JP6711091B2 - Lubricant applying device and image forming device - Google Patents

Description

The present invention relates to a lubricant applying device and an image forming device.

Generally, an image forming apparatus (printer, copier, facsimile, etc.) that uses electrophotographic process technology forms an electrostatic latent image by irradiating (exposing) a charged photoreceptor with laser light based on image data. Form. Then, by supplying toner from the developing device to the photosensitive drum (image carrier) on which the electrostatic latent image is formed, the electrostatic latent image is visualized to form a toner image. Further, after the toner image is directly or indirectly transferred to the paper, the toner image is formed on the paper by heating and pressing at the fixing nip to fix the toner image.

Generally, an image forming apparatus is provided with a cleaning blade for scraping off the transfer residual toner adhering to the surface of the photosensitive drum. However, the cleaning performance of the cleaning blade deteriorates as the cleaning blade wears and the surface of the photosensitive drum becomes rough. Therefore, in such an image forming apparatus, a lubricant applying device is provided to apply the lubricant to the photosensitive drum. By applying the lubricant to the photoconductor drum from the lubricant application device, the surface of the photoconductor drum becomes smooth, and deterioration of the cleaning performance of the cleaning blade is prevented.

By the way, in the case where the lubricant applying device is arranged on the upstream side of the cleaning blade in the rotation direction of the photosensitive drum, the lubricant is applied on the transfer residual toner before being scraped off by the cleaning blade. The amount of transfer residual toner is not constant depending on the printing rate and the like, and since the cleaning blade scrapes off the transfer residual toner and the lubricant on the transfer residual toner, the amount of lubricant applied in the lubricant applying device becomes uneven ( Hereinafter, “unevenness of coating”) is likely to occur.

In order to suppress the problem of coating unevenness in the lubricant coating device, a configuration in which the lubricant coating device is arranged on the downstream side of the cleaning blade as in the configuration described in Patent Document 1, for example, can be considered. According to this configuration, the lubricant is applied to the photoconductor drum after the transfer residual toner is cleaned from the photoconductor drum by the cleaning blade, so that the lubricant can be evenly applied to the photoconductor drum, which in turn stabilizes. It is possible to obtain the desired image quality.

JP 2012-58647 A

Incidentally, with the demand for higher image quality in the electrophotographic system, the diameter of the toner used for image formation is being reduced. Among them, there is a case where a toner is used in which an external additive such as silica having a small size is added to the toner in order to secure the fluidity and transferability of the toner. However, since the external additive added to the toner easily slips through the contact portion between the cleaning blade and the photoconductor drum, the external additive adheres to the lubricant application portion in the lubricant application device, and thus uneven coating is likely to occur. There was a problem.

An object of the present invention is to provide a lubricant applying device and an image forming device capable of suppressing the occurrence of unevenness in the amount of lubricant applied to an image carrier.

The lubricant applying device according to the present invention is
A brush roller is provided, and a brush roller that applies the lubricant scraped from the solid lubricant by the brush to the image carrier is provided.
The rotation direction of the brush roller is the same as the rotation direction at the contact position with the image carrier,
The brush is inclined to the opposite side to the rotation direction of the brush roller , and in the rotation direction of the brush roller, the brush is at the most upstream contact position on the most upstream side where the brush contacts the image carrier. The first angle formed by the direction of the force received from the image carrier and the reference line connecting the rotation center of the brush roller and the most upstream contact position is the first angle formed by the reference line and the tip of the brush. The brush roller is planted so as to be equal to two angles.

The image forming apparatus according to the present invention,
It is equipped with the above-mentioned lubricant application device.

According to the present invention, it is possible to suppress unevenness in the amount of lubricant applied to the image carrier.

FIG. 1 is a diagram schematically showing an overall configuration of an image forming apparatus according to this embodiment. FIG. 3 is a diagram showing a main part of a control system of the image forming apparatus according to the present embodiment. It is a figure which shows the coating operation of the lubricant in the conventional brush roller. It is a figure which shows the coating operation of the lubricant in the conventional brush roller. It is a figure which shows the coating operation of the lubricant in the conventional brush roller. It is an enlarged view of the brush roller which concerns on this Embodiment. It is a figure which shows the coating operation of the lubricant in the brush roller which concerns on this Embodiment. It is a figure which shows the 2nd angle with respect to the number of prints. FIG. 5 is a diagram showing the amount of bite of the brush roller into the solid lubricant relative to the number of printed sheets. It is a figure which shows the structure which has arrange|positioned the solid lubricant on the side of the brush roller. It is a figure which shows the state which moved the solid lubricant to the upper side rather than the position of FIG. It is a figure which shows the structure which moves a brush roller with respect to a photosensitive drum.

Hereinafter, the present embodiment will be described in detail with reference to the drawings. FIG. 1 is a diagram schematically showing the overall configuration of an image forming apparatus 1 according to this embodiment. FIG. 2 is a diagram showing a main part of a control system of the image forming apparatus 1 according to this embodiment.

An image forming apparatus 1 shown in FIGS. 1 and 2 is an intermediate transfer type color image forming apparatus using an electrophotographic process technique. That is, the image forming apparatus 1 primarily transfers the toner images of Y (yellow), M (magenta), C (cyan), and K (black) formed on the photosensitive drum 413 to the intermediate transfer belt 421. An image is formed by superimposing toner images of four colors on the intermediate transfer belt 421 and then secondarily transferring the toner images to the paper S.

Further, in the image forming apparatus 1, the photosensitive drums 413 corresponding to the four colors of YMCK are arranged in series in the running direction of the intermediate transfer belt 421, and the toner images of respective colors are sequentially transferred to the intermediate transfer belt 421 by one procedure. The tandem system is adopted.

The image forming apparatus 1 includes an image reading unit 10, an operation display unit 20, an image processing unit 30, an image forming unit 40, a sheet conveying unit 50, a fixing unit 60, and a control unit 90.

The control unit 90 includes a CPU (Central Processing Unit) 91, a ROM (Read Only Memory) 92, a RAM (Random Access Memory) 93, and the like. The CPU 91 reads out a program corresponding to the processing content from the ROM 92, expands it in the RAM 93, and centrally controls the operation of each block of the image forming apparatus 1 in cooperation with the expanded program. At this time, various data stored in the storage unit 72 is referred to. The storage unit 72 is composed of, for example, a nonvolatile semiconductor memory (so-called flash memory) or a hard disk drive.

The control unit 90 transmits/receives various data to/from an external device (for example, a personal computer) connected to a communication network such as a LAN (Local Area Network) and a WAN (Wide Area Network) via the communication unit 71. To do. The control unit 90 receives, for example, image data (input image data) transmitted from an external device, and forms an image on the paper S based on this image data. The communication unit 71 is composed of a communication control card such as a LAN card.

The image reading unit 10 includes an automatic document feeder 11 called an ADF (Auto Document Feeder), a document image scanning device 12 (scanner), and the like.

The automatic document feeder 11 conveys the document D placed on the document tray by a conveyance mechanism and sends it to the document image scanning device 12. With the automatic document feeder 11, it becomes possible to continuously read the images (including both sides) of a large number of documents D placed on the document tray at once.

The document image scanning device 12 optically scans a document conveyed from the automatic document feeder 11 onto the contact glass or a document placed on the contact glass, and reflects light from the document on a CCD (Charge Coupled Device). ) The original image is read by forming an image on the light receiving surface of the sensor 12a. The image reading unit 10 generates input image data based on the reading result of the original image scanning device 12. The input image data is subjected to predetermined image processing in the image processing unit 30.

The operation display unit 20 is composed of, for example, a liquid crystal display (LCD: Liquid Crystal Display) with a touch panel, and functions as a display unit 21 and an operation unit 22. The display unit 21 displays various operation screens, image states, operating states of each function, and the like in accordance with display control signals input from the control unit 90. The operation unit 22 includes various operation keys such as a numeric keypad and a start key, receives various input operations by the user, and outputs operation signals to the control unit 90.

The image processing unit 30 includes a circuit that performs digital image processing on input image data according to initial settings or user settings. For example, the image processing unit 30 performs the gradation correction based on the gradation correction data (gradation correction table) under the control of the control unit 90. Further, the image processing unit 30 performs various correction processing such as color correction and shading correction, compression processing, and the like on the input image data in addition to the gradation correction. The image forming unit 40 is controlled based on the image data that has been subjected to these processes.

The image forming section 40 includes image forming units 41Y, 41M, 41C, 41K and an intermediate transfer unit 42 for forming an image with each color toner of Y component, M component, C component, and K component based on the input image data. And so on.

The image forming units 41Y, 41M, 41C, and 41K for the Y component, the M component, the C component, and the K component have the same configuration. For convenience of illustration and description, common components are denoted by the same reference numeral, and when differentiating from each other, the reference numeral is appended with Y, M, C, or K. In FIG. 1, reference numerals are given only to the components of the image forming unit 41Y for the Y component, and reference numerals are omitted to the other components of the image forming units 41M, 41C, and 41K.

The image forming unit 41 includes an exposure device 411, a developing device 412, a photosensitive drum 413, a charging device 414, a drum cleaning device 415, a lubricant applying device 100, and the like.

The photosensitive drum 413 includes, for example, an undercoat layer (UCL: Under Coat Layer), a charge generation layer (CGL: Charge Generation Layer), a charge transport layer (on a peripheral surface of a conductive cylinder (aluminum tube) made of aluminum. It is a negative charge type organic photoconductor (OPC) in which CTL (Charge Transport Layer) is sequentially laminated. The photosensitive drum 413 may have an outer diameter of 60 mm, for example.

The charging device 414 uniformly charges the surface of the photoconductive drum 413 having photoconductivity to a negative polarity by generating corona discharge.

The exposure device 411 is composed of, for example, a semiconductor laser, and irradiates the photoconductor drum 413 with laser light corresponding to an image of each color component. Positive charges are generated in the charge generation layer of the photoconductor drum 413 and are transported to the surface of the charge transport layer, whereby surface charges (negative charges) of the photoconductor drum 413 are neutralized. An electrostatic latent image of each color component is formed on the surface of the photoconductor drum 413 due to the potential difference with the surroundings.

The developing device 412 is a two-component reversing type developing device, and makes toner of each color component adhere to the surface of the photosensitive drum 413 to visualize the electrostatic latent image and form a toner image. The developing device 412 forms a toner image on the surface of the photoconductor drum 413 by supplying the toner contained in the developer to the photoconductor drum 413. An external additive such as silica is added to the toner. The toner may have a particle size of 6 μm, for example, and the external additive may have a particle size of 80 nm, for example.

The drum cleaning device 415 includes a drum cleaning blade 415A that is in sliding contact with the surface of the photoconductor drum 413, and removes transfer residual toner remaining on the surface of the photoconductor drum 413 after the primary transfer. The drum cleaning blade 415A may be made of urethane rubber, for example.

The lubricant applying device 100 is arranged on the downstream side of the drum cleaning device 415 in the rotation direction of the photosensitive drum 413, and has a solid lubricant 110 and a brush roller 120. The brush roller 120 is disposed between the solid lubricant 110 and the photoconductor drum 413, and applies the lubricant scraped from the solid lubricant 110 to the photoconductor drum 413. As the lubricant, for example, one made of zinc stearate can be used.

The brush roller 120 has a core metal 121 and a brush 122 that is planted on the core metal 121 (see FIG. 6 ). The brush 122 is made of acrylic, for example, and has a density of 150 kF/inch ² and a Young's modulus of 3000 N/mm ² .

The brush roller 120 rotates in the width direction with respect to the rotation direction of the photosensitive drum 413. The with direction is a direction in which the rotating directions of the contact portions of the photoconductor drum 413 and the brush roller 120 are the same. The rotation speed of the brush roller 120 (for example, 150 mm/s) is set to be slower than the rotation direction of the photosensitive drum 413 (for example, 300 mm/s). Details of the brush roller 120 will be described later.

Further, in the present embodiment, a torque detection unit 73 for detecting the torque of the brush roller 120 is provided. The torque detection unit 73 detects, for example, a drive current for driving the brush roller 120. The torque detection unit 73 calculates the torque of the brush roller 120 according to the detected drive current value, and outputs the torque to the control unit 90.

The intermediate transfer unit 42 includes an intermediate transfer belt 421, a primary transfer roller 422, a plurality of support rollers 423, a secondary transfer roller 424, a belt cleaning device 426, and the like.

The intermediate transfer belt 421 is an endless belt, and is stretched around a plurality of support rollers 423 in a loop. At least one of the plurality of support rollers 423 is a driving roller, and the others are driven rollers. The rotation of the drive roller causes the intermediate transfer belt 421 to travel in the A direction at a constant speed.

The intermediate transfer belt 421 is a belt having conductivity and elasticity, and is rotationally driven by a control signal from the control unit 90.

The primary transfer roller 422 is arranged on the inner peripheral surface side of the intermediate transfer belt 421 so as to face the photoconductor drums 413 of the respective color components. The primary transfer roller 422 is pressed against the photoconductor drum 413 with the intermediary transfer belt 421 interposed therebetween, whereby a primary transfer nip for transferring a toner image from the photoconductor drum 413 to the intermediary transfer belt 421 is formed.

The secondary transfer roller 424 is arranged on the outer peripheral surface side of the intermediate transfer belt 421, facing the backup roller 423B arranged on the downstream side of the driving roller 423A in the belt traveling direction. The secondary transfer roller 424 is pressed against the backup roller 423B with the intermediate transfer belt 421 interposed therebetween, thereby forming a secondary transfer nip for transferring the toner image from the intermediate transfer belt 421 to the sheet S.

The belt cleaning device 426 removes transfer residual toner remaining on the surface of the intermediate transfer belt 421 after the secondary transfer.

When the intermediate transfer belt 421 passes through the primary transfer nip, the toner images on the photoconductor drum 413 are sequentially primary-transferred onto the intermediate transfer belt 421 in an overlapping manner. Specifically, a primary transfer bias is applied to the primary transfer roller 422, and a charge having a polarity opposite to that of the toner is applied to the back surface side of the intermediate transfer belt 421, that is, the side in contact with the primary transfer roller 422, to thereby obtain a toner image. Are electrostatically transferred to the intermediate transfer belt 421.

After that, when the sheet S passes through the secondary transfer nip, the toner image on the intermediate transfer belt 421 is secondarily transferred to the sheet S. Specifically, a secondary transfer bias is applied to the backup roller 423B, and a charge having the same polarity as the toner is applied to the surface side of the sheet S, that is, the side in contact with the intermediate transfer belt 421, so that the toner image is formed on the sheet. It is electrostatically transferred to S.

The fixing unit 60 includes an upper fixing unit 60A having a fixing surface side member arranged on the side of the sheet S on which the toner image is formed, and a fixing unit 60 on the opposite side of the fixing surface that is the back side of the sheet S. The lower fixing portion 60B and the like having the rear surface side supporting member arranged are provided. When the back surface side support member is pressed against the fixing surface side member, a fixing nip that holds and conveys the sheet S is formed.

The fixing unit 60 fixes the toner image on the sheet S by heating and pressurizing the sheet S that has been secondarily transferred with the toner image and conveyed, at the fixing nip. The fixing unit 60 is arranged in the fixing device F as a unit. Further, the fixing device F may be provided with an air separation unit that separates the sheet S from the fixing surface side member or the back surface side supporting member by blowing air.

The upper fixing unit 60A has an endless fixing belt 61 which is a fixing surface side member, a heating roller 62, and a fixing roller 63.

The lower fixing section 60B has a pressure roller 64 that is a back surface side supporting member. The pressure roller 64 forms a fixing nip for nipping and conveying the sheet S with the fixing belt 61.

The paper transport unit 50 includes a paper feed unit 51, a paper discharge unit 52, a transport path unit 53, and the like. The paper S (standard paper, special paper) identified on the basis of the basis weight, size, etc. is accommodated in each of preset types in the three paper feed tray units 51a to 51c constituting the paper feed unit 51. ..

The conveyance path portion 53 passes through a plurality of conveyance roller pairs such as a pair of registration rollers 53 a, a normal conveyance path 53 b that allows the sheet S to pass through the image forming portion 40 and the fixing portion 60, and is discharged to the outside of the machine, and the fixing portion 60. After the sheet S is turned upside down, it has an inversion conveyance path 53c which joins the normal conveyance path 53b again upstream of the image forming section 40. At the time of double-sided printing, a toner image is formed on the front surface of the paper S when first passing through the normal transport path 53b, and after passing through the reverse transport path 53c, the toner image is transferred onto the back surface of the paper S when passing through the normal transport path 53b again. Are formed.

The sheets S stored in the sheet feeding tray units 51 a to 51 c are sent out one by one from the uppermost portion, and are conveyed to the image forming section 40 by the conveyance path section 53. At this time, the registration roller unit provided with the registration roller pair 53a corrects the inclination of the fed paper S and adjusts the conveyance timing. Then, in the image forming section 40, the toner image on the intermediate transfer belt 421 is secondarily transferred onto one surface of the sheet S collectively, and the fixing section 60 performs a fixing step. The sheet S on which the image is formed is ejected to the outside of the machine by the sheet ejection unit 52 including the sheet ejection roller 52a.

Incidentally, with the demand for higher image quality in the electrophotographic system, the diameter of the toner used for image formation is being reduced. Among them, there is a case where a toner is used in which an external additive such as silica having a small size is added to the toner in order to secure the fluidity and transferability of the toner. The external additive added to the toner easily slips through the contact portion between the cleaning blade 415A and the photoconductor drum 413 in the drum cleaning device 415, and thus adheres to the brush roller 120 in the lubricant applying device 100, which eventually causes uneven coating. There was a problem that it tends to occur. Specific examples will be described separately for the case where the rotation direction of the brush roller 120 is the counter direction and the case where the rotation direction is the with direction. The counter direction is a direction in which the rotation directions of the contact portions of the photoconductor drum 413 and the brush roller 120 are opposite to each other.

3 to 5 are views showing a lubricant applying operation in the conventional brush roller 120. In addition, in FIGS. 3 to 5, the outer diameter of the core metal 121 is 6 mm. The brush 122 is planted in the cored bar 121 in a straight bristle state and has a length of 3 mm. The brush roller 120 is set to draw an arc having an outer diameter of 12 mm by rotating. The axial distance between the photoconductor drum 413 and the brush roller 120 is 35 mm, and the amount of the brush 122 biting into the photoconductor drum 413 is 1 mm. The friction coefficient of the frictional force acting on the brush 122 when the brush roller 120 contacts the photoconductor drum 413 is 0.2 to 0.4. The amount of bite of the brush 122 with respect to the solid lubricant 110 is 0.5 mm.

First, the case where the rotation directions of the brush roller 120 and the photoconductor drum 413 are set in the counter direction will be described. As illustrated in FIG. 3, the brush 122 of the brush roller 120 scrapes and holds the lubricant G from the solid lubricant 110, and contacts the photoconductor drum 413 to apply the lubricant to the photoconductor drum 413. At this time, when the external additive J is attached to the surface of the photoconductor drum 413, the external additive J is attached to the surface of the brush 122 that holds the lubricant G. When the external additive J adheres to the lubricant G holding surface of the brush 122, the lubricant G on the lubricant G holding surface of the brush 122 when the lubricant G is scraped off the solid lubricant 110 by the brush 122 again. The holding amount fluctuates. Further, the external additive J also adheres to the surface of the solid lubricant 110 via the brush 122, and the amount of the lubricant G held when the surface is scraped by another brush 122 varies. As a result, coating unevenness occurs on the brush roller 120. The rotation speed of the photosensitive drum 413 is set to, for example, 300 mm/s, and the rotation speed of the brush roller 120 is set to, for example, 150 mm/s.

Next, a case where the rotation directions of the brush roller 120 and the photoconductor drum 413 are set in the width direction will be described. As shown in FIG. 4, when the rotation speed of the brush roller 120 (for example, 450 mm/s) is higher than the rotation speed of the photosensitive drum 413 (for example, 300 mm/s), the brush 122 of the brush roller 120 is held as in FIG. The surface contacts the surface of the photoconductor drum 413. In this case also, as in FIG. 3, the external additive J adheres to the holding surface of the brush 122 of the brush roller 120, which eventually causes uneven coating.

Next, a case where the rotation speed of the brush roller 120 (for example, 150 mm/s) is slower than the rotation speed of the photosensitive drum 413 (for example, 300 mm/s) as in the present embodiment will be described. As shown in FIG. 5, in the case of the conventional brush roller, when the brush 122 comes into contact with the photosensitive drum 413, due to the influence of the frictional force (described later) that acts between the brush 122 and the photosensitive drum 413, The tip of the brush 122 is pulled in the rotation direction of the photoconductor drum 413. In this case, the brush 122 is inverted, and the surface of the brush 122 opposite to the surface holding the lubricant G contacts the photoconductor drum 413. For this reason, the lubricant G is less likely to be applied from the lubricant G holding surface of the brush 122, so that the application efficiency of the lubricant G on the brush roller 120 is deteriorated, resulting in uneven application.

However, in the present embodiment, as shown in FIG. 6, the external additive J is attached to the holding surface of the brush 122 by implanting the brush 122 not in the straight bristling state but in a state inclined with respect to the core bar 121. It is possible to suppress the adherence of the particles, and to suppress the uneven coating. Specifically, the brush 122 is planted in the core bar 121 with the tip 122A inclined toward the upstream side with respect to the rotation direction of the brush roller 120 so that the first angle α and the second angle β are the same. ing.

The first angle α is the direction of the stress F, which is the force received from the photoconductor drum 413 at the most upstream contact position on the most upstream side where the brush 122 contacts the photoconductor drum 413 in the rotation direction of the brush roller 120, and the maximum angle α. It is an angle formed by a reference line L connecting the upstream contact position and the center 121A of the core metal 121, that is, the rotation center of the brush roller 120. The second angle β is an angle formed by the reference line L and the tip 122A of the brush 122.

Here, the stress F will be described. The brush 122 applies the first force f1 to the photoconductor drum 413 in an obliquely upper right direction in the drawing at the most upstream contact position. As a result, the second force f2, which is a reaction force of the first force f1, is generated in the diagonally lower left direction opposite to the first force f1. Further, a frictional force f3 acts on the contact portion between the brush 122 and the photosensitive drum 413. In the present embodiment, the rotation speed of the photoconductor drum 413 is faster than the rotation speed of the brush roller 120, that is, the brush 122 moves to the left side in the drawing relative to the photoconductor drum 413. A frictional force f3 larger than the two reaction force f2 is generated in the diagonally downward right direction in the drawing. Due to the frictional force f3 and the second force f2, the stress F is generated in the diagonally right downward direction.

By arranging the brush 122 in the core metal 121 so that the first angle α and the second angle β are the same with respect to the stress F thus generated, the brush 122 contacts the photoconductor drum 413. In doing so, the tip 122A is not pulled by the rotation of the photosensitive drum 413 unlike the configuration shown in FIG. In the case of the configuration shown in FIG. 5, since the brush 122 of the brush roller 120 is in the straight bristling state, the reference line L and the brush 122 in FIG. 6 overlap each other. That is, the first angle α and the second angle β are not the same. Therefore, since the brush 122 is pulled by the stress F, the brush 122 is turned over. However, in the present embodiment, the stress F overlaps the brush 122, so the brush 122 is not pulled rightward in the drawing by the stress F. This makes it possible to apply the lubricant G holding surface of the brush 122 to the surface of the photoconductor drum 413 and improve the coating efficiency of the lubricant G.

Further, as shown in FIGS. 6 and 7, since the rotation direction of the brush roller 120 is set in the width direction, the tip surface A1 of the tip 122A of the brush 122 faces the upstream side in the rotation direction of the brush roller 120. It will be in the state where it was. The rotation speed of the photoconductor drum 413 is faster than the rotation speed of the brush roller 120, that is, the photoconductor drum 413 moves to the right in the figure relative to the brush roller 120, and thus adheres to the surface of the photoconductor drum 413. The external additive J collides with the tip surface A1 of the brush 122, and as a result, the external additive J is scraped from the surface of the photosensitive drum 413 by the tip surface A1 of the brush 122. Then, the lubricant G is applied from the holding surface of the lubricant G of the brush 122 to the surface of the photoconductor drum 413 after the external additive J is scraped off by the tip surface A1. As a result, it is possible to prevent the external additive J from adhering to the surface of the brush 122 that holds the lubricant G, and thus suppress uneven coating.

Further, when the brush 122 contacts the photoconductor drum 413 at the most upstream contact position, the external additive J located on the downstream side of the most upstream contact position moves away from the brush 122 to the right side in the drawing. The brush 122 does not adhere to the lubricant G holding surface. The external additive J is scraped from the photoconductor drum 413 by the tip surface A1 of the brush 122 located on the downstream side of the brush 122.

In the configuration of FIG. 4, the rotation speed of the brush roller 120 is faster than the rotation speed of the photoconductor drum 413, that is, the brush 122 moves to the right in the figure relative to the photoconductor drum 413. Therefore, since the tip surface A1 of the brush 122 is separated from the external additive J, the tip surface A1 of the brush 122 cannot scrape off the external additive J adhering to the surface of the photoconductor drum 413, and the coating is performed. Unable to solve the problem of unevenness. Further, in the case of this configuration, since the brush 122 moves in the right direction in the drawing relative to the photoconductor drum 413, the second force f2 becomes larger than the frictional force f3. Therefore, the direction of the stress F generated by the frictional force f3 and the second force f2 is substantially downward, and the first angle α and the second angle β are not equal.

In the configuration of FIG. 3, since the tip end surface A1 of the brush 122 faces the downstream side in the rotation direction of the photoconductor drum 413, that is, the side opposite to the lubricant J moving with respect to the brush 122, the lubricant J It cannot be scraped off, and the problem of uneven coating cannot be solved. Further, in the case of this configuration, as the first force f1 is generated in the diagonally upper left direction, which is the direction in which the brush 122 contacts the photoconductor drum 413, the second force f2 is changed to the diagonally lower right direction in the opposite direction. Become. Therefore, since the direction of the stress F generated by the frictional force f3 and the second force f2 is substantially rightward, the first angle α and the second angle β are not equal.

The first angle α and the second angle β are, for example, 10°. The brush 122 has a length of 4 mm. The radius of the core metal 121 is 3 mm. Further, the brush roller 120 is set so that the tip 122A of the brush 122 draws an arc C having a radius of 6 mm by rotating.

By the way, as the number of printed sheets increases, the surface of the photosensitive drum 413 becomes rough due to the influence of durability, and the brush 122 of the brush roller 120 deteriorates. As a result, the dynamic friction coefficient of the frictional force f3 acting between the brush roller 120 and the photosensitive drum 413 becomes large. Specifically, when the initial state is 0.2, the dynamic friction coefficient increases to 0.4 when the number of printed sheets reaches a predetermined number (for example, 300,000 sheets). That is, the frictional force f3 shown in FIG. 6 increases, and the force that pulls the brush 122 in the rotation direction of the photosensitive drum 413 increases. FIG. 8 is a diagram showing the second angle β with respect to the number of printed sheets.

In this case, as shown in FIG. 8, for example, as indicated by the solid line D1, the second angle β increases from 10° in the initial state as the number of printed sheets increases, and reaches 30° when the number of printed sheets reaches a predetermined number. Will rise. In this case, the tip 122A of the brush 122 is pulled by the photoconductor drum 413, so that the brush 122 is turned upside down, and the application efficiency of the lubricant G deteriorates.

Therefore, in the present embodiment, the control unit 90 controls the first angle α and the second angle β to be equal according to the torque of the brush roller 120 detected by the torque detection unit 73. Specifically, the control unit 90 increases the application amount of the lubricant G on the brush roller 120 as the torque of the brush roller 120 increases. By doing so, a large amount of the lubricant G is applied to the photosensitive drum 413, so that the surface of the photosensitive drum 413 becomes smooth. Therefore, it is possible to prevent the frictional force f3 from increasing, and as a result, it is possible to make the second angle β constant as indicated by the broken line D2, that is, to make the first angle α and the second angle β equal.

As the control of the application amount of the lubricant G, for example, the application amount of the lubricant G can be controlled by changing the bite amount of the brush roller 120 with respect to the solid lubricant 110. Specifically, the controller 90 moves the solid lubricant 110 upward so that the relative position between the solid lubricant 110 and the brush roller 120 becomes closer as the number of printed sheets increases, so that the brush roller 120 with respect to the solid lubricant 110 is moved. Increase the bite amount of. For example, as shown in FIG. 9, the control unit 90 gradually increases the biting amount of the brush roller 120 from 0.5 mm in the initial state as the number of printed sheets increases, and increases to 0.7 mm when the predetermined number is reached. .. Further, the application amount of the lubricant G may be controlled by changing the rotation speed of the brush roller 120.

According to the lubricant applying device 100 according to the present embodiment configured as described above, since the lubricant G holding surface of the brush 122 does not come into contact with the external additive J attached to the photoconductor drum 413, the holding is performed. It is possible to prevent the external additive J from adhering to the surface, and eventually to prevent uneven coating.

Further, since the external additive J is removed from the photoconductor drum 413 by the tip end surface A1 of the brush 122, the lubricant G is applied to the photoconductor drum 413 from the holding surface of the lubricant G of the brush 122. The coating efficiency of the lubricant G on the surface of the can be improved.

Further, since the first angle α and the second angle β are controlled to be equal to each other according to the torque of the brush roller 120, it is possible to suppress the occurrence of coating unevenness even if the durability is advanced.

In the above embodiment, the first angle α and the second angle β are made equal by controlling the application amount of the lubricant G, but the present invention is not limited to this, and for example, the second angle β is The control may be changed.

As a mode for changing the second angle β, for example, as shown in FIG. 10, a configuration in which the position of the solid lubricant 110 is arranged on the lateral side of the brush roller 120 can be considered. Specifically, in the rotation direction of the brush roller 120, the solid lubricant 110 is on the upstream side of the position on the most upstream side where the brush 122 contacts the photosensitive drum 413, and a part of the solid lubricant 110 is the center of the core metal 121. It is arranged so as to be located on the side of the photoconductor drum 413 with respect to 121A.

Here, for example, a case where the second stress F2 having a larger first angle α than the first stress F1 in the initial state is applied to the brush 122 will be described. When the control unit 90 determines that the first stress F1 has changed to the second stress F2 according to the detection result detected by the torque detection unit 73, the control unit 90 moves the solid lubricant 110 upward, that is, on the photosensitive drum 413 side. (See FIG. 11). By doing so, the brush 122 elastically deformed to scrape the solid lubricant 110 comes into contact with the photosensitive drum 413 before the brush 122 completely returns to its original shape. Therefore, the second angle β formed by the reference line L and the tip 122A of the brush 122 can be changed. The second angle β can be changed, for example, in the range of 10° in the initial state to 30°.

Further, as shown in FIG. 12, the second angle β may be changed by moving the brush roller 120 so that the relative position between the brush roller 120 and the photoconductor drum 413 is close to each other. Specifically, the control unit 90 moves the brush roller 120 from the two-dot chain line position in the initial state to the solid line position according to the detection result detected by the torque detection unit 73. By doing so, the second angle β can be changed.

Further, in the above embodiment, the photoconductor drum 413 is exemplified as the image carrier, but the present invention is not limited to this, and may be a belt member or a roller member.

In addition, each of the above-described embodiments is merely an example of the embodiment in carrying out the present invention, and the technical scope of the present invention should not be limitedly interpreted by these. That is, the present invention can be implemented in various forms without departing from the gist or the main features thereof.

The present invention can be applied to an image forming system including a plurality of units including an image forming apparatus. The plurality of units include external devices such as a post-processing device and a network-connected control device.

1 Image Forming Device 90 Control Unit 100 Lubricant Applying Device 110 Solid Lubricant 120 Brush Roller 121 Core Metal 122 Brush 413 Photosensitive Drum

Claims (10)

A brush roller is provided, and a brush roller that applies the lubricant scraped from the solid lubricant by the brush to the image carrier is provided.
The rotation direction of the brush roller is the same as the rotation direction at the contact position with the image carrier,
The brush is inclined to the opposite side to the rotation direction of the brush roller , and in the rotation direction of the brush roller, the brush is at the most upstream contact position on the most upstream side where the brush contacts the image carrier. The first angle formed by the direction of the force received from the image carrier and the reference line connecting the rotation center of the brush roller and the most upstream contact position is the first angle formed by the reference line and the tip of the brush. Planted in the brush roller so as to be equal to two angles,
Lubricant application device. The force that the brush receives from the image carrier is the reaction force of the force that the brush applies to the image carrier at the most upstream contact position, and the frictional force that acts at the contact portion between the brush and the image carrier. Is the combined stress,
The lubricant application device according to claim 1. A brush roller is provided, and a brush roller that applies the lubricant scraped from the solid lubricant by the brush to the image carrier is provided.
In the rotation direction of the brush roller, the brush has a direction in which the brush receives a force from the image carrier at the most upstream contact position on the most upstream side where the brush contacts the image carrier, and the rotation of the brush roller. A first angle formed by a reference line connecting the center and the most upstream contact position is planted in the brush roller so as to be equal to a second angle formed by the reference line and the tip of the brush .
The force that the brush receives from the image carrier is the reaction force of the force that the brush applies to the image carrier at the most upstream contact position, and the frictional force that acts at the contact portion between the brush and the image carrier. Is the combined stress,
Lubricant application device. Rotational speed before Symbol brush roller is slower than the rotational speed of the image bearing member,
The lubricant application device according to any one of claims 1 to 3 . A torque detector for detecting the torque of the brush roller,
A control unit that controls the amount of the lubricant applied to the brush roller so that the first angle and the second angle are equal in accordance with the torque of the brush roller detected by the torque detection unit;
With
The lubricant application device according to any one of claims 1 to 4 . The control unit moves the solid lubricant so that the relative positions of the solid lubricant and the brush roller are close to each other, thereby changing the bite amount of the brush roller with respect to the solid lubricant,
The lubricant application device according to claim 5 . The control unit changes the rotation speed of the brush roller,
The lubricant application device according to claim 5 or 6 . The control unit moves the solid lubricant in the rotation direction of the brush roller,
The lubricant application device according to claim 5 . The control unit changes the amount of biting of the brush roller with respect to the image carrier by moving the brush roller so that the relative positions of the brush roller and the image carrier are close to each other,
The lubricant application device according to claim 5 . Comprising a lubricant coating apparatus according to any one of claim 1 to 9
Image forming apparatus.

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