JP2016058046A - Coordinate input device, control method thereof, program, coordinate input system, and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the cost for manufacturing a coordinate input device.SOLUTION: A coordinate input device 100 includes two sensor bars 1L, 1R each having two sensor units 21L, 22L, 21R, 22R comprising projection means 30 and light-receiving means 40, and an arithmetic control circuit 3L. A main arithmetic operation section 71 of the arithmetic control circuit 3L functions as: touch position calculation means which calculates a position of touch operation on a coordinate input area 5, on the basis of a light quantity distribution of light received by the light-receiving means 40; request means which prompts touch operation on a position different from an intersection α of two straight lines connecting the two sensor units located in a diagonal direction, in a third overlap area 93 where all the four sensor units 21L, 22L, 21R, 22R can detect a touch position; and relative position calculation means which calculates a relative position between the four sensor units 21L, 22L, 21R, 22R, on the basis of a result of calculating the touch operation position.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a coordinate input device that optically detects the position of a touch operation on a coordinate input region, a control method for the coordinate input device, a program for executing the control method for the coordinate input device, and the coordinates The present invention relates to a coordinate input system having an input device and a control method of the coordinate input system. In particular, a coordinate input device that can be attached to and detached from the surface on which the coordinate input area is provided and is portable, a control method for the coordinate input device, a program for executing the control method for the coordinate input device, and the coordinate input device The present invention relates to a coordinate input system having a device and a control method of the coordinate input system.

  As a coordinate input device using light, a method is known in which a retroreflecting material is provided outside the coordinate input area, the light from the light projecting means is reflected by the retroreflecting material, and the light quantity distribution is detected by the light receiving means. ing. Patent Document 1 discloses a configuration in which, when a coordinate input area is touched with a finger or the like and the optical path is blocked, the touch position is calculated by detecting the shielded direction. Such an optical coordinate input device touches a coordinate input area based on information on the direction (angle) of the touch position detected by at least two sensor units and the distance between the two sensor units. The position is calculated geometrically.

JP 2004-272353 A

  By the way, in such a coordinate input device, the coordinates of the position of the touch operation cannot be calculated unless the relative position of the sensor unit is determined. In order to determine the relative position of the sensor unit, not only the relative direction (angle) of another sensor unit viewed from one sensor unit, but also the direction of the sensor unit with respect to a certain absolute reference direction is required. Become. Therefore, in manufacturing such a coordinate input device, after the sensor unit is incorporated into the housing, a reference direction (angle) is acquired and held in the coordinate input device. For example, the angle in the vertical direction of the housing is measured in advance using a dedicated jig and held as reference point angle information. However, when the reference angle is acquired after the sensor unit is incorporated into the housing, high working accuracy is required. For this reason, a dedicated jig that satisfies the requirement for high work accuracy and the number of steps for obtaining and giving such a reference direction are required, resulting in an increase in manufacturing cost.

  The present invention has been made to solve the above-described problems, and is intended to reduce the manufacturing cost by omitting the process of obtaining and assigning the reference direction in the manufacture of the coordinate input device.

  In order to solve the above problems, a coordinate input device according to the present invention includes a retroreflective unit that retroreflects incident light, a light projecting unit that projects light toward the retroreflective unit, and a light projected from the light projecting unit. A light receiving means for receiving reflected light retroreflected by the retroreflecting means, and a position of a touch operation on a rectangular coordinate input area based on a light quantity distribution received by the light receiving means. Touch position calculation means for calculating the position of the touch input operation, and two of the four sensor units located at the four corners of the coordinate input area, which are located in the diagonal direction in the overlapping area where the position of the touch operation can be detected. Request means for performing a process for prompting a touch operation to a position different from the intersection of the two straight lines connecting the sensor unit, the position of the touch operation is calculated, and the position of the touch operation is the overlap region Relative position calculation means for calculating the relative position of the four sensor units based on the calculation result of the position of the touch operation when the position is different from the intersection of To do.

  According to the present invention, the reference direction can be automatically acquired during use. For this reason, in the manufacture of the coordinate input device, the process of obtaining and assigning the reference direction can be omitted, and the manufacturing cost can be reduced.

It is a figure which shows typically the example of schematic structure of the coordinate input device and coordinate input system which concern on the 1st Embodiment of this invention. It is a figure which shows the structural example of PC typically. It is a figure which shows typically the example of schematic structure of a sensor unit. (A) is a figure which shows typically the example of schematic structure of a coordinate input device, and the arrangement | positioning of a light projection means and a light reception means, (B)-(D) is an example of distribution of received light intensity and light projection intensity | strength. It is a graph typically shown. It is sectional drawing which shows the example of schematic structure of a sensor bar. (A) is a block diagram showing an example of the functional configuration of the arithmetic control circuit, and (B) is a timing chart showing the operation of the sensor unit. It is a graph which shows typically an example of light quantity distribution detected by a photo acceptance unit. It is a figure which shows typically the visual field range and each overlapping area | region which a sensor unit detects. It is a figure which shows typically the relative positional relationship of four sensor units. It is a flowchart which shows the initial setting process after a power supply is turned on. It is a figure which shows typically the state in which the 3rd duplication area | region is included in the display area which a display apparatus displays. It is a figure which shows typically the example of the content of the process which guide | induces the position of touch operation to a 3rd duplication area | region.

  Hereinafter, the present invention will be described in detail based on preferred embodiments with reference to the accompanying drawings. For convenience of explanation, the term “light” includes electromagnetic waves (especially infrared rays) in a wavelength region other than visible light. The configurations shown in the following embodiments are merely examples of the present invention, and the present invention is not limited to the configurations shown in the following embodiments.

(First embodiment)
First, schematic configurations of the coordinate input device 100 and the coordinate input system 101 according to the first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram schematically illustrating an example of a schematic configuration of a coordinate input device 100 and a coordinate input system 101 according to the first embodiment of the present invention. As shown in FIG. 1, the coordinate input device 100 includes a pair of sensor bars 1L and 1R as two housings. The two sensor bars 1L and 1R are provided with at least two sensor units 21L, 22L, 21R and 22R, respectively. For this reason, the coordinate input device 100 has at least four sensor units 21L, 22L, 21R, and 22R as a whole.

  The coordinate input system 101 includes a coordinate input device 100, a computer (hereinafter referred to as a PC 300) that is an external device of the coordinate input device 100, and a display device 200. FIG. 2 is a diagram illustrating an example of the hardware configuration of the PC 300. As shown in FIG. 2, the PC 300 includes a CPU 301, a RAM 302, a ROM 303, an external memory 304, an input unit 305, a display unit 306, a communication I / F unit 307, and a bus. Yes. The CPU 301 controls the overall operation of the PC 300 and controls each part of the PC 300 via a bus. The RAM 302 functions as a main memory, work area, and the like for the CPU 301. The ROM 303 stores a program necessary for the CPU 301 to execute processing. The external memory 304 stores an application program for executing processing to be described later. As the external memory 304, various known storage devices such as HDD (Hard Disk Drive) and SSD (Silicon Solid Disk) can be applied. The input unit 305 is a part where a user or the like operates the PC 300. As the input unit 305, various known input devices such as a keyboard and a mouse can be applied. The display unit 306 displays various images and information according to the control of the CPU 301. Various known display devices such as a liquid crystal display device can be applied to the display unit 306. The communication I / F unit 307 manages communication with the outside (in this embodiment, the coordinate input device 100 and the display device 200). The bus connects the CPU 301, the RAM 302, the ROM 303, the external memory 304, the input unit 305, the display unit 306, and the communication I / F unit 307 so that they can communicate with each other. When executing the processing, the CPU 301 reads the computer program stored in the external memory 304 and executes the program by using the RAM 302 as a work area. As a result, various functional operations are realized.

  The PC 300 is not limited to the above configuration. The PC 300 may have any configuration as long as it can execute a predetermined application and can communicate with the coordinate input device 100 and the display device 200. For example, various known personal computers (including a laptop type and a PDA type) can be applied to the PC 300.

  The display device 200 projects (displays) an image generated by the coordinate input device 100 or an image generated by an application of the PC 300 inside the coordinate input area 5 (described later). A region where the display device 200 projects (displays) an image is a display region 111. The display device 200 may be any configuration that can project (display) an image input from the outside (in this embodiment, the coordinate input device 100 and the PC 300), and the specific configuration is not particularly limited. Various known display devices such as a known projector can be applied to the display device 200.

  As shown in FIG. 1, the sensor bars 1 </ b> L and 1 </ b> R of the coordinate input device 100 are arranged and used outside two opposing sides of a rectangular coordinate input region 5. In this state, each of the four sensor units 21L, 22L, 21R, and 22R is positioned near the four corners of the rectangular coordinate input area 5. More specifically, each of the two sensor units 21L, 22L, 21R, and 22R of each sensor bar 1L and 1R is located in the vicinity of both ends of the two opposing sides of the rectangular coordinate input area 5. . The coordinate input area 5 refers to an area in which coordinates can be input by the coordinate input device 100. In other words, the coordinate input area 5 is provided between the two sensor bars 1L and 1R arranged substantially in parallel. When a front projector is applied as the display device 200 and an image is projected onto the flat whiteboard 6 or the like, the display area 111 (display screen) by the display device 200 is the range of the coordinate input area 5 by the coordinate input device 100. Set in. The target on which the image is projected is not limited to the whiteboard 6 but may be a wall surface or a screen. For convenience of explanation, the horizontal direction in the planar and rectangular coordinate input area 5 is the X-axis direction (the rightward direction is +), the vertical direction is the Y direction (downward is +), and the normal direction (in FIG. 1). The direction perpendicular to the paper surface is defined as the Z direction.

  One sensor bar 1L (a sensor bar arranged on the left side in FIG. 1) includes at least two sensor units 21L and 22L and an arithmetic control circuit 3L. Similarly, at least two sensor units 21R and 22R and an arithmetic control circuit 3R are built in the other sensor bar 1R (sensor bar arranged on the right side in FIG. 1). Each of the sensor units 21L, 22L, 21R, and 22R includes a light projecting unit 30 and a light receiving unit 40. Further, retroreflective means 4L and 4R for retroreflecting incident light are provided on the side surfaces facing each other in the usage state of the sensor bars 1L and 1R. The retroreflective means 4L and 4R retroreflect the infrared rays projected by the light projecting means 30 of the sensor units 21L, 22L, 21R, and 22R of the sensor bars 1L and 1R provided on the two opposite sides of the coordinate input area 5, respectively. Let The retroreflective means 4L and 4R may be configured to retroreflect incident light. For this reason, various known retroreflective materials (such as a retroreflective tape) can be applied to the retroreflective means 4L and 4R.

  The calculation control circuit 3L built in one sensor bar 1L controls the sensor units 21L and 22L and calculates the output results thereof. Further, the calculation control circuit 3L built in one sensor bar 1L controls the calculation control circuit 3R built in the other sensor bar 1R. The calculation control circuit 3R built in the other sensor bar 1R controls the sensor units 21R and 22R and calculates the output results thereof. And the result of a calculation process is transmitted to the calculation control circuit 3L built in one sensor bar 1L. When the user or the like instructs or touches a desired position in the coordinate input area 5, the arithmetic control circuit 3L provided on one sensor bar 1L outputs from the four sensor units 21L, 22L, 21R, and 22R. The result is processed to calculate a position such as an instruction or a touch. In the embodiment of the present invention, an instruction or touch to the coordinate input area 5 by a user or the like is referred to as a “touch operation”, and a position where the touch operation is performed is referred to as a “touch position”. The touch operation may not be an operation of touching the surface of the coordinate input area 5. Then, the arithmetic control circuit 3L outputs the calculation result of the touch position to the PC 300. FIG. 1 shows a configuration in which a calculation control circuit 3L built in one sensor bar 1L and a calculation control circuit 3R built in the other sensor bar 1R are connected by a cable 7 to perform wired communication. However, the configuration may be such that the calculation control circuit 3L built in one sensor bar 1L and the calculation control circuit 3R built in the other sensor bar 1R communicate wirelessly.

  FIG. 3 is a diagram schematically illustrating an example of a schematic configuration of the sensor unit 21L. Specifically, FIG. 3A is a cross-sectional view taken along line AA in FIG. FIG. 3B is a front view of the light projecting means 30 included in the sensor unit 21L as viewed from the Z-axis direction. FIG. 3C is a front view of the light receiving means 40 included in the sensor unit 21L as viewed from the Z-axis direction. 3 shows the configuration of one sensor unit 21L among the four sensor units 21L, 22L, 21R, and 22R, the other sensor units 22L, 21R, and 22R are similar to the sensor unit 21L. It has the composition of. Specifically, the sensor units 22L and 21R have a mirror surface configuration with the sensor unit 21L, and the sensor unit 22R has a point-symmetric configuration (the configuration is the same and the arrangement direction is different) with the sensor unit 21L. .

  The sensor unit 21L is built in one sensor bar 1L. As shown in FIG. 3A, the sensor unit 21L includes a light projecting unit 30 and a light receiving unit 40. The optical axis Ap of the light projecting means 30 and the optical axis Ar of the light receiving means 40 are parallel to the coordinate input area 5 (that is, the XY plane) and are separated by a distance Lpd in the Z-axis direction. On the side surface of the sensor bar 1L, retroreflective means 4L is provided between the optical axis Ap of the light projecting means 30 and the optical axis Ar of the light receiving means 40. The side surface of the sensor bar 1L is provided with an opening through which the infrared ray emitted from the light projecting means 30 and the infrared ray reflected and incident by the retroreflecting means 4R pass, and has a light transmitting property so as to close the opening. A protective member 45 is provided. The protective member 45 prevents foreign matter such as dust from entering the sensor bar 1L by closing the opening.

  As illustrated in FIG. 3B, the light projecting unit 30 includes an infrared LED 31 that is an example of a light source, and a light projecting lens 32. The infrared LED 31 and the light projecting lens 32 are fixed by, for example, an adhesive layer 33. The infrared LED 31 emits infrared light. The light projecting lens 32 shapes the infrared light emitted from the infrared LED 31 into a light beam substantially parallel to the surface of the coordinate input area 5 (for example, the surface of the whiteboard 6). The light projecting means 30 is provided so as to illuminate the entire region of the retroreflective means 4R of the other sensor bar 1R provided on the opposite side. Specifically, the light projecting means 30 emits a fan-shaped light flux whose light projection range is from the direction g to the direction h and whose apex is at the point Op when viewed in the Z-axis direction. The optical axis of the light projecting means 30 is set in the direction f. The direction f is a direction toward the end in the longitudinal direction of the other sensor bar 1R and toward the end far from the sensor unit 21L (the end located in the diagonal direction). Specifically, based on the sensor unit 21L provided at the upper end of the left sensor bar 1L, the direction f is a direction from the sensor unit 21L toward the lower end of the right sensor bar 1R.

  As shown in FIG. 3C, the light receiving means 40 is reflected (recursively) by the retroreflective means 4L and 4R mounted on the sensor bars 1L and 1R provided on the opposite sides, which are projected by the light projecting means 30. The reflected light is detected. The light receiving means 40 includes a line CCD 41, which is an example of a detection means, a light receiving lens 42, a field stop 43, and an infrared passage filter 44. The protection member 45 may be provided with an infrared pass filter function, and the light receiving means 40 may not be provided with the infrared pass filter 44. The direction of the optical axis of the light receiving means 40 is set in a direction parallel to the X-axis direction. In FIG. 3C, the range from the direction g to the direction h is the visual field range of the light receiving means 40, and the position of the point Or is the optical center position. The light receiving means 40 is an optical system that is asymmetric with respect to the optical axis. The line CCD 41 has a configuration in which a plurality of pixels (photoelectric conversion elements) are arranged in a straight line. Then, the light is condensed on any pixel of the line CCD 41 of the light receiving means 40 according to the direction of the incident light. For this reason, the pixel number of the line CCD 41 represents information on the incident angle of the incident light.

  The light projecting means 30 and the light receiving means 40 are arranged so as to overlap in the Z-axis direction so that the positions of the point Op and the point Or and the direction g and the direction h substantially coincide with each other when viewed in the Z-axis direction. (See FIG. 3A).

  FIG. 4A is a diagram schematically illustrating an example of the schematic configuration of the coordinate input device 100 and the arrangement of the light projecting unit 30 and the light receiving unit 40. The light projecting means 30 of the sensor unit 21L of the sensor bar 1L projects infrared rays in the range from the direction g to the direction h. Of the infrared rays projected from the light projecting means 30 of the sensor unit 21L of the sensor bar 1L, a range in which the retroreflective means 4R of the other sensor bar 1R is mounted (in FIG. 4, from the direction j to the direction f). The light incident on (range) is retroreflected. The light retroreflected by the retroreflective means 4R is detected by the light receiving means 40 of the sensor bar 1L. In this way, the two sensor bars 1L and 1R are arranged between the direction g and the direction h when viewed from the two sensor units 21L, 22L, 21R and 22R of the counterpart sensor bar 1L and 1R. used. Furthermore, it is used in a state where the respective end portions of the other sensor bar 1R are positioned in the direction f as viewed from the sensor units 21L and 22L of the one sensor bar 1L. FIG. 4 shows directions f, g, and h for one sensor bar 1L, but the same applies to the other sensor bar 1R.

  By the way, the luminous flux emitted from the light projecting means 30 is not completely parallel, and the width of the luminous flux increases as the distance from the light projecting means 30 increases (see FIG. 3A). For this reason, the quantity of light retroreflected by the retroreflective means 4R decreases as the distance from the light projecting means 30 increases. Therefore, the intensity of incident light is low in the direction f far from the direction j where the distance from the center point Op of the light projecting means 30 to the retroreflective means 4R is short. Further, the retroreflected light rate in the retroreflective means 4R decreases as the incident angle increases as compared to the case where the retroreflective means 4R enters the retroreflective surface of the retroreflective means 4R from a right angle direction. In other words, the rate at which the incident light on the retroreflective means 4L and 4R is retroreflected as retroreflected light depends on the incident angle of the incident light on the retroreflective means 4L and 4R. And since the direction f is the direction where the incident angle to the retroreflective means 4L, 4R is the largest, the ratio of retroreflecting is the lowest. On the other hand, the optical axis Ar of the light receiving means 40 is set in a direction parallel to the X-axis direction. The angle formed between the incident reflected light and the optical axis Ar of the light receiving means 40 is the largest in the reflected light incident from the direction f. As for the lens characteristics of a general optical lens, the light collection efficiency decreases as the angle formed with the optical axis increases. For this reason, it can be said that the direction f is the darkest direction due to a decrease in the light collection efficiency. Therefore, even if the light projecting unit 30 can project (irradiate) light having a constant intensity in the entire range from the direction g to the direction h, the retroreflected light that can be detected by the light receiving unit 40 is retroreflected from the direction j. The light becomes the strongest and becomes weaker from the direction j toward the direction f (see FIG. 4B).

  On the other hand, the infrared intensity of the infrared LED 31 is generally maximum in the optical axis direction. And the intensity | strength of infrared rays falls as the angle made with an optical axis becomes large. As shown in FIG. 4C, the degree of decrease in such light projection intensity (irradiation intensity) is generally an angle “half-value angle” at which the light projection intensity (irradiation intensity) is half of the optical axis direction. Defined by In this embodiment, it is set as the structure which orient | assigns the optical axis Ap of the light projection means 30 to the direction f where the intensity | strength of retroreflection light becomes the weakest. Thereby, the light projection intensity in the direction f is increased, and the light projection intensity is relatively lowered in the direction from the direction f to the direction j. With such a configuration, as shown in FIG. 4D, non-uniformity in the intensity of the retroreflected light that can be detected can be reduced or eliminated in the range from the direction j to the direction f. Therefore, a stable signal can be obtained regardless of the direction. In the present embodiment, the configuration in which the optical axis of the light projecting means 30 is directed in the direction f where the retroreflected light level is the weakest according to the distribution of the light projection intensity of the infrared LED 31 is shown. However, the inclination angle of the light projecting means 30 with respect to the light receiving means 40 is not limited to the aforementioned angle. For example, when the light projecting lens 32 has asymmetric optical characteristics, the light amount distribution shown in FIG. 4C also has asymmetric property. In this case, a configuration in which the direction in which the light projection intensity is maximum in the distribution having the asymmetry is made to coincide with the direction f may be employed.

  Next, the configuration of the sensor bars 1L and 1R will be described with reference to FIG. In the present embodiment, the two sensor bars 1L and 1R are used by being attached to a planar region such as a white board 6 or a wall surface. Then, the display area 111 projected on the whiteboard 6 or the wall surface can be directly touch-operated. The size of the display area 111 is appropriately set by the user or the like according to the size of the whiteboard 6 or the size of the wall surface, and is not a fixed value. For example, even when the whiteboard 6 is used, commercially available whiteboards have various sizes. As a screen for a projection screen, there are sizes that can project a large screen, for example, vertical and horizontal dimensions of 900 × 1200 mm, 900 × 1800 mm, and 1200 × 1800 mm. However, these dimensions do not mean a range that can be effectively used as a whiteboard, but are often dimensions including a frame around the four sides. Accordingly, the area actually usable as the coordinate input area 5 is smaller than that, and the size varies depending on the manufacturer.

  Therefore, in the present embodiment, the sensor bars 1L and 1R of the coordinate input device 100 are provided with an expansion / contraction mechanism that expands and contracts in the longitudinal direction so as to correspond to various dimensions. And the distance of the two sensor units 21L, 22L, 21R, 22R built in each sensor bar 1L, 1R can be changed by extending / contracting the expansion / contraction mechanism of the sensor bars 1L, 1R. For example, a configuration in which the outer length of the sensor bars 1L and 1R is variable within a range of 820 to 1200 mm can be applied so that the size of the flat portion of the white board 6 having a vertical dimension of 900 to 1200 mm can be mounted from 820 mm to 1200 mm. .

  FIG. 5A is a cross-sectional view illustrating an example of a schematic configuration of the sensor bar 1L. The other sensor bar 1R has the same configuration as the sensor bar 1L. Each sensor bar 1 </ b> L, 1 </ b> R has an upper housing case 61 and a lower housing case 62. One of the upper housing case 61 and the lower housing case 62 is provided with an outer pipe 63, and the other is provided with an inner pipe 64. At least a part of the inner pipe 64 is fitted inside the outer pipe 63. The inner pipe 64 and the outer pipe 63 can reciprocate in a sliding manner in the axial direction. The outer pipe 63 is fixed to the upper casing case 61, and the inner pipe 64 is fixed to the lower casing case 62. However, the outer pipe 63 may be fixed to the lower casing case 62 and the inner pipe 64 may be fixed to the upper casing case 61. As shown in FIG. 5B, when the sensor bars 1L and 1R are expanded and contracted, the outer pipe 63 and the inner pipe 64 slide in a state in which the mating relationship is maintained. In the present embodiment, a configuration in which the outer pipe 63 and the inner pipe 64 are made of metal is applied. The outer pipe 63 and the inner pipe 64 are made of metal, so that the mechanical strength of the sensor bars 1L and 1R during expansion and contraction is ensured. One end of each of the outer pipe 63 and the inner pipe 64 made of metal is crushed by press molding or the like. The crushed portion is mechanically coupled to each of the upper housing case 61 and the lower housing case 62. Further, each of the sensor units 21L, 22L, 21R, and 22R is attached to the crushed portion.

  In the present embodiment, the sensor units 21L, 22L, 21R, and 22R are arranged so that the optical axis Ar of the light receiving means 40 is perpendicular to the longitudinal direction (stretching direction) of the sensor bars 1L and 1R. ing. The field of view of the light receiving means 40 is provided asymmetrically with respect to the optical axis Ar. According to such a configuration, the sensor bars 1L and 1R, which are housings, can be thinned. That is, the longitudinal direction of the line CCD 41 and the circuit board on which the line CCD 41 is mounted can be parallel to the longitudinal direction of the sensor bars 1L and 1R.

  For example, as shown in FIG. 5C, it is assumed that the sensor units 21L, 22L, 21R, and 22R have an axially symmetric optical system. In such a configuration, the optical axis of the optical system of the light receiving means 40 is set in the longitudinal direction of the sensor bars 1L and 1R (vertical direction in FIG. 5C) in order to secure the field of view necessary for the light receiving means 40. You must lean against it. For this reason, the width Lw of the sensor bars 1L and 1R that house the optical system is larger than that of the configuration in which the optical axis is perpendicular to the longitudinal direction. As a result, the sensor bars 1L and 1R, which are casings, are also increased and the weight is increased. For this reason, not only portability falls, but an area required in order to mount sensor bars 1L and 1R becomes larger. Therefore, in the case of mounting on the whiteboard 6 or the like, the area of the display area 111 by the display device 200 is reduced.

  Consider a configuration in which the optical system of the light receiving means 40 is axially symmetric with respect to the optical axis Ar, and the optical axis Ar is perpendicular to the sliding direction of the sensor bars 1L and 1R. Then, the light beam is bent by an optical member such as a mirror provided in the optical system of the light receiving means 40 to ensure a necessary visual field range. In such a configuration, a new optical element such as a mirror must be provided on the optical path, and the sensor units 21L, 22L, 21R, and 22R are increased in size. Therefore, in such a configuration, the widths of the sensor bars 1L and 1R are larger than the configuration using a non-axisymmetric optical system.

  Consider a configuration in which the optical system of the light receiving means 40 is axially symmetric with respect to the optical axis (X axis) and has a sufficiently large visual field range (for example, a visual field range of ± 50 ° with respect to the optical axis Ar). In this case, the visual field range of the optical system of the light receiving means 40 is a range from the direction h to the direction m as shown in FIG. The direction m is a direction symmetrical to the direction h with respect to the optical axis (X axis). In this case, the angle formed by the optical axis (X axis) and the direction h = the angle formed by the optical axis (X axis) and the direction h (= 50 °). On the other hand, the visual field range required by the coordinate input device 100 is a range that covers the entire area of the retroreflective means 4L and 4R provided on opposite sides, and this is only in the range from the direction f to the direction j. is there. For this reason, the visual field range (that is, the range from the direction j to the direction m) that is substantially half on one side of the optical axis (X axis) is an unused area. Therefore, even with such a configuration, the effective visual field range of the light receiving means 40 is substantially equivalent to the case where an asymmetric optical system with respect to the optical axis Ar is employed.

  In this embodiment, the coordinate input area 5 has a horizontally long rectangular shape, and sensor bars 1L and 1R are arranged on the left and right sides thereof (see FIG. 1). In this case, the amount of expansion / contraction of the sensor bars 1L and 1R is set based on the vertical dimension which is the short direction of the coordinate input area 5. However, the present invention is not limited to such a configuration. For example, a configuration in which the horizontally long rectangular coordinate input area 5 is arranged on the upper and lower sides of the coordinate input area 5 may be employed. In this case, the dimensions when the sensor bars 1L and 1R are extended to the maximum are increased as compared with the case where the rectangular coordinate input area 5 is mounted on both the left and right sides. Further, when a large screen is projected on a wall surface or the like, the expansion / contraction amount of the expansion / contraction mechanism of the sensor bars 1L and 1R is set according to the assumed size of the maximum display area.

  In the case where the horizontally long rectangular coordinate input area 5 is set on a horizontally long rectangular surface such as the whiteboard 6, the sensor bars 1L and 1R are mounted on the left and right sides (that is, short sides). It is preferable that That is, in general, the aspect ratio of the whiteboard 6 has a horizontally long ratio as compared with the aspect ratios of display areas of various known display devices. For this reason, when it is attempted to secure the maximum display area 111 of the display device 200 on the whiteboard 6, blanks (areas in which no image is displayed) are formed at the left and right ends of the whiteboard 6. For this reason, even if the sensor bars 1L and 1R are arranged at the left and right ends of the whiteboard 6, the display area 111 of the display device 200 does not become small. For this reason, it is possible to provide an operating environment in which a larger display area 111 can be used.

  Further, the aspect ratio of the display area 111 of the display device 200 has a ratio of being horizontally long. Therefore, if the sensor bars 1L, 1R are configured to be mounted on the left and right sides (that is, the short sides) of the coordinate input area 5, the sensor bars 1L, 1L, The maximum length of 1R can be reduced. The detachable coordinate input device 100 is preferably lightweight and small for convenience of handling and transportation. For example, a user or the like transports to a desired place of use (for example, a conference room), and uses the whiteboard 6 or wall surface installed at the place of use as the coordinate input area 5 so that it can be transported to the place of use and used immediately Preferably it can be done. If it is the structure attached to the short side of the rectangular coordinate input area 5, it can achieve size reduction and weight reduction compared with the structure attached to the long side. Therefore, conveyance and use preparation become easy.

  Further, if the sensor bars 1L and 1R are arranged on the left and right sides of the coordinate input area 5, the arrangement is easy. That is, in the configuration in which the coordinate input area 5 is mounted on each of the upper and lower sides, work at a high place may be required. On the other hand, if it is the structure installed in each of the right and left of the coordinate input area 5, such an aerial work is unnecessary.

  Next, an example of a functional configuration of the coordinate input device 100 will be described with reference to FIG. FIG. 6A is a block diagram illustrating an example of a functional configuration of the arithmetic control circuits 3L and 3R. In the present embodiment, the calculation control circuit 3L built in one sensor bar 1L and the calculation control circuit 3R built in the other sensor bar 1R have the same configuration except for the specifications of the interface to the outside. . The arithmetic control circuits 3L and 3R control the sensor units 21L, 22L, 21R, and 22R connected thereto and perform various calculations.

  The main calculation unit 71 is configured by a one-chip microcomputer including a CPU, a ROM, and a RAM. The main calculation unit 71 outputs a CCD control signal to the sensor units 21L, 22L, 21R, and 22R to perform shutter timing of the line CCD 41, data output control, and the like. The clock generator CLK72 generates a clock for the line CCD 41 and transmits it to the sensor units 21L, 22L, 21R, and 22R. This clock is also transmitted to the main calculation unit 71 in order to perform various controls in synchronization with the line CCD 41. Further, the main calculation unit 71 generates an LED drive signal for driving the infrared LEDs 31 of the sensor units 21L, 22L, 21R, and 22R, and transmits the LED drive signal to the sensor units 21L, 22L, 21R, and 22R.

  A detection signal from a line CCD 41, which is an example of detection means in the sensor units 21L, 22L, 21R, and 22R, is input to the A / D converter 73. The A / D converter 73 converts the detection signal from analog data to digital data according to control by the main calculation unit 71. The converted digital data of the detection signal is stored in the memory 74. The main calculation unit 71 performs angle calculation for calculating the incident direction (angle) of the light beam using the stored digital data of the detection signal. Then, the main calculation unit 71 calculates a geometric touch position from the calculated angle information of the incident direction of the light flux, and outputs it to the PC 300 via the USB interface 78 or the like.

  Arithmetic control circuits 3L, 3R built in each sensor bar 1L, 1R control two sensor units 21L, 22L, 21R, 22R built in each sensor bar 1L, 1R. For example, it is assumed that the arithmetic control circuit 3L incorporated in one sensor bar 1L performs the master function. In this case, the main calculation unit 71 of the calculation control circuit 3L transmits a control signal to the calculation control circuit 3R built in the other sensor bar 1R via the interface 77 that performs serial communication. Synchronize between 3L and 3R. Then, the calculation control circuit 3L built in one sensor bar 1L acquires necessary data from the calculation control circuit 3R built in the other sensor bar 1R. The two arithmetic control circuits 3L and 3R operate under master / slave control. In the present embodiment, a configuration in which the arithmetic control circuit 3L is a master and the arithmetic control circuit 3R is a slave is shown as an example. However, it is not limited which of the two arithmetic control circuits 3L and 3R is a master and which is a slave. For example, the two arithmetic control circuits 3L and 3R may be provided with a dip switch (not shown) or the like for inputting a switching signal to the port of the main arithmetic unit 71. In this case, the user or the like can switch between the master and the slave by operating the dip switch or the like.

  The arithmetic control circuit 3L, which is the master, sends control signals to the arithmetic control circuit 3R, which is the slave, via the interface 77 in order to acquire data of the sensor units 21R and 22R built in the sensor bar 1R provided on the opposite side. Send. Then, the arithmetic control circuit 3R as a slave calculates angle information of the touch position from the detection results of the sensor units 21R and 22R, and transmits the calculated angle information to the arithmetic control circuit 3L on the master side via the interface 77. . In this embodiment, the USB interface 78 is mounted on the arithmetic control circuit 3L that is a master.

  In addition, the arithmetic control circuits 3L and 3R have an infrared light receiving means 76 for detecting infrared rays emitted from a dedicated pen (not shown) and a sub-operation unit 75 for decoding a signal from the dedicated pen. The dedicated pen has switch means for detecting that the pen tip has been pressed against the input surface, and various switch means provided on the side portion of the pen housing. The dedicated pen transmits the state of the switch means and the identification information of the pen by the infrared light emitting means provided in the dedicated pen. The arithmetic control circuits 3L and 3R can detect the operation state of the dedicated pen by receiving and decoding the infrared rays emitted by the dedicated pen.

  Further, the arithmetic control circuits 3L and 3R include an indicator 79 and a speaker 80. The indicator 79 performs a predetermined display according to the control of the main calculation unit 71. Various known indicators such as a liquid crystal display device and an LED indicator can be applied to the indicator 79, for example. The speaker 80 emits sound according to the control of the main calculation unit 71. Note that the indicator 79 and the speaker 80 may be arranged at positions physically separated from the arithmetic control circuits 3L and 3R.

  The sensor units 21L and 22L of one sensor bar 1L and the sensor units 21R and 22R of the other sensor bar 1R operate alternately at different timings. Thereby, the sensor units 21L, 22L, 21R, and 22R of the sensor bars 1L and 1R do not detect the infrared rays from the light projecting means 30 of the other sensor units 21L, 22L, 21R, and 22R, respectively. For this reason, the infrared retroreflected light emitted by the light projecting means 30 provided in the device can be detected. Specifically, it is as follows.

  FIG. 6B is a timing chart showing the operation of the sensor units 21L and 22L. The SH signal 701, the ICGL signal 702, and the ICGR signal 703 are control signals for controlling the line CCD 41 of the sensor units 21L, 22L, 21R, and 22R. The shutter open time of the line CCD 41 is determined by the interval of the SH signal 701. The ICGL signal 702 is a gate signal to the sensor units 21L and 22L of one sensor bar 1L. The ICGR signal 703 is a gate signal to the sensor units 21R and 22R of the other sensor bar 1R. The ICGL signal 702 and the ICGR signal 703 are signals for transferring the charge of the line CCD 41 to the reading unit. The ICGR signal 703 is transmitted from the arithmetic control circuit 3L of one sensor bar 1L operating as a master to the arithmetic control circuit 3R of the other sensor bar 1R operating as a slave via the interface 77. Then, the arithmetic control circuit 3R generates a signal for transferring the charge of the line CCD 41 to the reading unit. The CCDL signal 704 is a signal indicating the shutter opening time of the line CCD 41 of the sensor units 21L and 22L of one sensor bar 1L. The CCDR signal 705 is a signal indicating the shutter opening time of the line CCD 41 of the sensor units 21R and 22R of the other sensor bar 1R.

  The LEDL signal 706 is a drive signal for driving the infrared LED 31 provided in the light projecting means 30 of the sensor units 21L and 22L of the one sensor bar 1L. The LEDR signal 707 is a drive signal for driving the infrared LED 31 provided in the light projecting means 30 of the sensor units 21R and 22R of the other sensor bar 1R. In the first cycle of the SH signal 701, the arithmetic control circuit 3L of one sensor bar 1L sends the LEDL signal 706 to the sensor units 21L and 22L in order to turn on the infrared LED 31 of the light projecting means 30 of the sensor units 21L and 22L. Send. Thereby, infrared LED31 of the light projection means 30 of sensor unit 21L, 22L light-emits. In the next cycle of the SH signal 701, the arithmetic control circuit 3L transmits the LEDR signal 707 to the arithmetic control circuit 3R of the other sensor bar 1R via the interface 77. When the calculation control circuit 3R of the other sensor bar 1R receives the LEDR signal 707 from the calculation control circuit 3L, the calculation control circuit 3R generates a signal for turning on the infrared LED 31 of the light projecting means 30 of the sensor units 21R and 22L. The LED 31 is caused to emit light.

  The arithmetic control circuits 3L and 3R read the signal of the line CCD 41 after the light emission of the infrared LED 31 and the shutter release of the line CCD 41 are completed, and calculate angle information by a method described later. Then, the calculation result of the calculation control circuit 3R that operates as a slave is transmitted via the interface 77 to the calculation control circuit 3L that operates as a master. Thereafter, such an operation is repeated. Thus, the sensor units 21L and 22L of one sensor bar 1L and the sensor units 21R and 22R of the other sensor bar 1R facing each other operate at different timings alternately. According to such a configuration, 21L, 22L, 21R, 22R of each sensor bar 1L, 1R does not detect the infrared light of sensor units 21L, 22L, 21R, 22R of the other sensor bar 1L, 1R. That is, it is possible to detect only the infrared retroreflected light emitted by the light projecting means 30 provided in itself.

  Next, signals output from the sensor units 21L, 22L, 21R, and 22R of the sensor bars 1L and 1R will be described with reference to FIG. FIG. 7A is a graph schematically showing the output of the light receiving means 40 when the light projecting means 30 is not projecting light. FIG. 7B is a graph schematically showing the output of the light receiving means 40 in a state where light is projected. The level A of the CCD output in FIG. 7B is an output when the maximum amount of light is detected, and the level B is an output when the amount of received light is 0 (that is, no light is received). .

  The sensor units 21L and 22L project infrared rays toward the retroreflective means 4L and 4R of the counterpart sensor bars 1L and 1R provided to face each other by the light projecting means 30. The infrared light retroreflected by the retroreflective means 4L, 4R is detected by the light receiving means 40 of the sensor units 21L, 22L. Therefore, as shown in FIG. 7B, the direction defined by the pixel number Ni at one end of the range in which the output of level A or a level close to level A is obtained is the direction j (see FIG. 4). Similarly, the direction defined by the pixel number Nf at one end on the opposite side of this range is the direction f (see FIG. 4). The light amount level in the range from the pixel number Nj to the pixel number Nf is the size of the display area 111, the aspect ratio thereof, and the arrangement state of the sensor bars 1L and 1R corresponding thereto (for example, the distance between the two sensor bars 1L and 1R). It changes depending on the expansion / contraction state.

  The main calculation unit 71 of the calculation control circuits 3L and 3R adjusts the SH signal 701 to control the shutter open time of the line CCD 41 and the exposure time of the infrared LED 31 so as to obtain an optimum light amount level. That is, when the light amount level is high, one or both of the shutter opening time and the exposure time are shortened, and when it is low, one or both of the shutter opening time and the exposure time are lengthened. In addition, the arithmetic control circuits 3L and 3R may adjust the current flowing through the infrared LED 31 according to the detected light amount level. As described above, the arithmetic control circuits 3L and 3R monitor the output signals of the sensor units 21L, 22L, 21R, and 22R to obtain an optimum light amount level. Note that the arithmetic control circuits 3L and 3R may appropriately perform such control when the detected light amount level varies. Further, once the sensor bars 1L and 1R are arranged and the state is maintained, the light amount level should be stable. Therefore, such a light amount adjustment may be performed when the power is turned on after the arrangement is completed.

  FIG. 7C is a graph schematically showing an example of the output level when the user or the like touches the coordinate input area 5 to block the optical path. As shown in FIG. 7C, when a touch operation is performed on the coordinate input area 5 to block the optical path, the pixel corresponding to the blocked optical path (here, the pixel number Nc is taken as an example) is recursed. The reflected light is not detected. Therefore, the light amount level detected at the position C corresponding to the blocked optical path is level B (or a level close to level B).

<Calculation of touch position>
The main calculation unit 71 of the calculation control circuits 3L and 3R functions as an example of touch position calculation means, and uses these signals shown in FIGS. 7A, 7B, and 7C to determine the direction of the touch position ( In other words, the angle) is calculated. Here, a method for calculating the direction of the touch position will be described.

  First, when the coordinate input device 100 is activated (when the power is turned on) or reset, the reference data is acquired automatically or by an operation of a user or the like. Specifically, it is as follows. The main calculation unit 71 of the arithmetic control circuit 3L serving as a master acquires the output level of the line CCD 41 in a state where the light projecting unit 30 does not emit infrared rays and the touch operation by the user or the like is not performed. . The acquired output level is A / D converted by the A / D converter 73 and stored in the memory 74 as reference data Base_Data [N] (N is the pixel number of the line CCD 41). This reference data Base_Data [N] is data having an output level near level B as shown in FIG. The reference data Base_Data [N] includes variations in the bias of the CCD that is the line CCD 41, and the like.

  In addition, the main calculation unit 71 acquires the output level of the line CCD 41 in a state where the light projecting unit 30 emits infrared rays and no touch operation is performed by the user or the like. Similarly to the above, the acquired output level is A / D converted by the A / D converter 73 and stored in the memory 74 as reference data Ref_Data [N]. This reference data is data as shown in FIG. That is, the output level in a certain range is level A or a level in the vicinity thereof, and the output level in other ranges is a level B or a level in the vicinity thereof. FIG. 7B shows an example in which the output level in the range of pixel numbers Nj to Nf is level A or a level in the vicinity thereof. The pixel number Nj is the number of the pixel corresponding to the direction j. The pixel number Nf is a pixel number corresponding to the direction f.

  Thereafter, the main calculation unit 71 starts sampling at the timing shown in FIG. If no touch operation is performed during sampling, sampling data as shown in FIG. 7B is acquired. Further, when a touch operation is performed, sampling data as shown in FIG. 7C is detected according to the position of the light shielding range generated by the touch operation. That is, a portion where the output level is locally level C close to level B appears depending on the position of the touch operation. The position of the level C level corresponds to the touch operation position. For this reason, the position of the part which becomes level C locally changes according to a touch position. Sampling data acquired in a state where the light projecting means 30 is projecting is assumed to be Norm_Data [N].

The main calculation unit 71 uses these data to determine whether or not the coordinate input area 5 has a light shielding range caused by a touch operation by the user or the like. First, in order to specify the light shielding range, the main calculation unit 71 calculates the absolute amount of the change in output level for each pixel of the line CCD 41. The absolute amount Norm_Data0 [N] of the change in the output level of each pixel is calculated by the following equation (1).

Norm_Data0 [N] = Norm_Data [N]-Ref_Data [N] (1)

Then, the main calculation unit 71 compares the value of Norm_Data0 [N] of each pixel with a preset threshold value Vtha. The main calculation unit 71 determines that there is a touch operation when Norm_Data0 [N] exceeding the threshold value is generated in, for example, a predetermined number or more of continuous pixels. By using the difference from the threshold value Vtha, erroneous determination due to noise or the like can be prevented, and a change in detection level can be reliably detected. Note that this process is possible in a short time because it is only necessary to calculate and compare the differences. For this reason, the main calculating part 71 can determine the presence or absence of a touch operation at high speed.

Next, the main calculation unit 71 calculates a ratio of change in the detection level in order to detect the coordinates of the position of the touch operation with higher accuracy. Then, based on the calculation result, the position of the touch operation is determined. The detection level change ratio Norm_DataR [N] is calculated by the following equation (2).

Norm_DataR [N] = Norm_Data0 [N] / (Base_Data [N]-Ref_Data [N]) (2)

A preset threshold value Vthr is applied to the ratio of the detection level changes. Then, the main calculation unit 71 extracts the pixel numbers of the rising and falling parts in the range where the change ratio exceeds the threshold value Vthr, and calculates the angle using the pixel located at the center of the extracted pixels as the input pixel. .

FIG. 7D is a graph illustrating an example of a calculation result of a ratio of detection level changes. As shown in FIG. 7D, it is assumed that the ratio of the change in the detection level at the rising portion of the light shielding region becomes the level Ls at the Ns-th pixel and exceeds the threshold value Vthr. In the falling portion, it is assumed that the ratio of change in the detection level becomes the level Lt at the Nt-th pixel and becomes equal to or lower than the threshold value Vthr. The center pixel Np can be calculated (determined) using the following equation (3).

Np = Ns + (Nt-Ns) / 2 (3)

However, in the method using Expression (3), the pixel interval of the line CCD 41 becomes the minimum detection resolution. Therefore, in order to detect more finely, a virtual pixel number that crosses the threshold value may be calculated using the level of each pixel and the level of the previous pixel. That is, for example, the detection level of the pixel Ns is Ls, the detection level of the pixel Ns-1 is Ls-1, the level of the pixel Nt is Lt, and the detection level of the pixel Nt-1 is Lt-1. Then, each virtual pixel number Nsv, Ntv is

Nsv = Ns-1 + (Vthr-Ls-1) / (Ls-Ls-1) (4)
Ntv = Nt-1 + (Vthr-Lt-1) / (Lt-Lt-1) (5)

Can be calculated. The virtual center pixel Npv is determined by the following equation (6).

Npv = Nsv + (Ntv-Nsv) / 2 (6)

Thus, by calculating (determining) a virtual pixel number from the pixel number and its detection level, detection with higher resolution can be performed.

  As described above, the pixel number of the central pixel of the light shielding area is obtained. In order to calculate an actual coordinate value from the obtained pixel number of the central pixel, it is necessary to convert the pixel number of the central pixel into angle information (coordinate information). In actual coordinate calculation, for convenience, it is preferable to obtain not the angle itself between the optical axis direction and the direction of the central pixel but the value of the tangent of the angle. As a method of converting the pixel number into tan θ, a method of referring to a table or a method of using a conversion formula can be applied. For example, when a high-order polynomial is used as the conversion formula, accuracy can be ensured. The order of the polynomial may be determined in view of the calculation capability of the main calculation unit 71 and the required accuracy.

Here, an example in the case of using a fifth-order polynomial is shown. When a fifth order polynomial is used, six coefficients are required. Therefore, this coefficient is stored in the memory 74 or the like at the time of shipment. If the coefficients of the fifth-order polynomial are L5, L4, L3, L2, L1, and L0, tan θ is calculated by the following equation (7).

tanθ = (L5 * Npr + L4) * Npr + L3) * Npr + L2) * Npr + L1) * Npr + L0
(7)

By executing the same calculation for each of the sensor units 21L, 22L, 21R, and 22R, the angle indicating the direction of the light shielding region can be determined for each of the sensor units 21L, 22L, 21R, and 22R. In the above formula (7), tan θ is calculated, but the angle itself may be calculated, and then tan θ may be obtained.

  As described above, in the present embodiment, the main calculation unit 71 of the calculation control circuit 3L that operates as a master functions as an example of a touch position calculation unit that calculates a touch position. However, the present invention is not limited to such a configuration. The main calculation unit 71 of the two calculation control circuits 3L and 3R may cooperate to function as a touch position calculation unit.

<Calculating the relative position of the sensor unit>
Next, a method for calculating the relative positions of the sensor units 21L, 22L, 21R, and 22R will be described. FIG. 8A is a diagram schematically showing the visual field range detected by the sensor units 21L, 22L, 21R, and 22R. The sensor unit 21L of the sensor bar 1L receives light from the retroreflective means 4R provided on the opposing sensor bar 1R. For this reason, the visual field range of the sensor unit 21L includes a range from the direction j to the direction f. The visual field range of the sensor unit 22L of the sensor bar 1L includes a range from the direction f to the direction j.

  FIG. 8B is a diagram schematically showing a region where the visual field ranges of the two sensor units 21L and 22L of one sensor bar 1L overlap. For convenience of explanation, this area is referred to as a first overlapping area 91. In FIG. 8B, the first overlapping region 91 is indicated by a bold line. The main calculation unit 71 of the calculation control circuit 3L functions as an example of a touch position calculation unit, and converts the coordinates of the position of the touch operation into the first overlapping area 91 into the detection results by the two sensor units 21L and 22L. Calculate based on

  Similarly, the visual field range of the sensor unit 21R of the sensor bar 1R includes a range from the direction g to the direction h. The visual field range of the sensor unit 22R includes a range from the direction h to the direction g. FIG. 8C is a diagram schematically showing a region where the field-of-view ranges of the two sensor units 21R and 22R of the other sensor bar 1R overlap. For convenience of explanation, this area is referred to as a second overlapping area 92. In FIG. 8C, the second overlapping area 92 is a bold line. The main calculation unit 71 of the calculation control circuit 3L functions as an example of a touch position calculation unit, and detects the coordinates of the position of the touch operation on the second overlapping area 92 by the two sensor units 21R and 22R. Calculate based on the results.

  Furthermore, a region where the first overlapping region 91 and the second overlapping region 92 overlap is defined as a third overlapping region 93. FIG. 8D is a diagram schematically showing the third overlapping region 93. In FIG. 8D, the third overlapping region 93 is indicated by a bold line. The third overlapping area 93 is located near the center of the coordinate input area 5. The main calculation unit 71 of the calculation control circuit 3L sets the position of the touch operation in the third overlapping area 93 to all of the four sensor units 21L, 22L, 21R, and 22R near the four corners of the coordinate input area 5. It is possible to calculate from the detection result.

  9A and 9B are diagrams schematically illustrating the relative positional relationship between the four sensor units 21L, 22L, 21R, and 22R. The angle θ1 in FIG. 9A is an angle formed by the straight line c and the straight line a. The straight line c is a straight line extending from the sensor unit 22L of one sensor bar 1L to the sensor unit 21R of the other sensor bar 1R located in the diagonal direction. The straight line a is a straight line extending from the sensor unit 22L to the other sensor unit 22R facing the sensor unit 22L. The calculation method of this angle θ1 is as follows. The main calculation unit 71 of the calculation control circuit 3L that operates as a master operates the light projecting means 30 of the sensor unit 21R, and detects the infrared rays by the line CCD 41 of the sensor unit 22L. Similarly, the light projecting means 30 of the sensor unit 22R is operated, and the infrared rays are detected by the line CCD 41 of the sensor unit 22L. The main calculation unit 71 calculates the direction (angle) of the sensor units 21R and 22L viewed from the sensor unit 22L from the pixel number of the line CCD 41 from which these infrared rays are detected, and calculates the angle θ1 from the calculated difference between these directions. To do.

  The angle θ2 in FIG. 9A is an angle formed by the straight line d and the straight line a. The straight line d is a straight line from the sensor unit 22R to the sensor unit 21L located in the diagonal direction. The angle θ3 is an angle formed by the straight line d and the straight line b. The straight line b is a straight line extending from the sensor unit 21L to the sensor unit 21R. The angle θ4 is an angle formed by the straight line b and the straight line c. These angles θ2 to θ4 are also calculated by the main calculation unit 71 by the same method as the angle θ1.

  9A and 9B, the angle θ5 is an angle formed by the straight line e and the straight line c. The straight line e is a straight line connecting the two sensor units 21L and 22L provided on one sensor bar 1L. When the angle θ5 is determined, the relative positions of the four sensor units 21L, 22L, 21R, and 22R are inevitably determined by using the angles θ1 to θ4 calculated as described above. However, since the sensor unit 22L and the sensor unit 21L cannot detect each other, even if the angles θ1 to θ4 are calculated, the relative positions of the four sensor units 21L, 22L, 21R, and 22R are not fixed.

  Accordingly, in order to determine the relative positions of the four sensor units 21L, 22L, 21R, and 22R, not only the relative angles θ1 to θ4 of the four sensor units 21L, 22L, 21R, and 22R but also a certain reference The angle from the direction must be detected. For example, the direction (vertical direction) of a straight line e connecting the sensor unit 21L and the sensor unit 22L is defined as a reference direction, and at least one of the four sensor units 21L, 22L, 21R, and 22R is separated from the reference direction. The angle must be detected. For this purpose, in the conventional configuration, in order to give information on the reference direction of the sensor unit 22L, it is necessary to accurately indicate the vertical direction of the line segment e. Furthermore, since it is necessary to perform measurement with the sensor units 21L and 22L incorporated in the sensor bar 1L, the input information obtained by specifying an accurate position using a tool or the like and instructing at that position is reflected. Must. On the other hand, in this embodiment, this work process in assembling can be omitted, and the manufacturing cost can be reduced. Specifically, it is as follows.

  The two straight lines c and d are two straight lines that connect the sensor units located in the diagonal direction. Let the intersection point of these two straight lines c and d be the intersection point α. Then, as shown in FIGS. 9A and 9B, the intersection α of the two straight lines c and d is in the third overlapping region 93 (in the overlapping region where all the sensor units can detect the touch position). To position. As shown in FIG. 9B, a case is considered in which a touch operation is performed on an instruction point P that is in the third overlapping region 93 and is at a position different from the intersection α. Here, each angle and straight line are defined as follows. A straight line from the sensor unit 22L to the designated point P is a straight line s, and an angle formed by the straight line a and the straight line s is an angle θ6. A straight line from the sensor unit 22R to the designated point P is a straight line t, and an angle formed by the straight line a and the straight line t is an angle θ7. An angle formed by the straight line d and the straight line t is defined as an angle θ8. A straight line from the sensor unit 21L to the designated point P is defined as a straight line u. An angle formed by the straight line d and the straight line u is defined as an angle θ9. An angle formed between the straight line e and the straight line u is an angle θ10, and an angle formed between the straight line e and the straight line s is an angle θ11. Further, it is assumed that the length of the straight line a is the reference length (= 1).

As described above, when the angle θ5 is determined, the relative positional relationship between the four sensor units 21L, 22L, 21R, and 22R is determined. Therefore, by arranging the angles in FIG. 9B using the sine theorem, the addition theorem, etc., the angle θ5 can be calculated as follows.

1 / sin (π- (θ6 + θ7)) = t / sinθ6 = s / sinθ7 (8)
u / sinθ8 = t / sinθ9 (9)
u / sinθ11 = s / sinθ10 (10)
θ6 + θ7 + θ8 + θ9 + θ10 + θ11 = π (11)

By equation (9)
s = sinθ7 / sin (θ6 + θ7) (12)

From equations (8), (9), (12)
u = t * sinθ8 / sinθ9 = s * sinθ6 / sinθ7 * sinθ8 / sinθ9
= (sinθ6 * sinθ8) / (sin (θ6 + θ7) * sinθ9) (13)

From equations (10) and (13),
tanθ11 = u / s * sinθ10
= u / s * sin (θ6 + θ7 + θ8 + θ9 + θ11)
= u / s * (sin (θ6 + θ7 + θ8 + θ9) cosθ11 + cos (θ6 + θ7 + θ8 + θ9) sinθ11))

And therefore
θ11 = tan-1 (sin (θ6 + θ7 + θ8 + θ9) / (s / u-cos (θ6 + θ7 + θ8 + θ9))
= tan-1 (sin (θ6 + θ7 + θ8 + θ9) /
(sinθ7 * sinθ9 / sinθ6 / sinθ8-cos (θ6 + θ7 + θ8 + θ9))) (14)

It becomes. Thereby, the angle θ11 can be calculated. And θ5 is

θ5 = θ11-(θ1-θ6) (15)

It becomes.

  The main calculation unit 71 of the calculation control circuit 3L that operates as a master functions as an example of the relative position calculation means, and determines the relative positions of the four sensor units 21L, 22L, 21R, and 22R as described above. That is, the main calculation unit 71 performs a touch operation request process that is an example of a process that prompts the user or the like to perform a touch operation on the indicated point P described above. That is, the main calculation unit 71 functions as an example of touch operation requesting means (requesting means). Furthermore, the touch operation request process for the pointing point P described above may be performed in a dedicated application on the PC 300 to which the coordinate input device is connected. That is, an application for executing a touch operation request process is installed in advance in the PC 300 (a computer program is stored in the external memory 304 in advance). Then, a touch operation request process is executed by this application (by the PC 300 executing this computer program), and the PC 300 functions as a touch operation request means. The main calculation unit 71 can determine the relative positions of the four sensor units 21L, 22L, 21R, and 22R by detecting the position of the touch operation. The details of the touch operation request process will be described later.

<Initial settings and touch instructions>
Next, processing for determining the relative positions of the four sensor units 21L, 22L, 21R, and 22R will be described with reference to FIG. FIG. 10 is a flowchart showing an initial setting process after the power is turned on. As described above, the main calculation unit 71 of the calculation control circuit 3L is configured by a one-chip microcomputer or the like. A one-chip microcomputer is a processing device in which a CPU, RAM, ROM, various input / output devices and the like are mounted on one IC chip. A computer program for executing this initial setting process is stored in advance in the ROM of the one-chip microcomputer. The CPU of the one-chip microcomputer reads this computer program from the ROM and executes it using the RAM as a work area. Thereby, the processing shown in FIG. 10 is realized. Note that an application for executing a part of each process described later is installed in the PC 300, and the coordinate input apparatus 100 and the PC 300 cooperate with each other as shown in FIG. 10 when the PC 300 executes these applications. The structure which a process implement | achieves may be sufficient.

  The initial setting process includes a relative position calculation process for determining the relative positions of the four sensor units 21L, 22L, 21R, and 22R. The main calculation unit 71 determines the relative positional relationship between the four sensor units 21L, 22L, 21R, and 22R by detecting a touch operation to a predetermined position by a user or the like. Prior to the start of the process shown in FIG. 10, the two sensor bars 1L and 1R are arranged by the user or the like so as to face the whiteboard 6 or the wall surface. A region between the two sensor bars 1L and 1R arranged is a coordinate input region 5. At this time, the user or the like adjusts the interval between the two sensor bars 1L and 1R so that the coordinate input area 5 includes the entire display area 111, which is a rectangular area on which the display device 200 projects an image. To do. When the power is turned on by a user or the like, the main arithmetic unit 71 of the arithmetic control circuit 3L operating as a master reads the computer program from the ROM as described above, expands the program in the RAM, and executes it. Thereby, the initial setting process is started.

  In step S1001, the main calculation unit 71 performs an initialization process. For example, the main calculation unit 71 performs various initializations regarding the coordinate input device 100 such as input / output port setting, timer setting, shutter opening time of the line CCD 41, lighting time of the infrared LED 31, and driving current.

  In step S1002, the main calculation unit 71 determines whether the positions of the sensor units 21L, 22L, 21R, and 22R are appropriate. Specifically, the main calculation unit 71 operates the light projecting means 30 of the sensor unit 21R, and detects the infrared rays by the line CCD 41 of the sensor unit 22L. Similarly, the light projecting means 30 of the sensor unit 22R is operated, and the infrared rays are detected by the line CCD 41 of the sensor unit 22L. The main calculation unit 71 calculates the direction (angle) of the sensor units 21R and 22L as viewed from the sensor unit 22L from the pixel numbers where these infrared rays are detected, and calculates the angle θ1 from these calculated directions. The main calculation unit 71 similarly calculates the other angles θ2 to θ4. At this time, the main calculation unit 71 determines whether or not the infrared rays emitted from the two sensor units 21L, 22L, 21R, and 22R of the opposing sensor bar can be detected by the sensor units 21L, 22L, 21R, and 22R. . When infrared rays cannot be detected, there is a possibility that the sensor units 21L, 22L, 21R, and 22R of the opposing sensor bars 1L and 1R are not located in the field of view of the light receiving means 40 of the sensor units 21L, 22L, 21R, and 22R. There is. Therefore, the main calculation unit 71 determines whether infrared rays emitted from the light projecting means 30 of the sensor units 21L, 22L, 21R, and 22R of the opposing sensor bars 1L and 1R can be detected for all the sensor units 21L, 22L, 21R, and 22R. To do. If all the sensor units 21L, 22L, 21R, and 22R can be detected, it is determined that the positions of the sensor bars 1L and 1R are appropriate. In this case, the process proceeds to step S1004. Otherwise, the main calculation unit 71 determines that the positions of the sensor bars 1L and 1R are not appropriate. In this case, the process proceeds to step S1003.

  In step S1003, the main calculation unit 71 of the calculation control circuit 3L executes a process of notifying the user or the like that the positions of the sensor bars 1L and 1R are not appropriate. For example, the main calculation unit 71 displays on the indicator 79 that the positions of the sensor bars 1L and 1R are not appropriate, or emits a predetermined sound via the speaker 80. This prompts the user or the like to reinstall the sensor bars 1L and 1R. Then, the process returns to step S1001.

  In step S1004, the main calculation unit 71 executes a calibration process. The calibration process is a process for acquiring information for correcting and converting the coordinate system (display image coordinate system) of the display area 111 by the display device 200 and the coordinate system of the coordinate input device 100. A conventionally known configuration can be applied to the calibration process. For this reason, the description of the calibration process is omitted. For example, as the calibration process, a process disclosed in JP 2013-210951 A can be applied.

  In step S1005, the main calculation unit 71 of the calculation control circuit 3L determines whether or not the third overlapping area 93 is included in the display area 111 displayed by the display device 200. FIG. 11 is a diagram schematically illustrating a state in which the third overlapping area 93 is included in the display area 111 displayed by the display device 200. At this time, the main calculation unit 71 uses the information acquired in the calibration process in step S1004 in order to convert the positional relationship between the coordinate input area 5 and the display area 111. When the third overlapping area 93 is not included in the display area 111, the process proceeds to step S1006. As shown in FIG. 11, when it is determined that the third overlapping area 93 is included, the process proceeds to step S1007.

  In step S <b> 1006, the main calculation unit 71 executes a process of notifying that the third overlapping area 93 is not included in the display area 111. For example, the main calculation unit 71 displays on the indicator 79 that the third overlapping area 93 is not included in the display area 111 or emits a predetermined sound via the speaker 80. In addition, an application for executing this processing is installed in the PC 300 in advance, and even if an alert is superimposed on an image projected (displayed) by the PC 300 and executed, the PC 300 displays the alert. Good. In this case, the main calculation unit 71 transmits a signal instructing execution of this process to the PC 300. And PC300 will perform the above-mentioned process, if this signal is received. This prompts the user or the like to readjust the position or range of the display area 111 by the display device 200. Then, the process returns to step S1004.

  In step S <b> 1007, the main calculation unit 71 executes a process (touch operation request process) that prompts the user or the like to perform a touch operation in the third overlapping area 93. For example, a process in which the main calculation unit 71 displays an instruction screen on the display device 200 can be applied. In addition, the main calculation unit 71 may cause the indicator 79 to perform a display that prompts a touch operation on the third overlapping area 93, and performs a touch operation on the third overlapping area 93 via the speaker 80. A sound that prompts the user may be emitted. Then, the process proceeds to step S1006. In addition, as described above, an application for executing the touch operation request process may be installed in the PC 300 in advance, and the CPU 301 of the PC 300 may execute the touch operation request process by executing this application.

  In step S1008, the main calculation unit 71 determines whether or not there has been a touch operation by a user or the like. Specifically, the main calculation unit 71 determines whether or not a light shielding area exists in the coordinate input area 5 from the detection levels of the sensor units 21L, 22L, 21R, and 22R. If there is a light shielding area, it is determined that a touch operation has been performed. In this case, the process proceeds to step S1009. Otherwise, the main calculation unit 71 determines that there is no touch operation. In this case, the process returns to step S1007.

  In step S1009, the main calculation unit 71 determines whether or not the position of the touch operation detected in step S1008 is within the third overlapping area 93. If it is determined that the touch operation is in the third overlapping area 93, the process proceeds to step S1011. If it is determined that the touch operation is outside the third overlapping area 93, the process proceeds to step S1010.

  In step S1011, the main calculation unit 71 determines whether or not the position of the touch operation detected in step S1008 is the same position as the intersection α. If it is determined that the position of the touch operation is different from the intersection α, the process proceeds to step S1012. If it is determined that the position of the touch operation is the same position as the intersection α, the process proceeds to step S1010.

  In step S1010, the main calculation unit 71 functions as an example of guidance means. Then, the main calculation unit 71 uses the information on the light shielding position acquired by the four sensor units 21L, 22L, 21R, and 22R to set the position of the touch operation to the user or the like in the third overlapping region 93. Execute the process of guiding to.

  Here, an example of processing for guiding the position of the touch operation into the third overlapping area 93 (in the overlapping area where all the sensor units can detect the touch position) will be described with reference to FIG. FIG. 12 is a diagram schematically illustrating an example of the content of processing for guiding the position of the touch operation into the third overlapping area 93. FIG. 12A shows an example in which a touch operation is performed at positions A to D of the coordinate input area 5. 12B to 12E are graphs schematically showing the light amount distribution detected by each of the sensor units 21L, 22L, 21R, and 22R when the touch operation is performed at the positions A to D. is there. That is, FIG. 12B shows a light amount distribution detected by the sensor units 21L and 21R when a touch operation is performed at the position A in FIG. FIG. 12C shows the light amount distribution when the touch operation is performed at the position B, FIG. 12D shows the position C, and FIG.

  The “third overlapping region” in each of FIGS. 12B to 12E is the direction in which the third overlapping region 93 exists when viewed from each sensor unit 21L, 22L, 21R, 22R. . For example, regarding the sensor unit 21L, a range (direction) between the direction in which light from the sensor unit 22R located in the diagonal direction enters and the end of the range in which retroreflected light from the retroreflective means 4R enters. ) Is the direction in which the third overlapping region 93 exists. When the light-shielding area (ie, the touch-operated position) is simultaneously detected in the third overlapping area 93 by all four sensor units 21L, 22L, 21R, and 22R, the touch position is the third position. It is shown that it is located in the overlapping area 93. Therefore, in this case, the main calculation unit 71 determines that the position of the touch operation is within the third overlapping area 93. Otherwise, it is determined that the position of the touch operation is not within the third overlapping area 93. Note that “simultaneous” here does not have to be simultaneous in a strict sense, and the timing may be shifted to such an extent that it can be regarded as simultaneous if it is a human action. As described above, if the sensor units 21R, 22L, 21R, and 22L of the two sensor bars 1L and 1R operate alternately, depending on the combination of the four sensor units 21L, 22L, 21R, and 22R, strictly This is because they cannot be detected at the same time.

  When the main calculation unit 71 determines that the position of the touch operation is not within the third overlapping area 93, the main calculation unit 71 performs a guidance process for guiding the position of the touch operation into the third overlapping area 93. When the position of the touch operation is within the coordinate input area 5 but outside the third overlapping area 93, the light-shielding area includes two or three of the four sensor units 21L, 22L, 21R, and 22R. Will be detected. Therefore, in this case, the main calculation unit 71 determines the current touch based on the detection results of the two sensor units that detect the light-shielding region among the four sensor units 21L, 22L, 21R, and 22R. Calculate the position. And the main calculating part 71 calculates the direction of the 3rd duplication area | region 93 seen from the present touch position, and performs the process which alert | reports the calculated direction. For example, as shown in FIG. 12A, the main calculation unit 71 displays an arrow indicating the direction of the third overlapping area 93 viewed from the current touch position via the display device 200 in the coordinate input area 5 (display area). 111). At this time, the main calculation unit 71 may use a dedicated application for executing such a guidance process. In addition, the main calculation unit 71 may display the direction of the third overlapping area 93 viewed from the current touch position on the indicator 79. Further, the main calculation unit 71 may notify the direction of the third overlapping region 93 viewed from the current touch position by voice via the speaker 80.

  For example, when the light amount distribution shown in FIG. 12B is obtained, it is indicated that the current touch position is the position A in FIG. For this reason, the main calculation unit 71 displays an arrow indicating the direction of the third overlapping area 93 viewed from the position A in the coordinate input area 5 via the display device 200, for example. Accordingly, the moving direction of the position of the touch operation can be notified to the user or the like, and the touch position can be guided into the third overlapping region 93. Even when the light quantity distributions shown in FIGS. 12C to 12E are obtained, the same applies except that the display position and direction of the arrows are different.

  In step S <b> 1012, the main calculation unit 71 completes the process of prompting the touch operation into the third overlapping area 93 and the process of guiding the position of the touch operation into the third overlapping area 93. As described above, in the present embodiment, in the third overlapping area 93, until the touch operation to the position different from the intersection α of the two straight lines is detected. Continues the process of prompting the user to touch. Then, the process proceeds to step S1013.

  In step S1013, the main calculation unit 71 functions as a relative position calculation unit and calculates and determines the relative positions of the four sensor units 21L, 22L, 21R, and 22R. The method for calculating the relative position is as described above. After the above steps, the initial setting process is terminated.

  According to this embodiment, the direction (angle θ5) of the sensor unit from the reference direction can be automatically acquired when the coordinate input device 100 is arranged. For this reason, in the manufacture of the coordinate input device 100, the process of obtaining and assigning the reference direction can be omitted, and the manufacturing cost can be reduced. Further, when the coordinate input device 100 is arranged for use, there is no restriction that the arrangement direction of the sensor bars 1L and 1R must be directed to the vertical direction accurately, for example. For this reason, the trouble of preparation for use can be omitted for the user or the like.

(Second Embodiment)
Next, a second embodiment will be described. In the first embodiment, the configuration in which the dedicated application, the speaker 80, or the indicator 79 is used as the notification unit in the process of guiding the touch position into the third overlapping area 93 has been described. However, the notification means is not limited to these. For example, when the PC 300 (computer) is applied as an external device, a configuration in which the main calculation unit 71 outputs the detected touch position to the PC 300 that is the external device and changes the display mode of the mouse cursor is applied. it can. Specifically, the main calculation unit 71 executes processing such as blinking and displaying the mouse cursor, rotating the mouse cursor within a certain range, and the like. Such processing can also prompt the user or the like to change the touch position. With such a configuration, it is not necessary to previously install a dedicated application, driver, or the like on the PC. For this reason, the trouble of preparation for use can be omitted for the user or the like. Therefore, convenience is improved.

(Other embodiments)
Although the embodiment has been described in detail above, the present invention can take an embodiment as a system, apparatus, method, program, recording medium (storage medium), or the like. Specifically, the present invention may be applied to a system composed of a plurality of devices (for example, a host computer, an interface device, an imaging device, a web application, etc.), or may be applied to a device composed of a single device. good.

  For example, in the above-described embodiment, the configuration in which the main calculation unit 71 of the coordinate input device 100 executes the above-described processes has been described, but the configuration is not limited to this configuration. For example, a part of each process may be realized by the PC 300. In this case, a computer program of an application for executing a part of each process described above is stored in the external memory 304 of the PC 300 in advance. Then, the CPU 301 executes this computer program, whereby the above-described processes are executed. In this case, the coordinate input device 100 and the PC 300 cooperate to realize the processing.

  The object of the present invention can also be achieved by the following configuration. That is, a recording medium (or storage medium) that records a program code (computer program) of software that implements the functions of the above-described embodiments is supplied to the system or apparatus. Needless to say, such a storage medium is a computer-readable storage medium. Then, the computer (or CPU or MPU) of the system or apparatus reads and executes the program code stored in the recording medium. In this case, the program code itself read from the recording medium realizes the functions of the above-described embodiment, and the recording medium on which the program code is recorded constitutes the present invention.

100: Coordinate input device 1L, 1R: Sensor bar 21L, 22L, 21R, 22R: Sensor unit 3L, 3R: Arithmetic control circuit 4L, 4R: Retroreflective means 5: Coordinate input effective area 6: Whiteboard 93: Third overlap region

Claims (17)

At least four light-receiving means for projecting incident light toward the retro-reflecting means for retro-reflecting, and light-receiving means for receiving the reflected light projected from the light projecting means and retroreflected by the retro-reflecting means; The basic sensor unit,
Touch position calculating means for calculating a position of a touch operation on a rectangular coordinate input area based on a light amount distribution received by the light receiving means;
Two straight lines connecting the two sensor units located in the diagonal direction in the overlapping area where all of the four sensor units located at the four corners of the coordinate input area can detect the position of the touch operation. Request means for performing a process of prompting a touch operation to a position different from the intersection of
When the position of the touch operation is calculated, and the position of the touch operation is a position different from the intersection in the overlap region, the four sensor units are configured based on the calculation result of the position of the touch operation. A relative position calculating means for calculating a relative position;
A coordinate input device comprising:   The relative position calculating means includes a straight line connecting the two sensor units that are not in the visual field range, and one sensor unit of the two sensor units and a sensor unit arranged in a diagonal direction of the one sensor unit. Is calculated using the position of the touch operation to a position different from the intersection in the overlapping region, and based on the calculation result of the position of the touch operation, the four sensors The coordinate input device according to claim 1, wherein the relative position of the unit is calculated.   The coordinate input device according to claim 1, wherein the request unit performs display for prompting a touch operation on the coordinate input region to a position that is not the intersection but the overlapping region.   3. The coordinate input device according to claim 1, wherein the request unit emits a voice prompting a touch operation to a position that is not the intersection but the overlap area in the coordinate input area.   The coordinate input device according to claim 1, wherein the request unit performs display for prompting a touch operation on the coordinate input region to a position that is not the intersection but the overlapping region.   6. The coordinate input according to claim 1, wherein the request unit continues the process until a touch operation to a position that is not the intersection in the overlapping region is detected. apparatus.   6. The apparatus according to claim 1, further comprising a guiding unit that performs a process of guiding the position of the touch operation to the overlapping area when the position of the touch operation is not in the overlapping area. The coordinate input device described. At least four light-receiving means for projecting incident light toward the retro-reflecting means for retro-reflecting, and light-receiving means for receiving the reflected light projected from the light projecting means and retroreflected by the retro-reflecting means; The basic sensor unit,
A control method of a coordinate input device having
A touch position calculating step of calculating a position of a touch operation to the rectangular coordinate input area based on a light amount distribution received by the light receiving means;
Two straight lines connecting the two sensor units located in the diagonal direction in the overlapping area where all of the four sensor units located at the four corners of the coordinate input area can detect the position of the touch operation. A request step for performing a process of prompting a touch operation to a position different from the intersection of
When the position of the touch operation is calculated, and the position of the touch operation is a position different from the intersection in the overlap region, the four sensor units are configured based on the calculation result of the position of the touch operation. A relative position calculating step for calculating a relative position;
A control method for a coordinate input device, comprising: At least four light-receiving means for projecting incident light toward the retro-reflecting means for retro-reflecting, and light-receiving means for receiving the reflected light projected from the light projecting means and retroreflected by the retro-reflecting means; The basic sensor unit,
A computer for controlling a coordinate input device having:
A touch position calculating step of calculating a position of a touch operation to the rectangular coordinate input area based on a light amount distribution received by the light receiving means;
Two straight lines connecting the two sensor units located in the diagonal direction in the overlapping area where all of the four sensor units located at the four corners of the coordinate input area can detect the position of the touch operation. A request step for performing a process of prompting a touch operation to a position different from the intersection of
When the position of the touch operation is calculated, and the position of the touch operation is a position different from the intersection in the overlap region, the four sensor units are configured based on the calculation result of the position of the touch operation. A relative position calculating step for calculating a relative position;
A program characterized by having executed. At least four light-receiving means for projecting incident light toward the retro-reflecting means for retro-reflecting, and light-receiving means for receiving the reflected light projected from the light projecting means and retroreflected by the retro-reflecting means; The basic sensor unit,
Touch position calculating means for calculating a position of a touch operation on a rectangular coordinate input area based on a light amount distribution received by the light receiving means;
Two straight lines connecting the two sensor units located in the diagonal direction in the overlapping area where all of the four sensor units located at the four corners of the coordinate input area can detect the position of the touch operation. Request means for performing a process of prompting a touch operation to a position different from the intersection of
When the position of the touch operation is calculated, and the position of the touch operation is a position different from the intersection in the overlap region, the four sensor units are configured based on the calculation result of the position of the touch operation. A relative position calculating means for calculating a relative position;
A coordinate input system comprising:   The relative position calculating means includes a straight line connecting the two sensor units that are not in the visual field range, and one sensor unit of the two sensor units and a sensor unit arranged in a diagonal direction of the one sensor unit. Is calculated using the position of the touch operation to a position different from the intersection in the overlapping region, and based on the calculation result of the position of the touch operation, the four sensors The coordinate input system according to claim 10, wherein the relative position of the unit is calculated.   The coordinate input system according to claim 10 or 11, wherein the request unit performs a display for prompting a touch operation on the coordinate input region to a position that is not the intersection but the overlapping region.   12. The coordinate input system according to claim 10 or 11, wherein the requesting unit emits a voice prompting a touch operation to a position that is not the intersection but the overlap area in the coordinate input area.   The coordinate input system according to claim 10 or 11, wherein the request unit performs a display for prompting a touch operation on the coordinate input region to a position that is not the intersection but the overlapping region.   The coordinate input according to any one of claims 10 to 14, wherein the request unit continues the processing until a touch operation to a position that is not the intersection point in the overlapping region is detected. system.   15. The apparatus according to claim 10, further comprising a guiding unit that performs a process of guiding the position of the touch operation to the overlapping area when the position of the touch operation is not in the overlapping area. Coordinate input system described. At least four light-receiving means for projecting incident light toward the retro-reflecting means for retro-reflecting, and light-receiving means for receiving the reflected light projected from the light projecting means and retroreflected by the retro-reflecting means; The basic sensor unit,
A control method of a coordinate input system having
A touch position calculating step of calculating a position of a touch operation to the rectangular coordinate input area based on a light amount distribution received by the light receiving means;
Two straight lines connecting the two sensor units located in the diagonal direction in the overlapping area where all of the four sensor units located at the four corners of the coordinate input area can detect the position of the touch operation. A request step for performing a process of prompting a touch operation to a position different from the intersection of
When the position of the touch operation is calculated, and the position of the touch operation is a position different from the intersection in the overlap region, the four sensor units are configured based on the calculation result of the position of the touch operation. A relative position calculating step for calculating a relative position;
A control method for a coordinate input system, comprising:

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