JPH0467207B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a coordinate detection device used as an input device for CAD, etc., and particularly to an electromagnetic induction type coordinate detection device that can send a function signal from a pickup to the main body of the device.

[Conventional technology]

FIG. 6 is a block diagram showing the main parts of a conventional device of this type, and numeral 11 in the figure is a pick-up such as a cursor or stylus pen. This pick up 1
1 includes an excitation oscillator 11a that oscillates an excitation signal for coordinate detection and a function signal generator 1.
1b, each of these drivers 11c, 11d, and a transmitting coil 11e that converts an excitation signal from the driver 11c into a magnetic field and outputs the magnetic field. 1
Reference numeral 2 denotes a coordinate detection device main body, which is provided with a phase detector 12a that inputs the magnetic field from the coil 11e, and a function signal detector 12b that inputs the function signal from the driver 11d via a transmission cable 13. .

[Problem that the invention seeks to solve]

That is, in the conventional device, a transmission cable 13 was provided between the pickup 11 and the device main body 12. Therefore, while the pickup 11 is moving, the transmission cable 13 has to be routed all the time, which impairs the freedom of movement of the pickup 11, resulting in a problem of low operability.

The present invention has been made to solve these problems, and an object of the present invention is to provide a coordinate detection device that allows mechanical pickup to be completely free and has improved operability.

[Means for solving problems]

The present invention combines the excitation signal and the function signal, such as by adding the function signal to the excitation signal for coordinate detection, converts it into a magnetic field and outputs it, which is received by the receiving coil of the device main body to generate an electrical signal. The signal is converted into an excitation signal and a function signal using a filter.

[Operation] If the excitation signal and the function signal are combined into one signal, converted into a magnetic field, and output to the main body of the device, no transmission cable is required between the pickup and the main body of the device. In other words, the device is wireless, and the pickup is free from any mechanical constraints, thereby achieving the above-mentioned purpose.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the main parts of an embodiment of the coordinate detection device according to the present invention, and in the figure 11a to 11.
d, 12a, and 12b are each the same as in FIG.
11 also shows a pick-up such as a cursor or stylus pen as in FIG. 6, but here it is further provided with a driver 11f. This driver 1
1f (for convenience, the driver 11c is the first driver,
The driver 11d is the second driver, and the driver 11f
(referred to as the third driver) is the first driver 11c
The excitation signal output from the
A signal added to the function signal (see FIG. 2B) output from the driver 11d (see FIG. 2C) is output. Similarly to FIG. 6, 11e also shows a transmitting coil, but here it converts the addition signal from the third driver 11f into a magnetic field and outputs it.

12 also shows the main body of the device in the same way as in FIG. It also includes filters 12d and 12e for separating the signal corresponding to the excitation signal into the excitation signal and the function signal.

That is, the device of the present invention adds an excitation signal and a function signal to combine them into a single signal, converts it into a magnetic field, and magnetically transmits it to the device main body 12, which is then sent to the receiving device provided in the device main body 12. The signal is received by a coil 12c and converted into an electric signal, and is separated into an excitation signal and a function signal by filters 12d and 12e, thereby realizing a completely wireless signal transmission path.

FIG. 3 is a diagram showing an example of the structure of the function signal. As shown in the figure, the function signal is composed of a start signal and a data signal.

FIG. 4 is a circuit diagram showing a specific example of a function signal generator 11b that generates such a function signal. In FIG. 4, 21 is an oscillator which outputs a clock signal. SWI~
SWN is a switch, and these N switches SWI
-Various function signals can be generated depending on the operating state of SWN. N resistors 221~22N
When switches SWI to SWN are in the ON state,
This is provided to prevent short-circuiting of the power supply Vcc. In addition, N inverters 231 to 23N, a J-K flip-flop (hereinafter referred to as J-K-FF) 241
~24N is provided to prevent chattering of switches SWI~SWN. J-K-FF241~24
The signal output from N is input to the encoder 25, becomes a binary signal corresponding to the operating state of J-K-FF 241 to 24N, and is sent to the shift register 26.
loaded into.

27 is an OR gate and N switches SWI ~
If even one SWN is ON, that output becomes active. The output of this OR gate 27 is
The clock signal inverted by the inverter 28 is latched by a D flip-flop (hereinafter referred to as D-FF) 29, and at the rising edge of the output, the multivibrator 30 operates, and the output of the encoder 25 is transferred to the shift register 29. Outputs a signal to be loaded into. The end of this load signal is detected by the D-FF 31, which outputs a signal to the AND gate 32 to permit the clock signal to be applied to the shift register 26.

The clock signal input to the shift register 26 is simultaneously counted by the counter 33, and when the count value reaches a predetermined number, the D-FF 33 is reset through the negative logic OR gate 34, and the clock signal input to the shift register 26 is stopped. make it stop. The output of the shift register 26 is input to the second driver 11d (see FIG. 1).

Note that the system reset IC 35 initializes all the FFs 241 to 24N, 29, and 31 and the multivibrator 30 when the circuit power is turned on.

That is, the circuit 11b sets binary data corresponding to these operations in the shift register 26 using the switches SWI to SWN which are protected against chattering, and outputs the data in series to the second driver 11d.

FIG. 5 shows the function signal detector 12.
It is a circuit diagram showing a specific example of b. As shown in the figure, the D-FF 41 first detects the rising edge of the start signal at the head of the function signal extracted by the filter 12e, and releases the reset of the binary counter 42. This counter 42 receives a clock signal from an oscillator 43 and continues counting up.

Here, the function signal generator 11b
The oscillation frequency of the oscillator 21 (see Figure 4) in
₂₁ and the oscillation frequency of the oscillator 43 in the function signal detector 12b is ₄₃ , then ₄₃ > ₂₁ , and the following _condition is required: _43/21 = C (C is a natural number).

When the value of the counter 42 reaches a predetermined value, a latch signal for loading the function signal into the shift register 44 is output from the output terminal O1 of the counter 42. Repeat this action several times,
When the function signal has been taken into the shift register 44, a trigger signal is output from the output terminal O2 of the counter 42, and in response to this, the multivibrator 45 converts the active low signal to negative logic.
Input to OR gate 46. Negative logic OR gate 4
The output of 6 clears the D-FF 41, and the counter 42 returns to the reset state and finishes receiving the signal.

The output of the counter 44 is latched by a data latch 47 at the rising timing when the multivibrator 45 becomes inactive.
The output of the data latch 47 is
Computer data line CPU DATA within 2
Connected to BUS.

〔Effect of the invention〕

As described above, according to the present invention, there is no need for a signal transmission cable between the pickup and the main body of the apparatus, so the pickup becomes completely free mechanically and has the effect of significantly improving operability.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the main parts of the device of the present invention;
2 is a diagram of signal waveforms at each part in FIG. 1, FIG. 3 is a diagram showing an example of the structure of a function signal, and FIGS. 4 and 5 are diagrams of the function signal generator and function signal detector in FIG. A circuit diagram showing a specific example, FIG. 6 is a circuit diagram showing main parts of a conventional device. 11...Pickup, 11a...Excitation oscillator, 11b...Function signal generator, 11
c, 11d, 11f...Driver, 11e...Transmission coil, 12...Device main body, 12a...Phase detector, 12b...Function detector, 12
c... Receiving coil, 12d, 12e... Filter.

Claims (1)

[Claims] 1. In an electromagnetic induction type coordinate detection device capable of sending a function signal from a pick-up to the main body of the device, the pick-up has a driver that converts an excitation signal and a function signal for coordinate detection into one signal, and an output signal of this driver. The device main body includes a transmitting coil that converts into a magnetic field,
The receiving coil inputs the magnetic field from the transmitting coil and converts it into an electric signal, and the filter separates the electric signal from the receiving coil into the excitation signal and the function signal and outputs the separated signals. A coordinate detection device characterized by: