JPH09105646A - Rotary encoder and rotary encoder system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect an abnormality easily and surely by generating and outputting an error detection code by a parity check code, checking output data and outputting a signal on whether the abnormality exists or not. SOLUTION: A rotary encoder 1A sends encoder data to a system control part 7A by a data output part 12, and it sends a parity check code to the control part 7A through a signal line 14 by a parity coding part 13. The control part 7A processes input encoder data so as to be a signal required for a control operation in a data processing part 8. A parity decoding part 15 checks the existence of the abnormality of the encoder data by a parity check code system on the basis of the encoder data and on the basis of a parity check code. Then, the direction of the control operation is judged by a control part 10 on the basis of the input signal required for the control operation and on the basis of a signal on whether the abnormality exists or not. In this manner, since the coding part 13 is constituted inside the encoder 1A, a detection is processed simply, and the abnormality can be detected surely.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary encoder and a rotary encoder system having a built-in error detection function and detecting and utilizing a rotation angle of a rotary shaft.

[0002]

2. Description of the Related Art Rotary encoders are roughly classified into an incremental type and an absolute type.

The above-mentioned incremental type rotary encoder detects the rotation angle or the rotation speed of the rotary shaft by the number of output pulses. Therefore, a counter for cumulatively adding the number of output pulses is required to detect the rotation angle and the rotation speed. On the other hand, there is also an advantage that the pulse generation frequency can be doubled or quadrupled by utilizing the rising and falling points of the pulse waveform to electrically improve the resolution.

Since the absolute rotary encoder detects the rotation angle of the rotary shaft from the pattern of the rotary slit, it is possible to always know the absolute position even when the rotary slit is stationary. Therefore, the rotational position can always be confirmed without the counter. Further, since the origin of the input rotary shaft is determined at the time of being incorporated into the machine, the rotation angle from the origin can be accurately represented even at the time of starting, after a power failure, and at power-on after an emergency stop.

The absolute type rotary encoder outputs a binary code (pure binary code), a gray code, a BCD code or the like as an output code.

The above binary code is the most basic code in digital processing, and is a code that advances with "0" and "1". However, when changing from one number to the next, two or more states (0 or 1) of each digit may change at the same time, but it is difficult to change each state at the same time. It may cause a reading error.

When the Gray code changes from one number to the next, only one state (0 or 1) change in all digits occurs, so that there is almost no reading error like the binary code.

In the BCD code, each decimal digit is 2
It is expressed in a decimal system. Numerical values up to “10” are expressed in a binary system, and the carry system uses a decimal system.

Further, the absolute type rotary encoder is classified into a one-track type and a multi-track type from the viewpoint of the number of tracks on which an absolute pattern is formed.

In the above-mentioned one-track type, one track of an absolute pattern is formed on a code plate, and a plurality of sensors are arranged in one line along the pattern in the detection section.
The sensor reads from the pattern "a binary address that is different but in random order". In this one-track type, only one absolute pattern is required, the sensors are arranged in one row at equal intervals, and there is no need to adjust the phase of the sensor arrangement between the tracks as in the multi-track type described later.

On the other hand, in the above-mentioned multi-track type, an absolute pattern consisting of a large number of parallel tracks is formed on a code plate, and a sensor is arranged in the detecting portion so as to correspond to each track. Read "regular address" of binary code or gray code.

FIG. 10 shows a conventional rotary encoder
This will be described with reference to FIG. FIG. 10 is a perspective view showing the structure of a conventional multi-track absolute rotary encoder. FIG. 11 is a block diagram showing the configuration of a conventional rotary encoder system using a multi-track type absolute rotary encoder.

In FIG. 10, 1 is a multi-track type absolute rotary encoder, 2 is a rotary shaft connected to various devices, 3 is a rotary plate which is connected to the rotary shaft 2 and has an absolute pattern formed thereon, and 4 is a rotary plate. Eight light emitting elements such as light emitting diodes provided on one side of the plate 3,
Reference numeral 5 is a light-receiving element such as a photodiode provided on the other side of the rotary plate 3 and 6 is a slit provided between the rotary plate 3 and the light-emitting element 4 and having 8 holes formed therein.

In FIG. 11, reference numeral 1 is a multi-track type absolute rotary encoder shown in FIG. 10, 7 is a system control unit of the above-mentioned various devices, 8 is a data processing unit, and 9 is a data processing unit.
Is an abnormality calculation unit, 10 is a control unit such as a CPU, and 11 is a signal line connecting the multi-track type absolute rotary encoder 1 and the system control unit 7.

Next, the operation of the conventional multi-track type absolute type rotary encoder will be described. The multi-track type absolute rotary encoder 1 dealt with here is for detecting the current positions of various devices. It is used to detect the rotation angle of the device by connecting the position or angle of the device to the device through a gear and directly connecting the position or angle of the device to the rotation axis of the device.

That is, the light emitted from the light emitting element 4 is transmitted and shielded by the slit 6 and the rotary plate 3 to cause the light receiving element 5 to perform an ON / OFF operation. At this time, the rotary shaft 2
The ON / OFF state is determined by the rotation angle of, and the rotation angle is detected by this. Therefore, even if the rotary shaft 2 is stopped, the absolute position can always be detected on the spot.

When particularly high reliability is required in the system using the rotary encoder 1 as described above, when the output from the rotary encoder 1 to the system control unit 7 becomes abnormal, for example, the rotary encoder 1 and the system control unit are used. It is necessary to add an abnormality detection function in preparation for a case where the signal line 11 connecting 7 is broken, the signal line is short-circuited, and the signal line is noisy.

In FIG. 11, the output from the rotary encoder 1 is processed into a signal required for control by the data processing unit 8 and the presence / absence of abnormality is checked by the abnormality calculating unit 9. When there is no abnormality, the control unit 10 performs control based on the signal from the data processing unit 8.

On the other hand, if there is an abnormality, the abnormality calculating unit 9
The control unit 10 performs control based on the abnormal signal from the.

In the process of the abnormality calculating section 9 in this case, the order of the output codes mainly due to the rotation of the rotary plate 3 is checked,
For example, when the code “1” is followed by the code “2”, it is normal, and when the code “1” is followed by the code “5”, it is abnormal. Was. However, it was complicated by the speed of rotation.

[0021]

In the conventional rotary encoder as described above, since it does not have an error detecting function inside, it is necessary to provide it in the system control section side and the load on the system control section side is large. There was a problem.

Further, there is a problem that complicated processing is required for error detection.

The present invention has been made in order to solve the above-mentioned problems, and makes it possible to detect errors relatively easily on the system controller side, and at the same time, a rotary encoder and a rotary encoder system capable of surely detecting errors. Aim to get.

It is another object of the present invention to obtain a rotary encoder and a rotary encoder system which do not require error detection on the system control side.

[0025]

A rotary encoder according to the present invention includes a rotary plate having a multi-track type absolute pattern, a detector for reading the absolute pattern, and an error for detecting an abnormality in the output of the detector. And a detection circuit.

Further, in the rotary encoder according to the present invention, the detecting portion is provided on one side of the rotary plate, and a plurality of light emitting elements are arranged in a row in a radial direction of the rotary plate, and the rotary plate. A plurality of light receiving elements provided on the other side of the rotary plate in a row in the radial direction of the rotary plate so as to correspond to the light emitting elements, and the rotary plate provided between the rotary plate and the light emitting element. The error detection circuit includes a slit having a plurality of holes arranged in a row in a radial direction, the error detection circuit detects an error based on output data of the data output unit for amplifying an output of the detection unit, and output data of the data output unit. And a coding unit that generates a code.

Further, in the rotary encoder according to the present invention, the detecting portion is provided on one side of the rotary plate, and a plurality of light emitting elements are arranged in a row in a radial direction of the rotary plate, and the rotary plate. A plurality of light receiving elements provided on the other side of the rotary plate in a row in the radial direction of the rotary plate so as to correspond to the light emitting elements, and the rotary plate provided between the rotary plate and the light emitting element. The error detection circuit includes a slit having a plurality of holes arranged in a row in a radial direction, the error detection circuit detects an error based on output data of the data output unit for amplifying an output of the detection unit, and output data of the data output unit. An encoding unit that generates a code and a decoding unit that detects an error in the output data based on the error detection code and outputs an abnormality presence / absence signal are included.

In the rotary encoder according to the present invention, the error detecting code is a parity check code.

Further, in the rotary encoder according to the present invention, the error detecting code is a cyclic code.

In the rotary encoder according to the present invention, the error detection code is a BCH code.

Further, in the rotary encoder according to the present invention, the error detection code is a Hamming code.

Further, a rotary encoder system according to the present invention comprises: the rotary encoder according to claim 2;
A second for detecting an abnormality in encoder data based on the error detection code sent from the rotary encoder
And a system control unit having an error detection circuit.

Further, in the rotary encoder system according to the present invention, the second error detection circuit processes the encoder data sent from the rotary encoder into a signal necessary for control, and the rotary encoder. Decoding unit that detects an error in the encoder data based on an error detection code sent from another system and outputs an abnormality presence / absence signal, and a direction of control from the signal necessary for the control and the abnormality presence / absence signal. And a control unit for judging.

Further, a rotary encoder system according to the present invention comprises: the rotary encoder according to claim 3;
A data processing unit that processes the encoder data sent from the rotary encoder into a signal necessary for control, and determines the direction of control from the signal necessary for control and the abnormality presence / absence signal sent from the rotary encoder. And a system control unit having a control unit for

Further, in the rotary encoder system according to the present invention, the error detecting code is a parity check code.

Further, in the rotary encoder system according to the present invention, the error detecting code is a cyclic code.

Further, in the rotary encoder system according to the present invention, the error detection code is a BCH code.

Furthermore, in the rotary encoder system according to the present invention, the error detection code is a Hamming code.

[0039]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 and 2. 1 is a block diagram showing a configuration of a rotary encoder system according to a first embodiment of the present invention. Further, FIG. 2 is a diagram for explaining the operation of the first embodiment. In the drawings, the same reference numerals indicate the same or corresponding parts.

In FIG. 1, 1A is a multi-track type absolute rotary encoder, 12 is a data output unit which is connected to the light receiving element 5 and amplifies its output, and 13 is a parity check code (parity ch) as an error detection code.
is a parity encoding unit that generates an eck code).

In addition to the above, the rotary encoder 1A includes, as shown in FIG. 10, a rotary shaft 2 connected to various devices, and a rotary plate 3 coupled to the rotary shaft 2 and having an absolute pattern formed thereon. , Eight light emitting elements 4 such as light emitting diodes provided on one side of the rotary plate 3, eight light receiving elements 5 such as photodiodes provided on the other side of the rotary plate 3, the rotary plate 3 and the light emission Provided between the elements 4 8
And a slit 6 in which individual holes are formed.

Further, in FIG. 1, 7A is a system control unit of the above-mentioned various devices, 8 is a data processing unit, and 10 is a CPU.
A control unit 15 and the like is a parity decoding unit that detects an error in the data similarly sent based on the parity check code which is the error detection signal sent from the rotary encoder 1A.

Further, in the figure, 11 is a signal line for connecting the rotary encoder 1A and the system control unit 7A to transmit data, and 14 is a signal line for connecting the rotary encoder 1A and the system control unit 7A to transmit an error detection code. It is a signal line.

Next, the operation of the rotary encoder system according to the first embodiment will be described. First, the parity check code will be briefly described. A redundant bit (parity bit) is configured such that a code in which 1 redundant bit is added to n-1 given information bits is added and the total number of "1" s in n bits is an even number or an odd number. Is to give. That is, extra bits that are not information bits are added so that the number of "1" s in a certain bit group that represents binary code information is always an even number or an odd number. An error in the information bit can be detected by checking whether or not the bits of are always even or odd.

In the rotary encoder 1A, the data output unit 12 sends the encoder data to the system control unit 7A via the signal line 11, and the parity encoding unit sends the parity check code to the system control unit via the signal line 14 which is a separate system. Send to 7A.

On the system control unit 7A side, the data processing unit 8 processes the input encoder data into a signal required for control. Further, the parity decoding unit 15 checks the input encoder data and the parity check code for abnormalities in the encoder data. And the control unit 1
At 0, the direction of control is determined from the input signal necessary for control and the abnormality presence / absence signal.

The specific example shown in FIG. 2 will be described below.
The data output unit 12 of the rotary encoder 1A is the 8-bit encoder data shown in FIG.
As “00001010” and as data 2 as “000
“01011” and “01101110” as the data 3 are output.

The parity encoder 13 of the rotary encoder 1A uses the 1-bit parity of "0" or "1" in FIG. 9A so that the total "1" of the encoder data is always an even number. The check code, "0" for the data 1, "1" for the data 2, and "1" for the data 3 are calculated and output.

On the other hand, the parity decoding unit 15 of the system control unit 7A uses the 8-bit encoder data shown in FIG. 3B, for example, "00001010" as data 1, "00001011" as data 2, and "0" as data 3.
1111110 ”is input. Further, the parity check code, "0" for the data 1, "1" for the data 2, and "1" for the data 3 are input.

The parity decoding unit 15 uses the data 1 and 2
With regard to, since the sum of the encoder data and the parity check code “1” is an even number, it is determined that the encoder data is normal. For data 3, since the sum of the encoder data “01111110” and the parity check code “1” “1” is an odd number, it is determined that the encoder data is abnormal.

The above-mentioned parity check code system, which is one of the error detection codes, is a generally recognized technique, and therefore will not be described in further detail here, but encoding and decoding can be realized by one general-purpose IC. .

As described above, according to the first embodiment, since the parity encoding unit 13 for error detection is constructed in the rotary encoder 1A, the abnormality detection processing in the system control unit 7A is simplified, Further, it is possible to reliably detect an abnormality.

Embodiment 2 Embodiment 2 of the present invention will be described with reference to FIG. FIG. 3 is a block diagram showing the configuration of the rotary encoder system according to the second embodiment of the present invention.

In the second embodiment, as shown in FIG.
The cyclic encoding unit 16 and the cyclic decoding unit 17 are provided in place of the parity encoding unit 13 and the parity decoding unit 15 of the above-described Embodiment 1, and the other operations and actions of the above-described Embodiment 1 are performed. It is similar to the effect.

In the second embodiment, an error is detected by the cyclic encoding unit 16 and the cyclic decoding unit 17, and this error detection coding method is called cyclic redundancy check (CRC). This is to create a code on the cyclic encoding unit 16 side so as to be divisible by the generator polynomial G (x), and to check on the cyclic decoding unit 17 side whether G (x) is divisible when the code is received. The rotary encoder 1B on the transmitting side divides the polynomial P (x) of (n−k) -bit information by the generator polynomial G (x) of order k.
The resulting polynomial R (x) of k bits is added as a check bit to the information bits to form an n-bit code F (x) = x ^k P (x) + R (x), which is then transmitted.
In the system control unit 7B on the receiving side, an error E (x) in the transmission line is added, so that the received code H (x) = F (x).
Divide + E (x) by G (x). If there is not much, there is no error.

Embodiment 3 Third Embodiment A third embodiment of the present invention will be described with reference to FIG. FIG. 4 is a block diagram showing the configuration of the rotary encoder system according to the third embodiment of the present invention.

In the third embodiment, as shown in FIG.
Instead of the parity encoding unit 13 and the parity decoding unit 15 of the first embodiment, a BCH encoding unit 18 and a BC
The H decoding unit 19 is provided, and the other points are the same as the operations and effects of the first embodiment.

Here, the BCH code (Bose Chau)
dhuri Hocquenghem code) is an error detection code that utilizes error detection by providing mt check bits for a code length of 2 ^m −1 bits or less, where m is a positive integer. Since this is a system and is a generally recognized technique, its detailed description is omitted.

Embodiment 4 FIG. A fourth embodiment of the present invention will be described with reference to FIG. FIG. 5 is a block diagram showing the configuration of the rotary encoder system according to the fourth embodiment of the present invention.

In the fourth embodiment, as shown in FIG.
A Hamming coding unit 20 and a Hamming decoding unit 21 are provided in place of the parity coding unit 13 and the parity decoding unit 15 of the first embodiment, and other operations and actions of the first embodiment are performed. It is similar to the effect.

This Hamming code (Hamming co
de) is one of the error detection codes, where the code length is n bits, and the check bits are m bits, and n ≦ 2.
It is a code configured to satisfy ^m −1. This code has an advantage that the number of check bits is relatively small as the code length n becomes longer. Since this is a generally recognized technique, detailed description thereof will be omitted.

Embodiment 5 The fifth embodiment of the present invention will be described with reference to FIG. 6 is a block diagram showing the configuration of a rotary encoder system according to Embodiment 5 of the present invention.

In the fifth embodiment, as shown in FIG.
The parity decoding unit 15 of the first embodiment is arranged in the rotary encoder 1E, and the signal indicating the presence / absence of abnormality is directly output to the system control unit 7E. as a result,
The system control unit 7E does not need to provide a circuit for determining whether there is an abnormality. An abnormality due to noise or the like on the rotary encoder 1E side can be detected. Others are the same as the operations and effects of the first embodiment.

Embodiment 6 FIG. A sixth embodiment of the present invention will be described with reference to FIG. FIG. 7 is a block diagram showing the configuration of a rotary encoder system according to the sixth embodiment of the present invention.

In the sixth embodiment, as shown in FIG.
The cyclic decoding unit 17 of the above-described second embodiment is arranged in the rotary encoder 1F, and a signal indicating the presence or absence of abnormality is directly output to the system control unit 7F. As a result, the system control section 7F does not need to be provided with a circuit for determining whether there is an abnormality. An abnormality due to noise or the like on the rotary encoder 1F side can be detected. Others are the same as the operations and effects of the second embodiment.

Embodiment 7 A seventh embodiment of the present invention will be described with reference to FIG. FIG. 8 is a block diagram showing the configuration of a rotary encoder system according to the seventh embodiment of the present invention.

In the seventh embodiment, as shown in FIG.
The BCH decoding unit 19 of the above-mentioned third embodiment is arranged in the rotary encoder 1G, and the signal indicating the presence / absence of abnormality is directly output to the system control unit 7G. As a result, the system control section 7G does not need to provide a circuit for determining whether there is an abnormality. An abnormality due to noise or the like on the rotary encoder 1G side can be detected. Others are the same as the operations and effects of the third embodiment.

Embodiment 8. The eighth embodiment of the present invention will be described with reference to FIG. 9 is a block diagram showing the configuration of a rotary encoder system according to Embodiment 8 of the present invention.

In the eighth embodiment, as shown in FIG.
The Hamming decoding unit 21 of the above-mentioned fourth embodiment is arranged in the rotary encoder 1H, and outputs a signal indicating the presence or absence of abnormality directly to the system control unit 7H. as a result,
The system control unit 7H does not need to provide a circuit for determining whether there is an abnormality. An abnormality due to noise or the like on the rotary encoder 1H side can be detected. Others are the same as the operations and effects of the fourth embodiment.

[0070]

The rotary encoder according to the present invention is
A rotating plate having a multi-track type absolute pattern, and a detection unit for reading the absolute pattern,
Since the error detection circuit for detecting an abnormality in the output of the detection unit is provided, there is an effect that abnormality detection processing in an external system can be simplified and reliable abnormality detection can be performed.

Further, in the rotary encoder according to the present invention, the detecting portion is provided on one side of the rotary plate, and a plurality of light emitting elements are arranged in a line in a radial direction of the rotary plate, and the rotary plate. A plurality of light receiving elements provided on the other side of the rotary plate in a row in the radial direction of the rotary plate so as to correspond to the light emitting elements, and the rotary plate provided between the rotary plate and the light emitting element. The error detection circuit includes a slit having a plurality of holes arranged in a row in a radial direction, the error detection circuit detects an error based on output data of the data output unit for amplifying an output of the detection unit, and output data of the data output unit. Since the encoding unit that generates the code is included, the abnormality detection process in the external system is simplified, and it is possible to perform reliable abnormality detection.

Further, in the rotary encoder according to the present invention, the detecting portion is provided on one side of the rotary plate, and the rotary plate has a plurality of light emitting elements arranged in a line in a radial direction of the rotary plate. A plurality of light receiving elements provided on the other side of the rotary plate in a row in the radial direction of the rotary plate so as to correspond to the light emitting elements, and the rotary plate provided between the rotary plate and the light emitting element. The error detection circuit includes a slit having a plurality of holes arranged in a row in a radial direction, the error detection circuit detects an error based on output data of the data output unit for amplifying an output of the detection unit, and output data of the data output unit. Since it includes an encoding unit that generates a code and a decoding unit that detects an error in the output data based on the error detection code and outputs an abnormality presence / absence signal, it is said that an abnormality detection process in an external system is unnecessary. Play the effect That.

Further, in the rotary encoder according to the present invention, since the error detection code is the parity check code, the abnormality detection process in the external system is simplified and the reliable abnormality detection can be performed. Play.

Further, in the rotary encoder according to the present invention, the error detecting code is a cyclic code, so that the abnormality detecting process in the external system is simplified, and reliable abnormality can be detected. Play.

Further, in the rotary encoder according to the present invention, since the error detection code is the BCH code, the abnormality detection process in the external system can be simplified, and reliable abnormality detection can be performed. Play.

Further, in the rotary encoder according to the present invention, since the error detecting code is the Hamming code, the abnormality detecting process in the external system is simplified and the reliable abnormality detecting can be performed. Play.

Further, the rotary encoder system according to the present invention comprises: the rotary encoder according to claim 2;
A second for detecting an abnormality in encoder data based on the error detection code sent from the rotary encoder
Since the system control unit having the error detection circuit is provided, the abnormality detection process in the external system is simplified, and reliable abnormality detection can be performed.

Further, in the rotary encoder system according to the present invention, the second error detection circuit processes the encoder data sent from the rotary encoder into a signal necessary for control, and the rotary encoder. Decoding unit that detects an error in the encoder data based on an error detection code sent from another system and outputs an abnormality presence / absence signal, and a direction of control from the signal necessary for the control and the abnormality presence / absence signal. Since it includes a control unit that makes a judgment, the abnormality detection process in the external system is simplified,
Further, there is an effect that it is possible to perform reliable abnormality detection.

Further, the rotary encoder system according to the present invention comprises: the rotary encoder according to claim 3;
A data processing unit that processes the encoder data sent from the rotary encoder into a signal necessary for control, and determines the direction of control from the signal necessary for control and the abnormality presence / absence signal sent from the rotary encoder. Since the system control unit having the control unit for controlling the external system is provided, the effect that the abnormality detection process in the external system is unnecessary is achieved.

Further, in the rotary encoder system according to the present invention, since the error detecting code is the parity check code, the abnormality detecting process in the external system can be simplified and the reliable abnormality can be detected. Alternatively, there is an effect that the abnormality detection process in the external system becomes unnecessary.

Further, in the rotary encoder system according to the present invention, since the error detection code is a cyclic code, the abnormality detection process in the external system can be simplified and the reliable abnormality detection can be performed. This has the effect of eliminating the need for abnormality detection processing in an external system.

Further, in the rotary encoder system according to the present invention, since the error detection code is the BCH code, the abnormality detection process in the external system can be simplified and the reliable abnormality detection can be performed. This has the effect of eliminating the need for abnormality detection processing in an external system.

Further, in the rotary encoder system according to the present invention, since the error detecting code is the Hamming code, the abnormality detecting process in the external system is simplified,
In addition, it is possible to perform reliable abnormality detection, or to eliminate the need for abnormality detection processing in an external system.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a functional configuration of a rotary encoder system according to a first embodiment of the present invention.

FIG. 2 is a diagram for explaining the operation of the rotary encoder system according to the first embodiment of the present invention.

FIG. 3 is a block diagram showing a functional configuration of a rotary encoder system according to a second embodiment of the present invention.

FIG. 4 is a block diagram showing a functional configuration of a rotary encoder system according to a third embodiment of the present invention.

FIG. 5 is a block diagram showing a functional configuration of a rotary encoder system according to a fourth embodiment of the present invention.

FIG. 6 is a block diagram showing a functional configuration of a rotary encoder system according to a fifth embodiment of the present invention.

FIG. 7 is a block diagram showing a functional configuration of a rotary encoder system according to a sixth embodiment of the present invention.

FIG. 8 is a block diagram showing a functional configuration of a rotary encoder system according to a seventh embodiment of the present invention.

FIG. 9 is a block diagram showing a functional configuration of a rotary encoder system according to an eighth embodiment of the present invention.

FIG. 10 is a perspective view showing the structure of a conventional rotary encoder.

FIG. 11 is a block diagram showing a functional configuration of a conventional rotary encoder system.

[Explanation of symbols]

1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H rotary encoder, 2 rotary shaft, 3 rotary plate, 4 light emitting element, 5 light receiving element, 6 slits, 7A, 7B, 7C,
7D, 7E, 7F, 7G, 7H system control unit, 8
Data processing unit, 10 control unit, 11 signal line, 12 data output unit, 13 parity encoding unit, 14 signal line,
15 parity decoding unit, 16 cyclic encoding unit, 17
Cyclic decoding unit, 18 BCH coding unit, 19 BCH decoding unit, 20 Hamming coding unit, 21 Hamming decoding unit.

Claims (14)

[Claims] 1. A rotary plate comprising a rotating plate having a multi-track type absolute pattern, a detection unit for reading the absolute pattern, and an error detection circuit for detecting an abnormality in the output of the detection unit. Encoder. 2. The detector is provided on one side of the rotary plate and is arranged in a row in a radial direction of the rotary plate, and a plurality of light emitting elements is provided on the other side of the rotary plate. A plurality of light receiving elements arranged in a row in the radial direction of the rotary plate so as to correspond to the light emitting elements; and a plurality of light receiving elements provided between the rotary plate and the light emitting element and arranged in a row in the radial direction of the rotary plate. The error detection circuit includes a slit having a plurality of holes, a data output unit for amplifying an output of the detection unit, and an encoding unit for generating an error detection code based on output data of the data output unit. The rotary encoder according to claim 1, further comprising: 3. The detector is provided on one side of the rotary plate and is arranged in a row in a radial direction of the rotary plate, and a plurality of light emitting elements is provided on the other side of the rotary plate. A plurality of light receiving elements arranged in a row in the radial direction of the rotary plate so as to correspond to the light emitting elements; and a plurality of light receiving elements provided between the rotary plate and the light emitting element and arranged in a row in the radial direction of the rotary plate. The error detection circuit includes a slit having a plurality of holes, and a data output section for amplifying an output of the detection section, and an encoding section for generating an error detection code based on output data of the data output section. 2. The rotary encoder according to claim 1, further comprising: a decoding unit that detects an error in the output data based on the error detection code and outputs an abnormality presence / absence signal. 4. The rotary encoder according to claim 2, wherein the error detection code is a parity check code. 5. The rotary encoder according to claim 2, wherein the error detection code is a cyclic code. 6. The rotary encoder according to claim 2, wherein the error detection code is a BCH code. 7. The rotary encoder according to claim 2, wherein the error detection code is a Hamming code. 8. A rotary encoder according to claim 2, and a second encoder for detecting an abnormality in encoder data based on an error detection code sent from the rotary encoder.
And a system control unit having an error detection circuit. 9. The second error detection circuit includes a data processing unit that processes encoder data sent from the rotary encoder into a signal required for control, and an error sent from the rotary encoder in a different system. A decoding unit that detects an error in the encoder data based on a detection code and outputs an abnormality presence / absence signal; and a control unit that determines the direction of control from the signal necessary for the control and the abnormality presence / absence signal. The rotary encoder system according to claim 8, which is characterized in that: 10. The rotary encoder according to claim 3, a data processing unit that processes the encoder data sent from the rotary encoder into a signal necessary for control, a signal necessary for the control, and a signal sent from the rotary encoder. A rotary encoder system, comprising: a system control unit having a control unit that determines the direction of control based on the received abnormality signal. 11. The rotary encoder system according to claim 9, wherein the error detection code is a parity check code. 12. The rotary encoder system according to claim 9, wherein the error detection code is a cyclic code. 13. The rotary encoder system according to claim 9, wherein the error detection code is a BCH code. 14. The rotary encoder system according to claim 9, wherein the error detection code is a Hamming code.