JPS5953570B2 - tablet input device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tablet input device for inputting address information such as figures and kanji characters into a computer or the like.

A conventional device of this type has a plurality of drive lines d, as shown in FIG.

, d, . . . , dm, a plurality of detection lines 5, , 5, . . . , Sm, and two adjacent ones from the drive line group a drive circuit 1 that selects a drive line and passes a varying drive current; a detection circuit 2 that sequentially selects two adjacent detection lines from a group of detection lines and detects an induced voltage generated between their terminals; It is comprised of a decoding circuit 3 that encodes position information corresponding to the drive line and detection line selected by the drive circuit and detection circuit, and an input pen 4 holding a magnetic material. The operation of this conventional device is as follows: drive circuit 1
The scanning pulse QD sent from the decoding circuit 3 sequentially connects the two drive lines d.

and d, d, and d2, ......, dm/, and dm are selected and a drive current is applied, and each time an arbitrary drive line is selected, the detection circuit 2 receives a signal from the decoding circuit 3. Using the sent scanning pulse Q, the two detection objects 51, 51 and 52, . . . , Sn/1 and Sn are successively selected,
It is detected whether the induced voltage between the terminals of the two selected detection lines is equal to or higher than a certain threshold voltage. Now, drive lines d, /, and d
,, If the input pen 4 exists within the rectangular area formed by the intersection of the detection lines Sj/, and Sj, the electromagnetic coupling between the drive line and the detection line becomes large, and the drive lines d, /, and d, , detection line s
, /, and s are selected, an induced voltage greater than a certain threshold voltage is generated between the terminals of the two selected detection lines. At this time, the detection circuit 2 sends the detection signal P to the decoding circuit 3.
By sending this, the decoding circuit 3 encodes and outputs the position information of the input pen 4, that is, the currently selected drive line number i and detection line number j. Since the conventional device was configured in this way, if the number of drive lines is m+1 and the number of detection lines is n+1, m drive line selections and drive operations are required to scan the input panel once. Also Mx
Since it is necessary to select the detection line and perform the detection operation n times,
When applied to kanji input, graphic input, etc., the number of input items increases and high resolution is required, so the number of drive lines m and the number of detection lines n increase, so the input panel surface must be scanned once. The disadvantages are that the time required for the process increases and the operability deteriorates. In order to eliminate the drawbacks of the conventional example, the present invention independently detects the position of the input pen in the row direction and the position of the input pen in the column direction, thereby reducing the time required to operate the input panel once. To provide a tablet input device with slightly improved operability. Hereinafter, embodiments will be described in detail with reference to the drawings. FIG. 2 shows an embodiment of the present invention, in which DO, dl, ......, D
m is a drive line, Sl, S2, ......, S. r
1 is a detection line, 1 is a drive circuit, 2 is a detection circuit, 3 is a decoding circuit, 4 is an input pen holding a magnetic body, and one end of the detection line is commonly connected and grounded.

Note that grounding here means returning current to the detection circuit in a manner that does not affect the electromagnetic induction phenomenon on the tablet surface. Next, the operation of this embodiment will be explained.

First, the drive circuit 1 uses the drive line D by the scan pulse Q sent from the decode circuit 3. and d1, and this drive line D. l:. A varying drive current, for example a rectangular wave current as shown in FIG. 3a, is applied to the drive loop formed by d1. The detection circuit 2 also selects the detection line S1 and determines whether the induced voltage generated at the terminal exceeds a certain threshold voltage.
Also, based on the phase of the waveform, it is detected whether the input pen 4 is present in either area A1 or A2. Hereafter, scan pulse Q is used in the same manner. What about the drive lines d1 and D2 and the detection line?
Select and press input pen 4 in either area A3 or A4.
is detected, and finally the drive line Dm/1 and the detection line S. n is selected, and it is detected whether the input pen 4 exists in either area A2m/1 or A2m. now,
The input pen 4 is in the area A2. /1 or A2, above, the drive circuit 1 selects the drive lines d1/1 and d1, and the drive loop formed by d1/1 and D is set as shown in FIG. 3a. When a drive current is applied, the vertical component of the magnetic flux generated by the drive current to the tablet surface is in the area A2, /
1 and A2. The directions of the voltages induced in the detection line S1 are opposite to each other depending on whether the input pen 4 indicates the right side or the left side of the detection line S1. Therefore, it is determined whether the input pen 4 pointed to the area A2,/1 or not. 3, an induced voltage exceeding a certain threshold voltage as shown in FIGS. 3B and 3C is detected at the terminal of the detection line S1 selected by the detection circuit 2. Note that the hexagonal shapes shown in FIGS. 3B and 3C are characterized by a 180° difference in phase. To determine this, for example, if only the positive direction component is rectified, FIG. 3b becomes FIG. 3d, and FIG. 3C becomes FIG. 3e. next,
By ANDing the sampling pulses as shown in FIG. 3 d or e and FIG. 3 f or g,
The logical product of and f or e and g in FIG. 3 is 1, and the logical product of d and g in FIG. 3 or e and f in FIG. 3 is O. In this way, it is possible to determine whether the input pen 4 has pointed on the area A2i/1 or on the area A2i. Further, when the detection circuit 2 detects the input pen 4, the area A2l/
A detection signal P containing identification information between A1 and A2l is sent to the decoding circuit 3. The decoding circuit 3 determines the position address (21-
1) or (21) is output. Since this embodiment is configured as described above, by selecting m driving lines and detection lines, the input pen position can be divided into 2 m addresses in a certain direction (for example, row direction or column direction). can be detected. FIG. 4 shows another embodiment of the present invention, in which the same reference numerals as in FIG. It differs from Fig. 2 in that it is also grounded.

The operation of this embodiment is to flow the drive current shown in FIG. 5a through one of the two selected drive lines, and to flow the drive current shown in FIG. 5b through the other drive line. This embodiment differs from the embodiment shown in FIG. 2 in this respect.

FIG. 6 shows still another embodiment of the present invention, D
xO, dxl, ......, Dxm is the drive line in the x direction, SXl, SX2, ゛゜゜゜゜゜゜゜゜゜, Sx
m is the detection line in the X direction, DYO, dYl,...
..., DYO is the drive line in the Y direction, SYl, SY2, ...
......, SYn is a detection line in the Y direction.
The operation of this embodiment changes the position of the input pen 4 in the x direction to the second position.
When the detection signal P is detected by the same operation as in the embodiment shown in the figure and sent to the decoding circuit 3, the decoding circuit 3 temporarily stores the detection address in the X direction.

Next, when the position of the input pen 4 in the Y direction is detected in the same manner as in the embodiment shown in FIG. 2 and the detection signal P is sent to the decoding circuit 3, the decoding circuit 3 temporarily stores the detected address in the Y direction. Outputs the detected address in the x direction. Incidentally, if the drive circuits and detection circuits for the X direction and the Y direction are provided independently, scanning in the X direction and scanning in the Y direction can be performed simultaneously. Since the present embodiment is configured as described above, by selecting the drive line and the detection line (m+n) times, (
2m)×(2n) matrix-like addresses can be detected.

As explained above, according to the present invention, addresses in the row direction or column direction can be detected by independent operations.
Even when applied to input devices that require a large number of 5 input items, such as kanji input and graphic input, or that require high resolution, the time required to scan the input panel once is significantly shorter than that of conventional devices of this type. The present invention can provide a very effective tablet input device.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional device, FIG. 2 is a block diagram of an embodiment of the present invention, and FIG. 3 is a waveform of drive current, detection voltage, etc. in the embodiment of FIG. FIG. 4 is a configuration diagram of another embodiment of the present invention, and FIG.
This figure is a diagram showing the waveform of the drive current in the embodiment of FIG. 4, and FIG. 6 is a diagram showing the configuration of still another embodiment of the present invention. 1... Drive circuit, 2... Detection circuit, 3... Decode circuit, 4... Input pen, DO, dl,...
..., Dml...drive line) PllS2ra 1110ra SmlO detection line) DXOra DXl9...
..., DXrrl...x-direction drive line, SXl,
SX2, ......, Sxn. ...Detection line in the X direction, DYO, dYl, ......, D
Yn...Y direction drive line, SYl, SY2,...
..., SYn...Detection line in the Y direction.

Claims (1)

[Claims] 1. A drive line group consisting of a plurality of parallel conductor wires whose ends are commonly connected, and a plurality of drive lines which are overlapped in parallel on the same plane as the drive line and whose ends are commonly connected and grounded. an input board formed of a detection line group made of parallel conductor wires, an input pen made of either a magnetic material or a conductor used to indicate an arbitrary position on the input board, and the drive line group a drive circuit that is connected to one end of the detection line group that is not commonly connected, selects any two drive lines from the drive line group, and supplies a varying drive current; and one end of the detection line group that is not commonly connected. selects one detection line from the detection line group to be included between the two selected drive lines, and connects this detection line to one of the two selected drive lines. When the input pen is brought close to or in close contact with either the area between the detection lines or the area between this detection line and the other of the two selected drive lines, the selected A tablet input device comprising: a detection circuit that detects the position of the input pen by detecting the magnitude and phase of an induced voltage generated in terminals of detection lines that are not commonly connected. 2. Each of the drive line group and the detection line group is
A first group arranged in the row direction and a second group arranged in the column direction.
The tablet input device according to claim 1, characterized in that the tablet input device comprises a group.