JP2004102141A - Process cartridge, developing device, and development bias voltage contact device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve assembly of a process cartridge and the operability in reproduction (replacement of a sleeve contact) of a process cartridge. <P>SOLUTION: A "developing bias voltage contact device" configured by a spring member made of a metal wire etc., to a cylindrical contact holding member having an electric contact made of plastic as an electric contact electrically connecting the outer circumferential surface of an electrode shaft extending from a CRG frame into a sleeve and the inner circumferential surface of a conductive sleeve flange to each other is engaged with the inner circumferential surface of the sleeve flange and then the spring member is rubbed against the outer circumferential surface of the electrode shaft to electrically be conductive. Or a "developing bias voltage contact device" formed by bending an end of the coil spring inward is engaged with the inner circumferential surface of the sleeve flange and then the bent part of the spring end part is made electrically conductive to the outer circumferential surface of the electrode shaft. Thus, the electric contact can be attached and detached without detaching the pressed-in sleeve flange. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a process cartridge and a developing device used for image formation of a copying machine, a printer, and the like, and a developing bias voltage contact device for applying a developing bias voltage to a developing roller used in the process cartridge or the developing device.
[0002]
[Prior art]
In an image forming apparatus using electrophotography, if the image forming apparatus is used for a long time, replacement of an image carrier (hereinafter, referred to as a photosensitive drum), replenishment and replacement of a developer (hereinafter, referred to as a toner), a charger, In addition, adjustment, cleaning, and replacement of the cleaner container and the like are required, but such maintenance work has been practically difficult except for service personnel having specialized knowledge.
[0003]
As means for solving this problem, a process cartridge in which image forming process means such as a photosensitive drum, a developing device, and a cleaning device are integrated as a unit body has been commercialized.
[0004]
As a result, if maintenance is required for the process equipment, the user can easily perform maintenance and replacement by himself / herself, and high-quality image quality can be obtained at low cost and easily. In such a process cartridge, various developing bias voltage contact devices are used to apply a developing bias voltage to the developing roller.
[0005]
Here, the developing bias voltage contact device disclosed in JP-A-2001-202096 will be described with reference to FIGS. Inside a hollow metal sleeve 118 constituting a developing roller, a plastic magnet roller bearing 127 for supporting one end side 126a of a magnet roller 126 and a thin metal sleeve contact plate 125 fixed to the magnet roller are provided. The bias voltage is applied to the developing roller by the tip end portion 124a of the metal electrode shaft 124 fixed to the housing 120 of the process cartridge and being in contact with the tongue piece portion 125a of the sleeve contact plate 125 in the sleeve 118. FIG. In FIG. 11, reference numeral 123 denotes a sleeve flange which is press-fitted into the sleeve 118; 130, a sleeve bearing for rotatably supporting the flange 123 (sleeve 118); 131, a sleeve gear for transmitting rotation to the sleeve 118; One end thereof contacts the base of the electrode shaft 124, and when the process cartridge is mounted on the image forming apparatus main body, the other end (not shown) contacts a contact on the image forming apparatus main body side. Is shown.
[0006]
[Problems to be solved by the invention]
The above-described prior art has made it possible to provide a process cartridge that has achieved space saving in the longitudinal direction of the process cartridge, improved reliability of the electrical contact portions, and achieved highly accurate positioning of the magnet roller.
[0007]
The object of the invention according to the present application is to further develop the above-described conventional technology, and to improve the operability when assembling and reproducing the used process cartridge while improving the reliability of the contacts. An object of the present invention is to provide a developing bias voltage contact device and a process cartridge which are improved.
[0008]
[Means for Solving the Problems]
A first configuration according to the present invention includes at least an image carrier, a hollow cylindrical sleeve portion made of a conductive material, and an opening fitted to one end of the sleeve portion and extending along an axial direction of the sleeve portion. And a developing roller for developing a latent image formed on the image carrier with a developer, the developing cartridge comprising: And is inserted along the rotation axis direction of the developing roller into the opening of the flange portion, and when the process cartridge is mounted on the image forming apparatus main body, the electrical contact of the image forming apparatus main body is formed. A substantially cylindrical first electrical contact that is electrically connected to the first electrical contact, the first electrical contact being fixed to the opening of the flange portion of the developing roller; A process cartridge and having a second electrical contact which elastically contact with.
[0009]
A second configuration according to the present invention is a conductive flange portion having a hollow cylindrical sleeve portion made of a conductive material and an opening fitted to one end of the sleeve portion and extending along the axial direction of the sleeve portion. In order to develop a latent image formed on the image carrier with a developer, the developing device includes a developing roller, and is fixed to a housing of the developing device in a developing device attachable to the image forming apparatus main body. Substantially inserted into the opening of the flange portion along the rotation axis direction of the developing roller and electrically connected to an electrical contact of the image forming apparatus main body when the developing apparatus is mounted on the image forming apparatus main body. A cylindrical first electrical contact, and a second electrical contact fixed to the opening of the flange portion of the developing roller and elastically contacting the peripheral surface of the first electrical contact. Development characterized by having It is the location.
[0010]
According to a third configuration of the present invention, a bias voltage is applied to a developing roller for developing a latent image formed on an image carrier with a developer in a process cartridge or a developing device that can be mounted on the image forming apparatus main body. A process cartridge or a developing device, wherein the process cartridge or the developing device is fitted into a hollow cylindrical sleeve portion made of a conductive material, and is fitted to one end of the sleeve portion, and extends along the axial direction of the sleeve portion. A developing roller for developing a latent image formed on the image carrier with a developer, and a flange fixed to a process cartridge or a housing of a developing device. The developing cartridge is inserted into the opening of the developing unit along the rotation axis direction of the developing roller, and the process cartridge or the developing device is A substantially cylindrical electrical contact that is electrically connected to an electrical contact of the image forming apparatus main body when mounted on the main body, wherein the developing bias voltage contact device is provided on the flange portion of the developing roller. A developing bias, comprising: a first portion fixed to the opening; and a second portion elastically contacting a peripheral surface of the cylindrical electrical contact provided on the housing. It is a voltage contact device.
[0011]
A fourth configuration according to the present invention is characterized in that the first portion is a contact holding member that has an opening through which the cylindrical electrical contact can penetrate and is fitted into the opening of the flange, The developing bias voltage contact device according to the third configuration, characterized in that a portion of the developing bias voltage contact device is a metal spring attached to the contact holding member and a part of which protrudes into an opening of the contact holding member. It is.
[0012]
A fifth configuration according to the present invention is the developing bias voltage contact device according to the fourth configuration, wherein the contact holding member has a flange portion that abuts on a longitudinally outer end of the flange. is there.
[0013]
In a sixth configuration according to the present invention, the first portion is a coil spring portion having an outer shape slightly larger than the inner diameter of the opening of the flange, and the second portion is at least one of the coil spring portions. The developing bias voltage according to the third configuration, wherein the end wire is formed by bending the wire inward of the coil, and the coil spring portion is press-fittable into the opening of the flange. It is a contact device.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
(First Embodiment)
An embodiment of the present invention will be described with reference to FIGS.
[0015]
[Description of Process Cartridge and Image Forming Apparatus Main Body]
FIG. 1 is a main cross-sectional view of a process cartridge according to the present embodiment, and FIG. 2 is a main cross-sectional view of an image forming apparatus of the present embodiment in which the process cartridge of FIG.
[0016]
The process cartridge includes an image carrier (hereinafter, referred to as a photosensitive drum) and a process unit that acts on the photosensitive drum. Here, as the process means, for example, a charging means for charging the surface of the photosensitive drum, a developing device for forming a toner image on an electrostatic latent image on the photosensitive drum, and a device for removing toner remaining on the surface of the photosensitive drum There is a cleaning means.
[0017]
As shown in FIG. 1, the process cartridge 15 of the present embodiment has a charging roller 12 serving as a charging unit and a developing roller 18 as a developing device, a developing blade, and toner stored around a photosensitive drum 11 serving as an image carrier. A cleaning blade 14 is disposed as a toner storage frame 16 and a cleaning means, and is integrally formed as a cartridge 15 by being covered with a housing, and is configured to be detachable from the image forming apparatus main body C.
[0018]
The process cartridge 15 is mounted on an image forming apparatus C as shown in FIG. 2 and used for image formation. In image formation, a sheet S is conveyed by a conveying roller 7 from a sheet cassette 6 mounted at a lower portion of the apparatus, and in synchronization with the sheet conveyance, the photosensitive drum 11 is selectively exposed from an exposing device 8 to form a latent image. Form. Thereafter, a thin layer of the toner stored in the toner storage container 16 is carried on the surface of the developing roller 18 by the developing blade, and a developing bias voltage is applied to the developing roller 18 to supply the toner according to the latent image. This toner image is transferred to a sheet S conveyed by applying a bias voltage to the transfer roller 9, the sheet S is conveyed to a fixing device 10 to fix the image, and is discharged by a discharge roller 1 to a discharge unit 2 on the upper portion of the device. I do.
[0019]
[Frame configuration of process cartridge]
3 and 4 are perspective views showing the frame structure. FIG. 3 is a diagram before the frame is assembled, and FIG. 4 is a diagram after the frame is assembled.
[0020]
The process cartridge 15 includes a cleaning frame 13 integrally supporting the photosensitive drum 11, the charging roller 12, and the cleaning blade 14, and a developing frame integrally supporting the developing roller 18 and the developing blade (not shown). The cleaning frame 13 and the toner storage frame 16 are disposed in opposition to each other, and the developing frame 17 is provided with the cleaning frame 13. And the toner storage frame 16.
[0021]
Further, in order to integrally support these three frames, the frames are fixed by side covers 19 and 20 on both side surfaces of the frames, and are integrated as a process cartridge.
[0022]
(1) Cleaning frame 13
A cleaning blade 14 is fixed to the cleaning frame 13 with screws or the like, and the charging roller 12 is rotatably supported on a cored bar at an end thereof via a bearing member (not shown).
[0023]
In addition, the photosensitive drum 11 is rotatably supported by flange portions 11a and 11b at both ends via bearing members 22, respectively.
[0024]
(2) Toner storage frame 16
The toner storage frame 16 stores toner together with a toner conveying member (not shown) therein. Details of the developing frame 17 will be described later. The one side cover 19 on the non-drive unit side has a size enough to cover the main cross section of the process cartridge 15, is disposed at one end in the longitudinal direction of the process cartridge, and has the cleaning frame 13 and the toner storage frame 16. Are integrally supported from both sides.
[0025]
The hole 19a of the side cover 19 is positioned coaxially with the center of the photosensitive drum 11 of the cleaning frame 13. At this time, it is determined precisely if the side cover 19 is positioned via the bearing member 22. The positioning portion 19b provided at a position as far as possible from the photosensitive drum 11 is provided on the side surface of the cleaning frame 13. The position in the rotation direction is determined with respect to the positioning portion 13b, and is fixed with several screws.
[0026]
Further, the positioning portion 16a, 16b is formed on one end surface of the toner frame 16, and the positioning portion 19c, 19d disposed on the side cover 19 determines the position, and is fixed with several screws.
[0027]
The other side cover 20 on the drive unit side also positions the developing frame 17 by a method described later.
[0028]
Further, the bearing member 22 also serves for positioning to the image forming apparatus. In order to supply toner from the toner storage frame 16 to the developing sleeve 18, the toner frame 16 and the developing frame 17 are provided with an opening 17a and an opening 16c, respectively.
[0029]
The developing frame 17 and the toner frame 16 are connected by a seal member 21 having an opening so as to connect the openings to each other.
[0030]
Toner frame 16 Further, since the toner frame 16 is positioned by the side covers 19 and 20, and the developing frame 17 is positioned by the cleaning frame 13, the dimensional error between the developing frame 17 and the toner frame 16 is reduced. May cause distortion in either of them. Therefore, the seal member 21 uses a flexible material.
[0031]
With this configuration, as described above, even when the amount of toner increases, the load due to the toner is applied to the side cover, and the developing sleeve does not occur. Therefore, a stable image can be obtained without applying an unnecessary load to the photosensitive drum.
[0032]
Furthermore, by connecting the side surfaces of each frame, the positioning of each frame can be performed with one part of the side cover, and the connection can be accurately performed.
[0033]
[Configuration of developing frame]
The developing frame 17 is provided with a developing roller including a developing roller 18 including a magnet roller 26 therein, a developing blade, and a magnetic seal (not shown).
[0034]
The magnet roller 26 is supported by the inner diameter of the developing sleeve 18 and maintains a gap with the developing sleeve 18. The power supply to the developing sleeve 18 is performed by providing an electric contact inside the developing sleeve 18. These will be described later in detail. Further, on the developing sleeve 18, there is provided a contact roller (not shown) for keeping a constant distance from the photosensitive drum 11.
[0035]
The developing frame 17 can be swung such that the center of the developing sleeve 18 is directed to the center of the photosensitive drum 11 with the hanging hole 17d provided on the driving side (the right side in FIG. 3) of the developing sleeve 18 as the center of rotation. It is supported by.
[0036]
That is, the developing frame 17 including the developing sleeve 18 is arranged on the driving side on the cleaning frame 13 so as to be swingable about the hanging hole 17d. Since the body 16 is fixed without relatively moving, the developing frame 17 is movable relative to the toner frame 16.
[0037]
Further, on the non-driving side of the developing frame 17, a developing roller pressing sleeve member 17e is provided on the longitudinal central axis of the developing sleeve 18 (one end of a magnet roller 26 of the developing roller is fitted to the sleeve member 17e). The developing roller pressing sleeve member 17 e is pressed toward the center of the photosensitive drum 11.
[0038]
The sleeve member 17e for pressing the developing roller is inserted into a long groove 19e (in this embodiment, a linear hole substantially parallel to the center direction of the photosensitive drum 11 and a linear hole) provided in the one side cover 19, and Is configured to be movable in the center direction. Further, a coil spring 43b having a contact piece 43a at the tip is disposed inside the long groove 19e so as to press the developing roller pressing sleeve member 17e toward the photosensitive drum 11.
[0039]
The groove 19e also plays a role of positioning for restricting the moving direction of the developing sleeve 18.
[0040]
Here, when a driving force acts on the developing device and the photosensitive drum, driving gears provided on the photosensitive drum 11 and the developing sleeve 18 (these gears are not shown, but the gear of the photosensitive drum and the developing sleeve) Gears are engaged with each other) with respect to the suspension holes 17a, so that a force acts in the direction of biting each other, and no force acts in a direction in which the photosensitive drum 11 and the developing sleeve 18 are separated from each other. I have. Also, the developing sleeve 18 is constantly pressed in the direction toward the photosensitive drum 11 by the developing roller pressing sleeve member 17e.
[0041]
That is, in the present embodiment, since the developing frame 17 and the toner frame 16 are relatively movable, the developing frame 17 and the toner frame 16 are connected by the seal member 21 that absorbs the moving range of both, so that toner leakage is prevented. . Desirably, the seal member 21 has a shape having a small repulsive force to hinder the movement of the developing device, and has a shape having at least one fold or a bellows shape.
[0042]
The seal member 21 according to the present embodiment has two folds (not shown) made of an elastomer to reduce the repulsive force, but the flexibility of the urethane foam member, low-hardness rubber, silicon, or the like. May be selected. In this case, if the repulsion is small, the same effect can be obtained even if the folds and bellows are omitted.
[0043]
[Power supply configuration and support configuration of developing roller]
Here, a configuration for supplying power to the developing roller according to the present embodiment will be described in detail. FIG. 5 is a perspective view showing a developing bias voltage contact device of the present embodiment, and FIG. 6 is an exploded perspective view of a developing roller according to the present embodiment and members related to a power supply configuration and a support configuration before assembly. 7 is an exploded perspective view before assembling the developing roller and the side cover, and FIG. 8 is a sectional view taken along the center axis of the developing roller.
[0044]
As shown in FIG. 6, the developing sleeve 18 constituting the developing roller is formed of a cylindrical member made of a metal material such as aluminum or stainless steel. Its outer diameter is about 16 to 20 mm, and its thickness is about 0.5 to 1 mm. In addition, a carbon coat, blast, or the like is applied to the surface of the developer to enhance the chargeability of the developer. In the present embodiment, only the carbon coat is used. At both ends, press-fit portions 18a for press-fitting and fixing a sleeve flange 23 described later to the inner peripheral portion are provided.
[0045]
As shown in FIG. 6, the sleeve flange 23 is a stepped cylindrical member made of a metal material such as aluminum or stainless steel which is press-fitted and fixed to the end of the developing roller 18. In FIG. Although shown in the drawing, they are similarly provided on the non-drive unit side.
[0046]
The sleeve flange 23 is formed in a stepped shape including a large-diameter portion and a small-diameter portion, and the large-diameter portion is a press-fit portion 23c that is press-fitted into the inner periphery of the developing roller 18 and fixed. By this press-fitting, the sleeve flange 23 is non-rotatably fixed to the developing sleeve 18.
[0047]
In addition, if the outer diameter of the developing sleeve 18 and the coaxiality of the sleeve flange 23 are poor, the density tends to be uneven on the image, so that the fixing is accurately performed.
[0048]
A fixing portion 23e for fixing a magnet roller bearing 27 to be described later and a groove 23d for restricting the rotation of the magnet roller bearing 27 are provided substantially at the same position as the axial direction of the developing sleeve 18 on the inner periphery of the press-fit portion 23c. ing.
[0049]
Outside the press-fit portion 23c of the sleeve flange 23, a flange outer diameter portion 23b coaxial with the press-fit portion and having a small outer diameter is provided.
[0050]
The flange outer diameter portion 23b includes a distance regulating member 29 for regulating the facing distance between the developing sleeve 18 and the photosensitive drum, a sleeve bearing 30 rotatably supported by the developing frame 17, and the photosensitive drum 11. The driving force is transmitted, and a sleeve gear 31 for rotating the developing sleeve 18 is fitted.
[0051]
The sleeve bearing 30 is fixed to the developing frame 17 by a support hole 30a. The sleeve gear 31 is fixed so as not to rotate with respect to the developing sleeve 18. The sleeve flange 23 is provided with a through hole 23a on the inner periphery thereof coaxially with the outer diameter portion 23b. The through-hole 23a is penetrated by a metal-made electrode shaft 24 which will be described later and is formed to be electrically connected to the developing bias voltage contact device 25 inside.
[0052]
As shown in FIG. 6, the magnet roller 26 has a structure in which shaft support portions 26b and 26c are formed on both sides of a large-diameter portion 26a. The large-diameter portion 26a is included in a developing sleeve and has a circumferential surface on the surface thereof. Along with a plurality of magnetic poles. Usually, one pole is arranged so as to substantially oppose the photosensitive drum 11, and the other magnetic poles are also arranged at optimal positions. In the present embodiment, four poles are formed.
[0053]
The distance between the surface of the large diameter portion 26a and the surface of the developing sleeve 18 is kept constant so that the magnetic force on the developing sleeve 18 is stabilized. In order to keep this distance constant, one shaft support portion 26c is supported by the side cover 19 shown in FIG. 3 (the one shaft support portion 26c is non-rotatably fitted to the developing roller pressing sleeve member 17e). The developing roller pressing sleeve member 17e is supported by fitting into the long groove 19e of the side cover 19).
[0054]
At this time, the D-cut portion 26c1 formed on the one shaft support portion 26c is fitted into the D-shaped fitting hole of the developing roller pressing sleeve member 17e so that the arrangement of the magnetic poles in the circumferential direction is reduced. Regulated to be stable.
[0055]
Further, the other shaft support portion 26b is supported by a magnet roller bearing 27 fitted to the fixing portion 23d of the sleeve flange 23.
[0056]
As shown in FIG. 6, the outer peripheral surface of the magnet roller bearing 27 is formed with an outer diameter portion 27d and a rotation stopper 27c protruding from the outer diameter portion 27d. The outer diameter portion 27d is fitted to the fixing portion 23e of the sleeve flange shown in FIG. 6, and the rotation stopping portion 27c is engaged with the groove portion 23d and rotates integrally with the rotation of the sleeve flange 23. .
[0057]
A positioning hole 27a for positioning the magnet roller 26 is formed in the inner periphery of the magnet roller bearing 27. This hole has a diameter of 5 to 10 mm and a depth of 3 to 8 mm. The inner diameter accuracy is 8 to 9 class in order to accurately position the magnet roller, and the surface roughness is about 0.8 μm Ra. Finished with precision.
[0058]
Further, the magnet roller 26 is fixed without rotating, and the magnet roller bearing 27 rotates integrally with the developing sleeve 18, so that it slides in the positioning hole 27a. Therefore, as the material of the bearing 27, a material having good sliding characteristics with the magnet roller 18, for example, a material such as PPS is used.
[0059]
The developing bias voltage contact device 25 is shown in FIGS. 5 (a) and 5 (b). FIG. 5A is an exploded perspective view, and FIG. 5B is a perspective view after assembly. As shown in FIG. 5, the developing bias voltage contact device 25 includes a contact holding member 32 and a spring member 33 made of a metal wire. The contact holding member 32 has an outer diameter portion 32 a for fitting into the through hole 23 a of the sleeve flange 23, an opening 32 b for the electrode shaft 24 to penetrate, and a flange for contacting the outer end surface of the sleeve flange 23. It has a portion 32c and grooves 32d and 32e for attaching a spring member. The contact holding member 32 is formed of a plastic material (for example, ABS, HIPS, or the like). The spring member 33 is formed of a metal wire for a spring (eg, a Cu alloy or an Fe-based alloy such as SUS), and has a pair of opposed linear portions 33a and a groove formed in the contact holding member by being bent from the linear portion. And locking portions 33b and 33c. Here, the interval between the pair of linear portions 33a is set slightly smaller than the diameter of the electrode shaft 24, and the locking portions 33b and 33c are inserted into the through holes 23a of the sleeve flange 23 when the through holes 23a are inserted. Is pressed into contact with the inner peripheral surface. When the engaging portions 33b and 33c are pressed against the through holes 23a of the sleeve flange 23, the developing bias voltage contact device 25 is prevented from dropping from the sleeve flange 23, and the electrical connection between the spring member 33 and the sleeve flange 23 is prevented. Secure connection. When the electrode shaft 24 is inserted and inserted while expanding the interval between the pair of linear portions 33b, the pair of linear portions 33b elastically contacts the outer peripheral surface of the electrode shaft 24. Thereby, the spring member electrically connects the electrode shaft 24 to the sleeve flange 23, and further electrically connects the sleeve 18 to which the sleeve flange 23 is press-fitted.
[0060]
As described above, since the spring member 33 elastically contacts the outer peripheral surface of the electrode shaft 24, even if the position of the electrode shaft 24 and the developing bias voltage contact device 25 are shifted due to the axial displacement of the developing sleeve 18, A constant contact pressure can be secured at the contact portion between the electrode shaft 24 and the spring member 33.
[0061]
As shown in FIGS. 6 and 7, the electrode shaft 24 stands inside the side cover 20 coaxially with the developing sleeve 18 toward the inside in the axial direction. The material of the electrode shaft 24 is plated with iron, stainless steel, or the like, and has an outer diameter of about 2 to 6 mm, and is insert-molded together with the side cover 20 or is later press-fitted so that it cannot rotate and cannot be pulled out. Fixed.
[0062]
When the side cover 20 is assembled, the electrode shaft 24 passes through the through hole 23 a of the sleeve flange 23 and the opening 32 b of the contact holding member 32, and the tapered distal end portion 24 a of the electrode shaft 24 has a pair of straight lines of the spring member 33. In a state where the parts 33a are inserted while being bent and assembled, the pair of linear parts 33a come into contact with the electrode shaft 24 with a desired contact pressure. It is preferable that conductive grease is interposed at a contact portion between the electrode shaft 24 and the pair of linear portions 33a. The electrode shaft 24 does not contact the inner periphery of the through hole 23 a of the sleeve flange 23. This is to prevent the position of the rotation center of the developing sleeve 18 from being disturbed. The base plate of the electrode shaft 24 is in contact with the main body connection contact plate 28.
[0063]
As shown in FIGS. 6 and 7, the main body connection contact plate 28 is a metallic (SUS, Cu alloy, etc.) leaf spring member having a thickness of 0.1 to 0.3 mm attached to the side cover 20. . A contact portion 28b is provided on the body connection contact plate 28 so as to be exposed to the outside through a hole 20z provided in the side cover 20, and when the process cartridge 15 is mounted on the device body, the device body is contacted. Is configured to be electrically connected to an electrode member (not shown) provided in the device.
[0064]
In addition, the tip 28 a of the main body connection contact plate 28 is electrically connected to the electrode shaft 24. Examples of a method of connecting the electrode shaft 24 and the main body connection contact plate 28 include crimping connection, a contact portion provided on the main body connection contact plate 28, and elastic contact with the electrode shaft.
[0065]
Alternatively, the electrode shaft 24 may be coupled to a conductive member (for example, a SUS plate) by caulking or the like, and the conductive member and the electrode plate may be electrically connected. Further, the electrode shaft and the main body connection contact plate may be integrally formed and attached to the side cover.
[0066]
When the above-described configuration is repeated along the assembling procedure based on FIGS. 6 and 8, the press-fit portion 23c of the sleeve flange 23 is press-fitted into the press-fit portion 18a of the developing sleeve 18 and completely fixed. Next, the magnet roller bearing 27 is inserted from the opposite side where the sleeve flange 23 is not press-fitted. Next, the magnet roller 26 is inserted and a sleeve flange (not shown) on the opposite side is attached, thereby completing the developing roller. Next, a developing bias voltage contact device (in which a spring member 33 is attached to a contact holding member 32) is fitted into the through hole 23a of the sleeve flange 23. At this time, the contact holding member 32 is positioned with respect to the sleeve flange 23 by inserting until the flange 32c of the contact holding member 32 comes into contact with the end face of the sleeve flange 23.
[0067]
Next, the distance regulating member 29, the sleeve bearing 30, and the sleeve gear 31 are assembled in this order, and integrated with a developing frame (not shown). This state is shown in FIG. In FIG. 8A, the distance regulating member 29, the sleeve bearing 30, and the sleeve gear 31 are omitted.
[0068]
Thereafter, when the side cover 20 is assembled, when the tip portion (tapered portion) 24a of the electrode shaft 24 passes between the pair of linear portions 33a of the spring member 33, and the side covers 19 and 20 are completely assembled, The pair of straight portions 33 a of the spring member 33 elastically contact the outer peripheral surface of the electrode shaft 24. This state is shown in FIG. In FIG. 8B, the distance regulating member 29, the sleeve bearing 30, and the sleeve gear 31 are omitted.
[0069]
As a result, the high-voltage power supply contact (not shown) of the image forming apparatus main body is connected to the main body connection contact plate 28, the electrode shaft 24, the spring member 33, the sleeve flange 23, and the developing sleeve 18, so that conduction is ensured. In particular, two contact portions are provided between the sliding portion, that is, the linear portion 33a of the spring member 33 and the outer peripheral surface of the electrode shaft 24, and it is possible to reliably apply a voltage.
[0070]
After the sleeve flange 23, the magnet roller bearing 27, the magnet roller 26, and the opposite sleeve flange (not shown) are assembled on the developing sleeve 18 as described in the above-described assembling procedure, the developing bias voltage contact device is formed. Since the developing bias voltage contact device 25 needs to be replaced when the process cartridge 15 is remanufactured, there is no need to remove the press-fitted sleeve flange. It becomes easy to remove the contact device 25 and replace it with a new one.
[0071]
In addition, as shown in FIGS. 11 and 12 shown as a conventional technique, when the sleeve contact plate 125 inside the developing roller is reused, it is checked whether the sleeve contact plate 125 can be reused. By adding a new developing bias voltage contact device 25 without (i.e., without removing the press-fit sleeve flange), conduction can be ensured.
[0072]
Although the contact holding member 32 is formed of a plastic material (for example, ABS, HIPS, etc.) in the present embodiment, the contact holding member 32 is formed of a conductive material such as a metal or a conductive plastic. The contact area can be increased to make the electrical connection more secure.
[0073]
Further, in the present embodiment, the portion in contact with the electrode shaft 24 is shown by the pair of straight portions 33a, but the present invention is not limited to this, and the portion in contact with the electrode shaft 24 may be curved. Further, the spring member may be formed of a thin metal plate.
[0074]
(Second embodiment)
A second embodiment according to the present invention will be described with reference to FIGS. In this embodiment, portions having the same configuration as in the first embodiment are denoted by the same reference numerals and described.
[0075]
FIG. 9 shows the developing bias voltage contact device, and FIG. 10 shows a state in which the developing bias voltage contact device is attached to the through hole 23 a of the sleeve flange 23. In FIG. 9, the developing bias voltage contact device 34 is formed of a metal wire (eg, a Cu alloy, an Fe-based alloy such as SUS, etc.), and its coil portion 34 a has a coil portion outer shape D in a natural state through the sleeve flange 23. It is set slightly larger than the inner diameter of the hole 23a. The bent portions 34b and 34c bent from the coil portion 34a toward the inside of the coil are portions that come into contact with the outer peripheral surface of the electrode shaft 24. That is, the outer shape of the coil portion 34 a of the developing bias voltage contact device 34 is engaged (lightly press-fit) with the inner diameter of the through hole 23 a of the sleeve flange 23, and then the electrode shaft 24 is inserted into the through hole 23 a of the flange 23. The bent portions 34b and 34c of the developing bias voltage contact device 34 elastically contact the outer peripheral surface of the electrode shaft 24. As a result, the high-voltage power supply contact (not shown) of the main body of the image forming apparatus is connected to the main body connection contact plate 28, the electrode shaft 24, the developing bias voltage contact device 34, the sleeve flange 23, and the developing sleeve 18, thereby ensuring the reliability. Can be conducted.
[0076]
As shown in FIG. 9B, the winding direction of the coil portion 34a of the developing bias voltage contact device 34 is different from the outer circumferential surface of the electrode shaft 24 when the developing roller rotates (the rotating direction is the direction of arrow X). It is desirable that the direction in which a force that increases the coil portion outer diameter D is generated by the forces Y and Z received by the bent portions 34b and 34c due to friction with the bent portions 34b and 34c. Thereby, it is possible to more reliably prevent the developing bias voltage contact device 34 from falling off the sleeve flange 23.
[0077]
The assembling procedure of the second embodiment is similar to that of the first embodiment, and therefore will be omitted. However, since the developing bias voltage contact device 34 can be made of a single piece, the assembling is further performed. It becomes easy and the cost can be reduced.
[0078]
In the first and second embodiments, a process cartridge has been described as an example. However, it is a matter of course that the present invention can be applied to a developing device having a similar developing configuration.
[0079]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a developing bias voltage contact device which is highly reliable, easy to disassemble and assemble. And a developing device and a process cartridge which can be easily disassembled.
[Brief description of the drawings]
FIG. 1 is a main cross-sectional view of a process cartridge according to the present invention.
FIG. 2 is a main cross-sectional view of an image forming apparatus in which a process cartridge according to the present invention is exchangeably mounted.
FIG. 3 is an exploded perspective view showing a frame structure of the process cartridge according to the present invention.
FIG. 4 is a perspective view showing a frame structure of a process cartridge according to the present invention.
FIG. 5 is a perspective view showing a developing bias voltage contact device according to the first embodiment of the present invention.
FIG. 6 is an exploded perspective view showing a developing roller according to the first embodiment of the present invention and a power supply configuration and a support configuration thereof.
FIG. 7 is an exploded perspective view showing a developing roller and a side cover according to the first embodiment of the present invention.
FIG. 8 is a longitudinal sectional view showing an assembling order of the developing roller according to the first embodiment of the present invention.
FIG. 9 is a view showing a developing bias voltage contact device according to a second embodiment of the present invention.
FIG. 10 is a longitudinal sectional view according to a second embodiment of the present invention.
FIG. 11 is a perspective view showing a conventional developing bias voltage contact device.
FIG. 12 is an exploded perspective view showing a conventional developing roller and its power supply configuration and support configuration.
[Explanation of symbols]
1 Discharge roller
2 discharge section
6 sheet cassette
7 Transport roller
8 Exposure equipment
9 Transfer roller
10 Fixing device
11 Photosensitive drum
13 Cleaning frame
14 Cleaning blade
15 Process cartridge
16 Toner storage container
17 Developing frame
18 Developing sleeve
19 Side cover
20 Side cover
21 Seal member
22 Bearing members
23 Sleeve flange
24 electrode shaft
25 Development bias voltage contact device
26 Magnet roller
27 Magnet roller bearing
28 Body connection contacts
32 Contact holding member
33 spring member
34 Development bias voltage contact device
C Image forming device
S sheet

Claims (6)

At least an image carrier,
A hollow cylindrical sleeve portion made of a conductive material, and a conductive flange portion fitted to one end of the sleeve portion and having an opening extending along the axial direction of the sleeve portion, are formed on the image carrier. A developing roller for developing the formed latent image with a developer, and a process cartridge attachable to the image forming apparatus main body.
The image forming apparatus is fixed to a housing of the process cartridge, inserted into the opening of the flange along the rotation axis direction of the developing roller, and electrically connected to the image forming apparatus main body when the process cartridge is mounted on the image forming apparatus main body. A substantially cylindrical first electrical contact electrically connected to the contact;
And a second electrical contact fixed to the opening of the flange portion of the developing roller and elastically contacting a peripheral surface of the first electrical contact. A hollow cylindrical sleeve portion made of a conductive material, and a developing roller having a conductive flange portion fitted to one end of the sleeve portion and having an opening extending along the axial direction of the sleeve portion, In order to develop the latent image formed on the image carrier with a developer, in a developing device that can be mounted on the image forming apparatus main body,
The developing device is fixed to a housing of the developing device, is inserted into the opening of the flange portion along the rotation axis direction of the developing roller, and when the developing device is mounted on the image forming device main body, the electric power of the image forming device main body is changed. A substantially cylindrical first electrical contact electrically connected to the contact;
And a second electric contact fixed to the opening of the flange portion of the developing roller and elastically contacting a peripheral surface of the first electric contact. A developing bias voltage contact device for applying a bias voltage to a developing roller for developing a latent image formed on an image carrier with a developer in a process cartridge or a developing device that can be mounted on an image forming apparatus main body. ,
The process cartridge or the developing device includes:
A hollow cylindrical sleeve portion made of a conductive material, and a conductive flange portion fitted to one end of the sleeve portion and having an opening extending along the axial direction of the sleeve portion, are formed on the image carrier. A developing roller for developing the latent image with the developer,
The process cartridge or the developing device is fixed to the housing of the developing device, is inserted into the opening of the flange portion along the rotation axis direction of the developing roller, and when the process cartridge or the developing device is mounted on the image forming apparatus main body. Having a substantially cylindrical electrical contact electrically connected to the electrical contact of the image forming apparatus main body,
The developing bias voltage contact device is configured such that a first portion fixed to the opening of the flange portion of the developing roller and a peripheral surface of the columnar electric contact individually provided on the housing are elastically attached. A developing bias voltage contact device having a second portion in contact therewith. The first portion is a contact holding member that has an opening through which the cylindrical electrical contact can pass and is fitted into the opening of the flange, and the second portion is attached to the contact holding member. The developing bias voltage contact device according to claim 3, wherein a part of the spring is a metal spring protruding from an opening of the contact holding member. 5. The developing bias voltage contact device according to claim 4, wherein said contact holding member has a flange portion which abuts on a longitudinally outer end of said flange. The first portion is a coil spring portion having an outer shape slightly larger than the inner diameter of the opening of the flange, and the second portion is configured to move a wire rod of at least one end of the coil spring portion in an inward direction of the coil. 4. The developing bias voltage contact device according to claim 3, wherein said coil spring portion is press-fittable into said opening of said flange.

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