JP4401737B2 - Coordinate input device, control method therefor, and program - Google Patents

Description

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

  There are coordinate input devices that are used to control a connected computer or to write characters, graphics, etc. by inputting coordinates on a coordinate input surface by pointing with a pointing tool or a finger.

  Conventionally, as this type of coordinate input device, various types of touch panels have been proposed or commercialized, and it is easy to operate terminals such as personal computers on the screen without using special equipment. Since it can be used, it is widely used.

  There are various coordinate input methods such as those using a resistive film and those using ultrasonic waves. For example, Patent Document 1 discloses a method using light. In Patent Document 1, a retroreflective sheet is provided outside the coordinate input area, and an illumination unit that illuminates light disposed at a corner end of the coordinate input area and a light receiving unit that receives the light are used in the coordinate input area. Discloses a configuration in which an angle between a light shielding unit and a light shielding unit that shields light such as a finger is detected, and an instruction position of the shielding material is determined based on the detection result.

  Further, as disclosed in Patent Documents 2 and 3 and the like, a coordinate input device is disclosed in which a retroreflective member is configured around a coordinate input region to detect the coordinates of a portion where retroreflected light is shielded.

  In these apparatuses, for example, in Patent Document 2, the angle of the light-shielding part relative to the light-receiving part is detected by detecting the peak of the light-shielding part by the shielding object received by the light-receiving part by waveform processing calculation such as differentiation, and the detection The coordinates of the shielding object are calculated from the result. Patent Document 3 discloses a configuration in which one end and the other end of a light shielding part are detected by comparison with a specific level pattern, and the center of those coordinates is detected.

  In Patent Document 1, each pixel of a RAM imager that is a light receiving unit is read and compared by a comparator to detect a light-shielding portion. When there is a light-shielding portion having a certain width or more, pixels at both ends thereof are detected. A method for detecting the center and calculating the coordinates of the shielding object based on the detection result is shown.

  Here, in order to operate as a touch panel, it is necessary to determine whether or not an pointing tool such as a finger has touched the coordinate input surface. The resistance film method described above detects a change in electrical resistance value by touching a coordinate input surface.

  On the other hand, the ultrasonic method detects a touch position by observing a phenomenon in which ultrasonic vibration propagating in the input surface is attenuated by touching the coordinate input surface. It is easy to determine whether or not the user touches the coordinate input surface.

  However, in the methods of calculating coordinates by detecting the light shielding position (hereinafter referred to as the light shielding method) as in Patent Documents 1 to 3, light is applied to a position having a height h1 in the vertical direction of the coordinate input surface. By providing a detection light beam and shielding the light beam with a shielding object, the shielding position is detected. Therefore, even if the coordinate input surface is not touched, the coordinate value is detected and output.

As an invention made in view of this point, for example, as shown in Patent Document 4 and Patent Document 5, when a plurality of threshold values for the light shielding amount are provided and a coordinate input operation is performed closer to the coordinate input surface A configuration for outputting coordinate values is disclosed.
U.S. Pat. No. 4,507,557 JP 2000-105671 A JP 2001-142642 A JP 2001-147776 A JP 2001-84106 A

  However, the above-described light shielding coordinate input device has the following problems. This problem will be described with reference to FIG.

  FIG. 19B is a layout diagram viewed from the front direction of the coordinate input device. By pointing a specific area (SW1 to SW3) provided in the lower left corner of the coordinate input area 4, for example, a specific application This is an example in which a plurality of switch areas that can be configured to start up are installed.

  That is, when the operator designates a predetermined specific area with the pointing tool 5 such as a finger, the coordinate input device outputs a coordinate value, but the output coordinate value is within the specific area. It is determined whether it is a coordinate value. And it is comprised so that the operation | movement allocated to the specific area | region may be performed with this determination result, and it acts as if it operate | moves as a switch means.

  FIG. 19A shows a cross-sectional view taken along the line AA in FIG. The coordinate input area 4 made of a planar member also serves as the display surface of the display device. The light beam illuminated by the light projecting unit in the sensor unit 1 is emitted substantially parallel to the surface of the display device, is retroreflected by the retroreflective member 3, and is detected by the detection unit in the sensor unit 1.

  Now, consider a case where the operator tries to execute a desired application by operating switch 2 (SW2) in the figure, for example. The operator's hand / finger is not aware of the movement only in the direction perpendicular to the display surface and does not perform the switch operation (act of touching the SW2 area in FIG. 19B). It is normal not to be aware of the movement trajectory of the hand / finger except that it is “just in the SW2 region”. For example, the movement operation is performed along the trajectory indicated by the thick arrow in FIG.

  The operation that the coordinate input device determines in accordance with this moving operation will be described. First, the operator tries to execute the control assigned to the SW2 area, and touches the SW2 area to display the coordinate input area (display surface). ) Suppose that the light beam set substantially parallel to 4 starts to be blocked and the finger / hand is moved to the position (1). Here, when the light beam starts to be blocked, the coordinates of the light blocking position start to be output. However, since the operator has not touched the coordinate input area 4 yet, the operator has not intended to operate the switch.

  Then, it is recognized that the switch operation is performed by pressing the SW2 area at the position (2) (the position in contact with the coordinate input area 4). The operator achieves the purpose of performing the switch operation and moves the finger / hand to the position of (3). Even at the position of (3), the coordinate input device sets the coordinate value. Continue to output. Then, when the light beam is no longer blocked after the position (4), the coordinate output is stopped.

  Now, what is a problem here is that the operator has only recognized that the SW2 area has been pressed in the state (2), while the coordinate input device is in the state (4). It is the point which is outputting the coordinate value up to.

  That is, when the coordinate value output last by the series of movement operations of the operator is in the SW3 area, the operator has surely pressed the SW2 area, but the execution assigned to the SW3 area. The instruction will be executed. This not only gives the operator an unintended operation, but depending on the contents of the execution command, there is a serious risk of causing an unrepairable state.

  As a countermeasure, for example, a sufficiently large space (gap) between the SW1 area and the SW2 area is taken, or the output coordinate value is continuously monitored, and for example, the coordinate value output during the period Means such as setting the center as a definite value are also conceivable.

  However, the former measure has a new problem such as an increase in the interval between the switch areas and poor operability, or a large number of switches cannot be arranged due to the size limit of the coordinate input area. The latter countermeasure is, for example, “I've pointed to the wrong area, so I can achieve the original purpose by moving my finger in the state of (2) and releasing my finger at the correct position”. Therefore, the center position is not necessarily the correct position intended by the operator, that is, the possibility of malfunctioning cannot be excluded.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a coordinate input device that can improve operability, a control method therefor, and a program.

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 surface height of the coordinate input surface is formed of a plurality of different planes,
A plurality of light receiving detection means provided at corners of the coordinate input surface ;
Retroreflective means for recursively reflecting incident light provided around the coordinate input surface ;
Projecting means for projecting a light beam substantially parallel to the coordinate input surface toward the retroreflecting means;
Based on the change rate of the light amount distribution obtained from the light receiving detection means, a calculation means for calculating the height of the indicated position with respect to the coordinate input surface and the coordinates of the indicated position ;
It is a threshold value δ for determining whether the coordinates of the designated position calculated by the calculating means belong to any one of the different planes, and is a threshold value δ for detecting the touched position of the designated position. Determining means for determining whether or not the indicated position has been touched based on the threshold value δ set for each of them .

Also, certain preferably having when said first coordinate input surface defined by the coordinate input surface and the distance between the light beam and h1, second coordinate input surface having a distance h1 to the first coordinate input surface A surface is configured in the coordinate input surface .

Also, preferably, the distance between the light beam and the first coordinate input surface defined by the coordinate input surface and h1, if the width of the light beam to is W, relative to the first coordinate input surface distance h1 + W × ( A third coordinate input surface having 1-δ) is configured in the coordinate input surface .

Also, preferably, the distance between the light beam and the first coordinate input surface defined by the coordinate input surface and h1, if the width of the light beam to is W, relative to the first coordinate input surface, the distance h1 + W × A fourth coordinate input surface is configured in the coordinate input surface at a distance greater than (1-δ) and less than the distance h1 + W.

In order to achieve the above object, a method for controlling a coordinate input device according to the present invention comprises the following arrangement. That is,
A light receiving unit provided at a corner of the coordinate input surface composed of a plurality of planes having different heights of the coordinate input surface, a reflection unit provided at the periphery of the coordinate input surface and recursively reflecting incident light; has a light projecting portion for projecting a substantially parallel light beam to the coordinate input surface, a method of controlling a coordinate input device for calculating the indicated position on the coordinate input surface,
A light projecting step of projecting the light flux toward the reflection unit by the light projecting unit;
A light receiving step of receiving a light beam reflected from the reflecting portion by the light receiving portion;
Based on the change rate of the light amount distribution obtained from the light receiving unit, a calculation step of calculating the height of the designated position with respect to the coordinate input surface and the coordinates of the designated position ;
It is a threshold value δ for determining whether the coordinates of the designated position calculated by the calculating step belong to any one of the different planes, and is a threshold value δ for detecting the touched position of the designated position. And a determination step of determining whether or not the indicated position has been touched based on the threshold value δ set for each .

In order to achieve the above object, a program according to the present invention comprises the following arrangement. That is,
A light receiving unit provided at a corner of the coordinate input surface composed of a plurality of planes having different heights of the coordinate input surface, a reflection unit provided at the periphery of the coordinate input surface and recursively reflecting incident light; has a light projecting portion for projecting a substantially parallel light beam to the coordinate input surface, a program for executing a control of a coordinate input device for calculating the indicated position on the coordinate input screen to the computer,
A light projecting step of projecting the light flux toward the reflection unit by the light projecting unit;
A light receiving step of receiving a light beam reflected from the reflecting portion by the light receiving portion;
Based on the change rate of the light amount distribution obtained from the light receiving unit, a calculation step of calculating the height of the designated position with respect to the coordinate input surface and the coordinates of the designated position ;
It is a threshold value δ for determining whether the coordinates of the designated position calculated by the calculating step belong to any one of the different planes, and is a threshold value δ for detecting the touched position of the designated position. And a determination step of determining whether or not the indicated position has been touched based on the threshold value δ set for each .

  As described above, according to the present invention, it is possible to provide a coordinate input device that can improve operability, a control method thereof, and a program.

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

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

  FIG. 1 is a diagram showing a schematic configuration of a coordinate input device according to a first embodiment of the present invention.

  In FIG. 1, 1L and 1R are sensor units each having a light projecting unit 30 (see FIG. 2) and a detecting unit 40 (see FIG. 3), parallel to the X axis of the coordinate input area 4 as shown, and Y It is installed at a position symmetrical to the axis and separated by a predetermined distance. The sensor units 1L and 1R are connected to a control / arithmetic unit 2 that performs control / calculation, receive a control signal from the control / arithmetic unit 2, and transmit a detected signal to the control / arithmetic unit 2.

  Reference numeral 3 denotes a retroreflective member having a retroreflective surface that reflects incident light in the direction of arrival, and directs light projected from the left and right sensor units 1L and 1R in a range of approximately 90 ° toward the sensor units 1L and 1R. To retroreflect.

  The light retroreflected by the retroreflective member 3 is detected one-dimensionally by the sensor units 1L and 1R, and the light quantity distribution is transmitted to the control / arithmetic unit 2.

  The coordinate input area 4 is configured as a display screen of a display device such as a PDP, a rear projector, or an LCD panel, so that it can be used as an interactive input device.

  In such a configuration, when an input instruction is made to the coordinate input area 4 by an indicator such as a finger, the light projected from the light projecting units 30 of the sensor units 1L and 1R is blocked and reflected by the retroreflective member 3. Since no light can be obtained, the amount of reflected light cannot be obtained only at the input instruction position. As a result, it is possible to determine from which direction the light could not be detected.

  Therefore, the control / arithmetic unit 2 detects the light-shielding range of the portion instructed to be input by the pointing tool from the light amount change detected by the sensor units 1L and 1R, and specifies information (detection points) within the light-shielding range. Thus, the direction of the light shielding position (the angle of the pointing tool) with respect to each of the sensor units 1L and 1R is calculated.

  Then, the pointing position of the pointing tool on the coordinate input area 4 is calculated from the calculated angle and the distance information between the sensor units 1L and 1R, and the USB terminal is connected to an external terminal such as a personal computer connected to the display device. Coordinate values are output via the interface.

  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.

<Detailed explanation of sensor unit>
Next, the configuration of the light projecting unit 30 in the sensor units 1L and 1R will be described with reference to FIG.

  FIG. 2 is a diagram illustrating a configuration example of a light projecting unit of the sensor unit according to the first embodiment of the present invention.

  FIG. 2A shows a case where the light projecting unit 30 is viewed from above (perpendicular to the input surface of the coordinate input area 4). Reference numeral 31 denotes an infrared LED that emits infrared light. The light emitted from the infrared LED 31 is projected in a range of approximately 90 ° by a light projection lens 32.

  FIG. 2B shows a case where the light projecting unit 30 is viewed from the side (horizontal direction with respect to the input surface of the coordinate input area 4). In this direction, the light from the infrared LED 31 is projected as a light beam limited in the vertical direction, and the light is mainly projected onto the retroreflective member 3.

  Next, the configuration of the detection units 40 of the sensor units 1L and 1R will be described with reference to FIG.

  FIG. 3 is a diagram illustrating a configuration example of the detection unit of the sensor unit according to the first embodiment of the present invention.

  FIG. 3 shows a case where the detection units 40 of the sensor units 1L and 1R are viewed from a direction perpendicular to the input surface of the coordinate input area 4. The broken line portion in the drawing indicates the arrangement of the light projecting unit 30 shown in FIG.

  The detection unit 40 includes a one-dimensional line CCD 41 composed of a plurality of light receiving elements (pixels), condensing lenses 42 and 43 as a condensing optical system, a diaphragm 44 for limiting the incident direction of incident light, and extra light such as visible light. It comprises an infrared filter 45 that prevents light from entering.

  The light from the light projecting unit 30 is reflected by the retroreflective member 3, passes through the infrared filter 45 and the diaphragm 44, and the light in the approximately 90 ° range of the input surface is detected by the line CCD 41 by the condensing lenses 42 and 43. The image is formed on the pixel depending on the incident angle on the surface. Thereby, the light quantity distribution for each angle of the incident angle is obtained. That is, the pixel number of each pixel constituting the line CCD 41 represents angle information.

  Next, the configuration of the sensor units 1L and 1R having the light projecting unit 30 in FIG. 2 and the detection unit 40 in FIG. 3 will be described with reference to FIG.

  FIG. 4 is a diagram illustrating a configuration example of the sensor unit according to the first embodiment of the present invention.

  FIG. 4 shows a case where the sensor unit 1L (1R) is configured by overlapping the light projecting unit 30 in FIG. 2B and the detection unit 40 in FIG. 3 when the coordinate input area 4 is viewed from the horizontal direction. ing. Here, the distance L between the optical axes of the light projecting unit 30 and the detection unit 40 is set to a sufficiently small value compared to the distance from the light projecting unit 30 to the retroreflective member 3, and has the distance L. In addition, a sufficient retroreflected light can be detected by the detection unit 40.

<Detailed description of retroreflective member>
Next, the retroreflective principle of the retroreflective member 3 will be described with reference to FIG.

  FIG. 5 is a view for explaining the principle of retroreflection of the retroreflective member of Embodiment 1 of the present invention.

  Regarding the structure of the retroreflective member 3, first, in order to simplify the explanation, a two-dimensional structure is schematically considered. As shown in FIG. 5A, a reflective surface having an angle of approximately 90 ° is continuously formed. Thus, the retroreflection phenomenon can be realized.

  However, in such a structure, as shown in FIG. 5B, the light vector in the Z direction is reflected and does not become retroreflective. Therefore, the retroreflective member 3 has a three-dimensional structure when viewed microscopically. At present, the retroreflective phenomenon is mainly achieved by regularly arranging bead-type retroreflective tapes or corner cubes by machining or the like. Retroreflective tape to wake up is known.

  However, in these retroreflective tapes, when the normal direction of the retroreflective tape viewed macroscopically is defined as an incident angle of 0 ° and the amount of light retroreflected is measured using the incident angle as a parameter, FIG. A retroreflective characteristic such as is obtained.

  According to FIG. 6, since the amount of reflected light obtained when the incident angle exceeds 45 ° clearly decreases, in the shielding type coordinate input device, the change is sufficiently suppressed in the shielding region by the shielding object. There is a risk that it cannot be detected.

    The amount of reflected light is determined by the light amount distribution (illumination intensity and distance), the reflectance of the retroreflective member 3 (incident angle, width of the reflecting member), and the imaging system illuminance (cosine fourth power law) in the coordinate sensor units 1L and 1R. .

  As a method of solving the shortage when the amount of reflected light is insufficient, it is conceivable to increase the illumination intensity of the light projecting unit 30. However, when the reflected light quantity distribution is not uniform, that is, in a coordinate input device that uses even an area where the incident angle exceeds 0 ° to 45 °, the light of the portion where the retroreflected light is strong (incident angle) When the light is received, the signal from the region may be saturated in the line CCD 41 in the sensor unit, and there is a limit to increasing the illumination intensity.

  Therefore, unless the reflected light amount distribution obtained as the reflection characteristic of the retroreflective member 3 is made as uniform as possible, it is not possible to increase the retroreflected light in the low light amount portion having a large incident angle by increasing the illumination intensity.

  From this point of view (measurement of uniformity with respect to the angle direction), in Embodiment 1, the member to which the retroreflective sheet is attached has a structure in which chevrons are arranged as shown in FIG. A retroreflective member 3 is configured by attaching a reflective tape.

  By comprising in this way, the incident angle of the light ray which injects into a retroreflection tape geometrically can be made smaller, and distribution of the reflective characteristic of the retroreflection member 3 can be made uniform.

  The apex angle or the like of the chevron may be determined from the reflection characteristics of the retroreflective member 3, and further, for example, an angle range of approximately 90 ° is decomposed by 100 pixels of the line CCD 41 of the sensor unit 1L (1R). Then, one pixel corresponds to about 0.9 °. At that time, if the light ray passing through the coordinate input area 4 has the shortest distance to the retroreflective tape and the length of the light ray is Lmin (see FIG. 1), Lmin × Sin (0.9 °) ) (That is, if the angular resolution is ε, Lmin × Sin (ε)) or less, it is preferable to set the pitch of the chevron of the retroreflective member 3.

  Further, as shown in FIG. 8, when there is a region where the incident angle from each sensor unit of the sensor units 1L and 1R does not exceed 45 °, the region is formed in the shape of the retroreflective tape as it is (planar shape). A similar effect can be obtained by attaching a retroreflective sheet to the member to constitute the retroreflective member 3 and forming only the remaining portion in a mountain shape.

<Description of control / arithmetic unit>
Between the control / arithmetic unit 2 and the sensor units 1L and 1R, the CCD control signal for the line CCD 41 in the detection unit 40, the clock signal and output signal for the CCD, and the drive signal for the infrared LED 31 of the light projecting unit 30 are mainly used. Are being exchanged.

  Here, the detailed configuration of the control / arithmetic unit 2 will be described with reference to FIG.

  FIG. 9 is a block diagram showing a detailed configuration of the control / arithmetic unit according to the first embodiment of the present invention.

  The CCD control signal is output from an arithmetic control circuit (CPU) 83 constituted by a one-chip microcomputer or the like, and shutter timing of the line CCD 41, data output control, and the like are performed. The arithmetic control circuit 83 operates in accordance with the clock signal from the main clock generation circuit 86. The clock signal for the CCD is transmitted from the clock generation circuit (CLK) 87 to the sensor units 1L and 1R, and arithmetic control is performed in order to perform various controls in synchronization with the line CCD 41 in each sensor unit. It is also input to the circuit 83.

  The LED drive signal for driving the infrared LED 31 of the light projecting unit 30 is sent from the arithmetic control circuit 83 to the infrared LED 31 of the light projecting unit 30 of the corresponding sensor units 1L and 1R via the LED drive circuits 84L and 84R. Have been supplied.

  Detection signals from the line CCD 41 of the detection unit 40 of each of the sensor units 1L and 1R are input to the corresponding A / D converters 81L and 81R of the control / arithmetic unit 2, and converted into digital values by the control from the arithmetic control circuit 83. Converted. The converted digital value is stored in the memory 82 and used for calculating the angle of the indicator. Then, a coordinate value is calculated from the calculated angle, and is output to an external terminal via a serial interface 88 (for example, USB, RS232C interface, etc.).

<Explanation of light intensity distribution detection>
FIG. 10 is a timing chart of control signals according to the first embodiment of the present invention.

  In FIG. 10, reference numerals 91 to 93 denote CCD control signals, and the shutter release time of the line CCD 41 is determined by the interval of the SH signal 91. The ICGL signal 92 and the ICGR signal 93 are gate signals to the sensor units of the sensor units 1L and 1R, and are signals for transferring the charge of the photoelectric conversion unit of the internal line CCD 41 to the reading unit.

  Reference numerals 94 and 95 denote drive signals for the light projecting units 30 of the sensor units 1L and 1R, respectively. Here, in order to turn on the light projecting unit 30 of the sensor unit 1L (light projecting period 96L) in the first cycle of the SH signal 91, the LEDL signal 94 is supplied to the light projecting unit 30 via the LED drive circuit 84L. . Further, in order to turn on the light projecting unit 30 of the sensor unit 1R (light projecting period 96R) at the next cycle of the SH signal 91, the LEDR signal 95 is supplied to the light projecting unit 30 via the LED drive circuit 84R.

  Then, after the driving of the light projecting units 30 of both the sensor units 1L and 1R is completed, the detection signals of both the detection units (line CCD 41) of the sensor units 1L and 1R are read.

  Here, the detection signals read from both the sensor units 1L and 1R are output from the respective sensor units as shown in FIG. 11A when there is no input to the coordinate input area 4 by the pointing tool. A light quantity distribution is obtained. Of course, such a light amount distribution is not necessarily obtained in any system, and the light amount distribution depends on the retroreflective characteristics of the retroreflective member 3, the characteristics of the light projecting unit 30, and changes with time (such as dirt on the reflecting surface). Change.

  In FIG. 11A, 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 retroreflective member 3, 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 converters 81L and 81R, and taken into the arithmetic control circuit 83 as digital data.

  On the other hand, when there is an input to the coordinate input area 4 by the pointing tool, a light amount distribution as shown in FIG. 11B is obtained as an output from the sensor units 1L and 1R.

  In part C of this light quantity distribution, the reflected light from the retroreflective member 3 is blocked by the pointing tool, so that it can be seen that the quantity of reflected light is reduced only in that part (light shielding range).

  In the first embodiment, the sensor unit 1L is based on the light amount distribution of FIG. 11A when there is no input by the pointing tool and the change of the light amount distribution of FIG. 11B when there is an input by the pointing tool. And the angle of the indicator with respect to 1R is calculated.

  Specifically, the light amount distribution of FIG. 11A is stored in advance in the memory 82 as an initial state. Then, whether or not there is a change in the light quantity distribution as shown in FIG. 11B in the sample period of the detection signals of the sensor units 1L and 1R is stored in the memory 82 and the light quantity distribution during the sample period. It is detected by the difference from the light quantity distribution in the initial state. Then, when there is a change in the light amount distribution, an operation for determining the input angle with the changed portion as the input point of the pointing tool is performed.

<Description of angle calculation>
In calculating the angle of the pointing tool with respect to the sensor units 1L and 1R, first, it is necessary to detect a light shielding range by the pointing tool.

  As described above, the light quantity distribution detected by the sensor units 1L and 1R is not constant due to factors such as changes over time. Therefore, the initial light quantity distribution (initial data) is stored in the memory 82 every time the system is started, for example. It is desirable to memorize.

  In other words, if initial data is set at the time of shipment from a factory or the like and the initial data is not updated sequentially, for example, when dust adheres to the retroreflective surface at a predetermined position, the retroreflective efficiency at that part decreases. As a result, the coordinate input operation is performed at that position (direction viewed from the sensor unit 1L or 1R), that is, a serious result of erroneous detection is caused.

  Therefore, by storing the initial data in the memory 82 at the time of starting up the system, even if the retroreflective surface is soiled with dust or the like over time and the retroreflective efficiency is lowered, the state is reset as the initial state. Therefore, there is no malfunction.

  Hereinafter, although the angle calculation of the pointing tool by one of the sensor units 1L and 1R (for example, the sensor unit 1L) will be described, it goes without saying that the same angle calculation is performed by the other (the sensor unit 1R).

  When the power is turned on, there is no input (there is no light shielding range), and first, the light amount distribution, which is the output of the detection unit 40, is stopped while the light projection from the light projecting unit 30 in the sensor unit 1L is stopped. This value is stored in the memory 82 as Bas_data [N].

  This value is data including variations in bias of the detection unit (line CCD 41), and is data near level B in FIG. Here, N is a pixel number of a pixel constituting the line CCD 41, and a pixel number corresponding to an effective input range (effective range) is used.

  Next, in a state in which light is projected from the light projecting unit 30, the light amount distribution that is the output of the detection unit 40 is A / D converted, and this value is stored in the memory 82 as Ref_data [N].

  This value is, for example, data indicated by a solid line in FIG.

  Then, using Bas_data [N] and Ref_data [N] stored as initial data in the memory 82, first, the presence / absence of input by the pointing tool and the presence / absence of the light shielding range are determined.

  Here, the pixel data of the Nth pixel within the sample period of the output of the sensor unit 1L (line CCD 41) is Norm_data [N].

  First, in order to specify the light shielding range, the presence or absence of the light shielding range is determined based on the absolute amount of change in the pixel data. This is to prevent erroneous determination due to noise or the like and to detect a certain amount of reliable change.

  Specifically, the absolute amount of change in the pixel data is calculated for each pixel of the line CCD 41 and compared with a predetermined threshold value Vtha.

Norm_data_a [N] = Norm_data [N] − Ref_data [N] (1)
Here, Norm_data_a [N] is an absolute change amount in each pixel of the line CCD 41.

  Since this process merely calculates the absolute change amount Norm_data_a [N] of each pixel of the line CCD 41 and compares it with the threshold value Vtha, the processing time is not so much required, and the presence / absence of input is determined at high speed. Is possible. In particular, when the number of pixels exceeding the threshold value Vtha for the first time is detected exceeding a predetermined number, it is determined that there is an input from the pointing tool.

  Next, a method for determining the input point by calculating the change ratio of the pixel data in order to detect the input by the pointing tool with higher accuracy will be described with reference to FIG.

  In FIG. 12, 121 is a retroreflective surface of the retroreflective member 3. Here, assuming that the reflectance of the α region is reduced due to dirt or the like, the pixel data distribution (light quantity distribution) of Ref_data [N] at this time corresponds to the α region as shown in FIG. The amount of reflected light at the part to be reduced is reduced. In this state, as shown in FIG. 12, if the indicator 5 is inserted and substantially covers the upper half of the retroreflective surface 121, the amount of reflected light is substantially halved. The distribution Norm_data [N] will be observed.

  When the expression (1) is applied to this state, the pixel data distribution is as shown in FIG. Here, the vertical axis represents the differential voltage from the initial state.

  If the threshold value Vtha is applied to this pixel data, the original input range may be deviated. Of course, if the value of the threshold value Vtha is lowered, detection is possible to some extent, but the possibility of being affected by noise or the like increases, resulting in a problem that the coordinate calculation performance is degraded.

  Therefore, the amount of light blocked by the pointing tool is the first half of both the α region and the β region (in FIG. 13B, the α region corresponds to the V1 level, and the β region corresponds to the level V2). Let's calculate the ratio of the change.

Norm_data_r [N] = Norm_data_a [N] / (Bas_data [N]-Ref_data [N]) (2)
If this calculation result is shown, since the change of the pixel data is represented by a ratio as shown in FIG. 14B, even if the reflectance of the retroreflective member 3 is different, it can be handled equally and with high accuracy. Detection is possible.

  By applying the threshold value Vthr to this pixel data, the pixel numbers corresponding to the rising and falling portions of the pixel data distribution corresponding to the light shielding range are obtained, and for example, the center of both is input by the pointing tool. By setting the corresponding pixel, it is possible to determine a more accurate input position of the pointing tool.

  FIG. 14B is schematically drawn for explanation, and does not actually rise like this, and shows a different data level for each pixel.

  Hereinafter, details of the detection result when Expression (2) is applied to the pixel data will be described with reference to FIG.

  FIG. 15 is a diagram showing details of the detection result of the first embodiment of the present invention.

In FIG. 15, when the rising portion of the pixel data distribution crossing the threshold value Vthr is the Nrth pixel and the falling portion is the Nfth pixel with respect to the threshold value Vthr for detecting the light shielding range by the pointing tool, both The center pixel Np of the pixel of
Np = Nr + (Nf-Nr) / 2 (3)
It is possible to calculate. However, in this calculation, the pixel interval of the line CCD 41 becomes the minimum resolution.

  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.

Here, the data level of the Nrth pixel is Lr, and the data level of the Nr-1th pixel is Lr-1. If the data level of the Nf-th pixel is Lf and the data level of the Nf-1th pixel is Lf-1, the respective virtual pixel numbers Nrv and Nfv are
Nrv = Nr-1 + (Vthr-Lr-1) / (Lr-Lr-1) (4)
Nfv = Nf-1 + (Vthr-Lf-1) / (Lf-Lf-1) (5)
Can be calculated. And the virtual center pixel Npv of these virtual pixel numbers Nrv and Nfv is
Npv = Nrv + (Nfv-Nrv) / 2 (6)
Determined by

  Thus, detection with higher resolution can be performed by calculating a virtual virtual pixel number that crosses the threshold Vthr from the pixel number of the pixel of the data level exceeding the threshold Vthr and the adjacent pixel number and the data level. Can be realized.

<Conversion from pixel number to angle information>
Next, in order to calculate the actual coordinate value of the pointing tool from the center pixel number indicating the center point of the light shielding range, it is necessary to convert this center pixel number into angle information (θ).

  Here, the relationship between the pixel number and θ will be described with reference to FIG.

  FIG. 16 is a diagram illustrating the relationship of the θ value with respect to the pixel number according to the first embodiment of the present invention.

Based on FIG. 16, when defining an approximate expression for obtaining θ from the pixel number,
θ = f (N) (7)
Thus, it is possible to convert the pixel number to θ using the approximate expression (conversion expression).

  In the first embodiment, the lens group of the detection unit 40 in the sensor unit 1L (1R) described above is configured so that it can be approximated by using a first-order approximation formula. It may be possible to obtain angle information with higher accuracy by using the following approximate expression.

  Here, what lens group is adopted is closely related to the manufacturing cost. In particular, when correcting optical distortions that are generally generated by lowering the manufacturing cost of a lens group using higher-order approximations, a certain amount of computing power (calculation speed) is required. In consideration of the coordinate calculation accuracy required for the target product, both may be set as appropriate.

  On the other hand, when the coordinate value is calculated from the angle information by the method described later, the calculation of the trigonometric function is performed by calculating the tangent value (Tangent) at the angle rather than calculating the angle itself from the obtained pixel number. This is convenient because it can be omitted.

  Therefore, as shown in FIG. 17, the relationship of Tanθ to the pixel number is obtained, an approximate expression is derived, and the conversion from the pixel number to the Tanθ value is performed using the approximate expression. For example, when a fifth-order polynomial is used as an approximate expression, six coefficients are required. Therefore, the coefficient data may be stored in the memory 82 at the time of shipment.

Here, if the coefficients of the fifth-order polynomial are L5, L4, L3, L2, L1, L0, Tanθ is Tanθ = (L5 * Npr + L4) * Npr + L3) * Npr + L2) * Npr + L1) * Npr + L0 (8)
Can be shown.

  If this is performed for the pixel numbers detected by the line CCD 41 of the detection unit 40 of each of the sensor units 1L and 1R, the corresponding angle data (Tan θ) can be determined from each.

<Description of coordinate calculation method>
Next, a coordinate calculation method for calculating the position coordinates of the pointing tool from the angle data (tan θ) converted from the pixel number will be described.

  Here, the positional relationship between the coordinates defined on the coordinate input area 4 and the sensor units 1L and 1L will be described with reference to FIG.

  FIG. 18 is a diagram showing the positional relationship between the coordinates defined on the coordinate input area and the sensor units 1L and 1L according to the first embodiment of the present invention.

  In FIG. 18, the X axis is defined in the horizontal direction of the coordinate input area 4 and the Y axis is defined in the vertical direction, and the center of the coordinate input area 4 is defined as the origin position O (0, 0). The sensor units 1L and 1R are attached symmetrically to the Y axis on the left and right sides of the upper side of the coordinate input range of the coordinate input area 4, and the distance between them is Ds.

  The light receiving surfaces of the sensor units 1L and 1R are arranged such that the normal direction forms an angle of 45 degrees with the X axis, and the normal direction is defined as 0 degrees.

  At this time, the sign of the angle is the clockwise direction in the case of the sensor unit 1L arranged on the left side, and the counterclockwise direction in the case of the sensor unit 1R arranged on the right side. Is defined as the “+” direction.

Further, P0 is the position of the intersection of the sensor units 1L and 1R in the normal direction, and the distance from the origin in the Y-axis direction is defined as P0y. At this time, if the angles obtained by the sensor units 1L and 1R are θL and θR, the coordinates P (x, y) of the point P to be detected are
x = Ds / 2 * (tanθR-tanθL) / (1-(tanθR * tanθL)) (9)
y = Ds / 2 * (tanθR + tanθL + (2 * tanθR * tanθL)) /
(1-(tanθR * tanθL)) + P0y (10)
Calculated by

  The shading type coordinate input device has been described above. Here, specific use examples and operation examples of the input / output integrated device in which the coordinate input device and the large display device are integrated will be described.

  The first usability is that the coordinate input device according to the first embodiment has, for example, a coordinate value of a specific region (for example, a specific region is, for example, a region having a radius R centered on a certain coordinate value or a certain coordinate value as a center of gravity. When a specific place having a certain area is output in the meaning of a polygon or the like, an operation assigned to the specific area is executed.

  In other words, an icon indicating a switch is displayed on a portion corresponding to the specific area by the display device, and the operator touches (clicks) the icon to change any coordinate value in the specific area to the embodiment. One coordinate input device outputs, and it is comprised so that the operation | movement allocated to the switch may be performed.

  The second ease of use is that the detected coordinate value corresponding to the movement is output continuously as the pointing device is moved by the operator, and based on the coordinate information, it is as if "pencil and paper". The movement of the pointing tool (hereinafter referred to as handwriting) is displayed on the display device. By configuring the device in which the display device and the coordinate input device are integrally combined in this way, it is possible to directly input characters and figures as in the well-known “white board using ink pen”.

  The third usability is the tapping operation of the pointing tool by the operator, that is, “double click” which is well known in the present situation, in particular, the mouse operation of the personal computer, for example, by continuously touching the display screen twice. It is easy to use. A normal coordinate input device can output coordinate values at predetermined intervals (for example, it has the ability to output coordinates every 5 msec at a coordinate detection sampling rate of 100 points / second). By monitoring the timing, it is possible to determine whether or not the pointing tool is tapping.

  More specifically, after the coordinate value A is output at a certain time, the coordinate value is not detected in the next coordinate sampling (for example, at the coordinate detection sampling rate of 100 points / second, 5 msec time elapses). If the coordinate value B to be output next is within a predetermined time from the time when the coordinate value A is output and the coordinate value A and the coordinate value B are substantially equal, the double click operation is performed. It is determined that

  Now, let us consider the operability of an operator who operates a light shielding coordinate input device.

  FIG. 19B is a layout diagram viewed from the front direction of the coordinate input device. By pointing a specific area (SW1 to SW3) provided in the lower left corner of the coordinate input area 4, for example, a specific application This is an example in which a plurality of switch areas that can be configured to start up are installed.

  That is, when the operator designates a predetermined specific area with the pointing tool 5 such as a finger, the coordinate input device outputs a coordinate value, but the output coordinate value is within the specific area. It is determined whether it is a coordinate value. And it is comprised so that the operation | movement allocated to the specific area | region may be performed with this determination result, and it acts as if it operate | moves as a switch means.

  FIG. 19A shows a cross-sectional view taken along the line AA in FIG. The coordinate input area 4 made of a planar member also serves as the display surface of the display device. The light beam illuminated by the light projecting unit in the sensor unit 1 is emitted substantially parallel to the surface of the display device, is retroreflected by the retroreflective member 3, and is detected by the detection unit in the sensor unit 1. As shown in FIG. 19A, the luminous flux is set in a range of heights h1 to h2 from the display surface (substantially equivalent to the installation range of the retroreflective member 3). Is difficult to set for the following reasons.

  In general, in a large display device, particularly in a conference system in which a large number of participants hold a conference using the display device, the display size is about 60 inches to 100 inches diagonal or larger. Is required. Furthermore, since the surface of the display device is a coordinate input surface, it is required that the display surface does not bend even when pressed by a finger or the like.

  Therefore, the display surface is manufactured with a material having rigidity, but considering that the display area is large and transparency is necessary, for example, if the display surface uses glass, the plate thickness Is required to be rather thick and must be a heavy device.

  Furthermore, in a rear projector type display device used as a current large display device, the display surface is usually composed of a transparent resin plate having optical characteristics such as a Fresnel lens and a lenticular lens. The increase in the plate thickness not only increases the weight but also deteriorates the light transmittance and the like, and decreases the function as a display device.

  Therefore, as a countermeasure usually taken, there is a method of increasing the apparent rigidity by providing a curvature on the display surface even if it is slight. Now, if the central portion of the display surface is configured to be convex, h1 at the central portion of the display area can be set to “0” as much as possible. Since it is convex, the luminous flux is blocked by the display surface, so h1 corresponding to at least the bulge height is naturally set (see FIG. 20A. Specifically, the bulge of the display surface 4). If, for example, 5 mm higher than the peripheral part, the h1 at the peripheral part is at least 5 mm). Conversely, if the central portion of the display surface is concave, it can be set to almost “0” at the periphery of the display area, but not at the central portion of the display area.

Although described above from the viewpoint of rigidity, even if sufficient rigidity is obtained, it is difficult to set h1 to “0”. More specifically, assuming that the display size is 70 inches diagonal and the aspect ratio is 3: 4, the size of the display area is about 1060 mm × 1420 mm and the area is about 1.times. equivalent to 5m ^2.

  Considering the flatness of the material of the display surface, the flatness of the mounting surface, or the influence of thermal expansion, the flatness of the display surface is maintained at almost “0” in a state where the display surface is incorporated in the apparatus. This is impossible, and even if the value is about ± 1 mm, there is a great industrial difficulty. Therefore, it can be said that it is difficult to set the value of h1 to “0”.

  Now, as shown in FIG. 19B, a plurality of switch areas are set in the coordinate input area 4 as shown. At this time, consider a case where the operator operates a switch 2 (SW2) in the drawing to execute a desired application. The operator's hand / finger is not aware of the movement only in the direction perpendicular to the display surface and does not perform the switch operation (act of touching the SW2 area in FIG. 19B). It is normal not to be aware of the movement trajectory of the hand / finger except that it is “just in the SW2 region”. For example, the movement operation is performed along the trajectory indicated by the thick arrow in FIG.

  The operation that the coordinate input device determines in accordance with this moving operation will be described. First, the operator tries to execute the control assigned to the SW2 area, and touches the SW2 area to display the coordinate input area (display surface). ) It is assumed that the light beam set substantially parallel to 4 starts to be blocked and the pointing tool 5 such as a finger / hand is moved to the position (1). Here, when the light beam starts to be blocked, the coordinates of the light blocking position start to be output. When the state (1) is reached, the down flag is set.

  This down flag is a determination flag that is output together with the coordinate value in order to determine whether or not the operator has touched the coordinate input area 4, and how much light is blocked by the pointing tool 5 (described above). As described with reference to FIG. 12, it can be determined by determining what percentage of the light beam is shielded).

  The position at which the down flag is set changes depending on the level at which the determination threshold is set. However, since at least the state (1) blocks almost all the light flux, the down flag is set. At this point in time, the operator has not yet touched the display surface (coordinate input area) 4 and has not yet intended to operate the switch.

  Then, it is recognized that the switch operation is performed by pressing the SW2 area at the position (2) (the position in contact with the coordinate input area 4). The operator achieves the object of performing the switch operation and moves the pointing tool 5 to the position (3). Even at the position (3), the coordinate input device displays the down flag. While the is set (because almost all of the light beam is blocked), the coordinate value continues to be output. And as it moves to the position of (4), the coordinate value is output continuously, but the amount of blocked light gradually decreases, the down flag is released at the position according to the value of the judgment threshold, and eventually When the light beam is no longer blocked, the coordinate output is stopped.

  Now, what becomes a problem here is that the operator only recognizes that “the SW2 area has been pressed” in the state (2), whereas the coordinate input device is shown in FIG. In this down flag area, a down flag set signal is output together with the coordinate value.

  In other words, when the coordinate value output last is in the SW3 area with the down flag set by a series of moving actions of the operator, the operator surely pressed the SW2 area. Instead, the execution instruction assigned to the SW3 area is executed. This not only gives the operator an unintended operation, but depending on the contents of the execution command, there is a serious risk of causing an unrepairable state.

  As a countermeasure, for example, a sufficiently large space (gap) between the SW1 area and the SW2 area or a coordinate value output when the down flag is set is continuously monitored. Means such as setting the center of the coordinate value output inside as a definite value is also conceivable.

  However, the former measure has a new problem such as an increase in the interval between the switch areas and poor operability, or a large number of switches cannot be arranged due to the size limit of the coordinate input area. The latter countermeasure is, for example, “I've pointed to the wrong area, so I can achieve the original purpose by moving my finger in the state of (2) and releasing my finger at the correct position”. Therefore, the center position is not necessarily the correct position intended by the operator, that is, the possibility of malfunctioning cannot be excluded.

  As described above, for example, an icon (which may be an icon displayed in a specific area set in advance, or an area in which the icon is displayed is detected and the information and the coordinate input device are displayed on the display screen. When the user wants to execute a desired application or the like by touching the output coordinate values of these and touching the switch means, the coordinate input device is The adverse effect that occurs when the touch operation (determination of whether or not the input surface has been pressed) cannot be accurately detected has been described, but another specific failure will be described.

  Assume that the operator moves the pointing tool as shown in FIG. 21B in order to input the character “A”. At this time, the operator moves the pointing tool 5 by touching the input surface with the solid line portion in FIG. 21A, and moves the pointing tool 5 without touching the input surface with the broken line portion in FIG. It will be.

  That is, it is assumed that the operator recognizes that “touch the input surface” and leaves a handwriting, but actually, “touch the input surface” immediately before / after touching the coordinate input area 4. In the state where the down flag is set although it is not, the character information actually displayed is as shown in FIG.

  In other words, an extra locus is displayed immediately before / after touching the coordinate input surface even though the character “a” is input, and a display different from the locus intended by the operator can be obtained. . This phenomenon is hereinafter referred to as “tailing”, but due to the occurrence of this tailing, the information intended by the operator is not displayed, “difficult to see”, “cannot write small letters”, “draw fine graphic information. Such as “No”.

  Further, for example, as shown in FIG. 22A, when the operator intends to realize the above-described double click operation, the operator can recognize only “whether or not the input surface is touched”. is there. Therefore, in the state (3) of FIG. 22A, when the down flag is not reset, that is, when the pointing tool 5 is not sufficiently separated from the coordinate input area 4, the operator says “releases the pointing tool”. Despite being recognized, the coordinate input device detects the state in which the down flag is set in the states (2) to (4) in FIG. Will be executed.

  In order to solve this problem and to realize the double-click operation with certainty, the operator must operate with “sufficient stroke” as shown in the state (3) of FIG. Moreover, since the operator cannot immediately recognize how much the “sufficient stroke” is, he has to perform an over action. That is, a coordinate input device with excellent operability cannot be realized.

  Therefore, in the first embodiment, by pressing the tip of the dedicated pointing tool on the coordinate input area 4, the switch means built in the dedicated pointing tool is operated. Then, when the switch means is operated, a signal indicating that the tip of the pointing tool has been pressed is generated, and by detecting the signal, it is determined whether or not the pointing tool has touched the coordinate input area 4. A coordinate input pen that can be configured is configured.

  FIG. 23 is a schematic configuration diagram of the coordinate input pen according to the first embodiment of the present invention.

  The coordinate input pen 60 includes a pen tip 67, a battery 66, a DC converter 65 for boosting the battery voltage, a pen tip switch 61 (pen down detection switch) built in the coordinate input pen 60, and a pen provided on the pen side. A pen control circuit 64 that detects an operating state of the side switch 62 and generates a signal for transmitting the detection result to an external device or the like, and a light emitting unit (for example, a plurality of light emitting units) that emits the generated signal as an optical signal Infrared light emitting LED) 63.

  For example, when the pen side switch 5 is in an operating state (ON state), the pen side switch 62 emits the switch signal from the light emitting unit 63. The coordinate input device main body that receives this switch signal is configured so that, for example, a specific application can be activated or a menu can be displayed on the display screen in the same way as a normal mouse right button.

  It should be noted that there may be a plurality of penside switches 62 depending on the application, or the penside switch 61 may not be provided.

  In the first embodiment, the pen control circuit 64 detects the operation state of the pen tip switch 61 and the pen side switch 62, emits the detection result as an optical signal by the light emitting unit 4, and detects the sensor unit of the coordinate input device. The signal is detected by 1L and 1R, and specific processing can be executed. However, the transmission medium does not have to be light, and may be radio waves or ultrasonic waves, for example.

  Further, the coordinate input pen 60 and the coordinate input device may be connected by a signal cable, and the signal from the coordinate input pen 60 may be transmitted to the coordinate input device main body via the signal cable. In this case, since the coordinate input pen 60 is connected to the coordinate input device main body by a signal cable, the operation range of the coordinate input pen 60 is limited, and there is a concern that workability and operability may be reduced.

  However, in this case, since the power can be supplied from the coordinate input device main body side to the coordinate input pen 60 via the signal cable, the coordinate input pen 60 does not require the battery 66 and can be reduced in weight. It can be a suitable configuration for applications that are used for a long time, that is, applications that care about battery life.

  Now, the switch signal radiated as an optical signal from the light emitting unit 63 is modulated at a predetermined frequency f so as not to be affected by disturbances or the like. Here, an example of the switch signal will be described with reference to FIG.

  FIG. 24 is a diagram illustrating an example of a switch signal according to the first embodiment of the present invention.

  As shown in FIG. 24, the switch signal is generated when the start signal (start bit) Start indicating the start of the signal, the pen down switch signal S0 generated when the pen tip switch 61 operates, and the pen side switch 61 operates. The pen side switch signal S1 is composed of the inverted signals / S0 and / S1 of the S0 and S1 signals, and the stop signal (stop bit) Stop indicating the end of the signal to determine the validity of the data, and each is modulated at the frequency f. Has been.

  The modulated light from the light emitting unit 63 is demodulated by the sensor unit 1L (1R) as shown in FIG. 25, and is output as a bit string to the arithmetic / control unit 2 in the coordinate input device. For example, the validity of the switch signal is determined by the arithmetic control circuit 83.

  When the arithmetic control circuit 83 in the arithmetic / control unit 2 detects the start signal Start at the start of the switch signal, it performs sampling at a constant period and determines 1 or 0 of each bit position. In this determination, for example, it is determined whether or not the logical value of the pen-down switch signal S0 and its inverted signal / S0 is present, and whether or not the stop signal Stop can be detected. Is configured to discard the data and perform detection again.

  When the coordinate input pen 60 that emits the state of the pointing tool as an optical signal is applied to the light shielding type coordinate input device as in the first embodiment, in actual operation, coordinate acquisition for coordinate acquisition is performed. Light emission for use (in FIG. 9, LED drive circuits 84L and 84R operating based on the control of the arithmetic control circuit 83, and the infrared LEDs 31 of the light projecting unit 30 in the sensor units 1L and 1R driven by the LED drive circuits 84L and 84R) ) And the pen light emission for the pen signal by the coordinate input pen 60 are not synchronized. Therefore, there are cases where the light emission for coordinate acquisition and the pen light emission overlap.

  FIG. 26 shows such a case, where the upper row is a pen light emission signal from the coordinate input pen 60, and the lower row is a light emission signal (drive signal) 94, 95 for coordinate acquisition of the light projecting unit 30 for coordinate acquisition. FIG. 10).

  In FIG. 26, when the pen light emission signal is A, there is no problem because the pen light emission and the coordinate light emission period are surely shifted, but in the case of FIG. 26B, a part of the pen light emission is the same. In the case of FIG. C, the pen light emission completely overlaps the coordinate light emission period. If there is such an overlap, saturation may occur in the light emission signal for coordinate acquisition, or it may cause waveform deformation and cause detection errors. Therefore, it is necessary to control so that the light emission of both does not overlap.

  FIG. 27 shows an example. In the figure, 510 is the output of the sensor unit 1L (1R). Reference numeral 511 denotes a coordinate acquisition prohibition signal that prohibits coordinate acquisition when the output signal 510 is active, and is active for a certain period of time (in this case, LOW) after the head light is received by the arithmetic control circuit 83.

  512 and 513 are light emission signals for coordinate acquisition. First, the arithmetic control circuit 83 in the arithmetic / control unit 2 emits light to acquire coordinates at certain time intervals, and performs an operation of determining whether or not the coordinate input pen 60 emits light before the light emission.

  That is, the coordinate acquisition prohibition signal 511 is monitored, and if it is not active, the arithmetic control circuit 83 starts the light emission operation for coordinate acquisition. If the coordinate acquisition prohibition signal 511 is active, the coordinate acquisition prohibition signal is Coordinates are acquired after waiting until inactive (point A in FIG. 27A).

  On the other hand, if pen light is emitted during light emission for coordinate acquisition, the coordinate acquisition prohibition signal 511 may become active. At that time, as shown in FIG. 27B, since the coordinate acquisition prohibition signal 511 is inactive, the arithmetic control circuit 83 starts the light emission operation for coordinate acquisition, but the coordinate acquisition prohibition signal 511 is active during the light emission operation. become. Therefore, in this case, the obtained data is invalidated, and after waiting for the coordinate acquisition prohibition signal 511 to become inactive, the coordinate acquisition light emission operation is performed again.

  In the first embodiment, since the coordinate acquisition prohibition signal 511 is set to be longer than the coordinate acquisition light emission period, the coordinate acquisition prohibition signal 511 is monitored immediately before and after the start of coordinate acquisition light emission. By doing so, it is possible to configure so that both the pen light emission and the coordinate obtaining light emission do not emit light simultaneously.

  In addition, as described above, the coordinate input device according to the first embodiment is configured to detect coordinates at a constant period. Therefore, when pen light emission is not detected, light emission for coordinate acquisition is performed at the predetermined period. Is done. When pen light emission is detected and both of them are overlapped, the coordinates are read again, and the coordinates are output every predetermined cycle with the timing of the rereading as a trigger.

  Accordingly, it is possible to avoid duplication of pen light emission and light emission for coordinate acquisition only by checking the coordinate acquisition prohibition signal 511 at the time of light emission for coordinate acquisition, and it is possible to prevent a decrease in coordinate detection accuracy and the like. It becomes.

  In the first embodiment, the coordinate acquisition prohibition signal 511 is actively held for a longer time than the coordinate acquisition light emission period. However, when the processing capacity of the arithmetic / control unit 2 has a margin, that is, In the case where the coordinate acquisition prohibition signal 511 can always be monitored, the coordinate acquisition prohibition signal 511 may be activated only for the time required for light emission. For example, if the switch signal of the coordinate input pen 60 has the signal configuration shown in FIG. 24, it is possible to prohibit the time from the start signal Start to the end of the emission of the stop signal Stop.

The coordinate calculation process of the coordinate input device based on the above configuration will be described with reference to FIG.
FIG. 28 is a flowchart showing a coordinate calculation process executed by the coordinate input device according to the first embodiment of the present invention.

  First, when the power of the coordinate input device is turned on, various initializations relating to the coordinate input device such as port setting and timer setting of the control / arithmetic unit 2 are performed in step S102.

  In step S103, the initial reading count of the initial reading operation of the line CCD 41 is set.

  This initial reading operation is an operation for removing unnecessary charges from the line CCD 41 when the coordinate input device is activated. In the line CCD 41, unnecessary charges may be accumulated when the line CCD 41 is not operated. If the coordinate input operation is executed in a state where the charges are accumulated, detection becomes impossible or erroneous detection is caused. . Therefore, in order to avoid this, in step S103, a predetermined number of reading operations are executed in a state in which the light projection by the light projecting unit 30 is stopped, thereby removing unnecessary charges.

  In step S104, the line CCD 41 is read. In step S105, it is determined whether or not reading has been performed a predetermined number of times or more. If reading has not been performed a predetermined number of times or more (NO in step S105), the process returns to step S104. On the other hand, when the reading is executed a predetermined number of times or more (YES in step S105), the process proceeds to step S106.

  In step S106, the pixel data (Bas_data [N]) of the line CCD 41 in a state where the light projection by the light projecting unit 30 is stopped is captured as the first reference data. In step S107, the first reference data is stored in the memory 82.

  Next, in step S108, the pixel data (Ref_data [N]) of the line CCD 41 in a state where light is emitted from the light projecting unit 30 is fetched as second reference data. In step S109, the second reference data is stored in the memory 82.

  The processing so far is the initial operation when the power is turned on. Needless to say, this initial setting operation may be configured to operate according to the operator's intention using a reset switch or the like configured in the coordinate input device. The state is shifted to the coordinate input operation state by the pen 60.

  First, in step S121, it is determined whether or not the coordinate acquisition prohibition signal 161 indicating whether or not the coordinate input pen 60 emits light is active. If the coordinate acquisition prohibition signal is active (YES in step S121), the determination is repeated until inactive. On the other hand, if the coordinate acquisition prohibition signal is inactive (NO in step S121), the process proceeds to step S110.

  In step S110, the normal reading operation of the line CCD 41 is executed in the coordinate input sampling state, and pixel data (Norm_data [N]) is captured. Next, in step S122, it is determined again whether the coordinate acquisition prohibition signal 161 is active. If the coordinate acquisition prohibition signal is active (YES in step S122), the determination is repeated until inactive. On the other hand, if the coordinate acquisition prohibition signal is inactive (NO in step S122), the process proceeds to step S111.

  In step S111, a difference value between the second reference data (Ref_data [N]) and the pixel data (Norm_data [N]) is calculated. In step S112, the presence / absence of input by the coordinate input pen 60 is determined based on the difference value and the threshold value Vthr. If there is no input (NO in step S112), the process returns to step S121. On the other hand, if there is an input (YES in step S112), the process proceeds to step S113.

  If the repetition period at this time is set to about 10 [msec], the sampling rate is 100 times / second.

  In step S113, the ratio of change in pixel data is calculated using equation (2).

  In step S114, the falling and rising of the pixel data distribution corresponding to the light shielding range by the coordinate input pen 60 are detected with respect to the calculated change ratio of the pixel data, and the detected falling and rising are detected ( 4), (5), and (6) are used to determine a virtual center pixel number that is the center of the light shielding range.

  In step S115, Tan θ is calculated from the determined center pixel number and equation (8). In step S116, the input coordinates P (x, y) of the coordinate input pen 60 are calculated from the Tan θ values for the sensor units 1L and 1R using the equations (9) and (10).

  Next, in step S117, it is determined whether or not the input by the coordinate input pen 60 is a touch-down input.

  In this determination, first, the presence or absence of light emission from the coordinate input pen 60 is determined based on the output of the sensor unit 1L (1R). In particular, when there is light emission from the coordinate input pen 60, it is a touch-down input by determining the operation state of the pen tip switch 61 of the coordinate input pen 60 by demodulating the obtained switch signal. Determine whether or not.

  Based on such a determination method, when the input by the coordinate input pen 60 is a touch-down input in step S117 (YES in step S117), the process proceeds to step S118 and is a touch-down input (that is, the pen tip 67 is changed). A down flag indicating that the pen point switch 9 is operating by pressing the coordinate input area 4 is set. On the other hand, if the input by the coordinate input pen 60 is not a touch-down input (NO in step S117), the process proceeds to step S119, and the down flag is reset.

  On the other hand, if it is determined in step S117 that no light is emitted from the coordinate input pen 60, it can be determined that the coordinate input is performed by an indicator such as a finger other than the coordinate input pen 60. The determination of the presence or absence of is performed as follows.

  As already described with reference to FIGS. 20 and 21, when an indicator such as a finger completely blocks light, that is, when the light is completely blocked by touching the coordinate input surface, The ratio value (see FIG. 22B) of the change in pixel data obtained by the output of the detected pixel approaches 1 (as described above, when about half of the light is shielded, the value is 0.5. ). Therefore, it is possible to determine whether or not an indicator such as a finger is touching the coordinate input surface by monitoring the value of the change ratio of the pixel data.

  As described above, the determination as to whether or not there is a touchdown with an indicator such as a finger other than the coordinate input pen 60 is realized by the determination method as described above. Based on the determination result, the down flag is set in step S118 or the down flag is reset in step S119.

  Note that the coordinate input by the pointing tool such as a finger cannot leave the locus intended by the operator faithfully compared to the input using the coordinate input pen 60 which is the dedicated pointing tool described above. Since there is an advantage that coordinate input can be performed without using a tool, the application may be switched according to the purpose of the operation.

  Further, in the case where coordinate input is performed using the coordinate input pen 60 which is the main focus of the first embodiment, a pen-down signal emitted according to the operation state of the coordinate input pen 60 is detected, and a down flag is set. (Step S118) or reset (Step S119) is performed.

  With this configuration, a state where the cursor on the display screen can be moved and a state where the cursor movement on the display screen is displayed as a handwriting by moving the coordinate input pen 60 (usually, In the case of a well-known mouse, it is possible to realize the operation of the mouse with the left mouse button pressed.

  In step S120, the state of the down flag (pen information (pen down or pen up)) and the calculated coordinate value are output to the external terminal. This output may be transmitted by serial communication such as a USB interface or RS232C interface, or may be transmitted by wireless communication such as a wireless LAN or Bluetooth.

  In the external terminal, the device driver that controls the coordinate input device interprets the received data, moves the cursor, and changes the mouse button state, thereby realizing the operation of the display screen.

  When the process of step S120 is completed, the process returns to step S110, and thereafter, the above process is repeated until the power is turned off or until the reset state is set by the operator's intention.

  As described above, by providing the pen tip switch 9 for accurately determining the positional relationship between the tip of the coordinate input pen 60 and the coordinate input surface, the above-described trouble such as “tailing” is provided. Alternatively, it is possible to avoid a decrease in operability. When such a dedicated indicator is used, a new advantage can be further obtained by configuring as follows.

  As described with reference to FIG. 19, when coordinates are input using a shield such as a finger, it is preferable that the value of the height h1 or h2 be as small as possible due to the restriction of the down flag setting. However, when a dedicated pointing tool is used, this restriction is eliminated because the down flag can be easily set by another means.

  Therefore, as shown in FIG. 20B, the value of the height h1 can be set intentionally, and the coordinate input can be performed even at a position away from the coordinate input area 4. As a convenience, the position of the pointing tool can be detected even at a position away from the coordinate input surface. Therefore, for example, by moving the displayed cursor with the coordinate detection value, the position of the pointing tool can be confirmed on the display screen, and the desired position on the display screen can be accurately indicated. it can.

  The function that allows coordinate input even at this distant position is generally called “proximity input”. In order to realize proximity input, a value of height h1 is intentionally set as shown in FIG. Various obstacles caused by setting the value of the height h1 are eliminated by detecting the state of the pen tip switch 61.

  Therefore, in the coordinate input device that can realize both the coordinate input by the self-luminous dedicated indicator such as the coordinate input pen 60 of the first embodiment and the coordinate input by an arbitrary shielding object such as a finger, When inputting coordinates using a shield, the value of height h1 is as small as possible. Conversely, when inputting coordinates using a self-luminous dedicated indicator (coordinate input pen 60), the value of height h1 is as large as possible. It is preferable to configure to set.

  Here, in the state in which the value of the height h1 is set intentionally, for example, the above-described obstacle such as “tailing” appears more noticeably by the coordinate input by the finger. Consider the operability related to the operation using the “coordinate input pen” and the operation using a finger or the like.

  Compared with finger touch input, using the "coordinate input pen" is more convenient for inputting fine characters and figures because the tip of the pen is sharper than the finger (use a ballpoint pen that is thinner than magic with a thick pen tip) It is clear that you can enter finer characters). In addition, by operating the pen side switch, more complicated operations (depending on the application, for example, when the pen side switch is operated, the writing function can be changed to the eraser function) It can be done while holding it).

  On the other hand, although the operation with a finger has the advantage of not requiring a specific writing instrument, there is a problem with the writing feeling due to the friction between the finger and the input surface (display surface) when considering inputting characters with the fingertip (operability) The problem is that the display surface is soiled by fingerprints (sweat). Considering these, it can be said that the input by the finger is convenient for an application such as a switch operation by touching a specific area of the coordinate input area.

  In other words, since coordinate input using a coordinate input pen is an optimal tool for fine character / graphic input, it is important that proximity input is possible, and it is required to completely eliminate problems such as tailing. On the other hand, it can be said that the input by the finger is the most suitable means for rough coordinate input.

  The first embodiment has been made in view of this point, and is a coordinate input device that realizes both coordinate input by a coordinate input pen and coordinate input by a finger, and is an area in which coordinate input is mainly performed by a finger. Is configured so as to make the value of h1 as small as possible, and conversely, the region where the coordinate input is mainly performed by the pen is configured so that the value of h1 is set as large as possible.

  Therefore, the coordinate input device according to the first embodiment configures at least two surfaces having different surface heights in the coordinate input region.

  Specifically, as shown in FIG. 29, in a region where coordinate input by a finger is mainly performed, a spacer member 7 having a thickness h3 is used to perform the second operation on the first coordinate input surface with respect to the coordinate input region 4. By configuring the coordinate input surface and making the distance of the light flux from the second coordinate input surface and the sensor unit 1L (1R) as small as possible, it is configured so as not to cause a malfunction caused by “tailing” or the like.

  On the other hand, in a region where coordinate input by the coordinate input pen 60 is mainly performed, a value of h1 is appropriately set to constitute a coordinate input device with good operability capable of “proximity input”. At this time, even in the region where the spacer member 7 is arranged, it is possible to input coordinates with the coordinate input pen 60, and it is needless to say that operability equivalent to that with a finger can be obtained.

  In addition, when the region where the spacer member 7 is disposed is configured within the display area of the display device, the region is configured by a transparent member. For example, by displaying an icon indicating the switch region at the location, It is also possible to let the operator know that there is. On the other hand, if it is arranged outside the display area, an object indicating a switch may be applied to the spacer member 7 by printing or the like.

  In particular, in the former case, the display icon can be switched depending on the application or the like, and a switch unit having a plurality of functions can be configured.

  In Embodiment 1, the display surface 4 (coordinate input region 4) and the spacer member 7 constitute two coordinate input surfaces having different heights. For example, when a rear projector is used as the display device, In general, a display surface having optical characteristics is manufactured by molding, and in that case, it may be possible to mold both of them together.

  Furthermore, a second coordinate input surface is configured using a spacer member having a thickness of h3 such that h3 = h1 with reference to an area where coordinate input is mainly performed using the coordinate input pen 60, and at this time, For example, if the down flag is generated when the light from the sensor unit 1L (1R) is blocked by 90% or more (threshold value δ = 0.9 for detecting touchdown information), the down flag This occurs almost when the operator touches the second coordinate input surface.

  Further, the configuration is such that the down flag is set when the light from the sensor unit 1L (1R) is blocked by 40% or more (threshold value δ = 0.4 for detecting touchdown information), as shown in FIG. As shown in the figure, for example, by setting the third coordinate input surface by the spacer member 7 at a surface height position where the approximately luminous flux from the sensor unit 1L (1R) is shielded by about 50%, the operator can substantially change the first coordinate input surface. A down flag may be generated when the three-coordinate input surface is touched.

  Needless to say, the spacer member 7 at this time is composed of a member capable of transmitting a light beam.

  Furthermore, since the coordinate input device according to the first embodiment can detect the position coordinates of the light-shielding portion, if the height of the coordinate input surface in the coordinate input area and the position information thereof are stored in advance, the detected coordinate value is obtained. Based on this, it is possible to determine which position (height) the portion is on the first, second, or third coordinate input surface. Therefore, for example, by controlling the threshold δ variably according to the height of the coordinate input surface, it is possible to contribute to improving the reliability of setting / resetting down flag information.

  Here, the height h3 of the third coordinate input surface is defined as follows with respect to a threshold δ for detecting desired touchdown information, where W is the light flux from the sensor unit 1L (1R). can do.

h3 = h1 + W × (1−δ)
Further, when the light flux from the sensor unit 1L (1R) is blocked by 90% or more (threshold δ = 0.9 for detecting touchdown information), a down flag is set, as shown in FIG. For example, it is also possible to set the fourth coordinate input surface at the position of the height h3 of the surface where the approximately luminous flux from the sensor unit 1L (1R) is shielded by about 50%.

  Here, the height h3 of the fourth coordinate input surface is h1 << h3 <h2 (this expression means that h3 is sufficiently larger than h1 and less than h2), or h1 + W × (1− δ) <h3 <h2 is satisfied.

  Here, the luminous flux width W is W = h2−h1, and for example, if h3 is set to (h1 + h2) / 2, 50% of the luminous flux width W, that is, to a position where the luminous flux of W / 2 is shielded. Spacer member 7 is installed. Needless to say, the spacer member 7 at this time is composed of a member capable of transmitting a light beam.

  On the fourth coordinate input surface defined by the spacer member 7, no matter how much the area is pressed with a finger or the like, the coordinate value can be detected but the down flag is not set (threshold δ = 0.9). , A situation where the light flux from the sensor unit 1 (1R) is shielded by 90% or more is physically impossible).

  That is, in order to operate as a switch, the coordinate input pen 60 is required (the down flag can be set together with the coordinate data of the area by operating the pen tip switch 61 of the coordinate input pen 60). In the case of a switch that enters an operating state when a person touches it unintentionally and performs a fatal execution operation, the switch means is constituted by the fourth coordinate input surface. It can be said that it is preferable.

  As described above, according to a plurality of types of coordinate input methods, each coordinate input can be performed by setting, on the coordinate input area, a coordinate input surface having a plurality of types of height that allows coordinate input by each coordinate input method to function. The operability in the method can be improved.

  Further, since the coordinate input device can detect the position coordinates of the light-shielding portion, if the height of the coordinate input surface in the coordinate input area and the position information thereof are stored in advance, the portion can be detected based on the detected coordinate value. It is possible to determine the height of the coordinate input surface. Therefore, for example, by variably controlling the threshold value δ according to the height of the coordinate input surface, it is possible to contribute to improving the reliability of setting / resetting down flag information.

  As described above, according to the first embodiment, both the coordinate input with the coordinate input pen (first coordinate input method) and the coordinate input with the finger (second coordinate input method) are realized, and the operability thereof is improved. In order to improve, a coordinate input device having excellent operability can be provided by setting a coordinate input surface in accordance with input characteristics in each coordinate input method in the coordinate input area.

  In addition, since the proximity input using the coordinate input pen is possible, fine characters and complex graphics can be easily input, and a predetermined operation is executed by touching a predetermined area on the coordinate input area. The switch means can be realized reliably according to the operator's intention and with an operation method having excellent operability.

  In addition, since the coordinates are detected even with an arbitrary shielding object, when the switch operation unintended by the operator occurs (for example, the operator's sleeve happens to have a light flux at the location of the switch region). For a switch that is supposed to execute an execution command that would cause a fatal injury, the down flag is not set by setting the coordinate input area higher than the coordinate input area. Therefore, it is possible to contribute to the improvement of reliability.

<< Embodiment 2 >>
Embodiment 2 demonstrates the modification of Embodiment 1. FIG.

  In the first embodiment, a plurality of coordinate input surfaces on which input by the input method functions are set according to the coordinate input method. In the second embodiment, as shown in FIG. 31, the light transmitting member is used. An area frame member 8 surrounding a specific area such as a switch area is provided, and the height thereof is set higher than the position of the light beam from the sensor unit 1L (1R).

  By configuring in this way, for example, when the operator wants to press the SW2 area on the coordinate input area 4, the state (2) in FIG. The coordinate value detected is not only in the state of touching the surface (coordinate input area) 4) but also in the state of (1), (3), (4) where the operator is not conscious. Since it is surely present in the SW2 region (the light-shielding part by the finger is physically surely present in the SW2 region), it is possible to provide a switch means having no operability and excellent operability.

  As described above, according to the second embodiment, in addition to the effects described in the first embodiment, an operation on a specific area on the coordinate input area 4 can be reliably executed.

<< Embodiment 3 >>
As described with reference to FIG. 28 of the first embodiment, the coordinate input device can set the down flag in accordance with the light shielding amount with respect to the light flux from the sensor unit 1L (1R).

For example, the pixel data change ratio is 1 when the light is completely shielded, and the pixel data change ratio is 0.5 when the light is shielded by about half. For example, the down flag is set when there is 90% light shielding. It is possible to set a threshold value (threshold value = 0.9) to be set. That is, since the down flag is not set at a light shielding amount lower than that, as shown in FIG. 32 according to the threshold value δ, the height of the wall (region frame member 8) surrounding the specific region (SW1 region to SW3 region) is increased. H3 as described above,
h3 = h1 + (h2-h1) × (1-δ)
As a result, an excellent effect of preventing malfunction can be obtained.

  As described above, according to the third embodiment, the height of the region frame member can be reduced as compared with the second embodiment, so that the operability can be further improved.

  Although the embodiments have been described in detail above, the present invention can take an embodiment as, for example, a system, an apparatus, a method, a program, or a storage medium, and specifically includes a plurality of devices. The present invention may be applied to a system that is configured, or may be applied to an apparatus that includes a single device.

  In the present invention, a software program (in the embodiment, a program corresponding to the flowchart shown in the drawing) that realizes the functions of the above-described embodiment is directly or remotely supplied to the system or apparatus, and the computer of the system or apparatus Is also achieved by reading and executing the supplied program code.

  Accordingly, since the functions of the present invention are implemented by computer, the program code installed in the computer also implements the present invention. That is, the present invention includes a computer program itself for realizing the functional processing of the present invention.

  In that case, as long as it has the function of a program, it may be in the form of object code, a program executed by an interpreter, script data supplied to the OS, or the like.

  As a recording medium for supplying the program, for example, floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, MO, CD-ROM, CD-R, CD-RW, magnetic tape, nonvolatile memory card ROM, DVD (DVD-ROM, DVD-R) and the like.

  As another program supply method, a client computer browser is used to connect to an Internet homepage, and the computer program of the present invention itself or a compressed file including an automatic installation function is downloaded from the homepage to a recording medium such as a hard disk. Can also be supplied. It can also be realized by dividing the program code constituting the program of the present invention into a plurality of files and downloading each file from a different homepage. That is, the present invention includes a WWW server that allows a plurality of users to download a program file for realizing the functional processing of the present invention on a computer.

  In addition, the program of the present invention is encrypted, stored in a storage medium such as a CD-ROM, distributed to users, and key information for decryption is downloaded from a homepage via the Internet to users who have cleared predetermined conditions. It is also possible to execute the encrypted program by using the key information and install the program on a computer.

  In addition to the functions of the above-described embodiments being realized by the computer executing the read program, the OS running on the computer based on an instruction of the program is a part of the actual processing. Alternatively, the functions of the above-described embodiment can be realized by performing all of them and performing the processing.

  Furthermore, after the program read from the recording medium is written to a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion board or The CPU or the like provided in the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are also realized by the processing.

It is a figure which shows schematic structure of the coordinate input device of Embodiment 1 of this invention. It is a figure which shows the structural example of the light projection part of the sensor unit of Embodiment 1 of this invention. It is a figure which shows the structural example of the detection part of the sensor unit of Embodiment 1 of this invention. It is a figure which shows the structural example of the sensor unit of Embodiment 1 of this invention. It is a figure for demonstrating the retroreflection principle of the retroreflection member of Embodiment 1 of this invention. It is a figure which shows the retroreflection characteristic of the retroreflection member of Embodiment 1 of this invention. It is a figure which shows the structural example of the retroreflection member of Embodiment 1 of this invention. It is a figure which shows the example of arrangement | positioning of the retroreflection member of Embodiment 1 of this invention. It is a block diagram which shows the detailed structure of the control / arithmetic unit of Embodiment 1 of this invention. It is a timing chart of the control signal of Embodiment 1 of the present invention. It is a figure which shows an example of the light quantity distribution obtained by the sensor unit of Embodiment 1 of this invention. It is a figure for demonstrating the input example of Embodiment 1 of this invention. It is a figure for demonstrating the light quantity change of the light quantity distribution obtained by the sensor unit of Embodiment 1 of this invention. It is a figure for demonstrating the light quantity change amount and light quantity change ratio in the light quantity distribution obtained by the sensor unit of Embodiment 1 of this invention. It is a figure for demonstrating the case where the several rise and fall in the light quantity distribution of Embodiment 1 of this invention are detected. It is a figure which shows the relationship of (theta) value with respect to the pixel number of Embodiment 1 of this invention. It is a figure which shows the relationship of Tan (theta) value with respect to the pixel number of Embodiment 1 of this invention. It is a figure which shows the positional relationship of the coordinate defined on the coordinate input area of Embodiment 1 of this invention, and sensor units 1L and 1L. It is a figure which shows the example of operation of the coordinate input device of Embodiment 1 of this invention. It is a figure for demonstrating the positional relationship of the light beam and coordinate input area of Embodiment 1 of this invention. It is a figure for demonstrating the malfunction which generate | occur | produces in the case of the character input of Embodiment 1 of this invention. It is a figure for demonstrating the malfunction which generate | occur | produces in the case of click operation of Embodiment 1 of this invention. It is a schematic block diagram of the coordinate input pen of Embodiment 1 of this invention. It is a figure which shows an example of the switch signal of Embodiment 1 of this invention. It is a figure which shows the process of transmission of the switch signal of Embodiment 1 of this invention. It is a figure for demonstrating the disorder | damage | failure which generate | occur | produces by light emission of the coordinate input pen of Embodiment 1 of this invention. It is a timing chart for avoiding the obstacle which generate | occur | produces by light emission of the coordinate input pen of Embodiment 1 of this invention. It is a flowchart which shows the coordinate calculation process which the coordinate input device of Embodiment 1 of this invention performs. It is a figure for demonstrating an example of the coordinate input surface of Embodiment 1 of this invention. It is a figure for demonstrating an example of the coordinate input surface of Embodiment 1 of this invention. It is a figure for demonstrating an example of the coordinate input surface of Embodiment 2 of this invention. It is a figure for demonstrating an example of the coordinate input surface of Embodiment 2 of this invention.

Explanation of symbols

1L, 1R Sensor unit 2 Control / arithmetic unit 3 Retroreflective member 4 Coordinate input area

Claims (6)

A coordinate input surface height of the coordinate input surface is formed of a plurality of different planes,
A plurality of light receiving detection means provided at corners of the coordinate input surface ;
Retroreflective means for recursively reflecting incident light provided around the coordinate input surface ;
Projecting means for projecting a light beam substantially parallel to the coordinate input surface toward the retroreflecting means;
Based on the change rate of the light amount distribution obtained from the light receiving detection means, a calculation means for calculating the height of the indicated position with respect to the coordinate input surface and the coordinates of the indicated position ;
It is a threshold value δ for determining whether the coordinates of the indicated position calculated by the calculating means belong to any one of the different planes, and is a threshold δ for detecting the touched position of the indicated position. A coordinate input apparatus comprising: a determination unit that determines whether or not the indicated position has been touched based on the threshold value δ set for each of them. If the distance between the first coordinate input surface wherein the light beam and h1 defined by the coordinate input surface, the specific surface having a second coordinate input surface having a distance h1 to the first coordinate input surface, the coordinates The coordinate input device according to claim 1, wherein the coordinate input device is configured in an input plane . The distance between the light beam and the first coordinate input surface defined by the coordinate input surface and h1, if the width of the light beam to is W, the distance h1 + W × respect to the first coordinate input surface (1-[delta]) the third coordinate input plane having the coordinate input apparatus according to claim 1, characterized in that it is configured on the coordinate input plane. The distance between the light beam and the first coordinate input surface defined by the coordinate input surface and h1, if the width of the light beam to is W, relative to the first coordinate input surface, the distance h1 + W × (1-δ ) The coordinate input device according to claim 1, wherein a fourth coordinate input surface is configured within the coordinate input surface at a distance within a distance range that is larger and less than the distance h1 + W. A light receiving unit provided at a corner of the coordinate input surface composed of a plurality of planes having different heights of the coordinate input surface, a reflection unit provided at the periphery of the coordinate input surface and recursively reflecting incident light; has a light projecting portion for projecting a substantially parallel light beam to the coordinate input surface, a method of controlling a coordinate input device for calculating the indicated position on the coordinate input surface,
A light projecting step of projecting the light flux toward the reflection unit by the light projecting unit;
A light receiving step of receiving a light beam reflected from the reflecting portion by the light receiving portion;
Based on the change rate of the light amount distribution obtained from the light receiving unit, a calculation step of calculating the height of the designated position with respect to the coordinate input surface and the coordinates of the designated position ;
It is a threshold value δ for determining whether the coordinates of the designated position calculated by the calculating step belong to any one of the different planes, and is a threshold value δ for detecting the touched position of the designated position. And a determination step of determining whether or not the indicated position has been touched based on the threshold value δ set for each . A light receiving unit provided at a corner of the coordinate input surface composed of a plurality of planes having different heights of the coordinate input surface, a reflection unit provided at the periphery of the coordinate input surface and recursively reflecting incident light; has a light projecting portion for projecting a substantially parallel light beam to the coordinate input surface, a program for executing a control of a coordinate input device for calculating the indicated position on the coordinate input screen to the computer,
A light projecting step of projecting the light flux toward the reflection unit by the light projecting unit;
A light receiving step of receiving a light beam reflected from the reflecting portion by the light receiving portion;
Based on the change rate of the light amount distribution obtained from the light receiving unit, a calculation step of calculating the height of the designated position with respect to the coordinate input surface and the coordinates of the designated position ;
It is a threshold value δ for determining whether the coordinates of the designated position calculated by the calculating step belong to any one of the different planes, and is a threshold value δ for detecting the touched position of the designated position. A program for causing a computer to execute a determination step of determining whether or not the indicated position is touched based on the threshold value δ set for each .

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