JP2014071279A - Image forming apparatus - Google Patents

Abstract

Of a plurality of image forming units arranged side by side so as to face an intermediate transfer member, a first image forming unit provided with a lubricant supply means, a second image forming unit provided with no lubricant supply means, An image forming apparatus capable of sufficiently attaching a lubricant at a predetermined timing to an image carrier of a second image forming unit in which no lubricant supply unit is installed is provided.
A contact member such as an intermediate transfer cleaning unit, a secondary transfer bias roller, and a cleaning blade is separated from an intermediate transfer member and an image carrier of a first image forming unit. The lubricant adhering to the image carrier 11 of the first image forming unit 10BK is moved through the intermediate transfer member 17 to adhere to the image carrier 11 of the second image forming units 10Y, 10M, and 10C. The “supply mode” can be executed at a predetermined timing.
[Selection] Figure 4

Description

  The present invention relates to an image forming apparatus using an electrophotographic system such as a copying machine, a printer, a facsimile, or a composite machine thereof, and more particularly, a plurality of image forming units so as to face an intermediate transfer body such as an intermediate transfer belt. Are related to the image forming apparatus.

  2. Description of the Related Art Conventionally, in image forming apparatuses such as copying machines and printers, tandem type color image forming apparatuses in which a plurality of image forming units are arranged in parallel so as to face an intermediate transfer body such as an intermediate transfer belt are widely known. (For example, refer to Patent Document 1).

  Specifically, in Patent Document 1 and the like, the tandem color image forming apparatus corresponds to four different colors (black, yellow, magenta, cyan) so as to face the intermediate transfer belt (intermediate transfer apparatus). The image forming unit is arranged side by side. The toner images respectively formed on the photosensitive drums (image carriers) of the four image forming units are primarily transferred to the intermediate transfer belt to form a color image, and then the color image is formed. Secondary transfer is performed on the recording medium at the position of the secondary transfer member (secondary transfer belt).

  Further, in such an image forming apparatus, by installing a lubricant supply unit that supplies a lubricant on the photosensitive drum (image carrier), a molecular film of the lubricant is generated on the photosensitive drum to perform photosensitivity. A technique for extending the life of the image forming unit by reducing the friction coefficient of the body drum and reducing the wear and loss of the cleaning blade and the deterioration of the photosensitive drum is widely used.

  On the other hand, in Patent Document 1 and the like, for the purpose of reducing the size and cost of the entire image forming apparatus, an image forming unit (for example, black) having a high use frequency (operation rate) among a plurality of image forming units. Technology that installs the lubricant supply means only in the image forming section (first image forming section), and does not install the lubricant supply means in the other image forming sections (second image forming section). Is disclosed.

As in the image forming apparatus disclosed in Patent Document 1 or the like, a lubricant supply unit is installed only in the first image forming unit among the plurality of image forming units, and a lubricant supply unit is provided in the other second image forming unit. Since the lubricant hardly adheres to the image carrier of the second image forming unit where the lubricant supply means is not installed (or is nonuniform even if it is attached). Therefore, the image carrier and the cleaning blade in the second image forming unit are worn, and an abnormal image may be generated.
In particular, a contact member such as an intermediate transfer cleaning unit or a secondary transfer member that contacts the intermediate transfer member is installed between the first image forming unit and the second image forming unit along the traveling direction of the intermediate transfer member. The lubricant adhering to the image carrier of the first image forming unit moves through the intermediate transfer member, and most of the lubricant adheres to the image carrier of the second image forming unit. However, such problems are conspicuous because they adhere to the contact member. Also, such a problem is likely to occur under specific conditions such as continuous paper feeding.

  The present invention has been made to solve the above-described problems, and among the plurality of image forming units arranged in parallel so as to face the intermediate transfer member, a first image forming unit provided with a lubricant supply means. And a second image forming unit in which no lubricant supply unit is installed, the lubricant is provided at a predetermined timing on the image carrier of the second image forming unit in which no lubricant supply unit is installed. It is an object of the present invention to provide an image forming apparatus capable of sufficiently adhering toner.

  In the image forming apparatus according to the first aspect of the present invention, a plurality of image forming units that respectively form toner images on an image carrier and the image carriers of the plurality of image forming units face each other. An intermediate transfer member that is arranged side by side and that travels in a predetermined direction and onto which the toner images formed on the image carriers in the plurality of image forming units are transferred in an overlapping manner. The image unit includes at least a first image forming unit in which a lubricant supply unit that supplies a lubricant to the surface of the image carrier and a second image forming unit in which the lubricant supply unit is not installed, respectively. A contact member that contacts the intermediate transfer member or the image bearing member of the first image forming unit so as to be relatively separable, the contact member being the intermediate transfer member or the first transfer member; The first image forming unit in a state separated from the image carrier of one image forming unit. In which the lubricant moving supply mode the lubricant adhered to the image bearing member is moved through the intermediate transfer member is adhered to the image bearing member of the second image forming section is executed at a predetermined timing.

  The present invention provides a first image forming unit provided with a lubricant supply means, and a second image forming unit provided with no lubricant supply means among a plurality of image forming parts arranged in parallel so as to face the intermediate transfer member. , The lubricant adhered to the image carrier of the first image forming unit in a state where the contact member is separated from the intermediate transfer member and the image carrier of the first image forming unit. The second image forming unit in which no lubricant supplying means is installed is provided so that the lubricant moving supply mode in which the toner is moved through the intermediate transfer member and adhered to the image carrier of the second image forming unit can be executed. It is possible to provide an image forming apparatus in which the lubricant is sufficiently adhered to the image carrier at a predetermined timing.

1 is an overall configuration diagram illustrating an image forming apparatus according to an embodiment of the present invention. It is sectional drawing which shows the process cartridge for black. FIG. 5 is a cross-sectional view showing process cartridges for yellow, magenta, and cyan. FIG. 4A is a schematic diagram illustrating a main part of an image forming apparatus in a normal state, and FIG. 4B is a schematic diagram illustrating a main part of the image forming apparatus in a lubricant movement supply mode. It is a flowchart which shows the control at the time of lubricant movement supply mode.

Embodiment.
Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the part which is the same or it corresponds, The duplication description is simplified or abbreviate | omitted suitably.

First, the configuration and operation of the entire image forming apparatus will be described with reference to FIGS.
FIG. 1 is an overall configuration diagram illustrating an image forming apparatus according to an embodiment. 2 is a cross-sectional view showing a black (black) process cartridge 10BK, and FIG. 3 is a yellow process cartridge 10Y (or magenta process cartridge 10M or cyan process cartridge 10C). FIG.
The four process cartridges 10Y, 10M, 10C, and 10BK (image forming units) are different in the color of the toner T (developer G) used in the image forming process, and the lubricant supply device 15 (lubricant). The supply means) is not installed, and the cleaning blade 14a as a blade member is not installed so as to be separable from the photosensitive drum 11. Since there are many parts (components), the overlapping description of the parts is omitted as appropriate. In FIG. 3, the yellow process cartridge 10Y, the magenta process cartridge 10M, and the cyan process cartridge 10C have substantially the same structure except that the color of the toner T used in the image forming process is different. Therefore, the process cartridges 10Y, 10M, and 10C are illustrated as common drawings.

  In FIG. 1, reference numeral 1 denotes an apparatus main body of a tandem color copier as an image forming apparatus, 2 a writing unit that emits laser light based on input image information, and 3 an original conveying unit that conveys an original D to an original reading unit 4. 4 is a document reading unit for reading image information of the document D, 7 is a paper feeding unit for storing a recording medium P such as transfer paper, and 9 is a registration roller (timing roller) for adjusting the conveyance timing of the recording medium P, 10Y Reference numerals 10M, 10C, and 10BK denote process cartridges as image forming units for forming toner images of respective colors (yellow, magenta, cyan, and black) on the photosensitive drum 11, and reference numeral 16 denotes each of the process cartridges 10Y, 10M, 10C, and 10BK. A transfer bias roller (primary transfer via) for transferring the toner images respectively formed on the photosensitive drum 11 while being superimposed on the intermediate transfer belt Rollers), 17 is an intermediate transfer belt as an intermediate transfer body onto which toner images of a plurality of colors are transferred, and 18 is a secondary transfer for secondary transfer of the toner image on the intermediate transfer belt 17 onto the recording medium P. A secondary transfer bias roller as a member, 19 is an intermediate transfer cleaning unit that cleans the surface of the intermediate transfer belt 17, and 20 is a fixing device that fixes a toner image (unfixed image) on the recording medium P.

  As shown in FIG. 1, the process cartridges 10Y, 10M, 10C, and 10BK (or the photosensitive drum 11) as the four image forming units are opposed (contacted) to the intermediate transfer belt 17 as the intermediate transfer member. Are installed side by side. Further, the intermediate transfer belt 17 is configured to run in a predetermined direction (the arrow direction in FIG. 1 and the clockwise direction) by a drive unit (not shown).

Hereinafter, an operation during normal color image formation in the image forming apparatus will be described.
First, the document D is transported from the document table in the direction of the arrow in the drawing by the transport rollers of the document transport unit 3 and placed on the contact glass 5 of the document reading unit 4. Then, the document reading unit 4 optically reads the image information of the document D placed on the contact glass 5.

  Specifically, the document reading unit 4 scans the image of the document D on the contact glass 5 while irradiating light emitted from an illumination lamp. Then, the light reflected by the document D is imaged on the color sensor via the mirror group and the lens. The color image information of the document D is read for each RGB (red, green, blue) color separation light by the color sensor, and then converted into an electrical image signal. Further, color conversion processing, color correction processing, spatial frequency correction processing, and the like are performed by the image processing unit based on the RGB color separation image signals to obtain yellow, magenta, cyan, and black color image information.

  Then, the image information of each color of yellow, magenta, cyan, and black is transmitted to the writing unit 2. Then, laser light (exposure light) based on the image information of each color is emitted from the writing unit 2 toward the photosensitive drums 11 of the corresponding process cartridges 10Y, 10M, 10C, and 10BK.

On the other hand, the photosensitive drums 11 (see FIGS. 2 and 3) of the four process cartridges 10Y, 10M, 10C, and 10BK are rotated in the directions of the arrows (counterclockwise), respectively. First, the surface of the photosensitive drum 11 as an image carrier is uniformly charged at a portion facing the charging unit 12 (this is a charging process). Thus, a charged potential is formed on the photosensitive drum 11. Thereafter, the surface of the charged photosensitive drum 11 reaches the irradiation position of each laser beam L.
In the writing unit 2, laser light L corresponding to the image signal is emitted from the four light sources corresponding to each color. Each laser beam L passes through a different optical path for each of the yellow, magenta, cyan, and black color components (this is an exposure process).

  The laser beam L corresponding to the yellow component is applied to the surface of the first photosensitive drum 11 (image carrier) from the left side of the sheet. At this time, the yellow component laser light is scanned in the rotation axis direction (main scanning direction) of the photosensitive drum 1Y by a polygon mirror that rotates at high speed. Thus, an electrostatic latent image corresponding to the yellow component is formed on the photosensitive drum 11 charged by the charging unit 12.

  Similarly, the laser beam corresponding to the magenta component is irradiated onto the surface of the second photosensitive drum 11 from the left side of the paper, and an electrostatic latent image corresponding to the magenta component is formed. The cyan component laser light is applied to the surface of the third photosensitive drum 11 from the left side of the drawing, and an electrostatic latent image of the cyan component is formed. The black component laser beam is applied to the surface of the fourth photosensitive drum 11 from the left side of the paper, and an electrostatic latent image of the black component is formed.

Thereafter, the surface of the photosensitive drum 11 on which the electrostatic latent image of each color is formed reaches a position facing the developing unit 13. Then, each color toner is supplied from each developing unit 13 onto the photosensitive drum 11, and the latent image on the photosensitive drum 11 is developed (this is a developing step).
Thereafter, the surface of the photoconductive drum 11 after the development process reaches a portion facing the intermediate transfer belt 17. Here, a transfer bias roller 16 is installed at each facing portion so as to contact the inner peripheral surface of the intermediate transfer belt 17. Then, the toner images of the respective colors formed on the photosensitive drum 11 are sequentially superimposed and transferred onto the intermediate transfer belt 17 at the position of the transfer bias roller 16 (this is a primary transfer process).

Then, the surface of the photosensitive drum 11 after the transfer process reaches a position facing the cleaning unit 14 (cleaning device). At this position, untransferred toner remaining on the photosensitive drum 11 is mechanically removed by a cleaning blade 14a as a blade member, and the removed untransferred toner is collected in the cleaning unit 14 as waste toner. (This is a cleaning process.)
Thereafter, the surface of the photoconductor drum 11 sequentially passes through the position of a static eliminating unit (not shown), and a series of image forming processes on the photoconductor drum 11 is completed.

On the other hand, the intermediate transfer belt 17 on which the toner of each color on the photosensitive drum 11 is transferred (carrying) is run in the clockwise direction in the drawing and is connected to the secondary transfer bias roller 18 (secondary transfer member). The counter position (contact position) is reached. Then, a color toner image carried on the intermediate transfer belt 17 is transferred onto the recording medium P at a position facing the secondary transfer bias roller 18 (secondary transfer step).
Thereafter, the surface of the intermediate transfer belt 17 reaches the position of the intermediate transfer cleaning unit 19. Then, the untransferred toner adhered on the intermediate transfer belt 17 is collected by the intermediate transfer cleaning unit 19 (intermediate transfer cleaning blade), and a series of transfer processes in the intermediate transfer belt 17 is completed.

The intermediate transfer cleaning unit 19 is provided with an intermediate transfer cleaning blade (contact member) that contacts the intermediate transfer belt 17 and cleans the surface of the intermediate transfer belt 17.
The intermediate transfer cleaning blade is made of a rubber material such as urethane rubber, and is interposed between the intermediate transfer belt 17 and a driven roller (one of a plurality of roller members that stretch and support the intermediate transfer belt 17). Is in contact with the surface of the intermediate transfer belt 17 at a predetermined angle and a predetermined pressure. As a result, non-transferred toner adhering to the intermediate transfer belt 17 (including paper dust generated from the recording medium P, discharge products generated on the intermediate transfer belt 17, additives added to the toner, etc.) are also included. .) Is mechanically scraped off and collected in the intermediate transfer cleaning unit 19. In this embodiment, the intermediate transfer cleaning blade is in contact with the intermediate transfer belt 17 in the counter direction with respect to the traveling direction (rotational direction) of the intermediate transfer belt 17.
Further, the untransferred toner collected in the intermediate transfer cleaning unit 19 is conveyed by a conveyance coil (not shown) installed in the intermediate transfer cleaning unit 19 and is discharged from the intermediate transfer cleaning unit 19 to be a waste toner collection container. (Not shown).

Here, the recording medium P transported between the intermediate transfer belt 17 and the secondary transfer bias roller 18 (secondary transfer nip) is transported from the paper supply unit 7 via the registration roller 9 and the like. It is a thing.
Specifically, the recording medium P fed by the paper feeding roller 8 from the paper feeding unit 7 that stores the recording medium P passes through the conveyance guide and is guided to the registration roller 9 (timing roller). The recording medium P that has reached the registration roller 9 is conveyed toward the secondary transfer nip at the same timing.

Then, the recording medium P on which the full-color image is transferred is guided to the fixing device 20 by the transport belt. In the fixing device 20, the color image (toner) is fixed on the recording medium P at the nip between the fixing belt and the pressure roller.
Then, the recording medium P after the fixing step is discharged as an output image outside the apparatus main body 1 by a paper discharge roller, and a series of image forming processes is completed.

Next, the process cartridge 10BK for black will be described in detail with reference to FIG.
As shown in FIG. 2, a black process cartridge 10BK (image forming unit) includes a photosensitive drum 11 as an image carrier, a charging roller 12 (charging unit), a developing unit 13 (developing device), and a cleaning unit. The device 14 (cleaning unit) and the lubricant supply device 15 as a lubricant supply means are integrally configured as a unit.
Unlike the other three color process cartridges 10Y, 10M, and 10C, the black process cartridge 10BK includes a lubricant supply device 15 (lubricant supply means) that supplies a lubricant to the surface of the photosensitive drum 11. It is installed and functions as the first image forming unit. Further, as shown in FIG. 1, the black process cartridge 10BK (first image forming unit) is located downstream of the intermediate transfer belt 17 in the traveling direction with reference to the position of the secondary transfer bias roller 18 (secondary transfer member). It arrange | positions so that it may be located in the side.

Here, the photosensitive drum 11 as an image bearing member is a negatively charged organic photosensitive member, and a photosensitive layer or the like is provided on a drum-shaped conductive support.
Although not shown, the photosensitive drum 11 has an undercoat layer that is an insulating layer, a charge generation layer and a charge transport layer as a photosensitive layer, and a protective layer (surface layer) in this order on a conductive support as a base layer. Are stacked.

Referring to FIG. 2, the charging roller 12 (charging unit) is a roller-like member in which an intermediate resistance elastic layer and a surface layer are sequentially laminated on the outer periphery of a conductive metal core. A predetermined voltage (a voltage obtained by superimposing an AC voltage and a DC voltage) is applied to the charging roller 12 from a power supply unit (not shown), thereby uniformly charging the surface of the opposing photosensitive drum 11. To do. As the elastic layer of the charging roller 12, silicone rubber, isoprene rubber, epichlorohydrin rubber or the like can be used, and the electrical resistance is preferably set to about 10 ³ to 10 ⁸ Ω · cm. As the surface layer of the charging roller 12, a material obtained by adding a melanin-based cured resin agent to a urethane resin containing conductive carbon and curing it can be used.
Here, in the present embodiment, the charging roller 12 is configured to be rotationally driven in a predetermined direction by a driving unit (not shown) in a state where the charging roller 12 is opposed to the photosensitive drum 11 with a small gap. . Thereby, the charging process can be performed satisfactorily while moving the facing surface facing the photosensitive drum 11 while preventing the problem of the lubricant adhering to the charging roller 12.

The developing device (developing unit) 13 mainly includes a developing roller 13a as a developer carrying member facing the photosensitive drum 11, a first conveying screw 13b facing the developing roller 13a, and a first conveyance via a partition member. The second conveying screw 13c is opposed to the screw 13b, and the doctor blade 13d is opposed to the developing roller 13a. The developing roller 13a includes a magnet that is fixed inside and forms a magnetic pole on the peripheral surface of the roller, and a sleeve that rotates around the magnet. A plurality of magnetic poles are formed on the developing roller 13a (sleeve) by the magnet, and the developer G (two-component developer) is carried on the developing roller 13a.
Note that a two-component developer G composed of a carrier C and a toner T is accommodated in the developing device 13.

The cleaning device 14 is provided with a cleaning blade 14a (contact member) as a blade member that contacts the photosensitive drum 11 to clean the surface of the photosensitive drum 11.
The cleaning blade 14a is made of a rubber material such as urethane rubber, and is in contact with the surface of the photosensitive drum 11 at a predetermined angle and a predetermined pressure. As a result, untransferred toner adhering to the photosensitive drum 11 (paper powder generated from the recording medium P, discharge products generated on the photosensitive drum 11 when discharged by the charging unit 12, additives added to the toner, etc. Are also scraped mechanically and collected in the cleaning device 14. In the present embodiment, the cleaning blade 14 a is in contact with the photosensitive drum 11 in the counter direction with respect to the traveling direction (rotating direction) of the photosensitive drum 11.
The untransferred toner recovered in the cleaning device 14 is transported by the transport coil 14b, discharged from the cleaning device 14 (process cartridge 10BK), and recovered in a waste toner recovery container (not shown). Will be.
In the present embodiment, a lubricant supply device 15 is provided in the cleaning device 14.

  The lubricant supply device 15 as a lubricant supply means includes a brush roller 15a as a lubricant supply rotating body that has a brush bristle that is slidably contacted with the photosensitive drum 11 and supplies the lubricant onto the photosensitive drum 11, and a brush. A solid lubricant 15b that is in sliding contact with the roller 15a (brush hair), a compression spring 15c as a biasing member that biases the solid lubricant 15b toward the brush roller 15a, and the like. The lubricant supply device 15 is arranged on the upstream side in the rotational direction of the photosensitive drum 11 with respect to the cleaning blade 14a and on the downstream side in the rotational direction of the photosensitive drum 11 with respect to the primary transfer nip (transfer bias roller 16). It is installed.

  Referring to FIG. 2, the brush roller 15 a is obtained by winding straight or looped brush hair around the outer periphery of a core metal (rotating shaft portion), and the brush hair is placed on the surface of the photosensitive drum 11. In the state of contact, the drive motor 55 rotates and drives counterclockwise in FIG. As a result, the lubricant is supplied (applied) onto the photosensitive drum 11 from the solid lubricant 15b via the brush roller 15a.

The brush roller 15a has a length (hair foot) wound in a spiral shape on a metal core, in which brush hair having a length (brush foot) in the range of 0.2 to 20 mm (preferably 0.5 to 10 mm) is planted on the base fabric. It is a thing. When the length of the brush hair exceeds 20 mm, the brush hair falls down in a predetermined direction due to repeated rubbing with the photosensitive drum 11 over time, and the scraping property of the solid lubricant 15b and the photosensitive drum 11 are removed. Lubricant supply ability will fall. On the other hand, if the length of the bristle is less than 0.2 mm, the physical contact force with respect to the solid lubricant 15b and the photosensitive drum 11 is insufficient. Therefore, it is preferable that the length of the bristle is in the above range.
As the bristles of the brush roller 15a, resin fibers such as polyester, nylon, rayon, acrylic, vinylon, and vinyl chloride can be used. If necessary, conductive fibers mixed with a conductivity-imparting agent such as carbon should be used. Can do. Moreover, it is preferable to use a brush hair having a brush density of 2-100,000 F / inch ² .

The brush roller 15a is rotationally driven so as to be in sliding contact with the photosensitive drum 11 rotating in the counterclockwise direction in FIG. 2 in the counter direction (reverse direction) (rotation in the counterclockwise direction in FIG. 2). That is, the rotation direction of the brush roller 15 a is configured to be opposite to the rotation direction (traveling direction) of the photosensitive drum 11 at the sliding contact position with the photosensitive drum 11.
The brush roller 15a is disposed so as to be in sliding contact with the solid lubricant 15b and the photosensitive drum 11, and the brush roller 15a rotates to scrape the lubricant from the solid lubricant 15b and remove the lubricant. Coating on the photosensitive drum 11.
In the present embodiment, the brush roller 15a is rotationally driven in the counterclockwise direction in FIG. 2, but can also be rotationally driven in the clockwise direction in FIG.

In the present embodiment, zinc stearate is used as the solid lubricant 15b. Specifically, this solid lubricant is preferably a lubricant obtained by dissolving a lubricating oil additive mainly composed of zinc stearate, having no side effects due to overcoating and having sufficient lubricity.
In particular, the solid lubricant 15b in the present embodiment is formed by pouring zinc stearate powder into a mold and solidifying it into a rectangular parallelepiped shape. The solid lubricant 15b formed by such a manufacturing method can simplify the manufacturing equipment and lower the cost of parts compared to that formed by compressing and solidifying zinc stearate powder. be able to.
Zinc stearate is a typical lamellar crystal powder. A lamellar crystal has a layered structure in which amphiphilic molecules are self-organized, and when a shearing force is applied, the crystal breaks along the layers and is slippery. Therefore, the surface of the photosensitive drum 11 can be made to have low friction. In other words, the surface of the photosensitive drum 11 can be effectively covered with a small amount of lubricant by the lamellar crystals that receive the shearing force and uniformly cover the surface of the photosensitive drum 11.
Further, by using the solid lubricant 15b containing zinc stearate and boron nitride, it is possible to further promote the low frictional engagement on the surface of the photosensitive drum 11.

  In addition to zinc stearate, solid lubricants include stearic acid groups such as barium stearate, iron stearate, nickel stearate, cobalt stearate, copper stearate, strontium stearate and calcium stearate. It can be used. In addition, the same fatty acid group zinc oleate, barium oleate, lead oleate, the same compound as stearic acid, zinc palmitate, barium palmitate, lead palmitate, the following compound similar to stearic acid May be used. In addition, caprylic acid, linolenic acid, corinolenic acid and the like can be used as the fatty acid group. In addition, waxes such as candelilla wax, canrunauba wax, rice wax, wax, coconut oil, beeswax, and lanolin can also be used. These easily become organic solid lubricants and have good compatibility with the toner.

Here, the cleaning blade 114 a (blade member) installed on the downstream side of the lubricant supply device 15 is configured to uniformly and appropriately supply the lubricant supplied onto the photosensitive drum 11 by the brush roller 15 a onto the photosensitive drum 11. It also functions as a thinning blade for thinning.
When the lubricant is applied from the solid lubricant 15b to the surface of the photosensitive drum 11 via the brush roller 15a, the powdery lubricant is applied to the surface of the photosensitive drum 11, but in this state, Since the lubricity is not sufficiently exhibited, the cleaning blade 14a (thinning blade) functions as a member for thinning and uniforming the lubricant, and the lubricant film is formed on the photosensitive drum 11. As a result, the lubricant exhibits its lubricity sufficiently.

Here, in the present embodiment, the black process cartridge 10BK as the first image forming unit in which the lubricant supply device 15 (lubricant supply means) is installed has a cleaning blade 14a (a The contact member is configured to come into contact with the photosensitive drum 11 (image carrier) so as to be separable.
Specifically, the cleaning blade 14a of the black process cartridge 10BK is centered on the support shaft 14a1 (rotating shaft) of the blade holder by a third contact / separation mechanism 53 (for example, a drive mechanism including a motor and a gear train). 2 is configured to be rotatable clockwise and counterclockwise in FIG. That is, the cleaning blade 14a in contact as shown in FIG. 2 can be separated from the photosensitive drum 11 by rotating counterclockwise in FIG. 2 about the support shaft 14a1, and the support is supported from the separated state. By rotating in the clockwise direction in FIG. 2 about the shaft 14a1, the photosensitive drum 11 can be contacted again. In this way, the cleaning blade 14a is configured to be separable from the photosensitive drum 11 only in the black process cartridge 10BK, and the other three process cartridges 10Y, 10M, and 10C are configured to be separable. It has not been.
In the present exemplary embodiment, the intermediate transfer belt 17 and the four image forming units 10Y, 10M, and 10C with the cleaning blade 14a separated from the photosensitive drum 11 at a predetermined timing during non-image formation. The “lubricant transfer supply mode” in which 10BK is idly rotated (idle drive) is performed, which will be described in detail later with reference to FIG.

  In the present embodiment, in the black process cartridge 10BK (first image forming unit), the lubricant supply device 15 is provided in the cleaning device 14, but the lubricant supply device 15 is provided in the cleaning device. 14, the lubricant supply device 15 can be installed on the downstream side of the cleaning device 14 and on the upstream side of the charging roller 12. In that case, it is preferable to install the thinning blade on the downstream side of the brush roller 15a separately from the cleaning blade 14a.

The image forming process described above will be described in more detail with reference to FIG.
The developing roller 13a rotates in the direction of the arrow in FIG. The developer G in the developing device 13 is moved from the toner replenishing portion 30 to the toner replenishing port by the rotation of the first conveying screw 13b and the second conveying screw 13c arranged with a partition member therebetween. The toner T is circulated in the longitudinal direction while being agitated and mixed with the toner T supplied through the toner T (in the direction perpendicular to the paper surface of FIG. 2).

  The toner T that is frictionally charged and adsorbed on the carrier C is carried on the developing roller 13a together with the carrier C. The developer G carried on the developing roller 13a then reaches the position of the doctor blade 13d. Then, after the developer G on the developing roller 13a is adjusted to an appropriate amount at the position of the doctor blade 13d, it becomes a brushed magnetic brush and reaches the position facing the photosensitive drum 11 (developing area). Thus, the magnetic brush comes into sliding contact with the photosensitive drum 11.

  Thus, the toner T in the developer G adheres to the electrostatic latent image formed on the surface of the photosensitive drum 11 in the development region. Specifically, the toner T is latently exposed by an electric field formed by a potential difference (development potential) between the latent image potential (exposure potential) of the image portion irradiated with the laser light L and the development bias applied to the developing roller 13a. Adhere to the image.

  Thereafter, most of the toner T adhering to the photosensitive drum 11 in the developing process is transferred onto the intermediate transfer belt 17. Then, the untransferred toner T remaining on the photosensitive drum 11 is collected in the cleaning device 14 by the cleaning blade 14a. Thereafter, the surface of the photosensitive drum 11 after the cleaning process passes through a position facing the charge eliminating unit (not shown), and a series of image forming processes is completed.

  Here, the toner replenishing unit 30 provided in the apparatus main body 1 includes a replaceable toner bottle 31 and a toner hopper unit 32 that holds and rotates the toner bottle 31 and replenishes the developing device 13 with new toner T. And is composed of. In addition, a new toner T (in FIG. 2, black toner) is accommodated in the toner bottle 31. In addition, a spiral protrusion is formed on the inner peripheral surface of the toner bottle 31.

  The new toner T in the toner bottle 31 is appropriately replenished into the developing device 13 from the toner replenishing port as the toner T in the developing device 13 (existing toner) is consumed. The toner T in the developing device 13 is consumed indirectly or directly by a reflective photosensor facing the photosensitive drum 11 and a magnetic sensor installed below the second conveying screw 13c of the developing device 13. Detected.

Next, the process cartridges 10Y, 10M, and 10C for yellow, magenta, and cyan will be described in detail with reference to FIG.
As shown in FIG. 3, the process cartridges 10Y, 10M, and 10C (image forming units) for yellow, magenta, and cyan have a photosensitive drum 11 as an image carrier and a charging roller 12 (charging unit), respectively. The developing unit 13 (developing device) and the cleaning device 14 (cleaning unit) are integrally configured as a unit.
The process cartridges 10Y, 10M, and 10C for yellow, magenta, and cyan are different from the process cartridge 10BK for black that functions as the first image forming unit, and are provided with a lubricant supply device 15 (lubricant supply means). It functions as the second image forming unit. Further, as shown in FIG. 1, the process cartridges 10Y, 10M, and 10C for yellow, magenta, and cyan are black process cartridges 10BK with reference to the position of the secondary transfer bias roller 18 (secondary transfer member). Are arranged side by side so as to be located upstream of the intermediate transfer belt 17 in the running direction (from the most upstream side, the process cartridge for yellow 10Y, the process cartridge for magenta 10M, and the process cartridge for cyan 10C in that order). .
The arrangement order of the yellow process cartridge 10Y, the magenta process cartridge 10M, and the cyan process cartridge 10C is not limited to that of the present embodiment.

  The other constituent members of the process cartridges 10Y, 10M, and 10C for yellow, magenta, and cyan (members such as the photosensitive drum 11, the charging roller 12, the developing device 13, and the cleaning blade 14a). The common process cartridge 10BK for black is configured and operates in the same manner as that described above with reference to FIG. However, the cleaning blade 14a in the process cartridges 10Y, 10M, and 10C for yellow, magenta, and cyan is not configured to be separable from the photoconductive drum 11, but has a predetermined angle with respect to the photoconductive drum 11. It is fixed so as to contact at a predetermined pressure.

  As described above, in the image forming apparatus according to the present embodiment, four process cartridges 10Y, 10M, 10C, and 10BK are installed as a plurality of image forming units. Among the four image forming units, a first image forming unit in which a lubricant supply device 15 (lubricant supply unit) for supplying a lubricant to the surface of the photosensitive drum 11 (image carrier) is installed, and lubrication At least one second image forming unit in which no agent supply means is installed is provided. Specifically, the black process cartridge 10BK is used as a first image forming unit, and the other three color process cartridges 10Y, 10M, and 10C are used as second image forming units. As described above, by providing the second image forming unit in which the lubricant supply unit is not installed, it is possible to compare all of the plurality of image forming units with the first image forming unit in which the lubricant supply unit is installed. The entire forming apparatus 1 can be reduced in size and cost.

  In the present embodiment, among the four process cartridges 10Y, 10M, 10C, and 10BK, only the black process cartridge 10BK is used as the first image forming unit in four colors even in the color image forming apparatus. This is because monochrome image formation using only black is overwhelmingly more than full-color image formation using, and the use frequency (operating rate) of the process cartridge 10BK for black is increased. In other words, by installing the lubricant supply device 15 only in the black process cartridge 10BK having a high use frequency (operating rate), the durability of the entire image forming apparatus 1 (extension of life) is maintained to some extent while the apparatus 1 is maintained. Can be reduced in size and cost.

The black process cartridge 10BK is disposed so as to be located on the most downstream side in the traveling direction of the intermediate transfer belt 17 with respect to the position of the secondary transfer bias roller 18 (secondary transfer member). This is because the use frequency of the black process cartridge 10BK is high as described above, and the print speed (print productivity) at the time of monochrome image formation is increased.
Further, the yellow process cartridge 10Y is disposed so as to be positioned on the most upstream side in the running direction of the intermediate transfer belt 17 with respect to the position of the secondary transfer bias roller 18 (secondary transfer member). Even if the yellow toner moves from the photosensitive drum 11 in the downstream image forming unit via the intermediate transfer belt 17 into the developing device 13 and is mixed with other color toners (or mixed colors), the image forming process is performed. This is because there is little influence on the image formed by.

  Here, referring to FIG. 4, in the present embodiment, the intermediate transfer cleaning unit 19 (intermediate transfer cleaning blade) abuts against the intermediate transfer belt 17 (intermediate transfer member) so as to be relatively separable. It is comprised so that it may function as a contact member. Specifically, the intermediate transfer cleaning unit 19 is configured to be movable in the left-right direction in FIG. 4 by a first contact / separation mechanism 51 (for example, a drive mechanism including a cam mechanism and an urging member). That is, as shown in FIG. 4A, the intermediate transfer cleaning unit 19 in contact is moved to the left (in the direction of the black arrow in FIG. 4B) as shown in FIG. 4B. Thus, the intermediate transfer belt 17 can be separated from the intermediate transfer belt 17, and the intermediate transfer belt 17 can be brought into contact again by being moved to the right from the separated state.

  Referring to FIG. 4, in the present embodiment, the secondary transfer bias roller 18 (secondary transfer member) also contacts the intermediate transfer belt 17 (intermediate transfer member) so as to be relatively separable. It is comprised so that it may function as a contact member. Specifically, the secondary transfer bias roller 18 is configured to be movable in the vertical direction in FIG. 4 by a second contact / separation mechanism 52 (for example, a drive mechanism including a cam mechanism and an urging member). . That is, the secondary transfer bias roller 18 in contact as shown in FIG. 4A moves downward (in the direction of the black arrow in FIG. 4B) as shown in FIG. 4B. Accordingly, the intermediate transfer belt 17 can be separated from the intermediate transfer belt 17, and the intermediate transfer belt 17 can be brought into contact again by moving upward from the separated state.

  Further, as described above with reference to FIG. 2, in the present embodiment, the cleaning blade 14a (thinning blade) installed in the black process cartridge 10BK (first image forming unit) is a photosensitive drum. 11 (image carrier of the first image forming unit) is configured to function as an abutting member that abuts so as to be relatively separable. Specifically, as shown in FIG. 4A, the cleaning blade 14a in contact is rotated counterclockwise (in the direction of the white arrow in FIG. 4B) as shown in FIG. 4B. The photosensitive drum 11 can be separated from the photosensitive drum 11 by being moved, and can be brought into contact again with the photosensitive drum 11 by being rotated clockwise from the separated state.

  Then, the intermediate transfer cleaning unit 19 and the secondary transfer bias roller 18 as contact members are separated from the intermediate transfer belt 17 and further contacted in the black process cartridge 10BK (first image forming unit). A lubricant (applied to the lubricant supply device 15) adhered to the photosensitive drum 11 of the black process cartridge 10BK (first image forming unit) in a state where the cleaning blade 14a as a member is separated from the photosensitive drum 11. Is moved through the intermediate transfer belt 17 to adhere to the photosensitive drums 11 of the color process cartridges 10Y, 10M, and 10C (second image forming unit). The “mode” is executed at a predetermined timing.

  Specifically, the “lubricant transfer supply mode” is used when the normal image forming process is not performed (when the series of image forming processes described above with reference to FIG. 1 is not performed and non-image forming is performed). To be executed). Specifically, in the present embodiment, the “lubricant transfer supply mode” is executed after a series of image forming processes (image forming processes) is finished (after the job is finished). That is, after a series of jobs are completed in the image forming apparatus 1 in the state shown in FIG. 4A, as shown in FIG. The intermediate transfer belt 17 and the four image forming units 10Y, 10M, 10C, and 10BK are moved with the transfer roller 18 separated and the cleaning blade 14a of the first image forming unit separated from the photosensitive drum 11. The “lubricant movement supply mode” in which idling (idle driving) is performed is performed.

By appropriately executing the “lubricant transfer supply mode” in this way, the use frequency (operation rate) is lower than that of the black process cartridge 10BK (first image forming unit) and the lubricant supply device 15 is installed. In contrast to the photosensitive drums 11 of the color process cartridges 10Y, 10M, and 10C (second image forming unit), the intermediate transfer belt from the photosensitive drum 11 of the black process cartridge 10BK (first image forming unit), respectively. The lubricant that moves through 17 is efficiently supplied without adhering to the contact member (intermediate transfer cleaning unit 19, secondary transfer bias roller 18, and cleaning blade 14a) and being taken away.
More specifically, the lubricant supplied to the photosensitive drum 11 of the black process cartridge 10BK (first image forming unit) by the lubricant supply device 15 is thinned and not reduced by the separated cleaning blade 14a. And adheres to the intermediate transfer belt 17. The lubricant adhering to the intermediate transfer belt 17 does not adhere to the intermediate transfer cleaning unit 19 and the secondary transfer bias roller 18 in the separated state, and the color process cartridges 10Y, 10M, and 10C (second image forming unit). Are supplied to the photosensitive drums 11 respectively.
As a result, it is possible to reduce the wear of the photosensitive drum 11 and the cleaning blade 14a in the color process cartridges 10Y, 10M, and 10C (second image forming unit) in which the lubricant supply device 15 is not installed. The occurrence of abnormal images can also be reduced.

Note that when the “lubricant transfer supply mode” is executed, the photosensitive drum 11 of the cyan process cartridge 10C located on the most downstream side with respect to the position of the black process cartridge 10BK (first image forming unit) is Since the amount of lubricant that initially adheres to the photosensitive drums 11 for yellow and magenta process cartridges 10Y and 10M on the upstream side increases, the amount of lubricant supplied initially decreases. However, such a phenomenon is caused by saturation of the amount of lubricant adhering to the photosensitive drums 11 of the upstream yellow and magenta process cartridges 10Y and 10M while the “lubricant transfer supply mode” is performed for a while. It becomes a state and will be resolved. That is, a sufficient amount of lubricant is also supplied to the photosensitive drum 11 of the cyan process cartridge 10C on the most downstream side.
Further, after the “lubricant transfer supply mode” is completed, the lubricant adhering to the intermediate transfer belt 17 is returned to the contact state (the state shown in FIG. 4A), and the intermediate transfer cleaning unit 19 is returned. Will be collected.

Here, in the present embodiment, in an operating condition in which abnormal images are likely to occur due to wear of the photosensitive drum 11 and the cleaning blade 14a in the color process cartridges 10Y, 10M, and 10C (second image forming unit). It is also possible to control to execute the “lubricant transfer supply mode”.
Specifically, when the image area ratio in the output image (the ratio of the area of the image formed to the area of the recording medium P) is a predetermined value or more (for example, 10% or more). It can be controlled to execute the “lubricant transfer supply mode”. This is because when the image area ratio (particularly the image area ratio of a color image) increases, abnormal images such as filming are likely to occur due to wear of the photosensitive drum 11 and the cleaning blade 14a. Note that the image area ratio of the output image is the size information of the recording medium P input to the operation panel 56 (or the size information directly detected by the size detection sensor) and the duty of the laser light emitted from the writing unit 2. It is calculated by the area ratio calculation unit 58 based on such information. Then, the contact / separation mechanisms 51 to 53 are driven by the control unit 50 based on the calculation result, and the “lubricant movement supply mode” is executed.

It is also possible to perform control so that the “lubricant transfer supply mode” is executed when the number of continuous sheets reaches a predetermined value (for example, 100 sheets) during continuous sheet passing. This is during continuous paper passing and when the number of continuous paper passes increases, the ambient temperature in the apparatus 1 rises, and abnormal images such as filming are likely to occur due to wear of the photosensitive drum 11 and the cleaning blade 14a. Because it becomes. It should be noted that the state in which the number of continuous sheets has reached the predetermined value is determined based on the information on the number of sheets to be passed through the recording medium P input to the operation panel 56 and the information on the number of sheets to be passed counted by the counter 57. Is done. Based on the determination result, the contact / separation mechanisms 51 to 53 are driven by the control unit 50 to execute the “lubricant movement supply mode”.
Since the ambient temperature in the apparatus 1 is also affected by the environmental temperature, the above-described “predetermined value of the number of continuously passing sheets” can be varied based on the result of the temperature sensor that detects the environmental temperature. .

  It is also possible to perform control so that the “lubricant movement supply mode” is executed every time the cumulative number of sheets passed reaches a predetermined value (for example, 500 sheets). This is because the lubricant applied to the photosensitive drum 11 gradually decreases as the cumulative number of sheets passed, and abnormal images such as filming are likely to occur due to wear of the photosensitive drum 11 and the cleaning blade 14a. It is. Note that the state where the cumulative number of sheets has reached a predetermined value is determined based on the information on the number of sheets that are counted by the counter 57. Based on the determination result, the contact / separation mechanisms 51 to 53 are driven by the control unit 50 to execute the “lubricant movement supply mode”.

FIG. 5 is a flowchart showing the control of the “lubricant transfer supply mode” reflecting the three operating conditions described above.
As shown in FIG. 5, when a print command is input to the control unit 50 of the apparatus body 1, first, a job related to the print command is started and it is determined whether the job is continuous paper passing. (Step S1). As a result, when it is determined that the job is continuous paper passing, it is further determined whether or not the continuous paper passing number in the job has reached a predetermined value (step S2). As a result, when it is determined that the number of continuous sheets in the job has not reached the predetermined value, the number of continuous sheets is counted up (step S7), and the flow after step S1 is repeated.
If it is determined in step S2 that the number of continuous sheets in the job has reached a predetermined value, it is further determined whether the image area ratio of the output image is equal to or greater than the predetermined value (step S3). ). As a result, when it is determined that the image area ratio of the output image is equal to or greater than the predetermined value, it is determined that the lubricant needs to be supplied to the photosensitive drum 11 of the second image forming unit, and the job is ended. After confirmation (step S4), the “lubricant transfer supply mode” is executed (step S5). Then, the continuous sheet passing number (counter) is cleared, and this flow is finished (step S6).
On the other hand, if it is determined in step S1 that the job is not continuous sheet passing, it is determined whether the cumulative number of sheets has reached a predetermined value (step S8). As a result, if it is determined that the cumulative number of sheets has reached the predetermined value, it is assumed that the lubricant needs to be supplied to the photosensitive drum 11 of the second image forming unit, and the above steps S4 and after. The flow is performed. On the other hand, if it is determined that the cumulative number of sheets has not reached the predetermined value, it is determined that the lubricant supply to the photosensitive drum 11 of the second image forming unit is unnecessary, and this flow is performed. finish.

In the present embodiment, a deceleration mode in which the sheet passing speed is reduced (such as when envelopes or cardboard are passed, and under certain conditions to secure the fixing time in the fixing device 20). When the operation is performed, the “lubricant transfer supply mode” is not executed, and the “lubricant transfer supply mode” is executed only in the normal mode where the sheet passing speed is faster than the deceleration mode. It can also be controlled. This is because the atmospheric temperature in the apparatus 1 is not so high in the deceleration mode as compared with the normal mode, and abnormal images such as filming are less likely to occur due to wear of the photosensitive drum 11 and the cleaning blade 14a.
In the case where the sheet passing speed is configured to be changed stepwise, for the same reason, the “lubricant movement supply mode” is executed only in the sheet passing mode where the sheet passing speed is high. Can be controlled.

In the present embodiment, when the “lubricant transfer supply mode” is executed, the lubricant supply device 15 of the black process cartridge 10BK (first image forming unit) is supplied to the surface of the photosensitive drum 11. It can also be controlled to increase the amount of lubricant supplied.
Specifically, as shown in FIG. 2, when the “lubricant movement supply mode” is executed with the drive motor 55 that rotationally drives the brush roller 15 a (lubricant supply rotating body) as a variable speed motor. The brush roller 15a is rotated by increasing the number of rotations. As a result, the “lubricant transfer supply mode” is executed in a state where the amount of lubricant supplied to the photosensitive drum 11 of the black process cartridge 10BK is increased, so that the color process cartridges 10Y, 10M, and 10C are executed. A sufficient amount of lubricant can be supplied to the photosensitive drum 11 of (second image forming unit) in a single hour.

  As described above, according to the present embodiment, among the plurality of process cartridges 10BK, 10Y, 10M, and 10C (image forming units) arranged in parallel so as to face the intermediate transfer belt 17 (intermediate transfer member), The black process cartridge 10BK (first image forming unit) in which the lubricant supply device 15 (lubricant supply means) is installed, and the color process cartridges 10Y, 10M, and 10C (second image forming in which the lubricant supply device 15 is not installed). 2), the contact member such as the intermediate transfer cleaning unit 19, the secondary transfer bias roller 18, and the cleaning blade 14a is used as the intermediate transfer belt 17 and the photosensitive drum 11 of the black process cartridge 10BK. The lubricant adhered to the photosensitive drum 11 of the black process cartridge 10BK while being separated from the photosensitive drum 11 Is moved through the intermediate transfer belt 17 so that the “lubricant movement supply mode” in which the toner is adhered to the photosensitive drums 11 of the color process cartridges 10Y, 10M, and 10C can be executed. A lubricant can be sufficiently adhered to the photosensitive drums 11 of the color process cartridges 10Y, 10M, and 10C that are not installed at a predetermined timing.

In the present embodiment, the process cartridges 10Y, 10M, 10C, and the like are formed by integrating the constituent members (the photosensitive drum 11, the charging roller 12, the developing device 13, the cleaning device 14, etc.) in the plurality of image forming units. 10BK is configured to reduce the size of the image forming unit and improve maintenance workability.
On the other hand, the constituent members in the plurality of image forming units can be installed in the apparatus main body 1 in a replaceable manner without forming the plurality of image forming units into a process cartridge. Even in such a case, the same effect as the present embodiment can be obtained.
In the present application, the “process cartridge” refers to a charging unit that charges the image carrier, a developing unit (developing device) that develops a latent image formed on the image carrier, and a cleaning on the image carrier. It is defined as a unit in which at least one of the cleaning unit (cleaning device) and the image carrier are integrated and installed detachably with respect to the image forming apparatus main body.

  In the present embodiment, the present invention is applied to the image forming apparatus equipped with the two-component developing type developing device 13 using the two-component developer. However, the one-component developing type using the one-component developer is used. Of course, the present invention can also be applied to an image forming apparatus equipped with a developing device. Even in this case, it is preferable to install the developing roller so as to face the photosensitive drum with a gap so that the lubricant does not adhere to the developing roller of the developing device.

  In the present embodiment, only the black process cartridge 10BK is used as the first image forming unit in which the lubricant supply device 15 (lubricant supply means) is installed, and the other color process cartridges 10Y, 10M, and 10C are used. Although the second image forming unit is not provided with the lubricant supply device 15 (lubricant supply means), the application of the present invention is not limited to this. For example, even when the number of first image forming units in which the lubricant supply device 15 (lubricant supplying means) is installed is two or more, the present invention is applied as long as there is at least one second image forming unit. can do. Even in such a case, substantially the same effect as that of the present embodiment can be obtained.

In the present embodiment, the brush roller 15a around which the bristle is provided is used as the lubricant supply rotator. However, the sponge roller (on the core metal) around which a sponge-like member is provided as the lubricant supply rotator. In addition, a roller member in which a foamed elastic layer made of foamed polyurethane or the like is formed can also be used.
In the present embodiment, the blade member (contact member) formed of a rubber material is used. However, the blade member (contact member) formed of another material (for example, a metal material) It is also possible to use a plate-like blade member made of
Even in such a case, the same effect as in the present embodiment can be obtained.

In the present embodiment, the intermediate transfer cleaning unit 19 itself is separated from the intermediate transfer belt 17 by the first contact / separation mechanism 51, but the intermediate transfer is performed to the intermediate transfer belt 17 by the contact / separation mechanism. Only the intermediate transfer cleaning blade of the cleaning unit 19 can be separated, or the intermediate transfer belt 17 can be separated from the intermediate transfer cleaning unit 19.
Similarly, it is sufficient that the secondary transfer bias roller 18 is configured so as to be relatively separated from the intermediate transfer belt 17, and the contact / separation form is not limited to that of the present embodiment. The same applies to the contact and separation of the cleaning blade 14a.
And even if it is such a case, the effect similar to this Embodiment can be acquired.

In this embodiment, when the “lubricant movement supply mode” is executed, the intermediate transfer cleaning unit 19 is separated from the intermediate transfer belt 17 and the secondary transfer bias roller is separated from the intermediate transfer belt 17. 18 was separated, and the cleaning blade 14a was separated from the black photosensitive drum 11 (all three contact members 14a, 18, 19 were separated).
On the other hand, when the “lubricant movement supply mode” is executed, one or two of the three contact members 14a, 18, 19 may be configured to be separated from each other. The same effect as this embodiment will be exhibited to some extent.
In addition to the three contact members 14 a, 18, and 19 described above, a contact member is provided in the lubricant movement path from the photosensitive drum 11 of the first image forming unit to the photosensitive drum 11 of the second image forming unit. If present, the contact member is preferably separated when the “lubricant transfer supply mode” is executed.

Further, in the present embodiment, when the “lubricant movement supply mode” is executed, the secondary transfer bias roller 18 is separated from the intermediate transfer belt 17 so that the lubricant is applied to the secondary transfer bias roller 18. I tried not to stick. In contrast, when the “lubricant movement supply mode” is executed, the secondary transfer bias roller 18 is charged with the lubricant while the secondary transfer bias roller 18 is kept in contact with the intermediate transfer belt 17. It is possible to prevent the lubricant from adhering to the secondary transfer bias roller 18 by applying a voltage having a polarity different from the polarity.
And even if it is such a case, the effect similar to this Embodiment can be acquired.

  It should be noted that the present invention is not limited to the present embodiment, and it is obvious that the present embodiment can be modified as appropriate within the scope of the technical idea of the present invention, other than suggested in the present embodiment. is there. In addition, the number, position, shape, and the like of the constituent members are not limited to the present embodiment, and the number, position, shape, and the like suitable for implementing the present invention can be achieved.

1 image forming apparatus body (apparatus body),
10Y, 10M, 10C, 10BK process cartridge (imaging part),
11 Photosensitive drum (image carrier), 12 Charging roller (charging unit),
13 Developing section (developing device),
14 Cleaning section (cleaning device),
14a Cleaning blade (blade member, contact member),
15 Lubricant supply device (lubricant supply means),
15a brush roller (lubricant supply rotating body),
15b solid lubricant,
15c compression spring (biasing member),
17 Intermediate transfer belt (intermediate transfer member),
18 secondary transfer bias roller (secondary transfer member, contact member),
19 Intermediate transfer cleaning unit (contact member).

JP 2011-13561 A

Claims (11)

A plurality of image forming sections that respectively form toner images on the image carrier;
The image carriers of the plurality of image forming units are arranged side by side so as to face each other and travel in a predetermined direction so that toner images respectively formed on the image carriers in the plurality of image forming units are superimposed. An intermediate transfer member to be transferred
With
The plurality of image forming units include a first image forming unit in which a lubricant supply unit that supplies a lubricant to the surface of the image carrier is installed, and a second image forming unit in which the lubricant supply unit is not installed. , Each having at least one,
A contact member that contacts the intermediate transfer member or the image carrier of the first image forming unit so as to be relatively separated;
In the state where the contact member is separated from the intermediate transfer member or the image carrier of the first image forming unit, the lubricant adhered to the image carrier of the first image forming unit is used to remove the intermediate transfer member. An image forming apparatus, wherein a lubricant movement supply mode in which the lubricant is moved and attached to the image carrier of the second image forming unit is executed at a predetermined timing.   The image forming apparatus according to claim 1, wherein the lubricant movement supply mode is executed when a normal image forming process is not performed.   The image forming apparatus according to claim 2, wherein the lubricant movement supply mode is executed after a series of image forming processes is completed.   The image forming apparatus according to claim 1, wherein the lubricant movement supply mode is executed when an image area ratio in an output image is a predetermined value or more.   5. The image forming apparatus according to claim 1, wherein the lubricant movement supply mode is executed when a continuous sheet passing number reaches a predetermined value during continuous sheet passing.   6. The image forming apparatus according to claim 1, wherein the lubricant movement supply mode is executed every time the cumulative number of sheets passed reaches a predetermined value.   The image forming apparatus according to claim 1, wherein the lubricant movement supply mode is not executed when a deceleration mode in which a sheet passing speed is reduced is performed.   The lubricant supply means of the first image forming unit is controlled to increase the amount of lubricant supplied to the surface of the image carrier when the lubricant movement supply mode is executed. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.   The abutting member abuts against the intermediate transfer member and removes untransferred toner adhered to the surface of the intermediate transfer member, and / or the intermediate transfer member abuts against the intermediate transfer member. The image according to claim 1, wherein the image is a secondary transfer member that secondarily transfers the toner image on the intermediate transfer member onto a recording medium conveyed between Forming equipment. The first image forming unit includes a lubricant supply rotating body that rotates while slidingly contacting the image carrier and a solid lubricant, and a downstream side in the rotation direction of the image carrier with respect to the lubricant supply rotating body. A blade member disposed so as to contact the image carrier on the upstream side in the rotation direction of the image carrier with respect to a position where the intermediate transfer member and the image carrier are opposed to each other.
The image forming apparatus according to claim 1, wherein the contact member is the blade member. A secondary transfer member that secondarily transfers the toner image on the intermediate transfer member onto a recording medium conveyed between the intermediate transfer member and the intermediate transfer member;
The plurality of image forming units are an image forming unit for black, an image forming unit for yellow, an image forming unit for magenta, and an image forming unit for cyan.
The first image forming section is the black image forming section disposed so as to be positioned on the most downstream side in the running direction of the intermediate transfer body with respect to the position of the secondary transfer member,
The second image forming unit is arranged in parallel with the black image forming unit on the upstream side in the running direction of the intermediate transfer member with respect to the position of the secondary transfer member. 11. The image forming apparatus according to claim 1, wherein the image forming apparatus includes an image forming unit, a magenta image forming unit, and a cyan image forming unit.

Images