JP4897155B2 - Developing device and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a developing device and an image forming apparatus, and more particularly to a structure for preventing developer scattering.
[0002]
[Prior art]
In an image forming apparatus such as a copying machine, a facsimile, a printer, or a printing machine, a visible image using a developer such as toner is applied to an electrostatic latent image carried on a photosensitive member that is a latent image carrier. Processing is performed.
[0003]
As the developer, there are a one-component developer using a magnetic or non-magnetic toner, and a two-component developer containing a toner containing a pigment and a magnetic carrier having the toner adhered to the surface.
In the case of a two-component developer among the developers, the developer is carried in a brush shape on a developing sleeve having a built-in magnet roller, and the toner contained in the developer is transferred onto a photosensitive member which is a latent image carrier. Visible image processing of the electrostatic latent image is performed by bringing it into contact with the electrostatic latent image.
[0004]
In the developing device, toner is replenished in order to keep the developer concentration constant. In the case of a two-component developer, the toner is replenished, mixed and stirred with a carrier, and the developer concentration is maintained to prepare for a new visible image processing.
As a constitution of the two-component developer, a constitution in which a magnetic carrier having an average particle diameter of about 30 to 100 μm and a non-magnetic toner having a particle diameter of about 6 μm is used in combination. In order to improve image characteristics such as tone and gradation, the average particle diameter of the carrier and toner tends to be reduced.
[0005]
In addition to the developing sleeve carrying the magnetic brush on the surface, the developing device using the developer is provided with a rotating member such as a stirring roller and a transport paddle for stirring and mixing the two, and for supporting these rotating members. A bearing member is provided.
The rotating member has an appropriate dimensional difference that does not cause rattling between the inner diameter of the support portion of the supporting bearing member and the shaft diameter of the rotating member so that smooth rotation is allowed. Is provided. When a developer having a small particle diameter is applied to the developing device having such a configuration, the toner and the carrier are easily scattered in the developing device by an air flow generated when the rotating member rotates. For this reason, it may enter into the gap between the rotating part of the rotating member and the bearing member.
[0006]
Since the core material component of the carrier is a relatively hard component such as iron or ferrite, it will function as an abrasive when entering the gap, and as a result, the surface of the rotating part and the inner surface of the bearing member Detrimental effects such as increased backlash due to dimensional changes due to grinding.
If toner enters the gap between the rotating member and the bearing member, the toner may pass through the gap and scatter to the outside of the developing device and contaminate the peripheral part. As a result, the acrylic resin may be dissolved and fixed, resulting in an increase in the load on the rotating member. In the worst case, the drive source may become overloaded and become unable to rotate.
[0007]
Conventionally, as a configuration for preventing the developer from entering the rotation support portion, a configuration in which a seal structure is provided in the rotation portion has been proposed (for example, JP 2000-147904 A).
FIG. 8 is a diagram showing a part of the configuration disclosed in the above publication. In FIG. 8A, a stirring roller, paddle wheel, or one of the rotating members arranged in the developing device is conveyed. A V-ring having a V-shaped cross-section along the axial direction between a rotation shaft end A1 of a screw (indicated by reference numeral A for convenience) and a bearing member (indicated by reference numeral B for convenience) that supports the rotating shaft end A1. As shown in FIG. 8B, G seals (shown by D for convenience) are arranged, and one part of these seals is brought into contact with the outer peripheral surface of the rotary shaft end A1. Thus, the toner and the carrier are prevented from entering the internal space F1 of the bearing support member (for convenience, indicated by reference numeral F) supporting the bearing member B.
[0008]
[Problems to be solved by the invention]
Even in the configuration shown in FIG. 8, it may be difficult to completely prevent the developer from entering the rotation support portion.
In the case where the V ring C is provided in FIG. 8A, the V ring support surface of the retainer (for the sake of convenience indicated by E) for supporting the ring is not a completely smooth surface, but is microscopically uneven. For this reason, a minute lift occurs at the contact portion between the V ring C supported by this and the rotating portion. For this reason, the developer may enter the internal space F <b> 1 of the bearing support member F from a gap generated by separating from the rotating portion due to floating.
[0009]
When the G seal D is used in FIG. 8 (B), a gap is generated between the surface of the rotating part and the contact surface of the G seal that is opposed to this surface due to the eccentricity of the rotating part. There is. For this reason, when the rotating portion rotates, the G seal D and the portion facing it periodically repeat contact and separation, and the developer enters the internal space F1 of the bearing support member F from the gap generated when the rotating portion is separated. I can't prevent you from doing it.
[0010]
When the developing device continues to be used for a long time, the developer reaches the interior space F1 of the bearing support member F from the gap generated between the rotating portion and the V ring C or G seal D facing the rotating portion. That is, when the carrier and toner are filled in the internal space F1, it becomes easy to enter the gap between the surface of the rotating part of the rotating member and the surface of the bearing member. As a result, the occurrence of rotation failure and an increase in rotation load are caused by the polishing phenomenon caused by the carrier and the toner melting and fixing phenomenon. Moreover, the developer that has entered the internal space F1 is likely to be dissipated from the inside of the developing device to the outside due to an increase in the internal pressure when the space is filled, resulting in contamination of the peripheral portion. In particular, in recent years, as described above, there are increasing opportunities to use carriers and toners having a small particle diameter, and thus the frequency of occurrence of the above-mentioned problems tends to increase.
[0011]
On the other hand, in recent years, many image forming apparatuses such as printers and facsimile machines for personal use that require low-cost equipment with a relatively low image forming speed unlike office use have been provided. In these image forming apparatuses, a process cartridge type configuration is employed in which the developing device including the toner cartridge is replaced as it is when the toner is completely consumed. For this reason, since the durability of the cartridge itself is determined by the replacement cycle, the viewpoint of lower cost than the durability is regarded as important. Accordingly, providing such a configuration with a V-ring or G-seal as shown in FIG. 8 leads to an increase in cost, which causes a new problem that it is difficult to achieve low cost.
[0012]
In view of the problems in the conventional developing device and the image forming apparatus using the same, an object of the present invention is to prevent rotation failure and increase in rotational load by reliably preventing the developer from entering the rotating portion. A developing device and an image forming apparatus.
[0013]
[Means for Solving the Problems]
The invention described in claim 1 is a developing device including a rotating member for supplying a developer accommodated therein and a bearing member for the rotating member, The bearing member is supported inside a cylindrical portion protruding toward the end of the rotating member, Above bearing The member is included in a developer shielding member that is provided on the rotating member and prevents the developer from entering the bearing member, The developer shielding member includes a conical surface that increases in diameter in the axial direction of the rotating member toward the bearing portion side of the bearing member, and a range in which the edge of the enlarged diameter opening portion does not contact the support portion of the bearing member In close proximity,
The developer shielding member and the bearing member are provided at positions that shield a space that directly communicates between the two members and prevent the movement of the developer that is used to directly enter the bearing portion. It is characterized by that.
[0015]
Claim 2 In the described invention, in the developer shielding member, a member capable of scraping the toner and the developer in a direction away from the bearing portion is provided on the outer peripheral surface opposite to the inner surface facing the bearing portion. It is characterized by that.
[0016]
Claim 3 According to the invention described above, in the developer shielding member, a scraping member capable of guiding the toner or the developer from the edge of the conical surface to the outside is provided on an inner peripheral surface corresponding to an inner surface facing the bearing portion. It is characterized by being.
[0017]
Claim 4 According to the invention described above, in the developer shielding member, a member capable of scraping the toner or the developer in a direction away from the bearing portion is provided on the outer circumferential surface opposite to the inner surface facing the bearing portion. A scraping member capable of guiding the toner or developer from the end of the conical surface to the outside is provided on an inner peripheral surface corresponding to an inner surface facing the bearing portion.
[0018]
Claim 5 The described invention is characterized in that the scraping member is composed of one or a plurality of blade members arranged in the circumferential direction.
[0019]
Claim 6 The described invention is characterized in that the blade member is inclined in the circumferential direction with respect to the axial direction of the rotating member.
[0020]
Claim 7 The described invention is characterized in that the blade member constituting the scraping member is formed in a spiral shape.
[0021]
Claim 8 In the described invention, the blade member that forms the scraping member may be configured such that the blade member positioned on the outer peripheral surface of the developer shielding member with respect to the rotation direction of the rotating member moves the toner or the developer away from the bearing portion. A spiral direction in which the blade member located on the inner peripheral surface of the developer shielding member allows the toner or developer to flow out from the enlarged end edge of the developer shielding member. It is characterized by being.
[0022]
Claim 9 The invention described in claims 1 to 8 The developing device described in one of the above is used in an image forming apparatus.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram showing an internal configuration of an image forming apparatus provided with a developing device according to an example used for explaining an embodiment of the present invention. In FIG. 1, the image forming apparatus 1 includes a latent image carrier. A drum-shaped photoreceptor (hereinafter referred to as a photoreceptor drum) 2 is provided.
Around the photosensitive drum 2, a charging device using a charging roller for executing image forming processing along the rotation direction indicated by an arrow 3, electrostatic light according to image information using writing light such as laser light. A writing exposure device 4 for forming a latent image 4, a developing device 5 that supplies toner or developer to the electrostatic latent image to perform visible image processing of the latent image, and is carried on the photosensitive drum 2. A transfer device for transferring a visible image onto the recording paper S using a transfer belt, a transfer roller and a charger, a cleaning device 7 for removing toner remaining on the photosensitive drum 2 after the transfer, and a static eliminator for neutralizing residual charges. 8 are arranged respectively.
[0024]
In the image forming apparatus 1, after the photosensitive drum 2 is uniformly charged by the charging device 3, an electrostatic latent image corresponding to the image information is formed by the writing exposure device 4. The image is subjected to visible image processing to form a toner image.
When the toner image on the photosensitive drum 2 is transferred onto the recording paper S by the transfer device 6, it is fixed by a fixing device (not shown). After the transfer, the photosensitive drum 2 is initialized after the residual toner is removed by the cleaning device 7 and the residual charge is neutralized by the neutralization device 8, and the charging device 3 performs uniform charging to perform the next image formation. Prepared for.
[0025]
The configuration of the developing device 5 is shown in FIG.
In FIG. 2, the structure and function of each member of the developing device 5 will be described together. The developing device 5 includes a developing container 5A corresponding to a developing processing unit and a toner replenishing unit 5B.
In the developing container 5A, a developing roller 51 as a developer carrying member is disposed so as to face the photosensitive drum 2 so as to be close to each other, and a developing region D is formed in a portion facing both of them. ing.
[0026]
The developing roller 51 is provided with a developing sleeve 52 formed of a non-magnetic material such as aluminum, brass, stainless steel, conductive resin or the like in a cylindrical shape. The developing sleeve 52 is provided by a rotation driving mechanism (not shown). It is provided to be rotated in the direction of the arrow, that is, in the counterclockwise direction.
[0027]
In the developing sleeve 52, a magnet roller body 53 that forms a magnetic field is provided in a fixed state so that the developer can be spiked on the surface of the developing sleeve 52. At this time, the carrier constituting the developer is sprinkled in a chain shape on the developing sleeve 52 along the magnetic force lines (indicated by broken lines in the figure) emitted from the magnet roller body 53, and in this chain shape. A charged brush is attached to the spiked carrier to form a magnetic brush. The magnet roller body 53 is provided with transporting magnetic poles P2 to P6 in addition to the magnets P1A to P1C serving as the developing main poles facing the above-described developing region, and among them, the magnetic poles facing the paddle wheel 55 described later. P3 is in a state where the magnetic brush has no magnetic force or almost no magnetic force.
The magnetic brush formed on the developing sleeve 52 is transferred in the same direction as the developing sleeve 52, that is, in the counterclockwise direction as the developing sleeve 52 rotates.
A doctor blade 54 that regulates the height of the spikes of the developer chain, that is, the amount of the developer, is installed on the upstream side of the development region D in the developer conveyance direction, that is, in the counterclockwise direction. Further, a stirring roller 55 and a paddle wheel 56 are provided in a rear region corresponding to the opposite side of the photosensitive drum 2 with the developing roller 51 interposed therebetween. The stirring roller 55 stirs and mixes the toner and the carrier. The paddle wheel 56 can be pumped up.
A developer case 57 as a developer containing member is arranged on the lower side so as to cover the lower side of each member so as to wrap the developing roller 51, the paddle wheel 56, and the stirring roller 55.
[0028]
The toner replenishing unit 5B directs the toner T toward the stirring roller 55 by the rotation of the toner replenishing roller 5B1, for example, when the toner concentration sensor 58 detects that the concentration of the toner supplied to the photosensitive drum 2 has decreased. It comes to pay out.
In the vicinity of the doctor blade 54, a separator 59 is disposed in which one end in the extending direction is positioned in the vicinity of the doctor blade 54 and the other end in the extending direction is positioned on the stirring roller 55. At the other end, a rotatable transport screw 60 is arranged.
[0029]
In the developing container 5A having such a configuration, the developer in which the carrier and the toner are stirred and mixed by the rotation of the paddle wheel 56 is pumped up and discharged toward the developing roller 51, and the developing roller is driven by the magnetic force of the magnet roller body 53. It is carried on the surface of 51.
The developer carried on the developing roller 51 moves on the surface with the rotation of the developing sleeve 52, the layer thickness is regulated by the doctor blade 54, and the developing roller 51 and the photosensitive drum 2 face each other. After passing through the region D, when passing through the gap between the developer case 57 and the developing sleeve 52, it falls to the bottom of the developing case 57 at a position facing the magnetic pole P3 where the magnetic force of the magnet roller body 44 stops working, and again The paddle wheel 56 is agitated.
[0030]
Excess developer scraped off by the doctor blade 54 is sequentially conveyed to the back side of the image forming apparatus by a plurality of inclined fins 59 </ b> A arranged on the separator 59. A developer guide path is disposed at the innermost end of the separator 59, and when guided toward the transport screw 60 located at the other end in the extension direction, the front side of the image forming apparatus is opposed to the above by the transport screw 60. And is dropped through a slit (not shown) facing the stirring roller 55 disposed at the foremost end. By adopting such a developer conveyance process, the amount of developer conveyance in each of the front and rear is simultaneously reduced while the toner density is agitated in the longitudinal direction of the image forming apparatus (perpendicular to the paper surface shown in FIG. 2). By setting them equally, the height of the developer deposit surface can be kept constant.
[0031]
A structure for preventing the developer from entering the rotation support portions of the stirring roller 55, the paddle wheel 56, and the conveying screw 60, which are rotating members used in the developing device 5, is provided.
FIG. 3 is a view showing a support structure for the rotating member. In FIG. 3, rotating members such as the agitating roller 55, the paddle wheel 56, and the conveying screw 60 (hereinafter, the reference numeral 56 of the paddle wheel is representatively shown in the figure). The main body itself is made of a resin molded product, and a support shaft 56A made of stainless steel or a metal plated with chemical nickel is pressed into both ends in the axial direction in consideration of wear resistance. Strength is increased.
In order to support the rotating member 56, a bearing 62 attached to the bearing housing 61 is provided on the apparatus main body side wall 5 </ b> A. In other words, the apparatus main body side wall 5A is made of molded parts such as die-casting using a resin material such as polystyrene, ABS, polycarbonate or the like, which is advantageous in terms of cost, or a metal material such as aluminum or zinc in consideration of heat dissipation. A bearing housing 61 is mounted, and a bearing 62 is loaded on the inner surface of the bearing housing 61.
[0032]
Support shafts 56A positioned at both ends in the axial direction of the rotating member 56 are inserted into the bearings 62 and are rotatably supported. The main motor, transmission gear group, or chain of the image forming apparatus is supported on the support shafts 56A. The rotational driving force is transmitted through the via. The bearing housing 61 described above may be integrated with the bearing 62 using a bearing material such as polyacetal when used in a place with a low load.
[0033]
The bearing housing 61 has a cylindrical cross-sectional shape, and a G seal 63 capable of contacting the outer peripheral surface of the support shaft 56A in a cylindrical portion protruding from the inner surface of the apparatus main body side wall 5A toward the axial end of the rotating member 56. Is provided.
The G seal 63 is a seal member made of an elastic rubber material such as nitrile, acrylic, silicon, or fluororesin, or a thermoplastic resin such as polyethylene, and is stationary on the bearing housing 61 side regardless of the rotation of the rotation member 56. Is held in sliding contact with the outer peripheral surface of the support shaft 56A. As the material of the G seal 63, it is possible to use an elastic body such as sponge or urethane foam in addition to the above-described materials, and the V ring shown in FIG. It is also possible to use (a member indicated by symbol C in FIG. 8A).
[0034]
In this embodiment, the bearing 62 has a function of supporting the load of the support shaft 56A and smoothly transmitting the rotational driving force, and a ball bearing is used as a configuration for this purpose. When a ball bearing is used, a sealed type is used rather than an open type, and a contact rubber seal type is used to prevent the developer from entering. Furthermore, it is possible to use an iron-based or copper-based sliding bearing at the time of use in a place where the load is low. In this embodiment, a bearing 62 and a G seal 63 are used as bearing members.
[0035]
The G seal 63, which is one of the bearing members, comes into contact with the outer peripheral surface of the support shaft 56A so that the inner space of the bearing housing 61 in which the bearing 62 is located from the rotating member 56 side (denoted by reference numeral F1 used in FIG. 8 for convenience) In this embodiment, apart from the G seal 63, a configuration for preventing the developer from moving toward the bearing 62 is provided.
[0036]
In FIG. 3, a developer shielding member 64 that includes a bearing member is provided at the shaft end of the rotating member 56.
The developer shielding member 64 is a member that is integrated with the shaft end portion of the rotating member 56 and that has a conical surface that increases in diameter in the axial direction toward the bearing 62 of the bearing member. They are arranged close to each other in a range that does not contact the main body side wall 5A.
[0037]
Since the present embodiment is configured as described above, the developer that floats and scatters in the apparatus main body due to the airflow generated by the rotation of the rotating member 56 is transferred between the bearing 62 of the bearing member by the developer shielding member 4. Since the space that directly communicates is shielded, it is difficult to move and the movement toward the bearing 62 is hindered. As a result, when the close contact between the G seal 63 and the outer peripheral surface of the support shaft 56A is unstable, the developer is shielded before the developer attempts to enter the gap at the contact position between the support shaft 56A and the G seal 63. Since the flow of the developer is easily blocked by the member 64, the amount entering the gap can be reduced. As a result, the amount of the developer entering the internal space F1 of the bearing housing 61 is reduced, so that the developer enters between the opposed surfaces of the bearing 62 and the support shaft 56A when the internal pressure is increased, or is scattered outside the developing device. Will be deterred. In this way, by suppressing the intrusion of the developer into the bearing surface, it becomes possible to prevent the rotation failure due to the polishing phenomenon and the increase of the rotation load due to the dissolution fixation.
[0038]
According to the present embodiment, the developer shielding member 64 that can prevent the developer from moving toward the bearing 62 in a non-contact state with the support shaft 56A is provided, so that the G seal 63 or the like is provided. Unlike the seal structure by contact, instability of the contact state does not occur, so that it is possible to effectively prevent the developer from entering the bearing 62.
[0039]
According to the present embodiment, even when a configuration in which the special provision of the G seal 63 and the V ring leads to an increase in cost is targeted, the G seal 63 and the V ring can be simply provided by providing the developer shielding member 64. Even if there is not, the movement of the developer toward the bearing 62 can be prevented, so that an increase in cost can be suppressed. In this embodiment, the developer shielding member 64 has a conical surface. However, the developer shielding member 64 is not limited to the conical surface, and may be a cylindrical portion including a bearing member.
[0040]
Next, another example according to the embodiment of the present invention will be described. In FIG. 4, the same components as those shown in FIG.
The embodiment shown in FIG. 4 is characterized in that a developer scraping member 64A is provided on the outer peripheral surface of the developer shielding member 64 opposite to the surface containing the bearing 62.
In FIG. 4, the developer shielding member 64 is integrated with the shaft end portion of the rotating member 56 in the same manner as the configuration shown in FIG. 3, and includes a conical surface whose diameter increases toward the bearing 62 in the axial direction. The conical surface contains the bearing 62.
One or a plurality of scraping members 64A are provided along the circumferential direction on the outer peripheral surface of the conical surface opposite to the surface containing the bearing 62. The scraping member 64 </ b> A in the present embodiment is configured by a blade member that is inclined in the circumferential direction in the axial direction, and the inclined direction is a direction in which the developer can be separated from the bearing 62 side by the rotation of the rotating member 56. It is said that.
[0041]
Since the present embodiment is configured as described above, when the rotating member 56 rotates, the developer shielding member 64 also rotates in conjunction with it.
Since the developer shielding member 64 includes the bearing 62, the developer to be moved toward the bearing 62 is shielded from the bearing 62 and directed to the bearing 62, as in the embodiment shown in FIG. 3. The developer to be moved can be moved away by the scraping member 64 having the outer peripheral surface. That is, when the scraping member 64 </ b> A rotates, the developer that moves toward the bearing 62 is captured by the scraping member 64 </ b> A and is pushed back toward the rotating member 56. As a result, the amount of developer traveling toward the bearing 62 can be reduced, and the amount of developer that enters the internal space F1 of the bearing housing 61 via the contact portion between the G seal 63 and the support shaft 56A can be reduced. . As a result, it is possible to prevent a situation in which the developer is filled in the internal space F1 of the bearing housing 61 and to prevent a rotation failure due to a polishing phenomenon on the bearing surface and an increase in rotational load due to a melting and fixing phenomenon.
[0042]
According to the present embodiment, the developer shielding member 64 that rotates together with the rotating member 56 not only prevents the developer from moving to the bearing 62 at the end but also pushes back the developer to be moved to the rotating member side. Therefore, the developer can be more effectively prevented from moving to the bearing 62. In the present embodiment, the scraping member 64A is shown inclined in the circumferential direction with respect to the axial direction. However, the scraping member 64A may be a blade member protruding in the radial direction without being inclined in the circumferential direction. .
[0043]
Next, another example according to the embodiment of the present invention will be described. In FIG. 5, the same components as those shown in FIG.
In the embodiment shown in FIG. 5, a scraping member is provided on the surface of the developer shielding member including the bearing 62, and the developer entering the bearing housing is captured by the scraping member outside the developer shielding member. It is characterized by being scraped toward.
In FIG. 5, the developer shielding member 64 is integrated with the shaft end portion of the rotating member 56 similarly to the configuration shown in FIG. 3, and includes a conical surface whose diameter increases toward the bearing 62 in the axial direction. The conical surface contains the bearing 62.
One or a plurality of scraping members 64B are provided along the circumferential direction on the surface including the bearing 62 in the conical surface. The scraping member 64 </ b> B in the present embodiment is constituted by a blade member that is inclined in the circumferential direction in the axial direction. It is supposed to be scraped from the edge.
[0044]
Since the present embodiment is configured as described above, when the rotating member 56 rotates, the developer shielding member 64 also rotates in conjunction with it.
Since the developer shielding member 64 includes the bearing 62, the developer that is moving toward the bearing 62 is shielded from the bearing 62 and the developer shielding member, as in the embodiment shown in FIG. The developer entering the inside of the developer shielding member 64 from between the edge of the enlarged diameter port 64 and the apparatus main body side wall 5A is scraped out from the edge of the enlarged diameter port by a scraping member 64B having an inner surface. That is, the developer that has entered the inside of the developer shielding member 64 spills out from the edge of the enlarged diameter opening. As a result, the developer that enters the developer shielding member 64 and tries to enter the bearing 62 through the gap formed on the contact surface between the G seal 63 and the support shaft 56 </ b> A is subjected to centrifugal force inside the developer shielding member 64. By being received, it is scraped by moving along the scraping member 64B, so that the amount entering the internal space F1 of the bearing housing 61 is reduced. As a result, it is possible to prevent a situation in which the developer is filled in the internal space F1 of the bearing housing 61 and to prevent a rotation failure due to a polishing phenomenon on the bearing surface and an increase in rotational load due to a melting and fixing phenomenon.
[0045]
According to the present embodiment, the developer that has entered the developer shielding member 64 can be scraped out of the developer shielding member 64, so that the edge of the enlarged diameter opening of the developer shielding member 64 and the apparatus main body side wall 5 </ b> A. Even if there is a gap between them, the amount of movement of the developer toward the bearing 62 can be reduced. As a result, even if the gap accuracy is somewhat poor, it is possible to reduce the developer that enters the bearing 62.
[0046]
Next, another example according to the embodiment of the present invention will be described. In FIG. 6, the same components as those shown in FIGS. 3 to 5 are indicated by the same reference numerals.
The embodiment shown in FIG. 6 is characterized in that a scraping member for preventing the developer from moving toward the bearing 62 is provided on the inner surface and the outer peripheral surface of the developer shielding member 64, respectively.
In FIG. 6, the developer shielding member 64 is integrated with the shaft end portion of the rotating member 56 similarly to the configuration shown in FIG. 3, and includes a conical surface whose diameter increases toward the bearing 62 in the axial direction. The conical surface contains the bearing 62.
One or a plurality of scraping members 64B are provided along the circumferential direction on the surface containing the bearing 62 in the conical surface, and one scraping member 64A is provided along the circumferential direction on the outer peripheral surface opposite to the inner packaging surface. Or a plurality are provided.
[0047]
As shown in FIG. 7, the scraping members 64A and 64B provided on the outer peripheral surface and the inner surface of the developer shielding member 64 penetrate the conical surface of the developer shielding member 64 at the same location along the circumferential direction. Is provided. The scraping members 64A and 64B are not limited to the blade members that are inclined in the circumferential direction along the axial direction as in the examples shown in FIGS. 4 and 5, but the inclination direction is changed as shown in FIG. It is also possible to use the same spiral blade member. When the spiral blade member is used, the developer can be smoothly moved when the centrifugal force acts on the developer.
[0048]
Since the present embodiment is configured as described above, when the rotating member 56 rotates, the developer shielding member 64 also rotates in conjunction with it.
Since the developer shielding member 64 includes the bearing 62, the developer to be moved toward the bearing 62 is shielded from the bearing 62 and directed to the bearing 62, as in the embodiment shown in FIG. 3. The developer to be moved is moved in the direction to be separated by the scraping member 64 on the outer peripheral surface, and is scraped to the outside from the edge of the enlarged diameter port by the scraping member 64B on the inner surface. Thereby, it is possible to prevent the developer from progressing toward the bearing 62 inside and outside the developer shielding member 64. As a result, it is possible to prevent a situation in which the developer is filled in the internal space F1 of the bearing housing 61 and to prevent a rotation failure due to a polishing phenomenon on the bearing surface and an increase in rotational load due to a melting and fixing phenomenon. The scraping member shown in FIGS. 4 to 6 can of course be a spiral blade member as shown in FIG. In addition, although the structure shown in FIG. 3 thru | or FIG. 7 has shown in figure for the one end part of a rotation member, it is needless to say for the edge part which has a bearing part.
[0049]
【Effect of the invention】
Claim 1 According to the described invention, since the developer shielding member for inward of the bearing portion of the bearing member is provided, the bearing portion is isolated from the inside of the apparatus main body in which the toner and the developer are accommodated. Progress can be prevented. In particular, the invention according to claim 2 is provided with a conical surface whose diameter increases toward the bearing portion, thereby preventing the developer from progressing toward the bearing portion. Easy to do In addition, it is possible to prevent an increase in rotational load due to a polishing phenomenon or dissolution and fixation when toner or developer enters the bearing portion.
[0050]
Claim 2 Thru 4 According to the described invention, since the scraping member is provided on each of the inner peripheral surface, the outer peripheral surface, or both surfaces of the developer shielding member, the toner and the developer that are going to advance toward the bearing portion are removed from the bearing portion. It becomes possible to move toward the point.
[0051]
Claim 5 According to the described invention, since the scraping member is constituted by the blade member, the toner and the developer that are about to move to the bearing portion including the scattered toner and the developer are captured, and the toner is removed at a place other than the bearing portion. It can be moved.
[0052]
Claim 6 Thru 8 According to the invention described above, the blade member forming the scraping member is inclined with respect to the axial direction. In particular, in the inventions according to claims 8 and 9, the toner and the developer are supported by the bearing according to the rotation of the scraping member. When moving in a direction away from the part, and in a spiral direction that can fall off from the conical edge near the bearing part, toner or developer is transferred from the bearing part according to the rotation of the scraping member. It is possible to keep away.
[0053]
Claim 9 According to the described invention, since it is possible to prevent the toner and developer from entering the rotation support portion of the rotation member provided in the developing device, it is possible to prevent rotation failure and increase in rotation load when entering. It becomes possible to improve durability.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating an example of an image forming apparatus in which a developing device according to an embodiment of the present invention is used.
FIG. 2 is a schematic diagram for explaining a configuration of a developing device according to an example of the embodiment of the present invention.
3 is a partial schematic diagram for explaining an embodiment relating to a support structure of a rotating member in the developing device shown in FIG. 2; FIG.
4 is a partial schematic diagram for explaining another embodiment related to the support structure of the rotating member in the developing device shown in FIG. 2; FIG.
FIG. 5 is a partial schematic view for explaining still another embodiment relating to the support structure of the rotating member in the developing device shown in FIG. 2;
6 is a partial schematic diagram for explaining another embodiment relating to the support structure of the rotating member in the developing device shown in FIG. 2; FIG.
7 is a perspective view showing a configuration of a scraping member used in the developer shielding member used in the support configuration shown in FIG. 6. FIG.
FIG. 8 is a schematic diagram showing a conventional example related to the support structure of the rotating member in the developing device.
[Explanation of symbols]
1 Image forming device
2 Photosensitive drum as a latent image carrier
5 Development device
5A Equipment body side wall
55 Agitating roller as one of rotating members
56 Paddle wheel as another rotating member
60 Conveying screw as another rotating member
61 Bearing housing
62 Bearing as a component of bearing member
63 G seal as another component of bearing member
64 Developer shielding member
64A Scraping member located on outer peripheral surface of developer shielding member
64B Scraping member located on inner surface of developer shielding member

Claims (9)

A developing device including a rotating member for supplying a developer contained therein and a bearing member of the rotating member,
The bearing member is supported inside a cylindrical portion protruding toward the end of the rotating member,
The bearing member is included in a developer shielding member that is provided on the rotating member and prevents the developer from entering the bearing member,
The developer shielding member includes a conical surface that increases in diameter in the axial direction of the rotating member toward the bearing portion side of the bearing member, and a range in which the edge of the enlarged diameter opening portion does not contact the support portion of the bearing member In close proximity,
The developer shielding member and the bearing member are provided at positions where the space directly communicating between the two members is shielded so as to prevent the movement of the developer used for direct entry into the bearing portion. Development device. The developing device according to claim 1,
The aforementioned developer shielding member, and wherein said toner and a developer capable scraping away from the bearing portion member is provided on the outer circumferential surface of the surface opposite inner faces on the bearing member Developing device. The developing device according to claim 1,
The developer shielding member is provided with a scraping member capable of guiding the toner and developer from the edge of the conical surface to the outside on an inner peripheral surface corresponding to an inner surface facing the bearing portion. A developing device. The developing device according to claim 1,
The aforementioned developer shielding member, the toner and a developer capable scraping away from the bearing unit member is provided on the outer peripheral surface of the surface opposite inner faces on the bearing member, to the bearing member A developing device, characterized in that a scraping member capable of guiding the toner and developer from the edge of the conical surface to the outside is provided on an inner peripheral surface corresponding to an opposing inner surface. The developing device according to any one of claims 2 to 4,
The developing device according to claim 1, wherein the scraping member is composed of one or a plurality of blade members arranged in the circumferential direction. The developing device according to claim 5, wherein
The developing device according to claim 1, wherein the blade member is inclined in a circumferential direction with respect to an axial direction of the rotating member. The developing device according to claim 5 or 6,
The developing device according to claim 1, wherein the blade member forming the scraping member is formed in a spiral shape. The developing device according to claim 7.
The blade member that forms the scraping member has a spiral direction in which the blade member positioned on the outer peripheral surface of the developer shielding member can move the toner and the developer away from the bearing member with respect to the rotation direction of the rotating member. The blade member positioned on the inner peripheral surface of the developer shielding member has a spiral direction that allows the toner or developer to flow out from the enlarged edge of the developer shielding member. Developing device.   An image forming apparatus using the developing device according to claim 1.

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