JPH08220938A - Electrophotographic equipment - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to provide an electrophotographic apparatus having high image quality and high reliability, which is provided with a detachable process cartridge in which there is no fluctuation in the rotation of the image carrier conveyance roller and there is no printing unevenness. . A main body device includes a drive unit 4, a drive transmission unit 6 meshing with the drive unit 4, and a circular drive rotation shaft unit 41 having a spline shape inside or outside the drive transmission unit 6, and The process cartridge 31 has a drive bearing portion that fits into the drive rotation shaft portion 41, and a circular rotation bearing portion 43 having a spline shape outside or inside the drive bearing portion, and the rotation bearing portion 43 is the drive rotation shaft portion. It is configured to be fitted into 41 and rotated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus which is an output device such as a laser printer or a copying machine equipped with a detachable process cartridge containing an image carrier and process means.

[0002]

2. Description of the Related Art In recent years, a process cartridge having an image carrier, a charger for uniformly applying an electric charge on the image carrier and a cleaning device for removing residual toner on the image carrier, and a process cartridge A cartridge accommodating portion for accommodating and supporting the apparatus main body, a paper conveying portion for conveying a transfer paper,
Also, there has been proposed an electrophotographic apparatus in which a process cartridge for fixing a toner image transferred on a transfer paper is built in and a process cartridge can be attached to and detached from the apparatus main body.

A conventional electrophotographic apparatus will be described below. FIG. 4 is a side sectional view of a main part of a conventional electrophotographic apparatus. FIG. 5 is a perspective view of a main part of a conventional electrophotographic apparatus when a process cartridge is replaced, and FIG. 6A shows a main part around a drive transmission section when the process cartridge is mounted on the main body of the conventional electrophotographic apparatus. 6B is a side sectional view of the portion of FIG.
FIG. 7 is a sectional view of an essential part taken along the line XX ′ of FIG. An image bearing member 1 has a resin belt such as polyethylene terephthalate as a base material, and a photosensitive receiving layer such as selenium (Se) or an organic photoconductor (OPC) is applied in a thin film on the outer periphery thereof. Image carrier transport rollers 2 and 3 form a vertical plane on the image carrier 1. Reference numeral 4 is a drive unit formed of a drive motor provided in the apparatus main body, 5 is a drive gear provided in the apparatus main body, and 6'is two claws provided on the side surface of the drive gear 5 and an image carrier conveying roller. 2 is a drive transmission part formed by engaging two claws provided on the end side surface of the rotating shaft part 2. The driving force from the driving unit 4 is driven by the drive transmission unit 6 ′ to drive the image carrier carrying roller 2 through the drive gear 5, and the image carrier 1 is moved along the image carrier carrying rollers 2 and 3 in the arrow A direction. Rotate around. 7 is a charger, 8 is a charging wire, 9 is a shield plate, and 10 is a grid plate. The charger 7 is composed of a charging line 8, a shield plate 9 and a grid plate 10 which are arranged above the image carrier 1 and close to the image carrier 1, and are generated by applying a high voltage to the charging line 8. The surface of the image carrier 1 is uniformly charged to a predetermined polarity by the corona discharge. Reference numeral 11 is an exposure optical system, and 12 is an exposure light beam emitted from the exposure optical system 11. An image signal input from the outside via an interface for forming an electrostatic latent image on the surface of the image carrier 1 is a laser beam. It is composed of a laser beam obtained by light intensity modulation or pulse width modulation by a drive circuit (not shown). This exposure light beam 12 is an exposure optical system 11
Thus, each dot is reciprocally scanned in the width direction of the image carrier 1, and the electric charges on the surface of the image carrier 1 uniformly charged by the charger 7 are erased to form an electrostatic latent image. A developing device 13 supplies toner to the electrostatic latent image and is detachably arranged in a storage portion provided in the apparatus main body. Reference numeral 14 is a cleaning device, which is provided with 15 cleaning blades for scraping off the toner remaining on the surface of the image carrier 1 and 16 residual toner storage portions. Reference numeral 17 denotes a static eliminator that removes charges remaining on the surface of the image carrier 1. Here, on the peripheral surface of the belt-shaped image carrier 1, the charger 7, the exposure optical system 11, the developing device 13, the image carrier, and the image carrier are sequentially arranged in the order of the process in the rotational direction of the image carrier 1 indicated by the arrow A. Cleaning device 1
4, a static eliminator 17 is arranged. 18 is a paper such as copy paper and recording paper, 19 is a paper cassette for storing the paper 18,
A sheet feeding roller 20 is formed in a half-moon shape (semi-circular shape), and takes out and conveys the sheets of paper 18 stored in the paper cassette 19 one by one. Reference numeral 21 is a paper conveyance path surface, and 22 is a registration roller, which has a function of temporarily stopping and waiting the paper 18 in order to match the positions of the paper 18 and the synthetic toner image formed on the surface of the image carrier 1. 23 is a registration roller 22
A driven roller abutted against the roller 24 is a transfer roller for transferring the synthetic toner image formed on the surface of the image carrier 1 to the paper 18. Reference numeral 25 denotes a fixing device, which includes a heat roller having a heat source inside 26 for heating the synthetic toner image transferred onto the paper 18, and a pressure roller for contacting the heat roller 26 and pressing the paper 18. It By the fixing device 25, the synthetic toner image transferred onto the paper 18 is fused and fixed by pressure and heat in accordance with the nip rotation. 28a,
28b is a pair of paper discharge rollers provided on the downstream side of the fixing device, and 2
Reference numeral 9 is a paper discharge tray provided on the side of the apparatus main body.

The structure and handling of each unit of the conventional electrophotographic apparatus having the above-described structure will be described below. Reference numeral 31 is a process cartridge in which the charger 7, the image carrier cleaning device 14 and the image carrier 1 are integrally configured, and can be attached to and detached from the apparatus main body. 32a and 32b are process cartridges 31
Is a guide portion that guides the device body to the device body for storage and support. Three
Reference numeral 3 denotes a fixing portion for fixing the process cartridge 31 to the apparatus main body, which uses a lock mechanism such as a screw. Three
Reference numeral 4 is a chassis frame of the apparatus main body, and 35 is an opening for attaching and detaching the process cartridge 31 to and from the chassis frame 34, which is provided at a peripheral position of the process cartridge 31. Reference numeral 36 is a handle used when the process cartridge 31 is attached to and detached from the apparatus main body.

The operation of the conventional electrophotographic apparatus constructed as above will be described below. First, when a print command is transmitted from a host computer (not shown), the drive motor, which is the drive unit 4, starts rotating. The driving force is transmitted to the image carrier 1 by the drive gear 5 and the two claw-shaped transmission driving means 6 ′ provided on the image carrier 1 and the image carrier 1 to transfer the image carrier 1. Rotate in the direction of arrow A. Next, high voltage power supply (4000V
High voltage is applied to the charging line 8 connected to (10000V to 10000V) to cause corona discharge, and the surface of the image carrier 1 is uniformly charged to about -700V to -800V via the grid plate 10. Next, an exposure light beam 12 such as a laser beam is radiated onto the surface of the image carrier 1 which is uniformly charged, and the charge on the image carrier 1 is erased to form an electrostatic latent image. It On the other hand, when a potential difference is applied between the developing device 13 and the image carrier 1 while the toner, which is the developer, is brought into contact with the image carrier 1, the toner is attached to the electrostatic latent image formed on the image carrier 1. The toner adheres to form a visible image and the development is completed. The visible image formed by the toner on the image carrier 1 thus formed is collectively transferred to the sheet 18 sent from the sheet cassette 19 along the sheet conveying path 21 by applying a high pressure to the transfer roller 24. It Then, the paper 18 is fixed to the fixing device 25.
Then, the toner is fixed by the heating of the heat roller 26 and the pressure of the heat roller 26 and the pressure roller 27, and an image is formed. The paper 18 that has passed through the fixing device 25 is discharged to the paper discharge tray 29 by the pair of paper discharge rollers 28a and 28b, and the printing operation is completed. The residual toner on the image bearing member 1 is scraped off by the cleaning blade 15 of the image bearing member cleaning device 14 and stored in the residual toner storing portion 16.

A procedure for replacing the process cartridge 31 of the conventional electrophotographic apparatus that operates as described above from the apparatus main body will be described below. First, the fixing portion 33 fixing the process cartridge 31 is rotated counterclockwise in order to unlock the lock mechanism, thereby releasing the fixing while pushing out the process cartridge 31 from the apparatus main body, and at the same time the drive transmission portion 6 ' The two claws are released so that the driving force from the driving unit 4 cannot be transmitted to the image carrier transporting roller 2. Next, the handle 3 of the process cartridge 31
6, the process cartridge 31 is pulled out from the apparatus main body along the pulling guide portions 32a and 32b in the direction of arrow B.

Next, holding the handle 36 of the new process cartridge 31, the process cartridge 31 is inserted in the direction of arrow C along the guide portions 32a and 32b of the apparatus main body. When the insertion of the process cartridge 31 is completed, the fixing portion 33 of the process cartridge 31 is rotated in the clockwise direction to push the process cartridge 31 into the apparatus main body and fix the process cartridge 31 with the lock mechanism. This completes the replacement of the process cartridge 31. on the other hand,
At the time when only the insertion of the process cartridge 31 is completed, the drive transmission portion 6 ′ has two claws which are not yet engaged with each other, and the fixing portion 33 is rotated clockwise to move the process cartridge 31 in the direction of arrow C. Then, the two claws of the drive transmission portion 6'are completely engaged with each other. Therefore, the driving force from the drive unit 4 is transmitted to the image carrier carrying roller 2, and the image carrier 1 rotates.

[0008]

However, in the above-mentioned conventional structure, in the case of the drive transmission section 6'which is a claw type in which the process cartridge 31 and the main body device are fitted to each other, the two claws are evenly formed due to the variation in dimensional accuracy. Since they do not mesh with each other, the driving force transmitted from the drive gear 5 of the apparatus main body to the carrier carrying roller 2 causes rotational fluctuation, and the drive gear 5 and the image carrier carrying roller 2 swirl. as a result,
There is a problem in that the pitch unevenness occurs in the image due to the rotation cycle of the two nails and the image quality deteriorates.

The present invention solves the above-mentioned problems of the prior art, and has a high image quality with an easily attachable / detachable process cartridge in which the rotational fluctuation of the image carrier is extremely small and the printing unevenness is small.
It is an object of the present invention to provide an electrophotographic device having excellent reliability.

[0010]

In order to achieve this object, an electrophotographic apparatus according to claim 1 of the present invention comprises an image carrier, a process cartridge arranged around the image carrier, and a process cartridge. A detachable main body device, wherein the main body device is a drive unit, a drive transmission unit meshing with the drive unit, and a circular shape having a spline shape inside or outside the drive transmission unit. A rotary bearing having a drive rotary shaft portion and a drive bearing portion into which the process cartridge fits with the drive rotary shaft portion, and a circular rotary bearing portion having a spline shape outside or inside the drive bearing portion. The part has a structure in which the part is fitted into the drive rotary shaft part and rotated.

Here, polyacetal or the like is used as the material of the rotary shaft portion and the rotary bearing shaft portion.

[0012]

With this structure, the drive transmission portion for engaging the image carrier conveying roller of the process cartridge detachably mountable to the main body of the apparatus and the drive gear from the main body apparatus has the spline-shaped fitting portion. Since the driving force from the main body can be evenly and reliably transmitted to the image carrier transport roller of the process cartridge, whirling of the image carrier due to rotational fluctuation can be prevented, and the unevenness of the image pitch can be made extremely small, resulting in a high quality printed image. Can be obtained. Also, since the fitting portion has a spline shape, when the process cartridge is mounted, the meshing between the image carrier conveying roller and the drive gear of the main body device becomes smooth, improving operability and workability, and applying unreasonable force. Therefore, the reliability and accuracy of the drive system can be secured and a high quality printed image can be obtained.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An electrophotographic apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a side sectional view of an essential part of an electrophotographic apparatus according to an embodiment of the present invention. 1 is an image carrier, 2 and 3 are image carrier transport rollers, 4 is a drive unit which is a drive motor, 7,
Charging device, 8 charging line, 9 shield plate, 10 grid plate, 11 exposure optical system, 12 exposure beam, 13 developing device, 14 image carrier cleaning device, 15 cleaning blade, 16 residual Toner container, 17 is a static eliminator, 18 is paper, 19 is a paper cassette, 20 is a paper feed roller, 21 is a paper conveyance path surface, 22 is a registration roller, and 23
Is a driven roller, 24 is a transfer roller, 25 is a fixing device, 26
Is a heat roller, 27 is a pressure roller, 28a and 28b are paper discharge roller pairs, 29 is a paper discharge tray, 31 is a process cartridge, 32a and 32b are guide portions, 34 is a chassis frame, 35 is an opening portion, and 36 is a grip. Is. Since these are the same as those in the conventional example, the same reference numerals are given and description thereof is omitted. What is different from the conventional example is a drive gear 5 for transmitting the drive force of the drive unit 4 of the main body device, and to the inside of the drive gear 5 for transmitting the drive force of the drive unit 4 of the main body device to the image carrier conveying roller 2. A spline-shaped drive rotation shaft portion 41 is provided, and a rotation bearing portion having a spline shape on the peripheral wall of the end portion of the rotation shaft 42 of the image carrier carrying roller 2 of the process cartridge so as to fit with the drive rotation shaft portion 41. This is the point where 43 is provided. As a result, the process cartridge 3
The image bearing member 1 is circumferentially rotated by fitting the rotary bearing portion 43 of No. 1 into the drive rotary shaft portion 41 of the main body device, and the process of the electrophotographic apparatus is executed.

The operation of the electrophotographic apparatus having the above structure according to the embodiment of the present invention will be described below. First, when a print command from a host computer (not shown) is sent to the electrophotographic apparatus, the process control unit (not shown) of the electrophotographic apparatus starts the drive motor of the drive unit 4 of the main body apparatus. . The driving force is the driving gear 5
The image transmission of the image carrier is performed by the drive transmission unit 6 in which the spline-shaped drive rotation shaft portion 41 provided on the drive gear 5 via the shaft and the spline-shaped rotation bearing portion 43 provided on the image carrier conveyance roller 2 are fitted. The image carrier 1 is transmitted to the roller 2.
Rotates in the direction of arrow A. As shown in the conventional process, the charging process, the exposing process, the developing process, the transferring process, the cleaning process, and the discharging process are repeatedly performed, and the printing is performed by the electrophotographic process.

A procedure for replacing the process cartridge 31 of the electrophotographic apparatus in the embodiment of the present invention which operates as described above from the apparatus main body will be described below. First, by rotating the screw portion 33 in the counterclockwise direction in order to unlock the lock mechanism of the fixing portion that fixes the process cartridge 31, the process cartridge 31 is released from the main body while releasing the fixing, and at the same time, the drive transmission portion 6 The fitting portion having the spline shape is released, and the driving force from the driving portion 4 cannot be transmitted to the image carrier transporting roller 2.
Next, the handle 36 of the process cartridge 31 is held and pulled out in the direction of arrow B from the main body of the process cartridge 31 along the guide portions 32a and 32b. Next, the new process cartridge 31 is inserted into the apparatus main body in the direction of arrow C along the guide portions 32a and 32b while holding the handle 36.
When the insertion of the process cartridge 31 is completed, the process cartridge 31 is fixed while being pushed into the apparatus main body by rotating the screw portion 33 having the lock mechanism in the clockwise direction. When it is pushed in, the spline-shaped fitting portion of the drive transmission portion 6 is fitted, and the driving force from the driving portion 4 can be transmitted to the image carrier conveying roller 2, and the electrophotographic process operates.

As described above, according to this embodiment, the drive transmission portion 6 in which the image carrier carrying roller 2 of the process cartridge 31 detachable from the apparatus main body and the drive gear 5 of the main body apparatus are splined. By using the fitting portion provided, since the driving force from the apparatus main body can be uniformly and surely transmitted to the image carrier conveying roller 2 of the process cartridge 31, it is possible to prevent whirling of the image carrier 1 due to rotation fluctuation. The pitch unevenness of the image can be made extremely small and a high quality printed image can be obtained. Further, because of the fitting portion having the spline shape, when the process cartridge 31 is mounted in the apparatus main body, the image carrier conveying roller 2 and the drive gear 5 from the main body apparatus are smoothly meshed with each other to improve workability. It is possible to obtain a high-quality printed image without reducing the reliability and accuracy of the drive system without applying excessive force.

[0018]

As described above, according to the present invention, the drive transmission section for transmitting the driving force from the drive gear of the apparatus main body to the image carrier conveying roller is provided with the spline-shaped fitting section, and the process cartridge is incorporated in the apparatus main body. With the detachable structure, the driving force from the drive unit of the main body of the device can be transmitted to the image carrier conveying roller of the process cartridge with high precision, so that the drive of the main unit due to the variation in the dimensional accuracy of the drive transmission unit can be driven. It is possible to prevent whirling of the drive gear and the image carrier carrying roller caused by poor meshing between the gear and the image carrier carrying roller of the process cartridge, and it is possible to realize an electrophotographic apparatus excellent in good print quality with less pitch unevenness. . Also, since the drive transmission part to the process cartridge has a splined fitting part, when the process cartridge is mounted, the image carrier conveying roller and the drive gear from the main body unit mesh smoothly, and operability and workability are improved. It is possible to realize an electrophotographic apparatus which is excellent in high-quality printing without improving the reliability of the drive system without lowering the reliability and accuracy of the drive system without applying excessive force.

[Brief description of drawings]

FIG. 1 is a side sectional view of an essential part of an electrophotographic apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view of an essential part showing a detached state of a conveyance roller and a drive gear of a process cartridge in one embodiment of the present invention.

FIG. 3 is a perspective view of an essential part showing a detached state of a conveyance roller and a drive gear of a process cartridge in one embodiment of the present invention.

FIG. 4 is a side sectional view of a main part of a conventional electrophotographic apparatus.

FIG. 5 is a perspective view of a main part when a process cartridge of a conventional electrophotographic apparatus is replaced.

FIG. 6A is a side sectional view of a main portion around a drive transmission portion when a process cartridge is mounted in a main body of a conventional electrophotographic apparatus. FIG. 6B is a sectional view of a main portion taken along line XX ′ of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 image carrier 2, 3 image carrier transport roller 4 drive unit 5 drive gear 6, 6'drive transmission unit 7 charger 8 charging line 9 shield plate 10 grid plate 11 exposure optical system 12 exposure beam 13 developer 14 image carrier Body cleaning device 15 Cleaning blade 16 Residual toner accommodating section 17 Static eliminator 18 Paper 19 Paper cassette 20 Paper feed roller 21 Paper transport road surface 22 Registration roller 23 Driven roller 24 Transfer roller 25 Fixing device 26 Heat roller 27 Pressure roller 28a, 28b Discharge Paper roller pair 29 Paper ejection tray 31 Process cartridge 32a, 32b Guide portion 33 Screw portion (fixed portion) 34 Chassis frame 35 Opening portion 36 Handle 41, 41 'Drive rotation shaft portion 42 Rotation shaft 43, 43' Rotation bearing portion

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshihiro Mizoguchi 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Yutaka Noda, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. 72) Inventor Nobuo Kishiyama 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (1)

[Claims] 1. An electrophotographic apparatus comprising an image bearing member, a process cartridge arranged around the image bearing member, and a main body device capable of detaching the process cartridge, wherein the main body device is driven. Section, a drive transmission section that meshes with the drive section, and a circular drive rotation shaft section having a spline shape inside or outside the drive transmission section, and the process cartridge includes the drive rotation shaft section. A drive bearing part to be fitted, and a circular rotary bearing part having a spline shape outside or inside the drive bearing part, wherein the rotary bearing part is fitted to the drive rotary shaft part and rotated. An electrophotographic device characterized by.