JP2016018455A - Coordinate input device and control method of the same, computer program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coordinate input technology that is excellent in responsiveness and curbs power consumption in a configuration of a light shield system enabling detection of an instruction input by a plurality of instruction tools.SOLUTION: A coordinate input device comprises: a plurality of detection means that detects light projected from projection means projecting the light toward a coordinate input area; determination means that determines a direction of an instruction tool input into the coordinate input area when viewing from the plurality of detection means on the basis of the detection result of the light; calculation means that calculates a coordinate corresponding to an input position of the instruction tool on the basis of the determined direction of the instruction tool when viewing from the plurality of determination means; and instruction means that instructs the instruction tool to emit light when the plurality of instruction tools is used and the coordinate of each instruction tool cannot be uniquely determined on the basis of the direction of the instruction tool when viewing from the plurality of detection means. The calculation means is configured to, when the instruction tool is instructed to emit the light by the instruction means, calculate a coordinate on the basis of a direction of the light emission from the instruction tool detected by the detection means.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a coordinate input device that detects a designated position on a coordinate input area, a control method therefor, and a computer program.

  A coordinate input device used to control a connected computer or to write characters, figures, etc. by inputting coordinates on a coordinate input surface by pointing with a pointing tool (for example, a dedicated input pen, finger, etc.) Exists.

  As this type of coordinate input device, various types of touch panels have been proposed or commercialized as touch panels. A touch panel is widely used because it can easily operate a terminal such as a personal computer or a tablet terminal on a screen without using a special instrument.

  As a coordinate input method, there are known methods using light in addition to a method using a resistive film and a method using ultrasonic waves (Patent Document 1). The configuration of Patent Literature 1 includes a retroreflective sheet outside the coordinate input region, and includes an illumination unit that illuminates light and a light receiving unit that receives light, which are arranged at the corner ends of the coordinate input region. . In such a configuration, an angle between a light shielding unit and a light shielding unit that shields light such as a finger in the coordinate input area is detected, and an indication position of the light shielding unit is determined based on the detection result. The method for detecting the light shielding position and calculating the coordinates in this way is hereinafter referred to as a light shielding method.

  In light-shielding coordinate input devices, particularly when the size of the coordinate input area is large, there is a demand to improve the convenience by allowing multiple operators to input at the same time and to utilize it for applications such as conferences. is there. Therefore, a coordinate input device corresponding to a plurality of simultaneous inputs has been devised. As a configuration that can detect a plurality of instruction inputs at the same time, a plurality of indicators emit light at different wavelengths, and a pair of sensors is installed at the top and bottom of the input area for each wavelength to detect a plurality of coordinates simultaneously. Is known (Patent Document 2).

  It is also known to detect the position of the electronic pen by photographing an electronic pen including a light emitting element and tracking the position of light emission (Patent Document 3). In the configuration of Patent Document 3, a signal instructing light emission for a predetermined time is transmitted from a projector equipped with an image sensor to the electronic pen, and the difference between the image of the electronic pen that is emitting light and the image that is not emitting light Detection accuracy is enhanced by detecting the position using an image.

U.S. Pat. No. 4,507,557 Japanese Patent Laid-Open No. 2003-256123 JP 2005-165981 A

  However, when a plurality of instruction inputs are performed with an indicator such as a pen, coordinates may not be calculated for the following reasons, and output data may be lost.

  In this type of device, detection information of pen input to the input area, switch information assigned to various functions such as the right button function of the pointing device, attribute (ID) information, etc. are transmitted by optical communication such as modulated infrared rays. Some are sent to the main unit. In this case, the timing at which the pen emits light is determined when the operator gives an input instruction and the switch is pressed when the pen tip contacts the input area.

  Here, the light-shielding method requires an illumination unit and a light-receiving unit for generating a light-shielding signal when an input instruction is given. From the above configuration, the light from the illumination unit and the light from the pen are superimposed. May fit. Therefore, when the light emission of the pen is superimposed on the light shielding signal, there is a case where a correct light shielding signal cannot be detected in the light receiving unit and coordinates cannot be calculated correctly.

  Further, even when a plurality of pens emit light at the same time, optical signals indicating pen switch information and attribute (ID) information may overlap each other, and a correct bit string may not be restored. Therefore, the switch state or the like may not be detected, and the coordinate state (for example, whether or not the pen touches the input surface) may not be determined.

  On the other hand, in the configuration of Patent Document 2, the wavelength is different for each pen, and each pen has a sensor for detecting coordinates. However, in order to detect the wavelengths of a plurality of pens used for instruction input for each pen, a pair (two) of sensors is required for one pen, and the cost required for the sensors is nearly doubled. In addition, two or more sets of sensor mounting space according to the number of pens to be used are required, wavelength filters are required for each pen, and pens must be managed for each wavelength. is there.

  In the configuration of Patent Document 3, since the electronic pen needs to continuously emit light periodically, continuously, and intermittently while detecting the position of the electronic pen, power is always consumed during that time. . For this reason, when the electronic pen is operated by a battery or a battery, there is a problem that the battery or the like is consumed greatly and the life is short.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a coordinate input technique that is excellent in responsiveness and suppresses power consumption in a configuration of a light shielding method capable of detecting an instruction input by a plurality of indicators. And

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 input to a coordinate input area and calculates coordinates corresponding to an input position,
A plurality of detecting means for detecting the light projected from the light projecting means for projecting toward the coordinate input area;
Based on the detection result of the light, a determination unit that determines the direction of the pointing tool input to the coordinate input area as viewed from the plurality of detection units;
Calculating means for calculating coordinates corresponding to the input position of the pointing tool based on the determined direction of the pointing tool as viewed from the plurality of detecting means;
When a plurality of pointing tools are used and the coordinates of the pointing tools cannot be uniquely determined based on the directions of the pointing tools viewed from the plurality of detecting means, the pointing tool is instructed to emit light. An instruction means,
The calculation means calculates the coordinates based on the direction of light emission from the pointing tool detected by the detection means when light emission is instructed by the instruction means.

  ADVANTAGE OF THE INVENTION According to this invention, in the structure of the light-shielding system which can detect the instruction | indication input by a some indicator, the coordinate input technique which was excellent in responsiveness and suppressed power consumption can be provided.

The figure which shows schematic structure of the coordinate input device of a light-shielding system Diagram showing the detailed configuration of the sensor unit The figure which shows the detailed structure of a coordinate input device Control signal timing chart The figure for demonstrating the light quantity distribution which a sensor unit detects Timing chart of control signals detected by multiple sensor units It is a figure which shows schematic structure of an indicator. Flow chart for determining conditions for transmitting control signals The figure explaining the example of the coordinate calculation when a several indicator is used The figure for demonstrating communication with a coordinate input device and an indicator The figure which shows schematic structure of an indicator Timing chart of control signals detected by multiple sensor units Timing chart of control signals detected by multiple sensor units The figure explaining the state of drawing with a plurality of indicating tools Flowchart for explaining another embodiment

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[Embodiment 1]
<Overview of device configuration>
FIG. 1 is a diagram showing a schematic configuration of a light shielding type coordinate input device according to an embodiment (Embodiment 1) of the present invention. The coordinate input device detects an input to the coordinate input area, and calculates coordinates corresponding to the input position. In FIG. 1, 1L and 1R are sensor units each having a light projecting unit and a light receiving unit. In this embodiment, the sensor units 1L and 1R are parallel to the X axis of the coordinate input effective area 3 which is a coordinate input surface (coordinate input area) as shown in FIG. It is arranged at a certain distance. The sensor units 1L and 1R are connected to the control / arithmetic unit 2 and receive control signals from the control / arithmetic unit 2 and transmit detected signals to the control / arithmetic unit 2.

  Reference numeral 4 denotes a retroreflective portion having a retroreflective surface that reflects incident light in the direction of arrival. As shown in FIG. 1, the retroreflecting unit 4 is arranged on the outer three sides of the coordinate input effective region 3, and the light projected from the left and right sensor units 1 </ b> L and 1 </ b> R in a range of about 90 ° is used as the sensor unit 1 </ b> L. Retroreflects toward 1R. Retroreflection refers to reflection in which incident light returns to the incident direction again.

  The light retroreflected by the retroreflecting unit 4 is detected one-dimensionally by the sensor units 1L and 1R, and the light quantity distribution is transmitted to the control / arithmetic unit 2. As will be described later, each of the sensor units 1L and 1R is provided with a one-dimensional line CCD, and the direction of the pointing tool viewed from the sensor unit is determined by the distribution of the amount of light detected by each pixel constituting the line CCD. Determined. When the sensor units 1L and 1R detect incident light, the light intensity distribution detected by each pixel of the line CCD is transmitted to the control / arithmetic unit 2.

  The coordinate input effective area 3 is an area in which the operator can input coordinates using the pointing tool. By configuring the coordinate input effective area 3 with a display screen of a display device such as a PDP, a rear projector, an LCD panel, a screen for projecting a front projector, a whiteboard, a wall surface, etc., it can be used as an interactive input device. .

  Reference numerals 9A and 9B are pens which are indicating tools. The pens 9 </ b> A and 9 </ b> B have a configuration for detecting a pressing state on the input surface with a switch at the tip. The pens 9A and 9B have a communication function for transmitting the pen ID (identification information) and the state of the switch signal, and receive a control signal output from the pen signal communication unit 5 or control signals. Communicate with the pen signal communication unit 5 at a timing according to. In this embodiment, an example in which a pen (stylus pen, touch pen) having such a configuration is applied as the pointing tool will be described. However, if the pen signal communication unit 5 has a communication function or the like, It is not limited to the pen type. For example, a ring-type or glove-type device provided with a communication function or the like may be realized as the pointing tool, and such a device may be used by being attached to a hand or a finger. In the configuration of the present embodiment, it is also possible to perform coordinate input using a finger without using a pointing tool. In this case, communication between the coordinate input side (finger) and the sensor unit is not performed.

  In such a configuration, a case is considered in which an input instruction is given to the coordinate input effective area 3 by a pointing tool such as a pen. When the light projected from the light projecting portions of the sensor units 1L and 1R is blocked by the indicator (light shielding portion), the light receiving portions of the sensor units 1L and 1R detect the light from the light shielding portions (reflected light due to retroreflection). do not do. As a result, it is possible to determine from which direction the light could not be detected. The light shielding portion refers to a portion of the coordinate input effective area 3 where light propagation is blocked by the pointing tool.

  Therefore, the control / arithmetic unit 2 detects a plurality of light-shielding ranges of the portion instructed to be input by the pointing tool from the light amount change detected by the left and right sensor units 1L, 1R. The light shielding range refers to a range of pixels in which light reception is blocked by the pointing tool in the line CCD. It is detected that the pointing tool exists at an angle viewed from the sensor unit corresponding to the light shielding range. From the position of the end of the light shielding range, the direction (angle) of the end of the light shielding range with respect to each of the sensor units 1L and 1R is calculated. Based on the number of detected light-shielding ranges, data obtained from the light-shielding ranges used for coordinate calculation is determined, and coordinate input is valid from the calculated direction (angle), distance information between the sensor units 1L and 1R, and the like. The light shielding position of the pointing tool on the area 3 is calculated geometrically. Finally, the coordinate value is output to an external terminal such as a host computer connected to the display device via an interface (not shown) (for example, USB).

  In this way, the operation of the external terminal such as drawing a line on the screen or operating an icon displayed on the display device can be performed by the pointing tool. In this embodiment, the position of the pointing tool is normally tracked based on the light shielding range of the light emitted from the sensor units 1L and 1R. However, a plurality of pointing tools are used, and the pointing tool cannot be distinguished only by the information on the light shielding range. Sometimes, it requires light emission to distinguish the pointing tool. In this way, the control / arithmetic unit 2 makes the indicators 9A and 9B emit light for distinguishing the indicator only when necessary, so that the responsiveness is excellent and the power consumption of the indicator can be suppressed. It becomes possible.

<Detailed explanation of sensor unit>
Configurations in the sensor units 1L and 1R will be described with reference to FIGS. FIG. 2 is a diagram showing a detailed configuration of the sensor unit according to the present embodiment. The sensor units 1L and 1R are roughly composed of a light projecting unit and a light receiving unit.

  In FIG. 2, 101A and 101B are infrared LEDs that emit infrared light, and are approximately 90 toward the retroreflective portion 4 provided in the peripheral portion of the coordinate input effective region 3 by the light projecting lenses 102A and 102B, respectively. ° Project light in range. Here, the light projecting units in the sensor units 1L and 1R are realized by the infrared LEDs 101A and 101B and the light projecting lenses 102A and 102B. As a result, each of the sensor units 1L and 1R includes two light projecting units. The infrared light projected from the light projecting unit is retroreflected in the arrival direction by the retroreflecting unit 4, and the light is detected by the light receiving units in the sensor units 1L and 1R.

  The light receiving unit limits the field of view of the light beam and limits the incident direction of the incident light, the one-dimensional line CCD 104 provided with the shield member 105 that performs electrical shielding, the light receiving lenses 106A and 106B as the condensing optical system. Apertures 108A and 108B are provided. In addition, infrared filters 107 </ b> A and 107 </ b> B are provided to prevent the incidence of extraneous light (disturbance light) such as visible light.

  The light reflected by the retroreflecting unit 4 passes through the infrared filters 107A and 107B and the stops 108A and 108B, and is collected on the detection element 110 surface of the line CCD 104 by the light receiving lenses 106A and 106B. In this way, each of the sensor units 1L and 1R includes two light receiving units that detect light from the light projecting unit.

  The member 103 and the member 109 are arranged for arranging optical components constituting the light projecting unit and the light receiving unit, preventing light projected by the light projecting unit from directly entering the light receiving unit, and cutting extraneous light. It functions as an upper hood 103 and a lower hood 109.

<Description of control / arithmetic unit>
Between the control / arithmetic unit 2 and the sensor units 1L and 1R, mainly the CCD control signal for the line CCD 104 in the light receiving unit, the CCD clock signal and output signal, and the driving of the infrared LEDs 101A and 101B in the light projecting unit Signals are being exchanged. Here, a detailed configuration of the control / arithmetic unit 2 will be described with reference to FIG. FIG. 3 is a block diagram showing a detailed configuration of the control / arithmetic unit according to the present embodiment.

  The CCD control signal is output from an arithmetic control circuit (CPU) 21 constituted by a one-chip microcomputer or the like, and is used for shutter timing of the line CCD 104, data output control, and the like. The arithmetic control circuit 21 operates in accordance with a clock signal from a clock generation circuit (CLK) 22 based on a predetermined computer program. The clock signal for the CCD is transmitted from the clock generation circuit 22 to the sensor units 1L and 1R, and is sent to the arithmetic control circuit 21 in order to perform various controls in synchronization with the line CCD 104 in each sensor unit. Is also entered.

  The LED drive signal for driving the infrared LEDs 101A and 101B of the light projecting unit is sent from the arithmetic control circuit 21 via the LED drive circuit (not shown) to the infrared LED 101A in the light projecting unit of the corresponding sensor unit 1L or 1R. , 101B. Detection signals from the line CCDs 104 in the light receiving portions of the sensor units 1L and 1R are input to the A / D converter 23 and converted into digital values under the control of the arithmetic control circuit 21. The converted digital value is stored in the memory 132 and used for calculating the angle of the pointing tool. Then, a coordinate value is calculated from the calculated angle, and is output to the external terminal via the serial interface 7 (for example, USB).

  When the pens 9A and 9B are used as the pointing tools, signals from the pens 9A and 9B are received by the pen signal communication unit 5, demodulated, and then output to the arithmetic control circuit 21. On the other hand, when a control signal for instructing the transmission timing of the pen signal or other control is output from the arithmetic control circuit 21, it is transmitted to the pens 9A and 9B via the pen signal communication unit 5. Details of the pen signal communication unit 5 will be described later.

<Explanation of light intensity distribution detection>
FIG. 4 is a timing chart of control signals in the present embodiment. In particular, FIG. 4 shows a timing chart of control signals to one light-receiving unit in the sensor unit 1L (1R) and the infrared LEDs 101A and 101B as illumination corresponding thereto.

  31 and 32 are control signals for CCD control. The interval of the SH signal 31 determines the shutter opening time of the line CCD 104. The ICG signal 32 is a gate signal to the sensor unit 1L (1R) and is a signal for transferring the charge of the photoelectric conversion unit of the internal line CCD 104 to the reading unit. Reference numeral 33 denotes a drive signal (LED signal) for the infrared LEDs 101A and 101B. The LED signal 33 is supplied to turn on the infrared LED in the cycle of the SH signal 31.

  After driving of the light projecting units of both sensor units 1L and 1R is completed, detection signals of both light receiving units (line CCD 104) of sensor units 1L and 1R are read. The detection signals read from both of the sensor units 1L and 1R are output from the respective sensor units when there is no input to the coordinate input effective area 3 by the pointing tool, as shown in FIG. 5A. give. FIG. 5 is a diagram showing an example of a light reception distribution detected in the line CCD constituting the sensor unit. 5A and 5B, the horizontal axis represents the CCD pixel number and corresponds to the angle in the detection direction as viewed from the sensor unit. The vertical axis represents the detected light amount, and in this drawing, the lower side of the drawing corresponds to the direction in which the received light intensity is large. Of course, such a light quantity distribution is not necessarily obtained in any system, and the light quantity distribution depends on the retroreflective characteristics of the retroreflective part 4, the characteristics of the light projecting part, and changes with time (such as dirt on the reflective surface). Will change.

  In FIG. 5A, level A is the maximum light amount and level B is the minimum light amount. That is, in a state where there is no reflected light from the retroreflecting unit 4, the light amount level obtained by the sensor units 1L and 1R is near level B, and the light amount level transitions to level A as the reflected light amount increases. In this way, the detection signals output from the sensor units 1L and 1R are sequentially A / D converted by the corresponding A / D converter 23 and taken into the arithmetic control circuit 21 as digital data.

  On the other hand, when there is an input to the coordinate input effective area 3 by the pointing tool, a light quantity distribution as shown in FIG. 5B is obtained as an output from the sensor units 1L and 1R. In the C1 and C2 portions of the light amount distribution, the reflected light from the retroreflecting unit 4 is blocked by the pointing tool, so that it can be seen that the reflected light amount is reduced only in that portion (light shielding range). In particular, in FIG. 5B, since the reflected light from the retroreflecting unit 4 is blocked by a plurality of pointing tools, a plurality of light shielding ranges are detected.

  In the present embodiment, the sensor units 1L and 1R are based on the light amount distribution of FIG. 5A when there is no input by the pointing tool and the change of the light amount distribution of FIG. 5B when there is an input by the pointing tool. The angle information of the pointing tool with respect to is calculated. That is, the direction of the pointing tool viewed from the light receiving unit is determined based on the range where the light is blocked by the input using the pointing tool for the coordinate input effective area 3 and the light receiving unit does not detect the light. Specifically, as the light quantity distribution of FIG. 5A, there is no light quantity distribution 41 in the state where there is no light projection (illumination) by the light projecting unit, and there is no input by the pointing tool in the light projection (illumination) (the shielding object is The light quantity distribution 42 in the state of (not present) is stored in advance in the memory 132 as an initial state. Then, whether or not there is a change in the light amount distribution as shown in FIG. 5B in the sample period of the detection signal of each of the sensor units 1L and 1R is stored in the memory 132 and the light amount distribution during the sample period. It is detected by the difference from the light quantity distribution in the initial state. When there is a change in the light amount distribution, the changed portion is set as an input point of the pointing tool, and an angle corresponding to the input point is determined as the input angle. In this way, the direction of the pointing tool input to the coordinate input effective area 3 as viewed from the light receiving unit is determined for each of the plurality of light receiving units based on the light detection result.

  FIG. 6 is a timing chart example of the control signal and the detection signal. First, detection is performed by one light receiving unit in the sensor unit 1L on the reading head side of the line CCD in the sensor unit 1L. In response to the SH signal 51, the infrared LED in the sensor unit 1L is driven at a timing like the LED signal 53. The line CCD signal is read by the ICG signal 52. At this time, the pixel data of the light receiving range on the head side of the line CCD is read (A portion in the signal 55).

  Next, the SH signal 51 is given to the same line CCD, and the drive signal 54 is supplied to the infrared LED for detection by the other light receiving unit in the sensor unit 1L. As for this output, the received signal is output to a region that does not overlap with the signal (broken line portion) of the head portion detected earlier, such as the B portion of the detection signal 55.

<Description of pen configuration>
For example, when a dedicated pen provided with a switch unit or a signal generation unit at the tip is used as the pointing tool, it is possible to realize smooth and sharp drawing without causing a “tailing” problem in character input or the like. . Here, “tailing” is different from the trajectory intended by the operator when touch is detected immediately before / after touching the coordinate input surface and an extra trajectory is displayed when drawing with the pointing tool. This is a phenomenon in which the display is output. When the dedicated pen is used, the touch intended by the operator is appropriately detected in the switch unit and transmitted to the pen signal communication unit 5, so that the display of the trajectory not intended by the operator can be prevented.

  Further, when the dedicated pen is used as the pointing tool, the information output from the coordinate input device to the external terminal such as the host computer is not only the coordinate value. Switch information (for example, pen up / down information corresponding to the left button information of the pointing device, side switch information corresponding to the right button of the pointing device) obtained from the dedicated pen, and pen ID information unique to the pointing device Etc. In addition, an identifier or the like indicating the continuity of coordinates is output to the external terminal. Hereinafter, switch information acquired from these pens, pen ID information unique to the pointing tool, and the like are collectively referred to as supplementary information. The pen signal communication unit 5 in FIG. 3 receives incidental information from the pointing tool, determines which coordinate value the signal is, and a pen up / down signal or pointing device when transmitting the coordinate value. The button signal is output to the arithmetic control circuit 21.

  FIG. 7 is a diagram showing the configuration of the pointing tool (pen 9A) in the coordinate input device according to the present embodiment. The pen includes a pen tip switch 61 that operates by pressing the tip of the pen, and a side switch 62 provided on the pen housing. The state in which any one of these switches is operating is transmitted from the pen as incidental information. Transmission of this signal and reception of a signal from the pen signal communication unit 5 of the main body are performed through the pen communication circuit 63. The pen communication circuit 63 includes an infrared light transmission / reception circuit, and further includes an infrared LED 66. Generation of data transmitted from the pen communication circuit 63 and processing of received data are performed by the pen control circuit 64. The pen control circuit 64 includes a circuit such as a CPU. The power for the pointing tool is supplied from a power supply unit 65 formed of a battery. Note that the output method of the incidental information transmitted from the pen communication circuit 63 is not limited to the method using the infrared LED 66, and sound waves, radio waves, or the like may be used. Note that the pointing tool of the present embodiment emits light for transmitting supplementary information, and emits light for distinguishing the pointing tool when a plurality of pointing tools are used. In the present embodiment, an example is described in which light emission for transmitting supplementary information and light emission for distinguishing an indicator are different from each other, but both may be configured to be the same.

<Explanation regarding input coordinate calculation with multiple pointing tools>
For example, a case where input coordinate values are calculated when a plurality of inputs are made by a plurality of pointing tools and output through the interface 7 will be described with reference to FIGS. When a plurality of coordinate values calculated by the same number as the number of pointing tools are output to the external terminal, it is necessary to output after adding the accompanying information of the pointing tool to each coordinate value. That is, in order to display each input coordinate value input with each pointing tool as an input locus that is continuous for each pointing tool, it is necessary for the computer to recognize which pointing tool is the coordinate value input. There is. Therefore, in the present embodiment, not only the pen signal communication unit 5 detects the light signal emitted from the pointing tool but also the coordinates (angles) of each sensor unit. Hereinafter, as an example, a case where there are two pointing tools that can be used simultaneously will be described.

  FIG. 8 is a flowchart showing a process of associating shading, pen light emission, and incidental information including pen ID in consideration of use of a plurality of pointing tools. Each step of FIG. 8 is executed based on the control of the CPU 21 of the control / arithmetic unit 2. First, coordinate detection is performed in S801, and it is determined whether or not there is a coordinate input in S802. Specifically, it is determined whether or not there is a light shielding range in any of the line CCDs of the sensor units 1L and 1R. When there is a light shielding range, it is determined that there is a coordinate input.

  If no coordinate is detected (NO in S802), the process returns to S801, and coordinate detection is repeated at a predetermined timing. When coordinate input is detected in S802 (YES in S802), the number of light shielding is determined in S803. In the present embodiment, whether or not there are a plurality of inputs is determined based on whether or not two or more light shielding ranges are detected from at least one of the sensor units 1L and 1R.

  If it is determined that the input is a single input (NO in S803), an angle is calculated from the light shielding signal and a coordinate calculation process is performed in S804. For example, let us consider a case where the pointing tool is present at the position of point A in FIG. At this time, the sensor unit 1L detects a light-shielding range at a pixel corresponding to θL1, and the sensor unit 1R detects a light-shielding range at a pixel corresponding to θR2. Therefore, the control / arithmetic unit 2 calculates the coordinates of the position of the pointing tool based on the distance between the sensor units 1L, 1R and the angles (θL1, θR2) corresponding to the light-shielding ranges detected by the sensor units. To do. Then, the coordinates calculated in S805 are output, and the process returns to S801.

  If it is determined in S803 that there are a plurality of shades (YES in S803), coordinate candidate points are calculated in S806. When a plurality of light shielding ranges are detected in both the line CCDs of the sensor units 1L and 1R, the coordinates other than the coordinates at which the pointing device actually exists are combined depending on the combination of detection directions (angles) corresponding to the light shielding ranges in each sensor unit. Coordinates are calculated. In such a case, a coordinate point corresponding to each combination of detection directions in each sensor unit is referred to as a coordinate candidate point. FIG. 9A is a diagram illustrating an example of a state in which a plurality of inputs (positions A and B indicated by black circles) are instructed in the coordinate input effective area 3, and the situation determined as a plurality of inputs in S803. Explains. In the case of FIG. 9A, the sensor unit 1L detects the light shielding range in the directions of θL1 and θL2 (θL1 <θL2), and the sensor unit 1R detects the light shielding range in the directions of θR1 and θR2 (θR1 <θR2). Therefore, as coordinate candidate points calculated in S806, real coordinates A and B corresponding to [θL1, θR2], [θL2, θR1], and imaginary corresponding to [θL2, θR2], [θL1, θR1]. Coordinates A ′ and B ′ are calculated. Here, among the coordinates of the coordinate candidate points, the coordinates of the position where the pointing tool actually exists are called real coordinates (real coordinates), and the other coordinates are called imaginary coordinates (imaginary coordinates).

  When coordinate candidate points including not only real coordinates but also imaginary coordinates are calculated, it is necessary to correctly select real coordinates from the coordinate candidate points and to assign ID information and switch information. For this purpose, a process for transmitting a control signal to the pointing device as necessary and acquiring desired information is required. Therefore, in this embodiment, when a plurality of pointing tools are used and the coordinates of each pointing tool cannot be uniquely determined based on the directions of the pointing tools viewed from a plurality of light receiving units, Instruct to fire. And the coordinate of a some indicator is calculated further using the light emission direction from the indicator according to the said instruction | indication. Details of such processing will be described in the following steps. In S807, it is determined whether or not a plurality of coordinate points are detected for the first time by utilizing a flag process on the program. If it is the first time (YES in S807), the process proceeds to S808 and a control signal is transmitted. If it is not the first time (NO in S807), the process proceeds to S809.

  Here, consider a case where a plurality of coordinate detection is not the first time, that is, a coordinate candidate point has been previously calculated and coordinate output is performed. In this case, in S809, it is determined whether all the coordinate candidate points calculated in S806 are within the input area. If it is determined that all of the coordinate candidate points are within the input area (YES in S809), the process proceeds to S812, and if it is not determined (NO in S809), the process proceeds to S810.

  In S810, it is determined whether the calculated coordinate candidate point is a real coordinate (judgment determination). If all of the coordinate candidate points are not in the input area and either of the imaginary coordinates A ′ or B ′ is calculated outside the area of the coordinate input area 3, there are two indicators that can be used simultaneously. The actual coordinates are inevitably determined to be a combination of A and B. For example, the sensor unit 1L detects the light shielding range in the direction of θL1, θL2 (θL1 <θL2), the sensor unit 1R detects the light shielding range in the direction of θR1, θR2 (θR1 <θR2), and [θL2, θR2]. It is assumed that the coordinates corresponding to are outside the coordinate input area 3. In this case, there cannot be an indicator at the coordinates corresponding to [θL2, θR2] that falls outside the coordinate input area 3. In addition, since there are two indicating tools and the light shielding range is detected in the directions of θL1, θL2 and θR1, θR2 from the sensor units 1L, 1R, the coordinates corresponding to [θL1, θR1] There can be no indicator. Therefore, it can be determined that the coordinates corresponding to [θL1, θR2] and [θL2, θR1] are real coordinates. Note that here, a case has been described in which there are two pointing tools for the sake of simplification, but the determination can be made in the same manner when there are three or more pointing tools.

  In this embodiment, when coordinate output has been performed previously, the coordinate value before one sampling, the pen-specific ID information, and the like are held in the memory 132 as inheritance information. Accordingly, in S810, a process of associating the coordinates determined as the actual coordinates with the inheritance information (inheritance process) is further performed. Specifically, if a combination of real coordinates is specified, the inheritance information is compared with the current real coordinates, and adjacent coordinate values are determined as continuous input (drawing or the like). Specifically, when the distance between the coordinates of the pointing tool corresponding to the direction of the newly determined pointing tool and the coordinates already held is within a certain value, the direction of the newly determined pointing tool The coordinates of the pointing tool corresponding to can be calculated on the assumption that the coordinates of the pointing tool are continuous with the held coordinates. In step S811, ID information is assigned to the actual coordinates on which the inheritance process has been performed using the inheritance information. That is, in S810, real coordinates are determined for each input, and ID information is assigned in S811. In step S805, coordinate output is performed, and the process returns to step S801.

  On the other hand, when all of the coordinate candidate points are within the input area (YES in S809), it is determined in S812 whether or not the plurality of detected light shieldings are separated and detected. The case where the light shielding is detected separately is a state where a plurality of light shielding shadows can be detected from both of the two sensors in S803. FIG. 9A shows a case where the light shielding is separated and detected among all coordinate candidate points within the coordinate input area 3, and FIG. 9B shows that the light shielding is not separately detected. Shows the case. Generally, light shielding is separated when the number of directions of the indicator determined for the first light-receiving unit and the number of directions of the indicator determined for the second light-receiving unit are different from each other. It can be said that this is not detected. If a plurality of shades are detected separately (YES in S812), the process proceeds to S810, and the actual coordinates A and B are determined by combining the inherited information and the currently obtained shaded signal in the same manner as described above. That is, the coordinates close to the coordinate values before one sampling are determined as the actual coordinates as continuous inputs. In S811, the ID information assigned to the coordinate value before one sampling is allocated, and the coordinate output is performed in S805.

  On the other hand, as shown in FIG. 9B, when the respective shaded shadows cannot be separated due to the overlap of two shaded signals (NO in S812), the process using the inheritance information performed in S810 is performed. There is a high possibility of incorrect assignment. For this reason, the process proceeds to S808, and the coordinate input device transmits a control signal to the pointing tool (pen), and requests light emission for distinguishing the pointing tool from the light emission for transmitting the auxiliary information to the pointing tool.

  The indicator that has received the control signal transmitted in S808 emits infrared light at a predetermined timing to transmit the requested incidental information, and also emits light to distinguish the indicator. In step S813, the sensor units 1L and 1R acquire light emitted from the pointing tool without illumination light (infrared LEDs 101A and 101B) being projected.

  In step S <b> 814, the acquired light emission position on the line CCD (pixel number) is compared with the pixel number of the light shielding signal to associate the light shielding signal with the light emission. The real coordinates can be specified by the association, and the ID information can be assigned to the coordinate values from the accompanying information received together (S811). In this manner, the coordinates corresponding to the input position of the pointing tool are calculated in association with the identification information for identifying the pointing tool received from the pointing tool.

  However, for example, when the light emitted from the pen cannot be acquired because it is hidden behind the other pointing tool among the plurality of pointing tools, it is not possible to determine whether to assign ID information or the like. In such a case, for example, the coordinate output may not be performed in step S805 but may be performed on the next coordinate detection cycle. As described above, in the present embodiment, the control signal is transmitted in S808 only when the coordinates are calculated for the first time (YES in S807) and in the case where the plurality of shadings are not detected separately (NO in S812). The indicator is caused to emit light for distinguishing the indicator. For this reason, it is possible to suppress the power consumption of the pointing tool by suppressing the number of times the pointing tool emits light, and to increase the response speed of coordinate detection. The incidental information is transmitted at a predetermined timing separately from the light emission for distinguishing the pointing tool. For example, the incidental information may be transmitted when the light emitting for distinguishing the pointing tool is performed.

<Transmission and reception of pen control signals and incidental information>
The control signals, supplementary information, infrared light transmission / reception, and ID information allocation processing in S813 and S814 will be described in detail with reference to FIGS. 10A and 10B show information communication between the pen signal communication unit 5 and the sensor units 1L and 1R and a plurality of pointing devices (pen 9A and pen 9B) and light emission in the present embodiment. FIG. 3 is a diagram conceptually illustrating the exchange.

  As shown in FIG. 10A, the pen signal communication unit 5 further includes a control signal transmission module 901 and an incidental information reception module 902. The control signal in S808 in FIG. 8 described above is transmitted from the control signal transmission module 901, and the control signals 904A and 904B including timing signals and command signals are output as infrared light signals to the pens 9A and 9B. To do.

  The output control signal 904A (904B) is received by the pen communication circuit 63 (63A, 63B) on the pointing device side (pens 9A, 9B). When the control signal is received, the pen control circuit 64 of the pointing tool determines whether the pen tip switch 61 or the side switch 62 is pressed. When the pen tip switch 61 or the side switch 62 is pressed, the pointing tool generates a predetermined signal indicating a pressed state of the switch and a signal indicating ID information. Then, as will be described with reference to FIG. 10B, the incidental information 905A (905B) is returned through the pen communication circuit 63 at a predetermined timing.

  Here, when the incidental information 905A (905B) is an optical signal, the modulated information is received and analyzed by the incidental information receiving module 902. On the other hand, by detecting the light emission 906A (906B), the sensor units 1L and 1R can perform allocation for coordinate input by the pen (S814 in FIG. 8). The assignment of the incidental information from the pointing tool to the coordinate value (S811 in FIG. 8) may be performed on the light shielding range at substantially the same position as the light shielding range by detecting the light emission 906A (906B). . Details will be described later with reference to FIG.

  Note that the shutter opening time of the light receiving portions (line CCD 104) of the sensor units 1L and 1R is determined when the light emitted from the infrared LEDs 101A and 101B and retroreflected is received and when the light emission 906A (906B) is detected. Change as appropriate. By doing so, it is possible to detect at an appropriate level in the range of the dynamic range of the line CCD 104. That is, it is possible to avoid light emission collisions by instructing the pointing tool so that the pointing tool emits light at a timing different from the timing at which the infrared LEDs 101A and 101B project light.

<Illustration (selection of real coordinates)>
In FIG. 11, the association between a plurality of light shields and pen incidental information signals will be described using an example of the coordinates in the coordinate input effective area 3 and a waveform detected by the light receiving unit (line CCD 104).

  In this case, the light-blocking CCD detection waveform formed by the infrared light from the sensor unit being blocked by the indicator is observed in the sensor unit 1L as shown in FIGS. 11 (1) (a) and (L). In the sensor unit 1R, observation is performed as shown in FIGS. 11 (1), (a), and (R). Further, for example, the light emission 906A from the pen 9A in FIG. 10 described above is detected as shown in FIGS. 11 (1) (b) (R) or FIGS. 11 (1) (b) (L).

  When coordinates are calculated using the respective light shields QL1, QL2, QR1, and QR2 in FIG. 11A, real coordinate A and B and imaginary coordinate A ′, as coordinate candidate points, as shown in FIG. B ′ is calculated, and it is necessary to determine whether the coordinates are correct. Here, when the pixel number NL1 calculated for the light shielding QL1 and the pixel number NL2 corresponding to the light emission PL1 of the pen are close to each other, for example, the difference between NL1 and NL2 falls within a predetermined value width. If it is, it can be determined that QL1 corresponds to PL1. Similarly, when the pixel numbers NR1 and NR2 are close to each other, QR1 can be determined to be light shielding corresponding to PR1. That is, by calculating the coordinates from the combination of the light shielding corresponding to these pens and the light emission from the pen 9A, the coordinates of the emitted pen 9A corresponding to the actual coordinates can be determined from the four candidate points. By determining that the other of the combinations of actual coordinates is based on another pointing tool (9B), the coordinates A and B that are actual pointing positions can be uniquely determined.

  Next, consider a case where the inputs A and B are arranged in a substantially straight line when viewed from the sensor unit 1R as shown in FIG. 9B. This is a state in which the input B on the rear side is only partially visible from the sensor unit so that the input is hidden behind the input A on the front side when viewed from the sensor unit side. This state is a case where a plurality of shades are not detected separately, and corresponds to the state determined through steps S807, S809, S812, and S808 according to the flowchart of FIG.

  At this time, the CCD detection waveform is detected as shown in FIGS. The waveform detected by the sensor unit 1R is a state in which the light shielding is not separated as shown in FIGS. 11 (2) (a) and (R), and the two light shieldings of QR1 and QR2 are combined and a light shielding with a large width is detected. It becomes. On the other hand, since the waveform detected by the sensor unit 1L has two light shields as shown in FIGS. 11 (2) (a) and 11 (L), it can be determined that there are a plurality of inputs.

  Here, a state where the control signal transmitted in S808 is received and the pen 9A as the input A emits the infrared light 906A in response to the request will be described. In the line CCD 104 of the sensor unit 1R, the light emission of the pen corresponding to the coordinate A is detected as shown in FIGS. From this result, it can be determined that the light shielding QR1 close to the position (pixel number) of NR2 corresponds to the detected light emission PR1. Further, if the pen light emission PL1 is detected in the sensor unit 1L, it can be determined that QL1 and PL1 correspond to each other. That is, the coordinates calculated by the pixel numbers NR1 and NL1 can be determined to be input by the pen 9A.

  As described above, in the present embodiment, when light shielding due to overlapping of inputs from a plurality of pointing tools cannot be determined, the pointing tool is instructed to emit light for distinguishing the pointing tool. For this reason, it is possible to accurately distinguish a plurality of pointing tools while minimizing the power consumption of the pointing tools. Further, by appropriately transmitting incidental information including the ID information of the pointing tool, it is possible to assign the accompanying information such as ID information to the light shielding signal of each pointing tool. In addition, the above processing is configured to detect the optical signal, which is incidental information of the pen, with the CCD 104 for coordinate detection (for shading detection), and thus can be configured at low cost without increasing the number of parts. It is possible to provide a coordinate input device capable of inputting with a plurality of pointing tools.

<Pen signal transmission / reception timing>
FIGS. 12A and 12B are timing sequence diagrams in the transmission / reception of the series of information described above. Note that this timing sequence diagram is not a process performed every time when coordinates are detected, but a process when it is determined that the control signal of S807 is transmitted in the flowchart of FIG.

  As described in FIG. 6, in FIG. 12A, the shutter of the line CCD 104 in the sensor units 1L and 1R is opened at the timing of 1101, in accordance with the projection timing 1102 of the infrared LED for coordinate detection. A shading signal is detected. A signal 1102 representing the light projection timing corresponds to the signals 53 and 54 in FIG.

  The control signal transmission module 901 in FIG. 10 outputs the control signals 904A and 904B at the timing of 1103 after reading out the pixel data from the line CCD 104 so as not to overlap with the timings of these 1101 and 1102. Upon receiving the control signal 904A, the pointing tool (pen 9A) generates a modulated optical signal from the switch information and ID information, transmits it as incidental information 905A at the timings 1104 and 1106, and replies. Further, when there is a second pointing tool (pen 9B), the transmission timing of the pen 9A and the pen 9B is controlled separately. That is, the pen 9B that has received the control signal 904B at the timing of 1103 outputs incidental information and emits light at the timings of 1105 and 1107 in the figure so that the transmission timings do not overlap with each other.

  As described with reference to FIG. 12B, the control signals 904A and 904B output from the control signal transmission module 901 may be output at the timing of 1113. In this case, the response of the incidental information from the pointing tool is controlled to be output at the timings 1114, 1116, or 1115, 1117 in the figure, and the time required for transmitting the control signal is shortened compared to FIG. it can. It should be noted that the control signal 904A (904B) signal for the pointing tool is output from the light projecting means of the sensor unit 1L (1R), so that the pen signal communication unit 5 does not have a transmission function but only a reception function. Since it becomes possible to comprise, you may comprise in this way.

  As described above, in the configuration of the present embodiment, an instruction is given to the indicator so that the indicator emits light at a timing different from the timing at which the sensor unit projects light. For this reason, coordinate detection, control signals, and transmission / reception of incidental information can be realized without overlapping of light projection from the infrared LEDs 101A and 101B and infrared light emission from the pen. Therefore, when coordinate values by a plurality of pointing tools are obtained, it is possible to associate the obtained signal information (switch signal and pen ID information of the pointing tool) with the coordinate values. Then, the switch information, the pen ID information unique to the pointing tool, the ID information indicating the continuity of the coordinate values, and the like can be added to the coordinate values as auxiliary information and output to the external terminal.

  In the configuration of the present embodiment, when a plurality of pointing tools are used and the coordinates of each pointing tool cannot be uniquely determined based on the direction of the pointing tool viewed from the light receiving unit, it is necessary. Only the indicator (pen) is required to emit infrared light to distinguish the indicator. For this reason, compared with the structure which always requires light emission of the infrared LED 66 of the pointing device, power consumption is reduced by suppressing unnecessary light emission, leading to an effect of extending the battery life.

[Embodiment 2]
In the above-described embodiment, transmission / reception of control signals and incidental information exchanged between the pen signal communication unit 5 and the pointing tool (pens 9A and 9B) has been described on the premise of a method using infrared light. However, the method of transmitting and receiving information is not limited to this, and other methods may be used. For example, transmission / reception of the control signal 904A (904B) and the auxiliary information 905A (905B) transmitted / received between the control signal transmission module 901 and the incidental information reception module 902 and the pen communication circuit 63 in FIG. It may be realized by communication. In this case, the infrared light 906A (906B) for distinguishing the pointing tool can be emitted in parallel with the pointing tool in order to more accurately calculate the true / false determination of the coordinate values of the plurality of pointing tools. Is desirable.

  13A and 13B illustrate a timing sequence in the case of using wireless communication using radio waves. Light emission 906A (906B) from the pen 9A (9B) needs to be controlled so as not to overlap with the timing of the light projection 903 in accordance with the coordinate detection by the line CCD 104. Here, the timing of the light projection 903 is indicated by 1201 and 1202 in FIG. 13A or 1211 and 1212 in FIG. Therefore, the pens 9A and 9B are controlled to emit light at the timings 1206 and 1207 in FIG. 13A or 1216 and 1217 in FIG.

  However, transmission / reception of the control signal 904A (904B) and the incidental information 905A (905B) is communication using radio waves, and collision with infrared light need not be considered. For this reason, in FIG. 13A, without regard to superimposition with the coordinate detection timing (1201, 1202), the transmission / reception of the control signal at the timing of 1203, or the incidental information at the timing of 1204, 1205. Can be sent and received.

  Further, in FIG. 13B, the transmission timing of the supplementary information 905A (905B) from the pen 9A (9B) is controlled to be 1214 or 1215, and is the timing at which the light emission 906A (906B) is superimposed. Of course.

  It has been described so far that when the coordinates of the pen 9A are specified, the coordinates indicated by the pen 9B are also determined at the same time. That is, even if there is no light emission 908 </ b> B from the pen 9 </ b> B, it is possible to perform the true / false determination when two pointing tools are input. If input is performed using three pointing tools and the true / false determination is performed, the light emitted from the two pointing tools may be detected by the line CCD 104 at different timings. In other words, when there are coordinate inputs by N pointing tools, if the light emission of N-1 pens can be detected at different timings, it is possible to determine whether the truth is true.

  That is, the second indicator (pen 9B) may not emit light at the timing 1207 in FIG. 13A and 1217 in FIG. 13B.

  As described above, in the present embodiment, wireless communication is utilized for transmission / reception of control signals or incidental information. For this reason, according to the configuration of the present embodiment, the overall processing time is shortened by controlling the timing and reducing the number of processes requiring wait processing. Further, by suppressing the indicator that emits light to the minimum necessary, it is possible to reduce power consumption when viewed in the entire system. As a result, it is possible to provide a coordinate input device having a large number of samplings and excellent responsiveness.

[Embodiment 3]
In the previous embodiment, it has been described that a control signal for causing the pointing device to emit light is transmitted from the control signal transmission module 901 as necessary when a plurality of pointing devices are simultaneously input.

  However, the present invention is not limited to this. For example, when an ID is used in an application based on the premise that the pointing tool holds a unique ID, such as displaying a black locus with ID = 1 and displaying a red locus with ID = 2, which ID instruction It is necessary to detect in advance whether the pointing operation is performed with the tool. Therefore, in such a case, for example, at the timing when one or more light shielding is detected from the state where there is no light shielding signal, a control signal is transmitted from the control signal transmission module 901 to acquire the indicator ID. Good.

  Further, when two lines are input simultaneously, coordinates as shown in FIG. 14 may be detected. The numbers in the figure indicate the course of time, and the white circles represent the coordinates sampled over time. FIG. 14A shows that, for example, coordinates A1 and B1 are detected at timing 1 and coordinates A2 and B2 are detected at timing 2.

  At this time, there are two cases where the operation of the pointing tool by the actual operator is input (drawn) as shown in FIG. 14B, FIG. 14C, and two cases. FIG. 14B shows a state where the input A started from A1 has moved to A2, X3, X4, and the input B started from B1 has moved to B2, Y3, Y4. Similarly, FIG. 14C shows a state where the input A started from A1 has moved to A2, Y3, Y4, and the input B started from B1 has moved to B2, X3, X4.

  In order to distinguish between the two cases, it is only necessary that at least one of the pointing tools emit light at a predetermined timing. That is, first, light emission may be performed at the time of detection of A1 or B1 when input is started, and further light emission may be performed at the time of X3 or Y3 when it is determined that the input A and the input B are close to each other. By causing the pointing tool to emit light at these timings and associating the pointing tool ID, the trajectory between the input A and the input B is erroneously distinguished from the case of FIG. 14 (B) and FIG. 14 (C) and malfunctions. Can be prevented.

[Embodiment 4]
As described above, this apparatus is configured to allow input with a plurality of pointing tools (pens) such as pens and fingers, and in particular when using a pointing tool (pen), the pen signal communication unit 5 And the internal circuits of the pens 9A and 9B are configured to allow bidirectional communication.

  Thus, by changing various input modes using this bidirectional communication function, it is possible to configure as a coordinate input device with further excellent operability. A method for changing the input mode will be described below.

  FIG. 15 is a flowchart for explaining the process of changing the input mode. This process is executed based on the control of the CPU 21 of the control / arithmetic unit 2.

  First, when the process of changing the input mode is started in S1301, the pen signal communication unit 5 transmits a command requesting communication to each pen in S1302. If the pen communication circuit receives this communication request, the pen returns a predetermined command signal.

  Next, in S1303, the coordinate input device determines whether or not there is a response from the pen. If there is no response (light reception), that is, if the pen is outside the light reception range with respect to the light emission of the pen signal communication unit (NO in S1303), nothing is done because this communication request command cannot be received. In this case, it is determined that the pen is not used, and processing for switching to the touch mode (finger input mode) is executed in S1307. That is, when there is no response to the light emission instruction, the coordinates are calculated on the assumption that an input other than the pointing tool has been made to the coordinate input effective area 3. If it is determined in S1303 that there is a response from the pen (YES in S1303), the number of responses from the pen is determined in S1304.

  If it is determined in S1304 that there are two or more replies from the pen (YES in S1304), the process proceeds to S1305 to execute a process of changing to a multi-pen mode that permits input of two or more pens. If the response from the pen is one (NO in S1304), the process proceeds to S1306, and a process of changing to the single pen mode permitting the input of one pen is executed.

  As described above, in the present embodiment, the operation mode is switched based on the response from the pointing tool to the light emission instruction. For this reason, according to the configuration of the present embodiment, it is possible to automatically select an appropriate and efficient operation according to the usage pattern of the operator.

  In the above description, the signal exchange between the pen signal communication unit 5 and the pen communication circuit is a signal using infrared light or radio. However, the present invention is not limited to this, and other methods are used. May be. Also, for example, when using wireless, when responding to a communication request, unnecessary power consumption can be achieved by detecting that the operator is holding the pen, etc. so that it is not always enabled. This can be realized with a configuration that avoids the above. The detection of the operator holding the pen may be detected, for example, by a change in capacitance.

  In the above embodiment, the line CCD is used as the light receiving element in the sensor unit. However, an area sensor type CCD or CMOS sensor may be used. In particular, in the case of a CMOS sensor, it is possible to read out a specific part of the exposure area, and it is not necessary to read out an unnecessary area, so that the reading speed can be increased. Also in the above embodiment, the reading start position of the data of the other light receiving unit is determined from the light shielding range detected by the data of one light receiving unit among the plurality of light receiving units in the sensor unit, and only data in a limited range is obtained. Can be speeded up as a whole system.

  Further, if the coordinate input effective area 3 of the coordinate input device is configured by, for example, a large screen display device and the coordinate value of the pointing tool is displayed on the display screen, simultaneous input by a plurality of persons is possible. Application of electronic whiteboard becomes configurable.

<< Other Embodiments >>
The present invention can also be realized by executing the following processing. 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.

  1L, 1R: Sensor unit, 2: Calculation / control unit, 3: Coordinate input effective area, 4: Retroreflective unit, 5: Pen signal communication unit, 9A, 9B: Indicator (pen)

Claims (13)

A coordinate input device that detects an input to a coordinate input area and calculates coordinates corresponding to an input position,
A plurality of detecting means for detecting the light projected from the light projecting means for projecting toward the coordinate input area;
Based on the detection result of the light, a determination unit that determines the direction of the pointing tool input to the coordinate input area as viewed from the plurality of detection units;
Calculating means for calculating coordinates corresponding to the input position of the pointing tool based on the determined direction of the pointing tool as viewed from the plurality of detecting means;
When a plurality of pointing tools are used and the coordinates of the pointing tools cannot be uniquely determined based on the directions of the pointing tools viewed from the plurality of detecting means, the pointing tool is instructed to emit light. An instruction means,
The coordinate input device according to claim 1, wherein when the light emission is instructed by the instruction means, the calculation means further calculates the coordinates based on a light emission direction from the indicator detected by the detection means.   The coordinate input device according to claim 1, wherein the instruction unit instructs the indicator so that the indicator emits light at a timing different from a timing at which the light projecting unit projects light. .   The determining means determines the direction of the pointing tool viewed from the detecting means based on a range where the light is blocked by the input using the pointing tool to the coordinate input area and the detecting means does not detect the light. The coordinate input device according to claim 1, wherein: The instructing unit instructs the indicating tool to transmit identification information for identifying the pointing tool,
4. The coordinate input device according to claim 1, wherein the calculation unit calculates coordinates corresponding to an input position of the pointing tool in association with the identification information. 5.   5. The coordinate input device according to claim 4, wherein the instruction unit instructs the instruction tool to transmit the identification information when the calculation unit calculates coordinates for the first time.   The indicating means determines the direction of the pointing tool determined for the first detecting means and the pointing tool determined when the number of pointing directions determined for the second detecting means is different. The coordinate input device according to claim 1, wherein the coordinate input device instructs to emit light.   The coordinate input device according to claim 1, wherein the light projecting unit projects infrared light.   The coordinate input device according to claim 1, wherein the instruction unit instructs the indicator to emit infrared light by emitting infrared light.   The coordinate input device according to claim 1, wherein the instruction unit instructs the indicator to emit infrared light by wireless communication. Further comprising holding means for holding the coordinates calculated by the calculating means;
When the distance between the coordinates of the pointing tool corresponding to the direction of the pointing tool newly determined by the determining means and the coordinates held in the holding means is within a certain value, the calculating means The coordinate is calculated on the assumption that the coordinates of the pointing tool corresponding to the determined direction of the pointing tool are continuous with the coordinates held in the holding means. The coordinate input device described.   The said calculation means calculates the said coordinate as what was input other than the said indicator with respect to the said coordinate input area when there is no response with respect to the light emission instruction | indication by the said instruction | indication means. The coordinate input device according to any one of 1 to 10. A method for controlling a coordinate input device that detects an input to a coordinate input area and calculates coordinates corresponding to an input position,
A plurality of detecting means for detecting light projected from the light projecting means for projecting toward the coordinate input area;
A determination step of determining a direction of the pointing tool input to the coordinate input area as viewed from the plurality of detection units based on the detection result of the light;
A calculating step of calculating coordinates corresponding to the input position of the pointing tool based on the determined direction of the pointing tool as viewed from the plurality of detecting means;
When the pointing unit cannot determine the coordinates of each pointing unit based on the direction of the pointing unit viewed from the plurality of detecting units using a plurality of pointing units, An instruction process for instructing light emission,
In the calculation step, when light emission is instructed by the instruction step, the coordinate is calculated based on the direction of light emission from the indicator detected in the detection step. Control method.   The computer program for functioning a computer as each means with which the coordinate input device of any one of Claim 1 to 11 is provided.

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