JP4447017B2 - Image forming apparatus - Google Patents

Description

The present invention relates to the images formed equipment.

JP-A-1-205171 Japanese Patent Laid-Open No. 7-333881 Japanese Patent Laid-Open No. 8-15887 JP-A-8-123053 Japanese Patent Laid-Open No. 8-146664 JP-A-8-179542 JP-A-11-30938 JP-A-11-174922

  In electrophotographic image forming apparatuses such as printers, facsimiles, and copying machines, the electrostatic latent image formed by charging and exposing the surface of the image carrier is developed with colored toner to form a toner image as a visible image. The toner image is transferred to a transfer medium such as transfer paper, and fixed with a heat roll or the like to form an image. On the other hand, since untransferred toner generally remains on the surface of the image carrier after the toner image has been transferred, it is necessary to remove this residual toner by a cleaning unit prior to the next image forming process. In general, other foreign matters attached to the surface of the image carrier are also removed together with the residual toner by the cleaning means.

  As described above, the photoconductor in the image forming apparatus is subjected to various mechanical and chemical actions in the repeated processes of charging, exposure, development, transfer, and cleaning in the electrophotographic process. In other words, mechanical deterioration such as wear and scratches occurs on the photosensitive member due to contact with a transfer member such as developer, paper, film, and intermediate transfer member, a cleaning member such as a blade, brush, and roller, and a charging member. However, the mechanical strength of the surface of the photoreceptor decreases due to oxidative degradation of components such as binder resin and charge transfer material due to chemically active substances such as ozone, NOx gas, and charged substances generated in the charging process. Further, the wear of the photoreceptor is further promoted with the mechanical action.

  In addition, due to oxidation degradation of the photoconductor constituent materials and accumulation of hydrophilic, low resistance substances generated during discharge, the photoconductor surface electrical resistance is lowered, the electrostatic latent image is disturbed, and image quality such as image blurring is reduced. appear.

  Furthermore, with the development of the information society in recent years, image forming devices have been downsized from the viewpoint of increasing the image forming speed and efficiently using the office environment, and further improving the image quality for the purpose of transmitting high-quality information. Further, from the viewpoint of protecting the global environment, it is required to extend the life of the apparatus, and the electrophotographic photosensitive member used in the image forming apparatus is also required to have high-speed response, miniaturization, and high durability. As the speed and size are reduced, the diameter of the photoreceptor is reduced, and the use conditions in the electrophotographic process are becoming more severe.

  In particular, when a rubber blade is used in the cleaning section, the rubber hardness and contact pressure must be increased for sufficient cleaning, which promotes the wear of the photoconductor, potential fluctuation, and sensitivity fluctuation. As a result, the color balance of the abnormal image and the color image is lost and a problem occurs in the color reproducibility.

Therefore, conventionally, a photoconductor excellent in wear resistance has been demanded, and as disclosed in Patent Document 1 to Patent Document 5, a particulate material is added to the photoconductor. Although the wear resistance is improved, the bright portion potential is increased by long-term continuous repetition, and image deterioration such as a decrease in image density occurs. Patent Document 6 discloses that a protective layer is provided. This has high mechanical strength and improved wear resistance, but the image resolution is reduced and the image is sufficiently thick, for example, thick characters are observed. Not.

  On the other hand, as cleaning means for removing residual toner after transfer of the image carrier, various types such as those using a fur brush, a magnetic brush, etc., or using a cleaning blade made of an elastic material are used. However, as described above, the means for scraping off the toner by rubbing the image carrier with the cleaning blade is generally used because it is inexpensive and has high performance stability. For the elastic body used as a material for the cleaning blade, polyurethane rubber having excellent wear resistance is often used.

  As a cleaning apparatus using such a cleaning blade, for example, as disclosed in Patent Document 7, a free end for cleaning the surface of an image carrier and a cleaning unit are positioned when cleaning is performed. A cleaning blade having a fixed end, and an ultrasonic cleaning auxiliary device that is provided on the cleaning blade fixed end and applies vibration energy to the blade to float and remove particles on the surface of the image carrier. In order to better clean the vibration energy, it is known to concentrate on a blade chip that contacts the surface of the image carrier to float residual toner particles and weaken the adhesion to the image carrier to perform cleaning.

  Also, as disclosed in Patent Document 8, a piezoelectric element that applies vibration to the cleaning blade is provided to cause problems such as toner omission, toner fusion to the surface of the image carrier, abnormal noise, abnormal vibration, and blade turning. There are things that try to eliminate.

  As described above, when cleaning is performed by the blade cleaning method, not only the residual toner on the image carrier is removed, but also the surface and wear of the image carrier are caused. Therefore, as a method of increasing the film strength on the surface of the image carrier and preventing abrasion and scratches by the cleaning blade, the outermost surface layer of the image carrier is made to contain relatively hard inorganic particles to increase the film strength. It has been broken.

  Such an image carrier has a photosensitive layer directly or via an intermediate layer on a conductive substrate, and the photosensitive layer contains at least a charge generating substance, a charge transporting substance, and a particulate substance. By increasing the content of the particulate matter on the surface side farthest from the conductive substrate side, it is intended to improve wear resistance and stabilize electrical characteristics, and to obtain high sensitivity and durability. It is.

  However, when such an image carrier is used, in the cleaning process for cleaning residual toner after transfer, the blade is inverted by the surface particulate matter, or the blade squeals and the blade member wear is accelerated during the blade cleaning. It has been found that there is a problem that a malfunction such as a problem occurs.

  Further, it has been found that the filming phenomenon in which the toner resin component adheres to the image carrier side due to the rubbing action between the blade and the image carrier causes the image quality to be remarkably deteriorated.

Therefore, it is conceivable to use an apparatus as disclosed in Patent Document 7 or Patent Document 8 described above.
However, in the apparatus disclosed in Patent Document 7, since a standing wave is formed in a waveguide that propagates ultrasonic waves, the state of propagation of sound waves varies greatly depending on environmental conditions, particularly temperature, so that a stable state is achieved. In addition, there is a problem that an extremely large vibrator is required to form a standing wave uniformly in the width direction of the image carrier. This configuration has a problem that the main object is to weaken the adhesion between the image carrier and the residual toner particles, and it is merely an auxiliary means for cleaning.

  Further, in the apparatus disclosed in Patent Document 8, since a vibration is applied by forming a standing wave in the longitudinal direction of the blade with a piezoelectric element, it varies depending on external factors such as environmental conditions, and the blade material is elastic. Since it is made of a material, vibration propagation efficiency is extremely poor, and there is a problem that efficient cleaning cannot be performed.

The present invention has been made in view of the above problems, and an object thereof is to enable cleaning without compromising the durability of the toner image carrier remaining on the image bearing member containing a particulate material.

In order to solve the above problems, an image forming apparatus according to the present invention provides:
In an image forming apparatus comprising an image carrier having a photosensitive layer containing particulate matter or an image carrier having a particulate matter-containing surface layer containing particulate matter on the photosensitive layer ,
The mounting surface of the plurality of vibrating means of the vibration transmission member fitted with a plurality of vibrating means is a blade member attached to the distal portion of the opposite surface,
The plurality of vibration means are arranged at intervals in the width direction of the image carrier,
The vibration transmission member is formed of a conductive member, and one electrode of each piezoelectric element constituting the plurality of excitation means is in direct contact with and electrically connected to the vibration transmission member. One electrode of each piezoelectric element constituting the plurality of vibration means is connected in common ,
A cleaning device is provided that vibrates the vibration transmission member by the plurality of vibration means, and the vibration of the vibration transmission member is propagated to the blade member to vibrate the blade member .

According to the image forming apparatus according to the present invention according to the present invention, the mounting surface of the plurality of vibration means of the vibration transmission member fitted with a plurality of vibrating means is a blade member attached to the distal portion of the opposite surface,
The plurality of vibration means are arranged at intervals in the width direction of the image carrier, the vibration transmission member is formed of a conductive member, and one electrode of each piezoelectric element constituting the plurality of vibration means is a vibration transmission member One electrode of each piezoelectric element constituting a plurality of vibration means is directly connected to and electrically connected to the vibration transmission member, and the vibration transmission member is connected by the plurality of vibration means. Is provided , and the life of the image carrier including the particulate matter and the blade member is improved because the cleaning device for vibrating the blade member by transmitting the vibration of the vibration transmitting member to the blade member is provided .

  According to the image forming apparatus of the present invention, since the cleaning apparatus according to the present invention is provided, the life of the image carrier and the blade member including the particulate matter is improved, and stable image formation can be performed over a long period of time. .

  According to the process cartridge of the present invention, since the cleaning device according to the present invention is provided, the downsizing of the device and the operability of desorption and replacement are improved, and the life of the image carrier and the blade member containing the particulate matter is improved. To do.

  According to the image forming apparatus of the present invention, since a plurality of process cartridges according to the present invention are provided, the apparatus for forming a color image can be reduced in size, and the life of the image carrier including the particulate matter and the blade member can be reduced. An improved color image forming apparatus is obtained.

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram of an image forming apparatus according to the present invention provided with a cleaning device according to the present invention.
In this image forming apparatus, around the photosensitive drum 2 as an image carrier, a charging device 3 for charging the surface of the photosensitive drum with a charging roller or the like, a uniform charging processing surface of the photosensitive drum 2 with a laser beam or the like. An exposure device 4 for forming a latent image on the photosensitive drum 2, a developing device 6 for forming a toner image by attaching a charged toner to the latent image on the photosensitive drum 2, a transfer belt or transfer roller, a charger and the like. The transfer device 7 for transferring the toner image formed thereon onto the recording paper 9, the cleaning device 16 for removing the toner remaining on the photosensitive drum 2 after the transfer, and the residual potential on the photosensitive drum 2 are removed. The static eliminating devices 18 are arranged in order.

  On the other hand, the recording paper 9 stored in a paper feed tray or the like is separated and fed one by one by a paper feed roller 10, and is formed between the photosensitive drum 2 and the roller 12a of the transfer device 7 through a transport roller 11 or the like. The nip portion 7a is fed. Further, the transfer device 7 has a conveying belt 12c stretched between a roller 12a and a roller 12b forming a transfer portion, and the recording paper 9 after the transfer is sent to the fixing device 14 by the conveying belt 12c. The fed recording paper 9 is discharged by a paper discharge roller 15 to a paper discharge stocker (not shown). The surface of the transport belt 12c of the transfer device 7 is cleaned by the cleaning unit 13.

  In such a configuration, the photosensitive drum 2 whose surface is uniformly charged by the charging roller of the charging device 3 is formed with an electrostatic latent image corresponding to the output image by the exposure device 4, and the latent image is developed by the developing device 6. Toner is attached to the toner and developed to form a toner image. This toner image is transferred from the surface of the photosensitive drum 2 by the transfer device 7 to the recording paper 9 conveyed from the paper feed tray. Thereafter, the recording paper 9 is sent to the fixing device 14 by the transfer device 7, and the toner image on the recording paper 9 is fixed to the recording paper 9 by the fixing device 14 and discharged through the paper discharge roller 15.

  On the other hand, the residual toner remaining on the photosensitive drum 2 without being transferred is collected by the cleaning device 16, and the photosensitive drum 2 from which the residual toner has been removed is initialized by the charge eliminating lamp 18 and used for the next image forming process. Is done.

First, an example in which the layer structure of the photosensitive drum 2 as an image carrier is different will be described with reference to FIGS.
The image carrier (photosensitive drum 2) is basically composed of a conductive substrate (support) 21 and a latent image carrier layer (photosensitive layer) 22 containing particulate matter 23, as shown in FIG. The In this case, as shown in FIG. 3, the particulate matter 23 is contained in the particulate matter-containing surface layer 23 provided on the latent image carrier layer 22, which is different from the latent image carrier layer 22, so as to be conductive. You may provide in the surface most distant from the base | substrate 21. FIG.

  Here, the latent image carrying layer 22 needs to be electrically insulating so that it can be charged, but a non-photoconductive dielectric layer or a photoconductive photosensitive layer can be used.

  Further, as a so-called electrophotographic photoreceptor in which photocarriers are generated by exposure, the photosensitive layer 22a is a single layer type as shown in FIG. 4, and is separated into a charge generation layer 22b and a charge transport layer 22c as shown in FIG. A stacked type in which the charge generation layer 22b and the charge transport layer 22c are sequentially stacked on the conductive substrate 21 via the intermediate layer 25, and separated into the charge generation layer 22b and the charge transport layer 22c as shown in FIG. It is possible to use a reverse stacked type in which the charge transport layer 22c and the charge generation layer 22b are sequentially stacked on the conductive substrate 21 via the intermediate layer 25.

  Here, the production method of the particulate matter-containing surface layer 24 will be described. The particulate matter is pulverized, dispersed, and coated with a binder resin, a low molecular charge transporting material, and a high molecular charge transporting material. The content of the particulate matter 23 in the particulate matter-containing surface layer 24 is 5 to 50% by weight, particularly preferably 10 to 40% by weight. If the content of the particulate matter 23 is less than 10% by weight, the wear resistance is not sufficient, but if it exceeds 50% by weight, the transparency of the photosensitive layer is impaired. The particulate material 23 is preferably pulverized and dispersed to an average particle size of 0.05 to 1.0 μm, preferably 0.05 to 0.8 μm. If the particle size is large, cueing cleaning blades are damaged on the surface, resulting in poor cleaning.

  As the particulate substance 23, any particulate substance that is harder than the constituent resin of the surface layer 24 can be used, and an inorganic substance or an organic substance can be used. Examples include metal oxides such as titanium oxide, silica, tin oxide, alumina, zirconium oxide, indium oxide, silicon nitride, calcium oxide, zinc oxide, and barium sulfate. Zirconium etc. can be mentioned.

  These particulate materials may be surface-treated with an inorganic material or an organic material for reasons such as improving dispersibility. In general, those treated with a silane coupling agent as a water repellency treatment, those treated with a fluorinated silane coupling agent, those treated with a higher fatty acid, and as inorganic treatment, the filler surface is treated with alumina, zirconia, tin oxide, silica. It is preferable to use what was done.

  As the binder resin, a thermoplastic resin or a curable resin can be used. For example, acrylic resins, polyesters, polycarbonates, polyamides, polyurethanes, polystyrenes, epoxy resins and the like can be mentioned. Particularly preferred binder resins are polycarbonates represented by the general formulas 2 and 3.

  In addition, examples of the charge transport material in the case where the surface charge of the photoreceptor is negative polarity include oxazole derivatives, oxadiazole derivatives, imidazole derivatives, triphenylamine derivatives, 9- (p-diethylaminostyrylanthracene), 1,1- Bis- (4-dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazoline, phenylhydrazones, α-phenylstilbene derivatives, thiazole derivatives, triazole derivatives, phenazine derivatives, acridine derivatives, benzofuran derivatives, benzimidazole derivatives, Examples include thiophene derivatives.

  These low molecular charge transport materials can be used singly or as a mixture of two or more kinds. The low molecular transport material (D), the binder resin (R) and the particulate material (F) in the particulate material-containing layer can be used. The content is D: R: F = 10 to 40:35 to 55: 5 to 40% by weight.

  When the amount of the low-molecular charge transporting material is less than 10% by weight, the bright portion potential is considered to be increased due to the charge mobility, and when it exceeds 40% by weight, the film strength is likely to be decreased. The binder resin fixes the low molecular transport material and the particulate matter, and if it is less than 35% by weight, embrittlement of the particulate material layer occurs, and if it exceeds 55% by weight, the low molecular transport material and the particulate matter are generated. In terms of balance with the amount, the electrical characteristics and film strength are not preferred. If the amount of the particulate matter is less than 5% by weight, it is not preferable from the viewpoint of abrasion resistance, and if it exceeds 40% by weight, image deterioration such as scumming due to film opacification occurs. In particular, the low-molecular transport material represented by the general formula 1 is preferable because of its high mobility and good compatibility with the binder resin.

  Dispersing solvents include methyl ethyl ketone, acetone, methyl isobutyl ketone, cyclohexanone ketones, ethers such as dioxane, tetrahydrofuran and ethyl cellosolve, aromatics such as toluene and xylene, halogens such as chlorobenzene and dichloromethane, ethyl acetate and acetic acid. Esters such as butyl are used, and they are dispersed and pulverized using a ball mill, sand mill, vibration mill or the like.

The amount of particulate matter added is 0.5 wt% to 50 wt%, preferably 5 wt% to 40 wt%. The particle size of the particulate material is 0.05 to 1.0 μm, preferably 0.05 to 0.8 μm. The film thickness in the case of laminating the particulate material addition layer is 0.5 to 10 μm, preferably 0.5 to 5 μm.

  As the coating method, a dipping method, a spray coating method, a ring coating method, a roll coater method, a gravure coating method, a nozzle coating method, a screen printing method, or the like is employed.

  When a particulate material layer is provided on a charge transport layer composed of a low molecular transport material and a binder resin, the structure of the binder resin used in the low molecular charge transport layer and the binder resin used in the particulate material layer are different. Is preferred. This constitutes an interface with the charge transport layer and measures the prevention of the diffusion of the particulate matter into the charge transport layer of the particulate matter, thereby stabilizing the electrical characteristics.

  Moreover, the diffusion of particulate matter can be prevented by the difference in the solubility of the low molecular transport material due to the difference in the low molecular transport material structure used between the same structures of the binder resin. The formation of the interface is stabilization of electrical characteristics and uniform distribution of particulate matter in the layer, thereby maintaining high durability, high sensitivity, and high stability.

Examples of the conductive substrate include those having a volume resistance of 10 ¹⁰ Ω or less, such as metals such as aluminum, nickel, chromium, nichrome, copper, silver, gold, platinum, and iron, and oxides such as tin oxide and indium oxide. Coated with a film or cylindrical plastic, paper or the like by vapor deposition or sputtering, or a plate made of aluminum, aluminum alloy, nickel, stainless steel, etc. I. I. I. It is possible to use a tube that has been surface-treated by cutting, superfinishing, polishing, or the like after being made into a raw tube by a method such as extrusion or drawing.

The photosensitive layer may be either a single layer type or a laminated type. First, the laminated type will be described.
The charge generation layer is a layer mainly composed of a charge generation material, and a binder resin may be used as necessary. As the charge generation substance, an inorganic material or an organic material can be used.

  Inorganic materials include crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, selenium-arsenic compounds, amorphous silicon, and the like. In amorphous silicon, dangling bonds that are terminated with hydrogen atoms or halogen atoms, or those that are doped with boron atoms, phosphorus atoms, or the like are preferably used.

  On the other hand, a known material can be used as the organic material. For example, phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine, azulenium salt pigments, squaric acid methine pigments, azo pigments having a carbazole skeleton, azo pigments having a triphenylamine skeleton, azo pigments having a diphenylamine skeleton, dibenzothiophene skeleton Azo pigments having fluorenone skeleton, azo pigments having oxadiazole skeleton, azo pigments having bis-stilbene skeleton, azo pigments having distyryl oxadiazole skeleton, azo pigments having distyrylcarbazole skeleton, perylene Pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane and triphenylmethane pigments, benzoquinone and naphthoquinone pigments, cyanine and azomethine pigments, Jigoido based pigments, and bisbenzimidazole pigments.

  These charge generation materials can be used alone or as a mixture of two or more.

  As a binder resin used as necessary for the charge generation layer, polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly-N-vinylcarbazole, Polyacrylamide or the like is used. These binder resins can be used alone or as a mixture of two or more. Furthermore, you may add a low molecular charge transport material as needed.

  Examples of the hole transporting material include the electron donating materials shown below and are used favorably. For example, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, triphenylamine derivatives, 9- (p-diethylaminostyrylanthracene), 1,1-bis- (4-dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazoline , Phenylhydrazones, α-phenylstilbene derivatives, thiazole derivatives, triazole derivatives, phenazine derivatives, acridine derivatives, benzofuran derivatives, benzimidazole derivatives, thiophene derivatives, and the like. These hole transport materials can be used alone or as a mixture of two or more.

  As a method for forming the charge generation layer, a vacuum thin film preparation method and a casting method from a solution dispersion system can be mentioned.

  As the former method, a vacuum deposition method, a glow discharge decomposition method, an ion plating method, a sputtering method, a reactive sputtering method, a CVD method, or the like is used, and the above-described inorganic materials and organic materials can be satisfactorily formed.

  Further, in order to provide a charge generation layer by a casting method, a ball mill, an attritor, or the like using a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, or butanone together with a binder resin, if necessary, the inorganic or organic charge generation material described above. It can be formed by dispersing with a sand mill or the like, and applying the solution after diluting the dispersion appropriately. The coating can be performed using a dip coating method, a spray coating method, a bead coating method, or the like.

  The film thickness of the charge generation layer thus provided is suitably about 0.01 to 5 μm, preferably 0.05 to 2 μm.

  Next, the charge transport layer will be described. The charge transport layer is dissolved and coated together with the charge transport material and the binder resin, and can be used as a charge transport layer. As the binder resin, polycarbonate having a good film property (bisphenol A type, bisphenol Z type, bisphenol C type, or both of them). Polymer), polyarylate, polysulfone, polyester, methacrylic resin, polystyrene, vinyl acetate, epoxy resin, phenoxy resin, and the like. These binders can be used alone or as a mixture of two or more.

  Low molecular charge transport materials used in the charge transport layer are oxazole derivatives, oxadiazole derivatives, imidazole derivatives, triphenylamine derivatives, benzidine derivatives, α-phenylstilbene derivatives, hydrazone derivatives, triphenylmethane derivatives, anthracene derivatives, A styryl derivative, a carbazole derivative, a pyrene derivative, or the like can be used.

  The charge transport layer can be used by dissolving and coating a polymer charge transport material. Examples of the polymer charge transport material include those having a triarylamine represented by general formulas 4 to 13 in the main chain and side chain, for example, an acrylic resin having a triarylamine skeleton described in JP-A-5-202135, polyvinyl Carbazole and the like are used.

  Next, the case where the photosensitive layer has a single layer structure will be described. In the case of providing a single-layer photosensitive layer by a casting method or the like, a function separation type composed of a charge generating material, a low molecule and a binder resin is often mentioned. That is, the above-described materials can be used for the charge generation material and the charge transport material. In addition, a polymer charge transport material can be used in place of the low molecular charge transport material and the binder resin. Again, the materials described above can be used.

  Moreover, a plasticizer and a leveling agent can also be added as needed. Furthermore, as a binder resin that can be used as needed, the binder resin mentioned above in the charge transport layer may be used as it is, or the binder resin mentioned in the charge generation layer may be used in combination. The film thickness of the single-layer photoconductor is suitably about 5 to 100 μm, and preferably about 10 to 40 μm.

  Next, a first embodiment of a cleaning device according to the present invention will be described with reference to FIGS. 7 is an enlarged explanatory view of the main part of the vibration blade of the cleaning device, FIG. 8 is an explanatory front view of the vibration blade, and FIG. 9 is an explanatory view of the vibration blade as viewed from the front end side.

  The vibration blade 30 of the cleaning device 16 includes a blade member 31, a vibration transmission member 32 to which the blade member 31 is attached, a vibration means 33 attached to the vibration transmission member 32, and one end of the vibration transmission member 32. And a support member 34 that supports one end of the excitation means 33.

  The blade member 31 is an elastic body made of, for example, polyurethane rubber, and has a thickness in the range of 50 to 1500 μm, preferably in the range of 100 to 500 μm. If the thickness is too thin, it becomes difficult to ensure the amount of pressing of the blade member 31 against the image carrier 2 due to the undulation of the surface of the image carrier 2 and the blade member 31 itself. If the thickness is too thick, the vibration from the vibration transmitting member 32 is absorbed, and the vibration is not sufficiently transmitted to the tip of the blade member 31, so that the toner cleaning property is deteriorated. When the blade member 31 is thick, vibration transmission efficiency can be increased by using a hard member having a JIS hardness in the range of 85 to 100 ° as the material of the blade member 31.

  Here, depending on the manufacturing method of the thin urethane blade, it is possible to adopt a configuration in which one member, or two or more other members are interposed between the blade member 31 and the vibration transmitting member 32. For example, when a thin urethane blade is molded, it is integrally formed by molding on an existing resin film such as PET having a higher hardness than urethane. As a result, the nip portion of the flade member needs a sharp edge, but the handling of the cutting work for that purpose is improved. In this case, after integrally cutting PET and urethane, the PFT side is attached to the vibration transmission member 32 and attached.

  The vibration transmitting member 32 is made of a material that can vibrate and has higher rigidity than the elastic blade member 31, such as a metal member such as a mild steel plate or a SUS plate, or a resin molded member in which carbon or glass fiber is mixed. ing. The vibration transmitting member 32 has one end fixed to a support member 34 and a blade member 31 attached to the other end. The support member 34 is fixed to the housing of the cleaning device 16 or the like.

  The vibration means 33 applies vibration to the vibration transmitting member 32, and here, a laminated piezoelectric element as an electromechanical conversion element is used. By using a laminated piezoelectric element as the vibration means 33, it is possible to configure a vibration means that can easily obtain a displacement amount at low cost. In addition, since the multilayer piezoelectric element has a high natural frequency of 50 to 100 kHz and has a very large displacement force, the thickness of the vibration transmitting member 32 is increased by using the multilayer piezoelectric element. However, a configuration capable of responding up to a high frequency becomes easy.

  Here, the laminated piezoelectric element constituting the excitation means 33 is formed by alternately laminating, for example, 100 μm piezoelectric layers 33a and internal electrodes 33b and 33c per layer, and the internal electrodes are alternately drawn to both end faces to end face electrodes ( It is connected to the external electrode), and is configured to utilize the displacement in the d33 direction, which is the displacement in the stacking direction.

  It is also possible to adopt a configuration utilizing a displacement in the plane direction perpendicular to the stacking direction in which a plurality of layers are stacked using stacked piezoelectric elements, that is, a displacement in the d31 direction. The cost of the driver (driving circuit) can be reduced.

  As shown in FIGS. 8 and 9, a plurality of the vibration means 33 are arranged in the axial direction (width direction) of the image carrier 2. The number of the vibration means 33 may be one, but by arranging a plurality of vibration means at intervals, it is easy to obtain uniformity of vibration in the width direction of the vibration transmitting member 32. Although it is conceivable to provide one long laminated piezoelectric element, it is preferable to arrange a plurality of laminated piezoelectric elements at intervals rather than using a long laminated piezoelectric element from the viewpoint of manufacturing yield. .

  The vibration means 33 is provided near the tip of the vibration transmitting member 32 on the image carrier 2 side, that is, on the surface opposite to the attachment surface of the blade member 31. Depending on the configuration of the vibration transmitting member 32, the mounting position of the vibration means 33 is not particularly limited as long as it can vibrate the vibration transmitting member 32 between the fixed end of the vibration transmitting member 22 and the blade tip.

  As shown in FIG. 10, the cleaning device 16 includes a drive circuit 38 for commonly applying a drive signal Pv to the piezoelectric elements constituting the plurality of vibration means 33 of the vibration blade 30. ing. In this way, when a plurality of vibration means are provided in the width direction of the blade member, driving with a common drive circuit can improve the uniformity of vibration in the width direction of the blade member.

  The drive circuit 38 is configured by a drive control unit of the image forming apparatus, and applies a drive signal Pv to the vibration means 33 at a predetermined timing. In this embodiment, the entire width in the width direction of the image carrier 11 is cleaned with one vibration blade 30, but a plurality of vibration blades 30 are provided to cover the entire width in the width direction. In this case as well, it is preferable to drive the vibration means of the plurality of vibration blades 30 with a common drive circuit.

  In addition, a metallic member (conductive member) is used as the vibration transmission member 32, and one electrode of the piezoelectric element constituting the plurality of vibration means 33 is in direct contact with and electrically connected to the vibration transmission member 32. Thus, one electrode of the plurality of vibration means 33 can be commonly connected via the vibration transmission member 32. As a result, the drive signal can be applied with a simple circuit configuration. The direct contact can be easily obtained by finishing the bonding surface side of the electrode to a rough surface and bonding it to the vibration transmitting member 32 with a thin adhesive layer. Good.

  In the cleaning device 16 configured as described above, a drive signal Pv having a required frequency is supplied from the drive circuit 38 to the plurality of vibration means 33 to deform the piezoelectric elements constituting the plurality of vibration means 33 in the d33 direction. By applying the vibration, the vibration transmitting member 32 vibrates, the vibration of the vibration transmitting member 32 is transmitted to the blade member 31 and the blade member 31 slightly vibrates, and the blade member 31 is applied to the particulate matter 22 on the surface of the image carrier 2. It is possible to reduce the probability of collision and decrease the durability due to the loss of the particulate matter 22 of the image carrier 2 and damage to the blade member 31 itself.

  Here, a principle diagram of blade cleaning will be described with reference to FIG. As the image carrier 2 rotates, the blade member 31 is turned over as shown by the broken line in FIG. The turn-up portion is deformed (called shear deformation or compressive deformation) in the traveling direction (arrow A direction) of the image carrier 2, and the energy accumulated in the cleaning blade edge portion due to the stress is restored (rebound resilience). As a result, a so-called stick-slip movement occurs that returns to the original state.

  The toner T staying in the wedge-shaped portion 41 is cleaned by receiving a force returned from the blade member 31 in the direction opposite to the traveling direction of the image carrier 2. At this time, if the blade member 31 is in contact with the surface of the image carrier 2, the blade member 31 is subjected to local stress by the particulate matter 23 protruding from the surface of the image carrier 2, and damage is accelerated. Is done.

  Therefore, in the cleaning device 16 of the present invention, vibration is applied to the blade member 31 via the vibration transmitting member 32 by the vibration means 33, so that the blade member 31 is relaxed before the shear deformation becomes large, and the turned-up state is obtained. Eliminates in a very short time.

  This was experimentally verified by providing a torque detector 46 between the image carrier 2 and the drive motor 45 as shown in FIG. 12 and changing the torque depending on whether or not the blade member 31 was vibrated. . FIG. 13 shows the measurement results of torque with and without this vibration. In the figure, the horizontal axis represents the rotational speed of the photosensitive member (image carrier) (V1 <V2 etc.), and the vertical axis represents the torque.

  From the results of FIG. 13, it can be seen that the torque is greatly reduced as compared to when the blade member 31 does not vibrate. This is because the torque is reduced because the amount of shear deformation of the blade member 31 is reduced. When the rotation speed of the image carrier 2 is high, the torque is reduced because the time during which there is no vibration is shortened and the torque decreases. On the other hand, when the vibration is present, the amount of deformation is large. Gradually increases.

  In this way, by applying vibration from the vibration means 33 to the blade member 31 via the vibration transmitting member 32, the blade member 31 can be restored from the shear deformation state in a short time, and is applied to the surface of the image carrier 2. The stress on the blade member 31 by the protruding particulate material 23 and the damage to the image carrier 2 by the blade member 31 are reduced. As a result, damage to the blade member and filming due to the resin or wax as the toner composition can be prevented, and the durability (life) of the blade and the image carrier is improved.

  Here, the amount of displacement of the blade member 31 will be described. When the vibration transmitting member 32 is vibrated by the piezoelectric element serving as the vibration means 33 and the blade member 31 is vibrated, the tip of the blade member 31 has a micrometer of several μm. Vibrate. At this time, the displacement amount of the piezoelectric element (vibration means) is proportional to the voltage. The voltage applied to the piezoelectric element and the torque reduction rate are in a substantially linear relationship as shown in FIG. Therefore, by increasing the applied voltage, ie, displacement, to the piezoelectric element that is the vibration means 33, the amount of the blade member 31 to be restored (restored) from the shear deformation state of the blade member 31 is increased, and the torque reduction rate is improved. .

  Accordingly, the displacement amount (amplitude) of the blade member 31 is preferably at least 1/5 of the average diameter of the particulate matter 23 since at least the particulate matter 23 is buried. For example, when the average diameter of the particulate material 23 is 0.05 to 1.0 μm, it is preferably 0.01 to 0.2 μm or more. Thereby, the collision probability with the particulate matter is lowered, and the damage to the blade member can be more reliably reduced.

  Next, the generated force of the vibration means 33 will be described. During cleaning, the blade member 31 is pressed against the image carrier 2 and is compressed and deformed. This force is determined by the pressing force by the vibration transmitting member 32, that is, the amount of bending. Therefore, by making the generated force by the vibration member 33 larger than the bending force, in other words, by making the pressing force of the blade member 31 smaller than the generation force of the vibration member 33, the blade member 31 operates actively. Thus, the restoring force for turning up the blade member 31 is obtained. In addition, a slight gap is formed between the image carrier 2 and the blade member 31 by this force relationship. Further, when the driving frequency is sufficiently high, a state in which no turning occurs is formed.

Next, the relationship between the contact angle of the blade member 31 and the cleaning angle will be described with reference to FIGS.
As shown in FIG. 15, a surface (tip surface) that faces the opposite side in the advancing direction (arrow A direction) of the image carrier 2 with respect to the point of contact with the image carrier 2 among the ends of the blade member 31. ) The angle formed by 31a and the surface of the image carrier 2 is the cleaning angle θ1, and the angle formed by the surface (side surface) 31b and the surface of the image carrier 2 facing the same side as the traveling direction (arrow A direction) of the image carrier 2 The contact angle θ2.

  At this time, the cleaning angle θ1 when the blade member 31 contacts the image carrier 2 greatly affects the cleaning performance. That is, the cleaning angle θ1 becomes a toner rebound force when the blade member 31 is restored. If the angle θ1 at this time is too large, the toner only rises up, and the rebound efficiency is poor.

  Further, as shown in FIG. 16, when the cleaning angle θ1 is decreased, the blade member 31 is caught in the image carrier 2 and the edge portion 31e is separated from the image carrier surface 2 (B portion in FIG. 16). Squeal and chatter of the blade member 31 occur.

  On the other hand, the contact angle θ2 has a function of scraping the toner adhering to the image carrier 2. Therefore, when the angle θ2 is high, the scraping function is lost. Therefore, as shown in FIG. 17, when the cleaning angle θ1 is increased (synonymously, but the contact angle θ2 is decreased), the blade member 31 itself comes into contact with the belly and the front end surface 31a of the blade member 31 is obtained. No curling occurs (C portion in the figure), and in this case, the force to dampen the toner becomes weak, resulting in poor cleaning.

  From these points, the optimum cleaning performance is obtained by setting the setting angle of the blade member 31 such that the cleaning angle θ1> the contact angle θ2 and the cleaning angle θ1 is 45 ° ≦ θ1 ≦ 80 °.

  Next, a second embodiment of the cleaning device 16 will be described with reference to FIGS. 18 is an enlarged explanatory view of the main part of the vibration blade of the cleaning device, and FIG. 19 is an enlarged explanatory view of the main part of FIG.

  The vibration blade 50 of the cleaning device 16 includes a blade member 31, a vibration transmission member 32 to which the blade member 31 is attached, a vibration means 53 attached to the vibration transmission member 32, and one end of the vibration transmission member 32. The support member 54 which supports a part is provided.

  In this apparatus, a piezoelectric element as an electromechanical transducer, particularly a plate (single plate) piezoelectric element, is used as the vibration means 53. By using a plate-like piezoelectric element as the vibration means 53, it is possible to configure a vibration means that can easily obtain a displacement amount at low cost.

  The vibration means 53 is provided on the surface opposite to the attachment surface of the blade member 31 on the support member 54 side of the vibration transmission member 32, but the attachment position is not particularly limited.

  As shown in FIG. 19, the single-plate piezoelectric element constituting the vibration means 53 is printed on both surfaces of the piezoelectric layer 53a such as lead zirconate titanate, that is, on the bonding surface with the vibration transmitting member 32 and on the opposite surface. It has electrodes 33b and 33c made of baked Ag or the like. When a voltage of 100 to 300 V is applied to a piezoelectric element (piezoelectric layer 33 a) having a thickness of 0.3 to 0.5 mm polarized using the electrodes 33 b and 33 c, shrinkage deformation in the plate surface direction is caused. As a result, it is possible to apply deformation vibration that bends the vibration transmitting member 32. This bending vibration has a good deformation efficiency when the rigidity of the piezoelectric element (vibration means 53) and the vibration transmission member 32 is substantially the same, for example, a metal vibration transmission member 32 having a thickness of 0.2 to 0.4 mm, or a thickness. It is preferable to use a resin vibration transmission member having a thickness of 0.3 to 1.0 mm.

  Next, a different example of the third embodiment of the cleaning device 16 will be described with reference to FIGS. In addition, each figure is a principal part expansion explanatory drawing of the vibration blade of the cleaning apparatus.

  The vibration blade 60 of the cleaning device 16 includes a blade member 31, a vibration transmission member 62 having a portion having a different thickness to which the blade member 31 is attached, and vibration means 33 attached to the vibration transmission member 62. The support member 34 that supports one end of the vibration transmitting member 62 and one end of the vibration means 33 is provided.

  In the example of FIG. 20, the vibration transmitting member 62 is formed by changing the thickness of the single layer member to form a thin portion 62a and a thick portion 62b, and in the example of FIG. 21, the thick portion 62b is changed to a thin portion 61a. The member 62b1 is stacked. Here, the blade member 31 is attached to the thick portion 62 a of the vibration transmitting member 62.

  That is, when the blade member 31 is joined to a plate-like vibration transmission member having a substantially constant thickness with an adhesive, the vibration propagation performance by the vibration means is poor, and inefficient particularly when flexural vibration occurs.

  Therefore, the rigidity is changed by partially changing the plate thickness like the vibration transmitting member 62, and a portion that is easy to bend (thin portion 62a) and a portion that is difficult to bend (thick portion 62b) are provided. As a result, the portion with low rigidity (thin portion 62a) can convert the vibration excitation energy into energy, and the blade member 31 is joined to the portion with high rigidity (thick portion 62b) to increase the scraping force of the blade member 31. At the same time, the rigidity in the width direction of the image carrier 2 can be improved, and uniform cleaning properties can be provided in the width direction.

  Such a vibration transmission member 62 can be manufactured by cutting, etching, or forging an iron-based mild steel plate such as SECC. Further, as in the example of FIG. 22 described above, a thin plate and a thick plate can be bonded together to produce a portion having a large rigidity and a portion having a small rigidity. At this time, it is important that the bonding bonding is not performed with spots but is performed over the entire surface.

Next, the protruding amount of the blade member 31 from the vibration transmitting member will be described with reference to FIG. In addition, the code | symbol demonstrates using the thing of 1st Embodiment.
The blade member 31 and the vibration transmitting member 32 need to be bonded on the entire surface in order to maintain the vibration propagation characteristics, and an epoxy type is preferable as an adhesive, but primer bonding or By performing surface modification by ion sputtering or the like on the blade member 31 side, the bonding performance can be further improved.

  In order to efficiently propagate the vibration transmitted from the vibration transmitting member 32 to the tip of the blade member 31, the distance from the vibration transmitting member 32 of the blade member 31 becomes a problem. Since the blade member 31 is essentially an elastic body, the attenuation increases as the distance increases. Therefore, when the blade member 31 has a free end that is not joined to the vibration transmission member 32, the length of the free end (projection amount) has a great influence on the propagation characteristics to the image carrier 2.

  According to the experiment, as shown in FIG. 22, when the thickness of the blade member 31 is h and the protrusion amount from the vibration transmission member 32 is d, the protrusion amount d of the blade member 31 from the end face of the vibration transmission member 32 is small. The propagation efficiency was better, and even when the blade member 31 protruded to the thickness h, no significant performance degradation was observed. However, it has been confirmed that when the protrusion amount d exceeds the thickness h of the blade member 31, the propagation performance gradually decreases. Therefore, the protrusion amount d is preferably smaller than the blade thickness h.

Next, a fourth embodiment of the cleaning device 16 will be described with reference to FIG. FIG. 2 is an enlarged explanatory view of the main part of the vibration blade of the cleaning device.
Here, the blade member 31 is attached to the free end portion side of the vibration transmitting member 32 via an intermediate member 35 having an acoustic impedance smaller than that of the material for forming the vibration transmitting member. For example, the vibration transmission member 32 is made of metal (for example, iron), and the intermediate member 35 is made of resin.

  That is, the vibration transmission member 32 is preferably formed using a metal material in order to obtain vibration propagation and ease of displacement (flexibility), but the blade member 31 is preferably formed of a rubber material. . In this case, there is a large difference in the specific acoustic resistance (ρc) between the vibration transmitting member 32 and the blade member 31, so that significant attenuation occurs when propagating from the larger acoustic resistance to the smaller one.

For example, in the experiment of material and specific acoustic resistance (g / s / cm ² ), the vibration transmitting member 32 is made of iron (ρc: 270 × 104), and the blade member 31 is made of rubber (ρc: 1.4 × 104). Sometimes a 190-fold gap occurs.

Therefore, by using a resin material (ρc: 44 × 10 ⁴ ) between the vibration transmission member 32 and the blade member 31 as the intermediate member 35, the gap between the vibration transmission member 32 and the intermediate member 35 is greatly increased to 6 times. Decrease.

  As described above, the dissimilar member (intermediate member) is interposed between the vibration transmitting member and the blade member so that the acoustic impedance is reduced in the vibration propagation direction, so that reduction in propagation efficiency can be prevented. Here, although the intermediate member is a single layer, it may be a multilayer structure. Moreover, it can also be set as the structure which does not interpose an intermediate member by partially changing the acoustic impedance of a vibration transmission member (a blade member side is made small).

Next, a fifth embodiment of the cleaning device 16 will be described with reference to FIG. In addition, the figure is a principal part plane explanatory view of the vibration blade of the cleaning device.
Here, the vibration transmitting member 32 is provided with a plurality of extraction regions (thickening portions) 32d in the width direction between the plurality of excitation means 33, and is made easy to bend by reducing the cross-section coefficient of the beam. .

  Thereby, the efficiency of the bending deformation of the vibration transmitting member 32 toward the tip of the vibration transmitting member 32 by the piezoelectric element (vibration means 33) is further improved, and the blade member 31 can be vibrated more efficiently. It should be noted that the thinned portion 32d can be processed with good accuracy by pressing, etching, or the like, and it is not necessary to provide it in all of the portions where the vibration means 33 is not provided, and it is provided partially. Also good.

  Next, the process cartridge according to the present invention including the cleaning device according to the present invention will be described with reference to FIG. FIG. 2 is a schematic sectional view of the process cartridge.

  The process cartridge 100 is configured by integrally combining a plurality of components such as the image carrier 101, the charging unit 102, the developing unit 103, and the cleaning device 106 according to the present invention as a process cartridge, This process cartridge is configured to be detachable from a main body of an image forming apparatus such as a copying machine or a printer.

By providing the cleaning device 106 in a detachable process cartridge, it is possible to improve maintenance and easily replace the device with another device.

Next, a color image forming apparatus according to the present invention using the process cartridge according to the present invention will be described with reference to FIG.
In the image forming apparatus, the above-described process cartridges 100M, 100C, 100Y, and 100K are arranged for each color of magenta, cyan, yellow, and black along a transfer belt 111 that extends horizontally and circulates. The development toner on the image carrier 101 developed by each process cartridge 100 is fed from the paper feed cassette 112 onto the transfer belt 111 and transferred to the recording paper 113 conveyed by the transfer belt 111. , 114Y, and 114K, and sequentially discharged and discharged by a discharge roller 116 fixed by a fixing device 115.

  The process cartridge 100 has been described in the order of magenta, cyan, yellow, and black. However, the process cartridge 100 is not specified in this order, and may be arranged in any order.

Usually, since a color image forming apparatus has a plurality of image forming units, the apparatus becomes large. In addition, when each unit such as cleaning and charging fails individually or it is time to replace it due to its life, the apparatus is complicated and it takes a lot of time to replace the unit.

  Therefore, a small and highly durable color image forming apparatus that can be replaced by the user is obtained by integrally connecting the components of the image carrier, the charging unit, the developing unit, and the cleaning unit as a process cartridge 100. Can be provided. The configuration in which a plurality of process cartridges are provided is not limited to a color image forming apparatus.

1 is a schematic configuration diagram of an image forming apparatus according to the present invention including a cleaning device according to the present invention. FIG. 3 is an explanatory diagram illustrating a first example of an image carrier configuration of the image forming apparatus. It is explanatory drawing explaining the 2nd example of the image carrier structure of the image forming apparatus. It is explanatory drawing explaining the 3rd example of the image carrier structure of the image forming apparatus. It is explanatory drawing explaining the 4th example of the image carrier structure of the image forming apparatus. It is explanatory drawing explaining the 5th example of the image carrier structure of the image forming apparatus. It is principal part expansion explanatory drawing of the vibration blade of 1st Embodiment of the cleaning apparatus which concerns on this invention. It is front explanatory drawing of the vibration blade. It is explanatory drawing which looked at the vibration blade from the front end side. It is explanatory drawing explaining an example of the drive circuit system with respect to the cleaning apparatus. It is explanatory drawing with which it uses for description of the principle of a blade cleaning. It is explanatory drawing with which it uses for description of the measurement experiment of the presence or absence of the vibration with respect to a blade member, and the relationship of a torque. It is explanatory drawing which shows an example of the measurement result of the presence or absence of the vibration with respect to a blade member, an image carrier rotational speed, and a torque. It is explanatory drawing which shows an example of the measurement result of the relationship between the applied voltage with respect to a vibration means, and a torque reduction rate. It is explanatory drawing with which it uses for description of the cleaning angle and contact angle of a blade member. It is explanatory drawing with which it uses for description of the cleaning angle and contact angle of a blade member similarly. It is explanatory drawing with which it uses for description of the cleaning angle and contact angle of a blade member similarly. It is principal part expansion explanatory drawing of the vibration blade of 2nd Embodiment of the cleaning apparatus which concerns on this invention. It is a principal part expansion explanatory drawing of FIG. It is principal part expansion explanatory drawing of the vibration blade of 3rd Embodiment of the cleaning apparatus which concerns on this invention. It is a principal part expansion explanatory drawing of the vibration blade of the other example of the embodiment. It is explanatory drawing with which it uses for description of the protrusion amount of a blade member. It is principal part expansion explanatory drawing of the vibration blade of 4th Embodiment of the cleaning apparatus which concerns on this invention. It is plane explanatory drawing of the vibration blade of 5th Embodiment of the cleaning apparatus which concerns on this invention. It is explanatory drawing with which it uses for description of the process cartridge which concerns on this invention. 1 is a schematic configuration diagram of an image forming apparatus according to the present invention including a process cartridge according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 ... Image carrier 16, 106 ... Cleaning apparatus 23 ... Particulate matter 30 ... Excitation blade 31 ... Blade member 32 ... Vibration transmission member,
33 ... Excitation member 100 ... Process cartridge.

Claims (1)

In an image forming apparatus comprising an image carrier having a photosensitive layer containing particulate matter or an image carrier having a particulate matter-containing surface layer containing particulate matter on the photosensitive layer ,
The mounting surface of the plurality of vibrating means of the vibration transmission member fitted with a plurality of vibrating means is a blade member attached to the distal portion of the opposite surface,
The plurality of vibration means are arranged at intervals in the width direction of the image carrier,
The vibration transmission member is formed of a conductive member, and one electrode of each piezoelectric element constituting the plurality of excitation means is in direct contact with and electrically connected to the vibration transmission member. One electrode of each piezoelectric element constituting the plurality of vibration means is connected in common ,
A cleaning device is provided , wherein the vibration transmitting member vibrates by the plurality of vibration means, and vibrations of the vibration transmitting member are propagated to the blade member to vibrate the blade member. Image forming apparatus .

Images