JP2006267399A - Charging roller estrangement member, integrated type process cartridge and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent generation of an image failure such as density unevenness resulting from deformation of a charging roller when a user starts using in an integrated type process cartridge even if the cartridge is left under any kind of state (length of unattended time and unattended environment). <P>SOLUTION: In the integrated type process cartridge integrally storing: at least a photoreceptor drum; a development sleeve; and the charging roller in a casing and bringing the charging roller into press contact with the photoreceptor drum by an elastic member, a charging roller estrangement member molded by resin for estranging the charging roller to the photoreceptor drum is constituted so as to be freely attachable/detachable to/from the integrated type process cartridge. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a separation member for a charging roller that is provided to prevent deformation of a charging roller that is in urging contact with a photosensitive drum in an integrated process cartridge.

  Conventionally, in an integrated process cartridge in which a photosensitive drum, a developing device, a charging roller, a cleaning device, and the like are housed in one package, in particular, from the manufacture of the integrated process cartridge to the start of use by the user. There was no separation member for separating the charging roller biased against the photosensitive drum from the photosensitive drum.

  As such an integrated process cartridge, for example, an integrated process cartridge described in Non-Patent Document 1 has been proposed.

  Hereinafter, a schematic overall configuration of an integrated process cartridge 500 conventionally proposed will be described with reference to FIG.

  In FIG. 10, reference numeral 501 denotes a photosensitive drum, 502 denotes a developing roller having an elastic layer, and 502A denotes a supply roller for supplying toner to the developing roller 502. Reference numeral 503 denotes a charging roller having an elastic layer, and reference numeral 504 denotes a compression coil spring for biasing the charging roller 503 against the photosensitive drum 501. Reference numeral 505 denotes a hopper chamber in which toner is stored, and has a stirring blade 506. Reference numeral 507 denotes a cleaning blade for removing residual toner on the surface of the photosensitive drum 501 after transfer to an intermediate transfer member (not shown) or a sheet material (not shown).

  Further, 510 as a casing for storing the above-described parts is a lower container and 511 is an upper container. A holding part for moving the integrated process cartridge 500 is a handle part 516. Since it is not directly related to the present invention, description of the process operation (image forming operation) of the integrated process cartridge 500 is omitted.

Canon Inc. Hybrid Laser Printer Catalog 2002.9P. 6 JP 2001-201915 A

  However, in the above-described conventional integrated process cartridge 500, the charging roller 503 is always urged to the photosensitive drum 501 by the compression coil spring 504 until the user starts using the integrated process cartridge 500 after the manufacture. Therefore, the elastic layer of the charging roller 503 may be deformed into the shape of the curvature of the surface of the photosensitive drum 501 depending on the leaving period and the leaving environment (generally, the leaving environment in which high temperature / high humidity is severe). Arise. When an image forming apparatus is used to form an image with the integrated process cartridge 500 having the charging roller 503 having such a deformation, the image output to the sheet material has a charging roller 503 pitch (in this conventional example, a pitch of about 44 mm). ) Density unevenness occurs, and the image quality of the output is greatly reduced.

  The present invention has been made in view of the above-described problems, and the intended process is that the user can start using the integrated process cartridge in any leaving state (leaving period length and leaving environment). The object is to prevent image defects such as density unevenness due to deformation of the charging roller.

  In order to achieve the above object, the present invention is an integrated process cartridge in which at least a photosensitive drum, a developing sleeve, and a charging roller are integrally housed in a casing, and the charging roller is attached to the photosensitive drum by an elastic member. In the integrated process cartridge that is in urging contact, a resin-molded charging roller separation member that allows the charging roller to be separated from the photosensitive drum is configured to be detachable from the integrated process cartridge. And

  In the integrated process cartridge of the present invention, the charging roller separation member for separating the photosensitive drum and the charging roller is detachable without disassembly of the integrated process cartridge. The charging roller separating member can be easily mounted in the final packing process of the manufacturing process. This prevents deformation of the charging roller that may occur due to the urging contact between the photosensitive drum and the charging roller, particularly after the integrated process cartridge is manufactured and before the user actually starts using the integrated process cartridge. be able to.

  As a result, it is possible to prevent the occurrence of image defects such as density unevenness due to deformation of the charging roller at the start of use by the user regardless of the neglected state (leaving period length and leaving environment). It becomes possible.

  Even when the user temporarily stops using the image forming apparatus after starting to use the integrated process cartridge, the charging roller separating member can be easily attached to the integrated process cartridge removed from the image forming apparatus. It can be attached and has the same effect as described above.

  Further, as an additional effect, the charging roller separating member of the present invention does not contact the surface of the photosensitive drum during attachment / detachment, thereby preventing the occurrence of rubbing scratches that may occur on the surface of the photosensitive drum during attachment / detachment. be able to.

  Embodiments of the present invention will be described with reference to FIGS.

  As an order of explanation, an outline description of the integrated process cartridge of the present invention, a description of the shape and operation method of the charging roller separating member of the present invention, and then the detachable integrated process cartridge of the present invention is detachable. An overall configuration of a simple image forming apparatus (color printer) will be described.

<Embodiment 1>
FIG. 1 is a schematic cross-sectional view showing the overall configuration of an integrated process cartridge 100 (hereinafter abbreviated as cartridge 100) according to an embodiment of the present invention. Hereinafter, each part will be described in the order of the symbols.

  101 is a photosensitive drum, 102 is a developing sleeve having a magnet roller therein, 103 is a charging roller, 104 is a cleaning blade formed of rubber formulated in a predetermined composition, and 105 is a support plate for supporting the cleaning blade 104 It is. Reference numeral 106 denotes a compression coil spring for urging the charging roller 103 to the photosensitive drum 101 with a predetermined force, and a load is applied to the charging roller 103 via bearings (not shown) provided at both ends of the charging roller 103. ing.

  Reference numeral 107 denotes a developing screw for supplying toner onto the developing sleeve 102, and reference numeral 108 denotes a toner supplied from a developer 112 and a toner supply unit provided outside the cartridge 100 (not shown because it is not directly related to the present invention). It is a stirring screw for mixing.

  Here, the developer 112 refers to a two-component developer composed of toner and carrier, or only a carrier.

  In the cartridge 100, the toner is replenished in a direction indicated by an arrow t from a replenishing port 109 provided on the container 111, and is transferred to the developing screw 107 while being mixed with the developer 112 by the stirring screw 108.

  Reference numeral 110 denotes a container under which the above-described parts are integrally stored. Reference numeral 111 denotes a container serving as a cover member that covers the upper surface of the cartridge 100. In the drawing, a cleaner unit for transporting the waste toner removed from the surface of the photosensitive drum 101 by the cleaning blade 104 to the outside of the cartridge 100 is not shown.

  The magnetized toner is pulled from the developing screw 107 onto the developing sleeve 102, and after the toner amount on the developing sleeve 102 is adjusted to a predetermined amount by the developing blade 106, the latent toner on the photosensitive drum 101 that rotates counterclockwise is used. It is drawn to the statue. After the toner image is transferred to a transfer portion (not shown because it is not directly related to the present invention), the transfer drum residual toner (= waste toner) on the surface of the photosensitive drum 101 is removed by the cleaner blade 104. Prepare for imaging.

  The above is the overall description of the cartridge 100 according to the present invention. Next, the charging roller separation member will be described.

  Reference numeral 120 denotes a charging roller separation member (hereinafter simply referred to as a separation member) for separating the charging roller 103 from the surface of the photosensitive drum 101. The spacing member 120 is substantially Y-shaped as shown in the figure, and 120a is a lower arm and 120b is an upper arm. As shown in the figure, the photosensitive drum 101 and the charging roller 103 can have a clearance 121 by mounting the separation member 120.

  Next, detailed description will be given of the arrangement state and mounting method of the separation member 120 according to the present invention with reference to FIGS.

  2 is a main part perspective view showing a state where the separation member 120 is mounted, FIG. 3 is an enlarged view showing the separation member 120, and FIG.

  The arrangement position of the separation member 120 in the cartridge 100 will be further described with reference to FIG.

  As shown in FIG. 2, the separation member 120 is mounted on the back side of the cartridge 100 (lower side in the figure), and the lower arm 120a side is locked to a concave locking portion 110b provided in the container lower 110, The upper arm 120 b side is locked and fixed to the metal shaft portion 103 a of the charging roller 103.

  Here, the upper arm 120b is inserted into the opening 110a provided in the lower container 110 to lock the shaft portion 103a. The opening 110a will be described later. In addition, a separation member 120 is also provided on the side of the cartridge 100 opposite to the main drawing in the same configuration.

  FIG. 3 shows the spacing member 120. In addition to the lower arm 120a and the upper arm 120b described above, the spacing member 120 includes a handle portion 120c that is held when a user or the like attaches or detaches, a hook portion 120d that is locked to the locking portion 110b, and a hook that is locked to the shaft portion 103a. A stop arc 120e is provided. Here, the curvature r of the locking arc 120e is the same as that of the shaft portion 103a. Further, the opening angle between the lower arm 120a and the upper arm 120b when the separation member 120 is in a natural state (= not mounted) is defined as θ.

  Subsequently, a mounting method of the separation member 120 will be described with reference to FIGS.

  When the separation member 120 is mounted, the handle 120c is held, and the hook 120d is pivoted in the direction s in FIG. At this time, the upper arm 120b is inserted into the opening 110a provided in the lower container 110, and when the rotation in the s direction is advanced, the locking arc 120e comes into contact with the shaft 103a. When the spacing member 120 is further rotated in the s direction after the contact, the upper arm 120b is bent about the fulcrum 120f in the u direction in FIG. Lock to. At this time, the lower arm 120a side is also slightly bent in the u direction in FIG. Since the spacing member 120 is formed of a resin material (preferably polyacetal resin (POM)), the above-described bending in the u and v directions can be allowed.

  After the separation member 120 is mounted on the cartridge 100, the opening angle θ ′ of the lower arm 120a and the upper arm 120b is θ ′> θ. That is, the opening angle θ between the lower arm 120a and the upper arm 120b in the natural state is set so that this relationship is established, and a restoring force for elastic deformation of the lower arm 120a and the upper arm 120b is generated. . Accordingly, when the separation member 120 is mounted, the arm 120a and the upper arm 120b try to return to the opening angle θ, and therefore the charging roller 103 is moved in the i direction in FIG. 4 by the clamping force f by the arm 120a and the upper arm 120b shown in FIG. And is separated from the surface of the photosensitive drum 101, and a clearance 121 is maintained between them.

  Here, the detailed shapes (= cross-sectional shapes) of the lower arm 120a and the upper arm 120b may be set according to the compression force of the compression coil spring 106, the own weight of the charging roller 103, and the direction of the gravity line thereof. In this embodiment, θ is set to 35 °, and the cross-sectional shape of the lower arm 120a and the upper arm 120b is a square cross-sectional shape of 4.5 mm × 2.5 mm.

  FIG. 5 is a main part perspective view showing a state in which the separation member 120 is removed from the lower side of the cartridge 100 in order to show the state.

  As shown in FIG. 5, an opening 110 a is provided in the lower container 110. The opening 110a is provided under the container 110 so that the shaft 103a is positioned inside the opening as shown in the figure. In addition, with the same structure, the opening part 110a is provided also in the axial part 103a position on the opposite side to illustration (the opening part 110a is provided in two places of right and left both ends).

  Next, a schematic overall configuration of an image forming apparatus (here, a color printer) to which the cartridge 100 of the present invention is mounted will be described with reference to FIG. Hereinafter, description will be made along the flow of conveyance of the sheet S in the apparatus.

  At the bottom of the image forming apparatus 10, a sheet feeding unit 20 that stores a sheet S as a recording medium and feeds and conveys the sheet S to the image forming unit is provided. The sheets S in the sheet feeding cassette 21 are fed one by one by the sheet feeding roller 22 and conveyed by the feeding roller pair 23 to the registration roller pair 24 along the conveying path. The registration roller pair 24 performs skew correction of the sheet S and synchronization with an image forming unit 30 described later.

  The image forming unit 30 conveys a toner image on the scanning optical device 40 that irradiates the photosensitive drum 101 with an optical image based on image information, a plurality of cartridges 100, and the photosensitive drum 101 along a conveyance path. An intermediate transfer device 50 for conveying the sheet S to the sheet S and a secondary transfer roller pair 60 for transferring a toner image on the intermediate transfer device 50 onto the sheet S.

  The image forming apparatus 10 is provided with a plurality of cartridges 100 for forming a color image. Specifically, four cartridges, a yellow color forming cartridge 100y, a magenta color forming cartridge 100m, a cyan color forming cartridge 100c, and a black color forming cartridge 100b, are provided from the right side in the drawing.

  The toner images on the photosensitive drums 101 of the respective colors are sequentially transferred by applying a voltage to the transfer belt 51 that is supported by a plurality of rollers, so that a full color image is formed on the transfer belt 51. Thereafter, a voltage is applied again on the secondary transfer roller pair 60, and the registration roller pair 24 aligns with the sheet S conveyed in synchronization with the image forming operation, and a full color image on the transfer belt 51 is obtained. Is transferred onto the sheet S.

  Subsequently, the sheet S on which the full-color transfer toner image is formed is conveyed to the fixing device 70. The fixing device 70 includes a driving roller 71 and a heater unit 72 that includes a heater and is covered with a rotatable film, and is transferred by applying heat and pressure to the sheet S when passing through the nip therebetween. Fix a full color toner image. Then, the sheet S is conveyed by the discharge roller pair 73 and discharged from the discharge unit 74 onto the discharge tray 81.

  Here, the overall overall configuration of the color printer has been described as an apparatus to which the image forming apparatus to which the cartridge 100 of the present invention is mounted is mounted, but the present invention is not limited to this apparatus configuration. The present invention can be applied to all apparatuses in which an integrated process cartridge can be mounted, such as a monochrome printer and a multifunction printer (MFP) having a reader function.

  As described above, in the cartridge 100 of the present invention, the separation member 120 for separating the photosensitive drum 101 and the charging roller 103 is configured to be detachable without disassembly of the cartridge 100. The separation member 120 can be easily mounted before the final shipment of the manufacturing process. As a result, in particular, deformation of the charging roller 103 that may occur due to the urging contact between the photosensitive drum 101 and the charging roller 103 after the manufacture of the cartridge 100 and before the user actually starts using the cartridge 100 is prevented. Can be prevented.

  As a result, it is possible to prevent the occurrence of image defects such as density unevenness due to deformation of the charging roller 103 at the start of use by the user regardless of the cartridge 100 in any leaving state (leaving period length and leaving environment). Is possible. Further, even when the user temporarily stops using the image forming apparatus 10 after starting to use the cartridge 100, the separation member 120 can be easily attached to the cartridge 100 removed from the image forming apparatus 10. And has the same effect as described above.

  At this time, the configuration on the side of the image forming apparatus to which the cartridge 100 is mounted does not matter. Further, as an additional effect, the separation member 120 of the present invention does not contact the surface of the photosensitive drum 101 during attachment / detachment. Can be prevented.

<Embodiment 2>
Next, a second embodiment of the present invention will be described with reference to FIGS. This embodiment relates to a charging roller separating member, and the cartridge 100 and the image forming apparatus 10 in this embodiment are the same as those in the first embodiment. Therefore, descriptions of the configurations of the cartridge 100 and the image forming apparatus 10 are omitted. Further, in the following description, the same elements are denoted by the same reference numerals and the description thereof is omitted.

  FIG. 7 is a cross-sectional view of the main part at the separation member mounting position in the present embodiment, FIG. 8 is a perspective view showing the state of FIG. 1, and FIG. 9 shows the separation member in the present embodiment.

  First, an overall outline when the separation member according to the second embodiment is mounted on the cartridge 100 will be described with reference to FIG.

  The separation member 130 has a front arm 130a and a rear arm 130b. As illustrated, the front arm 130 a is engaged with the shaft portion 103 a of the charging roller 103. Further, the rear arm 130 b is locked with a locking portion 110 c provided in the lower container 110. As shown in the figure, the photosensitive drum 101 and the charging roller 103 can have a clearance 121 by mounting the separation member 130. Reference numeral 130 denotes a handle portion that is held when the separation member 130 is attached or detached.

  The arrangement position of the separating member 130 in the cartridge 100 will be further described with reference to FIG.

  As shown in FIG. 8, the separation member 130 is mounted on the back side of the cartridge 100 (the lower side in the figure) as in the first embodiment. When the separation member 130 is mounted, the front arm 130 a side is engaged with the metal shaft portion 103 a of the charging roller 103, and the rear arm 130 b side is provided in the vicinity of the end of the container lower 110 opposite to the photosensitive drum 101. It is locked and fixed to the locking portion 110c.

  Here, the front arm 130a is inserted into an opening 110a provided in the lower container 110, and locks the shaft portion 103a. Note that a separation member 120 is also provided on the side surface of the cartridge 100 opposite to the main drawing in the same configuration.

  FIG. 9 shows the spacing member 130. In addition to the aforementioned front arm 130a, rear arm 130b, and handle portion 130c, the separation member 130 is provided with a hook portion 130d that is locked to the locking portion 110c and a locking arc 130e that is locked to the shaft portion 103a. . Here, the curvature r of the locking arc 130e is the same as that of the shaft portion 103a.

  Subsequently, a mounting method of the separation member 130 will be described with reference to FIGS.

  When mounting the separating member 130, first, the handle portion 130c is held, the front arm 130a is inserted into the opening 110a provided in the lower container 110, and the locking arc 130e is engaged with the shaft portion 103a.

  When attention is paid to the positional relationship between the hook portion 130d and the locking portion 110c provided in the lower container 110, the position α of the hook portion 130d is related to the position β of the locking portion 110c as shown in FIG. The separation member 130 is formed so as to be. Subsequently, in this state, the handle 130c is pulled up in the direction of the arrow w in FIG. Then, since the hook part 130d goes around the upper part in FIG. 7 of the locking part 110c provided in the container lower part 110, the hook part 130d and the locking part 110c are locked when the lifting force in the w direction is released. .

  When the rear arm 130b side is pulled up, the locking arc 130e relatively moves in the direction of the arrow y in FIG. 8, and the compression coil spring 106 is contracted through the shaft portion 103a. Accordingly, the charging roller 103 is pushed down in the i direction in FIG. 7 and is separated from the surface of the photosensitive drum 101, and a clearance 121 is maintained between them.

  Since the separating member 130 is formed of a resin material (preferably polyacetal resin (POM)), it is possible to allow the bending in the above-described w direction. Here, the position α of the hook portion 130d may be set by the center position of the shaft portion 103a and the position β of the locking portion 110c, and in this embodiment, the distance between α and β is set to 10 mm.

  Further, the detailed shape (= cross-sectional shape) of the forearm 130a in which the deformation is suppressed may be set according to the compression force of the compression coil spring 106, the own weight of the charging roller 103, the direction of the gravity line thereof, and the like. Is a square cross-sectional shape of 26 mm × 2.5 mm from the base portion of the front arm 130 a to the sign γ, and a square cross-sectional shape of 5 mm × 2.5 mm on the tip side (locking arc 130 e side) from there. ing.

  As described above, the separation member 130 in the present embodiment functions based on the so-called “principle principle”, and the charging roller 103 can be separated from the photosensitive drum 101 by mounting the separation member 130. Therefore, as in the first embodiment, the charging roller 103 can be prevented from being deformed, thereby preventing image defects.

1 is an overall schematic configuration showing an integrated process cartridge according to Embodiment 1 of the present invention. It is a principal part perspective view which concerns on Embodiment 1 of this invention. It is a charging roller separation member concerning Embodiment 1 of the present invention. It is principal part sectional drawing which concerns on Embodiment 1 of this invention. It is a principal part perspective view which concerns on Embodiment 1 of this invention. 1 is a schematic configuration of an image forming apparatus in which a charging roller separation member and an integrated process cartridge of the present invention can be mounted. It is principal part sectional drawing which concerns on Embodiment 2 of this invention. It is a principal part perspective view figure based on Embodiment 2 of this invention. It is a charging roller separation member concerning Embodiment 2 of the present invention. It is a whole schematic structure which shows the conventional integrated process cartridge.

Explanation of symbols

10 Image forming device (color printer)
DESCRIPTION OF SYMBOLS 100 Integrated process cartridge 101 Photosensitive drum 103 Charging roller 110 Under container 120 Charging roller separation member 130 Charging roller separation member 500 Conventional integrated process cartridge

Claims (8)

An integrated process cartridge in which at least a photosensitive drum, a developing sleeve, and a charging roller are integrally housed in a casing, and the charging roller is urged into contact with the photosensitive drum by an elastic member. In
1. An integrated process cartridge comprising: a resin-molded charging roller separating member that allows the charging roller to be separated from the photosensitive drum, and is detachable from the integrated process cartridge.   2. The integrated process according to claim 1, wherein the integrated process cartridge is provided with openings for attaching and detaching the charging roller separating member at two locations near both ends of the charging roller of the casing. cartridge.   A first arm portion; and a second arm portion, wherein the first arm portion and the second arm portion have a predetermined relative angle, and the first arm portion includes the first arm portion and the second arm portion. A claw shape for locking with a locking portion provided in the casing is formed, and an arc shape for engaging with the shaft portion is formed on the second arm portion. A charging roller separating member.   The charging roller separation member according to claim 3, wherein the charging roller separation member is configured such that the second arm portion can pass through the opening.   The charging roller separation member has a locking portion for engaging with the shaft portion and the casing, one end is formed with an arc shape for engaging with the shaft portion, and the other end is The charging roller separating member according to claim 3, wherein a claw shape for locking to a predetermined portion of the casing is formed.   The charging roller separation member according to claim 5, wherein the charging roller separation member is configured such that the one end can pass through the opening.   The charging roller separation member according to claim 3, wherein the charging roller separation member is formed of polyacetal resin (POM).   An image forming apparatus comprising the integrated process cartridge according to claim 1 detachably and having the charging roller separating member according to claim 3 as a packaging member.

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