JP3012457B2 - Encoding plate for detecting rotational angle position and method for detecting rotational angle position - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation angle position detection encoding plate and a rotation angle position detection method used, for example, for controlling the position of continuous paper in a printer.

In recent years, printer apparatuses have been reduced in size, price, and reliability, and accordingly, an inexpensive and reliable control method and control parts for transporting and positioning continuous paper have been developed. Development is desired.

[0003]

2. Description of the Related Art Conventionally, position control of continuous paper in a printer device is performed as follows.

FIG. 12 is a front view of an encoding plate 81 for detecting a rotational angle position which is conventionally used, and FIG. 14 is a diagram showing a detection signal S11 from the encoding plate 81. In FIG. 12, an encoding plate 81 is for detecting a reference angular position of a rotating shaft, and a detection through hole (detent slit) 83 is provided at one position in a circumferential direction of a disk-shaped main body 82. It is a thing. Encoding plate 81
Is mounted, for example, on a shaft of a DC motor (not shown) for feeding paper. The rotational driving force of the DC motor is transmitted to the wheels via a reduction gear (not shown), and drives the belt with the pins stretched between the wheels so that the continuous paper is fed and its position (the position in the line direction). ) Control.

[0005] A transmission type photosensor SE11 for detecting the through hole 83 is attached to the encoding plate 81. As shown in FIG.
One detection signal S11 is generated for each rotation.

When this encoding plate 81 is used,
The position where the detection signal S11 is generated is set as a reference position, and the step amount is determined with reference to the reference position. 13 is a front view of another encoding plate 85 for detecting a rotational angle position used in the related art, and FIG. 15 is a diagram showing a detection signal S12 from the encoding plate 85.

In the encoding plate 85, a large number of slits 87 are provided at regular intervals along the circumferential direction of a main body 86, and a through hole 88 is provided at one location in the circumferential direction. It is a thing. The encoding plate 85 is provided with transmissive photosensors SE12 and SE13 for detecting the slits 87 and the through holes 88. As shown in FIG. Detection signals S1 equal to
2, and a detection signal S13 that is turned on and off every half cycle is generated.

[0008]

However, when the former encoding plate 81 is used, since the through hole 83 has a size in the width direction, the width of the detection signal S11 becomes relatively wide. It is difficult to accurately determine the reference position. In addition, in order to obtain the reference position, it is necessary to rotate the encoding plate 81 close to 360 degrees at the maximum, and the amount of rotation for the initial setting increases. In this case, it takes time to determine the reference position, and the positional deviation of the continuous paper tends to increase accordingly, resulting in a decrease in positional accuracy.

When the latter encoding plate 85 is used, it is necessary to count the detection signal S12. Therefore, it is necessary to use a high-speed dedicated circuit by hard logic, which increases the cost. is there. Further, since the width of each slit 87 is narrow, it is necessary to form the slit 87 by, for example, etching, which complicates the manufacturing process.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has as its object to enable a reference position of a rotating shaft to be accurately determined by a rotation angle position detecting encoding plate having a simple structure. I do.

[0011]

According to the first aspect of the present invention, there is provided an encoding plate for detecting a rotational angular position, which is provided at N positions (N
Is an arbitrary integer) and a first mark for detecting a specific position provided at a specific position and an edge extending in the radial direction is defined as 2N in the circumferential direction.
And a second mark for area detection provided at N places in the circumferential direction so as to be equally divided.

According to a second aspect of the present invention, there is provided a method for detecting a rotational angular position, wherein the first mark for detecting a specific position is provided at N locations (N is an arbitrary integer) in a circumferential direction and extends in a radial direction. In order to make the edge equally divide the circumferential direction by 2N,
A second mark for area detection provided at a location, and a rotation angle position detection encoding plate comprising: A first sensor for detecting a mark, and a second sensor for detecting the second mark are provided, wherein the first sensor detects the first mark, and A method for detecting that the rotation axis is at a reference angular position when a second sensor detects an edge of the second mark.

According to a third aspect of the present invention, there is provided a method for detecting a rotational angular position, wherein the rotary shaft is rotationally driven by a stepping motor, and the reference angular position detected by the method of the second aspect and the number of steps of the stepping motor are determined. Is a method for detecting the rotation angle position of the rotation shaft.

According to a fourth aspect of the present invention, in the method for detecting a rotational angular position, the first mark and the second mark are through holes provided in the encoding plate, and the first sensor and the second The second sensor is a transmission type photo sensor.

According to a fifth aspect of the present invention, there is provided a method for detecting a rotational angular position, wherein the first mark for detecting a specific position provided at N positions (N is an arbitrary integer) in the circumferential direction extends in the radial direction. In order to make the edge equally divide the circumferential direction by 2N,
A second mark for area detection provided at a location, and a first rotation angle position detection encoding plate having a first rotation axis is attached so as to rotate integrally with the first rotation axis. The first mark for detecting a specific position provided at M locations in the circumferential direction (M is an arbitrary integer) and the edge extending along the radial direction divides the circumferential direction into 2M equally in the circumferential direction. And a second rotation angle position detection encoding plate having an area detection second mark provided at M locations is synchronized with the first rotation axis at a rotation speed of N / M. The rotation angle position detected by the first rotation angle position detection encoding plate and the second rotation angle position detection are attached so as to rotate integrally with a second rotation shaft that rotates. The rotation angle position detected by the encoding plate And by a method for detecting a deviation of rotation angle of said second rotary shaft and the first rotation axis.

[0016]

In the encoding plate according to the first aspect of the present invention,
When the first mark is detected and the edge of the second mark is detected, the position is set as the reference position.

For example, when the first mark is not detected and the second mark is not detected at the current stop position, the stepping motor is rotated so that the encoding plate rotates in one direction. And the time when the first mark is detected and the edge of the second mark is detected is set as the reference position. At the current stop position, if the first mark has not been detected and the second mark has been detected, the stepping motor is driven so that the encoding plate rotates counterclockwise, and the first mark is detected. The point in time when the mark is detected and the edge of the first mark is detected is set as the reference position.

[0018]

FIG. 1 is a perspective view showing a schematic configuration of a tractor device 3 using an encoding plate according to the present invention.

The tractor device 3 transports continuous paper and performs position control, and is incorporated in a printer device (not shown). The tractor device 3 includes wheels 11, 1
2. A belt 13 with pins stretched between the wheels 11 and 12, a stepping motor 14 for rotating and driving the wheel 11, a rotating shaft 14a of the stepping motor 14.
The motor shaft pulley 15 connected to the motor shaft, the wheel shaft pulley 16 connected to the rotation shaft 11a of the wheel 11, the timing belt 17 stretched between the motor shaft pulley 15 and the wheel shaft pulley 16, and the rotation shaft 14a. First encoding plate 1 attached so as to rotate integrally
8, a second encoding plate 19 attached to rotate integrally with the rotation shaft 11a, sensors SE1 and SE2 for detecting the first encoding plate 18, and a sensor SE3 for detecting the second encoding plate 19 , 4, control device 20
It is composed of

The stepping motor 14 includes a controller 20
Are rotated by a predetermined step angle according to the phase excitation current output from. When the stepping motor 14 rotates by 400 steps, the belt 13 with pins moves by one inch. That is, the stepping motor 14
Thus, the printing density can be controlled to 400 dpi in the row direction of the continuous paper.

Motor shaft pulley 15 and wheel shaft pulley 1
The ratio of the diameters of 6 is 1: 6. Therefore, when the rotating shaft 14a makes six rotations, the rotating shaft 11a makes one rotation. The control device 20 includes an MPU (microprocessor unit), a ROM, a RAM, an interface circuit, a drive circuit for the stepping motor 14, and the like.
A signal for phase switching is generated based on a program stored in M, and a reference position or a stop position is detected based on detection signals S1 to S4 of sensors SE1 to SE4. Control to perform acceleration, deceleration, constant speed rotation, stop, alarm generation, etc. The control device 20 is provided with a counter 55 for counting the number of steps of the stepping motor 14 (see FIG. 7), and the rotation angle position of the stepping motor 14 can be recognized based on the count value.

FIG. 2 is a front view of the first encoding plate 18,
FIG. 3 is a front view of the second encoding plate 19. The first encoding plate 18 has a disk-shaped main body 31, first through holes 32 for detecting a specific position provided at two equal angular positions in the circumferential direction of the main body 31, and an edge extending along the radial direction. 33
"a" comprises second through holes 33 for area detection provided at two places in the circumferential direction so as to divide the circumferential direction into four equal parts. Sensor S
E1 detects the first through hole 32, and the sensor SE2 detects the second through hole 33 and the edge 33a.

The second encoding plate 19 has a disk-shaped main body 41, first through holes 42 for detecting a specific position provided at twelve equiangular positions in the circumferential direction of the main body 41, and extends along the radial direction. A second through hole 43 for detecting a region is provided at 12 places in the circumferential direction so that the edge 43a extending so as to divide the circumferential direction into 24 equal parts. The sensor SE3 detects the first through hole 42, and the sensor SE4 detects the second through hole 43 and the edge 43a.
Is detected.

The first encoding plate 18 and the second encoding plate 19 can be manufactured, for example, by stamping a metal plate with a press, so that the manufacturing is easy.
Since there is no conventional narrow slit, it is resistant to contamination due to scattering of toner.

FIG. 4 is a diagram showing the state of detection signals S1 to S4 output from sensors SE1 to SE4, and FIG.
FIGS. 6 and 7 are enlarged views of FIGS. 1 and 2, FIG. 6 is a view showing a state where the detection signal S1 is shifted from the detection signal S3, and FIG.

In FIG. 4, the detection signal S1 is a pulse signal generated every time the first encoding plate 18 rotates 180 degrees, that is, once every half rotation, and the detection signal S2 is
It is a signal that repeats on and off at a duty ratio of 50% every half rotation. The detection signal S3 is a pulse signal generated once every time the second encoding plate 19 rotates 30 degrees, and the detection signal S4 is a signal that repeats on / off at a duty ratio of 50% every 30 degrees rotation. .

When the first encoding plate 18 makes a half turn,
The second encoding plate 19 is rotated by 30 degrees, whereby the pinned belt 13 moves by １ ／ inch. That is,
One cycle of the detection signals S1, 3 corresponds to a feed amount of 1/2 inch of the continuous paper.

As shown in FIG. 5, the positions of the sensors SE1 to SE4 are adjusted so that the detection signals S2 and 4 fall while the detection signals S1 and S3 are on. In FIG. 7, an edge is detected by the edge detection unit 52 based on the detection signal S2, and the edge and the detection signal S1 are detected.
Based on the above, the operation determining unit 51 generates an operation command that regulates the operation of the stepping motor 14 and outputs the generated operation command to the driver unit 54. Further, based on the on / off state of the detection signal S2, the position detection unit 53 detects an angular position, generates a rotation direction command for quickly moving to the reference position, and outputs the rotation direction command to the driver unit 54.

In the driver section 54, a counter 55 for counting the number of steps of the stepping motor 14 is provided. Every time the count value reaches 200, the determination section 56 determines the presence or absence of the detection signal S1, and the detection signal S
If there is no 1, an alarm is output assuming that the stepping motor 14 has lost synchronization.

Further, by combining the reference angle position detected by the first encoding plate 18 with the count value of the counter 55, the rotation angle position of the rotary shaft 14a is accurately detected, and based on this, the stepping motor 14 is controlled.

The comparator 57 compares the timing of the detection signal S1 with the timing of the detection signal S3. As shown in FIG. 6, when the time tg of the deviation is equal to or longer than a predetermined value, the deviation of the timing belt 17 is determined. Raises an alarm as the alarm occurs. The comparing section 58 also compares the timing of the detection signal S2 with the timing of the detection signal S4, and issues an alarm when the time th of the shift is equal to or longer than a predetermined value.

That is, when an excessive load is applied to the belt 13 with pins, the timing belt 17 may be shifted with respect to the motor shaft pulley 15 or the wheel shaft pulley 16. In this case, since the reference position of the continuous paper is shifted, an alarm is issued to prompt readjustment.

In the initial setting of the tractor device 3, a position where the detection signal S1 is on and the detection signal S2 falls is set as a reference position, and the belt with pin 1 is set at the reference position.
Stop 3 Thereby, the stepping motor 1
The reference position of the pin-attached belt 13 can be adjusted with high accuracy while rotating the belt 4 at a low speed. Also, the detection signal S
Reference numeral 1 is used to confirm that the belt 13 with pins is stopped at the reference position.

The operation for detecting the reference position will now be described. At the current stop position, the detection signal S1
Is output as the reference position. When the detection signal S1 is not output and the detection signal S2 is off at the current stop position, the first encoding plate 18 is rotated clockwise (in the direction opposite to the direction of the arrow M1). The time when the stepping motor 14 is driven and the detection signal S1 is output and the rise of the detection signal S2 is detected is set as a reference position. When the detection signal S1 is not output and the detection signal S2 is ON at the current stop position, the stepping motor 14 is rotated so that the first encoding plate 18 rotates in the counterclockwise direction (the direction of the arrow M1). Is driven, and the point in time when the detection signal S1 is output and the fall of the detection signal S2 is detected is set as a reference position.

Therefore, in any case, the reference position can be detected with high accuracy by rotating the first encoding plate 18 by an angle within 90 degrees.
The position of the continuous paper can be adjusted quickly and accurately with a short distance of movement.

Next, the processing operation in the tractor device 3 will be described with reference to a flowchart. FIG. 8 is a flowchart showing the synchronization deviation detection processing.

After the stepping motor 14 is rotated and the paper feeding is started (# 11), the pulses to the stepping motor 14 are counted (# 12), and the count value becomes 200.
Is reached (Yes in # 13), the presence or absence of the detection signal S1 is determined (# 14). If there is no detection signal S1, an alarm is issued (# 15), and a stop process is performed (# 16).

FIG. 9 is a flowchart showing the malfunction detection processing. During paper feeding (# 21), the timer is started (# 22), and when the rise of the detection signal S2 is detected (Yes in # 23), the timer is reset and restarted (# 24, 22). While the rise of the detection signal S2 is not detected (No in # 23), when the timer expires (Yes in # 25), an alarm is issued (# 26) and stop processing is performed (# 27).

As a result, an operation failure due to overload of the stepping motor 14 and the timing belt 17 is detected, and readjustment by the operator is performed. FIG. 10 is a front view showing an encoding plate 18a according to another embodiment.

In the encoding plate 18a, four first through holes 32 and four second through holes 33 are provided at equal angular positions with respect to each other. Thus, the first through hole 3
2 may be provided at N places (N is an arbitrary integer) in the circumferential direction of the main body 31, and the second through hole 33 is formed such that the edge 33 a extending along the radial direction divides the circumferential direction into 2N equal parts. To
It may be provided at N places in the circumferential direction. In addition, instead of the first through hole 32 and the second through hole 33 as marks, a reflector, a black mark, A mark including a magnetic material may be used. In this case, various sensors such as a reflection-type photosensor and a magnetic sensor can be used as the sensor.

FIG. 11 is a perspective view showing a schematic configuration of a tractor device 3a of another embodiment using an encoding plate according to the present invention. In the tractor device 3a, through holes 28 are provided at equal intervals between the pins of the belt 13 with pins, and sensors SE5 and SE6 for detecting the through holes 28 are attached. The detection signals S5 and S6 from the sensors SE5 and SE6 are
a, which is compared with the timing of the detection signals S1, S2, and issues an alarm if the time th of these deviations is equal to or greater than a predetermined value. As a result, the displacement of the timing belt 17 due to an excessive load is detected, and an alarm for prompting readjustment is issued.

In the above embodiment, the number of the first through holes or the second through holes in the first encoding plate 18 and the second encoding plate 19 depends on the diameters of the wheels 11, 12 and the motor shaft pulley 15. Various changes can be made according to the ratio of the diameter to the wheel shaft pulley 16 and the like. First through hole 32
The relative angular position between the sensor and the second through hole 33 is determined by the sensor S
Various changes may be made according to the mounting positions of E1 and E2. In addition, the configuration of the tractor device 3, the configuration, the circuit, the processing content, the order, and the like of the control device 20 can be variously changed in accordance with the gist of the present invention.

[0043]

According to the present invention, the reference position of the rotating shaft can be accurately determined by the rotation angle position detecting encoding plate having a simple structure.

According to the third aspect of the present invention, the rotation angle position of the stepping motor can be accurately controlled by the encoding plate having a simple structure. According to the fifth aspect of the present invention, the influence on the mechanical system due to overload or the like can be grasped, and the accuracy can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a schematic configuration of a tractor device using an encoding plate according to the present invention.

FIG. 2 is a front view of a first encoding plate.

FIG. 3 is a front view of a second encoding plate.

FIG. 4 is a diagram illustrating a state of a detection signal output from a sensor.

FIG. 5 is an enlarged view of a detection signal.

FIG. 6 is a diagram showing a state where detection signals S1 and S3 are shifted.

FIG. 7 is a block diagram illustrating a circuit example of a part of the control device.

FIG. 8 is a flowchart illustrating a synchronization shift detection process.

FIG. 9 is a flowchart illustrating a malfunction detection process.

FIG. 10 is a front view showing an encoding plate according to another embodiment.

FIG. 11 is a perspective view showing a schematic configuration of a tractor device according to another embodiment using the encoding plate according to the present invention.

FIG. 12 is a front view of a conventional encoding plate for detecting a rotational angle position.

FIG. 13 is a front view of another conventional encoding plate for detecting a rotational angle position.

FIG. 14 is a diagram showing a detection signal from a conventional encoding plate.

FIG. 15 is a diagram showing a detection signal from a conventional encoding plate.

[Explanation of symbols]

 11a rotating shaft (second rotating shaft) 14 stepping motor 14a rotating shaft (first rotating shaft) 18 first encoding plate (encoding plate) 19 second encoding plate (encoding plate) 32 first through hole ( First mark) 33 Second through hole (second mark) 42 First through hole (first mark) 43 Second through hole (second mark) SE1 Sensor (first sensor) SE2 Sensor (second sensor)

Continuation of the front page (72) Inventor Shinichiro Yamamoto 35th Saho, Kato-gun, Hyogo (No address) Inside Fujitsu Peripheral Machinery Co., Ltd. (56) References JP-A-3-20611 (JP, A) Japanese Patent Publication No. 51 −23915 (JP, B1)

Claims (5)

(57) [Claims] 1. A first mark for detecting a specific position provided at N places (N is an arbitrary integer) in a circumferential direction and an edge extending along a radial direction divides the circumferential direction into 2N equally. And a second mark for area detection provided at N places in the circumferential direction, and a rotation angle position detection encoding plate. 2. A first mark for detecting a specific position provided at N places in the circumferential direction (N is an arbitrary integer) and an edge extending along the radial direction divides the circumferential direction into 2N equal parts. A second mark for area detection provided at N places in the circumferential direction,
A rotation angle position detection encoding plate comprising: a first sensor for detecting the first mark; and a second sensor for detecting the first mark. A second sensor for detecting the mark is provided, wherein the first sensor has detected the first mark, and the second sensor has detected the edge of the second mark Detecting that the rotation axis is at a reference angle position. 3. The rotation axis is driven by a stepping motor, and the rotation angle position of the rotation axis is detected by the reference angle position detected by the method of claim 2 and the number of steps of the stepping motor. A rotation angle position detection method, characterized in that: 4. The first mark and the second mark are through holes provided in the encoding plate, and the first sensor and the second sensor are transmission type photo sensors. The rotation angle position detection method according to claim 2 or 3. 5. A first mark for detecting a specific position provided at N places in the circumferential direction (N is an arbitrary integer) and an edge extending along the radial direction divides the circumferential direction into 2N equal parts. A second mark for area detection provided at N places in the circumferential direction,
Is attached so as to rotate integrally with the first rotation axis, and is provided at M positions (M is an arbitrary integer) in the circumferential direction. A first mark for specific position detection provided, and a second mark for area detection provided at M locations in the circumferential direction such that an edge extending along the radial direction equally divides the circumferential direction by 2M. And a second rotation angle position detecting encoding plate, which is integrally rotated with respect to the first rotation axis at a rotation speed of N / M with respect to the second rotation axis. Comparing the rotation angle position detected by the first rotation angle position detection encoding plate with the rotation angle position detected by the second rotation angle position detection encoding plate. The first rotation axis and the second rotation Angular position detecting method for detecting a deviation of the rotation angle of the shaft, characterized in that.