JP2016038424A - Image forming apparatus and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus and a process cartridge that can stabilize the amount of lubricant to be supplied to an image carrier even when an environment is changed, a process linear velocity is changed, and during the course of time, without reducing the life of a lubricant supply device.SOLUTION: A brush-like roller 45 (toner adhesion amount adjustment means) adjusts the amount of adhesion of a toner adhered to the surface of a photoreceptor drum 11 (image carrier) according to predetermined conditions, and is disposed on the downstream side in the direction of rotation (on the downstream side in the direction of travel) of the photoreceptor drum 11 with respect to a cleaning device 14 and on the upstream side in the direction of rotation (upstream side in the direction of travel) of the photoreceptor drum 11 with respect to a lubricant supply device 15.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, or a complex machine thereof, and a process cartridge that is detachably installed therein.

  Conventionally, in image forming apparatuses such as copying machines and printers, a lubricant supply device (lubricant coating device) for supplying a lubricant is installed on the image carrier to reduce wear of the image carrier and cleaning blade. The technique which performs is known (for example, refer patent document 1, 2 grade | etc.,).

  Specifically, in Patent Document 1 and the like, the lubricant supply device includes a lubricant supply roller (brush roller) that is in sliding contact with the image carrier at a position downstream of the cleaning blade (blade member), and a solid that is in contact with the lubricant supply roller. Thinning blade (smoothing blade) as a biasing member that biases the lubricant, solid lubricant toward the lubricant supply roller, and a blade member that is downstream of the lubricant supply roller and contacts the image carrier , Etc. Then, the lubricant is gradually scraped off from the solid lubricant by the lubricant supply roller rotating in a predetermined direction, and the lubricant scraped off by the lubricant supply roller is applied (supplied) to the surface of the image carrier. Thereafter, the lubricant supplied onto the image carrier is thinned (homogenized) by a thinning blade.

On the other hand, in Patent Document 1, for the purpose of stabilizing the amount of lubricant supplied to the image carrier even when environmental fluctuation occurs or over time, based on the total travel distance of the environment and the lubricant supply roller, A technique for adjusting the amount of lubricant supplied to the image carrier by changing the number of revolutions of the lubricant supply roller is disclosed.
Japanese Patent Laid-Open No. 2004-228688 aims to stabilize the amount of lubricant supplied to the image carrier even when the process linear velocity is varied in an apparatus that can vary the process linear velocity (the number of rotations of the image carrier). When the process linear velocity is set to be slow, in addition to supplying the lubricant from the lubricant supply device to the image carrier, the image carrier is supplied from a second lubricant supply device provided separately from the lubricant supply device. Techniques for supplying lubricant to the body are disclosed.

The technique described in Patent Document 1 varies the rotational speed of the lubricant supply roller based on the environment and the total travel distance of the lubricant supply roller, so that the image carrier can be used even when environmental changes occur or over time. The lubricant supply roller (lubricant supply device) can be used when the lubricant supply roller is driven at a high speed for a long time, although the effect of stabilizing the amount of lubricant supplied to the motor can be expected. The mechanical life could be shortened.
Further, the technique described in Patent Document 2 supplies the lubricant from the two lubricant supply devices to the image carrier when the process linear speed is set to be slow. Although the effect of stabilizing the amount of lubricant supplied to the image carrier can be expected, the image carrier is used when the amount of lubricant supplied to the image carrier from one lubricant supply device becomes excessive. The amount of lubricant supplied to the body could not be reduced, and the charging roller could be soiled with lubricant or the lubricant contained in the lubricant supply device could be lost early. .

  The present invention has been made to solve the above-described problems, and can shorten the life of the lubricant supply device even when environmental fluctuations occur, when the process linear velocity is varied, and even over time. It is another object of the present invention to provide an image forming apparatus and a process cartridge that can stabilize the amount of lubricant supplied to an image carrier.

  According to a first aspect of the present invention, an image forming apparatus travels in a predetermined direction and includes an image carrier on which a toner image is carried and an untransferred toner attached to the surface of the image carrier. A cleaning device to be removed, a lubricant supply device that is disposed downstream of the cleaning device in the running direction of the image carrier, and that supplies a lubricant to the surface of the image carrier, and the cleaning device Disposed downstream of the image carrier in the running direction and upstream of the lubricant supply device in the running direction of the image carrier, and adheres to the surface of the image carrier according to a predetermined condition. And a toner adhesion amount adjusting means for adjusting the toner adhesion amount.

  According to the present invention, it is possible to stabilize the amount of lubricant supplied to the image carrier without shortening the life of the lubricant supply device even when the environment fluctuates, when the process linear velocity is varied, or over time. An image forming apparatus and a process cartridge can be provided.

1 is an overall configuration diagram illustrating an image forming apparatus according to an embodiment of the present invention. It is a block diagram which shows a process cartridge and its vicinity. (A) a graph showing the relationship between the cumulative number of sheets passed and the lubricant consumption, (B) a graph showing the relationship between the temperature and the lubricant consumption, (C) the rotational speed of the photosensitive drum and the lubricant consumption. And a graph showing the relationship with the quantity. It is a graph which shows the relationship between the amount of input toners to a lubricant supply apparatus, and lubricant consumption.

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. FIG. 2 is a cross-sectional view showing a configuration of a yellow process cartridge 10Y (image forming unit) installed in the image forming apparatus 1 of FIG.
Since the four process cartridges 10Y, 10M, 10C, and 10BK (image forming units) have substantially the same structure except that the color of the toner T used in the image forming process is different, the process cartridge 10Y for yellow is shown in FIG. Only a representative is shown.

  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 that reads image information of the document D, 7 is a paper feed unit that accommodates a recording medium such as transfer paper, and 9 is a registration roller that adjusts the conveyance timing of the recording medium, 10Y, 10M, 10C, and 10BK. Is a process cartridge on which toner images of each color (yellow, magenta, cyan, black) are formed, and 16 is a toner image formed on the photosensitive drum of each process cartridge 10Y, 10M, 10C, 10BK on the intermediate transfer belt 17. A primary transfer bias roller 17 for transferring the toner image, an intermediate transfer belt 17 on which toner images of a plurality of colors are transferred in an overlapping manner, and 18 an intermediate transfer belt 1 A secondary transfer bias roller for transferring the upper toner image onto the recording medium, 19 an intermediate transfer belt cleaning unit for cleaning the intermediate transfer belt 17, and 20 for fixing the toner image (unfixed image) on the recording medium. 1 shows a fixing device.

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, the laser beam (exposure light) based on the image information of each color is directed from the writing unit 2 toward the corresponding photosensitive drum 11 (image carrier) of the process cartridges 10Y, 10M, 10C, and 10BK. Be emitted.

On the other hand, the photosensitive drums 11 (refer to FIG. 2) of the four process cartridges 10Y, 10M, 10C, and 10BK rotate (run) in a predetermined direction (counterclockwise), respectively. First, the surface of the photosensitive drum 11 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 images of the respective colors are formed reaches a position facing the developing device 13. Then, each color toner is supplied from each developing device 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 primary transfer bias roller 16 is installed at each facing portion so as to be in contact with 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 device 14 (cleaning unit). At this position, the untransferred toner remaining on the photosensitive drum 11 is mechanically removed by the cleaning blade 14a as a blade member, and the removed untransferred toner is collected in the cleaning device 14 (cleaning). Process.) The untransferred toner collected in the cleaning device 14 is transported to the outside of the cleaning device 14 by the transport screw 14b, and is collected as waste toner in a waste toner collection container (not shown).
Thereafter, the surface of the photosensitive drum 11 sequentially passes through the positions of the lubricant supply device 15 and the charge eliminating unit (not shown), and a series of image forming processes on the photosensitive drum 11 is completed.

On the other hand, the intermediate transfer belt 17 on which the toners of the respective colors on the photosensitive drum 11 are transferred (carried) are run in the clockwise direction in the drawing and reach the position facing the secondary transfer bias roller 18. The color toner image carried on the intermediate transfer belt 17 is transferred onto the recording medium at a position facing the secondary transfer bias roller 18 (secondary transfer process).
Thereafter, the surface of the intermediate transfer belt 17 reaches the position of the intermediate transfer belt cleaning unit 19. Then, the untransferred toner adhered on the intermediate transfer belt 17 is collected by the intermediate transfer belt cleaning unit 19, and a series of transfer processes in the intermediate transfer belt 17 is completed.

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

Then, the recording medium on which the full-color image is transferred is guided to the fixing device 20 by the conveyance belt. In the fixing device 20, the color image (toner) is fixed on the recording medium at the nip between the fixing belt and the pressure roller.
Then, the recording medium after the fixing process 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 10Y will be described in detail with reference to FIG.
As shown in FIG. 2, the process cartridge 10Y includes a photosensitive drum 11 as an image carrier, a charging unit 12 (charging roller), a developing device 13 (developing unit), a cleaning device 14 (cleaning unit), The lubricant supply device 15 and a brush-like roller 45 (roller member) as toner adhesion amount adjusting means are integrally configured as a unit.

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 as an insulating layer, a charge generation layer and a charge transport layer as a photosensitive layer, and a surface layer (protective layer) in this order on a conductive support as a base layer. Are stacked.
The photosensitive drum 11 is driven to rotate counterclockwise in FIG.

Referring to FIG. 2, the charging unit 12 is a charging roller formed by covering an outer periphery of a conductive metal core with a medium resistance elastic layer. A predetermined voltage (a DC voltage is superimposed with an AC voltage) is applied to the charging roller 12 from a charging power supply unit (not shown), and thereby the surface of the opposing photosensitive drum 11 is made uniform. Charges up.
In this embodiment, the charging roller 12 is configured to be pressed against the photosensitive drum 11 by a compression spring (not shown). However, the charging roller 12 has a small gap with respect to the photosensitive drum 11. It can also be configured to open and face each other without contact. In this embodiment, the charging roller 12 with the DC voltage superimposed on the AC voltage is applied as the charging bias. However, only the DC voltage can be applied to the charging roller 12 as the charging bias.
In the present embodiment, the charging unit cleaning roller 40 for cleaning the surface of the charging roller 12 is disposed so as to be in pressure contact with the charging roller 12.

  The developing device 13 (developing unit) mainly includes a developing roller 13a that faces the photosensitive drum 11, a first conveying screw 13b that faces the developing roller 13a, and a first conveying screw 13b that faces the first conveying screw 13b via a partition member. It is comprised by the 2 conveyance screw 13c and the doctor blade 13d facing 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 is carried on the developing roller 13a.

In the developing device 13, a two-component developer G composed of carrier C and toner T is accommodated.
In this embodiment, in order to improve the image quality, the circularity is 0.93 or more, and the ratio (D4 / D1) of the weight average diameter D4 to the number average diameter D1 (D4 / D1) is 1.00 to 1.40. A spherical toner is used as the toner T.
The “circularity” of the toner T is the circumference of a circle having the same area as the particle projection area with respect to the circumference of the particle projection image. The flow type particle image analyzer “FPIA-2000” (manufactured by Toa Medical Electronics Co., Ltd.) ) Based on the measured value.
Further, the “weight average diameter” and “number average diameter” of the toner T can be measured by a particle size measuring instrument “SD2000” (manufactured by Hosokawa Micron Corporation).

The cleaning device 14 includes a cleaning blade 14a that contacts the photoconductor drum 11 to clean the surface of the photoconductor drum 11, and untransferred toner collected in the cleaning device 14 in the width direction (the direction perpendicular to the paper surface in FIG. 2). )) Is provided.
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, discharge products generated on the photosensitive drum 11 when discharged by the charging unit 12, additives added to the toner, etc.) It is assumed that the deposits are also included.) Is mechanically scraped off 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.

Referring to FIG. 2, the lubricant supply device 15 includes a lubricant supply roller 15 a that has a foamed elastic layer that is in sliding contact with the photosensitive drum 11 and supplies the lubricant onto the photosensitive drum 11, and a lubricant supply roller. The solid lubricant 15b slidably in contact with 15a (foaming elastic layer), the compression spring 15c as a biasing member for biasing the solid lubricant 15b toward the lubricant supply roller 15a, and the photosensitive drum 11 in contact with the photosensitive drum 11 11 is thinned (uniformized) by a thinning blade 15d (leveling blade), a holding member (holding plate) for holding a solid lubricant 15b, and a compression spring 15c. It comprises a guide member (holder) that guides the solid lubricant 15b held by the holding member.
The lubricant supply device 15 is downstream in the rotation direction of the photosensitive drum 11 (downstream in the traveling direction) with respect to the cleaning device 14 (cleaning blade 14a), and is in the rotation direction of the photosensitive drum 11 with respect to the charging unit 12. Arranged upstream. The thinning blade 15d is disposed on the downstream side in the rotation direction of the photosensitive drum 11 with respect to the lubricant supply roller 15a.

  The lubricant supply roller 15a is a roller-like member in which a foamed elastic layer made of foamed polyurethane (urethane foam) is formed on a shaft part (core metal) made of a metal material, and the foamed elastic layer is the photosensitive drum 11. It rotates counterclockwise in FIG. 2 while in contact with the surface. As a result, the lubricant is supplied from the solid lubricant 15b to the photosensitive drum 11 via the lubricant supply roller 15a.

Here, the lubricant supply roller 15a forms a polyurethane foam to be a foamed elastic layer in advance from a raw material of polyurethane foam into a block shape, cuts it into a necessary shape, polishes the surface, and forms a core metal (core material) After being inserted, the polyurethane foam is rotated, and a polishing blade is applied to move the blade parallel to the axial direction to cut (traverse grinding) to a predetermined sponge thickness. In order to improve the adhesiveness with the foamed elastic layer, an adhesive may be applied in advance to the core metal to be inserted. Moreover, irregular unevenness | corrugation can be formed in the surface of a foaming elastic layer by changing the rotational speed of foaming polyurethane, or the speed to which it moves when performing traverse grinding.
The manufacturing method of the lubricant supply roller 15a is not limited to this. For example, as another manufacturing method, a method of injecting a polyurethane foam raw material into a molding die containing a core metal and foaming and curing it is used. It can also be used.

The lubricant supply 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) (counterclockwise rotation in FIG. 2). ). That is, the rotation direction of the lubricant supply 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 lubricant supply roller 15a is disposed so as to be in sliding contact with the solid lubricant 15b and the photosensitive drum 11, and the lubricant supply roller 15a rotates to scrape the lubricant from the solid lubricant 15b. The lubricant is applied on the photosensitive drum 11.
A compression spring 15c is disposed behind the solid lubricant 15b (lubricant holding member 15e) in order to eliminate contact unevenness between the lubricant supply roller 15a and the solid lubricant 15b, and the solid lubricant 15b. Is urged to the lubricant supply roller 15a.

Here, the solid lubricant 15b is formed by adding an inorganic lubricant to fatty acid metal zinc. Moreover, as fatty acid metal zinc, what contains at least zinc stearate is preferable. The inorganic lubricant is preferably at least one of talc, mica, and boron nitride.
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. Then, the surface of the photosensitive drum 11 can be covered relatively evenly and well protected from electrical stress in the charging process.
Further, by using an inorganic lubricant having a plate-like structure such as talc, mica, and boron nitride, it is difficult for toner and lubricant to slip through the cleaning device 14 (cleaning blade 14a), and the charging roller 12 is It can be made difficult to get dirty.

  Further, the solid lubricant 15b in the present embodiment is formed in a substantially rectangular shape by pouring a raw material powder into a mold, compressing and solidifying it. The solid lubricant 15b formed by such a manufacturing method can simplify the manufacturing equipment and reduce the component cost.

The thinning blade 15d is a plate-like member 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. The thinning blade 15d is disposed on the downstream side in the rotational direction of the photosensitive drum 11 (downstream in the traveling direction) with respect to the cleaning blade 14a. The lubricant supplied onto the photoreceptor drum 11 by the lubricant supply roller 15a is thinned uniformly and in an appropriate amount on the photoreceptor drum 11 by the thinning blade 15d.
When the solid lubricant 15b is applied to the surface of the photosensitive drum 11 via the lubricant supply roller 15a, a powdery lubricant is applied to the surface of the photosensitive drum 11, but the lubricity is sufficient in this state. Therefore, the thinning blade 15d functions as a member for thinning and uniforming the lubricant. The thinning blade 15d forms a film of the lubricant on the photosensitive drum 11, and the lubricant exhibits its lubricity sufficiently.
In the present embodiment, the thinning blade 15d is in contact with the photosensitive drum 11 in the trading direction with respect to the traveling direction (rotating direction) of the photosensitive drum 11.

  As described above, in this embodiment, since the two blade members of the cleaning blade 14a and the thinning blade 15d are provided separately, the cleaning property and the lubricant application property can be maintained well. In addition, wear and deterioration of both blade members 14a and 15d can be reduced by supplying the lubricant to the photosensitive drum 11.

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 circulates in the longitudinal direction (in the direction perpendicular to the paper surface of FIG. 2) while being agitated and mixed together with the toner T replenished therethrough.

  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. The developer G on the developing roller 13a is adjusted to an appropriate amount at the position of the doctor blade 13d, and then reaches a position facing the photosensitive drum 11 (development area).

  Thereafter, in the developing region, the toner T in the developer G adheres to the electrostatic latent image formed on the surface of the photosensitive drum 11. 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 adhering (remaining) on the surface of 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 sequentially passes through a surface potential meter 47, a brush-like roller 45 (toner adhesion amount adjusting means), a lubricant supply device 15, and a charge eliminating unit (not shown). Thus, 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. Also, a new toner T (in FIG. 2, yellow 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. Consumption of the toner T in the developing device 13 is detected indirectly or directly by a magnetic sensor installed below the second conveying screw 13c of the developing device 13.

Hereinafter, the configuration and operation of the process cartridge 10Y (image forming apparatus 1), which is characteristic in the present embodiment, will be described.
Referring to FIG. 2, the process cartridge 10 </ b> Y according to the present embodiment includes a lubricant on the downstream side in the rotational direction (downstream in the traveling direction) of the photosensitive drum 11 (image carrier) with respect to the cleaning device 14. A brush-like roller 45 as a toner adhesion amount adjusting unit is disposed on the upstream side in the rotation direction (upstream in the running direction) of the photosensitive drum 11 (image carrier) with respect to the supply device 15. The brush-like roller 45 functions as a toner adhesion amount adjusting unit that adjusts the adhesion amount of toner that adheres to the surface of the photosensitive drum 11 in accordance with a predetermined condition, and is in contact with the surface of the photosensitive drum 11. It is a brush-like roller member.

Specifically, the brush-like roller 45 (toner adhesion amount adjusting means) is a conductive brush hair (for example, polyester, nylon, rayon, acrylic, vinylon, vinyl chloride, etc.) on a shaft portion (core metal) made of a metal material. This is a brush-like roller member in which a conductive imparting agent such as carbon is mixed in the resin fiber, and is driven by a drive motor 50 through a gear train (not shown). The brush bristles are slidably contacted with the surface of the photosensitive drum 11 by being driven to rotate in the clockwise direction in FIG. Further, the brush-like roller 45 is configured such that the electric field formed between the brush drum 45 and the photosensitive drum 11 can be varied by applying a voltage to the shaft portion from the variable voltage application type power supply unit 46.
Then, by controlling the power supply unit 46 by the control unit 60, the electric field is changed to remove and hold the untransferred toner that could not be removed by the cleaning device 14 from the photosensitive drum 11, and the cleaning device 14. The operation is switched between supplying the retained untransferred toner to the surface of the photosensitive drum 11 without removing the untransferred toner that could not be removed from the photosensitive drum 11.

  The surface of the photosensitive drum 11 that has passed through the position of the cleaning blade 14a adheres (residuals) to the surface of the photosensitive drum 11 without being completely removed and collected by the cleaning blade 14a, but a small amount of untransferred toner that has passed through the edge portion. ing. Such untransferred toner is input to the lubricant supply roller 15a (lubricant supply device 15) as scumming toner as it is. In the present embodiment, the brush roller 45 (toner adhesion amount adjusting means) increases or decreases the amount of untransferred toner (input toner amount) input to the lubricant supply roller 15a (lubricant supply device 15). To do. Then, the amount of untransferred toner (input toner amount) input to the lubricant supply roller 15a (lubricant supply device 15) is increased or decreased to be supplied from the lubricant supply device 15 to the surface of the photosensitive drum 11. The amount of lubricant can be increased or decreased.

Specifically, by applying a voltage having a polarity opposite to the toner polarity to the brush-like roller 45 under the control of the power supply unit 46, untransferred toner (ground toner) on the photosensitive drum 11 is positively applied by the brush-like roller 45. Will be removed and recovered. In such a case, as the amount of toner input to the lubricant supply roller 15a decreases, the amount of toner carried on the lubricant supply roller 15a is almost eliminated, and only by the foamed elastic layer without the toner functioning as an abrasive. Since the solid lubricant 15b is scraped off, the amount of lubricant supplied from the lubricant supply device 15 to the surface of the photosensitive drum 11 can be reduced.
On the other hand, by applying a voltage having the same polarity as the toner polarity to the brush roller 45 under the control of the power supply unit 46, the untransferred toner (ground toner) on the photosensitive drum 11 is removed by the brush roller 45. Instead, it passes through the position of the brush-like roller 45 as it is, and toner (untransferred toner) carried on the brush-like roller 45 is positively supplied onto the photosensitive drum 11. In such a case, as the amount of toner input to the lubricant supply roller 15a increases, the amount of toner carried on the lubricant supply roller 15a also increases, and the foamed elastic layer interposing the toner functioning as an abrasive solids. Since the lubricant 15b is scraped off, the amount of lubricant supplied from the lubricant supply device 15 to the surface of the photosensitive drum 11 can be increased.
In the present embodiment, in order to fully exhibit the function of the brush-like roller 45 described above from the initial stage, it is also possible to carry toner on the brush-like roller 45 in a new state in advance.

  Thus, in the present embodiment, the brush-like roller 45 (toner adhesion amount adjusting means) is used without increasing / decreasing the rotational speed of the lubricant supply roller 15a or installing a plurality of lubricant supply devices 15. By adjusting the amount of toner input to the lubricant supply roller 15a (lubricant supply device 15), the amount of lubricant supplied from the lubricant supply device 15 to the surface of the photosensitive drum 11 is adjusted. As a result, the amount of lubricant supplied to the photosensitive drum 11 can be stabilized without causing a problem that the mechanical life of the lubricant supply roller 15a (lubricant supply device 15) is shortened. Become.

More specifically, the image forming apparatus 1 according to the present embodiment includes a counter 49 as an operation time detecting unit that indirectly detects the accumulated operation time of the photosensitive drum 11 (image carrier) and the lubricant supply device 15. Is provided. Specifically, the counter 49 counts the cumulative number of sheets that have passed through the recording medium in the image forming apparatus 1 after a new process cartridge 10Y is installed in the image forming apparatus main body 1.
The brush-like roller 45 (toner adhesion amount adjusting means) has a cumulative number of passed sheets (cumulative operating time) when the cumulative number of sheets passed (cumulative operating time) detected by the counter 49 (operating time detecting means) is large. As compared with the case where the toner is small, the amount of toner attached to the surface of the photosensitive drum 11 is adjusted so as to increase.

Specifically, for a while (initial time) after the new process cartridge 10Y is used, lubrication is performed as shown in FIG. 3A because the solid lubricant 15b is easily scraped. Since the amount of lubricant supplied to the photosensitive drum 11 by the agent supply device 15 (the amount of lubricant consumed per unit revolution of the photosensitive drum 11) increases, the power supply unit 46 applies toner to the brush roller 45. A voltage having a polarity opposite to the polarity is applied so that untransferred toner is not input to the lubricant supply roller 15a.
On the other hand, over time, as shown in FIG. 3A, for example, a toner external additive or a lubricant film is deposited on the photosensitive drum 11 to change the surface state. In addition, since the amount of lubricant supplied to the photosensitive drum 11 by the lubricant supply device 15 is reduced, a voltage having the same polarity as the toner polarity is applied to the brush roller 45 by the power supply unit 46, and the lubricant supply roller 15a. The untransferred toner is input to.
By performing such control, the amount of lubricant supplied to the photosensitive drum 11 by the lubricant supply device 15 can be stabilized over time.

Here, as shown in FIG. 3A, since the lubricant consumption gradually decreases as the cumulative number of sheets passed increases, the voltage applied to the brush roller 45 from the power supply unit 46 is determined. By controlling so as to gradually change as the cumulative number of sheets passed, the amount of toner input to the lubricant supply roller 15a gradually increases and is supplied to the photosensitive drum 11 by the lubricant supply device 15 from the initial stage to the end. The amount of lubricant applied can be stabilized.
In the present embodiment, the counter 49 is used as an operation time detecting unit that indirectly detects the accumulated operation time of the photosensitive drum 11 and the lubricant supply device 15, but the photosensitive drum 11 and the lubricant supply are used. It is also possible to use operating time detection means (for example, a timer that detects the cumulative operating time of the drive motor 50) that directly detects the cumulative operating time of the device 15.

Further, the image forming apparatus 1 according to the present embodiment is provided with a temperature sensor 48 as a temperature detecting unit that detects the ambient temperature. Specifically, the temperature sensor 48 is installed in the vicinity of the process cartridge 10Y and detects the temperature in the vicinity thereof.
The brush roller 45 (toner adhesion amount adjusting means) adheres to the surface of the photosensitive drum 11 when the temperature detected by the temperature sensor 48 (temperature detection means) is higher than when the temperature is low. Adjustment is made so that the toner adhesion amount increases.

Specifically, when the ambient temperature is high, the solid lubricant 15b has high toughness and is difficult to be scraped, and the like, as shown in FIG. 11 (the amount of lubricant consumed per unit revolution of the photosensitive drum 11) is reduced, so that the power supply unit 46 applies a voltage having the same polarity as the toner polarity to the brush roller 45. Thus, the untransferred toner is input to the lubricant supply roller 15a.
On the other hand, when the ambient temperature is low, the solid lubricant 15b has low toughness and is easily scraped, etc., as shown in FIG. Since the amount of lubricant supplied to the drum 11 increases, the power supply unit 46 applies a voltage having a polarity opposite to the toner polarity to the brush roller 45 so that untransferred toner is not input to the lubricant supply roller 15a. ing.
By performing such control, the amount of lubricant supplied to the photosensitive drum 11 by the lubricant supply device 15 can be stabilized even if environmental fluctuation occurs.

  Here, as shown in FIG. 3B, the lubricant consumption gradually decreases as the temperature increases, so the voltage applied from the power supply 46 to the brush roller 45 increases. In addition, the amount of toner input to the lubricant supply roller 15a gradually increases, and the lubricant supplied to the photosensitive drum 11 by the lubricant supply device 15 from the low temperature range to the high temperature range is controlled. The amount can be stabilized.

In addition, the image forming apparatus 1 in the present embodiment is configured to be able to vary the rotational speed (running speed) of the photosensitive drum 11 (image carrier). Specifically, a driving motor 50 (a plurality of driving motors are used) that rotationally drives the photosensitive drum 11 and other rotating members (all rotating members involved in the process linear velocity in the above-described image forming process). In this case, all of these drive motors) are variable speed motors whose speed can be varied in multiple stages (two stages in this embodiment). When the normal mode is selected, the drive motor 50 is controlled by the control unit 60 so as to achieve a predetermined process linear velocity (and a recording medium conveyance speed). On the other hand, when the low speed mode is selected (when passing thick paper as a recording medium or when forming an image with high pixels), the process line is slower than in the normal mode. The drive motor 50 is controlled by the control unit 60 so as to be at a high speed (and a recording medium conveyance speed).
Then, the brush-like roller 45 (toner adhesion amount adjusting means) operates when the process linear speed (traveling speed of the photosensitive drum 11) is low (in the low speed mode) and the process linear speed (traveling of the photosensitive drum 11). As compared with the case where the speed is high (in the normal mode), the amount of toner attached to the surface of the photosensitive drum 11 is adjusted so as to increase.

Specifically, when the process linear velocity is low (low speed mode), the lubricant supply device 15 performs photosensitivity as shown in FIG. Since the amount of lubricant supplied to the body drum 11 (the amount of lubricant consumed per unit rotation number of the photosensitive drum 11) is reduced, the voltage of the same polarity as the toner polarity is applied to the brush roller 45 by the power supply unit 46. Thus, the untransferred toner is input to the lubricant supply roller 15a.
On the other hand, when the process linear velocity is high (in the normal mode), the lubricant supply device 15 causes the solid lubricant 15b to be scraped at a high speed as shown in FIG. Since the amount of lubricant supplied to the photosensitive drum 11 increases, the power supply unit 46 applies a voltage having a polarity opposite to the toner polarity to the brush roller 45 so that untransferred toner is not input to the lubricant supply roller 15a. I am doing so.
By performing such control, the amount of lubricant supplied to the photosensitive drum 11 by the lubricant supply device 15 can be stabilized even if the process linear velocity is varied.

  Note that, as shown in FIG. 3C, the lubricant consumption amount gradually decreases as the rotational speed of the photosensitive drum 11 decreases, and therefore the process linear speed can be varied in three or more stages. In other words, the amount of toner input to the lubricant supply roller 15a is increased stepwise by controlling the voltage applied from the power source 46 to the brush roller 45 so as to change stepwise as the rotational speed decreases. Thus, the amount of lubricant supplied to the photosensitive drum 11 by the lubricant supply device 15 can be stabilized at each process linear speed.

Here, in the present embodiment, the lubricant is supplied to the photosensitive drum 11 by the lubricant supply device 15 based on the three conditions of the cumulative number of sheets passed (cumulative operation time), the ambient temperature, and the process linear velocity. The amount of toner input to the lubricant supply roller 15a is adjusted by controlling the voltage applied to the brush roller 45 so that the amount of lubricant is stabilized.
However, as shown in FIG. 4, the proportional multiplier (gradient of the graph) in the proportional relationship between the amount of toner input to the lubricant supply device 15 (lubricant supply roller 15 a) and the amount of lubricant consumed is the cumulative sheet passing. Since the number of sheets is a variable (graph S1), the one where the ambient temperature is a variable (graph S2) and the one where the process linear velocity is a variable (graph S3), the brush is taken into consideration. It is necessary to control the voltage applied to the roller 45 and adjust the amount of toner input to the lubricant supply roller 15a.
Specifically, in the present embodiment, first, depending on whether the normal mode or the low speed mode is selected, the amount of lubricant supplied to the photosensitive drum 11 by the lubricant supply device 15 becomes a target value. Thus, the reference value of the voltage applied to the brush roller 45 is determined. Based on the temperature detected by the temperature sensor 48, the voltage applied to the brush roller 45 is a reference so that the amount of lubricant supplied to the photosensitive drum 11 by the lubricant supply device 15 becomes a target value. It is corrected from the value. Further, the voltage applied to the brush roller 45 so that the amount of lubricant supplied to the photosensitive drum 11 by the lubricant supply device 15 becomes a target value based on the cumulative number of sheets passed detected by the counter 49. Is further corrected.
In this embodiment, the voltage applied to the brush roller 45 is controlled based on the three conditions of the cumulative number of sheets to be passed (cumulative operation time), the ambient temperature, and the process linear velocity. The voltage applied to the brush-like roller 45 can be controlled based on any one of the conditions, or the voltage applied to the brush-like roller 45 can be controlled based on any two of the three conditions described above. It can also be controlled.

Referring to FIG. 2, the image forming apparatus 1 according to the present exemplary embodiment is on the downstream side in the rotation direction (downstream in the traveling direction) of the photosensitive drum 11 (image carrier) with respect to the cleaning device 14. A surface potential meter 47 for detecting the surface potential of the photosensitive drum 11 is provided on the photosensitive drum 11 on the upstream side in the rotation direction of the photosensitive drum 11 (upstream in the running direction) with respect to the brush roller 45 (roller member). It arrange | positions so that it may oppose.
In the present embodiment, the voltage applied to the brush roller 45 can be controlled based on the detection result of the surface electrometer 47. The surface of the photosensitive drum 11 that has passed through the position of the primary transfer bias roller 16 and reached the position of the brush roller 45 often has a surface potential that is not constant and is not stable. Even if the voltage applied to the brush roller 45 from the power supply unit 46 is controlled only by the conditions, a target electric field is not formed between the photosensitive drum 11 and the brush roller 45, and the lubricant supply roller 15a is not affected. The input toner amount may not be adjusted accurately. Therefore, the surface potential of the photosensitive drum 11 that has reached the position of the brush roller 45 is detected by the surface potentiometer 47, and the voltage applied to the brush roller 45 from the power supply unit 46 based on the detection result (described above). Is a voltage determined by a control flow based on a predetermined condition), a target electric field is formed between the photosensitive drum 11 and the brush roller 45, and the lubricant supply roller 15a. The amount of input toner can be adjusted with high accuracy.

  As described above, in the present embodiment, the photosensitive drum 11 (image carrier) is downstream in the rotation direction (downstream in the running direction) with respect to the cleaning device 14 and is further away from the lubricant supply device 15. A brush roller 45 (toner adhesion) that adjusts the amount of toner adhering to the surface of the photosensitive drum 11 according to a predetermined condition on the upstream side in the rotation direction (upstream in the running direction) of the photosensitive drum 11 (image carrier). Amount adjusting means) is provided. As a result, the amount of lubricant supplied to the photosensitive drum 11 can be stabilized without shortening the life of the lubricant supply device 15 even when the environment fluctuates, when the process linear velocity is varied, or over time. can do.

In the present embodiment, the cleaning device 14, the lubricant supply device 15, and the brush-like roller 45 (toner adhesion amount adjusting means) are integrated with the photosensitive drum 11, the charging unit 12, and the developing device 13, thereby integrating the process cartridge 10 </ b> Y. The image forming unit is made compact and the maintenance workability is improved.
On the other hand, these constituent members can be configured so as to be replaceable in the apparatus main body 1 without being a constituent member of the 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 in which the developing device 13 is mounted.
In this embodiment, the present invention is applied to the image forming apparatus 1 in which the lubricant supply device 15 for supplying the lubricant to the photosensitive drum 11 as the image carrier is installed. Naturally, the present invention can also be applied to an image forming apparatus provided with a lubricant supply device for supplying a lubricant to the photosensitive belt. Further, an image forming apparatus provided with a lubricant supply device for supplying a lubricant and an intermediate transfer belt cleaning unit 19 for removing untransferred toner to the intermediate transfer belt 17 as an image carrier in the present embodiment. In the apparatus, the present invention can also be applied by providing toner adhesion amount adjusting means for adjusting the amount of toner adhered to the surface of the intermediate transfer belt 17.

Further, in the present embodiment, the lubricant supply roller 15a having a foamed elastic layer formed on the core is used. However, the lubricant supply roller 15a has a straight or loop brush on the outer periphery of the core. What wound the hair can also be used. In that case, as the bristle, resin fibers such as polyester, nylon, rayon, acrylic, vinylon, and vinyl chloride can be used, and if necessary, conductive fibers mixed with a conductivity-imparting agent such as carbon can be used. it can. In addition, brush hair having a length (hair feet) of 0.2 to 20 mm and a brush density of 2 to 100,000 F / inch ² can be used.
In this embodiment, the brush-like roller 45 serving as a roller member is used as the toner adhesion amount adjusting unit. However, another type of roller member (for example, a metal roller) is used as the toner adhesion amount adjusting unit. It is also possible to use a roller member (for example, a metal plate) as the toner adhesion amount adjusting means. However, the brush-like roller 45 is a suitable member because it has a high function of removing or holding untransferred toner as the above-described toner adhesion amount adjusting means.
Even in such a case, substantially the same effect as that of the present embodiment can be obtained.

  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,
11 Photosensitive drum (image carrier), 12 Charging unit,
13 Developing device (developing part),
14 Cleaning device,
14a cleaning blade,
15 Lubricant supply device,
15a Lubricant supply roller,
15b solid lubricant,
15c compression spring (biasing member),
15d thinning blade,
45 Brush-like roller (toner adhesion amount adjusting means, roller member),
46 Power supply,
47 Surface electrometer,
48 Temperature sensor (temperature detection means)
49 Counter (operation time detection means).

JP 2013-20232 A Japanese Patent No. 5505862

Claims (8)

An image carrier that travels in a predetermined direction and carries a toner image on its surface;
A cleaning device for removing untransferred toner attached to the surface of the image carrier;
A lubricant supply device that is disposed on the downstream side in the running direction of the image carrier relative to the cleaning device and supplies a lubricant to the surface of the image carrier;
The image carrier is disposed downstream in the running direction of the image carrier with respect to the cleaning device and upstream in the running direction of the image carrier with respect to the lubricant supply device. A toner adhesion amount adjusting means for adjusting the adhesion amount of the toner adhering to the surface of the body;
An image forming apparatus comprising: An operation time detecting means for directly or indirectly detecting an accumulated operation time for the image carrier or / and the lubricant supply device;
The toner adhesion amount adjusting unit is configured to increase the amount of toner adhered to the surface of the image carrier when the cumulative operation time detected by the operation time detection unit is large compared to when the cumulative operation time is small. The image forming apparatus according to claim 1, wherein adjustment is performed. Equipped with a temperature detection means to detect the ambient temperature,
The toner adhesion amount adjusting means adjusts the toner adhesion amount to adhere to the surface of the image carrier when the temperature detected by the temperature detection means is high compared to when the temperature is low. The image forming apparatus according to claim 1 or 2. Configured to be able to vary the traveling speed of the image carrier,
The toner adhesion amount adjusting means adjusts so that the toner adhesion amount adhered to the surface of the image carrier is larger when the traveling speed of the image carrier is slow than when the traveling speed is fast. The image forming apparatus according to any one of claims 1 to 3. The toner adhesion amount adjusting means includes:
A roller member configured to be in contact with the surface of the image carrier and to change an electric field formed between the image carrier and the image carrier;
By changing the electric field, the operation of removing and holding the untransferred toner that could not be removed by the cleaning device from the image carrier, and the untransferred toner that could not be removed by the cleaning device from the image carrier. 5. The image forming apparatus according to claim 1, wherein the operation is switched between an operation of supplying the held untransferred toner to the surface of the image carrier without removing the toner. Disposed on the downstream side in the running direction of the image carrier relative to the cleaning device and upstream in the running direction of the image carrier relative to the roller member, and detects the surface potential of the image carrier. Equipped with a surface electrometer
The image forming apparatus according to claim 5, wherein a voltage applied to the roller member is varied based on a detection result of the surface electrometer. The lubricant supply device includes:
A lubricant supply roller that rotates in a predetermined direction and slidably contacts the image carrier;
A solid lubricant that is biased by a biasing member so as to be in pressure contact with the lubricant supply roller, and that is in sliding contact with the lubricant supply roller;
Comprising
The image forming apparatus according to claim 1, wherein the cleaning device includes a cleaning blade that contacts the image carrier. A process cartridge that is detachably attached to the image forming apparatus main body,
An image carrier that travels in a predetermined direction and carries a toner image on its surface;
A cleaning device for removing untransferred toner attached to the surface of the image carrier;
A lubricant supply device that is disposed on the downstream side in the running direction of the image carrier relative to the cleaning device and supplies a lubricant to the surface of the image carrier;
The image carrier is disposed downstream in the running direction of the image carrier with respect to the cleaning device and upstream in the running direction of the image carrier with respect to the lubricant supply device. A toner adhesion amount adjusting means for adjusting the adhesion amount of the toner adhering to the surface of the body;
A process cartridge comprising:

Images