle of the first to fourth mirrors 30 to 33 of the mirror 16 is a reflection angle that realizes an interval between adjacent circles of the first to fourth circles 35 to 38 shown in FIG. Each is set. Thus, the number of circles to be projected is set by setting the interval between adjacent circles of the first to fourth circles 35 to 38 so that the inner interval is “dense” and the outer interval is “sparse”. Can be a minimum number. Note that the size of the projected circle and the interval between adjacent circles may be variable.

  The coordinate detection system according to the first embodiment uses any one of the first to fourth circles 35 to 38 drawn on the operation surface 5 to determine the coordinates of the pointing device 1 on the operation surface 5. To detect. In addition, the coordinate detection system according to the first embodiment can detect coordinates by interpolating an incomplete locus when the circle or ellipse locus drawn on the operation surface 5 is an incomplete locus. It comes to use. Details will be described later. In this example, the mirror 16 is rotationally driven by the motor unit 17 to change the locus of the laser beam. In addition, for example, the locus of the laser beam is changed using a MEMS (Micro Electro Mechanical System) mirror. May be.

  Next, as illustrated in FIG. 2, the coordinate detection device 2 includes an imaging unit 3 and an information processing device 4. As shown by a dotted line in FIG. 2, the imaging unit 3 images the trajectories of the first to fourth circles 35 to 38 drawn on the operation surface 5 with the laser light reflected by the mirror 16 of the pointing device 1. As described above, the laser light is invisible light having a wavelength that is difficult for humans to see. The imaging unit 3 is provided with a band pass filter (BPF) 18 that transmits only imaging light having a wavelength of laser light. The imaging unit 3 receives imaging light having the wavelength of the laser beam taken in via the BPF 18 and images the first to fourth circles 35 to 38 drawn with the laser beam on the operation surface 5.

  FIG. 12 is a hardware configuration diagram of the information processing apparatus 4. As shown in FIG. 12, the information processing apparatus 4 can apply a general configuration of a computer apparatus. The information processing apparatus 4 includes a CPU 40, a ROM 41, a RAM 42, a hard disk drive (HDD) 43, an input / output interface (input / output I / F) 44, and a communication I / F 45. CPU is an abbreviation for “Central Processing Unit”. ROM is an abbreviation for “Read Only Memory”. RAM is an abbreviation for “Random Access Memory”. The CPU 40, ROM 41, RAM 42, HDD 43, input / output I / F 44 and communication I / F 45 are connected to each other via a bus line 46 so as to communicate with each other.

  The HDD 43 stores a coordinate detection program for operating the CPU 40. The CPU 40 operates according to the coordinate detection program stored in the HDD 43 using the RAM 42 as a work memory, and controls the coordinate detection operation of the entire information processing apparatus 4.

  The coordinate detection program may be stored in the ROM 41 or the RAM 42, for example, other than the HDD 43. Further, the coordinate detection program may be stored on a computer device of a predetermined network and downloaded and acquired via the network. The coordinate detection program is not limited to this, and may be a file in an installable or executable format recorded on a computer-readable recording medium such as a CD or DVD.

  The input / output I / F 44 is an interface for inputting / outputting data to / from the information processing apparatus 4. For example, the input / output I / F 44 is connected to an input device such as a keyboard that receives user input. The input / output I / F 44 is connected to a data interface such as a USB for performing data input / output with other devices. USB is an abbreviation for “Universal Serial Bus”. The input / output I / F 44 is connected to a drive device that reads data from a recording medium such as a CD or DVD. CD is an abbreviation for “Compact Disc (registered trademark)”. DVD is an abbreviation for “Digital Versatile Disc”. Further, the input / output I / F 44 can be connected to a display device that displays an image signal generated by the CPU 40.

  The communication I / F 45 performs communication via a network according to the control of the CPU 40.

  FIG. 13 shows a functional block diagram of the CPU 40 when operating according to the coordinate detection program. As illustrated in FIG. 13, the CPU 40 operates according to the coordinate detection program, thereby obtaining an image acquisition unit 51, a line extraction unit 52, an interpolation processing unit 53, a circle detection unit 54 (an example of a detection unit), coordinates, It functions as the calculation unit 55. In the following description, the description will be made on the assumption that the image acquisition unit 51 to the coordinate calculation unit 55 are realized as software by the CPU 40 operating according to the coordinate detection program. However, part or all of the image acquisition unit 51 to the coordinate calculation unit 55 may be configured by hardware. Also in this case, the same effects as those described later can be obtained.

  FIG. 14 is a flowchart showing the flow of the coordinate detection operation performed by the information processing apparatus 4. The coordinate detection program stored in the HDD 43 has a module configuration including an image acquisition unit 51 to a coordinate calculation unit 55. When the CPU 40 of the information processing apparatus 4 recognizes the start of operation of the operation surface 5 by the pointing device 1, the CPU 40 reads the coordinate detection program from the HDD 43. Then, the CPU 40 loads the image acquisition unit 51 to the coordinate calculation unit 55 onto a main storage device such as the RAM 42 and executes it.

  In step S <b> 1, the image acquisition unit 51 acquires a captured image of the operation surface 5 captured by the imaging unit 3. As shown in FIG. 1, the operator holds the pointing device 1 in his hand and operates the operation surface 5. When performing the operation, the operator presses the distal end portion 21 of the pointing device 1 shown in FIG. As a result, the switch 11 is turned on while the operator presses the distal end portion 21 of the pointing device 1 against the operation surface 5. When detecting the ON operation of the switch 11, the control unit 13 of the pointing device 1 controls the light emission of the invisible laser light source 14 so as to emit laser light. Further, when the control unit 13 detects the ON operation of the switch 11, the control unit 13 rotationally drives the motor unit 17. The mirror 16 is rotationally driven by the motor unit 17.

  In this example, the mirror 16 is rotationally driven via the motor unit 17 at the timing when the control unit 13 detects the ON operation of the switch 11. That is, in this example, the rotation operation of the mirror 16 is interlocked with the on / off operation of the switch 11. Since the motor unit 17 requires a predetermined time from the start of rotation to reach a certain number of rotations, the rotation of the mirror 16 is not stabilized at the start of rotation of the motor unit 17 and the drawing of the circle lacks stability. For this reason, when the switch 11 and the motor unit 17 are interlocked, when the switch 11 frequently repeats the on / off operation, the motor unit 17 also frequently rotates and stops, and the rotation of the mirror 16 is not stable. There is a risk that stable drawing of a circle may be difficult.

  In order to prevent such an inconvenience, a switch for driving the rotation of the mirror 16 may be provided separately from the switch 11 so that the mirror 16 can be driven to rotate regardless of the on / off operation of the switch 11. By rotating the mirror 16 first, the laser beam irradiated according to the on / off operation of the switch 11 can be reflected by the mirror 16 having a constant and stable rotational speed. For this reason, it is possible to stably draw a circle.

  Near the mirror unit 15 of the housing 22 of the pointing device 1 is a cylindrical transparent window 24. For this reason, when the mirror 16 is driven to rotate, the laser light is emitted to the operation surface 5 through the transparent window 24 in a conical shape having the mirror 16 as a vertex. Accordingly, as described with reference to FIGS. 6, 8, 9, and 10, the first to fourth circles 35 to 38 having a size corresponding to the inclination angle of the pointing device 1 with respect to the operation surface 5 are operated. It is displayed on the surface 5. The size of each of the circles 35 to 38 is a size (size) that allows the entire shape to be specified even if it is partially shielded by the operator. In addition, the operation surface 5 displays first to fourth circles 35 to 38 in which the interval between adjacent circles is set so that the inner interval is “dense” and the outer interval is “sparse”. .

  The imaging unit 3 images the entire operation surface 5 from behind the operator as shown in FIG. A BPF 18 that transmits only light having the wavelength of the laser beam is provided on the front surface of the imaging unit 3. For this reason, the imaging unit 3 captures the first to fourth circles 35 to 38 drawn with the laser beam on the operation surface 5 by receiving the imaging beam having the wavelength of the laser beam captured via the BPF 18. To do. In step S <b> 1, the image acquisition unit 51 acquires the captured images of the first to fourth circles 35 to 38 captured by the imaging unit 3 in this way. Thereby, a process progresses to step S2.

  In step S <b> 2, the line extraction unit 52 binarizes the captured image acquired by the image acquisition unit 51 into a black and white image, whereby the first to fourth circles 35 drawn on the operation surface 5 with laser light. -38 are converted into line images. Thereby, a process progresses to step S3. In step S <b> 3, the interpolation processing unit 53 determines a line segment that forms a circle and a circle segment that is missing due to occlusion by the operator. The interpolation processing unit 53 determines whether or not an interpolation process is required for making a circle with a missing circle a circle without a missing circle. In other words, the interpolation processing unit 53 determines whether or not a missing circle can be made a missing circle by performing an interpolation process in step S3. If the interpolation processing unit 53 determines in step S3 that interpolation processing is necessary (step S3: Yes), the process proceeds to step S6. On the other hand, when the interpolation processing unit 53 determines in step S3 that the interpolation process is not necessary (step S3: No), the process proceeds to step S4.

  Note that the case where it is determined in step S3 that the interpolation process is not necessary is a case where interpolation is difficult because there is no need for interpolation due to a minute chip and the parabolic circle shown in FIGS. This is the case of a perfect circle.

  In step S <b> 6, the interpolation processing unit 53 interpolates, for example, a circle that is missing due to shielding by the operator's body into a circle that is not missing. Specifically, the interpolation processing unit 53 first detects the start point of the missing part and the end point of the missing part. Next, the interpolation processing unit 53 calculates the curvature of the circle up to the start point of the missing part and the curvature of the circle from the end point of the missing part. Next, the interpolation processing unit 53 calculates the curvature of the missing circle from each calculated curvature. Then, the interpolation processing unit 53 forms a line segment of the calculated circle curvature of the missing part (= line part of the missing part), and interpolates the missing part of the circle with this line segment. . As a result, it is possible to interpolate a circle in which a chip is generated due to shielding or the like by the operator's body into a circle in which the chip is not generated.

  Next, in step S4, the circle detection unit 54 detects a circle used for coordinate calculation from the line segment extracted in step S2. In step S4, the circle detection unit 54 detects a circle used for coordinate calculation among the circles interpolated in step S6. At this time, when there are a plurality of circles as circle candidates used for coordinate calculation, the circle detection unit 54 detects the outermost circle as a circle used for coordinate calculation. Specifically, for example, as shown in FIG. 7, when the first circle 35 and the second circle 36 exist as circle candidates used for coordinate calculation, the circle detection unit 54 is located outside the first circle 35. The second circle 36 is detected as a circle used for coordinate calculation.

  Since the pointing device 1 is held and operated by the operator, the inner circle of the first circle 35 and the second circle 36 among the first to fourth circles 35 to 38 is closer to the operator's body. There is a concern that there will be more parts shielded by. That is, since each of the circles 35 to 38 drawn on the operation surface 5 is imaged by the imaging unit 3 through the operator, the inner circles such as the first circle 35 and the second circle 36 are closer to the operator. There is a concern that more parts will be shielded by the body. For this reason, by selecting and using the outer circle as much as possible as the circle used for coordinate calculation, the circle with the least part shielded by the operator's body is selected as the circle used for coordinate calculation, and accurate coordinate detection is performed. Can be made possible.

  In this example, in order to make it easier for the circle detection unit 54 to detect the circle used for coordinate calculation in step S4, in step S6, the missing circle is interpolated. However, the circle detection unit 54, for example, “Electronic Information and Communication Society Journal D-II Vol. J73-D-II No. 2 pp. 159-166 February 1990 Hough transform and generation of missing ellipse using layered image. The circle may be detected by using a detection method disclosed in the “detection” document. The circle detection unit 54 can also detect a circle with a chip by using the detection method disclosed in this document. For this reason, the interpolation process described in step S3 and step S6 can be omitted, and the overall process can be simplified.

  Next, in step S5, the coordinate calculation unit 55 detects the coordinates on the operation surface 5 of the pointing device 1 using the circle detected by the circle detection unit 54, and ends the process of the flowchart of FIG.

  FIG. 15 is a flowchart showing the flow of detailed coordinate calculation operation of the CPU 40 in step S5. When the CPU 40 functions as the coordinate calculation unit 55, the CPU 40 starts processing from step S11 of FIG. In step S11, the coordinate calculation unit 55 measures the major axis of the circle detected by the circle detection unit 54, and advances the process to step S12. In step S12, the coordinate calculation unit 55 measures the minor axis of the circle detected by the circle detection unit 54, and advances the process to step S13. In step S13, the coordinate calculation unit 55 calculates the apex angle α of the cone and the tilt angle θ of the pointing device 1 shown in FIG. In step S <b> 14, the coordinate calculation unit 55 calculates the coordinates of the pointing device 1 on the operation surface 5 using the apex angle α of the cone and the inclination angle θ of the pointing device 1.

  Hereinafter, each process will be described in order. First, the coordinate calculation unit 55 calculates “circle diameter (diameter)” or “ellipse major axis and minor axis”. For example, FIG. 17 is a diagram illustrating the ellipse two-dimensional image data (x, y) captured by the imaging unit 3 in the xy coordinates. When a circle is photographed by the imaging unit 3, the coordinate calculation unit 55 calculates two orthogonal diameters (corresponding to a major axis and a minor axis in the case of an ellipse). The calculation operation when the imaging unit 3 captures a circle and the calculation operation when the imaging unit 3 captures an ellipse are the same. For this reason, the description of the calculation operation will be made with the ellipse shown in FIG. 17 as an example. For the calculation operation when a circle is photographed by the imaging unit 3, refer to the following description. The two-dimensional image data (x, y) shown in FIG. 17 is binarized into a black and white image in the order from the upper left point to the lower right, as described above, and is recorded in the RAM 42, for example.

The coordinate calculation unit 55 first obtains the center point of the ellipse. The coordinate calculation unit 55 scans the two-dimensional image data stored on the RAM 42 in order from the upper left, and detects a point whose numerical value is different from the previous data. Thus, the point D ₁ of the upper right side of the ellipse shown in FIG. 17, is first detected. Next, scanning is performed in the same manner from the lower right of the image data, and a point whose numerical value is different from the previous data is detected. Thus, the point D ₂ of the lower left side of the ellipse shown in FIG. 17 are detected. The coordinate calculation unit 55 detects the center point P of the ellipse with the coordinates of the intermediate point between the points D ₁ and D ₂ as the coordinates of (x ₀ , y ₀ ) due to the symmetry of the figure.

Next, how to determine the length of the major axis of the ellipse, the length of the minor axis, the focus, and the inclination of the ellipse will be described. Here, in order to simplify the subsequent processing, the center point (x ₀ , y ₀ ) of the obtained ellipse is set as the origin (0, 0). A general ellipse (quadratic curve) equation is given by the following equation (1).

  In the equation (1), when the center point of the ellipse is the origin (0, 0), the following equation (2) is obtained.

Next, as shown in FIG. 17, the coordinate calculation unit 55 uses the points D ₁ and D ₂ obtained first as D ₁ → A ₁ (x ₁ , y ₁ ) with the origin (0,0) as a reference. , D ₂ → A ₂ (x ₂ , y ₂ ). The coordinate calculation unit 55 sets the intersection of the positive part of the x axis and the ellipse as A ₃ (x ₃ , 0), and sets the intersection of the positive part of the y axis and the ellipse as A ₄ (0, y ₄ ).

Note that both the point D ₁ and the point D ₂ are on the x-axis or the y-axis means a circle or an ellipse having no inclination. In the following, description will be given by taking an inclined ellipse as an example.

By substituting A ₁ , A ₃ , and A ₄ into the formula (2), the elliptic equation becomes the following formula (3).

  The equation (3) is an equation of an ellipse with a slope. FIG. 18 shows an ellipse having no inclination (hereinafter referred to as “standard type”) obtained by rotating the ellipse of FIG. 17 by −φ. By comparing an ellipse having no inclination with an ellipse having an inclination, the inclination φ of the ellipse having an inclination can be obtained.

If an arbitrary point on the standard ellipse is (X, Y), the following determinant (4) is established.

  When the formula (4) is expanded, the following formulas (5) and (6) can be obtained.

  Substituting the mathematical expression (5) and the mathematical expression (6) into the mathematical expression (3) yields the following mathematical expression (7).

  Since the standard ellipse shown in FIG. 18 has no inclination, the XY term is 0, and can be expressed by the following equation (8).

  When the formula of (8) is arranged, the following formula (9) is obtained.

  When the formula of (9) is further arranged, the following formula (10) is obtained, and the value of the inclination φ of the ellipse can be obtained.

Next, when the formula of (10) is changed back to the formula of (7), the XY term disappears, so that the following standard formula (11) is obtained.

  From the equation (11), the length a ′ of the major axis of the ellipse can be obtained by the following equation (12).

  Further, from the equation (11), the length b ′ of the minor axis of the ellipse can be obtained by the following equation (13).

  The coordinate calculation unit 55 performs such calculation in step S11 and step S12 in the flowchart of FIG. 15, so that the length a ′ of the major axis (major axis) of the ellipse and the length of the minor axis (minor axis) of the ellipse are obtained. B ′ is calculated.

Next, the coordinate calculation unit 55 calculates the three-dimensional position and rotation angle of the pointing device 1. In this case, the coordinate calculation unit 55 first sets the focus of the ellipse shown in FIG. 18 as S ₁ (s ₁ , 0), S ₂ (s ₂ , 0), s ₁ <0, s ₂ > 0, and The focal point of the ellipse is obtained by the equation (14) and the equation (15).

Next, the coordinate calculation unit 55 performs pointing from the length a ′ of the major axis of the ellipse, the length b ′ of the minor axis of the ellipse, and the focal points S ₁ (s ₁ , 0), S ₂ (s ₂ , 0). The three-dimensional coordinates and rotation angle of the device 1 are calculated.

First, how to obtain the three-dimensional coordinates (x, y, z) will be described. For example, assume that the pointing device 1 is inclined by θ with respect to the z-axis as shown in FIG. 19A. Since the length of the major axis of the ellipse is a ′ and the length of the minor axis is b ′, the x coordinate s ₁ of the focal point S ₁ can be obtained by the following equation (16).

The distance S from the origin to the focal point S ₁ can be calculated by formula below (17).

As shown in FIG. 19B, a straight line is drawn from the focus _{S 1} to y-axis positive direction, when the point of intersection with the ellipse _(s 1, _{y 1),} the value of _{y 1,} the value of _{L 1} shown in FIG. 19A Matches. The fact that the value of y ₁ matches the value of L ₁ will be described. Consider a truncated cone of height Z and an angle α between the central axis and the side as shown in FIG. 20A. As shown in FIG. 20B, the intersection between the central axis and the xy plane is S ₁ (a point on the x axis), and the intersection between the side surface of the truncated cone and the x axis is A ₁ and A ₂ .

Next, as illustrated in FIG. 20C, the pointing device 1 is rotated by θ from the z axis along the xz plane with S ₁ as the center. Thereby, the point A ₂ of the truncated cone rotates and moves to the point A ₂ ′ (Z is a radius of rotation, and the length of Z is fixed). Since rotational movement, the distance from the distance and _{S 1} from _{S 1} to _{A 2} to _{A 2} 'are equal.

Further, paying attention to the truncated cone before rotation, as shown in FIG. 20B, the projected image is a circle, so the distance from S ₁ to A ₂ is equal to the distance from S ₁ to point A ₃ on the same circle. On the other hand, paying attention to A ₃ , when the truncated cone rotates, the position of A ₃ of the truncated cone does not change because A ₃ is on the rotation axis (see FIGS. 20C and 20D). From the above, it can be said that the distance from S ₁ to A ₃ (the radius of the circle) and the distance from S ₁ to A ₂ ′ are equal, so the value of y ₁ matches the value of L ₁ shown in FIG. 19A. .

  The equation of the ellipse is represented by the following equation (18) when expressed by the major axis length a 'and the minor axis length b'.

When (x, y) → (s ₁ , y ₁ ) is substituted into the equation (18), y ₁ (= L ₁ ) becomes the value shown in the equation (19).

  The distance Z from the pointing device 1 to the intersection of the optical axis and the plane is a value represented by the following equation (20). “Α” is an angle between the optical axis and the side surface of the cone (a constant unique to the pointing device 1).

In FIG. 19A, when focusing on a right triangle including _{L 2} and Z ', sine (sin [theta) and cosine (cos [theta]) is represented by the formula in the formula and (22) of the following (21).

Since the two triangles sharing the apex angle α and having the bases L ₁ and L ₂ are similar, the relationship of the following equation (23) holds.

  Substituting the equations (21) and (22) into the equation (23) yields the following equation (24).

  When the formula of (24) is arranged, the following formula (25) is obtained.

  When trigonometric synthesis is used, the following equation (26) is obtained.

  The equation (26) can be transformed into the following equation (27).

  Thereby, the inclination θ of the optical axis of the pointing device 1 shown in FIG. 19A with respect to the z-axis can be obtained by the following equation (28).

  Next, using the inclination φ of the ellipse and the inclination θ of the optical axis of the pointing device 1 with respect to the z-axis, the three-dimensional coordinates (x, y, z) of the pointing device 1 represented by the following equation (29) are obtained. As can be seen from the equation (29), the coordinate values of x, y, and z can be obtained by a function of the inclination θ of the optical axis of the pointing device 1 with respect to the z axis.

In the above description, the center of the ellipse coincides with the origin for easy understanding. However, when the origin is set at the upper left end of the image or the like, when the center point of the ellipse takes the value (x _d , y _d ), x _d , it may be added to y _d. Thereby, the three-dimensional coordinate from another reference point can be calculated | required.

  The coordinate calculation unit 55 calculates the value of the x coordinate of the pointing device 1 on the operation surface 5 by calculating “−Z sin θ cos φ−S cos φ” in the equation (29). Further, the coordinate calculation unit 55 calculates the value of the y coordinate of the pointing device 1 on the operation surface 5 by calculating “−Zsinθsinφ−Ssinφ” in the equation (29).

  The CPU 40 of the information processing apparatus 4 shown in FIG. 12 detects the operation state of the pointing device 1 from the coordinate value of the pointing device 1 on the operation surface 5 calculated in this way. The CPU 40 performs information processing corresponding to the detected operation state of the pointing device 1. For example, it is assumed that an operation button is projected on the operation surface 5 from a projector device connected to the information processing device 4. Assume that the operator stops the pointing device 1 at a display position of the operation button projected on the operation surface 5 for a predetermined time or more. The CPU 40 detects the movement state of the coordinates of the pointing device 1 on the operation surface 5 calculated as described above. When the CPU 40 detects a stop operation for a predetermined time or longer on the operation button displayed on the operation surface 5, the CPU 40 recognizes that the operation button has been operated. Then, the CPU 40 reads an image corresponding to the operated operation button from the HDD 43 and projects it on the operation surface 5 via the projector device. Thereby, the operation surface 5 can be used like a display device with a so-called touch detection function.

  Next, the coordinates of the pointing device 1 may be calculated using an arithmetic expression described below. The coordinate calculation unit 55 sets “a” as the longest diameter (major axis) of the circle (ellipse). In addition, the coordinate calculation unit 55 sets “b” as the shortest diameter (minor axis) orthogonal to the major axis in the plane. In addition, the coordinate calculation unit 55 sets the apex angle of the cone to “α”. Further, the coordinate calculation unit 55 sets the length from the mirror 16 of the pointing device 1 to the distal end portion 21 as “L”. In addition, the coordinate calculation unit 55 sets the angle formed by the 90-degree pointing device 1 and the operation surface 5 to “θ”. a, b, α, L, θ are in the relationship shown in (Equation 30) and (Equation 31). The major axis “a” and the minor axis “b” are measured from an image photographed by the imaging unit 3. Since L is known, (Equation 30) and (Equation 31) are simultaneous equations with two unknowns. From here, α and θ are calculated. This calculation may be detected from a table. An example of a table is shown in FIGS. The table shown in FIG. 22 is a table that stores the value of the inclination angle θ of the pointing device 1 and the value of the apex angle α of the cone corresponding to the length of each major axis of the ellipse. The table shown in FIG. 23 is a table that stores the value of the inclination angle θ of the pointing device 1 and the value of the apex angle α of the cone corresponding to the length of each minor axis of the ellipse. Each table is stored in advance in a storage unit such as the HDD 43.

  Here, FIG. 21 is a diagram of the geometric relationship between the laser light emitted from the pointing device 1 and the operation surface 5 as seen from the side. A straight line including the line segment AB and the line segment AC indicates the locus of the laser light emitted from the pointing device 1. The line segment AF corresponds to the length “L” from the mirror 16 to the tip portion 21 of the pointing device 1. The line segment DE corresponds to the major axis of the ellipse projected by the laser light. At this time, the line segment DF: line segment FE can be expressed by the following equation (32) using the apex angle α and the inclination angle θ. The unit of the angle is “degree”.

  When calculating the major axis of the ellipse, the coordinates of point D and point E in FIG. 21 are known. Therefore, the coordinate calculation unit 55 can calculate the coordinates of the point F, that is, the coordinates of the distal end portion 21 of the pointing device 1 on the operation surface 5 by performing the calculation of the mathematical expression (32).

  The coordinate calculation unit 55 calculates the length of the major axis or minor axis of the ellipse using the above-mentioned “(12) and (13) formula” or “(30) and (31)”. To do. The coordinate calculation unit 55 refers to the table shown in FIG. 22 or the table shown in FIG. 23 using this calculated value. Then, the coordinate calculation unit 55 detects the apex angle α of the cone and the tilt angle θ of the pointing device 1 corresponding to the calculated major axis and minor axis from the table.

  For example, when the calculated major axis of the ellipse is 1305 mm, the coordinate calculation unit 55 refers to the table shown in FIG. 22 and sets the apex angle α to 135.2 ° (135.2 degrees) and the pointing device 1 The inclination angle θ is detected as 15 ° (15 °). When the calculated minor axis of the ellipse is 957 mm, the coordinate calculation unit 55 refers to the table shown in FIG. 23, and the apex angle α is 135.2 ° (135.2 degrees), and the pointing device 1 Is detected as 15 [deg.] (15 [deg.]).

  By referring to each table using the major axis and minor axis of the ellipse thus calculated, the apex angle α and the tilt angle θ of the pointing device 1 can be detected mechanically and uniquely. For this reason, the time required for calculating the tilt angle θ and the like can be shortened, and the time required for coordinate detection of the pointing device 1 can be greatly shortened.

  Note that the tables shown in FIGS. 17 and 18 are examples. For this reason, you may subdivide each element of a table. Further, the apex angle α is known in advance, and therefore, the necessary amount may be prepared. Further, the tilt angle θ of the pointing device 1 may be set finely as necessary.

  Next, in this embodiment, when a plurality of circles exist as circles used for coordinate calculation, the outermost circle is used for coordinate calculation. However, when a plurality of circles exist as circles used for coordinate calculation, an average value of coordinate values corresponding to the plurality of circles may be output as a final coordinate value.

  In this case, the coordinate calculation unit 55 calculates the coordinate value of the pointing device 1 for each circle used for coordinate calculation by performing the above-described calculation. And the coordinate calculation part 55 calculates the average coordinate value of each coordinate value corresponding to each circle, and outputs this average coordinate value as a final coordinate value. By outputting the average coordinate value in this way, the calculation error of the coordinate value can be reduced, and the coordinate value with high accuracy of the pointing device 1 can be output.

  Next, in the coordinate detection system of the first embodiment, the size of each of the circles 35 to 38 displayed on the operation surface 5 from the pointing device 1 is not limited even if the size of each circle 35 to 38 is partially shielded by the operator. The size was determined so that the shape could be specified. However, when the coordinates of the pointing device 1 are detected in a narrow range, it is necessary to reduce the size of each of the circles 35 to 38 projected from the pointing device 1 onto the operation surface 5. In the pointing device 1 used in the coordinate detection system of the embodiment, the mirror unit 15 shown in FIG. 3 can be replaced.

  FIG. 24 shows a mirror 60 of a mirror unit that projects small circles 35 to 38 on the operation surface 5. A mirror 60 shown in FIG. 24 includes a first mirror 61 to a fourth mirror 64. The first mirror 61 to the fourth mirror 64 correspond to the first mirror 30 to the fourth mirror 33 of the mirror 16 described above, and have the same transmittance and the like. However, in the case of the mirror 60, the reflection angle of the laser light is obtuse than that of the mirror 16.

  Therefore, the size of each circle 35 to 38 drawn on the operation surface 5 by the mirror unit provided with the mirror 60 is smaller than that of the mirror unit 15 provided with the mirror 16 as shown in FIG. Therefore, when the coordinates of the pointing device 1 are detected in a narrow range, if the mirror unit 15 of the pointing device 1 is replaced with a mirror unit provided with the mirror 60, the coordinate detection in the narrow range can be supported. it can.

  As is clear from the above description, the coordinate detection system according to the first embodiment is configured so that a circle having a size capable of specifying the entire shape is invisible to the pointing device 1 even if it is partially shielded by the operator. The information is displayed on the operation surface 5 using the optical laser light source 14. The coordinate detection system images the operation surface 5 with the imaging unit 3 and calculates the coordinates of the pointing device 1 on the operation surface 5 from the circle shown in the obtained captured image. Such a coordinate detection system can obtain the following effects.

  First, an invisible laser beam source 14 having high directivity and sufficient light quantity is used as a light source, and a circle for coordinate detection is drawn on the locus of the laser beam. For this reason, the circle drawn on the operation surface 5 can be clearly drawn with a sufficient amount of laser light even at a portion away from the pointing device 1. Therefore, it is possible to draw a circle for detecting the coordinates of the pointing device 1 on the operation surface 5 without being affected by the disturbance of sunlight or the like, and to enable accurate coordinate detection.

  In addition, a plurality of circles are drawn on the operation surface 5, and a circle suitable for coordinate calculation is selected from the circles and used for coordinate calculation. On the operation surface 5, a circle having a size capable of specifying the overall shape is drawn even if it is partially shielded by the operator. Therefore, even when the circle is shielded by the operator's body or the like of the pointing device 1, a circle that is not affected by this shielding can be selected and used for coordinate calculation. Therefore, accurate coordinate detection can be made possible.

  For this reason, the coordinate detection system according to the first embodiment can accurately detect the coordinates of the pointing device 1.

(Second Embodiment)
Next, a coordinate detection system according to the second embodiment will be described. In the coordinate detection system of the second embodiment, the pen pressure detected by the pressure sensor provided in the pointing device is transmitted to the operator by the line type of a circle drawn on the operation surface 5.

  FIG. 25 is a cross-sectional view of the pointing device 70 used in the coordinate detection system of the second embodiment, cut along the longitudinal direction. As shown in FIG. 25, the pointing device 70 includes a pressure sensor 72 (an example of a pressure detection unit) connected to the distal end portion 21 via a spring member 71.

  The spring member 71 urges the distal end portion 21 in a direction in which the distal end portion 21 is separated from the housing 22. When the operator presses the distal end portion 21 of the pointing device 70, the distal end portion 21 moves in the direction of the housing 22 against the urging force of the spring member 71, and a pressure corresponding to the writing pressure is applied to the pressure sensor 72. . The pressure sensor 72 detects this pressure (= writing pressure) and transmits it to the control unit 73.

  The control unit 73 controls the light emission of the invisible light source 14 so that a line type circle corresponding to the writing pressure is drawn on the operation surface 5. The “line type” means a line length, a line thickness, a line form, a line color, and the like. 26 and 27 show a circle drawn by the control unit 73 by controlling the light emission of the invisible laser beam source 14 so that the length of the line corresponds to the writing pressure. Of these, FIG. 26 shows a circle drawn when the writing pressure is high, and FIG. 27 shows a circle drawn when the writing pressure is low. FIG. 28 shows a circle drawn by controlling the light emission of the invisible laser light source 14 so that the control unit 73 has a line thickness corresponding to the writing pressure.

  As described above, the coordinate detection system according to the second embodiment can indicate the pen pressure information by the circle drawn on the operation surface 5 by changing the line type of the circle drawn on the operation surface 5. The same effect as that of the coordinate detection system of the first embodiment can be obtained.

  Each above-mentioned embodiment is shown as an example and is not intending limiting the range of the present invention. Each of the novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. Each embodiment and modifications of each embodiment are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 Pointing device 2 Coordinate detection device 3 Imaging part 4 Information processing apparatus 5 Operation surface 11 Switch 12 Light emission part 13 Control part 14 Invisible light laser light source 15 Mirror unit 16 Mirror 17 Motor part 18 Band pass filter (BPF)
21 Front end portion 22 Housing 23 Spring member 24 Transparent window portion 30 First mirror 31 Second mirror 32 Third mirror 33 Fourth mirror 35 First circle 36 Second circle 37 Third circle 38 First Circle of 4 40 CPU
41 ROM
42 RAM
43 HDD
44 I / F I / F
45 Communication I / F
46 Bus Line 51 Image Acquisition Unit 52 Line Extraction Unit 53 Interpolation Processing Unit 54 Circle Detection Unit 55 Coordinate Calculation Unit 60 Mirror 61 First Mirror 62 Second Mirror 63 Third Mirror 64 Fourth Mirror 70 Pointing Device 71 Spring Member 72 Pressure sensor 73 Control unit

JP 2012-53603 A Japanese Patent No. 3975892

Claims (10)

One or more of the circles or the circles used for calculating coordinates on the operation surface of the pointing device from an image obtained by imaging an operation surface operated by a pointing device that projects a plurality of circles or ellipses that are coaxial and have different sizes A detection unit for detecting an ellipse;
A coordinate detection apparatus comprising: a coordinate calculation unit that calculates coordinates on the operation surface of the pointing device from one or more of the detected circles or ellipses. The pointing device projects the circle or the ellipse with light having a wavelength in an invisible region to a human;
The coordinate detection apparatus according to claim 1, wherein the image obtained by imaging the operation surface is an image formed by imaging light that passes through a band-pass filter that transmits light of the wavelength. The coordinate calculation unit calculates the coordinates of the pointing device from the diameter of the circle, or the major axis and minor axis of the ellipse, and the length from the light emitting unit to the tip of the pointing device. The coordinate detection apparatus according to claim 1 or 2. The coordinate calculation unit calculates an average of coordinates calculated from a plurality of the circles or the ellipses as coordinates of the pointing device. Coordinate detection device. The coordinate calculation unit calculates coordinates of the pointing device using an outermost circle or ellipse when a plurality of the circles or ellipses are detected as the circle or ellipse used for coordinate calculation. The coordinate detection device according to any one of claims 1 to 3, wherein the coordinate detection device is a feature. 6. The pointing device according to claim 1, wherein the pointing device projects a plurality of the circles or the ellipses whose inner intervals are dense and the intervals are sparse toward the outer side. 7. Coordinate detection device. The pointing device performs projection of the circle or the ellipse with a line type indicating a pressure generated by pressing the tip portion against the operation surface,
The coordinate detection according to claim 1, further comprising: a pressure detection unit that detects the pressure from a line type of the circle or the ellipse detected by the detection unit. apparatus. A pointing device that projects a plurality of circles or ellipses, each coaxial and different in size, onto the operation surface;
An imaging unit that captures an image of the operation surface operated by the pointing device; and a detection unit that detects one or more of the circle or the ellipse used for calculating coordinates on the operation surface of the pointing device from the image; A coordinate detection device comprising: a coordinate calculation unit that calculates coordinates on the operation surface of the pointing device from the detected one or more circles or ellipses. One or more used by the detection unit to calculate coordinates on the operation surface of the pointing device from an image obtained by imaging an operation surface operated by a pointing device that projects a plurality of circles or ellipses that are coaxial and have different sizes Detecting the circle or the ellipse;
A coordinate calculation method comprising: a coordinate calculation step of calculating coordinates on the operation surface of the pointing device from the one or more detected circles or ellipses. Computer
One or more of the circles or the circles used for calculating coordinates on the operation surface of the pointing device from an image obtained by imaging an operation surface operated by a pointing device that projects a plurality of circles or ellipses that are coaxial and have different sizes A detection unit for detecting an ellipse;
A coordinate detection program that functions as a coordinate calculation unit that calculates coordinates on the operation surface of the pointing device from one or more detected circles or ellipses.

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