JP2014016556A - Lubricant supply device, process cartridge, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubricant supply device capable of increasing the amount of lubricant supplied onto an image carrier without the need to set an urging force large by an urging member of solid lubricant relative to a lubricant supply roller or set a rotation speed of the lubricant supply roller large, and to provide a process cartridge, and an image forming apparatus.SOLUTION: A lubricant supply device includes: a lubricant supply roller 15a that rotates in a predetermined direction to come into slide contact with an image carrier 11; a solid lubricant 15b that is urged by an urging member 15c into pressure contact with the lubricant supply roller 15a, and comes into slide contact with the lubricant supply roller 15a; and excitation means 15g for vibrating the solid lubricant 15b.

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 multifunction machine thereof, a lubricant supply device installed therein, and a process cartridge.

  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 to do is known (for example, refer patent documents 1-4).

  Specifically, the untransferred toner remaining on the image carrier after the transfer process should be completely removed by a cleaning blade (cleaning device) that contacts the image carrier. However, when the cleaning blade deteriorates with time due to contact with the image carrier (abrasion), cleaning failure may occur due to slipping through the gap between the cleaning blade where the untransferred toner is worn and the image carrier. Even when the cleaning blade is not deteriorated, when small toner or spherical toner is used, the toner enters a slight gap between the cleaning blade and the image carrier and eventually passes through the gap. A cleaning failure sometimes occurred. Furthermore, if toner or an external additive or paper dust contained in the toner slips through the gap between the cleaning blade and the image carrier, it adheres to the image carrier and forms a film. There was also.

  In response to such a problem, by applying a lubricant on the image carrier, the friction coefficient on the image carrier is reduced, so that deterioration of the cleaning blade and the image carrier is reduced. Since the removability of deposits such as untransferred toner adhering to the toner is improved, it is possible to suppress the occurrence of poor cleaning and filming over time.

  Specifically, in Patent Document 1 and the like, a lubricant supply device (lubricant application device) includes a lubricant supply roller (brush roller) that slidably contacts an image carrier at a position downstream of a cleaning blade (blade member), lubrication A solid lubricant that contacts the lubricant supply roller, a biasing member (spring) that biases the solid lubricant toward the lubricant supply roller, and a blade member that contacts the image carrier downstream of the lubricant supply roller The blade is made of a thinning blade (leveling blade). 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, Patent Documents 2, 3 and the like disclose a technique using a mixed powder of a fatty acid metal salt and boron nitride as a solid lubricant installed in a lubricant supply device.
Patent Document 4 discloses a technique that uses a foam roller with a foam layer formed as a lubricant supply roller installed in a lubricant supply device.

In a conventional lubricant supply device, in order to increase the amount of lubricant supplied onto the image carrier, the urging force of the solid lubricant urging member on the lubricant supply roller is set large, or the lubricant supply roller It is conceivable to set a large number of rotations.
However, in such a case, the lubricant supply roller is prematurely deteriorated. In particular, when a roller member having a foamed elastic layer is used as the lubricant supply roller, the eyes of the foamed elastic layer collapse early, and when a brush roller is used as the lubricant supply roller, the bristles are You will get stuck early.

  The present invention has been made to solve the above-described problems. The urging force of the solid lubricant urging member on the lubricant supply roller is set large, or the rotation speed of the lubricant supply roller is set large. It is an object of the present invention to provide a lubricant supply device, a process cartridge, and an image forming apparatus in which the supply amount of the lubricant onto the image bearing member is increased without increasing the amount.

  The inventor of the present application has conducted research to solve the above problems, and as a result, in the lubricant supply device, by applying vibration to the solid lubricant, the urging force of the solid lubricant urging member against the lubricant supply roller can be increased. It has been found that the amount of lubricant supplied onto the image carrier can be increased without setting it large or setting the rotational speed of the lubricant supply roller large.

  The present invention is based on the above-described matters, that is, the lubricant supply device according to the first aspect of the present invention is a lubricant for supplying a lubricant onto an image carrier on which a toner image is carried. A supply device that rotates in a predetermined direction and is slidably contacted with the image carrier, and is urged by a biasing member so as to be in pressure contact with the lubricant supply roller, and the lubricant supply A solid lubricant that is in sliding contact with the roller, and a vibration means that vibrates the solid lubricant.

  Since the present invention is configured to apply vibration to the solid lubricant by the vibration means, the urging force of the solid lubricant urging member on the lubricant supply roller can be set large, or the rotation of the lubricant supply roller can be set. It is possible to provide a lubricant supply device, a process cartridge, and an image forming apparatus in which the supply amount of the lubricant onto the image carrier is increased without setting the number large.

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 a process cartridge. It is an enlarged view which shows the vicinity of a lubricant supply apparatus. It is the schematic which shows a lubricant supply apparatus in the width direction. It is an enlarged view which shows the vicinity of the lubricant supply apparatus as a modification.

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 process cartridge 10Y for yellow 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 sheet feeding unit that accommodates a recording medium P such as transfer paper, and 9 is a registration roller that adjusts the conveyance timing of the recording medium P, 10Y, 10M, 10C. 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. 17 is a transfer bias roller (primary transfer bias roller) that is transferred on top of the transfer roller 17, and 17 is an intermediate transfer bell on which toner images of a plurality of colors are transferred in a superimposed manner (Image carrier) 18 is a secondary transfer bias roller for transferring the toner image on the intermediate transfer belt 17 onto the recording medium P, 19 is an intermediate transfer belt cleaning unit for cleaning the intermediate transfer belt 17, and 20 is a recording. 2 shows a fixing device that fixes a toner image (unfixed image) on a medium P.

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 (see FIG. 2) of the four process cartridges 10Y, 10M, 10C, and 10BK are rotated in the direction of the arrow (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 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 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. 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 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 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 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 unit 13 (developing device), a cleaning device 14 (cleaning unit), The lubricant supply device 15 is 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.
In particular, in the present embodiment, since the thermosetting resin is contained in the surface layer of the photosensitive drum 11 (image carrier), durability against mechanical stress on the photosensitive drum 11 can be further improved. .

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 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.
Here, in the present embodiment, the charging roller 12 is configured to come into pressure contact with the photosensitive drum 11 by a compression spring (not shown), but 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 the present embodiment, a cleaning roller 40 for cleaning the surface of the charging roller 12 is installed so as to be in pressure contact with the charging roller 12.

  The developing device (developing unit) 13 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).

In the cleaning device 14, a cleaning blade 14 a is installed as a blade member that contacts the photosensitive drum 11 and cleans 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.

Referring to FIGS. 2 to 4, the lubricant supply device 15 is lubricated as a lubricant supply member that is provided with a foamed elastic layer that is in sliding contact with the photosensitive drum 11 and supplies the lubricant onto the photosensitive drum 11. A lubricant supply roller 15a, a solid lubricant 15b in sliding contact with the lubricant supply roller 15a (foaming elastic layer), a compression spring 15c as a biasing member for biasing the solid lubricant 15b toward the lubricant supply roller 15a, and a photosensitive member A thinning blade 15d (leveling blade) as a blade member that abuts on the drum 11 and thins (uniformizes) the lubricant supplied onto the photosensitive drum 11, and a holding member that holds the solid lubricant 15b. 15e (holding plate), a guide member 15f (holder) for guiding the solid lubricant 15b held by the holding member 15e by being urged by the compression spring 15c, and the solid lubricant 15b are shaken. Ultrasonic transducer 15g as vibrating means for, and the like.
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 member 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 member in which a foamed elastic layer made of foamed polyurethane (urethane foam) is formed on a core metal, and the foamed elastic layer is in contact with the surface of the photosensitive drum 11 as shown in FIG. Rotate counterclockwise. 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.

As the raw material of the polyurethane foam, those added with an auxiliary such as polyol, polyisocyanate, catalyst, foaming agent, foam stabilizer and the like are used. In addition, components other than polyisocyanate are mixed in advance and mixed with the polyisocyanate component immediately before molding. As the polyol component, a polyol called a polyether polyol is preferable because it is easy to adjust processability, hardness of the polyurethane foam layer, and the like. As the polyether polyol, it can be appropriately selected from known various polyether polyols. Moreover, what is necessary is just to select suitably from polyether polyether polyol known as polyether polyol generally used for manufacture of a flexible polyurethane foam, polyester polyether polyol, polymer polyether polyol, etc., combining 1 type, or 2 or more types. It may be used. Further, when a polyether polyether polyol having 5 mol% or more of ethylene oxide bonded to a terminal is used, the moldability is improved.
Moreover, as polyisocyanate used for manufacture of a foaming elastic layer, it can select suitably from well-known various polyisocyanate, for example, 2, 4? And 2, 6? Tolylene diisocyanate (TDI), Tolidine diisocyanate (TODI), naphthylene diisocyanate (NDI), xylylene diisocyanate (XDI), 4,4'-diphenylmethane diisocyanate (MDI) and carbodiimide modified MDI, polymethylene polyphenyl polyisocyanate, polymeric polyisocyanate, etc. These may be used alone or in combination of two or more.
The catalyst used for the production of the foamed elastic layer can be appropriately selected from catalysts used for known urethanization reactions, such as triethylenediamine, dimethylethanolamine, bis (dimethylamino) ethyl ether. Examples thereof include amine-based catalysts such as dioctyltin, organometallic catalysts such as distearyltin dibutyrate, and modified catalysts thereof. Further, it may be a reactive catalyst such as dimethylaminoethanol having active hydrogen in itself. By appropriately selecting the catalyst and controlling the amount used, the cell wall width, open cell diameter, hardness, air flow rate, etc. of the polyurethane foam layer can be adjusted.
Moreover, as a foam stabilizer used for manufacture of a foaming elastic layer, although it can generally be used if it is generally used for polyurethane foam manufacture, a silicone type surfactant is used preferably.
There is no restriction | limiting in particular as a foaming agent used for manufacture of a foaming elastic layer, It can be used individually or in combination of multiple types from well-known various foaming agents, such as water, a low boiling point thing, and a gas body. However, it is preferable to use water as a foaming agent from the viewpoint of the environment. Also, other foaming agents can be used in combination. By changing the use amount and conditions of the foaming agent, the cell wall width, cell diameter, hardness, air flow rate and the like of the polyurethane foam layer can be controlled.
The raw material of the polyurethane foam layer described above may contain a crosslinking agent, a foam breaker, etc. so as to control the closed-cell property and open-cell property of the cells of the polyurethane foam layer, and give desired conductivity. In order to do so, a conductive agent, an antistatic agent, or the like may be added. Examples of the crosslinking agent include known ones such as triethanolamine and diethanolamine. Other additives such as conductive agents, flame retardants, thickeners, pigments, stabilizers, colorants, anti-aging agents, UV absorbers, antioxidants, antioxidants, etc. Can be blended.

The average value of the values measured by the following method is used for the number of cells p of the foamed elastic layer. Three measurement points are arbitrarily selected at both ends and the center in the axial direction on the surface of the foamed elastic layer. Next, two more points are selected in the circumferential direction at each measurement point, and a total of nine measurement points are determined. Next, the photograph screen of each measurement location is observed using a microscope. Then, a line having a length corresponding to an actual size of 1 inch (25.4 mm) is drawn at the center of the photo screen, the number of cells in the line is counted, and an average value of 9 points is obtained. A cell that touches even a 25.4 mm line is counted as one.
The number of cells p of the foamed elastic layer is preferably in the range of 40 to 100 cells / inch. This is because if the number of cells is too small, efficient application cannot be performed even if the linear velocity difference is increased. In general, the hardness increases as the number of cells increases. In the present embodiment, a linear velocity difference is provided between the photosensitive drum 11 and the lubricant supply roller 15a, and if the hardness is large, each driving torque increases, so the number of cells p is 100 cells / inch. The following is desirable.
The hardness of the foamed elastic layer is an average value of values measured based on JIS K 6400 at arbitrary points on the surface of the foamed elastic layer. The hardness of the foamed elastic layer is preferably 10 to 430 N (particularly 15 to 100 N) from the viewpoint of scraping off a relatively small particle size lubricant and supplying the lubricant particles to the photosensitive drum 11.

The metal core of the lubricant supply roller 15a is a cylindrical body made of a metal such as iron, aluminum or stainless steel or a non-metal such as a resin, and an adhesive layer may be provided on the surface in advance.
Moreover, in the manufacturing method using the mold containing the cored bar described above, it is preferable to provide a release layer such as a fluororesin coating agent or a mold release agent on the surface of the mold, which requires complicated processing. However, a foamed elastic layer having a suitable opening property can be easily formed.

The lubricant supply roller 15a configured as described above 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 in FIG. 2). Direction rotation). 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.
In addition, a compression spring 15c is disposed behind the solid lubricant 15b (holding member 15e) in order to eliminate uneven contact between the lubricant supply roller 15a and the solid lubricant 45, and lubricates the solid lubricant 15b. The agent supply roller 15a is urged.

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 becomes difficult for toner and lubricant to slip through the cleaning unit 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 thinned blade 15d as a blade member 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 counter direction with respect to the traveling direction (rotating direction) of the photosensitive drum 11. The contact pressure is set to about 10 to 60 g / cm, and the contact angle θ is set to about 75 to 90 degrees. By bringing the thinning blade 15d into contact with the counter direction, the lubricant can be efficiently thinned on the photosensitive drum 11.
The “contact angle θ” is an imaginary line passing through the edge portion in a state where the thinning blade 15d is in contact with the photosensitive drum 11 (the thinning blade 15d is bent). The angle formed by the tangent at the contact position (a line perpendicular to the normal).

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.
Here, in the present embodiment, the surfaces of the cleaning blade 14a and the thinning blade 15d (the portions that are in contact with the photosensitive drum 11) are each provided with an abrasion-resistant coating process (for example, a fluororesin coating process). ) Is given. As a result, frictional degradation of the cleaning blade 14a and the thinning blade 15d can be reduced (durability can be improved).

3 and 4 and the like, the holding member 15e (holding plate) is a plate-like member for holding the solid lubricant 15b, and the solid lubricant 15b is adhered to one surface, The ultrasonic transducer | vibrator 15g (vibration means) is affixed on the surface.
The guide member 15f (holder) is a substantially box-shaped member disposed so as to house a part of the solid lubricant 15b, the holding member 15e, and the compression spring 15c, and has a holding member on the inner wall surface thereof. 15e is configured to be in sliding contact. Further, one end side of the compression spring 15c is connected to the inner bottom surface of the guide member 15f, and the other end side of the compression spring 15c is connected to the holding member 15e. With this configuration, when the solid lubricant 15b is consumed, the holding member 15e is urged by the compression spring 15c and slides while being guided by the guide member 15f, so that the solid lubricant 15b moves to the lubricant supply roller 15a. It will be pressed.
Note that the configuration and operation of the ultrasonic vibrator 15g as a vibrating means for vibrating the solid lubricant 15b will be described in detail later.

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. 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 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 sequentially passes through the lubricant supply device 15 and the charge eliminating unit (not shown), and the 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. 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.

Hereinafter, the configuration and operation of the lubricant supply device 15 (lubricant application device), which is characteristic in the present embodiment, will be described.
Referring to FIGS. 3 and 4 and the like, the lubricant supply device 15 in the present embodiment is provided with an ultrasonic vibrator 15g as a vibration means for vibrating the solid lubricant 15b.
Specifically, the ultrasonic transducer 15g is a Langevin type transducer, and is substantially at the center of the surface of the holding member 15e (the surface opposite to the surface to which the solid lubricant 15b is adhered). It is installed (attached) with double-sided tape. The ultrasonic transducer 15g vibrates when a sine wave AC voltage oscillated by a function generator controlled by a control circuit (not shown) is amplified by a power amplifier. The vibration of the ultrasonic vibrator 15g is transmitted to the solid lubricant 15b via the holding member 15e, and the solid lubricant 15b vibrates in the direction of the double arrow in FIG. That is, the ultrasonic vibrator 15g (vibration means) vibrates the solid lubricant 15b in the direction in which the solid lubricant 15b comes into sliding contact with the lubricant supply roller 15a.

  As the solid lubricant 15b vibrates by the ultrasonic vibrator 15g in this way, the speed at which the solid lubricant 15b slides on the lubricant supply roller 15a is periodically accelerated, and the solid supply lubricant is supplied by the lubricant supply roller 15a. Since the amount of lubricant scraped off per unit time from 15b increases, the amount of lubricant supplied onto the photosensitive drum 11 also increases. As described above, in the present embodiment, the urging force of the solid lubricant 15b against the lubricant supply roller 15a by the compression spring 15c is set large, or the rotational speed of the lubricant supply roller 15a is not set large. Since the supply amount of the lubricant onto the photosensitive drum 11 can be increased, it is possible to reduce a problem that the foamed elastic layer of the lubricant supply roller 15a is crushed and deteriorated early.

Here, in the present embodiment, the vibration intensity (amplitude) of the ultrasonic vibrator 15g as the vibration means is formed so as to be variable, and the vibration intensity is variable according to environmental conditions and image forming conditions. Can be configured.
Specifically, since the hardness and friction coefficient of the foamed elastic layer (foamed urethane layer) of the lubricant supply roller 15a change depending on the temperature and humidity, the lubrication supplied to the photosensitive drum 11 by the lubricant supply device 15 at high temperature and high humidity. The amount of the agent decreases, and the amount of the lubricant supplied onto the photosensitive drum 11 by the lubricant supplying device 15 increases at the time of low temperature and low humidity. For this reason, the vibration intensity (amplitude) of the ultrasonic vibrator 15g is varied so that the amount of lubricant supplied onto the photosensitive drum 11 is constant even when temperature and humidity (environmental conditions) fluctuate.
Specifically, a temperature / humidity sensor is installed in the apparatus body 1 in the vicinity of the lubricant supply device 15, and the voltage applied to the ultrasonic transducer 15g at high temperature and high humidity is based on the detection result of the temperature / humidity sensor. The voltage is controlled to be larger than the voltage applied at low temperature and low humidity. For example, when the frequency of the voltage input to the ultrasonic transducer 15g is fixed at 20 kHz, the magnitude of the input voltage is 150 V at high temperature and high humidity, and the magnitude of the input voltage is 30 V at low temperature and low humidity. Note that the vibration intensity of the ultrasonic transducer 15g can be adjusted by changing the frequency of the input voltage without fixing it, or by changing the magnitude and frequency of the input voltage.
Since the lubricant supply roller 15a having the foamed elastic layer has a large change in the amount of supplied lubricant due to a change in temperature and humidity, it is useful to perform such control.

Further, when the amount of lubricant to be supplied to the photosensitive drum 11 in order to maintain the surface friction coefficient of the photosensitive drum 11 within a predetermined range depending on the image forming conditions, the photosensitive drum is accordingly changed. The vibration intensity (amplitude) of the ultrasonic vibrator 15g can be varied so that the amount of lubricant supplied onto the head 11 is optimized.
For example, when the image area ratio of the image formed on the photoconductor drum 11 is low (for example, the image area ratio is less than 5%), the photoconductor drum 11 is compared with the case where the image area ratio is high. Since the amount of toner adhering to the surface (functioning similar to a lubricant) is small and the frictional resistance of the photosensitive drum 11 is increased, the vibration strength by the ultrasonic vibrator 15g is increased. By controlling, the amount of lubricant supplied onto the photosensitive drum 11 is increased. Specifically, based on the duty of the writing unit 2, the input voltage of the ultrasonic transducer 15g is varied.
By performing such control, the amount of lubricant supplied onto the photoconductive drum 11 is optimized regardless of fluctuations in image forming conditions.

In the present embodiment, the ultrasonic vibrator 15g is used as the vibration means for vibrating the solid lubricant 15b, but the vibration means is not limited to this.
FIG. 5 is an enlarged view showing a lubricant supply device 15 in which a vibration means as a modification is installed.
The lubricant supply measure 15 shown in FIG. 5 includes a lubricant supply roller 15a, a solid lubricant 15b, a compression spring 15c as an urging member, a thinned blade 15d (leveling blade), a holding member 15e, and a guide member 15f ( Holder), a regulating member 15m (regulating plate), a pressure spring 15n as an urging means, and the like. The restricting member 15m is along a biasing direction (indicated by a solid arrow in FIG. 5) in which the solid lubricant 15b is biased by the compression spring 15c with respect to the holding member 15e that holds the solid lubricant 15b. And the position of the solid lubricant 15b with respect to the direction orthogonal to the biasing direction is regulated. Further, the pressure spring 15n as the urging means is disposed so as to urge the restricting member 15m in a direction (a white arrow direction in FIG. 5) in contact with the holding member 15e. Specifically, the regulating member 15m is installed so as to be slidable in the direction of the white arrow in the guide member 15f. One end of the pressure spring 15n is connected to the regulating member 15m, and the other end is connected to the inner wall of the guide member 15f. With such a configuration, the holding member 15e that holds the solid lubricant 15b is pressed against the inner wall on the opposite side of the guide member 15f by the restriction member 15m biased by the pressure spring 15n.
With this configuration, the solid lubricant 15b is vibrated by rotating the lubricant supply roller 15a in a predetermined direction (counterclockwise in FIG. 5). Specifically, when the lubricant supply roller 15a is driven to rotate, the solid lubricant 15b is tilted along the sliding contact direction due to frictional resistance with the lubricant supply roller 15a (to resist the pressure applied by the pressure spring 15n. And an operation that is regulated so that the falling of the solid lubricant 15b is corrected by the regulating member 15m pressurized by the pressure spring 15n. Are repeated in a short cycle, and the solid lubricant 15b vibrates. That is, the restricting member 15m and the pressure spring 15n function as a vibrating means that vibrates the solid lubricant 15b. And even if comprised in this way, since the solid lubricant 15b vibrates, the effect similar to the effect in this Embodiment mentioned above can be acquired.
As shown in FIG. 5, the regulating member 15m is preferably disposed so as to face the solid lubricant 15b on the downstream side in the rotation direction of the lubricant supply roller 15a. Thereby, it is possible to easily generate the vibration of the solid lubricant 15b described above (repetitive operation of the operation in the falling direction and the operation in the direction of correcting the falling).
In the configuration of FIG. 5, when the vibration intensity by the vibration means 15m, 15n is varied, for example, the inner wall of the guide member 15f to which the other end of the pressure spring 15n is connected is urged by a moving mechanism. This can be achieved by making it movable along the direction.

  As described above, according to the present embodiment, the solid lubricant 15b is vibrated by the ultrasonic vibrator 15g (vibration means), so that the solid lubricant for the lubricant supply roller 15a. Lubricant on the photosensitive drum 11 (image carrier) without setting a large biasing force by the compression spring 15c (biasing member) of 15b or setting a large number of revolutions of the lubricant supply roller 15a. The amount of supply can be increased.

In the present embodiment, the cleaning device 14 and the lubricant supply device 15 are integrated with the photosensitive drum 11, the charging unit 12, and the developing unit 13 to configure the process cartridge 20, thereby reducing the size of the image forming unit. The maintenance workability is improved.
On the other hand, the cleaning device 14 and the lubricant supply device 15 may be configured so as to be replaceable in the apparatus main body 1 without being a component 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 the present embodiment, the present invention is applied to the lubricant supply device 15 that supplies the lubricant to the photosensitive drum 11 as the image carrier. However, the lubricant is applied to the photosensitive belt as the image carrier. Of course, the present invention can also be applied to the lubricant supply device to be supplied. Furthermore, the present invention can naturally be applied to a lubricant supply device that supplies a lubricant to the intermediate transfer belt 17 as an image carrier in the present embodiment.

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.
Even in such a case, it is possible to obtain substantially the same effect as that of the present embodiment by providing the vibration means as in the present embodiment.

  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 section (developing device),
14 Cleaning section (cleaning device),
14a Cleaning blade (blade member),
15 Lubricant supply device,
15a Lubricant supply roller (lubricant supply member),
15b solid lubricant (protective agent),
15c compression spring (biasing member),
15d Thinning blade (blade member),
15e holding member,
15f guide member,
15g ultrasonic transducer (vibration means),
15m restriction member,
15n Pressure spring (biasing means).

JP 2007-140391 A JP 2006-350240 A JP 2010-39307 A JP 2009-150986 A

Claims (14)

A lubricant supply device for supplying a lubricant onto an image carrier on which a toner image is carried,
A lubricant supply roller that rotates in a predetermined direction and is in sliding contact with 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;
Vibration means for vibrating the solid lubricant;
A lubricant supply device comprising:   The lubricant supplying device according to claim 1, wherein the vibrating means vibrates the solid lubricant in a direction in which the solid lubricant slides on the lubricant supply roller.   The lubricant supply device according to claim 1 or 2, wherein the vibration means is formed so that the vibration intensity can be varied.   The lubricant supplying device according to claim 3, wherein the vibration unit varies a vibration intensity according to an image forming condition and / or an environmental condition.   The lubricant supplying device according to any one of claims 1 to 4, wherein the vibration means is an ultrasonic vibrator installed on a holding member that holds the solid lubricant.   6. The lubricant supply device according to claim 5, wherein the ultrasonic vibrator is controlled so that a voltage applied at high temperature and high humidity is larger than a voltage applied at low temperature and low humidity. The vibration means is
The solid lubricant with respect to a direction orthogonal to the biasing direction in contact with the holding member that holds the solid lubricant along the biasing direction in which the solid lubricant is biased by the biasing member. A regulating member that regulates the position of the agent;
An urging means for urging the regulating member in a direction in contact with the holding member;
Comprising
The lubricant supply apparatus according to claim 1, wherein the lubricant supply roller vibrates the solid lubricant by rotating in the predetermined direction.   The lubricant supply device according to claim 7, wherein the regulating member is disposed to face the solid lubricant on the downstream side in the rotation direction of the lubricant supply roller.   The lubricant supply device according to any one of claims 1 to 8, wherein the lubricant supply roller is a roller member in which a foamed elastic layer made of foamed polyurethane is formed on a metal core.   The lubricant supply device according to any one of claims 1 to 9, wherein the solid lubricant is formed by adding an inorganic lubricant to fatty acid metal zinc.   11. The lubricant supply device according to claim 10, wherein the inorganic lubricant is at least one of talc, mica, and boron nitride.   The lubricant supply device according to any one of claims 1 to 11, wherein the image carrier includes a thermosetting resin in a surface layer thereof. A process cartridge that is detachably attached to the image forming apparatus main body,
13. A process cartridge comprising the lubricant supply device according to claim 1 and the image carrier.   An image forming apparatus comprising the lubricant supply device according to claim 1 and the image carrier.

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