JP2013088390A - Method for detecting contamination state on surface of member, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide member surface contamination state detecting method capable of accurately detecting a contamination state on a surface of a member, and to provide an image forming apparatus using the member surface contamination state detecting method.SOLUTION: Adhesive force generated between the surface of a member such as a photoreceptor 2, a developing roller 50, a charging roller 3, and a transfer belt 6, and a probe 61 of a cantilever 60 is measured, and a contamination state on the surface of the member is detected based on relation of adhesive force generated between the surface of the member and the probe of the cantilever, which is previously found out from the measured adhesive force, with the contamination state on the surface of the member.

Description

  The present invention relates to a member surface contamination state detection method for detecting a contamination state of a member surface, and an image forming apparatus using the member surface contamination state detection method.

  In recent years, image forming apparatuses have been improved in image quality and stability. This tendency is particularly noticeable in high-speed machines targeting the production market (for example, a copy center in a company that handles printing of manuals and proposals). In such a market, there is a demand for an image forming apparatus that can stably output high image quality over a long period of time, more than an image forming apparatus for office use.

  One factor that causes instability of the image forming apparatus is contamination of the surface of each member provided in the image forming apparatus. For example, if a contaminant such as toner filming or toner adhesion adheres to the surface of the photoconductor to contaminate the surface of the photoconductor, charging failure or charging unevenness occurs and an abnormal image is generated, so that stable image formation cannot be performed.

  The degree of contamination on the surface of the photoconductor depends directly on the output environment such as image density, print output interval, and temperature and humidity environment, but the output environment varies depending on the customer who uses the image forming apparatus. Are not necessarily uniform.

  In the image forming apparatus described in Patent Document 1, a contamination state on the surface of the photoconductor is detected by detecting a current flowing on the surface of the photoconductor, and the surface of the photoconductor is scraped off with a blade based on the detection result. The surface of the photoreceptor is refreshed by removing contaminants from the surface. As a result, contaminants can be removed from the surface of the photoreceptor at an appropriate timing regardless of the output environment, and stable image formation can be performed.

  As in the image forming apparatus described in Patent Document 1, in the method of detecting the current flowing on the surface of the photoconductor to detect the contamination state on the surface of the photoconductor, when the degree of contamination on the surface of the photoconductor is large, the effect is the current value. And the degree of contamination on the surface of the photoreceptor is easy to detect. However, when the degree of contamination on the surface of the photosensitive member is small, such as when a contaminant adheres to the surface of the photosensitive member with a very thin film thickness, the effect is difficult to appear in the current value, and the degree of contamination on the surface of the photosensitive member cannot be accurately detected. Problems arise.

  The case where the member to be detected for the contamination state is the photosensitive member has been described so far, but the member to be detected may be another member provided in the image forming apparatus such as a developing roller, a transfer belt, or a charging roller. Even if it exists, the same problem as mentioned above arises.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a member surface contamination state detection method capable of accurately detecting the contamination state of the member surface and an image forming apparatus using the member surface contamination state detection method. Is to provide.

  In order to achieve the above object, according to the first aspect of the present invention, in the member surface contamination state detection method, the adhesion force generated between the surface of the member and the probe of the cantilever is measured, and the measured adhesion force is used in advance. The contamination state of the surface is detected based on the relationship between the obtained adhesion force and the contamination state of the surface.

  In the present invention, the adhesion force generated between the surface of the member and the probe of the cantilever is measured. If the contaminant surface adheres to the surface of the member and the state of the surface of the member changes even slightly, the adhesive force generated between the surface of the member and the probe of the cantilever changes, so the influence of contamination on the surface of the member affects the adhesive force. Easy to appear. Thereby, not only when the contamination level of a member surface is large, but also when the contamination level of a member surface is small, the said adhesive force can be measured with a sufficient precision. Therefore, based on the relationship between the adhesion force obtained in advance and the contamination state of the member surface, the contamination state of the member surface can be accurately detected from the measured adhesion force.

  As mentioned above, according to this invention, there exists the outstanding effect that the contamination state of the member surface can be detected accurately.

7 is a flowchart of contamination state detection control on the surface of a photoreceptor. FIG. 2 is a schematic diagram illustrating a main configuration of a printer according to the present embodiment. 1 is a schematic configuration diagram showing a printer of a tandem type full-color image forming apparatus. 1 is a schematic configuration diagram showing a printer of a revolver type full-color image forming apparatus. The figure which showed the photosensitive layer of the photoreceptor. The figure which represented the shape of the toner typically in order to demonstrate shape factor SF-1. FIG. 3 is a longitudinal sectional view of an example of an intermediate transfer member used in an image forming apparatus. Schematic diagram of a piezo built-in cantilever. The figure which shows the installation position of the photosensitive body vicinity of the sensing apparatus provided with the piezo built-in type cantilever. The schematic diagram of the sensing apparatus seen from the photoconductor longitudinal direction. The schematic diagram of the sensing apparatus seen from the photoreceptor surface side. FIG. 3 is a diagram illustrating an installation position in the vicinity of a developing roller of a sensing device including a piezo built-in cantilever in a one-component developing device. FIG. 4 is a diagram illustrating an installation position in the vicinity of a developing roller of a sensing device including a piezo built-in cantilever in a two-component developing device. The figure which shows the installation position of the transfer belt vicinity of the sensing apparatus provided with the piezo built-in type cantilever. The figure which shows the installation position of the transfer roller vicinity of the sensing apparatus provided with the piezo built-in type cantilever. The figure which shows the structure which arranged the piezo built-in type cantilever in the shape of an array.

Hereinafter, an embodiment of an electrophotographic printer (hereinafter simply referred to as a printer) will be described as an image forming apparatus to which the present invention is applied.

  FIG. 2 is a schematic diagram illustrating a main configuration of the printer 100 according to the present embodiment. In the printer 100 shown in FIG. 2, a photoreceptor 2 that is rotationally driven clockwise in FIG. 2 is housed in a main body housing (not shown). Around the photosensitive member 2, a charging roller 3 as a charging unit, an optical writing device 4 as an electrostatic latent image forming unit, a developing device 5 as a developing unit, a transfer roller 16 as a transferring unit, and a cleaning unit A cleaning device 15, a static elimination device 8 as a static elimination means, and the like are provided.

  The printer 100 includes a paper feed cassette (not shown) that stores recording paper P as a plurality of recording materials. The recording paper P in the paper feed cassette is sent to the registration roller pair 9 one by one by a paper feed roller (not shown), and the timing is adjusted by the registration roller pair 9 and then transferred between the transfer roller 16 and the photosensitive member 2. Sent to the area.

  When image formation is performed in the printer 100 shown in FIG. 2, first, the photosensitive member 2 is rotationally driven clockwise in FIG. 2 to uniformly charge the surface of the photosensitive member 2 with the charging roller 3. Thereafter, the surface of the photoconductor 2 that is uniformly charged is irradiated with a laser modulated with image data by the optical writing device 4 to form an electrostatic latent image on the surface of the photoconductor 2. Toner is attached to the electrostatic latent image on the surface of the photoreceptor 2 by the developing device 5, thereby forming a toner image. This toner image is transferred onto the recording paper P that has been transported to the transfer area between the photoreceptor 2 and the transfer roller 16. The recording paper P to which the toner image has been transferred is conveyed to the fixing device 10. The fixing device 10 includes a fixing roller heated to a predetermined fixing temperature by a built-in heater, and a pressure roller pressed against the fixing roller with a predetermined pressure, and heats and applies the recording paper P conveyed from the transfer region. To fix the toner image on the recording paper P to the recording paper P. The fixed recording paper P is discharged onto a paper discharge tray (not shown).

  On the other hand, the transfer residual toner remaining on the surface of the photoreceptor 2 after passing through the transfer region is scraped off by the fur brush 502 and the cleaning blade of the cleaning device 15 and removed from the surface of the photoreceptor 2. Thereafter, the surface of the photoreceptor 2 is neutralized by the neutralization device 8, and the process proceeds to the next image forming step.

  FIG. 3 is a schematic configuration diagram illustrating a printer of the tandem type full-color image forming apparatus. The printer shown in the figure includes four image forming process units 1Y, 1C, 1M, and 1K for yellow, cyan, magenta, and black (hereinafter referred to as Y, C, M, and K). These use Y, C, M, and K toners of different colors as image forming substances for forming an image, but the other configurations are the same. Around the photosensitive member 2 that is driven to rotate clockwise in the drawing by a driving means (not shown), there are a cleaning device 15, a static elimination means (not shown), a charging roller 3, an optical writing device 4, a developing device 5, and the like. ing.

  A charging bias is applied from a charging bias power supply (not shown) to the charging roller 3 disposed so as to contact the photoconductor 2 or to face the photoconductor 2 with a predetermined gap. The charging roller 3 causes the surface of the photosensitive member 2 to be uniformly charged by causing a discharge between the charging roller 3 and the photosensitive member 2 while rotating counterclockwise in the figure. Instead of the charging roller 3, a charging brush may be brought into contact therewith. Further, as a charging means for uniformly charging the photosensitive member 2, a device that uniformly charges the photosensitive member 2 by a charger method, such as a scorotron charger, may be used.

  The charging roller 3 has a roller portion formed of a hard conductive material and is opposed to the photoconductor 2 through a minute gap, and may have a configuration described below. desirable. That is, the dimension in the axial direction is set to be slightly longer than the maximum image width that can be output by the printer (about 290 [mm] for an A4 landscape paper machine). It has a gap roller portion as a large diameter and insulating spacer. In such a configuration, the gap roller portions at both ends are brought into contact with the non-image forming regions existing at both end portions in the axial direction of the photosensitive member 2, so that 5-100 [μm between the central portion of the photosensitive member 2 and the photosensitive member 2. ] (More desirably 20 to 65 [μm]) can be easily formed. In this embodiment, it is set to 55 [μm].

  The surface of the photoreceptor 2 that is uniformly charged by the charging roller 3 is exposed and scanned by the scanning light emitted from the optical writing device 4 to carry an electrostatic latent image. The optical writing device 4 emits laser light or LED light modulated based on image information sent from an external personal computer or the like.

  The developing device 5 serving as a developing unit develops the electrostatic latent image to obtain a toner image by attaching toner to the electrostatic latent image carried on the surface of the photosensitive member by a known technique. This toner image is primarily transferred to an intermediate transfer belt described later.

  The cleaning device 15 removes the transfer residual toner adhering to the surface of the photoreceptor after the primary transfer process. In the cleaning device of this embodiment, a cleaning blade is disposed so as to rub against the surface of the photoreceptor, and the transfer residual toner attached to the surface of the photoreceptor is removed. Note that the cleaning device is not limited to scraping off the transfer residual toner adhering to the surface of the photoconductor with a cleaning blade. For example, the cleaning device scrapes off the transfer residual toner adhering to the surface of the photoconductor with a fur brush. There may be.

  The surface of the photoreceptor subjected to the cleaning process by the cleaning device 15 is neutralized by a neutralizing unit (not shown) and is prepared for the next image formation.

  Below the image forming process units 1Y, 1C, 1M, and 1K, a transfer unit 20 is disposed that moves the intermediate transfer belt 6 endlessly in the counterclockwise direction while stretching the intermediate transfer belt 6. In addition to the intermediate transfer belt 6, the transfer unit 20 as transfer means includes a driving roller 22, a driven roller 23, four primary transfer rollers 24Y, 24C, 24M, 24K, a secondary transfer roller 7, a belt cleaning device (not shown), and the like. ing.

  The intermediate transfer belt 6 is endlessly moved counterclockwise in the figure by the rotational driving of the driving roller 22 while being stretched by the driving roller 22 and the driven roller 23 arranged inside the loop.

  The four primary transfer rollers 24Y, 24C, 24M, 24M, 24K, 24Y, 24C, 24M, and 24K sandwich the intermediate transfer belt 6 moved endlessly in this way between the photoreceptors 2 of Y, C, M, and K colors. , K primary transfer nips are formed. Then, a transfer bias having a polarity opposite to that of the toner (for example, plus) is applied to the back surface (loop inner peripheral surface) of the intermediate transfer belt 6. The intermediate transfer belt 6 sequentially passes through the primary transfer nips for Y, C, M, and K along with the endless movement thereof, and the Y, C, and M on the color photoconductors 2 are on the front surface. , K toner images are superimposed and primarily transferred. As a result, a four-color superimposed toner image (hereinafter referred to as a four-color toner image) is formed on the intermediate transfer belt 6.

  A secondary transfer roller 7 to which a secondary transfer bias output from a power source (not shown) is applied is disposed outside the loop of the intermediate transfer belt 6, and this is between the drive roller 22 inside the belt loop. A secondary transfer nip is formed by sandwiching the intermediate transfer belt 6.

  A sheet feeding cassette (not shown) is disposed below the transfer unit 20. In this paper feed cassette, a plurality of recording papers P as transfer members are accommodated in a state of a stack of recording papers, and the uppermost recording paper P is sent to a paper feeding path (not shown) at a predetermined timing. . A registration roller pair 31 is disposed at the end of the paper feed path. The registration roller pair 31 temporarily stops the rotation of both rollers as soon as the recording paper P is sandwiched between the rollers rotating while abutting each other. Then, the recording paper P is fed toward the secondary transfer nip at a timing at which the recording paper P can be synchronized with the four-color toner image on the intermediate transfer belt 6.

  The four-color toner image formed on the intermediate transfer belt 6 has a secondary transfer electric field formed between the secondary transfer roller 7 to which the secondary transfer bias is applied and the grounded driving roller 22 and a nip pressure. As a result, the secondary transfer is performed on the recording paper P in the secondary transfer nip. Then, combined with the white color of the recording paper P, a full color toner image is obtained.

  Untransferred toner that has not been transferred to the recording paper P adheres to the intermediate transfer belt 6 after passing through the secondary transfer nip. This is removed by a belt cleaning device (not shown) in which the intermediate transfer belt 6 is sandwiched between the driven roller 23.

  A fixing device (not shown) is disposed above the secondary transfer nip. As is well known in electrophotographic image forming apparatuses, this fixing device fixes a toner image on a recording sheet by pressurization or heating.

  The Y, M, C, and K toners on the photoreceptor 2 of each color of Y, C, M, and K have a primary transfer bias that is opposite in polarity to the primary transfer nip for Y, C, M, and K. When applied, it may receive charge injection with a reverse polarity. For this reason, normal transfer toner particles and reversely charged toner particles are mixed in the transfer residual toner on each color photoconductor 2.

  In the printer having the above basic configuration, the four image forming process units 1Y, 1C, 1M, and 1K form toner images on the endlessly moving surfaces of the photosensitive members 2 of the respective colors as image carriers. It functions as a forming means. Further, the combination of the four image forming process units 1Y, 1C, 1M, and 1K and the transfer unit 20 functions as a toner image forming unit that forms a toner image on the endlessly moving surface of the intermediate transfer belt 6 that is an image carrier. ing.

  FIG. 4 is a schematic configuration diagram showing a printer of a revolver type full-color image forming apparatus. In this figure, this printer has only one photoconductor as an image carrier. Around the photosensitive member 2, there are disposed a cleaning device 15, a charge eliminating unit (not shown), a charging roller 3, an optical writing device 4, and four developing devices 5Y, C, M, and K.

  Each of the four developing devices 5Y, 5C, 5M, and 5K is individually reciprocated by a moving mechanism (not shown). Specifically, the developing sleeve can be reciprocated between a developing position where the developing sleeve is brought into contact with or close to the photosensitive member 2 and a retracted position which is further away from the photosensitive member 2. Only the one at the development position develops the electrostatic latent image on the photoreceptor 2.

  The configurations of the charge eliminating unit, the charging roller 3, and the optical writing device 4 are the same as those of the image forming process unit 1Y according to the above-described embodiment.

  First, an electrostatic latent image for Y is formed on the surface of the photoreceptor, and this is developed into a Y toner image by the Y developing device 5Y. Then, primary transfer is performed on the intermediate transfer belt 6. Thereafter, while the intermediate transfer belt 6 moves endlessly by three rounds, C, M, and K toner images are sequentially formed on the surface of the photoreceptor, and are sequentially transferred to the Y toner image on the intermediate transfer belt 6 in order to be primary transferred. . As a result, a four-color toner image is formed on the intermediate transfer belt 6.

  The secondary transfer roller 7 disposed below the intermediate transfer belt 6 is brought into contact with and separated from the belt by a contact and separation mechanism (not shown). Then, in the process where the intermediate transfer belt 6 moves endlessly over a plurality of turns and the Y, C, M, and K toner images are sequentially superimposed on the belt surface, the secondary transfer roller 7 is separated from the belt surface. Yes. Thereafter, when a four-color toner image is formed on the surface of the belt by overlay transfer, the secondary transfer roller 7 contacts the belt to form a secondary transfer nip. At the secondary transfer nip, the four-color toner images on the belt surface are collectively transferred onto the recording paper P.

  The cleaning device 15 removes the transfer residual toner adhering to the surface of the photoreceptor after the primary transfer process. In the cleaning device 15, a cleaning blade is disposed so as to contact and rub against the surface of the photoconductor to remove the transfer residual toner attached to the surface of the photoconductor. Note that the cleaning device is not limited to scraping off the transfer residual toner adhering to the surface of the photoconductor with a cleaning blade. For example, the cleaning device scrapes off the transfer residual toner adhering to the surface of the photoconductor with a fur brush. There may be.

  The member used in this embodiment can be suitably used as a member mounted on any of these image forming apparatuses. In particular, the development of a member that is difficult for toner to adhere by using the present invention in an image carrier, a developing unit, an intermediate transfer member, a cleaning device 15 and a charging unit where toner adhesion is not desired due to mechanical contact with the toner. It can be done efficiently.

(Electrophotographic photoreceptor)
An image carrier will be described as one member mounted on the image forming apparatus used in the present embodiment.

  An electrophotographic photosensitive member can be used as the image carrier used in the present embodiment. Since the electrophotographic photosensitive member transfers a toner image to a recording paper or an intermediate transfer member, it is not preferable that the electrophotographic photosensitive member has a large adhesive force to the toner. Therefore, this embodiment can be preferably used.

  As the electrophotographic photoreceptor, other layers than the above may be formed as long as at least an intermediate layer and a photosensitive layer are provided on the conductive support. For example, a function-separated type electrophotographic photosensitive member in which the photosensitive layer shown in FIG. 5 includes a charge generation layer (CGL) and a charge transport layer (CTL) will be described.

Examples of the conductive support include those having a volume resistance of 10 ¹⁰ [Ω · cm] or less, for example, metals such as aluminum, nickel, chromium, nichrome, copper, gold, silver, and platinum, tin oxide, and indium oxide. Metal oxide such as film or cylindrical plastic or paper coated by vapor deposition or sputtering, or a plate of aluminum, aluminum alloy, nickel, stainless steel, etc., and extrusion, drawing, etc. After forming the tube, it is possible to use a tube that has been surface-treated by cutting, superfinishing, polishing, or the like. Endless nickel belts and endless stainless steel belts can also be used as the conductive support.

  In addition, the conductive support dispersed in an appropriate binder resin and coated on the conductive support can also be used as the conductive support of the present embodiment. Examples of the conductive powder include carbon black, acetylene black, metal powder such as aluminum, nickel, iron, nichrome, copper, zinc and silver, or metal oxide powder such as conductive tin oxide and ITO. It is done. The binder resin used at the same time is polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer. , Polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, Examples thereof include thermoplastic, thermosetting resins, and photocurable resins such as melamine resin, urethane resin, phenol resin, and alkyd resin. Such a conductive layer can be provided by dispersing and applying these conductive powder and binder resin in a suitable solvent such as tetrahydrofuran, methyl ethyl ketone, or toluene.

  Furthermore, it is electrically conductive by a heat-shrinkable tube in which the conductive powder is contained in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, Teflon (registered trademark) on a suitable cylindrical substrate. Those provided with a conductive layer can also be used favorably as the conductive support of the present embodiment.

Next, the intermediate layer will be described.
The intermediate layer is provided for the purpose of improving adhesiveness, preventing moire, improving the coatability of the upper layer, and reducing the residual potential.

  The intermediate layer generally comprises a resin as a main component, but these resins are resins having a high solubility resistance to general organic solvents in consideration of applying a photosensitive layer thereon using a solvent. It is desirable to be. Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane, melamine resin, alkyd-melamine resin, and epoxy resin. Examples thereof include curable resins that form a three-dimensional network structure. In particular, an alkyd-melamine resin is preferable because it can satisfy many of the functions required as an intermediate layer. Further, fine powders such as metal oxides exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide and the like, or metal sulfides and metal nitrides may be added as inorganic pigments. In particular, titanium oxide is white with little absorption in visible light and near infrared light, and is preferable for increasing the sensitivity of the electrophotographic photosensitive member.

  These intermediate layers can be formed by a common coating method using an appropriate solvent. In order to improve the charging performance of the electrophotographic photosensitive member, at least ethylene glycol monoisopropyl is included in the intermediate layer coating solution. Ether is preferably contained in an amount of 0.1 [wt%] or more and 3 [wt%] or less.

  Further, as the intermediate layer, a metal oxide layer formed by using, for example, a sol-gel method using a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like is also useful.

In addition, an organic material such as Al ₂ O ₃ provided by anodization, polyparaxylylene (parylene), or inorganic materials such as SnO ₂ , TiO ₂ , ITO, and CeO _{2 is} prepared by a vacuum thin film manufacturing method. It may be provided. The thickness of the intermediate layer is about 0.1 [μm] to 10 [μm], preferably 1 [μ] to 5 [μm].

Next, the charge generation layer will be described.
For the charge generation layer, known charge generation materials can be used, for example, metal phthalocyanines such as titanyl phthalocyanine and chlorogallium phthalocyanine, metal-free phthalocyanines, azulenium salt pigments, squaric acid methine pigments, and symmetrical carbazole skeletons. Type or asymmetric azo pigments, symmetric or asymmetric azo pigments having a triphenylamine skeleton, symmetric or asymmetric azo pigments having a diphenylamine skeleton, symmetric or asymmetric azo pigments having a dibenzothiophene skeleton, Symmetric or asymmetric azo pigments having a fluorenone skeleton, symmetric or asymmetric azo pigments having an oxadiazole skeleton, symmetric or asymmetric azo pigments having a bis-stilbene skeleton, distyryl oxadia Symmetric or asymmetrical azo pigments having a dye skeleton, symmetric or asymmetrical azo pigments having a distyrylcarbazole skeleton, perylene pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane and triphenyl Examples thereof include methane pigments, benzoquinone and naphthoquinone pigments, cyanine and azomethine pigments, indigoid pigments, and bisbenzimidazole pigments.

  Examples of the phthalocyanine pigment used in the present embodiment include metal-free phthalocyanine or metal phthalocyanine. The synthesis method described in Moser and Thomas's “phthalocyanine compound” (Rheinhold, 1963), and other suitable methods. Use what is obtained by the method.

  Examples of metal phthalocyanines include those having a central metal such as copper, silver, beryllium, magnesium, calcium, zinc, indium, sodium, lithium, titanium, tin, lead, vanadium, chromium, manganese, iron, cobalt, etc. . Further, a metal halide having a valence of 3 or more may be present in the central nucleus of phthalocyanine instead of the metal atom. Various crystal forms of phthalocyanine are known, but known forms such as crystal forms such as α-type, β-type, Y-type, ε-type, τ-type, and X-type, and amorphous forms can be used.

  Among these, titanyl phthalocyanine (hereinafter referred to as TiOPc) having titanium as a central metal is particularly desirable because of its particularly high sensitivity and excellent characteristics.

Next, the charge transport layer will be described.
As described above, the charge transport layer can be formed by dissolving or dispersing the charge transport material and the binder resin in an appropriate solvent, and applying and drying the solution on the charge generation layer. Moreover, a plasticizer, a leveling agent, antioxidant, etc. can also be added as needed.

  Charge transport materials include hole transport materials and electron transport materials. Examples of the charge transport material include chloranil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4 , 5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-tri Examples thereof include electron-accepting substances such as nitrodibenzothiophene-5,5-dioxide and benzoquinone derivatives.

  Examples of the hole transport material include poly-N-vinylcarbazole and derivatives thereof, poly-γ-carbazolylethyl glutamate and derivatives thereof, pyrene-formaldehyde condensates and derivatives thereof, polyvinylpyrene, polyvinylphenanthrene, polysilane, oxazole derivatives, Oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triarylmethane derivatives, 9-styrylanthracene derivatives, pyrazolines Derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, etc., bisstilbene derivatives, enamine derivatives, etc. Other known materials may be mentioned. These charge transport materials may be used alone or in combination of two or more.

  As the binder resin, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, Polyvinylidene chloride, polyarate, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol Examples thereof include thermoplastic or thermosetting resins such as resins and alkyd resins.

  The amount of the charge transport material is suitably 20 to 300 parts by weight, preferably 40 to 150 parts by weight, per 100 parts by weight of the binder resin. Further, as described above, the thickness of the charge transport layer needs to be 30 [μm] or more from the viewpoint of durability. Further, when the thickness of the charge transport layer is extremely increased, there is a problem in that the resolution is lowered. Therefore, the thickness is preferably set to 30 [μm] to 50 [μm]. As the solvent used here, it is desirable to use a non-halogen solvent for the purpose of reducing environmental burdens, specifically, cyclic ethers such as tetrahydrofuran, dioxolane and dioxane, and aromatics such as toluene and xylene. Hydrocarbons and their derivatives are used favorably.

  In the photoreceptor of this embodiment, a protective layer may be provided on the outermost layer for the purpose of protecting the photosensitive layer and maintaining a low surface friction coefficient. As the binder resin used for the protective layer, ABS resin, ACS resin, olefin-vinyl monomer copolymer, chlorinated polyether, aryl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallylsulfone, Polybutylene, polybutylene terephthalate, polycarbonate, polyethersulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylbenten, polypropylene, polyphenylene oxide, polysulfone, polystyrene, polyarylate, AS resin, butadiene-styrene copolymer, polyurethane, Examples thereof include resins such as polyvinyl chloride, polyvinylidene chloride and epoxy resin.

  Further, a filler material may be added to the protective layer of the photoreceptor for the purpose of improving the wear resistance. As the filler, there are an organic filler and an inorganic filler. From the viewpoint of the hardness of the filler, the use of the inorganic filler is advantageous for improving the wear resistance. Such inorganic filler materials include metal powders such as copper, tin, aluminum, and indium, silica, tin oxide, zinc oxide, titanium oxide, alumina, zirconium oxide, indium oxide, antimony oxide, bismuth oxide, and calcium oxide. Metal oxides such as tin oxide doped with antimony, indium oxide doped with tin, metal fluorides such as tin fluoride, calcium fluoride and aluminum fluoride, and inorganic materials such as potassium titanate and boron nitride. .

These fillers can be surface-treated with at least one surface treatment agent, and it is preferable to do so from the viewpoint of dispersibility of the filler. Decreasing the dispersibility of the filler not only increases the residual potential, but also decreases the transparency of the coating, causes defects in the coating, and decreases the wear resistance. It can develop into a big problem. As the surface treatment agent, all conventionally used surface treatment agents can be used, but a surface treatment agent capable of maintaining the insulating properties of the filler is preferable. For example, a titanate coupling agent, an aluminum coupling agent, a zircoaluminate coupling agent, a higher fatty acid, etc., or a mixing treatment of these with a silane coupling agent, Al ₂ O ₃ , TiO ₂ , ZrO ₂ , Silicone, aluminum stearate, or the like, or a mixture thereof is more preferable from the viewpoint of filler dispersibility and image blur. The treatment with the silane coupling agent is strongly influenced by image blur, but the influence may be suppressed by performing a mixing treatment of the surface treatment agent and the silane coupling agent. The surface treatment amount varies depending on the average primary particle size of the filler used, but 3 [wt%] to 30 [wt%] is suitable, and 5 [wt%] to 20 [wt%] is more preferable. If the surface treatment amount is less than this, the filler dispersion effect cannot be obtained, and if it is too much, the residual potential is significantly increased.

  As the solvent used, all solvents used in the charge transport layer such as tetrahydrofuran, dioxane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, methyl ethyl ketone, acetone and the like can be used.

  In addition, the addition of the charge transport materials mentioned in the charge transport layer to the protective layer is effective and useful for reducing the residual potential and improving the image quality.

  As a method for forming the protective layer, conventional methods such as dip coating, spray coating, beat coating, nozzle coating, spinner coating, ring coating, etc. can be used. preferable.

  Although the thickness of the protective layer can be set freely, it is recognized that when the protective layer thickness is significantly increased, the image quality tends to be slightly deteriorated. About 0.1 [μm] to 10 [μm] is appropriate.

<Description of toner>
As the toner, toner in which an additive is contained in particles is used. As this additive, conventionally known additives can be used. Specifically, oxides such as Si, Ti, Al, Mg, Ca, Sr, Ba, In, Ga, Ni, Mn, W, Fe, Co, Zn, Cr, Mo, Cu, Ag, V, and Zr And composite oxides. In particular, silica, titania, alumina and the like, which are oxides of Si, Ti, and Al, are suitable. The addition amount of the additive is preferably 0.5 to 1.8 parts by weight, particularly preferably 0.7 to 1.5 parts by weight with respect to 100 parts by weight of the base particles.

  Further, as the toner, it is desirable to use a toner that has been subjected to a surface treatment using a treatment agent. As the treating agent used for the surface treatment, an organic silane compound or the like is preferable. For example, alkylchlorosilanes such as methyltrichlorosilane, octyltrichlorosilane, and dimethyldichlorosilane, and alkylmethoxysilanes such as dimethyldimethoxysilane and octyltrimethoxysilane. Further, hexamethyldisilazane, silicone oil, etc. may be used. Examples of the surface treatment method include a method of dipping an additive in a solution containing an organosilane compound and drying, a method of spraying a solution containing an organosilane compound on the additive and drying.

  As the toner, it is desirable to use a toner having a volume average particle diameter in the range of 3 [μm] to 7 [μm].

<About toner shape>
Equation 1 shows a formula for calculating the toner shape factor SF-1. As shown in FIG. 6, the shape factor SF-1 is a numerical value indicating the ratio of roundness in the shape of the spherical material, and the maximum length MXLNG of the elliptical shape formed by projecting the spherical material on a two-dimensional plane. The square is divided by the graphic area AREA and is multiplied by 100π / 4. That is, it is defined by Equation 1.

  In the present embodiment, a spherical toner having a shape factor SF-1 of 100 to 150 is preferable.

<Description of career>
As the magnetic carrier C, conventionally known ones such as iron powder, ferrite powder, magnetite powder, magnetic resin carrier having a particle size of about 20 [μm] to 200 [μm] can be used. In this printer, a core made of metal or resin contains a magnetic material such as ferrite and the surface layer is coated with a silicone resin or the like and has an average particle size of 55 [μm].

  As the coating material for the surface layer, amino resins such as urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, epoxy resin and the like can be used. Further, polyvinyl resin, polyvinylidene resin, acrylic resin, polymethyl methacrylate resin, polyacrylonitrile resin, polyvinyl acetate resin, polyvinyl alcohol resin, polyvinyl butyral resin, polystyrene resin, and the like may be used. Further, polystyrene resins such as styrene acrylic copolymer resins, halogenated olefin resins such as polyvinyl chloride, polyester resins such as polyethylene terephthalate resin and polybutylene terephthalate resin, and the like may be used. Further, polycarbonate resins, polyethylene resins, polyvinyl fluoride resins, polyvinylidene fluoride resins, polytrifluoroethylene resins, polyhexafluoropropylene resins, copolymers of vinylidene fluoride and acrylic monomers, and the like may be used. Further, a copolymer of vinylidene fluoride and vinyl fluoride, a fluoroterpolymer such as a terpolymer of tetrafluoroethylene, vinylidene fluoride, and a non-fluorinated monomer, or a silicone resin may be used. In addition, you may contain electrically conductive powder etc. in coating resin as needed. As such conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide, or the like can be used. These conductive powders preferably have an average particle diameter of 1 [μm] or less. This is because when the average particle diameter is larger than [1 μm], it is difficult to control the electric resistance.

<Charging part>
One type of charging member is a charging roller using a roller system. The image bearing member is uniformly charged by the charging roller. If dirt is attached to the charging roller at this time, the image bearing member is unevenly charged, which causes disturbance of the image output from the image forming apparatus. Since most of the dirt adhering to the charging roller is toner, it is preferable that the toner is difficult to adhere to the charging roller. Therefore, the present invention can be preferably used.

The charging member has an ion conductive rubber layer formed on a stainless steel core. The resistance of the rubber layer is about 10 ⁴ [Ω] to 10 ⁸ [Ω] in terms of resistance value. The rubber hardness of the roller is 40 [°] or more, preferably 70 [°] or more, according to JIS-A. Moreover, what has electroconductivity other than rubber | gum may be sufficient and an elastomer, resin, etc. are mention | raise | lifted. These also desirably have a hardness corresponding to the rubber hardness. When a resin is used, since the material does not have elasticity, it is easy to maintain the gap accurately, that is, there is an advantage that a difference in gap between the photosensitive member and the photosensitive member is less likely to occur in the axial direction.

A surface layer having a resistance value of about 10 ¹⁰ [Ω] is formed on the surface layer. This is to prevent a phenomenon in which current flows in a concentrated manner when there is a low resistance part such as a pinhole on the photoconductor. This surface layer prevents the current from concentrating on the pinhole. It is out. The resistance value of the surface layer may be 10 ¹⁰ [Ω] or more.

<Development part>
A developing unit that develops an electrostatic latent image formed on a photoreceptor generally has a developing roller as a member that supplies toner to the photoreceptor. Since the developing roller has a function of delivering the toner to the image carrier, it is not preferable that the developing roller has a large adhesion force to the toner. Therefore, the present invention can be preferably used.

<Developing roller of one-component developing device>
The developing roller has a roller portion whose outer peripheral portion is formed of an elastic material having a low coefficient of friction such as rubber in order to charge toner of the one-component developer by friction, and a metal shaft portion penetrating the center of the roller portion. It consists of.

  Examples of the material used for the elastic material include elastic members such as elastic material rubber and elastomer. Specifically, butyl rubber, fluorine-based rubber, acrylic rubber, EPDM, NBR, acrylonitrile-butadiene-styrene rubber, natural rubber, Isoprene rubber, styrene-butadiene rubber, butadiene rubber, urethane rubber, syndiotactic 1,2-polybutadiene, epichlorohydrin rubber, polysulfide rubber, polynorbornene rubber, thermoplastic elastomer (for example, polystyrene, polyolefin, poly One type or two or more types selected from the group consisting of vinyl chloride, polyurethane, polyamide, polyurea, polyester, and fluororesin) can be used. However, it is not limited to the said material.

<Developing roller of two-component developing device>
A roller composed of a roller portion whose outer peripheral portion is formed of an elastic material having a low coefficient of friction such as rubber, and a metal shaft portion penetrating the center of the roller portion, like the developing roller of the one-component developing device, Further, a roller whose surface is made of metal, for example, metal such as aluminum, nickel, chromium, nichrome, copper, gold, silver, platinum, or the like is also used. The surface of the developing roller may be appropriately coated with a coating material in order to stabilize the quality over time. The surface layer coating material may have a polarity opposite to that of the toner, or may have the same polarity when the toner is not provided with a function of tribocharging the toner to a desired polarity. Examples of the former surface layer coating material include materials containing a resin, such as silicon, acrylic, and polyurethane, and rubber. Examples of the latter surface layer coating material include a material containing fluorine. A so-called Teflon (registered trademark) material containing fluorine has a low surface energy and excellent releasability, and therefore toner filming with time is extremely difficult to occur. Also, as general resin materials that can be used for the surface layer coating material, polytetrafluoroethylene (PTFE), tetrafluoroethylene perfluoroalkyl vinyl ether (PFA), tetrafluoroethylene / hexafluoropropylene polymer (FEP) , Polychlorotrifluoroethylene (PCTFE), tetrafluoroethylene / ethylene copolymer (ETFE), chlorotrifluoroethylene / ethylene copolymer (ECTFE), polyvinylidene fluoride, polyvinyl fluoride (PVF), etc. Can do. In order to obtain conductivity, a conductive material such as carbon black is often contained in this. In order to coat the developing roller more uniformly, other resins may be mixed together.

<Intermediate transfer member>
Since the intermediate transfer member transfers the toner image onto the recording paper, it is not preferable that the intermediate transfer member has a large adhesion to the toner. Therefore, the present invention can be preferably used.

  FIG. 7 is a longitudinal sectional view of an example of an intermediate transfer member used in an image forming apparatus to which the present invention can be applied. The intermediate transfer member used in the image forming apparatus is composed of at least a base layer, an elastic layer, and a surface coat layer. The intermediate transfer member is provided with an elastic layer having low hardness so that it can be deformed with respect to the toner layer and the paper having poor smoothness at the transfer nip portion. Since the surface of the intermediate transfer body can be deformed following local unevenness, it is possible to obtain good adhesion without excessively increasing the transfer pressure with respect to the toner layer, there is no loss of character transfer, It is possible to obtain a transfer image having excellent uniformity and having no transfer unevenness in a solid portion or the like even on paper having poor smoothness. Examples of the material used for the elastic layer include elastic members such as elastic material rubber and elastomer. Specifically, butyl rubber, fluorine rubber, acrylic rubber, EPDM, NBR, acrylonitrile-butadiene-styrene rubber, natural rubber, Isoprene rubber, styrene-butadiene rubber, butadiene rubber, urethane rubber, syndiotactic 1,2-polybutadiene, epichlorohydrin rubber, polysulfide rubber, polynorbornene rubber, thermoplastic elastomer (for example, polystyrene, polyolefin, poly One type or two or more types selected from the group consisting of vinyl chloride, polyurethane, polyamide, polyurea, polyester, and fluororesin) can be used. However, it is not limited to the said material.

  The thickness of the elastic layer depends on the hardness and the layer structure, but is preferably in the range of 0.07 [mm] to 0.3 [mm]. If it is thicker than 0.3 [mm], it will bend by the pressing force of the cleaning blade, or the cleaning blade will be pushed into the intermediate transfer member, thereby preventing smooth movement of the intermediate transfer member. On the other hand, when the thickness is as small as 0.07 [mm] or less, the pressure on the toner on the intermediate transfer member becomes high at the secondary transfer nip portion, the transfer is likely to be lost, and the toner transfer rate is lowered.

  The hardness of the elastic layer is preferably 10 ≦ HS ≦ 65 (JIS-A). Although the optimum hardness differs depending on the layer thickness of the intermediate transfer member, if the hardness is lower than 10 [°] JIS-A, transfer deficiency tends to occur. On the other hand, when the hardness is higher than 65 [°] JIS-A, it is difficult to stretch the roller, and since it is stretched by long-term stretching, there is no durability and early replacement is necessary.

  In addition, the base layer of the intermediate transfer member is made of a resin with little elongation. Specifically, materials used for the base layer include polycarbonate, fluororesin (ETFE, polyvinylidene fluoride, etc.), polystyrene, chloropolystyrene, poly-α-methylstyrene, styrene-butadiene copolymer, styrene-vinyl chloride copolymer. Polymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer (styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-acrylic acid) Butyl copolymer, styrene-octyl acrylate copolymer and styrene-phenyl acrylate copolymer), styrene-methacrylate copolymer (styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer) Coalescence, styrene-phenyl methacrylate Polymers), styrene resins such as styrene-α-chloroacrylic acid methyl copolymer, styrene-acrylonitrile-acrylic acid ester copolymer (monopolymer or copolymer containing styrene or a styrene-substituted product), methacryl Acid methyl resin, butyl methacrylate resin, ethyl acrylate resin, butyl acrylate resin, modified acrylic resin (silicone modified acrylic resin, vinyl chloride resin modified acrylic resin, acrylic / urethane resin, etc.), vinyl chloride resin, styrene-vinyl acetate Copolymer, pinyl chloride-vinyl acetate copolymer, rosin modified maleic acid resin, phenol resin, epoxy resin, polyester resin, polyester polyurethane resin, polyethylene, polypropylene, polybutadiene, polyvinylidene chloride, ionomer resin, polyureta Resins, silicone resins, ketone resins, ethylene - can be used ethyl acrylate copolymer, xylene resin and polyvinyl butyral resin, polyamide resin, one kind or two kinds or more selected from the group consisting of modified polyphenylene oxide resin. However, it is not limited to the said material.

  In addition, a method of forming a core layer made of a material that prevents elongation, such as canvas, from a rubber material having a large elongation in the base layer, and forming an elastic layer thereon can be used. As a material for preventing elongation used for the core layer at this time, for example, natural fibers such as cotton and silk, polyester fibers, nylon fibers, acrylic fibers, polyolefin fibers, polyvinyl alcohol fibers, polyvinyl chloride fibers, One kind selected from the group consisting of synthetic fibers such as polyvinylidene chloride fiber, polyurethane fiber, polyacetal fiber, polyfluoroethylene fiber and phenol fiber, inorganic fibers such as carbon fiber and glass fiber, and metal fibers such as iron fiber and copper fiber Alternatively, two or more types can be used and those in the form of yarn or woven fabric can be used. Of course, the material is not limited to the above. The above-described yarn may be twisted in any manner, such as one or a plurality of filaments twisted, one-twisted yarn, various twisted yarns, double yarn, or the like. Further, for example, fibers of a material selected from the above material group may be blended. Of course, the yarn can be used after being subjected to an appropriate conductive treatment. On the other hand, the woven fabric can be any woven fabric such as knitted weave, and of course, a woven fabric that has been woven can also be used and can be subjected to a conductive treatment.

  Further, the coating layer on the surface of the intermediate transfer body is for coating the surface of the elastic layer with, for example, a fluororesin, and is composed of a layer having good smoothness. The material used for the coating layer is not particularly limited, but generally, a material that reduces secondary toner transfer to the surface of the intermediate transfer member to improve secondary transferability is used. For example, one or more types of polyurethane, polyester, epoxy resin, etc., or materials that reduce surface energy and increase lubricity, such as fluorine fats, fluorine compounds, fluorocarbons, titanium oxide, silicon carbide, etc. Can be used by dispersing one type or two or more types or changing the particle size as required. Further, it is also possible to use a material such as a fluorine-based rubber material in which a heat treatment is performed to form a fluorine layer on the surface and the surface energy is reduced.

  If necessary, the base layer 11, the elastic layer 12 or the coat layer 13 is, for example, carbon black, graphite, metal powder such as aluminum or nickel, tin oxide, titanium oxide, antimony oxide, Conductive metal oxides such as indium oxide, potassium titanate, antimony oxide-tin oxide composite oxide (ATO), and indium oxide-tin oxide composite oxide (ITO) can be used. Here, the conductive metal oxide may be coated with insulating fine particles such as barium sulfate, magnesium silicate, and calcium carbonate. However, it is not limited to the said material.

  Here, this inventor devised the method of detecting the change of a member surface state by measuring the adhesive force produced between the detection target member surfaces with a cantilever. The inventor of the present application measures the adhesion force generated between the cantilever provided with the tip of the silicon and the member surface using the adhesion force measuring method described in Japanese Patent Application Laid-Open No. 2009-186965. Then, it was found that there is a correlation between the measured adhesion force and the contamination state of the surface of the member. That is, if the degree of contamination on the member surface is small, the amount of adhesion is small, and if the degree of contamination on the member surface is large, the adhesion is also large. Therefore, based on the adhesion force generated between the surface of the member and the probe of the cantilever, the contamination state on the surface of the member can be accurately detected based on the relationship between the adhesion force and the contamination state determined in advance.

  When the contamination progress of the member surface is detected by a sensing device provided with a cantilever, the member surface is detected by a cleaning blade of a cleaning device as in the image forming apparatus described in Patent Document 1 and Japanese Patent Application Laid-Open No. 9-230767. By shaving, the contaminant surface can be removed from the member surface to refresh the member surface. Further, in the case of adopting a configuration in which a lubricant such as zinc stearate is supplied to the surface of a member with a brush, as in the image forming apparatus described in Japanese Patent No. 4589011, the member can be obtained by increasing the amount of lubricant supplied. The surface can be refreshed.

  When the optical lever method is employed as the adhesion force measuring method, the sensing device is increased in size due to the configuration of the sensing device used for the adhesion force measurement. For this reason, it is easy to adopt as a dedicated measuring device for measuring the adhesion force with the surface of a member taken out from the image forming apparatus, but it has a compact size so that the adhesion force with the member surface can be measured in the image forming apparatus. Difficult to configure. In other words, a sensing device that employs an optical lever system irradiates a laser beam on the back surface of the cantilever and detects the reflected light with a four-divided detector. Adhesive force is generated between the member surface and the cantilever, and force is exerted on the cantilever. The amount of warping or bending of the cantilever when is applied is detected by the movement of reflected light on the quadrant detector. Therefore, a laser generation source, a quadrant detector, an optical system, and the like are required, and the sensing device cannot be made compact, and it is very difficult to install the sensing device in the image forming apparatus.

  Therefore, in the present embodiment, a cantilever with a built-in piezoresistor having a piezoresistor formed on the surface of the cantilever is used. A sensing device is used.

[Configuration example 1]
In this configuration example, a mechanism for sensing contamination of the photoreceptor 2 will be described.
The surface of the photosensitive member, and toner filming to deposit the toner adheres film shape, easy adhesion occurs blur substances that cause blurred images such as NO _X and SO _X generated by such discharge of the charging roller 3. In addition, there is a system for supplying a lubricant such as zinc stearate to the surface of the photosensitive member with a brush in order to improve the cleaning property of the surface of the photosensitive member. However, when the supply of the lubricant becomes insufficient in such a system, Tends to cause cleaning failure and toner filming. Therefore, a mode in which a change in the surface of the photoreceptor can be detected and the refresh mode can be appropriately started will be described.

  As shown in FIG. 8, a piezo built-in cantilever 60 is provided with a probe 61 at the tip, and a U-shaped piezoresistor 90 is formed on the surface of the cantilever. The piezoresistor 90 is formed as a p + piezoresistor, for example, by selectively implanting p-type impurity ions in a U-shape on the surface of an n-type silicon substrate. Conversely, when a p-type silicon substrate is used, n-type impurity ions are implanted into the substrate surface to form an n + piezoresistor.

  In the present configuration example, as shown in FIG. 9, the sensing device 80 including the piezo built-in cantilever 60 is disposed downstream of the cleaning device 15 in the photosensitive member rotation direction and upstream of the charging roller 3 in the photosensitive member rotation direction. Install. Thereby, the surface state of the photoreceptor 2 can be detected without adversely affecting image formation.

  In addition, as shown in FIG. 11, the adhesive force on the surface of the photoconductor can be detected by installing the piezo-embedded cantilever 60 at the center and both ends in the longitudinal direction of the photoconductor by holding it with a holding member 75. The area increases, and the surface state of the entire photoconductor can be detected.

  The measurement of the adhesion force between the photosensitive member surface and the cantilever using the piezo built-in cantilever 60 is basically the same as the method using an atomic force microscope (for example, Japanese Patent Application Laid-Open No. 2002-62253). reference).

  FIG. 1 shows a flowchart of the contamination state detection control on the surface of the photoreceptor. First, contact and separation between the surface of the photoreceptor and the probe 61 of the cantilever 60 are continuously performed (S1). Atomic force (attractive force or repulsive force) between the surface of the photosensitive member and the probe 61 of the cantilever 60 generated at that time bends the cantilever 60, and the cantilever 60 is bent in this way, thereby forming on the cantilever 60. The measured piezoresistance value varies. Further, the relationship between the piezo resistance value and the adhesion force corresponding to the amount of bending of the cantilever 60 is obtained in advance. Then, a change in the resistance value of the piezoresistor 90 corresponding to the amount of bending of the cantilever 60 at the moment of separation between the surface of the photoreceptor and the probe 61 of the cantilever 60 is detected (S2), and from the detected value of the resistance value, Based on the relationship between the piezoresistance value and the adhesion force obtained in advance, the adhesion force between the photoreceptor surface and the cantilever is obtained (S3).

  If the contaminant surface adheres to the surface of the photoconductor and the state of the photoconductor surface changes even slightly, the adhesion force generated between the photoconductor surface and the probe 61 of the cantilever 60 changes. The influence is likely to appear on the adhesion force. Thereby, not only when the degree of contamination of the photoreceptor surface is large, but also when the degree of contamination of the photoreceptor surface is small, the adhesion force can be measured with high accuracy. Therefore, based on the relationship between the adhesion force obtained in advance and the contamination state of the photoreceptor surface, the contamination state of the photoreceptor surface can be accurately detected from the measured adhesion force (S4). Therefore, contaminants can be removed from the surface of the photoreceptor at an appropriate timing, and stable image formation can be performed.

  Further, since the detector that detects the amount of bending of the cantilever 60, that is, the piezoresistor 90 is formed in the piezo built-in cantilever itself, the size can be smaller than the sensing device 80 that detects the amount of bending of the cantilever 60 by the optical lever type. be able to.

  However, when the sensing device 80 including a piezo built-in cantilever is incorporated in the image forming apparatus as in this configuration example, the cantilever 60 shown in FIG. 10 and FIG. This is performed by the holding driving mechanism 70. In addition, it is possible to use this drive mechanism 70 also comprising a piezo element or the like.

  Measurement of the adhesion force between the photosensitive member surface and the cantilever by the sensing device 80, that is, detection of the state of the photosensitive member surface, may be always performed during the operation of the image forming apparatus, or at every predetermined output interval (for example, every ten print outputs). You can do it. Further, it is not always necessary to perform the operation while the photoreceptor 2 is stationary. For example, a method in which the driving mechanism 70 of the piezo built-in cantilever 60 is vibrated at a frequency of 100 [Hz] so that the photosensitive member 2 and the piezo built-in cantilever 60 are brought into contact with each other and the adhesion force at that time is continuously measured. Is also possible.

  The selection of the piezo built-in cantilever 60 is most influenced by the spring constant. This is because if the spring constant is too small, the piezo built-in cantilever 60 cannot be peeled off from the surface of the photosensitive member, and if the spring constant is too large, the detection sensitivity of the adhesive force is deteriorated. Specifically, a piezo built-in cantilever 60 having a spring constant in the range of 0.1 [N / m] to 10 [N / m] is preferably used.

  The adhesion force between the photosensitive member surface and the piezo built-in cantilever increases when contamination such as toner filming or adhesion of a blur substance progresses on the photosensitive member surface or when the supply of lubricant is insufficient. Therefore, the adhesion force between the surface of the photosensitive member in the initial state where the surface of the photosensitive member is not soiled and the piezo built-in cantilever is measured in advance, and the value obtained by setting a predetermined margin for the initial adhesion force value is increased in contamination. The threshold value may be used.

  In the case of the piezo built-in type cantilever 60, the bending or warping of the cantilever tip is detected as a change in resistance of the piezoresistor 90 provided at the base of the cantilever. Therefore, it is possible to determine whether the contamination has progressed by setting a resistance change corresponding to the threshold adhesion force in advance.

  When the progress of contamination on the surface of the photosensitive member is detected by the sensing device 80 having such a piezo built-in cantilever 60, the surface of the photosensitive member is scraped by the cleaning blade of the cleaning device 15 to cause toner filming, a blur substance, or the like. Can be removed to refresh the surface of the photoreceptor. More specifically, the surface of the photoreceptor can be forcibly scraped with a cleaning blade by rotating the photoreceptor 2 in a state where the image forming process from the charging process to the transfer process is stopped.

  Further, as in the image forming apparatus described in Japanese Patent No. 4589011, the image forming apparatus according to the present configuration example may employ a configuration in which a lubricant such as zinc stearate is supplied to the surface of the photoconductor with a brush. . When such a configuration is adopted, the surface of the photoreceptor can be refreshed by increasing the supply amount of the lubricant. More specifically, the amount of lubricant supplied to the surface of the photoconductor is increased by increasing the contact pressure of the brush that supplies the photoconductor 2 to the photoconductor 2 or by increasing the rotational speed of the brush. The surface of the photoreceptor can be refreshed.

[Configuration example 2]
In this configuration example, a mechanism for sensing contamination of the developing roller 50 will be described.
The characteristics of the developing roller 50 are also deteriorated due to contamination called toner filming or sticking, like the photosensitive member 2.

  In the case of the one-component method, a streak image or the like is generated because the developing roller 50 cannot maintain the toner conveyance and charging functions. In the case of the two-component system, the developer transport function deteriorates and the pumping amount decreases, so that the image density changes. In either method, the contamination on the surface of the developing roller 50 directly affects the image quality characteristics. Therefore, it is important to accurately detect the contamination on the surface of the developing roller and refresh the developing roller surface appropriately.

  In this configuration example, the sensing device 80 including the piezoelectric built-in cantilever 60 similar to that in the configuration example 1 is used. However, the installation position and sensing timing of the sensing device 80 are different between the one-component method and the two-component method. . This is because in the two-component system, the surface of the developing roller is exposed if it is downstream of the agent separation pole in the developing roller rotation direction, but in the one-component system, the surface of the developing roller is not exposed unless a solid image is output.

  FIG. 12 shows an example of a one-component developing device, in which a sensing device 80 including a piezo built-in cantilever 60 is installed at a position after passing through the developing region. During the operation of the apparatus, the sensing device 80 is separated from the developing roller surface by about 100 [μm] so as not to contact the toner layer on the developing roller surface. Sensing of the surface of the developing roller by the sensing device 80 is performed while the device is stopped after outputting a solid image. At this time, the sensing device 80 is brought close to the surface of the developing roller by a driving device such as a stepping motor (not shown), and further, the developing roller surface and the tip of the cantilever are brought into contact with each other by a driving device driven by a piezo element. The operation for measuring the adhesion force between the developing roller surface and the piezo built-in type cantilever is the same as that in the configuration example 1, and the description thereof is omitted.

  FIG. 13 is a schematic diagram showing the two-component developing device 5 and the photosensitive member 2, and is an explanatory diagram showing a normal magnetic flux density (absolute value) distribution A on the surface of the developing sleeve 51 of the developing device 5. is there.

  A two-component developing device 5 shown in FIG. 13 includes a developing roller 50 in a casing 56. The developing roller 50 includes a developing sleeve 51 that is rotatably provided, and a magnet roll 52 that is included in the developing sleeve 51 and that is provided so as not to rotate. Is a developer carrying member carrying the developer on the surface. Further, the developing device 5 includes a developer container 54 that stores a developer to be supplied to the surface of the developing sleeve 51, and a transport screw that is a developer agitation transport member that stirs and transports the developer in the developer container 54. 55.

  The developer in the developer accommodating portion 54 in which the toner and the magnetic carrier are mixed is conveyed onto the surface of the developing sleeve 51 while being agitated by the conveying screw 55. At this time, the developer has a charge amount necessary for developing the latent image on the photoreceptor 2 while being stirred and transported by the transport screw 55.

  The developer transported while being stirred and charged is supplied onto the developing sleeve 51 and then transported toward the opposing position between the developing sleeve 51 and the photoreceptor 2 along the rotation direction of the developing sleeve 51. . After the conveyance on the developing sleeve 51 is started, the conveyance amount of the developer on the developing sleeve 51 is regulated by the layer thickness regulating member 53. That is, the positional relationship between the surface of the developing sleeve 51 and the layer thickness regulating member 53 is determined by the amount of developer to be supplied to the position facing the photoconductor 2, and the distance is 0.1 [mm] to 2.. It is in the range of 0 [mm]. More strictly, it is determined by the linear velocity of the photosensitive member 2 and the developing sleeve 51, the diameter of the developing sleeve 51, the toner concentration in the developer, and the like.

  A DC or DC + AC bias is applied to the developing sleeve 51 from a developer carrier bias power source (not shown). In this apparatus example, the developer in the developer accommodating portion 54 is supplied onto the developing sleeve 51 by the conveying screw 55. The developer supplied onto the developing sleeve 51 is conveyed in the rotation direction of the developing sleeve 51. The developer is transported to a position where the developing sleeve 51 and the layer thickness regulating member 53 are opposed to each other, and passes through this position, thereby forming a developer thin layer in an amount necessary for image output. Thereafter, the developer is transported to a facing portion between the developing sleeve 51 and the photoreceptor 2. At the opposite portion, the toner in the developer on the developing sleeve 51 moves to the latent image on the photosensitive member 2 due to the potential difference between the surface of the photosensitive member 2 and the surface of the developing sleeve 51, and the latent image on the photosensitive member 2 is moved. The image is developed.

  The magnet roll 52 included in the developing sleeve 51 is made of a magnetic powder of Sr ferrite or Ba ferrite, PA (polyamide) material such as 6PA or 12PA, EEA (ethylene / ethyl copolymer) or EVA (ethylene / ethylene copolymer). A plastic magnet or a rubber magnet in which an ethylene compound such as a vinyl copolymer), a chlorine material such as CPE (chlorinated polyethylene), or a polymer compound of a rubber material such as NBR is mixed can be used.

  Further, the magnet molded body constituting each magnetic pole of the magnet roll 52 is a rod-like block extending in the rotation axis direction of the developing sleeve 51. In order to obtain a narrow and high magnetic characteristic, it is desirable to use a material of Br> 0.5 [T], and many of them are Ne-based (Ne.Fe.B, etc.) or Sm-based (Sm.Co, Sm, Fe, N, etc.) rare earth magnets or plastic magnets or rubber magnets in which these magnet powders are mixed with a polymer compound similar to the above can be used.

  The magnet roll 52 is provided with a plurality of fixed magnetic poles, S1 poles, N1 poles, S2 poles, N2 poles, and S3 poles. Since the developing sleeve 51 rotates in the direction of the arrow in the figure, the developer moves on the surface of the developing sleeve 51 in the order of S1 pole → N1 pole → S2 pole → N2 pole → S3 pole → agent separation.

  The developer in the developer container 54 is pumped onto the surface of the developing sleeve 51 by the S1 pole that acts as a pumping pole. The developer that has been pumped up is carried on the surface of the developing sleeve 51 by the magnetic force of the S1 pole, and passes through a facing position between the developing sleeve 51 and the layer thickness regulating member 53 by the rotation of the developing sleeve 51. At this time, the S1 pole acts as a doctor pole. After that, the N1 pole magnetic force acting as a developing pole is raised at the opposing position between the developing sleeve 51 and the photosensitive member 2 and contributes to development. The developer on the developing sleeve 51 that has passed the position facing the photoreceptor 2 is carried on the developing sleeve 51 by the magnetic force of the S2 pole and the N2 pole acting as the transport pole, and the S3 pole is rotated by the rotation of the developing sleeve 51. Reach position. Thereafter, it drops from the developing sleeve 51 into the developer accommodating portion 54 by the repulsive force between the S3 pole and the S1 pole. At this time, the S3 electrode acts as an agent separating electrode.

  In the two-component developing device shown in FIG. 13, the sensing device 80 including the piezo built-in cantilever 60 is connected to the S3 pole and the S1 pole that is the pumping pole downstream of the S3 pole that is the agent separation pole in the developing sleeve rotation direction. Install between. In the two-component type developing device, the surface of the developing sleeve is exposed between the agent separating electrode and the pumping electrode downstream in the developing sleeve rotation direction from the agent separating electrode. There is no need to change the position of the sensing device 80 between operation and stop. Further, since the surface of the developing sleeve is exposed in this manner, the surface of the developing sleeve can be sensed by the sensing device 80 regardless of whether the apparatus is operating or stopped. The operation of measuring the adhesion force between the developing sleeve surface and the piezo built-in type cantilever is the same as that in the configuration example 1, and the description thereof is omitted.

  When the progress of contamination on the surface of the developing sleeve is detected by the sensing device 80 including the piezo built-in cantilever 60, the surface of the developing sleeve can be refreshed by continuously outputting an image with a high image area ratio on the photosensitive member 2. This is because a large amount of the external additive attached to the toner in the developer is transferred to the surface of the developing sleeve and acts as an abrasive that scrapes off the surface of the developing sleeve.

[Configuration example 3]
In this configuration example, a mechanism for sensing contamination of the intermediate transfer belt 6 will be described.
In the case of the intermediate transfer belt 6, surface contamination due to toner or the like and insufficient supply amount of a lubricant such as zinc stearate lead to a decrease in transferability and deterioration in image quality.

  In this configuration example, the sensing device 80 including the piezo built-in cantilever 60 is installed downstream of the secondary transfer position in the intermediate transfer belt rotation direction as shown in FIG. The operation for measuring the adhesion force between the surface of the intermediate transfer belt and the piezo built-in type cantilever is the same as that in the configuration example 1, and the description thereof is omitted.

  In the case where the progress of contamination on the surface of the intermediate transfer belt is detected by the sensing device 80 including the piezo built-in cantilever 60, the intermediate transfer belt is fed by a lubricant application device (not shown) that supplies a lubricant to the surface of the intermediate transfer belt with a brush. The surface of the intermediate transfer belt can be refreshed by increasing the amount of lubricant supplied to the surface. More specifically, the amount of lubricant supplied to the surface of the intermediate transfer belt 6 is increased by increasing the contact pressure of the brush supplying the lubricant to the intermediate transfer belt 6 or increasing the number of rotations of the brush. Thus, the surface of the intermediate transfer belt can be refreshed.

[Configuration Example 4]
In this configuration example, a mechanism for sensing contamination of the charging roller 3 will be described.
In the case of the charging roller 3, the toner is transferred from the photosensitive member 2 to the surface of the charging roller, or zinc stearate whose composition has been changed by the discharge at the charging roller 3 is transferred from the photosensitive member 2 to the surface of the charging roller. The surface of the charging roller is contaminated. If the surface of the charging roller is contaminated in this manner, uneven charging of the surface of the photosensitive member by the charging roller 3 is caused, and finally, unevenness of image density is generated.

  In this configuration example, as shown in FIG. 15, a sensing device 80 including a piezo built-in cantilever 60 is installed downstream of the cleaning roller 40 for cleaning the charging roller surface in the charging roller rotation direction. The operation for measuring the adhesion force between the surface of the charging roller and the piezo built-in cantilever is the same as that in the configuration example 1, and the description thereof is omitted.

  When the progress of contamination on the surface of the charging roller is detected by the sensing device 80 including the piezo built-in cantilever 60, the contact pressure of the cleaning roller 40 with respect to the charging roller 3 is increased, or the rotational speed of the cleaning roller 40 is increased. As a result, the charging roller surface can be refreshed.

[Configuration Example 5]
In the sensing device 80 of the configuration example 1, the configuration example 2, the configuration example 3 and the configuration example 4, since the single sensing device 80 has one piezo built-in cantilever 60, for example, a member to be detected When the sensing device 80 is arranged at each of the upper longitudinal center and both ends, the surface states at a total of three positions on the member are detected.

  On the other hand, as shown in FIG. 16, it is also possible to have a structure in which a plurality of piezo built-in cantilevers 60 are arranged in an array, and by using a single sensing device 80 to sense a plurality of points, It becomes possible to detect the contamination state of the surface of the member which becomes more accurate.

[Configuration Example 6]
In the configuration example 1, the configuration example 2, the configuration example 3, the configuration example 4 and the configuration example 5, a commercially available piezo built-in cantilever 60 is used, and the probe 61 of the cantilever 60 which comes into contact with a member to be detected is used. The tip diameter is about 10 [nm]. On the other hand, by fixing the toner or particles having a size almost equal to that of the toner to the tip of the cantilever 60 as the probe 61 and performing sensing using the cantilever 60, the contamination state of the member surface can be more accurately detected. Can be detected.

  As the size of the toner fixed to the tip of the cantilever or the particle having substantially the same diameter as the toner, 1 [μm] to 10 [μm] is preferable, and 5 [μm] is particularly preferable. As a result, the diameter of the probe 61 of the cantilever 60 is substantially equal to the toner diameter, and therefore the adhesion force between the surface of the member to be detected and the cantilever with built-in piezo measured by the sensing device 80 having the built-in piezo cantilever 60 is increased. , Closer to the adhesion force of the toner. Therefore, it is possible to more accurately detect the contamination state of the member surface with the toner.

  In addition, for attaching the toner or particles having the same diameter as the toner to the tip of the cantilever, a dedicated device as described in JP-A-2002-62253 or an atomic force microscope (AFM) is used. Can be done. Note that the toner or particles having substantially the same diameter as the toner may be fixed to the tip of the cantilever using an adhesive such as an epoxy resin.

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
(Aspect A)
In the member surface contamination state detection method, the adhesion force generated between the surface of the member and the probe of the cantilever is measured, and the relationship between the adhesion force obtained in advance and the contamination state of the surface is determined from the measured adhesion force. Based on this, the contamination state of the surface is detected. According to this, as described in the above embodiment, the contamination state of the member surface can be detected with high accuracy.
(Aspect B)
In (Aspect A), the cantilever is provided with a piezoresistor whose resistance value is changed by bending or warping of the cantilever tip, and the adhesion force is obtained based on the resistance value. According to this, as described in the above embodiment, the configuration can be made more compact than the optical lever method, and it can be easily arranged in the apparatus.
(Aspect C)
In (Aspect A) or (Aspect B), the probe has a diameter of 1 [μm] to 10 [μm]. According to this, as described in the above embodiment, the measured adhesion force becomes closer to the toner adhesion force, and the contamination state of the member surface can be detected more accurately.
(Aspect D)
In (Aspect A), (Aspect B) or (Aspect C), a plurality of the cantilevers are provided in an array. According to this, as described in the above embodiment, the area where the adhesion force on the member surface can be detected is expanded, and the contamination state of the member surface can be detected more accurately.
(Aspect E)
In (Aspect A), (Aspect B), (Aspect C), or (Aspect D), the member is at least one of a photoconductor, a transfer belt, a developing roller, and a charging roller. According to this, as described in the above embodiment, the surfaces of the photoconductor, the transfer belt, the developing roller, and the charging roller can be appropriately refreshed.
(Aspect F)
In an image forming apparatus including an image forming unit and a member surface contamination state detection unit that detects a contamination state of a member included in the image formation unit, the member surface contamination state detection unit includes (Aspect A) and (Aspect B). ), (Aspect C) or (Aspect E) member surface contamination state detection method is used. According to this, since the contamination state of the member can be accurately detected as described in the above embodiment, an abnormal image can be suppressed. Further, since the member can be replaced at an appropriate timing, the member life is not shortened more than necessary.
(Aspect G)
In (Aspect F), the apparatus has a lubricant application unit for applying a lubricant to the surface of the photoreceptor, and the lubricant is based on the contamination state of the photoreceptor surface detected by the member surface contamination state detection unit. The amount of the lubricant applied by the applying means is adjusted. According to this, as described in the above embodiment, an appropriate amount of lubricant can be supplied to the surface of the photoreceptor at an appropriate timing.
(Aspect H)
(Aspect F) having a lubricant application means for applying a lubricant to the transfer belt surface, and based on the contamination state of the transfer belt surface detected by the member surface contamination state detection means, The amount of the lubricant applied by the applying means is adjusted. According to this, as described in the above embodiment, an appropriate amount of lubricant can be supplied to the transfer belt surface at an appropriate timing.
(Aspect I)
(Aspect F) has a developer discharge mode for discharging the developer from the developing roller surface to the photoreceptor surface, and based on the contamination state of the developing roller surface detected by the member surface contamination state detection unit, The discharge amount of the developer discharged in the developer discharge mode is adjusted. According to this, as described in the above embodiment, the developer can be discharged by an appropriate amount at an appropriate timing.
(Aspect J)
(Aspect F) includes a rotatable cleaning roller that contacts the surface of the charging roller and cleans the surface of the charging roller, and is based on the contamination state of the surface of the charging roller detected by the member surface contamination state detection unit. The rotation amount of the cleaning roller is adjusted. According to this, as described in the above embodiment, the cleaning roller can be rotated at an appropriate timing and at an appropriate rotation speed.

DESCRIPTION OF SYMBOLS 1 Image forming process part 2 Photoconductor 3 Charging roller 4 Optical writing device 5 Developing device 6 Intermediate transfer belt 7 Secondary transfer roller 8 Static elimination device 9 Registration roller pair 10 Fixing device 11 Base layer 12 Elastic layer 13 Coating layer 15 Cleaning device 16 Transfer roller 20 Transfer unit 22 Drive roller 23 Driven roller 24 Primary transfer roller 31 Registration roller pair 50 Developing roller 51 Developing sleeve 52 Magnet roll 53 Layer thickness regulating member 54 Developer container 55 Conveying screw 56 Casing 60 Cantilever 61 Probe 70 Driving Mechanism 75 Holding member 80 Sensing device 90 Piezoresistor 100 Printer

Japanese Patent No. 4529395

Claims (10)

  The adhesion force generated between the surface of the member and the probe of the cantilever is measured, and the contamination state of the surface is determined based on the relationship between the adhesion force and the contamination state of the surface determined in advance from the measured adhesion force. Detecting a contamination state of a member surface. In the member surface contamination state detection method of claim 1,
A method for detecting a contamination state of a member surface, wherein the cantilever is provided with a piezoresistor whose resistance value is changed by bending or warping of the tip of the cantilever, and the adhesion force is obtained based on the resistance value. In the member surface contamination state detection method of Claim 1 or 2,
A member surface contamination state detection method, wherein the probe has a diameter of 1 [μm] to 10 [μm]. In the member surface contamination state detection method according to claim 1, 2, or 3,
A member surface contamination state detection method comprising a plurality of the cantilevers arranged in an array. In the member surface contamination state detection method according to claim 1, 2, 3 or 4,
The member surface contamination state detection method, wherein the member is at least one of a photoconductor, a transfer belt, a developing roller, and a charging roller. Image forming means;
In an image forming apparatus comprising a member surface contamination state detection unit for detecting a contamination state of a member included in the image forming unit,
6. The image forming apparatus according to claim 1, wherein the member surface contamination state detection means uses the member surface contamination state detection method according to claim 1, 2, 3, 4 or 5. The image forming apparatus according to claim 6.
It has a lubricant application means for applying a lubricant to the surface of the photoreceptor,
An image forming apparatus, wherein the amount of lubricant applied by the lubricant applying means is adjusted based on the contamination state of the photoreceptor surface detected by the member surface contamination state detecting means. The image forming apparatus according to claim 6.
It has a lubricant application means for applying a lubricant to the transfer belt surface,
An image forming apparatus comprising: adjusting the amount of lubricant applied by the lubricant applying unit based on a contamination state of the transfer belt surface detected by the member surface contamination state detecting unit. The image forming apparatus according to claim 6.
A developer discharge mode for discharging the developer from the surface of the developing roller to the surface of the photosensitive member, and in the developer discharge mode based on the contamination state of the surface of the developing roller detected by the member surface contamination state detection unit; An image forming apparatus that adjusts a discharge amount of the developer to be discharged. The image forming apparatus according to claim 6.
A rotatable cleaning roller that contacts the surface of the charging roller and cleans the surface of the charging roller;
An image forming apparatus characterized in that the rotation amount of the cleaning roller is adjusted based on the contamination state of the charging roller surface detected by the member surface contamination state detection means.

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