JPH09230989A - Digitizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an exact coordinate value even when an input pen is inclined a supported by providing an electromagnetic coordinate detection part and a pressure sensitive coordinate detection part and determining the instruction location coordinate on the location indicator based on the output coordinate value of these coordinate detection parts. SOLUTION: This device is provided with an electromagnetic coordinate detection 31 detecting the instruction location coordinate of an input pen 10 to be the location indicator from the output of a grid plate 30 and a pressure sensitive coordinate detection part 21 detecting the coordinate of the pressing location the input pen 10 from the output of a pressure sensitive panel 21. From the detection coordinate values of both of the pressure sensitive panel 20 and grid board 30, the inclined angle θ of the input pen is determined by an inclination detection part 41. This inclined angle data is outputted to a coordinate correction part 42, the location coordinate from the grid board 30 is corrected and the coordinate is outputted as a normal detection coordinate to a host device. This is because the detection coordinate for which an electromagnetic coupling principle using the grid board 30 is utilized is more accurate than the detection coordinate by the pressure sensitive panel 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digitizer having a coordinate detection plate and a position indicator, and more particularly to improvement of a digitizer using a pen-shaped position indicator.

[0002]

2. Description of the Related Art There have been various types of digitizers of this type. For example, there is one in which the position indicator has a coil and the coordinate detection plate has a grid plate which is electromagnetically coupled with the coil to generate a signal representing a position.

The electromagnetic coupling type digitizer as described above is
Generally, a plurality of conductors are arranged on the grid plate in relation to positions, and signals generated in the plurality of conductors are sequentially acquired based on electromagnetic coupling with the position indicator. Then, the existence coordinates of the position indicator are determined from the distribution of the acquired signal magnitudes.

[0004]

In the conventional device as described above, a pen-shaped position indicator (hereinafter,
When the input pen is used, there is a drawback in that when the coordinate detection plate is pointed with the input pen tilted, accurate coordinates of the pointed position cannot be obtained. That is, in order to detect an accurate coordinate, it is desirable that the coil of the input pen and the plurality of conductors of the coordinate detection plate have a right angle relationship, but for this purpose, the input pen should be perpendicular to the coordinate detection plate. Need to tell.
However, it is practically difficult to perform such a vertical instruction, and there is a drawback that an error occurs due to the inclination instruction.
The present invention has been made to eliminate the above drawbacks.

[0005]

Therefore, according to the present invention, a digitizer having a coordinate detection plate and a position indicator and determining the coordinates on the coordinate detection plate designated by the position indicator is In the container, the coil and the tip contact part,
The coordinate detection plate is provided with a grid plate having a conductor group that is electromagnetically coupled to the coil of the position indicator and outputs, and a pressure-sensitive panel that outputs according to the pressing of the tip contact portion of the position indicator. Further, an electromagnetic coordinate detection unit that detects the indicated position coordinates of the position indicator from the output of the grid plate, and a pressure-sensitive coordinate detection that detects the coordinates of the pressed position of the position indicator from the output of the pressure-sensitive panel. And a point position coordinate on the coordinate detection plate of the position indicator is obtained based on the output coordinate values of these two coordinate detecting sections.

[0006]

The tilt angle of the input pen can be calculated by the coordinate output from the two coordinate detecting units, and the tip coordinate of the input pen can be detected. Furthermore, by setting the inclination angle of the input pen itself as an input item, new data can be input.

[0007]

【Example】

The present invention will be described below with reference to an apparatus according to an embodiment of the drawings. In FIG. 1, FIG. 1 is a schematic configuration diagram of a digitizer of an embodiment of the present invention, FIG. 2 is an electrical configuration diagram of a pressure sensitive panel 20 shown in FIG. 1, FIG. 3 is an electrical configuration diagram of a grid board 30 shown in FIG. 1 is a mechanical configuration diagram of the input pen 10 shown in FIG. 1, FIG. 5 is an operation diagram for obtaining attribute data of the input pen 10, FIG. 6 is a relational diagram of a pen tip of the input pen 10 and a coil, and FIG. FIG. 3 is a relationship diagram between a pen tip and a coil. In the figure, 10 is an input pen, 20 is a pressure sensitive panel, 30 is a grid board, and 40 is a control circuit unit.

First, the outline of the present invention will be described with reference to FIG. The pressure-sensitive panel 20 and the grid board 30 are arranged so as to overlap each other, and form a coordinate detection plate. By operating the input pen 10 on the coordinate detection plate, the coordinates of the designated position can be input to a host device such as a computer.

The pressure sensitive panel 20 operates together with the coordinate detecting section 21. Pressure sensitive panel 20 used here
Is a resistance sheet 2 in the X direction, as shown in FIG.
10 and the resistance sheet 220 in the Y direction are overlapped and formed. The X resistance sheet 210 has two electrodes 211, 2
The opposite ends of the differential amplifier 2 via the differential amplifier 2 respectively.
14. Furthermore, this X resistance sheet 21
At both ends of 0, the current from the constant current source 215 is divided by the voltage dividing resistor 21.
They are applied so as to be equal in the normal time through the line 3.

On the other hand, the Y resistance sheet 220 is connected to the differential amplifier 224 via the electrodes 221 and 222 at both ends thereof. The electrodes 221 and 222 are also connected to the ground via a voltage dividing resistor 223.

Assuming now that the two resistance sheets 210 and 220 are brought into conduction at the position indicated by reference numeral A as shown in FIG. 2 by pressing the pen tip 15 of the input pen 10, the constant current source 2
The current from 15 flows to the Y resistance sheet 220 via the X resistance sheet 210. The current flow into the X resistance sheet 210 is inversely proportional to the position where the X resistance sheet 210 conducts with the Y resistance sheet 220, that is, the distance between the electrodes 211 and 212 on each side and the conduction point. Therefore, by detecting the difference in the inflow amount of the current by the differential amplifier 214, X
It is possible to detect the pointing position of the direction.

A current flows from the X-resistive sheet 210 to the Y-resistive sheet 220, and electrodes 221 and 2 at both ends thereof flow.
The current flowing toward 22 is inversely proportional to the distance between each electrode 221 and 222 of the Y resistance sheet 220 and the conduction point. Therefore, the indicated position coordinates in the Y direction can be detected by detecting these current amounts with the differential amplifier 224. The above operation is performed by the coordinate detection unit 21 shown in FIG.

The grid board 30 operates together with the coordinate detecting section 31 provided corresponding to the grid board 30. As shown in FIG. 3, this grid board 30 has x1, x on the plate surface.
An X-side conductor group composed of 2, x3, ..., xi, ... And a y-side conductor group composed of y1, y2, y3 ,. The x-side conductor group is independently switched by the X-axis scanner 31, and the y-side conductor group is independently switched by the Y-axis scanner 32. The x-side conductor group is sequentially switched and connected to the input side of the voltage amplifier 33 by the X-axis scanner 31, and the y-side conductor group is the Y-axis scanner 32.
Are sequentially connected to the output side of the current amplifier 34.

As shown in FIG. 4, the input pen 10 is provided with a coil 11. When the coil 11 approaches the grid board 30, the selected x-side conductor, the voltage amplifier 33, the current amplifier 34, and the selection. The formed y-side conductor and the coil 11 of the input pen 10 form an oscillating circuit, and an oscillating state is set by ambient noise or the like. The output at this time is taken out to determine the coordinates of the coil position on the grid board 30.

In this case, the input pen 10 is provided with a capacitor in parallel with the coil, and the capacity of this capacitor is used (input attribute, writing pressure, switch identification, etc.).
It is configured to be variable according to. Since the oscillation frequency of the oscillation circuit changes as the capacitance of the capacitor changes, the oscillation frequency is measured as shown in FIG. 5 in order to recognize the input attribute of the input pen 10. The number of rising edges of the signal is detected within a fixed time.

As described above, the digitizer of the present invention performs two coordinate detections, one using the pressure sensitive panel and the other using the grid board. As shown in FIG. 6, the pen tip 15 of the input pen 10 and the coil 11 are separated by a distance A. As shown by the solid line, if the pen tip 15 and the coil 11 are present perpendicularly to the digitizer plate surface, the detected coordinate values by both are almost the same. Further, as indicated by the broken line, when the input pen 10 is tilted and tilted by the angle θ, a difference indicated by B occurs between the detected coordinate values by both. Therefore, the inclination angle of the input pen 10 can be recognized by using a simple trigonometric function.

In the apparatus of this embodiment, as shown in FIG.
The position coordinates obtained by using the grid board 30 are prioritized. From the detected coordinate values of both the pressure-sensitive panel 20 and the grid board 30, the tilt detection unit 41 calculates the tilt angle θ of the input pen 10 using the method shown in FIG. This tilt angle data is output to the coordinate correction unit 42, and the grid board 3
The position coordinates from 0 are corrected and output as normal detected coordinates to the host device. This is generally a pressure sensitive panel 20.
This is because the detection coordinates using the electromagnetic coupling principle using the grid board 30 are more accurate than the detection coordinates according to.

The apparatus of the above embodiment obtains the inclination of the input pen 10 and obtains accurate pointing coordinate values from the inclination, but in this embodiment, data relating to the inclination of the input pen 10 is newly added. It can be attribute input data. For example, as shown in FIG. 7, the position D of the input pen coil 11 by the grid board 30 is moved by a predetermined amount around the position C of the input pen tip 15 by the pressure sensitive panel 20. This is an operation in which the operator rotates the input pen 10 by a predetermined amount with the pen tip position fixed. A case where the inclination of the input pen 10 due to the movement of the predetermined amount is within a certain range can be defined as one input attribute.

[0020]

As described above, according to the present invention, accurate coordinate values can be obtained even when the input pen is tilted and supported. Moreover, since the inclination angle of the input pen can be arbitrarily extracted, data based on the inclination angle of the input pen can be adopted as a new input item.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an apparatus according to an embodiment of the present invention.

FIG. 2 is an electrical configuration diagram of the pressure-sensitive panel of FIG.

FIG. 3 is an electrical configuration diagram of the grid board of FIG.

FIG. 4 is an explanatory diagram of a configuration of an input pen.

FIG. 5 is a frequency detection configuration diagram as an attribute identification unit in FIG.

FIG. 6 is a principle diagram of detecting an inclination angle of an input pen.

FIG. 7 is an explanatory diagram showing an example of input items depending on the inclination of the input pen.

[Explanation of symbols]

10: Input pen 20: Pressure sensitive panel 30: Grid board 41: Tilt detection unit 42: Coordinate correction unit 43: Attribute identification unit

Claims (1)

[Claims] 1. A digitizer having a coordinate detection plate and a position indicator, for determining coordinates on the coordinate detection plate pointed by the position indicator, wherein the position indicator includes a coil and a tip contact portion. The coordinate detection plate is provided with a grid plate having a conductor group that is electromagnetically coupled to the coil of the position indicator and outputs, and a pressure-sensitive panel that outputs according to the pressing of the tip contact portion of the position indicator. Further, an electromagnetic coordinate detection unit that detects the indicated position coordinates of the position indicator from the output of the grid board, and a pressure-sensitive coordinate detection that detects the coordinates of the pressed position of the position indicator from the output of the pressure-sensitive panel. A digitizer, and the pointed position coordinates on the coordinate detection plate of the position indicator are obtained based on the output coordinate values of these two coordinate detection parts.