JP2021008887A - Belt driving device and image forming device - Google Patents

Abstract

To provide a belt driving device capable of detecting abnormality of a belt in a simple constitution, and an image forming device.SOLUTION: A drive pulley 23 is rotated by a motor 22. A metal belt 24 is stretched to the drive pulley 23 and a driven pulley 25, and transmits the rotation of the drive pulley 23 to the driven pulley 25. A rotary encoder 27 detects the rotational speed of the driven pulley 25. An abnormality detection processing unit 161 detects an abnormality in the metal belt 24 based on the fluctuation of the rotational speed of the driven pulley 25 detected by the rotary encoder 27.SELECTED DRAWING: Figure 2

Description

The present invention relates to a belt drive device and an image forming device.

A metal belt is laid between the drive shaft and the peripheral surface of the pulley, and the drive shaft and the pulley are urged in a direction away from each other, and the metal belt is based on the distance between the axes of the drive shaft and the pulley. A drive device capable of detecting the tension state of the belt is known (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2014-47848

However, in the drive device, it is necessary to provide a detection unit for detecting a change in the distance between the drive shaft and the pulley, which complicates the configuration of the drive device.

An object of the present invention is to provide a belt driving device and an image forming device capable of detecting an abnormality of a belt with a simple configuration.

The belt drive device according to one aspect of the present invention includes a drive pulley, a driven pulley, a belt, a rotation speed detection unit, and an abnormality detection processing unit. The drive pulley is rotated by a motor. The belt is stretched on the drive pulley and the driven pulley, and transmits the rotation of the drive pulley to the driven pulley. The rotation speed detection unit detects the rotation speed of the driven pulley. The abnormality detection processing unit detects an abnormality in the belt based on the fluctuation of the rotation speed of the driven pulley detected by the rotation speed detection unit.

The image forming apparatus according to one aspect of the present invention includes an image forming unit, the belt driving device, and a driven body. The image forming unit forms an image on the sheet. The driven body is driven by the belt driving device.

According to the present invention, there is provided a belt driving device and an image forming device capable of detecting an abnormality of a belt with a simple configuration.

FIG. 1 is a block diagram showing a system configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing an example of a configuration of a belt drive unit in the image forming apparatus according to the embodiment of the present invention. FIG. 3 is a diagram showing an example of the configuration of a belt drive unit in the image forming apparatus according to the embodiment of the present invention. FIG. 4 is a diagram showing an example of a pulse signal used in the image forming apparatus according to the embodiment of the present invention. FIG. 5 is a diagram showing an example of a pulse signal used in the image forming apparatus according to the embodiment of the present invention. FIG. 6 is a flowchart showing an example of a processing procedure executed by the image forming apparatus according to the embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings for the purpose of understanding the present invention. The following embodiments are examples that embody the present invention, and do not limit the technical scope of the present invention.

[Configuration of image forming apparatus]
As shown in FIG. 1, the image forming apparatus 1 according to the embodiment of the present invention includes an operation display unit 10, an ADF (Auto Document Feeder) 11, an image reading unit 12, an image forming unit 13, a communication I / F 14, and a storage. A unit 15, a control unit 16, a rotary encoder 27, and the like are provided. Specifically, the image forming apparatus 1 is a multifunction device having a printer function, a scanner function, a copy function, a facsimile function, and the like. The image forming apparatus 1 is an example of the belt driving apparatus of the present invention. The present invention is not limited to multifunction devices, and can be applied to any image forming apparatus such as a copier, a printer, and a facsimile apparatus. Further, the present invention is not limited to the image forming apparatus, and can be applied to any belt driving apparatus provided with a belt driving mechanism such as the belt driving unit 20 described later.

The operation display unit 10 includes a display unit such as a liquid crystal display that displays information, and an operation unit such as a touch panel and operation buttons that accept user operations.

The ADF 11 is an automatic document transfer device that includes a document setting unit, a transfer roller, a document retainer, and a paper ejection unit, and conveys a document to be read by the image reading unit 12.

The image reading unit 12 includes a platen, a light source, a mirror, an optical lens, and a CCD (Charge Coupled Device), and can read an image of a document and output it as image data.

The image forming unit 13 can execute a printing process based on the image data by an electrophotographic method or an inkjet method, and forms an image on the sheet based on the image data. For example, when the image forming unit 13 forms an image on a sheet by an electrophotographic method, the image forming unit 13 includes a photoconductor drum, a charger, an exposure device, a developing device, a transfer device, a fixing device, and the like. The photoconductor drum is an example of a driven body 30 (see FIG. 2) described later.

The communication I / F14 executes communication processing according to a predetermined communication protocol with an external facsimile machine or an information processing device such as a personal computer via a communication network such as a telephone line, the Internet, or a LAN. Is a possible communication interface.

The storage unit 15 is a non-volatile storage unit such as a hard disk or EEPROM (registered trademark). Various control programs executed by the control unit 16 and various data are stored in the storage unit 15.

The control unit 16 includes control devices such as a CPU, ROM, and RAM. The CPU is a processor that executes various arithmetic processes. The ROM is a non-volatile storage unit in which information such as a control program for causing the CPU to execute various processes is stored in advance. The RAM is a volatile or non-volatile storage unit used as a temporary storage memory (working area) for various processes executed by the CPU.

The rotary encoder 27 detects the rotation speed of the driven pulley 25 (see FIG. 2), which will be described later. Specifically, the rotary encoder 27 outputs a pulse signal (see FIGS. 4 and 5) according to the rotation speed of the driven pulley 25 (see FIG. 2) described later. The pulse signal is input to the control unit 16. The rotary encoder 27 is an example of the rotation speed detection unit of the present invention.

[Structure of belt drive unit]
The image forming apparatus 1 includes a belt driving unit 20 as shown in FIGS. 2 and 3. The belt driving unit 20 is a mechanism for transmitting the rotational driving force of the motor 22 to the driven body 30 such as the photoconductor drum.

The belt drive unit 20 includes a support unit 21, a motor 22, a drive pulley 23, a metal belt 24, a driven pulley 25, an output shaft 26, and a rotary encoder 27. The rotary encoder 27 includes a pulse plate 27A having a disk shape and a photo sensor 27B.

The motor 22 and the photo sensor 27B are fixed to the support portion 21. Further, the support portion 21 rotatably supports the drive pulley 23 and the output shaft 26.

The motor 22 is driven by a motor drive circuit (not shown). The drive pulley 23 is connected to the rotation shaft of the motor 22, and is rotated by the motor 22.

The metal belt 24 is stretched on the drive pulley 23 and the driven pulley 25, and transmits the rotation of the drive pulley 23 to the driven pulley. The metal belt 24 is, for example, an endless belt made of stainless steel. The metal belt 24 is an example of the belt of the present invention.

The driven pulley 25 is fixed to the output shaft 26 and rotates integrally with the output shaft 26. A pulse plate 27A is fixed to one end of the output shaft (the left end in FIG. 2), and a driven body 30 such as the photoconductor drum is connected to the other end of the output shaft 26. Has been done. As a result, the rotational driving force of the motor 22 is transmitted to the driven body 30 via the drive pulley 23, the metal belt 24, the driven pulley 25, and the output shaft 26. As a result, the driven body 30 is driven by the rotational driving force of the motor 22.

By the way, in order to detect the tension state of the metal belt 24, an urging member for urging the drive pulley 23 and the driven pulley 25 in a direction away from each other is provided, and the distance between the axes of the drive pulley 23 and the driven pulley 25 is provided. It is conceivable to detect the tension state of the metal belt 24 based on the above. However, when such a configuration is adopted, it is necessary to provide a detection unit for detecting a change in the distance between the axes of the drive pulley 23 and the driven pulley 25, which complicates the configuration of the device. On the other hand, in the image forming apparatus 1 according to the present embodiment, it is possible to detect an abnormality in the metal belt 24 with a simple configuration.

Specifically, as shown in FIG. 1, the control unit 16 includes an abnormality detection processing unit 161 and a notification processing unit 162. The control unit 16 functions as each of these processing units by executing various processes according to the control program. Further, the control unit 16 may include an electronic circuit that realizes a part or a plurality of processing functions of each of these processing units.

The abnormality detection processing unit 161 detects an abnormality in the metal belt 24 based on the fluctuation of the rotation speed of the driven pulley 25 detected by the rotary encoder 27. Specifically, the abnormality detection processing unit 161 detects an abnormality in the metal belt 24 based on the pulse signal output from the rotary encoder 27. Hereinafter, the abnormality detection method in the abnormality detection processing unit 161 will be described with reference to FIGS. 4 and 5.

The pulse plate 27A of the rotary encoder 27 is provided with a plurality of slits at equal intervals along the circumferential direction. On the other hand, the photo sensor 27B of the rotary encoder 27 is provided with a light emitting unit and a light receiving unit at positions facing each other with the pulse plate 27A interposed therebetween. Then, when the pulse plate 27A rotates, the state in which the light from the light emitting portion is incident on the light receiving portion through the slit and the state in which the light from the light emitting portion is blocked by the pulse plate 27A are repeated. As a result, the amount of light incident on the light receiving unit changes periodically, and a pulse signal as shown in FIG. 4 is output from the rotary encoder 27.

When there is no abnormality in the metal belt 24 and the driven pulley 25 is rotating at a constant rotation speed, the pulse period of the pulse signal output from the rotary encoder 27 is a constant period (for example, the reference period shown in FIG. 4). It becomes D1). However, when an abnormality such as a crack or foreign matter adhering to the metal belt 24 occurs, the portion where the abnormality occurs (hereinafter referred to as an abnormal portion) is brought into contact with or detached from the driven pulley 25. The rotation speed of the driven pulley 25 fluctuates temporarily. As a result, the pulse period of the pulse signal output from the rotary encoder 27 is temporarily deviated from the reference period D1. For example, in the example shown in FIG. 4, the pulse period of the pulse signal is temporarily changed to the period D2 or the period D3 near the time T1. Therefore, the abnormality detection processing unit 161 can determine that an abnormality has occurred in the belt when the pulse period of the pulse signal deviates from the reference period D1.

The factors that fluctuate the pulse period of the pulse signal are not limited to the abnormality of the metal belt 24, and various other factors can be considered. For example, even when an impact is applied to the image forming apparatus 1 from the outside, the pulse period of the pulse signal may fluctuate. However, when an impact is applied to the image forming apparatus 1 from the outside, the pulse period of the pulse signal returns to the reference period D1 when the vibration of the image forming apparatus 1 due to the impact is stopped. On the other hand, when an abnormality occurs in the metal belt 24, the pulse period of the pulse signal fluctuates every time the abnormal portion of the metal belt 24 goes around, so that the pulse cycle of the pulse signal fluctuates periodically. It will be. For example, when an abnormality occurs in the metal belt 24, the pulse period is the same as the rotation cycle P1 of the metal belt 24 at time T1, time T2, and time T3, as shown in the pulse signal shown in FIG. Fluctuates temporarily. It should be noted that the pulse period may fluctuate a plurality of times while the metal belt 24 makes one revolution. For example, while the metal belt 24 makes one revolution, the fluctuation of the pulse cycle occurs when the abnormal portion comes into contact with the driven pulley 25, when the abnormal portion separates from the driven pulley 25, and when the abnormal portion separates from the driven pulley 25. It may occur four times, when it comes into contact with the 23 and when the abnormal portion separates from the drive pulley 23. Also in this case, these four fluctuations occur periodically at the same cycle as the rotation cycle P1 of the metal belt 24.

Therefore, the abnormality detection processing unit 161 may determine that the metal belt 24 has an abnormality when the rotational speed of the driven pulley 25 fluctuates periodically. More specifically, the abnormality detection processing unit 161 states that an abnormality has occurred in the metal belt 24 when the rotation speed of the driven pulley 25 fluctuates in the same cycle as the rotation cycle P1 of the metal belt 24. You may judge. This makes it possible to detect the abnormality of the metal belt 24 with higher accuracy.

When the abnormality detection processing unit 161 detects an abnormality in the metal belt 24, the notification processing unit 162 notifies that fact. For example, the notification processing unit 162 may transmit information indicating that an abnormality of the metal belt 24 has been detected to a server (not shown) of a business operator that undertakes maintenance work of the image forming apparatus 1. Alternatively, the notification processing unit 162 may display a message prompting the inspection or replacement of the metal belt 24 on the operation display unit 10.

As described above, according to the image forming apparatus 1 according to the present embodiment, when an abnormality such as a crack occurs in the metal belt 24, it is possible to detect the abnormality and notify the fact. Therefore, before the metal belt 24 is actually broken, it is possible to detect an abnormality in the metal belt 24 and prompt the replacement of the metal belt 24, so that the down time of the image forming apparatus 1 can be shortened. it can.

Further, in the present embodiment, since the abnormality of the metal belt 24 is detected based on the pulse signal output from the rotary encoder 27, it is possible to detect the abnormality of the metal belt 24 with a simple configuration.

Further, in general, the rotary encoder 27 may be provided in the image forming apparatus 1 for the purpose of monitoring the rotation speed of the driven body 30 such as the photoconductor drum. Therefore, when the rotary encoder 27 is provided in the image forming apparatus 1 for such a purpose, it is not necessary to separately provide a rotational speed detecting unit for detecting the rotational speed of the driven pulley 25. The cost can be suppressed.

[Modification example]
The driven body 30 is not limited to the photoconductor drum, but may be a developing roller provided in the developing device, a transfer belt provided in the transfer device (that is, a driving roller for rotating the transfer belt), or the like. There may be. In particular, for the photoconductor drum, the developing roller, and the transfer belt, belt driving is preferable to gear driving in order to avoid deterioration of image quality due to vibration generated by contact between gears.

Further, in the present embodiment, the abnormality of the metal belt 24 is detected, but the present invention is not limited to the metal belt, and can be applied to the detection of the abnormality of any kind of belt such as resin. ..

Further, in the present embodiment, the abnormality of the metal belt 24 is detected based on the fluctuation of the pulse period in the pulse signal, but in other embodiments, the spectrum analysis is performed based on the pulse signal, and the spectrum analysis is performed. An abnormality of the metal belt 24 may be detected based on the analysis result.

Further, in another embodiment, the image forming apparatus 1 may have a function of discriminating the type of abnormality occurring in the metal belt 24. FIG. 6 is a flowchart showing an example of a processing procedure executed by the control unit 16 in the other embodiment. For example, the variation mode of the pulse period in the pulse signal differs depending on whether the metal belt 24 is cracked or the back surface of the metal belt 24 (contact surface with the driven pulley 25) is foreign matter. Can be considered. For example, in one case, the fluctuation amount of the pulse period is relatively small, and in the other case, the fluctuation amount of the pulse period is relatively large. Alternatively, in one case, the pulse cycle may be momentarily shorter than the reference cycle D1, and in the other case, the pulse cycle may be momentarily longer than the reference cycle D1. Therefore, the control unit 16 (abnormality detection processing unit 161) determines that the metal belt 24 is cracked when the fluctuation mode of the pulse period in the pulse signal is the first predetermined mode. When the variation mode of the pulse period in the pulse signal is a predetermined second mode different from the first mode, it may be determined that foreign matter is attached to the back surface of the metal belt 24. Then, the control unit 16 (notification processing unit 162) may notify different contents depending on the determination result of the abnormality detection processing unit 161. For example, when the notification processing unit 162 determines that the metal belt 24 is cracked (S11: Yes), the notification processing unit 162 causes the operation display unit 10 to display a first message prompting the replacement of the metal belt 24 (S12). ), When it is determined that foreign matter is attached to the back surface of the metal belt 24 (S13: Yes), a second message prompting the cleaning of the metal belt 24 may be displayed on the operation display unit 10 (S14). ). This can prompt the user to take appropriate action.

1 Image forming device 13 Image forming unit 16 Control unit 161 Abnormality detection processing unit 162 Notification processing unit 20 Belt drive unit 21 Support unit 22 Motor 23 Drive pulley 24 Metal belt 25 Driven pulley 26 Output shaft 27 Rotary encoder 27A Pulse plate 27B Photo sensor 30 Driven body

Claims (8)

The drive pulley rotated by the motor and
With the driven pulley,
A belt stretched over the drive pulley and the driven pulley and transmitting the rotation of the drive pulley to the driven pulley.
A rotation speed detection unit that detects the rotation speed of the driven pulley,
An abnormality detection processing unit that detects an abnormality in the belt based on a fluctuation in the rotation speed of the driven pulley detected by the rotation speed detection unit.
A belt drive device. The abnormality detection processing unit determines that an abnormality has occurred in the belt when the rotational speed of the driven pulley fluctuates periodically.
The belt driving device according to claim 1. The abnormality detection processing unit determines that an abnormality has occurred in the belt when the rotation speed of the driven pulley fluctuates in the same cycle as the rotation cycle of the belt.
The belt driving device according to claim 2. The rotation speed detection unit is a rotary encoder that outputs a pulse signal according to the rotation speed of the driven pulley.
The belt driving device according to any one of claims 1 to 3. Further, a notification processing unit for notifying when an abnormality of the belt is detected by the abnormality detection processing unit is provided.
The belt drive device according to any one of claims 1 to 4. The belt is a metal belt,
The belt driving device according to any one of claims 1 to 5. An image forming part that forms an image on the sheet,
The belt drive device according to any one of claims 1 to 6.
The driven body driven by the belt driving device and
An image forming apparatus comprising. The driven body includes at least one of a photoconductor drum, a developing roller, and a transfer belt.
The image forming apparatus according to claim 7.

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