Rotary encoder with built-in microcomputer

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a rotary encoder, and more particularly to a rotary encoder with a built-in microcomputer.

【0002】

[Conventional technology]

A rotary encoder is an encoder that converts angular displacement into a digital code, and can be divided into incremental type and absolute type.

【0003】

FIG. 4A is a basic structural diagram of an incremental rotary encoder. In this figure, the light emitted from the light emitting diode 1 (light emitting element) passes through the slits (the slit of the fixed plate 2 and the slit of the rotating plate 3) and reaches the photodiode 4 (light receiving element), and the photodiode operates. (ON operation). Here, when the slit of the rotating plate 3 moves and the light-shielding portion matches the slit of the fixed plate 2, the light is blocked and the photodiode 4 does not operate (OFF operation). The rotary encoder outputs the output of the ON / OFF operation of the photodiode 4 as a pulse waveform by electrical processing. Therefore, in the case of the incremental type, the number of rotations of the rotating shaft 5 can be known by counting the number of output pulses, that is, the number of ON operations of the photodiode.

【0004】

FIG. 5A is a basic structural diagram of an absolute rotary encoder. In this figure, the photodiode 4 (light receiving element) is turned on / off by transmitting and blocking the emitted light from the light emitting diode 1 (light emitting element) through the slit of the rotating plate 3. Further, since the rotation angle of the rotation shaft 5 is read from the pattern of the rotation slit and output as a code signal, the pattern is combinatorially encoded and complicated. In the absolute type, since the rotation angle of the shaft is detected from the pattern of the rotation slit, the absolute position can be known even when the slit of the rotating plate 3 is stationary. Therefore, the rotation position can always be confirmed without a counter. Further, since the origin of the input rotation shaft is determined at the time of incorporating into the machine, the rotation angle from the origin can be accurately represented even when the power is turned on after starting, power failure, or emergency stop.

【0005】

[Problems to be Solved by the Invention]

FIG. 4B is an output waveform diagram of the incremental rotary encoder. As shown in this figure, in the incremental type, a track A slit and a track B slit shifted by 1/4 wavelength are usually provided as slits of the fixing plate 2, and the A signal from the A slit and the B signal from the B slit are used. , The direction of rotation is detected. Therefore, the incremental rotary encoder is characterized in that the required number of light emitting diodes 1 and photodiodes 4 is smaller than that of the absolute encoder, and the slit structure of the rotating plate 3 is also simple. However, the incremental type has a drawback that the absolute position becomes unknown once the power is turned off.

【0006】

FIG. 5B is a circuit configuration diagram of an absolute rotary encoder. As described above, the absolute type can always know the overall position, but it has the disadvantages that the required number of light emitting diodes 1 and photodiodes 4 is large (for example, 10 to 12 pairs) and the slit structure of the rotating plate 3 is complicated. was there.

【0007】

In addition, in the conventional rotary encoder, when communicating the output with an external device, prepare a dedicated parallel-serial conversion IC according to the serial communication (for example, RS-232C, RS-422, etc.) to be used. I needed it.

【0008】

Furthermore, in the conventional rotary encoder, in order to realize the functions of the preset counter and the cam positioner device by using this, it is necessary to separately prepare a device having the required function and connect this to the rotary encoder each time. there were. Further, in this case, if there is no preset counter or cam positioner device that satisfies the required functions, it is necessary to design, manufacture, and combine a new device.

【0009】

Further, in any of the above-mentioned usage methods, necessary equipment is prepared each time, and wiring and circuit configuration suitable for the interface of the equipment are required. Further, it is practically impossible to change the rotary encoder once incorporated into a machine or the like to another function.

【0010】

The present invention has been devised to solve the various problems described above. That is, the object of the present invention is (1) that the required number of light emitting diodes and photodiodes is small, and a rotary plate having a simple structure can be used, which can be used for both the incremental type and the absolute type (2). It can be applied to both serial communication and parallel communication without using a dedicated IC, and can support multiple communication methods without changing the equipment. (3) Realize the functions of preset counters and cam positioner devices without adding equipment. The purpose is to provide a rotary encoder with a built-in microcontroller that can (4) change its function without changing the interface or circuit configuration.

【0011】

[Means for solving problems]

According to the present invention, a rotating shaft (12) rotatably supported around the axis Z, a rotation detecting unit (14) that outputs a pulse signal according to the rotation of the rotating shaft, and a clock (15). A microcomputer (16) that has a built-in device and performs arithmetic processing of the pulse signal, and an interface circuit (18) that converts the output of the microcomputer into a communication signal and transmits and inputs the received communication signal to the microcomputer. A rotary encoder with a built-in microcomputer is provided, which is characterized by being provided.

【0012】

According to a preferred embodiment of the present invention, the microcomputer (16) has a ROM in which programs necessary for arithmetic processing, signal conversion processing, and transmission / reception are written, a RAM for temporarily storing data, and each data. It is equipped with a CPU that processes the operations of.

【0013】

According to the above-described configuration of the present invention, a microcomputer (16) having a CPU, ROM, and RAM and a serial or parallel input / output interface circuit (18) are built in the rotary encoder. Therefore, the necessary program is written in advance in the ROM of the microcomputer (16) and held, and the program can be freely changed by mounting the programmed ROM or the ROM element in the IC socket to perform a multifunctional rotary. An encoder can be realized.

【0014】

That is, by changing the program inside the rotary encoder, the functions of a commercially available electronic campojosina or an electronic counter can be easily realized by the rotary encoder alone. In addition, functions that cannot be realized by commercially available products can be realized by changing the program. Therefore, a plurality of functions can be realized in spite of the common rotary encoder. In addition, since the rotary encoder has a built-in CPU and high functionality, it is possible to control other devices.

【0015】

Furthermore, the signal conversion processing of the interface circuit (18) and the processing required for transmission and reception are stored in ROM as a program, and signals are freely signaled according to the communication procedure (protocol) used without using a dedicated IC for communication control. Can be converted. Further, the input / output signal line can be an incremental signal or an absolute signal as before, or can be used as a signal for controlling other devices such as a cam switch signal.

【0016】

Further, the rotation detection unit (14) includes a rotating plate (14a) fixed to the rotation shaft (12) and having a plurality of light transmitting slits spaced apart in the circumferential direction, and a light emitting element (14a) that irradiates the slits with light. 14b), at least one pair of light receiving elements (14c) for detecting light transmitted through the light transmitting slit, and a fixed plate (14d) located between the light emitting element and the light receiving element and having at least one pair of light transmitting slits. And, by the signal from the pair of light receiving elements, a pulse signal proportional to the rotation direction and the rotation angle is output. Further, although not shown, a reflection type rotation detection unit may be used.

【0017】

With this configuration, it can be used as it is as a conventional incremental rotary encoder. Further, by processing this output signal as data with a microcomputer (16) and storing necessary information in RAM, it can also be used as an absolute rotary encoder.

【0018】

Further, it is provided with an auxiliary storage device (19) capable of reading / writing a program and storing data without a power supply, and a memory rewriting circuit (20) for controlling the rewriting of the auxiliary storage device. Is preferable.

【0019】

With this configuration, an auxiliary storage device (19) such as a flash memory and a memory rewriting circuit (20) are further built in the rotary encoder. Therefore, the program is held in this auxiliary storage device, and an external memory content rewriting device can be used. The internal program of the rotary encoder can be rewritten by communication via communication. Therefore, by rewriting the program inside the common rotary encoder, the program can be changed after being incorporated into the device, so that it is possible to easily realize the function change and function improvement of the entire device in which the rotary encoder is incorporated. ..

【0020】

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In addition, the same reference numerals are given to common parts in each figure, and duplicate description is omitted.

【0021】

FIG. 1 is an overall configuration diagram showing a first embodiment of the rotary encoder with a built-in microcomputer of the present invention, and FIG. 2 is a circuit configuration diagram thereof. As shown in FIG. 1, the rotary encoder 10 with a built-in microcomputer of the present invention includes a rotation shaft 12, a rotation detection unit 14, a microcomputer 16, and an interface circuit 18.

【0022】

The rotating shaft 12 is rotatably supported around the axis Z by a bearing 12a. Further, the rotating shaft 12 is connected to a rotating portion of a mechanical device (not shown) and rotates in synchronization with the rotation of the rotating portion.

【0023】

The rotation detection unit 14 transmits the rotating plate 14a fixed to the rotating shaft 12 and having a plurality of light transmitting slits spaced apart in the circumferential direction, the light emitting element 14b that irradiates the light transmitting slits with light, and the light transmitting slits. It has at least one pair of light receiving elements 14c for detecting light, and a fixing plate 14d located between the light emitting elements 14b and the light receiving elements 14c and having at least one pair of light transmitting slits. That is, the rotation detection unit 14 has the same configuration as the rotation detection unit of the conventional incremental rotary encoder, and uses signals from at least one pair of light receiving elements 14c to generate a pulse signal proportional to the rotation direction and rotation angle. Output. In the present invention, the rotation detection unit 14 is not limited to the above-mentioned one, and may be a rotary encoder having a reflection type optical unit.

【0024】

As shown in FIG. 2, the microcomputer 16 has a ROM in which programs necessary for arithmetic processing, signal conversion processing, and transmission / reception are written, a RAM for temporarily storing data, and a CPU for processing the arithmetic of each data. And. Further, the microcomputer 16 has a built-in clock 15 and processes the pulse signal from the rotation detection unit 14 according to the program written in the ROM. In the present invention, the microcomputer 16 may have a CPU, a clock, a ROM, and a RAM configured by separate ICs. The interface circuit 18 converts the output of the microcomputer 16 into a communication signal, transmits and inputs the received communication signal to the microcomputer. The processing program in the interface circuit 18 is also written in ROM so that it can be rewritten if necessary.

【0025】

In the first embodiment shown in FIGS. 1 and 2, the ROM can be rewritten by mounting a programmed ROM or mounting a ROM element with an IC socket to freely change the program to realize a multifunctional rotary encoder. can do.

【0026】

That is, by changing the program inside the rotary encoder, the functions of a commercially available electronic campojosina or an electronic counter can be easily realized by the rotary encoder alone. In addition, functions that cannot be realized by commercially available products can be realized by changing the program. Therefore, a plurality of functions can be realized in spite of the common rotary encoder. In addition, since the rotary encoder has a built-in CPU and high functionality, it is possible to control other devices.

【0027】

Furthermore, the signal conversion processing of the interface circuit 18 and the processing required for transmission and reception are stored in the ROM as a program, and serial communication (for example, RS-232C, RS-422, RS) used without using a dedicated IC for the communication interface. You can freely convert signals according to (-485 etc.). Further, the input / output signal line can be an incremental signal or an absolute signal as before, or can be used as a signal for controlling other devices such as a cam switch signal.

【0028】

FIG. 3 is a circuit configuration diagram showing a second embodiment of the rotary encoder with a built-in microcomputer of the present invention. In this example, the rotary encoder 10 with a built-in microcomputer of the present invention further rewrites the auxiliary storage device 19 capable of reading / writing a program and storing data without a power supply, and the auxiliary storage device. It is provided with a memory rewriting circuit 20 to be controlled. A non-volatile memory such as a flash memory is used as the auxiliary storage device 19. Further, the memory rewriting circuit 20 incorporates a circuit necessary for erasing / writing the flash memory. The overall configuration diagram in the second embodiment is the same as that in FIG. 1, and the other configurations are also the same.

【0029】

With this configuration, an auxiliary storage device 19 such as a flash memory and a memory rewriting circuit 20 are further built in the rotary encoder. Therefore, the program is held in this auxiliary storage device, and communication is performed via an external memory content rewriting device. The internal program of the rotary encoder can be rewritten. Therefore, by rewriting the program inside the common rotary encoder, the program can be changed after being incorporated into the device, so that it is possible to easily realize the function change and function improvement of the entire device in which the rotary encoder is incorporated. ..

【0030】

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

【0031】

[Effect of the invention]

As described above, the rotary encoder with a built-in microcomputer of the present invention can be used for both the incremental type and the absolute type by using (1) a rotating plate having a small number of light emitting diodes and photodiodes and a simple structure. It can be applied to both serial communication and parallel communication without using a dedicated IC, and can support multiple communication methods without changing the device, and (3) preset counters and cams without adding devices. It has excellent effects such as being able to realize the functions of the positioner device and (4) being able to change the functions without changing the interface or circuit configuration.

[Simple explanation of drawings]

[Figure 1]

It is an overall block diagram which shows 1st Embodiment of the rotary encoder with built-in microcomputer of this invention.

[Figure 2]

It is a circuit block diagram of the rotary encoder of FIG.

[Fig. 3]

It is a circuit block diagram which shows the 2nd Embodiment of the rotary encoder with built-in microcomputer of this invention.

[Fig. 4]

It is explanatory drawing of the conventional incremental rotary encoder.

[Fig. 5]

It is explanatory drawing of the conventional absolute type rotary encoder.

[Explanation of symbols]

1 light emitting diode (light emitting element), 2 fixed plate, 3 rotating plate, 4 photodiode (light receiving element), 5 rotating shaft, 10 rotary encoder with built-in microcomputer, 12 rotating shaft, 14 rotating detector, 14a rotating plate, 14b light emitting Element, 14c light receiving element, 14d fixed plate, 15 clock, 16 microcomputer, 18 interface circuit, 19 auxiliary storage device, 20 memory rewriting circuit