JP2006226776A - Driving control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving control device for reducing cost of reference position detection by reducing the number of a light receiving section and a light emitting section. <P>SOLUTION: In the driving control device, a slit for detecting rotation speed is formed in an encoder disc 10, and a pulse-like output can be obtained from the light receiving section 30 by passing or blocking light from the light emitting section 20. A reference position of the encoder disc can be obtained by providing a means for giving light amount difference in one place of the slit formed in the encoder disc 10. The circuit shown in Figure provides both an encoder pulse signal and a reference mark signal from the output of the light receiving section obtained by the means for giving light amount difference in the slit in the encoder disc 10 by a voltage comparator (comparators 1 and 2) having a different voltage. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a drive control device used in a transfer device of an image forming apparatus.

The following techniques are known as methods for controlling the speed fluctuation of the transfer belt caused by the eccentricity of the disk attached to the driven roller.
JP 2000-47547 A

  In the invention described in Patent Document 1, the driving roller is rotated at a constant speed, the angular velocity information obtained from the encoder output is acquired for at least one period of the driving roller, and divided into 1/2 period of the driving roller and divided into the first half part and the second half part. By adding the parts, the eccentric speed fluctuation component due to the driving roller is canceled out, and only the speed fluctuation due to the driven roller is extracted. Further, at the time of image formation, the speed travel of the belt is made constant by taking the difference between the angular speed information detected from the driven roller and the speed fluctuation.

By the way, in the image forming apparatus, it is important to perform control to stabilize the belt speed fluctuation caused by the disk eccentricity of the encoder in the position control. For this purpose, the function of detecting the reference position of the encoder disk is used. Will be needed.
As a method of knowing the reference position of the encoder disk, in addition to the slit for detecting the rotational speed on the circumference of the encoder disk, a slit for detecting the reference position is provided on different circumferences, and the two light emitting units, What detects with one light-receiving part is known.
Accordingly, an object of the present invention is to provide a drive control device that reduces the cost of reference position detection by reducing the number of light receiving units and light emitting units.

According to the first aspect of the present invention, in the drive device driven by the rotational drive source, the encoder for detecting the rotation of the rotational drive source of the rotational drive source and the angular displacement of the encoder per unit time are constant. A control target value is set to the control target value, the drive control means for controlling the drive means to be equal to the control target value, and the angular displacement caused by the eccentricity of the encoder when the encoder is rotated once. A detection unit that detects an error, and a storage unit that holds data obtained from the detection unit as a characteristic value, and the drive control unit performs drive control by adding the characteristic value to a control target value, and The encoder consists of a transmissive sensor and a disk with radial slits engraved on the circumference, and the transmitted light quantity of at least one part of the slit is changed by differentiating the light quantity from other slits. By generating a mark as a reference for one rotation, to achieve the above object.
According to a second aspect of the present invention, in the first aspect of the present invention, the mark serving as a reference for one rotation of the disk is generated by a disk having a structure in which one portion of the slit has a higher transmittance than the other slits. Features.
According to a third aspect of the present invention, in the first aspect of the present invention, the mark used as a reference for one rotation of the disk is generated by a disk having a structure in which one portion of the slit has a lower transmittance than the other slits. Features.

According to a fourth aspect of the present invention, in the first aspect of the invention, the reference mark for one rotation of the disk is a disk having a slit structure in which one of the slits is longer in a direction perpendicular to the circumferential direction than the other slits. It is generated by.
According to a fifth aspect of the present invention, in the first aspect of the invention, the reference mark for one rotation of the disk is a disk having a slit structure in which one of the slits is shorter in a direction perpendicular to the circumferential direction than the other slits. It is generated by.
According to a sixth aspect of the invention, there is provided the encoder pulse according to any one of the first to fifth aspects, further comprising two voltage comparators having different comparison voltages with the output from the light receiving unit as inputs. Is output from one voltage comparator, and a mark signal serving as a reference for one disc rotation is output from the other voltage comparator.

In the invention according to claim 7, in the invention according to claim 1, the encoder is composed of a reflective sensor and a disk in which a reflection band that repeats light and dark in a radial pattern is engraved on the circumference. One location of the reflective sensor and the reflective band is generated by a reflective band having a structure that is longer in the direction perpendicular to the circumferential direction than the other reflective bands.
In the invention according to claim 8, in the invention according to claim 1, the encoder is composed of a reflective sensor and a disk in which a reflection band that repeats light and dark in a radial pattern is engraved on the circumference. One point of the reflective sensor and the reflection band is generated by a reflection band having a short structure in a direction perpendicular to the circumferential direction as compared with the other reflection bands.

  According to the ninth aspect of the present invention, in the seventh or eighth aspect of the present invention, there are two voltage comparators having different comparison voltages with the output from the light receiving section as inputs, and the output for counting the encoder pulse is A mark signal that is a reference for one rotation of the disk is output from the other voltage comparator from the output of the voltage comparator.

According to the first aspect of the present invention, the encoder pulse signal and the reference position are determined by making the light quantity of the single light emitting unit, the single light receiving unit, and the slit of at least one slit of the encoder disk engraved with the slit different from the others. Both can be detected.
According to the second aspect of the present invention, it is possible to detect both the encoder pulse signal and the reference position by making the transmittance of one slit higher than the others.
In the third aspect of the invention, it is possible to detect both the encoder pulse signal and the reference position by lowering the transmittance of one slit compared to the other.

According to the fourth aspect of the present invention, it is possible to detect both the encoder pulse signal and the reference position by lengthening one slit in a direction perpendicular to the circumferential direction.
In the invention according to claim 5, it is possible to detect both the encoder pulse signal and the reference position by shortening one slit in a direction perpendicular to the circumferential direction.
In a sixth aspect of the invention, a signal from a single light receiving unit is detected by a voltage comparator having a different comparison voltage, and an encoder pulse signal and a reference mark signal are output. Both reference positions can be detected.

According to the seventh aspect of the present invention, it is possible to detect both the encoder pulse signal and the reference position by elongating one reflection band in a direction perpendicular to the circumferential direction.
In the invention according to claim 8, by shortening one reflection band in a direction perpendicular to the circumferential direction, both the encoder pulse signal and the reference position can be detected.
According to the ninth aspect of the present invention, a signal from a single light receiving unit is detected by a voltage comparator having different comparison voltages, and an encoder pulse signal and a reference mark signal are output. Both reference positions can be detected.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS.
A feature of the present invention is a method for detecting a reference position of an encoder. Therefore, this reference position detection will be mainly described.
FIG. 1 is a diagram for explaining this embodiment. In FIG. 1, the encoder disk 10 is provided with a slit for detecting the rotational speed, and a pulse-like output is obtained from the light receiving unit 30 by transmitting / blocking light from the light emitting unit 20 through the slit. Be able to. In this embodiment, in order to cancel the eccentricity of the encoder disk 10, the encoder output for one rotation is stored in the memory, but it is necessary to know the reference position of the encoder when storing it.
In the example shown in FIG. 1, the reference position of the encoder disk can be obtained by providing means for making a light amount difference at one location of the slit carved in the encoder disk 10.

FIG. 6 shows a circuit for obtaining both the encoder pulse signal and the reference mark signal from the output of the light receiving unit obtained by the means for giving a light amount difference to the slit of the encoder disk 10 by a voltage comparator (comparator) having a different comparison voltage. ing.
FIG. 2 is a diagram showing an example of means for giving a light amount difference to one position of the slit of the encoder disk 10. In FIG. 2, one part of the encoder disk 10 has a structure having a higher transmittance than the other slits. For example, a semipermeable membrane for lowering the transmittance is pasted except for one slit.

FIG. 10 shows (1) the light receiving portion signal, (2) the encoder pulse signal, and (3) the reference mark signal in FIG. 6 when the encoder disk 10 having the structure of FIG. 2 is used. (1) In the light receiving portion signal, only the slit having a high transmittance has a high pulse level, and the others have a low pulse level.
FIG. 10 shows that (2) the encoder pulse signal can be obtained by lowering the comparison voltage of the comparator 1, and (3) the reference mark signal can be obtained by raising the comparison voltage of the comparator 2. .

  FIG. 3 is a diagram showing another example of means for giving a light amount difference to one portion of the slit of the encoder disk 10. In FIG. 3, one part of the encoder disk 10 has a structure with a lower transmittance than the other slits. For example, a semipermeable membrane for lowering the transmittance is attached to one slit.

  FIG. 11 shows (1) light receiving part signal, (2) encoder pulse signal, (3) comparator 2 signal, and (4) reference mark signal in FIG. 6 when the encoder disk 10 having the structure of FIG. 3 is used. It is a thing. (1) In the light receiving part signal, only the low transmittance slit has a low pulse level, and the others have a high pulse level. FIG. 11 shows that (2) the encoder pulse signal can be obtained by lowering the comparison voltage of the comparator 1, and (3) the comparator 2 signal can be obtained by raising the comparison voltage of the comparator 2. ing. (3) The comparator 2 signal has a waveform in which only the pulse at the reference position is missing. (2) By performing XOR (exclusive OR) with the encoder pulse signal, (4) a reference mark signal can be obtained.

  FIG. 4 is a diagram showing another example of means for giving a light amount difference to one place of the slit of the encoder disk. In FIG. 4, one part of the encoder disk has a slit structure that is longer in the direction perpendicular to the circumferential direction than the other slits. The waveforms of the encoder pulse signal and the reference mark signal in the case of FIG. 4 are the same as those in FIG. That is, as in the case of FIG. 2, the amount of light at one slit is greater than at the other.

FIG. 5 is a diagram showing another example of means for giving a light amount difference to one portion of the slit of the encoder disk 10. In FIG. 5, one part of the encoder disk has a short slit structure in a direction perpendicular to the circumferential direction as compared with other slits.
The waveforms of the encoder pulse signal and reference mark signal in the case of FIG. 5 are the same as those in FIG. That is, as in the case of FIG. 3, the amount of light is reduced at one slit compared to the other.

FIG. 9 is a diagram showing another embodiment of the present invention. In FIG. 9, the encoder disk 10 is provided with a bright and dark reflection band on the circumference for detecting the rotational speed, and the light from the light emitting unit 20 is reflected from the light receiving unit 30 by reflecting the light from the light emitting unit 20. A pulsed output can be obtained. In this embodiment, in order to cancel the eccentricity of the encoder disk 10, the encoder output for one rotation is stored in the memory. However, it is necessary to know the reference position of the encoder when storing.
In FIG. 9, the reference position of the encoder disk 10 can be obtained by providing means for making a light amount difference at one location of the reflection band engraved on the encoder disk 10.
FIG. 9 shows the output of the light receiving unit 30 obtained by the means for making a light amount difference at one part of the reflection band provided on the encoder disk 10 and the encoder pulse signal and the reference by a voltage comparator (comparator) having a different comparison voltage. A circuit for obtaining both mark signals is shown.

FIG. 7 is a view showing an example of means for giving a light amount difference to one part of the reflection band provided on the encoder disk 10. In FIG. 7, one portion of the encoder disk 10 has a structure that is longer in the direction perpendicular to the circumferential direction than the other reflection bands. In this structure, since the reflection band that is long in the direction perpendicular to the circumferential direction has a larger amount of reflected light than the other reflection bands, the amount of light reaching the light receiving unit 30 also increases.
FIG. 10 is a diagram showing (1) a light receiving portion signal, (2) an encoder pulse signal, and (3) a reference mark signal in FIG. 9 when the encoder disk 10 having the structure shown in FIG. 7 is used. (1) In the light receiving portion signal, only a long reflection band in a direction perpendicular to the circumferential direction has a high pulse level, and the others have a low pulse level.
FIG. 10 shows that (2) the encoder pulse signal can be obtained by lowering the comparison voltage of the comparator 1, and (3) the reference mark signal can be obtained by raising the comparison voltage of the comparator 2. .

FIG. 8 is a view showing another example of a means for giving a light amount difference to one part of a reflection band provided on the encoder disk 10. In FIG. 8, one part of the encoder disk 10 has a structure that is shorter in the direction perpendicular to the circumferential direction than the other reflection bands. In this structure, the reflection band that is short in the direction perpendicular to the circumferential direction has a smaller amount of reflected light than the other reflection bands, so that the amount of light reaching the light receiving unit 30 is also reduced.
FIG. 12 shows (1) light receiving part signal, (2) encoder pulse signal, (3) comparator 2 signal, and (4) reference mark signal in FIG. 9 when the encoder disk 10 having the structure shown in FIG. 8 is used. It is shown. (1) In the light receiving portion signal, only a short reflection band in a direction perpendicular to the circumferential direction has a low pulse level, and the others have a high pulse level.
FIG. 12 shows that (2) the encoder pulse signal can be obtained by raising the comparison voltage of the comparator 1, and (3) the comparator 2 signal can be obtained by lowering the comparison voltage of the comparator 2. . (3) The comparator 2 signal has a waveform in which only the pulse at the reference position is missing. (2) By performing XOR (exclusive OR) with the encoder pulse signal, (4) a reference mark signal can be obtained.

  As described above, when the encoder output for one rotation is stored in the memory in order to cancel the eccentricity of the encoder disk 10, when the reference position of the encoder is known according to the present embodiment, the light emitting unit 20 and the light receiving unit 30 The cost can be reduced by reducing the number.

It is a figure explaining a present Example. It is the figure which showed an example of the means to give the light quantity difference to one location of the slit of the encoder disk. It is the figure which showed the other example of the means to give a light quantity difference to one location of the slit of an encoder disk. It is the figure which showed the other example of the means to give a light quantity difference to one location of the slit of an encoder disk. It is the figure which showed the other example of the means to give a light quantity difference to one location of the slit of an encoder disk. It is the figure which showed the circuit which obtains both an encoder pulse signal and a reference mark signal by the voltage comparator from which the comparison voltage differs by the output of the light-receiving part obtained by the means which gives a light quantity difference. It is the figure which showed an example of the means to give a light quantity difference to one location of the reflective band provided in the encoder disk. It is the figure which showed the other example of the means to give a light quantity difference to one location of the reflective band provided in the encoder disk. It is the figure which showed the circuit of the means to give a light quantity difference to one location of the reflective band provided in the encoder disk. It is the figure which showed the signal at the time of using the encoder disk of the structure of FIG. It is the figure which showed the signal at the time of using the encoder disk of the structure of FIG. It is the figure which showed the signal at the time of using the encoder disk of the structure of FIG.

Explanation of symbols

10 Encoder disk 20 Light emitting part 30 Light receiving part

Claims (9)

In a drive device driven by a rotational drive source,
An encoder for detecting the rotation of the rotational drive source;
A drive control means for setting a control target value so that the angular displacement of the encoder per unit time is constant, and controlling the drive means to be equal to the control target value;
Detecting means for detecting an angular displacement error caused by the influence of the eccentricity of the encoder when the encoder is rotated once;
A storage unit for holding data obtained from the detection means as a characteristic value,
The drive control means performs drive control by adding a characteristic value to a control target value,
The encoder consists of a disk with a transmissive sensor and radial slits engraved on the circumference, and generates a mark that serves as a reference for one rotation of the disk by differentiating the amount of light transmitted through at least one of the slits from the other slit. A drive control device. 2. The drive control device according to claim 1, wherein the mark serving as a reference for one rotation of the disk is generated by a disk having a structure in which one portion of the slit has a higher transmittance than the other slits. 2. The drive control apparatus according to claim 1, wherein the mark serving as a reference for one rotation of the disk is generated by a disk having a structure in which one portion of the slit has a lower transmittance than other slits. 2. The drive control according to claim 1, wherein the mark serving as a reference for one rotation of the disk is generated by a disk having a slit structure in which one portion of the slit is longer in a direction perpendicular to the circumferential direction than the other slits. apparatus. 2. The drive control according to claim 1, wherein the mark serving as a reference for one rotation of the disk is generated by a disk having a slit structure in which one portion of the slit is shorter in a direction perpendicular to the circumferential direction than other slits. apparatus. Equipped with two voltage comparators with different comparison voltages that receive the output from the light receiving unit,
6. The output of counting encoder pulses is output from one voltage comparator, and a mark signal that is a reference for one rotation of the disk is output from the other voltage comparator. The drive control apparatus described in 1. The encoder is composed of a reflective sensor and a disk with a reflection band that repeats light and dark on the circumference, and the mark that serves as a reference for one rotation of the disk is compared with the other reflection bands at one point of the reflective sensor and the reflection band. The drive control device according to claim 1, wherein the drive control device is generated by a reflection band having a structure long in a direction perpendicular to the circumferential direction. The encoder is composed of a reflective sensor and a disk with a reflection band that repeats light and dark on the circumference, and the mark that serves as a reference for one rotation of the disk is compared with the other reflection bands at one point of the reflective sensor and the reflection band. 2. The drive control device according to claim 1, wherein the drive control device is generated by a reflection band having a short structure in a direction perpendicular to the circumferential direction. It has two voltage comparators with different comparison voltages that receive the output from the light receiving unit. The output for counting encoder pulses is output from the output of one voltage comparator, and the mark signal that is the reference for one rotation of the disk is the other. 9. The drive control device according to claim 7, wherein the output is output from a voltage comparator.

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