JPS6262201A - Displacement detector - Google Patents

Abstract

PURPOSE:To obtain the natural signal showing the displacement position, by constructing a displacement detector with a plurolity of electrode plates provided with an electrode with the specified distances apart an each periphery, connecting mutually the opposedly located electrodes, and allowing sliding electrode pieces projecting from a rotating shaft to be connected consecuyively with the topmost electrode plate in rotating and sliding manner on its electrode. CONSTITUTION:A rotary encoder, a kind of displacement detectors, is constructed with a cylindrical case 100 and a plurality of electrode plates 1-5 of the same circular shape positioned in the case with the specified distances apart and electrodes 10 are distributed on the peripheries of case and electrode plates with the same specified distances apart. Further, on the surfaces of these electrode plates 1-5, resistances and diodes 15 are installed and they are connected with the electric power source through a plurality of the opposedly located electrodes 10 respectively. Further, they are connected also with the same number of electrodes installed in the case 100 and a sliding piece 13 projecting from a rotating shaft which penetrates the case 100 is allowed to slide on electrodes 10 to obtain a required negative logic signal from the electrode plates 1-15 on the lowest stage in contact with this for specifying the displacement position.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a displacement detection device that detects an amount of rotation or an amount of displacement.

[Technical background of the invention and its problems]

Conventionally 1 For example, in a rotary encoder which is a type of displacement detection device, electrodes 400, shown as scratches in the figure, were formed at different radial positions for each predetermined central angle, as shown in FIG. A conductive brush 402 that slides into contact with a disc-shaped code plate 401 having a digital pattern for each channel on the code plate 401 is fixed to a rotating shaft 403 that rotates coaxially with the rotation of the object to be measured. An angle signal indicating the absolute value of the rotation angle of the object to be measured was obtained. In such an encoder, in order to improve the resolution of the detected rotation angle, it is necessary to increase the number of digits of the digital button, and for this reason, the diameter of the code plate 401 is large (which causes the problem that the device becomes large and expensive). be.

Further, when the number of digits is increased by arranging digital buttons finely in the radial direction on the code plate 401.

High scanning accuracy is required for the pushers 402 that slide on each channel while orbiting on the code plate 401.

[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 displacement detection device that can detect displacement positions with highly accurate absolute values.

[Summary of the invention]

The present invention has been made to achieve the above object.

A plurality of electrodes arranged in a row at a predetermined interval in a desired area, a sliding electrode that moves along the row of electrodes and sequentially slides into contact with the electrodes, and an electrode that contacts the sliding electrodes. The displacement detection device includes means for outputting a unique digital signal to the electrode that the sliding electrode is in contact with using electrical continuity between the sliding electrodes.

〔Effect of the invention〕

According to the present invention, since a unique digital signal is output according to each electrode that the sliding electrode contacts, it is possible to measure the displacement position with a highly accurate absolute value using a small device.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A rotary encoder as an embodiment of the present invention will be described in detail below with reference to the drawings. still.

The same parts are given the same reference numerals throughout the drawings.

The embodiment shown in FIGS. 1 to 2 is an example in which the present invention is applied to a rotary encoder.

To explain the structure of the rotary encoder of this example,
Case 1 has a cylindrical shape as shown by the dashed-dot line in Figure 1.
On the top surface of 00, a rotation shaft 101 that rotates coaxially with the rotation of the object to be measured is held by a rotation bearing 102 in a direction perpendicular to the top surface and inside the case 100 so that the other end of the rotation shaft 101 rotates. ing. At the other end of the rotating shaft 101 inside the case l, there is a rotating member 104 whose one end is fixed to the rotating shaft 101 and whose other end rotates around the axis of the rotating shaft 101.
is fixed. Five substrates 6 (first substrate II, second substrate 2, third substrate
Substrate 3. Fourth substrate 4. A fifth substrate 5) is supported by fixing columns 106 in parallel and spaced apart by a predetermined distance. The fixing column 106 holds the disk-shaped substrate 6 at intervals of 120 degrees at a central angle, with the ends of the substrate 6 being held in grooves carved in the fixing column 106, and both ends of the substrate 6 are connected to the upper surface of the case 100 and It is fixed to the bottom surface with screws 107. A plurality of circular electrodes 10 are provided on each substrate 6 at equal intervals in a ring shape, and these electrodes are provided at the same position in the vertical direction as the electrodes 10 arranged on each substrate 6 located above and below, and are in electrical conduction with each other. They are respectively connected by lead wires 108 as shown in FIG. Above the substrate 6, a sliding electrode 1 is provided at the other end of a rotating member 104, one end of which is supported by a rotating shaft 101 that rotates coaxially with the rotating shaft of the object to be measured.
3 sequentially scans the surface of the electrode 10 projected on the surface of the first substrate 1 while making sliding contact therewith. As shown in FIG. 2, a predetermined electrode 10 and a power source (not shown) are coupled to each substrate 6 via a resistor and a diode 15 (not shown).
Further, since the sliding electrode 13 is grounded, a negative logic signal can be obtained by contacting and conducting the sliding electrode 13 and any electrode 10.

The negative logic signal thus obtained is expressed as a set of digital signals by specifying the electrode coupled to the power supply via the resistor and diode 15 for each substrate 6, thereby determining the position of the sliding electrode 13. An absolute value indicating the amount of rotation of the object to be measured can be obtained. The process by which the digital signal is obtained will be explained below with reference to FIG.

The electrode 10 is located at the top of each substrate 6! The moss anode of the first substrate 1, which is in direct contact with the sliding electrode 13, is connected to a resistor R.
A plurality of diodes 15 commonly connected to each electrode 1o
! On the other hand, every other one is connected. In a second substrate located under the first substrate, a plurality of diodes 15 whose anodes are commonly connected to a resistor are connected in series to two electrodes with two electrodes in between for each electrode 10. Ori,
Electrode 10 connected to diode 15 on first substrate 1
and one end of the electrode on the second substrate 2 to which the diode 15 is continuously connected are electrodes located at the same position. Similarly, in the third substrate 3 located below the second substrate 2, the anode is common to the resistor R$ (a plurality of diodes 15 connected to this
The electrode 10 connected to the diode 15 on the second substrate 2 is connected to the diode 15 on the third substrate 3 in succession. The electrode 10 is located at the same position as one end of the electrode connected to the other end.

On the fourth substrate located below the third substrate 3, a plurality of diodes 15 whose anodes are commonly connected to the resistor R6 are connected in succession to the eight electrodes 10 across the eight electrodes 10, and the third One end of the electrode 10 to which the diodes 15 are continuously connected on the fourth substrate 3 and one end of the electrode 10 to which the diodes 15 are continuously connected on the fourth substrate 4 are the electrodes 10 at the same position. On the fifth substrate located below the fourth substrate 4, a plurality of diodes 15 whose anodes are commonly connected to the resistor R8 are connected in succession to the 16 electrodes 10 with the 16 electrodes 10 interposed between them. One end of the electrode 10 on the fourth substrate 4 to which the diodes 15 are continuously connected and one end of the electrode 10 on the fifth substrate 5 to which the diodes 15 are continuously connected are the electrodes 10 at the same position. be. Each resistor R1, R□R
□R6゜R1 has one end connected to the DC power supply V, and furthermore, a negative logic signal derivation point Pl + Pl + Pm + R4 * ” is connected to the anode of the diode 15.
I is provided.

That is, when the grounded sliding electrode 13 contacts one of the electrodes 10 on the first substrate 1, it is connected to the lead wire 108 of the second to fifth substrates 2.3.4.5 laminated below. Since each of the grounded electrodes 10 is similarly grounded, if the diode 15 is connected to each of the grounded electrodes 104, 1"f is the derivation point of the negative logic signal derived from each of the substrates 6, p1. A '0' signal is sent to p,, p,, p, and if the diode 15 is not connected, a '1' signal is sent to the derivation point PK, P,, P,, P,
, P, is sent to. From these first substrate 1 to fifth substrate 5, each derivation point P1. Pl, P,, P,, P,
The digits of the digital signal are sequentially reassigned as 29.21.21°2-24 to the negative logic signals sent to the respective negative logic signals.

For example, the sliding electrode 13 shown by the solid line in FIG.
The unconnected electrode 1 of the diode 15 on the substrate 1 of
When 0・aj contacts, the resistor R8 is not short-circuited to the ground via the diode 15, so a negative logic signal of 11" is output at the derivation points P and J. Then, the electrode 10・b on the substrate 2 of @2 is grounded via the electrode 10.a on the upper first substrate 1, as shown by the dotted line in the figure, so the electrode 1
The resistor R2 is short-circuited to ground by the diode 15 connected to the terminal 0.b, and a negative logic signal @θ'' is output to the derivation point P2.Similarly, the electrode 10.
The electrode 10.C located at the bottom of b is grounded as shown by the dotted line in the figure, and the resistor R3 is short-circuited to ground via the diode 15, so a negative logic signal "o" is output to the derivation point P3.
is output. Further, a diode 15 is connected to the electrode 10.d located at the lower part of the electrode 10.C on the fourth substrate 4.
Electrode on the fifth substrate 5] Electrode 10 located at the bottom of 0.d
- Since the diode 15 is not connected to e, negative logic signals 1'' and 11'' are output to the respective derivation points P, , P,. Therefore, from these, each derived point P,, P,, P
The signals output from a, P,, P, are 1.0.
0.0.1'', and this series of digital signals becomes an absolute value indicating the contact position of the sliding electrode 12 with the electrode 10, that is, the amount of rotation of the object to be measured.

In this way, the specific electrode on each board is connected to the DC power supply via a diode, so it comes into contact with the sliding electrode, and from the grounded electrode, a digital signal unique to that electrode is sent to each derivation point. Output to. That is, the amount of rotation of the object to be measured can be detected using the absolute value of the digital signal. Furthermore, since the diameter of the substrate does not increase as the resolution of the detected amount of rotation improves, the device can be kept compact.

Furthermore, since the electrodes disposed on the S plate may be contact points arranged at equal intervals with the annular number, a sliding electrode that contacts the electrodes can be constructed relatively easily.

Note that the embodiments of the present invention can be modified in various ways without sticking to the above-mentioned contents and without departing from the technical idea of the present invention. For example, in the above embodiment, five substrates 6 are used to obtain a predetermined unit detection angle for the detected rotation angle, but five or more substrates are used to realize a finer unit detection angle. It's okay.

In addition, the boards are supported by a fixing column, separated by a predetermined distance between parallel bars, but it is also possible to apply appropriate insulation treatment between each board and then fix each board closely together in the case. good. In this case, the electrodes arranged at the same position in the vertical direction between the respective substrates are brought into direct contact with each other without intervening lead wires, thereby maintaining the electric fishing field in a conductive state. Further, all the diodes arranged on the substrate can be replaced with conductive wires, and the diodes can be interposed between each resistor and the plurality of conductive wires. This allows the number of diodes used for each substrate to be reduced to one. In addition, in the same embodiment, the digital signal indicating the rotation angle is output in pinary code, but by changing the combination of diodes and electrodes on each board, it can be output in gray code, logarithmic output, etc. You can also do that. Further, the digital signal indicating the rotation angle, which is output as a negative logic signal, may be inverted by a NAND circuit or the like to obtain a positive logic signal. The shape of the electrodes arranged at equal intervals on the substrate is not limited to circular shapes.
Any shape such as an ellipse or a rectangle may be used.

As detailed above, it has been shown with the embodiments that the displacement detection device of the present invention can be applied to a rotary encoder, but a near (f') encoder can also be configured based on the technical idea of the present invention. .

[Brief explanation of the drawing]

FIG. 1 is an embodiment of the present invention, and is a perspective view showing the configuration when applied to a rotary encoder. Fig. 2 is a perspective view of a main part showing a part of the configuration of the same embodiment, Fig. 3 is a circuit diagram showing the circuit structure of the same embodiment, and Fig. 4 is a perspective view showing the structure of a conventional rotary encoder. It is. 10... Electrode, 13... Sliding electrode. Figure 4■ Figure 3

Claims (1)

[Claims] A plurality of electrodes arranged in a row at a predetermined interval in a desired area, a sliding electrode that moves along the row of electrodes and sequentially slides into contact with the electrodes, and an electrode that contacts the sliding electrodes. A displacement detection device comprising means for outputting a unique digital signal to the electrode in contact with the sliding electrode using electrical continuity between the sliding electrodes.