JPH05272986A - encoder - Google Patents

Abstract

(57) [Summary] [Purpose] To provide an encoder with high resolution that is inexpensive and can be manufactured in a short time. [Structure] In a rotary encoder, several Z-effect electromagnetic conversion elements 6 are mounted on a stationary support member 5.
And the magnetic layer 2 magnetized with a pattern on the surface of the rotating disk 1 is arranged, and the magnetoelectric conversion element 6 and the magnetic film on the disk are arranged in close proximity to each other, and the magnetic pattern of the magnetic layer 2 is arranged. The rotation angle of the disk is recognized by detecting with the magnetoelectric conversion element 6. Further, the magnetic force of the magnetic layer 2 is divided into three or more steps, and the magnetic layer 2 and the electromagnetic conversion element 6 are arranged on both front and back sides of the rotary disk 1. [Effect] Since semi-finished products that have been assembled can be kept in stock and magnetized into a disk according to the order and shipped, it can be done in a short delivery time and the disk can be processed in a large lot, so it is cheaper, high resolution and compact. It has the effect of being able to.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of an absolute encoder for detecting the position of a moving object.

[0002]

2. Description of the Related Art Encoders include linear encoders for linear motion and rotary encoders for rotary motion. Since the recognition principle is the same in both cases, the rotary type will be mentioned.

A conventional rotary encoder is shown in FIG.
The optical structure as shown in FIG. The rotating body is made by attaching a patterned light shielding film 32 on a disk 31 made of glass. Stationary support member 35 and base 38
In addition, the light source 36 and the light detection member 37 are opposed to each other so as not to contact both sides of the glass disk.

Light is blocked or transmitted by the glass disk 31. The photodetector changes the electrical signal to determine whether light is coming. The light-shielding film shape of the glass disc in the photodetector can be recognized from the output signal of the photodetector.

The absolute type is designed so that the pattern attached to the disk can be identified by its binary number as shown in FIG. In the example of FIG. 11, the outermost circumference represents the first digit and the next inner circumference represents the second digit. As shown in the block diagram of FIG. 12, when the output of the light detection unit 41 to which the light has reached is converted from a binary number to a decimal number by the binary-decimal conversion circuit 42 and the angle is converted by the angle conversion circuit 43, the rotation disk Can recognize the angular position. The value is displayed on the display 44
And is output to the external device 45 for use.

The pattern of the light-shielding film on the glass disk is processed by a printing or photolithography process. Changing the transmittance of the light-shielding film for each specific location requires a processing man-hour, and therefore has not been implemented because it is expensive. Therefore, the disk can only transmit light and can shield light, and the pattern of the light-shielding film has to be displayed in binary.

A magnetic type was also conceivable, but when the distance between the detecting member and the magnetic film was maintained to some extent, the spatial resolution of the detecting member was low, so that the cylindrical type had a low resolution and a large volume. ..

[0008]

In the prior art of the above-mentioned encoder, in the optical system, it was necessary to perform processing according to the number of divisions of the disk from the stage of processing the parts. Since the rotary disk operates as an optical switch and can only count binary numbers, it was necessary to convert binary numbers to decimal numbers.

An object of the present invention is, in an encoder,
It is an object of the present invention to provide a high-resolution and compact device capable of setting the resolution of a rotating disk during assembly and outputting N-ary numbers.

[0010]

SUMMARY OF THE INVENTION An encoder of the present invention is an encoder which recognizes the position of a moving object by detecting a pattern attached to a scale connected to a moving object with a detecting member. Arranging several magneto-electric conversion elements (phosphor / aluminum / gold-doped silicon, magneto-electric conversion pulse sensor having directivity by converting strength of magnetic field to frequency) on the supporting member, which has Z effect, A magnetic layer magnetized with a certain pattern is arranged on the surface of the moving scale, the magnetic conversion element and the magnetic layer on the scale are arranged in close proximity, and the magnetization pattern of the magnetic layer is detected by the magnetic conversion element. , Is characterized by recognizing the position of an object.

Further, the magnetic layer is characterized in that the magnetization of the magnetic layer is divided into three or more steps. Further, the magnetic layer and the magnetoelectric conversion element are arranged on both front and back sides of the rotating disk.

[0012]

【Example】

(Embodiment 1) FIG. 1 is a main configuration diagram in Embodiment 1 of the present invention. The rotating disk 1 is arranged in the central portion, and the rotating disk 1 is provided by the base 7 and the supporting member 5 via the pair of bearings 3 and 4.
Support. On the supporting member 5, the magnetoelectric conversion element array 6 by the Z effect is arranged in the diameter direction. A magnetizing window 9 is opened in the support member 5 so that the magnetic layer on the disk can be magnetized after assembly.

The magnetoelectric conversion element based on the Z effect has a thickness of 0.
25 ~ phosphorus, aluminum, and gold on a 3mm silicon plate
It was doped to a depth of 40 microns. 5 to electrode
When a voltage of about 15 V is applied, the element oscillates with an amplitude of about 1/3 of the applied voltage, and the oscillation frequency changes according to the magnetic strength. Further, there is a feature that the directivity of magnetic sensitivity is high.

FIG. 2 is a top view of the first embodiment of the present invention. The element holder 8 is arranged from the bearing 3 toward the outer periphery, and the magnetoelectric conversion element array 6 is provided on the side surface of the element holder 8.
Was placed. Further, several magnetoelectric conversion elements were arranged side by side on a straight line.

FIG. 3 is a detailed diagram of the vicinity of the magnetoelectric conversion element 6 and the magnetic layer 2 on the disk 1 according to the first embodiment of the present invention. The magnetoelectric conversion element 6 has an electrode (+) 10 and an electrode (-) 11 arranged on the front and back, and a voltage is applied between them. The magnetic field is placed so that it is perpendicular to the electric field. Four magnetoelectric conversion element arrays 6 are arranged side by side, and the electrode (-) 11 is common to each element. The electrode (+) 10 is attached to each element. In the magnetoelectric conversion element array 6, about 30 μm on the side of the doped surface 12 reacts. The permanent magnet 13 was arranged above the dope surface 12 so that N was at the bottom and S was at the top. this is,
This is because the magnetic-electric conversion element array 6 does not oscillate unless a magnetic field of a certain level or more is applied. Therefore, the magnetic field applied to the magnetic-electric conversion element is offset, and the lines of magnetic force easily pass through the inside of the magnetic-electric conversion element.

The magnetic layer 2 on the disk 1 was magnetized perpendicularly.
This makes it possible to increase the magnetization density and therefore the resolution as an encoder. However, since the magnetic force that can be generated is small, there is a risk of lack of reliability.

FIG. 4 shows an example in which the magnetizing direction is the plane direction in FIG. Although the resolution is lower than that of the example in Fig. 3,
Since the magnetic force of the magnetic layer can be increased, the reliability is improved.

The magnetic layer 2 of the rotating disk 1 was magnetized in the pattern shown in FIG. This pattern shows the 1st digit, the 2nd digit, and the 3rd digit from the outside by dividing one lap into 10 parts.
The blank part is recognized as 1. One magnetoelectric conversion element is required for each digit, and in the present Example 1, four were arranged side by side.

Since the magnetic layer 2 can be magnetized and demagnetized,
After assembled, it can be magnetized to change the magnetized pattern.

FIG. 6 shows a circuit block diagram in the first embodiment. The counter 18 counts the number of pulses of the output of the magnetoelectric conversion element 17 and checks the frequency. Arithmetic circuit unit 20
Then, high-order bit data of the frequency signal is fetched, it is determined whether or not the magnetic force is acting on the magnetoelectric conversion element, and the binary number is converted to the decimal number. Display the converted value and transfer the data to the external device.

Since the conventional magnetoelectric conversion element has a low sensitivity directivity, it has a poor resolution per rotation and is not suitable for an encoder. However, the magneto-electric conversion element based on the Z effect has a high directivity, so that the resolution can be increased. Further, since the magnetoelectric conversion element is processed by a semiconductor process, a large number of magnetoelectric conversion element arrays can be produced at the same time. (Embodiment 2) FIG. 7 is a magnetization pattern of the magnetic film of the rotating disk 1 in Embodiment 2 of the present invention. In this example, one lap is 60
It is a divided one. In Example 1, the magnetization was performed in two stages, whereas in Example 2, the magnetization was performed in ten stages. Figure 8
Is the distribution of the magnetic force in the outermost direction in the outermost direction. In the first embodiment, three columns are required for 10 divisions, but with this method, 60 columns can be divided into two rows, so the resolution can be increased. Furthermore, since the number of magnetoelectric conversion elements can be reduced, the manufacturing cost can be reduced.

The circuit block diagram is as shown in FIG. 6 and is the same as that of the first embodiment. In the first embodiment, only the higher order bits of the counter 18 are handled, but in the second embodiment, all the bits of the output of the counter 18 are used because the output of the magnetoelectric conversion element is multivalued.

The coercive force of the magnetic film on the disk is estimated from the output value of the counter 18, and the level of the coercive force in 10 steps is determined and converted into a decimal number. Performed for each digit, converted to an angle, displayed, and output to an external device.

(Third Embodiment) FIG. 9 is a main block diagram of the third embodiment. In Example 1, only one side of the disk 1 was used, but in Example 3, both sides of the disk 1 were used. Magnetic layer 2
Were placed on both sides of the disk 1 and magnetized. Further, the magnetoelectric conversion element array 6 was also installed at two locations facing the magnetic films on both sides so that the magnetic films on both sides could be detected. This method is not possible with the optical transmission type, but is possible with the magnetic type. As can be seen from the structure, the resolution can be double that of the single-sided method.

In this embodiment, the disk type rotary encoder is described, but the same method can be applied to the cylindrical type rotary encoder and the linear encoder.

[0026]

As described above, the present invention has the following effects.

(1) Since the pattern on the rotating disk is magnetized on the magnetic layer, it is held in the state of the latter half completed body in which the disk and the support are assembled, and the disk is magnetized according to the order. You can As a result, after receiving an order, the product can be delivered if it is magnetized according to the order, and the delivery time can be shortened.

(2) Since the magnetic layer can be easily demagnetized / magnetized, it is possible to easily correct or change the processing failure and reduce the cost increase due to defective product production.

(3) Since the disk is a common part at the parts stage, it is not necessary to divide the production lot into small parts according to various orders. Therefore, the production cost can be reduced by taking advantage of the mass production effect.

(4) As shown in the second embodiment, by magnetizing in multiple stages, the required number of rows of the circumference can be small, so that the resolution can be increased.

(5) As shown in the third embodiment, the pattern can be written and read on both sides of the rotating disk to double the resolution.

(6) By using the magnetoelectric conversion element based on the Z effect, it is possible to obtain an output voltage of several volts and to be resistant to electrical noise.

(7) Since the magnetoelectric conversion element based on the Z effect has a high directivity, it is possible to make the resolution high and downsize as compared with the case where another magnetoelectric conversion element is used.

[Brief description of drawings]

FIG. 1 is a main configuration diagram of an encoder according to a first embodiment of the present invention.

FIG. 2 is a top view of the encoder according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram of a magnetic detection unit according to the first embodiment of the present invention.

FIG. 4 is an explanatory diagram of a magnetization example of a magnetic layer according to the first embodiment of the present invention.

FIG. 5 is a magnetization pattern diagram of a disk according to the first embodiment of the present invention.

FIG. 6 is a block diagram of an electric signal circuit according to the first embodiment of the present invention.

FIG. 7 is a magnetization pattern diagram of a disk in Example 2 of the present invention.

FIG. 8 is a magnetic force distribution diagram of a disk in Example 2 of the present invention.

FIG. 9 is a main configuration diagram of an encoder according to a third embodiment of the present invention.

FIG. 10 is a main configuration diagram of a conventional encoder.

FIG. 11 is a conventional magnetic pattern of a disk.

FIG. 12 is a block diagram of a conventional electric signal circuit.

[Explanation of symbols]

 1 Disk 2 Magnetic Layer 3,4 Bearing 5 Supporting Member 6 Magnetoelectric Converter Element Array 7 Base 8 Holder Supporting Member 9 Magnetizing Window 10 Electrode (+) 11 Electrode (-) 12 Doped Surface 13 Permanent Magnet 14 Insulating Layer 15 Non-Adhesive Magnetic part 16 Magnetizing part 17 Magnetoelectric conversion element 18 Counter 19 Oscillation circuit 20 Arithmetic circuit 21 Display part 22 External device 23 Vcc 24 Magnetizing part 25 Outer peripheral direction position 26 Magnetic field strength 31 Disc 32 Light-shielding film 33, 34 Bearing 35 Support member 36 Light source 37 Photodetector section 38 Base 39 Non-magnetized section 40 Magnetized section 41 Photodetector section 42 Binary decimal conversion circuit 43 Angle conversion circuit 44 Display section 45 External device

Claims (3)

[Claims] 1. An encoder for recognizing the position of a moving object by detecting a pattern attached to a scale connected to a moving object with a detection member, and a plurality of Z effects on a stationary support member. A magnetic-electric conversion element (a silicon-doped phosphorus-aluminum-gold doped magnetic-electric conversion pulse sensor that converts magnetic field strength to frequency and has directivity) is placed on the surface of the moving scale. Characterized by arranging a magnetized magnetic layer, arranging the magnetoelectric conversion element and a magnetic layer on a scale in close proximity, and detecting the magnetization pattern of the magnetic layer by the magnetoelectric conversion element to recognize the position of the object. And the encoder. 2. The encoder according to claim 1, wherein the strength of the magnetic force of the magnetic layer is divided into three or more steps. 3. The encoder according to claim 1, wherein the magnetic layer and the magnetoelectric conversion element are arranged on both front and back sides of a rotating disk.