JP2018021986A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus that, in consideration of contact pressures of cleaning members respectively in contact with a plurality of image carriers carrying toner images respectively corresponding to different colors, can form toner bands required for the image carriers and an intermediate transfer body.SOLUTION: An image forming apparatus comprises a plurality of image carriers and an intermediate transfer body. The image forming apparatus includes a plurality of cleaning members that bring toner images not to be transferred into contact with the plurality of image carriers in the longitudinal direction; acquisition means that acquires information on contact pressures or information on a contact pressure distribution in the longitudinal direction of the respective image carriers; and toner band forming means that compares between the acquired pieces of information on contact pressures or pieces of information on the contact pressure distribution in the longitudinal direction, specifies the image carrier having a relatively high contact pressure or a position in the longitudinal direction of the image carrier, and forms toner bands in a color related to the specified image carrier on the intermediate transfer body and image carriers over the longitudinal direction or at positions in the longitudinal direction thereof.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an image forming apparatus, and includes a toner band for cleaning toner remaining on the surface of an image carrier, and is suitable for a copying machine, a printer, a facsimile machine, and the like.

  The toner image carried on the image carrier using an electrophotographic process is transferred to a recording material, and the recording material onto which the toner image has been transferred is heated and pressed at the nip portion of the fixing unit (fixing device) to record the image. 2. Description of the Related Art Image forming apparatuses that are fixed on a surface are widely used.

  In such an image forming apparatus, it is necessary to clean (remove) toner and other deposits remaining on the surface of the image carrier after the completion of one image forming process. As a cleaning device for removing residual toner and other deposits on the image carrier, a method of bringing an elastic cleaning blade into contact with the image carrier is known.

  However, since the cleaning blade is in contact with the rotation direction of the image carrier in the counter direction, the frictional force between the image carrier and the cleaning blade becomes excessive. As a problem when the frictional force is excessive, there is a case where the edge of the cleaning blade is chipped or the edge of the cleaning blade is reversed in the rotation direction of the image carrier to cause the cleaning blade to bend.

  Therefore, as a countermeasure against edge chipping or wobbling of the cleaning blade, it is known that the current value of the motor that drives the image carrier is detected and a toner band is supplied to the image carrier when a predetermined value is exceeded. (Patent Document 1).

JP 2007-328175 A

  However, simply supplying the toner band does not necessarily stabilize the attitude of the cleaning blade, and another problem occurs depending on the contact pressure (cleaning blade pressure) of the cleaning blade. That is, if the cleaning blade pressure is low, the toner band may not be dammed by the cleaning blade, and toner smear may occur on the image. On the other hand, if the cleaning blade pressure is high, the amount of the toner band is insufficient, and the cleaning blade may be immediately swollen.

  This phenomenon may occur even in a part of the cleaning blade in the longitudinal direction (axial direction of the image carrier). The state of the partial cleaning blade cannot be grasped by the motor current driving the image carrier. For this reason, the cleaning blade may be partially blown and the entire cleaning blade may be rolled from that point.

  The object of the present invention is to take into consideration the contact pressure of each cleaning member that comes into contact with a plurality of image carriers that carry toner images corresponding to different colors. An object of the present invention is to provide an image forming apparatus capable of forming a necessary toner band.

  In order to achieve the above object, an image forming apparatus according to the present invention transfers a plurality of image carriers each carrying a toner image corresponding to a different color and the respective toner images on the plurality of image carriers. An intermediate transfer member, and transferring the respective toner images on the intermediate transfer member onto a recording material, wherein the toner images not transferred on the plurality of image carriers are transferred to the plurality of image carriers. A plurality of cleaning members to be cleaned by abutting in the respective longitudinal directions, and contact pressure information of the plurality of cleaning members with respect to the plurality of image carriers or contact pressure distribution information in the respective longitudinal directions. Compare the acquisition means and the acquired contact pressure information for the plurality of image carriers or contact pressure distribution information in the respective longitudinal directions, The image carrier having a relatively high contact pressure or a position in the longitudinal direction of the image carrier is specified, and a color toner band related to the specified image carrier is transferred to the intermediate transfer member and the image carrier in the longitudinal direction. And a toner band forming means for forming in a longitudinal direction or at a position in the longitudinal direction.

  Further, another image forming apparatus according to the present invention includes a plurality of image carriers each carrying a toner image corresponding to a different color, and the recording material is transferred to the recording material to transfer the toner image to the recording material. An image forming apparatus having a conveyance member that conveys the plurality of image carriers so as to face each other, and a toner image that is not transferred on the plurality of image carriers is applied in each longitudinal direction of the plurality of image carriers. A plurality of cleaning members to be cleaned by contact; acquisition means for acquiring contact pressure information of the plurality of cleaning members with respect to the plurality of image carriers or contact pressure distribution information in the longitudinal direction thereof; Before comparing the contact pressure information with respect to the plurality of image carriers or the contact pressure distribution information in the respective longitudinal directions, and providing a relatively high contact pressure. A toner that specifies an image carrier or a position in the longitudinal direction of the image carrier, and forms a toner band of a color relating to the identified image carrier over the longitudinal direction or at a position in the longitudinal direction of the image carrier. And a band forming means.

  According to the present invention, the toner required for the image carrier and the intermediate transfer member is taken into account by taking into account the contact pressures of the respective cleaning members that are in contact with the plurality of image carriers that carry toner images corresponding to different colors. A band can be formed.

1 is an explanatory diagram of a configuration of an image forming apparatus according to an embodiment of the present invention. It is explanatory drawing of a structure of the photosensitive layer of the photosensitive drum which concerns on embodiment of this invention. It is explanatory drawing of the drum cleaning apparatus which concerns on embodiment of this invention. FIG. 3 is an explanatory diagram of a configuration of an intermediate transfer belt according to an embodiment of the present invention. It is explanatory drawing of the belt cleaning apparatus which concerns on embodiment of this invention. It is explanatory drawing of the drum cartridge which has a tag in connection with 1st Embodiment. FIG. 10 is a diagram illustrating a transition of a driving motor torque of a photosensitive drum according to a toner band density in relation to the third embodiment. FIG. 10 is a diagram illustrating a change in driving motor torque of a photosensitive drum due to blade pressure in relation to the third embodiment. It is explanatory drawing of the cleaning in the state which attached the distortion sensor in connection with 4th Embodiment. FIG. 10 is a diagram illustrating a relationship between toner band density and blade distortion in relation to the fourth embodiment.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<< First Embodiment >>
(Image forming device)
FIG. 1 is an explanatory diagram of the configuration of the image forming apparatus according to the present embodiment. As shown in FIG. 1, the image forming apparatus 1 is a tandem intermediate transfer type full-color printer in which stations (image forming units) 3Y, 3M, 3C, and 3K are arranged along an intermediate transfer belt 2. In the image forming unit 3Y, a yellow toner image is formed on the photosensitive drum 4Y and transferred to the intermediate transfer belt 2. In the image forming unit 3M, a magenta toner image is formed on the photosensitive drum 4M and transferred to the intermediate transfer belt 2. In the image forming units 3C and 3K, a cyan toner image and a black toner image are formed on the photosensitive drums 4C and 4K and transferred to the intermediate transfer belt 2.

  The four-color toner images transferred to the intermediate transfer belt 2 are conveyed to the secondary transfer portion T2 and are collectively secondary transferred to the recording material (transfer material, sheet) P.

  The separation roller 103 separates the recording material P drawn from the recording material cassette 101 by the pickup roller 102 one by one and sends it to the registration roller 104. The registration roller 104 sends the recording material P to the secondary transfer portion T2 in time with the toner image on the intermediate transfer belt 2. The recording material P on which the four-color toner images are secondarily transferred in the process of nipping and conveying the secondary transfer portion T2, is separated from the intermediate transfer belt 2 by the curvature and conveyed to the fixing portion (fixing device) 38, and is heated. The toner image is fixed on the surface by receiving heat and pressure at the nip portion between the pressure roller 35 and the pressure roller 36. Then, the recording material P on which the toner image is fixed is discharged out of the machine body.

  The stations (image forming units) 3Y, 3M, 3C, and 3K have substantially the same configuration except that the color of the toner (developer) used in the developing devices 7Y, 7M, 7C, and 7K is different from yellow, magenta, cyan, and black. Is done. Hereinafter, the image forming unit 3Y will be described, and the other image forming units 3M, 3C, and 3K will be denoted by Y at the end of the reference sign indicating the distinction between the image forming units 3Y, 3M, 3C, and 3K in the following description. It shall be explained by replacing with C and K. In addition, hereinafter, Y, M, C, and K may be omitted for each member.

  The image forming unit 3Y surrounds the photosensitive drum 4Y and includes a charging roller 5Y, an exposure device 6Y, a developing device 7Y, a primary transfer roller 8Y, and a drum cleaning device 10Y. The photosensitive drum 4Y has a photosensitive layer formed on the outer peripheral surface of an aluminum cylinder, and rotates in the arrow B direction at a predetermined process speed. The charging roller 5Y is applied with an oscillating voltage in which an AC voltage is superimposed on a negative DC voltage, and charges the surface of the photosensitive drum 4Y to a uniform negative dark potential VD.

  The exposure apparatus 6 is a laser scanner that performs scanning exposure of laser light having a wavelength λ = 780 nm. The exposure device 6 may be an analog exposure device that performs image projection exposure of a document image, or may be a digital exposure device such as a laser scanner or an LED array. The exposure device 6Y writes an electrostatic image of the image on the surface of the charged photosensitive drum 4Y by scanning with a rotating mirror a laser beam LY obtained by ON-OFF modulation of scanning line image data obtained by developing a yellow color separation image.

  The developing device 7Y stirs the developer in which the carrier is mixed with the toner to charge the toner to the negative polarity and the carrier to the positive polarity. The charged developer is carried on a developing sleeve 7s in which a magnet member 7m is fixedly arranged at the center, and rubs the photosensitive drum 4Y in a spiked state.

  The developing sleeve 7s is applied with an oscillating voltage obtained by superimposing an AC voltage on a negative DC voltage, and transfers toner to the electrostatic image on the photosensitive drum 4Y having a positive polarity relative to the developing sleeve 7s. The electrostatic image is reversely developed into a toner image.

  The primary transfer roller 8Y presses the intermediate transfer belt 2 to form a primary transfer portion between the photosensitive drum 4Y and the intermediate transfer belt 2. The primary transfer roller 8Y is applied with a positive DC voltage D1 to primarily transfer a negatively charged toner image on the photosensitive drum 4Y to the intermediate transfer belt 2. The drum cleaning device 10Y rubs (contacts) the cleaning blade 9Y with the photosensitive drum 4Y, and collects transfer residual toner (residual toner) attached to the surface of the photosensitive drum 4Y that has passed through the primary transfer portion.

  In FIG. 1, reference numeral 100 denotes a CPU as a control unit, which also serves as an acquisition unit (acquisition of contact pressure information on the photosensitive drum or contact pressure distribution information in each longitudinal direction) and a toner band forming unit, which will be described in detail later. Function.

(cartridge)
In this embodiment, a so-called drum cartridge is provided as a cartridge that is integrated and detachable from the main body of the image forming apparatus. The drum cartridge integrally includes a photosensitive drum 4 that carries a toner image corresponding to a predetermined color, a cleaning blade 9, and a memory member as a storage unit to be described later. As will be described in detail later, this memory member stores contact pressure information on the photosensitive drum 4 of the cleaning blade 9 or contact pressure distribution information in the longitudinal direction.

<Photosensitive drum>
FIG. 2 is an explanatory diagram of the configuration of the photosensitive layer of the photosensitive drum 4 (4Y). As shown in FIG. 2, in the photosensitive drum 4Y, a charge generation layer 54 containing a charge generation material and a charge transport layer 55 containing a charge transport material are sequentially laminated on a conductive base 51 having conductivity. And a laminated OPC photosensitive layer. An undercoat layer 52 having a barrier function and an adhesive function is provided on the surface of the conductive substrate 51.

  The undercoat layer 52 is used for improving the adhesion of the photosensitive layer, improving the coating property, protecting the support, covering the defective support on the support, improving the charge injection property from the support, or protecting the photosensitive layer from electrical breakdown. Formed for. A surface protective layer 56 is formed on a function separation type photosensitive layer in which a charge generation layer 54 and a charge transport layer 55 are sequentially laminated. The surface of the photosensitive drum 4Y is polished by a polishing tape (wrapping paper), buffing or the like, and a ten-point average roughness Rz (JIS B0601-1982) is 0.2 to 2 μm.

<Developer>
The developing device 7Y used a developer in which a carrier and a toner were mixed so that the weight ratio was 91: 9 (toner concentration: 9%). The total weight of the initial developer accommodated in the developing device 7Y was 350 g. The carrier uses ferrite particles coated with silicon resin, and the saturation magnetization for an applied magnetic field of 240 [kA / m] is 24 [Am ² / kg]. The specific resistance at an electric field strength of 3000 [V / cm] is 1 × 10 ⁷ [Ω · cm] to 1 × 10 ⁸ [Ω · cm], and the weight average particle size is 50 μm.

  The toner is composed of at least a binder, a colorant, and a charge control agent. Here, a styrene acrylic resin is used as the binder resin. However, resins such as styrene, polyester, and polyethylene can also be used. As the colorant, one type of colorant such as various pigments and various dyes may be used alone, or a plurality of types may be used in combination. As a charge control agent, you may contain the charge control agent for reinforcement as needed. As the charge control agent for reinforcement, nigrosine dyes, triphenylmethane dyes, and the like can be used. The weight average particle diameter of the toner is 5.7 μm.

  The toner includes wax. The wax is contained for the purpose of improving the releasability from the fixing member during fixing and the fixing property. As the wax, paraffin wax, carnauba wax, polyolefin or the like can be used, and kneaded and dispersed in a binder resin. Here, a resin obtained by kneading and dispersing a binder, a colorant, a charge control agent, and a wax by a mechanical pulverizer was used.

  The toner contains an external additive. Examples of the external additive include those obtained by subjecting amorphous silica to a hydrophobic treatment, or inorganic oxide fine particles such as titanium oxide and a titanium compound. These fine particles are added to the toner to adjust the powder fluidity and charge amount of the toner. The particle diameter of the external additive particles is preferably 1 nm or more and 100 nm or less. Here, 0.5 wt% of titanium oxide having an average particle diameter of 50 nm was added in a weight ratio, and amorphous silica having an average particle diameter of 2 nm and 100 nm was added by 0.5 wt% and 1.0 wt%, respectively.

<Cleaning device>
As the cleaning of the image carrier, there are a drum cleaning device 10 for the photosensitive drum 4 and a belt cleaning device 20 for the intermediate transfer belt 2, and it is necessary to supply a toner band (toner patch) to each. Here, the drum cleaning device 10 for the photosensitive drum 4 will be described.

  As shown in FIG. 1, the drum cleaning device 10 rubs the photosensitive drum 4 with a cleaning blade 9 in the longitudinal direction (axial direction of the photosensitive drum (rotational axis direction)) and passes through the primary transfer portion. Residual toner that has adhered to the surface and has not been transferred is collected. That is, not all of the toner constituting the toner image on the photosensitive drum 4 is transferred to the intermediate transfer belt 2 in the toner image transfer process from the photosensitive drum 4 to the intermediate transfer belt 2 in the primary transfer portion. A small amount of untransferred toner remains on the photosensitive drum 4 that has passed through the primary transfer portion, and the untransferred toner is conveyed to the drum cleaning device 10 and collected by the cleaning blade 9.

  FIG. 3 is an explanatory diagram of the configuration of the drum cleaning device 10. The cleaning blade 9 is composed of a cleaning sheet metal 9a as a support member and a rubber material having appropriate elasticity and hardness. Specifically, a polyurethane rubber material is used because it does not damage the photosensitive drum 4 due to friction and has high wear resistance. In consideration of small distortion, a two-component thermosetting polyurethane may be employed. In addition to polyurethane, styrene-butadiene copolymer, chloroprene, butadiene rubber, ethylene-propylene-diene rubber, chlorosulfonated polyethylene rubber, fluorine rubber, silicon rubber, and the like can also be employed.

  Here, the cleaning blade 9 is formed by molding a polyurethane rubber material to have a length of 340 mm, a thickness of 2 mm, and a width of 15 mm in the height direction. The length of the free end that is not supported by the cleaning sheet metal 9 a is 8 mm.

  A configuration in which the cleaning blade 9 is disposed downward, for example, and rubs against a surface to be cleaned (surface of the photosensitive drum 4) that rotates in the reverse direction (upward) is generally a configuration having high cleaning ability. A lower portion of the housing of the drum cleaning device 10 shown in FIG. A collection toner conveying screw (not shown) is arranged, and the collected toner is conveyed to one end side in the longitudinal direction of the drum cleaning device 10 (the axial direction of the photosensitive drum 4) and is collected in an external collection container.

  A scattering prevention sheet (not shown) provided in the drum cleaning device 10 prevents the toner in the housing from scattering to the outside. This anti-scattering sheet is formed of a polyethylene terephthalate resin sheet material having a thickness of 20 μm to 50 μm, and is arranged with its tip in contact with the photosensitive drum 4.

<Intermediate transfer belt>
The intermediate transfer belt 2 shown in FIG. 1 is supported by a tension roller 31, a drive roller 32, and a counter roller 33, and is driven by a drive motor 32M to rotate in the direction of arrow A. As the material of the intermediate transfer belt 2, a single layer intermediate transfer belt in which a known resin such as polyimide or polycarbonate, or a mixture thereof, and a conductive material is added to adjust the resistance can be used. Also, it is possible to use a coat belt in which these resin materials are used as a base material and a plurality of layers are laminated. As a material for the surface layer, a melamine resin, a simple substance of urethane resin, a mixture thereof, a composite material thereof or the like can be used.

  In the present embodiment, as shown in FIG. 4, a polyimide resin or a polyether ether ketone resin is used for the base material a, and a surface layer coat in which a fluororesin is added to an acrylic resin is used for the surface layer b.

<Belt cleaning device>
The belt cleaning device 20 shown in FIG. 1 has an intermediate transfer belt 2 that has passed through the secondary transfer portion T2 by sliding the intermediate transfer belt 2 with a cleaning blade 21 in the longitudinal direction (the axial direction (rotational axis direction) of the intermediate transfer belt). The remaining toner that has not been transferred and is attached to the toner image 2 is collected, that is, in the toner image transfer process from the intermediate transfer belt 2 to the recording material P in the secondary transfer portion T2, the toner image on the intermediate transfer belt 2 is Not all of the constituent toners are transferred to the recording material P.

  A small amount of untransferred toner remains on the intermediate transfer belt 2 that has passed through the secondary transfer portion T2, and this untransferred toner is conveyed to the belt cleaning device 20 and collected by the cleaning blade 21.

  FIG. 5 is an explanatory diagram of the configuration of the belt cleaning device 20. The cleaning blade 21 is composed of a cleaning sheet metal 21a as a support member and a rubber material having appropriate elasticity and hardness. Specifically, a polyurethane rubber material is used because the intermediate transfer belt 2 is not damaged by friction and has high wear resistance.

  In consideration of small distortion, a two-component thermosetting polyurethane may be employed. In addition to polyurethane, styrene-butadiene copolymer, chloroprene, butadiene rubber, ethylene-propylene-diene rubber, chlorosulfonated polyethylene rubber, fluorine rubber, silicon rubber, and the like can also be employed. Here, the cleaning blade 21 is formed by molding a polyurethane rubber material so as to have a length of 340 mm, a thickness of 2 mm, and a width of 15 mm in the height direction. The length of the free end that is not supported by the cleaning metal plate 22 is 8 mm.

  Similar to the cleaning blade 9, a configuration in which the cleaning blade 21 is disposed downward and rubbed against the surface to be cleaned (the surface of the intermediate transfer belt 2) rotating in the reverse direction (upward) is generally a configuration having high cleaning ability. Is.

  The lower portion of the housing 26 is a storage portion for the collected toner, and a collected toner conveying screw (not shown) is arranged to convey the collected toner to one end side of the cleaning device 20 and collect it in an external collecting container. The scattering prevention sheet 27 prevents the toner in the housing 26 from scattering to the outside. The anti-scattering sheet 27 is formed of a polyethylene terephthalate resin sheet material having a thickness of 20 μm to 50 μm, and is disposed with its tip in contact with the intermediate transfer belt 2.

<Blade pressure measurement>
The cleaning blade pressure measuring device includes the photosensitive drum 4 and the cleaning blade 9 of the image forming apparatus of the present embodiment, and a cleaning sheet metal 9a as a supporting member thereof, and further includes a load cell for measuring a load applied to the photosensitive drum 4. A cleaning sheet metal 9 a that is a support member of the cleaning blade 9 is movable, and presses the cleaning blade 9 against (intrudes into) the photosensitive drum 4. Then, the photosensitive drum 4 is divided in the longitudinal direction, and a load cell is disposed at each longitudinal position. Thereby, it becomes possible to acquire the cleaning blade pressure (blade pressure) at the position in the longitudinal direction of the cleaning blade 9.

  In this embodiment, the photosensitive drum 4 is divided into five in the longitudinal direction. The load obtained in each load cell is the partial pressure (g). Although this value may be used as it is, the contact pressure (g / cm) at the longitudinal position of the cleaning blade can be obtained by dividing each partial pressure by the longitudinal width (cm) of each divided drum. .

  When the cleaning blade pressure is measured, the cleaning blade 9 causes a variation in the measured cleaning blade pressure. This variation occurs due to manufacturing variations in the cleaning blade 9 alone. For example, the thickness and free length of the rubber material of the cleaning blade 9, the rubber hardness of the cleaning blade 9, and the amount of protrusion and thickness of the adhesive when the blade rubber is bonded to the cleaning sheet metal 9 a are also generated.

  Further, the drum cleaning device 10 also has manufacturing variations. For example, variation also occurs depending on the mechanical accuracy of a spring or a sheet metal constituting the drum cleaning device 10. For this reason, the variation in blade pressure increases as the number of parts constituting the drum cleaning device 10 increases.

<Storing blade pressure information in the drum cartridge>
In the present embodiment, a memory member (tag) serving as a storage unit that stores the blade pressure information described above is provided in the drum cartridge described above as the cartridge. That is, as shown in FIG. 6, the tag 50 is attached to the side cover of the drum cartridge. Specifically, the tag 50 has a memory chip 50a which is a storage element such as a RAM or a ROM, and tag contact portions 51a and 51b on both sides of the memory chip 50a on the substrate 50b. The memory chip 50a is arranged at the center, and protects the memory element with a resin coating layer (protection part).

  The tag contact portions 51a and 51b are for connecting to the main body electrical contact portion of the image forming apparatus main body in order to read / write information from / to the memory chip 50a, and two gold-plated phosphor bronze plates are attached to the substrate 50b. Implemented. The tag contact portions 51a and 51b are arranged on the same surface as the memory chip 50a and on both sides of the memory chip 50a.

  Necessary information (in this embodiment, the lot number of the drum cartridge and the cleaning blade, the longitudinal information of the cleaning blade pressure, etc.) is input in advance to the memory chip 50a. When the drum cartridge is mounted on the image forming apparatus main body, information on the length of the cleaning blade pressure is notified to the control board of the image forming apparatus main body by exchanging information with the image forming apparatus main body. Change (change the previously formed toner band).

  In addition, since data can be written to the memory chip 50a even during use, information on the toner band is written as needed. The longitudinal information of the cleaning blade pressure is obtained by measuring the blade pressure when assembling the drum cartridge and associating the longitudinal position with the partial pressure (g) data. However, although described as partial pressure (g), linear pressure (g / cm) may be used.

<Formation of toner band>
In this embodiment, the CPU 100 which is a control unit functioning as a toner band forming unit forms a toner band on the photosensitive drum 4 and transfers it to the intermediate transfer belt 2. At this time, the transfer efficiency is generally not 100%, and a toner band is formed not only on the intermediate transfer belt 2 but also on the photosensitive drum 4.

  In order to increase the amount of toner band supplied to the photosensitive drum 4, the primary transfer high pressure may be adjusted.

  The photosensitive drum 4 having a relatively high contact pressure or the position in the longitudinal direction based on the contact pressure information with respect to the photosensitive drum 4 stored in the tag 50 described above or the contact pressure distribution information in the longitudinal direction thereof. Is identified. In comparison, the photosensitive drum 4 or the position in the longitudinal direction is specified by comparing the plurality of photosensitive drums or comparing them with a predetermined pressure. Then, the toner band of the color related to the specified photosensitive drum 4 is formed on the intermediate transfer belt 2 and the photosensitive drum 4 over the longitudinal direction or at a position in the longitudinal direction.

<< Second Embodiment >>
<Storing blade pressure information in the main body of the image forming apparatus>
In the first embodiment, the image forming apparatus in which the longitudinal information of the cleaning blade pressure is stored in the tag of the drum cartridge has been described. On the other hand, in this embodiment, the longitudinal information of the cleaning blade pressure and the like are stored in the storage means in the image forming apparatus main body.

  In this embodiment, when the drum cartridge is mounted on the main body of the image forming apparatus, the user (user) inputs the length information of the cleaning blade pressure attached to the drum cartridge to the input unit of the image forming apparatus. The input information is stored in information storage means (storage means) in the image forming apparatus main body. The stored information is notified to the control board of the main body of the image forming apparatus, and the toner band is changed. Further, information such as toner band conditions is written as needed.

  Next, a case where the image forming apparatus main body is connected to a network will be described. The longitudinal information of the cleaning blade pressure and the like are stored in an external storage means such as a customer center together with the LOT number of the drum cartridge. The external storage means and the image forming apparatus main body are connected to a network.

  A user (user) inputs the LOT number of the drum cartridge to be mounted on the image forming apparatus main body to the input unit of the image forming apparatus. Then, the input LOT number of the drum cartridge is sent to an external storage means, from which the longitudinal information of the cleaning blade pressure is obtained. Then, the obtained longitudinal information of the cleaning blade pressure and the like are stored in the storage means in the image forming apparatus main body. The stored information is notified to the control board of the image forming apparatus main body, and the toner band is changed.

  Further, if necessary, the toner band conditions and the like are sent to an external storage means and stored as needed. The longitudinal information of the cleaning blade pressure is obtained by associating the partial pressure (g) data obtained by measuring the cleaning blade pressure with each longitudinal position when the drum cartridge is assembled. However, although described as partial pressure (g), linear pressure (g / cm) may be used.

<Formation of toner band>
Similarly to the first embodiment, in this embodiment, a toner band is formed on the photosensitive drum 4 and transferred to the intermediate transfer belt 2. At this time, the transfer efficiency is generally not 100%, and a toner band is formed not only on the intermediate transfer belt 2 but also on the photosensitive drum 4.

  In order to increase the amount of toner band supplied to the photosensitive drum 4, the primary transfer high pressure may be adjusted.

  As in the first embodiment, the photosensitive drum 4 having a relatively high contact pressure or the longitudinal direction of the photosensitive drum 4 based on the contact pressure information on the photosensitive drum 4 or the contact pressure distribution information in the longitudinal direction thereof. Identify the location. Then, when making a relative comparison, the photosensitive drum 4 or its position in the longitudinal direction is specified by making a relative comparison among a plurality of photosensitive drums or by making a relative comparison with a predetermined pressure. Then, the toner band of the color related to the specified photosensitive drum 4 is formed on the intermediate transfer belt 2 and the photosensitive drum 4 over the longitudinal direction or at a position in the longitudinal direction.

<< Third Embodiment >>
In this embodiment, the station (image forming unit) of the toner band is adjusted. That is, the drum cartridges built in the image forming apparatus main body are relatively compared based on the longitudinal information of the cleaning blade pressure described in the first and second embodiments. As a result of comparison, in the image forming unit having a drum cartridge having a high total pressure obtained by adding the cleaning blade pressure or the partial pressure, the toner band is moved in the longitudinal direction or the longitudinal direction of the photosensitive drum and the intermediate transfer member. Form.

  FIG. 7 shows the drive motor torque of the photosensitive drum when an image is formed using the image forming apparatus as shown in FIG. 1 and a solid white recording material is continuously fed after forming each density toner band. It is the result shown. When the density of the toner band is 15 and the density is lowered to 14, 13, 12,... 2, 1, the density becomes lighter.

  When the density of the toner band is changed, the amount of toner existing in the vicinity of the cleaning blade varies. Therefore, as shown in FIG. 7, as the number of sheets (the number of sheets to be passed) increases, the drive motor torque of the photosensitive drum increases. However, when the toner band is darker, the rate of change is suppressed to be smaller than when the toner band is thin.

  That is, in the case of a toner band with a low density (for example, density setting 4), the drive motor torque of the photosensitive drum suddenly increases. However, in the case of a toner band having a high density (for example, the density setting is 15), the increase in the drive motor torque of the photosensitive drum is small. The driving motor torque of the photosensitive drum varies depending on the density of the toner band. When the density decreases, the driving motor torque of the photosensitive drum tends to increase.

  This is because when the amount of toner per unit area decreases, the amount of toner present in the vicinity of the cleaning blade decreases, and the toner, which is a lubricant, is depleted and the frictional force between the cleaning blade and the photosensitive drum increases. Thereby, when the blade pressure is high, the cleaning blade is liable to curl.

  On the other hand, when the amount of toner per unit area increases, the amount of toner existing in the vicinity of the cleaning blade 12 increases, and these toners become lubricants, reducing the frictional force between the cleaning blade 12 and the photosensitive drum. Thereby, even when the blade pressure is high, the cleaning blade does not curl immediately.

  Here, if the toner band is not supplied to the drum cleaning (for the photosensitive drum) and the transfer cleaning (for the intermediate transfer member), the cleaning blade may be swung in both cases. Therefore, in this embodiment, by setting the primary transfer high voltage to 0 V, the toner band is embraced between the photosensitive drum and the intermediate transfer body, and the toner band can be supplied at the same time, so that the control time can be shortened. In this embodiment, the primary transfer high voltage is set to 0 V. However, by changing the value, the ratio of the toner band can be changed.

<Formation of toner band>
In this embodiment, by comparing blade pressure information in a plurality of drum cartridges, a photosensitive drum having a relatively high contact pressure or a position in the longitudinal direction thereof is specified. Then, the toner band of the color relating to the identified photosensitive drum is formed in the intermediate transfer belt and the photosensitive drum over the longitudinal direction or at a position in the longitudinal direction.

  In the present embodiment, the toner band is supplied to the intermediate transfer member in an image forming unit having a drum cartridge having a high cleaning blade partial pressure or total pressure. At this time, since the primary transfer voltage is 0 V as described above, the toner band is also supplied to the photosensitive drum. In a drum cartridge having a low partial pressure or total pressure, there is a low possibility that the cleaning blade will be swung, so there is no need to create a toner band at that station, and wasteful toner consumption is reduced.

  That is, in the present embodiment, a necessary toner band is provided on a required image carrier in consideration of the contact pressure of each cleaning member that abuts a plurality of image carriers that carry toner images corresponding to different colors. Can be formed.

  FIG. 8 corresponds to the cleaning blade pressure (blade pressure) when the image forming apparatus as shown in FIG. 1 is used to form an image, each toner band is formed, and solid white recording material is continuously fed. FIG. 6 is a result showing a driving motor torque of the photosensitive drum. As shown in FIG. 8, when the blade pressure is changed, the frictional force between the drum and the cleaning blade changes. When the blade pressure is high, the frictional force between the drum and the cleaning blade is increased, the drive motor torque of the photosensitive drum is greatly increased, and the time until rolling is shortened.

  On the other hand, when the cleaning blade pressure is low, the frictional force between the drum and the cleaning blade is small, the increase in the drive motor torque of the photosensitive drum is small, and the time until dripping is long.

(Frequency of toner band formation)
As shown in FIG. 8, when the blade pressure is high, the frictional force between the drum and the cleaning blade increases, the increase in the drive motor torque of the photosensitive drum increases, and the time until dripping decreases. Therefore, in this embodiment, while ensuring the amount of toner necessary for transfer cleaning (for the intermediate transfer member), a relative comparison is made according to the longitudinal information of the cleaning blade pressure described in the first and second embodiments, The frequency of forming the toner band described above is changed.

  That is, as a result of the relative comparison, in the station (image forming unit) where there is a drum cartridge having a high cleaning blade partial pressure or total pressure, the longitudinal direction of the photosensitive drum and the intermediate transfer member or the toner band in the longitudinal direction Increase the frequency of forming. As a result, it is possible to suppress the occurrence of blade curl while minimizing toner consumption.

  In this embodiment, it is assumed that the toner band is formed in one station (image forming unit) by one toner band control in relation to the frequency of forming the toner band, but it is necessary for the transfer cleaning. Any number of toners may be used as long as the toner amount is secured. That is, the toner band may be formed by a plurality of stations (image forming units) by one toner band control.

  In addition, while ensuring the amount of toner necessary for transfer cleaning (for the intermediate transfer member), the longitudinal dimension (length) of the toner band formed at each station is determined according to the longitudinal information of the cleaning blade for each station. It may be different. That is, the length in the longitudinal direction of the toner band may be increased at a station where the blade pressure is high.

<< Fourth Embodiment >>
In this embodiment, if the contact pressure of the cleaning blade with respect to the photosensitive drum (blade pressure) is taken into account, the toner band density is increased as the distribution in the longitudinal direction (longitudinal distribution) of the toner band. And / or increasing the longitudinal dimension. The other points are the same as in the third embodiment.

<Longitudinal distribution of toner band>
Regarding the blade pressure, FIG. 9 shows a schematic configuration of a drum cleaning device 10 provided with a strain measuring gauge as a measuring means for measuring the strain of the cleaning blade 9. A strain measurement gauge (for example, manufactured by Kyowa Denki Co., Ltd.) is attached to the back surface of the cleaning blade 9 that is in contact with the rotation direction of the photosensitive drum 4 in the counter direction. The measurement result of the strain measurement gauge is sent as a voltage to the voltmeter via the signal amplifier.

  FIG. 10 shows an image formation using the image forming apparatus as shown in FIG. 1, and changes the toner band density from the station corresponding to the 100th sheet (image forming unit) every 100 sheets. It is the result of having measured the distortion of the cleaning blade 9 when forming. When the density of the toner band is changed, the distortion amount of the cleaning blade 9 when the toner band reaches the cleaning blade 9 is different.

  When the density of the toner band is lowered to 14, 13, 12,..., 2, 1, with 15 being the highest density, the density becomes lighter, and the setting 0 indicates that there is no toner band. In the case of a toner band having a low density (for example, density setting 4), the cleaning blade 9 is hardly distorted. However, when the toner band has a high density (for example, the density setting is 15), the cleaning blade 9 has a large distortion. The distortion of the cleaning blade 9 changes depending on the density of the toner band, and as the density increases, the distortion of the cleaning blade tends to increase.

  This is because as the amount of toner per unit area increases, the load of the cleaning blade 9 due to the toner increases, and the cleaning blade 9 is pushed up in the traveling direction of the photosensitive drum 4. For this reason, when the density of the toner band is increased, the blade pressure needs to be high. That is, when the blade pressure is low, this load cannot be endured, and cleaning failure occurs (occurrence of slipping through).

  On the other hand, when the density of the toner band is decreased, it is not necessary that the blade pressure is high. That is, when the amount of toner per unit area decreases, the load of the cleaning blade 9 due to the toner decreases and the cleaning blade 9 is not pushed up, so that the cleaning blade 9 hardly distorts. For this reason, defective cleaning does not occur even when the blade pressure is low.

  Here, as shown in FIG. 7 of the third embodiment, when the toner band density is increased, the photosensitive drum drive motor torque is decreased, and when the toner band density is decreased, the photosensitive drum drive motor is decreased. Torque increases. In view of FIGS. 7 and 10 (blade distortion and photosensitive drum driving torque), when the blade pressure is low, the driving motor torque of the photosensitive drum is low, so that the time until blade curl occurs is long. Accordingly, the density of the toner band is reduced, and a toner band having a density that does not pass through is supplied.

  However, when the blade pressure is high, the drive motor torque of the photosensitive drum is high, so that the time until blade curl occurs is short. Therefore, it is necessary to increase the density of the toner band. In this case, even if the density of the toner band is increased, the blade pressure is high and the cleaning blade is not distorted, so that no slip-through occurs.

  In this embodiment, the density of the toner band is changed at the position in the longitudinal direction of the toner band in accordance with the information on the cleaning blade pressure in the longitudinal direction (contact pressure distribution information) described in the first and second embodiments. It has become possible to suppress the occurrence of blade curling and slip-through. At that time, it is necessary to supply a certain amount of toner for transfer cleaning in order to twist the blade for transfer cleaning. At that time, the primary transfer high voltage is set to 0 V as described in the third embodiment in order to supply the photosensitive drum simultaneously. Thereby, the control time can be shortened.

  Thus, in this embodiment, the density of the toner band is set at the longitudinal position for each partial pressure of the drum cartridge built in the image forming apparatus main body. At a position where the partial pressure is high, the density of the toner band is increased, and at a position where the partial pressure is low, the density of the toner band is decreased. Then, adjustment is made so that the toner band formed in this way becomes an amount necessary for transfer cleaning in the entire longitudinal area.

  In this way, in this embodiment. It has become possible to suppress the occurrence of blade curl while minimizing toner consumption.

  In the present embodiment described above, it has been described that the density of the toner band is increased at the longitudinal position where the partial pressure is high, but the present invention is not limited to this. That is, since the toner amount is sensitive, the same result can be obtained by increasing the length in the longitudinal direction of the toner band at the longitudinal position where the partial pressure is high.

  In other words, if the toner band is long, the load increases when the blade pressure is low, and slip-through occurs. However, when the blade pressure is high, the toner amount near the blade edge increases and the time until blade curling increases. . Conversely, if the toner band is short, if the blade pressure is low, the load is reduced and slipping does not occur. However, if the blade pressure is high, the amount of toner near the blade edge is reduced, and the time until blade blunting is shortened. .

  As described above, as a method for adjusting the toner amount corresponding to the blade pressure, even when the length of the toner band is changed at the longitudinal position, the same phenomenon and effect as when the density of the toner band is changed are obtained. It is done.

<Toner band formation, frequency of toner band formation>
This is the same as in the third embodiment, and a description thereof will be omitted.

(Modification)
As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary, and each embodiment mentioned above is combined suitably. You can also. The dimensions, materials, shapes, relative positions, and the like of each component are not intended to limit the scope of the present invention unless otherwise specified.

(Modification 1)
In the embodiment described above, the contact pressure information of the cleaning blade or the contact pressure distribution information in the longitudinal direction is applied to the toner bands (the same for Y, M, C, and K) formed in advance for cleaning the remaining toner. The toner band is changed by forming the toner band on the basis of this. However, the present invention is not limited to this, and includes a case where there is no pre-formed toner band and a toner band is newly formed based on the contact pressure information of the cleaning blade or the contact pressure distribution information in the longitudinal direction. .

(Modification 2)
In the above-described embodiment, the configuration in which the toner image is once transferred to the intermediate transfer belt 66 and then transferred again to the recording material (transfer material) is shown. However, the present invention is not limited to this, and as another configuration, the intermediate transfer belt 66 can be replaced with a transport belt as a transport member for transporting the recording material (transfer material).

  In this case, the conveyance belt conveys the recording material (transfer material) so as to face the plurality of photosensitive drums in order to transfer the toner image of each photosensitive drum to the recording material (transfer material). That is, the toner image on the photosensitive drum is directly transferred to the recording material (transfer material) while the recording material (transfer material) is sandwiched between the photosensitive drum and the conveyance belt.

  Then, contact pressure information for a plurality of photosensitive drums or contact pressure distribution information in the longitudinal direction of each of the photosensitive drums is compared, a photosensitive drum having a relatively high contact pressure or a position in the longitudinal direction is specified, and a toner band is determined. Form. That is, the toner band of the color relating to the specified photosensitive drum is formed on the photosensitive drum over the longitudinal direction or at a position in the longitudinal direction. Also in this case, the technical matters described in the above-described embodiments can be similarly applied.

(Modification 3)
In the above-described embodiment, the drum cartridge integrally including the photosensitive drum 4, the cleaning blade 9, and the memory member 50 as the storage unit is illustrated as the cartridge. However, the process cartridge further including the developing device 7 may be used. good.

(Modification 4)
In the embodiment described above, the recording paper (sheet) has been described as the recording material, but the recording material in the present invention is not limited to paper. Generally, a recording material is a sheet-like member on which a toner image is formed by an image forming apparatus. For example, regular or irregular plain paper, cardboard, thin paper, envelope, postcard, seal, resin sheet, OHP sheet, Includes glossy paper. In the above-described embodiment, for the sake of convenience, the handling of the recording material (sheet) P has been described using the terms “continuous paper passing” and “number of paper passing”. However, the recording material in the present invention is not limited to paper. Absent.

2 .... Intermediate transfer belt, 4 .... Photosensitive drum, 9 .... Cleaning blade (photosensitive drum side), 100 ... CPU

Claims (14)

A plurality of image carriers each carrying a toner image corresponding to a different color;
An intermediate transfer member to which the respective toner images on the plurality of image carriers are transferred;
An image forming apparatus for transferring the respective toner images on the intermediate transfer member to a recording material,
A plurality of cleaning members for cleaning the toner images that are not transferred on the plurality of image carriers by contacting each other in the longitudinal direction of the plurality of image carriers;
Acquisition means for acquiring contact pressure information of the plurality of cleaning members with respect to the plurality of image carriers or contact pressure distribution information in the respective longitudinal directions;
Compare the acquired contact pressure information for the plurality of image carriers or the contact pressure distribution information in each longitudinal direction, and specify the image carrier having a relatively high contact pressure or its longitudinal position. A toner band forming means for forming a toner band of a color relating to the specified image carrier over the longitudinal direction or at a position in the longitudinal direction in the intermediate transfer body and the image carrier;
An image forming apparatus comprising:   2. The image forming apparatus according to claim 1, wherein when comparing, the plurality of image carriers are relatively compared or relatively compared with a predetermined pressure. The image carrier and the cleaning member are detachably integrated with the image forming apparatus main body as respective cartridges corresponding to the different colors,
The cartridge has storage means for storing the contact pressure information or contact pressure distribution information in each longitudinal direction,
The image forming apparatus according to claim 1, wherein the acquisition unit acquires the contact pressure information stored in the storage unit or contact pressure distribution information in each longitudinal direction.   The obtained contact pressure information for the plurality of image carriers or the contact pressure distribution information in the longitudinal direction thereof is compared, and the image carrier having a relatively high contact pressure or a position in the longitudinal direction is compared. The image forming apparatus according to claim 1, wherein the frequency of forming the toner band is increased accordingly.   The obtained contact pressure information for the plurality of image carriers or the contact pressure distribution information in the longitudinal direction thereof is compared, and the image carrier having a relatively high contact pressure or a position in the longitudinal direction is compared. The image forming apparatus according to claim 1, wherein the density of the toner band is increased accordingly.   The obtained contact pressure information for the plurality of image carriers or the contact pressure distribution information in the longitudinal direction thereof is compared, and the image carrier having a relatively high contact pressure or a position in the longitudinal direction is compared. 6. The image forming apparatus according to claim 1, wherein the length of the toner band in the longitudinal direction is increased accordingly.   The image forming apparatus according to claim 1, wherein the image carrier is a photosensitive drum, and the intermediate transfer member is an intermediate transfer belt. A plurality of image carriers each carrying a toner image corresponding to a different color;
A conveying member that conveys the recording material to face the plurality of image carriers in order to transfer each of the toner images to the recording material;
An image forming apparatus having
A plurality of cleaning members for cleaning the toner images that are not transferred on the plurality of image carriers by contacting each other in the longitudinal direction of the plurality of image carriers;
Acquisition means for acquiring contact pressure information of the plurality of cleaning members with respect to the plurality of image carriers or contact pressure distribution information in the respective longitudinal directions;
Compare the acquired contact pressure information for the plurality of image carriers or the contact pressure distribution information in each longitudinal direction, and specify the image carrier having a relatively high contact pressure or its longitudinal position. A toner band forming means for forming a toner band of a color relating to the specified image carrier over the longitudinal direction or at a position in the longitudinal direction of the image carrier;
An image forming apparatus comprising:   The image forming apparatus according to claim 8, wherein the comparison is performed by comparing the plurality of image carriers with each other or comparing with a predetermined pressure. The image carrier and the cleaning member are detachably integrated with the image forming apparatus main body as respective cartridges corresponding to the different colors,
The cartridge has storage means for storing the contact pressure information or contact pressure distribution information in each longitudinal direction,
The image forming apparatus according to claim 8, wherein the acquisition unit acquires the contact pressure information stored in the storage unit or contact pressure distribution information in each longitudinal direction.   The obtained contact pressure information for the plurality of image carriers or the contact pressure distribution information in the longitudinal direction thereof is compared, and the image carrier having a relatively high contact pressure or a position in the longitudinal direction is compared. The image forming apparatus according to claim 8, wherein the frequency of forming the toner band is increased accordingly.   The obtained contact pressure information for the plurality of image carriers or the contact pressure distribution information in the longitudinal direction thereof is compared, and the image carrier having a relatively high contact pressure or a position in the longitudinal direction is compared. The image forming apparatus according to claim 8, wherein the density of the toner band is increased accordingly.   The obtained contact pressure information for the plurality of image carriers or the contact pressure distribution information in the longitudinal direction thereof is compared, and the image carrier having a relatively high contact pressure or a position in the longitudinal direction is compared. The image forming apparatus according to claim 8, wherein the length of the toner band in the longitudinal direction is increased accordingly.   The image forming apparatus according to claim 8, wherein the image carrier is a photosensitive drum, and the conveyance member is a conveyance belt.