JP6646891B2 - Image forming device - Google Patents

Description

  The present invention relates to an image forming apparatus using an electrophotographic method, such as a copier, a printer, a facsimile, or a multifunction peripheral thereof.

  2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine or a printer, an image is formed based on a predetermined condition based on a predetermined condition in order to always supply a stable amount of lubricant to a surface of an image carrier such as a photosensitive drum or an intermediate transfer belt. There is known a technique for varying the number of rotations of a lubricant supply roller that is in sliding contact with a carrier (for example, see Patent Document 1).

Specifically, in Patent Document 1, a lubricant supply device includes a lubricant supply roller that slides on a photosensitive drum (image carrier), a solid lubricant that contacts the lubricant supply roller, and a solid lubricant that is supplied to the lubricant supply roller. It is composed of an urging member that urges toward. Then, the lubricant is gradually scraped off from the solid lubricant by a lubricant supply roller rotating in a predetermined direction, and the lubricant scraped and transported by the lubricant supply roller is applied (supplied) to the surface of the photosensitive drum. You.
Patent Literature 1 discloses that the amount of lubricant supplied to a photoreceptor drum is varied by varying the number of revolutions of the lubricant supply roller based on predetermined conditions such as the total travel distance of the lubricant supply roller and the environment. There is disclosed a technology for preventing excess and deficiency from occurring.

In the conventional image forming apparatus, the number of rotations of the lubricant supply roller is changed to an optimum value based on a predetermined condition, so that the amount of the lubricant supplied to the surface of the image carrier is less likely to be excessive or insufficient. Can be expected.
However, when the rotational speed of the lubricant supply roller is changed, the meshing frequency of the gear at that time coincides with the natural frequency of the other members and resonates. As a result, an image formed on the surface of the image carrier sometimes has a problem such as image unevenness.

  The present invention has been made in order to solve the above-described problems, and even when performing control to vary the number of rotations of the lubricant supply roller, the image carrier vibrates greatly, causing image unevenness. An object of the present invention is to provide an image forming apparatus which does not cause the above-mentioned problem.

The image forming apparatus according to the first aspect of the present invention provides an image carrier on which a toner image is carried, a lubricant supply roller for supplying a lubricant to a surface of the image carrier, and the lubricant supply roller A variable means for varying the number of revolutions, an environment detecting means for detecting the ambient absolute humidity, and a predetermined value for the number of revolutions of the lubricant supply roller to be varied by the variable means based on a predetermined condition. When the absolute humidity detected by the environment detecting means is equal to or higher than a predetermined absolute humidity, the rotation speed is increased by a predetermined value or a ratio so as not to match the predetermined value. and controlling the variable means, reducing the absolute humidity detected by the environment detection means by a predetermined value or percentage as its rotation speed does not match the predetermined value when it is below a predetermined absolute humidity A control unit for controlling the varying means so as to, those having a.

  ADVANTAGE OF THE INVENTION According to the present invention, even when performing control to vary the number of rotations of a lubricant supply roller, an image forming apparatus does not vibrate the image carrier greatly and cause problems such as image unevenness. Can be provided.

1 is an overall configuration diagram illustrating an image forming apparatus according to Embodiment 1 of the present invention. FIG. 2 is a configuration diagram illustrating a process cartridge and its vicinity. 5 is a flowchart illustrating control for varying the number of rotations of a lubricant supply roller. 10 is a flowchart illustrating a control for varying the number of rotations of a lubricant supply roller as a first modification. 9 is a flowchart illustrating control for varying the number of revolutions of a lubricant supply roller as a second modification. In the control of the lubricant supply device according to the second embodiment, (A) a diagram showing the relationship between the absolute humidity and the rotation speed of the lubricant supply roller, and (B) the total travel time and the rotation speed of the lubricant supply roller. FIG. FIG. 14 is a schematic diagram illustrating a gear train installed in a lubricant supply device according to a third embodiment. It is the schematic which shows the modification of the gear train of FIG. It is the schematic which shows the further another modification of the gear train of FIG. FIG. 14 is a schematic diagram illustrating a gear train installed in a lubricant supply device according to a fourth embodiment. It is the schematic which shows the modification of the gear train of FIG. It is the schematic which shows the further another modification of the gear train of FIG.

  Hereinafter, embodiments for implementing the present invention will be described in detail with reference to the drawings. In each of the drawings, the same or corresponding portions are denoted by the same reference characters, and a repeated description thereof will be appropriately simplified or omitted.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described in detail with reference to FIGS.
First, the overall configuration and operation of the image forming apparatus will be described with reference to FIGS.
FIG. 1 is an overall configuration diagram illustrating the image forming apparatus according to the first embodiment. FIG. 2 is a cross-sectional view illustrating a configuration of the yellow process cartridge 10 </ b> Y (image forming unit) installed in the image forming apparatus 1 of FIG. 1.
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. FIG.

  In FIG. 1, reference numeral 1 denotes a tandem type color copier as an image forming apparatus, 2 denotes a writing unit that emits a laser beam based on input image information, 3 denotes a document transport unit that transports a document D to a document reading unit 4, and 4 denotes a document transport unit. An original reading unit for reading image information of the original D, a paper feeding unit 7 for accommodating a recording medium such as transfer paper, a registration roller 9 for adjusting the conveyance timing of the recording medium, 10Y, 10M, 10C, and 10BK each color ( A process cartridge 16 on which toner images of yellow, magenta, cyan, and black are formed, and a toner cartridge 16 formed by superposing toner images formed on the photosensitive drums of the process cartridges 10Y, 10M, 10C, and 10BK on an intermediate transfer belt 17 A primary transfer bias roller for transferring, 17 an intermediate transfer belt on which toner images of a plurality of colors are transferred in an overlapping manner, and 18 a toner on the intermediate transfer belt 17. A secondary transfer bias roller for transferring an image onto a recording medium; 19, an intermediate transfer belt cleaning unit for cleaning the intermediate transfer belt 17; 20, a fixing device for fixing a toner image (unfixed image) on the recording medium; Is shown.

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

  More 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 a color sensor via a mirror group and a lens. The color image information of the document D is read by a color sensor for each of RGB (red, green, blue) color separation light, and then converted into an electrical image signal. Further, based on the RGB color-separated image signals, the image processing unit performs color conversion processing, color correction processing, spatial frequency correction processing, and other processing 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, from the writing unit 2, laser light (exposure light) based on the image information of each color is directed 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 rotate (run) in predetermined directions (counterclockwise), respectively. Then, first, the surface of the photoconductor drum 11 is uniformly charged at a portion facing the charging roller 12 (charging step). Thus, a charged potential is formed on the photosensitive drum 11. Thereafter, the charged surface of the photosensitive drum 11 reaches the irradiation position of each laser beam L.
In the writing unit 2, laser light L corresponding to an image signal is emitted from each of the four light sources corresponding to each color. Each laser beam L passes through another optical path for each of the yellow, magenta, cyan, and black color components (this is an exposure step).

  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 drawing. At this time, the laser light of the yellow component is scanned in the rotation axis direction (main scanning direction) of the photosensitive drum 11 by a polygon mirror that rotates at a 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 12.

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

After that, the surface of the photoconductor drum 11 on which the electrostatic latent images of each color are formed reaches the position facing the developing device 13, respectively. Then, toner of each color is supplied from the developing devices 13 onto the photosensitive drum 11 to develop the latent image on the photosensitive drum 11 (this is a developing step).
Thereafter, the surfaces of the photosensitive drums 11 after the developing process reach the portions facing the intermediate transfer belt 17, respectively. Here, a primary transfer bias roller 16 is provided at each of the opposing portions so as to contact the inner peripheral surface of the intermediate transfer belt 17. Then, at the position of the transfer bias roller 16, the toner images of each color formed on the photosensitive drum 11 are sequentially superimposedly transferred onto the intermediate transfer belt 17 (this is a primary transfer step).

Then, the surface of the photoconductor drum 11 after the transfer process reaches a position facing the cleaning device 14 (cleaning unit). Then, at this position, the untransferred toner remaining on the photosensitive drum 11 is mechanically removed by the cleaning blade 14a, and the removed untransferred toner is collected in the cleaning device 14 (this is a cleaning step). ). The untransferred toner collected in the cleaning device 14 is transported out of the cleaning device 14 by the transport screw 14b, and is recovered as waste toner in a waste toner recovery container (not shown).
Thereafter, the surface of the photosensitive drum 11 sequentially passes through the positions of the lubricant supply device 15 and the charge removing 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) in an overlapping manner travels clockwise in the drawing and reaches a position facing the secondary transfer bias roller 18. Then, the color toner image carried on the intermediate transfer belt 17 is transferred onto the recording medium at a position facing the secondary transfer bias roller 18 (this is a 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 to the intermediate transfer belt 17 is collected by the intermediate transfer belt cleaning unit 19, and a series of transfer processes on the intermediate transfer belt 17 is completed.

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

Then, the recording medium on which the full-color image has been transferred is guided to the fixing device 20 by the transport belt. In the fixing device 20, a color image (toner) is fixed on a recording medium by a nip between a fixing belt and a pressure roller.
Then, the recording medium after the fixing step is discharged as an output image to the outside of the apparatus main body 1 by a discharge roller, and a series of image forming processes is completed.
In the first embodiment, when thick paper is passed as a recording medium, the process linear velocity (conveying speed of the recording medium, image formation of the photosensitive drum 11 or the like) is required to secure a good fixed image. (The linear velocity of the member) is slowed down to perform the image forming process. That is, from the “normal mode” in which the image forming process is performed at the normal process linear speed by the user's selection through the operation of the operation panel, the “low speed” in which the image forming process is performed at a process linear speed lower than the normal process linear speed is performed. Mode "can be changed.

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 roller 12 as a charging unit, a developing device 13 (developing unit), a cleaning device 14 (cleaning unit), The lubricant supply device 15 and the lubricant supply device 15 are integrally configured as a unit. The process cartridge 10 </ b> Y is installed detachably (replaceable) with respect to the image forming apparatus main body 1, so that the process cartridge 10 </ b> Y is appropriately removed from the image forming apparatus main body 1 and replaced with a new one or repaired. Become.

Here, the photoconductor drum 11 as an image carrier is a negatively charged organic photoconductor, and is provided with a photosensitive layer or the like on a drum-shaped conductive support.
Although not shown, the photoconductor drum 11 includes a conductive support as a base layer, 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). It is laminated.
The photoconductor drum 11 is driven to rotate in a counterclockwise direction in FIG. 2 by a motor (not shown) (main motor).

Referring to FIG. 2, charging roller 12 as a charging unit is a roller member formed by coating a conductive cored bar with a medium-resistance elastic layer on the outer periphery. A predetermined voltage (which is obtained by superimposing an AC voltage on a DC voltage) is applied to the charging roller 12 from a charging power supply unit (not shown), so that the surface of the opposing photosensitive drum 11 is uniformly formed. Charges.
Here, in the first embodiment, the charging roller 12 is configured to be pressed against the photosensitive drum 11 by a compression spring (not shown). Can be configured so as to face each other without contact. In the first embodiment, the charging roller 12 is applied with a charging voltage in which an AC voltage is superimposed on a DC voltage as the charging bias. However, the charging roller 12 may be applied with only the DC voltage as the charging bias.
In the first embodiment, the charging unit cleaning roller 40 for cleaning the surface of the charging roller 12 is provided so as to be in pressure contact with the charging roller 12.

The developing device 13 (developing unit) mainly includes a developing roller 13a facing the photosensitive drum 11, a first transport screw 13b facing the developing roller 13a, and a first transport screw 13b facing the first transport screw 13b via a partition member. It is composed of a two-conveying screw 13c and a 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.
The developing device 13 contains a two-component developer G including a carrier C and a toner T.

The cleaning device 14 includes a cleaning blade 14a that contacts the photoconductor drum 11 to clean the surface of the photoconductor drum 11, and the untransferred toner collected in the cleaning device 14 is moved in the width direction (the direction perpendicular to the paper surface of FIG. 2). ) Is provided.
The cleaning blade 14a is made of a rubber material such as urethane rubber, and is in contact with the surface of the photoconductor drum 11 at a predetermined angle and a predetermined pressure. As a result, untransferred toner (paper dust generated from a recording medium, a discharge product generated on the photoconductor drum 11 at the time of discharging by the charging roller 12, an additive added to the toner, etc. (Including adhering matter) is mechanically scraped off and collected in the cleaning device 14. In the first embodiment, the cleaning blade 14a is in contact with the photosensitive drum 11 in a counter direction with respect to the traveling direction (rotation direction) of the photosensitive drum 11.

Referring to FIG. 2, a lubricant supply device 15 includes a lubricant supply roller 15 a (a lubricant supply rotation unit) that is provided with a foamed elastic layer that is in sliding contact with the photoconductor drum 11 and supplies lubricant onto the photoconductor drum 11. Body), a solid lubricant 15b slidably in contact with the lubricant supply roller 15a (foam elastic layer), a compression spring 15c as an urging member for urging the solid lubricant 15b toward the lubricant supply roller 15a, a solid lubricant 15b (Holding plate) 15d (holding plate), a thinning blade 15f (leveling blade) for contacting the photosensitive drum 11 and thinning (homogenizing) the lubricant supplied on the photosensitive drum 11; Etc.
The lubricant supply device 15 is on the downstream side (downstream in the running direction) of the photosensitive drum 11 with respect to the cleaning device 14 (cleaning blade 14 a), and the rotational direction of the photosensitive drum 11 with respect to the charging roller 12. It is located upstream. The thinning blade 15f is disposed downstream of the lubricant supply roller 15a in the rotation direction of the photosensitive drum 11.

The lubricant supply roller 15a is a roller-shaped member in which a foamed elastic layer made of foamed polyurethane (urethane foam) is formed on a shaft portion (core metal) made of a metal material. While being in contact with the surface, it is rotationally driven counterclockwise in FIG. 2 by the drive motor 45. Specifically, a drive gear provided on a motor shaft of the drive motor 45 meshes with a driven gear provided on a rotation shaft portion of the lubricant supply roller 15a, so that the drive motor 45 drives the lubricant supply roller 15a to rotate. Force will be transmitted. As a result, the lubricant is supplied from the solid lubricant 15b onto the photosensitive drum 11 via the lubricant supply roller 15a.
Here, the drive motor 45 for rotationally driving the lubricant supply roller 15a is provided independently of the motor for rotationally driving the photosensitive drum 11 and the like, and varies the rotational speed of only the lubricant supply roller 15a. This is a variable rotation speed motor that is driven to rotate. That is, the drive motor 45 functions as a variable unit that varies the rotation speed of the lubricant supply roller 15a. The variable control of the number of rotations of the lubricant supply roller 15a using the drive motor 45 will be described later in detail with reference to FIG.

The lubricant supply roller 15a is formed by previously forming a polyurethane foam to be a foamed elastic layer into a block shape from a raw material of the polyurethane foam, cutting the polyurethane foam into a required shape, polishing the surface, and inserting a core metal (core material). It is manufactured by a method of cutting (traverse grinding) to a predetermined sponge thickness by rotating the foamed polyurethane and moving the blade in parallel to the axial direction by applying a polishing blade. An adhesive may be applied to the core metal to be inserted in advance in order to increase the adhesiveness with the foamed elastic layer. Also, by changing the rotational speed or moving speed of the polyurethane foam when performing traverse grinding, irregular irregularities can be formed on the surface of the foamed elastic layer.
The method of manufacturing 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 mold containing a metal core and foaming and hardening the material is used. It can also be used.

The lubricant supply roller 15a is rotationally driven so as to be in sliding contact with the photosensitive drum 11 rotating counterclockwise in FIG. 2 in the counter direction (reverse direction) (rotation in the counterclockwise direction in FIG. 2). ). That is, the rotation direction of the lubricant supply roller 15 a is configured to be opposite to the rotation direction (running direction) of the photosensitive drum 11 at the position where the lubricant supply roller 15 a is in sliding contact with the photosensitive drum 11.
The lubricant supply roller 15a is disposed so as to be in sliding contact with the solid lubricant 15b and the photosensitive drum 11, and the lubricant supply roller 15a rotates to scrape the lubricant from the solid lubricant 15b, The lubricant is applied on the photosensitive drum 11.
A compression spring 15c is disposed behind the solid lubricant 15b (lubricant holding member 15e) to eliminate uneven contact between the lubricant supply roller 15a and the solid lubricant 15b. To the lubricant supply roller 15a.

Here, the solid lubricant 15b is formed by adding an inorganic lubricant to fatty acid metal zinc. The zinc fatty acid metal preferably contains at least zinc stearate. The inorganic lubricant is preferably at least one of talc, mica, and boron nitride.
Zinc stearate is a typical lamellar crystalline powder. The lamella crystal has a layered structure in which amphipathic molecules are self-organized. When a shearing force is applied, the crystal breaks along the layers and easily slips. Therefore, the surface of the photosensitive drum 11 can be reduced in friction. That is, the surface of the photosensitive drum 11 can be effectively covered with a small amount of the lubricant by the lamella crystal that uniformly covers the surface of the photosensitive drum 11 under the shearing force. Then, the surface of the photoconductor drum 11 is covered relatively evenly, and it is possible to satisfactorily protect the surface of the photoconductor drum 11 from electric stress in the charging process.
Further, by using an inorganic lubricant having a plate-like structure such as talc, mica, and boron nitride, the toner and the lubricant do not easily pass through the cleaning device 14 (the cleaning blade 14a), and the charging roller 12 is used. Stain can be reduced.

  The solid lubricant 15b according to the first embodiment is formed by pouring a material as a raw material into a mold, compressing the solid, solidifying it, and forming it into a substantially rectangular shape. The solid lubricant 15b formed by such a manufacturing method can simplify the manufacturing equipment and reduce the cost of parts.

The thinning blade 15f is a plate-shaped 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 15f is provided downstream of the cleaning blade 14a in the rotation direction of the photosensitive drum 11 (downstream in the running direction). Then, the lubricant supplied onto the photosensitive drum 11 by the lubricant supply roller 15a is uniformly and appropriately thinned on the photosensitive drum 11 by the thinning blade 15f.
When the solid lubricant 15b is applied to the surface of the photoconductor drum 11 via the lubricant supply roller 15a, a powdery lubricant is applied to the surface of the photoconductor drum 11, but the lubricity remains in this state. Since it is not sufficiently exhibited, the thinning blade 15f functions as a member for thinning and uniforming the lubricant. The thinning blade 15f forms a film of the lubricant on the photoreceptor drum 11, and the lubricant sufficiently exhibits its lubricity.
In the first embodiment, the thinning blade 15f is in contact with the photosensitive drum 11 in the trading direction with respect to the running direction (rotation direction) of the photosensitive drum 11.

  As described above, in the first embodiment, since the two blade members of the cleaning blade 14a and the thinning blade 15f are separately provided, it is possible to maintain good cleaning properties and lubricant applicability. In addition, by supplying the lubricant to the photosensitive drum 11, wear and deterioration of both blade members 14a and 15f can be reduced.

Referring to FIG. 2, the image forming process described above will be described in more detail.
The developing roller 13a is rotating in the direction of the arrow in FIG. The developer G in the developing device 13 is moved from the toner replenishing unit 30 to the toner replenishing port by the rotation of the first transport screw 13b and the second transport screw 13c arranged in such a manner that a partition member is interposed therebetween. The toner T circulates in the longitudinal direction (the direction perpendicular to the paper surface of FIG. 2) while being stirred and mixed with the supplied toner T.

  Then, the toner T that has been 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 thereafter reaches the position of the doctor blade 13d. Then, 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 (a developing area).

  After that, in the developing area, the toner T in the developer G adheres to the electrostatic latent image formed on the surface of the photosensitive drum 11. More specifically, the toner T is latently generated by an electric field formed by a potential difference (developing potential) between a latent image potential (exposure potential) of the image area irradiated with the laser beam L and a developing bias applied to the developing roller 13a. Attaches to image.

  After that, most of the toner T attached to the photosensitive drum 11 in the developing process is transferred onto the intermediate transfer belt 17. Then, the untransferred toner T attached (remaining) on the surface of the photosensitive drum 11 is collected into the cleaning device 14 by the cleaning blade 14a. After that, the surface of the photosensitive drum 11 after the cleaning step sequentially passes through the lubricant supply device 15 and the charge removing unit (not shown), and a series of image forming processes is completed.

  Here, a 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 Further, a new toner T (a yellow toner in FIG. 2) is stored in the toner bottle 31. A spiral projection is formed on the inner peripheral surface of the toner bottle 31.

  The new toner T in the toner bottle 31 is appropriately supplied from the toner supply port into the developing device 13 as the toner T (the existing toner) in the developing device 13 is consumed. The consumption of the toner T in the developing device 13 is indirectly or directly detected by a magnetic sensor provided below the second conveying screw 13c of the developing device 13.

Hereinafter, the configuration and operation of the image forming apparatus 1 (the lubricant supply device 15 and the process cartridge 10Y), which is a characteristic of the first embodiment, will be described.
As described above with reference to FIG. 2, the lubricant supply device 15 (process cartridge 10Y) according to the first embodiment rotates in a predetermined direction (counterclockwise in FIG. 2) to rotate the photosensitive member. A lubricant supply roller 15a for supplying a lubricant to the surface of the drum 11 is provided. Also, in order to supply the lubricant from the lubricant supply device 15 onto the photosensitive drum 11 without excess or deficiency even when the environment changes or over time, the rotation speed of the lubricant supply roller 15a is changed as a variable means. (A variable-speed drive motor) is provided.

When the rotational speed of the lubricant supply roller 15a to be varied by the drive motor 45 (variable means) on the basis of the predetermined condition coincides with a predetermined value X, the rotational speed becomes the predetermined value X. A control unit 60 (see FIG. 2) that controls the drive motor 45 so as to increase or decrease the rotation speed of the lubricant supply roller 15a so as not to coincide with each other is provided. From another viewpoint, when the rotation speed of the lubricant supply roller 15a, which is to be regularly varied by the drive motor 45 (variable means) based on the predetermined condition, matches the predetermined value X, the drive motor By the control of 45, the rotation speed is irregularly varied.
Specifically, the drive motor 45 (variable means) adjusts the number of rotations of the lubricant supply roller 15a to be varied based on a predetermined condition to one predetermined value X (or two or more predetermined values X). In the case where the rotation speed coincides with the predetermined value X, the speed is increased (or decelerated) by a predetermined ratio A (or a predetermined value) so that the rotation speed does not match the predetermined value X. Is controlled to vary. That is, the drive motor 45 (variable means) adjusts the rotational speed R 'of the lubricant supply roller 15a to be varied based on the predetermined condition to one predetermined value X (or two or more predetermined values X). Of the rotation speed R ′ to be varied, the rotation speed is increased (or decelerated) by a predetermined ratio A (or a predetermined value). The number is controlled to be set as a variable number of revolutions.

  Here, the above-mentioned predetermined value X is equal to the mesh frequency of the gear train in which the driving force is transmitted from the drive motor 45 to the lubricant supply roller 15a when the rotation speed of the lubricant supply roller 15a is matched. The natural frequency (resonance frequency) of other members such as the photoconductor drum 11, the charging roller 12, and the writing unit 2 coincide with each other and resonate. Such a predetermined value X (the number of revolutions to be avoided) is generally not a single value but a plurality of values, and the lubricant supply to any one of the plurality of predetermined values X is performed. When the rotation speeds of the rollers 15a match, the lubricant supply roller 15a resonates with the member having the natural frequency (resonance phenomenon occurs), whereby the photosensitive drum 11 becomes large. Due to the vibration, an image (toner image) formed on the surface of the photosensitive drum 11 may have a problem such as image unevenness.

Therefore, by setting two or more of the above-mentioned “predetermined predetermined values X”, the number of rotations R ′ of the lubricant supply roller 15a to be varied based on the predetermined conditions becomes two or more of the predetermined values. When the rotation speed R 'does not match the predetermined value, the rotation speed of the lubricant supply roller 15a is increased or decreased so that the rotation speed R' does not match the predetermined value. The motor 45 can also be controlled by the control unit 60. For example, assuming that two predetermined values of 130 rpm and 140 rpm are set as the “predetermined predetermined value X”, the rotation speed R ′ of the lubricant supply roller 15 a to be varied based on the predetermined condition is set. However, the rotation speed of the lubricant supply roller 15a is adjusted so that the rotation speed R ′ does not match either 130 rpm or 140 rpm even when the rotation speed R ′ matches 130 rpm or 140 rpm. The speed is increased or reduced (for example, the speed is changed to 135 rpm).
Further, the above-mentioned "predetermined predetermined value X" is set as a continuous value within a predetermined range, and the rotational speed R 'of the lubricant supply roller 15a to be varied based on the predetermined condition is set in advance. When the rotation speed R 'does not fall within the predetermined range, the drive motor 45 is driven to increase or decrease the rotation speed of the lubricant supply roller 15a so that the rotation speed R' does not fall within the predetermined range. Can be controlled by the control unit 60. For example, assuming that the range of 120 rpm to 150 rpm is set as the “predetermined predetermined value X”, the rotation speed R ′ of the lubricant supply roller 15 a to be varied based on the predetermined condition is set to 120 rpm to 120 rpm. When the rotation speed falls within the range of 150 rpm, the rotation speed of the lubricant supply roller 15a is increased or reduced so that the rotation speed R 'does not fall within the range of 120 rpm to 150 rpm (for example, reduced to 110 rpm). Is done).

On the other hand, in the first embodiment, when the rotation speed of the lubricant supply roller 15a to be changed based on the predetermined condition matches the predetermined value X at which resonance occurs, the change is performed. Since the rotation speed is changed (corrected) so that the rotation speed does not match the predetermined value X, it is possible to prevent a problem in which the photosensitive drum 11 vibrates greatly to cause image unevenness or the like. That is, the meshing frequency of the gear train in which the driving force is transmitted from the drive motor 45 to the lubricant supply roller 15a and the natural frequency (resonance frequency) of the other members such as the photosensitive drum 11, the charging roller 12, and the writing unit 2 ) And resonance are prevented.
Here, when the rotational speed of the lubricant supply roller 15a that is to be changed based on the predetermined condition matches the predetermined value X, the variable speed is adjusted so that the variable speed does not match the predetermined value X. When the change is made, the amount of the lubricant supplied to the surface of the photosensitive drum 11 by the lubricant supply roller 15a becomes larger than the intended amount, but the lubricant is surely added to the surface of the photosensitive drum 11 Can be supplied.
On the other hand, when the rotational speed of the lubricant supply roller 15a, which is to be changed based on the predetermined condition, matches the predetermined value X, the variable speed is decelerated so as not to match the predetermined value X. When changing to the side, the amount of the lubricant supplied to the surface of the photosensitive drum 11 by the lubricant supply roller 15a is smaller than the target amount, but the consumption of the solid lubricant 15b can be suppressed. Will be possible.

  Here, in the first embodiment, the predetermined conditions for varying the number of revolutions of the lubricant supply roller 15a include a total travel time (or a total drive time) of the lubricant supply roller 15a (or the photosensitive drum 11) and Temperature and humidity (absolute humidity) around the lubricant supply device 15 are used. That is, the rotation speed of the lubricant supply roller 15a is appropriately changed by controlling the drive motor 45 by the control unit 60 based on the total travel time of the lubricant supply roller 15a and the surrounding temperature and humidity.

More specifically, the drive motor 45 (variable means) rotates the lubricant supply roller 15a (or the photosensitive drum 11) as the total travel distance (or total drive time) of the lubricant supply roller 15a increases. The number will be varied so as to increase continuously (or stepwise).
Specifically, the total travel distance of the lubricant supply roller 15a is indirectly obtained from the number of prints counted by the counter 49 installed in the apparatus main body 1, and as the total travel distance increases, the lubricant supply roller 15a The control unit 60 controls the drive motor 45 so that the rotation speed of the drive motor 45 gradually increases. Accordingly, even if the ability to supply the lubricant from the lubricant supply device 15 to the photosensitive drum 11 gradually decreases over time, the rotational speed of the lubricant supply roller 15a is increased so as to offset the decrease. Therefore, the lubricant can be supplied from the lubricant supply device 15 onto the photosensitive drum 11 without any excess or deficiency over time.
In the first embodiment, the rotation speed of the lubricant supply roller 15a is variably controlled based on the information of the counter 49. However, the rotation speed of the lubricant supply roller 15a is controlled based on information on the operation time of the drive motor 45. Can be variably controlled.

Referring to FIG. 2, a temperature / humidity sensor 50 is provided near the process cartridge 10Y as environment detecting means for detecting the surrounding absolute humidity (temperature / humidity). The absolute humidity detected by the temperature / humidity sensor 50 is obtained based on the temperature and the humidity detected by the temperature / humidity sensor 50 in the same manner as a known one.
The drive motor 45 (variable means) causes the rotational speed of the lubricant supply roller 15a to be continuous (or stepwise) as the absolute humidity detected by the temperature / humidity sensor 50 (environment detecting means) increases. To be increased.
Specifically, the control unit 60 controls the drive motor 45 so that the rotational speed of the lubricant supply roller 15a gradually increases as the absolute humidity detected by the temperature and humidity sensor 50 increases. Accordingly, even if the ability to supply the lubricant from the lubricant supply device 15 to the photosensitive drum 11 gradually decreases with an increase in the ambient absolute humidity, the lubricant supply roller 15a is controlled so as to offset the decrease. Since the speed is increased to increase the capacity, even if a change in temperature and humidity (environmental fluctuation) occurs, the lubricant can be supplied from the lubricant supply device 15 onto the photosensitive drum 11 without excess or deficiency. become.
In the first embodiment, the rotational speed of the lubricant supply roller 15a is continuously variably controlled in accordance with the temperature and humidity change. However, the rotational speed of the lubricant supply roller 15a is variably controlled in a stepwise manner in accordance with the temperature and humidity change. You can also. Specifically, the rotational speed of the lubricant supply roller 15a is variable so as to be increased in three stages of a low temperature (for example, 15 ° C. or less), a normal temperature (15 to 25 ° C.), and a high temperature (25 ° C. or more). It can also be controlled.

Hereinafter, control for varying the number of rotations of the lubricant supply roller 15a according to the first embodiment will be collectively described with reference to the flowchart of FIG.
First, a rotation speed R (basic rotation speed) serving as a reference of the lubricant supply roller 15a is determined based on a process linear speed when an image forming process is performed (step S1). As described above, the image forming apparatus 1 according to the first embodiment is configured to be able to select the “low speed mode” in addition to the “normal mode”. A basic rotational speed R of the lubricant supply roller 15a in two stages is prepared. That is, in step S1, in the normal mode, the basic rotation speed R of the lubricant supply roller 15a at the normal speed is determined, and in the low speed mode, the basic rotation speed R of the lubricant supply roller 15a at the low speed is determined.
When the process linear velocity is constant without being changed, the flow of step S1 is omitted.

Then, the coefficient α is determined based on the information of the temperature / humidity sensor 50 (information on the absolute humidity of the surroundings) (step S2). As described above, the coefficient α varies the number of rotations of the lubricant supply roller 15a even when the temperature and humidity (absolute humidity) change, and the amount of the coefficient α is not excessive or insufficient on the photosensitive drum 11 from the lubricant supply device 15. This is a correction coefficient that is multiplied by the basic rotation speed R of the lubricant supply roller 15a to supply the lubricant.
Further, the coefficient β is determined based on the information of the counter 49 (information on the total traveling distance) (step S3). As described above, the coefficient β is used to supply the lubricant from the lubricant supply device 15 onto the photosensitive drum 11 by changing the number of revolutions of the lubricant supply roller 15a even with the lapse of time. This is a correction coefficient multiplied by the basic rotation speed R of the agent supply roller 15a.
Then, the coefficients α and β determined in steps S2 and S3 are multiplied by the basic rotation speed R to determine the target rotation speed R ′ (= R × α × β) of the lubricant supply roller 15a. (Step S4).

Thereafter, it is determined whether the target rotational speed R ′ determined in step S4 matches a predetermined value X (avoided rotational speed) to be avoided (step S5).
As a result, if it is determined that the target rotation speed R 'does not match the predetermined value X (the avoidance rotation speed), it is determined that the resonance phenomenon described above does not occur, and the target rotation speed determined in step S4. The number R 'is determined as the final rotation speed (step S6). Then, the image forming process is executed while controlling the drive motor 45 to rotate the lubricant supply roller 15a at the rotation speed R '.

On the other hand, if it is determined in step S5 that the target rotation speed R 'matches the predetermined value X (the avoidance rotation speed), it is determined that the resonance phenomenon described above occurs as it is. The target rotation speed R ′ determined in step S4 is multiplied by a correction coefficient A (a value larger than 0 and a value other than 1), and the final rotation speed R ′ × A that does not match the predetermined value X is obtained. It is determined as a number (step S7). Then, the image forming process is executed while controlling the drive motor 45 so as to rotate the lubricant supply roller 15a at the rotation speed R ′ × A. As a result, it is possible to reliably reduce the occurrence of problems such as image unevenness due to the resonance phenomenon.
In the first embodiment, in step S7, the target rotational speed R 'is multiplied by a predetermined ratio (coefficient A) to obtain a rotational speed R' × A which does not finally match the predetermined value X. Although set, a predetermined value Z may be added to or subtracted from the target rotation speed R 'to set a rotation speed R' ± Z that does not finally match the predetermined value X.

  In the first embodiment, the number of rotations of the lubricant supply roller 15a to be changed based on the predetermined condition is set to one predetermined value X (or any one of two or more predetermined values). When the absolute humidity detected by the temperature / humidity sensor 50 (environment detecting means) is equal to or higher than a predetermined absolute humidity M, the rotation speed does not match the predetermined value X. When the absolute humidity detected by the temperature / humidity sensor 50 is equal to or less than a predetermined absolute humidity M so that the speed is increased by a predetermined value B (or a predetermined ratio), the rotation speed does not match the predetermined value X. In this manner, the drive motor 45 (variable means) can be controlled by the control unit 60 so as to be decelerated by the predetermined value C (or a predetermined ratio).

Specifically, as shown in FIG. 4, the flow of steps S1 to S6 is performed in the same manner as in FIG. When it is determined in step S5 that the target rotation speed R 'matches the predetermined value X (the avoidance rotation speed), it is determined whether the surrounding absolute humidity is higher than the predetermined absolute humidity M. (Step S10).
As a result, when it is determined that the ambient absolute humidity is higher than the predetermined absolute humidity M, the environment is relatively high in temperature, the supply amount of the lubricant is likely to decrease, Assuming that the resonance phenomenon described above occurs, a predetermined value B is added to the target rotation speed R 'determined in step S4, and the rotation speed (R' + B) does not match the predetermined value X. (Step S11). Then, the image forming process is executed while controlling the drive motor 45 to rotate the lubricant supply roller 15a at the rotation speed (R ′ + B). Thus, it is possible to reliably reduce the occurrence of problems such as image unevenness due to the resonance phenomenon, and to prevent the problem that the amount of the lubricant supplied to the photosensitive drum 11 becomes insufficient.
On the other hand, when it is determined that the ambient absolute humidity is smaller than the predetermined absolute humidity M, the environment is relatively low in temperature and the supply amount of the lubricant is likely to increase, and Assuming that the above-described resonance phenomenon occurs, a predetermined value C is subtracted from the target rotation speed R ′ determined in step S4, and the rotation speed (R′−C) does not match the predetermined value X. The rotation speed is determined (step S11). Then, the image forming process is executed while controlling the drive motor 45 so as to rotate the lubricant supply roller 15a at the rotation speed (R'-C). Accordingly, it is possible to reliably reduce the occurrence of problems such as image unevenness due to the resonance phenomenon, and to prevent the problem that the amount of the lubricant supplied to the photosensitive drum 11 becomes excessive.

Further, in the first embodiment, as shown in FIG. 2, a torque detecting unit 46 as a torque detecting unit for detecting a driving torque when the lubricant supply roller 15a rotates can be provided. Such a torque detecting section 46 (torque detecting means) detects a driving torque applied to the driving motor 45 from a change in a current flowing through the driving motor 45, and a known one can be used.
Then, when the driving torque detected by the torque detecting section 46 (torque detecting means) is large by the control section 60, the driving force of the lubricant supply roller 15 a is smaller than when the driving torque detected by the torque detecting section 46 is small. The drive motor 45 (variable means) can be controlled so that the degree of increase or decrease in the number of rotations is increased. Specifically, when the driving torque detected by the torque detecting unit 46 (torque detecting means) is large, the predetermined ratio A (or the predetermined ratio) is smaller than when the driving torque detected by the torque detecting unit 46 is small. The drive motor 45 (variable means) can also be controlled so that the value (variable value) increases.
Such control is performed when the rotational speed of the lubricant supply roller 15a, which is to be varied based on the predetermined condition, matches the predetermined value X (avoided rotational speed). When the driving torque of the supply roller 15a is large, the width of the meshing frequency of the gear train in which the driving force is transmitted from the driving motor 45 to the lubricant supply roller 15a is also large. This is because the resonance phenomenon described above may occur unless it largely varies from (the avoidance rotation speed).

More specifically, as shown in FIG. 5, the flow of steps S1 to S6 is performed in the same manner as in FIG. Then, in step S5, when it is determined that the target rotation speed R 'matches the predetermined value X (the avoidance rotation speed), the coefficient γ is determined based on the drive torque detected by the torque detection unit 46. (Step S20). The coefficient γ is set at the predetermined ratio A (, as described above, in order to prevent the problem that the driving torque of the lubricant supply roller 15a increases and the resonance phenomenon easily occurs even under the same conditions as described above. Or a predetermined value). The coefficient γ increases as the driving torque detected by the torque detector 46 increases.
Then, the target rotation speed R ′ determined in step S4 is multiplied by the correction coefficient A, and further multiplied by the coefficient γ determined in step S20, and the rotation speed (R ′ × A × γ) is set to a predetermined value X. A final rotational speed that does not match is determined (step S21). Then, the image forming process is executed while controlling the drive motor 45 so as to rotate the lubricant supply roller 15a at the rotation speed (R ′ × A × γ). This makes it possible to reliably reduce the occurrence of problems such as image unevenness due to resonance irrespective of fluctuations in the drive torque of the lubricant supply roller 15a.

As described above, in the image forming apparatus 1 according to the first embodiment, the number of rotations of the lubricant supply roller 15a to be varied by the drive motor 45 (variable means) based on the predetermined condition is set to a predetermined value. A control unit 60 is provided for controlling the drive motor 45 so as to increase or decrease the rotation speed of the lubricant supply roller 15a so that the rotation speed does not match the predetermined value X when the rotation speed does not match the predetermined value X. ing.
As a result, even when control is performed to vary the number of revolutions of the lubricant supply roller 15a, the photosensitive drum 11 (image carrier) vibrates greatly, and problems such as image unevenness hardly occur.

Embodiment 2 FIG.
Referring to FIG. 6, a second embodiment of the present invention will be described in detail.
FIG. 6A is a diagram illustrating a relationship between the absolute humidity detected by the temperature and humidity sensor 50 and the rotation speed of the lubricant supply roller 15a in the control of the lubricant supply device 15 according to the second embodiment. . FIG. 6B is a diagram illustrating a relationship between the total traveling time and the number of revolutions of the lubricant supply roller 15a in the control of the lubricant supply device 15 according to the second embodiment.
The image forming apparatus 1 according to the second embodiment is characterized in that the range of the number of rotations of the lubricant supply roller 15a in which resonance is likely to occur is predetermined in terms of the number of rotations of the lubricant supply roller 15a in which resonance is likely to occur. The value (predetermined value X) is different from that of the first embodiment in which the value (predetermined value X) is predetermined.

As in the first embodiment, the lubricant supply device 15 in the second embodiment is also provided with a foamed elastic layer slidably in contact with the photosensitive drum 11 as shown in FIG. A lubricant supply roller 15a for supplying lubricant thereon, a solid lubricant 15b slidably contacting the lubricant supply roller 15a, a compression spring 15c for urging the solid lubricant 15b toward the lubricant supply roller 15a, a solid lubricant 15b , And a thinning blade 15f that comes into contact with the photosensitive drum 11 to reduce the thickness of the lubricant supplied onto the photosensitive drum 11.
Also, in the second embodiment, similarly to the first embodiment, the drive motor 45 as a drive source for driving the lubricant supply roller 15a (the lubricant supply device 15) is provided with an environment (absolute humidity). It functions as a variable unit that varies the number of revolutions of the lubricant supply roller 15a based on predetermined conditions such as the total travel distance and the like.

Here, in the image forming apparatus 1 according to the second embodiment, the control unit 60 changes the rotation number of the lubricant supply roller 15a that is regularly varied by the drive motor 45 (variable means) based on a predetermined condition to a predetermined number. The drive motor 45 is controlled so as to be varied irregularly within a range (a range of the number of rotations at which resonance can occur and a range of the number of rotations to be avoided).
That is, the drive motor 45 (variable means) adjusts the rotational speed R 'of the lubricant supply roller 15a to be varied based on the predetermined condition to one predetermined value X (or two or more predetermined values X). Is not within the range of the predetermined range, the rotation speed R ′ to be varied is within the range of the above-mentioned predetermined range. It is controlled so as to be changed to the outside rotation speed.

Specifically, referring to FIG. 6A, in image forming apparatus 1 according to the second embodiment, in principle, as the absolute humidity (temperature and humidity) detected by temperature and humidity sensor 50 increases, lubrication increases. The drive motor 45 is controlled so that the number of revolutions of the agent supply roller 15a continuously increases. That is, as shown in FIG. 6A, when a graph is drawn in which the horizontal axis is the absolute humidity and the vertical axis is the rotation speed of the lubricant supply roller 15a, a linear graph shown by a broken line has a basic form. It will be. However, if the rotation speed control is performed so as to be a linear (regular) graph over the entire range of the absolute humidity as shown by a broken line in FIG. Sometimes, the rotational speed of the lubricant supply roller 15a falls within the range of rotational speed to be avoided (the range of rotational speed at which resonance can occur).
Therefore, in the second embodiment, when the predetermined absolute humidity is reached, the rotation speed of the lubricant supply roller 15a is out of the range of the rotation speed to be avoided (the range of the rotation speed at which resonance may occur). Thus, the whole range as shown by the broken line is not a linear (regular) graph, but the partial range as shown by the solid line is an irregular graph This is a graph that does not change proportionately.).

Further, referring to FIG. 6B, in image forming apparatus 1 according to the second embodiment, in principle, as the total traveling distance of lubricant supply roller 15a determined by counter 49 increases, lubricant supply increases. The drive motor 45 is controlled so that the number of rotations of the roller 15a increases stepwise. That is, as shown in FIG. 6B, when a graph is drawn in which the horizontal axis is the total traveling distance of the lubricant supply roller 15a and the vertical axis is the rotation speed of the lubricant supply roller 15a, a regular line as shown by a broken line is obtained. A basic step-like graph (a graph in which the number of revolutions increases by a certain value each time the total traveling distance increases by a certain value) becomes a basic form. However, if the rotational speed control is performed so as to form a regular step-like graph over the entire range of the total traveling distance as shown by a broken line in FIG. In this case, the rotation speed of the lubricant supply roller 15a falls within the range of the rotation speed to be avoided (the range of the rotation speed at which resonance can occur).
Therefore, in the second embodiment, when the predetermined total traveling distance is reached, the rotation speed of the lubricant supply roller 15a is out of the range of the rotation speed to be avoided (the range of the rotation speed at which resonance may occur). Thus, the whole range shown by the broken line is not a regular step-like graph, but a part of the range shown by the solid line is an irregular step-like graph (total mileage and rotation speed). This is a graph in which the degree of change is different and the shape of the steps is different.)

As described above, the image forming apparatus 1 according to the second embodiment sets the rotational speed of the lubricant supply roller 15a that is to be regularly varied by the drive motor 45 (variable means) based on the predetermined condition to the predetermined value. A control unit 60 that controls the drive motor 45 so as to vary irregularly in a range is provided.
As a result, even when control is performed to vary the number of revolutions of the lubricant supply roller 15a, the photosensitive drum 11 (image carrier) vibrates greatly, and problems such as image unevenness hardly occur.

Embodiment 3 FIG.
Embodiment 3 Embodiment 3 of the present invention will be described in detail with reference to FIGS.
FIG. 7 is a schematic diagram illustrating a gear train installed in the lubricant supply device 15 according to the third embodiment, and is a diagram illustrating a state in which a combination of gear trains is switched by a switching unit. FIG. 8 is a schematic diagram showing a modified example of the gear train of FIG. 7, and FIG. 9 is a schematic diagram showing still another modified example of the gear train.
In the image forming apparatus 1 according to the third embodiment, when resonance is about to occur, the switching means switches the combination of gear trains for transmitting the drive from the drive source 45 to the lubricant supply roller 15a, thereby changing the uniqueness of the drive. The point that the frequency is varied is different from that of the first embodiment in which the number of revolutions of the lubricant supply roller 15a is varied when resonance is about to occur.

As in the first embodiment, the lubricant supply device 15 according to the third embodiment is also provided with a foamed elastic layer slidably in contact with the photosensitive drum 11 as shown in FIG. A lubricant supply roller 15a for supplying lubricant thereon, a solid lubricant 15b slidingly contacting the lubricant supply roller 15a, a compression spring 15c for urging the solid lubricant 15b toward the lubricant supply roller 15a, a solid lubricant 15b , And a thinning blade 15f that comes into contact with the photosensitive drum 11 to reduce the thickness of the lubricant supplied onto the photosensitive drum 11.
Also, in the third embodiment, as in the first embodiment, the drive motor 45 as a drive source for driving the lubricant supply roller 15a (the lubricant supply device 15) is provided with a process linear speed, an environmental (Absolute humidity), and functions as variable means for varying the number of revolutions of the lubricant supply roller 15a based on the total traveling distance and the like.

Here, the lubricant supply device 15 in the third embodiment switches the combination of gear trains for transmitting the drive from the drive motor 45 as a drive source to the lubricant supply roller 15a to change the natural frequency related to the drive. Variable switching means is provided.
More specifically, as shown in FIG. 7, the switching means includes a drive gear 80 provided on the motor shaft of the drive motor 45 as a drive source, and a driven gear 84 provided on the rotation shaft of the lubricant supply roller 15a. And a swing gear 82 that swings so as to switch the combination of the relay gears 81 to 83 that are relayed between the first gear and the second gear.

More specifically, a lower gear 81a of a first relay gear 81 having a two-stage gear structure meshes with the drive gear 80, and a swing gear 82 (second relay gear) engages with an upper gear 81b of the first relay gear 81. Are engaged.
The swing gear 82 is rotatably supported by the swing arm 100 and swings the swing gear 82 about the rotation axis of the first relay gear 81 irrespective of the rotation of the first relay gear 81 or the swing gear 82. It is configured to be able to. When the swing gear 82 swings together with the swing arm 100 to the position shown in FIG. 7A and the state is maintained, the swing gear 82 meshes with the third relay gear 83 meshing with the driven gear 84. Become. On the other hand, when the swing gear 82 swings to the position shown in FIG. 7B together with the swing arm 100 and the state is maintained, the swing gear 82 is attached to the driven gear 84 without passing through the third relay gear 83. Will be engaged.

  That is, as shown in FIG. 7A, the oscillating arm 100 functioning as a switching unit is configured by combining a gear train that transmits drive from the drive motor 45 to the lubricant supply roller 15a with the first relay gear 81 and the oscillating gear 82. (Second relay gear), a third relay gear 83, or a combination of gear trains for transmitting drive from the drive motor 45 to the lubricant supply roller 15a as shown in FIG. The swing gear 82 (second relay gear) can be used or can be switched. In the third embodiment, the combination of the gear trains shown in FIG. 7A is a reference combination (a normal state, which is appropriately referred to as a “reference state”). Further, the swing arm 100 has its rotation center axis connected to the motor, and is swinged by the motor independently of the rotation of the first relay gear 81 and the swing gear 82.

  When the combination of the gear trains is switched in this manner, the mesh frequency of the gear trains also changes, and the natural frequency associated with driving the lubricant supply roller 15a (the lubricant supply device 15) also changes. . That is, FIG. 7B shows the natural frequency (meshing frequency of the gear train) when the lubricant supply roller 15a (the lubricant supply device 15) is driven by the combination of the gear trains shown in FIG. The natural frequency (meshing frequency of the gear train) when driving the lubricant supply roller 15a (the lubricant supply device 15) differs depending on the combination of the gear trains shown.

  Further, in the third embodiment, when the combination of gear trains is switched from the reference combination shown in FIG. 7A to the state shown in FIG. The lubricant supply roller 15a is configured to be rotatable in forward and reverse directions so that the rotation direction of the lubricant supply roller 15a does not change.

Specifically, the drive motor 45 is a forward / reverse rotation type drive motor. When the combination of the gear trains is in the state shown in FIG. 7A, the drive motor 45 is driven in the forward direction and is in the forward direction (the direction of the arrow in FIG. 7A and the counterclockwise direction). ) Is transmitted from the rotating driving gear 80 to the driven gear 84 via the first relay gear 81, the swing gear 82, and the third relay gear 83, and the lubricant supply roller 15a is moved together with the driven gear 84 in FIG. It rotates in the counterclockwise direction (a direction that matches the rotation direction shown in FIG. 2). On the other hand, when the combination of the gear trains is in the state shown in FIG. 7B, the drive motor 45 is driven in the reverse direction (in the direction of the arrow in FIG. The drive is transmitted from the rotating driving gear 80 to the driven gear 84 via the first relay gear 81 and the swing gear 82, and the lubricant supply roller 15a is moved together with the driven gear 84 in the counterclockwise direction in FIG. This is a direction that matches the rotation direction shown in FIG. 2). In the state of FIG. 7B, the third relay gear 83 idles clockwise due to meshing with the driven gear 84.
Although not shown, the lubricant supply device 15 is provided with a position sensor that optically detects the position at which the swing arm 100 swings, and the control unit 60 performs control based on the detection result of the position sensor. The motor that swings the swing arm 100 (switching means) is swing-controlled.

Here, in the image forming apparatus 1 according to the third embodiment configured as described above, the combination of the gear trains is set to a reference combination as shown in FIG. When the rotational speed of the lubricant supply roller 15a to be varied by the drive motor 45 (variable means) on the basis of the predetermined condition in the same manner as that of The switching unit is controlled by the control unit 60 so as to switch from the reference combination shown in FIG. 7A to the combination shown in FIG. 7B.
Then, the combination of the gear trains is switched to the combination shown in FIG. 7 (B), and after a series of lubricant supply operations (image forming process) by the lubricant supply device 15 are completed, the combination of the gear trains is changed by the switching means. 7B is returned to the reference combination shown in FIG. 7A again.

  Here, similarly to the first embodiment, when the predetermined value X coincides with the rotation speed of the lubricant supply roller 15a, the driving force is applied from the drive motor 45 to the lubricant supply roller 15a. The transmission frequency of the gear train (the gear train of the combination shown in FIG. 7A) and the natural frequency of other members such as the photosensitive drum 11, the charging roller 12, and the writing unit 2 ( (Resonance frequency) and resonance.

  On the other hand, in the third embodiment, when the rotation speed of the lubricant supply roller 15a to be varied based on the predetermined condition matches the predetermined value X at which resonance occurs, the drive motor 45 7B is switched to the combination shown in FIG. 7B so that the mesh frequency of the gear train is changed to the photosensitive drum 11, the charging roller 12, the writing unit 2 and the like. Since it does not match the natural frequency (resonance frequency) of other members and does not resonate, it is possible to prevent a problem that the photosensitive drum 11 vibrates greatly and image unevenness or the like occurs. .

  In the third embodiment, as in the first embodiment, two or more of the above-mentioned "predetermined predetermined values X" are set, and the lubrication to be varied based on the predetermined condition is performed. When the rotation speed R 'of the agent supply roller 15a matches any one of two or more predetermined values, the combination of the gear trains is determined based on the reference shown in FIG. The switching unit may be controlled by the control unit 60 so as to switch from the combination shown in FIG. 7B to the combination shown in FIG. Further, the above-described “predetermined predetermined value X” is set as a continuous value within a predetermined range, and the rotational speed R ′ of the lubricant supply roller 15a to be varied based on the predetermined condition is set in advance. When the vehicle falls within the predetermined range, the switching unit controls the switching unit so that the combination of the gear trains is switched from the reference combination shown in FIG. 7A to the combination shown in FIG. 7B. Can also be controlled by

Here, in the third embodiment, a torque detecting unit 46 (see FIG. 2) as a torque detecting unit that detects a driving torque when the lubricant supply roller 15a rotates is provided. Then, the control unit 60 controls the above-described predetermined value X to be variable according to the driving torque detected by the torque detecting unit 46 (torque detecting means).
More specifically, a control table in which the relationship between the value of the drive torque of the lubricant supply roller 15a and the variable predetermined value X is determined is stored in the control unit 60 in advance. Then, the driving torque detected by the torque detecting section 46 (torque detecting means) is compared with the control table, and the predetermined value X serving as a criterion for switching by the switching means is changed to an optimum value. .
Such control is performed when the rotational speed of the lubricant supply roller 15a, which is to be varied based on the predetermined condition, matches the predetermined value X (avoided rotational speed). When the driving torque of the supply roller 15a is large, the width of the meshing frequency of the gear train in which the driving force is transmitted from the driving motor 45 to the lubricant supply roller 15a is also large, and the number of rotations to be avoided (predetermined) This is because if the value X) is not changed to an appropriate value, the above-described resonance phenomenon may occur.

In the third embodiment, when the combination of the gear trains is switched by the switching unit, the rotation direction of the drive motor 45 (drive gear 80) is also switched at the same time.
On the other hand, as shown in FIG. 8, the rotation direction of the drive motor 45 (drive gear 80) is fixed in a predetermined direction (clockwise in the example of FIG. 8), and the gear train is switched by the switching means. When the combination is switched, the rotation direction of the drive motor 45 (drive gear 80) may not be switched.
Specifically, in the state of FIG. 8A, which is the reference state, the drive is transmitted from the driving gear 80 rotating clockwise to the driven gear 84 via the first relay gear 81 and the swing gear 82, and the lubricant The supply roller 15a rotates counterclockwise together with the driven gear 84. On the other hand, when the state of FIG. 8A, which is the reference state, is switched from the state of FIG. 8A to the state of FIG. 8B by the swing of the swing arm 100, the drive gear 80 that rotates clockwise from the first relay gear 81. The drive is transmitted to the driven gear 84 via the oscillating gear 82, the third relay gear 85, and the fourth relay gear 86, so that the lubricant supply roller 15a rotates counterclockwise with the driven gear 84.
Even with such a configuration, the same effect as that of the third embodiment described above can be obtained.

In the third embodiment, when the combination of the gear trains is switched from the reference combination by the switching means, only one combination of the gear trains is switched.
On the other hand, referring to FIG. 9, when the combination of the gear trains is switched from the reference combination by the switching means, the combination of the gear trains to be switched can be selected from a plurality of sets. Can also.
Specifically, referring to FIG. 9, the combination of gear trains is changed from the reference combination as shown in FIG. 9A by the switching means to the combination shown in FIG. 9B and the combination shown in FIG. It can also be configured to be able to switch to any of the combinations.

Specifically, in the state of FIG. 9A which is the reference state, the driving is transmitted from the driving gear 80 rotating counterclockwise to the driven gear 84 via the first relay gear 81 and the swing gear 82, The lubricant supply roller 15a rotates counterclockwise with the driven gear 84. On the other hand, at the time of the first switching, the swinging of the swing arm 100 switches from the reference state shown in FIG. 9A to the state shown in FIG. The drive is transmitted to the driven gear 84 via the first relay gear 81, the swing gear 82, and the third relay gear 87, and the lubricant supply roller 15a rotates counterclockwise with the driven gear 84. Further, at the time of the second switching, the swinging of the swing arm 100 switches the state from the reference state shown in FIG. 9A to the state shown in FIG. 9C, and the first relay from the driving gear 80 rotating clockwise. The drive is transmitted to the driven gear 84 via the gear 81, the swing gear 82, and the fourth relay gear 88, so that the lubricant supply roller 15a rotates counterclockwise with the driven gear 84.
It should be noted that the third relay gear 87 and the fourth relay gear 88 are configured such that the meshing frequency of the gear train differs between the combination of the gear train shown in FIG. 9B and the combination of the gear train shown in FIG. 9C. In addition, the number of gears (number of teeth) is configured to be different.

  In this manner, when the combination of the gear trains is switched from the reference combination by the switching means, the combination of the gear trains to be switched can be selected from a plurality of sets, so that the meshing frequency of the gear trains can be selected. Can be changed more in accordance with the number of sets (because there are more choices of the meshing frequency to be changed), so that the effect of the third embodiment is more reliably exhibited.

As described above, the image forming apparatus 1 according to the third embodiment switches the combination of the gear train that transmits the drive from the drive motor 45 (drive source) to the lubricant supply roller 15a to switch the natural frequency related to the drive. Is provided. The combination of the gear trains is set to a reference combination, and the number of rotations of the lubricant supply roller 15a to be varied by the drive motor 45 (variable means) based on a predetermined condition is set to a predetermined value. A control unit 60 is provided for controlling the switching means so as to switch the combination of the gear train from the reference combination when the value of X is matched.
As a result, even when control is performed to vary the number of revolutions of the lubricant supply roller 15a, the photosensitive drum 11 (image carrier) vibrates greatly, and problems such as image unevenness hardly occur.

Embodiment 4 FIG.
Embodiment 4 Embodiment 4 of the present invention will be described in detail with reference to FIGS.
FIG. 10 is a schematic diagram illustrating a gear train installed in a lubricant supply device 15 according to Embodiment 4, and is a diagram illustrating a state in which a combination of gear trains is switched by a switching unit. FIG. 11 is a schematic diagram showing a modified example of the gear train of FIG. 10, and FIG. 12 is a schematic diagram showing another modified example of the gear train.
The image forming apparatus 1 according to the fourth embodiment switches the combination of gear trains for transmitting the drive from the driving source 45 to the lubricant supply roller 15a by the switching unit, and in addition to the meshing frequency of the gear train, supplies the lubricant. The point that the rotation speed of the roller 15a is also variable is different from that of the third embodiment in which only the meshing frequency of the gear train is changed.

As in the first embodiment, the lubricant supply device 15 according to the fourth embodiment is also provided with a foamed elastic layer slidably contacting the photosensitive drum 11 as shown in FIG. A lubricant supply roller 15a for supplying lubricant thereon, a solid lubricant 15b slidably contacting the lubricant supply roller 15a, a compression spring 15c for urging the solid lubricant 15b toward the lubricant supply roller 15a, a solid lubricant 15b , And a thinning blade 15f that comes into contact with the photosensitive drum 11 to reduce the thickness of the lubricant supplied onto the photosensitive drum 11.
Also, in the fourth embodiment, similarly to the first embodiment, the drive motor 45 as a drive source for driving the lubricant supply roller 15a (the lubricant supply device 15) is provided with a process linear speed, an environmental (Absolute humidity), and functions as variable means for varying the number of revolutions of the lubricant supply roller 15a based on the total traveling distance and the like.
Also, in the lubricant supply device 15 in the fourth embodiment, similarly to the third embodiment, a combination of a gear train for transmitting the drive from the drive motor 45 as a drive source to the lubricant supply roller 15a is used. Switching means is provided for switching to change the natural frequency of the drive.

Here, the switching means in the fourth embodiment differs from that in the third embodiment in that when the combination of gear trains is switched from the reference combination, the rotation speed of the lubricant supply roller 15a increases. It is configured to be speeded or decelerated.
More specifically, the driven gear 84 provided on the lubricant supply roller 15a is configured as a two-stage gear including two gears having different numbers of gears (a first driven gear 84a and a second driven gear 84b). I have.
A lower gear 81a of a first relay gear 81 having a two-stage gear structure meshes with the drive gear 80, and a swing gear 82 (second relay gear) meshes with an upper gear 81b of the first relay gear 81. I have. The swing gear 82 is rotatably supported by the swing arm 100 and swings the swing gear 82 about the rotation axis of the first relay gear 81 irrespective of the rotation of the first relay gear 81 or the swing gear 82. It is configured to be able to.
When the swing gear 82 swings with the swing arm 100 to the position shown in FIG. 10A and the state is maintained, the third relay meshing with the first driven gear 84a of the driven gear 84 having the two-stage gear structure. The swing gear 82 meshes with the gear 83. On the other hand, when the swing gear 82 swings together with the swing arm 100 to the position shown in FIG. 10B and the state is maintained, the driven gear 84 having the two-stage gear structure without the third relay gear 83 is interposed. The swing gear 82 meshes with the second driven gear 84b.

  That is, as shown in FIG. 10A, the oscillating arm 100 functioning as a switching unit is configured by combining a gear train that transmits drive from the drive motor 45 to the lubricant supply roller 15a with the first relay gear 81 and the oscillating gear 82. (The second relay gear), the third relay gear 83, and the first driven gear 84a, or, as shown in FIG. 10B, a combination of gear trains for transmitting the drive from the drive motor 45 to the lubricant supply roller 15a. The first relay gear 81, the swing gear 82 (second relay gear), and the second driven gear 84b can be used or can be switched. In the fourth embodiment, the combination of the gear trains shown in FIG. 10A is a reference combination (a normal state, which is appropriately referred to as a “reference state”).

  When the combination of the gear trains is switched in this manner, the mesh frequency of the gear trains also changes, and the natural frequency associated with driving the lubricant supply roller 15a (the lubricant supply device 15) also changes. . That is, FIG. 10B shows the natural frequency (meshing frequency of the gear train) when driving the lubricant supply roller 15a (the lubricant supply device 15) by the combination of the gear trains shown in FIG. The natural frequency (meshing frequency of the gear train) when driving the lubricant supply roller 15a (the lubricant supply device 15) differs depending on the combination of the gear trains shown.

  Further, in the fourth embodiment, the number of rotations of the lubricant supply roller 15a when the lubricant supply roller 15a (the lubricant supply device 15) is driven by the combination of the gear trains shown in FIG. The driven gear 84 (the first driven gear 84a) is set so that the number of rotations of the lubricant supply roller 15a when the lubricant supply roller 15a (the lubricant supply device 15) is driven by the combination of the gear trains shown in FIG. And a second driven gear 84b). That is, when the combination of the gear train shown in FIG. 10A in the reference state is switched to the combination of the gear train shown in FIG. 10B, the rotation speed of the lubricant supply roller 15a is increased. become.

  In the fourth embodiment, similarly to the third embodiment, the drive motor 45 changes the combination of the gear train from the reference shown in FIG. When switched to the state B), the lubricant supply roller 15a is configured to be rotatable in the forward and reverse directions so that the rotation direction of the lubricant supply roller 15a does not change.

Here, in the lubricant supply device 15 according to Embodiment 4 configured as described above, the combination of gear trains is set to a reference combination as shown in FIG. As in the first embodiment, the number of rotations of the lubricant supply roller 15a to be varied by the drive motor 45 (variable means) on the basis of the predetermined condition is changed to one predetermined value X (or two or more predetermined values X). If any of the values matches one of the values, the switching means switches the combination of the gear trains from the reference combination shown in FIG. 10A to the combination shown in FIG. 10B.
Then, the combination of the gear trains is switched to the combination shown in FIG. 10B, and after a series of lubricant supply operation (image forming process) by the lubricant supply device 15 is completed, the combination of the gear trains is changed by the switching means. The combination shown in FIG. 10B is returned to the reference combination shown in FIG.

  Here, similarly to the first embodiment, when the predetermined value X coincides with the rotation speed of the lubricant supply roller 15a, the driving force is applied from the drive motor 45 to the lubricant supply roller 15a. The transmission frequency of the gear train (the gear train of the combination shown in FIG. 10A) and the natural frequency of other members such as the photosensitive drum 11, the charging roller 12, and the writing unit 2 ( (Resonance frequency) and resonance.

  On the other hand, in the fourth embodiment, when the rotation speed of the lubricant supply roller 15a to be varied based on the predetermined condition matches the predetermined value X at which resonance occurs, the drive motor 45 10B is switched to the combination shown in FIG. 10B so that the mesh frequency of the gear train is changed to the photosensitive drum 11, the charging roller 12, the writing unit 2, and the like. Since it does not match the natural frequency (resonance frequency) of other members and does not resonate, it is possible to prevent a problem that the photosensitive drum 11 vibrates greatly and image unevenness or the like occurs. .

  Further, in the fourth embodiment, when the rotation speed of the lubricant supply roller 15a that is to be changed based on the predetermined condition matches the predetermined value X at which resonance occurs, the lubricant is supplied from the drive motor 45. The gear train in which the driving force is transmitted to the supply roller 15a is switched to the combination shown in FIG. 10B, and the rotation speed of the lubricant supply roller 15a is changed (increased) so as not to match the predetermined value X. For this reason, it is possible to prevent a problem that the photosensitive drum 11 vibrates greatly and causes image unevenness or the like.

Here, when the rotational speed of the lubricant supply roller 15a to be varied based on the predetermined condition matches the predetermined value X, the switching of the gear train combination by the switching unit is performed as in the fourth embodiment. At the same time, when the rotational speed of the lubricant supply roller 15a is changed to the speed increasing side so as not to be equal to the predetermined value X, the amount of the lubricant supplied to the surface of the photosensitive drum 11 by the lubricant supply roller 15a is larger than the target amount. However, the lubricant can be surely supplied to the surface of the photosensitive drum 11.
On the other hand, when the rotational speed of the lubricant supply roller 15a, which is to be varied based on the predetermined condition, matches the predetermined value X, the combination of the gear trains is switched by the switching means and the lubricant supply roller 15a is switched. When the rotation speed is changed to the deceleration side so that it does not match the predetermined value X (for example, in the relationship between FIG. 10A and FIG. 10B, FIG. 10B instead of the state of FIG. 10A) In this case, the amount of the lubricant supplied to the surface of the photosensitive drum 11 by the lubricant supply roller 15a is smaller than the target amount. It is possible to suppress consumption of the lubricant 15b.

Here, in the fourth embodiment, a torque detecting unit 46 (see FIG. 2) as a torque detecting unit that detects a driving torque when the lubricant supply roller 15a rotates is provided. Then, the above-described one predetermined value X (or two or more predetermined values) is controlled to be variable according to the driving torque detected by the torque detecting unit 46 (torque detecting means).
More specifically, a control table in which the relationship between the value of the drive torque of the lubricant supply roller 15a and the variable predetermined value X is determined is stored in the control unit 60 in advance. Then, the driving torque detected by the torque detecting section 46 (torque detecting means) is compared with the control table, and the predetermined value X serving as a criterion for switching by the switching means is changed to an optimum value. .
Such control is performed when the rotational speed of the lubricant supply roller 15a, which is to be varied based on the predetermined condition, matches the predetermined value X (avoided rotational speed). When the driving torque of the supply roller 15a is large, the width of the meshing frequency of the gear train in which the driving force is transmitted from the driving motor 45 to the lubricant supply roller 15a is also large, and the number of rotations to be avoided (predetermined) This is because if the value X) is not changed to an appropriate value, the above-described resonance phenomenon may occur.

In the fourth embodiment, when the combination of the gear trains is switched by the switching unit, the rotation direction of the drive motor 45 (drive gear 80) is also switched at the same time.
On the other hand, as shown in FIG. 11, the rotation direction of the drive motor 45 (drive gear 80) is fixed in a predetermined direction (clockwise in the example of FIG. 11), and the gear train is switched by the switching means. When the combination is switched, the rotation direction of the drive motor 45 (drive gear 80) may not be switched.
Specifically, in the state of FIG. 11A which is the reference state, the driving is transmitted from the driving gear 80 rotating clockwise to the second driven gear 84b via the first relay gear 81 and the swing gear 82, The lubricant supply roller 15a rotates counterclockwise with the driven gear 84. On the other hand, when the state of FIG. 11A, which is the reference state, is switched from the state of FIG. 11A to the state of FIG. 11B by the swing of the swing arm 100, the drive gear 80 that rotates clockwise from the first relay gear 81. The drive is transmitted to the first driven gear 84a via the oscillating gear 82, the third relay gear 85, and the fourth relay gear 86, and the lubricant supply roller 15a rotates counterclockwise with the driven gear 84. .
Even in the case of such a configuration, the same effect as that of the above-described fourth embodiment can be obtained.

In the fourth embodiment, the number of rotations of the lubricant supply roller 15a is increased when the combination of the gear trains is switched from the reference combination by the switching unit.
On the other hand, referring to FIG. 11, when the combination of gear trains is switched from the reference combination as shown in FIG. 11A to the combination shown in FIG. The number of rotations of the agent supply roller 15a may be reduced.

Further, referring to FIG. 12, the switching means switches the combination of gear trains from the reference combination as shown in FIG. 12 (A) to the combination shown in FIG. 12 (B) to rotate the lubricant supply roller 15a. The number can be reduced, the number of rotations of the lubricant supply roller 15a can be increased by switching to the combination shown in FIG. 12C, or the switching unit can be controlled by the control unit 60.
More specifically, in the state shown in FIG. 12A, which is the reference state, the driving gear 80 that rotates counterclockwise from the driving gear 80 through the first relay gear 81 and the oscillating gear 82 forms the second gear of the driven gear 84 having a three-stage gear structure. The drive is transmitted to the driven gear 84b, and the lubricant supply roller 15a rotates counterclockwise with the driven gear 84. On the other hand, at the time of deceleration, the swinging of the swing arm 100 switches from the reference state shown in FIG. 12A to the state shown in FIG. Drive is transmitted to the first driven gear 84a of the three-stage driven gear 84 via the gear 81, the swing gear 82, and the third relay gear 87, and the lubricant supply roller 15a rotates counterclockwise with the driven gear 84. Will do. At the time of speed increase, the swinging of the swing arm 100 switches from the reference state shown in FIG. 12A to the state shown in FIG. 12C, and the drive gear 80 rotating clockwise from the first relay gear 81. The driving is transmitted to the third driven gear 84c of the driven gear 84 having the three-stage gear structure via the oscillating gear 82 and the fourth relay gear 88, and the lubricant supply roller 15a rotates counterclockwise with the driven gear 84. Will be.
The third relay gear 87, the fourth relay gear 88, and the driven gear 84 (the first driven gear 84a, the second driven gear 84b, and the third driven gear 84c) mesh with the above-described acceleration / deceleration. The number of each gear is set so that the frequency can be changed.

When the combination of the gear trains is switched from the reference combination shown in FIG. 12A by the switching means using the gear trains shown in FIG. 12, the temperature and humidity sensor 50 ( When the absolute humidity detected by the method is equal to or higher than a predetermined absolute humidity, the gear train is switched to a gear train as shown in FIG. 12C to increase the rotation speed of the lubricant supply roller 15a. When the absolute humidity detected by the temperature and humidity sensor 50 is equal to or lower than a predetermined absolute humidity, the control unit 60 switches to a gear train as shown in FIG. 12B to reduce the rotation speed of the lubricant supply roller 15a. Thus, the switching means can be controlled.
Such a control is performed when the surrounding environment (absolute humidity) is determined to be higher than the predetermined absolute humidity M, and the lubricant supply amount is relatively high temperature and high humidity. If the ambient environment (absolute humidity) is determined to be smaller than the predetermined absolute humidity M, the environment is relatively low in temperature and humidity and the supply amount of the lubricant is likely to increase. . By performing such control, while the occurrence of problems such as image unevenness due to the resonance phenomenon is reliably reduced, the amount of the lubricant supplied to the photosensitive drum 11 becomes insufficient or excessive. Can be prevented.

As described above, the image forming apparatus 1 according to the fourth embodiment switches the combination of the gear train that transmits the drive from the drive motor 45 (drive source) to the lubricant supply roller 15a to switch the natural frequency related to the drive. Is provided. The combination of the gear trains is set to a reference combination, and the number of rotations of the lubricant supply roller 15a to be varied by the drive motor 45 (variable means) based on a predetermined condition is set to a predetermined value. A control unit 60 is provided for controlling the switching means so as to switch the combination of the gear train from the reference combination when the value of X is matched.
As a result, even when control is performed to vary the number of revolutions of the lubricant supply roller 15a, the photosensitive drum 11 (image carrier) vibrates greatly, and problems such as image unevenness hardly occur.

In each of the above-described embodiments, the process cartridge 10 </ b> Y is configured by integrating the lubricant supply device 15 with the photosensitive drum 11, the charging roller 12 (charging unit), the developing device 13, and the cleaning device 14. The unit is made compact and maintenance workability is improved.
On the other hand, these components may be configured so as to be individually replaceable and installed in the apparatus main body 1 instead of being components of the process cartridge. In such a case, the same effects as those of the above embodiments can be obtained.
In the present application, the “process cartridge” includes 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 unit that cleans the image carrier. At least one of the cleaning unit (cleaning device) and the image carrier are defined as a unit that is integrated and removably installed in the image forming apparatus main body.

In each of the above embodiments, the present invention is applied to an image forming apparatus equipped with a two-component developing device 13 using a two-component developer. The present invention can naturally be applied to an image forming apparatus in which the developing device 13 is mounted.
Further, in each of the above embodiments, the present invention is applied to the image forming apparatus 1 in which the lubricant supply device 15 for supplying the lubricant to the photosensitive drum 11 as the image carrier is installed. Naturally, the present invention can also be applied to an image forming apparatus provided with a lubricant supply device for supplying a lubricant to a photoreceptor belt. Further, the present invention can be applied to the lubricant supply device that supplies the lubricant to the surface of the intermediate transfer belt 17 as the image carrier in each of the above embodiments.

Further, in each of the above-described embodiments, the lubricant supply roller 15a having a foamed elastic layer formed on a core metal is used. However, the lubricant supply roller 15a has a straight hair or loop shape on the outer periphery of the core metal. A brush hair can be used. In that case, as the brush bristles, 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. The brush bristles having a length (hair length) of 0.2 to 20 mm and a brush density of 2 to 100,000 F / inch ² can be used.
And even in such a case, it is possible to obtain substantially the same effects as those of the above embodiments.

  It should be noted that the present invention is not limited to the above embodiments, and that the embodiments can be appropriately modified in addition to those suggested in the embodiments within the scope of the technical idea of the present invention. Is clear. In addition, the number, position, shape, and the like of the constituent members are not limited to the above-described embodiments, and can be set to numbers, positions, shapes, and the like suitable for implementing the present invention.

1 image forming apparatus (image forming apparatus main body),
10Y, 10M, 10C, 10BK process cartridge,
11 photoconductor drum (image carrier),
15 lubricant supply device,
15a lubricant supply roller,
15b solid lubricant,
15c compression spring (biasing member),
45 drive motor (variable means, drive source),
46 torque detecting unit (torque detecting means),
49 counter, 50 temperature and humidity sensor (environment detecting means), 60 control unit.

JP 2013-20232 A

Claims (11)

An image carrier on which the toner image is carried;
A lubricant supply roller for supplying a lubricant to the surface of the image carrier,
Variable means for varying the number of rotations of the lubricant supply roller,
Environment detection means for detecting the absolute humidity of the surroundings,
When the rotational speed of the lubricant supply roller to be varied by the variable means based on a predetermined condition matches a predetermined value, the absolute humidity detected by the environment detecting means is equal to or higher than a predetermined absolute humidity. If the absolute humidity detected by the environment detecting means is equal to or greater than a predetermined absolute humidity, the variable means is controlled so that the rotation speed is increased by a predetermined value or ratio so as not to match the predetermined value. A control unit that controls the variable means so that the rotation speed is decelerated by a predetermined value or a ratio so that the rotation speed does not match the predetermined value when :
An image forming apparatus comprising: A torque detecting unit that detects a driving torque at the time of rotation of the lubricant supply roller,
The control unit increases or decreases the rotation speed of the lubricant supply roller when the driving torque detected by the torque detecting unit is large as compared with when the driving torque detected by the torque detecting unit is small. The image forming apparatus according to claim 1, wherein the variable unit is controlled so that a degree of the change is increased. An image carrier on which the toner image is carried;
A lubricant supply roller for supplying a lubricant to the surface of the image carrier,
Variable means for varying the number of rotations of the lubricant supply roller,
When the rotational speed of the lubricant supply roller to be varied by the variable means based on a predetermined condition coincides with a predetermined value, the lubricant is controlled so that the rotational speed does not coincide with the predetermined value. A control unit that controls the variable unit so as to increase or decrease the rotation speed of the supply roller,
Torque detection means for detecting a drive torque during rotation of the lubricant supply roller ,
With
The control unit increases or decreases the rotation speed of the lubricant supply roller when the driving torque detected by the torque detecting unit is large as compared with when the driving torque detected by the torque detecting unit is small. An image forming apparatus that controls the variable unit so that the degree of the change is increased. An image carrier on which the toner image is carried;
A lubricant supply roller for supplying a lubricant to the surface of the image carrier,
Variable means for varying the number of rotations of the lubricant supply roller,
Switching means for switching a combination of gear trains for transmitting drive from a drive source to the lubricant supply roller to vary a natural frequency related to the drive,
When the combination of the gear trains is set to a reference combination, and the number of revolutions of the lubricant supply roller to be varied by the variable means based on a predetermined condition is equal to a predetermined value. A control unit that controls the switching unit to switch the combination of the gear train from the reference combination;
Torque detection means for detecting a drive torque during rotation of the lubricant supply roller,
Bei to give a,
The image forming apparatus according to claim 1, wherein the control unit changes the predetermined value according to a driving torque detected by the torque detecting unit . The switching means is configured to increase or decrease the rotation speed of the lubricant supply roller when the combination of the gear trains is switched from the reference combination. 5. The image forming apparatus according to 4. Equipped with environment detection means for detecting the absolute humidity of the surroundings,
The controller, when switching the combination of the gear train from the reference combination by the switching means, when the absolute humidity detected by the environment detecting means is equal to or higher than a predetermined absolute humidity, the lubricant supply roller The switching means is controlled such that the rotation speed is increased, and the rotation speed of the lubricant supply roller is reduced when the absolute humidity detected by the environment detection means is equal to or lower than a predetermined absolute humidity. The image forming apparatus according to claim 4, wherein the switching unit is controlled. An image carrier on which the toner image is carried;
A lubricant supply roller for supplying a lubricant to the surface of the image carrier,
Variable means for varying the number of rotations of the lubricant supply roller,
Switching means for switching a combination of gear trains for transmitting drive from a drive source to the lubricant supply roller to vary a natural frequency related to the drive,
When the combination of the gear trains is set to a reference combination, and the number of revolutions of the lubricant supply roller to be varied by the variable means based on a predetermined condition is equal to a predetermined value. A control unit that controls the switching unit to switch the combination of the gear train from the reference combination;
Environment detection means for detecting the absolute humidity of the surroundings ,
With
The controller, when switching the combination of the gear train from the reference combination by the switching means, when the absolute humidity detected by the environment detecting means is equal to or higher than a predetermined absolute humidity, the lubricant supply roller The switching means is controlled such that the rotation speed is increased, and the rotation speed of the lubricant supply roller is reduced when the absolute humidity detected by the environment detection means is equal to or lower than a predetermined absolute humidity. An image forming apparatus, wherein the switching unit is controlled. The switching means is a combination of a relay gear relayed between a drive gear provided on a motor shaft of a drive motor serving as the drive source and a driven gear provided on a rotation shaft of the lubricant supply roller. Equipped with a swing gear that swings to switch
The drive motor is configured to be rotatable in forward and reverse directions so that the rotation direction of the lubricant supply roller does not change when the combination of the gear trains is switched from the reference combination by the switching unit. The image forming apparatus according to any one of claims 4 to 7, wherein:   9. The method according to claim 1, wherein the predetermined value is set to two or more, or is set as a continuous value within a predetermined range. Image forming device. The controller is configured such that, as the total travel distance or the total drive time of the image carrier or the lubricant supply roller increases, the rotational speed of the lubricant supply roller increases continuously or stepwise. The image forming apparatus according to claim 1, wherein the variable unit is controlled. Equipped with environment detection means for detecting the absolute humidity of the surroundings,
The control unit controls the variable unit so that the rotational speed of the lubricant supply roller increases continuously or stepwise as the absolute humidity detected by the environment detecting unit increases. The image forming apparatus according to claim 1.

Images