JPS62110101A - Displacement detector - Google Patents

Abstract

PURPOSE:To accurately detect the quantity of the displacement of an object to be measured in an absolute value by applying an alternating voltage to electric conductors arranged at predetermined spaces and outputting coded signals peculiar to the electric conductors. CONSTITUTION:A rotating shaft 2 is held in a casing 1 at one end and supports a revolving member 4 revolving about the shaft 2 at the other end. A disk-shaped semi conductor chip 5 is mounted in a position opposite to one end of the shaft 2 and a plurality of electric conductors 10 are arranged at predetermined spaces in a circle on the chip 5. A ring-shaped electrode 5 concentric with the circle of the conductors 10 is provided on the chip 5 along its periphery. A high-frequency alternating electric field is applied (8) to the electrode 6. Thus, the rotation of an object to be measured causes the shaft 2 to oppose the member 4 to the conductor 10 corresponding to the rotating angle of the member 4. At this time, since the neighborhood of the tip of the member 4 is opposed also to the electrode 6, the electrode 6, member 4 and the conductor 10 form a capacitor and the alternating electric field applied to the electrode 6 is transmitted to the conductor 10. The electric field generated in the conductor 10 is detected by coding means arranged on the chip 5 and converted to the code peculiar to the conductor 10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a displacement detection device for detecting the amount of displacement such as rotation or linear motion of an object to be measured.

[Technical background of the invention and its problems]

Conventionally, for example, in a rotary encoder device, which is a type of displacement detection device, as shown in FIG.
6 (indicated by a scratch in the figure) and opening 605
A disc-shaped code board 6 having a digital button consisting of
04 is attached coaxially to a rotating shaft 600 held by a bearing 602 in a case 601 indicated by il in the figure, and a light source placed on one side of a code plate 604 in a detection unit 603 irradiates the digital button. By detecting the transmitted light with an optical sensor, the absolute value of the rotation angle of rotation @600 is obtained as a hooded digital signal. In such a rotary encoder device, it is necessary to increase the number of digits of the digital pattern in order to improve the resolution of the detected rotation angle.

For this reason, the diameter of the high-resolution rotary encoder device's hood plate 604 increases, which increases the weight and bulk of the device.
He placed a high burden on the vessel in terms of design.

Furthermore, if the number of digits is increased by arranging the digital pattern finely in the radial direction on the code plate 604,
In the detection unit 603, a light source and an optical sensor are required to have high working precision.

[Purpose of the invention]

The present invention has been made in view of the problems of the prior art described above, and its purpose is to provide a compact and highly reliable displacement detection device that can accurately detect the amount of displacement of an object to be measured in absolute value. It is in.

[Summary of the invention]

The present invention, which has been made to achieve the above object, includes a plurality of electrical conductors arranged in a row at predetermined intervals, and a plurality of electrical conductors arranged movably along the rows of the electrical conductors, and a position of an object to be measured. an alternating electric field applying means for applying an alternating electric field supplied from an alternating power supply in response to changes in the alternating electric field; A displacement detection device characterized by comprising a displacement detection signal output means that converts the displacement detection signal into a unique code signal corresponding to a position and outputs the displacement detection signal.

〔Effect of the invention〕

According to the present invention, qθ is applied to each of the electric conductors according to the electric conductor induced by the alternating electric field applied from the alternating electric field applying means moving along the electric conductors arranged at a predetermined interval α. Since a positive sign signal is output, the amount of displacement of the object to be measured can be accurately detected in absolute value.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described in detail with reference to the attached page N. An embodiment of the present invention shown in FIGS. 1 to 3 is a rotary encoder device in which the displacement detection device of the present invention is applied. As shown in FIG. 1, the configuration of this embodiment is as follows: First, as shown in FIG. 'Wed rotating bearing 3
supports a rotating shaft 2 which is interlocked with the rotation of the object to be measured so that its axis is perpendicular to the upper surface. One end of the rotating shaft 2 is held within the case 1, and one end is fixed to the rotating shaft 2, and the other end is a needle-shaped needle made of a conductive material that orbits around the center of the rotating shaft 2 within the case 1. It supports the rotating member 4. Further, a disk-shaped semiconductor chip 5 is laid inside the lower surface side of the case 1 at a position opposite to one end of the rotation M2, and a rotation IIfl+2
A plurality of electrical conductors 10 having substantially square surfaces exposed are disposed on a semiconductor chip 5 made of a conductive material arranged in rows at predetermined intervals in a circumferential manner centered on the intersection of the axes of the semiconductor chips 5 and 5. ing. Further, the electric conductor 10 arranged in a circumferential manner
A band-shaped annular electrode 6 made of a 74vL substance is disposed on the semiconductor chip 5 along the edge of the disk-shaped semiconductor chip 5, which has a substantially concentric circumferential shape.

An alternating electric field is applied to this annular electrode 6 by a high frequency power source 8 provided on the semiconductor chip 5 and activated by electric power (not shown). That is, as shown in FIG. 2, the rotating shaft 2, which rotates with the rotation of the object to be measured, causes the rotating member 4 to face the electrical conductor 10 corresponding to the rotation angle of the object to be measured.

At this time, since the vicinity of the tip of the rotating member 4 also faces the annular electrode 6, the annular 'Fl! The pole 6, the rotating member 4, and the electrical conductor 10 corresponding to the above-mentioned rotation angle form a capacitor, and the alternating electric field applied to the annular electrode 6 propagates to the electrical conductor 10 corresponding to the above-mentioned rotation angle. The alternating electric field generated in each electrical conductor 10 is detected by a conversion circuit 30, which is an encoding means disposed on the semiconductor chip 5, and is converted into a code signal unique to each electrical conductor 10.

The conversion circuit 30 will be explained below. As shown in FIG. 3, each electrical conductor 10 disposed on the semiconductor chip 5 is connected to a load resistor 32 whose one end is connected to the ground 31, and the t% Bunji Electric is generated at the connection point between the load resistor 32 and the electric conductor 10 by an alternating electric field.

Further, each electric conductor 10 is connected to an amplifier 33 which is supplied with M power by the electric current t+V, and amplifies the Bunji electric power generated in the electric conductor 10 to a predetermined electric power [E]. The amplified Bunji Denko signal is then converted into direct current by a rectifier 34, binarized by a NANI) circuit 35 having a built-in Seamit circuit, and then inverted. The output terminals of this NAND circuit 35 are connected via a diode 37 to one of a plurality of pull-up resistors 36, one end of which is connected to the power supply V, in different combinations for each NANDl path corresponding to each electrical conductor 10. The anode side of this diode 37 is connected to the pull-up resistor 36. That is, the electrical conductor lO
The alternating current voltage generated by applying an alternating electric field to the amplifier 3
3 and becomes DC electrons by the rectifier 34, N
The puller is connected through a diode 37 because the AND circuit 35 outputs a binary and inverted signal.

The pull resistor 36 is short-circuited to a ground (not shown) built in the NAND circuit 35. The WEE of each pull-up resistor 36 at the time of this short circuit is all connected to the NAND circuit from between each NAND circuit 35 and each pull-up resistor 36 or via a diode 37.
The pull-up resistors 36 connected to the Dl path 35 are each led out from the anode side of the diode 37, and each NAND
The signal is inverted via the circuit 38 and is led to the code signal output terminal 39 as a positive logic signal. In other words, the positive logic signal l'' is output from the output terminal 39 corresponding to the pull-up resistor 36 that is short-circuited to ground via the diode 37, and the output terminal 39 corresponding to the pull-up resistor 36 that is not short-circuited to ground is
A positive logic signal J+''OII is outputted from each of them. In this embodiment, an alternating binary code (Gray code) is assigned to each electric conductor 10 in turn, and an alternating electric field is applied to the electric conductor 10. so that an alternating binary code divided according to the conductor is obtained from each output terminal 39 as a code signal.
Each NAND circuit 35 and each pull-up resistor 36 are connected through a diode 37. Each output terminal 39 receives each digit of the alternating binary code "2, 21, 22...2".
'1.2 n l' corresponds to this.

For example, when the rotating member 4 is guided by the rotating shaft 2 to a region H surrounded by a dotted line in FIG. It is applied to the conductor 10 and grounded via the resistor 32. Then, the AC 1 generated in the electrical conductor 10! The signal is amplified by an amplifier 33, rectified by a rectifier 34, binarized by a NAND circuit 35, and then inverted to produce a zero output. As a result, N
A pull-up resistor 36 connected to the output terminal of ANDl path 35 is shorted to ground. Therefore, each NAND circuit 38
inverts the inputted negative logic signal and outputs a positive logic sign signal to the output terminal 39. In this case, each output terminal 39
A set of code signals output from 0110...Ol
”, and each digit is the digit of the alternating binary code in order “2' + 2
' * 2" + 2' *... 2n-1, 2n"
It corresponds as follows.

In this way, the electrical conductor 10 to which an alternating electric field is applied can be identified from a set of alternating binary codes, which are the code signals output from each output terminal 39. The position of member 4, in other words,
In conjunction with the rotation of the object to be measured, the position of the rotating member that rotates while facing each electric conductor 10 in sequence can also be specified at the same time. Therefore, according to the rotary encoder according to the present embodiment, the rotation angle of the object to be measured can be accurately detected as an absolute value from the code signal output from the output terminal 39.

It should be noted that various modifications and limitations may be added to the rotary encoder which is one embodiment of the invention described above without departing from the technical idea of the present invention. For example, in the embodiment, the NANDl path 35 and the pull-up resistor 36 are connected via the diode 37, but this can be simply replaced with a conductive wire, and instead, one diode for each pull-up resistor +fj: A negative logic signal may subsequently be obtained from this connection point. In addition, the electric conductor 1
The amplifier 33,
Alternatively, even if the rectifier 34, NAND circuit 35, etc. are omitted, the effects of this embodiment will not be impaired. Furthermore, the frequency of the alternating electric field applied to the annular electrode 6 is determined by various conditions of the annular electrode 6, the rotating member 4, and the electric conductor 10 that constitute the capacitor, and the most efficient frequency according to each condition must be selected. Bye.

Furthermore, the alternating electric field applied to the annular 'm pole 6 in the same embodiment may be applied to the rotating member 4 as shown in FIG. 4 (same parts are given the same numbers). In this field, the annular electrode is omitted, and instead, a single conductive band 40 is wound around the rotating shaft 2, and a high frequency wave is connected to the band 40.
A contact piece 42 to which an alternating electric field supplied from 41 is applied, and a lead wire 43 shown by a dotted line in the figure for transmitting the alternating electric field applied to the rotating member 4 are added. In this case, only the portion of the rotating member 4 facing the electric conductor 10 is made of a conductive member to apply an alternating electric field.

Next, the displacement detection device of the present invention was installed as a linear encoder @50
An example applied to this will be explained. That is, as shown in FIG. 5, this linear encoder device 501 includes a column 50 having an elongated prismatic shape and made of a non-conductive material;
A semiconductor chip is a flat plate having a rectangular surface that is in close contact with the upper surface in the longitudinal direction of 0; Electrodes 51 which are a large number of electrical conductors protruding from the surface
and a bottom plate 53 having a rectangular plane fixed to a surface opposite to the upper surface and forming seven rungs 57 on both sides of the column 50 in the longitudinal direction;
The electrode 5 is supported at both ends by two supports 55 made of a non-conductive material that are placed on the object to be measured in the longitudinal direction and then slide.
The needles 54 made of a conductive material are sequentially opposed to the electrodes 1 and to which an alternating electric field is applied by a high-frequency power source (not shown), and the electrodes 51t to which the alternating electric field is applied are detected and each electrode 51 has a unique code. It consists of a conversion circuit that is an encoder integrated on a semiconductor chip that outputs a signal. In these configurations, the alternating electric field applied to the needle 54 causes the fII
The needle 54 moves according to the position of the support that is linked to the treasure.
An alternating electric field is applied to the seven electrodes 51 facing each other. Kan 81I printed with this alternating electric field! 51 is output as the code signal unique to each electrode 5 by the conversion circuit, so that the electrode to which the alternating electric field is applied can be identified from this code signal. Therefore, the position of the needle 54 facing the 'electrode to which an alternating electric field is applied, that is, the moving support 55
The position of the object to be measured, which moves in a straight line in succession, is specified by an absolute value from the code signal. Here, for the configuration of the conversion circuit, a conversion circuit or the like applied to the rotary encoder device described above is used. In this way, the above-described embodiments of the present invention and their modifications do not have reading errors between the receiving and emitting elements unlike the Jiu-Tian type rotary encoder, and also significantly reduce the volume of the device compared to the photoelectric type at the same resolution. It has high reliability, environmental resistance, shock resistance, and noise resistance, such as being able to be small in size and eliminating the need to enclose the entire device in an airtight container to ensure the blocking of external light that can cause malfunctions. Excellent.

As described above, the displacement detection device of the present invention has been described together with the embodiments, but various changes can be made to the embodiments described above without departing from the technical idea of the present invention. For example, a custom I
It can be configured as C. In addition, in order to convert the code signal output from the conversion circuit into a binary IJ-code output other than an alternating binary code, or a double output, a diode is connected between the pull-up resistor and the NAND circuit. can be changed to connect in a different arrangement. Furthermore, the number of electrical conductors arranged in rows at predetermined intervals on the semiconductor chip can be increased as much as possible in order to obtain the desired detection accuracy. increases.

In addition, circuit elements disposed on the semiconductor chip, such as conversion circuits, annular electrodes, and electrical conductors, are formed according to conventional manufacturing processes for making integrated circuits.

As described above, in the various embodiments and modifications thereof for realizing the displacement detection device of the present invention, the shape of each part, that is, the configuration of the main parts, can be changed at will as long as the essential functions of the main parts are not impaired. Yes, without adding unnecessary limitations.

[Brief explanation of drawings]

Figure 1 shows a real fill to which the displacement detection device of the present invention is applied.
2 is a perspective view showing the overall configuration of the rotary encoder device, FIG. 2 is a sectional view showing the main parts of the same embodiment, and FIG. 3 is a partially cutaway diagram showing the arrangement of the conversion circuit applied in the same embodiment. 4 is a transparent perspective view showing the structure of a modification of the same embodiment; FIG. 5 is a perspective view showing the inverted structure of a rear enhooder device to which the displacement detecting device of the present invention is applied; FIG.
FIG. 6 is a transparent perspective view showing the configuration of a conventional example. l... Case, 4... Rotating member, 5... Semiconductor chip, 6... Annular electrode, 10... Electric conductor. Agent Patent Attorney Nori Ken Yudo Takehana Kikuo Figure 1 Figure 4 Figure 11 Figure 5 Figure 6

Claims (1)

[Claims] A plurality of electrical conductors are arranged in a row at predetermined intervals, and the electrical conductors are arranged so as to be movable in accordance with the displacement of the position of the object to be measured along the row of the electrical conductors, and correspond to the position of the object to be measured. an alternating electric field applying means for applying an alternating electric field to the electric conductor; and a detection signal from the electric conductor obtained by the alternating electric field applied by the alternating electric field applying means to a unique signal corresponding to the displacement position of the object to be measured. 1. A displacement detection device comprising: encoding means for converting into a code signal.