JPH0836457A - Coordinate input device - Google Patents

Abstract

PURPOSE:To provide a coordinate input device which does not generate electromagnetic noise, is not affected by the electromagnetic noise of an external circuit and the internal circuit of the present machine, is high in detection accuracy, is low current consumption and is inexpensive. CONSTITUTION:This device is provided with a guide plate 3 supporting a pen guide part 2 for guiding a pen 1 for a coordinate input so that the guide part 2 may move ire-axis direction and a support moving mechanism 4 supporting the guide plate 3 so that the plate may move in the X-axis direction, and the magnetizing belt 5 supported so that it may be freely wound and unwound by a motor 6 and a tensioner 7 is supported by pulleys 9 and 10 in parallel to the X-coorinate axis and the Y-coordinate axis. Magnetic resistance elements a and b are arranged in the vicinity of each part parallel to the X-coordinate axis and the Y-coordinate axis of the magnetizing belt 5 and the moving amount of the magnetizing belt 5 is detected. After the origin location of the pen guide part 2 is set, the coordinate of the pen 1 is detected based on the moving direction of the pen 1 and the difference of the moving amount.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coordinate input device, and more particularly to a coordinate input device for detecting a two-dimensional coordinate value and inputting it to a computer or the like.

The present invention relates to a coordinate detection input device used as, for example, an input device of a pen computer, and more particularly to reduction of power consumption, reduction of radiation noise, and improvement of detection accuracy.

[0003]

2. Description of the Related Art In recent years, personal computers and LCDs
With the reduction in power consumption and the reduction in size and thickness of (liquid crystal display devices),
A pen input computer without a keyboard has appeared. This type of device is opening up a new field in the computer market with its usability and portability as a weapon, and in the future, it is expected to be a tool in the paperless era replacing a notebook and a notebook.

This type of device has a device for detecting pen input. Conventionally, as a coordinate input technology, an electromagnetic coupling method, an electrostatic capacity method, a resistance film method, and an ultrasonic method are known.

15 and 16 show the structure of an electromagnetically coupled coordinate input device as an example of a conventional example. FIG.
Shows a schematic configuration of a pen computer having an electromagnetically coupled coordinate input device.

As shown in FIG. 15, the device comprises a tablet / LCD unit 100 which is an input / display unit and a printed circuit board unit 200 which is an arithmetic processing / interface unit. The printed circuit board section 200 is reinforced by the lower case 300. Since the tablet / LCD unit 100 is configured by overlapping the input unit on the display surface of the LCD, a computer without a keyboard and having excellent portability can be configured.

The printed circuit board portion 200 includes an input connector of the AC adapter 400, a battery 210, and an inverter 2.
11, a power supply unit such as the DC-DC converter 212, a logic circuit unit 220 for performing arithmetic processing, an IC card 230
Interface part 24
It consists of 0 and so on. The interface cable 5 is provided between the tablet / LCD unit 100 and the printed circuit board unit 200.
00 for connection.

FIG. 16 illustrates the detection principle when the tablet of the tablet / LCD unit 100 is constructed by the electromagnetic coupling method. Loop antenna group 10 on the tablet surface
1 are arranged in large numbers, and this loop antenna group 10
1 is three loop coils X1, X2, X for detecting the X coordinate
3, 3 loop coils Y1, Y2, Y for Y coordinate detection
3 and 3.

On the other hand, a transmission / reception coil 102 is embedded at the tip of the electronic pen, and constitutes a resonance circuit composed of a coil and a capacitor. The electronic pen only has this resonance circuit and does not have a built-in battery.

In such a configuration, when a signal matching the resonance frequency of the transmitting / receiving coil 102 of the electronic pen is input to the loop antenna group 101 from the high frequency signal sources 103 and 104, an electromagnetic wave matching the resonance frequency of the electronic pen is loop antenna. Emitted from.

The transmitting / receiving coil 102 of the electronic pen resonates and stores electromagnetic energy. At the next moment, the loop antenna group on the tablet is connected to the receiving circuits 105 and 106, switches to the receiving state, and detects the electromagnetic wave emitted from the transmitting / receiving coil 102. The coils X1 to X3 and Y1 to Y3 are used in time division during the above transmission and reception, and the position of the pen tip can be obtained from the intensity distribution of the detection signals of these loop coils.

[0012]

As described above,
An electromagnetically coupled pen input tablet is a wireless station composed of multiple loop antennas. Therefore, it is difficult to avoid the problem of radiating electromagnetic noise to the outside, and as shown by the broken line arrow in FIG.
There is a problem that the detection accuracy is affected by the near magnetic field generated from the C-DC converter 212 and the logic circuit unit 220. Further, there is a problem that the housing shield disturbs the electromagnetic waves transmitted and received between the loop antenna 101 and the transmission / reception coil 102 inside the electronic pen.

Further, since the above electromagnetic coupling method uses a high frequency circuit, it consumes a large amount of current, and if the control circuit is included, the cost is relatively high.

Other coordinate input methods include a resistance film method and an electrostatic capacity method. However, the electrostatic capacity method uses a high frequency circuit like the electromagnetic coupling method, and therefore consumes a large amount of current and has a problem in cost. is there.

The resistance film method consumes less current and is inexpensive, but has a problem that the detection accuracy is reduced by one digit as compared with the electromagnetic coupling method and the capacitance method. Further, the electrostatic capacitance method and the resistance film method have a problem that the writing pressure cannot be detected.

The object of the present invention is to solve the above problems, to generate no electromagnetic noise, and not to be influenced by the electromagnetic noise of the external or internal circuit of the machine itself, so that the detection accuracy is high and the writing pressure can be detected. It is therefore to provide a coordinate input device that can be implemented at low cost with low current consumption.

[0017]

In order to solve the above problems, in the present invention, in a coordinate input device for detecting a two-dimensional coordinate value and inputting it to a computer or the like, a pen for instructing coordinates, and A pen guide part to which a pen can be attached and detached, a support mechanism for movably supporting the pen guide part in the X-axis and Y-axis directions, and according to the movement of the pen guide part,
A configuration including a magnetizing member and a magnetoelectric conversion element that move relative to each other and a processing circuit that determines the coordinates of the pen according to an electric signal obtained from the magnetoelectric conversion element is adopted.

[0018]

According to the above construction, the relative movement of the magnetizing member and the magnetoelectric conversion element according to the movement of the pen guide portion causes
Coordinate information can be generated.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in the drawings. The coordinate input device of the present invention performs coordinate input using a magnetoelectric conversion element such as a magnetoresistive element. An embodiment in which the coordinate input device is applied to a pen computer will be described below.

<First Embodiment> FIG. 1 shows a first embodiment of a pen computer adopting the coordinate input device of the present invention. In this embodiment, the pen tip of the pen 1 is inserted into the round hole portion of the pen guide portion 2 and freely moved in the XY plane to input coordinates.

A switch for confirming the mounting of the pen 1 and a writing pressure detector are installed in the pen guide portion 2. Pen guide 2
Is held by the guide plate 3 and is freely movable in the X direction. The guide plate 3 has a support moving mechanism 4 inside the housing at both ends.
It is slidably engaged with and can move freely in the X direction.

One end of a magnetizing belt 5 magnetized with a specific pattern is fixed to the pen guide 2, and the other end is a motor 6
Tensioner 7 with a latch mechanism directly connected to the output shaft of
It is fixed to. The magnetizing belt 5 is tensioned by a tensioner 7 and guided by a pulley 9 fixed to a base 8 and a pulley 10 fixed to a guide plate 3 so as to be parallel to the X axis and the Y axis. There is. After the pen 1 is attached, the pen guide unit 2 moves along the X axis as the pen 1 moves.
Although it moves on the Y plane, even after the pen 1 is attached or detached, the latch mechanism provided on the tensioner 7 keeps the tension at a constant value and stays at the coordinate that was moved last.

A stopper A for origin detection is installed on the two support movement mechanisms 4 to limit movement of the guide plate 3 in the X direction. A stopper B for detecting the origin is also installed on the guide plate 3 to restrict the movement of the pen guide portion 2 in the Y direction.

Along the magnetizing belt 5, a magnetoresistive element a is fixed to the base 8 in a portion stretched in parallel with the X-axis in the figure, and a magnetic resistance is stretched in a portion stretched in parallel with the Y-axis. Element b
Are fixed to the guide plate 3.

The magnetoresistive elements a and b measure the moving distance of the magnetizing belt 5 from the change in the magnetizing pattern when the magnetizing belt 5 is moved. The magnetoresistive element a measures the entire amount of extension of the magnetizing belt 5, that is, a value corresponding to the sum of the X coordinate value and the Y coordinate value, and the magnetoresistive element b changes from the magnetoresistive element b to the pen guide portion. The amount of extension to the position of 2, that is, the value corresponding to the Y coordinate value is measured, and the X coordinate value and the Y coordinate value can be obtained by subtraction thereof.

Further, in FIG. 1, the switch 11 is a function key, and is used for performing an input specification such as the type of line and a special operation such as resetting the origin. PCB
Reference numeral 12 constitutes a coordinate detection input circuit.

The above-mentioned constituent units are arranged inside the base 8 to form a coordinate input device. A computer 13 is arranged below the coordinate input device.

The movable range of the pen guide portion 2 of the coordinate input device is an opening O as shown in the drawing, and this opening O has a position and size corresponding to the display portion D on the upper surface of the computer. are doing. In addition, the detected pen guide unit 2
The coordinate system of 1 and the coordinate system of the display unit D are usually associated with each other one-to-one in the coordinate detection process.

In this embodiment, the pen 1 does not have any circuit member and is merely a coordinate indicating member. The pen 1 can be engaged with the pen guide 2 and the pen 1 can be easily handled. Good.

With such a configuration, the pen input computer is configured, and the menu displayed on the display unit D is operated by the pen 1 and the locus input from the pen 1 is displayed on the display unit D. So-called handwriting input is possible.

FIG. 2 shows an example of a method of holding the pen guide member 2 on the guide plate 3. As shown in the drawing, the guide plate 2 has V or U grooves carved on both sides, and the guide portion 2b is held via a buffer member 2e having elasticity. The bearing member 2f, which is a steel ball in the figure, is held movably in the groove direction by being fitted in the V or U groove. With such a structure, the pen guide member 2 can be moved smoothly.

The pen holding portion 2a is held by the guide portion 2b via a leaf spring 2c. When the pen is attached to the round hole 2d, the pen holding portion 2a rotates in the direction of the arrow in the drawing, and the probe 14a of the switch / writing pressure detector 14 fixed to the guide portion 2b is pressed to move the pen guide portion of the pen. Detection of attachment to the pen and detection of writing pressure are performed.

The support moving mechanism 4 shown in FIG. 1 is a sliding shaft installed substantially parallel to each other, and the guide plate 3 is X-shaped by an oil-impregnated metal having a round hole and a U groove fitted into the sliding shaft. It is supported so that it can move in any direction.

The detector 14 is for detecting the presence / absence of an operation by the pen 1 via the probe 14a and for detecting the pressing amount of the probe 14a as writing pressure information. When the biasing force and the biasing force of the leaf spring 2c are known, the pressing amount of the probe 14a can be converted into the writing pressure amount.

FIG. 3 shows a configuration example of the detector 14. When the probe 14a is pushed by the pen holder 2a, the electrode plate 1
Since 4e contacts the electrode plate 14f, the mounting of the pen 1 can be detected. When the probe 14a is further pushed, the elastic member 14b containing the dielectric is pushed and the electrode plate 1 is pushed.
The distance between 4f and the electrode plate 14g changes. Pulse circuit 14c
When a more current is supplied to the capacitor composed of the electrodes 14f and 14e and the expansion / contraction member 14b including a dielectric, the change in the thickness of the expansion / contraction member 14b can be detected by the change in the capacitance. The change in the thickness of the elastic member 14b can be detected as a writing pressure detection signal.

Next, the characteristics and operation of the magnetoresistive elements a and b, which are magnetoelectric conversion elements for detecting coordinates, will be described. FIG. 4 shows the dependence of the electric resistance value on the change in the magnetic field strength of the magnetoresistive element. As shown in the figure, when a magnetic field is applied, the electric resistance value decreases regardless of the N pole and the S pole, and saturates at a certain strength of the external magnetic field.

That is, the magnetoresistive element has the highest electric resistance value when there is no magnetic field, and the rate of change in resistance value corresponding to the change in magnetic field is about 3 to 4%. As a typical magnetoresistive element material, there is Permalloy.

FIG. 5 shows the magnetizing pattern of the magnetizing belt 5 and the structure of the magnetoresistive element (the magnetoresistive element b will be exemplified below).

The magnetizing belt 5 is magnetized by alternating N poles and S poles at equal pitches as shown in the figure. This pitch can be set to, for example, 0.05 mm or less. As shown in the figure, the magnetoresistive element b is vapor-deposited on a glass substrate and then photoetched in a dendrite shape in accordance with the period of the S and N poles of the magnetizing belt 5. When the magnetizing pitch width of the magnetizing belt 5 is 360 °, the A-phase and B-phase signals whose phases are deviated by 90 ° can be output as the differential signals A1, A2, B1, and B2, respectively. it can.

In the upper part of FIG. 6, the A phase B when the magnetoresistive element detects the magnetizing pattern of the magnetizing belt shown in FIG.
The phase differential signal output is shown. The middle arrow indicates the moving direction of the magnetoresistive element with respect to the magnetizing belt, and it can be seen that signals with a phase shift of ± 90 degrees are output depending on the moving direction. Here, the moving direction of the pen is reversed in the central portion of the drawing.

This moving direction can be detected by binarizing and inputting the A-phase and B-phase signals to the D latch circuit 17 shown in FIG. The lower part of FIG. 6 shows the binarized signal and the detector output in the moving direction by the D latch circuit 17 shown in FIG.

FIG. 8 shows a block diagram of the coordinate detection circuit.
The signals output from the magnetoresistive elements a and b are the differential amplifier 1
After being inputted to 5, it is binarized by the binarization circuit 16. Differential signals 90 degrees out of phase are obtained from the magnetoresistive elements a and b, and a moving direction signal is detected by the D latch circuit 17 (the same as that in FIG. 7), and the Y coordinate U is obtained respectively.
U / D of / D counter 18 and X coordinate U / D counter 19
Input to the terminal. On the other hand, either the A-phase signal or the B-phase signal is input to the clock terminal of the counter, and the counters 18 and 19 output the count values X ′ and Y ′ of the magnetoresistive element output signal to the arithmetic processing circuit 20.

In the above structure, the XY coordinates of the pen guide unit 2, that is, the pen 1 can be obtained by performing the following calculation by the calculation processing circuit 20.

Y = Y 'X = X'-Y' Although this calculation ignores the mounting offset of the magnetoresistive element, by performing the following origin detection processing,
The coordinate detection can be calibrated accurately.

That is, the arithmetic processing circuit 20 drives the motor 6 via the motor driver 21 to detect the origin of the pen and the pen guide portion.

The coordinate origin detection command is the arithmetic processing circuit 2 of FIG.
When 0 is input, the arithmetic processing circuit 20 drives the motor 6 to start winding the magnetizing belt 5 around the tensioner 7. The pen guide portion 2 collides with a stopper B fixed to the guide plate 3 and is fixed. Further, the guide plate support portion 4a has a sliding shaft 4b.
It collides with the stopper A installed above and is fixed. When both the pen guide portion 2 and the guide plate support portion 4a are fixed, the counts of X'and Y'will not change even though the motor is being driven. The arithmetic processing circuit 20 detects this state, outputs a reset signal, and resets the Y coordinate U / D counter 18 and the X coordinate U / D counter 19.

In the origin detection method, it is also possible to arrange a photo interrupter or the like on the XY axes and make a determination based on the output signal thereof.

The coordinate detection accuracy can be increased to the order of the magnetizing pitch (about 50 μm) because the magnetizing belt is stretched by the tensioner mechanism while always maintaining a constant tension.

Further, since the tensioner having the latch function is used, even when the pen 1 is released from the pen guide portion 2, the pen guide portion 2 does not return to the origin, but stops at the coordinate that was moved last. The operability is also excellent, and it is possible to realize the operability and the detection accuracy equivalent to those of the conventional coordinate detection input device at low cost.

Further, the current flowing through the magnetoresistive element is sufficient to be 1 mA or less, low power consumption can be realized, and the apparatus can be configured simply and inexpensively. Furthermore, since a high frequency circuit is not required, electromagnetic noise is not radiated, and it is possible to perform highly accurate coordinate input without being affected by noise generated by an internal circuit.

<Second Embodiment> FIG. 10 shows, as a second embodiment of the present invention, a configuration in which the coordinate input device is applied to a pen computer as in the above. In the following, the same parts as those in the above embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 10, the difference from the first embodiment is that magnetizing belts are provided in the X and Y directions, respectively, and movements of the guide plate 3 and the pen guide portion 2 are detected by the magnetoresistive elements that move together. That is the point.

That is, the Y-coordinate magnetizing belt 22 is fixed at both ends to the guide plate 3 and stretched in parallel with the Y-axis, and the Y-coordinate magnetoresistive element 24 is fixed to the pen guide portion 2. The magnetization pattern 22 is detected.

The X-coordinate magnetizing belt 23 is fixed at both ends to the base 8 and stretched in parallel with the X-axis, that is, the support moving mechanism 4,
The coordinate magnetoresistive element 25 is fixed to one end of the guide plate 3,
The magnetizing pattern of the X-coordinate magnetizing belt 23 is detected.

Compared to the configuration diagram of the first embodiment shown in FIG. 1, a magnetizing belt 5 and a tensioner 7, a motor 6, a pulley 9, for holding the magnetizing belt 5 so that it can be unwound and unwound. 10, the stoppers A and B are abolished, and the mechanical structure becomes simpler.

Further, in the present embodiment, the movable portion is the magnetoresistive element, and the magnetizing belt and the magnetoresistive element can be handled as one part as a set, so that the structure is simplified and the assemblability is improved.

The support moving mechanism 4 of the first embodiment is composed of sliding shafts installed in parallel at both ends of the guide plate 3 and an oil-impregnated metal having round holes and U-grooves fitted to these sliding shafts. 2 (FIG. 2), in this embodiment, a plurality of bearing members 4c such as ball bearings are arranged, and the round rod-shaped sliding shafts 4a and 4b are sandwiched by elastic cushioning members (not shown). There is. The guide plate support portion 4d has a triangular prism shape.

With the above structure, it is not necessary to control the machining accuracy and clearance of the oil-impregnated metal and the sliding shaft, and the machining accuracy of parts is relaxed.

In this embodiment, since the magnetizing belts 22 and 23 are fixed, a magnetizing pattern as shown in FIG. 11 can be used. FIG. 11 shows the magnetic belts 22 and 23.
2 shows an example of the magnetization pattern and etching patterns of the magnetoresistive elements 24 and 25. In this configuration, the pen 1
The pen guide unit 2 has an advantage of being able to detect the coordinates of the pen guide unit 2 without returning to the origin as in the above embodiment.

In FIG. 11, the magnetizing belt is magnetized in the following three patterns.

1) NS with equal pitch, for example 0.1 mm width
Magnetized clock generation pattern 262 2) Absolute coordinate information at regular intervals, for example 1.0 mm intervals,
For example, as 8-bit data, a magnetized absolute coordinate pattern 27 3) A sync signal pattern magnetized at a position spaced apart from the absolute coordinate data by a predetermined distance 28. In FIG. 11, absolute position coordinates and a sync pattern are clock-generated. It is magnetized with a width of about half of the pattern, and the synchronization pattern is shifted by 2 clocks from the absolute position coordinate pattern.

On the other hand, in the magnetoresistive element, the clock / moving direction detecting element 29, the absolute coordinate detecting element 30, and the synchronous pattern detecting element 31 are etched on the same glass substrate in correspondence with the position of the magnetization pattern. ing. Each element uses the ground as a common terminal, and the phase differs by 180 ° when the corresponding magnetization width is 360 °.
(-), So that the SN ratio of the detection signal can be improved. Further, the clock / moving direction detecting element 29 is
The signals that are 90 ° out of phase are output, and this is used to detect the moving directions of the pen 1 and the pen guide 2.

FIG. 12 shows a timing chart of a signal obtained by binarizing the signal output from the magnetoresistive element of FIG. Taking the rising edge of the clock 32 as a clock and taking a time axis in which the value increases to the right in the figure, the synchronization signal 34 is output in the first two clocks, and the absolute coordinate data 33 for eight clocks is output from the next clock. To be done.

The absolute coordinate data 33 is P0 of the clock 32.
When the clock / moving direction detecting element 29 moves in the positive direction and outputs the P1 clock, the position is the absolute coordinate + (P1−P0). Therefore, the magnetization pitch of the clock generation pattern 26 is Is 0.1 mm, P
The coordinate data of 0 is 11001000 → 1100100 (binary) → 100
(Decimal system) → If 10.0 mm is determined, the position of P1 can be calculated as 10.0 + 0.1 × 4 = 10.4 mm.

An example of a circuit for realizing the above coordinate detection method is
This is shown in the block diagram of FIG. Although only the Y coordinate detection circuit is shown in the drawing, it goes without saying that a similar circuit is used for the X coordinate.

The four sets of differential signals output from the magnetoresistive element of FIG. 11 are input to the differential amplifier 35 and then binarized by the binarizing circuit 36. After that, as in the case of FIG. 7, the movement direction signal is generated from the clock phase, and the clock signal 32, the absolute coordinate signal 33, and the synchronization signal 3 are generated.
4 is generated. The sync signal 34 is a sync signal detection circuit 38.
To generate a reset / trigger signal for the shift register 39. The reset / trigger signal is generated only when the movement direction signal indicates the forward direction.

The moving direction signal is input to the arithmetic processing circuit 40, and the value obtained by counting the clock signal is added to the absolute coordinate signal input from the 8-bit shift register 39, or
Or used to determine whether to subtract.

The clock signal 32 is input to the shift register 39 and used as a latch timing signal, and is also input to and measured by an up / down counter incorporated in the arithmetic processing circuit 40.

The up / down counter of the arithmetic processing circuit 40 is reset by the same reset / trigger signal as that of the shift register 39. The absolute coordinate data 33 is input to the data terminal of the shift register 39, converted into 8-bit data at an appropriate timing determined from the reset / trigger signal, and input to the arithmetic processing circuit 40.

The reset / trigger signal is input to the shift register 39 to start the latch / shift operation of the shift register 39. The data is also input to the arithmetic processing circuit 40, and based on this, the arithmetic processing circuit 40 determines an appropriate timing for fetching data from the shift register 39.

In this embodiment, the arithmetic processing circuit 40 recognizes the upper 7 bits of the input 8-bit data as coordinate data in 0.1 mm units. In addition, a value obtained by adding or subtracting a constant from the built-in counter output value, that is, in FIG.
The difference between the P1 point and the P0 point in 2 is calculated according to the traveling direction of the magnetoresistive element, that is, the addition / subtraction signal, and the Y coordinate is output. That is, Y = Y '± (value of built-in counter).

In the second embodiment, the pen and the pen guide unit detect absolute position coordinates at regular intervals, for example, at 1.0 mm intervals, and the coordinates between them detect clocks at 0.1 mm intervals, for example. It is intended to perform highly accurate position detection by adding or subtracting to absolute position coordinates depending on the moving direction.

The reading of the absolute position information is necessary only when the origin detection of the coordinate detection input device according to the present invention is necessary, for example, when the power is turned on, the system is reset, or the user. You only have to do it when you feel it. Otherwise, the position of the pen can be detected with high accuracy by using the clock signal and the movement direction signal to calculate only the difference caused by the movement by the counter incorporated in the arithmetic processing circuit 40. is there.

11 and 12, the absolute coordinate pattern 27 and the synchronization pattern 28 have a non-magnetized portion, and when the magnetoresistive element is in the non-magnetized portion, the binarization circuit output of FIG. 13 is output. Seems to be indeterminate. However, the binarization circuit 3
When 6 is provided with a hysteresis characteristic as shown in FIG. 14, if it is set to either 0 or 1, it will not become undetectable.

Further, in the configurations of FIGS. 11 to 13,
The absolute position coordinates can be detected only when the pen and the pen guide portion move in one direction, for example, the positive direction. However, by placing the sync signal pattern before and after the absolute coordinate data,
It is possible to read the absolute coordinates by moving in both directions. In this case, the configuration as shown in FIG. 17 can be used.

FIG. 17 shows a timing chart of the magnetizing belt 22, the magnetic resistance element 24, the clock signal 32, the moving direction signal 41, the absolute coordinate signal 33, and the synchronizing signal 34. The arrow in the figure indicates the moving direction of the magnetoresistive element 24.

The magnetizing belt 22 differs from that shown in FIG. 11 only in the synchronization pattern 42. That is, the synchronization pattern is 4 bits, and is asymmetrical when read from the right and read from the left (0010 in the figure).

When the movement direction signal 41 is 1 (positive), the clock is latched at the rising edge of the clock, but when it is 0 (negative), the latching is performed at the falling edge. If the movement direction is negative, the arithmetic processing unit 40 sequentially replaces the upper bits of the input 8-bit data with the lower bits and treats this as coordinate data.

With this structure, even if the pen 1 (pen guide portion 2) moves in both directions, the absolute coordinates can be read.

[0080]

As is apparent from the above, according to the present invention, the coordinate information is generated by the relative movement of the magnetizing member and the magnetoelectric conversion element according to the movement of the pen guide portion. It is possible to provide a coordinate input device that does not generate electromagnetic noise and is not affected by electromagnetic noise from the external or internal circuits of the device itself, has high detection accuracy, low current consumption, and is inexpensive.

[Brief description of drawings]

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

FIG. 2 is a plan view showing a holding structure of a pen guide unit and a guide plate of the coordinate input device of FIG.

FIG. 3 is an explanatory diagram showing the configuration and operation of the switch / writing pressure detector of FIG.

FIG. 4 is a graph illustrating the operating principle of the magnetoresistive element used in the present invention.

5 is an explanatory diagram showing a configuration of a magnetizing pattern and a magnetoresistive element of a magnetizing belt for explaining a coordinate detecting method of the apparatus of FIG.

6 is a timing chart illustrating the coordinate detection method of FIG.

FIG. 7 is a block diagram of a circuit that detects a traveling direction of a pen.

8 is a block diagram of a coordinate detection circuit of the apparatus of FIG.

FIG. 9 is an explanatory diagram showing a method of detecting the origin of the apparatus of FIG.

FIG. 10 is a perspective view showing the configuration of a second embodiment of the coordinate input device according to the present invention.

11 is an explanatory diagram showing a magnetizing pattern of a magnetizing belt and a configuration of a magnetoresistive element for explaining a coordinate detecting method of the apparatus of FIG.

12 is a timing chart illustrating the coordinate detection method of FIG.

13 is a block diagram of a coordinate detection circuit of the device of FIG.

14 is a graph illustrating characteristics of a binarization circuit used with the circuit of FIG.

FIG. 15 is a perspective view illustrating a conventional coordinate detection input circuit.

FIG. 16 is a perspective view illustrating a detection principle of an electromagnetic coupling method, which is one of conventional coordinate detection methods.

FIG. 17 is an explanatory diagram showing a modification of the magnetizing pattern of the magnetizing belt and the magnetoresistive element for explaining the coordinate detecting method of the apparatus of FIG.

[Explanation of symbols]

 1 Pen 2 Pen Guide 3 Guide Plate 4 Support Moving Mechanism 5 Magnetizing Belt 6 Motor 7 Tensioner 8 Base 9 Pulley 14a Probe 17 D Latch Circuit 18 Up / Down Counter 19 Up / Down Counter 20 Arithmetic Processing Circuit 22 Y Coordinate Magnetizing Belt 23 X-coordinate magnetizing belt 24 Magnetic resistance element 25 Magnetic resistance element 29 Clock / moving direction detection element 30 Absolute coordinate detection element 31 Synchronous pattern detection element 32 Clock signal 33 Absolute coordinate signal 34 Synchronization signal 35 Differential amplifier 36 Binarization circuit 38 Sync signal detection circuit 39 Shift register 40 Arithmetic processing circuit A Stopper B Stopper D Display section a Magnetoresistive element b Magnetoresistive element

Claims (7)

[Claims] 1. A coordinate input device for detecting a two-dimensional coordinate value and inputting it to a computer or the like, a pen for instructing coordinates, a pen guide part to which the pen can be attached and detached, and the pen guide part for the X axis and A support mechanism that movably supports in the Y-axis direction, a magnetizing member and a magnetoelectric conversion element that move relative to each other in response to movement of the pen guide portion, and an electric signal obtained from the magnetoelectric conversion element. A coordinate input device comprising a processing circuit for obtaining the coordinates of the pen. 2. The magnetizing member is a magnetized wire or belt that is supported so that it can be unwound and unwound.
The coordinate input device according to claim 1, wherein a part of the coordinate input device is supported parallel to the X coordinate axis and the Y coordinate axis of the coordinate to be detected. 3. The support mechanism has a first support portion that supports the pen guide portion so as to be movable in the X-axis direction and a second support portion that supports the pen guide portion so as to be movable in the Y-axis direction. The magnetizing means are arranged along the first and second supporting portions, and the first and second magnetizing means are arranged according to the movement of the pen guide portion.
2. The coordinate input device according to claim 1, wherein a magnetoelectric conversion element provided in association with the support portion of is moved. 4. The coordinate input device according to claim 1, further comprising a detection circuit including a switch circuit for detecting attachment of the pen to the pen guide portion and a detection circuit for detecting writing pressure of the pen. 5. The processing device, after setting the origin position of the pen guide unit, obtains a difference in the direction and amount of movement of the pen thereafter, and calculates the current position from this difference. The coordinate input device according to item 1. 6. The magnetizing pattern of the magnetizing means,
The magneto-electric conversion element is configured to output two-phase differential signals that are 90 degrees out of phase with each other, and the moving direction of the pen is detected based on the phase difference between the two-phase differential signals. Item 5. The coordinate input device according to item 5. 7. The XY to be detected by the magnetizing means.
4. The coordinate input device according to claim 3, wherein absolute coordinate value information in the coordinate system is provided as a magnetizing pattern.