JP2007322861A - Developing device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing device in which toner is prevented from leakage from a developing roller end. <P>SOLUTION: The developing device is constituted so that a smooth belt-like member is provided on a sealing member provided at an end of a developer carrier, wherein the belt-like member is provided obliquely, such that its length-side part faces the inner side of the developer carrier toward downstream, in the rotating direction of the developer carrier. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a developing device in which a seal member is provided at an end portion of a developing roller.

  In general, an electrophotographic image forming apparatus such as a printer, a copying machine, or a facsimile is equipped with a developing cartridge that can be freely attached and detached. The developing cartridge includes a toner container that contains toner and a developing roller that carries the toner supplied from the toner container. At the time of image formation, the developing roller in the developing device mounted on the apparatus main body is rotated to supply toner to the electrostatic latent image formed on the photosensitive drum to form a visible image. A toner image is formed by transferring and fixing to a transfer sheet.

  Such a developing cartridge is provided with a seal member in order to prevent toner carried on the roller from leaking from both ends in the axial direction due to the rotational driving of the developing roller. This seal member is disposed at both ends in the axial direction of the developing roller so as to slide on the outer peripheral surface of the developing roller, so that the toner carried on the developing roller does not leak out from the end of the roller.

  The seal member is required to prevent toner leakage and ensure a stable rotational drive of the developing roller. In order to satisfy this requirement, there is a technique that realizes a reduction in adhesion and rotational torque by applying a pressing force to the developing roller by applying a tensile force to a seal member integrally attached to the developing device main body ( For example, see Patent Document 1).

  In addition, in order to ensure the above-described pressing force and rotational torque, the material of the seal member has also been examined, and for example, a Teflon (registered trademark) felt material has been used. Furthermore, in order to provide durability that can cope with high-speed operation of the developer carrier, for example, a convex weave is provided on the seal member obliquely, and the toner that comes to the roller end along the weave is placed on the developing chamber side. A seal member that can be returned is also disclosed (see, for example, Patent Document 2).

By the way, with the recent development of digital technology, there has been a demand for an image forming technology that accurately reproduces a minute dot image of, for example, 1200 dpi (dpi; number of dots per inch (2.54 cm)) level. Then, in order to accurately reproduce such a fine dot image, a reduction in the diameter of the toner has been studied, and a polymerized toner that can be subjected to various controls in the manufacturing process (for example, see Patent Document 3). As a result, it has become possible to obtain a small-diameter toner having a particle size of several microns.
JP-A-2-230172 JP 2003-107902 A JP 2000-214629 A

  As described above, as the diameter of the toner used for image formation is reduced, the toner leakage prevention function of the developing cartridge has been required to have a higher level. That is, as the toner diameter is reduced, the toner easily enters the gap between the seal member and the developing roller, and the need to prevent toner leakage from the end portion of the developing roller has emerged.

  The present invention relates to a developing device in which a seal member is provided at an end portion of a developing roller, and an object thereof is to provide a developing device in which toner does not leak from the end portion of the developing roller even when toner of several micron level is filled.

  The object is achieved by the following means.

  According to the first aspect of the present invention, "in the developing device in which the seal member is provided at the end portion of the developer carrier, a smooth belt-like member is provided on the seal member, and a longitudinal portion of the belt-like member is And provided on the seal member so as to be inclined with respect to the longitudinal direction of the developer carrier and to face the inside of the developer carrier toward the downstream side in the rotation direction of the developer carrier. A developing device. ].

  According to a second aspect of the present invention, “the belt-like member is provided on the seal member with the portion on the longitudinal side inclined by 30 ° to 75 ° with respect to the longitudinal direction of the developer carrying member, and has a thickness of 50 μm. The developing device according to claim 1, wherein the developing device is about 200 μm. ].

  According to a third aspect of the invention, “the developing device according to the first or second aspect, wherein the belt-like member is made of polytetrafluoroethylene”. ].

  According to a fourth aspect of the present invention, there is provided an image forming apparatus comprising the developing device according to any one of the first to third aspects. ].

  According to the present invention, the smooth belt-like member provided on the seal member provided at the end of the developing roller has its longitudinal side facing the inside of the developer carrying member toward the downstream in the rotation direction of the developer carrying member. In this way, toner leakage from the end of the developing roller was eliminated. In particular, according to the configuration of the present invention, toner leakage from the end of the developing roller is surely prevented, so that toner leakage from the end of the developing roller is prevented even when image formation is performed using a small-diameter toner of several microns. It came to be.

  As described above, according to the present invention, the smooth belt-like member is provided on the seal member attached to the end portion of the developing roller, and the rotation of the developing roller is performed when the long side portion constituting the belt-like member rotates the developing roller. It was provided so as to face the inside of the developing roller toward the downstream in the direction. That is, the belt-like member is provided on the seal member so that the longitudinal side portion thereof is inclined with respect to the longitudinal direction of the developing roller, and when the developing roller is rotated, the developing roller is moved downstream in the rotational direction. It is arranged to face the inside.

  By arranging the belt-like member in this manner, the toner leakage from the end of the developing roller has been eliminated. The presence of the belt-like member improves the adhesion between the developing roller and the seal member, and the gap between the roller and the seal member. This is presumably because the belt-like member can reliably prevent the movement of the toner that has entered. That is, the belt-like member on the seal member blocks the toner that has entered the gap between the developing roller and the seal member to prevent movement, and the longitudinal side portion is slanted so that the longitudinal side portion faces downward when the developing roller rotates. It is estimated that no toner spills from the end of the developing roller.

  Hereinafter, the present invention will be described in detail.

  First, the developing device according to the present invention will be described.

  FIG. 1 shows an example of a developing device according to the present invention. FIG. 1A shows a cross section of a developing device 31 (hereinafter also referred to as a developing device 31). As shown in FIG. 1A, the developing device 31 presses the developing roller 32 that supplies toner to the photosensitive drum 10, the hopper portion 34 that stores the toner supplied to the developing roller 32, and the developing roller 32. The seal member 36 and the toner regulating member 38 and the like are disposed on the surface. The toner regulating member 38 regulates the amount of toner supplied from the developing roller 32 to the photosensitive drum 10 and charges the toner supplied to the photosensitive drum 10.

  FIG. 1B is a perspective view showing the developing roller 32 corresponding to the developer carrier referred to in the present invention constituting the developing device 31 and the seal members 36 disposed at both ends of the developing roller 32. The seal member 36 is provided outside a region where a toner layer is formed on the developing roller 32 when an image is formed. A belt-like member 37 is disposed on the seal member 36, and the belt-like member 37 is composed of the seal member 36 and the developing roller 32. It is arranged to be sandwiched between.

  Here, the seal members 36 disposed at both ends of the developing roller 32 will be described. As shown in FIG. 1A, the seal member 36 is disposed between the developing roller 32 and the developing device main body. A curved surface is formed between the developing roller 32 and the developing device main body, and the seal member 36 is arranged in a state bent along the curved surface.

  The seal member 36 will be further described with reference to FIG. FIG. 2 is a schematic diagram showing the positional relationship between the developing roller 32, the seal member 36, and the belt-like member 37.

  As shown in FIG. 2, the seal member 36 provided with the belt-like member 37 is an area adjacent to the outside of the area where the toner layer is formed on the developing roller 32 during image formation (hereinafter, this area (hereinafter, the outside of the toner layer forming area). (Adjacent region) is arranged at the end of the developing roller 32). Further, the longitudinal direction of the developer carrier and the inner side in the longitudinal direction in the present invention are directions indicated by solid arrows in FIG. 2 (a), and the longitudinal direction of the developing roller and the inner side of the developing roller in the drawing. It is shown. Further, the white arrow in the figure is the sliding direction of the developing roller 32 on the seal member 36.

  As shown in FIG. 1, the seal member 36 is disposed along the curved surface in the developing device and the developing roller 32. Therefore, the seal member 36 is preferably made of a material having a certain degree of flexibility, and can be formed as a flexible film. Made of resin material. Examples of the resin material that can be molded as a flexible film include vinyl resins such as low density polyethylene, high density polyethylene, and Teflon (registered trademark), polyester resins such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate. Examples thereof include polyamide resins such as nylon and cellulose resins such as cellulose acetate.

  Next, the strip member 37 will be described. As shown in FIG. 2A, a smooth belt-like member 37 is provided on the surface of the seal member 36 that contacts the developing roller 32. The band-shaped member 37 is arranged in the form shown in FIG. That is, the longitudinal portion of the belt-like member 37 is disposed so as to face the inner side in the longitudinal direction of the developing roller 32 toward the downstream side in the rotation direction of the developing roller 32 (the direction indicated by the white arrow in the drawing). . That is, the belt-like member 37 is provided on the seal member 36 so that the longitudinal side portion thereof is inclined with respect to the longitudinal direction of the developing roller 32, and toward the downstream side in the rotational direction with respect to the rotational direction of the developing roller 32. It is arranged so that the longitudinal direction faces the inside of the developing roller 32 in the longitudinal direction. In the present invention, this is expressed as “the long side portion is provided so as to face the inside of the developer carrying member downstream in the rotation direction of the developer carrying member”.

  FIG. 2B shows the configuration of the seal member in which the longitudinal side portions of the seal member 36 and the belt-like member 37 are attached obliquely, and the longitudinal side portion of the belt-like member 37 referred to in the present invention is shown in the drawing. It refers to a part.

  Moreover, the strip | belt-shaped member 37 used by this invention has smoothness, and this smoothness is expressed by selecting the resin material represented by polytetrafluoroethylene. A resin material that imparts smoothness to the belt-shaped member 37 will be described later.

  In the present invention, the belt-like member 37 is provided on the seal member 36 so that the longitudinal portion thereof is inclined with respect to the inner side in the longitudinal direction of the developing roller 32. In this manner, by providing the belt-like member 37 between the developing roller 32 and the seal member 36, the adhesion between the developing roller 32 and the seal member 36 is improved, and a gap is hardly generated between them. Even if toner enters between the developing roller 32 and the seal member 36, the toner that moves through the gap by the rotation of the developing roller 32 is blocked by the end of the belt-like member 37 and does not move any further. Further, since the longitudinal side portion of the belt-like member 37 is disposed obliquely with respect to the inner side in the longitudinal direction of the developing roller 32, the toner blocked by the belt-like member 37 gradually moves on the developing roller 32 as the developing roller 32 rotates. Move inward in the longitudinal direction. That is, the belt-like member 37 improves the adhesion between the developing roller 32 and the seal member 36 and also functions as a guide member that returns the toner that has entered the gap between the two to the inside in the longitudinal direction of the developing roller 32.

  In this way, the belt-like member 37 is provided on the seal member 36 so that the longitudinal side portion of the belt-like member 37 is inclined with respect to the longitudinal direction of the developing roller on the sealing member 36, thereby being near the end of the developing roller 32. This prevents toner from leaking from the end of the developing roller.

  The band-shaped member 37 provided on the seal member 36 will be further described. The belt-like member 37 is preferably provided on the seal member 36 with the longitudinal side portion thereof being inclined by 30 ° to 75 ° with respect to the longitudinal direction of the developing roller 32. In the present invention, the belt-like member 37 is provided on the seal member 36 so that the longitudinal side portion thereof is inclined with respect to the longitudinal direction of the developing roller 32. This will be described with reference to FIG.

  In FIG. 3A, θ represents an angle between the longitudinal side portion of the belt-shaped member 37 and the longitudinal direction of the developing roller 32. Also, the white arrow in the figure indicates the sliding direction of the developing roller 32 on the seal member 36. In the present invention, as shown in FIG. 3A, the longitudinal side portion of the belt-like member 37 is disposed obliquely with respect to the sliding direction of the developing roller 32 so as to face the inner side in the longitudinal direction of the developing roller 32. . By arranging in this way, it is possible to dam the toner moving by the rotation of the developing roller 32 at the longitudinal side portion of the belt-shaped member 37 and to move the developing roller 32 inward in the longitudinal direction.

  The specific value of the angle θ is preferably 30 ° to 75 ° as described above. By setting the angle at which the belt-shaped member 37 is provided within this range, the toner is blocked and the developing roller 32 is moved inward in the longitudinal direction. Ensure that the move can be carried out reliably. In particular, when a small-diameter toner having a volume-based median diameter of about 3 to 8 μm is used, the effect is more clearly expressed.

  Examples of the arrangement of the belt-like members 37 that do not correspond to the present invention are shown in FIGS. FIG. 3B shows an arrangement in which the longitudinal portion of the belt-shaped member 37 is inclined with respect to the sliding direction of the developing roller 32 so as to face the outside in the longitudinal direction of the developing roller 32. FIG. The long side part of 37 is not arrange | positioned diagonally. In the case where the seal member 36 of (b) is arranged so that the longitudinal side portion of the belt-like member 37 is lowered toward the inner side in the longitudinal direction of the developing roller 32, that is, the state of (b) is inverted. However, (c) cannot achieve the effect of the present invention.

  The band-shaped member 37 preferably has a thickness of 50 μm to 200 μm. By setting the thickness within this range, no gap is generated due to the arrangement of the band-shaped member 37, and the seal member 36 and the developing roller The toner that has entered between 32 passes over the belt-shaped member 37 and does not leak to the outside. Therefore, it is possible to prevent toner leakage from the end portion of the developing roller 32 for a long period of time even when image formation is repeated.

  Moreover, since the strip | belt-shaped member 37 is arrange | positioned along a curved surface like the sealing member 36, what has a certain amount of flexibility is preferable. Furthermore, since it is disposed on the seal member 36, it is preferable that the film has a certain degree of smoothness so as not to affect the sliding of the developing roller 32. Therefore, a resin material that can be molded as a flexible film and that can form a smooth surface is selected. Specifically, vinyl resins such as low density polyethylene and high density polyethylene, fluorine resins such as polytetrafluoroethylene (Teflon (registered trademark)), polyester resins such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate. And polyamide resins such as nylon and cellulose resins such as cellulose acetate. Among these, fluorine resin films represented by polytetrafluoroethylene (PTFE; Teflon (registered trademark)) are particularly preferable because the resin itself has lubricity and high smoothness. Fluorine resins other than polytetrafluoroethylene (PTFE) include ethylene-tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene / hexafluoropropylene copolymer Examples thereof include a polymer (FEP) and polyvinylidene fluoride (PVDF).

  The same effect can be obtained even with a resin film other than the fluororesin film or with a resin film treated with a slipping improver such as silica or magnesium silicate (talc).

  In addition, as a method for molding a resin film, for example, cast molding in which a resin material is dissolved in a solvent or the like, a melt is formed into a film on a glass plate, and the solvent is removed to produce a sheet-like film is representative. is there. In addition, a biaxial stretching method in which a resin material is stretched to form a film, a method in which a heat-melted resin material is cooled to form a film, and the like can be given.

  The seal member 36 preferably has a thickness 4.5 to 30.0 times the volume reference median diameter of the toner accommodated in the developing device 31. By using a seal member having a thickness in this range, toner leakage from the end of the developing roller 32 is reliably prevented. Further, since the seal member can be disposed in close contact along the curved surface of the developing roller 32 or the casing, sufficient durability can be exhibited without causing partial wear with respect to the sliding of the developing roller.

  The specific thickness of the seal member 36 is, for example, a developing device that uses a toner having a volume reference median diameter (D50v diameter) of 5.5 μm, which is attracting attention as a small-diameter toner, and the thickness of the seal member is 25 μm to 165 μm. Thus, the above effect can be obtained. Further, when a toner having a volume-based median diameter (D50v diameter) of 8 μm is used, it is preferable to use a seal member having a thickness of 36 μm to 240 μm.

  An example of a full-color image forming apparatus that can be used by the developing device 31 according to the present invention is shown in FIG. The image forming apparatus that can be used by the developing device 31 according to the present invention is not limited to the one shown in FIG. In the image forming apparatus of FIG. 4, a charging brush 111 for uniformly charging the surface of the photosensitive drum 10 to a predetermined potential and a cleaner 112 for removing residual toner on the photosensitive drum 10 are provided around the photosensitive drum 10 that is rotationally driven. Is provided.

  The laser scanning optical system 20 scans and exposes the photosensitive drum 10 uniformly charged by the charging brush 111 to form an electrostatic latent image on the photosensitive drum 10. The laser scanning optical system 20 includes a laser diode, a polygon mirror, and an fθ optical element, and print data for each of yellow, magenta, cyan, and black is transferred from the host computer to the control unit. A laser beam is sequentially output based on the print data of each color, and the photosensitive drum 10 is scanned and exposed to form an electrostatic latent image for each color.

  The developing device unit 30 containing the developing device 31 according to the present invention performs development by supplying each color toner to the photosensitive drum 10 on which the electrostatic latent image is formed. The developing device unit 30 is provided with four developing devices 31Y, 31M, 31C, and 31Bk each containing non-magnetic one-component toners of yellow, magenta, cyan, and black around the support shaft 33. The developing device 31 is guided to a position facing the photosensitive drum 10 by rotating to the center.

  The developing device unit 30 rotates around the support shaft 33 each time an electrostatic latent image of each color is formed on the photosensitive drum 10 by the laser scanning optical system 20, and stores the corresponding color toner. 31 is guided to a position facing the photosensitive drum 10. Then, each of the developing devices 31Y, 31M, 31C, and 31Bk sequentially supplies each charged color toner to the photosensitive drum 10 to perform development.

  In the image forming apparatus of FIG. 4, an endless intermediate transfer belt 40 is provided downstream of the developing device unit 30 in the rotation direction of the photosensitive drum 10, and is driven to rotate in synchronization with the photosensitive drum 10. The intermediate transfer belt 40 contacts the photosensitive drum 10 at a portion pressed by the primary transfer roller 41, and transfers the toner image formed on the photosensitive drum 10. Further, a secondary transfer roller 43 is rotatably provided so as to face the support roller 42 that supports the intermediate transfer belt 40, and the portion on the intermediate transfer belt 40 is opposed to the support roller 42 and the secondary transfer roller 43. The toner image is pressed and transferred onto the recording material S such as recording paper.

  A cleaner 50 that removes residual toner on the intermediate transfer belt 40 is provided between the full-color developing device unit 30 and the intermediate transfer belt 40 so as to be able to contact and separate from the intermediate transfer belt 40.

  A paper feeding unit 60 that guides the recording material S to the intermediate transfer belt 40 includes a paper feeding tray 61 that houses the recording material S, and a paper feeding roller 62 that feeds the recording material S stored in the paper feeding tray 61 one by one. It comprises a timing roller 63 that feeds the fed recording material S to the secondary transfer site.

  The recording material S on which the toner image is pressed and transferred is conveyed to the fixing device 70 by a conveying means 66 constituted by an air suction belt or the like, and the toner image transferred by the fixing device 70 is fixed on the recording material S. After fixing, the recording material S is transported through the vertical transport path 80 and discharged onto the upper surface of the apparatus main body 100.

  Next, the toner that can be used in the present invention will be described.

  The toner that can be used in the present invention is not particularly limited, but a toner that is used in a non-magnetic one-component development system is preferably used. The toner used in the non-magnetic one-component development method is not particularly limited in its production method, but is produced through a process of polymerizing a polymerizable monomer in an aqueous medium to form resin particles. The so-called polymerized toner is preferred.

  The reason for this is that in the production process of polymerized toner, toner particles can be produced while controlling the shape and size, and it is easy to obtain a small diameter toner having the same shape and size. That is, a small-diameter toner having a uniform shape and size is preferable for reproducing a high-definition digital image that is often produced by a non-magnetic one-component developing method and for forming a pictorial image at the photographic image level. Specific methods for preparing the polymerized toner include, for example, those described in JP-A No. 2000-214629, JP-A No. 2001-42564, JP-A No. 2002-116574, and the like.

  In the present invention, the thickness of the seal member 36 used in the developing device 31 is set to 4.5 to 30.0 times the volume-based median diameter of the toner stored in the developing device 31, so that the effect of the present invention is achieved. It is played more reliably.

  The volume-based median diameter (D50v diameter) of the toner can be measured and calculated using a device in which a computer system for data processing is connected to Multisizer 3 (manufactured by Beckman Coulter, Inc.).

  As a measurement procedure, 0.02 g of toner is blended with 20 ml of a surfactant solution (for example, a surfactant solution obtained by diluting a neutral detergent containing a surfactant component 10 times with pure water for the purpose of dispersing the toner). After that, ultrasonic dispersion is performed for 1 minute to prepare a toner dispersion. This toner dispersion is injected into a beaker containing ISOTON II (manufactured by Beckman Coulter, Inc.) in a sample stand with a pipette until a measurement concentration of 5 to 10% is reached, and the measuring machine count is set to 2500. To do. The aperture size of the multisizer 3 is 50 μm. In the present invention, even when image formation is performed using toner having a volume-based median diameter (D50v diameter) of 3 to 8 μm, toner leakage from the end of the developing roller 32 is prevented by the belt-shaped member 37 provided on the seal member 36. It is possible to prevent it reliably.

Hereinafter, embodiments of the present invention will be specifically described by way of examples, but the embodiments of the present invention are not limited thereto.
1. Production of Evaluation Members 1 to 13 Using the commercially available films shown below, a sealing member having the shape shown in FIG. 3 was produced.
(1) Polyethylene film High leak MB (thickness 100 μm) Toko Material Industries Co., Ltd. (2) Polytetrafluoroethylene film 903UL (thickness 80 μm) Nitto Denko Co., Ltd. (3) Polyethylene terephthalate film Teijin Tetron film and HS (thickness 175 μm and 240 μm) Teijin DuPont Films, Inc.

  Next, a strip-shaped member having the conditions shown in Table 1 was provided on the seal member, and evaluation members No. 1 made of a seal member provided with strip-shaped members having different conditions were provided. 1-13 were prepared. In addition, the angle in the strip | belt-shaped member conditions in Table 1 is shown to Fig.3 (a). The band-shaped member was attached to the seal member using a commercially available double-sided tape “467MP” (thickness 50 μm, manufactured by Sumitomo 3M Limited) using an acrylic adhesive.

The following plastic sheet film was used for the band-shaped member. That is,
(1) Polytetrafluoroethylene film Nitoflon No. 903UL (thickness 130 μm) Nitto Denko Corporation, abbreviated as PTFE in Table 1.
(2) Polyethylene terephthalate film Teijin Tetron film G2 (thickness: 45 μm, 80 μm) and HS (thickness: 130 μm, 210 μm) Teijin DuPont Films, Inc., abbreviated as PET in Table 1.
2. Evaluation Conditions Next, the evaluation members 1 to 13 were mounted on both ends of the developing roller as shown in FIG. 2A to prepare the developing devices 1 to 13 shown in FIG. As shown in Table 1, a predetermined amount of black toner having a volume-based median diameter (D50v diameter) of 5.5 μm, 3.0 μm, and 8.0 μm was stored in the developing device.

  The produced developing devices 1 to 13 were mounted on a commercially available color laser printer “Magicolor 2430DL (manufactured by Konica Minolta Business Technology Co., Ltd.)” for evaluation. In the evaluation, continuous printing of 4500 sheets was performed for each developing device in a low temperature and low humidity environment (10 ° C., 15% RH). That is, in each developing device, an image with a pixel rate of 10% (a character image with a pixel rate of 7% (characters with 4 points, 6 points, and 8 points), a human face photo, a solid white image, and a solid black image) An original image that is divided into ¼ equal parts) was filled with a black toner in an amount sufficient for continuous printing of 4,500 sheets. A4 quality paper (CF paper (manufactured by Konica Minolta Business Technology Co., Ltd.)) was used as the print paper, and monochrome image formation was performed. To 13 were used as Comparative Examples 1 to 4. Table 1 shows the configurations of Examples 1 to 9 and Comparative Examples 1 to 4.

3. Evaluation item <In-flight dirt>
The state of toner scattering from the developing device after the continuous printing of 4500 sheets by each developing device was visually evaluated, and the degree of soiling of the hand when the developing device was removed from the image forming apparatus was evaluated. The following four ranks were classified and judged.

◎: No toner adherence to the upper lid of the developing device or in-machine dirt inside the device, and even when the developing device was removed, the hands were not soiled at all. ○: In the developing device, a slight amount of toner adhered to the upper lid near the developing roller. In other locations, toner adhesion is not observed. Also, there was no toner scattering inside the device, and even when the developing device was removed, the hands did not get dirty. Δ: Toner adhered to a part of the upper lid of the developing device, but no toner scattering inside the device was seen and development Even if the apparatus was removed, the hands did not get dirty. ×: Toner scattering into the machine was confirmed, and when the developing apparatus was removed, the hands became dirty to the extent that hand washing was necessary.
<Image dirt>
When 4500 sheets were continuously printed by each developing device, the image stain on the 1000th, 2000th, 3000th, and 4500th prints was evaluated. Specifically, in the 1000th evaluation, the 998th, 999th, and 1000th prints, and in the 2000th evaluation, the 1998th, 1999th, 2000th prints, and the 3000th evaluation In the evaluation, the 2998th sheet, 2999th sheet, 3000th sheet print, and 4500th sheet evaluation, the 4498th sheet, 4499th sheet, and 4500th sheet were visually observed with a magnifier with a scale, and dropped from the developing device. The presence or absence of black spots caused by the toner was evaluated.

○: No black spots were confirmed from the three prints. Δ: Black spots were confirmed during the three prints, but the size was less than 0.4 mm and it was judged that there was no problem with the image. X: Black spots with a size of 0.4 mm or more were observed during the printing of three sheets.

  The results are shown in Table 2.

  As shown in Table 2, in Examples 1 to 9 corresponding to the present invention, even if the continuous printing of 4500 sheets was performed, no in-machine stains or image stains were observed, or occurrences were observed. It was a problem-free level. On the other hand, in Comparative Examples 1 to 4 outside the present invention, image smearing was more noticeable as the number of printed sheets increased, and in-machine smearing was noticeable at the end of printing for 4500 sheets.

  In this manner, by providing a seal member provided with a belt-like member at the end of the developing roller and arranging the belt-like member on the seal member so as to satisfy the above-described configuration, when the developing roller rotates, the toner at the roller end is It was regulated and returned to the inside of the developing roller, and it was confirmed that toner leakage from the end of the developing roller was eliminated.

FIG. 2 is a schematic diagram illustrating an example of a developing device according to the present invention. It is the schematic which shows the relationship between the developing roller and the sealing member which provided the strip | belt-shaped member. It is the schematic which shows the positional relationship of a strip | belt-shaped member and a sealing member. 1 is a schematic view of an image forming apparatus in which a developing device according to the present invention can be mounted.

Explanation of symbols

10 Photosensitive drum 11 Charging device 12, 50 Residual toner removing device 20 Laser scanning optical system 30 Developing device unit 31 Developing device (developer)
32 Developer carrier (developing roller)
34 Hopper 36 Seal member 37 Band member 38 Toner regulating member 40 Intermediate transfer belt 41 Primary transfer roller 42 Support roller 43 Secondary transfer roller 60 Paper feed means 70 Fixing device 100 Device body S Recording material

Claims (4)

In the developing device in which the seal member is provided at the end of the developer carrier,
A smooth belt-like member is provided on the seal member,
The longitudinal part of the strip member is
It is provided on the seal member so as to be inclined with respect to the longitudinal direction of the developer carrier, and is provided so as to face the inside of the developer carrier toward the downstream in the rotation direction of the developer carrier. A developing device. The belt-like member is provided on the seal member with a portion on the longitudinal side inclined by 30 ° to 75 ° with respect to the longitudinal direction of the developer carrying member, and has a thickness of 50 μm to 200 μm. Item 2. The developing device according to Item 1. The developing device according to claim 1, wherein the belt-shaped member is made of polytetrafluoroethylene. An image forming apparatus comprising the developing device according to claim 1.

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