JPH03191416A - Coordinate detector - Google Patents

Abstract

PURPOSE:To obtain a correct coordinate value even if a stylus pen is used in an inclined state by providing the stylus pen with two coils, and executing prescribed operation based upon respective coordinate values detected at the time of exciting respective coils. CONSTITUTION:When an optional position on a tablet 1 is specified by the stylus pen 20, a processing part 35 controls the switching of a switching circuit 34, an exciting current from an exciting circuit 31 is supplied to one, e.g. the exciting coil 21, of plural exciting coils 21, 22. Thereby, an induced voltage is generated on the conductor of a tablet 1, the induced voltage is processed by a detecting circuit 32 and a coordinate value is calculated by a processing part 34. When the coordinate value concerned is calculated, the processing part 35 controls the switching of the circuit 34 and the exciting current is supplied to the other coil 22. Thereby, the processing part 35 corresponding to the coil 22 executes the operation of an equation based upon the coordinate value due to the coil 21 which has been previously stored and the coordinate value due to the coil 22 to obtain a ture coordinate value pointed out by the tip of a pen 20. The inclination angle of the pen 20 can be detected by the execution of another expression.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a coordinate detection device using a stylus pen.

[Conventional technology]

A coordinate detection device is a device that detects the coordinates of an arbitrary position on the surface of a tablet, on which a large number of conductive wires are wired in a predetermined shape and size, when indicated by an indicator. In such coordinate detection devices, a cursor and a stylus pen are often used as the indicator. Hereinafter, a coordinate detection device using a stylus pen will be explained with reference to the drawings.

FIG. 4 is a schematic diagram of the configuration of the coordinate detection device.

In the figure, 1 is a tablet, 2 is a stylus pen that indicates an arbitrary point on the tablet 1, 21 is an excitation coil provided in the stylus pen 2, and 3 is an arithmetic control unit that performs coordinate detection. The arithmetic control unit 3 includes an excitation circuit 31 that excites the excitation coil 21 of the stylus pen 2, a detection circuit 32 that processes the signal output from the tablet 1 and detects a voltage or numerical value proportional to the coordinate value, and It is comprised of a processing section 33 consisting of a microcomputer that calculates coordinate values based on voltages or numerical values and controls the operation of the detection circuit.

When an excitation current is supplied from the excitation circuit 31 to the excitation coil 21 of the stylus pen 2, a magnetic flux is generated from the excitation coil 21, thereby generating an induced voltage in each of the plurality of types of wiring of the tablet 1. The processing unit 33 sequentially switches each induced voltage and inputs it to the detection circuit.
By processing each input induced voltage, a voltage with an amplitude proportional to the coordinate value of the tip position of the stylus pen 2,
Or generate a count value. The processing unit 33 calculates the coordinate value based on this voltage or count value, and
This is stored at a predetermined address in a predetermined storage means. Such a coordinate detection device is disclosed in, for example, Japanese Patent Application Laid-Open No. 55-56230.
It is publicly known from the publication No.

[Problem to be solved by the invention]

In the coordinate detection device described above, the stylus pen 2 is, in principle, used in a position perpendicular or nearly perpendicular to the tablet 1. However, the stylus pen 2 is often used in the same way as a general writing instrument such as a pencil or a ballpoint pen, and in such usage, the stylus pen 2 is tilted considerably with respect to the tablet 1. There is. This state is shown in FIG.

In FIG. 5, the same parts as those shown in FIG. 4 are given the same reference numerals. θ indicates the inclination angle of the stylus pen 2 with respect to the vertical line of the tablet 1.

Here, if the tip of the stylus pen 2, that is, the coordinate value in the X-axis direction of the coordinate to be detected is Xo, then the stylus pen 2
is tilted at an angle θ as shown in the figure, the coordinate value X. (true value) cannot be detected, and a coordinate value Xθ that is a distance d away from the tip in the direction of inclination is detected, resulting in an error in detection. This distance dl, that is, the amount of deviation is -
For example, when θ=30', about 2.5 mm, θ=45
The deviation is large, such as approximately 3.75 mm when the angle is ', and approximately 5 mm when the angle is θ-60°.

The purpose of the present invention is to solve the problems in the above-mentioned prior art,
To provide a coordinate detection device capable of detecting correct coordinate values even when a stylus pen is used in an inclined state.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a tablet on which a large number of conductive wires are wired, a stylus pen for indicating an arbitrary position on the tablet, and a coordinate value of the position indicated by the stylus pen. A coordinate detection device comprising a calculation control unit that performs detection based on a voltage induced in a conducting wire, wherein a plurality of coils are provided at different positions on the longitudinal axis of the stylus pen, and the calculation control unit includes the switching excitation means that sequentially switches and excites each coil; a calculation means that calculates a coordinate value when the stylus pen tilt is 0; and a calculation means that calculates a coordinate value when the stylus pen tilt is 0, based on each coordinate value obtained by excitation of each coil; The present invention is characterized in that it is provided with one or both of the other calculation means for calculating the value.

[Effect]

When detecting coordinates, one coil of the stylus pen is energized to detect the coordinate value of that coil, and then another coil is switched and energized to detect the coordinate value of that coil. By performing predetermined calculations by the calculation control unit using these coordinate values, one or both of the true coordinate values of the pointing device of the stylus pen and the inclination of the stylus pen are obtained.

〔Example〕

Hereinafter, the present invention will be explained based on illustrated embodiments.

FIG. 1 is a schematic diagram of the configuration of a coordinate detection device according to an embodiment of the present invention. In the figure, parts that are the same as or equivalent to those shown in FIG. 4 are given the same reference numerals and their explanations will be omitted. 20 is a stylus pen of this embodiment.

This stylus pen 20 is provided with an excitation coil 22 in addition to the excitation coil 21 which is the same as the conventional one. Excitation coil 22
are provided coaxially with the excitation coil 21 and at different positions (for example, 4 mm apart from the excitation coil 21). A switching circuit 34 sequentially switches and supplies the excitation current output from the excitation circuit 31 to the excitation coils 21 and 22. 35 is a processing section, in addition to the conventional processing section 33, other calculation means and control means for the switching circuit 34 are added. These other calculation means and control means will be described later. An arithmetic control section 30 is configured by the excitation circuit 31, the detection circuit 32, the switching circuit 34, and the processing section 35.

Next, the operation of this embodiment will be explained with reference to a side view of the stylus pen shown in FIG. 2 when the stylus pen is in use.

Components shown in FIG. 2 that are the same as those shown in FIG. 1 are given the same reference numerals. In Fig. 2, Xo is the X-axis coordinate value (true value) of the tip of the stylus pen 20, and X, (θ) is the X-axis coordinate detected by the excitation coil 21 when the stylus pen 20 is tilted by an angle θ. The value, X, (θ) is the coordinate value of the X axis detected by the excitation coil 22 in the same state, dl is the deviation amount of the coordinate value X, (θ) from the true value X0, and d is the coordinate value XZ( θ) from the true value X0. In this embodiment, first, when the excitation coil 21 is excited, the amount of deviation d of coordinate values is determined by the tilt angle θ of the stylus pen.
Check by actual measurement how it changes. According to this actual measurement, it was found that the deviation amount d is approximately equal to the value obtained by multiplying the angle θ by a certain constant. That is, for d and #, ・θ0 ・・・・・・・・・(
1) Furthermore, when similar measurements were made for the excitation coil 22, it was found that the amount of deviation dt was approximately equal to the value obtained by multiplying the constant at the angle θ by 2. That is, dt=Kz ・θ 0 ・・・・・・
... (2) Here, assuming that both sides of equations (1) and (2) are equal, the following equation is derived.

KI Kg Also, between each coordinate value Xo, X+(θ), Xt(θ) and each deviation amount d, dt,
・・・・・・・・・Since the relationship shown in (4) exists, from this formula, d, az=x+(θ) X2(θ)・
......(5). Substituting equation (5) into equation (3) yields K.

K.

becomes. Also, since d, = ・θ, from equation (4), X0=X, (θ)−, ・θ ・・・・・・・・・(
7), and by substituting equation (6) into equation (7), xo
−(K, −K!(θ) K t−x I(θ)) KI
K!・・・・・・・・・ (8) It becomes.

In equation (8), the value K1. K! is known, the coordinate value X, (θ
), XZ(θ) are coordinate values obtained by exciting the excitation coils 21 and 22, so even if an instruction is given with the stylus pen 20 tilted, the excitation coil 2
If 1.22 is individually excited and the respective coordinate values are determined, the true value X0 can be obtained.

Now, it is assumed that the processing unit 35 is provided with calculation means for calculating the above equations (6) and (8), and coordinates are detected. When an arbitrary position on the tablet 1 is specified by the stylus pen 20, the processing section 35
4 is switched and controlled to supply the excitation current of the excitation circuit 31 to one of the excitation coils 21 and 22, for example, the excitation coil 21.

As a result, an induced voltage is generated in the conductor of the tablet l,
This induced voltage is processed by a detection circuit 32, and a coordinate value is calculated by a processing section 35. This coordinate value is temporarily stored in the memory within the processing section 35. When the coordinate values are calculated, the processing unit 35 controls the switching circuit 34 to supply an excitation current to the other excitation coil 22 .

Thereby, coordinate values corresponding to the excitation coil 22 are obtained. The processing unit 35 calculates the equation (8) based on the previously stored coordinate values of the excitation coil 21 and the excitation coil 22 to obtain the true coordinate values indicated by the tip of the stylus pen 20. Furthermore, by performing the calculation of equation (6), the tilt angle of the stylus pen 20 can be detected.

In this way, in this embodiment, the two excitation coils are individually excited, their coordinate values are determined, and the necessary calculations are performed based on these coordinate values, so even if the stylus pen is tilted, Even when instructions are given, accurate coordinate values can be obtained. Also, the seat 4j, which is used especially in conjunction with a display device:! In the case of the detector, since the tip of the stylus pen 20 and the display point coincide with each other, there is no discomfort in the operation and smooth operation is possible.

Furthermore, this embodiment also has the following effects.

As is clear from equation (6) above, if the coordinate values corresponding to the excitation of each excitation coil are known, the inclination θ of the stylus pen 20 can be calculated. Therefore, the processing unit 35 (6
), the angle θ can be detected, and this angle θ can be used as an operator command. That is, the operator can issue a corresponding command by intentionally tilting the stylus pen.

Examples of such commands include line thickness commands, line type (
There are commands such as solid lines, dotted lines, broken lines, -dotted and chain lines, etc.
When performing such intentional tilting, the stylus pen may be provided with a push button switch, etc., and by pressing this button, information on instructing the processing unit by tilting the stylus pen may be inputted. .

In addition, in the description of the above embodiment, an example was described in which the inclination of the stylus pen with respect to a vertical line is used as a specific command.

However, such a command applies not only to the above-mentioned tilt angle but also to
This can also be done by the tilt angle with respect to the axis (or Y axis). This will be explained with reference to FIG. FIG. 3 is a top view of the state in which the stylus pen 20 is giving instructions. In the figure, (Xl(θ), Yl(θ)) is the excitation coil 2
The coordinate values detected by the excitation of 1, (X, (θ),
Yz(θ)) is a coordinate value detected by excitation of the excitation coil 22. d
(θ) indicates the amount of deviation of the coordinate values of the excitation coil 22. or,
α is the tilt angle of the stylus pen 20 with respect to the X axis (the direction of the tilt of the stylus pen 20). The tilt angle α can be determined from each detected coordinate value using the following equation.

(9) Therefore, the operator consciously moves the stylus pen to
By tilting with respect to the axis (or Y-axis), corresponding commands can be issued.

〔Effect of the invention〕

As described above, in the present invention, the stylus pen is provided with two coils, and predetermined calculations are performed based on each coordinate value detected when each of these coils is excited. Correct coordinate values can be obtained even if instructions are given in the current state. Furthermore, since the magnitude of the tilt of the stylus pen can be determined by a predetermined calculation, this tilt can also be used as information by intentionally tilting the stylus pen.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the configuration of a coordinate detection device according to an embodiment of the present invention, FIGS. 2 and 3 are side views and top views showing the pointing state of the stylus pen, and FIG. 4 is a conventional coordinate detection device. FIG. 5 is a side view showing the pointing state of the stylus pen. 1......Tablet, 20...
... Stylus pen, 21.22... Excitation coil, 30... Arithmetic control unit, 31.
......Excitation circuit, 32......Detection circuit, 34...Switching circuit, 35...
・・・・・・Processing department. Figure 1 Figure 1 Figure 1

Claims (1)

[Claims] A tablet on which a large number of conductive wires are wired, a stylus pen that indicates an arbitrary position on the tablet, and an arithmetic control that detects the coordinate value of the position indicated by the stylus pen based on the voltage induced in the conductive wire. A coordinate detection device comprising: a plurality of coils provided at different positions on the longitudinal axis of the stylus;
The arithmetic control section includes switching excitation means for sequentially switching and energizing each of the coils, and a calculation means for calculating a coordinate value when the stylus pen is tilted at 0 based on each coordinate value obtained by excitation of each of the coils. and at least one of other calculation means for calculating the inclination of the stylus pen.