JPH07110732A - Coordinate input device - Google Patents

Abstract

PURPOSE:To shorten the time required for first detection of a coordinate indicator or in a cordless coordinate input device. CONSTITUTION:A sense line group 1 laid in the coordinate input device main body is divided into plural blocks, and first and second scanning circuits 2 and 3 are provided which can simultaneously excite respective blocks of one axis S1 of the sense line group 1, and a coordinate indicator 20 is provided with a resonance circuit which resonates to the frequency of an exciting signal 100, and third and fourth scanning circuit 4 and 5 are provided which can simultaneously detect respective blocks of the other axis S2 of the sense line group 1 which receives the guide signal from the coordinate indicator 20, and the block in which the coordinate indicator 20 exists after detection of the guide signal of the coordinate indicator 20 is confirmed to considerably shorten the detection time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cordless coordinate input device that applies an electromagnetic induction phenomenon, and more particularly to a coordinate input device that can significantly reduce the time for detecting the position of a coordinate indicator.

[0002]

2. Description of the Related Art As a conventional method for detecting the position of a coordinate indicator in a cordless coordinate input device, there is an invention (hereinafter referred to as prior application 1) proposed by the present applicant prior to this application. To briefly explain the present invention, one of the two sense line groups laid along each of the XY orthogonal coordinate axes is sequentially excited by the exciting circuit one line at a time and resonated with this excitation signal. When the coordinate indicator having a resonance circuit is moved closer to the sense line, the induction signal induced in the other sense line group is sequentially processed by the signal processing circuit, and the position of the coordinate indicator is determined from the magnitude of the processed induction signal. That is, the coordinates are obtained.

[0003]

When the position of the coordinate indicator is first detected, it is necessary to scan the entire plate surface in the worst case. Therefore, the time obtained by multiplying the number of sense lines for each of X and Y,
That is, assuming that the number of X-axis sense lines is Xm, the number of Y-axis sense lines is Ym, and the scanning time per sense line is Ts, the time required is Xm × Ym × Ts. Therefore, when the reading range is large, it takes a considerable time until the coordinate indicator is detected, and there is a problem that operability is deteriorated.

An object of the present invention is to provide a coordinate input device which has a significantly shortened detection time of the coordinate indicator and has good operability.

[0005]

In order to solve the above-mentioned problems of the prior art, the present invention has a first sense line having a plurality of sense lines which are parallel to one of the XY rectangular coordinate axes and which are laid at equal intervals. Parallel to the sense line group and the other axis,
And a second sense line group having a plurality of sense lines laid at equal intervals from each other and divided into appropriate blocks, and the sense lines of the i blocks of the first sense line group are sequentially arranged. I scanning circuits to be selected, excitation means for supplying an excitation signal to each of the blocks, a first selection circuit selecting the i scanning circuits, and j scanning lines of the second sense line group. J scanning circuits that sequentially select each sense line of the block, a second selection circuit that selects the j scanning circuits, and lead to the second sense line group connected to the j scanning circuits. A guided signal processing circuit for amplifying and shaping the guided signal to be generated, a comparison circuit for comparing a signal from the guided signal processing circuit with a certain appropriate threshold, and a scanning signal controlled by the signal from the comparing circuit Control A coordinate input unit body and a circuit, is composed of a coil and a capacitor, and constitutes a coordinate input device by the coordinate indicator having a resonant circuit tuned to resonate in the excitation signal.

[0006]

In the coordinate input device according to the present invention, first, a plurality of blocks of the first sense line group simultaneously start scanning,
Generates an alternating magnetic field. Also, in the second sense line group, a plurality of blocks simultaneously start scanning. When the coordinate indicator exists, the resonant circuit of the coordinate indicator resonates due to the alternating magnetic field from the first sense line group, and an induction signal is induced in the second sense line group. The induced signal is amplified and shaped into a waveform, compared with an appropriate threshold value by a comparison circuit, and when the threshold value is exceeded, the control circuit recognizes the presence of the coordinate indicator.

Next, the control circuit uses the first sense line group,
In order to detect in which block of the second sense line group the coordinate indicator exists, scanning is started in block units. At this time, since the guidance signal is generated only in the block where the coordinate indicator exists, the position of the coordinate indicator can be detected by the signal from the comparison circuit.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a block diagram of a coordinate input device according to the present invention. In the figure, 1 indicates a sense line group, S1
Is a first sense line group having sense lines y _{11 to} y _1n and y _{21 to} y _2n , and S 2 is sense lines x _{11 to} x _1m and x _21.
Second sense line group having a ~x _2m, 2 the first scanning circuit for sequentially selecting y ₁₁ ~y _1n of the first sense line group S1, 3 is y ₂₁ ~ of the first sense line group S1 A second scanning circuit for sequentially selecting y _2n , 4 is a third scanning circuit for sequentially selecting x _{11 to} X _1m of the second sense line group S2, and 5 is x ₂₁ to of the second sense line group S2. A fourth scanning circuit for sequentially selecting x _2m , 6 for a first scanning circuit for selecting a first scanning circuit or a second scanning circuit, and 8 for selecting a third scanning circuit or a fourth scanning circuit A second selection circuit, 10 is an exciting circuit for supplying an exciting signal to the first sense line group S1, 11 is an oscillating circuit for supplying a clock signal to the exciting circuit, and 12 is an induction generated in the second sense line group S2. An induction signal processing circuit for amplifying a signal and shaping the waveform; and 13 for the induction signal processing circuit. A comparison circuit for comparing the signal waveform-shaped by the path with an appropriate threshold value, 14 is a control circuit composed of a general CPU circuit, 15 is a memory circuit for storing a scanning address, 20 is a coordinate indicator, The resonance circuit is composed of a coil and a capacitor adjusted to resonate with the excitation signal frequency.

FIG. 2 shows a detailed configuration diagram of the first scanning circuit 2. The same symbols as in FIG. 1 indicate the same components as in FIG. 30 is a decoder, 31 is a switch element 311-3
Analog switch group having 1n, 106 is an excitation circuit 1
An excitation signal supplied from 0, 102 is an excitation scan address signal output from the control circuit 14, and 107 is a selection signal output from the first selection circuit 6. The second scanning circuit 3 has the same configuration as the first scanning circuit 2 except that the selection signal 107 in FIG. 2 is changed to a selection signal 108. In addition, the third and fourth scanning circuits 4, 5
Has the same configuration as the first and second scanning circuits 2 and 3, except that the excitation signal 106 is input to the first and second scanning circuits 2 and 3. 3 and the fourth scanning circuits 4 and 5 output the induction signal 111, the excitation scanning address signal 102 receives the detection scanning address signal 103, and the first selection circuit 6 outputs. The selection signals 107 and 108 are changed to selection signals 110 and 109 from the second selection circuit, respectively.

3 and 4 are detailed block diagrams of the first selection circuit 6. As shown in FIG. In FIG. 3, reference numeral 40 is an AND circuit. Reference numeral 101 is an excitation block scanning signal from the control circuit 14 (upper bit of the excitation scanning address signal), 100 is an excitation high-speed scanning mode signal from the control circuit 14, and 107 is a first
Is a selection signal to be output to the scanning circuit 2.

Further, in FIG. 4, 41 is a negation circuit and 42
Is an AND circuit. Reference numerals 101 and 100 are the same signals as those described above, and reference numeral 108 is a selection signal to be output to the second scanning circuit 3. The second selection circuit 8 also has the same configuration as the first selection circuit 6, except that the excitation block scanning signal 101 from the control circuit 14 is input in the case of the first selection circuit 6 in FIG. On the other hand, in the case of the second selection circuit 8, the detection block scanning signal 104 (upper bit of the detection scanning address signal) is input, and the excitation high-speed scanning mode signal 100 is input. While the detection high-speed scanning mode signal 105 is input and the selection signal 107 is output to the first scanning circuit 2,
The selection signal 110 is output to the third scanning circuit 4.

4 is different from the first selection circuit 6 in that the excitation block scanning signal 101 from the control circuit 14 is input, whereas the second selection circuit 8 is different.
In this case, the detection block scanning signal 104 is input, the excitation high-speed scanning mode signal 100 is input, whereas the detection high-speed scanning mode signal 105 is input, and the second scanning circuit 3 While the selection signal 108 is output to the fourth scanning circuit 5, the selection signal 109 is output to the fourth scanning circuit 5.

FIG. 5 is a block diagram of the induction signal processing circuit.
Reference numeral 50 is an amplifier circuit, 51 is a rectifier circuit, and 52 is a smoothing circuit. Reference numeral 111 is an induction signal from the third and fourth scanning circuits, and 112 is a direct current induction signal output to the comparison circuit 13. FIG. 6 shows an example of the circuit configuration of the coordinate indicator.
Reference numeral 0 is a coil, 61 is a capacitor, and 62 is a trimmer capacitor for adjustment. A parallel resonant circuit is formed by these components, and the constant is set so as to resonate with the frequency of the excitation signal 106.

Further, in FIG. 1, reference numeral 113 is a comparison circuit 13.
Is a valid signal output to the control circuit 14 when a signal equal to or higher than the appropriate threshold is input. Next, the operation of this embodiment will be described. In FIG. 1, the case where the coordinate indicator 20 is located at the intersection of the sense line x ₁₃ and the sense line y ₁₃ (FIG. 1-A part) will be described. The oscillator circuit 11 supplies a clock signal having an excitation frequency of 614.4 kHz to the excitation circuit 10. The excitation circuit 1
0 waveform-shapes the clock signal into a sine wave, and voltage-
The current is converted and the excitation signal 106 (sinusoidal current of 614.4 kHz) is supplied to the first and second scanning circuits 2 and 3.

First, the control circuit 14 sets the exciting high speed scanning mode signal 100 to "L" to set the high speed scanning mode. At this time, the selection signals 107 and 108 from the first selection circuit 6
Irrespective of the state of the excitation block scanning signal 101
L ″, the first and second scanning circuits 2 and 3 are both in the selected state, and in accordance with the excitation scanning address signal 102 from the control circuit 14, y _{11 of} the first sense line group S1,
y ₂₁ is selected. That is, in FIG.
0 The analog switch 311 is turned on by the exciting scanning address signal 102, and supplies the excitation signal 106 to y ₁₁ of the first sense line group S1, from the sense line y ₁₁ 61
An alternating magnetic field of 4.4 kHz is generated. Similarly, since the second scanning circuit 3 is also selected, y _{21 of} the first sense line group S1 also generates an alternating magnetic field of 614.4 kHz.

Similarly, the control circuit 14 detects the high speed scanning mode.
The drive signal 105 is also set to "L" to set the high speed scanning mode. this
At this time, the selection signals 110 and 109 from the second selection circuit 8 are also
"L" regardless of the state of the detection block scanning signal 104
And the third and fourth scanning circuits 4 and 5 are both in the selected state.
Therefore, the detection scan address signal 103 from the control circuit 14
In accordance with x of the second sense line group S2₁₁And x_{twenty one}, X
₁₂And x_{twenty two}... x _1mAnd x_2mAnd select scanning sequentially. So
If the scanning of the second sense line group is completed,
Next, the first and second scanning circuits 2 and 3 are connected to the control circuit 14
Excitation scan address signal 102 from the first sense
Sense line y of line group S1₁₂And y _{twenty two}Select the
The third and fourth scanning circuits 4 and 5 are again fed from the control circuit 14.
The second sense signal according to the detection scan address signal 103 of
X of line group S2₁₁And x_{twenty one}, X₁₂And x_{twenty two}... x_1m
And x_2mAnd select scanning sequentially. Repeat this scan in the same way
In return, the sense line y of the first sense line group S1_1nOver
Y_2nWhen is finished, y₁₁And y_{twenty one}Return to the above operation
Repeat.

At this time, if the coordinate indicator 20 is present near the sense line selected by the excitation scan address, the resonance circuit built in the coordinate indicator 20 is configured to resonate with the excitation signal 106. Therefore, an inductive signal of 614.4 kHz is induced in the resonant circuit. Further, the inductive signal of the resonant circuit causes the inductive signal to be generated in any of the second sense line group S2 near the resonant circuit. That is, the excitation scanning address signal 102 from the control circuit 14 causes the first and second scanning circuits 2 and 3 to
Sense lines y ₁₃ and y _{23 of} the first sense line group S1
When is selected, the resonance circuit of the coordinate indicator 20 resonates with the alternating magnetic field generated from the sense line y ₁₃ , and further an induction signal is generated at the sense line x ₁₃ of the second sense line group S2. The detection scan address signal 103 from the control circuit 14 causes the third and fourth scanning circuits 4 and 5 to move to the second scanning circuit.
When the sense lines x ₁₃ and x ₂₃ of the sense line group S2 are selected, the induction signal generated in the sense line x ₁₃ is sent to the induction signal processing circuit 12.

The generated induction signal is applied to the induction signal processing circuit 1
It is amplified and waveform-shaped by 2 and supplied to the comparison circuit 13. The comparison circuit compares the threshold value with an appropriate threshold value to separate noise from an induction signal, and when it is determined that the signal is an induction signal, a valid signal 113 is generated in the control circuit 14.

When the control circuit 14 confirms the existence of the coordinate indicator by the valid signal, it stops scanning and stores the excitation scanning address and the detection scanning address at that time in the memory circuit 15. The excitation scan address and the detection scan address are fixed to the addresses stored in the memory circuit 15, and the detection block scan signal 104 is set to "L".

Subsequently, the detection high speed scanning mode signal 105 is set to "
H "is set to the normal scanning mode. At this time, the selection signal 110 from the second selection circuit 8 is" L ", and the selection signal 109 is set.
Becomes "H", the third scanning circuit 4 is in the selected state,
The fourth scanning circuit 5 is in a non-selected state. Therefore, it is understood that only the sense line x13 is selected, the guidance signal is detected at this time, the valid signal 113 is generated, and the coordinate indicator is present on the third scanning circuit 4 side. The control circuit 14
The detection block scanning signal 104 at this time is stored in the storage circuit.

Next, the excitation block scanning signal 101 is set to "L" similarly to the detection side, and the excitation high speed scanning mode signal 100 is set.
Is set to "H" to set the normal scanning mode. The selection signal 107 from the first selection circuit 6 is "L", and the selection signal 108 is "
H ", the first scanning circuit 2 is in the selected state, and the second scanning circuit 2
The scanning circuit 3 of is in the non-selected state. Therefore, only the sense line y ₁₃ is selected, and the alternating magnetic field is generated only from the sense line y ₁₃ . At this time, the guidance signal is detected, the valid signal 113 is generated, and the coordinate indicator 20 causes the first scanning circuit 2 to move.
You can see that it exists on the side.

In this way, the control circuit 14 can detect the position of the coordinate indicator 20. If the coordinate indicator 20 exists in another block, the excitation block scanning signal 101 or the detection block scanning signal 104 is set to "
By switching to H ", the second scanning circuit 3 or the fourth scanning circuit 3
Since the scanning circuit 5 can be selected, the block in which the coordinate indicator 20 exists can be detected.

Further, in the above embodiment, 614.4 kHz is used as the basic signal of the oscillation circuit 11 and a sine wave is used as the excitation signal, but the frequency and waveform are not limited to this. Further, the number of blocks is set to two for each axis for simplification of description, but it is further effective to select an appropriate number of divisions according to the size and the like.

[0024]

As described above, according to the present invention, X
A sense line group laid along each of the Y orthogonal coordinate axes is divided into a plurality of blocks, and when the sense line group laid along one axis is excited by an exciting circuit, a sense for each block is detected. A coordinate indicator that is capable of exciting the lines at the same time, and is capable of simultaneously detecting each block when detecting an induction signal by the other axis, and having a resonance circuit capable of resonating with the excitation signal. By doing so, the detection time can be greatly reduced.

Therefore, when the operator uses the coordinate indicator on the coordinate input device, it is possible to provide a coordinate input device having good operability, which does not limit the movement of the coordinate indicator at all. Further, there is no failure due to the disconnection of the cable between the coordinate input device main body and the coordinate indicator, which is one of the drawbacks of the conventional coordinate input device, and the reliability of the coordinate input device can be improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a coordinate input device according to the present invention.

FIG. 2 is a detailed configuration diagram of a first scanning circuit in the embodiment of the coordinate input device according to the present invention.

FIG. 3 is a detailed configuration diagram of a part of a first selection circuit in the embodiment of the coordinate input device according to the present invention.

FIG. 4 is a detailed configuration diagram of another part of the first selection circuit in the embodiment of the coordinate input device according to the present invention.

FIG. 5 is a configuration diagram of a guidance signal processing circuit in an embodiment of the coordinate input device according to the present invention.

FIG. 6 is a circuit configuration diagram of a coordinate indicator in an embodiment of the coordinate input device according to the present invention.

[Explanation of symbols]

 1 Sense Line Group 2 1st Scanning Circuit 3 2nd Scanning Circuit 4 3rd Scanning Circuit 5 4th Scanning Circuit 6 1st Selection Circuit 8 2nd Selection Circuit 10 Excitation Circuit 11 Oscillation Circuit 12 Induction Signal Processing Circuit 13 Comparison circuit 14 Control circuit 15 Memory circuit 20 Coordinate indicator

Claims (1)

[Claims] 1. A coordinate input device composed of a coordinate input device main body and a coordinate indicator, wherein the coordinate input device main body is a plurality of parallel to one of the XY orthogonal coordinate axes and laid at equal intervals. A first sense line group having a plurality of sense lines, and a second sense line group having a plurality of sense lines parallel to the other axis and laid at equal intervals to each other; A first plurality of scanning circuits that simultaneously select different sense lines sequentially, a first selection circuit that selects the first plurality of scanning circuits at appropriate times, and an excitation signal is supplied to the first plurality of scanning circuits. An exciting circuit; a second plurality of scanning circuits for simultaneously and sequentially selecting different sense lines of the second sense line group; a second selecting circuit for timely selecting the second plurality of scanning circuits; An induction signal processing circuit that amplifies and waveform-shapes induction signals from the plurality of scanning circuits, a comparison circuit that compares the waveform-shaped signal from the induction signal processing circuit with an appropriate threshold, and the comparison circuit. And a control circuit which controls a scanning signal by a signal from the coordinate input device, wherein the coordinate indicator has a resonance circuit capable of resonating with the excitation signal.