JP4595473B2 - Process unit and image forming apparatus - Google Patents

Description

  The present invention relates to a process unit including a cleaning unit that removes dirt adhering to a charging wire that charges a surface of a photoreceptor, and an image forming apparatus in which the process unit is detachable.

  2. Description of the Related Art Conventionally, there has been proposed a process unit including a wire cleaner that removes dirt adhered to a charging wire by folding the sponge member in half, sandwiching the charging wire, and sliding along the charging wire.

  With this configuration, it is possible to remove dirt at the longitudinal end of the charging wire in contact with the charging wire of the wire cleaner, and the wire cleaner can have a simple configuration and cost can be reduced. It becomes.

  However, as the charging wire is cleaned, dirt on the charging wire accumulates at the end of the wire cleaner in the longitudinal direction where the wire contacts the charging wire, and the dirt that eventually accumulates settles on the grid or photosensitive drum surface. However, it causes uneven charging and black and white spots.

  Accordingly, there has been proposed an image forming apparatus provided with a cleaning device that wipes off the deposit on the charging wire with a cleaning tool and receives the deposit on the lower protrusion even if the deposit wiped off from the charging wire falls off the cleaning tool. (Patent Document 1).

  This cleaning device has a cleaning member having a cleaning tool or the like as a wiping member, and wipes the charged wire with the cleaning tool for cleaning.

  The cleaning member includes a cleaning tool made of a metal piece and a sponge member, a protrusion that receives the cleaning tool from below, and a connecting member that fixes the protrusion. The cleaning tool is provided with a metal piece bent to be biased inward and having a spring property, and the charging wire is sandwiched between the metal piece from above and below or from the left and right via a sponge member or the like. It comes to contact with. The protruding portion is configured to support the cleaning tool upward from the central portion thereof, and receives the dirt of the charging wire wiped off by the cleaning tool.

  From the above, even if the deposits wiped off from the charging wire fall off from the cleaning tool, they can be received by the lower protrusion.

Japanese Patent No. 3462825

  However, in the technique of the conventional patent document 1 described above, the configuration of the cleaning device such as the biasing means, the operation interlocking means, the member that connects the protruding portion with the cleaning tool, and the member that fixes the protruding portion is complicated. There are many members that constitute For this reason, there is a problem that the cost is increased and the cleaning device is increased in size.

  SUMMARY OF THE INVENTION Accordingly, the present invention provides a process unit having a compact and low-cost cleaning unit that removes dirt adhering to a charging wire that charges the surface of a photosensitive drum, and an image forming apparatus in which the process unit can be attached and detached. With the goal.

In order to achieve the above object, according to the first aspect of the present invention, in the process unit having a charging wire for charging the surface of the photoreceptor, the process unit is provided slidably along the charging wire and cleaned from the charging wire. A cleaning unit for storing a cleaning object, the cleaning unit cleaning the charging wire by sandwiching the charging wire; a protrusion that receives the cleaning object that has been cleaned by the cleaning member and dropped from the charging wire or the cleaning member; has a protrusion, as than the charging wire longitudinal end of the contact portion in contact with the charging wire of the cleaning member longer in charging wire longitudinally, the cleaning member and is integrally formed, the charging wire longitudinally Protrusions are provided at the ends. When the cleaning means slides along the charging wire and reaches the protrusions, the protrusions are pushed down and the cleaning objects are collected in the cleaning means. Wherein the dropping from the cleaning means.

The invention according to claim 2 is characterized in that the cleaning member is mounted perpendicularly to the longitudinal direction of the charging wire and sandwiches the charging wire from a gap formed by bending the cleaning member into a U shape. .

According to a third aspect of the present invention, the charging wire is vertically above the photosensitive member, and the projecting portion has a portion recessed below the end portion of the projecting portion in the longitudinal direction of the charging wire.

According to a fourth aspect of the present invention, the process unit is detachable from the image forming apparatus.

According to the process unit of the first aspect, in the process unit including the charging wire for charging the surface of the photosensitive member, the cleaning unit is provided so as to be slidable along the charging wire and collects the cleaning material cleaned from the charging wire. The cleaning unit includes a cleaning member that cleans the charging wire by sandwiching the charging wire, and a protrusion that receives the cleaning object that has been cleaned by the cleaning member and dropped from the charging wire or the cleaning member. The protruding portion is integrally formed with the cleaning member so as to be longer in the longitudinal direction of the charging wire than the end portion of the charging wire in the longitudinal direction of the contact portion in contact with the charging wire of the cleaning member. Therefore, even when the cleaning object falls from the charging wire or the cleaning member when the charging wire is cleaned by the cleaning member, the cleaning object can be received by the protruding portion. Moreover, since the cleaning member and the protrusion are integrally formed, the structure of the cleaning means is simple, the number of members constituting the cleaning means is small, the cost can be kept low, and the cleaning means is further downsized. It becomes possible. And the protrusion is provided in the charging wire longitudinal direction edge part, and when the cleaning means slides along the charging wire and reaches the protrusion, the protrusion presses the protrusion and is stored in the cleaning means. Is dropped from the cleaning means. Therefore, even if the cleaning object accumulates in the cleaning means, the cleaning object can be dropped by the protrusions, so that it is possible to eliminate the need to replace the cleaning means. Furthermore, the cleaning object can be dropped with a simple configuration, and since it is not necessary to store a large amount of the cleaning object, the cleaning means can be reduced in size, and as a result, the cleaning means is provided.
The process unit can also be reduced in size.

According to the process unit of claim 2 , the cleaning member is mounted perpendicular to the longitudinal direction of the charging wire and sandwiches the charging wire from a gap formed by bending the cleaning member into a U shape. Yes. Therefore, the cleaning means can be easily attached to the charging wire.

According to the process unit of the third aspect , the charging wire is located above the photosensitive member in the vertical direction, and the projecting portion has a portion recessed below the end portion of the projecting portion in the longitudinal direction of the charging wire. Therefore, it becomes possible to prevent the cleaning object once received by the protrusion from falling from the protrusion.

According to a fourth aspect of the present invention, the process unit is detachable. Therefore, the process cartridge can be reduced in size, and the entire image forming apparatus can also be reduced in size.

  FIG. 1 is a side sectional view of an essential part showing an embodiment of a laser printer 1 as an image forming apparatus of the present invention.

  In FIG. 1, a laser printer 1 is an electrophotographic laser printer that forms an image by a non-magnetic one-component developing method, and includes a feeder unit 4 for feeding paper 3 into a main body casing 2, And an image forming unit 5 for forming an image on the fed paper 3. In the following description, one side on which a later-described paper feed roller 11 is provided is referred to as the front side of the laser printer 1, and the other side on which a later-described fixing unit 17 is provided is referred to as the rear side of the laser printer 1.

(Feeder unit configuration)
The feeder unit 4 has a paper feed tray 6 that is detachably attached to the bottom of the main casing 2, a paper feed mechanism portion 7 that is provided at the front end of the paper feed tray 6, and a paper feed mechanism portion 7. And a registration roller 9 provided on the downstream side in the conveyance direction of the sheet 3.

(Structure of paper tray)
The paper feed tray 6 has a box shape with an open upper surface that can accommodate the sheets 3 in a stacked manner, and is detachable from the bottom of the main casing 2 in the horizontal direction from the front of the main casing 2. A sheet pressing plate 10 is provided in the sheet feeding tray 6. The paper pressing plate 10 can stack the papers 3 in a stacked manner, and is supported so as to be swingable at the rear side end portion, so that the front side end portion can be moved in the vertical direction. It is urged upward by. Therefore, the sheet pressing plate 10 is swung downward against the urging force of the spring, with the rear end portion serving as a fulcrum, as the amount of stacked sheets 3 increases.

(Structure of paper feed mechanism)
The paper feed mechanism unit 7 includes a paper feed roller 11, a separation pad 8 facing the paper feed roller 11, and a spring (not shown) disposed on the back side of the separation pad. By the biasing force of the spring, The separation pad 8 is pressed toward the paper feed roller 11.

  The uppermost sheet 3 on the sheet pressing plate 10 is pressed toward the sheet feeding roller 11 by a spring (not shown) from the back side of the sheet pressing plate 10, and the sheet feeding roller 11 is rotated by the rotation of the sheet feeding roller 11. After being sandwiched between the separation pads 8, they are separated and fed one by one by their cooperation. The fed paper 3 is sent to the registration roller 9.

(Registration roller configuration)
The registration roller 9 is composed of a pair of rollers, and is an image forming position after registering the paper 3, that is, a transfer position for transferring the toner image onto the paper 3. It is trying to send to the contact part.

(Configuration of image forming unit)
The image forming unit 5 includes a scanner unit 15, a process unit 16, a transfer roller 14, a fixing unit 17, and the like.

(Configuration of scanner unit)
The scanner unit 15 is provided in the upper part of the main casing 2 and includes a laser light emitting unit (not shown), a polygon mirror 18 that is rotationally driven, a lens 19, a reflecting mirror 20, and the like. In the scanner unit 15, a laser beam based on image data emitted from the laser light emitting unit passes or reflects in the order of the polygon mirror 18, the lens 19, and the reflecting mirror 20, as indicated by a chain line, to be described later. The surface of the photosensitive drum 21 is irradiated with high-speed scanning.

(Process unit configuration)
The process unit 16 includes a photosensitive drum 21 as a photosensitive member, a process cartridge 23, and a scorotron charger 24 as a charger in a substantially rectangular box-shaped casing 51. The process unit 16 is detachably attached to the main casing 2 below the scanner unit 15.

  More specifically, a front cover 13 whose lower end is rotatably supported via a hinge 12 and whose upper end is swung back and forth is provided on the front surface of the main casing 2. The process unit 16 can be attached to and detached from the main casing 2 by opening 13 as indicated by a virtual line and moving the process unit 16 in the front-rear direction.

(Process cartridge configuration)
The process cartridge 23 is detachably attached to the casing 51 of the process unit 16, and includes a toner hopper 26, a supply roller 27 provided on the side of the toner hopper 26, a developing roller 28 for carrying toner, and a layer thickness. And a regulating blade 29. By providing the process cartridge 23 detachably with respect to the housing 51 of the process unit 16, the photosensitive drum 21 and the process cartridge 23 can be exchanged in accordance with their respective lifetimes. Therefore, the running cost can be reduced by exchanging the photosensitive drum 21 and the process cartridge 23 at appropriate timings.

The process cartridge 23 is configured to be attached to and detached from the body casing 2 integrally with the housing 51 of the process unit 16. That is, this process cartridge 2
3, the process cartridge 23 alone cannot be attached to or detached from the main casing 2. When the process cartridge 23 is attached or detached, the casing 51 of the process unit 16 is removed from the main casing 2, and the removed process is removed. The process cartridge 23 is configured to be attached to and detached from the casing 51 of the unit 16.

  For example, when replacing the process cartridge 23, first, the casing 51 of the process unit 16 is removed from the main body casing 2, and then the used process cartridge 23 is removed from the casing 51 of the detached process unit 16 and removed. A new process cartridge 23 is mounted on the casing 51 of the process unit 16, and then the casing 51 of the process unit 16 to which the new process cartridge 23 is mounted is mounted on the main casing 2.

  In this embodiment, the process cartridge 23 is detachably provided on the housing 51 of the process unit 16, but the process cartridge 23 and the process unit 16 may be provided detachably on the main casing 2. Even in such a configuration, the photosensitive drum 21 and the process cartridge 23 can be exchanged in accordance with their respective lifetimes. Therefore, the running cost can be reduced by exchanging the photosensitive drum 21 and the process cartridge 23 at appropriate timings.

  The toner hopper 26 is filled with a positively charged nonmagnetic one-component toner as a developer. Examples of the toner include polymerizable monomers such as styrene monomers such as styrene, and acrylic monomers such as acrylic acid, alkyl (C1 to C4) acrylate, and alkyl (C1 to C4) methacrylate. Polymerized toners obtained by copolymerization by a known polymerization method such as suspension polymerization are used. Such a toner is blended with a colorant such as carbon black, wax, and the like, and an additive such as silica is added to improve fluidity. The average particle size is about 6 to 10 μm.

  The toner hopper 26 is provided with an agitator 30. The agitator 30 includes a rotating shaft 31 that is rotatably supported at the center in the toner hopper 26, and a stirring blade 32 provided around the rotating shaft 31. Then, the rotation of the rotating shaft 31 of the agitator 30 in the direction of the arrow (clockwise) causes the stirring blade 32 to move in the circumferential direction, and the toner in the toner hopper 26 is conveyed toward the supply roller 27 described below. The

  The supply roller 27 is disposed on the side of the toner hopper 26 along the width direction of the casing 51 of the process unit 16 (the direction substantially perpendicular to the attaching / detaching direction of the process unit 16, hereinafter the same), and in the direction of the arrow It is provided to be rotatable (counterclockwise). The supply roller 27 has a metal roller shaft covered with a roller portion made of conductive urethane foam.

  The developing roller 28 is provided on the side of the supply roller 27 such that its axial direction is arranged along the width direction of the casing 51 of the process unit 16 and is rotatable in the direction of the arrow (counterclockwise). In the developing roller 28, a roller portion made of a conductive elastic material is coated on a metal roller shaft. More specifically, the developing roller 28 includes a conductive urethane rubber containing carbon fine particles or the like. The surface of the roller portion made of silicone rubber is coated with a coating layer of urethane rubber or silicone rubber containing fluorine. A developing bias is applied to the roller shaft of the developing roller 28.

The supply roller 27 and the development roller 28 are arranged to face each other, and are pressed against the development roller 28 in a state where the supply roller 27 is compressed to some extent. The supply roller 27 and the development roller 28 are These opposing contact portions are set to rotate in opposite directions.

  The layer thickness regulating blade 29 is disposed above the supply roller 27 and is opposed to the developing roller 28 along the axial direction of the developing roller 28. The layer thickness regulating blade 29 includes a leaf spring member 34 and a pressure contact portion 35 that is provided at the tip of the leaf spring member 34 and made of insulating silicone rubber that comes into contact with the developing roller 28. The layer thickness regulating blade 29 is pressed against the surface of the developing roller 28 by the elastic force of the leaf spring member 34 with the leaf spring member 34 supported by the process cartridge 23.

  The toner conveyed to the supply roller 27 by the rotation of the agitator 30 is supplied to the developing roller 28 by the rotation of the supply roller 27. When the toner is supplied from the supply roller 27 to the developing roller 28, the toner is rubbed between the supply roller 27 and the developing roller 28 and charged to a positive polarity.

  The charged toner is carried on the surface of the developing roller 28, and is moved between the developing roller 28 and the pressure contact portion 35 of the layer thickness regulating blade 29 as the developing roller 28 rotates, and the surface of the developing roller 28. Supported as a thin layer on top.

(Configuration of photosensitive drum)
The axial direction of the photosensitive drum 21 is disposed along the width direction of the casing 51 of the process unit 16 so as to face the developing roller 28 on the side of the developing roller 28. The body 51 is supported so as to be rotatable in the direction of the arrow (clockwise) via a bearing (not shown). The photosensitive drum 21 is formed of a positively chargeable photosensitive layer made of polycarbonate or the like while the drum body is grounded.

The surface of the photosensitive drum 21 is uniformly positively charged by a scorotron charger 24 described later, and then exposed by high-speed scanning of a laser beam from the scanner unit 15 to form an electrostatic latent image based on predetermined image data. Is done. In the laser printer 1, the potential of the portion exposed by the laser beam on the surface of the photosensitive drum 21 is set to 150 to 170 V (configuration of the charger).
The scorotron charger 24 is a positively-charged scorotron charger that generates corona discharge. The scorotron charger 24 is disposed above the photosensitive drum 21 so as not to come into contact with the photosensitive drum 21 with a predetermined interval therebetween. It is supported by the casing 51 of the unit 16. The scorotron charger 24 includes a wire 45 as a charging wire, a grid electrode 46, and a wire cleaner 47 as a cleaning means.

  The wire 45 is made of a tungsten wire or the like, and is disposed so as to face along the axial direction of the photosensitive drum 21. The wire 45 is configured such that corona discharge can be generated by applying a voltage to the wire 45 itself, whereby the surface of the photosensitive drum 21 can be uniformly charged to a positive polarity. In the laser printer 1, the charged potential on the surface of the photosensitive drum 21 after charging is set to 870V.

  The grid electrode 46 is provided along the longitudinal direction of the wire 45 in the opening of the casing of the scorotron charger 24 opened toward the photosensitive drum 21.

  As will be described later, the wire cleaner 47 includes a sponge member 47a as a cleaning member that slidably holds the wire 45 therebetween.

(Configuration of transfer roller)
The transfer roller 14 is disposed below the photosensitive drum 21 so that the axial direction of the transfer roller 14 faces the photosensitive drum 21 along the width direction of the casing 51 of the process unit 16. It is supported so that it can rotate counterclockwise. The transfer roller 14 has a metal roller shaft covered with a roller portion made of a conductive rubber material, and a transfer bias is applied during transfer.

(Configuration of fixing unit)
The fixing unit 17 is provided on the side of the process unit 16 and on the downstream side in the conveyance direction of the paper 3, and includes a heating roller 37, a pressing roller 38, and a conveyance roller 39. The heating roller 37 includes a halogen lamp as a heater in a metal base tube. The pressing roller 38 is disposed so as to face the lower side of the heating roller 37 and is provided so as to press the heating roller 37 from below. Further, the transport roller 39 is provided on the downstream side in the transport direction of the paper 3 with respect to the heating roller 37 and the pressing roller 38.

  The electrostatic latent image formed on the surface of the photosensitive drum 21 when the toner carried on the developing roller 22 and positively charged comes into contact with the photosensitive drum 21 by the rotation of the developing roller 22, that is, The surface of the photosensitive drum 21 that is uniformly positively charged is supplied to a portion of the photosensitive drum 21 that is exposed to a laser beam and the potential of which is lowered, and is selectively carried to be visualized, whereby reversal development is performed. Is achieved. In the laser printer 1, a voltage of 400 to 450 V is applied to the developing roller 22 as a bias voltage.

(Example of image forming operation)
In the laser printer 1 of this embodiment as described above, the operation during printing will be described with reference to FIG.

  The surface of the photosensitive drum 21 is first positively charged uniformly by the scorotron charger 24 as the photosensitive drum 21 rotates, and then exposed by high-speed scanning of the laser beam from the scanner unit 15 to obtain image data. An electrostatic latent image based on is formed.

  Next, the toner carried on the surface of the developing roller 28 and charged with positive polarity is formed on the surface of the photosensitive drum 21 when the developing roller 28 rotates and contacts the photosensitive drum 21. The electrostatic latent image, that is, the surface of the uniformly positively charged photosensitive drum 21 is supplied to the exposed portion where the potential is lowered by being exposed to the laser beam, and the visible image is selectively carried. Thus, reversal development is achieved and a toner image is formed.

  When the toner image carried on the surface of the photosensitive drum 21 comes into contact with the paper 3 conveyed from the registration roller 9 of the feeder unit 4 after registration by the rotation of the photosensitive drum 21, the paper 3 is While passing between the photosensitive drum 21 and the transfer roller 14, the image is transferred to the paper 3. The sheet 3 on which the toner image has been transferred is conveyed toward the fixing unit 17.

The sheet 3 conveyed to the fixing unit 17 is heat-fixed while passing between the heating roller 37 and the pressing roller 38, and then is conveyed by the conveying roller 39 and the conveying roller 40 provided in the main body casing 2 and discharged. It is conveyed toward the roller 41. The conveyance roller 40 is provided on the downstream side in the conveyance direction of the paper 3 with respect to the conveyance roller 39, and the paper discharge roller 41 is provided above the paper discharge tray 42. The sheet 3 transported by the transport roller 39 is transported to the paper discharge roller 41 by the transport roller 40, and then discharged onto the paper discharge tray 42 by the paper discharge roller 41.

(Configuration and operation of wire cleaner)
Next, the configuration and operation of the wire cleaner 47 for cleaning the wire 45 of the scorotron charger 24 provided in the process unit 16 will be described with reference to FIGS.

2A to 2D are a plan view before the plastic member 47b of the sponge member 47a of the wire cleaner 47 is mounted, a side view seen from the longitudinal direction of the wire 45, a perspective view, and a wire 45, respectively. It is the side view seen from the direction perpendicular | vertical to the longitudinal direction. 3A is a plan view of the wire cleaner 47 as viewed from the photosensitive drum 21 side, and FIG. 3B is a side view of the wire cleaner 47 as viewed from the longitudinal direction of the wire 45. FIG. These are the side views of the wire cleaner 47 seen from the side of the laser printer 1, and FIG.3 (d) is the perspective view which looked at the wire cleaner 47 from diagonally upward. 4 is an enlarged view of a part of FIG. 3A before and after the sponge member 47a attached to the plastic member 47b is pressed by the plastic member 47b.

As shown in FIGS. 2 to 4, the sponge member 47 a is mounted perpendicularly to the longitudinal direction of the wire 45 from the gap S formed by being bent into a U shape, and sandwiches the wire 45. Note that a cut may be formed in the sponge member 47a and the wire 45 may be attached from the cut. The sponge member 47a is attached to the longitudinal central portion of the wire 45 of the sponge member 47a by the plastic member 47b and presses the wire 45. As a result, the pressing force at the center portion in the longitudinal direction of the wire 45 of the sponge member 47a becomes stronger than the pressing force at the end portion. That is, the pressing force of the portion pressed by the plastic member 47b of the sponge member 47a is maximized. Then, as shown in FIG. 4, the gap S of the sponge member 47a opens toward the longitudinal end of the wire 45, and the wire 45 is pressed in a state where the opening S ′ is formed.

Then, when the wire cleaner 47 is slidable along the wire 45, an operation for cleaning dirt adhering to the wire 45 is started. The dirt adhering to the wire 45 is reduced from the opening S ′ to the longitudinal center portion of the wire 45 of the sponge member 47a while being scraped from the wire 45 by the portion where the sponge member 47a is rubbed against the wire 45. Go. The reduced dirt (cleaned material) is further pushed into the central portion by the cleaned material that has been reduced later. For this reason, the wire cleaner 47 can store the cleaned cleaning object without dropping it.

Next, the rib 48 that causes the wire cleaner 47 to clean the collected wire 45 and drop the cleaned material will be described with reference to FIGS. 5A to 5C are a plan view of the wire cleaner 47 viewed from the photosensitive drum 21 side, a side view viewed from a direction perpendicular to the longitudinal direction of the wire 45, and a view viewed from the longitudinal direction of the wire 45, respectively. 5 is a side view of the wire cleaner 47. FIG. 6A and 6B are a side view showing a fixing position of the rib 48 with respect to the wire 45 when the scorotron charger 24 is seen from the side of the laser printer 1, and a side view seen from the longitudinal direction of the wire 45. It is. FIG. 7A is a plan view showing the state after the wire cleaner 47 passes through the rib 48 as viewed from the photosensitive drum 21 side, and the plan view showing the state after the wire cleaner 47 passes through the rib 48. FIG. FIG. 7B is a side view showing the wire cleaner 47 passing through the rib 48 as viewed from the side of the laser printer 1, and shows the state after the wire cleaner 47 has passed through the rib 48. It is a figure which shows a side view on the left.

The wire 45 is above the photosensitive drum 21 in the vertical direction. In the wire 45, above the non-image forming region P of the photosensitive drum 21, the flat rib 48 is placed on the wire 45 so as to be lower than the gap height of the wire cleaner 47. It is fixed. Then, when the wire cleaner 47 storing the cleaning material is slid and passes so as to cover the rib 48, the rib 48 enters the wire cleaner 47 through the gap S of the wire cleaner 47. Therefore, the gap S of the wire cleaner 47 is widened by the width of the rib 48 in the longitudinal direction of the wire 45. The same applies to the central portion in the longitudinal direction of the wire 45 of the wire cleaner 47, and the central portion is also expanded. As a result, the cleaning object stored in the central portion falls from the widened gap S, and the wire cleaner 47 can store the dirt adhering to the wire 45 again. Therefore, it is possible to prevent the wire cleaner 47 from collecting too much cleaning material and preventing the newly cleaned cleaning material from entering the wire cleaner 47 and dropping onto the photosensitive drum 21 as it is. Further, the wire cleaner 47 does not need to be enlarged in order to collect a large amount of the cleaning object by collecting the cleaning object by the rib 48.

  Incidentally, the cleaning object stored in the wire cleaner 47 is dropped from the wire cleaner 47 by the rib 48, but the rib 48 is fixed to the wire 45 so that the cleaning object falls into the non-image forming region P. There is no concern that the photosensitive drum 21 is soiled by the cleaning object.

  The rib 48 is provided to collect the cleaning object from the wire cleaner 47, but it goes without saying that it can be used in place of the rib 48 as long as the gap of the wire cleaner 47 can be increased. .

  The rib 48 is provided on the wire 45 above the non-image forming area P. However, if there is a mechanism for receiving the cleaning material so that it does not fall on the photosensitive drum 21 below the rib 48, the rib 48 is formed in the image forming area P ′. It may be provided.

  An image forming apparatus and a process unit according to a second embodiment of the present invention will be specifically described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the component corresponding to Example 1, and the description which overlaps with Example 1 is abbreviate | omitted. 8A to 8D are a plan view before the plastic member 47b of the sponge member 47a of the wire cleaner 47 is mounted, a side view seen from the longitudinal direction of the wire 45, a perspective view, and a wire 45, respectively. It is the side view seen from the direction perpendicular | vertical to the longitudinal direction. 9A to 9D are a plan view of the wire cleaner 47 viewed from the photosensitive drum 21 side, a side view of the wire cleaner 47 viewed from the longitudinal direction of the wire 45, and a side view of the laser printer 1, respectively. It is the side view of the wire cleaner 47, and the perspective view which looked at the wire cleaner 47 from diagonally upward.

  In FIG. 9, the plastic member 47b is omitted so that the sponge member 47a can be seen.

As shown in FIGS. 8 and 9, the H-shaped sponge member 47 a is mounted perpendicularly to the longitudinal direction of the wire 45 from the gap S formed by being bent into a U shape, and sandwiches the wire 45. . When the H-shaped sponge member 47a is bent into a U-shape, a protruding portion 47c that receives dirt (cleaned material) cleaned from the wire 45 is formed, but it contacts the wire 45 of the sponge member 47a. The sponge member 47a is integrally formed so as to be longer in the longitudinal direction of the wire 45 than at least one of the longitudinal ends A or B of the wire 45 of the contact portion. Note that a cut may be formed in the T-shaped sponge member 47a and the wire 45 may be attached from the cut. Then, when the wire cleaner 47 is slidable along the wire 45, an operation for cleaning dirt adhering to the wire 45 is started. The dirt adhering to the wire 45 is removed from the wire 45 by the longitudinal end portion A or B of the wire 45 where the sponge member 47 a is in contact with the wire 45. It accumulates in between. Dirt (cleaning matter) that has accumulated between the end A or B and the wire 45 cannot eventually remain between the end A or B and the wire 45, and the end A or B It spills from the wire 45 and falls. Since the fallen cleaning material is received by the protrusion 47c formed by bending the H-shaped sponge member 47a, the cleaning material does not contaminate the photosensitive drum 21. In this way, the cleaning object is the protrusion 47c.
It will be accumulated in.

Next, a description will be given of the rib 48 for collecting the cleaning object collected by the wire cleaner 47 by cleaning the wire 45 and collecting in the protruding portion 47c with reference to FIGS. 10A to 10C are a plan view of the wire cleaner 47 viewed from the photosensitive drum 21 side, a side view of the wire cleaner 47 viewed from the longitudinal direction of the wire 45, and a side view of the laser printer 1, respectively. It is the side view of the wire cleaner which looked. FIG. 11 is a side view showing a fixing position of the rib 48 with respect to the wire 45 when the scorotron charger 24 is viewed from the side of the laser printer 1. FIG. 12A is a plan view showing the state after the wire cleaner 47 has passed through the rib 48 as viewed from the photosensitive drum 21 side, and the plan view showing the state after the wire cleaner 47 has passed through the rib 48. FIG. FIG. 12B shows the wire cleaner 4 as viewed from the longitudinal direction of the wire 45.
It is a side view which shows a mode that 7 passes a rib. FIG. 12C shows the laser printer 1.
The side view which shows a mode that the wire cleaner 47 passes the rib 48 seen from this side is shown on the right, and the side view which shows the mode after the wire cleaner 47 passes the rib 48 is shown on the left.

In the wire cleaner 47 of the present embodiment, as in the first embodiment, the cleaning object stored in the protruding portion 47c is formed as a gap S formed by bending the sponge member 47a as shown in FIGS. However, when the wire cleaner 47 is slid and passed through the gap rib 48, the wire cleaner 47 is greatly expanded, and is thereby dropped from the protrusion 47c to the non-image forming region P of the photosensitive drum 21.

  13A to 13C are a plan view of a wire cleaner 47 as a modified example of the present embodiment viewed from the photosensitive drum 21 side, a side view viewed from the side of the laser printer 1, and a perspective view, respectively. is there. As shown in FIG. 13, the protrusion 47 c may be formed to have a portion C that is recessed below the longitudinal end of the wire 45 of the protrusion 47 c. In this way, it is possible to prevent the cleaning object that has fallen on the protrusion 47c or the cleaning object that has been received once by the protrusion 47c from falling from the protrusion 47c.

Other variations are also conceivable. FIG. 14 is a side view showing the state before the wire cleaner 47 reaches the protrusion 49 as viewed from the side of the laser printer 1, and the side view showing the state when the wire cleaner 47 reaches the protrusion 49. It is a figure which shows a figure on the left. As shown in FIG. 14, instead of the rib 48, a conical protrusion 49 extending toward the longitudinal center of the wire 45 is provided at the longitudinal end of the wire 45, and the tip of the protrusion 49 is a protrusion. It may be positioned slightly above 47c. In this manner, when the wire cleaner 47 slides along the wire 45 and reaches the protrusion, the protrusion presses the protrusion 47c, and the cleaning object stored in the wire cleaner 47 falls.

  The present invention has been described above based on each embodiment, but the present invention is not limited to the above embodiment, and various improvements and modifications can be made without departing from the technical idea thereof.

1 is a cross-sectional side view of a main part showing an embodiment of a laser printer 1 as an image forming apparatus of the present invention. (a) is a plan view before the plastic member 47b of the sponge member 47a of the wire cleaner 47 is mounted, and (b) is a view of the plastic member 47b of the sponge member 47a of the wire cleaner 47 as viewed from the longitudinal direction of the wire 45. The side view before mounting, (c) is a perspective view before mounting the plastic member 47b of the sponge member 47a of the wire cleaner 47, (d) is a wire viewed from the direction perpendicular to the longitudinal direction of the wire 45 FIG. 5 is a side view of the sponge member 47a of the cleaner 47 before the plastic member 47b is mounted. (a) A plan view of the wire cleaner 47 viewed from the photosensitive drum 21 side, (b) a side view of the wire cleaner 47 viewed from the longitudinal direction of the wire 45, and (c) a wire cleaner viewed from the side of the laser printer 1. 47 is a side view of the wire cleaner 47 as viewed obliquely from above. It is the figure which expanded a part of Fig.3 (a) before and after the sponge member 47a with which the plastic member 47b was mounted | worn is pressed by the plastic member 47b. (a) is a plan view of the wire cleaner 47 as viewed from the photosensitive drum 21 side, (b) is a side view of the wire cleaner 47 as viewed from a direction perpendicular to the longitudinal direction of the wire 45, and (c) is a longitudinal direction of the wire 45. It is the side view of the wire cleaner 47 seen from. (a) is a side view showing the fixing position of the rib 48 to the wire 45 when the scorotron charger 24 is seen from the side of the laser printer 1, and (b) is a view of the scorotron charger 24 seen from the longitudinal direction of the wire 45. FIG. (a) is a plan view showing a state in which the wire cleaner 47 passes through the rib 48 as viewed from the photosensitive drum 21 side, and a plan view showing the state after the wire cleaner 47 has passed through the rib 48 on the left. (B), The side view which shows a mode that the wire cleaner 47 passes the rib 48 seen from the side of the laser printer 1 is shown on the right, and the side view that shows the mode after the wire cleaner 47 passes the rib 48 is shown on the left FIG. (a) is a plan view before the plastic member 47b of the sponge member 47a of the wire cleaner 47 is mounted; (b) is the plastic member 47b of the sponge member 47a of the wire cleaner 47 as viewed from the longitudinal direction of the wire 45; (C) is a perspective view before the plastic member 47b of the sponge member 47a of the wire cleaner 47 is mounted, and (d) is a wire cleaner as viewed from a direction perpendicular to the longitudinal direction of the wire 45. It is a side view before the plastic member 47b of 47 sponge members 47a is mounted | worn. (a) A plan view of the wire cleaner 47 viewed from the photosensitive drum 21 side, (b) a side view of the wire cleaner 47 viewed from the longitudinal direction of the wire 45, and (c) a wire cleaner viewed from the side of the laser printer 1. 47 is a side view of the wire cleaner 47 as viewed obliquely from above. (a) is a plan view of the wire cleaner 47 viewed from the photosensitive drum 21 side, (b) is a side view of the wire cleaner 47 viewed from the longitudinal direction of the wire 45, and (c) is a wire viewed from the side of the laser printer 1. It is a side view of a cleaner. FIG. 3 is a side view showing a fixing position of a rib 48 to a wire 45 when the scorotron charger 24 is viewed from the side of the laser printer 1. (a) A plan view showing the wire cleaner 47 passing through the rib 48 as viewed from the photosensitive drum 21 side on the right, and a plan view showing the wire cleaner 47 after passing through the rib 48 on the left. (b) is a side view showing the wire cleaner 47 passing through the rib as viewed from the longitudinal direction of the wire 45, and (c) is a view of the wire cleaner 47 passing through the rib 48 as seen from the side of the laser printer 1. FIG. 5 is a right side view and a left side view showing a state after the wire cleaner 47 has passed through the rib 48. (a) The top view which looked at the wire cleaner 47 as a modification of a present Example from the photosensitive drum 21 side, (b) The side which looked at the wire cleaner 47 as a modification of a present Example from the side of the laser printer 1 FIG. 4C is a perspective view of a wire cleaner 47 as a modification of the present embodiment. The side view showing the state before the wire cleaner 47 reaches the protrusion 49 as viewed from the side of the laser printer 1 is shown on the right, and the side view showing the state when the wire cleaner 47 reaches the protrusion 49 is shown on the left. FIG.

DESCRIPTION OF SYMBOLS 1 Laser printer 4 Feeder unit 5 Image forming unit 21 Photosensitive drum 24 Scorotron type charger 28 Developing roller 45 Wire 46 Grid electrode 47 Wire cleaner 47a Sponge member 47b Plastic member 47c Protrusion part 48 Rib

Claims (4)

In a process unit having a charging wire for charging the surface of a photoreceptor,
A cleaning means provided so as to be slidable along the charging wire, and storing a cleaning object cleaned from the charging wire;
The cleaning means includes
A cleaning member for cleaning the charging wire by sandwiching the charging wire;
A protrusion that receives the cleaning object that has been cleaned by the cleaning member and dropped from the charging wire or the cleaning member;
The protrusion is
The cleaning member is integrally formed with the cleaning member so as to be longer in the longitudinal direction of the charging wire than the longitudinal end portion of the charging wire in contact with the charging wire.
Protrusions are provided at the longitudinal ends of the charging wire,
The protrusion is
When the cleaning means is slid along the charging wire and reaches the protrusion, the protrusion is pushed down and the cleaning object stored in the cleaning means is dropped from the cleaning means. unit. The cleaning member is
The process unit according to claim 1 , wherein the cleaning member is mounted perpendicularly to a longitudinal direction of the charging wire and sandwiches the charging wire from a gap formed by bending the cleaning member into a U shape. The charging wire is vertically above the photoconductor,
The protrusion is
3. The process unit according to claim 1 , wherein the process unit has a portion that is recessed below an end portion of the charging wire in the longitudinal direction of the charging wire. An image forming apparatus having a detachable process unit according to any one of claims 1 to 3.

Images