JP3710127B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus that uses liquid toner or dry type dry toner, and in the recovery of surplus toner in each cleaning object constituting the image forming apparatus, the recovered surplus toner falls downward due to the gravity of the toner. The present invention relates to an image forming apparatus that preferably prevents image quality and maintains image quality.
[0002]
[Prior art]
In the electrophotographic process using toner executed by the image forming apparatus, a latent image carrier (photosensitive drum), a developing roller, an intermediate transfer member, a carrier removal unit, and the like are arranged, and charging, exposure, and development are performed every rotation. A series of processes such as transfer, fixing, and cleaning are executed.
[0003]
At the end of the electrophotographic process, it is necessary to scrape the residual toner and oil with a blade in order to clear the dirt in the previous rotation. Since the structure of this portion is such that the residual toner and oil drop due to gravity, as shown in FIG. 8, when cleaning the cleaning object 70 which is a rotating body, it is necessary to arrange a cleaner blade 81 directly below the cleaning object 70. There is.
[0004]
As shown in FIG. 9, for example, an image forming apparatus employing a tandem structure will be described. The image forming apparatus mainly includes developing units 54, 55, 56, and 57, an intermediate transfer member 51, and a fixing unit 53. The developing units 54, 55, 56, and 57 are provided on the intermediate transfer member 51 in association with yellow / magenta / cyan / black. The developing units 54, 55, 56, and 57 are each provided with a photosensitive drum and a developing roller.
[0005]
The developing roller is biased to a predetermined voltage and adheres toner to an exposed portion on the photosensitive drum according to an electric field between the developing drum and develops the electrostatic latent image on the photosensitive drum to form an image. . Liquid toner is supplied to the developing roller from the toner reservoir. Thus, the liquid toner is applied on the developing roller with a predetermined layer thickness.
[0006]
The intermediate transfer member 51 transfers the toner attached to the photosensitive drum in accordance with the electric field between the photosensitive drums. Thus, the four color toner images developed on the respective photosensitive drums are sequentially superimposed on the intermediate transfer member 51 while the intermediate transfer member 51 is rotated once, thereby forming a color image. The carrier liquid is removed from the four color image superimposed on the intermediate transfer member 51 in this way by the first carrier removing unit 61 to the fifth carrier removing unit 65.
[0007]
Thereafter, the four-color image is transferred to the print medium using the pressure roller 52 at the contact portion with the print medium, and then fixed through the fixing unit 53.
[0008]
In many cases, the developing roller, the intermediate transfer member 51, and the carrier removing unit are formed of a rubber-based material. On the other hand, the photosensitive drum is often formed of a resin material such as polycarbonate.
[0009]
Next, a mechanism for transferring the toner adhered to the photosensitive drum to the intermediate transfer member will be described with reference to FIG.
[0010]
A scoroton charger 85, an LED unit 86, and a developing roller 91 are arranged upstream of the process of transferring the toner attached to the photosensitive drum 71a to the intermediate transfer member 51 so as to face the photosensitive drum 71a.
[0011]
The scoroton charger 85 charges the photosensitive drum 71a and generally applies a bias voltage of about 800 V to the photosensitive drum 71a.
The LED unit 86 irradiates the photosensitive drum 71a with light energy so that the potential of the charged photosensitive drum 71a is lowered to a predetermined value. The developing roller 91 is the same as described above, and a detailed description thereof is omitted.
[0012]
On the other hand, a cleaner blade 81 and a static elimination LED 87 are disposed downstream of the process of transferring the toner attached to the photosensitive drum 71a to the intermediate transfer member 51 so as to face the photosensitive drum 71a.
[0013]
The cleaner blade 81 scrapes off excess toner when liquid toner is used. In addition, after scraping, the toner is dropped by gravity and collected by a lower tray (not shown). The neutralization LED 87 removes the residual charge of the charged photosensitive drum 71a. The static elimination LED 87 can be removed only when a positive (+) potential remains, and cannot be removed when a negative (-) potential remains.
[0014]
As shown in FIG. 11, when liquid toner is used, a cleaner blade 81 is brought into contact with a cleaning object 70 including any of a developing roller, an intermediate transfer member, a carrier removal unit, and a photosensitive drum, and excess toner is scraped off. In addition, after the excess toner is scraped off by the cleaner blade 81, there is a structure in which the toner is dropped by gravity without being attached and collected by a lower tray (not shown).
[0015]
Further, as shown in FIG. 12, in addition to the cleaner blade 81 that contacts the cleaning object 70 and scrapes off excess toner, the cleaning liquid is sprayed from the liquid blowing part 83 toward the cleaning object 70, and the sponge roller 82 and the like. Some have a recovery mechanism. These require a roller and the structure is complicated.
[0016]
On the other hand, when a dry type dry toner is used, various types of a cleaner blade having a sheet for preventing backflow have been proposed. For example, as disclosed in Japanese Patent Laid-Open No. 8-194420, what is expressed as a “rake sheet” is for preventing leakage during toner collection.
[0017]
As shown in FIG. 13, these structures are arranged with respect to the cleaning object 70 such that the attachment position of the rake sheet 72 faces the cleaner blade 71, and the cleaning container 73 is used for discharging the taken-out toner. In addition, there is a discharge mechanism including a scraping member 74, a reservoir 75, and a partition member 76, and the discharge mechanism requires more space.
[0018]
[Problems to be solved by the invention]
As described above, the conventional techniques have the following problems.
[0019]
When a tandem structure using an intermediate transfer member is considered, the latent image carrier (photosensitive drum) and the developing roller constituting the developing unit must be arranged at arbitrary positions. For this reason, when considering miniaturization, it is necessary to provide a degree of freedom in the arrangement of the latent image carrier (photosensitive drum) constituting the developing unit and the developing roller.
[0020]
Cleaner blades for scraping do not undergo permanent deformation (compression set) or permanent deformation of the roller rubber material, but it takes several seconds to return, so there is a dent at the development point. , Streaks appear in the image and the image quality deteriorates. This appears as streaky white spots parallel to the main scanning direction in the image.
[0021]
For this reason, when the cleaning object stops the electrophotographic process (standby), the cleaner blade must be retracted from the cleaning object. Also in this case, it is necessary to prevent the toner from leaking and falling.
[0022]
The subject of this invention is
Latent image carrier (photosensitive drum) constituting the developing unit by relaxing restrictions on the mounting angle of the cleaner blade and preventing the recovered excess toner from falling downward due to the gravity of the toner. And providing a degree of freedom in the arrangement of the developing roller.
[0023]
Furthermore, the image quality is maintained even if a mechanism for preventing the excess toner to be collected from dropping downward due to the gravity of the toner is provided.
[0024]
Further, the object is to remove the charge on the latent image carrier (photosensitive drum) that is the object to be cleaned, thereby facilitating cleaning, eliminating the need for a static elimination LED in the next rotation, and simplifying the configuration.
[0025]
[Means for Solving the Problems]
In order to solve the above problems, the present invention takes the following means.
[0026]
Even when the cleaner blade is retracted from the cleaning object by placing a sheet-like sheet member that contacts the object to be cleaned and presses the toner over the cleaner blade, the toner is formed in the space formed by the cleaner blade and the sheet member. Configure to confine.
[0027]
By taking the above-described means, toner leakage can be easily prevented without taking up a mounting space. Further, the toner is prevented from dropping even when the cleaner blade is retracted.
[0028]
Further, the sheet member is formed of a conductive material, and a bias voltage is applied to the sheet member in a direction to cancel the residual charge on the latent image carrier (photosensitive drum).
[0029]
By taking the above-mentioned means, the charge on the latent image carrier (photosensitive drum) that is the object to be cleaned is removed, thereby facilitating cleaning and eliminating the need for a static elimination LED in the next rotation.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
The present invention takes the following embodiments.
[0031]
As shown in FIG. 1, in an image forming apparatus that has an electrophotographic process using toner and includes a cleaning device that removes excess toner in an electrophotographic process that is repeatedly executed, the cleaning apparatus is an object to be cleaned. A cleaner blade 2 that contacts 1 and scrapes off excess toner, and is disposed so as to overlap the cleaner blade 2 so as to contact the cleaning object 1 and press the excess toner. And a sheet member 3 formed in a sheet shape sandwiched between the two.
[0032]
By taking the above-described form, the scraped excess toner can be sandwiched between the cleaner blade and the sheet member in the collection of the surplus toner in each cleaning object constituting the image forming apparatus. Prevents toner from falling downward due to gravity. In other words, in the image forming apparatus using liquid toner or dry toner, the excess toner is pressed, and the fall of the scraped liquid toner due to dripping is prevented. Also, the dry toner is prevented from falling.
[0033]
Furthermore, as shown in FIG. 1 and FIG.
When the cleaning object 1 performs the electrophotographic process, the cleaner blade 2 is brought into contact with the cleaning object 1, and when the cleaning object 1 stops the electrophotographic process, the cleaner blade 2 is retracted from the cleaning object 1. Constitute.
[0034]
By adopting the above-described form, when the object to be cleaned has a compression history, it is possible to prevent problems such as white spots due to contact between the cleaner blade and the object to be cleaned on the image.
[0035]
Furthermore, as shown in FIG. 1 and FIG.
When the cleaner blade 2 is brought into contact with the object 1 to be cleaned, the sheet member 3 is not in contact with the cleaner blade 2, and when the cleaner blade 2 is withdrawn from the object 1 to be cleaned, the sheet member 3 is brought into contact with the cleaner blade 2. Configure to be in state.
[0036]
By taking the above-described form, when the excess toner is collected in each cleaning object constituting the image forming apparatus, the scraped excess toner is sandwiched between the cleaner blade and the sheet member.
[0037]
Furthermore, the cleaning device includes:
The sheet member 3 is formed of a thin flexible resin sheet.
[0038]
By adopting the above-described form, the present invention is applied to a case where the cleaning object is a developing roller, an intermediate transfer member, a carrier removal unit, etc., formed from a rubber-based material.
[0039]
Furthermore, the cleaning device includes:
The cleaner blade 2 is formed of a thin metal plate that is less deformed than rubber.
[0040]
By adopting the above form, for example, by using a metal plate such as stainless steel, the bending of the sheet can be reduced. Therefore, the amount of displacement when the cleaner blade is retracted from the cleaning object by the rotation mechanism or the like is small. It effectively prevents toner leakage. Note that the present invention is applied to a case where the object to be cleaned is a developing roller formed of a rubber-based material, an intermediate transfer member, a carrier removal unit, or the like.
[0041]
Furthermore, the image forming apparatus includes:
The cleaning object 1 is a latent image carrier (photosensitive drum 1a).
[0042]
By taking the above form, the excess toner scraped off by the cleaner blade and the sheet member in the recovery of the excess toner on the latent image carrier (photosensitive drum) is sandwiched between the toner and the gravitational force of the toner. Prevents falling down due to.
[0043]
Furthermore, the cleaning device includes:
The cleat blade 2 is formed of an elastic material including rubber.
[0044]
By adopting the above form, the present invention is applied to a case where the object to be cleaned is a photosensitive drum formed of a resin material such as polycarbonate.
[0045]
Furthermore, the cleaning device includes:
The sheet member 3 is formed of a thin rubber sheet.
[0046]
By taking the above form, when considering the cleaning of a hard resin layer such as a photosensitive drum, the use of a soft rubber sheet suppresses the generation of scratches and increases the durability of the photosensitive drum. That is, the present invention is applied to the case where the object to be cleaned is a photosensitive drum formed of a resin material such as polycarbonate.
[0047]
Furthermore, the cleaning device includes:
The sheet member 3 is formed of a rubber material that is chemically inert to the organic photoreceptor.
[0048]
By using such a material by adopting the above form, it can be applied to the case where the object to be cleaned is a photosensitive drum formed of a resin material such as polycarbonate, and the contamination of the photosensitive drum is prevented and stable. Form an image.
[0049]
Furthermore, as shown in FIG.
When forming the sheet member 3, a thin rubber layer 3c is formed on the surface of the flexible plate 3b made of plastic or metal.
It is best that the cleaning object 1 is a latent image carrier (photosensitive drum 1a).
[0050]
By taking the above-mentioned form, the substrate is required to have a stable rigidity, and the surface is softly contacted with the mating member (cleaning object) by the elasticity of rubber.
[0051]
Furthermore, as shown in FIG.
A toner recovery mechanism for recovering excess toner that is scraped and held;
The toner collection mechanism forms a cylindrical toner collection unit 21 that collects excess toner, and also forms a hole 22 that guides excess toner into the toner collection unit 21 on the surface of the toner collection unit 21.
[0052]
By taking the above-described form, the remaining toner is collected in the toner collecting section through the hole, and the remaining toner is collected without taking a space to a predetermined position.
[0053]
Furthermore, as shown in FIG.
The toner collecting unit 21 includes a suction mechanism unit 23 that sucks the collected toner.
[0054]
By taking the collected toner by sucking the collected toner, it is possible to further prevent the toner from falling downward due to gravity in collecting the excess toner in the cleaning target.
[0055]
Furthermore, as shown in FIG.
The sheet member 3 is formed of a conductive material, and a bias voltage (DC voltage 12) in a direction to cancel the residual charge is applied to the sheet member 3.
[0056]
By taking the above form, cleaning on the latent image carrier (photosensitive drum), which is the object to be cleaned, is removed (cancelling residual charge on the photosensitive drum), making cleaning easier and unnecessary for the next rotation. The neutralizing LED for removing the residual charge of the latent image carrier (photosensitive drum) can be made unnecessary, and the cost is reduced by simplifying the configuration.
[0057]
Furthermore, as shown in FIG.
When the bias voltage is applied, an AC bias voltage (AC voltage 13) is superimposed and applied.
[0058]
By taking the above-described form, for example, static electricity is removed so that the potential is zero with respect to an arbitrary residual potential. That is, the positively charged latent image carrier (photosensitive drum) cannot remove the negative potential by the neutralizing LED when a negative potential remains due to transfer or the like. Applying it also cancels negative potentials.
[0059]
【Example】
A typical embodiment of the present invention will be described with reference to FIGS. In the following, the same portions are denoted by the same reference numerals, and detailed description may be omitted.
[0060]
1 and 2 show an embodiment of the present invention.
[0061]
In the drawing, for example, a cleaning device for removing excess toner in an image forming apparatus employing a tandem structure using an intermediate transfer member is shown. The cleaning device includes a cleaner blade 2 that is brought into contact with a cleaning object 1 and a sheet member 3. The cleaning object 1 includes any of a developing roller, an intermediate transfer member, a carrier removal unit, and a photosensitive drum.
[0062]
The cleaner blade 2 contacts one end of the cleaning object 1 to scrape excess toner, and the other end is fixed to the support 2a. The support 2a causes the cleaner blade 2 to contact the object 1 to be cleaned. Alternatively, the cleaner blade 2 is configured to be movable by a drive unit (not shown) so that the cleaner blade 2 can be retracted from the cleaning target body 1.
[0063]
The sheet member 3 is arranged so as to overlap the cleaner blade 2, and the tip side thereof is brought into contact with the cleaning object 1 to press the excess toner, and the scraped excess toner is sandwiched between the cleaner blade 2. The other end is fixed to the support portion 3a. The support portion 3a is fixed to the support portion 2a that fixes the cleaner blade 2, and the cleaner blade 2 is attached to the cleaning object 1. It operates following the operation of bringing it into contact or withdrawing.
[0064]
As shown in FIG. 1, when the cleaning object 1 performs an electrophotographic process, the support portion 2 a is rotated in the direction of the arrow to bring the cleaner blade 2 into contact with the cleaning object 1. At this time, the sheet member 3 is brought into a non-contact state with the cleaner blade 2. That is, excess toner scraped by the cleaner blade 2 is accumulated between the cleaner blade 2 and the sheet member 3.
[0065]
As shown in FIG. 2, when the cleaning object 1 stops the electrophotographic process, the support portion 2a is rotated in the direction of the arrow to retract the cleaner blade 2 from the cleaning object 1. At this time, the sheet member 3 is brought into contact with the tip of the cleaner blade 2. That is, excess toner accumulated between the cleaner blade 2 and the sheet member 3 is retained.
[0066]
1 and 2 can prevent the scraped excess toner from dropping downward due to the gravity of the toner even when the electrophotographic process is stopped in collecting the excessive toner in the cleaning target 1. . Further, even when the cleaning object 1 has a compression history, it is possible to prevent problems such as white spots due to contact between the cleaner blade 2 and the cleaning object 1 on the image.
[0067]
When the cleaning object 1 is a developing roller, an intermediate transfer member, or a carrier removal unit formed of a rubber-based material, the sheet member 3 is formed of a thin resin sheet having flexibility. Is desirable. Further, it is desirable that the cleaner blade 2 is formed of a thin metal plate such as stainless steel which is less deformed than rubber. Since a thin metal plate such as stainless steel can reduce the bending of the sheet member, the amount of displacement when the cleaner blade 2 is retracted from the cleaning object 1 by a rotating mechanism or the like can be reduced, and toner leakage is effectively prevented. be able to.
[0068]
On the other hand, when the cleaning object 1 is a latent image carrier (photosensitive drum) formed of a resin material such as polycarbonate, it is desirable that the cleaner blade 2 be formed of a material rich in elasticity including rubber. Further, it is desirable to form the sheet member 3 with a thin rubber sheet.
[0069]
As a result, in collecting the excess toner on the latent image carrier (photosensitive drum), the excess toner scraped by the cleaner blade 2 and the sheet member 3 is sandwiched, so that the scraped excess toner is moved downward due to the gravity of the toner. Can be prevented from falling. In addition, the use of a soft rubber sheet can suppress the generation of scratches and increase the durability of the photosensitive drum.
[0070]
Further, when the cleaning object 1 is a latent image carrier (photosensitive drum) formed of a resin material such as polycarbonate, the sheet member 3 may be formed of a rubber material that is chemically inert with the organic photoconductor. Good. As such a material, for example, there is thermosetting urethane rubber which is a two-component compound of polyol and isocyanate. Since such a material is used, contamination of the photosensitive drum can be prevented and a stable image can be formed.
[0071]
Further, as shown in FIG. 3, when the sheet member is formed, a thin rubber layer 3c is formed on the surface of the flexible plate 3b having flexibility by plastic or metal to form the cleaning object 1. You may make it contact. As a result, the substrate is required to have stable rigidity, and the surface is softly contacted with the cleaning object 1 by the elasticity of rubber. Also in this case, it is best that the cleaning object 1 is a latent image carrier (photosensitive drum).
[0072]
FIG. 4 shows an embodiment of the present invention.
[0073]
In the drawing, for example, a cleaning device for removing excess toner in an image forming apparatus employing a tandem structure using an intermediate transfer member is shown. The cleaning device includes a cleaner blade 2 that is brought into contact with the object 1 to be cleaned, a sheet member 3, and a toner recovery mechanism that recovers excess toner that is scraped and held. The cleaning object 1 includes any of a developing roller, an intermediate transfer member, a carrier removal unit, and a photosensitive drum.
[0074]
The cleaner blade 2 and the sheet member 3 have the same configuration as that described with reference to FIGS. 1 and 2 described above, and detailed description thereof is omitted here.
[0075]
The toner collecting mechanism forms a cylindrical toner collecting portion 21 that collects excess toner, and the toner collecting portion 21 collects excess toner collected between the cleaner blade 2 and the sheet member 3 on the surface of the toner collecting portion 21. A hole 22 is formed leading into the inside. Further, the toner collecting unit 21 includes a suction mechanism unit 23 for sucking the collected toner. Note that it is desirable that the toner recovery unit 21 to the suction mechanism unit 23 be formed of a flexible material.
[0076]
With this configuration, surplus toner is collected in the toner collecting unit 21 through the hole 22 and the remaining toner can be collected without taking a space to a predetermined position. Further, by sucking the collected toner, it is possible to further prevent the toner from falling downward due to the gravity in collecting the excessive toner in the cleaning object 1.
[0077]
FIG. 5 shows an embodiment of the present invention.
[0078]
In the figure, a mechanism for transferring the toner adhered to the photosensitive drum to the intermediate transfer member will be described.
[0079]
A scoroton charger 5, an LED unit 6, and a developing roller 11 are arranged upstream of the process of transferring the toner attached to the photosensitive drum 1a to the intermediate transfer member 10 so as to face the photosensitive drum 1a.
[0080]
The scoroton charger 5 charges the photosensitive drum 1a, and generally applies a bias voltage of about 800 V to the photosensitive drum 1a. The LED unit 6 irradiates the photosensitive drum 1a with light energy so that the potential of the charged photosensitive drum 1a is lowered to a predetermined value. The developing roller 11 is the same as described above, and a detailed description thereof is omitted.
[0081]
On the other hand, a cleaner blade 2 and a sheet member 3 are disposed downstream of the process of transferring the toner attached to the photosensitive drum 1a to the intermediate transfer member 10 so as to face the photosensitive drum 1a. Note that the mechanical parts of the cleaner blade 2 and the sheet member 3 have the same configurations as those described with reference to FIGS. 1 and 2, and detailed description thereof is omitted here.
[0082]
In this example, the sheet member 3 is formed of a conductive material, and is configured to apply a bias voltage composed of a DC voltage 12 in a direction to cancel the residual charge on the intermediate transfer body 10 to the sheet member 3. is there. The bias voltage is preferably about 0V to -400V.
[0083]
Next, the timing for rotating the photosensitive drum to execute the electrophotographic process, the timing for bringing the cleaner blade into contact with or retracting from the photosensitive drum, and the timing for applying or stopping the bias voltage to the sheet member will be described.
[0084]
FIG. 7 is a diagram showing a timing chart of the embodiment of the present invention.
[0085]
In the figure, the timing at which the cleaner blade 3 is brought into contact with or retracted from the photosensitive drum 1a is such that the cleaner blade 2 is brought into contact with the photosensitive drum 1a after the photosensitive drum 1a starts rotating to execute the electrophotographic process. The cleaner blade 2 is retracted from the photosensitive drum 1a before the photosensitive drum 1a stops rotating to stop the electrophotographic process.
[0086]
The bias voltage is applied to the sheet member 3 or stopped after the cleaner blade 2 is brought into contact with the photosensitive drum 1 a and then the bias voltage is applied to the sheet member 3. Further, the application of the bias voltage to the sheet member 3 is stopped before the cleaner blade 2 is retracted from the photosensitive drum 1a.
[0087]
With this configuration, by removing the charge on the photosensitive drum that is the object to be cleaned (cancelling the residual charge on the photosensitive drum), it is possible to facilitate cleaning and eliminate the need for a neutralizing LED that was necessary in the past. .
[0088]
FIG. 6 shows an embodiment of the present invention.
[0089]
In this figure, the difference from FIG. 5 described above is that, when a bias voltage is applied to the sheet member 3, in addition to a bias voltage consisting of a DC voltage 12 in a direction to cancel the residual charge on the intermediate transfer member 10, an AC The bias voltage 13 is applied in a superimposed manner. The AC bias voltage is preferably about 2000 V at the peak voltage.
[0090]
The timing for applying or stopping the bias voltage to the sheet member 3 is the same as that in FIG.
[0091]
With this configuration, for example, static electricity can be removed so that the potential is zero with respect to an arbitrary residual potential. That is, the positively charged latent image carrier (photosensitive drum) cannot remove the negative (−) potential by the neutralizing LED when the negative (−) potential remains due to transfer or the like. However, a negative (−) potential can be canceled by applying an AC bias voltage.
[0092]
【The invention's effect】
According to the present invention, the following effects can be expected.
[0093]
In the collection of excess toner in each cleaning object constituting the image forming apparatus, the scraped excess toner can be sandwiched between the cleaner blade and the sheet member, so that the scraped excess toner is moved downward due to the gravity of the toner. Falling can be prevented. In other words, in an image forming apparatus using liquid toner or dry toner, it is possible to suppress excess toner and to prevent the liquid toner that has been scraped off from dropping due to dripping. In addition, the dry toner can be prevented from falling.
[0094]
Further, the cleaning blade is brought into contact with the cleaning object when the cleaning object performs the electrophotographic process, and the cleaning blade is retracted from the cleaning object when the cleaning object stops the electrophotographic process. When the object to be cleaned has a compression history, it is possible to prevent problems such as white spots due to contact between the cleaner blade and the object to be cleaned on the image.
[0095]
Further, when the cleaner blade is brought into contact with the object to be cleaned, the sheet member is brought into a non-contact state with the cleaner blade, and when the cleaner blade is withdrawn from the object to be cleaned, the sheet member is brought into contact with the cleaner blade. As a result, when the excess toner is collected in each cleaning object constituting the image forming apparatus, the scraped excess toner can be sandwiched between the cleaner blade and the sheet member.
[0096]
Furthermore, the sheet member is formed of a thin flexible resin sheet, so that the object to be cleaned is applied to a developing roller, an intermediate transfer body, a carrier removal unit, etc., which are formed from a rubber-based material. can do.
[0097]
Further, since the cleaner blade is formed of a thin metal plate that is less deformed than rubber, and using a metal plate such as stainless steel, the sheet bending can be reduced. The amount of displacement when the blade is retracted from the cleaning object can be reduced, and toner leakage can be effectively prevented. Note that the present invention can be applied to a case where the cleaning target body is formed of a rubber-based material, such as a developing roller, an intermediate transfer body, and a carrier removal unit.
[0098]
Furthermore, when the object to be cleaned is a latent image carrier (photosensitive drum), the scraped excess toner is sandwiched between the cleaner blade and the sheet member in collecting the excess toner on the latent image carrier (photosensitive drum). Thus, the scraped excess toner can be prevented from falling downward due to the gravity of the toner.
[0099]
Furthermore, the cleaner blade can be applied to a photosensitive drum in which the cleaning object is formed of a resin material such as polycarbonate by forming the cleaner blade from a material having a high elasticity including rubber.
[0100]
Further, when considering the cleaning of a hard resin layer such as a photosensitive drum by forming the sheet member with a thin rubber sheet, the object to be cleaned is made of a resin material such as polycarbonate by using a soft rubber sheet. This can be applied to the photosensitive drum to be formed, and the generation of scratches can be suppressed and the durability of the photosensitive drum can be increased.
[0101]
Furthermore, by forming the sheet member from a rubber material that is chemically inert to the organic photoreceptor, the sheet member can be applied to a photosensitive drum in which the object to be cleaned is formed of a resin material such as polycarbonate. Contamination can be prevented and a stable image can be formed.
[0102]
Further, when forming the sheet member, a thin layer of rubber is formed on the surface of a flexible plate material made of plastic or metal, thereby obtaining a stable rigidity in the base material, and an elastic property of the rubber on the surface. Thus, soft contact with the mating member (cleaning object) can be realized.
[0103]
Furthermore, a toner collecting mechanism that collects excess toner that is scraped and held is provided. The toner collecting mechanism forms a cylindrical toner collecting unit that collects excess toner, and the toner is collected on the surface of the toner collecting unit. By forming the hole leading into the toner collecting portion, the remaining toner can be collected in the toner collecting portion through the hole, and the remaining toner can be collected without taking a space to a predetermined position.
[0104]
Further, the toner collecting mechanism includes a suction mechanism that sucks the collected toner in the toner collecting unit, and sucks the collected toner, thereby reducing the excess toner in the cleaning target due to the gravity of the toner. Falling in the direction can be further prevented.
[0105]
Further, the sheet member is formed of a conductive material, and a bias voltage in a direction for canceling the residual charge is applied to the sheet member, whereby a latent image carrier (photosensitive drum) that is a cleaning object. Eliminating the upper charge (cancelling the residual charge on the photosensitive drum) makes cleaning easier and eliminates the need for a static elimination LED that removes the residual charge on the latent image carrier (photosensitive drum) that is not required in the next rotation. And the configuration can be simplified.
[0106]
Furthermore, when the bias voltage is applied, the AC bias voltage is applied in a superimposed manner, so that, for example, the static electricity can be removed so that the potential is zero with respect to an arbitrary residual potential. That is, the positively charged latent image carrier (photosensitive drum) cannot remove the negative potential by the neutralization LED when a negative potential remains due to transfer or the like, but even in such a case, the AC bias voltage is applied. By doing so, a negative potential can also be removed (cancelled).
[Brief description of the drawings]
FIG. 1 is a diagram of an embodiment of the present invention.
FIG. 2 is a diagram of an embodiment of the present invention.
FIG. 3 is a diagram of an embodiment of the present invention.
FIG. 4 is a schematic view of an embodiment of the present invention.
FIG. 5 is a schematic view of an embodiment of the present invention.
FIG. 6 is a schematic view of an embodiment of the present invention.
FIG. 7 is a timing chart of an embodiment of the present invention.
FIG. 8 is a diagram of the prior art.
FIG. 9 is a diagram of the prior art.
FIG. 10 is a diagram of the prior art.
FIG. 11 is a diagram of the prior art.
FIG. 12 is a diagram of the prior art.
FIG. 13 is a diagram of the prior art.
[Explanation of symbols]
1: Cleaning object
1a: Photosensitive drum
2: Cleaner blade
2a: Support part
3: Sheet member
3a: Support part
3b: Flexible plate
3c: Rubber layer
12: DC voltage
13: AC voltage
21: Toner recovery unit
22: Hole
23: Suction mechanism

Claims (6)

In order to remove excess toner in an electrophotographic process that is repeatedly performed, and having an electrophotographic process using toner, a cleaner blade that contacts the object to be cleaned and scrapes off the excess toner, and is superposed on the cleaner blade An image forming apparatus including a cleaning device including a sheet member that is arranged in such a manner as to press a surplus toner by contacting the object to be cleaned and that forms a sheet member that sandwiches the scraped surplus toner with the cleaner blade . ,
The cleaning device includes:
When the cleaning object performs the electrophotographic process, the cleaner blade is brought into contact with the cleaning object without contacting the sheet member, and when the cleaning object stops the electrophotographic process, the cleaner blade is moved to the sheet member. It is configured to be in contact with and retracted from the object to be cleaned.
An image forming apparatus. The image forming apparatus includes:
The object to be cleaned is a latent image carrier;
The image forming apparatus according to claim 1. The cleaning device includes:
A toner recovery mechanism for recovering excess toner that is scraped and held;
The toner collecting mechanism forms a cylindrical toner collecting portion that collects excess toner, and forms a hole in the surface of the toner collecting portion for guiding the excess toner into the toner collecting portion.
The image forming apparatus according to claim 1 . The toner recovery mechanism includes:
A suction mechanism for sucking the collected toner in the toner collecting section;
The image forming apparatus according to claim 3 . The cleaning device includes:
The sheet member is formed of a conductive material and is configured to apply a bias voltage in a direction to cancel the residual charge to the sheet member.
The image forming apparatus according to claim 1. The cleaning device includes:
When applying the bias voltage, the AC bias voltage is configured to be superimposed and applied.
The image forming apparatus according to claim 5 .

Images