JPH1124828A - Tablet device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To reduce the number of parts, the number of manufacturing steps and the number of work steps. SOLUTION: Although a tablet input plate 2 has Y electrodes Yi extended in the X-axis direction arranged at equal intervals in the Y-axis direction,
There is no right angle X electrode on the Y electrode. A test signal waveform (rectangular wave, sine wave, or the like) is transmitted from the input pen 3 to an arbitrary point on the tablet input plate 2 at each time interval T, and the Y signal selector 5 outputs a signal from the terminal C (X = 0) of each electrode Yi. The waveform VYi is selected for each T, amplified, A / D converted, input to the CPU 10, and the Y coordinate of the input pen is measured from the amplitude of each waveform VYi '.
Next, the CPU calculates the waveform VY of the electrode Yj closest to the Y coordinate.
j, the Y signal selector 5 is controlled, the corresponding A / D conversion output is input, the propagation delay time τ (j) from the input pen 3 to the CPU is measured, and the input pen X coordinate (x) is measured. Relationship between X coordinate (x) of Y electrode and propagation time Δτ from point X = x to terminal C, and delay time τa (j) from terminal C of each electrode to CPU input (j = 1 to M) Is determined in advance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tablet device, and more particularly to a tablet device in which electrodes of a tablet input plate are formed only on one surface.

[0002]

2. Description of the Related Art A conventional electrostatically-coupled tablet device (hereinafter simply referred to as a tablet device) 1 is, as shown in FIG.
X electrodes X1 to XN (N ≧ 2) extended in the vertical direction (Y-axis direction) on the upper surface side (input pen side) of tablet input plate 2
Are arranged at equal intervals in the X-axis direction. In addition, Y extended in the left-right direction (X-axis direction) on the bottom side of the tablet input plate 2.
The electrodes Y1 to YM (M ≧ 2) are arranged at equal intervals in the vertical direction (Y-axis direction).

[0003] When the input pen 3 is brought into contact with an arbitrary point on the tablet input plate 2, a capacitance is formed between the input pen 3 and the X and Y electrodes. A test voltage of a rectangular wave is applied from the input pen 3 to the tablet input plate 2 at each time interval T (FIG. 7B), and the X signal selector 4 sequentially switches and selects the test voltage of each Xi electrode at each time interval T (FIG. 7B). FIG.
C), input to the amplifier 6. The signal amplified to a required level by the amplifier 6 is converted into a digital signal by the A / D converter 8 and input to the CPU 10. The CPU 10 measures the X coordinate (x) of the input pen 3 from the input amplitude of the test voltage VXi 'of each electrode Xi.

Similarly, test voltages of the Y electrodes Y1 to YM are sequentially selected by a Y signal selector 5 (FIG. 7D), amplified by an amplifier 7, converted to a digital signal by an A / D converter 9, and converted to a digital signal.
The input is input to the PU 10 and the Y coordinate (y) of the input pen 3 is measured in the same manner as before. The CPU 10 controls the input pen 3 and supplies a synchronization signal Sa (FIG. 7A). Also X
Control signals (including clocks) SX and SY are supplied to the signal selector 4 and the Y signal selector 5, respectively.

[0005] As shown in FIG.
An insulating substrate 13 having X electrodes X1 to XN formed on its inner surface and an insulating substrate 14 having Y electrodes Y1 to YM formed on its inner surface are bonded to one flat plate with an insulating plate 15 interposed therebetween. In particular, when a screen input tablet is superimposed on a display screen such as an LCD or a CRT, transparent glass is used as the insulating substrates 13 and 14, and transparent ITO is used for the X and Y electrodes. Further, a transparent adhesive sheet is used as the insulating plate 15.

[0006]

The tablet input plate 2 used in the conventional tablet device requires an insulating substrate 13 on which an X electrode is formed, an insulating substrate 14 on which a Y electrode is formed, and an insulating plate 15. There was a problem that the number of processes increased. The tablet input plate 2 has to align both substrates so that the X electrodes and the Y electrodes are orthogonal to each other with high accuracy, and join them while maintaining the positions. .

An object of the present invention is to solve these conventional problems and to provide an economical tablet device which requires a small number of parts, a small number of manufacturing steps and a small number of working steps.

[0008]

[Means for Solving the Problems]

(1) The tablet device according to the first aspect is characterized in that the X
.., YM (M ≧ 2) are arranged at equal intervals in the Y-axis direction, and a tablet input plate having no X electrode orthogonal to the Y electrodes, and an upper surface of the tablet input plate , And an input pen for applying a test signal waveform at predetermined time intervals T, and one end of each of the Y electrodes Y1, Y2,. 0) transmitted to the test signal waveform VY1,
.., VYM at time intervals T, and an A / D converter for converting the test signal waveforms VY1, VY2,..., VYM of the Y electrodes selected by the Y signal selector into digital signals. , The output of the A / D converter is input, and the test signal waveform VYi (i = 1 to
M) means for measuring the Y coordinate of the input pen from the amplitude of M), and controlling the Y signal selector to select the test signal waveform VYj of the Y electrode Yj closest to the measured Y coordinate;
Means for receiving the output of the A / D converter of the test signal waveform VYj, measuring the propagation delay time τ (j) from the input pen, and measuring the X coordinate of the input pen from the measured value. .

(2) In the invention of claim 2, in (1), the test signal waveform applied from the input pen to the tablet input plate is a rectangular wave or a sine wave. (3) In the invention of claim 3, in (1), the input pen is electrostatically coupled to the tablet input plate. (4) In the invention of claim 4, in (1), the means for measuring the X or Y coordinate is constituted by a microprocessor.

(5) In the invention of claim 5, in the above (1), the coordinate X = x on the Y electrode and the propagation delay time of the test signal from the point of the coordinate X = x to the point of X = 0. A memory is provided for storing a conversion table between Δτ. (6) According to the invention of claim 6, in the above (1), the propagation delay time τa (t) from the output terminal (terminal C) of the Y electrode Yi (i = 1 to M) of the test signal to the means for measuring the X coordinate. i)
Is provided.

[0011]

1 and 2 show an embodiment of the present invention.
6 are denoted by the same reference numerals as in FIGS. 6 and 8. The tablet input plate 2 used in the present invention has Y electrodes Y1, Y2,.
YMs are arranged at equal intervals. In the example of FIG. 2, a Y electrode Yi (i = 1 to M) is formed on the bottom surface of the insulating substrate 14. The tablet input plate 2 used in the present invention is not provided with the X electrode as in the conventional example.

One end of the electrode Yi (i = 1 to M) (X coordinate is set to X = 0) is connected to the Y signal selector 5, and the test signal selected by the Y signal selector 5 is supplied to the level required by the amplifier 7. A / D converter 9 converts the signal to a digital signal and inputs it to CPU 10. A synchronization signal Sa is supplied from the CPU 10 to the input pen 3, and a control signal SY including the synchronization signal is supplied to the Y signal selector 5. CPU
Reference numeral 10 denotes a microprocessor constituted by, for example, one or a plurality of LSI chips.

The operation for detecting the Y coordinate of the input pen 3 is the same as that described in the conventional example, and a description thereof will be omitted.
When the measurement of the Y coordinate (y) of the input pen 3 is completed, the CPU 10 controls the Y signal selector 5 to select the signal of the Y electrode Yj closest to the coordinate (y) just obtained. The signal selector 5 is controlled. As a result, CP
U10 determines the test signal VYj 'input to itself.
The propagation delay time τ (j) from the time when the signal is sent from the input pen 3 to the time when the signal is input to the CPU 10 is measured.

The propagation delay time τ (j) includes a delay time τa (j) from the terminal C of the electrode Yj to the CPU 10, and this τa (j) (j = 1 to M) is experimentally determined in advance. It is measured and stored in the RAM 21. Propagation time Δτ = τ (j) −τa from input pen 3 to terminal C of electrode Yj
(J) shows almost the same value for every Y electrode as long as the coordinate x is the same, even if the value of j changes according to the coordinate (y) of the input pen 3. Therefore, Δτ = τ (j) −τa (j); j = 1, 2,..., M (1) Δτ = f (x) (2) Δτ is the value of the terminal C from the coordinate X = x of each Y electrode.
It is almost equal to the propagation time up to (X = 0). From equation (2), the coordinates x can be expressed as x = g (Δτ) (3). The relationship between the expressions (2) and (3) is obtained experimentally in advance as shown in FIG. RA
M21 may be provided with a conversion table from Δτ to x.

The CPU 10 measures the propagation delay time τ (j), finds the propagation time Δτ of the electrode Yj from equation (1),
The coordinates (x) can be obtained from the equation (3). In addition,
The test signal output from the input pen 3 is not limited to the rectangular wave shown in FIG. FIG. 4 shows a case where a sine wave is used. The ROM 22 in FIG. 1 stores a system program that regulates the operation of the tablet device 1,
The PU 10 decodes and executes this program to perform necessary operations.

In the above description, the tablet input plate 2
In the drawings, the left-right direction is the X-axis direction, and the up-down direction is the Y-axis direction. However, the up-down direction may be the X-axis direction, and the left-right direction may be the Y-axis direction. In the above description, the input pen 3 and the tablet input plate 2 are electrostatically coupled. However, the present invention is not limited to this case, and may be electromagnetic coupling.

[0017]

The tablet input plate 2 used in the present invention only needs to have the insulating substrate 14 on which the Y electrode is formed, and does not require the conventional insulating substrate 13 on which the X electrode is formed. The number can be reduced. In the prior art, since there is no need to attach the insulating substrates 13 and 14 which requires a large number of man-hours, the number of man-hours can be significantly reduced together with the work, and an economical tablet device can be provided.

Since the tablet input plate 2 does not need the X electrode and only needs to be placed on the insulating substrate 14 on which the Y electrode is formed, a thin screen input tablet having excellent transmittance can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a perspective view of the tablet input plate 2 of FIG.

FIG. 3 is a diagram showing an example of a signal waveform of a main part of FIG. 1;

FIG. 4 is a diagram showing another example of a signal waveform of a main part of FIG. 1;

5 is a graph showing a relationship between coordinates X = x of a Y electrode in FIG. 1 and a propagation time Δτ from a point of X = x to a terminal C (X = 0).

FIG. 6 is a block diagram of a conventional electrostatic coupling type tablet device.

7 is an operation waveform diagram of a main part of FIG. 6;

8 is an exploded perspective view of the tablet input plate 2 of FIG.

Claims (6)

[Claims] 1. Y extended in the X-axis direction of XY rectangular coordinates
The electrodes Y1, Y2,..., YM (M ≧ 2) are arranged at equal intervals in the Y-axis direction, and a tablet input plate having no X electrode orthogonal to the Y electrodes; , An input pen for applying a test signal waveform at predetermined time intervals T, and the Y electrodes Y1, Y2,..., YM of the tablet input plate.
, VYM propagated to each end (X coordinate of each end is set to X = 0) at each time interval T, and a Y signal selector for switching and selecting the test signal waveforms VY1, VY2,. A / D converter for converting the Y-electrode test signal waveforms VY1, VY2,..., VYM into digital signals, and the output of the A / D converter is input to the test signal waveform VYi (i = 1 to M) means for measuring the Y coordinate of the input pen from the amplitude of M), and controlling the Y signal selector to select the test signal waveform VYj of the Y electrode Yj closest to the measured Y coordinate. The output of the A / D converter having the signal waveform VYj is input, and a propagation delay time τ from the input pen is input.
(J), and means for measuring the X coordinate of the input pen from the measured value. 2. The tablet device according to claim 1, wherein a test signal waveform applied from the input pen to the tablet input plate is a rectangular wave or a sine wave. 3. The tablet device according to claim 1, wherein the input pen is electrostatically coupled to the tablet input plate. 4. The tablet device according to claim 1, wherein the means for measuring the X or Y coordinate comprises a microprocessor. 5. The conversion table according to claim 1, wherein an X coordinate X = x on the Y electrode and a propagation time Δτ of the test signal from a point X = x to a point X = 0. A tablet device comprising a stored memory. 6. The propagation delay time τa (i) from the output terminal (terminal C) of the Y electrode Yi (i = 1 to M) of the test signal to the means for measuring the X coordinate according to claim 1, A tablet device comprising a stored memory.