JPS60140418A - Coordinate input device - Google Patents

Abstract

PURPOSE:To obtain a small size and inexpensive device by using an input means generating an electric signal whose phase represents an input coordinate to generate an analog signal representing the input coordinate. CONSTITUTION:An input section 8 of the coordinate input device is provided with a tablet 11 and a pen 13 or the like, an exciting circuit 12 transmits a switch signal to a switch 9 and also a reference signal advancing the switch signal is phase by 90 deg. is fed to a sawtooth generating circuit 25 and an inverter 24. A signal (a) from the pen 13 via a detection circuit 16 is fed to filters 20, 21 via the switch 9 and fed to a sample and hold circuit 27 via phase detectors 22, 23. Signals x, y proportional to X, Y coordinates of the input position are obtained together with the sawtooth wave of the sawtooth wave generating circuit 25 at the circuit 27. The signals x, y become analog signals having a voltage proportional to the phase of the voltage induced in the coil of the pen 13.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coordinate input device, and particularly to a coordinate input device equipped with an input section that generates an electrical signal whose phase is proportional to the coordinates of an input point on an input tablet.

As an input means that generates an electric signal with a phase proportional to the human coordinates, a plurality of rotating coils or magnetostrictive wires are used.Equipped with the input amount of this tablet and an input pen with a built-in coil, input with the pen. Conventionally, an input section has been used that generates a stain signal by electromagnetic coupling that occurs between an electromagnetic coil or magnetostrictive wire on the input surface and a coil in the pen when an input is made on the surface. A conventional coordinate input device generates a digital signal indicating the phase of the signal in response to an electrical signal generated by such an input section, and a central processing unit (CPU)
etc., to process data indicating input characters and figures by sending it to an external device.

FIG. 1 and FIG. 2 are a block diagram and a time chart, respectively, showing a conventional coordinate input device. Input section 1
On the input surface of the tablet 10, a plurality of elongated coils 11 parallel to the ordinate (X coordinate) are arranged in the direction of the abscissa (X coordinate). Also, although not shown,
A plurality of elongated coils are arranged orthogonally to this coil 11 and also in the direction of the X coordinate. The dual gain circuit 12 sends polyphase signals to these coils to sequentially scan and excite them.The excitation circuit 12 sends polyphase signals to the coils 11 and scans and excites them sequentially from the leftmost coil 11 to the rightmost coil 11, for example. Excite one by one. When the switching signal is at a low level (L) of 7 m pressure, for example from time t3 to time t5 t, the excitation circuit 12 sends a multiphase signal to a coil group (not shown) arranged orthogonally to the coil 1. Send to.

For example, the coils are excited one by one from the lower end coil to the upper end coil. Therefore, the timing at which a certain coil 11 is excited indicates the X coordinate of the arrangement position of that coil 11.

The excitation timing of a coil arranged in the direction of the X coordinate also indicates the X coordinate of the position of the coil. Due to the scanning excitation of B, a magnetic field traveling in the direction of the X coordinate and a magnetic field traveling in the direction of the X coordinate are alternately generated on the input surface of Taplet 10.

When an input pen 13 having a coil 14 arranged to interlink with this traveling magnetic field is used to input information on the input surface of the tablet 10 as shown by the broken line arrow A, the coil 14 has a coil 14 interlinked with the traveling magnetic field. A pulse-like voltage is induced at the appropriate timing. The detection circuit 15 receives the induced voltage of the coil 14, generates, for example, a pulse signal that rises at the peak of the induced voltage, and sends out the pulse signal as a phase signal. From the rising time t1 of the switching signal to the rising time t2-! of the phase signal! The time at is proportional to the X coordinate of the Ben 130 input position.

This phase signal is sent to each input of AND gates 2 and 4. Also, a switching signal is sent to the AND gate 20 input terminal, and is also sent to the AND gate 40 via the inverter 3.
being sent to the input terminal. The counting circuit 5 (or 6) is
When the switching signal (or the signal obtained by inverting the switching signal by the inverter 3) rises, for example, at time n (or [3
), the pulse counting of the clock signal is stopped at the pulse rise time of the phase signal 12 (or t4), and the digital signal indicating the count value at that time is held until time t3 (or t5), and the gate is activated. Send to circuit 7. Gate circuit 7 passes only the digital signal sent from counting circuit 5 (or 6) at time t3 (or t5) and sends it to bus B. The bus B is led to the CPU, and the digital signal sent out by the gate circuit 7 is sent to the CPU for predetermined processing.

A digital signal sent to bus B via gate circuit 7,
The signal has a phase of one phase signal, for example from time t1 to time 12.
(or a count value that is substantially proportional to the time from time t3 to time [4), and therefore a value that is proportional to the X coordinate (or X coordinate) of the input location of the pen 13.

Such a conventional coordinate input device sends out a plurality of bits in parallel in order to guide a digital signal to a bus B having a plurality of signal lines arranged in parallel. However, when it is necessary to increase the signal transmission distance to the CPU, or when using it for a method that requires compatibility with other coordinate input devices that send out analog coordinate signals, the device becomes complicated and The disadvantage is that the equipment cost is high. In other words, in order to extend the transmission distance between the coordinate input device and the CPU using a differential serial interface, it is necessary to add and connect a driver circuit for each signal line of bus B, and it is also necessary to change to a serial interface. If you try to lengthen the transmission distance, you will need to add and connect a parallel-to-serial converter circuit to convert parallel digital signals to serial digital signals, and in any case, it will be necessary to add an extra circuit and the device becomes larger and more expensive. In addition, 1. For example, an analog format is used that uses a tablet equipped with a resistor that allows current to flow into a location corresponding to the input device, and generates an analog signal indicating the input coordinates according to the current diversion ratio at the resistor. When configuring a system in which both a coordinate input device and a digital coordinate input device as described above can be used with a plug-in, it is necessary to match the signal formats sent to the interface. A digital conversion (or digital-to-analog conversion) circuit must be additionally connected to the coordinate input device, making the device larger and more expensive.

An object of the present invention is to eliminate the above-mentioned drawbacks and to generate an analog signal indicating the input coordinates using an input means that generates an electric signal in which one phase indicates the input coordinates, thereby making the signal transmission distance longer than before. When compatibility with analog type coordinate input devices is required, PJ can be used without increasing the size or price. ! The purpose of this invention is to provide a user input device.

The uninvented device includes a tablet for inputting coordinates, a first electric signal of a phase indicating a reference point of the coordinates of the human power surface of the tablet, and a first electric signal of a phase indicating the reference point and the human power surface of the plan 1 electric signal. coordinate detection means for generating a second electrical signal 43 having a phase difference substantially proportional to the coordinate distance between the input positions and indicating the coordinate detection timing, and responding to the electrical signals of the first and &32; and coordinate signal generating means for generating and transmitting an analog signal of a voltage substantially proportional to the phase difference between the two.

Next, the present invention will be described in detail with reference to the drawings.

3 and 4 are a block diagram and a time chart, respectively, showing the first embodiment of the present invention. Input section 8
The tablet 11 is similar to the input unit 1 shown in FIG.
．． It includes an excitation circuit 12, a pen 13, and a detection circuit 16. The excitation circuit 12 sends a switching signal to the switch 9, and also sends a reference signal with the phase of the switching signal closer to QOfε to the sawtooth wave generation circuit 25 and the inverter 24. Detection circuit 16
sends a signal (a), which is an amplified pulse voltage induced in a coil (not shown) in the pen 13, to the switch 9.

The switch 9 is activated when the switching signal is 14 voltage (for example, from time t1 to time t2), that is, the tablet 1
1, when scanning excitation in the X-coordinate direction is performed, the signal (al) is guided to the filter 20, and when the switching signal is Li pressure (for example, from time t2 to time t3), that is, the tablet 11 Scanning in the direction m oscillation is performed n
When the signal (ALE filter 21 is in the φ range), the filter 20 extracts the fundamental wave component contained in the signal (b) led from the switch 9 and outputs a sinusoidal signal (C) which is passed through the filter. Send to phase detector 22. To phase detector 22,
When the voltage of the signal (C) changes from the negative side to the positive side and becomes zero (for example, at times t5 and t6), a rising pulse is generated, and this pulse is sent to the sample-hold circuit 27 as the total signal (d). send to - 10,000, the sawtooth wave generation circuit 25 generates a sawtooth wave whose voltage increases linearly from the pulse rising edge of the reference signal (for example, time tQ) to the pulse rising edge υ, and converts this into the signal ( e) Zampuru hold circuit 2
Send to 7. The Zanzoru hold circuit 27 receives the signal (d)
At the rising edge of the pulse (for example, time t5 > and t6
) of signal (e) (e.g. voltages v5 and v5
) is sampled and bolded and sent as a signal (X). Signal (C) is a sinusoidal voltage signal that reaches a peak at the time when the pulse of signal (b) appears), and the voltage of signal (C) changes from the negative side to the positive side from the rise of the pulse of the reference signal. The time to zero toward zero is substantially proportional to the X coordinate of the input location. Therefore, the four pressures of signal 0[) have a magnitude proportional to the X coordinate of the input location.

In the above explanation, the filter 20. ls: ゛About CX
Signal indicating tail mark (progress and indication leading to generation and transmission of Xl)
Koga.

The process leading to the generation and transmission of the signal (y) indicating the X coordinate is the same as in the original process, so a redundant explanation will be omitted.

In this way, in this embodiment, the signal (X
) and (y) are generated and sent. Signal (X) and (
Since y) is an analog signal, it can be directly transmitted over a long distance (for example, several tens of meters) over a normal signal line, and is also compatible with other analog coordinate input devices. Therefore, even if it is necessary to extend the transmission distance or to be compatible with an analog type device, there is no need to add an extra circuit as in the conventional case, and a small and inexpensive device can be realized. In this embodiment, sample-and-hold circuits 27 and 28 generate a sawtooth wave IL! as a means for converting one phase into a voltage. , because the pressure is sampled and held.

It has the advantage that coordinate signals (ie, signals (X) and (y)) with little ripple and good followability can be obtained, and conversion efficiency is also good.

FIGS. 5 and 6 are a block diagram and a time chart, respectively, showing a second embodiment of the present invention. As in the first embodiment, a switching signal is sent from the input section 8 to the switch 9, and a signal (a) is sent from the detection circuit (not shown) of the input section 8 to the switch 9. Further, the reference signals (1) and (2) are signals in which the pulse rises at the pulse rise and the pulse fall of the reference signal in the first embodiment, respectively. It shows. switch 9 to filters 2o and 21
The operation from passing through the phase detectors 22 and 23 is the same as in the first embodiment, and the signal (d) generated by the phase detector 22 is sent to the reset terminal of the flip-flop (FF) 30. Guided by R.

The reference signal (1) is led to the set terminal S of FF3Q.
FF3Q rises when the pulse of the reference signal (]) rises, and then falls when the pulse of the signal (d) falls at 9.
/< generates a signal and sends it to the filter 3 as a signal (f).
Send to 2. Filter 32 is a low pass filter.

A low frequency component near DC included in the signal (f) is extracted and sent as a signal (X). Since each pulse width of the signal (signal) is proportional to the X coordinate of the input location, the voltage of its low frequency component is also proportional to the X coordinate of the input location. In other words, the voltage and voltage of the signal (X) are proportional to the X coordinate of the manual point.

The FF 31 and the filter 33 also receive the reference signal (
2) and the signal sent from the phase detector 23, it generates and sends out a voltage signal (y) proportional to the X coordinate of the manual point.

In this manner, in this embodiment as well, analog signals (X) and (y) of voltages proportional to the X coordinate and the X coordinate of the input location are generated and sent out.

Therefore, even if compatibility with other devices in the cyanalog format with extended transmission distances is required, there is no need to add extra circuits as in the conventional case, and a compact and inexpensive device can be realized.

In both the first and second embodiments, the electromagnetic coil on the input surface of the tablet 10 is scanned rFr! The case is shown in which the input section 8 is of the type that detects the traveling magnetic field generated by the J shake with the coil in the Ben 13 and generates a signal (a) with a phase proportional to the coordinates of the input point. The scope of non-invention is not limited to this. For example, an input unit equipped with a tablet that excites magnetostrictive wires placed on the human input surface, or a coil inside the ben 13 that excites the electromagnetic coil on the input surface of the tablet 10 to scan the induced voltage. It is clear that the present invention can be applied and similar effects can be obtained by using an input means that generates an electrical signal with a phase proportional to the input coordinates, such as a detection type input section.

As explained above, the present invention can provide a coordinate input device that is smaller and cheaper than the conventional one when a longer transmission distance or compatibility with other analog coordinate input devices is required. effective.

[Brief explanation of drawings]

Figures 1 and 2 are block diagrams and time charts showing conventional coordinate input devices, respectively, and Figures 3 and 5 are
Each figure is a block diagram showing an embodiment of the present invention, and each of FIGS. 4 and 6 is a time chart showing an embodiment of the present invention. 1.8... Input section, 10... Tablet, 11... Coil % 12... Excitation circuit, 13... River pen, 14... ...Coil, 1
5.16...Detection circuit% 9...Switch, 20, 21, 32.33...Filter,
22, 23... Phase detector, 24...
Inverter, 25, 26...Sawtooth wave generation circuit, 2
7.28...Sample-Hole) 'times M, 30
．． 31...Flip-flop (FF). KaI 圀1 1 1 tt ffz f, 3i4 i5 h? circle

Claims (3)

[Claims] (1) A tablet for inputting coordinates, a first electrical signal having a phase indicating a reference point of coordinates on the input surface of the tablet, and
and a second electrical signal indicative of coordinate detection timing having a phase difference substantially proportional to the coordinate distance between the reference point and the input position on the input surface with respect to the phase of the electrical signal of the coordinate system. and a coordinate signal generating means for generating and transmitting an analog signal of a voltage substantially proportional to the phase difference between the first and second electrical signals in response to the first and second electrical signals. coordinate input device. (2) The coordinate signal generating means generates a third electric signal having a voltage proportional to the elapsed time that starts rising when the phase of the first electric signal indicates the reference point. a wave generating circuit; and a sample-hold circuit that samples and holds the voltage of the third electrical signal when the phase of the second electrical signal indicates the coordinate detection timing and sends it out as the analog signal. A coordinate input device according to claim (1). (3) The coordinate signal generating means is set when the phase of the first electrical signal indicates the reference point, and then reset when the phase of the second electrical signal indicates the coordinate detection timing. A coordinate input device according to claim 1, comprising: a flip-flop; and a low-pass filter that extracts a low-frequency signal component included in a signal sent from the flip-flop and sends it out as the analog signal. .