JP2014048957A - Coordinate input device, method for controlling the same and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coordinate input device capable of controlling a display screen with a touch to a projection surface that is an existing whiteboard or wall surface of a meeting room or the like.SOLUTION: Each of a first casing and a second casing has at least two sensor units built therein and each including: at least two light projection parts, a first light projection part and a second light projection part, having mutually different distances from an input surface; and a light reception part for receiving light. Each of the first casing and the second casing has a retroreflection part mounted on a longitudinal side surface different from a mounting surface, with the casing mounted thereon, of a coordinate input effective area, the retroreflection part retro-reflecting incident light. An indicated position in the coordinate input effective area is calculated on the basis of variation in light quantity distribution obtained from the light reception part of each of the first casing and the second casing with the first casing and the second casing mounted in the vicinity of two facing sides of the coordinate input effective area.

Description

  The present invention relates to a coordinate input device that optically detects a coordinate position input to a coordinate input surface by an indicator such as a finger in order to input or select information. In particular, the present invention relates to a coordinate input device that is detachable and has portability.

  Conventionally, various types of coordinate input devices (touch panels and digitizers) have been proposed or commercialized as this type of coordinate input device. For example, a touch panel that can easily operate a terminal such as a PC (personal computer) by touching the screen with a finger without using a special instrument is widely used.

  As a coordinate input method, there are various methods such as a method using a resistance film or a method using ultrasonic waves. As a method using light, a retroreflective material is provided outside the coordinate input surface, the light from the light projecting part is reflected by the retroreflective material, and the light quantity distribution is detected by the light receiving part (optical shading method). (For example, see Patent Documents 1 and 2). In this method, the direction of a light-shielding portion (area) shielded by a finger or the like in the coordinate input area is detected, and the light-shielding position, that is, the coordinates of the coordinate input position are determined.

  As an example in which the configuration of Patent Document 1 is generalized, the configuration of FIG. 20 is shown. FIG. 20 shows the sensor units 2L and 2R arranged at both ends of the coordinate input surface and the coordinate input effective area 5 which is a coordinate input surface used when inputting coordinates. Then, on the three sides around the coordinate input effective area 5, there are provided retroreflecting portions 4 that recursively reflect the incoming light in the incoming direction.

  The sensor units 2L and 2R have a light projecting unit and a light receiving unit (not shown). The light projecting unit projects light that spreads in a fan shape substantially parallel to the input surface of the coordinate input effective area 5, and the light receiving unit receives the light that is retroreflected by the retroreflecting unit 4 and returned. The coordinate input device is a touch position input to the coordinate input effective area 5 based on the light shielding direction (light shielding angles θL and θR) detected by the two sensor units 2L and 2R and the distance between the sensor units. P can be calculated.

  In the drawing, the visual field ranges of the sensor units 2L and 2R are set symmetrically as shown, with the optical axis direction of the sensor units 2L and 2R as the symmetry line. In this type of coordinate input device using a lens optical system, when the angle with the optical axis increases, the optical performance usually deteriorates due to the influence of aberration, and an axially symmetric optical system is adopted. By doing so, a higher performance device can be realized.

  In the figure, reference numeral 3 denotes an arithmetic control circuit that controls the sensor units 2L and 2R, processes the acquired output signals of the sensor units 2L and 2R, or outputs the processing results to an external device.

  Patent Document 2 shows an example of a specific configuration of a light projecting unit and a light receiving unit of a sensor unit in the optical light-shielding coordinate input device disclosed in Patent Document 1.

  Furthermore, Patent Document 3 discloses a configuration for controlling lighting of a light projecting unit in each sensor unit. Specifically, in Patent Document 3, in order to prevent the light emitted from the light projecting unit of one sensor unit from being received as disturbance light by the light receiving unit of the other sensor unit, each posting of the sensor unit is performed. Control is performed so that light is emitted from the unit alternately.

  Furthermore, Patent Document 4 discloses a configuration in which a plurality of sensor units are arranged on two opposite sides of the coordinate input effective area, and the sensor units are provided in a gap between the retroreflective member and the coordinate input surface. .

  By integrating this type of coordinate input device with the display device, the display state can be controlled by touching the display screen of the display device, and the locus of the touch position can be traced as if it were a pencil and paper. Can be displayed. As display devices, flat panel displays and front projectors of various types such as liquid crystal display devices are known. In the case of a flat panel display, such an operation environment can be realized by arranging coordinate input devices in a stacked manner, and a portable device such as a smartphone can be said to be a representative example. With the increase in size of flat panel displays, in combination with large touch panels, for example, digital signage has been introduced.

  In the case of a front projector that can display a large image, a position detection unit is incorporated in a screen board or the like that is the projection surface, and an image is projected onto the screen board. Therefore, the size of the coordinate input device depends on the size of the screen board serving as the touch operation surface, and is a relatively large device. For this reason, a stand for moving the screen board is usually mounted on the screen board, or the screen board is fixedly installed on the wall for use. In addition, as the price increases, the selling price increases exponentially, which greatly hinders the spread of large coordinate input devices or applications using the coordinate input devices.

  In the case of the optical shading type coordinate input device shown in FIG. 20, the sensor unit 2, the calculation control circuit 3, and the retroreflective unit 4 are main components, and these are mounted on the screen board. Therefore, even if the apparatus is increased in size, the configuration of the main parts remains the same, and the cost increase due to the increase in size is due to the material cost of the screen board occupying the majority.

  Patent Documents 5 and 6 disclose a configuration in which a plurality of light projecting units are arranged in the vertical direction with respect to the coordinate input surface. These have a constant configuration without always changing the light emission form of the light projecting unit in the vertical direction.

U.S. Pat. No. 4,507,557 JP 2004-272353 A JP 2001-43021 A Patent Registration No. 4118664 Patent Registration No. 3830121 JP 2012-03434 A

  The user interface operated by touching the display screen of the display device is intuitive and can be used by anyone, and is now common in portable devices. As a matter of course, it is desired that such an operation can be performed even for a device having a larger display screen.

  Specific applications using a large screen are highly demanded by the market for ICT education and digital signage in educational settings as presentation and whiteboard functions for conference applications. In order to respond to this, it is necessary to significantly reduce the introduction cost for realizing the operating environment.

  There are many cases where whiteboards and front projectors are already installed as equipment in current conference rooms and educational sites. An object of the present invention is to provide an operation environment that allows a user to perform a touch operation at a low price even on a large screen by effectively utilizing these devices already purchased by a user.

  As described above, the main components of the coordinate input device of the optical shading method are at least two sensor units 2, an arithmetic control circuit 3, and a retroreflecting unit 4 that detect the direction in which the optical path is blocked by the touch operation. is there. If these main components can be mounted on a whiteboard, for example, in a predetermined positional dimension relationship, the touch position of the whiteboard can be detected. If an existing whiteboard is used as the screen board, the screen board, which accounts for the majority of the cost, is eliminated from the essential components. Therefore, the price of the product can be greatly reduced, and a touch operation environment can be provided at a low cost even if it is large.

  The principle of position detection of this optical light shielding type coordinate input device is to calculate the touch position geometrically based on the light shielding direction (= angle) of the touch position output by at least two sensor units and the distance information between the sensor units. . Therefore, in order to detect the touch position with high accuracy, the sensor unit must be positioned and attached with high accuracy. More preferably, it is preferable that the user can easily perform the installation.

  On the other hand, even if the sensor unit is mounted with rough positioning by the user, the following ease of use can be realized if the touch position can be detected with high accuracy. Carry only the main components of the optical shading type coordinate input device, for example, easily mounted in a short time in a whiteboard installed in a conference room where the conference is held. At the end of the conference, the main components are removed and taken home, or taken to another conference room and used there. In short, by being detachable and portable, “anyone” can operate “anytime”, “anywhere”, and “easy”. Moreover, it is preferable that the number of components of the product itself for realizing them is also smaller. Furthermore, it is desired to be small and lightweight assuming portability.

  For example, a magnet can be used to mount and remove the main components so that the main components can be mounted on, for example, an already purchased whiteboard. By using the whiteboard as a projection surface, an input / output integrated touch operation environment is provided. In general, white boards of various sizes are commercially available, and of course, if a larger white board is used, it can be projected onto a larger display screen. Therefore, it is preferable that the main components can be installed according to the size of various whiteboards installed in the conference room and that the touch position can be detected with high accuracy.

  However, when a commercially available whiteboard is used or when a wall or the like is used as the projection surface, there is no guarantee that the flatness of the whiteboard wall is ensured. FIG. 21 is a cross-sectional view from the side of the optical shading type coordinate input device mounted on a whiteboard or wall. The state of FIG. 21A is a case where the flatness of the whiteboard and the wall is ensured. However, a commercially available whiteboard, wall, or the like may be convexly curved on the input side as shown in FIG. Therefore, when the optical shading type coordinate input device is installed on a commercially available whiteboard whose flatness cannot be maintained, a problem occurs. FIG. 21 (B) is a diagram illustrating this problem. As shown in FIG. 21 (B), the light indicated by the arrow emitted from the light projecting unit 30 of the sensor bar 1L of the coordinate input device is a whiteboard or the like. It is blocked by the convex portion 114 of the input surface 6. Because of this phenomenon, it results in hindering the performance of the optical shading type coordinate input device.

  The present invention has been made to solve the above-described problems, and coordinates using the projection plane are not affected by the degree of flatness of the wall surface of an existing whiteboard or conference room as the projection plane. An object of the present invention is to provide a coordinate input device capable of performing input.

In order to achieve the above object, a coordinate input device according to the present invention comprises the following arrangement. That is,
A coordinate input device that detects an indicated position with respect to a coordinate input effective area for inputting coordinates by indicating an input surface,
A first housing and a second housing, each housing being
As a light projecting unit that projects light parallel to the coordinate input effective area, at least two light projecting units of a first light projecting unit and a second light projecting unit having different distances from the input surface, Including at least two sensor units each including a light receiving unit that receives light;
A retroreflecting portion that recursively reflects incident light is mounted on a side surface in a longitudinal direction different from the mounting surface of the coordinate input effective region on which the housing is mounted.
A first housing and a second housing;
The amount of light obtained from the light receiving portions of the first and second casings in a state where the first casing and the second casing are mounted in the vicinity of two opposing sides of the coordinate input effective area. Calculation means for calculating the indicated position of the coordinate input effective area based on a variation in distribution;
Determining means for determining a light receiving state of the light receiving unit for each of the first housing and the second housing;
Based on the determination result of the determination means, light is emitted using at least one of the first light projecting unit and the second light projecting unit for each of the first housing and the second housing. Thus, it has a control means which controls the light projection form by the 1st light projection part and the 2nd light projection part.

  As described above, according to the present invention, it is possible to input coordinates using the projection plane without being affected by the degree of flatness of the wall surface of an existing whiteboard or conference room as the projection plane. A coordinate input device can be provided.

It is a schematic block diagram of the coordinate input device of Embodiment 1. It is a figure which shows the detailed structure of the sensor unit of Embodiment 1. FIG. FIG. 5 is a diagram for explaining a visual field range of a light projecting unit and a light receiving unit according to the first embodiment. It is a figure which shows schematic structure of the sensor bar of Embodiment 1. FIG. FIG. 5 is a diagram for explaining an operation in a first detection mode of the arithmetic control circuit according to the first embodiment. It is a figure explaining the process of the detection signal waveform of Embodiment 1. FIG. It is a figure explaining the coordinate calculation of Embodiment 1. FIG. FIG. 3 is a diagram for explaining a digitizer coordinate system and a screen coordinate system according to the first embodiment. FIG. 6 is a diagram for explaining an operation in a second detection mode of the arithmetic control circuit according to the first embodiment. It is a figure for demonstrating calculation of the relative positional relationship of the sensor unit of Embodiment 1. FIG. 3 is a flowchart illustrating an initial setting process according to the first embodiment. It is a figure for demonstrating the characteristic of the coordinate input device of Embodiment 1. FIG. 4 is a flowchart illustrating normal operation and calibration processing according to the first exemplary embodiment. It is a figure for demonstrating the characteristic of the coordinate input device of Embodiment 2. FIG. It is a figure for demonstrating the light reception intensity | strength of Embodiment 2. FIG. 10 is a flowchart illustrating an initial setting process according to the second embodiment. It is a figure for demonstrating the characteristic of the coordinate input device of Embodiment 3. FIG. It is a plane block diagram of the coordinate input device of Embodiment 3. It is a figure for demonstrating the characteristic of the coordinate input device of Embodiment 4. It is a figure for demonstrating the basic composition of the conventional optical coordinate input device. It is a figure for demonstrating the conventional optical coordinate input device.

  Hereinafter, the present invention will be described in detail based on preferred embodiments with reference to the accompanying drawings. The configurations shown in the following embodiments are merely examples, and the present invention is not limited to the illustrated configurations.

<Embodiment 1>
A schematic configuration of the coordinate input device of the present invention will be described with reference to FIG.

  In the figure, 1L and 1R are housings equipped with at least two sensor units 2-L1 and 2-L2, and 2-R1 and 2-R2 (collectively referred to as sensor unit 2). This is a sensor bar.

  Each sensor bar 1L and 1R (generally referred to as sensor bar 1) is provided on two opposing sides of the rectangular coordinate input effective area 5 as shown in the figure. If the display device is a front projector, the display area is set within the coordinate input effective area 5 and on the same plane, and is projected onto the input surface 6 such as a flat whiteboard. Of course, it is not limited to the input surface 6 and may be a wall surface or the like.

  Retroreflective portions 4L and 4R (collectively referred to as retroreflecting portions 4 when collectively referred to) are attached to the side surfaces of the sensor bars 1L and 1R, respectively, as shown in the figure. Each of the retroreflective portions 4L and 4R is configured to recursively reflect the infrared light projected by the sensor unit 1L or the sensor unit 2 of the 1R provided on the opposite side. In other words, the retroreflective portion 4 is mounted on the side surface in the longitudinal direction different from the mounting surface of the sensor bars 1L and 1R to the coordinate input effective area 5. The retroreflecting unit 4 is mounted at a position where the light projection from the sensor unit 2 after the light projection control is sufficiently retroreflected even when the input surface 6 is curved in a convex shape. Details of this will be described later.

  The sensor bar 1L includes sensor units 2-L1 and 2-L2, and the sensor bar 1R includes sensor units 2-R1 and 2-R2. The arithmetic control circuit 3L built in the sensor bar 1L controls the sensor units 2-L1 and 2-L2, performs arithmetic processing on the output results, and controls the arithmetic control circuit 3R of the sensor bar 1R. The arithmetic control circuit 3R of the sensor bar 1R controls the sensor units 2-R1 and 2-R2, performs arithmetic processing on the output result, and transmits the result to the arithmetic control circuit 3L of the sensor bar 1L. Then, the arithmetic control circuit 3L of the sensor bar 1L processes the output results from the four sensor units 2-L1, 2-L2, 2-R1 and 2-R2, calculates the touch position, and externally outputs the personal computer or the like. Output the result to the device.

  In FIG. 1, the calculation control circuit 3L of the sensor bar 1L and the calculation control circuit 3R of the sensor bar 1R are connected by a cord (that is, wired connection), but the present invention is not limited to this. For example, wireless communication functions may be mounted on each other, and data transmission / reception (wireless connection) may be performed using these communication functions.

  In the following description, the horizontal direction will be described as the X axis (+ on the right side of the drawing), and the vertical direction will be described as the Y axis (lower side is +).

  FIG. 2 is a diagram showing a detailed configuration of the sensor units 2-L1, 2-L2, 2-R1, and 2-R2. 2A is a cross section AA in FIG. 1, and FIGS. 2B and 2C are front views as seen from the direction of the arrows in the figure.

  2A, the sensor unit 2 is housed in the sensor bar 1 and includes two light projecting units 301 and 302 and a light receiving unit 40. The distances between the light projecting units 301 and 302 and the light receiving unit 40 are L_pd, respectively, and the retroreflective units 4-1 to 4-3 (represented as the retroreflecting unit 4 when collectively referred to) in the vicinity and in the vicinity thereof are illustrated. Is provided. The light projecting unit 301 is disposed on the side closer to the input surface 6, and the light projecting unit 302 is disposed on the side farther from the input surface 6. That is, the light projecting unit 302 is disposed at a position away from the input surface 6 by a distance L_pd × 2 as compared with the light projecting unit 301. In other words, when the input surface 6 is used as a reference, it can be said that the light projecting unit 301 is a lower light projecting unit (first light projecting unit) and the light projecting unit 302 is an upper light projecting unit (second light projecting unit). The light projecting forms of the light projecting section 301 and the light projecting section 302 are changed by the light projecting form control section 61 b in the arithmetic control circuit 3. This light projecting form control will be described later.

  The mounting position where the retroreflective portion 4 of FIG. 2 is divided into a plurality of parts and separated is at least a mounting form only in the vicinity of the light projecting / receiving window of the sensor unit 2. Therefore, the mounting positions other than the sensor unit 2 may be continuously mounted within a predetermined distance from the input surface 6.

  Reference numeral 45 denotes a light transmissive member, which is a protective member for preventing foreign matter such as dust from entering the sensor bar 1.

  2B, the light projecting unit 301 includes an infrared LED 311 which is a light emitting unit, a light projecting lens 321, and an adhesive layer 331 for fixing both. Similarly, the light projecting unit 302 includes an infrared LED 312 (FIG. 2A), a light projecting lens 322 (FIG. 2A), and an adhesive layer (not shown). Since it is the same as the light part 301, it demonstrates here paying attention to the light projection part 301. FIG.

  The light projecting lens 321 is configured so that the light from the infrared LED 311 becomes a light beam substantially parallel to the input surface 6 serving as a coordinate input surface. The light projection range is a range from g to h and the vertex is the position of the point O (the position of the center of gravity of the sensor unit 2) so as to illuminate the entire region of the retroreflective portion 4 of the sensor bar 1 provided on the opposite side. ) Is emitted. At this time, the optical axis of the light projecting unit 301 is set in the f direction, and the reason will be described later.

  In FIG. 2 (C), the light receiving unit 40 receives the light retroreflected by the retroreflecting unit 4 attached to the sensor bar 1 provided on the opposite sides of the light projected by the light projecting units 301 and 302. To detect. 41 is a line CCD which is a photoelectric conversion element, 42 is a light receiving lens, 43 is a field stop, and 44 is an infrared ray passing filter. Further, the infrared pass filter 44 may be eliminated by providing the protective member 45 (FIG. 2A) with an infrared pass filter function.

  The optical axis of the light receiving unit 40 is set in the X-axis direction. The visual field range is the g to h range, and the position of the point O is the optical center position. Further, the light receiving section 40 is an optical system that is asymmetric with respect to the optical axis as shown in the figure. The light projecting unit 30 and the light receiving unit 40 are arranged so as to overlap each other so that the position of the point O and the directions g and h substantially coincide with each other, as shown in FIG. Further, since the light receiving unit 40 is focused on the pixels of the line CCD 41 in accordance with the direction of the incident light, the pixel number of the line CCD 41 represents angle information of the incident light. The light receiving unit 40 has a visual field range substantially parallel to the coordinate input surface of the coordinate input effective area 5, and its optical axis direction is arranged to coincide with the normal direction of the light receiving surface of the line CCD 41. .

  FIG. 3A is a diagram showing an outline of the coordinate input device, a light projecting unit 301 (similar to the light projecting unit 302, and will be described below focusing on the light projecting unit 301), and an arrangement of the optical system of the light receiving unit 40. is there. The range illuminated toward the retroreflective portion 4R provided on the sensor bar 1R provided on the side facing the light projecting portion 301 of the sensor bar 1L is a range from g to h. Then, light in the direction of the range j to f in which the retroreflecting unit 4R is actually mounted is retroreflected and detected by the light receiving unit 40.

  The luminous flux of the light projected by the light projecting unit 301 schematically shown in FIG. 2A is not completely parallel, and the luminous flux width increases as the projection distance increases. Accordingly, the amount of light retroreflected by the retroreflective portion 4R decreases as the distance to reach the retroreflective portion 4R increases. Therefore, the retroreflective efficiency is poor in the direction f far from the direction j where the distance from the projection point O to the retroreflective portion 4R is short.

  Furthermore, the retroreflective portion 4R has a lower retroreflective efficiency as the angle becomes oblique than when it enters the retroreflective surface from the vertical direction. In other words, the rate at which the light incident on the retroreflective portion 4R is retroreflected as retroreflected light depends on the incident angle, and the direction f can be said to be the direction in which the retroreflective efficiency decreases most.

  Furthermore, the optical axis of the light receiving unit 40 is set in the direction X, and the direction formed by the direction f and the optical axis is the largest direction. It is known that the lens characteristics of a general optical lens deteriorate in performance as the angle with the optical axis increases. For example, the direction in which the direction becomes the darkest due to a decrease in light collection efficiency in the direction f It can be said.

  As described above, even if the light projecting unit 301 can illuminate with a constant intensity regardless of the direction, the light receiving unit moves from the direction j toward the direction f as compared with the retroreflected light returning from the direction j. The retroreflected light that can be detected at 40 becomes weak (see FIG. 3B).

  On the other hand, the infrared LED 311 is generally configured so that the light emission intensity is maximized in the optical axis direction. The radiation intensity decreases as the angle formed from the optical axis increases, but the degree is usually defined by an angle “half-value angle” that is half the illumination intensity in the optical axis direction ( (See FIG. 3C).

  Therefore, by directing the optical axis of the light projecting unit 301 in the direction f where the retroreflected light level is the weakest, the illumination intensity in the direction f is increased, and the illumination intensity is relatively lowered from the direction f toward the direction j. ing. As a result, the intensity of the retroreflected light that can be detected can be made uniform from the direction j to the direction f (see FIG. 3D), so that a more stable signal can be obtained regardless of the direction. . Here, in the first embodiment, for example, a threshold value indicated by a broken line is provided for the light reception intensity at the light receiving unit 40 in FIG. If the received light intensity is determined to be less than the threshold value at the time of initial setting, the light projection form is changed. Details of this will be described later.

  In this embodiment, the configuration in which the optical axis of the light projecting unit 301 is directed in the direction f where the retroreflected light level is the weakest based on the radiation intensity distribution of the infrared LED 311 is shown. The inclination angle with respect to 40 is not limited to this. For example, when an optical system in which the optical axis of the light projecting lens 321 itself is asymmetric is mounted, the light amount distribution and the radiation intensity distribution in FIG. In this case, the inclination angle of the light projecting unit 301 with respect to the light receiving unit 40 may be set so that the direction in which the distribution having the asymmetry becomes maximum coincides with the direction f.

  Details of the configuration of the sensor bar 1L will be described with reference to FIG. In FIG. 4, the sensor bar 1L will be described while focusing on the sensor bar 1L. However, the sensor bar 1R has the same configuration.

  As described above, the two sensor bars 1L and 1R are mounted on, for example, a flat whiteboard or a wall surface, and can be operated by directly touching the display screen projected on the whiteboard or wall surface. Is also the aim of this device. The size of the display screen is appropriately set by the user according to the size of the whiteboard and the size of the wall surface, and is not a fixed value. Furthermore, commercially available whiteboards are available in various sizes, and standard sizes that can project a large screen as the screen of the projection screen include vertical and horizontal dimensions of 900 × 1200 mm, 900 × 1800 mm, and 1200 × 1800 mm.

  However, this dimension does not define a range that can be effectively used as a whiteboard, and is often a dimension including a frame around the four sides of the whiteboard serving as the input surface 6. Therefore, there is a present situation that the plane area that can be actually used is smaller than that, and the size varies depending on the manufacturer.

  Therefore, the coordinate input device of the present invention is provided with an expansion / contraction mechanism (expansion / contraction part extending / contracting in the direction of the line segment connecting the centers of gravity of the two sensor units) on the sensor bar 1. Thus, the length of the sensor bar 1, in other words, the distance between the sensors of the two sensor units 2 built in the sensor bar 1 can be made variable. Actually, for example, the external length of the sensor bar 1 can be varied from 820 mm to 1200 mm so that the size of the flat portion of the whiteboard having a vertical dimension of 900 to 1200 mm can be mounted from 820 mm to 1200 mm.

  In FIG. 1, the sensor bar is mounted at two positions on the left and right sides of the whiteboard, and the amount of expansion / contraction is set based on the vertical dimension of the whiteboard. However, the present invention is not limited to this. For example, in the case where it is assumed that the whiteboard is mounted not on the left and right sides but on the top and bottom, the maximum dimension when the sensor bar 1 is extended is set longer. Furthermore, when it is assumed that the screen can be used even when a large screen is projected on a wall surface or the like, the expansion / contraction amount of the sensor bar is set according to the assumed size of the maximum display screen.

  Also, assuming that the sensor bar is mounted on the whiteboard, mounting the sensor bar on the left and right is considered to be more advantageous than mounting on the top and bottom.

  The first reason is that, considering the aspect ratio of the display device and the aspect ratio of the whiteboard, when the display area is set to the maximum possible on the whiteboard, blank areas (areas that are not displayed) ) Is possible. Therefore, if the sensor bar 1 is installed in the blank portion, the trouble that the display image must be reduced does not occur. In other words, it is possible to provide an operating environment that can use a larger screen.

  The second reason is that the aspect ratio of the display screen is usually horizontally long, such as 16: 9. In order to be able to perform a touch operation on an area equal to the display screen, the sensor unit 2 needs to be provided at the corner of the display screen. Therefore, by providing the sensor bar 1 on the left and right sides of the display screen, the length of the sensor bar 1 can be reduced as compared with the case where the sensor bar 1 is provided above and below.

  One of the aims of the coordinate input device is to carry it to a conference room or the like desired by the user and use it immediately by using a whiteboard already installed in the conference room or a wall surface of the conference room. Therefore, the size and weight of the sensor bar 1 are preferably smaller and lighter, and a specification that is attached to the left and right that can suppress the length of the sensor bar 1 is a more preferable form.

  The third reason is that installation is facilitated by adopting the left and right mounting specifications. In other words, in the case of the upper and lower mounting specifications, if the display screen is enlarged, a work at a high place occurs after preparing a stepladder or the like when mounting the sensor bar 1 on the upper side. Therefore, the specifications for mounting up and down may not be easy to install depending on the display size.

  FIG. 4A shows a schematic configuration of the sensor bar 1, and the sensor bar 1 includes an upper casing 51 and a lower casing 52. Reference numeral 53 denotes an outer pipe, and reference numeral 54 denotes an inner pipe. The inner diameter of the outer pipe 53 and the outer shape of the inner pipe 54 are in a substantially fitting relationship. The outer pipe 53 is fixed to the upper casing 51, and the inner pipe 54 is fixed to the lower casing 52. If the length of the sensor bar 1 is to be expanded and contracted by the upper casing 51 and the lower casing 52, the outer pipe 53 and the inner pipe 54 slide while maintaining the fitting relationship (see FIG. 4B). By making these pipes made of metal, the direction of expansion and contraction and the mechanical strength of the sensor bar 1 during expansion and contraction are obtained. One end of the metal pipe is drawn and crushed, and is mechanically coupled to the housing at that portion, and the sensor unit 2 is mounted.

  The optical axis of the light receiving unit 40 of the sensor unit 2 is arranged in a direction perpendicular to the extending and contracting direction of the sensor bar 1. As described above, the visual field range of the light receiving unit 40 is asymmetric with respect to the optical axis. By comprising in this way, it becomes possible to comprise the housing of the sensor bar 1 thinly. This is because the longitudinal direction of the line CCD 41 and the circuit board (not shown) on which the line CCD 41 is mounted coincides with the longitudinal direction of the sensor bar 1 and is successfully arranged.

  FIG. 4C is an example of a light projecting unit that employs an axially symmetric optical system, which is a conventional technique. In order to secure the field of view necessary for the light receiving unit 40, the optical axis of the optical system of the light receiving unit 40 must be inclined with respect to the sliding direction of the sensor bar. As a result, the width Lw of the sensor bar 1 that houses the optical system becomes larger than the width of the sensor bar 1 of the first embodiment. This not only leads to an increase in weight and a decrease in portability, but also means that an area necessary for mounting the sensor bar 1 becomes larger. Therefore, when it is mounted on a whiteboard or the like, the projection area of the display device is reduced.

  In FIG. 4 (C), the optical system of the light receiving unit 40 is set in a direction perpendicular to the sliding direction of the sensor bar 1 using an axially symmetric optical system, and the necessary viewing range is secured by bending the light beam with the optical system. Consider the case. As a matter of course, a new optical element such as a mirror is provided on the optical path, and it is inevitable that the sensor unit 2 becomes larger. That is, even with such a configuration, the width Lw of the sensor bar 1 is larger than when the non-axisymmetric optical system of the present invention is used.

  Furthermore, an optical system of the light receiving unit 40 having a sufficiently large visual field range (for example, a case where a visual field range of ± 50 ° with the optical axis as the center is adopted is considered. In FIG. The field-of-view range is a range from the direction h to the direction m, and has a relationship of angle Xoh = angle Xom = 50 ° with respect to the optical axis direction X. The field-of-view range required by the coordinate input device is provided on opposite sides. Only the range (the range from the direction f to the direction j) that covers the entire region of the retroreflective portion 4 is obtained, and therefore, the visual field range (the range from the direction j to the direction m) on one side is an invalid area. Even in such a case, it can be said that the effective visual field range of the light receiving unit 40 is equivalent to the visual field range in the case where a substantially asymmetric optical system is employed.

  FIG. 5A is a block diagram of the arithmetic control circuit 3. The calculation control circuit 3L of the sensor bar 1L and the calculation control circuit 3R of the sensor bar 1R in this embodiment have the same circuit configuration except for interface specifications to the outside, and control and calculation of the corresponding sensor unit 2 connected thereto. I do. FIG. 5A particularly shows the configuration of the arithmetic control circuit 3L of the sensor bar 1L.

  The CCD control signals for the line CCD 41 of the sensor units 2-L1 and 2-L2 are output from the CPU 61 constituted by a one-chip microcomputer or the like, and perform shutter timing of the line CCD 41, data output control, and the like. The CCD clock is transmitted from the clock generation circuit CLK62 to each of the sensor units 2-L1 and 2-L2, and is also input to the CPU 61 for performing various controls in synchronization with the line CCD 41. The LED drive signal for driving the infrared LEDs 311 of the sensor units 2-L1 and 2-L2 is supplied from the CPU 61.

  Detection signals from the line CCDs 41 of the sensor units 2-L1 and 2-L2 are input to the A / D converter 63 and converted into digital values under the control of the CPU 61. The converted digital value is stored in the memory 64 and used for angle calculation. Then, a geometric touch position is calculated from the calculated angle information, and is output to an information processing apparatus such as an external PC via an interface 68 (for example, a USB interface).

  As described above, the arithmetic control circuit 3 of each sensor bar 1 controls two sensor units 2 each. If the arithmetic control circuit 3L of the sensor bar 1L fulfills the main function, the CPU 61 transmits a control signal to the arithmetic control circuit 3R of the sensor bar 1R via the serial communication unit 67 to synchronize the circuits. . Then, necessary data is acquired from the arithmetic control circuit 3R.

  The operation between the arithmetic control circuits 3L and 3R is performed by master / slave control. In the present embodiment, the arithmetic control circuit 3L is a master, and the arithmetic control circuit 3R is a slave. Each arithmetic control circuit can be either a master or a slave, but the master / slave can be switched by inputting a switching signal to the CPU port with a switching unit such as a DIP switch (not shown). It has become.

  In order to acquire data of the sensor units 2-R1 and 2-R2 of the sensor bar 1R provided on the opposite side from the arithmetic control circuit 3L of the sensor bar 1L as the master, the control signal is sent to the slave arithmetic control circuit 3R. It is transmitted via the serial communication unit 67. Then, the angle information obtained by the sensor units 2-R1 and 2-R2 is calculated and transmitted to the arithmetic control circuit 3L on the master side via the serial communication unit 67.

  In the case of this embodiment, the interface 68 is mounted on the arithmetic control circuit 3L on the master side.

  The arithmetic control circuit 3L includes the clock generation circuit CLK62, the A / D converter 63, and the memory 64 with the CPU 61 as the center as described above. In the arithmetic control circuit 3L, the light receiving determination unit 61a for determining the light receiving state of the light receiving unit and the light projecting form of the two light projecting units 301 and 302 in the sensor unit 2 are controlled according to the determination result. The light projection form control unit 61b is realized by the CPU 61. Details of the control of the projection mode will be described later.

  Reference numeral 66 denotes an infrared light receiving unit when a dedicated pen (not shown) that emits infrared light is used as an indicator. Reference numeral 65 denotes a sub CPU for decoding a signal from the dedicated pen. The dedicated pen has a switch for detecting that the pen tip has pressed the input surface, and various switches on the side of the pen housing. It is possible to detect the operation state of the dedicated pen by transmitting the state of those switches and the identification information of the pen by the infrared light emitting unit provided in the dedicated pen.

  FIG. 5B is a timing chart showing a control signal output from the CPU 61 of the arithmetic control circuit 3L on the master side in order to operate the sensor unit 2 and the operation of the sensor unit 2.

  71, 72 and 73 are control signals for controlling the line CCD 41, and the shutter opening time of the line CCD 41 is determined by the interval of the SH signal 71. The ICGL signal 72 is a gate signal to the sensor units 2-L1 and 2-L2 of the sensor bar 1L, and is a signal for transferring the charge of the photoelectric conversion unit in the line CCD 41 to the reading unit.

  The CCDL signal 74 is a signal indicating the shutter opening time of the line CCD 41 of the sensor units 2-L1 and 2-L2. The ICGR signal 73 is a gate signal to the sensor units 2-R1 and 2-R2 of the opposing sensor bar 1R, and is transmitted to the arithmetic control circuit 3R of the sensor bar 1R via the serial communication unit 67. Then, the arithmetic control circuit 3R generates a signal for transferring the charge of the photoelectric conversion unit in the line CCD 41 to the reading unit. The CCDR signal 75 is a signal indicating the shutter opening time of the line CCD 41 of the sensor units 2-R1 and 2-R2.

  In addition, regarding the following drive timing, the lighting timing of the infrared LED 311 of the light projecting unit 301 and the infrared LED 312 of the light projecting unit 302 may be different. However, since the relationship with the operation timing related to the line CCD is common, the infrared LED 311 is representatively shown here.

  The LEDL signal 76 and the LEDR signal 77 are drive signals for the infrared LED 311 of each sensor unit 2. In order to turn on the infrared LEDs 311 of the sensor units 2-L1 and 2-L2 of the sensor bar 1L in the first cycle of the SH signal 71, an LEDL signal 76 is supplied to the infrared LEDs 311 via respective LED drive circuits (not shown). Is done.

  Then, in order to turn on the infrared LEDs 311 of the sensor units 2-R1 and 2-R2 of the sensor bar 1R provided on opposite sides in the next cycle of the SH signal 71, the LEDR signal 77 is transmitted via the serial communication unit 67. To the arithmetic control circuit 3R. Then, the arithmetic control circuit 3R generates a signal to be supplied to each LED drive circuit.

  After the driving of the infrared LED 311 and the shutter release of the line CCD 41 are completed, the signal of the line CCD 41 is read from the sensor unit 2 and angle information is calculated by a method described later. Then, the calculation result of the slave-side calculation control circuit 3R is transmitted to the master-side calculation control circuit 3L.

  By operating as described above, the sensor units 2-R1 and 2-R2 of the sensor bar 1R facing the sensor units 2-L1 and 2-L2 of the sensor bar 1L operate at different timings. By comprising in this way, only the retroreflected light which sensor unit itself emitted can be detected, without detecting the infrared light of the sensor unit provided in the edge | side which opposes.

  A signal output from the sensor unit 2 of the sensor bar 1 will be described with reference to FIG. First, the output of the light receiving unit 40 when there is no light emission of the light projecting unit 30 of the sensor unit 2 is FIG. 6A, and the output of the light receiving unit 40 when there is light emission is FIG. 6B. . In FIG. 6B, level A is the maximum level of light quantity detected, and level B can be said to be a level at which no light can be detected (received).

  The infrared light emitted from the sensor unit 2 is retroreflected by the retroreflecting unit 4 provided on the opposite side and is detected by the sensor unit 2 itself. Therefore, the direction of the pixel number Nj from which the light output starts to be obtained is the direction j in FIG. 3, and similarly, the direction of the pixel number Nf is the direction f in FIG. The amount of light from the pixel number Nj to the pixel number Nf varies depending on the size of the display screen, the aspect ratio, the arrangement state of the sensor bar 1 (particularly the distance between the two sensor bars 1), the expansion / contraction state, and the like.

  The coordinate input device of the present invention adjusts the shutter open time of the line CCD 41 and the exposure time of the infrared LED 311 by controlling the SH signal so that an optimum light amount level is obtained. If the amount of light obtained from the sensor unit 2 is large, the time can be shortened. Conversely, if the amount of light is small, the time can be set long. Further, the current flowing through the infrared LED 311 may be adjusted according to the detected light amount level. By monitoring the output signal in this way, an optimum light amount can be obtained. Such adjustment may be made as appropriate when there is a level fluctuation. Alternatively, a stable and constant signal should be obtained while the sensor bar 1 is installed and its state is maintained, and thus such light quantity adjustment may be performed when the power is turned on after installation is completed.

  Returning again to FIG. 6, if the optical path is blocked by touching the input surface of the coordinate input effective area 5, for example, the light quantity cannot be detected with the pixel number Nc as shown in FIG. 6C. The touched direction, in other words, the angle is calculated using the signals shown in FIGS.

  First, reference data is acquired when the system is started, when the system is reset, or automatically. Hereinafter, the data processing of one sensor unit 2 will be described, but the same processing is performed in other sensor units.

  When the power is turned on, the output of the line CCD 41 is A / D converted by the A / D converter 63 in a state where no touch operation is performed by the operator and the illumination unit 30 is not illuminated, and this value is converted to Base_Data [ N] is stored in the memory 64. This is data including variations in the bias of the line CCD 41 and the like, and is data in the vicinity of level B in FIG. Here, [N] is the CCD pixel number of the line CCD 41, and a pixel number corresponding to an effective input range is used.

  Similarly, a light amount distribution in a state where light is projected from the light projecting unit 30 in a state where no touch operation is performed by the operator is acquired and stored. This is data represented by a solid line in FIG. 6B and is stored in the memory 64 as Ref_Data [N]. This manages the storage of two types of data as initial data.

  Thereafter, sampling is started. If no touch operation is performed, the data shown in FIG. 6B is a diagram in which a shadow C is detected according to the touch position when the touch operation is performed. Data shown in 6 (C) is detected. Sample data obtained when the light projecting unit 30 is illuminated is defined as Norm_Data [N].

  Using these data (Base_Data [N] and Ref_Data [N] stored in the memory 64), first, the presence / absence of the input of the pointing tool and the presence / absence of the light shielding portion are determined. First, in order to identify the light-shielding portion, the absolute amount of data change is calculated for each pixel and compared with a preset threshold value Vtha.

Norm_Data0 [N] = Norm_Data [N]-Ref_Data [N] (1)
Here, Norm_Data0 [N] is an absolute change amount in each pixel, and prevents erroneous determination due to noise or the like by threshold comparison, and detects a certain amount of reliable change. Then, when data exceeding the threshold value is generated in, for example, a predetermined number or more of continuous pixels, it is determined that there is a touch operation. Since this process only takes a difference and compares it, it is possible to perform a calculation in a short time and to determine whether or not there is an input at high speed.

  Next, in order to detect with higher accuracy, the ratio of changes in pixel data is calculated, and the input point is determined using equation (2).

Norm_DataR [N] = Norm_Data0 [N] / (Base_Data [N]-Ref_Data [N]) (2)
A separately set threshold value Vthr is applied to the pixel data (light quantity distribution). Then, based on the pixel numbers of the rising and falling portions of the light amount fluctuation region corresponding to the light shielding portion in the light amount distribution corresponding to the point crossing the threshold value Vthr, the center of both is set as the pixel corresponding to the input by the pointing tool. Thus, the angle is calculated.

  FIG. 6D shows an example of the detection result after the calculation of the change ratio. Now, when detecting with the threshold value Vthr, it is assumed that the rising portion of the light-shielding portion becomes the level Ls at the Ns-th pixel and exceeds the threshold value Vthr. Furthermore, it is assumed that the level becomes Lt at the Ntth pixel and falls below the threshold value Vthr.

  At this time, the pixel number Np of the line CCD 41 to be output may be calculated as the median value of the pixel numbers of the rising and falling portions as in Expression (3), but in this case, the pixel interval of the line CCD 41 is output. It becomes the resolution of the pixel number.

Np = Ns + (Nt-Ns) / 2 (3)
Therefore, in order to detect with higher resolution, a virtual pixel number crossing the threshold value Vthr is calculated using the data level of each pixel and the data level of the immediately preceding adjacent pixel.

If the level of the pixel Ns is Ls, the level of the pixel Ns-1 is Ls-1, the level of the pixel Nt is Lt, and the level of the pixel Nt-1 is Lt-1, the respective virtual pixel numbers Nsv and Ntv are ,
Nsv = Ns-1 + (Vthr-Ls-1) / (Ls -LS-1) (4)
Ntv = Nt-1 + (Vthr-Lt-1) / (Lt -Lt-1) (5)
Can be calculated. According to this calculation formula, a virtual pixel number corresponding to the output level, that is, a pixel number smaller than the pixel number of the line CCD 41 can be acquired. And the virtual center pixel Npv of these virtual pixel numbers Nsv and Ntv is determined by Expression (6).

Npv = Nsv + (Ntv-Nsv) / 2 (6)
Thus, by calculating the virtual virtual pixel number that crosses the threshold value Vthr of the predetermined level from the pixel number of the pixel of the data level exceeding the threshold value Vthr, the adjacent pixel number, and the data level thereof, the resolution can be further increased. High detection can be realized.

  In order to calculate the actual coordinate value of the pointing tool from the center pixel number obtained in this way, it is necessary to convert the center pixel number into angle information.

  In actual coordinate calculation described later, it is more convenient to calculate the value of the tangent at the angle rather than the angle itself. A table reference or a conversion formula is used for conversion from the pixel number to tan θ. For example, a high-order polynomial can be used as the conversion formula to ensure accuracy, but the order and the like may be determined in consideration of calculation capability, accuracy specifications, and the like.

Here, an example in the case of using a 5th order polynomial requires 6 coefficients when using a 5th order polynomial, so this coefficient data is stored in a memory such as a non-volatile memory at the time of shipment or the like. Just keep it. Now, when the coefficients of the fifth-order polynomial are L5, L4, L3, L2, L1, and L0, tan θ is
tanθ = (((((L5 * Npr + L4) * Npr + L3) * Npr + L2) * Npr + L1) * Npr + L0 (7)
Can be represented. If the same thing is done for each sensor unit, the respective angle data can be determined. Of course, in the above example, tan θ is calculated, but the angle data itself may be calculated, and then tan θ may be calculated.

  FIG. 7 is a diagram illustrating a positional relationship with the screen coordinates. The visual field range of the sensor unit 2-L1 of the sensor bar 1L is a range from the direction j to the direction f, and the positive and negative angles are set as illustrated. The optical axis of the sensor unit 2-L1 is the X-axis direction, and the direction is defined as an angle of 0 °. Similarly, the field-of-view range of the sensor unit 2-L2 is a range from the direction f to the direction j, the positive / negative of the angle is set as illustrated, and the direction of the optical axis of the sensor unit 2-L2 is an angle of 0 °. Define. Then, if a line segment connecting the optical axis center of the sensor unit 2-L1 and the optical axis center of the sensor unit 2-L2 is defined as the Y axis, the optical axis of each sensor unit is the normal direction of the line segment. Further, the distance between the optical axis center of the sensor unit 2-L1 and the optical axis center of the sensor unit 2-L2 is defined as dh.

  Assume that a touch operation is performed at the point P.

  The angle calculated by the sensor unit 2-L1 is θL1, and the angle calculated by the sensor unit 2-L2 is θL2. The coordinates of the touch position P can be calculated geometrically using the two angle information and the distance dh.

x = dh ・ tan (π / 2-θL2) ・ tan (π / 2-θL1) / (tan (π / 2-θL2) + tan (π / 2-θL1)) (8)
y = dh · tan (π / 2-θL2) / (tan (π / 2-θL2) + tan (π / 2-θL1)) (9)
Even if the output of one sensor unit is θL1 = 0 or θL2 = 0, the touch position can be easily calculated geometrically based on the angle information output by the other sensor unit. It is.

  Here, it is possible to calculate the touch position from the field of view range of the sensor unit 2-L1 and the sensor unit 2-L2 only when the touch position P is within the hatched range of FIG. 7B. When the touch position is not within the range, as shown in FIGS. 7C, 7 </ b> D, and 7 </ b> E, the touch of the entire coordinate input effective area 5 can be performed by changing the combination of sensor units used for calculation. The position can be detected. Therefore, based on the presence / absence of the light shielding direction detected by each sensor unit 2 and the light shielding direction, a sensor unit necessary for coordinate calculation is selected to calculate the touch position. And according to the combination of the selected sensor units 2, the parameters of Equation (8) and Equation (9) may be changed to perform coordinate conversion.

  As shown in FIG. 7F, if the touch position P exists in the vicinity of the boundary area for sensor unit selection, in this case, the combination of sensor units in the state of FIG. 7B or FIG. The touch position can be calculated. As a specific configuration, for example, the visual field range of the sensor unit 2-L2 and the visual field range of the sensor unit 2-R1 are configured to overlap in the diagonal direction of the coordinate input effective region 5. And when it touches in the overlapping area | region, a coordinate calculation is attained by the combination of a plurality of types of sensor units. In that case, an average value of coordinate values calculated by a combination of the two may be output as definite coordinates.

  The coordinate value calculated in this way is the value of the first coordinate system of the coordinate input device (hereinafter referred to as the digitizer coordinate system), and the effective area where the position can be calculated is the coordinate input effective in FIG. Region 5. The display surface of the display is provided in the range of the coordinate input effective area 5. If the display is a front projector, the display area 8 that is a projected image is set in the coordinate input effective area 5 as shown in FIG. In FIG. 8, it consists of the 2nd coordinate system (henceforth a screen coordinate system) which is a display coordinate system which consists of dx-axis and dy-axis by making d1 into an origin. In order to perform a tap operation of an icon or the like by directly touching the displayed image, it is necessary to obtain a correlation between the digitizer coordinate system and the screen coordinate system.

  Usually, in order to obtain this kind of correlation, dedicated application software is installed in a personal computer (PC) performing display control. When the application is activated, an indicator such as a cross is displayed on the display screen, and the user is prompted to touch the position (cross position) indicated by the indicator. The coordinate system is converted so that the coordinate value of the digitizer coordinate system obtained by repeating the operation a predetermined number of times at different positions matches the coordinate value of the screen coordinate system at the position where the index is displayed.

  In the coordinate input device, this coordinate conversion is performed by touching the four corner vertices of the display screen instead of displaying and touching the position of the index using application software. By configuring in this way, it is possible to obtain an excellent effect that it can be used immediately without installing special software by connecting to a PC on the spot. In particular, the coordinate input device is a portable type in which the sensor bar 1 is carried and installed in the conference room, and it is a great advantage that there is no need to carry the PC together. Using the local PC and the local display device, you can easily complete the installation and use it immediately.

  The transition to the mode for matching the coordinate systems is performed by, for example, a mode transition switch (not shown) provided in the sensor bar 1. When the mode is switched by the mode transition switch, guidance is given so that the four corners are sequentially touched by an output unit such as a speaker built in the sensor bar 1. Also, a buzzer sound indicating that the input has been completed may be notified every time the corner touch is completed. Alternatively, the operation may be prompted by an indicator built in the sensor bar 1.

  Now, in the coordinate calculation in the digitizer coordinate system, it is necessary that the distance dh between the sensor units 2 used for calculation in the equations (8) and (9) is known. However, in the case of use as shown in FIG. 1 used in combination with a display device, this distance dh does not necessarily have to be known. That is, information on the four corners indicating the size of the display is sequentially acquired as angle information at each sensor unit in the digitizer coordinate system by performing a touch operation. As a result, it is possible to calculate the touch position coordinates in the screen coordinate system only by calculation based on the ratio.

  Now, it is assumed that the coordinate input device is used by a user wearing two sensor bars 1 on display surfaces of various display sizes. The relative positional relationship between the two sensor bars is as shown in FIG. 7A (the two sensor bars are parallel, have the same length, and the sensor unit of the other sensor bar is disposed in the X-axis direction). This makes it possible to detect the position with high accuracy in the digitizer coordinate system. Although it is possible to provide a mechanism in which the two sensor bars 1 have such an arrangement, in that case, the user is forced to perform appropriate installation work. If the two sensor bars can be easily mounted with an appropriate amount, the convenience will be improved and the installation time will be greatly shortened. Therefore, in order to improve convenience, the second detection mode is provided as the coordinate detection mode.

  FIG. 9A is a timing chart showing a control signal output from the CPU 61 of the master-side sensor bar 1L and an operation of the sensor unit 2 for explaining the second detection mode.

  91, 92 and 93 are control signals for controlling the line CCD 41, and the shutter opening time of the line CCD 41 is determined by the interval of the SH signal 91. The ICGL signal 92 is a gate signal to the sensor units 2-L1 and 2-L2 of the sensor bar 1L, and is a signal for transferring the charge of the photoelectric conversion unit in the line CCD 41 to the reading unit.

  The CCDL signal 94 is a signal indicating the shutter opening time of the line CCD 41 of the sensor units 2-L1 and 2-L2. The ICGR signal 93 is a gate signal to the sensor units 2-R1 and 2-R2 of the opposing sensor bar 1R, and is transmitted to the arithmetic control circuit 3R of the sensor bar 1R via the serial communication unit 67. Then, the arithmetic control circuit 3R generates a signal for transferring the charge of the photoelectric conversion unit in the line CCD 41 to the reading unit. The CCDR signal 95 is a signal indicating the shutter opening time of the line CCD 41 of the sensor units 2-R1 and 2-R2.

  The LEDL signal 96 and the LEDR signal 97 are drive signals for the infrared LED 311 of each sensor unit 2. In order to turn on the infrared LEDs 311 of the sensor units 2-R1 and 2-R2 of the sensor bar 1R in the first cycle of the SH signal 91, the LEDR signal 97 is transmitted to the arithmetic control circuit 3R of the sensor bar 1R via the serial communication unit 67. Is done. Then, the arithmetic control circuit 3R generates a signal to be supplied to each LED drive circuit.

  Then, in order to turn on the infrared LEDs 311 of the sensor units 2-L1 and 2-L2 of the sensor bar 1L in the next cycle of the SH signal 91, the LEDL signal 96 is supplied to the infrared LEDs 311 via the respective LED drive circuits. .

  After the driving of the infrared LED 311 and the shutter release of the line CCD 41 are completed, the signal of the line CCD 41 is read from the sensor unit 2 and angle information is calculated by a method described later. Then, the calculation result of the slave-side calculation control circuit 3R is transmitted to the master-side calculation control circuit 3L.

  By operating as described above, the sensor units 2-L1 and 2-L2 of the sensor bar 1L directly detect the infrared light of the infrared LED 311 emitted by the sensor units 2-R1 and 2-R2 of the opposing sensor bar 1R. To do. Similarly, the sensor units 2-R1 and 2-R2 of the sensor bar 1R directly detect the infrared light of the infrared LED 311 emitted by the sensor units 2-L1 and 2-L2 of the opposing sensor bar 1L.

  FIG. 5B shows a coordinate detection mode in which the sensor units 2-L1 and 2-R2 of the sensor bar 1R facing the sensor units 2-L1 and 2-L2 of the sensor bar 1L are operated at different timings. The first detection mode is entered.

  FIG. 9B shows a detection signal waveform obtained by the sensor unit 2 when operating in the second detection mode. Since light emitted from the light projecting units 30 of the two sensor units 2 provided on the opposite sides is received, two peak signals are generated. Then, the respective directions are calculated by the same method as the angle calculation method described above. In addition, the broken line in a figure shows the output (light quantity distribution) of the light-receiving part 40 shown to FIG. 6 (B), and has shown that the peak signal is produced | generated between the direction Nj and the direction Nf.

  As described above, it is one of the objects of the present invention to realize highly accurate position detection even when the user wears the two sensor bars 1 with the reference amount. Therefore, each sensor unit 2 detects in which direction the opposing sensor unit 2 is located by detecting the light of the light projecting unit 30 of the sensor unit 2 housed in the opposing sensor bar 1.

  This will be described with reference to FIG.

  In FIG. 10, if the line segment connecting the optical axis center of the sensor unit 2-L1 and the optical axis center of the sensor unit 2-L2 is the Y axis and the normal direction is the X axis, the sensor units 2-L1 and 2- The optical axis of L2 is parallel to the X axis. The opposing sensor unit 2-R1 is in the direction of the angle θ1 when viewed from the sensor unit 2-L1, and is the direction of the angle θ3 when viewed from the sensor unit 2-L2. Similarly, an angle from θ1 to θ8 can be calculated. As a result, an angle θ9 formed by the optical axis of the sensor unit 2-L1 of the sensor bar 1L and the optical axis of the sensor unit 2-R1 of the sensor bar 1R is obtained. Calculated.

  In other words, the relative inclination of the sensor bar 1L and the sensor bar 1R can be detected. Furthermore, even when the length of the sensor bar 1 in the longitudinal direction changes due to expansion and contraction, the absolute distance between the sensor units 2 cannot be known, but the relative positional relationship between the four sensor units Is possible to get. If the information on the four corners indicating the size of the display described above is acquired by touch operation, it is possible to calculate the coordinates in the screen coordinate system with high accuracy only by the calculation by the ratio. Become.

  FIG. 11 is a flowchart showing an initial setting process after power-on.

  First, when the sensor bar 1 is mounted on the input surface 6 by the operator in order to form a rectangular coordinate input effective area 5 including the entire display area 8 as a projection image, for example, power is turned on. The initial setting is performed (step S101).

  Next, various initializations related to the coordinate input device such as port setting and timer setting of the CPU 61 are performed, and the line CCD 41 is also initialized such as removing excess charges remaining in the photoelectric conversion elements (step S102). . Next, the amount of light detected by the line CCD 41 is optimized. As described above, the size of the display area 8 is not unique depending on the size of the input surface 6. Even in such a case, the length of the sensor bar 1 is expanded or contracted, and the distance between the sensor bars 1 is appropriately set by the user. Accordingly, since the detected light intensity varies depending on the state of mounting, the operation setting is performed in the second detection mode including the setting of the shutter opening time of the line CCD 41, the lighting time of the infrared LED 311 or the driving current of the infrared LED 311. Is performed (step S103). Next, the output signal of the line CCD 41 is captured (step S104).

  Here, the operation setting in step S103 is a state of the operation of receiving light directly from the opposing sensor unit 2 (second detection mode in FIG. 9), and the relative positional relationship between the four sensor units 2 is determined. The purpose is to derive. In step S103, if the initial operation setting is set so that the maximum amount of light can be obtained, the state in which light cannot be detected in step S105 is at a position facing the visual field range of the light receiving unit 40 of the sensor unit 2. This means that the sensor unit 2 is not located. That is, the arrangement / installation of the sensor bar 1 by the user is in an unsuitable state, and this is notified in step S106 to prompt the user to re-install the sensor bar. Then, when the reinstallation by the user is completed, Step S101 is started again. Note that the signals detected in step S105 and step S106 are signals as shown in FIG. 9B, and in this embodiment, the state in which two signals are output can be said to be a normal state.

  Next, the waveform of the detection signal is checked (step S107). If the light of the sensor unit 2 at the opposite position is too strong, for example, if at least a part of the waveform (waveform level) of the detection signal exceeds a predetermined threshold (NO in step S107), the process returns to step S103, for example, Reset such as shortening the exposure time. This time, the detection signal waveform checked in step S107 should have a lower light intensity. If the signal level is appropriate (YES in step S107), for example, if at least a part of the detection signal waveform is equal to or less than a predetermined threshold, the process proceeds to step S108. This operation is executed by each sensor unit (four in this embodiment), and when all the signals are optimized, the relative positional relationship of the sensor unit 2 is calculated (step S108).

  In step S1081 descending, the infrared light projected by the sensor unit 2 is retroreflected by the retroreflecting unit 4 provided in the opposing sensor bar 1, and the signal level when the light is detected by its own light receiving unit 40 is obtained. Optimize. As described above, the arrangement of the sensor bar 1 is not unique, and an object is to obtain a stable signal by optimizing the detection level according to the arrangement. The items to be set are the shutter opening time of the line CCD 41, the lighting time of the infrared LED 311 or the setting of the drive current of the infrared LED 311 and the light projecting mode. First, as a default state, a control signal is issued so that light is projected by the light projecting unit 301 having a distance close to the input surface 6 to the light projecting form control unit 61b. Then, operation setting is performed in the first detection mode (step S109). In step S109, if the initial operation setting is set so as to obtain the maximum amount of light, the output signal of the line CCD 41 at that time is captured (step S110).

  The captured output signal is data at the time of illumination, and has a waveform as shown in FIG. If the light is too strong, the output exceeds the range of the dynamic range of the line CCD 41 and the output is saturated, making it difficult to calculate an accurate angle. In that case, in step S111, it is determined that the waveform of the detection signal is inappropriate (NO in step S111), the process returns to step S109, and resetting is performed so that the waveform (waveform level) of the detection signal becomes smaller. Since the retroreflected light is detected, the light is projected significantly compared to the case where the light receiving unit 40 directly detects the light projection of the sensor unit 2 in the processing in step S103 to step S108 (that is, the second detection mode). The light amount is set to be large.

  If it is determined in step S111 that the waveform level is optimal (YES in step S111), the light reception determination unit 61a determines the light reception state (step S1111). When the light reception determination unit 61a determines that the level (light reception amount) of the detection signal waveform is less than the threshold value in FIG. 3D (NO in step S1111), this is indicated to the light projection form control unit 61b. Outputs a judgment signal. In step S <b> 1112, the light projecting form control unit 61 b changes the light projecting form, that is, changes so that the light projecting unit 302 that is far from the input surface 6 projects light, and again. The process returns to step S110.

  The change of the light projection mode will be further described with reference to FIG. 12, which is a schematic diagram of the main configuration of the present invention. FIG. 12 is a cross-sectional view in a direction perpendicular to the input surface 6 as viewed from the side when the sensor bars 1L and 1R are attached to the input surface 6. FIG. FIG. 1A shows a case where the input surface 6 is flat, and FIG. 1B shows a case where the input surface 6 is curved in a convex shape. Normally, as described in step S1081, as a default state, a control signal is issued to the light projecting form control unit 61b so that light is projected by the light projecting unit 301 that is close to the input surface 6.

  When the input surface 6 is flat as shown in FIG. 12 (A), as shown in FIG. 21 (A), the light projecting / receiving path is also used when light is projected by the light projecting unit 301 that is close to the input surface 6. Is ensured and sufficient light receiving intensity is obtained. On the other hand, when the input surface 6 is convexly curved as shown in FIG. 12B, light is projected by the light projecting unit 301 that is close to the input surface 6 as shown in FIG. In this state, the projection light path is blocked by the convex portion of the input surface, and the light receiving unit 40 cannot obtain sufficient light intensity.

  That is, the light intensity at the light receiving unit 40 in FIG. 3D is equal to or less than a predetermined threshold value. The threshold value in this case is a value derived from an S / N limit value that can be detected without error in the arithmetic control circuit 3. In this case, based on the determination in step S1111, in step S1112, the light projecting form control unit 61 b performs control so that the light projecting unit 302 that is farther from the light projecting unit 301 than the light projecting unit 301 is changed to light projection. At this time, the light projection unit 301 that is close to the input surface 6 may be turned off (non-light projection) or may be maintained as it is.

  As described with reference to FIG. 2A, the light projecting unit 302 that is far from the input surface 6 is separated from the input surface 6 by a distance L_pd × 2 compared to the light projecting unit 301. Has been placed. At this time, in the optical path from the light projection to the light reception from the light projecting unit 302, the light path is set so as not to be blocked at the projected portion of the input surface. That is, the light receiving unit 40 is closer to the input surface 6 than the light projecting unit 302. The light projection of the light projecting unit 302 is reflected from the retroreflecting unit 4 of the sensor bar 1 so that the optical path to the light receiving unit 40 is not blocked by the convex portion of the input surface. The position is preset.

  More specifically, when the input surface 6 has a curved shape that is convex upward, the mounting surface of the sensor bar 1L is inclined upward from the direction parallel to the input surface 6, and the projection of the sensor unit 2 to be mounted thereon The optical path is also directed upward with respect to the input surface. Therefore, it is necessary to attach the retroreflecting part 4 attached to the corresponding opposing sensor bar 1R to the upper side with respect to the input surface. Therefore, in the case where the input surface 6 is flat and the curved surface is convex upward, in order to cover the light projecting / receiving path in both cases, it is necessary to arrange the retroreflective portion 4 wider than the input surface. is there.

  In this way, when there is a convex portion of the input surface 6, light is projected from the light projecting unit 302 that is spaced from the light projecting unit 301 to the input surface 6, thereby projecting light at the convex portion of the input surface. Will not be blocked. Therefore, sufficient light intensity can be obtained at the light receiving unit 40. After step S110 again, in step S111, it is determined whether or not the waveform level is saturated. This is a process assuming that the received light intensity is excessively increased by the control in which the light projecting form control unit 61b in step S1112 is changed to project the light projecting unit 302. If it is determined that it is saturated, the process returns to step S109 again, and resetting is performed so that the light detection level becomes smaller. The degree of resetting at this time may be gradual after changing the projection mode. In subsequent step S1111, since the light is emitted from light projecting unit 302, sufficient light intensity is obtained, and the received light intensity is equal to or higher than the threshold value in FIG. 3D (YES in step S1111), and the output level is optimum. Determined.

  Then, the signal Base_Data [N] (see FIG. 6A) in a state without illumination is acquired and stored in the memory 64 (step S112). Next, a signal Ref_Data [N] (see FIG. 6B) in a lighting state is acquired and stored in the memory 64 (step S113).

  In this way, when data for all sensor units is acquired, a series of initial setting processes is completed.

  In FIG. 12, the processing in the sensor bar 1L is described, but the same applies to the processing in the sensor bar 1R.

  With the above configuration, even when the sensor bar 1 is mounted on the curved input surface 6 in the initial setting described above, the light projecting / receiving path is formed on the convex portion of the input surface without any special work by the user. The light path is secured without being blocked. Accordingly, it is possible to secure a sufficient received light intensity for performing highly accurate designated position coordinate detection described below.

  FIG. 13A is a flowchart showing a normal sampling operation after the initial setting process.

  The initial setting process of FIG. 11 is executed (step S101). Thereafter, as a normal capturing operation (first detection mode), the infrared light projected by the sensor unit 2 is retroreflected by the retroreflecting unit 4 provided in the opposing sensor bar 1, and the light is reflected by itself. A signal when detected by the light receiving unit 40 is detected (step S201). The data at that time is Norm_data [N]. If there is a touch operation and the optical path is interrupted, an optical signal cannot be detected around the pixel number Nc as shown in FIG. 6C.

  It is determined whether or not such a light-shielding portion is generated by any one of the sensor units 2, that is, whether or not there is an input (step S202). When it is determined that there is no input (NO in step S202), the process returns to step S201 again, and sampling is repeated. On the other hand, when it is determined that there is an input (YES in step S202), a sensor unit in which a light shielding portion is generated in the output signal is selected (step S203). Using the selected sensor unit, the direction (angle) in which the light shielding part is generated is calculated (step S204). Based on the calculated angle, the touch position coordinates in the digitizer coordinate system are calculated (step S205). The calculated touch position coordinates are converted into a screen coordinate system using the conversion parameters, and the coordinate values are output (transmitted) to an external device of the personal computer (step S206).

  At this time, a touchdown signal / touchup signal indicating whether or not the input surface 6 is touched may be output together. In this type of coordinate input device, the optical path is blocked by 100% by touching the touch surface, but light is gradually transmitted by floating little by little from the touch state. Therefore, by calculating how much light is blocked, it is touched or not touched, but the light path is blocked (angle calculation is possible, and even that position can be calculated) Whether it is in a state can be determined by setting a threshold value.

  The operation of a switching unit such as a switch configured in the sensor bar 1 makes a transition to a calibration mode (second detection mode) for matching the digitizer coordinate system with the screen coordinate system. Therefore, a flowchart of the calibration mode will be described with reference to FIG.

  The calibration mode is performed when the display position of the display is deviated at some point even immediately after the sensor bar 1 is mounted or after the installation is completed. When transitioning to the calibration mode, first, initial setting processing is performed (step S101). This assumes that the installation state is shifted while the sensor bar is in use, and that the optical output is optimized and the positional deviation of the sensor unit is corrected.

  Then, in order to cause the user to perform a touch operation on the four corner vertices of the display area 8, it is determined whether or not the touch at one position has been performed through steps S <b> 201 and S <b> 202. In step S203 and step S204, necessary angle information is calculated. In step S205, the touch position coordinates in the digitizer coordinate system are calculated based on the calculated angle information. Thereafter, it is notified that the data acquisition is completed (step S301). This notification outputs, for example, a beep sound indicating completion.

  Next, it is determined whether or not acquisition of all information (touch position coordinates) of the four corner vertices of the display area 8 has been completed (step S302). If acquisition has not been completed (NO in step S302), the process returns to step S201. On the other hand, if the acquisition has been completed (YES in step S302), the positional relationship of the touch position coordinates in the four calculated digitizer coordinate systems is recognized (step S303).

  For example, the sensor bar 1L in FIG. 8 has a left and right specification so that the sensor bar 1L is arranged on the left side with respect to the display area 8, and the sensor bar 1R is arranged on the right side with respect to the display area 8. In that case, the positional relationship of the touch position coordinates d1, d2, d3, d4 in the four digitizer coordinate systems calculated in step S205, that is, the vertical / horizontal positional relationship can be uniquely recognized in step S303. .

  In the above-described embodiment, the left and right specification of the sensor bars 1L and 1R depends on the specifications. However, the function of detecting the position of the sensor bar is not limited to this, and is not limited to the left and right and is arranged vertically. It is also possible to deal with cases. For example, the sensor bars 1L and 1R may be provided with position detection units such as an angle sensor, an angular velocity sensor, a geomagnetic sensor, and an identification changeover switch.

  As described above, according to the first embodiment, since the light projecting and receiving path for coordinate detection can be adjusted according to the state of the input surface, even when the flatness of the input surface is not ensured, Coordinates can be input with high accuracy without being affected by the state.

<Embodiment 2>
In the first embodiment, the light receiving determination unit 61a of the arithmetic control circuit 3 determines the level of the detection signal waveform, and the light projecting form control unit 61b changes the light projecting form. Further, the light reception determining unit 61a determines not the level of the detection signal waveform but the level ratio in different directions (light receiving direction) from the sensor unit 2, that is, the pixel areas of different line CCDs, and the light projection form control unit 61b. The projection form may be changed by

  In order to describe the second embodiment, a side sectional view and a light receiving / emitting light path diagram when the sensor bar 1 is mounted in accordance with the curved state of the input surface 6 will be described with reference to FIG. The received light intensity corresponding to each curved state will be described with reference to FIG. The processing in the second embodiment will be described with reference to the flowchart of FIG.

  In FIG. 14, the retroreflective portion 4 is simply mounted at a single position. However, as in the first embodiment, a plurality of vertical positions are provided in the vicinity of the light projecting / receiving window of the sensor unit. You may disperse and install in the place. In the flowchart of FIG. 16 of the second embodiment, the difference from the flowchart of FIG. 11 of the first embodiment is only the process of determining the received light intensity in step S1111a, and the other processes are the same as the processes of the flowchart of FIG. It is.

  As shown in FIG. 14A, when the input surface 6 is flat, in FIG. 3A, in the retroreflecting portion 4 of the sensor bar 1R in the direction j and the direction f related to the sensor unit 2-L1 of the sensor bar 1L. There is nothing to block the light emitting / receiving optical path involved, and the light receiving intensity is as shown in FIG. That is, the light reception intensity corresponding to the light reception angle direction j and the direction f related to the sensor unit 2 on the horizontal axis is substantially equal. Therefore, if the received light intensity corresponding to the direction j and the direction f of the angle related to the sensor unit 2 is F and J, respectively, F≈J. Here, F≈J means the same as the light quantity distribution combining the original light projecting characteristics, distance attenuation characteristics, and light receiving characteristics.

  As shown in FIG. 14B, when the input surface 6 is convexly curved as shown in FIG. 14B, the light is projected by the light projecting unit 301 that is close to the input surface 6 as shown in FIG. In the state, the light path of the light projection is blocked by the convex portion 114 of the input surface 6 and the light receiving portion 40 cannot obtain a sufficient light intensity as described above. When the state where the input surface 6 is curved in a convex shape is viewed two-dimensionally in FIG. 3, the convex state of the normal input surface 6 is convex in a spherical shape where the convexity of the central portion is larger than the periphery. There are many cases.

  In this case, the convexity of the input surface is larger in the direction f than in the direction j of the angle related to the sensor unit 2, and the light projecting / receiving path is blocked more greatly. Accordingly, in the distribution of received light intensity, the received light intensity F in the direction f tends to be smaller than the received light intensity J in the direction j. It is necessary that the ratio J / F of the received light intensity is not less than a predetermined value that satisfies a dynamic range that falls within a light reception intensity range that is not erroneously detected, that is, between the saturation level and the noise limit level.

  Accordingly, in step S1111a in the flowchart of FIG. 16, the light reception determination unit 61a determines whether or not the light reception intensity ratio J / F is equal to or greater than a predetermined value that satisfies the dynamic range falling between the saturation level and the noise limit level. To do. As described in step S <b> 1081, in the default state, a control signal is issued to the light projecting form control unit 61 b so that light is projected by the light projecting unit 301 that is close to the input surface 6.

  Therefore, as shown in FIG. 14B, when the convexity of the input surface 6 increases, the light projecting / receiving path of the light projecting unit 301 is blocked by the convex portion 114 of the input surface 6, and the ratio J / F of the received light intensity is predetermined. May be smaller than the value. In that case, in step S1111a, the light reception determination unit 61a proceeds to step S1112 by determining that J / F <predetermined value (NO in step S1111a). In step S <b> 1112, the light projecting form control unit 61 b performs control so that the input surface 6 is changed to the light projecting unit 302 that is further away from the light projecting unit 301 and is projected. At this time, it is the same as in the first embodiment that either the light projecting unit 301 close to the input surface 6 may be turned off or the light projection may be maintained as it is.

  As described with reference to FIG. 2A, the light projecting unit 302 that is far from the input surface 6 is separated from the input surface 6 by a distance L_pd × 2 compared to the light projecting unit 301. Has been placed. At this time, in the optical path from the light projection to the light reception from the light projection unit 302, a dynamic range in which the ratio J / F of the received light intensity falls between the saturation level and the noise limit level at the projected portion 114 of the input surface 6 is assumed. It is set to be equal to or more than a predetermined value to be satisfied. That is, the light receiving unit 40 is closer to the input surface 6 than the light projecting unit 302. Accordingly, an optical path in which the reflected light reflected by the retroreflecting unit 4 attached to the sensor bar 1 corresponding to the light projected from the light projecting unit 302 is received by the light receiving unit 40 is set as follows.

  That is, the light path is not blocked by the convex portion 114 of the input surface 6, and the light receiving section 40 and the light receiving section 40 and the light receiving intensity ratio J / F are equal to or larger than a predetermined value satisfying a dynamic range that falls between the saturation level and the noise limit level. A mounting position of the retroreflecting unit 4 from the input surface 6 is set in advance. Accordingly, in the case of light projection from the light projecting unit 302, a light receiving / emitting path as shown in FIG. 14C is obtained, and the received light intensity distribution at that time is as shown in FIG. 15C. In this case, the ratio J / F of the received light intensity is not less than a predetermined value that satisfies the dynamic range that falls between the saturation level and the noise limit level. Steps S110 and S111 after step S1112 are the same as those in the first embodiment, and again in step S1111a, when the light reception determination unit 61a determines that J / F ≧ predetermined value (YES in step S1111a), the process proceeds to step S112. . The subsequent steps are the same as in the first embodiment.

  On the other hand, when the input surface 6 is concave, a light projecting / receiving optical path as shown in FIG. In this case, since the light projecting path is projected so as to be reflected on the input surface 6, it is reflected on the surface of the input surface 6, reaches the retroreflective portion 4, is further retroreflected, and is reflected again on the surface of the input surface 6. Thus, the light path is received. In this case, contrary to the case where the input surface 6 is convex, the concave portion at the center of the input surface 6 has the largest degree of recession. Therefore, compared with the light receiving path in the direction j in FIG. 3, the height of the input surface 6 that is relatively blocked by the light receiving path in the direction f is reduced, and the reflected light from the input surface 6 that receives light increases. . Accordingly, in the distribution of received light intensity, as shown in FIG. 15D, the ratio J / F of received light intensity is not less than a predetermined value. Therefore, if the input surface is concave, in step S1111a, the light reception determination unit 61a determines that J / F ≧ predetermined value (YES in step S1111a), and proceeds to step S112. The subsequent steps are the same as in the first embodiment. As described above, in FIG. 14, the process in the sensor bar 1 </ b> L has been described, but the same applies to the process in the sensor bar 1 </ b> R.

  As described above, according to the second embodiment, in addition to the effects described in the first embodiment, the dynamic range that falls between the saturation level and the noise limit level is determined by determining the change in the received light intensity depending on the state of the input surface. The light projection form of the light projecting unit is controlled so as to obtain the received light intensity satisfying the above. As a result, a coordinate detection environment with a more ideal received light intensity is realized, and highly accurate coordinate detection is possible.

<Embodiment 3>
In the first and second embodiments, the sensor unit 2 has a configuration in which the light projecting units 301 and 302 are arranged at two positions, a position close to the input surface 6 and a position far from the input surface 6 with the light receiving unit 40 interposed therebetween. And the change of the light reception intensity | strength by the curved convex state of the input surface 6 is responded by changing the light projection form of the light projection parts 301 and 302 of the two places. However, as shown in FIG. 17, as a configuration of the sensor unit 2, one light projecting unit 301 (reference light projecting unit) is disposed in the vicinity of the light receiving unit 40, and the mounting surface of the sensor bar 1 on the input surface 6 is provided. It may be configured to be turned upside down. That is, the mounting surface includes a front surface (first mounting surface) and a back surface (second mounting surface) opposite to the front surface.

  FIG. 17 is a cross-sectional view of a state in which the sensor bar 1 is mounted on the input surface 6 in the configuration of the third embodiment. FIG. 17A shows a case where the input surface 6 is flat, and FIG. 17B shows a case where the input surface 6 is convex and curved. The configuration of the sensor unit 2 is a configuration in which one light projecting unit 301 is disposed in the vicinity of the light receiving unit 40 as in the conventional case. Further, a contact button 801 is attached to the sensor bar 1L.

  When the input surface 6 is flat, in the sensor unit 2, the surface (first mounting surface) is mounted on the input surface 6 so that the light projecting unit 301 is positioned closer to the input surface 6 than the light receiving unit 40. To do. At this time, the contact button 801 is disposed on the back surface (second mounting surface) opposite to the input surface 6 and is not in a load state. That is, the light projecting unit 301 is disposed on the first mounting surface side, while the contact button is disposed on the second mounting surface side. Then, according to the pressed state of the contact button 801, it can be determined whether the light projecting unit is at a position close to or far from the input surface 6. In other words, it can be determined whether the mounting surface is the front surface or the back surface.

  Here, when the input surface 6 is flat, there is no influence by the input surface 6 as described in the first embodiment. Therefore, a light projecting / receiving path is secured, and a sufficient light quantity or an appropriate distribution of received light intensity is obtained. Is obtained.

  On the other hand, as shown in FIG. 17B, when the sensor bar 1 is attached to the input surface 6 that is curved and convex, and the light projecting unit 301 is disposed closer to the input surface 6 than the light receiving unit 40, the embodiment As described in 1, the light projecting / receiving path is blocked by the convex portion of the input surface 6, and a sufficient light receiving intensity cannot be obtained. This is detected by the light reception determination unit 61a of the arithmetic control circuit 3, and the display lamp 900 mounted on the side surface of the sensor bar 1L is turned on to notify the user.

  Regarding this detection, not only the sensor bar 1L but also the sensor bar 1R is notified of the determination result of the light reception determination by the display lamp 900. The user turns the sensor bar 1L and the sensor bar 1R upside down and attaches them to the input surface 6 by the notification on the display lamp 900 (notification for prompting the change of the mounting surface to the coordinate input effective area). FIG. 17B shows such a case. In this state, the arrangement of the sensor unit with respect to the input surface is reversed, the light projecting unit 301 is disposed farther from the light receiving unit 40 with respect to the input surface 6, and the light projecting form changes. In this case, the optical arrangement is the same as that in FIG. 12B of the first embodiment, and sufficient light receiving intensity can be obtained without blocking the light projecting / receiving path by the convex portion 114 of the input surface 6. In this case, since the opposite surface to FIG. 17A is installed on the input surface, the contact button 801 is pressed.

  FIG. 18 is a plan configuration diagram of the third embodiment. FIG. 18A shows a case where the input surface is flat, and FIG. 18B shows a case where the input surface is convex and curved. 18A and 18B, the positional relationship of the sensor unit 2 with respect to the input surface 6 is the same on the left and right, but upside down. Therefore, in calculating the coordinates, it is necessary to reverse the sign in the Y-axis direction. Accordingly, when the input surface is convex and curved, the pressing of the contact button 801 is detected in FIG. 18B, and the process of reversing the sign in the Y-axis direction is performed in the coordinate calculation.

  18A and 18B, contact buttons 801 and 802 are arranged on the left and right sensor bars 1L and 1R, respectively, and it is confirmed that the left and right sensor bars 1L and 1R are mounted on the back and front. You can also Therefore, if it is detected that they are not aligned, the notification unit (not shown) may leave the state and prompt the operator to correct it.

  As described above, according to the third embodiment, the physical position of the built-in light projecting unit can be changed depending on the mounting state of the front and back of the sensor bar by adopting a configuration that can be mounted on both the front and back of the sensor bar. It becomes possible. Accordingly, it is possible to substantially realize a configuration in which the light projecting modes of the two light projecting units are switched as in the first and second embodiments. The same effect as 2 can be obtained.

<Embodiment 4>
In the first to third embodiments, the retroreflecting unit 4 is configured to be fixedly attached to a plurality of parts or one part of the side surface of the sensor bar 1. As described above, the mounting position is assumed to be an optical path until the light receiving unit 40 receives the reflected light reflected by the retroreflecting unit 4 mounted on the sensor bar 1 to which the light projection from the light projecting unit 302 corresponds. The light path is also set in advance so that the light path is not blocked even at the convex portion of the input surface.

  Specifically, when the input surface 6 is flat and there is nothing to block the light projecting / receiving path, when light is projected by the light projecting unit 301 close to the input surface 6, the distance from the input surface 6 is short. The retroreflective part 4 is mounted at the position. On the other hand, when the light is projected by the light projecting unit 302 that is far from the input surface 6 in order to secure the light projecting / receiving path, the retroreflecting unit 4 is also a distance from the input surface 6 in order to secure the light projecting / receiving path. Install at a distant position. Further, as described above, when the input surface 6 has a curved shape that is convex upward, the mounting surface of the sensor bar 1 is inclined upward from the direction parallel to the input surface 6, and the sensor unit 2 that is mounted thereon The light emitting / receiving path is also directed upward with respect to the input surface.

  Therefore, the retroreflecting part 4 to be mounted on the corresponding opposing sensor bar 1 must also be mounted on the input surface. In the above embodiment, since the position of the retroreflective portion 4 is fixed, in order to cover any of the above cases, the retroreflection is performed in a wide range of a position far from a position where the distance from the input surface 6 is short. It is necessary to attach the part 4.

  However, in the case of this fixed mounting form, even when the input surface 6 is flat, the reflected light from the wide retroreflecting portion 4 is received. In this case, the light projecting / receiving path from the input surface 6 is received. The width becomes deeper. In this case, the light shielding by the instruction starts from a place where the distance from the input surface 6 is large, and the input feeling is hindered.

  In order to cope with this, in the fourth embodiment, the configuration in which the mounting position of the retroreflecting unit 4 from the input surface 6 is changed depending on whether the input surface 6 is flat or curved and convex (position changing mechanism). And Specifically, as shown in FIG. 19, the retroreflective portion 4 of the fourth embodiment is indicated as a retroreflective member 400. The retroreflective member 400 includes a holding member 402, a retroreflective sheet 401, and a hinge 403 that forms a rotation axis. A retroreflective sheet 401 is mounted on both sides of the holding member 402, and the holding member 402 is fixed at a substantially intermediate position on the side surface of the sensor bar 1.

  When the input surface 6 is flat, the retroreflective member 400 is disposed at a position close to the input surface 6 by being rotated downward from the holding member 402 on the input surface side. When the input surface 6 is flat, there is nothing to block the light projecting / receiving path, so that a sufficient light receiving intensity can be ensured at the position of the retroreflective member 400, and the input feeling is not impaired.

  On the other hand, when the input surface 6 is convex upward and curved, the light reception determination unit 61a determines that the light reception intensity is insufficient. In this case, in the drawing, the display lamp 900 is turned on, and the operator is warned (notification for prompting the arrangement change) to move the retroreflective member 400 by lifting it from the input surface. By the operation of the operator, the retroreflective member 400 is rotated about 180 ° about the hinge 403, and the retroreflective sheet 401 on the opposite side to the case where the input surface 6 is flat is located above the input surface 6 on the side surface of the sensor bar 1. And fixed by a fixing member (not shown). The configuration related to the light projection mode change of the fourth embodiment accompanying the determination of the light reception determination unit 61a is the same as that of the first or second embodiment.

  That is, when the input surface 6 is convex upward and curved according to the determination of the received light intensity, the light projecting form control unit 61b projects the light projecting unit 302 away from the light projecting unit 301 with respect to the input surface 6. Control to do. Therefore, according to the fourth embodiment, a light projecting / receiving path can be ensured regardless of the state of the input surface 6, and at the same time, a configuration that does not affect the input feeling when the input surface is flat can be realized.

  In the fourth embodiment, the display lamp 900 is turned on based on the determination that the received light intensity is insufficient, and the operator is urged to move the retroreflective member 400. However, a power mechanism is added to the hinge 403, and according to the received light intensity, It is good also as a structure which changes the position of the retroreflection member 400 automatically. Further, the configuration for changing the position of the retroreflective member 400 is not limited to the rotation mechanism including the hinge 403, and a mechanism that moves in the direction perpendicular to the input surface 6 may be provided. Further, a retroreflective member 400 having a different height may be prepared separately and attached to the sensor bar according to the received light intensity, that is, according to the notification.

  As described above, according to the fourth embodiment, by making the arrangement position of the retroreflective part variable, the optimal position for the light projection form of the light projecting part without arranging the retroreflective parts at a plurality of locations. By arranging the retroreflective portion, the same effect as in the first and second embodiments can be obtained.

<Embodiment 5>
In the first and second embodiments, the light projecting units 301 and 302 are arranged at two positions, a position near and far from the input surface 6 with the light receiving unit 40 interposed therebetween. However, the light projecting units 301 and 302 are not necessarily arranged with the light receiving unit 40 interposed therebetween, and may be arranged in other ways as long as the distances from the input surface 6 of the light projecting units 301 and 302 are different. Further, the number of light projecting units is not limited to two, and may be configured to be arranged at three or more locations if the distance from the input surface 6 is different.

<< Characteristic configuration and effect of the present invention >>
As described above, the present invention is a coordinate input device that calculates the coordinates of a designated position with respect to a substantially rectangular coordinate input effective area, and includes a first casing and a second casing (including at least two sensor units). Sensor bar). Each casing is provided with a retroreflecting portion for returning incident light to the original direction, and the first casing and the second casing are respectively provided on two opposite sides of the substantially rectangular coordinate input effective region. Provided.

  The sensor unit provided in each housing includes a light projecting portion that projects infrared rays toward a retroreflecting portion of the housing provided on the opposite side, and a light receiving unit that receives light retroreflected by the retroreflecting portion. It consists of parts. The optical path is blocked by touching the coordinate input effective area, and at least two sensor units can detect the direction in which the light according to the touch position is blocked. Based on the angle information detected by at least two sensor units and the distance information between the two sensor units, the touch position can be calculated by geometric calculation.

  The first housing and the second housing are provided with an attaching / detaching portion for enabling attachment and detachment to the screen surface which is a coordinate input surface, so that the first housing and the second housing can be carried. Composed.

  In consideration of carrying, it is desirable that the first casing and the second casing are configured to be smaller and smaller and lighter. Although the light receiving optical system of the sensor unit of the present invention has a field of view designated in advance (about 50 °), the optical axis of the light receiving optical system is set in the normal direction of the pixel of the photoelectric conversion element, The visual field range is not set to be symmetric with respect to the optical axis, and has an optical system that is optically asymmetric. The optical axis (or the normal direction of the pixel of the photoelectric conversion element) is set to be perpendicular to a straight line connecting at least two sensor units (optical axis centers of the light receiving optical system) housed in the housing. ing. By comprising in this way, the housing which stores a sensor unit can be comprised more compactly.

  Various sizes or aspect ratios are assumed for the size of the screen surface, and the coordinate input effective area is preferably set in accordance with the size and shape of the screen surface. Accordingly, the first casing and the second casing are provided with expansion / contraction portions, and by adjusting the amount of expansion / contraction, the distance of the sensor unit provided in the casing can be varied, and the sensor unit can be adjusted according to the size of the screen surface. It is comprised so that it can arrange | position suitably.

  Furthermore, when the first housing and the second housing having the sensor unit are mounted, it is preferable that the touch position can be detected with high accuracy even if the relative positional relationship between the two is not precisely positioned. . Therefore, when the chassis is mounted, a detection unit that detects relative positional information between the sensor units stored in each chassis is provided, and the chassis can be easily mounted without being conscious of the user.

  Further, if it is not necessary to install dedicated driver software in a personal computer or the like that receives information output from the coordinate input device, for example, it can be used immediately regardless of which personal computer or the like is connected. Therefore, the coordinate system (digitizer coordinate system) of the coordinate input device and the coordinate system (screen coordinate system) of the display device can be matched (calibrated) without using a personal computer.

  The main part of the present invention in the above coordinate input device is as follows.

A coordinate input device that detects an indicated position with respect to a coordinate input effective area for inputting coordinates by indicating an input surface,
A first housing and a second housing, each housing being
As a light projecting unit that projects light parallel to the coordinate input effective area, at least two light projecting units of a first light projecting unit and a second light projecting unit having different distances from the input surface, Including at least two sensor units each including a light receiving unit that receives light;
A retroreflecting portion that recursively reflects incident light is mounted on a side surface in a longitudinal direction different from the mounting surface of the coordinate input effective region on which the housing is mounted.
A first housing and a second housing;
The amount of light obtained from the light receiving portions of the first and second casings in a state where the first casing and the second casing are mounted in the vicinity of two opposing sides of the coordinate input effective area. Calculation means for calculating the indicated position of the coordinate input effective area based on a variation in distribution;
Determining means for determining a light receiving state of the light receiving unit for each of the first housing and the second housing;
Based on the determination result of the determination means, light is emitted using at least one of the first light projecting unit and the second light projecting unit for each of the first housing and the second housing. Thus, it has a control means which controls the light projection form by the 1st light projection part and the 2nd light projection part.

  As described above, according to the present invention, the components necessary for detecting the touch position are all housed in the two housings, and the housings are mounted on, for example, a flat white board or a wall surface. The touch position can be detected. That is, the coordinate input device of the present invention does not have a touch input surface that is a coordinate input effective area as an essential component. Therefore, even if the coordinate input effective area becomes large (for example, 90 inch class), the operating environment can be realized anywhere by carrying only the two casings. Furthermore, since the touch input surface is not provided as a component, the product cost can be significantly reduced as a matter of course. In other words, by using an existing whiteboard or the like owned by the user, a great effect of reducing the introduction cost can be obtained.

  Furthermore, since all the structural elements are provided in the two casings, an effect that the user can easily attach the whiteboard, perform wiring, and the like can be obtained. Of course, if it is assumed to be carried, it is preferable to have a lighter / smaller housing. By making the light receiving optical system of the sensor unit asymmetrical to the optical axis, the housing can be made lighter / smaller and more portable. Can be improved.

  Furthermore, for example, when considering mounting on an existing whiteboard, there are various sizes depending on the manufacturer, the product model number, and the like. Therefore, the fact that the user can utilize the whiteboard that has already been purchased and used has an excellent effect in terms of reduction in introduction cost or effective use of resources.

  Furthermore, in the coordinate input device that enables highly accurate position detection, it is possible to obtain the effect of greatly reducing the troublesome installation and the installation time by making it possible to mount the housing to be mounted with reasonable accuracy. .

  For example, it is assumed that the coordinate input device composed of two housings is brought into a conference room in which a whiteboard, a personal computer, and a front projector have already been introduced, and an environment in which the screen is directly touched and operated is constructed. .

  At this time, it is preferable that the personal computer already installed in the conference room can be used immediately. Installation of a driver or the like is not required to operate the coordinate input device, thereby improving installation ease and portability. That is, it is not necessary to carry a dedicated personal computer in which a driver or the like is already installed together with the coordinate input device. Or since the installation work to the personal computer in the conference room is not required, it is possible to obtain an excellent advantage that the conference can be started immediately without extra setup time.

  In addition, even when the coordinate input device is mounted on an input surface such as a convex / concave curved whiteboard or wall, high-precision coordinate detection is possible without adding a special member.

  The process (flow chart) in the coordinate input device of the present invention can also be realized by executing the following process. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, or the like) of the system or apparatus reads the program. It is a process to be executed.

Claims (9)

A coordinate input device that detects an indicated position with respect to a coordinate input effective area for inputting coordinates by indicating an input surface,
A first housing and a second housing, each housing being
As a light projecting unit that projects light parallel to the coordinate input effective area, at least two light projecting units of a first light projecting unit and a second light projecting unit having different distances from the input surface, Including at least two sensor units each including a light receiving unit that receives light;
A retroreflecting portion that recursively reflects incident light is mounted on a side surface in a longitudinal direction different from the mounting surface of the coordinate input effective region on which the housing is mounted.
A first housing and a second housing;
The amount of light obtained from the light receiving portions of the first and second casings in a state where the first casing and the second casing are mounted in the vicinity of two opposing sides of the coordinate input effective area. Calculation means for calculating the indicated position of the coordinate input effective area based on a variation in distribution;
Determining means for determining a light receiving state of the light receiving unit for each of the first housing and the second housing;
Based on the determination result of the determination means, light is emitted using at least one of the first light projecting unit and the second light projecting unit for each of the first housing and the second housing. As described above, a coordinate input device comprising: a control unit that controls a light projection mode by the first light projecting unit and the second light projecting unit. The determination means determines whether the amount of light received by the light receiving unit is equal to or greater than a threshold as the light receiving state of the light receiving unit,
As a result of the determination by the determination unit, when the amount of light received by the light receiving unit is greater than or equal to a threshold, the control unit performs light projection by the first light projecting unit,
2. The control unit according to claim 1, wherein if the amount of light received by the light receiving unit is less than a threshold as a result of the determination by the determination unit, the control unit performs light projection by at least the second light projecting unit. Coordinate input device. As a result of the determination by the determination means, it is determined whether the ratio of the received light intensity from two different light receiving directions is equal to or greater than a threshold as the light receiving state of the light receiving unit,
As a result of the determination by the determination unit, when the ratio of the received light intensity of the light receiving unit is a threshold value or more, the control unit performs light projection by the first light projecting unit,
2. The control unit according to claim 1, wherein, as a result of the determination by the determination unit, when the ratio of the received light intensity of the light receiving unit is less than a threshold value, the control unit performs at least light projection by the second light projecting unit. The coordinate input device described. The first housing and the second housing are respectively
Including one reference light projecting unit of the first light projecting unit and the second light projecting unit,
As a mounting surface to the coordinate input effective area, it has a first mounting surface that is the surface of the housing, and a second mounting surface that is the back surface of the housing and faces the first mounting surface,
The reference light projecting unit is disposed on the first mounting surface side,
A contact button for detecting whether the mounting surface to the coordinate input effective area is the first mounting surface or the second mounting surface is disposed on the second mounting surface side,
The coordinate input device according to claim 1, further comprising notification means for notifying a change of a mounting surface to the coordinate input effective area based on a determination result of the determination means. The coordinate input device according to claim 1, further comprising position changing means for changing the arrangement of the retroreflecting unit at a position where the distance from the input surface is different. The coordinate input device according to claim 5, further comprising a notification unit that performs notification that prompts the user to change the arrangement of the retroreflecting unit based on a determination result of the determination unit. The coordinate input device according to claim 5, wherein the position changing unit changes the arrangement of the retroreflecting unit based on a determination result of the determining unit. As a coordinate input device that detects a designated position with respect to a coordinate input effective area for inputting coordinates by designating an input surface,
A first housing and a second housing, each housing being
As a light projecting unit that projects light parallel to the coordinate input effective area, at least two light projecting units of a first light projecting unit and a second light projecting unit having different distances from the input surface, Including at least two sensor units each including a light receiving unit that receives light;
A retroreflecting portion that recursively reflects incident light is mounted on a side surface in a longitudinal direction different from the mounting surface of the coordinate input effective region on which the housing is mounted.
A control method of a coordinate input device comprising a first housing and a second housing,
The amount of light obtained from the light receiving portions of the first and second casings in a state where the first casing and the second casing are mounted in the vicinity of two opposing sides of the coordinate input effective area. A calculation step of calculating the indicated position of the coordinate input effective area based on a distribution variation;
A determination step of determining a light receiving state of the light receiving unit for each of the first housing and the second housing;
Based on the determination result of the determination step, light is projected using at least one of the first light projecting unit and the second light projecting unit for each of the first housing and the second housing. Thus, the control method of controlling the light projection form by the said 1st light projection part and the said 2nd light projection part, The control method of the coordinate input device characterized by the above-mentioned. As a coordinate input device that detects a designated position with respect to a coordinate input effective area for inputting coordinates by designating an input surface,
A first housing and a second housing, each housing being
As a light projecting unit that projects light parallel to the coordinate input effective area, at least two light projecting units of a first light projecting unit and a second light projecting unit having different distances from the input surface, Including at least two sensor units each including a light receiving unit that receives light;
A retroreflecting portion that recursively reflects incident light is mounted on a side surface in a longitudinal direction different from the mounting surface of the coordinate input effective region on which the housing is mounted.
A program for causing a computer to control a coordinate input device comprising a first housing and a second housing,
The computer,
The amount of light obtained from the light receiving portions of the first and second casings in a state where the first casing and the second casing are mounted in the vicinity of two opposing sides of the coordinate input effective area. Calculation means for calculating the indicated position of the coordinate input effective area based on a variation in distribution;
Determining means for determining a light receiving state of the light receiving unit for each of the first housing and the second housing;
Based on the determination result of the determination means, light is emitted using at least one of the first light projecting unit and the second light projecting unit for each of the first housing and the second housing. As described above, the program is made to function as a control unit that controls a light projection mode by the first light projecting unit and the second light projecting unit.

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