JP5068068B2 - Rotary encoder device, rotating body drive control device, and image forming apparatus - Google Patents

Description

  The present invention measures an angular displacement or an angular velocity with high accuracy, and uses an encoder device, a rotating body drive control device, an image forming device, a rotary encoder wheel, and a rotary encoder used for position and velocity measurement or control in a roller / belt drive device. It relates to the device.

In a configuration of a general angular displacement or angular velocity control device, there is a method in which a rotary encoder is mounted on the same axis of a rotating body and drive control is performed using a signal measured by the rotary encoder.
2. Description of the Related Art An optical rotary encoder is a conventionally used measuring device for measuring angular displacement or angular velocity fluctuation of a rotating body. The optical rotary encoder is arranged with a wheel portion provided with a pattern comprising a slit-like light transmitting portion or light reflecting portion and a light shielding portion or a non-reflecting portion at a fixed period, and sandwiching the wheel portion or facing each other. Data is obtained by the optical means and the light receiving means.
However, when the wheel portion of the rotary encoder is mounted eccentrically with respect to the rotating shaft, a rotational fluctuation that should not originally be present on the rotating shaft appears due to the mounting eccentricity, and is measured as angular displacement or angular velocity fluctuation.

Generally, when attaching the wheel part of a rotary encoder to a shaft, it is very difficult to make sure that the shaft is not eccentric, or it is necessary to make a strict adjustment to avoid the eccentricity. In order to meet such a demand, the manufacturing cost inevitably increases. In addition, even if the shaft can be accurately mounted in the center, there is a gap between the shaft and the bearing, so that the shaft receives a force from a specific direction due to the load applied to the shaft, and the eccentricity inevitably occurs. Become.
Furthermore, if the wheel part itself has some eccentricity with respect to the wheel pattern center point with respect to the wheel part rotation center, it is also eccentric.
In summary, as long as the center of the rotary encoder pattern is not ideally aligned with the axis of the rotating object being measured, the mounting eccentricity, the eccentricity during wheel pattern processing, and the deformation eccentricity due to changes over time All eccentric components including it become errors.

Conventionally, several techniques for reading a pattern with a rotary encoder and measuring a driving state are known (see, for example, Patent Documents 1 to 3).
In the rotary encoder of Patent Document 1, a line sensor arranged in the radial direction is used, the pattern is configured with an inclination with respect to the radial direction, and this pattern is read to measure the driving state. Furthermore, a circular pattern is formed, which is also measured by a line sensor at the same time, and the eccentricity is measured by reading the signal.
The rotary encoder of Patent Document 2 has a radial scale and an annular scale on the wheel portion, and each is measured by a sensor. The rotary scale is driven from the radial scale, and light is emitted from the annular scale to the edge of the annular scale. The amount of eccentricity is measured by the amount of displacement of the edge portion.
In the rotary encoder and the eccentricity correction method of Patent Document 3, a main slit pattern for detecting a rotation angle and a concentric auxiliary slit for detecting eccentricity are provided on a disk, and each is measured and corrected.

In addition, the scale pattern is read by light with a certain area and a light receiving element, the driving state of the rotating body is measured by the presence or absence of the pattern, and the eccentricity is detected by the intensity change of the light received by the light receiving element. Devices and rotating body drive devices also exist. There is also a rotating body drive detection device that provides a plurality of scales having different detection wavelength bands in parallel to the belt driving direction, detects the meandering amount of the belt, and corrects the meandering.
Further, in the conventional general rotary encoder, if the rotation axis does not coincide with the center of the radial scale plate of the wheel part (if it is in an eccentric state), the pulses are equally spaced with respect to the rotation angle of the rotation axis. Since the signal cannot be obtained and it is not suitable as a signal for rotating the rotating shaft at equal speeds based on the pulse, the wheel part of the rotary encoder must be aligned with the center of the rotating shaft as much as possible. there were.

By the way, the wheel section of this rotary encoder needs to be assembled with high accuracy one by one in order to align and join with the rotating shaft with high accuracy, and an expensive assembly device is required. There is a problem that the inspection process becomes longer and labor costs increase.
Even if the wheel part is assembled with the rotary shaft core with high accuracy once, the initial high-precision assembly is possible due to changes in the environment handled in the market, changes over time, and reassembly due to maintenance work such as repairs. There is a problem that the state cannot be secured due to external factors.
Japanese Patent Laid-Open No. 10-281811 Japanese Patent No. 2715562 JP 2001-264119 A JP 2004-109074 A

However, in Patent Document 1, a pattern is required for driving measurement, a circular pattern and two types of patterns are required for measuring eccentricity, and a line sensor is required for measurement. As the amount of eccentricity increases, the line sensor width needs to be wider, and the sensor cost increases. Conversely, when using a low-cost line sensor, it is necessary to keep the amount of eccentricity of the rotary encoder within the range that can be measured by the line sensor, which increases the manufacturing cost when attaching the rotary encoder to the measurement target. is there.
Further, in Patent Document 2, the wheel unit has a radial scale and an annular scale, each of which is measured by a sensor, and light is applied to the edge of the annular scale from the radial scale by driving the rotating body from the radial scale. Thus, the amount of eccentricity is measured by the amount of displacement of the edge portion, and at least two types of patterns and a light receiving unit are required, which has a drawback that the component cost is increased.

Similarly, in the rotary encoder and the eccentricity correction method of Patent Document 3, a main slit pattern for detecting the rotation angle and a concentric auxiliary slit for detecting the eccentricity are provided on the disk, and each is measured and corrected. Yes. Similarly, in this case, two patterns and two sensors are required, and the number of components is simply increased, resulting in an increase in cost.
Further, in the rotation amount detection device and the rotator driving device described above, the eccentric amount is detected based on the intensity change of the light received by the light receiving element, but the actual eccentric amount is several μm to several tens of μm, The light intensity change is very small, and since the SN ratio is small, there is a drawback that the eccentricity cannot be detected with high accuracy.

In order to solve the conventional problems, for example, as in Patent Document 3, the first and second tracks are provided on the wheel portion of the rotary encoder, and each is detected by two optical sensors whose phases are shifted by 90 degrees. The first sensor extracts the angle pulse signal, and the second sensor detects the amount of eccentricity, thereby devising a method that can correct even if the amount of eccentricity changes with time due to deterioration due to bearing wear from the initial setup state. However, there is a problem that two scales (tracks) and two optical sensors are required and the cost of parts increases.
Further, in Patent Document 4, two scales (a slit pattern row formed at an angle in the traveling direction of the pulse plate and a slit pattern row formed radially from the center on a wheel portion of a rotary encoder called a pulse plate) There is a system in which two optical sensors are provided in the same phase with a track), but there is also a problem in that the cost of parts increases.

  Therefore, in view of the above-described circumstances, the object of the present invention is to have a color sensor and a color dividing portion without requiring a special device or high-precision assembly in driving measurement or drive control of a rotating body. Measure the drive eccentricity of the rotating body at the same time as the rotational measurement of the rotating body with the scale pattern and band, perform drive measurement of the rotating body or drive control based on the measurement, and also detect or correct the encoder eccentricity A rotary encoder device, an angular displacement or angular velocity control device, a rotating body drive control device, and an image forming apparatus using the same.

  Another object is to drive a rotating body with a color sensor and a scale pattern or band having a color-separated portion without requiring special equipment or high-precision assembly in the drive measurement or control of the rolling element. Rotary encoder wheel and rotary encoder that simultaneously measure the eccentricity attached to the rotating body at the same time as measurement, perform drive control of the rotating body or drive control based on the measurement, and detect or correct the eccentricity of the rotary encoder. An apparatus and an image forming apparatus are provided.

In order to solve the above problems, the invention according to claim 1, a wheel unit for synchronization with the rotating body rotating in the circumference of the wheel unit, a predetermined radial position from a predetermined center point A plurality of patterns that are radially formed at predetermined angular intervals, and a plurality of strips that are concentrically arranged to overlap the pattern centered on the center point and reflect or transmit light in different wavelength bands the a pattern and a light emitting means for irradiating light to the strip portion, wherein with the rotation of the wheel unit detects the light amount change of the transmitted light or reflected light of said light emitting means is irradiated on the pattern the wheel unit And a light receiving means for outputting a rotation signal of the light receiving means , the light receiving means having sensitivity characteristics for independently detecting light amounts in a plurality of wavelength bands, and a plurality of wavelengths generated when straddling the boundary of the band-shaped portion Light By detecting and, and outputs an eccentricity signal representing the eccentricity of the center point of the pattern with respect to the rotation center of the wheel unit.

A second aspect of the present invention provides a wheel portion that rotates in synchronization with a rotating body, and a plurality of patterns that are formed radially and at predetermined angular intervals from a predetermined radial position from a predetermined center point on a circumference of the wheel portion. A plurality of strips arranged concentrically so as to overlap the pattern centered on the center point, and reflecting or transmitting light of different wavelength bands formed integrally with the pattern, the pattern and the strip A light emitting means for irradiating light to the part and a change in the amount of transmitted light or reflected light of the light emitting means irradiated to the pattern in accordance with the rotation operation of the wheel part and detecting a rotation signal of the wheel part A light receiving means, wherein the light receiving means has sensitivity characteristics for independently detecting the light amounts of a plurality of wavelength bands, and independently detects a plurality of wavelength lights generated when straddling the boundary of the band-shaped portion. You It makes and outputs an eccentricity signal representing the eccentricity of the center point of the pattern with respect to the rotation center of the wheel unit.

A third aspect of the present invention provides a wheel portion that rotates in synchronization with a rotating body, and a plurality of patterns that are radially formed at predetermined angular intervals from a predetermined radial position from a predetermined center point on a circumference of the wheel portion. And the pattern includes a divided region that reflects or transmits a specific wavelength band with a concentric circle centered on the center point as a boundary, and on the outer diameter side of the concentric circle other than the divided region in the pattern A band-shaped portion that is arranged to overlap with the region, and reflects or transmits light in a wavelength band different from the specific wavelength band, light emitting means for irradiating the pattern and the band-shaped portion with light, and rotation of the wheel portion A light receiving means for detecting a change in the amount of transmitted light or reflected light of the light emitting means irradiated on the pattern in accordance with the operation, and outputting a rotation signal of the wheel unit;
The light receiving means has a sensitivity characteristic for independently detecting the light amounts of a plurality of wavelength bands, and straddles the boundary of the band-shaped part, the boundary of the divided area, or the boundary between the band-shaped part and the divided area. By detecting a plurality of wavelength light beams generated independently, an eccentric signal indicating an eccentric amount of the center point of the pattern with respect to the rotation center of the wheel portion is output .

According to a fourth aspect of the present invention, there is provided a rotary body drive control device having a controller for generating a control command value from a difference between a measurement signal from the rotary encoder device and a target value for driving the rotary body driven by a motor. The rotary encoder device according to any one of claims 1 to 3 , further comprising an eccentricity correction mechanism that corrects eccentricity using an eccentricity signal from the rotary encoder device.
According to a fifth aspect of the present invention, the eccentricity correction mechanism is provided immediately after the controller.
According to a sixth aspect of the present invention, the eccentricity correction mechanism is provided in a feedback mechanism that feeds back the measurement signal.

According to a seventh aspect of the present invention, the eccentricity correction mechanism is provided in a mechanism that generates the target value.
According to an eighth aspect of the present invention, in the image forming apparatus for forming an image by rotating the image carrier, the drive control of the image carrier is performed by the rotary body drive control device according to any one of claims 4 to 7 , The image carrier is a photosensitive drum.
According to a ninth aspect of the present invention, in the image forming apparatus for forming an image by rotating the image carrier, the drive control of the image carrier is performed by the rotary body drive control device according to any one of claims 4 to 7 , The image carrier is a transfer drum.

According to a tenth aspect of the present invention, in the image forming apparatus for forming an image by rotating the image carrier, the drive control of the image carrier is performed by the rotary body drive control device according to any one of claims 4 to 7 , The image carrier is a photosensitive belt.
11. The image forming apparatus for forming an image by rotating the image bearing member, carried out by rotary body drive control device of any one of claims 4 to 7 the drive control of the image bearing member, wherein The image carrier is a transfer belt.
According to a twelfth aspect of the present invention, in the paper conveyance device that conveys the paper by rotating a belt or a roller, the drive control of the paper conveyance device is performed by the rotating body drive control device according to any one of the fourth to seventh aspects. It is characterized by.

  According to the present invention, the light detection means has a sensitivity characteristic in which the light detection means independently detects the light amounts of a plurality of specific wavelength bands, and is independent according to the wavelength band of the sensitivity characteristics. An eccentric signal indicating the amount of eccentricity with respect to the wheel pattern center point with respect to the rotation center of the rotary encoder wheel portion by detecting at least two color division band portions that can be detected by the light receiving means and detecting the color division band portions. With the function of outputting the signal, it is possible to obtain signals other than driving while performing highly accurate driving measurement.

  Even with a simple rotary encoder wheel assembly method, the angular velocity error of the rotary encoder pulse due to the eccentricity of the wheel pattern center point with respect to the rotational center of the rotary encoder wheel portion relative to the actual rotational body angular velocity. By correcting (shift) and obtaining an accurate angular velocity, the rotating body can be accurately controlled and driven to a desired angular velocity. In addition, once the wheel part is assembled with the rotary shaft core with high accuracy, the initial high-precision assembly state is due to environmental changes handled in the market, changes over time, and reassembly due to maintenance work such as repairs. Even if it changes due to external factors, it is possible to correct the eccentricity without being affected and to control the driving with an accurate angular velocity. In addition, even if a two-scale scale (track) and two optical sensors are not required, driving with an accurate angular velocity can be controlled with a simple configuration (one scale and only one sensor).

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic perspective view showing a rotating body driving device used in some embodiments of the present invention.
In the rotating body drive device 1 of FIG. 1, a drive target 3 is attached so as to be coaxial with the gear 2. The motor 4 drives the drive target 3 through the gear 5. The wheel portion 6 </ b> A is attached on the opposite side to the motor 4 of the drive target 3 so as to be coaxial. When the sensor 7 reads the patterns 6a and 6b on the wheel portion A6, the drive state of the drive target 3 is measured.
A drive signal 3 is driven by generating a control signal based on the value measured by the sensor 7 and rotating the motor 4. In FIG. 1, the wheel portion 6 </ b> A is attached to the opposite side to the motor 4, but this may be attached to the same side as the motor 4, that is, the gear 2 side.

FIG. 2 is a schematic perspective view showing a belt driving device used in some embodiments of the present invention. In the belt drive device 8 of FIG. 2, a drive shaft 9 is attached so as to be coaxial with the gear 2.
The motor 4 is attached so as to be coaxial with the gear 5, and driving force is transmitted from the motor 4 through the gear 5 and the gear 2 to drive the drive shaft 9. A belt 12 to be driven is hung on the drive shaft 9, the tension roller 10, and the driven shaft 11, and a certain tension is applied by the tension roller 10.
A wheel portion 6A is attached to the driven shaft 11 so as to be coaxial, and the driving state of the belt 12 is measured by the sensor 7 reading the patterns 6a and 6b on the wheel portion 6A.
A control signal is generated based on the value measured by the sensor 7, and the driving target belt 12 is driven by rotating the motor 4 as a driving source. Here, the belt 12 has the wheel portion 6A attached to the driven shaft 11, but may be attached coaxially to the tension roller 10 if there is no problem in the system.

FIG. 3 is a schematic diagram showing a simple principle configuration of pattern detection in FIGS. In FIG. 3, two types of patterns 6 a and 6 b having different amounts of reflected light are formed on the wheel portion 6 </ b> A of the rotary encoder device 6.
The pattern can be made by pasting patterns 6a and 6b having different reflected light on the wheel portion 6A, printing directly on the wheel portion 6A, or using the wheel portion 6A as a metal plate. Alternatively, an etching method may be used.
The main body of the sensor 7 has a light emitting unit 7a and a light receiving unit 7b, and light is output from the light emitting unit 7a. The output light hits the wheel portion 6A, and the reflected wave is received by a light receiving element (not shown) of the light receiving portion 7b.
On the wheel portion 6A, there are patterns 6a and 6b having different amounts of reflected light. Therefore, by reading the difference in the intensity of light received by each of these patterns 6a and 6b, for example, a waveform such as a sine wave can be obtained, and the driving state of the rotating body can be measured. Become. Here, the reflection type has been described, but a transmission type may be used as long as the same performance can be obtained. However, in the following description, the reflection type is described.

FIG. 4 is a waveform diagram showing a method of converting a signal obtained from the rotary encoder device into a pulse wave. In FIG. 4, when the light output from the light emitting part 7a of the sensor 7 of the rotary encoder device 6 of FIG. Then, a sinusoidal signal 12 is obtained.
An arbitrary threshold voltage value 13 is provided for this signal 12, and a rectangular wave pulse 14 is obtained by setting an H signal if it is higher than the threshold voltage value 13 and an L signal if it is lower than the threshold voltage value 13. Can do.

FIG. 5 is a block diagram showing the configuration of a control system that digitally controls the angular displacement of the motor based on the output signal of the motor shaft rotary encoder. In FIG. 5, the microcomputer 30 includes a microprocessor 31, a read only memory (ROM) 32, and a random access memory (RAM) 33. A microprocessor 31, a read only memory (ROM) 32, and a random access memory (RAM) 33 are respectively connected via a bus 34.
The command generator 35 outputs a state command signal for commanding the angular displacement of the motor 4 and generates a target angular displacement command signal. The output side of the command generator 35 is also connected to the bus 34. The detection interface device 36 processes the output pulse of the rotary encoder 6 and converts it into a digital numerical value.

This detection interface device 36 includes a counter (not shown) that counts the output pulses of the rotary encoder 6 and multiplies the value counted by this counter by a predetermined conversion constant of the number of pulses and diagonal displacement. Convert to angular displacement of motor shaft. A motor drive current is taken into the microcomputer 30 from the current sensor 37 via the I / O 38.
Similarly, the detection interface device 28 processes the output pulse of the detection device 29 and converts it into a digital numerical value. The detection interface device 28 includes a counter that counts the output pulses of the detection device 42. The detection device 42 is multiplied by a predetermined conversion number of the diagonal displacement of the number of pulses multiplied by the counted value of the counter. Convert to angular displacement of the attached shaft.

The DC motor driving interface 39 constitutes the motor (DC motor) driving device 40 based on the calculation result of the feedback control system shown in the following embodiments by the microcomputer 30 based on the motor shaft angular displacement and the target angular displacement. It is converted into a pulse signal (control signal) for operating a power semiconductor, for example, a transistor.
The DC motor driving device 40 operates based on the pulse signal from the DC motor driving interface 39 and controls the voltage applied to the motor 4. As a result, the motor 4 is subjected to additional value control to a predetermined angular displacement by the command generator 35.
The angular displacement of the motor 4 is detected by the motor shaft rotary encoder 6 and the interface device 36, the detection device 29 and the interface device 28, and is taken into the microcomputer 30 and the control is repeated.
Here, the angular displacement from both the detection device 29 and the motor shaft rotary encoder 6 is detected, but depending on the drive control system intended by the designer, it is possible to select which one is the main measurement signal. The same can be considered for angular velocity instead of angular displacement. Although the current control system has been described here, the control system may be a voltage control system.

FIG. 6 is a block diagram showing the configuration of the analog control system in the PLL drive system. In FIG. 6, the drive of the motor 4 is transmitted to drive the rotating body, and a pulse wave 41 is output from the rotary encoder 6 in accordance with the driving of the rotating body and input to the amplifier unit 42. The amplifier unit 42 removes noise from the output from the rotary encoder 6 and outputs a waveform-shaped signal to the speed control system PLL 43 and the speed discriminator 44.
On the other hand, the reference clock 45 is input to the VCO PLL unit 46 and a clock obtained by multiplying the reference clock 45 to an arbitrary multiplication number is output to the speed discriminating unit 44. At the same time, the reference clock 45 is also input to the speed control system PLL unit 43 as it is.

The speed discriminating unit 44 outputs a speed difference from the reference clock 45 for each period of the pulse wave 41, and the speed control system PLL unit 43 outputs a phase difference from the reference clock 45 for each period of the pulse wave 41. is doing. Each output is input to the integrating amplifier unit 47.
The integration amplifier unit 47 integrates and adds the output of the speed difference and the output of the phase difference to generate a torque command value and output it to the output drive circuit 48. The output drive circuit 48 adjusts the motor torque using PWM control.
The torque command value is compared with the triangular wave, the duty of PWM control is changed according to the magnitude relationship, and which phase of the driving phase of the motor 4 is driven is determined from the Hall signal 49 that detects the rotor position from the motor 4. . The motor 4 drives a signal obtained from the output drive circuit 48 via the driver 50.

FIG. 7 is a block diagram showing basic control for rotating and driving the motor. FIG. 7 shows a basic control block diagram for driving the motor 4 by rotating the rotating body 3 and the belt 12 shown in FIGS. 1 and 2.
In the case of normal feedback control, a control signal is output from the controller 51. Upon receipt of the control signal, the driver 52 generates a drive signal for moving the motor 4 (FIG. 1) so as to satisfy the control signal. A motor which is a driving source of 53 is driven.
Here, the controller 51 also includes a current control loop, and the plant 53 is the entire rotating body 3 or belt 12 driven by the motor 4 as shown in FIGS. 1 and 2. A signal value 54 is obtained by measuring the driving state of the rotating body 3 and the belt 12 by the rotary encoder device 6 attached coaxially to the rotating body 3 and the rotary encoder device 6 attached coaxially to the driven shaft of the belt 12. .
This signal value 54 is fed back and compared with the reference signal 55 by a subtracter to determine a deviation 56 between the current displacement or speed and the target displacement or speed. By inputting this deviation 56 to the controller 51, a new control signal is generated. This is a normal basic feedback control system.

However, in the drive measurement by the rotary encoder device 6, since the eccentricity itself with respect to the rotary encoder wheel part rotation center is not normally detected, the eccentricity of the rotary encoder wheel part rotation center with respect to the wheel pattern center point is not detected. The effect cannot be avoided. Therefore, when only the above-described normal feedback control is performed, the eccentricity of the rotary encoder wheel portion rotation center of the rotary encoder device 6 with respect to the rotational center of the rotary encoder device 6 which is a variation that does not exist is detected and corrected. As a result, the rotation of the rotating body itself to which the rotary encoder device 6 is attached to cause a fluctuation in the period.
Therefore, in the first embodiment of the present invention to be described later, with respect to the drive control system that drives the rotating body by feeding back the measurement signal from the rotary encoder 6 device, The eccentricity with respect to the wheel pattern center point or the mounting eccentricity to the rotating body is detected and corrected to the output value of the controller 51. Color division strip color division pattern

FIG. 8 is an explanatory diagram showing the angular velocity fluctuation or angular displacement fluctuation caused by the eccentricity of the wheel pattern center of rotation with respect to the wheel portion rotation center of the rotary encoder device. In FIG. 8, a pattern 6a is formed on the wheel portion 6A. This pattern 6a is read at the measurement position 14 by a sensor not shown here.
At this time, if the rotation center of the wheel portion 6A is 15, the rotation center 15 rotates by an eccentric amount as indicated by reference numeral 16 due to the eccentricity of attachment. Due to this eccentric rotation, the actual rotation radius differs from the measurement rotation radius. For example, the position 17 has the shortest measurement radius and the position 18 has the longest measurement radius. As a result, the angular velocity or angular displacement fluctuates like a sine wave 20 with respect to the target angular velocity or angular displacement 19 in the rotation cycle of the rotary encoder device.

FIG. 9 is a schematic diagram showing color division band portions and pulses as color components of reflected light provided in the circumferential direction so as to overlap the pattern. In FIG. 9, in order to detect the eccentric amount of eccentricity with the wheel pattern center point with respect to the wheel portion rotation center of the rotary encoder, a non-reflective pattern 21 is formed on the totally reflecting wheel portion 6 </ b> A. The color component of the reflected light is provided with a color division band portion in the circumferential direction so as to overlap.
Here, as an example, it is assumed that a red belt portion 22 (dotted strip) is provided on the outside and a blue belt portion 23 (solid line strip) is provided on the inside. Here, it is assumed that only the color is not reflected from the color division band-like portion. That is, the red band portion 22 does not include the R wavelength band component in the reflected light, and the blue band portion 23 does not include the B wavelength band component in the reflected light.

Further, a gap 24 is provided in the red belt portion 22 and the blue belt portion 23, and the wheel portion 6A is exposed here. Here, the waveforms of the R wavelength band component and the B wavelength band component when white light is applied will be described.
However, although the R component and the B component are described here for simplification of description, other color components may be used as long as other color division band portions are used, and it is sufficient that at least two types or more can be detected. However, in the following description, description will be made using the R wavelength band component and the B wavelength band component. In addition, here, the change in the pulse wave measured by providing the gap 24 is made easy to understand, but a configuration in which the gap 24 is not provided is also possible.
Suppose that the sensor position apparently passes a locus 25 (a thin strip with a solid line) on the pattern due to the influence of eccentricity. The pulse wave obtained from each of the R wavelength band component and the B wavelength band component at this time is shown in the lower part of FIG.

First, in the locus 26, the sensor detects the red band portion 22 and the non-reflective pattern 21, so that a pulse wave is obtained for the B component, but a pulse wave is obtained because the R wavelength band component is always non-reflective. Absent. Thereafter, when moving to the locus 27 portion, the gap 24 and the non-reflective pattern 21 are detected by the sensor, so that a pulse wave is obtained for both the R wavelength band component and the B wavelength band component.
Thereafter, when moving to the locus 66 portion, the blue band-like portion 23 and the non-reflective pattern 21 are detected by the sensor, so that a pulse wave is obtained for the R wavelength band component, but a pulse wave is obtained because the B wavelength band component is always non-reflective. Cannot be obtained. Then, a waveform similar to that of the locus 27 is obtained from the locus 67 and a waveform similar to that of the locus 26 is obtained from the locus 68.
The waveforms of the R wavelength band component and the B wavelength band component from the locus 26 portion to the locus 68 portion are 69 and 70 pulse waves, respectively. Here, as one example of how to make the color division strip portion, there is a method of attaching a color film to the color division strip portion.

FIG. 10 is a schematic view showing a pattern formed as one by a non-reflective pattern and a color division pattern divided in the radial direction. In FIG. 10, a pattern formed as one by non-reflective patterns 71 and 72 and color division patterns 73 and 74 divided in the radial direction is provided on the totally reflecting wheel portion 6A.
Here, as an example, the non-reflective pattern 72 will be described. On the non-reflective pattern 72, a red pattern 73 consisting of a thin solid strip of the locus 25 and a dotted strip that is the next outer color division pattern, It is composed of a blue strip 74 of a solid strip which is an inner color division pattern.

It is assumed that the sensor position apparently passes the locus 25 on the pattern due to the influence of eccentricity. The pulse wave obtained from each RB component at this time is shown in the lower part of FIG. First, in the locus portion 26, the sensor detects the wheel portion 6A and the non-reflective pattern 71, so that a pulse wave is obtained for both the R component and the B component.
After that, when moving to the locus 27 portion, the sensor detects the red pattern 73 on the wheel portion 6A, so that a pulse wave is obtained for the R wavelength band component, but since all of the B wavelength band component is reflected light, the pulse wave is generated. I can't get it.
After that, when moving to the locus 66 part, the sensor detects the wheel portion 6A and the blue pattern 74, so that a pulse wave is obtained for the B wavelength band component, but since the R wavelength band component is all reflected light, the pulse wave is generated. I can't get it.

Thereafter, when moving to the locus 67 portion, the sensor detects the wheel portion 6A and the non-reflective pattern 72, so that a pulse wave is obtained for both the R wavelength band component and the B wavelength band component. Then, a trajectory 68 is obtained from the trajectory 66, a trajectory 75 is obtained from the trajectory 27, and a trajectory 76 is obtained from the trajectory 26.
The waveforms of the R wavelength band component and the B wavelength band component from the locus 26 portion to the locus 76 portion are 77 and 78 pulse waves, respectively. Here, as an example of the color division strip portion, there is a method of attaching a color film to the color division strip portion.

FIG. 11 is a schematic diagram showing color division band portions and pulses as color components of reflected light provided in the circumferential direction so as to overlap the pattern. Next, in FIG. 11, a pattern formed as one by the non-reflective pattern 21 and the color division pattern 23 divided in the radial direction is provided on the totally reflecting wheel portion 6A, and the circumferential direction is overlapped with the pattern. The color component of the reflected light is provided with a color division band portion.
Here, as an example, it is assumed that a red pattern 23 (a half dotted line portion of the non-reflective pattern 21) and a color division band-like portion are provided with a blue belt-like portion 79 (solid-line circumferential strip). It is assumed that the sensor position apparently passes the locus 25 on the pattern due to the influence of eccentricity.
A pulse wave obtained from each of the R wavelength band component and the B wavelength band component at this time is shown in the lower part of FIG. First, in the locus 26 portion, the sensor detects the non-reflective pattern 21 on the wheel portion 6A, so that a pulse wave is obtained for both the R wavelength band component and the B wavelength band component.

Thereafter, when moving to the locus 27 portion, the blue band 79 and the non-reflective pattern 21 are detected by the sensor, so that a pulse wave is obtained for the R wavelength band component, but a signal is obtained for the B wavelength band component because there is no reflected light. Absent. Thereafter, when moving to the locus 66 portion, the sensor detects the wheel pattern 6A and the red pattern 23, so that a pulse wave is obtained for the R wavelength band component. I can't get it.
Then, a waveform similar to that of the locus 27 is obtained from the locus 67 and a waveform similar to that of the locus 26 is obtained from the locus 68. The waveforms of the R wavelength band component and the B wavelength band component from the locus 26 to the locus 68 are 80 and 81 pulse waves, respectively. Here, as an example of how to make the color division band portion or the color division pattern portion, there is a method of attaching a color film to the color division region.
As a method of measuring the drive of the rotating body and the eccentricity of the wheel pattern center point with respect to the wheel rotation center of the rotary encoder device from the pulse wave from the rotary encoder device of FIGS. Since one continuous pulse wave can be obtained by adding together the pulse waves obtained from the wavelength band component and the B wavelength band component, it is used for drive measurement. Since the same pattern is basically read by the same sensor, only the wavelength of reflected light to be measured is different, and the period and timing of the pulse wave are the same for the R wavelength band component and the B wavelength band component.

FIG. 12 is a waveform diagram showing an example of a specific method for measuring the eccentricity with respect to the wheel pattern center point with respect to the wheel portion rotation center of the rotary encoder device. Here, an example will be described using the lower pulse wave of FIG. 9, but the eccentricity can be similarly measured by the same timing detection in the lower pulse wave of FIG. 10 and the lower pulse wave of FIG. 11. The eccentric cycle of the rotary encoder wheel portion is the rotation cycle of the rotary encoder device itself, and the shape can be considered as a sine wave.
Therefore, the basic form of eccentricity is represented by a sine wave 82. The sine wave 82 represents the eccentric position of the wheel portion, and becomes an eccentric waveform as it is. That is, when the amplitude is 0, the pattern is at the specified position, the actual radius is maximum due to eccentricity at the upper peak, and the actual radius is minimum due to eccentricity at the lower peak.

The case where there is no R component pulse wave and only the B wavelength band component is present is when the sensor position is at position 23 due to eccentricity. From there, a timing 83 at which a pulse wave is obtained for both the R wavelength band component and the B wavelength band component indicates that the position of the sensor has moved from 23 to the gap.
After that, a pulse wave is obtained for the R wavelength band component, but a timing 84 at which the pulse wave of the B wavelength band component cannot be obtained indicates that the position of the sensor has moved from the gap to 79. Furthermore, at timing 85 when the B wavelength band component is obtained again, it indicates that the position of the sensor has moved from 79 to the gap again.
Thereafter, at timing 86 when the pulse wave of the R wavelength band component cannot be obtained, the position of the sensor moves from the gap to 23. Here, the gap interval is clear in advance from the design stage, the cycle of the sine wave 82 is the rotation cycle of the rotary encoder device, and the amplitude of the sine wave 82 from the timings 83, 84, 85, 86. The current phase is uniquely determined.
In this way, the shape of the eccentricity can be obtained. However, here, even if it is not the start timing, for example, even if the measurement is started from the timing 85, the amount of eccentricity can be obtained similarly. In addition, in order to detect the amount of eccentricity with higher accuracy, the frequency of crossing the color division region increases as the number of divisions and the density of the color division band portion or color division pattern portion increases, and the detection resolution is improved. And it can detect with sufficient precision.

FIG. 13 is a block diagram showing a portion for generating an eccentricity amount. In FIG. 13, the R wavelength band component pulse wave 87 and the B wavelength band component pulse wave 88 of FIG. 12 are input to the comparison operation unit 91 as the input signal 90. The information is input to the comparison calculation unit 91 from the memory 92 in which a sine wave representing basic eccentricity is stored.
The comparison operation unit 91 compares the required timing from the R wavelength band component pulse wave 87 and the B wavelength band component pulse wave 89 with the sine wave from the memory 92 as described in FIG. The amplitude and phase are obtained and output as an eccentricity amount 93, which is input to the correction unit shown below. The eccentric amount 93 may be output as a sine wave or may be changed to a pulse wave by a subsequent mechanism.

FIG. 14 is a block diagram of the first embodiment of the drive control system that performs correction processing on the output value of the controller. In FIG. 14, drive control is performed using the rotary encoders of FIGS. 9 to 11, the eccentric eccentric phase of the wheel portion of the rotary encoder is detected, and the output value of the controller is corrected.
A control signal is output from the controller 51. A pulse wave 93 indicating eccentricity from the rotary encoder device is input to the correction unit 57. The correction unit 57 includes the configuration shown in FIG. 13 and is converted into a signal that can be added to the control signal and can cancel the eccentric component of the wheel portion of the rotary encoder. .
The signal from the correction unit 57 and the control signal from the controller 51 are added and input to the driver 52. The driver 52 generates a drive signal for moving the motor so as to satisfy the control signal, thereby driving the motor that is the drive source of the plant 53.

Here, the controller 51 also includes a current control loop, and the plant 53 is a rotating body or an entire belt driven by a motor as shown in FIGS. A signal value 54 is obtained by reading the driving state of the rotating body and the belt with a rotary encoder coaxial with the rotating body and a rotary encoder attached to the driven shaft of the belt.
This signal value 54 is fed back and compared with the reference signal 55 by a subtracter to determine a deviation 56 between the current angular displacement or angular velocity and the target angular displacement or angular velocity. By inputting this deviation 56 to the controller 51, a new control signal is generated. This is a feedback control system that takes into account the mounting eccentricity of the wheel portion of the rotary encoder.

FIG. 15 is a block diagram showing the configuration of the analog control system in the PLL drive system. In FIG. 15, the drive of the motor 4 is transmitted to drive the rotating body, and the pulse wave 41 is output from the rotary encoder 6 in accordance with the driving of the rotating body and input to the amplifier unit 42. The amplifier unit 42 removes noise from the output from the rotary encoder device 6 and outputs a waveform-shaped signal to the speed control system PLL 43 and the speed discriminator 44.
On the other hand, the reference clock 45 is input to the VCO PLL unit 46 and a clock obtained by multiplying the reference clock 45 to an arbitrary multiplication number is output to the speed discriminating unit 44. At the same time, the reference clock 45 is also input to the speed control system PLL unit 43 as it is.
The speed discriminating unit 44 outputs a speed difference from the reference clock 45 for each period of the pulse wave 41, and the speed control system PLL unit 43 outputs a phase difference from the reference clock 45 for each period of the pulse wave 41. is doing. Each output is input to the integrating amplifier unit 47.

The integrating amplifier unit 47 integrates and adds the output of the speed difference and the output of the phase difference to generate a torque command value. The generated torque command value is input to the eccentricity correction unit 57. An eccentricity signal 58 is also fed back and input from the rotary encoder 6 to the eccentricity correction unit 57.
The eccentricity correction unit 57 generates a signal that has an opposite phase to the eccentricity signal 58 and is amplified to a necessary amplitude. The new torque command value generated by the eccentricity correction unit 57 is output to the output drive circuit 48. The output drive circuit 48 adjusts the motor torque using PWM control.
The torque command value is compared with the triangular wave, the duty of PWM control is changed according to the magnitude relationship, and which phase of the driving phase of the motor 4 is driven is determined from the Hall signal 49 that detects the rotor position from the motor 4. . The motor 4 drives the signal obtained from the output drive circuit 48 via the driver 50.
According to the first embodiment configured as described above, even if there is eccentricity of the wheel portion of the rotary encoder device or attachment eccentricity to the rotating body, the rotating body 3 and the belt 12 are affected by the eccentricity. And can be driven with high accuracy.

FIG. 16 is a block diagram showing a second embodiment of a drive control system that detects a mounting eccentric phase of a wheel portion of a rotary encoder and corrects a feedback value. In the second embodiment, an eccentricity of the rotary encoder device itself and an eccentricity attached to the rotating body are detected with respect to a drive control system that feeds back a measurement signal from the rotary encoder device to drive the rotating body, and a feedback value is obtained. To correct. The configuration method of the rotary encoder device for obtaining the eccentricity can be considered as in the first embodiment.
In the second embodiment in which the wheel part of the rotary encoder device is detected and the eccentricity phase is detected and the feedback value is corrected, a control signal is output from the controller 51 and input to the driver 52. The driver 52 generates a drive signal for moving the motor so as to satisfy the control signal, thereby driving the motor that is the drive source of the plant 53.
Here, the controller 51 also includes a current control loop, and the plant 53 is the entire rotating body 3 or belt 12 driven by the motor 4 as shown in FIGS. A signal value 54 is obtained by reading the rotary encoder device coaxial with the rotary member 3 and the rotary encoder device attached to the driven shaft 11 of the belt 12 with respect to the driving state of the rotary member 3 and the belt 12. This signal value 54 is fed back and input to the correction unit 57.

Separately, a pulse wave 93 indicating eccentricity from the rotary encoder device is input to the correction unit 57, and the correction unit 57 includes a configuration as shown in FIG. The attachment eccentric component is also added, and a corrected feedback value 94 is output.
The correction feedback value 94 is compared with the reference signal 55 by a subtracter, and a deviation 56 between the current angular displacement or angular velocity and the target angular displacement or angular velocity is obtained. By inputting this deviation 56 to the controller 51, a new control signal is generated. This is a feedback control system that takes into account the mounting eccentricity of the wheel portion of the rotary encoder device.

FIG. 17 is a block diagram showing the configuration of the analog control system in the PLL drive system. FIG. 17 shows a case where the same thing as FIG. 16 is configured by analog PLL drive.
In FIG. 17, the driving of the motor 4 is transmitted to drive the rotating body, and the pulse wave 41 is output from the rotary encoder device 6 according to the driving of the rotating body and is input to the eccentricity correction unit 57. An eccentricity signal 58 is also fed back and input from the rotary encoder device 6 to the eccentricity correction unit 57.
The eccentricity correction unit 57 adds the eccentricity information to the current driving state measured by the rotary encoder device 6, thereby creating a new pulse wave 64 including eccentricity information that cannot be measured originally. A new pulse wave 64 is output from the eccentricity correction unit 57 and input to the amplifier unit 42. The amplifier unit 42 removes noise from the output from the rotary encoder 6 and outputs a waveform-shaped signal to the speed control system PLL 43 and the speed discriminator 44.
On the other hand, the reference clock 45 is input to the VCO PLL unit 46 and a clock obtained by multiplying the reference clock 45 to an arbitrary multiplication number is output to the speed discriminating unit 44. At the same time, the reference clock 45 is also input to the speed control system PLL unit 43 as it is.

The speed discriminating unit 44 outputs a speed difference from the reference clock 45 for each period of the pulse wave 41, and the speed control system PLL unit 43 outputs a phase difference from the reference clock 45 for each period of the pulse wave 41. is doing. Each output is input to the integrating amplifier unit 47.
The integration amplifier unit 47 integrates and adds the output of the speed difference and the output of the phase difference to generate a torque command value and output it to the output drive circuit 48. The output drive circuit 48 adjusts the motor torque using PWM control.
The torque command value is compared with the triangular wave, the duty of PWM control is changed according to the magnitude relationship, and which phase of the driving phase of the motor 4 is driven is determined from the Hall signal 49 that detects the rotor position from the motor 4. . The motor 4 drives a signal obtained from the output drive circuit 48 via the driver 50. A method of generating an eccentric signal as a digital signal such as a pulse wave can be considered in the same manner as in the first embodiment.
According to the second embodiment configured as described above, even if there is eccentricity of the wheel portion of the rotary encoder device or attachment eccentricity to the rotating body, the rotating body 3 and the belt 12 are affected by the eccentricity. It can be driven with high accuracy without giving.

FIG. 18 is a block diagram showing the control of the third embodiment of the present invention for rotating and driving the motor. FIG. 18 shows a block diagram of a drive control system that detects a mounting eccentric phase of the wheel portion of the rotary encoder device and corrects the target value.
In the third embodiment, a control signal is output from the controller 51 and input to the driver 52. The driver 52 generates a drive signal for moving the motor so as to satisfy the control signal, thereby driving the motor that is the drive source of the plant 53.
Here, the controller 51 also includes a current control loop, and the plant 53 is the entire rotating body 3 or belt 12 driven by a motor as shown in FIGS. A signal value 54 is obtained by reading the driving state of the rotating body 3 and the belt 12 with a rotary encoder apparatus coaxial with the rotating body and a rotary encoder apparatus attached to the driven shaft of the belt.

This signal value 54 is input to the feedback subtractor. On the other hand, the pulse wave 93 indicating the eccentricity from the rotary encoder device is input to the correction unit 57. The correction unit 57 includes the configuration shown in FIG. 13 and can be added to the target value 55. It is shaped into a waveform that can correct the eccentricity of the rotary encoder and is output, and is actually added to the target value 55 to generate a corrected target value.
The corrected target value and the signal value 54 are compared with a subtracter to obtain a deviation 56 between the current angular displacement or angular velocity and the target angular displacement or angular velocity. By inputting this deviation 56 to the controller 51, a new control signal is generated. This is a feedback control system that takes into account the mounting eccentricity of the wheel portion of the rotary encoder device.

FIG. 19 is a block diagram showing a configuration of an analog control system in the PLL drive system. FIG. 19 also shows a case where the same thing as FIG. 18 is configured by analog PLL drive.
In FIG. 19, the driving of the motor 4 is transmitted to drive the rotating body, and the pulse wave 41 is output from the rotary encoder device 6 and input to the amplifier unit 42 according to the driving of the rotating body. The amplifier unit 42 removes noise from the output from the rotary encoder device 6 and outputs a waveform-shaped signal to the speed control system PLL 43 and the speed discriminator 44.
On the other hand, the reference clock 45 is input to the eccentricity correction unit 57 and, at the same time, the eccentric signal 58 is also input from the rotary encoder device 6. The eccentricity correction unit 57 generates a signal including an eccentric component by the eccentric signal 58, converts the signal into a pulse wave that can be added to or subtracted from the reference clock 45, and outputs a new reference clock 65.

The new reference clock 65 is input to the VCO PLL unit 46, and the reference clock 45 multiplied to an arbitrary multiplication number is output to the speed discriminating unit 44. At the same time, the new reference clock 65 is also input to the speed control system PLL unit 43 as it is.
The speed discriminating unit 44 outputs a speed difference from the new reference clock 65 for each period of the pulse wave 41, and the speed control system PLL unit 43 calculates the phase difference from the new reference clock 65 for each period of the pulse wave 41. Output. Each output is input to the integrating amplifier unit 47.
The integration amplifier unit 47 integrates and adds the output of the speed difference and the output of the phase difference to generate a torque command value and output it to the output drive circuit 48. The output drive circuit 48 adjusts the motor torque using PWM control.

The torque command value is compared with the triangular wave, the duty of PWM control is changed according to the magnitude relationship, and which phase of the driving phase of the motor 4 is driven is determined from the Hall signal 49 that detects the rotor position from the motor 4. . The motor 4 drives a signal from the output drive circuit 48 via the driver 50. A method of generating an eccentric signal as a digital signal such as a pulse wave can be considered in the same manner as in the first embodiment.
According to the third embodiment configured as described above, even if there is eccentricity of the wheel portion of the rotary encoder device or attachment eccentricity to the rotating body, the rotating body 3 and the belt 12 are affected by the eccentricity. And can be driven with high accuracy.

  FIG. 20 is a diagram illustrating an example of a rotating body driving device. 101: The rotational torque of the motor is driven by 102: the motor gear, and 113: the driving roller is driven by the 113: roller gear. 114: Parallel to the drive roller 115: Tension roller, 116: Roller, 102: Opposing to the motor gear 105: 106 at the tip of the rotating body shaft: To the wheel mounting shaft portion 108: 107: Wheel coaxial with the center of the rotary encoder wheel The boss portion is inserted and fixed by a joining means (screw fastening, adhesion, press fitting, etc.) not shown. 108: There are 109: pattern portions arranged at an equiangular pitch around the rotary encoder wheel, and 110: a pattern portion at a fixed position is subjected to photoelectric conversion of a light amount change that changes depending on a rotation angle by an optical sensor, and angle detection is performed. .

  FIG. 21 is a diagram illustrating another example of the rotating body driving device. 101: The rotational torque of the motor is driven by 102: the motor gear, and 111: the driving roller is driven by the 111: roller gear. 112: Parallel to the driving roller, 113: Tension roller, 114: Driven roller are arranged at their functioning positions, and an endless 115: belt is put on the outer peripheral surfaces of each other by frictional contact. 113: In the tension roller, 115: imparts a conveying force to the belt by applying a uniform tension load to both end shafts by a tension applying means (coil spring or the like) (not shown), and 114: torque for rotating the driven roller Is communicating. 114: driven roller 116: roller shaft tip 117: wheel mounting shaft portion 108: coaxial with the center of the rotary encoder wheel 107: wheel boss portion is inserted, and joining means (not shown) (screw fastening, adhesion, press fitting) Etc.). 107: 109: pattern portions arranged at an equiangular pitch around the rotary encoder wheel, 110: at a fixed position 110: photoelectric conversion of a light amount change that changes depending on a rotation angle by an optical sensor, and angle detection is performed. . The 121: rotary encoder wheel 109: pattern part 110: the optical sensor detects 115: the belt conveying linear velocity is measured. 110: A belt conveyance speed control signal is generated based on a pulse signal detected by the optical sensor, and a desired 115: belt conveyance linear velocity can be obtained by controlling a rotation angular speed for rotating a motor 101: a motor. I can do it.

In FIG. 21, the 108: rotary encoder wheel is mounted on the 112: driven roller shaft. However, if there is no problem in the system, it may be mounted on the 113: tension roller shaft.
In FIGS. 20 and 21, 108: rotary encoder wheel 109: pattern portion 110: optical sensor recognizes the difference in transmittance and converts it into H, L, binary digital signals. Not only the transmission type optical sensor but also a reflection type optical sensor (not shown) may be used to recognize patterns having different reflectivities.
FIGS. 22A, 22B, 22C, and 22D are diagrams showing the state of rotation of the roller encoder eccentric mounting. For comparison, the rotary encoders shown in FIGS. 23-a, b, c, d, a ′, and c ′ of the conventional example are also shown. The state is shown by shifting the rotation phase by 90 degrees.

The edges of the conventional rotary encoder pattern (FIG. 22) are formed radially from the center, whereas the rotary encoder as shown in FIG. 23 (details are FIGS. 23-a ′ and c ′). One side of the pattern edge is a line connecting the points c and d on the normal line (in the effective pattern area of the rotary encoder), and the other side facing the line is a line connecting the points a and b. On the other hand, an angle θ2 is provided as shown. (Θ1 indicates an arrangement pitch angle of a plurality of patterns.)
In both FIGS. 22-a and 23-a, the pattern on the angular phase of the rotary encoder eccentric to the outside at the position of the optical sensor is referred to as a pattern 1 for convenience, and the pattern is formed counterclockwise from that point. It is divided into 2, 3, 4. 22-b and FIG. 23-b show a state where the rotary encoder is rotated 90 degrees clockwise, FIG. 22-c and FIG. 23-c are sequentially 180 degrees, and FIG. 22-d and FIG. 23-d are 270 degrees. The rotated state is shown.

  FIG. 24 is a detailed view of an embodiment of the present invention. 109S: The shape of the pattern portion is a side (normal portion) on the normal passing through the wheel center point (O), and the other side is a straight line having a certain inclination angle (θa). The intersection of the sides passes through the intersection Xout on the outside of the pattern portion in the figure, but the position of the intersection is not particularly limited to the inside or outside of the pattern portion, and the angle to the normal ( It is characterized by having θ).

FIG. 25 is a detailed view of an embodiment of the present invention. 109R: The shape of the pattern portion forms an angle of α, β, γ, and δ with the side on the normal passing through the wheel center point (O) (the normal portion) and the other side having the normal as a reference line This indicates that the tangent angle is constant at each of the radial positions a, b, c, and d where the hypotenuse of the pattern portion is different from another normal line. Therefore, the hypotenuse does not become a straight line. It becomes a continuous curve with a constant tangential slope. (Involute curve)
Here, a side (normal portion) on the normal line passing through the wheel center point (O) shown in FIG. 24 and another side form angles of α, β, γ, and δ with the normal as a reference line. Unlike the normal line 109S: the intersections at the radial positions a, i, c, and d in which the hypotenuses of the pattern portions are different from those in FIG. This shows that the tangent angle becomes larger (as the center is closer to O), and this is a different important point in the present invention in that the tangential slope is a constant curve.

  FIG. 26 is a detailed view of an embodiment of the present invention. 109T: The shape of the pattern part is a straight line (normal line part) on the normal passing through the wheel center point (O), and the other side is a straight line having a certain inclination angle (θb). The intersection of the two sides passes through the intersection Xin outside the pattern portion in the drawing.

  FIG. 27 is a detailed view of an embodiment of the present invention. 108A made of a transparent disk-like plate such as a transparent resin or glass having a high light transmittance: The wheel portion transparent plate has a low transmittance that can be detected (identified) by 110T: a transmission type optical sensor (different transmittance) 109A: The pattern (coloring) is drawn by a method regardless of means such as printing, etching, or baking. One side of the pattern is on the normal line of the wheel, and the other side is a method of the wheel portion. On the line, the other side is a pattern sandwiched between two sides that are straight or curved.

  FIG. 28 is a detailed view of an embodiment of the present invention. 108B made of an opaque disk-shaped plate such as colored resin or metal having low light transmittance, and the wheel portion has an opening 109B: pattern (opening) portion that can be detected (identified) by a transmission optical sensor, It is formed by any method such as press processing, etching, laser processing, etc. What is characteristic is that the intersection of 109B: pattern part is inside the radius detected by 110T: transmission optical sensor Therefore, the shape is written in a sawtooth shape, but it is not always necessary to have such a shape. For example, a pattern that becomes a wheel portion is formed on a disk made of a transparent material (glass or transparent resin). It may be drawn by any method such as printing, etching or baking.

  29 is a detailed view of an embodiment of the present invention. The 108C made of an opaque disk-shaped plate such as colored resin or metal having low light transmittance, and the wheel portion has an opening 109C that can be detected (identified) by a transmission optical sensor, and a pattern (opening) portion. It is formed by any method such as press processing, etching, laser processing, etc., and the characteristic is that 109C: the intersection of the pattern part is outside the radius detected by 110T: transmissive optical sensor Therefore, the shape is written in the shape of a lotus root of a triangular triangular hole, and because the triangular hole 109C: pattern part is open, 120: the wheel outer ring part is not provided on the outside, and the adjacent 109C: between the pattern parts This shading region is provided because it is inconvenient because it is easy to bend because the shape of the light-shielding region becomes thinner near the center and it is difficult to ensure the strength.

  FIG. 30 is a detailed view of an embodiment of the present invention. The reflectance is reduced by means that do not limit the means such as coloring or plating on colored resin or metal plate with low light reflectance 108D: By means that are not limited to printing or plating as the wheel part By increasing the reflectivity, at least 110H: high transmittance reflectivity (differing reflectivity) with high reflectivity that can be detected (identified) by the reflective optical sensor 109D: pattern portion is printed or It is drawn by any method such as etching or baking, and one side of the pattern of the present invention is on the normal line of the wheel part, and the other side is on the normal line of the wheel part, and the other side. The side of the pattern is a pattern sandwiched between two sides that are curved.

  FIG. 31 is a detailed view of an embodiment of the present invention. 108E made of a disk-shaped plate such as colored resin or metal having high light reflectivity: The wheel part is formed by pressing an opening 109E: pattern (opening) part that can be detected (identified) by 110H: a reflective optical sensor. In addition, it is formed by a method regardless of processing means such as etching, laser processing, etc., and is characterized in that 109E: the intersection of the pattern part is inside 110H: radius detected by the reflective photosensor. Therefore, the shape is written in a sawtooth shape, but it is not necessarily such a shape. For example, 108E: a pattern that becomes a wheel portion is printed on a disk made of a transparent material (glass or transparent resin) It may be drawn by any method such as etching or baking.

  FIG. 32 is a detailed view of an embodiment of the present invention. 108F made of a disk-shaped plate such as colored resin or metal having a high light reflectivity: The wheel part has a 109H: pattern (opening) part that can be detected (identified) by 110H: a reflective optical sensor, and is pressed. In addition, it is formed by a method regardless of processing means such as etching or laser processing, and is characterized in that 109F: the intersection of the pattern portion is outside the radius 110H: detected by the reflective photosensor. Therefore, the shape is written in the shape of a lotus root of a triangular triangular hole, and 109F of the triangular hole: the pattern portion is open, so that 120: the wheel outer ring portion is not provided on the outside thereof, and the adjacent 109F: light shielding between the pattern portions The region is provided because the shape of the region is narrower toward the center and it is difficult to ensure the strength, which makes it easier to bend.

FIG. 33 shows a pulse output waveform in a normal state without mounting eccentricity by a conventional pattern (an encoder having a pattern as shown in FIG. 22), and FIG. 36 is an expression showing a relationship between pulse widths for one week. is there.
First, in FIG. 33, the pulse widths of the H level (hereinafter referred to as H) or the L level (hereinafter referred to as l) from the encoder pattern 1 to the pattern 72 for one turn are equal, and the equation (1) shown in FIG. It becomes as follows.

  FIG. 34 shows a pulse output waveform when the wheel portion of the conventional rotary encoder is mounted eccentrically, and FIG. 37 shows the pulse width of H with respect to the (H + L) inter-pattern pulse width in a typical pattern at that time. The ratio is shown. (P1 is a state in which the encoder wheel shown in FIG. 22a is attached most outward with respect to the center of rotation, P19 is a state rotated 90 degrees clockwise from the state of FIG. 22a as shown in FIG. 22-b, and P37 is a figure. As shown by 22c, it is rotated 180 degrees clockwise from the state of FIG. 22a, and P55 is rotated by 270 degrees clockwise from the state of FIG. 22a as shown in FIG. 22d.) P1 is the state with the coarsest pulse width. However, the ratio of H / (H + L) is the same as the other P19, the densest P37, and P55.

  FIG. 35 shows a pulse output waveform when a rotary encoder having a pattern shape according to the present invention is mounted eccentrically, and FIG. 38 shows a pulse of H with respect to (H + L) inter-pattern pulse width in a typical pattern at that time. The ratio to the width is shown. (P1 is the state in which the encoder wheel shown in FIG. 23a is attached most outward relative to the center of rotation, P19 is the state rotated 90 degrees clockwise from the state shown in FIG. 23a, and P37 is the state shown in FIG. 23c. As shown in FIG. 23a, it is rotated 180 degrees clockwise, and P55 is rotated 270 degrees clockwise as shown in FIG. 23d.) P1 is the coarsest pulse width state. , H / (H + L) ratios are the same as P19, the densest P37, and P55.

The relationship of the typical pulse width in the normal mounting state with the rotary encoder pattern is
H1 / (H1 + L1) <H19 / (H19 + L19) <H37 / (H37 + L37)
H19 / (H19 + L19) = H55 / (H55 + L55)
However,
H1>H19>H37>, H19 = H55
L1>L19>L37>, L19 = L55
It shows that the pulse width rate of the H level in P1 to P19 to P37 to P55 to P1 varies depending on the Sin function. (From the “Relationship Between Rotary Encoder Pulse No. and H / (H + L)” shown in FIG. 39, the average value of the ratio of H / (H + L) is 0.5, from 0.4 (Min.) To 0.6 ( Max.), Assuming that 0.4 is generated in pulse No. 19 and 0.6 is generated in pulse No. 55, the eccentric phase of the rotary encoder is outside the phase of pattern 55. It will be eccentric.)

  FIG. 40 is a block diagram showing an embodiment of a system for extracting a rotary encoder eccentricity signal and generating a normalized pulse by eccentricity correction according to the present invention. First, in (150), the analog output from the rotary encoder is A / D converted in (151), and in (152), it is output for each pattern such as P1, P2, P3. The component extraction and (154) eccentric signal component extraction are performed. Specifically, “by the eccentricity of the rotary encoder relative to the rotation axis according to the ratio of the H and L level pulse width to the rotation angle. The amount of H / (H + L) Sin function periodic fluctuation obtained from the pattern of one round of the rotary encoder (P1, P2, P3... The amplitude and phase are obtained and the fluctuation components are separated (filtered).

Further, by knowing the fluctuation component (amplitude), the eccentric amount of the rotary encoder is obtained from the preliminarily tabulated (155) eccentric amount calculation reference table, and at the same time, the peak value of the Sin function is obtained at (154). No. of the pattern indicating (Max. Or Min.). (157) Eccentric phase is detected, and based on the amount of eccentricity obtained in (156) and the eccentric phase obtained in (157), the pulse width of the rotational pulse signal component obtained in (153) is corrected. By applying (159), the rotation signal pulse width correction output is executed. For example, even if the rotary encoders shown in FIGS. 20 and 104 and the rotating rollers shown in FIGS. 21 and 116 and the driven rollers are attached to the respective rollers 108 and the rotary encoder are attached in an eccentric state, these series of block diagrams are used. 101: By controlling the rotational speed of the motor, it becomes possible to operate these rotating bodies accurately at an equal angular speed.
The series (152 to 159) of digital processing units may use a device such as a DSP (Digital Signal Processor) that can perform high-speed arithmetic processing, but is not limited to this as long as a similar circuit can be easily configured. Absent.

FIG. 41 is a schematic view showing an image forming apparatus comprising a color copying machine as a fourth embodiment of the present invention. In FIG. 41, reference numeral 110 denotes an apparatus main body according to the fourth embodiment. The apparatus main body 110 includes a drum-shaped photoconductor (photosensitive drum) 312 as an image carrier, slightly to the right of the center in the exterior case 111.
Around the photoreceptor 312, a rotating type developing device 114, an intermediate transfer unit 115, a cleaning device 116, as developing means, in order from the charger 113 installed on the photoreceptor 312 in the direction of the arrow (counterclockwise). A static eliminator 117 and the like are arranged.
On these charger 113, rotary developing device 114, cleaning device 116, and static eliminator 117, an optical writing device as an exposure unit, for example, a laser writing device 118 is installed.

The rotary developing device 114 includes developing devices 120A, 20B, 20C, and 20D each having a developing roller 121 that stores toners of yellow, magenta, cyan, and black, and rotates around the central axis to develop each color. The devices 120A, 20B, 20C, and 20D are selectively moved to an angular displacement that enables development that faces the outer periphery of the photoreceptor 312.
In the intermediate transfer unit 115, an endless intermediate transfer body as an image carrier, for example, an intermediate transfer belt 324 is wound around a plurality of rollers 123, and the intermediate transfer belt 324 is brought into contact with the photoconductor 312. A transfer device 125 is installed inside the intermediate transfer belt 324, and a transfer device 126 and a cleaning device 127 are installed outside the intermediate transfer belt 324. The cleaning device 127 is provided so as to be able to contact with and separate from the intermediate transfer belt 324.
The laser writing device 118 receives image signals of each color from the image reading device 129 via an image processing unit (not shown), and sequentially applies the laser light L modulated by the image signals of each color to the uniformly charged photoconductor 312. An electrostatic latent image is formed on the photoreceptor 312 by irradiating and exposing the photoreceptor 312.

The image reading device 129 color-separates and reads the image of the document G set on the document table 130 provided on the upper surface of the apparatus main body 110, and converts it into an electrical image signal. The recording medium conveyance path 132 conveys a recording medium such as a sheet from right to left.
In the recording medium conveyance path 132, a registration roller 133 is installed on the upstream side of the intermediate transfer unit 115 and the transfer device 126. 136 is arranged.
The apparatus main body 110 is placed on the sheet feeding device 150. A plurality of paper feed cassettes 151 are provided in multiple stages in the paper feed device 150, and any one of the paper feed rollers 152 is selectively driven to send a recording medium from any one of the paper feed cassettes 151. . This recording medium is conveyed to the recording medium conveyance path 132 through the automatic paper feeding path 137 in the apparatus main body 110.
Further, a manual feed tray 138 is provided on the right side of the apparatus main body 110 so as to be freely opened and closed. The A paper discharge tray (not shown) is detachably attached to the left side of the apparatus main body 110, and the recording medium discharged by the paper discharge roller 136 through the recording medium conveyance path 132 is accommodated in the paper discharge tray.

In the fourth embodiment, when a color copy is taken, a copy operation is started by setting the document G on the document table 130 and pressing a start switch (not shown). First, the image reading device 129 reads the image of the document G on the document table 130 by color separation. At the same time, the recording medium is selectively sent out from the paper feeding cassette 151 in the paper feeding device 150 by the paper feeding roller 152, and the recording medium hits the registration roller 133 through the automatic paper feeding path 137 and stops.
The photoconductor 312 rotates counterclockwise, and the intermediate transfer belt 324 rotates clockwise by the rotation of the drive roller of the plurality of rollers 123. The photoconductor 312 is uniformly charged by the charger 113 as it rotates, and laser light modulated by an image signal of the first color applied from the image reading device 129 to the laser writing device 118 via the image processing unit is written into the laser. Irradiation from the device 118 forms an electrostatic latent image.
The electrostatic latent image on the photoconductor 312 is developed by the first color developing device 120A of the rotary developing device 114 into a first color image. The first color image on the photoconductor 312 is transferred to the intermediate transfer belt by the transfer device 125. 324 is transferred. After the transfer of the first color image, the photoconductor 312 is cleaned by the cleaning device 116 to remove the residual toner, and is neutralized by the static eliminator 117.

Subsequently, the photosensitive member 312 is uniformly charged by the charger 113, and laser light modulated by the image signal of the second color applied from the image reading device 129 to the laser writing device 118 via the image processing unit is written into the laser. Irradiation from the device 118 forms an electrostatic latent image.
The electrostatic latent image on the photoconductor 312 is developed by the second color developing device 120B of the rotary developing device 114 to become a second color image. The second color image on the photoconductor 312 is intermediately transferred by the transfer device 125. The image is transferred onto the belt 324 so as to overlap with the first color image. After the transfer of the second color image, the photoconductor 312 is cleaned by the cleaning device 116 to remove the residual toner, and is neutralized by the static eliminator 117.
Next, the photosensitive member 312 is uniformly charged by the charger 113, and laser light modulated by the image signal of the third color applied from the image reading device 129 to the laser writing device 118 via the image processing unit is applied to the laser writing device. Irradiation from 118 forms an electrostatic latent image.
The electrostatic latent image on the photoconductor 312 is developed by the third color developing device 120C of the rotary developing device 114 to become a third color image, and the third color image on the photoconductor 312 is intermediately transferred by the transfer device 125. The first color image and the second color image are superimposed and transferred onto the belt 324. After the transfer of the image of the third color, the photoconductor 312 is cleaned by the cleaning device 116 to remove the residual toner, and the static eliminator 117 is discharged.

Further, the photosensitive member 312 is uniformly charged by the charger 113, and the laser beam modulated by the image signal of the fourth color applied from the image reading device 129 to the laser writing device 118 via the image processing unit is laser writing device 118. To form an electrostatic latent image.
The electrostatic latent image on the photosensitive member 312 is developed by the fourth color developing device 120D of the rotary developing device 114 to become a fourth color image. The fourth color image on the photoreceptor 312 is transferred onto the intermediate transfer belt 324 by the transfer device 125 so as to be superimposed on the first color image, the second color image, and the third color image, thereby forming a full color image. After the image of the fourth color is transferred, the photoconductor 312 is cleaned by the cleaning device 116 to remove the residual toner, and is neutralized by the static eliminator 117.
Then, the registration roller 133 is rotated at a timing to send out a recording medium, and a full color image on the intermediate transfer belt 324 is transferred to the recording medium by the transfer device 126. This recording medium is transported by a transport belt 134 and a full color image is fixed by a fixing device 135, and is discharged to a paper discharge tray by a paper discharge roller 136. Further, the intermediate transfer belt 324 is cleaned by a cleaning device 127 after the transfer of the full-color image to remove residual toner.

The operation for forming a four-color superimposed image has been described above. In the case of forming a three-color superimposed image, three different single-color images are sequentially formed on the photoconductor 312 and transferred onto the intermediate transfer belt 324 in a superimposed manner. After that, it is transferred to a recording medium all at once.
In the case of forming a two-color superimposed image, two different single-color images are sequentially formed on the photoreceptor 312, transferred onto the intermediate transfer belt 324 in an overlapping manner, and then transferred to a recording medium at a time. In the case of forming a single color image, one single color image is formed on the photoconductor 312 and transferred onto the intermediate transfer belt 324 and then transferred to a recording medium.
In such a color copying machine, the drive accuracy of the photoconductor 312, the registration roller 133, the intermediate transfer belt 324, and the conveyance belt 134 greatly affects the quality of the final image. Therefore, it is desired to drive the photoconductor 312, the registration roller 133, the intermediate transfer belt 324, and the conveyance belt 134 with higher accuracy.
Therefore, in the fourth embodiment, the photosensitive member 312 and the registration roller 133 are configured as a driving device that is the driving target 3 in FIG. 1, and the intermediate transfer belt 324 and the conveyance belt 134 are replaced with the belt 12 in FIG. With the configuration of the driving device as described above, the driving accuracy of the photoconductor 312, the registration roller 133, the intermediate transfer belt 324, and the conveying belt 134 is improved, and fluctuations during image formation are reduced. An image can be obtained.

FIG. 42 is a schematic view showing an image forming apparatus including a color copying machine as a fifth embodiment of the present invention. The photoreceptor 161 as an image carrier is a photoreceptor belt in which a photosensitive layer such as an organic optical semiconductor (OPC) is formed in a thin film shape on the outer peripheral surface of a closed loop belt base material. The photosensitive member 161 is supported by three photosensitive member conveying rollers 162 to 164, and is rotated in the direction of arrow A by a drive motor (not shown).
Around the photosensitive member 161, the charger 165, an exposure optical system (hereinafter referred to as LSU) 166 as an exposure unit, black, yellow, magenta, and cyan are sequentially arranged in the rotation direction of the photosensitive member 161 indicated by an arrow A. Developing units 167 to 170, an intermediate transfer unit 171, a photosensitive member cleaning unit 172, and a static eliminator 173 are provided. A high voltage of about several kV is applied to the charger 165 from a power supply device (not shown), and a portion of the photoconductor 161 facing the charger 165 is charged to give a uniform charging potential.

The LSU 166 sequentially modulates light intensity or pulse width of each color image signal from a gradation converting means (not shown) by a laser driving circuit (not shown), and a semiconductor laser (not shown) is modulated by the modulated signal. The exposure light beam 174 is obtained by driving, and the photosensitive member 161 is scanned by the exposure light beam 174 to sequentially form an electrostatic latent image corresponding to the image signal of each color on the photosensitive member 161.
Each of the developing units 167 to 170 stores toner corresponding to each development color, and selectively contacts the photoconductor 161 at a timing corresponding to the electrostatic latent image corresponding to the image signal of each color on the photoconductor 161. The electrostatic latent image on the photoconductor 161 is developed with toner to form an image of each color, thereby forming a full-color image by a four-color superimposed image.

The intermediate transfer unit 171 includes a transfer drum 177 as an intermediate transfer member in which a belt-like sheet made of a conductive resin or the like is wound around a metal tube such as aluminum, and an intermediate transfer member cleaning unit in which rubber or the like is formed in a blade shape. 178. While the four-color superimposed image is formed on the intermediate transfer member 177, the intermediate transfer member cleaning unit 178 is separated from the intermediate transfer member 177.
The intermediate transfer member cleaning unit 178 contacts the intermediate transfer member 177 only when the intermediate transfer member 177 is cleaned, and removes toner remaining without being transferred from the intermediate transfer member 177 to the recording paper 179 as a recording medium. The recording paper 179 is sent one by one from the recording paper cassette 180 to the paper transport path 182 by the paper feed roller 181.

A transfer unit 183 as a transfer unit transfers a full color image on the intermediate transfer member 177 to the recording paper 179. The transfer unit 183 includes a transfer belt 184 in which conductive rubber or the like is formed in a belt shape, and a transfer unit 185 that applies a transfer bias for transferring a full color image on the intermediate transfer body 177 to the recording paper 179 to the transfer belt 184. And a separator 186 that applies a bias to the intermediate transfer body 177 so as to prevent the recording paper 179 from electrostatically sticking to the intermediate transfer body 177 after the full-color image is transferred to the recording paper 179. Yes.
The fixing device 187 includes a heat roller 188 having a heat source therein and a pressure roller 189. The full-color image transferred onto the recording paper 179 is fixed to the recording paper 179 by applying pressure and heat to the recording paper 179 as the recording paper is nipped and rotated by the heat roller 188 and the pressure roller 189. Form.
The operation of the fifth embodiment configured as described above will be described below. Here, the description will proceed assuming that the development of the electrostatic latent image is performed in the order of black, cyan, magenta, and yellow.

The photosensitive member 161 and the intermediate transfer member 177 are driven in the directions of arrows A and B by respective driving sources (not shown). In this state, first, a high voltage of about several kV is applied to the charger 165 from a power supply device (not shown), and the charger 165 uniformly charges the surface of the photoreceptor 161 to about several hundred volts.
The photosensitive member 161 is irradiated with an exposure light beam 174 of a laser beam corresponding to the black image signal from the LSU 166, and the electric charge of the portion irradiated with the exposure light beam 174 is erased to form an electrostatic latent image.

On the other hand, the black developing device 167 is brought into contact with the photosensitive member 161 at a predetermined timing. The black toner in the black developing device 167 is given a negative charge in advance, and the black toner adheres only to the portion (electrostatic latent image portion) where the charge has disappeared due to the irradiation of the exposure light beam 174 on the photoreceptor 161. Development by a so-called negative-positive process is performed.
The black toner image formed on the surface of the photosensitive member 161 by the black developing device 167 is transferred to the intermediate transfer member 177. Residual toner that has not been transferred from the photoconductor 161 to the intermediate transfer body 177 is removed by the photoconductor cleaning means 172, and the charge on the photoconductor 161 is removed by the charge eliminator 173.

Next, the charger 165 uniformly charges the surface of the photoreceptor 161 to about several hundred volts. The exposure light beam 174 of the laser beam corresponding to the cyan image signal is irradiated from the LSU 166 to the photoconductor 161, and the charge of the portion irradiated with the exposure light beam 174 disappears from the photoconductor 161 and an electrostatic latent image is formed.
On the other hand, a cyan developing device 168 is brought into contact with the photoconductor 161 at a predetermined timing. The cyan toner in the cyan developing unit 168 is given a negative charge in advance, and the cyan toner adheres only to the portion (electrostatic latent image portion) where the charge disappears due to the irradiation of the exposure light beam 174 on the photoreceptor 161. Development by a so-called negative-positive process is performed.

The cyan toner image formed on the surface of the photosensitive member 161 by the cyan developing device 168 is transferred onto the intermediate transfer member 177 so as to overlap the black toner image. Residual toner that has not been transferred from the photoconductor 161 to the intermediate transfer body 177 is removed by the photoconductor cleaning means 172, and the charge on the photoconductor 161 is removed by the charge eliminator 173.
Next, the charger 165 uniformly charges the surface of the photoreceptor 161 to about several hundred volts. The exposure light beam 174 of the laser beam corresponding to the magenta image signal is irradiated from the LSU 166 to the photoconductor 161, and the charge of the portion irradiated with the exposure light beam 174 disappears from the photoconductor 161 and an electrostatic latent image is formed.
On the other hand, a magenta developing unit 169 is brought into contact with the photoconductor 161 at a predetermined timing. The magenta toner in the magenta developing unit 169 is previously charged with a negative charge, and the magenta toner adheres only to a portion (electrostatic latent image portion) where the charge is eliminated by irradiation of the exposure light beam 174 on the photoreceptor 161. Development by a so-called negative-positive process is performed.

The magenta toner image formed on the surface of the photoreceptor 161 by the magenta developing unit 169 is transferred onto the intermediate transfer member 177 so as to overlap the black toner image and the cyan toner image. Residual toner that has not been transferred from the photoconductor 161 to the intermediate transfer body 177 is removed by the photoconductor cleaning means 172, and the charge on the photoconductor 161 is removed by the charge eliminator 173.
Further, the charger 165 uniformly charges the surface of the photoreceptor 161 to about several hundred volts. The photosensitive member 161 is irradiated with an exposure light beam 174 of a laser beam corresponding to the yellow image signal from the LSU 166, and the electric charge of the portion irradiated with the exposure light beam 174 is erased to form an electrostatic latent image.
On the other hand, the yellow developing device 170 is brought into contact with the photoconductor 161 at a predetermined timing. The yellow toner in the yellow developing unit 170 is given a negative charge in advance, and the yellow toner adheres only to the portion (electrostatic latent image portion) where the charge disappears due to the irradiation of the exposure light beam 174 on the photoreceptor 161. Development by a so-called negative-positive process is performed.

The yellow toner image formed on the surface of the photoreceptor 161 by the yellow developing unit 170 is transferred onto the intermediate transfer member 177 so as to overlap the black toner image, the cyan toner image, and the magenta toner image, and a full-color image is formed on the intermediate transfer member 177. It is formed. Residual toner that has not been transferred from the photoconductor 161 to the intermediate transfer body 177 is removed by the photoconductor cleaning means 172, and the charge on the photoconductor 161 is removed by the charge eliminator 173.
In the full-color image formed on the intermediate transfer member 177, the transfer unit 183 that has been separated from the intermediate transfer member 177 so far contacts the intermediate transfer member 177, and a high voltage of about several kV is applied to the transfer device 185 by a power supply device ( By being applied from the recording paper cassette 180, the transfer device 185 collectively transfers the recording paper 179 conveyed along the paper conveyance path 182.
Further, a voltage is applied from the power supply device to the separator 186 so that an electrostatic force that attracts the recording paper 179 acts, and the recording paper 179 is peeled off from the intermediate transfer member 177. Subsequently, the recording paper 179 is sent to the fixing device 187 where the full color image is fixed by the nipping pressure between the heat roller 188 and the pressure roller 189 and the heat of the heat roller 188, and the paper discharge tray 190 by the paper discharge roller 190. It is discharged to 191.

Further, residual toner on the intermediate transfer member 177 that has not been transferred onto the recording paper 179 by the transfer unit 183 is removed by the intermediate transfer member cleaning unit 178. The intermediate transfer member cleaning means 178 is at an angular displacement away from the intermediate transfer member 177 until a full color image is obtained. After the full-color image is transferred to the recording paper 179, the residual toner on the intermediate transfer member 177 is removed by contacting the intermediate transfer member 177. The full color image formation for one sheet is completed by the series of operations described above.
In such a color copying machine, the driving accuracy of the photosensitive belt 161, the transfer drum 177, and the transfer belt 184 greatly affects the quality of the final image. In particular, the high-precision driving of the high-precision photosensitive belt 161 and the transfer belt 184 Is desired.
Therefore, in the fifth embodiment, the photosensitive belt 161 and the transfer belt 184 are configured as a driving device such that the belt 12 shown in FIG. 2 is used, and the transfer drum 177 is used as the driving target 3 shown in FIG. As a result, the driving accuracy of the photosensitive belt 161, the transfer belt 184, and the transfer drum 177 is improved, and fluctuations during image formation are reduced, so that a high-quality image can be obtained.

FIG. 43 is a schematic view showing an image forming apparatus comprising a color copying machine as a sixth embodiment according to the present invention. The sixth embodiment is an example of a tandem image forming apparatus. In the sixth embodiment, images of a plurality of colors, for example, black (hereinafter referred to as Bk), magenta (hereinafter referred to as M), yellow (hereinafter referred to as Y), and cyan (hereinafter referred to as C) are displayed. A plurality of image forming units 221Bk, 221M, 221Y, and 221C to be formed are arranged in the vertical direction.
The image forming units 221Bk, 221M, 221Y, and 221C are respectively image bearing members 222Bk, 222M, 222Y, and 222C made of a drum-shaped photoconductor, charging devices (for example, contact charging devices) 223Bk, 223M, 223Y, and 223C, and developing. The apparatus 224Bk, 224M, 224Y, 224C, the cleaning apparatus 225Bk, 225M, 225Y, 225C, etc. are comprised.

The photoconductors 222Bk, 222M, 222Y, and 222C are arranged in the vertical direction so as to face the endless transport belt 226, and are driven to rotate at the same peripheral speed as the transport belt 226. The photoconductors 222Bk, 222M, 222Y, and 222C are uniformly charged by the charging devices 223Bk, 223M, 223Y, and 223C, respectively, and then exposed by the exposure units 227Bk, 227M, 227Y, and 227C, which are optical writing devices, respectively. An electrostatic latent image is formed.
The optical writing devices 227Bk, 227M, 227Y, and 227C drive the semiconductor laser by the semiconductor laser driving circuit based on the image signals of Y, M, C, and Bk, respectively, and the laser beams from the semiconductor laser are polygon mirrors 229Bk, 229M, and 229Y. 229C is deflected and scanned.

The respective laser beams from the polygon mirrors 229Bk, 229M, 229Y, and 229C are imaged on the photoconductors 222Bk, 222M, 222Y, and 222C via an unillustrated fθ lens and mirror, thereby forming the photoconductors 222Bk, 222M, 222Y, and 222C. Is exposed to form an electrostatic latent image.
The electrostatic latent images on the photoreceptors 222Bk, 222M, 222Y, and 222C are developed by the developing devices 224Bk, 224M, 224Y, and 224C, respectively, and become toner images of Bk, M, Y, and C colors.
Therefore, the charging devices 223Bk, 223M, 223Y, and 223C, the optical writing devices 227Bk, 227M, 227Y, and 227C and the developing devices 224Bk, 224M, 224Y, and 224C are Bk, M, and Y on the photosensitive members 222Bk, 222M, 222Y, and 222C, respectively. , C constitutes image forming means for forming each color image (toner image).

On the other hand, recording paper such as plain paper and OHP sheet is fed from the paper feeding device 230, which is installed at the lower part of the present embodiment, using a paper feeding cassette, toward the registration roller 231 along the recording paper conveyance path. Paper is fed.
The registration roller 231 transfers the recording paper to the conveying belt 226 in synchronization with the toner image on the photoconductor 222Bk in the first color image forming unit (image forming unit that first transfers the image on the photoconductor to the recording paper) 221Bk. It is sent to the transfer nip portion with the body 222Bk.
The conveyor belt 226 is stretched between a driving roller 232 and a driven roller 233 arranged in the vertical direction, and the driving roller 232 is rotated by a driving unit (not shown) so that the conveyor belt 226 is the same as the photosensitive members 222Bk, 222M, 222Y, and 222C. Rotates at peripheral speed.

The recording paper fed from the registration roller 231 is conveyed by a conveying belt 226, and toner images of Bk, M, Y, and C colors on the photosensitive members 222Bk, 222M, 222Y, and 222C are transferred to a transfer unit 234Bk that includes a corona discharger. A full-color image is formed by being sequentially superimposed and transferred by the action of the electric field formed by 234M, 234Y, and 234C, and at the same time, it is electrostatically attracted to the conveyance belt 226 and reliably conveyed.
The recording paper is gradually electrified by a separating means 236 comprising a separating charger and separated from the conveying belt 226, and then a full-color image is fixed by a fixing device 237. The recording paper is provided at the top of the present embodiment by a paper discharge roller 238. The paper is discharged to the paper discharge unit 239. The photosensitive members 222Bk, 222M, 222Y, and 222C are cleaned by the cleaning devices 225Bk, 225M, 225Y, and 225C after the toner image is transferred to prepare for the next image forming operation.

In such a color copying machine, the driving accuracy of the conveyance belt 226 and the photoconductors 222Bk, 222M, 222Y, and 222C greatly affects the quality of the final image, and the higher-precision conveyance belt 226 and photoconductors 222Bk, 222M, and 222Y. , 222C is desired.
Therefore, in the sixth embodiment, the conveying belt 226 is configured as a driving device that becomes the belt 12 in FIG. 2, and the photosensitive members 222Bk, 222M, 222Y, and 222C are the driving target 3 in FIG. With this configuration, the driving accuracy of the conveyance belt 226 and the photosensitive members 222Bk, 222M, 222Y, and 222C is improved, and fluctuations during image formation are reduced, so that a high-quality image can be obtained.
In addition, although the description has been made with the configuration of a copying machine or the like, in the ink jet paper transport device, for example, the transport belt configuration as shown in FIG. 2 or the transport roller configuration of FIG. It is also possible to carry out the paper transport with high accuracy.

  The present invention relates to a high-precision measuring device for angular displacement or angular velocity, or a high-precision driving device based on the measurement, a hard disk drive (Hard Disk Drive), a position detection or positioning control device for a robot, and a transfer belt using an electrophotographic system. Positioning / speed measurement and control device in driving device, transfer / photosensitive drum driving device, belt driving in printing machine and output machine, position / speed measurement and control device in roller driving device, roller / belt driving device in paper transport device Can be used for position or velocity measurement and control device.

It is a schematic perspective view which shows the rotary body drive device used in some embodiment after this invention. It is a schematic perspective view which shows the belt drive device used in several embodiment after this invention. It is the schematic which shows the simple principle structure of the pattern detection in FIG.1 and FIG.2. It is a wave form diagram which shows the method of making the signal obtained from the rotary encoder apparatus into a pulse wave. It is a block diagram which shows the structure of the control system which digitally controls the angular displacement of a motor based on the output signal of a motor shaft encoder. It is a block diagram which shows the structure of the analog control system in a PLL drive system. It is a block diagram which shows the basic control which rotates and drives a motor. It is explanatory drawing shown about the angular velocity fluctuation | variation or angular displacement fluctuation | variation which the attachment eccentricity of the wheel part of a rotary encoder apparatus exists, and it generates. It is the schematic which shows the color division strip | belt-shaped part and pulse in the color component of the reflected light provided in the circumferential direction so that it may overlap with a pattern. It is the schematic which shows the pattern formed as one by the non-reflective pattern divided | segmented by the radial direction, and a color division | segmentation pattern. It is the schematic which shows the color division strip | belt-shaped part and pulse in the color component of the reflected light provided in the circumferential direction so that it may overlap with a pattern. It is a wave form diagram which shows an example of the concrete method of measuring the attachment eccentricity of the wheel part of a rotary encoder apparatus. It is a block diagram which shows the part which produces the amount of eccentricity. FIG. 2 is a block diagram of a first embodiment of a drive control system that performs a correction process on an output value of a controller. It is a block diagram which shows the structure of the analog control system in a PLL drive system. It is a block diagram which shows 2nd Embodiment of the drive control system which detects the attachment eccentric phase of the wheel part of a rotary encoder, and performs a correction process to a feedback value. It is a block diagram which shows the structure of the analog control system in a PLL drive system. It is a block diagram which shows control of the 3rd Embodiment of this invention which rotates and drives a motor. It is a block diagram which shows the structure of the analog control system in a PLL drive system. It is a figure which shows the example of a rotary body drive device. It is a figure which shows the other example of a rotary body drive device. It is a figure which shows the mode of rotation of the wheel part eccentric attachment of a rotary encoder. It is a figure which shows the mode of rotation of the wheel part eccentric attachment of a rotary encoder. It is detail drawing of the Example of this invention. It is detail drawing of the Example of this invention. It is detail drawing of the Example of this invention. It is detail drawing of the Example of this invention. It is detail drawing of the Example of this invention. It is detail drawing of the Example of this invention. It is detail drawing of the Example of this invention. It is detail drawing of the Example of this invention. It is detail drawing of the Example of this invention. It is a figure which shows the pulse output waveform in the normal state without the wheel part attachment eccentricity by the conventional rotary encoder pattern. It is a figure which shows a pulse output waveform when the wheel part of the conventional rotary encoder is attached eccentrically. It is a figure which shows the pulse output waveform at the time of attaching the wheel part of the rotary encoder by the pattern shape in this invention eccentrically. It is a figure which shows the relationship between the pulse widths for one week. It is a figure which shows the ratio with the pulse width of H with respect to the pulse width between (H + L) patterns in a typical pattern. It is a figure which shows the ratio with the pulse width of H with respect to the pulse width between (H + L) patterns in a typical pattern. Rotary encoder pulse No. It is a figure which shows the relationship between H / (H + L). It is a block diagram of the system which shows the Example of this invention. FIG. 10 is a schematic diagram illustrating an image forming apparatus including a color copying machine as a fourth embodiment of the present invention. FIG. 10 is a schematic diagram illustrating an image forming apparatus including a color copying machine as a fifth embodiment of the present invention. It is the schematic which shows the image forming apparatus which consists of a color copying machine as 6th Embodiment by this invention.

Explanation of symbols

1 Rotating body drive device
3 Rotating body (Drive target)
4 Motor 6 Rotary encoder (device)
6A wheel part 6a pattern 6b pattern 7 sensor (light detection means)
7a Light emitting part 7b Light receiving part 8 Belt drive device 12 Belt (drive target)
24 Non-reflective pattern 51 Controller 57 Eccentricity correction unit (eccentricity correction mechanism)
212 Image carrier (photosensitive drum)
224 Intermediate transfer belt 161 Image carrier (photosensitive belt)
177 Image carrier (transfer drum)
222Bk image carrier (photosensitive drum)
226 Conveying belt (paper conveying device)
DESCRIPTION OF SYMBOLS 101 Motor 102 Motor gear 103 Rotating body gear 104 Rotating body 105 Rotating body shaft 106 Wheel mounting shaft portion 107 Wheel boss portion 108 Rotary encoder wheel 109 Pattern portion 110 Optical sensor 111 Roller gear 112 Driving roller 113 Tension roller 114 Followed roller 115 Belt 116 Roller shaft 117 Wheel mounting shaft

Claims (12)

A wheel unit that rotates in synchronization with the rotating body ;
On the circumference of the wheel unit, a plurality of patterns formed by and predetermined angular intervals radially from a predetermined radial position from a predetermined central point,
A plurality of strips that are concentrically arranged so as to overlap the pattern centered on the central point, and that reflect or transmit light of different wavelength bands;
A light emitting means for irradiating the pattern and the belt-shaped portion with light ;
Wherein with the rotation operation of the wheel unit, and a light receiving means for outputting a rotation signal of the wheel unit detects the light amount change of the transmitted light or reflected light of said light emitting means is irradiated to the pattern,
The light receiving means has a sensitivity characteristic for independently detecting light amounts in a plurality of wavelength bands, and independently detects a plurality of wavelength lights generated when straddling the boundary of the band-shaped portion, thereby the wheel unit. A rotary encoder device that outputs an eccentric signal indicating an eccentric amount of the center point of the pattern with respect to the rotation center of the pattern.   A wheel unit that rotates in synchronization with the rotating body;
  A plurality of patterns radially formed at predetermined angular intervals from a predetermined radial position from a predetermined center point on the circumference of the wheel portion;
  A plurality of strips that are concentrically arranged so as to overlap the pattern centered on the center point, and that reflect or transmit light of different wavelength bands formed integrally with the pattern;
  A light emitting means for irradiating the pattern and the belt-shaped portion with light;
  A light receiving means for detecting a change in the amount of transmitted light or reflected light of the light emitting means irradiated on the pattern in accordance with the rotation operation of the wheel portion, and outputting a rotation signal of the wheel portion;
  The light receiving means has a sensitivity characteristic for independently detecting light amounts in a plurality of wavelength bands, and independently detects a plurality of wavelength lights generated when straddling the boundary of the band-shaped portion, thereby the wheel unit. A rotary encoder device that outputs an eccentric signal indicating an eccentric amount of the center point of the pattern with respect to the rotation center of the pattern.   A wheel unit that rotates in synchronization with the rotating body;
  A plurality of patterns radially formed at predetermined angular intervals from a predetermined radial position from a predetermined central point on the circumference of the wheel portion;
  The pattern includes a divided region that reflects or transmits a specific wavelength band with a concentric circle centered on the center point as a boundary,
  A band-like portion that is disposed on the outer diameter side of the concentric circle so as to overlap with a region other than the divided region in the pattern, and reflects or transmits light in a wavelength band different from the specific wavelength band;
  A light emitting means for irradiating the pattern and the belt-shaped portion with light;
  A light receiving means for detecting a change in the amount of transmitted light or reflected light of the light emitting means irradiated on the pattern in accordance with the rotation operation of the wheel portion, and outputting a rotation signal of the wheel portion;
  The light receiving means has a sensitivity characteristic for independently detecting the light amounts of a plurality of wavelength bands, and straddles the boundary of the band-shaped part, the boundary of the divided area, or the boundary between the band-shaped part and the divided area. A rotary encoder device that outputs an eccentricity signal indicating an eccentricity amount of a center point of the pattern with respect to a rotation center of the wheel portion by independently detecting a plurality of wavelength lights generated in the wheel.   In a rotating body drive control device having a controller that generates a control command value from a difference between a measurement signal from a rotary encoder device and a target value for driving a rotating body driven by a motor.
  The rotary encoder device includes the rotary encoder device according to any one of claims 1 to 3, and includes an eccentricity correction mechanism that corrects eccentricity using an eccentricity signal from the rotary encoder device. Rotating body drive control device.   5. The rotating body drive control device according to claim 4, wherein the eccentricity correction mechanism is provided immediately after the controller.   5. The rotating body drive control device according to claim 4, wherein the eccentricity correction mechanism is provided in a feedback mechanism that feeds back the measurement signal.   5. The rotating body drive control device according to claim 4, wherein the eccentricity correction mechanism is provided in a mechanism that generates the target value.   8. An image forming apparatus for forming an image by rotating an image carrier, wherein drive control of the image carrier is performed by the rotary body drive control device according to claim 4, wherein the image carrier is photosensitive. An image forming apparatus comprising a body drum.   8. An image forming apparatus for forming an image by rotating an image carrier, wherein the image carrier is controlled by the rotary body drive control device according to any one of claims 4 to 7, wherein the image carrier is transferred. An image forming apparatus comprising a drum.   8. An image forming apparatus for forming an image by rotating an image carrier, wherein drive control of the image carrier is performed by the rotary body drive control device according to claim 4, wherein the image carrier is photosensitive. An image forming apparatus comprising a body belt.   8. An image forming apparatus for forming an image by rotating an image carrier, wherein the image carrier is controlled by the rotary body drive control device according to any one of claims 4 to 7, wherein the image carrier is transferred. An image forming apparatus comprising a belt.   8. A paper conveying apparatus that conveys paper by rotating a belt or a roller, wherein the drive control of the paper conveying apparatus is performed by the rotating body drive control device according to any one of claims 4 to 7. Forming equipment.

Images