JPH0883030A - Cleaning device - Google Patents

Abstract

PURPOSE: To make it possible to execute cleaning stably over a long period of time and to obtain an image having high quality by continuously changing the position in the axial direction of grooves formed on the surface of a magnetic cleaning roller in the circumferential direction of this roller. CONSTITUTION: A cleaning plate is arranged in this cleaning device when viewed toward the traveling direction of the peripheral surface of a photoreceptor and the magnetic cleaning roller 4 arranged in proximity to the surface of the photoreceptor rotates at a relative speed with the peripheral surface of the photoreceptor on the upstream side therefrom. The groove 4a is spirally formed on the surface of the magnetic cleaning roller 4 formed by dispersing a magnetic material into silicone rubber so that the axial position of the groove 4a changes continuously in the circumferential direction of the cleaning roller 4. As a result, the fusion of toners near the part where the photoreceptor and the cleaning roller is proximate and the unequal rubbing, etc., of the protective layer on the surface of the photoreceptor by the fusion is effectively prevented. The recovered toner in an earing state comes into contact intermittently with the photoreceptor surface, thereby, the cleaning capacity is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning device in an image forming apparatus utilizing an electrostatic transfer process such as an electrophotographic copying machine and a printer.

[0002]

2. Description of the Related Art In a well-known image forming apparatus that repeats the step of transferring a transferable toner image formed on the surface of a photoconductor to a transfer material such as paper, after the transfer, the residual toner remains on the surface of the photoconductor. It is necessary to remove the toner with cleaning means. Therefore, conventionally, as this type of cleaning means, a cleaning blade made of an elastic material such as rubber has been widely used.

However, with this cleaning blade alone, fused toner, paper powder, and the like, which are fixed or adhered to the surface of the photosensitive member,
It is not always effective in removing precipitates such as rosin and talc.

In order to make up for such drawbacks of the cleaning blade, a cleaning roller made of an elastic material such as silicon rubber is rubbed against the surface of the photosensitive member under pressure to rub the various kinds of adhering foreign matter and toner (hereinafter, collected toner). Say)
There has already been proposed a cleaning device adapted to remove.

However, in a cleaning device using these elastic rollers, the collected toner and paper dust attached to the elastic rollers are scattered. The collected toner is pressed against the photoconductor again due to the pressure contact and rubbing, and the collected toner is rubbed against the photoconductor.

To address these drawbacks such as toner scattering, a magnetic cleaning roller composed of a roller and a magnetic material is used, and the magnetic cleaning roller is brought close to the surface of the photosensitive member.
There has already been proposed a cleaning device that removes various kinds of adhered foreign matters as described above.

While the elastic cleaning roller presses the roller itself against the photoconductor and rubs it for cleaning, the cleaning device using the magnetic cleaning roller has a gap between the magnetic cleaning roller and the photoconductor. To do. In the gap, as shown in FIG. 4, the collected toner 14 having residual toner, paper dust, and the like between the magnetic cleaning roller 40 and the photoconductor 2 is in a state in which the spikes are formed so as to follow the magnetic lines of force of the magnetic cleaning roller 40. Since the surface of the photoconductor 2 is cleaned by the collected toner 14 in the spiked state, the cleaning property is further improved, and the uneven rubbing hardly occurs.

The magnetic cleaning roller 40 is arranged in a cleaning device, and a scraper is arranged in contact with the magnetic cleaning roller 40.

The surface of the magnetic cleaning roller 40 is coated with the collected toner 14, and a portion where the collected toner 14 is accumulated is formed between the surface of the magnetic cleaning roller 40 and the photoconductor 2.
The surface is rubbed, and paper dust, toner, etc. on the surface of the photoconductor 2 are sucked and removed.

In the cleaning device having such a magnetic cleaning roller 40, when the magnetic cleaning roller 40 is rotated in the same direction as the rotation direction of the photoconductor 2, the photoconductor 2 and the magnetic cleaning roller 40 are rotated. Since the peripheral surfaces of the respective peripheral surfaces move in opposite directions to each other, the relative speeds of the peripheral surfaces of the photoconductor 2 and the magnetic cleaning roller 40 are increased, and the magnetic cleaning roller 40 is rotated at a high speed. The cleaning effect can be increased without any. This is a consideration for the motor that rotates the magnetic cleaning roller 40, and the reverse rotation may be performed at an appropriate relative speed. Also, the cleaning ability improves as the gap becomes smaller.

However, when the relative speed between the photoconductor 2 and the peripheral surface of the magnetic cleaning roller 40 increases, the collected toner 14
The speed of rubbing against the photoconductor 2 increases, even between the magnetic cleaning roller 40 and the photoconductor 2, especially the photoconductor 2
When rotating in the same direction as the magnetic cleaning roller 4
The collected toner 14 and paper dust excessively accumulate on the immediate downstream side of the vicinity of the photosensitive member 2 in the moving direction of the peripheral surface of 0, which is a so-called toner reservoir, and fusion is likely to occur on the surface of the photosensitive member 2. In consideration of the cleaning property, the gap latitude for changing the gap between the magnetic cleaning roller 4 and the photoconductor 2 becomes narrow.

On the contrary, if the gap between the magnetic cleaning roller 40 and the photoconductor 2 is increased, the cleaning ability is lowered.

Therefore, the gap latitude between the magnetic cleaning roller 40 and the photosensitive member 2 is narrowed as in the above.

Further, even after the toner has not aggregated after a long period of rest, in the image forming process, the temperature in the vicinity of the photoconductor 2 in the electrophotographic apparatus thereafter rises, and the surface of the photoconductor 2 and the magnetic cleaning roller 40. In some cases, the toner at the point of closeness to the toner agglomerates when the temperature rises. In particular, in an electrophotographic apparatus using an amorphous silicon (hereinafter a-Si) type photoconductor having at least amorphous silicon and hydrogen atoms in the photoconductive layer, the temperature of the photoconductor is adjusted, so that the photoconductor is inactive for a long time. In the subsequent image formation process at the time of starting, the surface temperature of the photoconductor may rise, and the toner at the approach point between the photoconductor surface and the magnetic cleaning roller 40 may be aggregated when the temperature rises.

When the magnetic cleaning roller 40 is rotated in this state, the magnetic cleaning roller 40 is rotated.
In addition to reducing the cleaning ability of the cleaning blade, it may cause blocking that damages the cleaning blade.

Further, in such a state, the toner coating on the surface of the magnetic cleaning roller 40 may be locally changed, and uneven cleaning may occur.

Further, in such a state, the state of the toner pool between the magnetic cleaning roller 40 and the photoconductor 2 is locally changed in the major axis direction of the magnetic cleaning roller 40, and the magnetic substance in the toner or Part of the surface protective layer of the photoconductor 2 is ground by hard particles or the like formed by agglomeration of the toner itself, and unevenness is generated, and as a result, a difference in refraction of incident light with which the photoconductor 2 is irradiated, Due to the interference, the effective amount of light to the photoconductive layer of the photoconductor 2 may be locally different, which may cause unevenness in image density, resulting in remarkable deterioration of image quality.

An elastic cleaning roller having a spiral groove formed on its surface and an elastic cleaning roller having a spiral magnet built-in are disclosed in JP-A-60-119591 and JP-A-60-119592. . While they use an elastic roller that comes into contact with the surface of the photoconductor and have the effect of preventing the scattering of the collected toner, in the present invention, the collected toner ears on the surface of the magnetic cleaning roller that is not in contact with the photoconductor. The cleaning power is further improved not only by controlling the rising and moving the collected toner as described later, but also by intermittently applying the spikes to the surface of the photoconductor.

The present invention solves the above-mentioned problems, suppresses the above-mentioned defects, obtains a stable cleaning action for a long period of time, obtains a high-quality image, and has excellent total performance in electrophotography. An object is to provide a cleaning device for an apparatus.

[0020]

SUMMARY OF THE INVENTION In the present invention, in a cleaning device in which a magnetic cleaning roller as described above is rotated at an appropriate relative speed with respect to a photoconductor, attention is paid to collected toner coated on the magnetic cleaning roller. did.

The collected toner that adheres to the magnetic cleaning roller and contributes to the removal of foreign matters on the photoconductor magnetically adheres to the magnetic cleaning roller, and exists in the form of magnetic lines on the surface of the roller. As shown in FIG. It will be like a spike between them. In cleaning the photoconductor with a cleaning device having a magnetic cleaning roller, the collected toner in the spiked state mainly has a cleaning effect.

At this time, in order to improve the cleaning ability,
When the relative speed between the magnetic cleaning roller and the peripheral surface of the photoconductor is increased and / or the gap between the magnetic cleaning roller and the photoconductor is reduced, and the rotation directions of the photoconductor and the magnetic cleaning roller are the same, the magnetic cleaning is performed. It is necessary to control the collected toner including a toner pool formed immediately downstream of the vicinity of the photosensitive member in the moving direction of the peripheral surface of the roller.

In view of this point, the recovery toner adhering to the magnetic cleaning roller is provided with a mechanism for controlling the distribution of the recovery toner adhering to the magnetic cleaning roller in order to control the spike of the coating. Is.

According to the first aspect of the present invention, there is provided a cleaning device provided with a magnetic cleaning roller which is disposed in proximity to a surface of a moving photosensitive member and which is in proximity to the surface of the photosensitive member. In the cleaning device, a groove is formed, and the axial position of the groove continuously changes in the circumferential direction of the cleaning roller.

A second aspect of the present invention is a cleaning device provided with a magnetic cleaning roller which is disposed in proximity to the surface of a moving photosensitive member and which is in proximity to the surface of the photosensitive member.
A cleaning characterized in that a substance made of a non-magnetic material is combined on the surface of the magnetic cleaning roller, and the axial position of the non-magnetic material is continuously changed in the circumferential direction of the cleaning roller. It is a device.

According to a third aspect of the present invention, the shortest distance between the magnetic cleaning roller and the surface of the photosensitive member is 0.05 to 3 m.
The cleaning device according to the first or second invention is characterized in that the cleaning device is up to m.

With such a structure, the excessive toner pool generated immediately downstream of the moving direction of the peripheral surface of the magnetic cleaning roller between the magnetic cleaning roller and the photosensitive member is locally changed, and the photosensitive drum is exposed for a long time. It is no longer pressed against the body. As a result, the surface state and polishing ability of the magnetic cleaning roller are not deteriorated, the above-mentioned cleaning unevenness and blocking that damages the cleaning blade can be prevented, and uneven wear of the photoreceptor surface protective layer can be prevented.

Further, since the groove on the surface of the magnetic cleaning roller or the non-magnetic material portion is continuously changed in the circumferential direction, the edge portion of the spike of the recovered toner intermittently hits the surface of the photosensitive member and the cleaning force is increased. Is improved.

As a result of the above, a good and stable cleaning effect can always be obtained.

Further, it also has an effect of effectively rubbing the surface of the photoconductor to remove the corona product and prevent the image flow.

[0031]

Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] FIG. 3 is an explanatory view showing a case where the cleaning device according to the present invention is applied to an electrophotographic apparatus, for example, an electrophotographic copying machine.

It is assumed that the photoconductor 2 rotates in the direction of arrow A, and around it, as is well known, the cleaning device 1, the main charge eliminating light 9, the primary charger 10, the image signal applying means 1 are provided.
1, a developing device 12, a transfer electrode 15, a fixing device 1 for fixing the toner image transferred onto a transfer material such as paper to the transfer material.
3, a transport system 8 that transports the transfer material from the paper feed unit to the transfer position of the photoconductor 2 and transports it from the photoconductor 2 to the fixing device 13, and other image forming members.

A cleaning blade 3 is disposed inside the cleaning device 1 as viewed in the traveling direction of the peripheral surface of the photoconductor 2, and a magnetic cleaning roller 4 is provided upstream of the cleaning blade 3.
Are arranged in proximity to the surface of the photoconductor 2 and are rotated at a proper relative speed with respect to the peripheral surface of the photoconductor 2 by a suitable drive source (not shown).

A scraper 6 is disposed in contact with the magnetic cleaning roller 4 in the cleaning device 1, and the cleaning blade 3 or the magnetic cleaning roller 4 is disposed.
The toner and other foreign matter removed by the scraping are scraped off and dropped downward in the cleaning device 1, and then discharged to the outside by the screw conveyor 7.

The magnetic cleaning roller 4 is preferably made of an elastic material such as silicone rubber or urethane rubber. In order to have magnetism, magnetic powder is mixed into the roller 4 or another rubber magnet is used. May be used,
As shown in FIG. 1, a continuous groove 4a having different axial positions in the circumferential direction is provided on the outer circumference. Various kinds of grooves 4a can be adopted, for example, a single or multiple spiral, forward and reverse spirals, and various mesh patterns can be adopted.

The photoconductor 2 is an a-Si type photoconductor containing at least amorphous silicon and hydrogen atoms.

After the image forming process, the surface of the photosensitive member 2 is uniformly charged by the primary charger 10 arranged around the cylindrical photosensitive member 2 rotating in the direction of arrow A in FIG. An electrostatic latent image is formed on the photoconductor 2 by the image signal giving means 11 and the toner image visualized by the developing device 12 is introduced into a transfer portion having the transfer electrode 15 as a transfer material mainly composed of paper. Is transcribed to. The transfer material is the fixing device 13 after that.
The residual toner or the like remaining on the surface of the photoconductor 2 that does not contribute to the transfer at the transfer site is conveyed to the cleaning device 1 and is removed from the surface, and the residual charge is removed by the main discharge light 9. Is removed, the surface of the photoconductor 2 is ready for the next copying operation and again reaches the charged portion.

In this example, a magnetic roller in which a magnetic material is dispersed in silicon rubber is used as the magnetic cleaning roller 4 having the groove 4a, and the groove 4a is formed in a spiral shape as shown in FIG. Further, as an apparatus, the magnetic cleaning roller 4 is rotated in the same direction as or in a direction opposite to the rotating direction of the photoconductor 2, and the peripheral speed thereof is at a point close to the photoconductor 2.
The relative speed with respect to the peripheral speed of the photoconductor 2 was set to 0% to 500%, and the gap between the magnetic cleaning roller 4 and the photoconductor 2 was set to 150 μm.

The toner to be used is an insulating toner having at least a binder resin, and the binder resin is
For example, polystyrene, poly-P-chlorostyrene, homopolymers of styrene such as polyvinyltoluene and substitution products thereof, styrene-P-chlorostyrene copolymers, styrene-vinyltoluene copolymers, styrene-vinylnaphthalene copolymers. , Styrene-acrylic acid ester copolymer,
Styrene-α-methyl chloromethacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-
Styrene-based copolymers such as isoprene copolymer, styrene-acrylonitrile-indene copolymer, polyvinyl chloride, phenol resin, natural resin modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, Polyurethane, polyamide resin, furan resin, polyvinyl butyral, epoxy resin, xylene resin, polyvinyl butyral, terpene resin, coumarone indene resin, petroleum resin and the like can be used.

The toner used in the present invention is formed by mixing the binder resin with a colorant. As a colorant,
Magnetic powder, pigment, dye, etc. can be used. As magnetic powder,
For example, surface-oxidized or non-oxidized metals such as iron, nickel, copper, manganese, chromium, rare earths and their alloys, or oxides and ferrites can be used. Carbon black or the like can be used as the pigment.

In addition to these components, a toner formed by adding a lubricant for improving the fluidity of the toner, for example, a material such as SiO ₂ , titanium sanstrontium, cerium oxide or the like is used.

The collected toner 14 is attached to the magnetic cleaning roller 4, and SiO ₂ in the collected toner 14
The photoconductor 2 is rubbed and polished with oxidized / unoxidized iron or the like. This component varies depending on the degree of contribution of the collected toner 14 to rubbing and polishing. In addition, the collected toner 14 that has deteriorated due to the sliding friction and the collected toner 14 that has not deteriorated are
There are also differences in shape.

These collected toners 14 are in a state of standing up along the magnetic lines of force formed by the grooves 4a formed in the magnetic cleaning roller 4, and have substantially the same shape as the cross section of the grooves 4a of the magnetic cleaning roller 4 and the photosensitive member 2. A space is created between them. Therefore, as the magnetic cleaning roller 4 rotates, the toner pool of the collected toner 14 moves in the axial direction of the magnetic cleaning roller 4, and the cleaning ability of the surface of the photoconductor 2 does not locally change.

In this embodiment, an electrophotographic copying machine (model name NP6060 manufactured by Canon Inc.) is used as an extreme example, and the temperature is 30.
A test chart suitable for determining image stability or image deletion after being installed in an environment of 80 ° C and 80% humidity and adjusting the current value of the primary charger 10 so that an appropriate image can be obtained in a normal state. (Canon Co., Ltd. model name FY9-9060) is used to make continuous copies on Japanese Industrial Standard Paper size A3 copy paper (hereinafter referred to as A3 paper), and the above test chart FY9-9060 is used to determine image deletion. Suitable test chart (Model name FY9-905 manufactured by Canon Inc.)
8) and a test chart suitable for observing the cleaning performance (manufactured by Canon Inc., model name FYP-9073, which is a manuscript for producing a colored image in the first half of the transfer material feeding direction and a white image in the latter half thereof in the feeding direction of the transfer material. ), 1 to 1
The images copied up to 30,000 sheets were evaluated for stability in the long axis direction of the photoconductor 2, presence / absence of cleaning failure, or presence / absence of image deletion. Table 1 shows the results when the cleaning roller 4 was rotated in the same direction as the photosensitive member 2 and the peripheral speed was set to 150% relative to the peripheral speed of the photosensitive member 2.

The test charts used in this example are as follows.

Test chart FY9-9058 In a chart in which a minute pattern (in this chart, Iroha characters) is included on the entire surface, the character end portion in the copy is visually observed including a microscopic observation.

If there is no "image deletion", the edges are clearly visible without disappearing, blurring or crushing.

Test chart FY9-9060 A chart containing a plurality of patterns such as a pattern for observing a change in density of an image, a pattern for observing an image flow, etc., and particularly a number (8. 0, 7.0
Etc.) indicates the fineness of the line, that is, how many lines are included in 1 mm when the thickness and the interval of the line are the same,
If there is no "image deletion", large numbers, that is, finer lines, are clearly visible without blurring.

Test Chart FY9-9073 In the so-called "solid black" original, the original is shifted and overlapped with the transfer material to produce a colored image in the first half of the copy and a non-colored image in the latter half of the copy.

At this time, if the cleaning property is poor, the toner remaining on the surface of the photoconductor without being completely cleaned is developed in the non-colored portion and appears as a black streak.

The colored image portion is provided in the first half in order to develop the toner on the photosensitive member.

The judgment method of each evaluation in the upper column of Table 1 and the meaning of the symbols in Table 1 are shown below.

(Determination of Image Stability in Longitudinal Direction of Photoreceptor) An image is produced using a test chart FY9-9060, and the photoconductor 2 is tested.
The difference in the density of the images in the same density area of the document from the back to the front was visually checked and judged using a Macbeth reflection densitometer.

∘: Density difference is less than 0.02, density difference cannot be visually recognized. O ... Density difference is 0.02 or more and less than 0.05, most density difference cannot be visually recognized. -The density difference is 0.05 or more and less than 0.15, and the density difference can be visually recognized ▲ ... The density difference is 0.15 or more, and the density difference can be clearly recognized visually.

(Determination of Cleaning Property) Test chart FY9-9073 and copy sheet test chart FY9
-9073 is shifted so that it is closer to the front end side than the white original part, and stacked, and a copy is made with A3 paper. A copy image of the chart of the obtained copy image on the copy sheet and a copy image of the white original having a streak in the longitudinal direction behind the branch point of the copy image of the copy original portion of the white original portion, that is, the rotation direction of the photoconductor 2. The presence or absence of cleaning failure was evaluated by the presence or absence of the above. If the streaks were visually confirmed, it was determined that cleaning was defective.

∘: No cleaning failure ○: Streaks in the rotation direction of the photoconductor 2 within width 3 mm and within 2 lines △ ... Streaks in the rotation direction of the photoconductor 2 within width 3 mm Two or more objects and one or less 3 mm or more ▲ ... Two or more objects with a width of 3 mm or less in the rotation direction of the photoconductor 2 and two or more objects of 3 mm or more.

(Presence or absence of image deletion) Test chart FY9
An image was printed on A3 paper using -9060, and 8.0 (the number indicates the number of fine lines in 1 mm on the chart. The larger the number, the smaller the line thickness and the line interval.
Without "image deletion", small lines can be seen without blurring or crushing. It was judged by whether or not the thin line in) can be distinguished without being crushed.

Also, in the test chart FY9-9058,
The lighting voltage for image exposure was set higher than the lighting voltage for obtaining an appropriate image by 10 v, a copy was made on A3 paper, and the end portions of the characters were visually observed and evaluated.

∘: 8.0 and finer lines of 9.0, which are finer than that, can be discriminated without being crushed. Also, there is no blur at the end of the character in the test chart FY9-9058. 7. The thin line can be identified without being crushed, and there is no blur at the end of the characters in the test chart FY9-9058.
The thin line of 0 is indistinguishable. In addition, the test chart FY9-9058 has a blurred character end. ▲ ... The thin line of 7.0 is indistinguishable, and the test chart FY9-9058 has a blurred character end. There are many places.

(Cleaning blade) After continuous copying,
The side of the cleaning blade 3 in contact with the surface of the photoconductor 2 was observed with a microscope, and the presence or absence of a burr-like portion and the overall image were determined.

∘: No burr-like portion as before continuous copying Δ: Burr-like portion is present, but it is minute and does not lead to cleaning failure. ▲ ... There is a burr-like portion, and cleaning failure appears in the image.

(Fusion) After continuous copying, the side of the cleaning blade 3 in contact with the surface of the photoconductor 2 and the photoconductor 2
The surface was observed and judged based on the blade condition and the image.

∘: No fusing as in the case of continuous copying Δ: Fusing is partially present, but cleaning defects are small and not reached ▲ ... Fusing occurs, cleaning defects appear in the image .

The speed ratio of the peripheral speeds of the magnetic cleaning roller 4 and the photoconductor 2 used in the above-described embodiment was set to 150% of the peripheral speed of the photoconductor 2 as described above. However, by changing this, a preferable result was obtained when the peripheral speed of the magnetic cleaning roller 4 was in the range of 30 to 99.5% to 100.5 to 300% relative to the peripheral speed of the photoconductor 2. More preferably 50-9
It was in the range of 5% to 105 to 200%.

With the configuration of the present invention, the amount of the collected toner 14 including the toner pool between the magnetic cleaning roller 4 having the groove 4a and the photoconductor 2 and the position of the photoconductor 2 in the long axis direction can be controlled, and the fusing is performed. With respect to the anti-rubbing force, the performance is improved, and the cleaning property can be improved while maintaining a good state.

Further, the collected toner 14 is intermittently discharged from the photosensitive member 2
By hitting the surface, toner 1 that is always collected as in the past
The cleaning ability is improved as compared with the case where 4 is in contact with the surface of the photoconductor 2.

Further, the movement of the collected toner 14 by the magnetic cleaning roller 4 makes the sliding abrasion force of the collected toner 14 adhering to the magnetic cleaning roller 4 uniform, thereby improving the uniformity of the cleaning ability, and It is possible to prevent interference unevenness due to uneven rubbing of No. 2 and the like, and a high-quality image can be stably obtained by the synergistic effect of these.

[Embodiment 2] In this embodiment, a nonmagnetic material 4b made of a resin such as Teflon (trade name) is spirally formed on the peripheral surface of the magnetic cleaning roller 4 as shown in FIG. The electrophotographic copying machine is the same as that in the first embodiment.

As a combination method, for example, a spiral groove may be formed on the surface of the magnetic cleaning roller 4 and a non-magnetic material 4b formed in the same shape as the spiral groove may be put in the spiral groove of the magnetic cleaning roller 4. Non-magnetic material 4b made of resin such as Teflon and nylon (both are trade names)
May be coated on the spiral groove portion of the surface of the magnetic cleaning roller 4 in which the spiral groove has been previously formed to fill the spiral groove.

The non-magnetic material 4b may be higher than the surface of the magnetic cleaning roller 4. The height is preferably 3 mm or less in order to effectively maintain the toner suction force by the magnetic force of the magnetic cleaning roller 4. More preferably 1
mm or less, optimally 0.5 mm or less.

The non-magnetic material 4b has a high mechanical strength in the structure of the present invention, has little or no change in characteristics due to the environment, and has a high contact angle so that the photoconductor or the toner does not easily aggregate. And the like are necessary conditions.

In this embodiment, PTFE is used because of its workability.
(Teflon manufactured by DuPont), high melting point polyester resin, or the like is used.

The polyester is a binding polymer of an acid component and an alcohol component, and is a polymer obtained by condensation of dicarboxylic acid and glycol or condensation of a compound having a hydroxy group and a carboxy group of hydroxybenzoic acid. Aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalene dicarboxylic acid as acid components,
Aliphatic dicarboxylic acids such as succinic acid, adipic acid, and sebacic acid, alicyclic dicarboxylic acids such as hexahydroterephthalic acid, and oxycarboxylic acids such as hydroxyethoxybenzoic acid can be used. As the glycol component, ethylene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, cyclohexane dimethylol, polyethylene glycol, polypropylene glycol or the like can be used. It should be noted that polyfunctional compounds such as pentaerythritol, lolimethylolpropane, pyromellitic acid, and ester-forming derivatives thereof may be copolymerized within a range where the polyester resin is substantially linear. As the high melting point polyester resin, one having an intrinsic viscosity of 0.4 dl / g or more, preferably 0.5 dl / g or more, more preferably 0.65 dl / g or more, measured in orthochlorophenol at 36 ° C. is used. Examples of preferable high melting point polyester resins include polyalkylene terephthalate resins. The polyalkylene terephthalate resin is mainly composed of terephthalic acid as an acid component and alkylene glycol as a glycol component. Specific examples thereof include polyethylene terephthalate (PET) mainly composed of a terephthalic acid component and an ethylene glycol component,
Polybutylene terephthalate (PBT) mainly composed of a terephthalic acid component and 1,4-tetramethylene glycol (1,4-butylene glycol) component, and polycyclohexyl dimethylene terephthalate (PCT) mainly composed of a terephthalic acid component and a cyclohexane dimethylol component. ) Etc. can be mentioned. Examples of other preferable high molecular weight polyester resins include polyalkylene naphthalate resins. The polyalkylene naphthalate-based resin is mainly composed of a naphthalenedicarboxylic acid component as an acid component and an alkylene glycol component as a glycol component, and specific examples thereof include polyethylene naphthalene dicarboxylic acid component and an ethylene glycol component. Examples thereof include phthalate (PEN). The high melting point polyester resin has a melting point of preferably 160 ° C. or higher, particularly preferably 200 ° C. or higher. The high melting point polyester resin has high crystallinity because it has a high melting point. As a result, it is considered that the entanglement between the cured resin polymer chain and the high melting point polymer chain becomes uniform and dense, and a highly durable surface layer can be formed. In the case of a low-melting point polyester resin, since the crystallinity is low, there are places where the degree of entanglement with the cured resin polymer chain is large and places where the degree of entanglement is small, and the durability is considered to be poor.

Copying was performed under the same conditions as in Example 1 and each evaluation was performed.

The magnetic cleaning roller 4 is rotated in the circumferential direction together with the photosensitive member 2, and the peripheral speed thereof is relative to the peripheral speed of the photosensitive member 2.
Table 2 shows the results when the relative speed was set to 150%.

The judgment method of each evaluation shown in Table 2 and the meanings of the symbols in the table are the same as in Example 1.

When the peripheral speed of the magnetic cleaning roller 4 is further changed, the peripheral speed of the magnetic cleaning roller 4 is 30 to 99.5% to 100.5 to 300% relative to the peripheral speed of the photosensitive member 2. A favorable result was obtained within the range. More preferably 50-95% or 105-2
It was in the range of 00%.

With the configuration of the present invention, the amount of collected toner 14 and the position of the photoconductor 2 in the long axis direction including the toner pool between the magnetic cleaning roller 4 provided with the non-magnetic material 4b and the photoconductor 2 are controlled. As a result, in terms of fusion prevention and rubbing force, the performance was improved and the good state was maintained, and the cleaning property was improved.

Further, the collected toner 14 is intermittently discharged from the photosensitive member 2.
By hitting the surface, toner 1 that is always collected as in the past
The cleaning ability is improved as compared with the case where 4 is in contact with the surface of the photoconductor 2.

Further, when the collected toner 14 is moved by the magnetic cleaning roller 4, the scraping / polishing force of the collected toner 14 adhering to the magnetic cleaning roller 4 is made uniform, whereby the uniformity of the cleaning property is improved and the photosensitive toner is exposed. It is possible to prevent uneven interference and the like due to uneven rubbing of the body 2, and due to the synergistic effect of these, a high-quality image can be stably obtained.

[Embodiment 3] The electrophotographic copying machine used in this embodiment is the same as that used in Embodiment 1. In this embodiment, the magnetic material is dispersed in silicon rubber in the magnetic cleaning roller 4. Using the magnetic cleaning roller 4,
As described above, the groove 4a is formed in a spiral shape, and then the groove 4a is coated with a non-magnetic material such as Teflon or high melting point polyester. As the coating material, the material shown for the non-magnetic material 4b of the first embodiment can be used.

Using this magnetic cleaning roller 4 with a non-magnetic coating groove, copying and evaluation were carried out in the same manner as in Example 1.

The magnetic cleaning roller 4 with the non-magnetic coating groove is rotated in the direction opposite to that of the photosensitive member 2 so that the peripheral speed of the magnetic cleaning roller 4 is 70% relative to the peripheral speed of the photosensitive member 2. Table 3 shows the results when the test was performed.

The determination method for each evaluation in Table 3 and the symbols in the table are in accordance with Example 1.

When the above test was conducted by changing the peripheral speed of the magnetic cleaning roller 4 with the non-magnetic coating groove, the peripheral speed of the magnetic cleaning roller 4 with the non-magnetic coating groove was found to be relative to the peripheral speed of the photoconductor 2. 30-9
Preferable results were obtained in the range of 9.5% to 100.5 to 300%. It is more preferably in the range of 50 to 95% or 105 to 200%.

With the configuration of the present invention, the amount of the collected toner 14 including the toner pool between the magnetic cleaning roller 4 and the photoconductor 2 and the position of the photoconductor 2 in the long axis direction can be controlled to prevent fusion and sliding. The cleaning performance was improved while the performance of rubbing force was improved and it was kept good.

Further, the collected toner 14 is intermittently discharged from the photosensitive member 2.
By hitting the surface, the cleaning ability is improved as compared with the conventional case where the collected toner always hits the surface of the photoconductor 2.

Further, the movement of the collected toner 14 by the magnetic cleaning roller 4 makes the scraping and polishing force of the collected toner 14 adhering to the magnetic cleaning roller 4 uniform, thereby improving the uniformity of the cleaning property and exposing It is possible to prevent uneven interference and the like due to uneven rubbing of the body 2, and due to the synergistic effect of these, a high-quality image can be stably obtained.

"Comparative Example 1" This comparative example was prepared using the same electrophotographic copying machine as in Example 1 above.

The cleaning roller used in this comparative example is made of the same material as in Example 1 and has no groove.
A conventional cylindrical magnetic cleaning roller 40 as shown in FIG. 8 was used.

Using the magnetic cleaning roller 40,
Copying was performed under the same conditions as in Example 1 and each evaluation was performed.

Table 4 shows the results when the magnetic cleaning roller 40 was rotated in the same direction as the photosensitive member 2 and the peripheral speed thereof was set to 150% relative to the peripheral speed of the photosensitive member 2.

The determination method of each evaluation in Table 4 and the meaning of the symbols in the table are in accordance with Example 1.

It is considered that the cleaning blade 3 and the cleaning property are affected by the occurrence of fusion.

Comparative Example 2 This comparative example was prepared by using the electrophotographic copying machine used in Example 1.

As the cleaning roller used in this comparative example, as shown in FIG. 9, a magnetic cleaning roller made of the same material as in Example 1 was intermittently cut at equal intervals in the longitudinal direction of the magnetic cleaning roller. A large number of circumferential grooves 4c were provided in parallel to form a magnetic cleaning roller.

Using this magnetic cleaning roller, copying was performed under the same conditions as in Example 1 and each evaluation was performed.

Table 5 shows the results when the magnetic cleaning roller was rotated in the same direction as the photosensitive member 2 and the peripheral speed thereof was set to 150% relative to the peripheral speed of the photosensitive member 2.

The determination method for each evaluation in Table 5 and the meaning of the symbols in the table are in accordance with Example 1.

It is considered that the cleaning blade and the cleaning property are affected by the occurrence of fusion.

Comparative Example 3 This comparative example was prepared by using the electrophotographic copying machine used in Example 1.

As the cleaning roller used in this comparative example, a magnetic cleaning roller made of the same material as in Example 1 was used, and as shown in FIG. 10, grooves 4d were formed at equal intervals in the circumferential direction of the roller and perpendicular to the longitudinal direction of the roller. To form a magnetic cleaning roller.

Using this magnetic cleaning roller, copying was performed under the same conditions as in Example 1 and each evaluation was performed.

Table 6 shows the results when this magnetic cleaning roller was rotated in the same direction as the photosensitive member 2 and the peripheral speed thereof was set to 150% as a relative speed to the peripheral speed of the photosensitive member 2.

The determination method for each evaluation in Table 6 and the meaning of the symbols in the table are in accordance with Example 1.

It is considered that the cleaning blade 3 and the cleaning property are affected by the occurrence of fusion.

In the above embodiment, as the electrophotographic apparatus,
The copying machine using the a-Si type photoconductor has been described.
The present invention is not limited to the above-described embodiments and can be applied to other electrophotographic apparatuses such as printers, and the photoconductor is not limited to the a-Si based photoconductor, and the OP
It is a material for which a photoconductor such as C, Se, or CdS can be used.

Further, as means for moving the toner pool or the like between the cleaning roller and the photosensitive member in the cleaning device, other shapes such as a corrugated groove can be used in addition to the spiral groove. Further, a resin other than Teflon high melting point polyester may be used as the insulating material and the non-magnetic material.

In each of the above-mentioned embodiments, the gap latitude between the photoconductor and the cleaning blade can be changed in the magnetic cleaning roller of the present invention in the following Experimental Example 1 of non-sheet passing.

[Experimental Example 1] The same as Example 1 except for the electrophotographic copying machine, the magnetic cleaning roller 4, and the gap between the toner co-photoreceptor 2 and the magnetic cleaning roller 4.
An extreme example of an electrophotographic device is an air temperature of 30 ° C and a humidity of 80%.
Installed in the above environment, the current value of the charging device 10 and the image exposure amount are adjusted so that an appropriate image can be obtained in a normal state, and a constant amount of toner is applied to the photoconductor 2 from the developing device 12 without passing paper. Meanwhile, the photoconductor 2 was rotated for 6 hours.

After the rotation of the photoreceptor 2 was stopped, the amount of residual toner adhering to the surface of the photoreceptor 2 and the cleaning blade 3 downstream of the magnetic cleaning roller 4 was measured to evaluate the cleaning property.

In order to examine the allowable range of the gap between the photoconductor 2 and the magnetic cleaning roller 4, that is, the gap latitude, the gap between the magnetic cleaning roller 4 and the photoconductor 2 was changed from 10 μm to 5.50 mm and an experiment was conducted. It was

Further, the same experiment was conducted on the magnetic cleaning roller 40 having no groove 4a, and the cleaning property was evaluated.

The results of this Experimental Example 1 are shown in FIG.

In the conventional type magnetic cleaning roller 40, the cleaning property is improved as the gap between the magnetic cleaning roller 40 and the photosensitive member 2 is decreased from the larger side to the smaller side, and in the vicinity of 100 (μm × 10). Reach rank 5 below. Further, if the gap is made smaller, the toner is likely to be fused to the surface of the photoconductor, and the cleaning property is apparently deteriorated.

On the other hand, in the magnetic cleaning roller 4 having the groove 4a, the magnetic cleaning roller 4 and the photosensitive member 2 are
The gap area between the photoconductor 2 and the magnetic cleaning roller 4 is improved as the gap becomes smaller from the larger side to the smaller side, and the area of the gap between the photoconductor 2 and the magnetic cleaning roller 4 is shifted to the far side, and the gap is further reduced. Also, good cleaning ability is maintained. In the ranks described below, the electrophotographic apparatus is preferably rank 3 or higher in practical use,
The magnetic cleaning roller 4 having the groove 4a according to the present invention has a width of 0.02 to 3 mm, which is wider than the conventional magnetic cleaning roller 40 having a width of 0.5 to 3 mm.

Similar effects were obtained also with the magnetic cleaning roller 4 in which a non-magnetic material as shown in FIG. 2 was combined with a magnetic roller.

(Determination Criteria for Cleaning Property) In the evaluation of the cleaning property, the following ranking was made.

When a so-called conventional type magnetic cleaning roller 40 having no groove is used and the gap between the photoconductor 2 and the cleaning roller 40 is 5.0 mm, the amount of residual toner is rank 1. The rank was increased by 1 each time the amount decreased by 20%.

The second experimental example is to obtain the result by changing the width of the groove 4a.

(Experimental Example 2) When the spiral groove 4a is formed in the magnetic cleaning roller as in Experimental Example 1, the width of the groove 4a is changed so that the developing device 12 does not pass through the paper from the developing device 12 as in Experimental Example 1. The photoconductor 2 was rotated for 6 hours while applying a certain amount of toner to the photoconductor 2.

To evaluate the fusion, the state of the residual toner adhering to the surface of the photosensitive member 2 and the cleaning plate 3 downstream of the magnetic cleaning roller 4 after the rotation is stopped is visually checked,
Further, the side of the cleaning blade 3 in contact with the surface of the photosensitive member 2 was observed with a microscope, and the presence or absence of the burr-like portion was judged comprehensively.

When the lengths of the groove 4a and the non-groove portion in the axial direction are A and B, respectively, the magnetic cleaning roller 40 without the groove 4a, that is, the magnetic cleaning roller of A / (A + B) = 0 Alternatively, the same experiment was performed and the cleaning property was evaluated for the magnetic cleaning roller 4 in which the entire surface was cut as the groove 4a, that is, A / (A + B) = 1.

The gap between the surface before the groove 4a was formed and the surface of the photosensitive member 2 was defined as the gap.

FIG. 6 shows the result of this experimental example when the gap was 0.3 mm.

As a result, the cleaning property was remarkably improved when the ratio of the portion of the magnetic cleaning roller 4 where the groove 4a was formed to the portion where the groove 4a was not formed was 10% or more and 80% or less.

Although the cause is not clear, there is a portion where the collected toner 14 with the spikes hits the surface of the photoconductor 2 and a portion where it does not hit, and the edge portion of the collected toner 14 is the photoconductor 2.
It is conceivable that the cleaning property is improved by hitting the above-mentioned condition, compared with the case where the collected toner 14 simply rubs against the surface of the photoconductor 2 at all times.

Similar effects were obtained also in the case of the magnetic cleaning roller 4 formed by combining a non-magnetic material and a magnetic roller in the shape as shown in FIG.

[Evaluation of Cleaning Property] The cleaning property was evaluated by ranking the width of the groove 4a in the same manner as in Experimental Example 1. That is, the total width of the grooves 4a is A,
The relationship between the ratio [A / (A + B)] of the portion where the groove 4a was formed and the cleaning property was evaluated, where B is the total width of the portion where a is not formed. The rank was defined as in Experimental Example 1.

In the following Experimental Example 3, the relationship between the fusion of the recovered toner and the gap latitude was examined.

(Experimental Example 3) In the same manner as in Experimental Example 1, the photosensitive member 2 was rotated for 6 hours while applying a constant amount of toner from the developing device 12 to the photosensitive member 2 without passing paper.

To evaluate the fusion, the state of residual toner adhering to the surface of the photosensitive member 2 and the cleaning blade 3 downstream of the magnetic cleaning roller 4 after the rotation is stopped is visually checked,
Further, the side of the cleaning blade 3 in contact with the surface of the photosensitive member 2 was observed with a microscope, and the presence or absence of the burr-like portion was judged comprehensively.

The experiment was conducted by changing the gap between the magnetic cleaning roller 4 and the photosensitive member 2 from 10 μm to 5 mm.

Further, with respect to the magnetic cleaning roller 40 in which the groove 4a is not formed, the same experiment was conducted to evaluate the fusion.

The results are shown in FIG.

As a result, in the conventional magnetic cleaning roller 40 having no groove 4a, the gap between the cleaning roller 40 and the photosensitive member 2 is 0.200 mm (2.0 mm).
In the magnetic cleaning roller 4 having the groove 4a according to the first embodiment of the present invention, the fusion rank is improved.
(Isn't it 5mm?) And above, the fusion rank is good and the gap latitude is widening.

Similar effects were obtained with the magnetic cleaning roller 4 in which a non-magnetic material as shown in FIG. 2 is combined with a magnetic cleaning roller.

(Evaluation of Fusion) The evaluation of fusion was performed as follows.

After continuous copying, the side of the cleaning blade 3 in contact with the surface of the photoconductor 2 was observed with a microscope, and the presence or absence of a burr-like portion and the state of the toner on the surface of the photoconductor 2 were collectively judged.

Using the conventional type magnetic cleaning roller 40, the result of testing with a gap of 2.0 mm, which is almost close to the conventional gap, was 2.5, and the rank was 5 when no fusion occurred. The case where the cleaning blade had 10 or more burrs due to the adhesion was evaluated as rank 0.

When Experimental Examples 1 and 3 are combined, the amount, position, and distribution of the collected toner between the magnetic cleaning roller 4 and the photosensitive member 2 can be controlled, and a good range of cleaning property and fusion property, that is, a practical range can be obtained. Gap latitude X is 2 mm of the magnetic cleaning roller 40 with no groove.
From ≦ × ≦ 3 mm, the magnetic cleaning roller 4 of the present invention
Then, it spreads to 0.5 mm ≦ × ≦ 3 mm.

[0143]

Each of the inventions of the present invention is a cleaning device provided with a magnetic cleaning roller which is disposed in proximity to the surface of a moving photoconductor and which is in proximity to the surface of the photoconductor. Means that a groove is formed on the surface of the magnetic cleaning roller, and the axial position of the groove continuously changes in the circumferential direction of the cleaning roller. The second invention of the present invention is the surface of the magnetic cleaning roller. In the first and second aspects of the present invention, since the non-magnetic material is combined with a substance, and the axial position of the non-magnetic material continuously changes in the circumferential direction of the cleaning roller. Can effectively prevent fusion of the toner in the vicinity of the vicinity of the photoconductor and the cleaning roller, and damage such as uneven rubbing of the photoconductor surface protective layer due to the fusion.

Also, the cleaning ability is improved by intermittently hitting the surface of the photoconductor with the collected toner in the spiked state.

Further, since the state where the collected toner hits the surface of the photoconductor continuously changes in the axial direction at the circumferential position, the uniformity of the cleaning property is well protected, and uneven rubbing, uneven cleaning, etc. are prevented. ..

Further, the durability of the cleaning device and the cleaning blade is improved, the overall cleaning property is improved, and a stable image can be obtained.

Further, by improving the rubbing ability of the surface of the photosensitive member,
By effectively removing the corona product adhering to the surface of the photoconductor in the vicinity of the charger before the image forming step, it also has the effect of preventing the trace of the charger after a long period of rest.

[Brief description of drawings]

FIG. 1 is a perspective view of a grooved magnetic cleaning roller according to an embodiment of the present invention.

FIG. 2 is a perspective view of a magnetic cleaning roller combined with a non-magnetic material according to an embodiment of the present invention.

FIG. 3 is a vertical sectional view of a main part of the electrophotographic copying machine.

FIG. 4 is an enlarged view of a photosensitive member and a cleaning roller portion in FIG.

FIG. 5 is a diagram showing a relationship between a gap between a photoconductor and a cleaning roller and a cleaning property.

FIG. 6 is a diagram showing the relationship between the groove width of the cleaning roller and the cleaning property.

FIG. 7 is a diagram showing a relationship between a gap between a photoconductor and a cleaning roller and a fusion degree.

FIG. 8 is a perspective view of a conventional magnetic cleaning roller.

FIG. 9 is a perspective view of a magnetic cleaning roller of Comparative Example 2.

FIG. 10 is a perspective view of a magnetic cleaning roller of Comparative Example 3.

[Explanation of symbols]

 2 photoconductor 3 cleaning blade 4 magnetic cleaning roller 4a groove 4b non-magnetic material 14 collected toner

Claims (3)

[Claims] 1. A cleaning device provided with a magnetic cleaning roller which is disposed in proximity to a surface of a moving photosensitive member and is in proximity to the surface of the photosensitive member, wherein a groove is formed on the surface of the magnetic cleaning roller, Further, the cleaning device is characterized in that the position of the groove in the axial direction continuously changes in the circumferential direction of the cleaning roller. 2. A cleaning device provided with a magnetic cleaning roller which is disposed close to a surface of a moving photosensitive member and is close to the surface of the photosensitive member, wherein a substance made of a non-magnetic material is attached to the surface of the magnetic cleaning roller. A cleaning device comprising a combination of the cleaning device and the non-magnetic material, wherein the position of the non-magnetic material in the axial direction continuously changes in the circumferential direction of the cleaning roller. 3. The cleaning device according to claim 1, wherein the range of the shortest distance between the magnetic cleaning roller and the surface of the photoconductor is 0.05 to 3 mm.