JPH02201520A - Output correcting method for electromagnetic induction type coordinate analyzer - Google Patents

Abstract

PURPOSE:To read coordinates with a high precision by correcting (x) and (y) coordinate values of a stylus pen with its inclination to a tablet at the time of inclination of the stylus pen to the tablet. CONSTITUTION:Correction values of a stylus pen 4 corresponding to inclination phiof the stylus pen 4 to the X or Y coordinate axis on the surface of a tablet 2 and inclination theta to a Z coordinate axis perpendicular to the surface of the tablet 2 are experimentally obtained and are preliminarily stored in a ROM 20 of a controller. A CPU 22 operates and outputs a signal of correct (x) and (y) coordinates of the tablet, which the front end of the stylus pen 4 points, based on x-axis and y-axis position correction values corresponding to angles phiand theta of inclination which are set in the table of the ROM 20. Thus, a defect that error of (x) and (y) coordinate axes occurs by the change of inclination of the stylus pen 4 is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an output correction method for an electromagnetic induction type coordinate analysis device.

[Conventional technology]

As a device for measuring the X-Y coordinate values of the tip of a stylus pen or the center point of a cursor on a tablet, an electronic guided coordinate analyzer is disclosed in Japanese Patent Publications No. 50-24571 and No. 52-3.
It is publicly known as seen in publications such as No. 7342. In this type of coordinate analyzer, a pulse counter starts counting clock pulses at the same time as an electromagnetic signal is generated from a coordinate reference position on the tablet 2. An induced voltage is generated in the coil 6 of the stylus pen by the electromagnetic signal, and at the point where this voltage first becomes zero, a counter stop pulse is generated, and this counter stop pulse stops the pulse counting operation of the pulse counter. The count value of the pulse counter at this time is taken as the coordinate value of the tip of the stylus pen on the tablet.

[Problem that the invention seeks to solve]

However, since the coil built into the stylus pen is located at a distance from the tip of the stylus pen, if the inclination of the stylus pen with respect to the tablet surface changes, the position of the coil on the tablet surface 1- changes. Therefore, even if the tip of the stylus pen points to a single point on the tablet, changes in the tilt of the stylus pen cause a shift in the timing of the voltage induced in the coil. The object of the present invention is to eliminate the above-mentioned defects.

[Means to solve problems]

In order to achieve the above object, the present invention generates an induced voltage in the coil of a stylus pen by a signal from the tablet side, stops the counting operation of a pulse counter with a stop pulse based on this induced voltage, and generates a stylus position signal. In the electromagnetic induction coordinate analysis device, the stylus pen is provided with two coils at a predetermined interval in the longitudinal direction, and the tilt of the stylus pen with respect to the X or Y coordinate axis on the tablet surface is determined. The correction value of the stylus pen corresponding to φ and the tilt O with respect to the Z seat tilt axis perpendicular to the tablet surface is experimentally determined and stored in memory tα in advance, and the position of the stylus pen on the tablet is analyzed. edge,
The inclination φθ of the stylus pen is determined from the deviation of the count values of the pulse counters controlled by the stop pulses of the two coils, and the position correction value of the stylus pen corresponding to this inclination φθ is determined from the stored data in the memory. The stylus pen position signal corrected using the correction value is output.

〔Example〕

The structure of the present invention will be described in detail below with reference to embodiments shown in the accompanying drawings.

In FIG. 2, 2 is a tablet of a known electromagnetic induction coordinate analyzer equipped with an XY matrix electrode line, and the tip of the stylus pen 4 is placed at an arbitrary position on the surface of the tablet.
When the record switch is turned on, an electromagnetic signal is generated by the current flowing through the 7 trix electrodes in the X direction from a predetermined reference position of the tablet 2, and then an electromagnetic signal is generated in the Y direction, and this electromagnetic signal causes the stylus pen 4 to An induced voltage is generated in the coils 6.8 built into the upper and lower positions.

This induced voltage is detected by the pulse counter 10 on the controller side.
, 12 stop pulse 14.1
A coil 6.8 built into the stylus pen 4, which is waveform-shaped into 6 signals, is placed at a predetermined distance above t, as shown in FIG. It is located with the following in mind. The lower coil 6 is in the same position as the coil in a conventional stylus pen.

The pulse counter 10 counts clock pulses when the record switch is thrown, and when the coil 6 outputs a stop pulse 14 due to an electromagnetic signal from the
The 6-pulse counter 12 that counts coordinate values is based on the same principle as above.

Count the X coordinate value of the coil 8. Coil 6°8 y
The m target value is also counted by a pulse counter (not shown) according to a known principle. As shown in FIG. 2, the tilt of the stylus pen 4 is determined by the angle φ formed by the projection of the central axis of the stylus pen 4 on the surface of the tablet 2 with respect to the X coordinate axis set on the surface of the tablet 2. ,
The central axis line is Z perpendicular to the surface of the tablet 2.
An angle θ formed with the coordinate axis can be considered. The X+y count value due to the stop pulse obtained from coil 6 is expressed as (
X engineering, y □) The x, y count values by coil 8 are
+3'z) and the difference between x2,

Since it is derived as a function of Δy, the relationship between ΔX, Δy and the θ angle is expressed as shown in Figure 6, and the Φ angle is also ΔX.

Since it is derived as a function of Δy, the relationship between ΔX, Δy, and the ψ angle is expressed as shown in FIG.

From the inclination θ angle and ψ angle of the stylus pen 4, the X-axis and y-axis correction values of the position signal of the stylus pen 4 are obtained experimentally as shown in FIGS. 4 and 5. In the ROM 20 of the controller, the X-axis and y-axis correction values shown in FIGS. 4 and 5 are stored as a table corresponding to the θ angle and the ψ angle. The CPU 22 of the controller is the ROM 20
Based on the X-axis and y-axis position correction values corresponding to the θ angle and ψ angle of the stylus pen 4 set in the table of
'Calculate and output the coordinate position signal.

〔effect〕

As described above, even if the stylus pen is tilted with respect to the tablet, the present invention allows the stylus pen to be
Since the coordinate values are corrected, there is an advantage that highly accurate coordinate reading is possible.

[Brief explanation of the drawing]

FIG. 1 is a block explanatory diagram, FIG. 2 is an explanatory diagram, FIG. 3 is an explanatory diagram, and FIGS. 4 to 7 are explanatory diagrams. 2...Tablet, 4...Stylus pen, 6,8
... Coil, 10.12 ... Counter, 14.1
6...stop pulse. Patent applicant: Muto Kogyo Co., Ltd. Representative Patent attorney Aya Nishijima

Claims (1)

[Claims] (1) An electromagnetic induction type that generates an induced voltage in the coil of the stylus pen by a signal from the tablet side, and uses a stop pulse based on this induced voltage to stop the counting operation of the pulse counter and detect the stylus position signal. In the coordinate analysis device, the stylus pen is provided with two coils at a predetermined interval in the longitudinal direction, and an inclination φ of the stylus pen with respect to the X or Y coordinate axis on the tablet surface and a vertical axis perpendicular to the tablet surface are determined. The correction value of the stylus pen corresponding to the inclination θ with respect to the Z coordinate axis is experimentally determined and stored in memory in advance, and when the position of the stylus pen on the tablet is analyzed, it is determined by the stop pulse of the two coils. The inclination φθ of the stylus pen is determined from the deviation of the count value of the controlled pulse counter, the position correction value of the stylus pen corresponding to this inclination φθ is retrieved from the data stored in the memory, and the stylus is corrected using this correction value. An output correction method characterized by outputting a pen position signal.