JPS6315117A - Encoder - Google Patents

Abstract

PURPOSE:To realize an encoder capable of corresponding to all of measures by one kind, by making it possible to form a beam blocking part and a beam transmitting part based on arbitrary resolving power required by the encoder. CONSTITUTION:After a Cr-thin film is on the single surface of a rotary disc 20, the rotary disc 20 is incorporated in an encoder 1. This encoder 1 is fixed to a servo motor 65 and the drive shaft 30 of the encoder 1 is connected to a drive shaft 66 on one side of the servo motor 65. Next, a reference encoder 70 equipped with predetermined resolving power required by a customer is connected to a shaft 67 on the other side of the servo motor 65. Next, the motor driving circuit 81 of a slit forming apparatus 80 is energized to drive a motor 65 and the output from the encoder 70 is detected by a laser control circuit 82. Then, the beam emission of laser 100 is turned ON and OFF in synchronous relation to said detection output and the Cr vapor deposition surface of the rotary disc 20 is selectively burnt off to form slits 21.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an encoder that can perform positioning with a desired resolution.

[Prior art and its problems] In recent years, with the development of robots and self-excited machines, encoders (position code generators), which are rotational or linear position detection devices, have been widely used to control them. There are many different types. An example of an incremental rotary encoder that is most commonly used as a rotary encoder for measuring rotational angular displacement (for generating and producing rotational angular position numbers) will be described.

Currently, there are both optical and magnetic types on the market, but FIG. 5 shows the configuration of the optical disc of the optical rotary encoder, which is the most commonly used optical rotary encoder. Note that for convenience of explanation, only one track is shown here.

As shown in FIG. 5, the optical disk 20 is fixed to a drive @30 that rotates in response to the movement of the object to be controlled so as to pass through the center of rotation thereof. In the optical dial 20, slits 21 for transmitting/blocking light are arranged in the thickness direction of the disk 20 at every predetermined angle α radially when viewed from the center on the entire circumference 22 of a predetermined radius from the center. ing.

Conventionally, the optical disc and the slit are formed by forming a light-shielding substance such as Cr on a glass disc to a slight thickness by vapor deposition.
It was manufactured by removing only the slit part (light-transmitting part) by photo-etching.

The light emitting element 10 and the light receiving element 11 were disposed facing each other with the slit row 21 in between, as shown in FIG. 20, the light emitted from the light emitting element 10 passes through the slit 21 and reaches the light receiving element 11, and the light is blocked by a portion other than the slit 21 and does not reach the light receiving element 11, alternately occurring. do. Therefore, the light receiving element 11
By detecting this light, the amount of rotation of the optical disc 20 can be detected.

However, the optical disk 20 is manufactured by photo-etching or the like, and in order to generate slits according to the resolution desired by each customer, it is necessary to prepare the necessary number of encoders for each required resolution. , very diverse,
A large amount of inventory was required.

[Object of the Invention] The present invention has been made in view of the problems of the prior art described above.
It is an object of the present invention to provide an encoder that can handle all specifications with one type by making it possible to generate a light-shielding part and a light-transmitting part with any resolution required by the encoder.

[Example] Hereinafter, an example according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view of an embodiment according to the present invention, and in the figure,
1o is a light emitting element similar to that in FIG. 6, 11 is a light receiving element, 20
30 is a rotating disk made of a glass substrate, with a Cr thin film deposited on the left side of the figure to have a light-shielding effect; 30 is a rotating disk 20;
40 is a control board that controls light emission from the light emitting element 10 and detection of the amount of light received by the light receiving element 11; 41 is an interface cable;
2 is a transparent hole portion formed at a predetermined position of the control board 40;
Reference numeral 1 denotes a protective cover for protecting the control board, and the protective cover 51 has a transparent hole 54 similar to the transparent hole 42 formed therein.

Reference numerals 52 and 53 denote a main body support base that rotatably supports the drive shaft 30, and a main body main base, and the main body main base 53 also has a transparent hole 55 similar to the transparent hole 42. . These light-transmitting holes 42, 54, 55 allow light from an external light-emitting means, for example, a He-Ne gas laser 100, to directly pass through the light-emitting element 10 and light-receiving element 1 of the rotating disk 20.
They are arranged in alignment with each other so as to transmit light at the same circumferential position as the first arrangement position.

More Jft! The process of assembling the encoder of this embodiment, which is provided with an axle, will be described below with reference to FIG.

A thin Cr film is deposited on one side of the rotating disk 20 by a known method. Here, a reference position M mark (Z mark), which is a transparent portion, is formed in advance at a predetermined position indicating the reference position of rotation of the rotary disk 20. This reference position is common to all encoders, and is located on one circumference of the rotating disk 20.
One is formed.

In this state, the rotary encoder shown in FIG. 1 is assembled in step S1. In this state, it is sold, for example, to a servo motor manufacturer. Thereafter, the servo motor manufacturer generates slits (FIG. 5, 21) with a predetermined resolution according to various specifications requested by the customer. Various methods can be considered for creating this slit, but
In this embodiment, as shown in FIG. 5 in step S2, the servo motor 65 and the encoder 1 of this embodiment are assembled together regardless of the customer's specifications, that is, the main body main base 53 of the encoder 1 and the main body support base. 52 to mounting bracket 6
0 to the servo motor 65, and the drive shaft 30 is connected to one of the drive shafts 66 of the servo motor 65.

Then, after the various specifications requested by the customer have been determined in steps 33 and subsequent steps, a slit generation process (FIG. 5, 21) with a predetermined resolution is performed. First, in step S3, the reference encoder 70, which serves as a reference and is equipped with a slit of a predetermined resolution requested by the customer, is assembled into the other rotating shaft of the servo motor 65 to which the encoder of this embodiment is not attached, and in the subsequent step S4, the slit is The motor drive circuit 81 of the generation device 80 is energized to drive the motor 65.

When the motor 65 is driven, the laser control circuit 82 of the slit generating device 80 switches to the reference encoder 70 in step S5.
Detect the output of Then, the light emission of the laser 100 is controlled on/off in synchronization with this detection output.

In this embodiment, a He-Ne gas laser is used as the laser 100, but it may also be a carbon dioxide laser, an argon gas laser, a ruby laser, a GaAs laser, etc., which can burn out the Cr thin film. It is fine as long as it is something.

Further, as shown in FIG. 1, the laser 100 is located at a position where the laser light from the laser 10 passes through the transparent holes 54, 42° 53 and directly irradiates the Cr-deposited surface of the rotating disk 20. Consistent housing fixtures are fixed.

Therefore, the Cr thin film on the Cr-deposited surface of the rotating disk 20 that is irradiated with the laser beam from the laser 100 is burned out and becomes translucent. Therefore, the light emitting element 10 between the light emitting element 10 and the light receiving element 11 of the rotating disk 20
A slit is generated at a predetermined resolution in a portion that is irradiated with light. In this way, according to this embodiment, by simply forming aligned holes in the encoder that can directly irradiate external light onto a predetermined circumferential surface of the rotating disk 20,
Slits can be freely formed with desired resolution after assembly as an encoder.

When the slit generation (writing) for one rotation is completed in this way, the detection output from the writing slit is compared with the detection output from the reference encoder 70 in the following step S6 to determine whether the slit generation was performed normally. It is checked whether or not the encoder has been generated normally, and if it has been generated normally, the process is terminated and the manufacture of the encoder with a predetermined resolution is completed. This rear hole 54 may be closed with a cap or the like.

Although the above explanation describes an example in which slits are written based on the output from the reference encoder, the present invention is not limited to this. The laser control circuit 82 turns on and off the laser 100 at a predetermined time period based on the rotation speed to generate slits at predetermined intervals. It may also be integrated with

Furthermore, in order to burn out the Cr thin film of the rotating disk 20, the encoder may be provided with a light emitting element that emits high-output light for generating slits, instead of using external irradiation light.

An example equipped with the light emitting element is shown in FIG.

In FIG. 4, a light emitting element 56 with a high output power is implanted in the hole 55 in FIG. After the slit is generated, it is preferable to protect the slit from emitting light so that it is not inadvertently energized.

Furthermore, since the light emitting drive control for the light emitting element 56 is performed only once, the light emitting drive circuit is not mounted on the control board 40, and the signal lines connected to both terminals of the light emitting element 56 are connected via the interface cable 41. The light emitting element 56 may be controlled to emit light by outputting the signal to the outside and connecting the signal line to an external drive circuit.

The slit generated (written) in this way is
The B-phase signal (pulse edge of the A-phase (a signal for detecting the rotational direction based on the B-phase signal level) and a Z signal that outputs only one pulse per rotation
Outputs three phase signals.

Furthermore, this embodiment is not limited to the rotating disk 20 in which a CrR film is deposited on a glass substrate, but a thin film with a light-shielding property may be formed on a substrate with a light-transmitting property. ,
You can burn this out.

Furthermore, the rotating disk has a structure similar to that of an optical disk of an optical disk storage device, and a laser beam 1 is applied to the optical disk as shown in FIG.
The laser beam from 00 passes through the transparent holes 54, 42, 53 and is irradiated onto the rotating disk, or as shown in FIG. Data may be written on the optical disk using light emitted from 56, and read by a known read head disposed, for example, at light emitting element 10 4 in FIG. By growing 41 in this way, an encoder with even higher resolution can be obtained. In addition, this optical disc is rewritable.
Of course, Yusei would also be fine.

[Effects of the Invention] As explained above, according to the present invention, even if the required resolutions are diverse, it is possible to easily obtain any resolution without having to manufacture various types of rotating disks according to specifications. It is possible to provide a highly versatile encoder.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the relationship between a rotating disk and a magnetic head in one embodiment of the present invention, Fig. 2 is a schematic cross-sectional diagram of this embodiment, and Fig. 3 is a schematic diagram of the write/read control section of this embodiment. Figure 4 is a schematic cross-sectional view of another embodiment of the present invention, Figure 5 is a diagram showing the structure of an optical disc of an optical rotary encoder, and Figure 6 is a schematic diagram of an optical rotary encoder. . In the figure, 10... Magnetic head, 14... Write/read control circuit, 16... Detection circuit, 2o... Rotating disk, 30... Drive shaft, 40... Control board, 52 .53
...Body plate, 54...Elastic body, 55...Back plate, 56...High output light emitting element, 101...
- Slit, 105... Light emitting element, 106... Light receiving element.

Claims (5)

[Claims] (1) a rotating plate that rotates according to an external driving body; a writing device that writes position information on the rotating plate at a predetermined resolution;
An encoder comprising: reading means for reading position information written by the writing means. (2) The encoder according to claim 1, wherein the rotary plate has a light-transmitting member as a base, and a light-shielding material is slightly thickly formed on one side of the base. (3) The writing means consists of an opening formed in such a way that light from the outside can be irradiated onto a predetermined radius of rotation of the rotating plate, and the writing means receives external light through the opening and uses the external light. 3. The encoder according to claim 2, wherein the encoder can alternately form light-blocking parts and transmitting parts with a predetermined resolution by burning out the light-blocking material. (4) The writing means is provided with a light irradiation means that irradiates light onto a predetermined turning radius, and the light irradiation means burns out the light-blocking material and alternates between the light-blocking part and the transmitting part at a predetermined resolution. 3. The encoder according to claim 2, wherein the encoder is formed as follows. (5) The reading means includes a light emitting means disposed at opposing positions on a predetermined rotation radius of the rotary plate and emits light onto the surface of the rotary plate, and a light emitting means that emits light transmitted through the rotary plate. An encoder according to any one of claims 1 to 4, characterized in that the encoder comprises a light receiving means for receiving light.