JP2007286552A - Removal blade, image forming apparatus, photoreceptor unit and image forming system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a ghost phenomenon and so on, thereby properly preventing deterioration in the image quality of an image formed by an image forming apparatus. <P>SOLUTION: A removal blade is for removing developer from a developer carrying member, the developer having base particle and an external additive agent externally added to the base particle. The removal blade includes: a first abutting part and a second abutting part disposed in the lengthwise direction of the removal blade and abutting on the developer carrying member; and an external additive agent storage part disposed between the first and the second abutting parts and used for storing the external additive agent. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a removal blade, an image forming apparatus, a photoreceptor unit, and an image forming system.

An image forming apparatus that forms an image by developing a latent image using a developer is already well known. Such an image forming apparatus is provided with various developer carrying members for carrying the developer. For example, examples of the developer carrying member include a photosensitive member and an intermediate transfer member serving as an intermediate medium when a developer image on the photosensitive member is transferred to a medium.
Further, the image forming apparatus is provided with a removing blade that contacts the developer carrying member at a contact portion and removes the developer from the developer carrying member.
Japanese Patent Laid-Open No. 9-258632

  By the way, as the developer, a developer having mother particles and an external additive externally added to the mother particles may be used. When the removal blade comes into contact with the developer carrying member carrying the developer at the contact portion to remove the developer, the particle size of the external additive is small. An event occurs in which a part of the external additive of the agent slides through the contact portion. The external additive that has passed through the contact portion causes a so-called ghost (sometimes referred to as a memory) phenomenon, and causes deterioration in image quality of an image formed by the image forming apparatus.

  The present invention has been made in view of such a problem, and an object of the present invention is to appropriately prevent deterioration in image quality of an image.

  A main aspect of the present invention is a removal blade for removing the developer from a developer carrying member carrying mother particles and a developer having an external additive externally added to the mother particles, the removal blade Are provided along the longitudinal direction of the first and second contact portions that contact the developer carrying member, and between the first contact portion and the second contact portion. And a removal blade comprising: an external additive accommodating portion for accommodating the external additive.

  Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

  At least the following will be made clear by the description of the present specification and the accompanying drawings.

A removal blade for removing the developer from a developer carrying member carrying a mother particle and a developer having an external additive externally added to the mother particle, and is along the longitudinal direction of the removal blade A first abutting portion and a second abutting portion that abut on the developer carrying member, and are provided between the first abutting portion and the second abutting portion, and the external additive A removal blade comprising: an external additive storage portion for storing the external additive.
According to such a removal blade, deterioration of the image quality of the image is appropriately prevented.

Further, the first contact portion, the second contact portion, and the external additive accommodating portion may be provided from one longitudinal end to the other longitudinal end of the removal blade.
In such a case, the uneven distribution of the external additive is more effectively eliminated.

  Further, a plurality of sets of the first contact portion and the second contact portion and a plurality of the external additive storage portions may be provided.

The developer carrying member may be a photoconductor.
In such a case, the occurrence of ghost on the photoconductor is suppressed, and deterioration of the image quality of the image is appropriately prevented.

The developer carrying member may be an intermediate transfer member serving as an intermediate medium when transferring a developer image on the photosensitive member to the medium.
In such a case, the occurrence of a ghost on the intermediate transfer member is suppressed, and deterioration of the image quality of the image is appropriately prevented.

The developer carrying member may be a charging member for charging the photosensitive member.
In such a case, uneven charging is suppressed and image quality deterioration is appropriately prevented.

Further, a removal blade for removing the developer from a developer carrying member carrying a mother particle and a developer having an external additive externally added to the mother particle, the longitudinal direction of the removal blade And a first abutting portion and a second abutting portion that abut against the developer carrying member, and are provided between the first abutting portion and the second abutting portion. An external additive accommodating portion for accommodating an additive, wherein the first abutting portion, the second abutting portion, and the external additive accommodating portion are arranged in a longitudinal direction from one end in the longitudinal direction of the removal blade. A plurality of sets of the first contact portion and the second contact portion, and a plurality of the external additive accommodating portions, and the developer carrying member is a photosensitive member. It may be a body.
In this way, the object of the present invention can be achieved more effectively because most of the effects described above can be achieved.

A developer carrying member carrying a mother particle and a developer having an external additive externally added to the mother particle, and a removal blade for removing the developer from the developer carrying member; A first abutting portion and a second abutting portion that are provided along the longitudinal direction of the removal blade and abut against the developer carrying member, and between the first abutting portion and the second abutting portion. It is also possible to realize an image forming apparatus including a removal blade provided with an external additive accommodating portion for accommodating the external additive.
According to such an image forming apparatus, deterioration of the image quality of the image is appropriately prevented.

A photosensitive member carrying a mother particle and a developer having an external additive externally added to the mother particle; and a removing blade for removing the developer from the photosensitive member, Provided along the longitudinal direction, provided between the first contact portion and the second contact portion that contact the developer carrying member, and between the first contact portion and the second contact portion, It is also possible to realize a photoconductor unit comprising a removal blade including an external additive storage portion for storing the external additive.
According to such a photoreceptor unit, deterioration of the image quality of the image is appropriately prevented.

Further, a computer and an image forming apparatus connectable to the computer, a developer carrying member carrying mother particles and a developer having an external additive externally added to the mother particles, and the developer Removal blades for removing the developer from the carrying member, each provided along the longitudinal direction of the removal blade, and a first abutting portion and a second abutting portion that abut against the developer carrying member, An image forming apparatus having a removal blade provided between the first contact portion and the second contact portion and including an external additive storage portion for storing the external additive. It is also possible to realize an image forming system characterized by comprising.
According to such an image forming system, deterioration of the image quality of the image is appropriately prevented.

=== Example of Overall Configuration of Image Forming Apparatus ===
Next, an outline of a laser beam printer (hereinafter also referred to as a printer) 10 as an example of the image forming apparatus will be described with reference to FIG. FIG. 1 is a diagram illustrating main components constituting the printer 10. In FIG. 1, the up and down direction (vertical direction) is indicated by an arrow. For example, the paper feed tray 92 is disposed at the lower part of the printer 10, and the fixing unit 90 is disposed at the upper part of the printer 10. Has been.

  As shown in FIG. 1, the printer 10 according to the present embodiment includes a charging unit 30, an exposure unit 40, a YMCK developing unit 50, and a primary transfer along the rotation direction of a photoconductor 20 as an example of a developer carrying member. A unit 60, an intermediate transfer belt 70 as an example of an intermediate transfer member, and a photosensitive member cleaning unit 75 are provided, and further, a secondary transfer unit 80, an intermediate transfer belt cleaning unit 85, a fixing unit 90, and a means for notifying a user are provided. A display unit 95 (FIG. 3) made up of a liquid crystal panel and a control unit 100 that controls these units and operates as a printer are provided.

The photoreceptor 20 has a cylindrical conductive substrate and a photosensitive layer formed on the outer peripheral surface thereof, and is rotatable around a central axis. In the present embodiment, the photoreceptor 20 is indicated by an arrow in FIG. Rotate clockwise.
The charging unit 30 is a device for charging the photoconductor 20. The charging unit 30 includes a charging roller 32 and a charging roller cleaning blade 34 as an example of a charging member.
The charging roller 32 rotates to be in contact with the photoconductor 20 to charge the photoconductor 20. The charging roller 32 rotates in a direction (counterclockwise in FIG. 1) opposite to the rotation direction of the photoconductor 20 (clockwise in FIG. 1). The central axis is below the central axis of the photoconductor 20.

  The charging roller cleaning blade 34 is a rubber blade for removing the toner adhering to (carried on) the surface of the charging roller 32 from the charging roller 32. The charging roller cleaning blade 34 has a function of contacting the charging roller 32 and scraping off the toner on the charging roller 32. The charging roller cleaning blade 34 is provided so that the longitudinal direction thereof is along the longitudinal direction (axial direction, ie, the direction orthogonal to the paper surface in FIG. 1) of the charging roller 32, and the tip thereof is the charging roller. It arrange | positions so that it may face to the upstream of the rotation direction of 32.

  The exposure unit 40 is a device that forms a latent image on the photoreceptor 20 charged by irradiating a laser. The exposure unit 40 includes a semiconductor laser, a polygon mirror, an F-θ lens, and the like, and charges the modulated laser based on an image signal input from a host computer (not shown) such as a personal computer or a word processor. The irradiated photoconductor 20 is irradiated.

  The YMCK developing unit 50 converts the latent image formed on the photoconductor 20 into toner as an example of a developer contained in the developing device, that is, black (K) toner contained in the black developing device 51, magenta development. An apparatus for developing using magenta (M) toner stored in the device 52, cyan (C) toner stored in the cyan developing device 53, and yellow (Y) toner stored in the yellow developing device 54. is there.

  The YMCK developing unit 50 can move the positions of the four developing devices 51, 52, 53, 54 by rotating with the four developing devices 51, 52, 53, 54 mounted. Yes. That is, the YMCK developing unit 50 holds the four developing devices 51, 52, 53, 54 by four holding portions 55a, 55b, 55c, 55d, and the four developing devices 51, 52, 53, 54 is rotatable around the central axis 50a while maintaining the relative position thereof. Each time image formation for one page is completed, it is selectively opposed to the photoconductor 20, and is formed on the photoconductor 20 with the toner accommodated in each developing device 51, 52, 53, 54. The latent images are developed sequentially. Each of the four developing devices 51, 52, 53, 54 described above is detachably attached to the image forming apparatus main body, more specifically, the holding portions 55a, 55b, 55c, 55d of the YMCK developing unit 50. It is possible.

  The primary transfer unit 60 is a device for transferring a single color toner image formed on the photoconductor 20 to the intermediate transfer belt 70. When four color toners are sequentially transferred in a superimposed manner, a full color toner is transferred to the intermediate transfer belt 70. An image is formed.

  The intermediate transfer belt 70 is an intermediate medium for transferring a toner image as an example of a developer image on the photoreceptor 20 to a medium (paper, film, cloth, etc.), and transfers the toner (toner image) to the medium. For this purpose, the toner (toner image) is rotated while being carried to move the toner (toner image). The intermediate transfer belt 70 is an endless belt in which a tin vapor deposition layer is provided on the surface of a PET film, and a semiconductive paint is formed and laminated on the surface layer. The intermediate transfer belt 70 is stretched around a driving roller 71, a driven roller 72, and the like, and is driven to rotate at substantially the same peripheral speed as the photoconductor 20.

  The photoconductor cleaning unit 75 is provided above the exposure unit 40 and is for cleaning the photoconductor 20 after the toner image on the photoconductor 20 is transferred to the intermediate transfer belt 70. The photoconductor cleaning unit 75 includes a photoconductor cleaning blade 76 for removing from the photoconductor 20 toner that is not transferred to the intermediate transfer belt 70 but remains (carried) on the surface of the photoconductor 20. The photoconductor cleaning blade 76 will be described in detail later.

The secondary transfer unit 80 is a device for transferring a single color toner image or a full color toner image formed on the intermediate transfer belt 70 to a medium.
The intermediate transfer belt cleaning unit 85 is provided above the YMCK developing unit 50 and is for cleaning the intermediate transfer belt 70 after the toner image on the intermediate transfer belt 70 is transferred to the medium. A cleaning blade 87 is provided.

  The intermediate transfer belt cleaning blade 87 is a rubber blade for removing toner remaining (carrying) on the surface of the intermediate transfer belt 70 from the intermediate transfer belt 70. The intermediate transfer belt cleaning blade 87 has a function of contacting the intermediate transfer belt 70 and scraping off the toner on the intermediate transfer belt 70. The intermediate transfer belt cleaning blade 87 is provided such that its longitudinal direction is along the width direction of the intermediate transfer belt 70 (a direction orthogonal to the paper surface in FIG. 1), and its tip is the intermediate transfer belt 70. It arrange | positions so that it may face to the upstream of a rotation direction.

The fixing unit 90 is a device for fusing a single-color toner image or a full-color toner image transferred onto a medium to form a permanent image.
As shown in FIG. 2, the control unit 100 includes a main controller 101 and a unit controller 102. An image signal and a control signal are input to the main controller 101, and in response to a command based on the image signal and the control signal. A unit controller 102 controls each of the units and forms an image.

  The photosensitive member 20, the charging unit 30, the photosensitive member cleaning unit 75, and the like described above are unitized, and the unitized device, that is, the photosensitive unit 18 is connected to the image forming apparatus main body. It is removable.

Next, the operation of the printer 10 configured as described above will be described.
First, when an image signal and a control signal from a host computer (not shown) are input to the main controller 101 of the printer 10 via the interface (I / F) 112, the unit controller 102 based on a command from the main controller 101. The photoreceptor 20 and the intermediate transfer belt 70 are rotated by the control. The photoconductor 20 is sequentially charged by the charging unit 30 at the charging position while rotating.

  The charged area of the photoconductor 20 reaches an exposure position as the photoconductor 20 rotates, and a latent image corresponding to image information of the first color, for example, yellow Y, is formed in the area by the exposure unit 40. . In the YMCK developing unit 50, a yellow developing device 54 that contains yellow (Y) toner is located at a developing position facing the photoconductor 20.

  The latent image formed on the photoconductor 20 reaches the development position as the photoconductor 20 rotates, and is developed with yellow toner by the yellow developing device 54. That is, the yellow developing device 54 visualizes the latent image carried on the photoreceptor 20 as a toner image with toner. As a result, a yellow toner image is formed on the photoreceptor 20 (yellow toner is carried on the photoreceptor 20).

  The yellow toner image formed on the photoconductor 20 reaches the primary transfer position T1 as the photoconductor 20 rotates, and is transferred to the intermediate transfer belt 70 by the primary transfer unit 60. At this time, a primary transfer voltage is applied to the intermediate transfer belt 70 by the primary transfer unit 60. During this time, the photoconductor 20 and the intermediate transfer belt 70 are in contact with each other, and the secondary transfer unit 80 is separated from the intermediate transfer belt 70.

  The above processing is sequentially executed for each developing device for the second color, the third color, and the fourth color, so that four color toner images corresponding to the respective image signals are transferred to the intermediate transfer belt 70. It is transcribed and superimposed. As a result, a full-color toner image is formed on the intermediate transfer belt 70.

The full-color toner image formed on the intermediate transfer belt 70 reaches the secondary transfer position T2 as the intermediate transfer belt 70 rotates, and is transferred to the medium by the secondary transfer unit 80. The medium is conveyed from the paper feed tray 92 to the secondary transfer unit 80 via the paper feed roller 94 and the registration roller 96. Further, when performing the transfer operation, the secondary transfer unit 80 is pressed against the intermediate transfer belt 70 and a secondary transfer voltage is applied to the secondary transfer unit 80. Further, the toner remaining on the intermediate transfer belt 70 without being transferred to the medium is removed by the intermediate transfer belt cleaning blade 87.
The full color toner image transferred to the medium is heated and pressed by the fixing unit 90 and fused to the medium.

  On the other hand, the photoreceptor 20 is cleaned by the photoreceptor cleaning unit 75 after the primary transfer position T1 has passed. That is, the toner remaining on the photoreceptor 20 without being transferred to the intermediate transfer belt 70 is removed by the photoreceptor cleaning blade 76. Then, the photoconductor 20 is prepared for charging for forming the next latent image.

  As described above, the photoconductor cleaning blade 76 contacts the photoconductor 20 at the contact portion to remove the toner remaining on the photoconductor 20, but the toner that slides through the contact portion is also small. Exists. Then, the toner that has passed through the contact portion reaches a contact position where the charging roller 32 comes into contact with further rotation of the photoconductor 20, and a part of the toner may adhere to the charging roller 32. The toner thus removed is removed by the charging roller cleaning blade 34.

=== Overview of Control Unit ===
Next, the configuration of the control unit 100 will be described with reference to FIG. The main controller 101 of the control unit 100 is electrically connected to a host computer via an interface 112 and includes an image memory 113 for storing an image signal input from the host computer. The unit controller 102 includes units (photosensitive member 20, charging unit 30, exposure unit 40, YMCK developing unit 50, primary transfer unit 60, intermediate transfer belt 70, secondary transfer unit 80, fixing unit 90, display unit of the apparatus main body. 95), each unit is controlled based on a signal input from the main controller 101 while detecting a state of each unit by receiving a signal from a sensor included therein.

=== Configuration of toner ===
Next, the configuration of the toner according to the exemplary embodiment will be described. The toner has mother particles and an external additive externally added to the mother particles. The mother particles and the external additive are attached to each other by dry-mixing them using a high-speed fluid mixer such as a Henschel mixer or Pappenmeier or a mixer such as a mechanochemical method. The toner according to this exemplary embodiment has a negative polarity, but may be a positive polarity toner. The external additive has a property of covering the toner (adhering to the toner) and covering the toner to improve the fluidity of the toner.

  The mother particles include materials such as a colorant, a charge control agent, a release agent (WAX), and a resin. Using these materials, mother particles are produced by a pulverization method such as a kneading pulverization method. The mother particles may further contain a dispersant, a magnetic material, other additives, and the like.

  Base particles include polystyrene and copolymers such as hydrogenated styrene resin, styrene / isobutylene copolymer, ABS resin, ASA resin, AS resin, AAS resin, ACS resin, AES resin, and styrene / P chlorostyrene copolymer. Styrene / propylene copolymer, styrene / butadiene cross-linked polymer, styrene / butadiene / chlorinated paraffin copolymer, styrene / allyl / alcohol copolymer, styrene / butadiene rubber emulsion, styrene / maleic ester copolymer, styrene・ Isobutylene copolymers, styrene / maleic anhydride copolymers, acrylate resins or methacrylate resins and copolymers thereof, styrene / acrylic resins and copolymers thereof, such as styrene / acrylic copolymers, styrene / Diethylamino Ethyl methacrylate copolymer, styrene / butadiene / acrylic acid ester copolymer, styrene / methyl methacrylate copolymer, styrene / n-butyl methacrylate copolymer, styrene / methyl methacrylate / n-butyl acrylate copolymer Styrene / methyl methacrylate / butyl arylate / N- (ethoxymethyl) acrylamide copolymer, styrene / glycidyl methacrylate copolymer, styrene / butadiene / dimethyl / aminoethyl methacrylate copolymer, styrene / acrylate・ Maleic acid ester copolymer, styrene / methyl methacrylate / acrylic acid 2-ethylhexyl copolymer, styrene / n-butyl arylate / ethyl glycol methacrylate copolymer, styrene / n Butyl methacrylate / acrylic acid copolymer, styrene / n-butyl methacrylate / maleic anhydride copolymer, styrene / butyl acrylate / isobutyl maleic acid half ester / divinylbenzene copolymer, polyester and copolymer thereof, Polyethylene and its copolymers, epoxy resins, silicone resins, polypropylene and its copolymers, fluorine resins, polyamide resins, polyvinyl alcohol resins, polyurethane resins, polyvinyl butyral resins, etc. Can be used.

  As colorants, carbon black, spirit black, nigrosine, rhodamine, triaminotriphenylmethane, cationic, dioxazine, copper phthalocyanine, berylene, azo, metal-containing azo pigment, azochrome complex, carmine, benzidine, Solar pure yellow 8G, quinacridone, polytungstophosphoric acid, indanthrene blue, sulfonamide derivatives and the like can be used.

  As the charge control agent, an electron-accepting organic complex, chlorinated polyester, nitrofunnic acid, quaternary ammonium salt, pyridinyl salt and the like can be used.

  As the release agent (WAX), paraffinic waxes such as low molecular weight polypropylene, low molecular weight polyethylene, ethylene bisamide, microcrystalline wax, carnauba wax, and beeswax are preferably used, but are compatible with the toner base particles. There is no particular limitation as long as it has liberty. In the present embodiment, “incompatible” means a state in which, when melt-kneaded, the wax is dispersed in the form of islands in the mother particles and is not taken into the resin molecular chain. The amount of the release agent added is 2% by weight or more and 7% by weight or less with respect to the mother particles.

  As the dispersant, metal soap, polyethylene glycol or the like can be used. As other additives, zinc stearate, zinc oxide, cerium oxide and the like can be used.

  Magnetic agents include metal powders such as Fe, Co, Ni, Cr, Mn, Zn, metal oxides such as Fe3O4, Fe2O3, Cr2O3, and ferrite, alloys that exhibit ferromagnetism by heat treatment such as alloys containing manganese and acid, etc. May be used, and a pretreatment such as a coupling agent may be performed in advance.

  As the external additive, various materials having a hydrophobic surface can be used. In the toner according to the exemplary embodiment, silica is used as an external additive. In addition to silica, titanium oxide, aluminum oxide, strontium titanate, cerium oxide, magnesium oxide, chromium oxide, zinc oxide, iron oxide, and copper oxide are used. Fine particles of metal oxides such as tin oxide, fine particles of nitrides such as silicon nitride, fine particles of carbides such as silicon carbide, fine particles of metal salts such as calcium sulfate, barium sulfate and calcium carbonate, and inorganic fine particles such as composites thereof, Organic fine particles such as acrylic fine particles can be used. In addition, as these surface treatment agents, silane coupling agents, titanate coupling agents, fluorine-containing silane coupling agents, silicone oils, and the like can be used. The hydrophobization rate of the external additive treated with these treating agents is preferably 60% or more according to the conventional methanol method. If it is less than this, in high temperature and high humidity, the chargeability and fluidity are liable to decrease due to moisture adsorption, which is not preferable. The particle size of the external additive is preferably 0.001 to 1 μm from the viewpoint of transportability and chargeability. Further, the coverage of the toner with the external additive is preferably 30% or more, more preferably 50 to 90% in order to improve the effect of applying the fluid. The external additive is not limited to one type, and a mixture of two or more types can be used.

=== Regarding the problem caused by the external additive slipping through the contact portion of the removal blade ===
As described in the section of the problem to be solved by the invention, the removal blade is brought into contact with the developer carrying member carrying the mother particles and the external additive added to the mother particles. When the developer is removed by contact, the phenomenon that the part of the external additive of the developer slips through the contact portion due to the small particle size of the external additive. appear. The external additive that has passed through the contact portion causes a so-called ghost (sometimes referred to as a memory) phenomenon, and causes deterioration in image quality of an image formed by the image forming apparatus.

  Here, the case where the developer carrying member is the photosensitive member 20 will be described as an example with respect to the above matters, that is, the point that the external additive that has passed through the contact portion causes deterioration in image quality. This will be described in detail with reference to FIG. FIG. 3 is a schematic diagram showing a latent image and a toner image formed on the photoconductor 20 on the nth circumference of the rotating photoconductor 20. FIG. 4 is a schematic diagram showing a latent image and a toner image formed on the photoconductor 20 on the (n + 1) th rotation of the photoconductor 20 rotating. FIG. 5 shows a toner image formed on the photoconductor on the nth turn and transferred to the intermediate transfer belt 70, and a toner image formed on the photoconductor on the n + 1th turn and transferred to the intermediate transfer belt 70. FIG. 4 is a schematic diagram illustrating a state in which the intermediate transfer belt is supported side by side.

  3 and 4, the latent image and the toner image formed on the photoconductor 20 are schematically shown on the peripheral surface of the photoconductor 20 developed, and the circumferential direction of the photoconductor 20 is the same. The axial direction is indicated by arrows. The length L shown in FIGS. 3 and 4 corresponds to the length of one circumference of the circumferential surface of the photoconductor 20. In FIG. 5, the circumferential direction, the axial direction, and the rotation direction of the intermediate transfer belt 70 are indicated by arrows, and the length L is also indicated in FIG. 5. 3 and 4, the axial end of the photoconductor 20 is omitted, and in FIG. 5, the widthwise end of the intermediate transfer belt 70 is omitted.

  As described above, around the photosensitive member 20, the charging unit 30, the exposure unit 40, the YMCK developing unit 50, the intermediate transfer belt 70 (primary transfer unit 60), and the photosensitive member cleaning unit 75 are arranged in the rotational direction of the photosensitive member 20. It is provided along. Then, the following processes sequentially executed when the photoconductor 20 makes one round, that is, a charging process by the charging unit 30, an exposure process by the exposure unit 40 (formation of a latent image), and a development process (toner by the YMCK developing unit 50). Image formation), a primary transfer process of the toner image to the intermediate transfer belt 70 by the primary transfer unit 60, and a residual toner removal process by the photosensitive member cleaning unit 75, so that a plurality of rotations of the photosensitive member 20 occur. Will be implemented once.

  Here, in this section, the toner image representing the alphabet “O” is visualized and primarily transferred by the above-described series of processes on the nth round of the photoconductor 20, and the above series of the n + 1th round of the photoconductor 20. The toner image representing the alphabet “I” is visualized and primarily transferred by the above process, and the above processes on the n-th and n + 1-th rounds of the photoconductor 20 will be considered. And the reason which the external additive which slipped through the contact part becomes a factor which degrades an image quality is clarified by the said consideration.

  A latent image representing “O” is formed in the charged region of the photoconductor 20 by the exposure unit 40 on the nth circumference of the photoconductor 20 (see the left diagram in FIG. 3). Then, the area where the latent image is formed reaches the developing position, and the latent image is visualized with black toner by a developing device (here, black developing device 51) in the YMCK developing unit 50, and “O”. Is formed (see the right figure of FIG. 3). The black toner image formed on the photoconductor 20 reaches the primary transfer position T1, and is transferred to the intermediate transfer belt 70 by the primary transfer unit 60 (see the upper part in FIG. 5). Residual toner (also a residual toner image representing “O”) that has not been transferred to the intermediate transfer belt 70 and remains on the photoconductor 20 is the above-described toner of the photoconductor cleaning blade 76 provided in the photoconductor cleaning unit 75. It reaches the contact portion and is removed by the photoconductor cleaning blade 76. However, as described above, due to the small particle size of the external additive, an event occurs in which the external additive of the residual toner slips through the contact portion. Therefore, the external additive that has passed through the contact portion is in the state of imitating the letter “O” (hereinafter, the external additive imitating the letter “O” It is also referred to as an additive image) and goes to a charging position where charging by the charging unit 30 is performed.

  A latent image representing “I” is formed on the charged region of the photoconductor 20 by the exposure unit 40 on the (n + 1) th round of the photoconductor 20 (see the left diagram in FIG. 4). Then, the area where the latent image is formed reaches the development position, the latent image is visualized with black toner, and a black toner image representing “I” is formed (see the right diagram in FIG. 4).

  However, the external additive image representing “O” formed on the nth circumference of the photoreceptor 20 is positioned on the photoreceptor 20 in a state where it overlaps the latent image representing “I”. Therefore, when the latent image is visualized with the black toner, the toner adheres to the external additive due to the property of the external additive covering the toner (adhering to the toner), and as shown in FIG. As shown in the figure on the right, the black toner image representing “O” in a state of being superimposed on the black toner image representing “I” (this is a very thin toner image, and this toner image is called a ghost or memory. Is formed).

  Then, the black toner image (ghost) representing “O” formed on the photoconductor 20 is transferred to the intermediate transfer belt 70 together with the black toner image representing “I” at the primary transfer position T1 ( In the end, a ghost appears in the image on the medium. As described above, the external additive that has passed through the contact portion causes deterioration of the image quality on the medium, and it is necessary to take measures against this.

=== Regarding Configuration Example and Effectiveness of Photoconductor Cleaning Blade 76 ===
In the above, the problem caused by the external additive slipping through the contact portion of the photoconductor cleaning blade 76 has been described. However, the photoconductor cleaning blade 76 according to the present embodiment can solve the problem. It has become. In this section, first, the configuration of the photoconductor cleaning blade 76 according to the present embodiment will be described with reference to FIGS. 1 and 6, and subsequently, the effectiveness of the photoconductor cleaning blade 76, that is, the present embodiment will be described. The reason why the photoconductor cleaning blade 76 according to the embodiment can solve the above-described problem will be described. FIG. 6 is an enlarged schematic view showing a state where the photoconductor cleaning blade 76 is in contact with the photoconductor 20.

  The photoconductor cleaning blade 76 is for removing from the photoconductor 20 toner that is not transferred to the intermediate transfer belt 70 but remains (carried) on the surface of the photoconductor 20. The photoconductor cleaning blade 76 has a function of contacting the photoconductor 20 and scraping off the toner on the photoconductor 20. The photoconductor cleaning blade 76 is provided so that the longitudinal direction thereof is along the longitudinal direction of the photoconductor 20 (the direction perpendicular to the paper surface in FIGS. 1 and 6), and the tip of the photoconductor cleaning blade 76 is the same. It arrange | positions so that it may face to the upstream of a rotation direction.

  Further, as shown in FIG. 6, the photosensitive member cleaning blade 76 is provided along the longitudinal direction of the photosensitive member cleaning blade 76 (a direction orthogonal to the paper surface in FIG. 6), and is in contact with the photosensitive member 20. A contact portion 76a and a second contact portion 76b are provided. That is, the photoconductor cleaning blade 76 according to the present embodiment is in contact with the photoconductor 20 at two ridge lines along the longitudinal direction. Further, an external additive storage portion 76c for storing the external additive is provided between the first contact portion 76a and the second contact portion 76b. That is, in the present embodiment, when the toner on the photoconductor 20 reaches the first contact portion 76a of the photoconductor cleaning blade 76, the toner base particles and a part of the external additive are removed. Thus, part of the external additive slides through the first contact portion 76a, but the toner that has passed through the first contact portion 76a is stored in the external additive storage portion 76c.

  In the present embodiment, the first contact portion 76a, the second contact portion 76b, and the external additive storage portion 76c are provided from one longitudinal end to the other longitudinal end of the photosensitive member cleaning blade 76. ing. That is, FIG. 6 shows a cross section of the photoconductor cleaning blade 76, but the cross section of the photoconductor cleaning blade 76 is the same as that shown in FIG. It becomes.

  As described above, the photoconductor cleaning blade 76 according to this exemplary embodiment is provided along the longitudinal direction of the photoconductor cleaning blade 76, and the first contact portion 76 a and the second contact portion that contact the photoconductor 20. A portion 76b, and an external additive accommodating portion 76c provided between the first abutting portion 76a and the second abutting portion 76b for accommodating the external additive. The photoconductor cleaning blade 76 having such a configuration solves the above-described problems caused by the external additive.

  That is, when the toner is removed by the photoconductor cleaning blade 76 according to the present embodiment, a part of the external additive slides through the first contact portion 76a. It will reach the medicine container 76c. Then, the external additive that has reached the external additive accommodating portion 76c is mixed with the external additive already stored in the external additive accommodating portion 76c. Therefore, even if a part of the external additive in the external additive accommodating portion 76c passes through the second contact portion 76b and goes to the charging position, the external additive going to the charging position Is locally eliminated (the external additive is not present in the longitudinal direction of the photoconductor cleaning blade 76, or the external additive is unevenly distributed) (the longitudinal direction). There are even external additives from one end to the other).

  Therefore, in the present embodiment, for example, even if the residual toner image representing “O” is removed by the photoconductor cleaning blade 76 as described above, an external additive image representing “O” is not formed. Accordingly, a toner image representing “O”, that is, a ghost (memory) is not formed. Therefore, according to the photoconductor cleaning blade 76 according to the present embodiment, deterioration of the image quality of the image is appropriately prevented.

In the above embodiment, the first contact portion 76a, the second contact portion 76b, and the external additive storage portion 76c are provided from one longitudinal end to the other longitudinal end of the photosensitive member cleaning blade 76. However, the present invention is not limited to this. For example, it is good also as the external additive accommodating part 76c not being provided in the longitudinal direction one end and the other end.
However, the embodiment described above is more desirable in that the uneven distribution of the external additive in the longitudinal direction can be more effectively eliminated.

=== Regarding Variations Related to the Shape of the Photoconductor Cleaning Blade 76 ===
FIG. 6 shows the shape of the photoconductor cleaning blade 76 according to this exemplary embodiment. The photoconductor cleaning blade 76 that can solve the above problem is provided along the longitudinal direction of the photoconductor cleaning blade 76. 20 is provided between the first contact portion 76a and the second contact portion 76b, which are in contact with the first contact portion 76b, and between the first contact portion 76a and the second contact portion 76b. 6 is not limited to the photoconductor cleaning blade 76 having the shape shown in FIG.

  7A to 7C show variations related to the shape of the photoconductor cleaning blade 76. FIG. For comparison, FIG. 7D shows the shape of the photoconductor cleaning blade 76 according to the present exemplary embodiment. In each of FIGS. 7A to 7D, two diagrams are shown. In the left diagram, the shape of the photoconductor cleaning blade 76 when not in contact with the photoconductor 20 is shown. The shape of the photosensitive member cleaning blade 76 when in contact with the photosensitive member 20 is shown.

  The photosensitive member cleaning blade 76 according to the present embodiment is a blade in which a concave portion is provided on a side portion close to the tip portion, and is brought into contact with the photosensitive member 20 (see FIG. 7D). Thus, a blade having a notch at the tip may be brought into contact with the photoconductor 20. Further, as shown in FIG. 7B, a blade having a notch in the side portion close to the tip portion may be brought into contact with the photosensitive member 20.

  Further, the photoconductor cleaning blade 76 according to the present exemplary embodiment includes two contact portions (a first contact portion 76a and a second contact portion 76b) and one external additive storage portion 76c. However, the present invention is not limited to this, and as shown in FIG. 7C, a plurality of sets of first contact portions and second contact portions and a plurality of external additive storage portions may be provided. .

=== Other Embodiments ===
Although the removal blade and the like according to the present invention have been described based on the above embodiment, the above embodiment of the present invention is for facilitating the understanding of the present invention and does not limit the present invention. Absent. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes the equivalents thereof.

  In the above embodiment, an intermediate transfer type full color laser beam printer has been described as an example of the image forming apparatus. However, the present invention is not limited to the intermediate transfer type, such as a full color laser beam printer, a monochrome laser beam printer, a copying machine, and a facsimile. The present invention can be applied to various image forming apparatuses.

  Also, the photosensitive member is not limited to a so-called photosensitive roller, which is configured by providing a photosensitive layer on the outer peripheral surface of a cylindrical conductive substrate, and is configured by providing a photosensitive layer on the surface of a belt-shaped conductive substrate. A so-called photosensitive belt may be used.

In the above embodiment, the toner carrying member that carries the toner is the photoconductor 20, and the first abutting portion, the second abutting portion, and the external additive container for removing the toner from the toner carrying member. The removal blade provided with the portion is the photosensitive member cleaning blade 76, but is not limited thereto. That is, the removal blade provided with the first contact portion, the second contact portion, and the external additive storage portion is used as a removal blade for removing toner from the toner carrier other than the photoreceptor 20. May be.
As an example, the removal blade having the above-described configuration may be applied to an intermediate transfer belt cleaning blade 87 for removing toner from the intermediate transfer belt 70 as a toner carrier.

  When the intermediate transfer belt cleaning blade 87 is a blade (conventional blade) not having the above-described configuration, for example, when the printer 10 is performing a monochrome image forming operation, n turns of the intermediate transfer belt 70 are performed. The external additive image is formed on the eyes, and the formed external additive image reaches the primary transfer position T1 on the (n + 1) th round of the intermediate transfer belt 70. At the primary transfer position T1, the toner image is transferred from the photoreceptor 20 to the intermediate transfer belt 70. At this time, a part of the toner (image) is close to the toner (image). The image is attracted to (image) and moves to a region where the external additive image is located, and this becomes the ghost (memory) and appears on the intermediate transfer belt 70.

  On the other hand, when the intermediate transfer belt cleaning blade 87 is a blade having the above-described configuration, no ghost (memory) is formed because no external additive image is formed. Therefore, according to the intermediate transfer belt cleaning blade 87, deterioration of the image quality of the image is appropriately prevented.

  Further, the removal blade having the above-described configuration may be applied to the charging roller cleaning blade 34 for removing the toner from the charging roller 32 as the toner carrier.

  When the external additive image formed on the nth turn of the photoconductor 20 reaches the charging position on the (n + 1) th turn of the photoconductor 20, and the external additive image reaching the charging position moves to the charging roller 32. There is. When the charging roller cleaning blade 34 is a blade (conventional blade) that does not have the above-described configuration, the external additive image transferred to the charging roller 32 moves as the charging roller 32 rotates. Then, it passes through the charging roller cleaning blade 34 as it is and reaches the charging position (turns back around). In such a situation, charging unevenness may occur when charging by the charging roller is performed due to uneven distribution of the external additive at the charging position.

  On the other hand, when the charging roller cleaning blade 34 is a blade having the above configuration, the external additive image disappears after the external additive image transferred to the charging roller 32 passes through the charging roller cleaning blade 34. Therefore, the occurrence of the charging unevenness is suppressed. Therefore, according to the charging roller cleaning blade 34, deterioration of the image quality of the image is appropriately prevented.

=== Configuration of Image Forming System etc. ===
Next, an image forming system according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 8 is an explanatory diagram showing an external configuration of the image forming system. The image forming system 700 includes a computer 702, a display device 704, a printer 706, an input device 708, and a reading device 710. In this embodiment, the computer 702 is housed in a mini-tower type housing, but is not limited thereto. The display device 704 is generally a CRT (Cathode Ray Tube), a plasma display, a liquid crystal display device, or the like, but is not limited thereto. As the printer 706, the printer described above is used. In this embodiment, the input device 708 uses a keyboard 708A and a mouse 708B, but is not limited thereto. In this embodiment, the reading device 710 uses a flexible disk drive device 710A and a CD-ROM drive device 710B, but is not limited to this. For example, an MO (Magneto Optical) disk drive device or a DVD (Digital Versatile) is used. Disk) etc. may be used.

  FIG. 9 is a block diagram showing a configuration of the image forming system shown in FIG. An internal memory 802 such as a RAM and an external memory such as a hard disk drive unit 804 are further provided in a housing in which the computer 702 is housed.

  In the above description, the example in which the printer 706 is connected to the computer 702, the display device 704, the input device 708, and the reading device 710 to configure the image forming system has been described. However, the present invention is not limited to this. Absent. For example, the image forming system may include a computer 702 and a printer 706, and the image forming system may not include any of the display device 704, the input device 708, and the reading device 710.

  For example, the printer 706 may have a part of the functions or mechanisms of the computer 702, the display device 704, the input device 708, and the reading device 710. As an example, the printer 706 includes an image processing unit that performs image processing, a display unit that performs various displays, a recording medium attachment / detachment unit for attaching / detaching a recording medium that records image data captured by a digital camera or the like. It is good also as a structure to have.

  The image forming system realized in this way is a system superior to the conventional system as a whole system.

FIG. 2 is a diagram illustrating main components constituting the printer. FIG. 2 is a block diagram illustrating a control unit of the printer 10 in FIG. 1. FIG. 4 is a schematic diagram showing a latent image and a toner image formed on the photoconductor 20 on the n-th rotation of the rotating photoconductor. FIG. 4 is a schematic diagram showing a latent image and a toner image formed on the photoconductor 20 on the (n + 1) th rotation of the photoconductor 20 rotating. The toner image formed on the photoconductor on the nth turn and transferred to the intermediate transfer belt 70 and the toner image formed on the photoconductor on the n + 1th turn and transferred to the intermediate transfer belt 70 are transferred to the intermediate transfer belt 70. It is the schematic diagram which showed a mode that it was carry | supported along with the top. FIG. 6 is an enlarged schematic view showing a state where the photoconductor cleaning blade 76 is in contact with the photoconductor 20. 7A to 7D are explanatory views for explaining variations related to the shape of the photoconductor cleaning blade 76. 1 is an explanatory diagram showing an external configuration of an image forming system. It is a block diagram which shows the structure of the image forming system shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Laser beam printer 18 Photoconductor unit 20 Photoconductor 30 Charging unit 32 Charging roller 34 Charging roller cleaning blade 40 Exposure unit 50 YMCK developing unit 50a Center axis 51 Black developing device 52 Magenta developing device 53 Cyan developing device 54 Yellow developing device 55a, 55b, 55c, 55d Holding section 60 Primary transfer unit 70 Intermediate transfer belt 71 Drive roller 72 Driven roller 75 Photoconductor cleaning unit 76 Photoconductor cleaning blade 76a First contact section 76b Second contact section 76c External additive storage section 80 Secondary transfer unit 85 Intermediate transfer belt cleaning unit 87 Intermediate transfer belt cleaning blade 90 Fixing unit 92 Paper feed tray 94 Paper feed roller 95 Display unit 96 Registration roller 100 Control unit 101 Main controller 102 Unit controller 112 Interface 113 Image memory 700 Image forming system 702 Computer 704 Display device 706 Printer 708 Input device 708A Keyboard 708B Mouse 710 Reading device 710A Flexible disk drive device 710B CD-ROM drive device 802 Internal memory 804 Hard disk Drive unit T1 Primary transfer position T2 Secondary transfer position

Claims (10)

A developer carrying member carrying a mother particle and a developer having an external additive externally added to the mother particle;
A removal blade for removing the developer from
A first abutting portion and a second abutting portion that are provided along the longitudinal direction of the removal blade and abut against the developer carrying member;
An external additive accommodating portion for accommodating the external additive provided between the first abutting portion and the second abutting portion;
A removal blade comprising: The removal blade according to claim 1,
The removal blade, wherein the first contact portion, the second contact portion, and the external additive storage portion are provided from one longitudinal end to the other longitudinal end of the removal blade. The removal blade according to claim 1 or 2,
A removal blade comprising a plurality of sets of the first contact portion and the second contact portion and a plurality of the external additive storage portions. The removal blade according to any one of claims 1 to 3,
The removal blade, wherein the developer carrying member is a photoconductor. The removal blade according to any one of claims 1 to 3,
The removing blade, wherein the developer carrying member is an intermediate transfer member serving as an intermediate medium when a developer image on the photosensitive member is transferred to the medium. The removal blade according to any one of claims 1 to 3,
The removing blade, wherein the developer carrying member is a charging member for charging the photosensitive member. A developer carrying member carrying a mother particle and a developer having an external additive externally added to the mother particle;
A removal blade for removing the developer from
A first abutting portion and a second abutting portion that are provided along the longitudinal direction of the removal blade and abut against the developer carrying member;
An external additive accommodating portion for accommodating the external additive provided between the first abutting portion and the second abutting portion;
With
The first contact portion, the second contact portion, and the external additive storage portion are provided from one longitudinal end to the other longitudinal end of the removal blade,
A plurality of the first contact portion and the second contact portion, and a plurality of the external additive storage portions are provided,
The removal blade, wherein the developer carrying member is a photoconductor. A developer carrying member carrying a mother particle and a developer having an external additive externally added to the mother particle;
A removal blade for removing the developer from the developer carrying member,
A first abutting portion and a second abutting portion that are provided along the longitudinal direction of the removal blade and abut against the developer carrying member, and between the first abutting portion and the second abutting portion. An external additive storage portion for storing the external additive, and a removal blade comprising:
An image forming apparatus comprising: A photoreceptor carrying a mother particle and a developer having an external additive externally added to the mother particle;
A removal blade for removing the developer from the photoreceptor, and a first contact portion and a second contact portion that are provided along the longitudinal direction of the removal blade and contact the developer carrying member. And a removal blade provided between the first contact portion and the second contact portion, and an external additive storage portion for storing the external additive,
A photoreceptor unit comprising: Computer and
An image forming apparatus connectable to the computer, comprising: a developer carrying member carrying mother particles and a developer having an external additive externally added to the mother particles; and the developer carrying member from the developer carrying member A first abutting portion and a second abutting portion that are provided along the longitudinal direction of the removing blade and abut against the developer carrying member, and the first abutting portion. An image forming apparatus comprising: a removal blade provided between the first contact portion and the second contact portion, and an external additive storage portion for storing the external additive,
An image forming system comprising: