JPS62135723A - Displacement detecting device - Google Patents

Abstract

PURPOSE:To detect with a high accuracy a displacement quantity of an object to be measured, by an absolute value, by coupling plural sensors which have been placed in a line, in a matrix shape, and encoding them. CONSTITUTION:Light beam, emitting from a light emitting diode 6 is led to one photodiode 7 placed in a position opposed to the other end side of a rotary member 4, by an optical fiber 8 build-in the rotary member 4. Subsequently, a detecting signal of the photodiode 7 is converted to a code signal peculiar to each photodiode 7, by a converting circuit being a code signal output means which has been accumulated on a semiconductor chip 5. That is to say, the photodiode 7 can be determined from a reflected binary code being one group of binary-coding signals outputted from each pattern of the converting circuit, therefore, a phase angle of a revolving shaft 2 for turning the rotary member 4 provided with the optical fiber 8 for leading a radiation light can also be determined simultaneously. Accordingly, a displacement quantity of an object to be measured can be derived with a high accuracy by an absolute value.

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.
A disc-shaped code plate 604 having a digital pattern consisting of a hole (indicated by a scratch in the figure) and an opening 605
(i- It is attached coaxially to a rotating shaft 600 held by a bearing 602 in a case 601 shown by a dashed line in the figure, and a light source placed on one side of a code plate 604 in a detection unit 603 irradiates the digital pattern with light. By detecting the transmitted light with an optical sensor, the absolute value of the 6000 rotation angle of the rotation axis is obtained as a coded digital signal.In such a rotary encoder device, the resolution of the detected rotation angle is improved. Therefore, in a high-resolution rotary encoder device, the diameter of the code plate 604 increases by 1, which increases the weight and bulk of the device. In addition, if the number of digits is increased by 1 by finely arranging the digital buttons in the radial direction on the code plate 604, the detection unit 60
In step 3, high machining accuracy is required for the light source and optical sensor.

[Purpose of the invention]

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

[Summary of the invention]

In order to achieve the above object, the present invention includes a number of sensors that are arranged in a row at a predetermined interval and output a detection signal according to the position of an object to be measured that moves along the row;
This sensor is connected to each intersection of a group of conducting wires arranged in rows and columns of nine columns in a matrix, and when at least one of the sensors operates, the detection signal obtained from each conducting wire constituting the group of conducting wires is transmitted to the four wires. and displacement detection signal output means for generating an individual code signal corresponding to the position of the sensor, generating a unique code signal corresponding to the arrangement position of the sensor from the generated code signal, and outputting a displacement detection signal. This is a displacement detection device characterized by:

(Effects of the Invention) According to the present invention, a plurality of sensors arranged in a row are combined in a matrix and encoded, thereby generating a code signal consisting of a large number of digits according to the arrangement position of each of the sensors. Since a detection signal is obtained, it is possible to construct a displacement detection device with a high #IIi number of digits.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail below with reference to the drawings. An embodiment of the present invention shown in FIGS. 1 to 6 is as follows:
The displacement detection device of the present invention is applied to a rotary encoder device.

As shown in FIG. 1, the configuration of this embodiment is such that a rotary bearing 3 disposed at the center of the upper surface of a flat cylindrical case 1 indicated by a dashed line in the cross section rotates a constant core 11i. The rotating shaft 2 is held so that its axis is perpendicular to the upper surface. One end of the rotating shaft 2 is held within the case 1, one end is fixed to the rotating shaft 2, and the other end is rotated around the rotating shaft 20 within the case 1! It supports a rotating member 4 that revolves around ll. A flat semiconductor chip 5 having a square plane is laid inside the lower surface of the case 1, and a light emitting diode 6 as a light source is arranged on the semiconductor chip 5 at a position where the axes of the rotating shaft 2 intersect. It is set up. Furthermore, on the semiconductor chip 5, a light emitting diode 6
A plurality of photodiodes 7, which are optical sensors, are disposed circumferentially around the center at predetermined intervals at positions facing the other end of the rotating member 4. As shown in detail in FIG.
The photodiode 7 is guided to one photodiode 7 located opposite the other end of the photodiode 7. That is, the light-emitting diode 6 is always turned on by a power source (not shown), and the light-emitting diode 6 is illuminated by an optical fiber 8 that is inserted into a rotating member 4 that is rotated within the case 1 by a rotating shaft 2 that is linked to the rotation of the object to be measured. The output light from the rotary shaft 2 is incident on one photodiode 7 according to the rotation angle of the rotary shaft 2 . The detection signal of the photodiode 7 into which the light from the light emitting diode 6 is incident is converted into a code signal unique to each photodiode 7 by a conversion circuit which is a code signal output means integrated on the semiconductor chip 5.

The above conversion circuit will be explained below.

As shown in FIG. 3, in this embodiment, a large number of photodiodes 7 are arranged at predetermined intervals on the circumference of the semiconductor chip 5, which is indicated by a dashed line 30 in the upper figure. Each set mO, ml, m2 whose area is indicated by
, ..., ml-1, ml, and each set mo, m, , m2. ..., rl'J-1, ff
A plurality of photodiodes 7 constituting J are arranged on the semiconductor chip 5 as shown in FIG.
, m2, ·, ml-1, K 7 otodiodes n per ml. + nl '+ "2 +...+"
Classified as l-1+ ni.

According to demand, each group m6. m1, m2. ..., ITJ-1
, ml, each set rno, rnl is surrounded by a dashed line in the figure, as shown in FIG.
, m! ,..., rni-,.

Each photodiode n constituting m. +nl+
n2+...+ ``I-1+ nl The side opposite to the anode side of the photodiode 7 with the same symbol is connected to the first connection line S, which is a common column conductor. That is, each set m.

m, , m, . . . Symbol n among the photodiodes 7 constituting ffJ-1ml. The side opposite to the anode side of the photodiode 7 to which symbols n1 to n1 are assigned is connected to the common first connection line S through each set, and is connected to the anode side of the photodiode 7 to which symbols n1 to n1 are assigned in the same way. The opposite side is connected to a second connection line P, which is a conductor of a common row, through each set for each symbol n to ni.

Also, each group m. , m, , m2,...

Photodiode nO+ constituting In(-1, ml
"l + "2 +" + 'j-1+ ni is each set m6, ml, ml, -, ml-1, ffJ
The anode side of each is connected to a common second connection line P.

In this embodiment, the photodiodes 7 and their matrix-like connection state are collectively referred to as a photodiode matrix 50.

As shown in FIG. 6, the photodiode matrix 50 includes each set m in which the anode sides of the photodiodes 7 are connected in common. , ml, m2, =1ml-1, m1
A load resistor R whose one end is connected to the negative pole of the DC power supply V is connected to each of the second connection lines P, and the symbol ""O+n
I + 12 +... nj-,, nj '', the positive electrodes of direct I!ftN and momme V are connected to the first tangent Me wire S, which is commonly connected to the opposite side of the anode side of the photodiode 7 with the same symbol. A load resistor R4 whose one end is connected to Schmitt trigger circuit A20
The input terminals are connected to each other. The output terminal of each non-inverting Schmitt trigger circuit A] is connected to a+3 (a is a predetermined natural number) resistors R2, one end of which is connected to the negative pole of the DC power supply V, in a different combination for each Schmitt trigger circuit A1. , a diode 6 whose anode side is connected to the resistor 2
Connected via 0. The output terminal of the inverted Schmitt trigger circuit A2 is connected to n-a-2 (n is a predetermined natural number satisfying the condition n>a) resistors R3, one end of which is connected to the positive terminal of the DC power source (■). The anode side is connected to a resistor R so that each Schmitt trigger circuit A2 has a different combination.
It is connected via a diode 60 connected to 3.

Each load resistor R2 connected to the diode 60 in this way
The load resistor R3 connects the connection end with the diode 60 to each load resistor 2. Inverter 61.6 installed every 3 units
Connected to input terminal 2.

In the conversion circuit 600 configured as described above, the process in which the detection signal of the photodiode 7 into which light from the light emitting diode 6 is incident is converted into a unique code signal and output will be described with reference to a specific example. .

The emitted light from the light emitting diode 6 is transmitted via the optical fiber 8 built into the rotating member 4 to the photodiode 7 indicated by the arrow I in FIG. When the photodiode 7 that receives the synchrotron radiation is irradiated, an open circuit is established between the first connecting line S to which the photodiode 7 that receives the synchrotron radiation is connected, the second reading line P, the load resistance ratio 0, the load resistance R1, and the DC power supply V. An open circuit can be created. At this time, the voltage at the end of the load resistor R-0 connected to the photodiode 7 increases and exceeds the threshold of the inverted Schmitt circuit A2. The output of the inverted Schmitt circuit A2 becomes a koto, and a predetermined load resistor R3 connected to the inverted Schmitt circuit A2 whose output becomes zero via the diode 60 is connected to the inverted Schmitt circuit A2.
Short-circuited to the built-in ground (not shown). Therefore, the voltage across the short-circuited load resistor R3 drops, and the inverter 61 connected to the load resistor R3 outputs a binary signal of 61'', which is a code signal. Due to the above-mentioned open circuit formed by the diode 7, the voltage at the connection end of the load resistor R・1 to the photodiode 7 drops and becomes below the threshold value of the non-inverting Schmitt circuit 1. Schmitt circuit A1
The output of is zero, and a predetermined load resistor R2 connected to the non-inverting Schmitt circuit A1 whose output is zero via the diode 60 is connected to the ground (not shown) built in this non-inverting Schmitt circuit A1. Short circuited. Therefore, the voltage of the short-circuited load resistance ratio 3 drops, and the inverter 62 connected to the load resistance outputs the sign signal 2 (directed signal ``1''. In the conversion circuit 600 shown in the figure, a set of binary signals, which are displacement detection signals, are sequentially output from a total of a+3 inverters 61 and a total of na-2 inverters 62 to 11...0001000.
0'' is obtained. In this embodiment, an alternating binary code (Gray code) is assigned to each of the photodiodes 7 arranged circumferentially, and a set of binary values obtained from each inverter 61 and 62 is obtained. Each non-inverting Schmitt circuit AI and each load resistor R2 and each inverting Schmitt circuit 2 and each load resistor A3 are connected so that the signal is the same as the alternating binary code applied to the photodiode 7KII1 receiving the emitted light. are connected to each other through the diode 60. That is, as shown in the drawing, each output terminal of the inverter 61 has an alternating voltage of 2.
Each digit of the base code is 2°, 2', ..., 2", 2"+
1°21+2 is assigned, and the inverter 62
Each output terminal has 2m'', which is each digit of the alternating binary code.
″3゜2 #+4 , 2m+1 , - , Qryl
, 2+1.5! Allocate in order. Although the output may be output in parallel as described above, it is also possible to transmit the output in series using a shift register or a scanner.

As described above, according to the rotary encoder device of this embodiment, the photodiode 7 is irradiated with radiation light from the alternating binary code, which is a set of binary signals output from each inverter 61 and 62 of the conversion circuit 600. Therefore, the position of the rotating member 4 equipped with the optical fiber 8 that guides the emitted light, in other words, the phase angle of the rotating shaft 20 that rotates the rotating member 4 in conjunction with the rotation of the object to be measured can also be determined at the same time. can. Therefore, the rotation angle of the object to be measured can be accurately obtained in absolute value from the digital rotation angle signal, which is a set of binary signals obtained from the rotary encoder device of this embodiment.

Further, in the conversion circuit 600 used in this embodiment, the photodiode matrix 50 is configured using the photodiodes 7 arranged circumferentially on the semiconductor chip 5, and each of the first connection lines S and the second connection line By providing output means for a binary signal on the continuous line P, the conversion circuit can be significantly simplified compared to the case where all photodiodes 7 are provided with output means for a binary signal. This becomes clear as the measurement accuracy of the rotation angle improves. For example, 4096 phototransistors 7 are arranged circumferentially at equal intervals on the semiconductor chip 5, and 1
In the case where a 2-digit alternating binary code is output, if means for outputting a 12-digit binary signal is arranged in each phototransistor 7, a means for outputting a 12-digit binary signal of 4096 types is provided. That is, in this embodiment, the non-inverting Schmitt circuit A2 or the inverting Schmitt circuit A2 and 1
A connection pattern of a diode 60 connected between two load resistors R2 and R3 is required. 409 for this
6 photodiodes 7 and 64 first connection lines S and 6
A photodiode matrix 50 consisting of four second connection lines P is configured, and six load resistors R2'i corresponding to the first connection line S are arranged, and the lower six digits of the 12-digit alternating binary code are The non-inverting Schmitt circuit AI and the load resistor R2 are connected using diodes 60 in 64 different connection patterns for each first connection line S so that a binary signal of is output from the inverter 61. On the other hand, six load resistors TL3 corresponding to the second connection line P side are arranged, and a 12-digit number 2 is provided.
An inverted Schmitt circuit input 2 and a load resistor R are connected so that each binarized number of the upper six numbers of the decimal code is output from the inverter 62.
3 using the diode 60 in 64 different connection patterns for each second connection line P, 128
It is sufficient to arrange a binarized signal output means that outputs a binarized signal for six cases. Generally speaking, when the number of photodiodes 7 constituting the photodiode matrix 50 is mXn (m and n are natural numbers larger than 1), the means for outputting the binarized signal is mXn.
The number can be reduced from n to m+n.

The embodiments of the present invention described above are not limited to the contents described above, and various changes may be made within the scope of the technical idea of the present invention.

For example, as a digital rotation angle signal, each inverter 61
．． A set of binary signals outputted from 62 is an alternating binary code assigned to each photodiode 7, and is composed of inverting or non-inverting Schmitt circuits AI, A2 and each load resistor R2', By changing the arrangement of the diode 60 connected between R3, it is possible to output in binary code or logarithm. Furthermore, a linear encoder device can be constructed using the configuration of this embodiment.

Note that the conversion circuit 600 such as the light emitting diode 6 and photodiode 7 provided on the semiconductor chip 5 is arranged according to a normal manufacturing process for creating an integrated circuit. Further, the condition of each photodiode 7 constituting the photodiode matrix 50 can be inspected using the apparatus shown in FIG. (The photodiode is omitted in the drawing.)
This means that the angle signal output from each inverter 61.62
This configuration utilizes the case where all the angle signals are "0" as a set of binary signals, which are indicated by alternating binary codes, and the photodiode 7 is in a conductive state when all the angle signals are "0". Inverters 703 and 704 that respectively invert the signals of the respective Schmitt circuits connected to the first connecting line S.1 and the second connecting line P. It consists of OR circuits 704 and 705 into which the signals of each Schmitt circuit connected to the line P are input for each first connection line S and second connection line P, and
An AND circuit 706 that takes the logical product of the output of the OR circuit 704 and the output of the inverter 703, and an AND circuit 707 that takes the logical product of the output of the OR circuit 705 and the output of the inverter 704.
It further includes an AND circuit 708 which takes the AND of the outputs of the two AND circuits 706 and 707. In such a configuration, when the angle signals indicated by the alternating binary codes are all 0'', the inverter 704 connected to the first connection line S.1 via the non-inverting Schmitt circuit A]
An output signal of "1" is obtained from the inverter 703 connected to the second connection line P via the inverted Schmitt circuit 2. In this case, an output signal of '0' is obtained from the OR circuit 705 which takes the logical sum of the signals input via the non-inverting Schmitt circuit A1 of each of the other first connection lines S, and A signal of 0'' is obtained from the OR circuit 704 which performs the logical sum of the signals input via the inverted Schmitt circuit A2 of each second connection line P. Therefore, the output signals of AND circuits 706 and 707 are
0'°, and as a result, a 0'' signal is obtained from the AND circuit 708. However, if a defective photodiode 7 is mixed into the photodiode 7 constituting the photodiode matrix 50 and remains in a conductive state without incident light, OR circuit 704
．． 705 outputs a 1'' signal, and the subcircuit 708 outputs a 1'' signal. All normal angle signals are IO
Since the photodiode 7 to be set to `` may be a dummy or be in a non-conducting state, the photodiode matrix 5 (
All of the photodiodes 7 can be inspected at once based on the state of the output signal from the AND circuit 708. In addition, it is desirable that the number of photodiodes 7 forming the photodiode matrix 50 be approximately the same for each classified group, but even if there is a group whose number is not adjusted, the connection state of the diodes 60 should be reconsidered. By doing so, it is possible to enjoy the effects of applying the photodiode matrix 50.

[Brief explanation of drawings]

FIG. 1 is a transparent perspective view showing the configuration of a rotary encoder device according to an embodiment to which the displacement detection device of the present invention is applied, and FIG.
The figure is a sectional view showing the structure of the same embodiment, FIGS. 3 and 4 are front views for explaining the main parts of the same embodiment, and FIG. 5 is a circuit diagram showing the photodiode matrix in the same embodiment. Fig. 6 is a circuit diagram showing the conversion circuit of the same embodiment, Fig. 7 is a circuit diagram of a device for inspecting the state of the photodiode matrix of the same embodiment, and Fig. 8 shows the configuration of a conventional rotary encoder. FIG. 1... Case 2... Rotating shaft table 4 Rotating member 5 - Semiconductor tip 6... Light emitting diode 7... Photo diode 8... Optical fiber agent Patent attorney Nori Chikaon Yudo Kikuo Takehana 6 shots 7 degrees Iode 1 Figure 2D Figure 5 Seven Ru Figure 7

Claims (1)

[Claims] A plurality of sensors are arranged in rows at predetermined intervals and output detection signals according to the position of the object moving along the rows, and these sensors are arranged in rows and columns in a matrix. connected to the intersection, and generating an individual code signal corresponding to the conductor using the detection signal obtained from each of the conductors constituting the conductor group when at least one of the sensors operates, and the generated code signal A displacement detection device comprising displacement detection signal output means for generating a unique code signal corresponding to the arrangement position of the sensor and outputting a displacement detection signal.