JP2011237534A - Lubricant applicator and image-forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubricant applicator which can control a change of a friction coefficient through equalization of an application quantity of a lubricant at the time of initial supply and temporal supply of the lubricant.SOLUTION: A lubricant-supplying device 13 comprises a solid lubricant 13A, a supplying member 13B which contacts the solid lubricant 13A and supplies a lubricant supplied object 5A with the lubricant that is scraped off by rubbing the solid lubricant 13A, and a pressing mechanism 13C which depresses the solid lubricant 13A toward the supplying member 13B. Lubricant application quantity stabilization means 50 which is provided near the supplying member 13B and contacts the lubricant supplied object 5A has a structure enabling incorporation of the lubricant supplied to the lubricant supplied object 5A, and equalizes a supply quantity of the lubricant at the lubricant supplied object 5A at the time of initial supply and at the time of time-dependent change by conducting an act of incorporation in accordance with a quantity of the lubricant supplied to the lubricant supplied object 5A.

Description

  The present invention relates to a lubricant application device and an image forming apparatus, and more particularly to a lubricant supply mechanism.

  As is well known, in an image forming apparatus such as a copying machine, a printer, or a printing machine, frictional resistance is reduced during cleaning of a photoconductor after image transfer or a transfer belt subjected to image transfer, and worm-feeding phenomenon during transfer. There is a configuration for supplying a lubricant for preventing the occurrence (for example, Patent Document 1).

As for the coefficient of friction when a lubricant is used, approximately 0.2 to 0.35 is required, and if it is lower than this range (for example, 0, 2 or less), the photosensitive member is transferred to the transfer belt. The transfer efficiency of the toner image is deteriorated, and the worm-eaten phenomenon that part of the image is lost becomes remarkable.
Apart from this, if it is too higher than the above range (for example, 0.4 or more), there arises a problem that the tip of the cleaning blade is dragged and drowned.

The following configuration is known as an example of a configuration for supplying a lubricant to a photoconductor and a transfer belt.
A brush roller that can rotate in contact with the solid lubricant is used, and a portion of the solid lubricant that is urged by an elastic body such as a compression coil spring so as to always contact the brush roller is scraped when the brush roller rotates. It is configured to be applied to the surface of a photoreceptor or a transfer belt by being taken (for example, Patent Document 1).

  When the solid lubricant is scraped off and applied by the brush roller, the thickness of the solid lubricant changes from the initial state as the lubricant is consumed. For this reason, the application state of the lubricant, particularly the supply amount, may become unstable over time.

Hereinafter, the reason for this will be described. The reference numerals used in the description are the same as those used in the embodiments of the present invention.
FIG. 8 is a diagram showing an initial stage of supplying lubricant (FIG. 8A) and a change with time (FIG. 8B) when a lubricant supply mechanism for a transfer belt is used as an example. is there.
In the figure, the lubricant supply mechanism includes an application brush 13B configured by a brush roller that can rotate while being in contact with the transfer belt 5A, and an elastic body 13C using a compression coil spring inserted into the application brush 13B. The solid lubricant 13A is integrated with the fall prevention guide 13D. In the figure, reference numeral 13E denotes a lubricant holder in which the fall prevention guide 13D is inserted, and reference numeral 13F denotes a counter roller having a backup function.

  The application amount of the solid lubricant 13A changes according to the load of the elastic body 13C at the time change shown in FIG. 8B with respect to the initial supply shown in FIG. 8A. That is, as the consumption of the solid lubricant 13A progresses, the thickness of the solid lubricant 13A also decreases, and when the load of the elastic body 13C decreases accordingly, the contact pressure of the solid lubricant 13A with respect to the application brush 13B decreases, and the application amount Tends to decrease. In other words, it can be said that the larger the load on the elastic body 13C, the greater the amount of solid lubricant scraped by the application brush 13B.

Now, the compression constant of the compression coil spring used as the elastic body 13C is k (N / mm), the natural length is L (mm), the initial use length L ₀ (mm), and the total mass of the lubricant 53 and the lubricant holder 54 Is M ₀ (kg), and gravitational acceleration is g (m / sec ² ), the initial contact force shown on the left side of FIG.
2k (L−L ₀ ) + M ₀ g (N) (1)
It becomes.

When the solid lubricant 13A is consumed over time and the use length is L1 (mm) and the combined weight is M ₁ (kg), the contact force at the time of change shown in FIG.
2k (L−L ₁ ) + M ₁ g (N) (2)
It becomes.
Therefore, the difference in the contact force between the initial time and the time-dependent change is (1) − (2) 2k (L ₁ −L ₀ ) + (M ₀ −M ₁ ) g (N) (3)
It becomes.
Since L ₁ > L ₀ and M ₀ > M ₁ , the expression (3) is always positive.
Specifically, when numerical values are substituted, k = 0.02, L = 35, L ₀ = 20, L ₁ = 30, M ₀ = 0.1, M ₁ = 0.09, and g = 10. The initial contact force is 1.6 N, the initial contact force is 1.1 N, and the difference is 0.5 N, and the contact force is reduced by about 30% when time changes.

FIG. 9 shows the results of actual evaluation using the above parameters. The horizontal axis represents the number of sheets passed, the vertical axis (left) represents the amount of lubricant scraped (the amount of lubricant removed), and the vertical axis (right) represents intermediate. It is the graph which took the transfer belt friction coefficient. Since the initial amount of lubricant scraping is large, the friction coefficient of the intermediate transfer belt is 0.2 or less. When the friction coefficient of the intermediate transfer belt is low, toner transfer efficiency from the photoreceptor is poor, and a blurred image or a worm-eaten image is generated in which a part of the image is missing.
In order to prevent the occurrence of abnormal images at the initial stage, if the coating amount at the initial stage is reduced, the coating amount will be insufficient when changing over time, and new problems such as poor cleaning of the intermediate transfer belt and cleaning blade curling will occur. Resulting in.
Therefore, at present, an abnormal image at the initial stage is sacrificed, the amount of lubricant applied at the initial stage is set to be large, and an originally unnecessary lubricant is mounted, so that the application efficiency is poor.

As a configuration for uniformly applying the lubricant, as disclosed in Patent Document 1, there is a configuration in which the lubricant after application is leveled by a blade or the like.
However, it is not intended to eliminate the change in the application amount at the application stage, in other words, the change in the application efficiency, not the applied lubricant.

  The object of the present invention is to solve the problem in the above-described conventional lubricant application device, and can suppress the change in the friction coefficient by equalizing the amount of lubricant applied at the initial stage of supply of the lubricant and at the time of change over time. It is an object of the present invention to provide a lubricant coating device and an image forming apparatus that can prevent the occurrence of abnormal images using the lubricant coating device.

In order to achieve this object, the present invention has the following configuration.
(1) a solid lubricant;
A supply member that contacts the solid lubricant and supplies the lubricant that has been scraped by rubbing the solid lubricant to a lubricant supply target;
In a lubricant supply device comprising a pressing mechanism for pressing the solid lubricant against the supply member,
Lubricant application amount stabilization means provided with a configuration capable of taking in the lubricant supplied to the lubricant supply object in contact with the lubricant supply object,
The lubricant application amount stabilizing means performs a take-in operation according to the amount of lubricant supplied to the lubricant supply target, thereby reducing the lubricant supply amount in the lubricant supply target at the initial supply time and over time. Lubricant coating apparatus characterized by equalizing when changing.

(2) The lubricant application amount stabilizing means uses a member having a space capable of taking in the lubricant, and the lubricant is applied during the period from the initial supply of the lubricant to saturation in the space. The lubricant application device according to claim 1, wherein the lubricant application device is capable of being incorporated.

(3) The lubricant application apparatus according to claim 1 or 2, wherein the lubricant application amount stabilizing means includes a foamed portion that can contact the surface of the lubricant supply target.

(4) The lubricant application device according to claim 3, wherein the foaming portion is provided so as to be interlocked with the movement of the lubricant supply target.

(5) The lubricant according to claim 1 or 2, wherein the lubricant application amount stabilizing means is a brush that can contact the surface of the lubricant supply target and has a space between adjacent fibers. Coating device.

(6) The lubricant application amount stabilizing means is arranged on the downstream side of the supply member in the moving direction of the lubricant supply target. Lubricant application equipment.

(7) The lubricant application amount stabilizing means can be rotated along or opposite to the moving direction of the lubricant supply target. Lubricant application equipment.

(8) An image forming apparatus using the lubricant application device according to any one of claims 1 to 7.

(9) The image forming apparatus according to (8), wherein a latent image carrier or a transfer body is used as a lubricant supply target in the lubricant application apparatus.

  According to the present invention, at the initial stage of supplying the lubricant, the amount of applied lubricant increases due to the strong pressing force of the pressing mechanism, but the lubricant is taken into the lubricant applied amount stabilizing means. Excess lubricant is recovered. Thereby, it is possible to suppress the occurrence of poor transfer and worm-eaten phenomenon due to the tendency to reduce friction generated when the lubricant becomes excessive.

  In particular, the lubricant application amount stabilization means can take in excess lubricant until it reaches saturation, so that the same state as the coefficient of friction at the time of change can be maintained at the initial stage of supply. It is possible to stabilize the coating efficiency (coating thickness) at all times from the initial time to the time-dependent change and suppress the change in the friction coefficient.

It is a schematic diagram for demonstrating the structure of the image forming apparatus using the lubricant coating device by this invention. FIG. 2 is a diagram for explaining a configuration of a lubricant application device for a transfer belt that is one of lubricant supply targets used in the image forming apparatus illustrated in FIG. 1. FIG. 3 is a front view of the lubricant application device shown in FIG. 2. It is a diagram which shows the result of having experimented about the change of the friction coefficient on the transfer belt surface at the time of using the lubricant application | coating apparatus shown in FIG. It is a figure for demonstrating the structure regarding the principal part modification of the lubricant coating device shown in FIG. It is a figure for demonstrating the whole structure of the lubricant application | coating apparatus shown in FIG. It is a figure which shows the principal part modification of the lubricant coating device shown in FIG. It is a figure for demonstrating the structure of the conventional lubricant application apparatus. It is a diagram which shows the result of having experimented the relationship between the change of the pressing force with respect to the lubricant in the conventional lubricant application device shown in FIG. 6, and the change of the friction coefficient.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to embodiments shown in the drawings.
FIG. 1 is a view showing an image forming apparatus to which a lubricant applying apparatus according to the present invention is applied. An image forming apparatus 1000 shown in FIG. 1 is a color printer using a tandem system.
In FIG. 1, the image forming apparatus is intended for an intermediate transfer belt 5 </ b> A on which an image at an image forming station, which will be described later, is primarily transferred sequentially as an image carrier.

  In FIG. 1, an image forming station for each color along the extended surface of the intermediate transfer belt 5A used as an intermediate transfer member (for convenience, image forming stations for yellow, magenta, cyan, and black, which are complementary color toners, and processes described later). A part number is added to the part number for the cartridge as a target).

  The image forming station includes a process cartridge having the same configuration. The process cartridge includes a photosensitive drum 1 and a charging device 2 and a writing device arranged around the photosensitive drum 1 (for the sake of convenience, writing light is indicated by L), A developing device 3 and a cleaning device 4 are provided. In FIG. 1, the part numbers of the respective devices provided in the respective process cartridges are shown with the above-described symbols for the respective colors.

In the process cartridge, the photosensitive drum 1 is uniformly charged by the charging device 2, and an electrostatic latent image corresponding to the image information is formed by a writing operation from the writing device (L).
The electrostatic latent image formed on the photosensitive drum 1 is visualized by toner supplied from the developing device 3 and is transferred to an intermediate transfer belt 5A used as a visible image carrier in a transfer device 5 described later. The primary transfer is performed by receiving a transfer bias from the transfer roller 6 as a primary transfer device.
At the time of full color image formation, the visible images formed at the respective image forming stations are sequentially transferred onto the intermediate transfer belt 5A and superimposed.

  After the transfer, the photosensitive drum 1 is freed of residual toner by a cleaning blade 4A provided in the cleaning device 4 and is uniformly charged by the charging device 2 to be ready for the next image forming process.

The transfer device 5 includes an intermediate transfer belt 5A that is wound around a plurality of rollers 5B, 5C, 5D, and 5E, and a primary transfer roller 6 that faces each photosensitive drum 1 with the intermediate transfer belt 5A interposed therebetween. I have.
In the configuration shown in FIG. 1, the intermediate transfer belt 5A has a moving speed of, for example, 150 mm / sec set as a process speed set by a driving roller using one of a plurality of rollers, and is stretched in the direction of the arrow shown in the drawing. The plane is moved.

Among the rollers around which the intermediate transfer belt 5A is wound, the roller denoted by reference numeral 5B is used as the above-described drive roller and a secondary transfer device used as a secondary transfer device facing the intermediate transfer belt 5A. It is used as a backup roller for the roller 7.
A roller denoted by reference numeral 5C is used as a tension roller that is urged in an extending direction by an elastic body such as a spring (not shown).

A transfer roller 6 as a primary transfer device is biased toward the photosensitive drum 1 by an elastic body 6A such as a spring, and a bias power source 8 (for convenience, only one transfer roller is shown). A visible image is transferred to the intermediate transfer belt 5A by a transfer bias fed from the intermediate transfer belt 5A.
The primary transfer bias used in the configuration shown in FIG. 1 is, for example, + 1800V. A secondary transfer bias is also applied to the secondary transfer roller 7 by power supply from the bias power source 10.

The intermediate transfer belt 5A is composed of PVDF (vinylidene fluoride), ETFE (ethylene-tetrafluoroethylene copolymer), PI (polyimide), PC (polycarbonate) or the like in a single layer or a plurality of layers, such as carbon black. The conductive material is dispersed, and the volume resistivity is adjusted to be in the range of 10 ⁸ to 10 ¹² Ωcm, and the surface resistivity is adjusted to be in the range of 10 ⁹ to 10 ¹³ Ωcm. If necessary, a release layer may be coated on the surface of the intermediate transfer belt 10. Materials used for the coating include ETFE (ethylene-tetrafluoroethylene copolymer), PTFE (polytetrafluoroethylene), PVDF (vinylidene fluoride), PEA (perfluoroalkoxy fluororesin), FEP (four-fluorocarbon). Fluorine resin such as ethylene fluoride-propylene hexafluoride copolymer) or PVF (vinyl fluoride) can be used, but is not limited thereto.

The method for manufacturing the intermediate transfer belt 5A includes a casting method, a centrifugal molding method, and the like, and the surface thereof may be polished if necessary. Note that if the volume resistivity of the intermediate transfer belt 5A exceeds the above-mentioned range, it is not preferable because power consumption at the power source increases due to an increase in bias required for transfer. desirable. In addition, since the charging potential of the intermediate transfer belt 10 becomes high and self-discharge becomes difficult in the transfer process, the transfer paper peeling process, etc., it is necessary to provide a static eliminating means. Also, if the volume resistivity and surface resistivity are below the above ranges, the charge potential decays quickly, which is advantageous for static elimination by self-discharge, but toner scatter occurs because the current during transfer flows in the surface direction. End up.
Accordingly, the volume resistivity and surface resistivity of the intermediate transfer belt 10 in the present invention are preferably within the above ranges. The volume resistivity and the surface resistivity were measured by connecting an HRS probe (inner electrode diameter 5.9 mm, ring electrode inner diameter 11 mm) to a high resistivity meter (manufactured by Mitsubishi Chemical Corporation: Hiresta IP). The measured value 10 seconds after applying the voltage of 100V (surface resistivity is 500V) to the front and back of the was used.

The intermediate transfer belt 5A is configured such that the residual toner is removed by the belt cleaning device 11 when all the transferred images are secondarily transferred.
The cleaning device 11 includes a cleaning blade 11A made of an elastic material such as urethane rubber that comes into contact with the intermediate transfer belt 5A. The cleaning blade 11A can be contacted and separated by a swingable blade holder (not shown). It is supported. When the cleaning blade 11A comes into contact, the toner remaining on the intermediate transfer belt 5A is blocked and cleaned.
Instead of the cleaning blade 11A, it is also possible to use a conductive brush or a roller, and it is possible to adopt a configuration in which toner as an electrostatic deposit is collected from the intermediate transfer belt 5A by applying a bias.
Although not shown, the toner collected from the intermediate transfer belt 5A is conveyed to the back side of the apparatus by a conveying member provided in the cleaning apparatus and is dropped downward by gravity. A toner collection bottle is disposed at a position where the toner falls, and although not shown, the toner collection bottle is provided with a fullness detection sensor so that it can be monitored so as to prompt replacement when full.

A lubricant application device 13 is provided in the vicinity of the belt cleaning device 11 in order to prevent rubbing damage by the cleaning blade 11A and to improve toner removal performance.
As shown in FIG. 1, the lubricant applying device 13 scrapes the lubricant 13A by rotating while contacting the solid lubricant 13A, and applies the shaved lubricant 13A to the surface of the intermediate transfer belt 5A. And an elastic body 13C composed of a compression coil spring used in a pressing mechanism that presses and urges the solid lubricant 13A toward the coating brush 13B.
A counter roller 13F having a backup function is disposed at a position facing the application brush 13A across the intermediate transfer belt 5A.
FIG. 2 is a diagram showing details of the lubricant application device. In FIG. 2, as the solid lubricant 13A is consumed, the fall prevention guide 13D is pressed against the elastic body 13C as its thickness decreases. Thus, the lubricant holder 13E is moved, but when it moves, it is prevented from falling with respect to the moving direction by sliding of the falling prevention guide member 13D, and moves while keeping the posture in the moving direction constant.

  In this embodiment, a fatty acid metal salt having a linear hydrocarbon structure is used as the solid lubricant 13A. The fatty acid metal salt contains at least one fatty acid selected from stearic acid, palmitic acid, myristic acid and oleic acid, and at least one metal selected from zinc, aluminum, calcium, magnesium and lithium The fatty acid metal salt containing is mentioned. Among them, zinc stearate is the most preferable material in terms of cost, quality stability, and reliability because it is produced on an industrial scale and has been used in many fields. However, the higher fatty acid metal salt generally used industrially is not a single compound composition of its name, but includes other fatty acid metal salts, metal oxides, and free fatty acids that are more or less similar. Fatty acid metal salts are no exception.

The application brush 13B shown in FIG. 2 is configured by adhering a flock of polyester on a metal core such as SUS, and the bristles used for this have an outer diameter of φ12 and a length of 4 mm. The density is configured to be about 100,000 / in 2.
The application brush 13B is a member that can be rotated by a drive mechanism (not shown), and can rotate along the moving direction of the intermediate transfer belt 5A or in the opposite direction. The counter roller 13F is a metal roller having an outer diameter of φ16, and the amount of biting with the application brush 13B is set to 1 mm.

Part of the solid lubricant 13A is scraped off by the application brush 13B and is made into powder and applied to the intermediate transfer belt 5A by a small amount, thereby reducing the friction coefficient on the surface of the intermediate transfer belt 5A. ing.
That is, when the solid lubricant 13A is not applied, the toner that has not been transferred to the transfer paper increases the friction coefficient, and the transfer residual toner may slip through the cleaning blade 11A, resulting in poor cleaning. The edge of the
Further, when the friction coefficient of the intermediate transfer belt 10 is high, there is a problem that transfer efficiency onto the transfer paper is lowered, and a part of the image is lost and a blurry image or a worm-eaten image is generated. In order to prevent such a problem, the solid lubricant 13A is applied to the intermediate transfer belt.

On the other hand, in FIG. 1, the secondary transfer roller 7 is configured by covering a metal core such as SUS with an elastic body such as urethane adjusted to a resistance value of 10 ⁶ to 10 ¹⁰ Ω with a conductive material. Has been. The reason for setting the resistance value in the secondary transfer roller 7 is as follows.
When the resistance value of the secondary transfer roller 7 exceeds the above range, current hardly flows. Therefore, in order to obtain the required transferability, a higher voltage must be applied, which increases the power supply cost. In addition, since a high voltage is applied, a discharge occurs in the gap before and after the transfer portion nip, so that white spots are lost due to the discharge on the halftone image. On the contrary, if the resistance value of the secondary transfer roller 7 is below the above range, the transferability between the multi-color image portion (for example, three-color superimposed image) and the single-color image portion existing on the same image cannot be achieved.

  This is because the resistance value of the secondary transfer roller 7 is low, and a sufficient current flows to transfer the monochrome image portion at a relatively low voltage. Since a voltage value higher than the voltage is required, setting a voltage that can transfer a plurality of color image portions causes an excessive transfer current in a single-color image, resulting in a reduction in transfer efficiency. The resistance value of the secondary transfer roller 7 is measured by installing the secondary transfer roller 7 on a conductive metal plate and applying a load of 4.9 N on one side (total of 9.8 N on both sides) to both ends of the core metal. In this state, it was calculated from the value of the current flowing when a voltage of 1000 V was applied between the metal core and the metal plate. The secondary transfer roller 7 is given a driving force by a driving gear (not shown), and its peripheral speed is adjusted to be substantially the same as the peripheral speed of the intermediate transfer belt 10. The secondary transfer is controlled by a constant current, and in this embodiment, the set value is +30 μA.

In FIG. 1, a recording sheet S used as a recording sheet is conveyed by a sheet feeding roller 14 and a transfer sheet conveying roller 15, and is formed on an intermediate transfer belt 5A by a registration roller 16 composed of a pair of rollers 16A and 16B. Are fed in accordance with the timing at which the leading end of the four-color superimposed image reaches the secondary transfer position. The recording sheet S on which the four-color superimposed image has been transferred is conveyed to the fixing device 19 along the guide member 30 serving as a transfer outlet and a fixing inlet guide, and is fixed by the fixing device 19 and then discharged by the paper discharge roller 20. Is done.
Although not shown, it is also possible to remove the toner adhering to the back surface of the transfer paper by discharging the recording paper S after transfer.

The features of the present invention will be described below with the above configuration as an object.
A feature of the present invention is that a lubricant that is supplied to a lubricant supply target such as a photoconductor or an intermediate transfer belt, such as an application brush, is taken in at an initial stage of supply to recover excess lubricant and aged over time. A lubricant application amount stabilizing means for equalizing the application efficiency of the lubricant between the time of change, specifically, the application thickness, is provided.

  That is, as described with reference to FIG. 8 and the mathematical expression, the elastic body 13C changes in length according to the decrease in thickness accompanying the consumption of the solid lubricant, and this change causes the solid lubricant 13A to the application brush 13B. The contact force changes on the side, and the contact force is weaker at the time of change than at the initial time. For this reason, the amount of lubricant applied is the largest at the beginning of supply and decreases with time, and as a result, the thickness of lubricant applied on the belt surface is different. In particular, when a large amount of lubricant is supplied at the initial stage, the occurrence of abnormal images as described above becomes noticeable when the friction coefficient becomes a predetermined value or less. Therefore, in the present invention, the change in the friction coefficient is suppressed by equalizing the efficiency of applying the lubricant between the initial time and the time-dependent change.

FIG. 2 is a diagram showing a main part of the lubricant application device according to the first embodiment of the present invention.
In the figure, the lubricant application device 13 includes a solid lubricant 13A that is pressed toward the application brush 13B by an elastic body 13C loaded in a slidable fall prevention guide 13D located in a holder 13E. Is provided. As shown in FIG. 3, the solid lubricant 13A is uniformly pressed along the axial direction, which is the longitudinal direction of the coating brush 13B, by being pressed by the elastic body 13C in the longitudinal direction, that is, both sides in the image width direction. It is pressed.
In this configuration, as a characteristic member, as indicated by reference numeral 50 in FIG. 2, the lubricant application amount stabilizing means is provided on the same side as the application brush 13B and downstream of the application brush 13B in the moving direction of the intermediate transfer belt 5A. Is provided.
Lubricant application amount stabilizing means 50 is made of a foamed rubber roller (hereinafter referred to as reference numeral 50) made of foamed elastic material such as urethane on the surface of a metal core made of tail metal such as SUS, and is provided with intermediate transfer belt 5A. It can be brought in contact with the surface of the.

  The foamed rubber roller 50 has a roller hardness (Asker-C) of 30 degrees and a foamed cell diameter of about 200 μm, and a part of the lubricant applied to the surface of the intermediate transfer belt 5A is used in the space of the foamed part. So that it can be collected.

  The lubricant is taken in until the filling of the lubricant in the space of the foaming portion is saturated. As the foamed portion is clogged, the amount of the lubricant taken in and held in the foam decreases.

  In this example, when the application amount at the initial stage is large by combining the above characteristics using the foamed part with the characteristic that the application amount decreases according to the elapsed time from the initial supply of the lubricant. The uptake of the lubricant increases, and the uptake decreases as the coating amount decreases with time. In other words, the function of reducing the amount of recovered lubricant is exhibited. In other words, the foamed rubber roller 50 controls the amount of lubricant recovered according to the amount of lubricant applied to the lubricant supply target, and equalizes the application efficiency (application thickness) between the initial supply and the change over time. It is supposed to make it.

  Since the present embodiment is configured as described above, at the initial supply of the solid lubricant 13A, the pressing force from the elastic body 13C against the application brush 13B is also due to the thick thickness of the solid lubricant 13A. The amount of scraping by the application brush 13 increases due to the strongness. As a result, the amount of lubricant applied to the intermediate transfer belt 5A increases, but a part of the lubricant applied when the intermediate transfer belt 5A faces the foamed rubber roller 50 is collected. That is, the take-in to the foamed part is performed and the take-in is continued until the saturated state at the foamed part is reached.

On the other hand, when the solid lubricant 13A is consumed, the thickness of the lubricant is scraped by the application brush 13B due to a decrease in the pressing force of the elastic body 13C against the application brush 13B when the solid lubricant 13A is consumed. The application amount is also reduced.
Therefore, by balancing the lubricant coating thickness at the time of change with the coating thickness at the beginning of supply, it is possible to suppress the change in the friction coefficient at the initial time and at the time of change.

FIG. 4 is a line showing the results of experiments on the change in the coefficient of friction between the initial time and the time-dependent change for the configuration of this example and the case where the lubricant application amount stabilizing means used in this example is not used. FIG.
As is apparent from FIG. 4, according to this embodiment, the recovery is promoted when the amount of lubricant applied is large, and the recovery is hardly performed at the time of change over time. Since the coating thickness of the lubricant was balanced, the friction coefficient was almost unchanged. As a result, it is possible to prevent the worm-eaten phenomenon that the transfer efficiency is deteriorated and part of the image is lost due to excessive application at the initial stage.

The contact pressure of the foam rubber roller 50 with respect to the intermediate transfer belt 5A is preferably set to a pressure at which a recovery amount capable of setting the coating thickness at the time of change is obtained, and the same applies to the degree of foaming.
Further, since the recovered lubricant may be scraped off when the coefficient of friction on the surface of the intermediate transfer belt 5A becomes high over time, even a part of the lubricant shortage on the intermediate transfer belt 5A may occur. It can be expected to supplement.

  In this embodiment, since the state of recovery of the lubricant is different between the initial supply of the lubricant and the time-dependent change, for example, after applying a large amount of lubricant, scraping with a blade or the like to equalize Compared with, coating efficiency can be improved as much as the amount recovered with time changes. In other words, when performing leveling work, it is necessary to supply a large amount of lubricant even when it changes over time in anticipation of the amount scraped off by leveling. It is possible to eliminate waste such as the formation of a lubricant that does not pass through the blade and does not pass through the blade.

Next, a second embodiment of the present invention will be described.
FIG. 5 is a view showing a modification of the main part of the lubricant application device shown in FIG. 2, and the configuration shown in FIG. 5 is characterized in that a brush roller 51 is used as a lubricant application amount stabilizing means. .

The brush roller 51 has a space in which a lubricant can be taken in between adjacent brush fibers, and rotates in a direction opposite to the moving direction of the intermediate transfer belt 5A.
Since the brush roller 51 can take in the lubricant in the space located between the adjacent fibers, the lubricant is taken in and accumulated between the fibers at the initial supply stage of the lubricant, and is taken up when saturated. Recovery will not be performed.

  Since the present embodiment is configured as described above, the intermediate transfer belt is scraped off by the application brush 13B since the pressing force of the elastic body 13C is strong at the initial stage of supplying the lubricant, as in the above-described embodiment. More lubricant is applied to 5A. At this time, since the lubricant is taken in and accumulated in the space between the brush fibers on the brush roller 51, it is possible to obtain the application efficiency equivalent to the case where the amount of the lubricant applied during the change with time is reduced. become. In other words, a part of the lubricant that has been applied in large quantities is collected by the brush roller 51, so that an application amount with an application thickness that is almost equivalent to the application thickness over time can be obtained.

  Since the brush roller 51 is configured to rotate in a direction opposite to the moving direction of the intermediate transfer belt 5A, (brush surface moving speed + belt moving speed) is obtained as a relative speed to the intermediate transfer belt 5A. Therefore, by rotating in the same direction as the moving direction of the intermediate transfer belt 5A, it is possible to improve the recovery ability of the lubricant as compared with the case of tracing.

FIG. 6 is a diagram showing a configuration in which the application brush 13B used in the lubricant application mechanism in the lubricant application device and the brush roller 51 shown as an example of the lubricant application amount stabilizing means are collectively accommodated in the same unit 130. is there.
With such a configuration, when replacing the solid lubricant 13A due to the life of the lubricant, the lubricant application amount stabilizing means corresponding to the lubricant supply unit and the recovery unit can be replaced at the same time. The friction coefficient of the belt 5A can be prevented from being lowered, and a stable friction coefficient can be maintained.

FIG. 7 is a view showing a modification of the lubricant application amount stabilizing means. The lubricant application amount stabilizing means shown in FIG. 7 is not a movable member described above, but a bowl-shaped brush in which a large number of brush fibers are arranged. The member 52 is configured.
The brush member 52 is obtained by integrally joining a PET fiber cloth to a stationary metal plate with a double-sided tape or the like, and can capture and collect the lubricant in a space located between the brush fibers. .

  In this configuration, as in the above-described embodiment, the lubricant is taken in and deposited in the space between the brush fibers at the initial stage of supply when the amount of lubricant applied increases, particularly in the case of using a brush roller. Therefore, the coating efficiency equivalent to the case where the amount of the lubricant applied during the change with time is reduced can be obtained.

  In the above-described embodiment, the intermediate transfer belt 5A has been described as the lubricant supply target. However, in the present invention, the photosensitive member, which is a member that requires cleaning, or a transfer body configured in a drum shape instead of a belt shape is targeted. It is also possible to do.

1 Photosensitive drum 5A Intermediate transfer belt 13 Lubricant coating device 13A Solid lubricant 13B Coating brush 13C Elastic body 50 Foam rubber roller 51 Brush roller 130 Unit 1000 Image forming apparatus

JP 2001-305907 A

Claims (9)

Solid lubricant,
A supply member that contacts the solid lubricant and supplies the lubricant that has been scraped by rubbing the solid lubricant to a lubricant supply target;
In a lubricant supply device comprising a pressing mechanism for pressing the solid lubricant against the supply member,
Lubricant application amount stabilization means provided with a configuration capable of taking in the lubricant supplied to the lubricant supply object in contact with the lubricant supply object,
The lubricant application amount stabilizing means performs a take-in operation according to the amount of lubricant supplied to the lubricant supply target, thereby reducing the lubricant supply amount in the lubricant supply target at the initial supply time and over time. Lubricant coating apparatus characterized by equalizing when changing.   The lubricant application amount stabilizing means uses a member having a space in which the lubricant can be taken in, and can take in the lubricant from the initial supply of the lubricant to saturation in the space. The lubricant application device according to claim 1, wherein the lubricant application device is configured.   The lubricant application apparatus according to claim 1 or 2, wherein the lubricant application amount stabilizing means includes a foaming portion that can contact a surface of the lubricant supply target.   The lubricant application apparatus according to claim 3, wherein the foaming portion is provided so as to be interlocked with a movement of the lubricant supply target.   The lubricant application apparatus according to claim 1 or 2, wherein the lubricant application amount stabilization means uses a brush that can contact the surface of the lubricant supply target and has a space between adjacent fibers.   The lubricant according to any one of claims 1 to 5, wherein the lubricant application amount stabilizing means is disposed downstream of the supply member in a moving direction of the lubricant supply target. Coating device.   The lubricant according to any one of claims 3 to 6, wherein the lubricant application amount stabilizing means is rotatable along or opposite to a moving direction of the lubricant supply target. Coating device.   An image forming apparatus using the lubricant application device according to claim 1.   The image forming apparatus according to claim 8, wherein a latent image carrier or a transfer body is used as a lubricant supply target in the lubricant application apparatus.

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