JP2017076102A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus that, even when performing control of varying the number of rotations of a lubricant supply roller, prevents image carriers from being largely vibrated to cause a trouble, such as image unevenness.SOLUTION: A control part 60 is provided that, when the number of rotations of a lubricant supply roller 15a to be varied by a drive motor 45 (varying means) on the basis of a predetermined condition matches with a predetermined value X determined in advance, controls the drive motor 45 to increase or decrease the number of rotations of the lubricant supply roller 15a so that the number of rotations does not match with the predetermined value X.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an image forming apparatus using an electrophotographic system, such as a copying machine, a printer, a facsimile machine, or a complex machine thereof.

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

Specifically, in Patent Document 1, the lubricant supply device includes a lubricant supply roller that is in sliding contact with the photosensitive drum (image carrier), a solid lubricant that is in contact with 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 the surface. Then, the lubricant is gradually scraped off from the solid lubricant by the lubricant supply roller rotating in a predetermined direction, and the lubricant scraped off and transported by the lubricant supply roller is applied (supplied) to the surface of the photosensitive drum. The
In Patent Document 1, the amount of lubricant supplied onto the photosensitive drum is varied by changing the number of revolutions of the lubricant supply roller based on predetermined conditions such as the total travel distance and environment of the lubricant supply roller. A technique for preventing excess and deficiency from occurring is disclosed.

In the conventional image forming apparatus, since the number of rotations of the lubricant supply roller is changed to an optimum value based on a predetermined condition, the amount of lubricant supplied to the surface of the image carrier is less likely to be excessive or insufficient. I can expect.
However, when the number of rotations of the lubricant supply roller is varied, the image carrier is vibrated greatly because the gear meshing frequency at that time coincides with the natural frequency of other members and resonates. As a result, defects such as image unevenness may occur in the image formed on the surface of the image carrier.

  The present invention has been made to solve the above-described problems. Even when control is performed to vary the rotation speed of the lubricant supply roller, the image carrier vibrates greatly, resulting in image unevenness, etc. It is an object of the present invention to provide an image forming apparatus that does not cause the above problem.

  According to a first aspect of the present invention, an image forming apparatus includes an image carrier on which a toner image is carried, a lubricant supply roller that supplies a lubricant to a surface of the image carrier, and the lubricant supply roller. When the rotation speed of the lubricant supply roller to be varied by the variable means based on a predetermined condition matches a predetermined value, the rotation speed is the predetermined speed. And a controller that controls the variable means so as to increase or decrease the rotational speed of the lubricant supply roller so as not to coincide with the value.

  According to the present invention, even when control for changing the rotation speed of the lubricant supply roller is performed, the image carrier does not vibrate greatly and a defect such as image unevenness does not occur. Can be provided.

1 is an overall configuration diagram illustrating an image forming apparatus according to Embodiment 1 of the present invention. It is a block diagram which shows a process cartridge and its vicinity. It is a flowchart which shows the control which changes the rotation speed of a lubricant supply roller. 10 is a flowchart showing control for changing the number of rotations of a lubricant supply roller as a first modification. 10 is a flowchart showing control for changing the number of rotations of a lubricant supply roller as a second modification. In the control of the lubricant supply device in 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 running time and the rotation speed of the lubricant supply roller. It is a figure which shows a relationship. 6 is a schematic diagram showing a gear train installed in a lubricant supply device in Embodiment 3. FIG. It is the schematic which shows the modification of the gear train of FIG. It is the schematic which shows another modification of the gear train of FIG. FIG. 10 is a schematic diagram showing a gear train installed in a lubricant supply device in a fourth embodiment. It is the schematic which shows the modification of the gear train of FIG. It is the schematic which shows another modification of the gear train of FIG.

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

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

  In FIG. 1, 1 is a tandem color copier as an image forming apparatus, 2 is a writing unit that emits laser light based on input image information, 3 is a document conveying unit that conveys a document D to a document reading unit 4, and 4 is A document reading unit that reads image information of the document D, 7 is a paper feed unit that accommodates a recording medium such as transfer paper, 9 is a registration roller that adjusts the conveyance timing of the recording medium, 10Y, 10M, 10C, and 10BK are each color Yellow, magenta, cyan, and black) process cartridges 16 are formed by superimposing toner images formed on the photosensitive drums of the process cartridges 10Y, 10M, 10C, and 10BK on the intermediate transfer belt 17. A primary transfer bias roller 17 for transfer, an intermediate transfer belt 17 on which toner images of a plurality of colors are transferred in an overlapping manner, and a toner 18 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, and 20 a fixing device for fixing a toner image (unfixed image) on the recording medium, Indicates.

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

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

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

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

  The laser beam L corresponding to the yellow component is applied to the surface of the first photosensitive drum 11 (image carrier) from the left side of the drawing. At this time, the yellow component laser light is scanned in the rotation axis direction (main scanning direction) of the photosensitive drum 11 by a polygon mirror that rotates at high speed. Thus, an electrostatic latent image corresponding to the yellow component is formed on the photosensitive drum 11 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 side of the paper, and an electrostatic latent image corresponding to the magenta component is formed. The cyan component laser light is applied to the surface of the third photosensitive drum 11 from the left side of the drawing 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 side of the drawing, and an electrostatic latent image of the black component is formed.

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

Then, the surface of the photosensitive drum 11 after the transfer process reaches a position facing the cleaning device 14 (cleaning unit). At this position, the untransferred toner remaining on the photosensitive drum 11 is mechanically removed by the cleaning blade 14a, and the removed untransferred toner is collected in the cleaning device 14 (cleaning process). ). The untransferred toner collected in the cleaning device 14 is transported to the outside of the cleaning device 14 by the transport screw 14b, and is collected as waste toner in a waste toner collection container (not shown).
Thereafter, the surface of the photosensitive drum 11 sequentially passes through the positions of the lubricant supply device 15 and the charge removal unit (not shown), and a series of image forming processes on the photosensitive drum 11 is completed.

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

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

Then, the recording medium on which the full-color image is transferred is guided to the fixing device 20 by the conveyance belt. In the fixing device 20, the color image (toner) is fixed on the recording medium at the nip between the fixing belt and the pressure roller.
Then, the recording medium after the fixing process is discharged as an output image outside the apparatus main body 1 by a paper discharge roller, and a series of image forming processes is completed.
In the first embodiment, when thick paper is passed as a recording medium, in order to ensure a good fixed image, the process linear velocity (recording medium conveyance speed, image formation on the photosensitive drum 11, etc.) is performed. The linear velocity of the member), and the “low speed mode” in which the image forming process is performed at a low speed is executed. In other words, the “low-speed” image forming process is performed at a process line speed slower than the normal process line speed from the “normal mode” in which the image forming process is performed at a normal process line speed by user selection through the operation of the operation panel. Change to "mode" is possible.

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 is integrally configured as a unit. The process cartridge 10Y is detachably (replaceable) with respect to the image forming apparatus main body 1, and is appropriately removed from the image forming apparatus main body 1 to be replaced with a new one or repaired. Become.

Here, the photosensitive drum 11 as an image bearing member is a negatively charged organic photosensitive member, and a photosensitive layer or the like is provided on a drum-shaped conductive support.
Although not shown, the photosensitive drum 11 has an undercoat layer as an insulating layer, a charge generation layer and a charge transport layer as a photosensitive layer, and a surface layer (protective layer) in this order on a conductive support as a base layer. Are stacked.
The photosensitive drum 11 is rotationally driven counterclockwise in FIG. 2 by a motor (main motor) (not shown).

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

The developing device 13 (developing unit) mainly includes a developing roller 13a that faces the photosensitive drum 11, a first conveying screw 13b that faces the developing roller 13a, and a first conveying screw 13b that faces the first conveying screw 13b via a partition member. It is comprised by the 2 conveyance screw 13c and the doctor blade 13d facing the developing roller 13a. The developing roller 13a includes a magnet that is fixed inside and forms a magnetic pole on the peripheral surface of the roller, and a sleeve that rotates around the magnet. A plurality of magnetic poles are formed on the developing roller 13a (sleeve) by the magnet, and the developer G is carried on the developing roller 13a.
In the developing device 13, a two-component developer G composed of carrier C and toner T is accommodated.

The cleaning device 14 includes a cleaning blade 14a that contacts the photoconductor drum 11 to clean the surface of the photoconductor drum 11, and untransferred toner collected in the cleaning device 14 in the width direction (in the direction perpendicular to the paper in FIG. 2). And a transporting screw 14b for transporting the same.
The cleaning blade 14a is made of a rubber material such as urethane rubber, and is in contact with the surface of the photosensitive drum 11 at a predetermined angle and a predetermined pressure. As a result, untransferred toner adhering to the photosensitive drum 11 (paper powder generated from the recording medium, discharge products generated on the photosensitive drum 11 when discharged by the charging roller 12, additives added to the toner, etc.) It is assumed that the deposits are also included.) Is mechanically scraped off and collected in the cleaning device 14. In the first embodiment, the cleaning blade 14 a is in contact with the photosensitive drum 11 in the counter direction with respect to the traveling direction (rotating direction) of the photosensitive drum 11.

Referring to FIG. 2, the lubricant supply device 15 includes a lubricant supply roller 15 a (lubricant supply rotation) in which a foamed elastic layer that is in sliding contact with the photosensitive drum 11 is provided to supply the lubricant onto the photosensitive drum 11. Body), a solid lubricant 15b in sliding contact with the lubricant supply roller 15a (foaming elastic layer), a compression spring 15c as a biasing member for biasing the solid lubricant 15b toward the lubricant supply roller 15a, and a solid lubricant 15b. A holding member 15d (holding plate) for holding the thin film, a thinning blade 15f (leveling blade) for making the lubricant supplied to the photosensitive drum 11 in contact with the photosensitive drum 11 thin (uniform) Etc.
The lubricant supply device 15 is downstream in the rotational direction of the photosensitive drum 11 (downstream in the traveling direction) with respect to the cleaning device 14 (cleaning blade 14a), and is in the rotational direction of the photosensitive drum 11 with respect to the charging roller 12. Arranged upstream. The thinning blade 15f is disposed on the downstream side in the rotation direction of the photosensitive drum 11 with respect to the lubricant supply roller 15a.

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

The lubricant supply roller 15a is formed by previously forming a polyurethane foam as a foamed elastic layer from a polyurethane foam raw material into a block shape, cutting it 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 a foamed polyurethane while applying a polishing blade and moving the blade parallel to the axial direction. In order to improve the adhesiveness with the foamed elastic layer, an adhesive may be applied in advance to the core metal to be inserted. Moreover, irregular unevenness | corrugation can be formed in the surface of a foaming elastic layer by changing the rotational speed of foaming polyurethane, or the speed to which it moves when performing traverse grinding.
The manufacturing method of the lubricant supply roller 15a is not limited to this. For example, as another manufacturing method, a method of injecting a polyurethane foam raw material into a molding die containing a core metal and foaming and curing it is used. It can also be used.

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

Here, the solid lubricant 15b is formed by adding an inorganic lubricant to fatty acid metal zinc. Moreover, as fatty acid metal zinc, what contains at least zinc stearate is preferable. The inorganic lubricant is preferably at least one of talc, mica, and boron nitride.
Zinc stearate is a typical lamellar crystal powder. A lamellar crystal has a layered structure in which amphiphilic molecules are self-organized, and when a shearing force is applied, the crystal breaks along the layers and is slippery. Therefore, the surface of the photosensitive drum 11 can be made to have low friction. In other words, the surface of the photosensitive drum 11 can be effectively covered with a small amount of lubricant by the lamellar crystals that receive the shearing force and uniformly cover the surface of the photosensitive drum 11. Then, the surface of the photosensitive drum 11 can be covered relatively evenly and well protected from electrical stress in the charging process.
Further, by using an inorganic lubricant having a plate-like structure such as talc, mica, and boron nitride, it is difficult for toner and lubricant to slip through the cleaning device 14 (cleaning blade 14a), and the charging roller 12 is It can be made difficult to get dirty.

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

The thinning blade 15f is a plate-like member made of a rubber material such as urethane rubber, and is in contact with the surface of the photosensitive drum 11 at a predetermined angle and a predetermined pressure. The thinning blade 15f is disposed on the downstream side in the rotation direction of the photosensitive drum 11 (downstream in the traveling direction) with respect to the cleaning blade 14a. The lubricant supplied onto the photoreceptor drum 11 by the lubricant supply roller 15a is thinned uniformly and in an appropriate amount on the photoreceptor drum 11 by the thinning blade 15f.
When the solid lubricant 15b is applied to the surface of the photosensitive drum 11 via the lubricant supply roller 15a, a powdery lubricant is applied to the surface of the photosensitive drum 11, but in this state, the lubricity is low. Since it is not sufficiently exhibited, the thinning blade 15f functions as a member for thinning and uniformizing the lubricant. The thinning blade 15f forms a film of the lubricant on the photosensitive drum 11, and the lubricant exhibits its lubricity sufficiently.
In the first embodiment, the thinning blade 15f is in contact with the photosensitive drum 11 in the trading direction with respect to the traveling direction (rotating direction) of the photosensitive drum 11.

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

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

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

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

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

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

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

Hereinafter, the configuration and operation of the image forming apparatus 1 (the lubricant supply device 15 and the process cartridge 10Y), which are characteristic in the first embodiment, will be described.
As described above with reference to FIG. 2, the lubricant supply device 15 (process cartridge 10Y) in the first embodiment rotates in a predetermined direction (counterclockwise in FIG. 2) and the photosensitive member. A lubricant supply roller 15 a that supplies a lubricant to the surface of the drum 11 is provided. In addition, as a variable means for changing the rotation speed of the lubricant supply roller 15a in order to supply the lubricant from the lubricant supply device 15 onto the photosensitive drum 11 without excess or shortage even when environmental fluctuations occur or over time. Drive motor 45 (a rotation speed variable type drive motor) is provided.

When the rotational speed of the lubricant supply roller 15a to be varied by the drive motor 45 (variable means) based on a predetermined condition matches a predetermined value X, the rotational speed becomes the predetermined value X. A controller 60 (see FIG. 2) that controls the drive motor 45 is provided so as to increase or decrease the rotational speed of the lubricant supply roller 15a so as not to coincide. From another viewpoint, when the rotational speed of the lubricant supply roller 15a to be regularly changed by the drive motor 45 (variable means) based on a predetermined condition coincides with the predetermined value X, the drive motor by the control unit 60 With the control of 45, the rotation speed is varied irregularly.
Specifically, the drive motor 45 (variable means) is configured so that the number of rotations of the lubricant supply roller 15a to be varied based on a predetermined condition is a predetermined value X (or two or more predetermined values). If it matches any one of the predetermined values), the speed is increased (or decelerated) by a predetermined ratio A (or a predetermined value) so that the rotational speed does not match the predetermined value X. It is controlled to be variable. That is, in the drive motor 45 (variable means), the rotation speed R ′ of the lubricant supply roller 15a to be varied based on a predetermined condition is set to one predetermined value X (or two or more predetermined values). , The rotation speed is increased (or decelerated) by a predetermined ratio A (or a predetermined value) with respect to the rotation speed R ′ to be varied. The number is controlled to be set as a variable rotation speed.

  Here, the predetermined value X described above is the meshing frequency of the gear train to which the driving force is transmitted from the drive motor 45 to the lubricant supply roller 15a when the rotational speed of the lubricant supply roller 15a coincides. The natural frequency (resonance frequency) of other members such as the photosensitive drum 11, the charging roller 12, and the writing unit 2 coincides and resonates, and is the rotation number to be avoided. In general, such a predetermined value X (the number of rotations to be avoided) is not limited to one but often exists in plural, and the lubricant is supplied to any one of the plurality of predetermined values X. When the rotation speed of the roller 15a coincides, the lubricant supply roller 15a and the member having the natural frequency resonate (resonance phenomenon occurs), and thus the photosensitive drum 11 becomes large. As a result of the vibration, an image (toner image) formed on the surface of the photosensitive drum 11 has a defect such as image unevenness.

Therefore, two or more of the above-mentioned “predetermined predetermined value X” are set, and the rotational speed R ′ of the lubricant supply roller 15a to be varied based on the predetermined condition is set to two or more predetermined. Drive to increase or decrease the rotation speed of the lubricant supply roller 15a so that the rotation speed R ′ does not match the predetermined value when it matches any of the predetermined values. 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 rotational speed R ′ of the lubricant supply roller 15a to be varied based on the predetermined condition However, the rotational speed of the lubricant supply roller 15a is set so that the rotational speed R 'does not match either 130 rpm or 140 rpm, even if it matches 130 rpm or 140 rpm. It will be accelerated or decelerated (e.g., shifted to 135 rpm).
Furthermore, 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 determined in advance. If the rotational speed R ′ does not fall within the predetermined range when it falls within the predetermined range, the drive motor 45 is set so as to increase or decrease the rotational speed of the lubricant supply roller 15a. Can also be controlled by the control unit 60. For example, assuming that a range of 120 rpm to 150 rpm is set as the “predetermined predetermined value X”, the rotational speed R ′ of the lubricant supply roller 15a to be varied based on the predetermined condition is 120 rpm to 150 rpm. If the rotation speed is within the range of 150 rpm, the rotation speed of the lubricant supply roller 15a is increased or decreased so that the rotation speed R ′ is not within the range of 120 rpm to 150 rpm (for example, the rotation speed is decreased to 110 rpm). )

On the other hand, in the first embodiment, when the number of rotations of the lubricant supply roller 15a to be varied based on a predetermined condition coincides with a predetermined value X at which resonance occurs, the change is made. Since the rotation speed is changed (corrected) so as not to coincide with the predetermined value X, it is possible to prevent a problem that the photosensitive drum 11 vibrates greatly and image unevenness occurs. 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 other members such as the photosensitive drum 11, the charging roller 12, and the writing unit 2. ) And the resonance that coincides with each other is prevented.
Here, when the rotational speed of the lubricant supply roller 15a to be varied based on a predetermined condition coincides with the predetermined value X, the speed increasing side is set so that the variable rotational speed does not coincide with the predetermined value X. However, the amount of lubricant supplied to the surface of the photoconductor drum 11 by the lubricant supply roller 15a will be larger than the target, but the lubricant on the surface of the photoconductor drum 11 is surely provided. Can be supplied.
On the other hand, when the rotational speed of the lubricant supply roller 15a to be varied based on a predetermined condition coincides with the predetermined value X, the variable rotational speed is decelerated so as not to coincide with the predetermined value X. When changing to the side, the amount of lubricant supplied to the surface of the photosensitive drum 11 by the lubricant supply roller 15a will be less than the target, but the consumption of the solid lubricant 15b can be suppressed. It becomes possible.

  Here, in the first embodiment, as a predetermined condition for changing the rotation speed of the lubricant supply roller 15a, the total running time (or total drive time) of the lubricant supply roller 15a (or the photosensitive drum 11), The temperature and humidity (absolute humidity) around the lubricant supply device 15 is used. That is, based on the total running time of the lubricant supply roller 15a and the ambient temperature and humidity, the rotational speed of the lubricant supply roller 15a is appropriately varied by the control of the drive motor 45 by the control unit 60.

Specifically, the drive motor 45 (variable means) rotates the lubricant supply roller 15a as the total travel distance (or total drive time) of the lubricant supply roller 15a (or the photosensitive drum 11) increases. The number will be variable 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 the lubricant supply roller 15a increases as the total travel distance increases. The drive motor 45 is controlled by the control unit 60 so that the number of rotations increases gradually. As a result, even if the ability to supply the lubricant from the lubricant supply device 15 to the photosensitive drum 11 gradually decreases with time, the rotational speed of the lubricant supply roller 15a is increased so as to offset it. Therefore, the lubricant can be supplied from the lubricant supply device 15 onto the photosensitive drum 11 without undue deficiency over time.
In the first embodiment, the rotational speed of the lubricant supply roller 15a is variably controlled based on the information of the counter 49. However, the rotational speed of the lubricant supply roller 15a is based on information related to the operating time of the drive motor 45. Can be variably controlled.

Referring to FIG. 2, a temperature / humidity sensor 50 is provided in the vicinity of the process cartridge 10 </ b> Y as environment detection 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 humidity detected by the temperature / humidity sensor 50 in the same manner as known ones.
In the drive motor 45 (variable means), as the absolute humidity detected by the temperature / humidity sensor 50 (environment detection means) increases, the rotational speed of the lubricant supply roller 15a is continuous (or stepwise). It will be variable to increase.
Specifically, the drive motor 45 is controlled by the control unit 60 so that the rotational speed of the lubricant supply roller 15a gradually increases as the absolute humidity detected by the temperature / humidity sensor 50 increases. As a result, 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 surrounding absolute humidity, the lubricant supply roller 15a is offset so as to offset it. Since the ability is increased by increasing the rotational speed, it is possible to supply the lubricant from the lubricant supply device 15 onto the photosensitive drum 11 without excess or deficiency even if a change in temperature and humidity (environmental fluctuation) occurs. become.
In the first embodiment, the rotational speed of the lubricant supply roller 15a is continuously variably controlled as the temperature and humidity change, but the rotational speed of the lubricant supply roller 15a is variably controlled stepwise as the temperature and humidity change. You can also Specifically, the rotational speed of the lubricant supply roller 15a can be increased in three stages: low temperature (for example, 15 ° C. or lower), normal temperature (15 to 25 ° C.), and high temperature (25 ° C. or higher). It can also be controlled.

Hereinafter, the control for changing the rotation speed of the lubricant supply roller 15a in the first embodiment will be described collectively with reference to the flowchart of FIG.
First, based on the process linear speed when the image forming process is performed, the rotation speed R (basic rotation speed) serving as a reference for the lubricant supply roller 15a is determined (step S1). Since 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” as described above, the image forming apparatus 1 corresponds to two stages of process line speeds. A basic rotational speed R of the two-stage lubricant supply roller 15a is prepared. That is, in step S1, the basic rotational speed R of the normal speed lubricant supply roller 15a is determined in the normal mode, and the basic rotational speed R of the low speed lubricant supply roller 15a is determined in the low speed mode.
If the process linear velocity is constant without being changed, the flow of step S1 is omitted.

Then, the coefficient α is determined based on information from the temperature / humidity sensor 50 (information on the ambient absolute humidity) (step S2). As described above, the coefficient α is not excessively insufficient on the photosensitive drum 11 from the lubricant supply device 15 by changing the rotational speed of the lubricant supply roller 15a even if the temperature and humidity (absolute humidity) change. This is a correction coefficient multiplied by the basic rotational speed R of the lubricant supply roller 15a in order to supply the lubricant.
Further, the coefficient β is determined based on the information of the counter 49 (information relating to the total travel distance) (step S3). As described above, the coefficient β is lubricated in order to supply the lubricant from the lubricant supply device 15 to the photosensitive drum 11 without excess or deficiency by changing the rotational speed of the lubricant supply roller 15a over time. This is a correction coefficient multiplied by the basic rotational 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 rotational speed R to determine the target rotational speed R ′ (= R × α × β) of the lubricant supply roller 15a. (Step S4).

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

On the other hand, if it is determined in step S5 that the target rotation speed R ′ matches the predetermined value X (avoidance rotation speed), the resonance phenomenon described above is generated as it is. The target rotation speed R ′ determined in step S4 is multiplied by a correction coefficient A (a value greater than 0 and a value other than 1), and the rotation speed R ′ × A does not match the predetermined value X. It is determined as a number (step S7). Then, the image forming process is executed while controlling the drive motor 45 so as to rotationally drive the lubricant supply roller 15a at the rotational 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 number of rotations R ′ is multiplied by a predetermined ratio (coefficient A), and finally the number of rotations R ′ × A that does not match the predetermined value X is obtained. Although set, the predetermined value Z can be added to or subtracted from the target rotational speed R ′ to finally set the rotational speed R ′ ± Z that does not coincide with the predetermined value X.

  In the first embodiment, the number of rotations of the lubricant supply roller 15a to be varied based on a predetermined condition is 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 detection means) is equal to or higher than the predetermined absolute humidity M, the rotational speed does not match the predetermined value X. When the absolute humidity detected by the temperature / humidity sensor 50 is equal to or lower than the predetermined absolute humidity M so that the speed is increased by a predetermined value B (or a predetermined ratio), the rotational speed does not match the predetermined value X. In this way, the drive motor 45 (variable means) can be controlled by the control unit 60 so as to be decelerated by a 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. If it is determined in step S5 that the target rotational speed R ′ matches the predetermined value X (avoidance rotational 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 supply amount of the lubricant is likely to decrease in a relatively high temperature environment, and the previous state is left as it is. Assuming that the resonance phenomenon described in the above occurs, a predetermined value B is added to the target rotational speed R ′ determined in step S4, and the rotational speed (R ′ + B) does not coincide with the predetermined value X. (Step S11). Then, the image forming process is executed while controlling the drive motor 45 so as to rotationally drive the lubricant supply roller 15a at the rotational speed (R ′ + B). Thereby, it is possible to prevent a problem that the amount of lubricant supplied to the photosensitive drum 11 is insufficient while reliably reducing the occurrence of a problem such as image unevenness due to a resonance phenomenon.
On the other hand, when it is determined that the ambient absolute humidity is lower than the predetermined absolute humidity M, the lubricant supply amount is likely to increase in a relatively low temperature environment, and Then, assuming that the resonance phenomenon described above occurs, a predetermined value C is subtracted from the target rotational speed R ′ determined in step S4, and the rotational speed (R′−C) does not coincide with the predetermined value X. Is determined as the correct rotation speed (step S11). Then, the image forming process is executed while controlling the drive motor 45 so as to rotationally drive the lubricant supply roller 15a at the rotational speed (R'-C). Thereby, it is possible to prevent the problem that the amount of lubricant supplied to the photosensitive drum 11 becomes excessive while reliably reducing the problem such as image unevenness due to the resonance phenomenon.

Further, in the first embodiment, as shown in FIG. 2, a torque detection unit 46 as a torque detection unit that detects a driving torque when the lubricant supply roller 15a rotates can be provided. Such a torque detection unit 46 (torque detection means) detects a drive torque applied to the drive motor 45 from a change in the current flowing through the drive motor 45, and a known one can be used.
And when the drive torque detected by the torque detection part 46 (torque detection means) by the control part 60 is large, compared with the case where the drive torque detected by the torque detection part 46 is small, the lubricant supply roller 15a. It is also possible to control the drive motor 45 (variable means) so that the degree to which the rotational speed is increased or decreased is increased. Specifically, when the drive torque detected by the torque detection unit 46 (torque detection means) is large, a predetermined ratio A (or a predetermined value) is compared to when the drive torque detected by the torque detection unit 46 is small. It is also possible to control the drive motor 45 (variable means) so as to vary so that the value) increases.
Such control is performed when the rotational speed of the lubricant supply roller 15a to be varied based on a predetermined condition coincides with a predetermined value X (avoidance rotational speed), and the lubricant at that time 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 also becomes large, and the rotation speed is set to a predetermined value X. This is because the resonance phenomenon described above may occur unless it is greatly varied from (avoidance rotation speed).

Specifically, as shown in FIG. 5, the flow of steps S1 to S6 is performed in the same manner as in FIG. In step S5, when it is determined that the target rotational speed R ′ matches the predetermined value X (avoidance rotational speed), the torque is detected by the torque detector 46 and the coefficient γ is determined by the driving torque. (Step S20). As described above, the coefficient γ is set to the predetermined ratio A (described above) in order to prevent a problem that the driving torque of the lubricant supply roller 15a increases and the resonance phenomenon easily occurs even under the same conditions. Or a correction coefficient multiplied by a predetermined value). The coefficient γ increases as the drive torque detected by the torque detector 46 increases.
Then, the target rotational 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 rotational speed (R ′ × A × γ) is set to a predetermined value X. The 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 rotationally drive the lubricant supply roller 15a at the rotational speed (R ′ × A × γ). Accordingly, it is possible to reliably reduce the occurrence of problems such as image unevenness due to the resonance phenomenon regardless of fluctuations in the driving 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 a predetermined condition is predetermined. 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 it matches the value X. ing.
As a result, even when control is performed to vary the rotation speed of the lubricant supply roller 15a, the photosensitive drum 11 (image carrier) vibrates greatly, and problems such as image unevenness are less likely to occur.

Embodiment 2. FIG.
A second embodiment of the present invention will be described in detail with reference to FIG.
FIG. 6A is a diagram showing the relationship between the absolute humidity detected by the temperature / humidity sensor 50 and the rotational speed of the lubricant supply roller 15a in the control of the lubricant supply device 15 in the second embodiment. . FIG. 6B is a diagram showing the relationship between the total running time and the rotational speed of the lubricant supply roller 15a in the control of the lubricant supply device 15 according to the second embodiment.
In the image forming apparatus 1 according to the second embodiment, the range of the rotational speed of the lubricant supply roller 15a at which resonance is likely to occur is predetermined. The rotational speed of the lubricant supply roller 15a at which resonance is likely to occur is determined. This 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 that is in sliding contact with the photosensitive drum 11 as shown in FIG. Lubricant supply roller 15a for supplying lubricant, solid lubricant 15b in sliding contact with lubricant supply roller 15a, compression spring 15c for urging solid lubricant 15b toward lubricant supply roller 15a, solid lubricant 15b 15d, a thinning blade 15f that abuts on the photosensitive drum 11 and thins the lubricant supplied onto the photosensitive drum 11, and the like.
Also in the second embodiment, as in the first embodiment, the drive motor 45 as a drive source for driving the lubricant supply roller 15a (lubricant supply device 15) has an environment (absolute humidity). It functions as a variable means that varies the rotational speed 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 sets a predetermined number of rotations of the lubricant supply roller 15a that is regularly changed by the drive motor 45 (variable means) based on a predetermined condition. The drive motor 45 is controlled so as to vary irregularly within a range (a range of the number of rotations in which resonance can occur and a range of the number of rotations to be avoided).
That is, in the drive motor 45 (variable means), the rotation speed R ′ of the lubricant supply roller 15a to be varied based on a predetermined condition is set to one predetermined value X (or two or more predetermined values). The rotation speed R ′ to be varied is not within the predetermined range described above but is within the predetermined range. It is controlled to be changed to an outside rotational speed.

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

Further, referring to FIG. 6B, in the image forming apparatus 1 according to the second embodiment, in principle, as the total travel distance of the lubricant supply roller 15a obtained by the counter 49 increases, the lubricant is supplied. 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 with the horizontal axis as the total travel distance of the lubricant supply roller 15a and the vertical axis as the rotation speed of the lubricant supply roller 15a, a regular line as shown by a broken line is drawn. A staircase-like graph (a graph in which the rotation speed increases by a certain value whenever the total travel distance increases by a certain value) has a basic shape. However, as shown in the graph shown by the broken line in FIG. 6 (B), if the rotational speed control is performed so as to form a regular stepped graph over the entire range of the total travel distance, the predetermined total travel distance is obtained. In this case, the rotational speed of the lubricant supply roller 15a falls within the range of the rotational speed to be avoided (the rotational speed range in which resonance can occur).
Therefore, in the second embodiment, when the predetermined total travel distance is reached, the rotational speed of the lubricant supply roller 15a is outside the range of the rotational speed that should be avoided (the rotational speed range in which resonance can occur). As shown, the entire range as shown by the broken line is not a regular stepped graph, but a part of the range as shown by the solid line is an irregular stepped graph (the total distance The rotation speed is controlled so that the degree of change is different and the shape of the staircase is different.

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

Embodiment 3 FIG.
A third embodiment 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 illustrates a state in which a combination of gear trains is switched by the switching unit. FIG. 8 is a schematic diagram showing a modification of the gear train of FIG. 7, and FIG. 9 is a schematic diagram showing a further modification of the gear train.
In the image forming apparatus 1 according to the third embodiment, when the resonance is about to occur, the switching unit switches the combination of the gear trains that transmits the drive from the drive source 45 to the lubricant supply roller 15a, so The fact that the frequency is variable is different from that of the first embodiment in which the rotational speed of the lubricant supply roller 15a is variable when resonance is likely to occur.

As in the first embodiment, the lubricant supply device 15 in the third embodiment is also provided with a foamed elastic layer in sliding contact with the photosensitive drum 11 as shown in FIG. Lubricant supply roller 15a for supplying lubricant, solid lubricant 15b in sliding contact with lubricant supply roller 15a, compression spring 15c for urging solid lubricant 15b toward lubricant supply roller 15a, solid lubricant 15b 15d, a thinning blade 15f that abuts on the photosensitive drum 11 and thins the lubricant supplied onto the photosensitive drum 11, and the like.
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 (lubricant supply device 15) has the process linear velocity and the environment. It functions as a variable means that varies the rotational speed of the lubricant supply roller 15a based on (absolute humidity), total travel distance, and the like.

Here, in the lubricant supply device 15 according to the third embodiment, the combination of gear trains that transmit drive from the drive motor 45 as a drive source to the lubricant supply roller 15a is switched, and the natural frequency related to the drive is changed. A variable switching means is provided.
Specifically, as shown in FIG. 7, the switching means includes a drive gear 80 installed on the motor shaft of the drive motor 45 as a drive source, and a driven gear 84 installed on the rotating shaft portion of the lubricant supply roller 15a. And a peristaltic gear 82 that peristates so as to switch the combination of the relay gears 81 to 83 relayed between them.

More specifically, the drive gear 80 meshes with the lower gear 81a of the first relay gear 81 having a two-stage gear structure, and the upper gear 81b of the first relay gear 81 has a peristaltic gear 82 (second relay gear). Meshed.
The peristaltic gear 82 is rotatably supported by the peristaltic arm 100 and perturbs the peristaltic gear 82 around the rotation axis of the first relay gear 81 regardless of the rotation of the first relay gear 81 or the peristaltic gear 82. It is configured to be able to. When the swing gear 82 swings with the swing arm 100 to the position of FIG. 7A and is maintained in this state, the swing gear 82 meshes with the third relay gear 83 that meshes with the driven gear 84. Become. In contrast, when the peristaltic gear 82 is peristally moved to the position of FIG. 7B together with the peristaltic arm 100 and the state is maintained, the peristaltic gear 82 is not connected to the driven gear 84 without passing through the third relay gear 83. Will be engaged.

  That is, as shown in FIG. 7A, the swing arm 100 functioning as the switching means is a combination of a gear train that transmits drive from the drive motor 45 to the lubricant supply roller 15a as the first relay gear 81 and the swing gear 82. (Second relay gear), the third relay gear 83, or as shown in FIG. 7B, a combination of gear trains for transmitting drive from the drive motor 45 to the lubricant supply roller 15a is the first relay gear 81, Peristaltic gear 82 (second relay gear) can be used or switched. In the third embodiment, the combination of 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 a 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.

  In this way, when the gear train combination is switched, the meshing frequency of the gear train also changes, and the natural frequency related to the drive of the lubricant supply roller 15a (lubricant supply device 15) also changes. . That is, the natural frequency (gearing frequency of the gear train) when the lubricant supply roller 15a (lubricant supply device 15) is driven by the combination of the gear train shown in FIG. 7 (A) and FIG. 7 (B). The natural frequency (gearing frequency of the gear train) when driving the lubricant supply roller 15a (lubricant supply device 15) is different depending on the combination of the gear trains shown.

  Further, in the third embodiment, when the drive motor 45 is switched from the reference combination shown in FIG. 7A to the state shown in FIG. 7B by the switching means described above, 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 direction rotation type drive motor. When the combination of 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 arrow direction in FIG. 7A and the counterclockwise direction). 7), the drive is transmitted to the driven gear 84 via the first relay gear 81, the peristaltic gear 82, and the third relay gear 83, and the lubricant supply roller 15a together with the driven gear 84 in FIG. It rotates in the counterclockwise direction (the direction that coincides with the rotation direction shown in FIG. 2). On the other hand, when the combination of gear trains is in the state shown in FIG. 7B, the drive motor 45 is driven in the reverse direction, and the reverse direction (the arrow direction in FIG. 7), the driving force is transmitted to the driven gear 84 via the first relay gear 81 and the peristaltic gear 82, and the lubricant supply roller 15a together with the driven gear 84 is counterclockwise in FIG. The rotation direction is the same as the rotation direction shown in FIG. In the state shown in FIG. 7B, the third relay gear 83 idles in the clockwise direction by 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 where the swing arm 100 swings, and the controller 60 controls the lubricant supply device 15 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 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) based on a predetermined condition is the same as that of the motor, the gear train combination is changed. The switching unit is controlled by the control unit 60 so that the combination shown in FIG. 7A is switched to the combination shown in FIG. 7B.
Then, after the gear train combination is switched to the combination shown in FIG. 7B and a series of lubricant supply operations (image forming process) by the lubricant supply device 15 is completed, the gear train combination is displayed by the switching means. The combination shown in FIG. 7B is returned to the reference combination shown in FIG.

  Here, the predetermined value X described above is the driving force from the drive motor 45 to the lubricant supply roller 15a when the rotational speed of the lubricant supply roller 15a coincides with that of the first embodiment. Is transmitted to 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 resonates, and is the number of rotations that should be avoided.

  On the other hand, in the third embodiment, when the rotational speed of the lubricant supply roller 15a to be varied based on a predetermined condition coincides with a predetermined value X at which resonance occurs, the drive motor 45 The gear train in which the driving force is transmitted to the lubricant supply roller 15a is switched to the combination shown in FIG. 7B, and the meshing frequency of the gear train is changed so that the photosensitive drum 11, the charging roller 12, the writing unit 2, etc. Since the resonance does not coincide with the natural frequency (resonance frequency) of other members, it is possible to prevent a problem that the photosensitive drum 11 vibrates greatly and causes image unevenness. .

  In the third embodiment as well, as in the first embodiment, two or more “predetermined predetermined values X” described above are set and lubrication is to be varied based on predetermined conditions. When the rotation speed R ′ of the agent supply roller 15a coincides with any one of two or more predetermined values, a combination of gear trains is set as a reference shown in FIG. The switching means can also be controlled by the control unit 60 so that the combination shown in FIG. Furthermore, 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 determined in advance. When it falls within the predetermined range, the switching means is controlled by the control unit 60 so that the combination of gear trains is switched from the reference combination shown in FIG. 7A to the combination shown in FIG. 7B. Can also be controlled.

Here, in the third embodiment, a torque detection unit 46 (see FIG. 2) is installed as torque detection means for detecting the drive torque when the lubricant supply roller 15a rotates. And the control part 60 is controlled to vary the predetermined value X mentioned above according to the drive torque detected by the torque detection part 46 (torque detection means).
Specifically, a control table in which the relationship between the value of the driving torque of the lubricant supply roller 15a and the predetermined value X that is variable is defined in the control unit 60 in advance. Then, the drive torque detected by the torque detection unit 46 (torque detection means) is collated with the control table, and the predetermined value X serving as a determination criterion for switching by the switching means is varied to an optimum value. .
Such control is performed when the rotational speed of the lubricant supply roller 15a to be varied based on a predetermined condition coincides with a predetermined value X (avoidance rotational speed), and the lubricant at that time 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 also increases, and the number of rotations to be avoided (predetermined) This is because the resonance phenomenon described above may occur unless the value X) is changed to an appropriate value.

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

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

Specifically, in the state of FIG. 9A that is the reference state, driving is transmitted from the driving gear 80 that rotates counterclockwise to the driven gear 84 via the first relay gear 81 and the peristaltic gear 82. The lubricant supply roller 15a rotates with the driven gear 84 in the counterclockwise direction. On the other hand, at the time of the first switching, the state is changed from the reference state of FIG. 9A to the state of FIG. Drive is transmitted to the driven gear 84 via the first relay gear 81, the peristaltic gear 82, and the third relay gear 87, and the lubricant supply roller 15 a rotates counterclockwise together with the driven gear 84. Further, at the time of the second switching, the reference state is switched from the state shown in FIG. 9A to the state shown in FIG. 9C by the swing of the swing arm 100, and the first relay from the drive gear 80 rotating in the clockwise direction. Drive is transmitted to the driven gear 84 via the gear 81, the peristaltic gear 82, and the fourth relay gear 88, and the lubricant supply roller 15 a rotates counterclockwise together with the driven gear 84.
Note that the third relay gear 87 and the fourth relay gear 88 have different gear train meshing frequencies for the combination of gear trains in FIG. 9B and the gear train of FIG. 9C. In addition, the number of gears (the number of teeth) is different.

  In this way, when the gear train combination is switched from the reference combination by the switching means, the gear train meshing frequency can be selected by selecting from among a plurality of gear train combinations to be switched. Can be changed in accordance with the number of sets (because there are more choices of meshing frequency to be changed), 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 gear trains that transmit drive from the drive motor 45 (drive source) to the lubricant supply roller 15a, and the natural frequency related to the drive. There is provided switching means for varying. The combination of gear trains is set as a reference combination, and the rotational speed of the lubricant supply roller 15a to be varied by the drive motor 45 (variable means) based on a predetermined condition is a predetermined value. A control unit 60 is provided for controlling the switching means so that the combination of gear trains is switched from the reference combination when it matches X.
As a result, even when control is performed to vary the rotation speed of the lubricant supply roller 15a, the photosensitive drum 11 (image carrier) vibrates greatly, and problems such as image unevenness are less likely to occur.

Embodiment 4 FIG.
A fourth embodiment 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 the lubricant supply device 15 according to the fourth embodiment, and illustrates a state in which a combination of gear trains is switched by the switching unit. FIG. 11 is a schematic diagram showing a modification of the gear train of FIG. 10, and FIG. 12 is a schematic diagram showing a further modification of the gear train.
The image forming apparatus 1 according to the fourth embodiment switches the combination of gear trains that transmit drive from the drive source 45 to the lubricant supply roller 15a by the switching unit, and supplies the lubricant in addition to the meshing frequency of the gear train. The point that the rotational 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 variable.

As in the first embodiment, the lubricant supply device 15 in the fourth embodiment is also provided with a foamed elastic layer that is in sliding contact with the photosensitive drum 11 as shown in FIG. Lubricant supply roller 15a for supplying lubricant, solid lubricant 15b in sliding contact with lubricant supply roller 15a, compression spring 15c for urging solid lubricant 15b toward lubricant supply roller 15a, solid lubricant 15b 15d, a thinning blade 15f that abuts on the photosensitive drum 11 and thins the lubricant supplied onto the photosensitive drum 11, and the like.
Also in the fourth embodiment, as in the first embodiment, the drive motor 45 as a drive source for driving the lubricant supply roller 15a (lubricant supply device 15) has the process linear velocity, the environment. It functions as a variable means that varies the rotational speed of the lubricant supply roller 15a based on (absolute humidity), total travel distance, and the like.
Further, in the lubricant supply device 15 according to the fourth embodiment, a combination of gear trains for transmitting the drive from the drive motor 45 as a drive source to the lubricant supply roller 15a is the same as in the third embodiment. Switching means is provided for switching to vary the natural frequency associated with the drive.

Here, the switching means in the fourth embodiment differs from that in the third embodiment in that the rotation speed of the lubricant supply roller 15a increases when the gear train combination is switched from the reference combination. It is configured to be decelerated or decelerated.
Specifically, the driven gear 84 installed on the lubricant supply roller 15a is configured as a two-stage gear composed of two gears (a first driven gear 84a and a second driven gear 84b) having different numbers of gears. Yes.
Further, the lower gear 81a of the first relay gear 81 having the two-stage gear structure is engaged with the drive gear 80, and the peristaltic gear 82 (second relay gear) is engaged with the upper gear 81b of the first relay gear 81. Yes. The peristaltic gear 82 is rotatably supported by the peristaltic arm 100 and perturbs the peristaltic gear 82 around the rotation axis of the first relay gear 81 regardless of the rotation of the first relay gear 81 or the peristaltic gear 82. It is configured to be able to.
When the swing gear 82 swings with the swing arm 100 to the position of FIG. 10A and is maintained in this state, the third relay meshes with the first driven gear 84a of the driven gear 84 having the two-stage gear structure. The peristaltic gear 82 meshes with the gear 83. On the other hand, when the peristaltic gear 82 is peristally moved to the position of FIG. 10B together with the peristaltic arm 100 and the state is maintained, the driven gear 84 having a two-stage gear structure is not provided via the third relay gear 83. The second driven gear 84b meshes with the peristaltic gear 82.

  That is, as shown in FIG. 10A, the peristaltic arm 100 functioning as the switching means has a combination of gear trains for transmitting driving from the drive motor 45 to the lubricant supply roller 15a as the first relay gear 81 and peristaltic gear 82. (Second relay gear), third relay gear 83, and first driven gear 84a, or a combination of gear trains that transmits drive from the drive motor 45 to the lubricant supply roller 15a as shown in FIG. The first relay gear 81, the peristaltic gear 82 (second relay gear), and the second driven gear 84b can be selected or switched. In the fourth embodiment, the combination of gear trains shown in FIG. 10A is a reference combination (a normal state, which is appropriately referred to as a “reference state”).

  In this way, when the gear train combination is switched, the meshing frequency of the gear train also changes, and the natural frequency related to the drive of the lubricant supply roller 15a (lubricant supply device 15) also changes. . That is, the natural frequency (gearing frequency of the gear train) when the lubricant supply roller 15a (lubricant supply device 15) is driven by the combination of the gear train shown in FIG. 10 (A) and FIG. 10 (B). The natural frequency (gearing frequency of the gear train) when driving the lubricant supply roller 15a (lubricant supply device 15) is different depending on the combination of the gear trains shown.

  Furthermore, in the fourth embodiment, the rotational speed of the lubricant supply roller 15a when the lubricant supply roller 15a (lubricant supply device 15) is driven by the combination of gear trains shown in FIG. The driven gear 84 (first driven gear 84a is set to be smaller than the rotational speed of the lubricant supply roller 15a when the lubricant supply roller 15a (lubricant supply device 15) is driven by the combination of gear trains shown in FIG. And a second driven gear 84b). That is, when the gear train combination shown in FIG. 10A, which is the reference state, is switched to the gear train combination shown in FIG. 10B, the rotational speed of the lubricant supply roller 15a is increased. become.

  Further, in the fourth embodiment, the drive motor 45 is changed from the combination in which the gear train combination becomes the reference shown in FIG. It is configured to be able to rotate in the forward and reverse directions so that the rotation direction of the lubricant supply roller 15a does not change when switched to the state B).

Here, in the lubricant supply device 15 according to the fourth embodiment configured as described above, the combination of gear trains is set to a reference combination as shown in FIG. The rotational speed of the lubricant supply roller 15a to be varied by the drive motor 45 (variable means) based on a predetermined condition as in the case of 1 is a predetermined value X (or two or more predetermined values). When the values match any one of the predetermined values), the switching means switches the gear train combination from the reference combination shown in FIG. 10A to the combination shown in FIG. 10B.
Then, after the gear train combination is switched to the combination shown in FIG. 10B and a series of lubricant supply operations (image forming process) by the lubricant supply device 15 is completed, the gear train combination is displayed by the switching means. The combination shown in FIG. 10B is returned to the reference combination shown in FIG.

  Here, the predetermined value X described above is the driving force from the drive motor 45 to the lubricant supply roller 15a when the rotational speed of the lubricant supply roller 15a coincides with that of the first embodiment. Is transmitted to 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 section 2 ( Resonance frequency) and resonates, and is the number of rotations that should be avoided.

  On the other hand, in the fourth embodiment, when the rotational speed of the lubricant supply roller 15a to be varied based on a 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, and the meshing frequency of the gear train is changed so that the photosensitive drum 11, the charging roller 12, the writing unit 2, etc. Since the resonance does not coincide with the natural frequency (resonance frequency) of other members, it is possible to prevent a problem that the photosensitive drum 11 vibrates greatly and causes image unevenness. .

  Further, in the fourth embodiment, when the rotational speed of the lubricant supply roller 15a to be varied based on a predetermined condition coincides with a 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 number of rotations of the lubricant supply roller 15a is changed (accelerated) so as not to match the predetermined value X. Therefore, it is possible to prevent a problem that the photosensitive drum 11 is vibrated greatly to cause image unevenness.

Here, when the rotational speed of the lubricant supply roller 15a to be varied based on a predetermined condition coincides with the predetermined value X, the gear train combination is switched by the switching means 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 coincide with the predetermined value X, the amount of 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 reliably supplied to the surface of the photosensitive drum 11.
On the other hand, when the rotational speed of the lubricant supply roller 15a to be varied based on a predetermined condition coincides with the predetermined value X, the switching of the gear train combination by the switching means and the lubricant supply roller 15a When the rotational speed is changed to the deceleration side so as not to coincide with the predetermined value X (for example, in the relationship between FIG. 10 (A) and FIG. 10 (B), FIG. 10 (B) instead of the state of FIG. 10 (A). In this case, the amount of lubricant supplied to the surface of the photosensitive drum 11 by the lubricant supply roller 15a is less than the target, but the solid state is solid. It becomes possible to suppress consumption of the lubricant 15b.

Here, in the fourth embodiment, a torque detection unit 46 (see FIG. 2) is installed as a torque detection unit that detects a drive torque when the lubricant supply roller 15a rotates. And it controls so that one predetermined value X (or two or more predetermined values) mentioned above may be varied according to the drive torque detected by the torque detection part 46 (torque detection means).
Specifically, a control table in which the relationship between the value of the driving torque of the lubricant supply roller 15a and the predetermined value X that is variable is defined in the control unit 60 in advance. Then, the drive torque detected by the torque detection unit 46 (torque detection means) is collated with the control table, and the predetermined value X serving as a determination criterion for switching by the switching means is varied to an optimum value. .
Such control is performed when the rotational speed of the lubricant supply roller 15a to be varied based on a predetermined condition coincides with a predetermined value X (avoidance rotational speed), and the lubricant at that time 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 also increases, and the number of rotations to be avoided (predetermined) This is because the resonance phenomenon described above may occur unless the value X) is changed to an appropriate value.

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

Further, in the fourth embodiment, the rotation speed of the lubricant supply roller 15a is increased when the gear train combination is switched from the reference combination by the switching means.
On the other hand, referring to FIG. 11, when the gear train combination is switched from the reference combination to the combination shown in FIG. 11B by the switching means as shown in FIG. The rotation speed of the agent supply roller 15a may be reduced.

Furthermore, referring to FIG. 12, the combination of the gear train is switched by the switching means from the reference combination as shown in FIG. 12A to the combination shown in FIG. 12B, and the lubricant supply roller 15a rotates. The number can be decelerated, the combination shown in FIG. 12C can be switched to increase the rotational speed of the lubricant supply roller 15a, or the switching means can be controlled by the controller 60.
Specifically, in the state shown in FIG. 12A, which is the reference state, the second of the driven gear 84 having a three-stage gear structure from the drive gear 80 rotating in the counterclockwise direction via the first relay gear 81 and the swing gear 82 is used. The drive is transmitted to the driven gear 84b, and the lubricant supply roller 15a rotates together with the driven gear 84 in the counterclockwise direction. On the other hand, at the time of deceleration, the reference state is switched from the state of FIG. 12A to the state of FIG. 12B by the peristaltic movement of the peristaltic arm 100, and the first relay from the drive gear 80 rotating in the clockwise direction. Drive is transmitted to the first driven gear 84a of the three-stage driven gear 84 via the gear 81, the peristaltic gear 82, and the third relay gear 87, and the lubricant supply roller 15a rotates counterclockwise together with the driven gear 84. Will do. Further, at the time of speed increase, the state of FIG. 12A which is the reference state is switched from the state of FIG. 12A by the swing of the swing arm 100, and the first relay gear 81 from the drive gear 80 rotating in the clockwise direction is switched. The drive is transmitted to the third driven gear 84c of the three-stage driven gear 84 via the peristaltic gear 82 and the fourth relay gear 88, and the lubricant supply roller 15a rotates counterclockwise together with the driven gear 84. It will be.
Note that 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 acceleration / deceleration as described above. The number of gears is set so that the frequency can be changed.

Then, using the gear train as shown in FIG. 12, when the gear train combination is switched from the reference combination shown in FIG. 12A by the switching device, the temperature / humidity sensor 50 ( 2), when the absolute humidity detected is equal to or higher than the predetermined absolute humidity, the gear train as shown in FIG. 12C is switched to increase the rotational speed of the lubricant supply roller 15a. When the absolute humidity detected by the temperature / humidity sensor 50 is equal to or lower than the predetermined absolute humidity, the control unit 60 switches to the gear train as shown in FIG. 12B to decelerate the rotational speed of the lubricant supply roller 15a. Can control the switching means.
Such control is performed when the surrounding environment (absolute humidity) is determined to be greater than the predetermined absolute humidity M, and the environment is a relatively high temperature and high humidity environment and the amount of lubricant supplied is This is because when the ambient environment (absolute humidity) is determined to be smaller than the predetermined absolute humidity M, the amount of lubricant supplied is likely to increase in a relatively low temperature and low humidity environment. . By performing such control, the occurrence of defects such as image unevenness due to resonance phenomenon is reliably reduced, and the amount of lubricant supplied to the photosensitive drum 11 is insufficient or excessive. Can be prevented.

As described above, the image forming apparatus 1 according to the fourth embodiment switches the combination of gear trains that transmit drive from the drive motor 45 (drive source) to the lubricant supply roller 15a, and the natural frequency related to the drive. There is provided switching means for varying. The combination of gear trains is set as a reference combination, and the rotational speed of the lubricant supply roller 15a to be varied by the drive motor 45 (variable means) based on a predetermined condition is a predetermined value. A control unit 60 is provided for controlling the switching means so that the combination of gear trains is switched from the reference combination when it matches X.
As a result, even when control is performed to vary the rotation speed of the lubricant supply roller 15a, the photosensitive drum 11 (image carrier) vibrates greatly, and problems such as image unevenness are less likely to occur.

In each of the above embodiments, the lubricant supply device 15 is integrated with the photosensitive drum 11, the charging roller 12 (charging unit), the developing device 13, and the cleaning device 14 to constitute the process cartridge 10 </ b> Y to form an image. The parts are made compact and maintenance workability is improved.
On the other hand, these constituent members can be configured so as to be replaceable in the apparatus main body 1 without being a constituent member of the process cartridge. Even in such a case, the same effects as those of the above embodiments can be obtained.
In the present application, the “process cartridge” refers to a charging unit that charges the image carrier, a developing unit (developing device) that develops a latent image formed on the image carrier, and a cleaning on the image carrier. It is defined as a unit in which at least one of the cleaning unit (cleaning device) and the image carrier are integrated and detachably installed on the image forming apparatus main body.

In each of the above embodiments, the present invention is applied to the image forming apparatus on which the two-component developing type developing device 13 using the two-component developer is mounted. However, the one-component developing method using the one-component developer is used. Naturally, the present invention can also be applied to an image forming apparatus on which the developing device 13 is mounted.
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. As a matter of course, the present invention can also be applied to an image forming apparatus in which a lubricant supply device for supplying a lubricant to the photosensitive belt is installed. Furthermore, the present invention can also be applied to a lubricant supply device that supplies a lubricant to the surface of the intermediate transfer belt 17 as an image carrier in each of the embodiments.

In each of the above embodiments, the lubricant supply roller 15a has a foamed elastic layer formed on the core metal. However, the lubricant supply roller 15a has a straight or loop shape on the outer periphery of the core metal. What wound the bristle can also be used. In that case, as the bristle, resin fibers such as polyester, nylon, rayon, acrylic, vinylon, and vinyl chloride can be used, and if necessary, conductive fibers mixed with a conductivity-imparting agent such as carbon can be used. it can. In addition, brush hair having a length (hair feet) of 0.2 to 20 mm and a brush density of 2 to 100,000 F / inch ² can be used.
Even in such a case, it is possible to obtain substantially the same effects as those of the above embodiments.

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

1 image forming apparatus (image forming apparatus main body),
10Y, 10M, 10C, 10BK process cartridge,
11 Photosensitive 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 detector (torque detector),
49 counter, 50 temperature / humidity sensor (environment detection means), 60 control unit.

JP 2013-20232 A

Claims (12)

An image carrier on which a toner image is carried;
A lubricant supply roller for supplying a lubricant to the surface of the image carrier;
Variable means for varying the rotational speed 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 matches a predetermined value, the lubricant does not match the predetermined value. A control unit for controlling the variable means so as to increase or decrease the rotation speed of the supply roller;
An image forming apparatus comprising: It is equipped with an environmental detection means that detects the ambient absolute humidity,
The controller controls the absolute humidity detected by the environment detection unit when the number of rotations of the lubricant supply roller to be changed by the variable unit matches a predetermined value based on a predetermined condition. The absolute value detected by the environment detection means is controlled by controlling the variable means so that the rotational speed is increased by a predetermined value or rate so that the rotational speed does not coincide with the predetermined value. 2. The variable means according to claim 1, wherein when the humidity is equal to or lower than a predetermined absolute humidity, the variable means is controlled so as to be decelerated by a predetermined value or a rate so that the rotation speed does not coincide with the predetermined value. Image forming apparatus. Comprising torque detecting means for detecting a driving torque during 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 compared to 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 the degree of the change is increased. An image carrier on which a toner image is carried;
A lubricant supply roller for supplying a lubricant to the surface of the image carrier;
Variable means for varying the rotational speed of the lubricant supply roller;
Switching means for switching a combination of gear trains for transmitting driving from the driving source to the lubricant supply roller to vary the natural frequency related to the driving;
When the gear train combination is set as a reference combination, and the number of rotations of the lubricant supply roller to be varied by the variable means based on a predetermined condition matches a predetermined value. A control unit for controlling the switching means so as to switch the combination of the gear trains from the reference combination;
An image forming apparatus comprising: Comprising torque detecting means for detecting a driving torque during rotation of the lubricant supply roller;
The image forming apparatus according to claim 4, wherein the control unit varies the predetermined value in accordance with a driving torque detected by the torque detection unit.   The switching means is configured to increase or decrease the rotational speed of the lubricant supply roller when the combination of the gear trains is switched from the reference combination. The image forming apparatus according to claim 4 or 5. It is equipped with an environmental detection means that detects the ambient absolute humidity,
The control unit switches the combination of the gear trains from the reference combination by the switching unit, and when the absolute humidity detected by the environment detection unit is equal to or higher than a predetermined absolute humidity, the lubricant supply roller The switching means is controlled so that the rotational speed is increased so that the rotational speed of the lubricant supply roller is decelerated when the absolute humidity detected by the environment detection means is equal to or lower than a predetermined absolute humidity. 6. The image forming apparatus according to claim 4, wherein the switching unit is controlled. The switching means is a combination of a relay gear relayed between a drive gear installed on a motor shaft of a drive motor as the drive source and a driven gear installed on a rotating shaft portion of the lubricant supply roller. A peristaltic gear that can be moved to
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 claim 4, wherein the image forming apparatus is an image forming apparatus.   9. The predetermined value set in advance is set to two or more or set as a continuous value within a predetermined range. Image forming apparatus. An image carrier on which a toner image is carried;
A lubricant supply roller for supplying a lubricant to the surface of the image carrier;
Variable means for varying the rotational speed of the lubricant supply roller;
A controller that controls the variable means so that the number of rotations of the lubricant supply roller that is to be regularly varied by the variable means based on a predetermined condition is irregularly varied within a predetermined range;
An image forming apparatus comprising:   The controller is configured to increase the rotational speed of the lubricant supply roller continuously or stepwise as the total travel distance or total drive time of the image carrier or the lubricant supply roller increases. The image forming apparatus according to claim 1, wherein the variable unit is controlled. It is equipped with an environmental detection means that detects the ambient absolute humidity,
The control unit controls the variable unit so that the number of rotations of the lubricant supply roller increases continuously or stepwise as the absolute humidity detected by the environment detection unit increases. The image forming apparatus according to claim 1.

Images