JPH0417457B2 - - Google Patents

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 filed patent application No. 214301 of 1980 and patent application No. 113442 of 1988 as a tablet input device with improved electrode wire connection of the tablet.

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

[Problem that the invention seeks to solve]

However, in this conventional tablet input device, in order to set the segment spacing to 6 mm, for example, in addition to arranging normal electrode wires at 6 mm intervals, it is necessary to arrange digit electrode wires between them.
The spacing between the electrode wires is 3 mm, which is half the segment spacing, which increases the number of man-hours for pattern creation, increases the difficulty of processing, and lowers the signal level related to the lower electrode due to the increased shielding effect of the upper electrode. There was a problem.

[Means for solving problems]

Therefore, in the tablet input device of the present invention, the first
The electrode wires and the second electrode wires are arranged alternately in the same direction, and the first electrode wires are connected in parallel every m and the second electrode wires are connected in parallel every m+n (n is an odd number). A tablet formed into a group of wires, a pulse application means that contacts the tablet and applies a desired driving pulse, a detection means that detects a pulse signal generated in each electrode wire group when the driving pulse is applied, and The numbers of the first electrode and the second electrode related to the contact area of the detection means are calculated based on the magnitude of the detected scanning pulse signal, and
A table defining combinations of electrode numbers is provided with means for determining the contact area at that time by referring to the calculated number.

[Effect]

That is, if the first electrode wire and the second electrode wire are connected in parallel in different numbers, for example, m
=7, n=-1, the 1st, 8th, 15th, etc. of the first electrode wires belong to the same electrode wire group, while the second electrode located next to them For example, the 8th line is the 2nd line, the 15th line is the 3rd line, etc.
As such, they belong to different electrode wire groups.

Therefore, from the magnitude of the pulse signal generated in each electrode line group when a driving pulse is applied to the indicating means,
By determining the electrode wire group number of the first electrode wire and the electrode wire group number of the second electrode wire that are closest to the contact position of the indicating means, it is possible to determine which first electrode wire and the second electrode wire the contact position is from the combination. It becomes possible to judge whether the position is between the two electrode lines.

〔Example〕

The details of the present invention will be explained below based on illustrated embodiments. FIG. 1 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 to distinguish them, they are numbered A to L from the left.
The following subscripts shall be added. (The electrode wires 2Z will be described later) In this embodiment, the first electrode wires 1 are connected in parallel every third from the left to form the electrode wire groups 3, 4,
5 and 6, and the second electrode wires 2 are connected every second from the left to form electrode wire groups 7, 8, and 9.

FIG. 2 shows an example of the block configuration. In the figure 1
Reference numeral 1 designates a tablet, in which in addition to the electrode wire groups 3 to 9 in the X direction shown in FIG. 1, electrode wire groups 21 to 27 having the same structure are also arranged in the Y direction. 12 is an input pen and a central processing unit, which will be described later.
Drive pulses are supplied from the CPU. 13 is a pen switch built into the input pen 12.
MPX is a multiplexer, and according to the switching signal CH from the central processing unit CPU, each electrode line group 3 to 6, 7 to
The pulse signals generated at 9, 21 to 27 are sent to an amplifier.
Switch and supply to AMP. A/D is an analog-to-digital converter that converts the analog value of the amplified pulse signal into a digital value. The CPU is a central processing unit that operates according to programs written in read-only memory ROM and random access memory RAM
to perform the specified processing. 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 names of each block will be omitted.

When the input pen 12 is brought into contact with the tablet 11, the pen switch 13 is activated and the signal is output.
PSW is supplied to the CPU via IO. In response to the arrival of the signal PSW, the CPU supplies the switching signal CH to the MPX, and sets the connection destination to the electrode line group 3. Next, the CPU sends a drive pulse SP to the input pen 12.
supply. If it is difficult to generate direct drive pulses due to the CPU, insert a one-shot multi-valve generator between the input pen 12 and the IO.
The one-shot multi-valve generator may be driven by the CPU to supply the drive pulse SP. By applying this driving pulse, a pulse signal S corresponding to the coupling capacitance between each of the electrode line groups 3 to 6, 7 to 9, and 21 to 27 and the tip of the input pen 12 is generated. At this point, MPX has selected electrode line group 3, so the pulse signal S3 generated in this electrode line group 3 is supplied to AMP.
The output is converted into digital by A/D and supplied to IO. The CPU stores this digital value in a predetermined location in RAM.

Thereafter, in the same manner, the CPU applies drive pulses to the input pen 12 while sequentially switching the connection of MPX to the electrode line groups 4 to 6, 7 to 9, and 21 to 27, and the digital value of each pulse signal generated at that time. is stored in a specified location in RAM.

Pulse signals S3~ generated in electrode wire groups 3~6
An example of S6 is shown in FIG. 3, and an example of pulse signals S7 to S9 generated in the electrode line groups 7 to 9 is shown in FIG.
In each figure, the vertical axis H is the height of the pulse signal, and 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 by a combination of subscripts of the first electrode wire 1 and the second electrode wire 2, and for example, between the electrode wires 1A and 2A is expressed as AA.

First, the CPU compares the digital values of the signals S3 to S6 generated in the first electrode line groups 3 to 6 in the X direction, and extracts the signal S having the maximum value among them.
In the example of FIG. 3, signal S4 is extracted. The fact that this maximum value signal is S4 means that the input pen 12
This means that the electrode line group 4 is in contact with the area Z4 of the electrode wire group 4 shown in FIG. Next, the CPU transmits the signal S7 generated to the second electrode line group 7 to 9 in the X direction.
Extract the largest one and the second one of ~S9. 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 largest one is S8 means that
This means that the input pen 12 is in contact with the range Z8 in FIG. 12 means that they are in contact.

Therefore, from this result, the region where the signal S shown in FIGS. 3 and 4 occurs is the above-mentioned Z4 and Z.
The area where 87 overlaps, that is, area BB, becomes the contact area of input pen 12 at this time. Note that this area can be specified in advance by creating a table like the one shown in Figure 5.
This can be done by storing it in RAM and applying the above determination result to the table. (In Figure 5, the initial letter S of the signal is omitted.) Furthermore, the area
Regarding AA, the signal generated in the first electrode line group is the largest in S3, the signal generated in the second electrode line group is largest in S7, and the signal S8 is the second, which is the same as that in the area DE. Therefore, in this example,
As shown in FIG. 1, the dummy electrode wire 2Z connected to the electrode wire group 9 is placed next to the electrode wire 1A, and the area AA is
For each signal of the second electrode line group when the input pen 12 is brought into contact with the input pen 12, S9 is the second signal, thereby distinguishing it from the area DE. Note that when the area AA is an unused area, there is no need to provide such a dummy electrode 2Z.

The above processing is similarly performed for the signal S generated in the Y electrode line groups 21 to 27, and the contact areas AA to LL in the Y direction are specified.

Then, the CPU sends data TD indicating the respective contact areas in the X direction and the Y direction to a data processing device (not shown) or the like via the 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 digit electrode method, and the areas between the electrode lines can be made into independent areas. An input device can be obtained.

In this embodiment, in order to specify the contact position, the largest signal generated in the first electrode wire group, the largest signal generated in the second electrode wire group, and the second signal are used. However, the area can be specified in the same way by using the maximum signal occurring in the first electrode line group, the second signal occurring in the first electrode line group, and the maximum signal occurring in the second electrode line group.

[Brief explanation of drawings]

The figures show one embodiment of the tablet input device of the present invention, in which Fig. 1 is an arrangement of electrode lines in the X direction, Fig. 2 is a block diagram of the device, and Fig. 3 is a pulse signal generated in the first electrode line group. FIG. 4 is a waveform diagram showing pulse signals generated in the second electrode line group, and FIG. 5 is a diagram showing a table for specifying the contact area. 1...First electrode line, 2...Second electrode line, 3
~7,21~27...electrode wire group, 11...tablet, 12...instruction means, CPU, ROM...pulse application means, MPX, CPU, ROM, RAM...signal detection means, CPU, ROM, RAM ...Discrimination means.

Claims (1)

[Claims] 1 First electrode wires and second electrode wires are alternately arranged in parallel, and the first electrode wires are connected in parallel every m and the second electrode wires are connected in parallel every m+n, respectively, to form an electrode wire group. a tablet, an instruction means for contacting the tablet and instructing a desired coordinate, and a pulse application means for applying a predetermined driving pulse to the instruction means;
a detection means for detecting a pulse signal generated in each electrode line group when the drive pulse is applied; and a detection means for detecting a pulse signal generated in each electrode line group when the drive pulse is applied; The numbers of the electrode wire and the second electrode wire are calculated, and the calculated numbers are checked against a table that defines the combination of each position and the number of the first electrode wire and the second electrode wire, and the current number is calculated. What is claimed is: 1. A tablet input device characterized by comprising contact area determining means for determining a contact area.