JPH04182814A - Position voltage converting device with separable sliding part - Google Patents

Abstract

PURPOSE:To obtain the voltage converting device whose sliding part can be separated by constituting the sliding part which is placed on a detection plate and indicates a position by using only a passive circuit, and eliminating the need to connect an external signal. CONSTITUTION:A position signal ps which turns on/off the switch of the sliding part 8 is varied. An operator places the sliding part 8 on the detection plate 1 without pressing the switch. Then the sliding part 8 is moved on the detection plate 1 with the switch pressed so that a desired voltage signal vs is outputted. When the desired voltage signal vs is outputted, the switch is released. After the switch is released, the voltage signal vs is not varied even if the sliding part 8 is moved or removed. The voltage signal Vs is varied only while the switch is pressed, so even if the sliding part 8 is varied in height by being placed or removed, the variation has no influence. Thus, the signal vs varied only in a position detection direction can be outputted.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a position voltage conversion device that outputs one-dimensional position information as voltage information and has a function similar to a sliding variable resistor. It is.

[Prior Art] A coordinate reading device is a technology similar to the present invention. Coordinate reading devices generally convert two-dimensional position information directly into digital data and transmit it to a computer or the like.

An example of the configuration of the coordinate reading device is shown in Figure 9.
A coordinate reading plate 101 is constructed by laying a plurality of loop coils 103 called mm-ci lines and loop coils 102 called sense lines, and a coordinate indicator 106 is constructed by a resonant circuit of coils and capacitors.

To read the coordinates, move the coordinate indicator 106 to the coordinate reading plate 10.
This is done by placing it on top of 1.

An electronic switch state called a scanning circuit 107 selects the excitation line 103 and the sense line 102 by +1 [next].
An alternating current signal is applied to the excitation line 103 and the sense line 102 is observed. A guidance signal is generated on the sense line 102 according to the position where the coordinate indicator 106 is placed. After signal processing of this induced signal by an amplification/detection circuit 105, it is inputted to a control circuit 108 composed of a microprocessor or the like, and coordinate values are obtained by performing a process.

[Problem to be solved by the invention]

The main objective of the invention is to realize a device for converting a one-dimensional position into a voltage.

This device can be said to have a similar function to a sliding type variable resistor, but in a sliding type variable resistor, the sliding part is attached to the main body and cannot be separated. The sliding part only needs to be used when operating the device, and by making it separable when not in use, the degree of freedom in design can be increased. The present invention is based on such a gist, and its second purpose is to realize a position voltage conversion device in which a sliding portion can be separated from a main body.

Furthermore, it is also an object of the present invention to solve problems from a technical point of view.

The coordinate reading device described in [Prior Art] is intended to detect coordinate values of a wide two-dimensional area with high precision, and therefore has a rather complicated configuration. Even if this technique were applied to detecting one-dimensional coordinate values, its complexity would not be solved.

One source of complexity in the construction is that the loop coils must be selected sequentially.

Real-time processing is impossible because a processing configuration must be used in which signals are input once while being selected sequentially and then reproduced later. For this reason, by employing microprocessors and the like, it is necessary to perform processing divided in time. This is how traditional coordinate reading equipment works! This technique is too complicated and cannot be applied to the device targeted by the present invention due to cost.

A third object of the present invention is to realize a position voltage conversion device with a small-scale configuration and at low cost.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a sense line, which is a loop coil whose width is changed along the direction of detecting the position, and an excitation line around the sense line. The detection board is composed of an excitation circuit connected to the excitation line and giving an alternating current signal, and a circuit in which a series circuit of a switch and a second capacitor is connected in parallel to a parallel resonant circuit of a coil and a first capacitor. A sliding part that is placed on the detection plate and used to indicate the position is connected to the sense line, and when the sliding part is placed on the detection plate, a guiding signal that is guided to the sense line is manually generated. an amplification detection circuit that amplifies and detects the signal and outputs an amplitude signal, a phase detection circuit that inputs an induction signal and compares it with an excitation signal to detect the phase of the induction signal and outputs it as a phase signal, and a phase detection circuit that outputs an amplitude signal and a phase signal. A position voltage conversion device is constructed by providing a control circuit that inputs the voltage, detects the state of the switch of the sliding part from the phase signal, and selectively outputs an amplitude signal when the switch is in a predetermined state.

[Function] In the position voltage converter configured as described above, when an excitation signal, which is an alternating current signal, is applied to the excitation line and a sliding part is placed on the sense line, an induced signal due to twt induction is generated on the sense line. .

Since the sense line is laid with varying width in the direction of detecting the position, the amplitude of the induced signal changes depending on the position where the sliding part is placed.

The amplification and detection circuit amplifies and detects the induced signal guided to the sense line, and outputs an amplitude signal of the induced signal. This amplitude signal is a voltage value indicating the position of the sliding part.

The phase detection circuit receives the induction signal and the excitation signal, detects the phase of the induction signal, and outputs the detected phase as a phase signal. This phase signal is a signal that changes depending on the state of the switch in the sliding section.

The control circuit receives an amplitude signal and a phase signal.

The switch state is determined from the phase signal, and an amplitude signal is output as a voltage signal when the switch state is determined. When the switch is operated, a voltage signal representing the position of the sliding part is output.

[Embodiment 2 (Structure of Position Voltage Conversion Device)] A first embodiment of the present invention will be described below with reference to Figs. 7 to 7.

First, the configuration will be explained. FIG. 1 is a block diagram of a position voltage conversion device according to the present invention.

In FIG. 1, 1 is a detection plate, on which a sense line 2 and an excitation line 3 are laid. The sense line 2 is a loop coil whose width changes along the position detection direction. Further, the excitation line 3 is a loop coil arranged around the sense line 2.

Although these sense lines 2 and excitation lines 3 are shown as one-turn coils in the figure, this is for simplification of the figure, and in reality they are loops with multiple turns. Although it may be one turn, it is better to use multiple turns because ii) the magnetic coupling becomes weaker and the amplitude of the induced signal induced into the sense line becomes smaller.

Reference numeral 4 denotes an excitation circuit, which is connected to the excitation line 3 and provides an excitation signal ds, which is an alternating current signal. Also, the excitation signal d
An excitation clock dc having a certain phase difference with s is also provided to a phase detection circuit to be described later.

Reference numeral 5 denotes an amplification and detection circuit that amplifies and detects the induced signal is induced into the sense line 2 and outputs an amplitude signal as of the induced signal. The circuit configuration has a certain degree of amplification.
This is an M detection circuit.

6 is a phase detection circuit that detects the phase signal ps of the induction signal is. A detailed configuration explanatory diagram is shown in FIG. 61 is an amplifier circuit, and 62 is a comparator. The induction signal is is input to the amplifier circuit 61 from the sense line 2 . The output of the comparator 62 is connected to one input of the exclusive OR circuit 63. The excitation clock dc is input to the other input of the exclusive OR circuit 63, and the output is connected to an integrating circuit 64 composed of a resistor and a capacitor. In this circuit, the excitation clock dc is used as a reference phase signal,
The phase of the induction signal is is detected as a voltage signal charged in the integrating circuit 64.

The configuration of the phase detection circuit 6 shown in this embodiment is a circuit that detects the phase difference of the induction signal is with respect to the excitation clock da, and cannot detect lead or lag.However, as a design matter, phase detection is required. There is a degree of freedom in how to take a reference signal for this purpose, circuit characteristics, etc., and depending on the design, it is conceivable that the induced signal may lead or exhibit delayed behavior compared to the reference signal. In such a case, a circuit for detecting phase lead/lag may be provided, and this circuit can be easily realized.

The configuration of the phase detection circuit is not essential to the present invention; in short, it may be any circuit that detects the phase difference between two signals, and is not limited to this circuit.

Let's return to Figure 1 and continue the explanation. The control circuit 7 inputs the amplitude signal as and the phase signal ps, and determines the state of the switch provided in the sliding part, which will be described later, from the phase signal ps.
The amplitude signal as is output as a voltage signal v3 in a predetermined switch state.

Although various configurations of the control circuit 7 can be considered, the configuration according to the most basic embodiment is shown in FIG.
and a sample hold circuit 72. Other configurations will be described later.

The comparator 71 inputs the phase signal p3, compares it with a certain threshold value, determines the state of the switch, and outputs it as a switch signal ss. The sample and hold circuit 72 is a circuit that manually inputs the amplitude signal as and the switch signal ss, outputs the amplitude signal as as is when the switch signal ss is on, and holds the previous amplitude signal as when the switch signal ss is off. Amplitude signal a by switch signal ss
This is a general circuit that samples and holds S.

8 is a sliding part, and a coil 81 whose circuit diagram is shown in FIG.
and the first capacitor 82 constitute a parallel resonant circuit. The resonant dark wave number of this resonant circuit is approximately matched to the frequency of the excitation clock dc output from the excitation circuit 4, but does not necessarily need to be matched.

Further, a series circuit including a switch 83 and a second capacitor 84 is connected in parallel to the resonant circuit. A resistor may be inserted into this series circuit to adjust the effect of the second capacitor.

(Operation of position voltage converter) Next, the operation will be explained.

When the sliding part 8 is placed on the sense line 2 as shown in FIG. The coupling generates an inductive signal IS.

This induced signal is is amplified and detected by an amplification/detection circuit 5 and converted into an amplitude signal as.

Since the width of the sense line 2 changes along the coordinate detection direction, the i of the guiding signal depends on the position where the sliding part 8 is placed.
The amplitude signal as of s changes. The amplitude signal as tends to become smaller as the width of the sense line becomes narrower, and becomes larger as the width becomes wider, and this amplitude signal as indicates the position where the sliding part is placed.

By the way, it is clear that the amplitude signal as changes not only depending on the position where the sliding part 8 is placed but also depending on the height. Further, since the excitation line 3 and the sense line 2 are directly coupled, the induction signal is is generated and the amplitude signal as takes a constant value even if the sliding part 8 is not placed on the detection plate 1. Therefore, the 0 phase detection circuit 6 and the control circuit 7, which detect the state of the switch 83 provided in the sliding part 8 and output the amplitude signal as when the switch 83 is in a predetermined state, are designed for this purpose. It was established in The operation will be explained below.

In FIG. 0, which describes the operation of the phase detection circuit 6 using a timing diagram in FIG. 6, da is an excitation clock, ds is an excitation signal, and is is an induction signal.

When the switch 83 of the sliding part 8 is not pressed, the resonant circuit resonates at a frequency determined by the constants of the coil 81 and the first capacitor 82, and the induction signal is is equal to the excitation signal d.
s with a phase difference corresponding to this state.

The process by which the guidance signal is is processed will be explained. First, the guided signal is is amplified by the amplifier circuit 61 in the phase detection circuit 6, and further converted into a square wave by the comparator 62, resulting in a shaped guided signal wave ip. The induced signal shaped wave ip and the excitation clock dc are phase-detected by an exclusive OR circuit 63 to become a detected signal pp. Further, the detection signal pp is converted into a DC signal by an integrating circuit 64 and a phase signal ps
becomes.

When the switch 83 is pressed, the second capacitor 84 is connected in parallel to the resonant circuit, so the resonant frequency changes to the lower side, and the phase of the induction signal is changes to the delayed direction.

In FIG. 6, the induction signal ish is obtained when the switch 83 is pressed, and shows that the phase is delayed from the induction signal is when the switch 83 is not pressed. This signal is similarly converted into a phase signal p by the phase detection circuit 6.
Converted to sh.

As is clear from the operation of the circuit, the magnitude of the phase signal psh is larger than that of the phase signal ps, and it can be seen that a change in phase can be detected.

Moreover, even if the sliding part 8 is not on the detection plate 1, the sense line 2
As described above, the induced signal is is generated, but the phase at this time is different from the phase of the induced signal is when the sliding part 8 is placed on the detection plate 1, and it is detected in the same way. be able to.

Next, the operation of the control circuit 7 will be explained with reference to FIG. In the figure, the amplitude signal as is a signal representing the position, as already explained. It has also been explained that when the switch 83 of the sliding part 8 is turned on/off, the phase signal ps changes.

A comparator 71 constituting the control circuit 7 receives a phase signal p
s is input and compared with a predetermined threshold value to determine the switch state and output as a switch signal SS.

The Zamble hold circuit 72 inputs the amplitude signal as,
When the switch signal ss is on, the amplitude signal as is output as it is, and when the switch signal ss is turned off, the amplitude signal as is sampled and thereafter held and output.

The specific operating method is as follows.

First, the operator moves the sliding part 8 without pressing the switch 83.
W onto the detection plate 1. Next, while pressing the switch 83, the sliding part 8 is moved on the detection plate 1 so that the desired voltage signal vs is output. When the desired voltage signal VS is reached, the switch 83 is closed.

After releasing the switch 83, even if the sliding part 8 is moved,
Alternatively, even if it is removed, the voltage signal vs does not change.

Since the voltage signal vs changes only while the switch 83 is pressed, it changes only in the 6-position detection direction, which is not affected even if the height changes when the sliding part 8 is removed or removed. Therefore, it is possible to output a voltage signal vs.

(Regarding other embodiments related to the control device) Although the control device according to the first embodiment was realized by an analog circuit, it is also possible to realize it by a digital circuit or a combination of an analog circuit and a digital circuit. be.

FIG. 5 shows an embodiment in which a one-chip microcomputer is used in the control circuit. The microcomputer 74 has an A/D converter 73 with a two-channel input multiplexer.
It has internal organs.

The amplitude signal as and the phase signal ps are digitized by A/D conversion [173] and then input to a microcomputer and processed by a program. Although a detailed explanation of the program processing will be omitted, it is easy to determine the switch state by comparing the phase signal ps with a threshold value, and to sample and hold the phase signal as according to the switch state.

The output of the voltage signal vs may be output as a digital value, or
It may be converted into an analog value by a D/A converter.

As an additional note, as an example of a hybrid circuit of digital and analog circuits, it is also possible to process the phase signal ps with an analog comparator, output the switch signal SS, and input this to a microcomputer. It is. Other easily conceivable configurations will be omitted.

(Other Examples Regarding Sense Lines) In the above embodiments, the width of the sense lines uniformly decreases or increases along the position detection direction. The width of the sense line is not limited to this, and the width of the sense line may be changed depending on the purpose. For example, as shown in FIG. 8, along the position detection direction, the maximum value is set at a certain point P, and decreases as the distance from that point increases. According to this sense line, the obtained voltage signal tends to be maximum when the sliding part 8 is at the point P, and decrease as it moves away from the sliding part 8 in both directions.

Various other patterns can be considered for the sense line, but they will be omitted.

[Effects of the Invention] As explained above, in the present invention, an excitation line and a sense line are laid, a resonant circuit is provided in the sliding part, and the amplitude of an induced signal due to t-magnetic coupling between the excitation line, the resonant circuit, and the sense line is reduced. The position of the sliding part can be found from The sliding part is composed only of passive circuits, and there is no need to connect an external signal. Therefore, it is possible to realize a position voltage conversion device in which the sliding part can be separated.

In addition, as explained in the example, this device does not use the sense line selection technology used in coordinate reading devices, and the signal processing circuit can be extremely small, resulting in extremely low cost. The device can be realized.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the configuration of an embodiment of the position voltage converter according to the present invention, Fig. 2 is a circuit diagram of the sliding part, Fig. 3 is an explanatory diagram of the configuration of the phase detection circuit, and Fig. 4 is an explanatory diagram of the control circuit. 5 is an explanatory diagram of the configuration of the second embodiment of the control circuit. FIG. 6 is a timing diagram of phase detection operation. FIG. 7 is an explanatory diagram of the operation of the control circuit. FIG. 8 is an explanatory diagram of another embodiment regarding the sense line, and FIG. 9 is an explanatory diagram of the configuration of a conventional coordinate reading device. 1...Detection plate 2...Sense line 3...Excitation line 4...Excitation circuit 5...Amplification detection circuit 6...Phase detection circuit 7...Control circuit 8...Sliding part 81...Coil 82...First capacitor 83...Switch 84...Second capacitor and above Applicant Seiko Electronic Industries Co., Ltd. Representative Patent Attorney Takayuki Hayashi Configuration of one embodiment of the position voltage converter 1 (2) Figure 1 81 Coil 82 Circuit diagram of the me section of the first capacitor Figure 2 Phase detection circuit Figure 3 shows the structure of the second embodiment of the control circuit. Fig. 4 shows the structure of the second embodiment of the control circuit. Timing diagram of the phase detection operation. Figure 6: An explanatory diagram of the operation of the control circuit. Figure 7: An explanatory diagram of another embodiment regarding the false line in the position detection direction. Figure 8:

Claims (1)

[Claims] A detection plate is constructed by: a) a sense line consisting of a loop coil arranged with a width varying along the direction in which the position is detected; and b) an excitation line laid around the sense line. c. an excitation circuit connected to the excitation line and giving an alternating current signal to the excitation line; d. a resonant circuit including a coil and a first capacitor;
a sliding part configured by connecting at least a series circuit of a switch and a second capacitor in parallel to the resonant circuit, and placed on the detection plate and used to indicate the position; e, connected to the sense line; an amplification/detection circuit that inputs an induction signal to be induced into the sense line, amplifies and detects the induction signal, and outputs an amplitude signal; f) an AC signal applied to the excitation line; a phase detection circuit that inputs the amplitude signal and the phase signal, detects the phase of the induction signal, and outputs it as a phase signal; g. and a control circuit that detects the amplitude signal and selectively outputs the amplitude signal when the switch is in a predetermined switch state.