JP5640676B2 - Lubricant supply device, process cartridge, and image forming apparatus - Google Patents

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.

  2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine or a printer, a technique using a lubricant supply device that supplies a lubricant onto an image carrier such as a photosensitive drum or an intermediate transfer belt is known (for example, Patent Documents). (See 1, 2 etc.).

  Specifically, the untransferred toner remaining on the photosensitive drum after the transfer process should be completely removed by a cleaning blade (cleaning device) in contact with the photosensitive drum. However, when a chipping (deletion) occurs in the contact portion of the cleaning blade due to friction with the photosensitive drum, a cleaning failure occurs due to slipping through the gap between the cleaning blade where the untransferred toner is lost and the photosensitive drum. I was sorry.

  In response to such a problem, by applying a lubricant on the photosensitive drum, the friction coefficient on the photosensitive drum is reduced, so that the abrasion / defect of the cleaning blade and the deterioration of the photosensitive drum are reduced. It is possible to suppress the occurrence of poor cleaning in

  Specifically, in Patent Document 1, a lubricant application device includes a brush roller (lubricant supply roller) that is in sliding contact with a photosensitive belt (image carrier), a solid lubricant that is in contact with the brush roller, and a solid lubricant that is applied to the brush roller. It is comprised with the compression spring etc. which are urged | biased in the press-contact direction toward. Then, the lubricant is gradually scraped off from the solid lubricant by the brush roller rotating in a predetermined direction, and the lubricant scraped off and transported by the brush roller is applied (supplied) to the surface of the image carrier.

  In such a lubricant supply device, when the solid lubricant is consumed over time and the thickness of the solid lubricant is reduced, the length of use of the compression spring for biasing the solid lubricant is increased accordingly. As a result, there is a known problem that the amount of lubricant supplied onto the image carrier is insufficient as the pressure contact force of the solid lubricant against the brush roller decreases.

  On the other hand, in Patent Document 2 and the like, a pair of pressing members (rotating members) for pressing the solid lubricant is provided in order to solve the above-described problem that the lubricant supply amount becomes insufficient with time in the lubricant supply device. A technology that is provided at a position separated in the width direction and presses the solid lubricant against the brush roller with a uniform force by simultaneously rotating a pair of pressing members with the urging force of the tension spring as the solid lubricant is consumed. Is disclosed.

The above-described lubricant supply device such as Patent Document 2 can be sufficiently expected to solve the problem that the lubricant supply amount becomes insufficient over time.
However, in the lubricant supply device disclosed in Patent Document 2, the solid lubricant is momentarily subjected to a large reaction force from the brush roller when the brush roller (lubricant supply roller) is started to rotate from a stopped state. In some cases, the pressure member (moving member) momentarily moves in the direction opposite to the pressing direction so as to resist the pressing force of the pressing member (rotating member). And, when the solid lubricant instantaneously moves in the direction opposite to the pressure contact direction, the phenomenon that the pressing member (rotating member) falls down (the solid lubricant is pressed against the brush roller). And the posture is changed so that it is inclined and pressed, or the posture is changed so that the pressing member is inclined and pressed against the solid lubricant). Thereafter, the lubricant on the brush roller scraped off from the solid lubricant may become non-uniform due to the uneven contact of the solid lubricant or the pressing member. When such a problem occurs, the lubricant supplied onto the photosensitive drum by the lubricant supply device also becomes non-uniform, resulting in partial loss of the cleaning blade, poor cleaning, and the like. It will be.

  The present invention has been made in order to solve the above-described problems, and the lubricant to be supplied to the image carrier is not insufficient even over time, and the lubricant is always stably and uniformly applied to the image carrier. It is an object to provide a lubricant supply device, a process cartridge, and an image forming apparatus that can be supplied.

According to a first aspect of the present invention, there is provided a lubricant supply device for supplying a lubricant onto an image carrier on which a toner image is carried, wherein the lubricant supply device rotates in a predetermined direction and the image is supplied. Lubricant supply roller in sliding contact with the carrier, solid lubricant in sliding contact with the lubricant supply roller, a holding member for holding the solid lubricant, and a direction in which the solid lubricant is in pressure contact with the lubricant supply roller A case formed so as to accommodate at least the holding member together with the solid lubricant so as to be movable, and a pair of rotating members that are rotatably supported by the holding member at positions separated in the width direction. An urging member that urges the holding member in a direction approaching the lubricant supply roller by rotating the pair of rotating members in different directions so as to come into pressure contact with the case. Scan, the rotating member is formed so as to face substantially parallel to a virtual plane which rotates, the rotating member is restricted from being fallen plane in a direction intersecting the virtual plane guide Part.

  According to a second aspect of the present invention, there is provided the lubricant supply device according to the first aspect of the invention, wherein the guide portion is the solid lubricant with respect to the pressure contact surface of the case with which the rotating member is pressed. It is formed in a convex shape so as to protrude in a direction approaching.

  According to a third aspect of the present invention, in the lubricant supply device according to the second aspect, the guide portion is attached to the side wall of the case.

  According to a fourth aspect of the present invention, there is provided the lubricant supply device according to the first aspect of the present invention, wherein the pressure contact surface of the case where the rotating member is pressed against the guide portion is separated from the solid lubricant. It is a side wall surface of the groove formed so as to be recessed in the direction to be.

  The lubricant supply device according to a fifth aspect of the present invention is the lubricant supply device according to any one of the first to fourth aspects, wherein the guide portion is the lubricant among both side surfaces of the rotating member. It is formed only on the side surface corresponding to the upstream side in the rotation direction of the supply roller.

  The lubricant supply device according to claim 6 is the invention according to any one of claims 1 to 5, wherein each of the pair of rotating members consumes the solid lubricant. Along with the solid lubricant, the holding member is provided with a cam-shaped portion that is rotated by an urging force of the urging member so as to move in a direction approaching the lubricant supply roller, and press-contacts the case. A tension spring that is connected to the pair of rotating members and rotates the pair of rotating members so that the span between the portions where the pair of rotating members press-contact the case is gradually reduced. It is what.

  A process cartridge according to a seventh aspect of the present invention is a process cartridge that is detachably installed on the main body of the image forming apparatus, and the lubrication according to any one of the first to sixth aspects. An agent supply device and the image carrier are provided.

  The process cartridge according to an eighth aspect of the present invention is the process cartridge according to the seventh aspect, wherein a cleaning unit that cleans the image carrier is rotated with respect to the lubricant supply device. This is provided on the upstream side in the direction.

  An image forming apparatus according to a ninth aspect of the present invention includes the lubricant supply device according to any one of the first to sixth aspects and the image carrier.

  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. At least one of the cleaning units and the image carrier are defined as a unit that is integrated and detachably installed on the image forming apparatus main body.

  In the present application, the “width direction” is defined as a direction orthogonal to the conveyance direction of the recording medium and the same direction as the main scanning direction of the image carrier.

  According to the present invention, the rotation member is prevented from falling down in a case that houses a holding member in which a pair of rotation members for pressing the solid lubricant against the lubricant supply roller is rotatably installed. A guide part is provided. As a result, the lubricant supply device, the process cartridge, and the image formation in which the lubricant is supplied to the image carrier stably and uniformly without a shortage of lubricant supplied to the image carrier over time. An apparatus 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 an image creation part. It is a perspective view which shows the holding member of the state with which the solid lubricant was hold | maintained. It is a side view which shows a rotation member. It is a front view which expands and shows a part of lubricant supply apparatus. It is a figure which shows operation | movement of the rotation member accompanying consumption of a solid lubricant. It is a schematic diagram which shows the press contact state of solid lubricant and a rotation member with respect to a lubricant supply roller. It is a front view which shows the lubricant supply apparatus with which the case of another form was installed. It is a front view which shows the lubricant supply apparatus with which the case of another form was installed.

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 FIG.
The image forming apparatus 1 according to the present embodiment is a tandem color image forming apparatus in which process cartridges 10Y, 10M, 10C, and 10BK as a plurality of image forming units are arranged in parallel so as to face the intermediate transfer belt 17. .

  In FIG. 1, 1 is an apparatus main body of a color copying machine as an image forming apparatus, 3 is a document conveying unit that conveys a document to a document reading unit 4, 4 is a document reading unit that reads image information of a document, and 6 is input image information. A writing unit (exposure unit) that emits laser light based on the above, 7 is a paper feeding unit that accommodates a recording medium P such as transfer paper, and 10Y, 10M, 10C, and 10BK are colors (yellow, magenta, cyan, and black). A process cartridge as a corresponding image forming unit, 17 is an intermediate transfer belt on which toner images of a plurality of colors are transferred in an overlapping manner, and 18 is a secondary transfer that transfers a toner image formed on the intermediate transfer belt 17 to a recording medium P. A roller, 20 a fixing unit for fixing an unfixed image on the recording medium P, and 28 a toner for each color is supplied to the developing unit of each process cartridge (image forming unit) 10Y, 10M, 10C, 10BK. Toner container of the eye, showing the.

Here, each of the process cartridges 10Y, 10M, 10C, and 10BK (image forming unit) includes a photosensitive drum 11 as an image carrier, a charging unit 12, a developing unit 13 (developing device), and a cleaning unit 15 (cleaning device). ), The lubricant supply device 16 (lubricant supply unit) is integrated (see FIG. 2). The process cartridges 10Y, 10M, 10C, and 10BK are replaced with the apparatus main body 1 when the lifetime is reached.
A toner image of each color (yellow, magenta, cyan, black) is formed on the photosensitive drum 11 (image carrier) in each of the process cartridges 10Y, 10M, 10C, and 10BK.

Hereinafter, an operation during normal color image formation in the image forming apparatus will be described.
First, the document is transported from the document table by the transport rollers of the document transport unit 3 and placed on the contact glass of the document reading unit 4. Then, the document reading unit 4 optically reads the image information of the document placed on the contact glass.
Specifically, the document reading unit 4 scans an image of a document on the contact glass while irradiating light emitted from an illumination lamp. Then, the light reflected from the original is imaged on the color sensor via the mirror group and the lens. The color image information of the original is read for each color separation light of RGB (red, green, blue) by the color sensor, and then converted into an electrical image signal. Further, an image processing unit (not shown) performs color conversion processing, color correction processing, spatial frequency correction processing, and the like on the basis of RGB color separation image signals, so that yellow, magenta, cyan, and black are processed. Get color image information.

  Then, image information of each color of yellow, magenta, cyan, and black is transmitted to the writing unit 6. Then, laser light (exposure light) based on the image information of each color is emitted from the writing unit 6 toward the photosensitive drums 11 of the corresponding process cartridges 10Y, 10M, 10C, and 10BK, respectively.

On the other hand, the four photosensitive drums 11 rotate in the clockwise direction in the figure. First, the surface of the photosensitive drum 11 is uniformly charged at a position facing the charging roller 12a (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.
In the writing unit 6, laser light corresponding to the image signal is emitted from the light source corresponding to each color. Although not shown, the laser light is incident on the polygon mirror and reflected, and then passes through a plurality of lenses. The laser light after passing through the plurality of lenses passes through different optical paths for each of the yellow, magenta, cyan, and black color components (this is an exposure process).

  Laser light corresponding to the yellow component is irradiated onto the surface of the photosensitive drum 11 of the first process cartridge 10Y from the left side of the drawing. At this time, the yellow component laser light is scanned in the rotational axis direction (main scanning direction) of the photosensitive drum 11 by a polygon mirror (not shown) that rotates at high speed. Thus, an electrostatic latent image corresponding to the yellow component is formed on the photosensitive drum 11 after being charged by the charging roller 12a.

  Similarly, the cyan component laser light is applied to the surface of the photosensitive drum 11 of the second process cartridge 10 </ b> C from the left side of the sheet, thereby forming an electrostatic latent image of the cyan component. The laser beam corresponding to the magenta component is irradiated onto the surface of the photosensitive drum 11 of the third process cartridge 10M from the left side of the paper, and an electrostatic latent image corresponding to the magenta component is formed. The black component laser light is applied to the surface of the photosensitive drum 11 of the process cartridge 10BK (black image forming unit), which is fourth from the left side of the drawing (the most downstream side with respect to the traveling direction of the intermediate transfer belt 17). Thus, 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 photosensitive drum 11 after the development process reaches a position facing the intermediate transfer belt 17. Here, a primary transfer roller 14 is installed at each facing position so as to contact the inner peripheral surface of the intermediate transfer belt 17. Then, at the position of the primary transfer roller 14, the toner images of the respective colors formed on the photosensitive drum 11 are sequentially transferred onto the intermediate transfer belt 17 (first transfer process).

Then, the surface of the photosensitive drum 11 after the first transfer process reaches a position facing the cleaning unit 15. The untransferred toner remaining on the photosensitive drum 11 is collected by the cleaning unit 15 (this is a cleaning process).
Thereafter, the surface of the photosensitive drum 11 sequentially passes through the position of the lubricant supply device 16 and the position of 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 surface of the intermediate transfer belt 17 on which the images of the respective colors on the photosensitive drum 11 are transferred in an overlapping manner travels in the direction of the arrow in the drawing and reaches the position of the secondary transfer roller 18. Then, the full color image on the intermediate transfer belt 17 is secondarily transferred onto the recording medium P at the position of the secondary transfer roller 18 (second transfer step).
Thereafter, the surface of the intermediate transfer belt 17 reaches the position of an intermediate transfer belt cleaning unit (not shown). The untransferred toner on the intermediate transfer belt 17 is collected by the intermediate transfer belt cleaning unit, and a series of transfer processes on the intermediate transfer belt 17 is completed.

Here, the recording medium P at the position of the secondary transfer roller 18 is conveyed from the paper supply unit 7 via the conveyance guide, the registration roller 19 and the like.
Specifically, the transfer paper P fed by the paper feed roller 8 from the paper feed unit 7 that stores the recording medium P is guided to the registration roller 19 after passing through the conveyance guide. The recording medium P that has reached the registration roller 19 is conveyed toward the position of the secondary transfer roller 18 in synchronization with the toner image on the intermediate transfer belt 17.

Thereafter, the recording medium P on which the full-color image is transferred is guided to the fixing unit 20. In the fixing unit 20, the color image is fixed on the recording medium P at the nip between the fixing roller and the pressure roller.
The recording medium P after the fixing step is discharged as an output image outside the apparatus main body 1 by the paper discharge roller 29 and then stacked on the paper discharge unit 5 to complete a series of image forming processes.

Next, the image forming unit of the image forming apparatus will be described in detail with reference to FIG.
FIG. 2 is a block diagram showing a process cartridge 10BK (monochrome process cartridge) as a black image forming unit. The monochrome process cartridge 10BK and the color process cartridges 10Y, 10M, and 10C are configured by substantially the same constituent members except that the color of the toner used in the image forming process is different. The illustration and description of the process cartridges 10Y, 10M, and 10C are omitted as appropriate.

  As shown in FIG. 2, the process cartridge 10BK includes a photosensitive drum 11 as an image carrier, a charging unit 12 (charging roller) for charging the photosensitive drum 11, and a static electricity formed on the photosensitive drum 11. A developing unit 13 that develops the electrostatic latent image, a cleaning unit 15 that collects untransferred toner on the photosensitive drum 11, and a lubricant supply device 16 that supplies a lubricant to the photosensitive drum 11 are provided in the case. It is housed in one piece.

Here, the photosensitive drum 11 as an image bearing member is a negatively charged organic photosensitive member, and a photosensitive layer or the like is provided on a drum-shaped conductive support.
Although not shown, the photosensitive drum 11 has an undercoat layer that is an insulating layer, a charge generation layer and a charge transport layer as a photosensitive layer, and a protective layer (surface layer) in this order on a conductive support as a base layer. Are stacked.
As the conductive support (base layer) of the photosensitive drum 11, a conductive material having a volume resistance of 10 ¹⁰ Ωcm or less can be used.

The charging unit 12 (charging roller) is a roller member formed by covering an outer periphery of a conductive metal core with a medium-resistance elastic layer, and is disposed downstream of the lubricant supply device 16 in the rotation direction of the photosensitive drum 11. It is arranged. Further, the charging unit 12 (charging roller) is disposed so as to face the photosensitive drum 11 in a non-contact manner so that the lubricant supplied onto the photosensitive drum 11 by the lubricant supply device 16 does not adhere. Has been.
A predetermined voltage is applied to the charging unit 12 from a power supply unit (not shown), thereby uniformly charging the surface of the opposing photosensitive drum 11.

  The developing unit (developing device) 13 mainly includes a developing roller 13a that faces the photosensitive drum 11, a first transport screw 13b1 that faces the developing roller 13a, and a first transport screw 13b1 that faces the first transport screw 13b1 via a partition member. It is comprised by the 2 conveyance screw 13b2 and the doctor blade 13c 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 is carried on the developing roller 13a.

In the developing unit 13, a two-component developer composed of a carrier and a toner is accommodated.
As the toner, spherical toner having a circularity of 0.98 or more is used to improve the image quality. The “circularity” is an average circularity measured by a flow type particle image analyzer “FPIA-2000” (manufactured by Toa Medical Electronics Co., Ltd.). Specifically, 0.1 to 0.5 ml of a surfactant (preferably an alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of water from which impure solids have been removed in advance. Further, about 0.1 to 0.5 g of a measurement sample (toner) is added. Thereafter, the suspension in which the toner is dispersed is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the dispersion liquid concentration is set to 3000 to 10000 / μl in the above-described analyzer. Then, the shape and distribution of the toner are measured.

As the spherical toner, it is possible to use an irregularly shaped toner (pulverized toner) whose shape is distorted by a pulverization method that has been widely used so far, which is spheroidized by heat treatment or the like, or a toner manufactured by a polymerization method. it can.
When such a spherical toner is used, conventionally, there is a case in which a slight gap between the cleaning blade 15a and the photosensitive drum 11 enters the gap and eventually passes through the gap, resulting in poor cleaning. However, in the present embodiment, a lubricant is applied to the surface of the photosensitive drum 11 by the lubricant supply device 16 to improve the toner peelability (removability) on the photosensitive drum 11, so that a cleaning failure occurs. Is suppressed.

  The cleaning unit 15 is disposed on the upstream side in the rotation direction of the photosensitive drum 11 with respect to the lubricant supply device 16. The cleaning unit 15 includes a cleaning blade 15a that is in contact with the photosensitive drum 11, a transport coil 15b that transports the toner collected in the cleaning unit 15 as waste toner toward a waste toner collection container (not shown). Etc. are installed. The cleaning blade 15a 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, deposits such as untransferred toner adhering to the photosensitive drum 11 are mechanically scraped and collected in the cleaning unit 15. Here, examples of the deposit that adheres to the photosensitive drum 11 include untransferred toner, paper dust generated from the recording medium P (paper), and a discharge product generated on the photosensitive drum 11 when discharged by the charging roller 12a. And additives added to the toner.

The lubricant supply device 16 includes a solid lubricant 16b, a lubricant supply roller 16a (brush roller) that is in sliding contact with the photosensitive drum 11 and the solid lubricant 16b, a holding member 16c that holds the solid lubricant 16b, and a holding member 16c. 16f with the solid lubricant 16b, a rotating member 16g for urging the solid lubricant 16b with the holding member 16c toward the lubricant supply roller 16a, a tension spring 16h (pressure mechanism), and a lubricant supply roller 16a. The blade-like member 16d for thinning the lubricant supplied onto the photosensitive drum 11 is formed by the above. The blade-like member 16d is configured to contact the photosensitive drum 11 in the counter direction at a position downstream of the lubricant supply roller 16a in the rotation direction of the photosensitive drum 11.
The lubricant supply device 16 configured as described above supplies the thinned lubricant on the photosensitive drum 11. The configuration and operation of the lubricant supply device 16 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 arrow direction (counterclockwise direction) in FIG. The developer in the developing unit 13 is replenished from the toner container 28 by a toner replenishing unit (not shown) by the rotation of the first transport screw 13b1 and the second transport screw 13b2 that are disposed so as to interpose a partition member therebetween. The toner circulates in the longitudinal direction while being agitated and mixed with the toner (the direction perpendicular to the paper surface of FIG. 2).

  The toner that is frictionally charged and adsorbed on the carrier is carried on the developing roller 13a together with the carrier. The developer carried on the developing roller 13a then reaches the position of the doctor blade 13c. The developer on the developing roller 13a is adjusted to an appropriate amount at the position of the doctor blade 13c and then reaches a position facing the photosensitive drum 11 (development region).

  Thereafter, in the developing region, the toner in the developer adheres to the electrostatic latent image formed on the surface of the photosensitive drum 11. Specifically, the latent image potential (exposure potential) of the image portion irradiated with the laser beam L and the electric field formed by the potential difference (development potential) between the development bias applied to the developing roller 13a cause the toner to become a latent image. (Toner image is formed).

  Thereafter, most of the toner adhering to the photosensitive drum 11 in the developing process is transferred onto the intermediate transfer belt 17. The untransferred toner remaining on the photosensitive drum 11 is collected in the cleaning unit 15 by the cleaning blade 15a.

  Here, although not shown in the figure, the toner replenishing portion provided in the apparatus main body 1 includes a bottle-shaped toner container 28 configured to be replaceable, and holds and rotates the toner container 28, and the developing unit 13 is newly installed. And a toner hopper for replenishing toner. Also, a new toner (any one of yellow, magenta, cyan, and black) is accommodated in the toner container 28. In addition, a spiral protrusion is formed on the inner peripheral surface of the toner container 28 (toner bottle).

  The new toner in the toner container 28 is appropriately supplied from the toner supply port into the developing unit 13 as the toner in the developing unit 13 (existing toner) is consumed. Although illustration is omitted, the consumption of toner in the developing unit 13 is indirectly caused by a reflection type photosensor facing the photosensitive drum 11 and a magnetic sensor installed below the second conveying screw 23b2 of the developing unit 13. Or detected directly.

Hereinafter, the configuration and operation of the lubricant supply device 16 (lubricant supply unit) in the present embodiment will be described in detail.
As shown in FIG. 2, the lubricant supply device 16 includes a solid lubricant 16b, a lubricant supply roller 16a (brush-shaped roller) in which brush bristles that are in sliding contact with the photosensitive drum 11 and the solid lubricant 16b are provided. A holding member 16c for holding the solid lubricant 16b, a case 16f for storing the holding member 16c together with the solid lubricant 16b, a rotating member 16g for biasing the solid lubricant 16b toward the lubricant supply roller 16a together with the holding member 16c, and A tension spring 16h (pressure mechanism), a blade-like member 16d (thinning blade) for thinning the lubricant supplied onto the photosensitive drum 11 by the lubricant supply roller 16a, and the like.

  The case 16f is a substantially box-shaped member that houses the holding member 16c together with the solid lubricant 16b so that the solid lubricant 16b can move in a direction in pressure contact with the lubricant supply roller 16a (so as not to prevent movement). The lubricant supply device 16 (process cartridge 10BK) is fixed. The case 16f is in contact with the members 16b and 16c as long as the movement of the solid lubricant 16b and the holding member 16c in the pressure contact direction (the direction in which the solid lubricant 16b presses the lubricant supply roller 16a) is not hindered. The gap is set to be relatively small, and the solid lubricant 16b is prevented from being inclined and pressed against the lubricant supply roller 16a to some extent. Here, the case 16f is formed with a convex portion 16f10 (guide portion) for preventing the surface of the pair of rotating members 16g rotatably supported by the holding member 16c. Will be described in detail later.

The lubricant supply roller 16a (brush-shaped roller) is a core in which brush hairs having a length (hair feet) in the range of 0.2 to 20 mm (preferably 0.5 to 10 mm) are planted on the base fabric. Wrapped in a spiral on gold.
When the length of the bristle exceeds 20 mm, the bristle falls in a predetermined direction due to repeated rubbing with the photosensitive drum 11 over time, and the scraping property of the solid lubricant 16b or from the photosensitive drum 11 is reduced. Toner removability is reduced. On the other hand, if the length of the bristle is less than 0.2 mm, the physical contact force with respect to the solid lubricant 16b and the photosensitive drum 11 is insufficient. Therefore, it is preferable that the length of the bristle is in the above range.

The lubricant supply roller 16a rotates so as to come into contact with the photosensitive drum 11 rotating clockwise in FIG. 2 in the counter direction (clockwise rotation in FIG. 2). The lubricant supply roller 16a (brush bristles) is disposed so as to be in sliding contact with the solid lubricant 16b and the photosensitive drum 11, and the lubricant supply roller 16a rotates to rotate the lubricant from the solid lubricant 16b. After the scraped lubricant is conveyed to the sliding contact position with the photosensitive drum 11, the lubricant is applied onto the photosensitive drum 11.
In order to eliminate uneven contact between the lubricant supply roller 16a and the solid lubricant 16b, pressure mechanisms 16g and 16h are arranged at the rear portion of the solid lubricant 16b and are held (attached) to the holding member 16c. The solid lubricant 16b in a heated state is urged toward the lubricant supply roller 16a. Here, the pressurizing mechanism includes a pair of rotating members 16g rotatably supported by the holding member 16c, and a tension spring 16h as an urging member connected to the pair of rotating members 16g. Although it is configured, this will be described in detail later.

In the present embodiment, the solid lubricant 16b is mainly formed of zinc stearate. Specifically, the solid lubricant 16b is preferably prepared by dissolving a lubricating oil additive mainly composed of zinc stearate, having no side effects due to overcoating, and having sufficient lubricity.
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.

  As the solid lubricant 16b, in addition to zinc stearate, stearic acid groups such as barium stearate, iron stearate, nickel stearate, cobalt stearate, copper stearate, strontium stearate, calcium stearate, etc. The thing which has can be used. In addition, the same fatty acid group zinc oleate, barium oleate, lead oleate, the same compound as stearic acid, zinc palmitate, barium palmitate, lead palmitate, the following compound similar to stearic acid May be used. In addition, caprylic acid, linolenic acid, corinolenic acid and the like can be used as the fatty acid group. In addition, waxes such as candelilla wax, canrunauba wax, rice wax, wax, coconut oil, beeswax, and lanolin can also be used. These easily become organic solid lubricants and have good compatibility with the toner.

When the solid lubricant 16b is applied to the surface of the photosensitive drum 11 via the lubricant supply roller 16a, a powdery lubricant is applied to the surface of the photosensitive drum 11, but the lubricity is sufficient in this state. Therefore, the blade-like member 16d (thinned blade) functions as a member for uniformizing the lubricant. The blade-like member 16d forms a film of the lubricant on the photosensitive drum 11, and the lubricant exhibits its lubricity sufficiently.
At this time, the finer the powdery lubricant applied by the lubricant supply roller 16a, the thinner the film on the photosensitive drum 11 by the blade-like member 16d.

Hereinafter, the configuration and operation of the lubricant supply device 16 which are characteristic in the present embodiment will be described in detail.
Referring to FIG. 3, in lubricant supply device 16 in the present embodiment, solid lubricant 16b is stuck and held on holding member 16c. Specifically, a double-sided tape, an adhesive, or the like is interposed between the holding member 16c and the solid lubricant 16b, and the holding member 16c holds and holds the solid lubricant 16b. Here, the holding member 16c is a sheet metal bent into a U-shape, and a plurality of holes 16c2 (bearing portions) for holding the rotating member 16g are formed on both side surfaces thereof.

Here, referring to FIG. 3, FIG. 4, FIG. 6, etc., the holding member 16c is located at a position away from the width direction (the vertical direction in FIG. 2 and the left-right direction in FIG. 6). A pair of rotating members 16g (pressing members) are supported so as to be rotatable. The pair of rotating members 16g are rotated in predetermined directions by an urging force of a tension spring 16h (urging member) and indirectly press the solid lubricant 16b via the holding member 16c, thereby solid-lubricating. The agent 16b is pressed against the lubricant supply roller 16a.
Specifically, referring to FIG. 4 and FIG. 5, support shafts 16g1 (shaft portions) serving as rotation centers are formed on both side surfaces of the rotation member 16g. Then, the support shaft 16g1 of the rotating member 16g is inserted into the hole 16c2 of the holding member 16c, and the rotating member 16g is rotatably held by the holding member 16c. As shown in FIGS. 3 and 6, the two rotating members 16 c are installed on the holding member 16 c so as to be symmetrical in the width direction.

3 and 6 and the like, the pair of rotating members 16g are connected by a tension spring 16h as an urging member. Specifically, the hook portions at both ends of the tension spring 16h are respectively connected to the hole portions 16g4 (see FIG. 4) of the rotating member 16g.
The tension spring 16h rotates the pair of rotating members 16g in different directions so as to come into pressure contact with the case 16f, and urges the holding member 16c in a direction approaching the lubricant supply roller 16a. Will function as. Specifically, the tension spring 16h (the urging member) has a pair of rotating members 16g so that the span between the cam-shaped portions 16g2 where the pair of rotating members 16g are pressed against the case 16f gradually decreases. Rotate.
That is, the two rotating members 16g receive a spring force (biasing force) from the tension spring 16h in a direction in which the cam-shaped portions 16g2 (see FIG. 4 and the like) contacting the inner wall surface of the case 16f approach each other. Thereby, the left turning member 16g in FIG. 6 is urged to turn counterclockwise in FIG. 6 with the support shaft 16g1 as the turning center. On the other hand, the right rotating member 16g in FIG. 6 is urged to rotate in the clockwise direction in FIG. 6 with the support shaft 16g1 as the rotation center.

More specifically, as shown in FIGS. 6A to 6B, as the cumulative operation time in the image forming apparatus 1 increases, the solid lubricant 16b is gradually consumed by supplying the lubricant to the lubricant supply roller 16a. As a result, the thickness (thickness in the pressure-contact direction with respect to the lubricant supply roller 16a) becomes thinner. The pair of rotating members 16g are rotated in the above-described direction by the urging force of the tension spring 16h as the solid lubricant 16b is consumed (thinned).
In other words, the cam-shaped portions 16g2 formed on the pair of rotating members 16g move so that the holding member 16c approaches the lubricant supply roller 16a together with the solid lubricant 16b as the solid lubricant 16b is consumed. Then, it is rotated by the urging force of the tension spring 16h and comes into pressure contact with the case 16f.
Thus, when the pair of rotating members 16g rotate, the position (operation point) at which the rotating member 16g (cam-shaped portion 16g2) contacts the case 16f along with the rotation (consumption of the solid lubricant 16b). ) And the supporting shaft 16g1 (fulcrum), and the rotation direction angle formed by the imaginary straight line in the pressing direction in which the holding member 16c (solid lubricant 16b) moves is gradually reduced. Further, along with the rotation (consumption of the solid lubricant 16b), an imaginary line segment connecting the position (force point) of the rotation member 16g receiving the urging force of the tension spring 16h and the support shaft 16g1 (support point), and the tension spring 16h The angle in the rotational direction formed by the virtual straight line in the urging direction on which the urging force acts is gradually increased.

Hereinafter, the operation of the rotating member 16g accompanying consumption (thinning of the solid lubricant 16b) will be described in detail with reference to FIGS.
First, as shown in FIG. 6A, a new solid lubricant 16b (attached to and held by the holding member 16c) is set in the lubricant supply device 16 (device main body 1). Then, in the state where the span of the cam-shaped portion 16g2 of the pair of rotating members 16g (the distance in the width direction between the two press contact portions with the case 16f) is the longest, the holding member 16c (additional member) The solid lubricant 16b is pressed against the lubricant supply roller 16a by the pressure mechanisms 16g and 16h). In this state, supply of the lubricant onto the photosensitive drum 11 by the lubricant supply device 16 (lubricant supply roller 16a) is started. Note that the hole 16c2 is a long hole so that the support shaft 16g1 can slide, and the pressing portion 16g3 (see FIG. 4) of the rotating member 16g presses the ceiling surface inside the holding member 16c. It can also be configured.
Thereafter, as shown in FIG. 6B, when the supply of the lubricant onto the photosensitive drum 11 is advanced by the lubricant supply device 16 (lubricant supply roller 16a) over time, a pair of rotating members The span of the 16g cam-shaped portion 16g2 gradually decreases, and in this state, the solid lubricant 16b is pressed against the lubricant supply roller 16a by the holding member 16c (pressure mechanisms 16g and 16h).

  Finally, although illustration is omitted, the supply of the lubricant onto the photosensitive drum 11 by the lubricant supply device 16 (lubricant supply roller 16a) is further advanced, and the thickness of the solid lubricant 16b is increased. The solid lubricant 16b is taken out from the lubricant supply device 16 (device main body 1) together with the holding member 16c in a state where the amount of the lubricant is reduced, and replacement maintenance of the solid lubricant 16b is performed. It should be noted that the time when the replacement maintenance of the solid lubricant 16b is performed is a detection means for detecting the consumption of the solid lubricant 16b directly or indirectly (for example, a means for counting the cumulative operating time of the device 16 or the solid lubricant 16b). For example, a means for optically detecting the thickness of the material.).

Here, referring to FIGS. 5 and 6, the lubricant supply device 16 according to the present embodiment has a virtual surface (a surface parallel to the paper surface of FIG. 4) on which the rotation member 16 g rotates. On the other hand, a convex portion 16f10 is provided on the case 16f as a guide portion for restricting the surface from falling in the intersecting direction (installed on each of the two rotating members 16g).
Specifically, referring to FIG. 5, the convex portion 16f10 (guide portion) is convex so as to protrude in a direction approaching the solid lubricant 16b with respect to the pressure contact surface 16f1 of the case 16f with which the rotating member 16g is pressed. Is formed. Moreover, in this Embodiment, the convex-shaped part 16f10 is formed so that it may respectively oppose both the side surfaces of the rotation member 16g so that the rotation member 16g may be pinched | interposed. Thus, by providing the convex part 16f10 (guide part) in the case 16f, the rotating member 16g rotates so as to be guided by the convex part 16f10.

With such a configuration, even when the solid lubricant 16b is momentarily subjected to a large reaction force from the lubricant supply roller 16a at the start-up when the lubricant supply roller 16a starts to rotate from a stopped state, the rotating member The malfunction that 16g falls down will be suppressed reliably. In other words, the posture is changed so that the rotating member 16g is inclined and pressed against the solid lubricant 16b (change from the state of FIG. 7A to the state of FIG. 7B1). ), Or the phenomenon that the solid lubricant 16b is inclined and pressed against the lubricant supply roller 16a together with the rotating member 16g (from the state of FIG. 7A to FIG. 7B2). It is possible to prevent the change to the state of.
That is, even if the turning member 16g is about to fall down, the turning member 16g comes into contact with the convex portion 16f10 (guide portion), so that the turning member 16g with respect to the solid lubricant 16b does not fall down. The posture and the posture of the solid lubricant 16b with respect to the lubricant supply roller 16a are maintained (the state shown in FIG. 7A is maintained). Accordingly, when the solid lubricant 16b is biased and comes into contact with the lubricant supply roller 16a, the lubricant on the lubricant supply roller 16a scraped off from the solid lubricant 16b becomes non-uniform, and the lubricant supply device. The lubricant supplied onto the photosensitive drum 11 by the roller 16 (lubricant supply roller 16a) also becomes non-uniform so that defects such as missing or defective cleaning of the cleaning blade 15a are suppressed. become.

Here, in the present embodiment, the convex portion 16f10 as the guide portion is formed so as to face both side surfaces of the rotating member 16g so as to sandwich the rotating member 16g.
On the other hand, as shown in FIG. 8A, the convex portion 16f10 as a guide portion is provided on both side surfaces of the rotating member 16g (surfaces parallel to the paper surface of FIG. It can also be formed only on the side surface corresponding to the upstream side in the rotation direction of the lubricant supply roller 16a. That is, as shown in FIG. 8A, one convex portion 16f10 is formed to face the right side surface of the rotating member 16g. Even in such a case, as described above with reference to FIG. 7, the direction in which the rotating member 16g tilts is substantially determined on the side surface corresponding to the upstream side in the rotational direction of the lubricant supply roller 16a. Therefore, similarly to the present embodiment, the effect of suppressing the tilting of the rotating member 16g can be sufficiently obtained.
Further, as shown in FIG. 8 (B), a convex portion 16f10 as a guide portion can be formed so as to be attached to the side wall 16f2 of the case 16f. That is, as shown in FIG. 8B, the length of the convex portion 16f10 is extended to the position of the side wall 16f2 so as to be integrated with the side wall 16f2 of the case 16f. This increases the strength of the convex portion 16f10 with respect to the force received from the rotating member 16g, and reliably prevents the rotating member 16g from being damaged when the rotating member 16g is prevented from falling down. Can do.

Furthermore, in the present embodiment, the convex portion 16f10 that protrudes with respect to the inner wall surface (bottom surface) formed on the same plane as the pressure contact surface 16f1 of the case 16f is used as the guide portion.
On the other hand, as shown in FIG. 9A, as the guide portion, the pressure contact surface 16f1 of the case 16f with which the rotating member 16g is pressure-contacted is formed so as to be recessed in a direction away from the solid lubricant 16b. The side wall surface 16f15a of the groove portion 16f15 can also be used. That is, as shown in FIG. 9A, the pressure contact surface 16f1 of the rotating member 16g that presses against the case 16f is a bottom surface of the groove portion 16f15 formed on the inner wall surface (bottom surface), and both side wall surfaces 16f15a of the groove portion 16f15 are formed. It functions as a guide portion so as to face both side surfaces of the rotating member 16g so as to sandwich the rotating member 16g. Even in such a case, the effect of suppressing the surface tilt of the rotating member 16g can be obtained as in the case of the present embodiment. In particular, when the groove portion 16f15 is formed on the bottom surface of the case 16f, the height of the case 16f (the length in the vertical direction in FIG. 9) can be made relatively low. It becomes possible.
Further, as shown in FIG. 9B, the side wall surface 16f15a functioning as a guide portion is formed on both side surfaces of the rotating member 16g (surfaces parallel to the paper surface of FIG. 4 and provided with the support shaft 16g1). In this case, it can be formed only on the side surface corresponding to the upstream side in the rotation direction of the lubricant supply roller 16a. That is, as shown in FIG. 9B, one side wall surface 16f15a in the groove portion 16f15 is formed so as to face and face the right side surface of the rotating member 16g. Even in such a case, as described above with reference to FIG. 7, the direction in which the rotating member 16g tilts is substantially determined on the side surface corresponding to the upstream side in the rotational direction of the lubricant supply roller 16a. Therefore, similarly to the present embodiment, the effect of suppressing the tilting of the rotating member 16g can be sufficiently obtained.

  As described above, according to the present embodiment, the pair of rotating members 16g for bringing the solid lubricant 16b into pressure contact with the lubricant supply roller 16a accommodates the holding member 16c that is rotatably installed. The case 16f is provided with a convex portion 16f10 (guide portion) that restricts the turning member 16g from falling down. As a result, the lubricant can be supplied to the photoconductive drum 11 stably and uniformly without a shortage of the lubricant supplied to the photoconductive drum 11 (image carrier) over time.

In this embodiment, the process cartridges 10Y, 10M, and the process cartridges 10Y, 10M, and the like in the image forming unit (the photosensitive drum 11, the charging unit 12, the developing unit 13, the cleaning unit 15, and the lubricant supply device 16) are integrated. 10C and 10BK are configured to reduce the size of the image forming unit and improve maintenance workability.
In contrast, each of the image forming units 11, 12, 13, 15, and 16 can be configured to be installed in the apparatus main body 1 in a replaceable manner 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 embodiment, the present invention is applied to the image forming apparatus equipped with the two-component developing type developing unit 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 unit 13 is mounted.

  In the present embodiment, the present invention is applied to a tandem type color image forming apparatus using the intermediate transfer belt 17. In contrast, a tandem color image forming apparatus using a transfer conveyance belt (a recording in which toner images on a plurality of photosensitive drums arranged in parallel so as to face the transfer conveyance belt are conveyed by the transfer conveyance belt. The present invention can also be applied to other image forming apparatuses such as a monochrome image forming apparatus. Even in such a case, the same effect as in the present embodiment can be obtained.

  In the present embodiment, the present invention is applied to the lubricant supply device 16 that supplies the lubricant onto the photosensitive drum 11 as the image carrier. However, the image carrier other than the photosensitive drum 11 is lubricated. Naturally, the present invention can also be applied to a lubricant supply device that supplies a lubricant (for example, a lubricant supply device that supplies a lubricant to the intermediate transfer belt 17). Even in such a case, the same effect as that of the present embodiment can be obtained by providing the case 16f with the guide portion 16f10 that restricts the tilting of the rotating member 16g as in the present embodiment. Can do.

  In the present embodiment, a brush-like roller having brush bristles is used as the lubricant supply roller 16a. However, a sponge-like roller having a sponge-like member (elastic material) is provided as the lubricant supply roller 16a. Can also be used. Even in such a case, the same effect as that of the present embodiment can be obtained by providing the case 16f with the guide portion 16f10 that restricts the tilting of the rotating member 16g as in the present embodiment. Can do.

  In the present embodiment, the case 16f is configured to store the holding member 16c together with the solid lubricant 16b. However, the case may be configured to store other members. For example, the case may be configured as a housing case (housing) of the entire lubricant supply device 16. Even in such a case, the same effect as that of the present embodiment can be obtained by providing the case 16f with the guide portion 16f10 that restricts the tilting of the rotating member 16g as in the present embodiment. Can do.

  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),
11 Photosensitive drum (image carrier),
15 Cleaning section,
16 Lubricant supply device (lubricant supply unit),
16a Lubricant supply roller (brush roller),
16b solid lubricant,
16c holding member,
16f case,
16f1 pressure contact surface, 16f2 side wall,
16f10 convex portion (guide portion),
16f15 groove,
16f15a side wall surface (guide portion),
16g rotating member (pressing member),
16g1 spindle (rotation center),
16g2 Cam-shaped part.

JP 2001-305907 A JP 2007-293240 A

Claims (9)

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 in sliding contact with the lubricant supply roller;
A holding member for holding the solid lubricant;
A case formed so as to accommodate at least the holding member together with the solid lubricant so that the solid lubricant can move in a direction in pressure contact with the lubricant supply roller;
A pair of rotating members that are rotatably supported at positions away from each other in the width direction in the holding member;
An urging member that urges the holding member in a direction approaching the lubricant supply roller by rotating the pair of rotating members in different directions so as to be in pressure contact with the case;
With
The case is formed so as to oppose substantially parallel to a virtual surface on which the rotating member rotates , and restricts the surface of the rotating member from falling in a direction intersecting the virtual surface. A lubricant supply device comprising a guide portion.   2. The lubrication according to claim 1, wherein the guide portion is formed in a convex shape so as to protrude in a direction approaching the solid lubricant with respect to a pressure contact surface of the case with which the rotating member is pressure contacted. Agent supply device.   The lubricant supply device according to claim 2, wherein the guide portion is attached to a side wall of the case.   The said guide part is a side wall surface of the groove part formed so that the press-contact surface of the said case where the said rotation member press-contacts might be recessedly provided in the direction spaced apart from the said solid lubricant. The lubricant supply device according to 1.   The said guide part was formed only in the side surface corresponding to the rotation direction upstream of the said lubricant supply roller among the both sides | surfaces of the said rotation member, The any one of Claims 1-4 characterized by the above-mentioned. The lubricant supply device according to 1. The pair of rotating members are rotated by the urging force of the urging member so that the holding member moves together with the solid lubricant in a direction approaching the lubricant supply roller as the solid lubricant is consumed. A cam-shaped portion that press-contacts the case,
The urging member is connected to the pair of rotating members, and rotates the pair of rotating members so that a span between portions where the pair of rotating members are pressed against the case gradually decreases. The lubricant supply device according to any one of claims 1 to 5, wherein the lubricant supply device is a tension spring. A process cartridge that is detachably attached to the image forming apparatus main body,
A process cartridge comprising the lubricant supply device according to any one of claims 1 to 6 and the image carrier.   8. The process cartridge according to claim 7, further comprising a cleaning unit that cleans the image carrier on the upstream side in the rotation direction of the image carrier with respect to the lubricant supply device.   An image forming apparatus comprising the lubricant supply device according to claim 1 and the image carrier.

Images