JPS6160117A - Tablet input device - Google Patents

Abstract

PURPOSE:To specify the positions of contacts with a small number of scan frequency by applying the prescribed drive pulse to an indication means for desired coordinates with a contact secured with a table and discriminating the positions of contacts according to the size of the pulse signal produced at each electrode line group. CONSTITUTION:When an input pen 12 has a contact with a tablet 11 where the 1st and 2nd electrode lines are set alternately and in parallel in the prescribed number of pieces at the same intervals as segments, a CPU receives the signal PSW to have switching to electrode line groups 3-6, 7-9 and 21-27 and supplies the drive pulse SP to the pen 12. Then the pulse signal S is produced in response to the coupling capacity between each line group and the point of the pen 12. Then the CPU stores the digital value of each pulse to the prescribed address of a RAM after A/D conversion. The CPU compares signals S3-S6 produced at the 1st line group in the direction X to extract the maximum signal. Then the CPU extracts the maximum and the second maximum ones out of signals S7-S9 produced at the 2nd line groups 7-9 and discriminates that the pen 12 has a contact with the level close to the next maximum signal. Then the CPU sends the data TD showing the areas of contacts in the X and Y directions respectively to a data processor, etc. via an IO.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a tablet input device, and more particularly to a tablet input device with improved electrode wire connection and signal detection method of the tablet.

[Conventional technology]

The applicant previously proposed a tab/let input device that improved the electrode wire connection of a tablet in patent application No. 2143 filed in 1982.
No. 01 and Patent Application No. 113442 filed in 1982.

In these tablet input devices, in addition to normal electrode lines for specifying coordinates, digit electrode lines are arranged to scan these electrode lines block by block in order to shorten the scanning time.

[Problem that the invention seeks to solve]

But with this traditional tablet input device.

For example, in order to set the segment spacing to 6 sweetfish, in addition to arranging two normal electrode wires at 6 sweetfish spacing, it is necessary to place an additional digit electrode wire between them. This results in half the number of sweetfish, resulting in problems such as an increase in the number of man-hours for pattern creation, an increase in the difficulty of processing, and a decrease in the level of the signal related to the lower electrode due to an increase in the shielding effect of the upper electrode.

[Means for solving problems]

Therefore, in the tablet input device of the present invention, the first electrode wires and the second electrode wires are alternately arranged in parallel on the tablet at the same intervals as the segments, and the first electrode wires are arranged every m.
The second electrode wires are connected in parallel every m10n (n is an odd number) to form an electrode wire group, and a predetermined driving pulse is applied to the indicating means that contacts the tablet and indicates the desired coordinates. At this time, the contact position of the indicating means is determined based on the magnitude of the pulse signal generated in each of the electrode wire groups.

[Effect]

That is, if the first electrode wire and the second electrode wire are connected in parallel in different numbers in this way, 2 For example, when rn = near and n knee 1, the 1st and 8th of the first electrode wire , 15
. . . belong to the same electrode line group, while the 1st and 8th electrode lines located next to them belong to the same electrode line group.
No. 15.

......... is 1. For example, the 8th is the 2nd, the 15th is the 3rd, etc., each has a different electrode line. It will belong to the group.

Therefore, from the magnitude of the pulse signal generated in each electrode wire group when a driving pulse is applied to the indicating means, the electrode wire group number of the first electrode wire closest to the contact position of the indicating means and the electrode wire group number of the second electrode wire are determined. By determining the electrode wire group number, it becomes possible to determine between which first electrode wire and second electrode wire the corresponding contact position is located from the combination thereof.

〔Example〕

The details of the present invention will be explained below based on illustrated embodiments. 1st
The figure shows an example of the electrode line arrangement in the X direction. In the figure, 1 is the first electrode line, 2 is the second electrode line, and in order to distinguish p1, subscripts from A to L are given to each from the left. (The electrode wires 22 will be described later.) In this embodiment, the first electrode wires 1 are connected in parallel every sixth from the left to form the electrode wire group 3.
, 4, 5.6, and the second electrode wires 2 are still connected every second from the left to form an electrode wire group of 7°8.9.

FIG. 2 shows an example of the block configuration. In the figure, 11 is a tablet, and electrode wire groups 3 to 9 in the X direction shown in FIG.
In addition, electrode wire groups 21 to 27 having the same configuration are also arranged in the Y direction. Reference numeral 12 denotes an input pen to which driving pulses are supplied from a central processing unit CPU, which will be described later.

13 is a pen switch built into the input pen 12. MPX is a multiplexer, and according to the switching signal OHK from the central processing unit CP'U, each electrode line group 6-6.7-9.
The pulse signals generated at 21 to 27 are transmitted to amplifiers A, M P
Switch to supply. A and /D are analog-to-digital converters that convert the analog value of the amplified pulse signal into a digital value.

CPU is a central processing unit, read-only memory ROMK
According to the written program, predetermined processing is executed using the random access memory RAM. IO is an input/output port through which data is exchanged between the central processing unit CPU and external circuits. Note that in the following explanation, the name of each block will be omitted.

When the input pen 12 is brought into contact with the tablet 11, the pen switch 16 is activated and the signal PSW is supplied to the CPU via the IO.

In response to the arrival of the signal PSW, the CPU supplies the switching signal OH to the MPX, and sets the connection destination to the electrode line group 3. Next, the CPU supplies the input valve 12 with a drive pulse SP. Note that when it is difficult to generate direct drive pulses from CP'[JK, input pen 12. ! = Insert a one-shot multipulp plater between IO and C! The one-shot multi-pulp plater may be driven by the PU to supply the drive pulse SP. By applying this driving pulse, each electrode wire group 3-6, 7-9°21-27 has
A pulse signal S corresponding to the coupling capacitance between each and the tip of the input pen 12 is generated. At this point, MPX has selected the electrode line group 5, so the pulse signal S3 generated in this electrode line group 5 is supplied to AM and P, and its output is digitally converted by A and /D to ■0. Supplied. C
The PU stores this digital value in a predetermined location in RAM.

In the same manner, the CPU connects MPX to electrode wire groups 4 to 4.
The input pen 12 is switched sequentially to 6, 7-9, 21-27.
A driving signal is applied to the signal, and the digital value of each pulse signal generated at that time is stored in a predetermined location in the RAM.

FIG. 6 shows examples of pulse signals S3 to S6 (generated in electrode wire groups 3 to 6), and FIG. 4 shows examples of pulse signals 87 to S9 generated in electrode wire groups 7 to 9. Vertical axis 1 in each figure
1 is <the height of the Luz signal.

The horizontal axis t indicates the passage of time. .

The procedure for determining the contact position of the input pen 12 in the X direction will be explained using FIG. 1 and FIGS. 3 and 4. Note that the contact position in the X direction is expressed as 1, and for example, the position between the electrode wire IA and the two people is expressed as AA.

Then, the CPU compares the digital values of the signals 86 to S6 generated in the first electrode line groups 3 to B in the X direction, and extracts the signal S having the maximum value among them. In the example of Fig. 6, the signal S
4 is extracted.

This maximum value signal is 84, which means that the input pen 1
2 means that it is in contact with the area name 4 of the electrode wire group 4 shown in FIG. Next, the largest and second signals among the signals 87 to S9 generated in the second electrode line groups 7 to 9 in the OP UI-tX direction are extracted. In the example of FIG. 4, signal S8 is detected as the largest one, and signal S7 is detected as the second one. The fact that the maximum value is 88 means that the input pen 12 is in contact with the range Z8 in FIG.

Furthermore, the second one is 87.

This means that the detection pen 12 is in contact with the half Z87 that is closer to the electrode wire group S7.

Therefore, from this result, the area where the signal S shown in FIGS. 6 and 4 occurs is the area where Z4 and Z87 overlap, that is, area BB, which is the contact area of the input pen 12 at this time. Note that this area can be specified by previously storing a table as shown in FIG. 5 in the RAM and applying the above determination result to the table. (
In Fig. 5, the initial letter S of the signal is omitted. ) Note that for area AA, the signal generated in the first electrode line group is S3.
is maximum, the signal generated in the second electrode line group is maximum at S7,
Similarly, the signal S8 is the second one, and is the same as that of the area DB. Therefore, in this example.

Dummy electrode wire 2 connected to electrode wire group 9 as shown in FIG.
Place Z next to electrode line 1A, and insert input pen 1 in area AA.
S for each signal of the second electrode wire group when 2 is brought into contact with
Make 9 the second one.

It is distinguished from the area DB. Note that when the area AA is set as an unused area, there is no need to provide such a dummy electrode 2Z.

The above processing is performed using the signal S generated in the Y electrode line groups 21 to 27.
The same process is performed for K, and the contact areas A-T and L in the Y direction are specified.

Then, OP'U sends data Tp indicating the respective contact areas in the X direction and the Y direction to a data processing device (not shown) or the like via IO.

〔Effect of the invention〕

As explained above, according to the present invention, the contact position of the detection means can be specified with a smaller number of scans than the single-digit electrode method, and the areas between the electrode lines can be made into independent areas. An input device can be obtained.

In the second embodiment, the maximum signal is generated among the signals generated in the first electrode line group for pinpointing the contact position.

The largest and second signals occurring in the second electrode line group were used; however, the largest and second signals occurring in the first electrode line group, and The region can be identified in the same way using the maximum signal that occurs.

[Brief explanation of drawings]

The figure shows one embodiment of the tablet input device of the present invention.
The figure shows the arrangement of the electrode wires in the FIG. 5 is a waveform diagram showing a pulse signal to be used. FIG. 5 is a diagram showing a table for specifying the excavation area. 1...First electrode wire, 2...Second
electrode wire. 3-7, 21-27...electrode wire groups. 11...Tablet, 12...Instruction means. CPU, R, OM... Pulse application means. M T) X, C! P fJ , r(OM
, rt AM...Signal detection means, ' 0
To PrJ, ROM, RA...Discrimination means.

Claims (1)

[Claims] The first electrode wire and the second electrode wire are alternately arranged in parallel,
a tablet in which every m first electrode wires and every m+n second electrode wires are connected in parallel to form an electrode wire group; and an indicating means that comes into contact with the tablet and instructs desired coordinates; pulse application means for applying a predetermined drive pulse to the instruction means; signal detection means for detecting a pulse signal generated in each electrode line group when the drive pulse is applied; 1. A tablet input device comprising: a determining means for determining a contact position of the indicating means.