JPH0560523B2 - - Google Patents

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, for example, a rotary encoder, which is a type of displacement detection device, has a digital pattern in which electrodes 400, shown as scratches in the figure, are formed at different radial positions for each predetermined central angle, as shown in FIG. The object to be measured 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 was obtained. In such an encoder, it is necessary to increase the number of digits of the digital pattern in order to improve the resolution of the detected rotation angle.
There is a problem that the diameter of 1 becomes large, making the device large and expensive. In addition, the digital pattern is printed on the code board 4.
If the number of digits is increased by finely arranging the code plate 401 in the radial direction, the brush 402 comes into sliding contact with each channel while orbiting on the code plate 401.
requires high scanning accuracy.

[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,
n substrates (where n is a natural number) arranged in a stacked manner, electrodes arranged corresponding to ²ⁿ equally divided areas on these substrates and electrically conductive in the stacking direction; 2 ⁿ /2) pieces are arranged,
and a diode whose one end is connected to the electrode so as to form a periodic pattern that is different for each substrate;
A power supply connected to each of the substrates via the other end of the diode, a sliding electrode that moves along the electrode of the substrate and sequentially slides on the electrode, and a contact of the sliding electrode. means for outputting a digital signal specific to the amount of movement of the sliding electrode by weighting the electrical signal obtained between the sliding electrode and the power source differently for each substrate according to the electrode; This is a displacement detection device having a

〔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.
Note that the same parts are given the same reference numerals throughout the drawings.

One embodiment shown in FIGS. 1 and 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 embodiment, as shown by the dashed line in FIG.
The other end of the rotating shaft 101 is held in the case 100 so as to rotate in a direction perpendicular to the upper surface. 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 to the other end of the rotating shaft 101 inside the case 1 . Five substrates 6 (first substrate 1, second substrate 2, third substrate 3, third substrate 3, A fourth substrate 4 and a fifth substrate 5) are supported in parallel and spaced apart by a predetermined distance by fixing columns 106. The fixing support 106 holds the disk-shaped substrate 6 at a central angle.
The ends of the board 6 are narrowed and held in grooves carved in the fixing column 106 every 120 degrees, and both ends are fixed to the upper and lower surfaces of the case 100 with screws 107. A plurality of circular electrodes 10 are provided on each substrate 6 at regular intervals in a ring shape, and these electrodes are provided at vertical positions with respect to the electrodes 10 arranged on each substrate 6 located above and below, and are electrically connected to each other. They are respectively connected by lead wires 108 as shown in FIG. Above the substrate 6, a sliding electrode 13 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, is connected to the first substrate 1. The exposed surface of the electrode 10 is sequentially scanned while making sliding contact. As shown in FIG. 2, a predetermined electrode 10 and a power source (not shown) are connected to each substrate 6 via a resistor and a diode 15 (not shown), and the sliding electrode 13 is grounded. A negative logic signal is obtained by contacting and conducting the sliding electrode 13 and any electrode 10. The position of the sliding electrode 13, that is, the position of the sliding electrode 13, is determined by representing the negative logic signal thus obtained as a set of digital signals by specifying the electrode connected to the power supply via the resistor and diode 15 for each substrate 6. 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.

A plurality of diodes 15 whose anodes are commonly connected to a resistor R ₁ are connected to the first substrate 1 located at the top of each substrate 6 and having a sliding electrode 13 in direct contact with the electrode 10 , one for each electrode 10 . I am connected every now and then. In a second substrate located below the first substrate, a plurality of diodes 15 whose anodes are commonly connected to a resistor R ₂ are successively connected to two electrodes with two electrodes in between for each electrode 10. The first
Electrode 1 connected to diode 15 on substrate 1 of
0 and one end of the electrode to which the diode 15 is continuously connected on the second substrate 2 are electrodes located at the same position. Similarly, the third substrate located at the bottom of the second substrate 2
In the substrate 3, a plurality of diodes 15 whose anodes are connected in common to the resistor _R3 are successively connected to the four electrodes 10 with the four electrodes 10 in between.
The electrode 10 to which the diode 15 is connected on the third substrate 2 and one end of the electrode to which the diode 15 is continuously connected on the third substrate 3 are the electrodes 10 at the same position. On the fourth substrate located below the third substrate 3, a plurality of diodes 15 whose anodes are commonly connected to a resistor R ₄ are connected to the eight electrodes 10 with eight electrodes 10 in between. Electrode 1 to which diodes 15 are connected in succession on substrate 3 of 3
One end of the electrode 0 and one end of the electrode to which the diode 15 on the fourth substrate 4 is connected are in the same position.
It is 0. On the fifth substrate located at the bottom of the fourth substrate 4, a plurality of diodes 15 whose anodes are commonly connected to a resistor R ₅ are connected consecutively to the 16 electrodes 10 with the 16 electrodes 10 in between. , one end of the electrode 10 to which the diode 15 is continuously connected on the fourth substrate 4 and the diode 15 on the fifth substrate 5.
is the electrode 10 at the same position as one end of the electrodes 10 to which the electrodes 10 are continuously connected. In this way, in this example, 5
Sixteen diodes 15 are arranged on each of the substrates 1 to 5, and the connection patterns are all different for each substrate. Moreover, the connection pattern is a periodic pattern such as ``m diodes are successively connected to every m electrodes (m is 1, 2, 4, 8, 16)''. Each resistor R ₁ ,
One end of R ₂ , R ₃ , R ₄ , and R ₅ is connected to the DC power supply V, and furthermore, the connection part with the anode of the diode 15 has negative logic signal derivation points P ₁ , P ₂ , P ₃ , and P _{4 .} ,
_P5 is provided. That is, when the grounded sliding electrode 13 comes into contact with one of the electrodes 10 on the first substrate 1, it is connected by the lead wires 108 of the second to fifth substrates 2, 3, 4, and 5 laminated below. Since each of the electrodes 10 is similarly grounded, if a diode 15 is connected to each of the grounded electrodes 10, the negative logic signals derived from each of the substrates 6 will be derived from the points P ₁ , P ₂ , P ₃ , _P4 , _P5 , and if the diode 15 is not connected, a "1" signal is sent to the derivation points _P1 , _P2 , _P3 , _P4 ,
Sent to _P5 . The negative logic signals sent from the first board 1 to the fifth board 5 to the respective derivation points P ₁ , P ₂ , P ₃ , P ₄ , P ₅ have digital signal digits of 2 ⁰ and 2 ¹ respectively. , 2 ² , 2 ³ , 2 ⁴ . Note that the circuit shown in Figure 3 is a logic circuit.
It constitutes an OR.

For example, the sliding electrode 1 shown by the solid line in FIG.
3 comes into contact with the unconnected electrode 10.a of the diode 15 on the first substrate 1, the resistor _R1 is not short-circuited to the ground via the diode 15, so the derivation point _P1 receives the negative theoretical signal "1". is output.
The electrode 10.b on the second substrate 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 10.b
The resistor _R2 is short-circuited to ground by the diode 15 connected to the resistor R2, and a negative logic signal "0" is outputted to the derivation point _P2 . Similarly, the electrode 10.c located below the electrode 10.b on the third substrate 3 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 that the derivation point A negative logic signal "0" is output to _P3 . Furthermore, the diode 15 is connected to the electrode 10.d located below the fourth substrate 4 electrode 10.c, and the electrode 10.d located below the electrode 10.d on the fifth substrate 5 is connected to the diode 15.
Since the diode 15 is not connected to 0 and e, negative logic signals "0" and "1" are output to the respective derivation points P ₄ and P ₅ . Therefore, from these, the signals output from each derivation point P ₁ , P ₂ , P ₃ , P ₄ , P ₅ are “1, 0, 0, 0, 1”, and this series of digital signals is It is an absolute value indicating the contact position with the 12 electrodes 10, that is, the amount of fixation of the object to be measured.

In this way, the specific electrode on each board is connected to the DC power supply via the diode, so the electrode that is in contact with the sliding electrode and grounded outputs a digital signal unique to that electrode to each derivation point. be done. That is, the amount of rotation of the object to be measured can be detected as an absolute value from 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. Further, since the electrodes disposed on the substrate need only be contacts arranged in a ring shape at equal intervals, the sliding electrodes that come into contact with such electrodes can be constructed relatively easily.

It should be noted that the embodiments of the present invention are not limited to the above-mentioned contents, and various changes can be made without departing from the technical idea of the present invention. For example, in the above-mentioned embodiment, five substrates 6 are used to obtain a predetermined unit detection angle for the detected rotation angle, but in order to realize a finer unit detection angle, five substrates 6 are used.
More than one substrate may be used.

In addition, the boards are supported parallel to each other by fixing columns, separated by a predetermined distance, 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 kept in an electrically conductive state by directly contacting each other without using a lead wire. 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 binary 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 it. Furthermore, the digital signal indicating the rotation angle, which is output as a negative logic signal, may be inverted using a NAND circuit or the like to obtain a positive logic signal. The shape of the electrodes arranged annularly at equal intervals on the substrate is not limited to a circle, but may be any shape such as an ellipse or a rectangle.

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 linear 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.

Claims (1)

[Scope of Claims] 1. n substrates arranged in a stacked manner (n is a natural number), arranged corresponding to ²ⁿ equally divided areas on these substrates, and electrically conductive in the stacking direction. an electrode; (2 ⁿ /2) diodes arranged on each of the substrates, one end of which is connected to the electrode so as to form a periodic pattern that differs from one substrate to another; and the diodes connected to each of the substrates. a power source connected through the other end; a sliding electrode that moves along the electrode of the substrate and slides on the electrode in sequence; means for weighting the electric signal obtained from the power source differently for each substrate and outputting a digital signal specific to the amount of movement of the sliding electrode; Detection device. 2. The displacement detection device according to claim 1, wherein the periodic pattern includes 2 ^(n-1) sets of diodes arranged at equal intervals. 3. The displacement detection device according to claim 1, wherein the sliding electrode has a rotating shaft, and the electrodes are arranged in a ring shape around the rotating shaft.