JP2024147379A - Process Unit - Google Patents

Abstract

To reduce the size of an image forming apparatus comprising cleaning rollers and cleaning shafts.SOLUTION: A process unit comprises: photoconductor drums (3); cleaning rollers (32); cleaning shafts (36); a frame (21) having a support plate (23) and side plates (22); cleaning roller electrodes (33); cleaning shaft electrodes (361); a first input electrode (43); and a second input electrode (46). When seen from the outside of the side plate (22) in a first direction, the first input electrode (43) and the second input electrode (46) are arranged at positions at least partially overlapping each other across the side plate (22).SELECTED DRAWING: Figure 1

Description

This disclosure relates to a process unit that is installed in an electrophotographic image forming apparatus.

In an image forming device such as an electrophotographic color printer, a process unit equipped with four photosensitive drums is provided. The process unit described in Patent Document 1 includes a frame and a side plate located on the outside of the frame.

The frame supports four photosensitive drums, cleaning rollers in contact with each photosensitive drum, unit-side electrodes electrically connected to the cleaning rollers, main body-side electrodes electrically connected to the unit-side electrodes, and a charger.

JP 2010-128337 A

Incidentally, a cleaning shaft may be provided in an image forming apparatus to remove foreign matter such as paper powder from the cleaning roller. A voltage is applied to the cleaning shaft from an electrode, and the foreign matter on the cleaning roller is collected by the cleaning shaft due to the potential difference between the cleaning shaft and the cleaning roller. When a cleaning shaft is provided in the image forming apparatus described in Patent Document 1, it is desirable to position the electrode of the cleaning shaft and the electrode of the cleaning roller as close as possible to reduce the size of the image forming apparatus. However, in order to prevent discharge between the electrode of the cleaning shaft and the electrode of the cleaning roller, it is necessary to position the two electrodes apart, and it is difficult to position the two electrodes close to each other.

This disclosure was made in consideration of the above problems, and its purpose is to achieve a smaller image forming device equipped with a cleaning roller and a cleaning shaft.

In order to solve the above problem, the process unit of the first aspect of the present disclosure includes a photosensitive drum rotatable about a first rotation axis extending in a first direction, a cleaning roller in contact with the surface of the photosensitive drum, a cleaning shaft in contact with the surface of the cleaning roller, a frame located at an end of the photosensitive drum in the first direction and having a support plate that supports the cleaning roller and a side plate located outside the support plate in the first direction, a cleaning roller electrode provided at one end of the cleaning roller in the first direction, electrically connected to the one end of the cleaning roller in the first direction and located inside the side plate in the first direction, and a cleaning shaft provided at one end of the cleaning shaft in the first direction and configured to detect the cleaning roller in the first direction. The cleaning shaft electrode is electrically connected to one end of the cleaning shaft and is located inside the side plate in the first direction, a first input electrode is attached to the side plate and has a roller power receiving portion located outside the side plate in the first direction, and a roller power supply portion located inside the side plate in the first direction and supplies power to the cleaning roller electrode, and a second input electrode is attached to the side plate and has a shaft power receiving portion located outside the side plate in the first direction, and a shaft power supply portion located inside the side plate in the first direction and supplies power to the cleaning shaft electrode, and the first input electrode and the second input electrode are arranged in positions where they at least partially overlap with each other across the side plate when viewed from the outside of the side plate in the first direction.

The second aspect is a process unit according to the first aspect, in which the first input electrode and the shaft power supply part are arranged in a position where they overlap with each other across the side plate when viewed from the outside of the side plate in the first direction.

The third aspect is a process unit according to the first aspect, in which the first input electrode and the second input electrode are arranged at a position where the roller power receiving part and the shaft power supply part overlap with the side plate in between, as viewed from the outside of the side plate in the first direction.

The fourth aspect is a process unit according to the first aspect, in which the roller power receiving portion and the shaft power receiving portion are spaced apart in the second direction when viewed from the outside of the side plate in the first direction.

The fifth aspect is the process unit of the first aspect, in which the roller power receiving portion and the shaft power receiving portion are configured to contact a main body electrode provided on the main body of the image forming device in the first direction when the process unit is attached to the image forming device to which the process unit is attached.

The sixth aspect is the process unit of the fifth aspect, in which a first voltage of a polarity opposite to the first charging polarity of the developer remaining on the photosensitive drum is applied to the roller power receiving portion from the body side electrode, a second voltage of a second charging polarity opposite to the first charging polarity is applied to the shaft power receiving portion from the body side electrode, and the withstand voltage of a portion of the side plate exceeds the difference between the first voltage and the second voltage.

The seventh aspect is the process unit of the first aspect, in which the first input electrode further has a first extension extending from an edge of the roller power supply part to the outside of the side plate in the first direction, the second input electrode further has a second extension extending from an edge of the shaft power supply part to the outside of the side plate in the first direction, and the side plate further has a first slit through which the first extension and the roller power receiving part can be inserted, and a second slit through which the second extension and the shaft power receiving part can be inserted.

The eighth aspect is the process unit of the first aspect, in which the side plate is made of insulating resin.

According to the process unit of the first aspect, a side plate is sandwiched between the first input electrode and the second input electrode. Furthermore, the first input electrode and the second input electrode are arranged in a position where they at least partially overlap with each other, sandwiching the side plate. This makes it possible to reduce the distance between the cleaning shaft electrode and the cleaning roller electrode compared to conventional methods, thereby realizing a miniaturized image forming device equipped with a cleaning roller and a cleaning shaft.

According to the process unit of the second aspect, the first input electrode and the shaft power supply section are arranged in a position where they overlap with the side plate in between. This allows the distance between the cleaning shaft electrode and the cleaning roller electrode to be further reduced compared to conventional cases, making it possible to miniaturize the image forming device.

According to the process unit of the third aspect, the roller power receiving portion and the shaft power receiving portion are arranged in a position where they overlap with the side plate in between. This allows the distance between the cleaning shaft electrode and the cleaning roller electrode to be further reduced than before, making it possible to miniaturize the image forming device.

The process unit of the fourth aspect can prevent discharges from occurring between the roller power receiving part located on the outside of the side plate and the shaft power receiving part.

According to the process unit of the fifth aspect, the first input electrode and the second input electrode contact the main body electrode in the first direction at the roller power receiving portion and the shaft power receiving portion arranged on the outer surface of the side plate. This allows the first input electrode and the second input electrode to be electrically connected to the main body electrode by mounting the process unit to the device main body.

According to the process unit of the sixth aspect, a first voltage having a polarity opposite to the first charge polarity of the developer remaining on the photosensitive drum is applied from the main body side electrode. In addition, a second voltage having a second charge polarity opposite to the first charge polarity is applied from the main body side electrode to the shaft power receiving portion. Furthermore, the side plate is configured so that the withstand voltage of a portion of the side plate exceeds the difference between the first and second voltages. As a result, the portion of the side plate where the first input electrode and the second input electrode overlap when viewed from the outer surface side of the side plate has a withstand voltage that exceeds the voltage difference between the voltages applied to the two electrodes. Therefore, discharge between the first input electrode and the second input electrode can be prevented.

According to the seventh aspect of the process unit, the first input electrode and the second input electrode can be attached by inserting them through the slits in the side plate, which makes the installation process more efficient.

According to the process unit of the eighth aspect, the side plate is made of insulating resin, so that discharge between the relay electrode and the multiple electronic components can be avoided. As a result, it is possible to provide a process unit that allows the relay electrode and the multiple electronic components to be arranged in a small space.

1 is a side cross-sectional view illustrating an example of an image forming apparatus of the present invention. FIG. 2 is a perspective view of the process unit shown in FIG. 1 . FIG. 3 is a right side view of the process unit shown in FIG. 2 with the film removed; FIG. 4 is a side view corresponding to FIG. 3, showing a state in which a side plate has been removed. FIG. 4 is an enlarged view of the portion XA shown in FIG. 3 . FIG. 6 is a view of the part corresponding to FIG. 5 as seen from the inside. 6 is a cross-sectional view taken along the line X1-X1 of FIG. 5. 6 is a cross-sectional view taken along the line X2-X2 of FIG. 5. 7A is a perspective view of the portion corresponding to FIG. 6 as seen obliquely from the front, and FIG. 7B is a schematic view showing the state in which a side plate has been removed from FIG.

[General Configuration of Image Forming Apparatus 1]
Hereinafter, a first embodiment of the present disclosure will be described with reference to Figures 1 to 9. Figure 1 is a side cross-sectional view showing an example of an image forming apparatus 1 of the present invention. When directions are mentioned, the directional arrows shown in Figures 1 to 9 will be referred to. Here, the left-right direction is the same as the width direction, and the up-down direction is the same as the vertical direction. The horizontal direction includes the width direction and the front-rear direction.

As shown in FIG. 1, the image forming device 1 is, as an example, a color laser printer. The image forming device 1 has a main body casing 2 that is generally box-shaped and extends in the front-rear direction. A process unit 16 is provided inside the main body casing 2 so as to be movable along the front-rear direction, and the process unit 16 can be attached to and detached from the main body casing 2 by moving in the front-rear direction. The insertion direction is indicated by an arrow 19 in FIG. 1 and FIG. 2.

The main body casing 2 is equipped with an openable front cover 2A. The front cover 2A constitutes the front side wall of the main body casing 2. A user can open the front cover 2A and remove the process unit 16 to the outside of the main body casing 2. A user can also install the process unit 16 in the main body casing 2 by opening the front cover 2A and inserting the process unit 16 along an insertion direction from the front to the rear. The insertion direction is indicated by an arrow 19 in Figures 1 and 2.

The main casing 2 also includes main body electrodes 48, 49. The main body electrode 48 is an electrode for supplying power to the roller input electrode 43 of the process unit 16. The main body electrode 49 is an electrode for supplying power to the shaft input electrode 46 of the process unit 16.

The process unit 16 includes four photosensitive drums 3. The four photosensitive drums 3 are rotatably provided in the process unit 16. The four photosensitive drums 3 are arranged in the front-rear direction in the order of the photosensitive drum 3 corresponding to the yellow toner, the photosensitive drum 3 corresponding to the magenta toner, the photosensitive drum 3 corresponding to the cyan toner, and the photosensitive drum 3 corresponding to the black toner. As shown in FIG. 4, the photosensitive drum 3 includes a ground shaft 17 and a bearing member 18 that supports both ends of the ground shaft 17. In addition, the process unit 16 includes four scorotron type chargers 4 arranged facing the four photosensitive drums 3. The ground shaft 17 is an example of a first rotating shaft and a second rotating shaft extending in a first direction. That is, the first direction is the axial direction of the ground shaft 17. The axial direction is the same as the left-right direction. The second direction, which is different from the first direction, is a direction perpendicular to the axial direction and is the same as the front-rear direction.

The process unit 16 also includes a developing cartridge 6 that contains yellow toner, a developing cartridge 6 that contains magenta toner, a developing cartridge 6 that contains cyan toner, and a developing cartridge 6 that contains black toner. Toner is an example of a developer. The developing cartridge 6 is disposed adjacent to the photosensitive drum 3 and includes a developing roller 5 that faces the photosensitive drum 3. The surface of the developing roller 5 carries toner corresponding to each color.

After the surfaces of the four photosensitive drums 3 are uniformly charged by the charger 4, they are exposed to a laser beam emitted from an exposure unit 7 provided at the top of the main casing 2. As a result, an electrostatic latent image based on image data is formed on the surfaces of the four photosensitive drums 3. The laser beam emitted from the exposure unit 7 is indicated by a dashed line in FIG. 1. The electrostatic latent images on the four photosensitive drums 3 are visualized by toner of each color carried on the surfaces of the four developing rollers 5 corresponding to the four photosensitive drums 3, and a toner image of each color is formed on the surfaces of the four photosensitive drums 3.

Four cleaning rollers 32 are arranged to contact the four photosensitive drums 3 from behind. The cleaning rollers 32 are equipped with a metallic rotating shaft 34, an elastic roller 35 that covers the rotating shaft 34, and bearings (not shown) that support both ends of the rotating shaft 34. The cleaning rollers 32 remove toner remaining on the surfaces of the photosensitive drums 3 that have formed an image on the paper S. The toner remaining on the photosensitive drums 3 is collected from the photosensitive drums 3 by the cleaning rollers 32 due to the potential difference between the cleaning rollers 32 and the photosensitive drums 3. The paper S is not limited to paper media, and may also be other resin media made of plastic, such as overhead projector sheets.

A metal cleaning shaft 36 is arranged so as to contact the cleaning roller 32 arranged at the frontmost side in the front-to-rear direction from behind. The cleaning shaft 36 has bearings (not shown) that support both ends. The cleaning shaft 36 removes toner, paper dust, etc. that have adhered to the surface of the elastic roller 35 of the cleaning roller 32. As shown in FIG. 1, the cleaning shaft 36 is arranged only for the cleaning roller 32 arranged at the frontmost end, and is not arranged for the three cleaning rollers 32 on the rear side in the front-to-rear direction.

The sheets S are stored in a vertically stacked state in the sheet feed cassette 8 located at the bottom of the main casing 2. Of the sheets S stored in the sheet feed cassette 8, the topmost sheet S is fed by a sheet feed roller 9 provided above the front end of the sheet feed cassette 8. The sheet S then turns from the front to the rear and enters between a pair of registration rollers 10. The pair of registration rollers 10 transport the sheet S toward the front conveyor belt 11 at a predetermined timing.

The conveyor belt 11 is endless, and in its inner region, four transfer rollers 12 are disposed. The four transfer rollers 12 are disposed opposite the four photosensitive drums 3 with the conveyor belt 11 interposed therebetween.

The paper S is then transported by the transport belt 11. The transport belt 11 rotates in the opposite direction to the rotation direction of the photosensitive drums 3, transporting the paper S from the front side to the rear side. The toner images on the surfaces of the four photosensitive drums 3 are transferred by a transfer bias applied to the transfer roller 12 so as to be superimposed on the paper S being transported by the transport belt 11. In this way, a color image is formed on the paper S.

The paper S is then transported by the transport belt 11 to the fixing section 13 at the rear. The color image transferred onto the paper S is thermally fixed in the fixing section 13. The paper S is then transported by the transport rollers 14, turns from the rear to the front, and is discharged onto the paper discharge tray 15 at the top of the main casing 2.

[General Configuration of Process Unit 16]
The schematic configuration of the process unit 16 will be described with reference to Figures 2 to 4. Figure 2 is a perspective view of the process unit 16 shown in Figure 1. For ease of explanation, the developing cartridge 6 is omitted from Figure 2. Figure 3 is a right side view of the process unit 16 shown in Figure 2 with the film 47 removed. Figure 4 is a side view corresponding to Figure 3 with the side plate 22 removed.

As shown in Figures 2, 3, and 4, the process unit 16 includes a frame 21 and a pair of side plates 22 arranged on the outside of the frame 21. The frame 21 includes a support plate 23 arranged between the frame 21 and the side plates 22. The support plates 23 are provided on the left and right sides of the frame 21. The support plates 23 include a front beam 24 that is installed between the front ends of the support plates 23, and a rear beam 25 that is installed between the rear ends of the support plates 23. The frame 21 also includes four drum units 26 that are arranged in parallel at intervals between the front beam 24 and the rear beam 25. The frame 21 is an example of a frame.

In this embodiment 1, the configurations related to the electrodes, such as the cleaning roller electrode 33, the roller input electrode 43, and the relay electrode 45, are all provided on the right side of the process unit 16, and not on the left side. Therefore, in the following description, the right side plate 22 and the right support plate 23 will be described in detail. The right side plate 22 and the right support plate 23 will be simply referred to as the side plate 22 and the support plate 23, respectively. The configurations related to the electrodes, such as the cleaning roller electrode 33, the roller input electrode 43, and the relay electrode 45, are not limited to being provided on the right side of the process unit 16, and may be provided on the left side.

[Configuration of side plate 22]
Details of the side plate 22 will be described with reference to Figures 2 and 3. As shown in Figures 2 and 3, the side plate 22 is formed in a generally rectangular shape extending in the front-rear and up-down directions. The side plate 22 may be formed of an insulating resin. The side plate 22 is provided with a positioning boss (not shown) on the inner surface in the left-right direction for positioning the side plate 22 with respect to the frame body 21. The positioning boss is appropriately designed according to the shape of the side plate 22. The positioning boss is provided at a position corresponding to the positioning hole 130.

A groove 61 is formed on the outer surface of the side plate 22 in the left-right direction. The groove 61 extends from the through hole 55 diagonally downward toward the rear side parallel to the roller power receiving portion 43A, and then extends rearward along the front-rear direction so as to connect the upper sides of each opening 58. The groove 61 extends to a position slightly rearward of the rearmost opening 58. The groove 61 is formed in a generally U-shaped cross section that is recessed inward in the left-right direction from the outer surface of the side plate 22 in the left-right direction.

The roller input electrode 43 and the shaft input electrode 46 are attached to the side plate 22. The relay electrode 45 is also attached along the groove portion 61.

A roughly rectangular insulating resin film 47 that extends in the front-to-rear and up-to-down directions is attached to the outer surface of the side plate 22 in the left-to-right direction. The film 47 covers almost the entire surface of the side plate 22 in the front-to-rear direction, from the position facing the charger 4 located at the frontmost position to the rear end of the side plate 22. As a result, the film 47 covers almost the entire length of the relay electrodes 45 that are arranged along the front-to-rear direction on the outer surface of the side plate 22 in the left-to-right direction.

As shown in FIG. 2, the film 47 has an opening 47A formed on the lower front side when the film 47 is viewed from the side. The opening 47A is formed so that the roller power receiving portion 43A of the roller input electrode 43 and the shaft power receiving portion 46A of the shaft input electrode 46, which is electrically connected to the right end of the cleaning shaft 36, are exposed to the outside through the opening 47A. As a result, as shown in FIG. 2, when the process unit 16 is installed in the main casing 2, the roller power receiving portion 43A and the main body side electrode 48, and the shaft power receiving portion 46A and the main body side electrode 49 are electrically connected in the left-right direction through the opening 47A.

[Configuration of support plate 23]
4, the support plate 23 is a flat plate extending in the front-rear direction and is made of a metal such as stainless steel. The support plate 23 also includes a drum support hole 27 for supporting the photosensitive drum 3, an insertion hole 28 disposed behind the drum support hole 27, and positioning holes 130 disposed at the front end and the rear end of the support plate 23, one each.

The drum support holes 27 are circular in side view, and the bearing members 18 of the photosensitive drum 3 are inserted through them to support the bearing members 18. As a result, the support plate 23 supports both left and right ends of the photosensitive drum 3. In addition, the cleaning roller electrodes 33 can be inserted through the four insertion holes 28 located on the rear side of each drum support hole 27.

Each positioning hole 130 is positioned so as to overlap with a positioning boss of the side plate 22, and the positioning boss is inserted through it. The front positioning hole 130 is an elongated hole extending in the left-right direction, and the rear positioning hole 130 is generally circular in side view.

The front beam 24 and rear beam 25 are made of hard resin or the like, and both ends of the beams are fixed to the support plate 23 by screws or the like.

As shown in Figures 1 and 2, the drum unit 26 located at the frontmost side in the front-to-rear direction includes a photosensitive drum 3, a charger 4, a cleaning roller 32, and a cleaning shaft 36. The three drum units 26 located at the rear side also include a photosensitive drum 3, a charger 4, and a cleaning roller 32.

[Configuration of roller input electrode 43]
The configuration of the roller input electrode 43 will be described in detail with reference to Figures 2, 3, 5, 6 and 9. Figure 5 is an enlarged view of the XA portion shown in Figure 3. Figure 6 is a view of the portion corresponding to Figure 5 as seen from the inside. Figure 9 (A) is a perspective view of the portion corresponding to Figure 6 as seen from an oblique front, and (B) is a schematic view showing the state in which the side plate 22 has been removed from (A).

The roller input electrode 43 is an electrode for inputting the power supplied from the main body electrode 48 to the cleaning roller electrode 33. As shown in FIG. 2, FIG. 3, FIG. 5, FIG. 6, and FIG. 9, the roller input electrode 43 has a substantially rectangular roller power supply portion 43B arranged on the inner surface in the left-right direction of the side plate 22. The roller input electrode 43 is an example of a first input electrode. The roller power supply portion 43B is arranged facing the compression coil spring 39 of the cleaning roller electrode 33 that is electrically connected to the right end of the rotation shaft 34 of the cleaning roller 32 that is the frontmost side in the front-rear direction. The roller power supply portion 43B contacts the right end of the compression coil spring 39 and supplies power to the cleaning roller electrode 33 via the compression coil spring 39. The rotation shaft 34, the cleaning roller electrode 33, and the compression coil spring 39 will be described in detail later.

As shown in FIG. 9B, the roller input electrode 43 has a roller extension portion 43C that extends from the rear edge of the roller power supply portion 43B at a substantially right angle to the outside of the side plate 22 in the left-right direction. The roller extension portion 43C is an example of a first extension portion. The roller power receiving portion 43A extends from the outer edge of the roller extension portion 43C in the left-right direction along the outer surface of the side plate 22, and receives power from the main body side electrode 48 shown in FIG. 2. When the process unit 16 is attached to the main body casing 2, the roller power receiving portion 43A comes into contact with the main body side electrode 48.

The side plate 22 has a slit 51 formed at a position facing the rear edge of the roller power supply unit 43B, through which the roller extension unit 43C and the roller power receiving unit 43A can be inserted. The slit 51 is an example of a first slit. The roller input electrode 43 is attached to the side plate 22 with the roller extension unit 43C and the roller power receiving unit 43A inserted through the slit 51. The roller input electrode 43 is bent from the inside of the side plate 22 along the slit 51 of the side plate 22, and the roller power receiving unit 43A, which is located outside the side plate 22 from the slit 51, is further bent along the outer surface of the side plate 22.

[Configuration of shaft input electrode 46]
The configuration of the shaft input electrode 46 will be described in detail with reference to Figs. 2, 3, 5, 6 and 9. The shaft input electrode 46 is an electrode for inputting the power supplied from the main body electrode 49 to the cleaning shaft 36. As shown in Figs. 2, 3, 5, 6 and 9, the shaft input electrode 46 has a shaft power supply portion 46B arranged on the inner surface in the left-right direction of the side plate 22 below and behind the roller power supply portion 43B. The shaft power supply portion 46B is a substantially rectangular shape extending in the front-rear direction and the up-down direction. The shaft input electrode 46 is an example of a second input electrode. The shaft power supply portion 46B is arranged facing the compression coil spring 363 of the cleaning shaft electrode 361 electrically connected to the right end of the rotation shaft 364 of the cleaning shaft 36, and supplies power to the cleaning shaft electrode 361. The rotation shaft 364, the cleaning shaft electrode 361 and the compression coil spring 363 will be described in detail later.

As shown in FIG. 9B, the shaft input electrode 46 has a shaft extension portion 46C that extends from the rear edge of the shaft power supply portion 46B at a substantially right angle to the outside of the side plate 22 in the left-right direction. The shaft extension portion 46C is an example of a second extension portion. The shaft power receiving portion 46A extends from the outer edge of the shaft extension portion 46C in the left-right direction along the outer surface of the side plate 22 and receives power from the main body electrode 49. When the process unit 16 is attached to the main body casing 2, the shaft power receiving portion 46A comes into contact with the main body electrode 49.

The side plate 22 is also formed with a slit 53 at a position facing the lower edge of the shaft power supply unit 46B, through which the shaft extension 46C and the shaft power receiving unit 46A can be inserted. The slit 53 is an example of a second slit. The shaft input electrode 46 is attached to the side plate 22 with the shaft extension 46C and the shaft power receiving unit 46A inserted into the slit 53. The shaft input electrode 46 is bent from the inside of the side plate 22 along the slit 53 of the side plate 22, and the shaft power receiving unit 46A, which is located outside the side plate 22 from the slit 53, is further bent along the outer surface of the side plate 22.

[Configuration of relay electrode 45]
The configuration of the relay electrode 45 will be described in detail with reference to Figs. 3, 5 and 6. The relay electrode 45 is an electrode for distributing the power supplied from the main body electrode 48 to the roller input electrode 43 to the three rear cleaning roller electrodes 33. The relay electrode 45 is a metal conductor. As shown in Figs. 3, 5 and 6, the front end of the relay electrode 45 is inserted into a rectangular through hole 55 formed in the side plate 22, and is bent at a right angle diagonally downward toward the front along the inner surface of the side plate 22. The front end of the relay electrode 45 is sandwiched between the roller power supply unit 43B and the inner surface of the side plate 22, and is electrically connected to the roller power supply unit 43B.

Specifically, the roller power supply unit 43B has a slit located in the center and a pressing portion 57 surrounded by the slit. As shown in FIG. 6, the slit penetrates the roller power supply unit 43B in a U-shape when viewed from the front. The pressing portion 57 is bent outward in the left-right direction at a small bending angle, for example, about 15 degrees to 30 degrees. The front end of the relay electrode 45 is pressed against the inner surface of the side plate 22 by the pressing portion 57 of the roller power supply unit 43B. The relay electrode 45 is electrically connected to the roller power supply unit 43B by the front end coming into contact with the pressing portion 57 of the roller power supply unit 43B.

The relay electrode 45 is also fitted into the groove 61. As a result, the relay electrode 45 is arranged on the outer surface in the left-right direction of the side plate 22 while being fitted and accommodated in the groove 61. By arranging the relay electrode 45 in the groove 61 in this way, it comes into contact with the compression coil spring 39 of the cleaning roller electrode 33 so as to compress it to the left. As a result, the relay electrode 45 is electrically connected to the right ends of the rotation shafts 34 of the three rear cleaning rollers 32 via each cleaning roller electrode 33.

[Configuration of cleaning roller electrode 33]
The configuration of each cleaning roller electrode 33 will be described in detail with reference to Fig. 7. Fig. 7 is a cross-sectional view taken along the line X1-X1 in Fig. 5. The cleaning roller electrode 33 is an electrode for applying a voltage to the cleaning roller 32. The cleaning roller electrode 33 is composed of a contact electrode 38 made of conductive resin and a compression coil spring 39 made of metal.

The abutment electrode 38 is generally cylindrical and consists of a head 38A and a shaft 38B with a diameter shorter than that of the head 38A, with an axial cross section formed in a generally T-shape. The abutment electrode 38 is arranged in the left-right direction so that the head 38A abuts against the right end surface of the rotating shaft 34 of the cleaning roller 32. The abutment electrode 38 is supported by a support member 41, the head 38A of which is inserted into the insertion hole 28 of the support plate 23, so that it can slide left-right. The tip of the head 38A of the abutment electrode 38 is formed into a spherical shape.

The compression coil spring 39 is formed to have a diameter longer than the diameter of the shaft portion 38B of the contact electrode 38, and is inserted into the shaft portion 38B of the contact electrode 38 so as to be expandable and contractible. The compression coil spring 39 inserted into the shaft portion 38B is pressed toward the cleaning roller 32 by the roller input electrode 43 arranged on the inner surface of the side plate 22. More specifically, it is pressed toward the cleaning roller 32 by the roller power supply unit 43B. As a result, the head portion 38A of the contact electrode 38 is abutted against the right end surface of the rotating shaft 34 of the cleaning roller 32, and the cleaning roller 32 on the front-to-rear direction can be electrically connected to the roller input electrode 43. Alternatively, the relay electrode 45 is abutted against the roller input electrode 43 on the inner surface of the side plate 22, and is arranged at a position where it can be electrically connected. As a result, the relay electrode 45 can be electrically connected to the right end of the rotating shaft 34 of the three rear cleaning rollers 32 via each cleaning roller electrode 33.

[Configuration of cleaning shaft electrode 361]
The configuration of the cleaning shaft electrode 361 will be described in detail with reference to Fig. 8. Fig. 8 is a cross-sectional view taken along the line X2-X2 of Fig. 5. The cleaning shaft electrode 361 is an electrode for applying a voltage to the cleaning shaft 36. The cleaning shaft electrode 361 is composed of a contact electrode 362 made of conductive resin and a compression coil spring 363 made of metal.

The abutment electrode 362 is generally cylindrical and consists of a head 362A and a shaft 362B with a diameter shorter than that of the head 362A, with an axial cross section formed in a generally T-shape. The abutment electrode 362 is arranged in the left-right direction so that the head 362A abuts against the right end surface of the rotating shaft 364 of the cleaning shaft 36. The abutment electrode 362 is supported by a support member 365, the head 362A of which is inserted into the insertion hole 231 of the support plate 23 so that it can slide left-right. The tip of the head 362A of the abutment electrode 362 is formed in a spherical shape.

The compression coil spring 363 is formed to have a diameter greater than the diameter of the shaft portion 362B of the contact electrode 362, and is inserted into the shaft portion 362B of the contact electrode 362 so as to be expandable and contractible. The compression coil spring 363 inserted into the shaft portion 362B is pressed toward the cleaning shaft 36 by the shaft input electrode 46 arranged on the inner surface of the side plate 22. More specifically, it is pressed toward the cleaning shaft 36 by the shaft power supply portion 46B. As a result, the head portion 362A of the contact electrode 362 is pressed against the right end surface of the rotating shaft 364 of the cleaning shaft 36, and the cleaning shaft 36 and the shaft input electrode 46 can be electrically connected.

[Regarding the arrangement of the roller input electrode 43 and the shaft input electrode 46]
The arrangement of the roller input electrode 43 and the shaft input electrode 46 will be described in detail with reference to FIGS.

As shown in Figure 5, the roller input electrode 43 and the shaft input electrode 46 are arranged in a position where they partially overlap with the side plate 22 in between when the side plate 22 is viewed from the outer surface side in the axial direction of the cleaning shaft 36. In Figure 5, the roller power receiving portion 43A of the roller input electrode 43 that is exposed and arranged on the outer surface side of the side plate 22 is shown by a solid line. Also, the roller power supply portion 43B of the roller input electrode 43 that is arranged on the inner surface side of the side plate 22 is shown by a dashed line.

The shaft power receiving portion 46A of the shaft input electrode 46 is exposed on the outer surface of the side plate 22 and is shown by a solid line. The portion of the shaft input electrode 46 other than the shaft power receiving portion 46A that is located on the inner surface of the side plate 22 is shown by a dashed line. The portion other than the shaft power receiving portion 46A shown by the dashed line includes the shaft power supply portion 46B. In other words, when the side plate 22 is viewed from the outer surface side, the shaft power supply portion 46B is located at a position where it overlaps with the roller input electrode 43, sandwiching the side plate 22. More specifically, as shown in FIG. 5 and FIG. 9A, when the side plate 22 is viewed from the outer surface side in the axial direction of the cleaning shaft 36, the roller power receiving portion 43A and the shaft power supply portion 46B are located at a position where they overlap with the side plate 22.

When the side plate 22 is viewed from the outside in the axial direction, the roller power receiving portion 43A and the shaft power receiving portion 46A are disposed at positions spaced a predetermined distance apart in the front-to-rear direction. The predetermined distance may be set appropriately depending on the sizes of the side plate 22, the roller power receiving portion 43A, and the shaft power receiving portion 46A, but it is preferable that the distance be set to a distance that does not cause proximity discharge between the roller power receiving portion 43A and the shaft power receiving portion 46A.

The thickness of the side plate 22 at the portion sandwiched between the roller power receiving part 43A and the shaft power supply part 46B shown in FIG. 9A is preferably about 1.7 mm to 2 mm. By making the thickness of the side plate 22 at the portion sandwiched between the roller power receiving part 43A and the shaft power supply part 46B 1.7 mm to 2 mm, it is possible to prevent discharge from occurring between the roller power receiving part 43A and the shaft power supply part 46B. The thickness of the side plate 22 at the portion sandwiched between the roller power receiving part 43A and the shaft power supply part 46B is appropriately designed depending on the voltage value applied to the roller input electrode 43 and the shaft input electrode 46.

[Regarding toner and paper dust collection]
Here, the recovery of toner and the recovery of paper dust and the like will be described. It is known that toner and paper dust and the like have different charge polarities. For example, when the toner is positive, for example, the paper dust and the like adhering to the paper S tends to be negatively charged because a voltage is applied to the transfer roller 12 to provide a transfer bias of the opposite polarity to the charge polarity of the toner. Therefore, voltages of different charge polarities are applied to the roller input electrode 43 and the shaft input electrode 46, respectively, so that the toner and paper dust are removed from the surface of the photosensitive drum 3 by utilizing the difference in charge polarity. Each of these will be described below.

When collecting toner, for example, if the toner polarity is positive, a negative voltage, which is the opposite polarity to the toner polarity, is applied to the roller input electrode 43 via the main body side electrode 48 during printing. The negative voltage is an example of a first voltage, for example -400V. By applying a negative voltage to the roller input electrode 43 via the main body side electrode 48 during printing, positive toner is collected from the surface of the photosensitive drum 3 onto the cleaning roller 32. The "toner polarity" is an example of the first charging polarity. Also, the "negative voltage, which is the opposite polarity to the toner polarity" is an example of the first voltage.

When collecting paper dust, a positive voltage is applied to the cleaning roller 32 and the cleaning shaft 36, and the paper dust adhering to the surface of the paper S is electrostatically attracted to the cleaning roller 32 by the electrostatic attraction force generated between the cleaning roller 32 and the paper dust. As a result, the paper dust is collected by the cleaning shaft 36 via the cleaning roller 32.

At this time, the absolute value of the positive voltage applied to the shaft input electrode 46 via the body side electrode 49 is controlled to be greater than the absolute value of the positive voltage applied to the roller input electrode 43 via the body side electrode 48. For example, the positive voltage applied to the roller input electrode 43 via the body side electrode 48 is +600 V. The positive voltage applied to the shaft input electrode 46 via the body side electrode 49 is an example of a second voltage, for example, +700 V. As a result, paper powder and the like electrostatically attracted to the cleaning roller 32 is moved to the cleaning shaft 36 by electrostatic attraction and collected from the cleaning roller 32.

As described above, the voltages that are set appropriately are applied when collecting toner and when collecting paper dust and the like. It is preferable that the withstand voltage of the side plate 22 in the portion sandwiched between the roller power receiving portion 43A and the shaft power supply portion 46B is designed to exceed the difference between the first voltage and the second voltage. In other words, in one example of the present disclosure, it is preferable that it is designed to exceed the difference between -400V and +700V.

[Assembly of side plate 22 to frame 21]
2 to 5, the assembly of the side plate 22 to the frame 21 will be described. To assemble the side plate 22 to the frame 21, an operator inserts the front end of the relay electrode 45 shown in Figs. 3 and 5 into the through hole 55 of the side plate 22, and then fits it into a groove 61 formed on the outer surface of the side plate 22 in the left-right direction. Next, the operator inserts the roller extension 43C and the roller power receiving part 43A of the roller input electrode 43 into the slit 51 of the side plate 22, and attaches the side plate 22 so that the roller power supply part 43B presses the front end of the relay electrode 45 against the inner surface of the side plate 22.

The worker also inserts the shaft extension 46C and shaft power receiving portion 46A of the shaft input electrode 46 into the slit 53, and attaches the shaft power supply portion 46B so that it is positioned diagonally below and behind the roller power supply portion 43B. This attaches the roller input electrode 43, shaft input electrode 46, and relay electrode 45 to the side plate 22.

Then, the worker inserts the positioning bosses provided on the side plate 22 into the positioning holes 130 of the support plate 23 shown in FIG. 4, and assembles the side plate 22 to the frame body 21 from the right side so as to position the side plate 22 relative to the frame body 21. The positioning bosses only need to be formed in positions corresponding to the positioning holes 130, and only need to be formed in optimal locations according to the design of the side plate 22. The side plate 22 is fixed to the frame body 21 by screws or the like. After that, the worker attaches the film 47 shown in FIG. 2 to the outer surface of the side plate 22, and exposes the roller power receiving portion 43A of the roller input electrode 43 and the shaft power receiving portion 46A of the shaft input electrode 46 from the opening 47A.

As described above, when the side plate 22 is assembled to the frame 21, the roller power supply 43B of the roller input electrode 43 is positioned so that it can be electrically connected to the cleaning roller electrode 33 of the cleaning roller 32 that is the frontmost in the front-to-rear direction. In addition, the shaft power supply 46B of the shaft input electrode 46 is positioned so that it can be electrically connected to the cleaning shaft electrode 361 of the cleaning shaft 36.

In addition, the relay electrode 45 arranged on the outer surface of the side plate 22 in the left-right direction comes into contact with the compression coil springs 39 of the three rear cleaning roller electrodes 33 in the left-right direction. As a result, the roller input electrode 43 and the relay electrode 45 position each cleaning roller electrode 33 so that it can be electrically connected to the right end of the four cleaning rollers 32.

[Power supply to process unit 16]
To supply power to the process unit 16, first, the front cover 2A of the main body casing 2 is opened, and the process unit 16 is moved from the front to the rear to be attached to the main body casing 2. As a result, as shown in Fig. 2, the roller power receiving portion 43A of the roller input electrode 43 comes into contact with the main body electrode 48, and the shaft power receiving portion 46A of the shaft input electrode 46 comes into contact with the main body electrode 49. When power is input to the image forming apparatus 1 with the roller power receiving portion 43A and the shaft power receiving portion 46A in contact with the main body electrodes 48, 49, respectively, power is input to the roller power receiving portion 43A and the shaft power receiving portion 46A via the main body electrodes 48, 49.

As a result, power is input from the roller power supply 43B of the roller input electrode 43 to the right end of the rotation shaft 34 of the cleaning roller 32 located at the rearmost position via the cleaning roller electrode 33. Also, power is input to the right end of the cleaning shaft 36 via the shaft power supply 46B of the shaft input electrode 46.

The power input to the roller power receiving section 43A of the roller input electrode 43 is distributed to the relay electrode 45 via the roller power supply section 43B. The power distributed to the relay electrode 45 is distributed to the three rear cleaning roller electrodes 33 that are in contact with the relay electrode 45. The power distributed to the three rear cleaning roller electrodes 33 is distributed to the rotation shafts 34 of the cleaning rollers 32 that correspond to each cleaning roller electrode 33.

As a result, the power input from the main body side electrode 48 of the main body casing 2 to the roller input electrode 43 is distributed to the rotating shaft 34 of each cleaning roller 32 via the roller input electrode 43 and the relay electrode 45.

[Action and Effect]
As described above in detail, according to the process unit 16 according to this embodiment, the side plate 22 is sandwiched between the roller input electrode 43 and the shaft input electrode 46. Furthermore, the roller input electrode 43 and the shaft input electrode 46 are disposed at positions where they at least partially overlap with each other with the side plate 22 in between.

In addition, with the above configuration, the roller input electrode 43 and the shaft power supply unit 46B are positioned so that they overlap with the side plate 22 in between.

In addition, with the above configuration, the roller power receiving part 43A and the shaft power supply part 46B are positioned so that they overlap with the side plate 22 in between.

This allows the distance between the roller input electrode 43 and the shaft input electrode 46 to be reduced compared to conventional techniques, making it possible to miniaturize an image forming device equipped with a cleaning roller and cleaning shaft.

In addition, with the above configuration, the roller power receiving part 43A and the shaft power receiving part 46A are positioned at a predetermined distance in the front-rear direction when the side plate 22 is viewed from the outside in the axial direction. This makes it possible to prevent discharge from occurring between the roller power receiving part 43A and the shaft power receiving part 46A, which are located on the outside of the side plate 22.

Furthermore, according to the above configuration, the roller input electrode 43 and the shaft input electrode 46 are in contact in the first direction with the roller power receiving portion 43A arranged on the outer surface of the side plate 22 and the main body side electrode 48. Also, the shaft power receiving portion 46A arranged on the outer surface of the side plate 22 is in contact with the main body side electrode 49 in the first direction. As a result, by mounting the process unit 16 to the main body casing 2, the roller power receiving portion 43A and the shaft power receiving portion 46A can be electrically connected to each of the main body side electrodes 48, 49.

In addition, according to the above configuration, a voltage of the opposite polarity to the toner remaining on the photosensitive drum 3, for example a negative voltage, is applied to the roller power receiving section 43A via the main body side electrode 48. A positive voltage is applied to the shaft power receiving section 46A via the main body side electrode 49. Furthermore, the side plate 22 is configured so that the withstand voltage of a portion of the side plate 22 exceeds the difference between the voltage applied to the roller power receiving section 43A and the voltage applied to the shaft power receiving section 46A when viewed from the outer surface side. As a result, the portion of the side plate 22 where the roller input electrode 43 and the shaft input electrode 46 overlap when viewed from the outer surface side has a withstand voltage that exceeds the voltage difference between the voltages applied to the roller input electrode 43 and the shaft input electrode 46, respectively. Therefore, discharge between the roller input electrode 43 and the shaft input electrode 46 can be prevented.

In addition, with the above configuration, the roller input electrode 43 can be attached by inserting it through the slit 51 in the side plate 22. Also, the shaft input electrode 46 can be attached by inserting it through the slit 53 in the side plate 22, which makes the installation work more efficient.

In addition, with the above configuration, since the side plate 22 is made of insulating resin, it is possible to prevent discharge between the relay electrode 45 and multiple electronic components for operating the process unit that are arranged on the inside in the axial direction across the side plate 22. As a result, it is possible to arrange the relay electrode 45 and multiple electronic components in a small space.

REFERENCE SIGNS LIST 1 Image forming apparatus, 2 Main casing, 3 Photosensitive drum, 16 Process unit, 17 Ground shaft, 21 Frame, 22 Side plate, 23 Support plate, 32 Cleaning roller, 33 Cleaning roller electrode, 43 Roller input electrode (first input electrode), 43A Roller power receiving portion, 43B Roller power supply portion, 43C Roller extension portion, 45 Relay electrode, 46 Shaft input electrode (second input electrode), 46A Shaft power receiving portion, 46B Shaft power supply portion, 46C Shaft extension portion, 47 Film, 47A Opening, 48, 49 Main body side electrode, 51, 53 Slit

Claims (8)

a photosensitive drum rotatable about a first rotation axis extending in a first direction;
a cleaning roller that contacts the surface of the photosensitive drum;
a cleaning shaft in contact with the surface of the cleaning roller;
a frame that is located at an end of the photosensitive drum in the first direction and that has a support plate that supports the cleaning roller and a side plate that is located outside the support plate in the first direction;
a cleaning roller electrode provided at one end of the cleaning roller in the first direction, electrically connected to the one end of the cleaning roller in the first direction, and positioned inside the side plate in the first direction;
a cleaning shaft electrode provided at one end of the cleaning shaft in the first direction, electrically connected to the one end of the cleaning shaft in the first direction, and positioned inside the side plate in the first direction;
a first input electrode attached to the side plate and having a roller power receiving portion located on an outer side of the side plate in the first direction and a roller power supplying portion located on an inner side of the side plate in the first direction and supplying power to the cleaning roller electrode;
a second input electrode attached to the side plate, the second input electrode having a shaft power receiving portion located on an outer side of the side plate in the first direction, and a shaft power supplying portion located on an inner side of the side plate in the first direction and supplying power to the cleaning shaft electrode;
Equipped with
a process unit characterized in that, when viewed from the outside of the side plate in the first direction, the first input electrode and the second input electrode are arranged in a position where they at least partially overlap with each other across the side plate. The process unit according to claim 1, characterized in that the first input electrode and the shaft power supply part are arranged in a position where they overlap with each other across the side plate when viewed from the outside of the side plate in the first direction. The process unit according to claim 1, characterized in that the first input electrode and the second input electrode are arranged at a position where the roller power receiving part and the shaft power supply part overlap with each other across the side plate when viewed from the outside of the side plate in the first direction. The process unit according to claim 1, characterized in that, when viewed from the outside of the side plate in the first direction, the roller power receiving portion and the shaft power receiving portion are spaced apart in the second direction. The process unit according to claim 1, characterized in that the roller power receiving portion and the shaft power receiving portion contact a body side electrode provided on the device body of the image forming device in the first direction when the process unit is attached to the image forming device to which the process unit is attached. a first voltage having a polarity opposite to a first charging polarity of the developer remaining on the photosensitive drum is applied from the main body electrode to the roller power receiving portion;
a second voltage having a second polarity opposite to the first polarity is applied from the main body electrode to the shaft power receiving portion;
6. The process unit according to claim 5, wherein a withstand voltage of a portion of the side plate exceeds a difference between the first voltage and the second voltage. The first input electrode is
a first extension portion extending from an edge of the roller power supply portion to an outside of the side plate in the first direction,
The second input electrode is
a second extension portion extending from an end edge of the shaft power supply portion to an outside of the side plate in the first direction,
The side plate is
a first slit through which the first extension portion and the roller power receiving portion can be inserted;
The process unit according to claim 1 , further comprising a second slit through which the second extension and the shaft power receiving portion can be inserted. 2. The process unit according to claim 1, wherein the side plate is made of an insulating resin.

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