JP2004191737A - Image forming apparatus - Google Patents

Image forming apparatus Download PDF

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Publication number
JP2004191737A
JP2004191737A JP2002360754A JP2002360754A JP2004191737A JP 2004191737 A JP2004191737 A JP 2004191737A JP 2002360754 A JP2002360754 A JP 2002360754A JP 2002360754 A JP2002360754 A JP 2002360754A JP 2004191737 A JP2004191737 A JP 2004191737A
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JP
Japan
Prior art keywords
toner
transfer
friction
photoreceptor
toner band
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
JP2002360754A
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Japanese (ja)
Inventor
Hiroe Okuyama
Naoki Ota
Satoshi Shigesaki
Kanji Shintaku
Taichi Yamada
直己 太田
浩江 奥山
太一 山田
寛治 新宅
聡 重崎
Original Assignee
Fuji Xerox Co Ltd
富士ゼロックス株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Publication date
Application filed by Fuji Xerox Co Ltd, 富士ゼロックス株式会社 filed Critical Fuji Xerox Co Ltd
Priority to JP2002360754A priority Critical patent/JP2004191737A/en
Publication of JP2004191737A publication Critical patent/JP2004191737A/en
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Abstract

An object of the present invention is to prevent the frictional force between the surface of a photoreceptor and a cleaning blade from becoming excessive, and to prevent the occurrence of cleaning failure. To extend the life of cleaning blades, photoconductors, etc.
When it is detected that photoconductors PRy to PRk mounted on an image forming apparatus are in an unused state, or when the photoconductor traveling cycle number q reaches a set traveling cycle number q1, The toner band creation start determination means C3 determines that it is time to start the friction reduction toner band creation. At this time, the friction reduction toner band creation means C4 has the maximum width that can be developed in the photosensitive member axial direction and the photosensitive member has the maximum width. A friction reducing toner band having a predetermined length in the rotation direction and having an image density of 10 to 100% is formed on the surfaces of the photoconductors PRy to PRk.
[Selection diagram] FIG.

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electrophotographic image forming apparatus that forms a toner image on a photoreceptor surface, transfers the toner image to a recording sheet or an intermediate transfer material, and removes residual toner on the photoreceptor surface after transfer by a cleaning blade. More particularly, the present invention relates to an image forming apparatus configured to reduce damage due to friction between a photosensitive member surface and the cleaning blade.
The present invention is used in an electrophotographic image forming apparatus such as a copying machine, a printer, and a facsimile.
[0002]
[Prior art]
Conventionally, in an electrophotographic method, an electrostatic latent image created by charging and exposing a photoreceptor surface is developed into a toner image, the toner image is transferred to a transfer paper or the like, and the image is fixed by a hot roll or the like. Is formed. Since untransferred toner (transfer residual toner), external additives, and discharge products remain on the photoreceptor surface after the transfer process, it is necessary to remove these by cleaning means prior to the next image forming process. become. As a cleaning means for removing transfer residual toner and the like, various methods such as a method using a fur brush, a magnetic brush, and the like, and a method using an elastic cleaning blade are used. A means for scraping off the toner by rubbing is generally used because it is simple and inexpensive.
[0003]
Originally, the frictional resistance between the elastic cleaning blade and the photoreceptor was large, and the elastic cleaning blade could not be slid by itself. However, the fine particles added to the toner caused the friction between the cleaning blade and the photoreceptor. It is thought to be responsible for lubrication. However, in the early stage when the process cartridge including the photoconductor and the cleaning blade is almost unused, use of fine particles between the cleaning blade and the photoconductor is not stable. For example, when a contact charging member such as a charging roll for applying an alternating electric field is used, the lubricating component may be unstable, and the friction between the elastic cleaning blade and the photoconductor may be locally increased.
[0004]
Due to the increase in friction, the cleaning blade is turned up, and damage such as chatter, chipping and abrasion of the cleaning edge is caused, and the surface of the photoconductor is scratched. The performance of removing objects and the like deteriorates, and it becomes impossible to maintain stable cleaning performance for a long period of time.
[0005]
On the other hand, in recent years, image quality has been improved in this type of image forming apparatus, and as one direction for improving the image quality, a polymerization method is used to reduce the toner diameter, make it spherical, and sharpen the particle size distribution. It is becoming possible. By reducing the diameter of the toner, the reproducibility of the dots formed on the photoreceptor can be improved, and by making the toner spherical, the developability and transferability can be improved. However, a toner having a sharp particle size distribution and a nearly spherical shape has a better fluidity than a conventional irregular-shaped pulverized toner, so that the retention of the toner at the cleaning edge of the blade is poor, and it is more difficult to ensure stable lubrication of the blade. .
[0006]
It is difficult to clean the spherical toner with the blade. Particularly, when the damage of the blade or the damage of the photoreceptor is deteriorated, the cleaning performance is remarkably deteriorated as compared with the conventional irregular toner. Actually, it is difficult to extend the life of a cleaning blade, a process cartridge including a photosensitive member, and the like due to the cleaning failure.
The following technology is conventionally known as an image forming apparatus that prevents the occurrence of the cleaning failure and extends the life of a cleaning blade, a photoconductor, and the like.
[0007]
[Patent Document 1] Japanese Patent Application Laid-Open No. HEI 5-188463 (JP-A 2nd column, line 42 to 3rd column, line 28)
[Patent Document 2] Japanese Patent Application Laid-Open No. 11-38656 (publication, page 4, right column, upper row, lines 1-20)
[Patent Document 3] JP-A-11-184106 (publication, page 4, right column, lines 12 to 25)
[Patent Document 4] JP-A-11-316468 (Gazette, page 6, left column, lines 6 to 30)
[Patent Document 5] JP-A-2001-51576 (publication, page 3, right column, lines 24-44)
[0008]
[Problems to be solved by the invention]
A method of supplying a lubricant or the like to a photoreceptor in an image forming apparatus using the spherical toner has been proposed. For example, there is JP-A-5-188463 (Patent Document 1). However, even in the technique described in Patent Document 1, if the lubricant supply to the photoconductor is insufficient, cleaning failure occurs, and if the lubricant is excessively supplied, adverse effects due to filming on the photoconductor are likely to occur. It needs to be supplied to the body, but it is very difficult to design.
[0009]
Japanese Patent Application Laid-Open No. H11-38656 (Patent Document 2) proposes a photoreceptor having an outermost surface layer that is advantageous for scratching and abrasion of the photoreceptor. Japanese Unexamined Patent Publication No. Hei 11-316468 (Patent Document 4) proposes a photoreceptor having a surface layer containing a charge-transporting substance and a siloxane-based resin that is advantageous for scratching and abrasion of the photoreceptor.
Discharge products and the like that have been effectively removed by abrasion of the surface in the conventional photoreceptor are difficult to remove in the proposed photoreceptor, and particularly when spherical toner is used, in places where the image density is low or in non-image forming cycles. There is a problem that the friction rise is large and the blade damage is worsened.
[0010]
Japanese Patent Application Laid-Open No. 2001-51576 (Patent Document 5) discloses that a specific brush roll and an elastic rubber blade are used as a means for using a photoreceptor using a siloxane-based resin having a high film hardness to effectively remove deposits on the photoreceptor surface. Combinations have been proposed, but this method cannot effectively avoid blade damage when spherical toner or a contact charging member is used.
In view of the above circumstances, the present invention forms a toner image on the surface of a photoconductor, transfers the toner image to a recording sheet or an intermediate transfer material, and then uses a cleaning blade having elasticity to remove the residual toner image on the surface of the photoconductor. In a scraping electrophotographic image forming apparatus, the following contents (O01) and (O02) are technical subjects.
(O01) To prevent the frictional force between the photoreceptor surface and the cleaning blade from becoming excessive, and to prevent the occurrence of cleaning failure.
(O02) To extend the life of the cleaning blade, the photoconductor, and the like.
[0011]
[Means for Solving the Problems]
Next, a description will be given of the present invention which has solved the above-mentioned problem. In the present invention, the reference numerals of the elements of the embodiment are enclosed in parentheses in order to facilitate correspondence with the elements of the embodiment described later. Things are added. The reason why the present invention is described in association with the reference numerals of the embodiments described below is to facilitate understanding of the present invention and not to limit the scope of the present invention to the embodiments.
[0012]
(The present invention)
(First invention)
In order to solve the above-mentioned problems, an image forming apparatus according to a first aspect of the present invention is characterized in that the image forming apparatus includes the following constituent elements (A01) to (A07).
(A01) A photoreceptor (PRy to PRk) having a photosensitive layer provided on a conductive substrate; a charging member (CRy to CRk) for charging the surface of the photoreceptor (PRy to PRk); Toner image formation including a latent image forming device (ROS) for exposing a body (PRy to PRk) to form an electrostatic latent image and a developing device (Gy to Gk) for developing the electrostatic latent image into a toner image Devices (Uy to Uk),
(A02) Toner image transfer members (T1y to T1k) for transferring a toner image on the surface of the photoreceptor (PRy to PRk) to the transfer target (B);
(A03) A cleaner having elastic cleaning blades (CBy to CBk) in contact with the surfaces of the photoconductors (PRy to PRk) in the counter direction to remove residual toner on the surfaces of the photoconductors (PRy to PRk) after transfer. (CLy to CLk),
(A04) Toner band creation start determining means (C3) for determining whether or not the start of creation of the friction reducing toner band;
(A05) A friction having an image density of 10 to 100% having a maximum width developable in the axial direction of the photoconductor and a predetermined length in the rotation direction of the photoconductor when it is determined that the toner band for friction reduction is started. Friction-reducing toner band forming means (C4) for forming a toner band for reduction on the surface of the photoconductor (PRy to PRk);
(A06) In order to prevent the friction-reducing toner band from being transferred to the transfer-receiving member (B), a gap between the toner image transfer member and the photoconductors (PRy to PRk) is supplied when the friction-reducing toner band is supplied. Transfer bias control means (C6c) for controlling a transfer bias to be applied;
(A07) An unused photoconductor detection unit (C3b) for detecting whether the photoconductors (PRy to PRk) mounted on the image forming apparatus is in an unused state, and the unused state is detected. The toner band creation start determining means (C3) for determining that it is time to start toner band creation.
[0013]
(Operation of the first invention)
In the image forming apparatus according to the first aspect of the present invention having the above-mentioned constitutional requirements (A01) to (A07), the photoconductors (PRy to PRk) each having a photosensitive layer provided on a conductive substrate of a toner image forming apparatus (Uy to Uk) are provided. Is charged by the charging members (CRy to CRk). The exposure device (ROS) exposes the surface of the charged photoconductor (PRy to PRk) to form an electrostatic latent image on the surface of the photoconductor (PRy to PRk). Developing devices (Gy to Gk) develop the electrostatic latent image into a toner image.
The toner image transfer members (T1y to T1k) transfer the toner images on the surfaces of the photoconductors (PRy to PRk) to the transfer target (B).
The elastic cleaning blades (CBy to CBk) of the cleaners (CLy to CLk) are in contact with the surface of the photoconductor (PRy to PRk) in the counter direction, and the residual toner on the surface of the photoconductor (PRy to PRk) after the transfer. Is removed.
The toner band creation start determining means (C3) for determining whether or not the creation of the friction reducing toner band has started is performed when the photoconductors (PRy to PRk) mounted on the image forming apparatus are in an unused state. When an unused state is detected by the unused photoconductor detecting means (C3b) for detecting whether or not the toner band creation is started.
[0014]
When it is determined that the toner band for friction reduction has been started, the friction-reducing toner band preparation means (C4) has a maximum width developable in the photoconductor axis direction and a predetermined length in the photoconductor rotation direction. Is formed on the surface of the photoreceptor (PRy to PRk) having an image density of 10 to 100% having the following.
The damage to the blade edges of the cleaning blades (CBy to CBk) is mainly caused at the start of rotation when the cohesive force between the photoreceptors (PRy to PRk) and the cleaning blade (CBy to CBk) is increased, and at the start of rotation after long-term storage Get up sometimes. Therefore, when the unused photoconductors (PRy to PRk) start rotating, frictional contact between the photoconductors (PRy to PRk) and the cleaning blades (CBy to CBk) starts. In this case, as soon as possible after the unused photoconductors (PRy to PRk) start rotating, toner is applied to the contact portions between the cleaning blades (CBy to CBk) and the photoconductors (PRy to PRk). Need to supply. Therefore, it is preferable to start the production of the friction-reducing toner band between the time when the unused photoconductors (PRy to PRk) start rotating and the time when they rotate once.
[0015]
The transfer bias control means (C6c) supplies the friction-reducing toner band to a contact portion between the cleaning blades (CBy to CBk) and the photoconductors (PRy to PRk). The transfer bias applied between the toner image transfer member and the photoconductors (PRy to PRk) is controlled so that the transfer is not performed on the transfer target (B).
By applying as much toner and external additives as possible to the blade edge without transferring the toner band developed to alleviate blade edge damage, higher lubricity is created, blade damage is reduced, and high cleaning performance is achieved. Maintenance becomes possible.
When the transfer object (B) is an intermediate transfer member (B), the friction reducing toner band formed on the surface of the photoconductor (PRy to PRk) is transferred to the intermediate transfer member (transfer member) (B). While passing through the transfer regions (Q3y, Q3m, Q3c, Q3k), a transfer electric field of 0 V or a reverse electric field is applied to control so as not to transfer to the intermediate transfer member (transfer member) (B).
[0016]
Therefore, when the photoconductors (PRy to PRk) are determined to be unused, the friction-reducing toner band formed on the surface of the photoconductors (PRy to PRk) by the toner image forming device (Uy to Uk) is not used. The sheet is conveyed to a contact portion with the cleaning blades (CBy to CBk) without being transferred to the transfer target (B). The toner of the friction-reducing toner band conveyed to the contact portion is accumulated in the contact portion, and reduces friction between the cleaning blades (CBy to CBk) and the photoconductors (PRy to PRk). Therefore, in the initial stage of using the photoconductors (PRy to PRk), the cleaning blades (CBy to CBk) and the photoconductors (PRy to PRk) are prevented from exerting an excessive frictional force therebetween. . Therefore, the cleaning blades (CBy to CBk) and the photoconductors (PRy to PRk) are prevented from being worn or damaged due to excessive friction therebetween, so that high cleaning performance can be maintained for a long period of time. . That is, since the service life of the cleaning blades (CBy to CBk) and the photoconductors (PRy to PRk) can be extended, the image forming apparatus can obtain high image quality over a long period of time.
[0017]
Further, in the image forming apparatus of the first invention, even when a spherical toner having an average shape index SF of 100 to 140 is used, abrupt cleaning blade distortion generated at the start of rotation of the photoconductor is suppressed and further supplied. Since the toner is held between the photoconductors (PRy to PRk) and the cleaning blades (CBy to CBk) as a lubricant, the cleaning blades (CBy to CBk) and the photoconductor (Cby) are stable regardless of the use environment and the image density. PRy to PRk) can be lubricated, cleaning performance can be maintained for a long time, and edge damage of the cleaning blades (CBy to CBk) can be suppressed. Particularly, by adding monodispersed spherical silica having a specific gravity of 1.3 to 1.9 and a particle size of 80 to 300 nm, it is possible to further suppress the friction between the blade and the photoconductor (PRy to PRk).
[0018]
(Second invention)
An image forming apparatus according to a second aspect of the invention is characterized by having the following components (A01) to (A06), (A08), and (A09).
(A01) A photoreceptor (PRy to PRk) having a photosensitive layer provided on a conductive substrate; a charging member (CRy to CRk) for charging the surface of the photoreceptor (PRy to PRk); Toner image formation including a latent image forming device (ROS) for exposing a body (PRy to PRk) to form an electrostatic latent image and a developing device (Gy to Gk) for developing the electrostatic latent image into a toner image Devices (Uy to Uk),
(A02) Toner image transfer members (T1y to T1k) for transferring a toner image on the surface of the photoreceptor (PRy to PRk) to the transfer target (B);
(A03) A cleaner having elastic cleaning blades (CBy to CBk) in contact with the surfaces of the photoconductors (PRy to PRk) in the counter direction to remove residual toner on the surfaces of the photoconductors (PRy to PRk) after transfer. (CLy to CLk),
(A04) Toner band creation start determining means (C3) for determining whether or not the start of creation of the friction reducing toner band;
(A05) A friction having an image density of 10 to 100% having a maximum width developable in the axial direction of the photoconductor and a predetermined length in the rotation direction of the photoconductor when it is determined that the toner band for friction reduction is started. Friction-reducing toner band forming means (C4) for forming a toner band for reduction on the surface of the photoconductor (PRy to PRk);
(A06) In order to prevent the friction-reducing toner band from being transferred to the transfer-receiving member (B), a gap between the toner image transfer member and the photoconductors (PRy to PRk) is supplied when the friction-reducing toner band is supplied. Transfer bias control means (C6c) for controlling a transfer bias to be applied;
(A08) Photoconductor running cycle number detecting means (ME1) for detecting the running cycle number (p, q) of the photoconductors (PRy to PRk) mounted on the image forming apparatus (U);
(A09) There is a set running cycle number storage means (C3c) for storing the set running cycle number (q1) for determination at the start of toner band creation, and when the determination is performed, the photoconductor running cycle number (q) is set to The toner band creation start determining means (C3) for determining that the toner band creation has started when the set running cycle number (q1) has been reached.
[0019]
In the specification of the present application, the term "photoconductor running cycle number" as a term of the second invention means a numerical value related to "use time" of the photoconductors (PRy to PRk). Therefore, as the “number of running cycles”, “the rotation time of the photoconductors (PRy to PRk)”, “the number of rotations of the photoconductors (PRy to PRk)”, or “the number of recorded images” can be used. is there.
[0020]
(Operation of the second invention)
In the image forming apparatus according to the second aspect of the present invention, which has the above constitutional requirements (A01) to (A06), (A08), and (A09), the start of toner band creation for determining whether or not the start of the creation of the friction reducing toner band has been started. The set traveling cycle number storage means (C3c) of the time discriminating means (C3) stores the set traveling cycle number (q1) for discriminating the start of toner band creation of the photoconductor traveling cycle number (q). The photoconductor traveling cycle number detecting means (ME1) detects the photoconductor traveling cycle number (q). Then, when the toner band creation start determining means (C3) performs the determination, the detected photoconductor travel cycle number (q) reaches the set travel cycle number (q1) for the start time determination. In this case, it is determined that the toner band creation has started.
In the second invention, when the toner band creation start determining means (C3) executes the determination as to whether or not the toner band creation is started, the number of traveling cycles (q) of the photoconductors (PRy to PRk) is increased. When it is determined that the set running cycle number (q1) for starting determination has been reached, a friction-reducing toner band is created each time. The friction-reducing toner band is transported to a contact portion between the cleaning blades (CBy to CBk) and the photoconductors (PRy to PRk). Then, the toner of the friction reducing toner band stays in the contact portion and reduces the friction between the cleaning blades (CBy to CBk) and the photoconductors (PRy to PRk). Therefore, the cleaning blades (CBy to CBk) and the photoconductors (PRy to PRk) are prevented from being worn or damaged due to excessive friction therebetween, so that high cleaning performance can be maintained for a long period of time. . That is, since the service life of the cleaning blades (CBy to CBk) and the photoconductors (PRy to PRk) can be extended, the image forming apparatus (U) can obtain high image quality over a long period of time.
[0021]
In the second invention, each time the detected number of photoconductor traveling cycles (q) reaches the set number of traveling cycles for starting determination (q1), a toner band that is determined to be at the start of toner band creation. The creation start determination unit (C3) can be configured to execute the determination operation only when the power of the image forming apparatus U is turned on. In this case, according to the photoconductor running cycle number (q) detected when the power is turned on, the photoconductors (PRy to PRk) start rotating as soon as possible after the power is turned on (preferably the photoconductor (PRy)). ~ PRk) makes one rotation), the creation of the friction-reducing toner band can be started.
[0022]
(Third invention)
An image forming apparatus according to a third aspect of the present invention is characterized by having the following components (A01) to (A06) and (A010).
(A01) A photoreceptor (PRy to PRk) having a photosensitive layer provided on a conductive substrate; a charging member (CRy to CRk) for charging the surface of the photoreceptor (PRy to PRk); Toner image formation including a latent image forming device (ROS) for exposing a body (PRy to PRk) to form an electrostatic latent image and a developing device (Gy to Gk) for developing the electrostatic latent image into a toner image Devices (Uy to Uk),
(A02) a photoreceptor (PRy to PRk) surface toner image transfer member for transferring the toner image on the photoreceptor (PRy to PRk) surface to the transfer target (B);
(A03) A cleaner having elastic cleaning blades (CBy to CBk) in contact with the surfaces of the photoconductors (PRy to PRk) in the counter direction to remove residual toner on the surfaces of the photoconductors (PRy to PRk) after transfer. (CLy to CLk),
(A04) Toner band creation start determining means (C3) for determining whether or not the start of creation of the friction reducing toner band;
(A05) A friction having an image density of 10 to 100% having a maximum width developable in the axial direction of the photoconductor and a predetermined length in the rotation direction of the photoconductor when it is determined that the toner band for friction reduction is started. Friction-reducing toner band forming means (C4) for forming a toner band for reduction on the surface of the photoconductor (PRy to PRk);
(A06) In order to prevent the friction-reducing toner band from being transferred to the transfer-receiving member (B), a gap between the toner image transfer member and the photoconductors (PRy to PRk) is supplied when the friction-reducing toner band is supplied. Transfer bias control means (C6c) for controlling a transfer bias to be applied;
(A010) A charging bias control unit (C6a) configured to apply no charging bias to the charging members (CRy to CRk) when the friction-reducing toner image is formed.
[0023]
(Operation of the third invention)
In the image forming apparatus according to the third aspect of the present invention having the above-mentioned constituent features (A01) to (A06) and (A010), the charging bias control means (C6a) controls the charging member (CRy) when forming the friction-reducing toner image. CRCRk) is not applied with a charging bias. Therefore, the friction reducing toner band formed on the surface of the photoconductor (PRy to PRk) is formed only by the developing bias.
One of the factors that increases the surface slippage of the photoconductors (PRy to PRk) and causes damage to the blade edge and an increase in photoconductor rotation torque is discharge generation by a contact-type charging member, particularly, a BCR (bias charge roll, charging roll). There is adhesion of things. In the third aspect, before applying a discharge stress by the charging members (CRy to CRk), a lubricating component such as a toner or an external additive is interposed between the photoreceptor (PRy to PRk) and the cleaning blade (CBy to CBk). By intervening, it is possible to suppress an increase in initial torque and blade edge damage, and it is possible to ensure cleaning maintainability.
[0024]
The image forming apparatuses according to the first to third aspects of the invention can have the following configuration requirement (A011).
(A011) When the maximum perimeter of the toner particles is ML, and the maximum value of the projected area of the toner particles is A, the toner particles having an average shape index SF of 100 to 140 represented by SF = 100π (ML) 2 / 4A can be used. The developing device to be used (Gy to Gk).
In the developing device (Gy to Gk) using the spherical toner particles having the average shape index SF of 100 to 140, the toner easily passes through the contact portion between the cleaning blade (CBy to CBk) and the photoconductor (PRy to PRk). Therefore, it is difficult for the toner to stay in the contact portion. However, in the image forming apparatus having the above-described configuration requirement (A011), when the toner band creation start determination unit (C3) determines that the time has come to start the creation of the friction reduction toner band, the friction reduction toner band is created. Then, the toner can be supplied to the contact portion between the cleaning blades (CBy to CBk) and the photoconductors (PRy to PRk), and the toner can stay in the contact portion. Therefore, even when a developing device (Gy to Gk) using toner particles (spherical toner) having the average shape index SF of 100 to 140 is used, the cleaning blades (CBy to CBk) and the photoconductors (PRy to PRk) can be used. Can be reduced.
In other words, the present invention provides a good blade cleaning performance of the photoconductors (PRy to PRk) irrespective of the operating temperature environment without reducing the cleaning performance over a long period of time even in an image forming apparatus (U) using spherical toner. It is possible to provide an inexpensive image forming apparatus (U) that ensures the above. In addition, the present invention provides an image forming apparatus capable of achieving a long life of a cleaning blade (CBy to CBk) and a photoreceptor (PRy to PRk). It is possible.
[0025]
The image forming apparatus having the first to third inventions or the component (A011) can have the following component (A012).
(A012) 3 mm to 10 in the photoconductor rotation direction 6 mm, wherein the toner band has a length of 0.1 mm.
In the image forming apparatus, the amount of toner supplied to the contact portion between the cleaning blades (CBy to CBk) and the photoconductors (PRy to PRk) is determined by the length of the friction reducing toner band in the photoconductor rotation direction; It is determined by the image density of the friction-reducing toner band. In the image forming apparatus having the above-mentioned constitutional requirement (A012), the image density of the friction-reducing toner band is set to an appropriate value within the range of 10 to 100%, and the rotation of the photosensitive member of the friction-reducing toner band is adjusted. The length in the direction is 3 mm to 10 6 By setting the length to a suitable length within the range of mm, a required amount of toner can be conveyed to the contact portion between the cleaning blades (CBy to CBk) and the photoconductors (PRy to PRk). . Therefore, an amount of toner necessary for reducing friction can be supplied to the contact portion.
[0026]
The image forming apparatus provided with the first to third inventions or the component (A011) or (A012) can have the following component (A013).
(A013) While the friction-reducing toner band passes through the transfer area (Q3y, Q3m, Q3c, Q3k) to the transferee (B), the photoconductors (PRy to PRk) and the transferee (B) Transfer member position control means for controlling the position of the transfer member (B) so that the transfer member is not transferred to the transfer member (B).
In the image forming apparatus having the above-mentioned configuration requirement (A013), while the toner band for reducing friction passes through the transfer area to the transfer object (B), the transfer object position control means controls the photosensitive member (PRy to PRy). Since the position of the transfer-receiving member (B) is controlled so that the transfer-receiving member (PRk) does not contact the transfer-receiving member (B), the toner of the toner band for friction reduction formed on the surface of the photosensitive member (PRy to PRk) is controlled. Is supplied to a contact portion between the cleaning blades (CBy to CBk) and the photoconductors (PRy to PRk) without being transferred to the transfer target (B). Therefore, the toner can be efficiently supplied to the contact portion.
By applying as much toner and external additives as possible to the blade edge without transferring the toner image developed to alleviate blade edge damage, higher lubricity is created, blade damage is reduced, and high cleaning performance is achieved. Maintenance is possible.
[0027]
The image forming apparatus provided with any one of the first to third inventions or any one of the above-mentioned components (A012) to (A013) can include the following components (A014) and (A015). .
(A014) A use environment detecting member (SN1, SN2) for detecting a use environment including temperature or humidity,
(A015) The higher the temperature detected by the use environment detecting members (SN1, SN2), the higher the detected humidity, the lower the temperature or the lower the humidity. The friction-reducing toner band creating means (C4) for creating the friction-reducing toner band such that the amount of toner supplied to the contact portion between the photoconductors (PRy to PRk) and the photoconductors (PRy to PRk) increases.
[0028]
When the use environment of the image forming apparatus (U) is high temperature and high humidity, the frictional force between the cleaning blades (CBy to CBk) and the photoconductors (PRy to PRk) is higher than when the usage environment is low temperature and low humidity. There is a tendency. However, in the image forming apparatus provided with the above-mentioned constitutional requirements (A014) and (A015), the friction-reducing toner band forming means (C4) increases as the detection temperature of the use environment detecting members (SN1, SN2) increases. Alternatively, as the detected humidity becomes higher, the amount of toner supplied to the contact portion between the cleaning blades (CBy to CBk) and the photoconductors (PRy to PRk) increases as compared with the case where the detected humidity is low or low. Thus, the toner band for reducing friction is prepared.
[0029]
The increase in friction between the cleaning blades (CBy to CBk) and the photoconductors (PRy to PRk) is particularly remarkable under high-temperature and high-humidity conditions, and has a function of monitoring the use environment as described above. At least one of the width in the rotation direction and the image density of the created toner band is changed from the time when the unused photoconductors (PRy to PRk) are started to be used, so that the cleaning blade (CBy to CBk) can be formed with a minimum toner band. And lubrication of the photoconductors (PRy to PRk) can be controlled.
That is, a necessary amount of toner can be effectively supplied to the contact portion between the cleaning blades (CBy to CBk) and the photoconductors (PRy to PRk) according to the environment.
[0030]
The image forming apparatus having any one of the first to third inventions or any one of the above-mentioned components (A012) to (A015) can have the following component (A016).
(A016) A long-term idle state detecting means (C3d) for detecting that a long time has elapsed from the latest date and time when the photoconductor has been rotated, wherein the determination is performed when the power is turned on and the determination is performed The toner band creation start determining means (C3) for determining that the toner band creation has started when the apparatus has been left for a long time;
[0031]
The damage to the edges of the cleaning blades (CBy to CBk) mainly occurs at the start of the initial rotation when the cohesive force between the photoconductors (PRy to PRk) and the cleaning blade (CBy to CBk) increases and at the start of the rotation after a long period of standing. . Therefore, in the image forming apparatus having the above-described configuration requirement (A016), it is possible to suppress blade edge damage at the start of rotation when it is determined that the image forming apparatus has been left for a long time when the power is turned on. After leaving for a long period of time, although the toner and the external additive are interposed between the photoreceptor (PRy to PRk) and the cleaning blade (CBy to CBk), the adhesion of both is high due to the pressure of the cleaning blade (CBy to CBk). As a result, the initial torque is increased, and the resulting blade edge damage is accelerated. Here, after the toner band has not been used for a long period of time, an appropriate friction-reducing toner band can be supplied, so that the initial torque can be increased and the blade edge damage can be suppressed.
[0032]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiment.
To facilitate understanding of the following description, in the drawings, the front-rear direction is the X-axis direction, the left-right direction is the Y-axis direction, the up-down direction is the Z-axis direction, and arrows X, -X, Y, -Y, The directions or sides indicated by Z and -Z are front, rear, right, left, upper, lower, or front, rear, right, left, upper, and lower, respectively.
Also, in the figure, those with “•” in “を” mean an arrow pointing from the back of the paper to the front, and those with “x” in “○” indicate the front of the paper. From the back to the back.
[0033]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments.
(Embodiment 1)
FIG. 1 is a front sectional view of an image forming apparatus according to a first embodiment of the present invention.
In FIG. 1, the image forming apparatus U includes an automatic document feeder U1 and an image forming apparatus main body (copier) U2 supporting the same and having a platen glass PG at an upper end.
The automatic document feeder U1 moves a document feed tray TG1 on which a plurality of documents Gi to be copied are placed in a stack, and a copy position (document reading position) on the platen glass PG from the document feed tray TG1. A document discharge tray TG2 from which the document Gi conveyed through is discharged is provided.
The image forming apparatus main body U2 has a UI (user interface) through which a user inputs an operation command signal such as a copy start signal, and an exposure optical system A.
[0034]
Reflected light from a document conveyed on the platen glass PG by the automatic document feeder U2 or a document (not shown) manually placed on the platen glass PG is transmitted through the exposure optical system A to a CCD (CCD). The signals are converted into R (red), G (green), and B (blue) electric signals by a solid-state imaging device.
The IPS (image processing system) converts the RGB electrical signals input from the CCD into Y (yellow), M (magenta), C (cyan), and K (black) image data, and temporarily stores them. The image data is output to the laser drive circuit DL as image data for forming a latent image at a predetermined timing.
When the document image is monochrome, only K (black) image data is input to the laser drive circuit DL.
The laser drive circuit DL has laser drive circuits (not shown) for the respective colors Y, M, C, and K, and outputs a laser drive signal corresponding to input image data at a predetermined timing to the exposure device ROS. Output to a latent image writing laser diode (not shown) of each color.
[0035]
In FIG. 1, above the ROS, toner image forming devices Uy, Um, Uc, which form toner images of Y (yellow), M (magenta), C (cyan), and K (black), respectively. Uk is arranged.
The laser beams Ly, Lm, Lc, Lk of Y, M, C, K emitted from the respective laser diodes (not shown) of the exposure apparatus ROS enter the rotating photoconductors PRy, PRm, PRc, PRk, respectively. Each of the photoconductors PRy, PRm, PRc, PRk has a photosensitive layer provided on a conductive substrate.
[0036]
FIG. 2 is an enlarged explanatory view of the Y (yellow) toner image forming apparatus.
1 and 2, the Y toner image forming apparatus Uy includes a rotating photoconductor PRy, a charging roll (charging member) CRy, a developing device Gy, and an elastic cleaning blade CBy (see FIG. 2). Cleaner CLy.
The photoreceptor PRy and the charging roll (charging member) CRy are configured as a CRU (cartridge unit), and the CRU is replaced when the life of the component has expired. A non-volatile memory Me (see FIG. 3) is attached to the CRU (cartridge unit), and counts and stores the number of rotations (number of running cycles) of the photoconductor PRy, and stores the latest cycle date and time. The memory Me (see FIG. 3) is mounted. This memory Me will be described later with reference to FIG. Even when the power of the image forming apparatus is off, the stored value of the memory Me is held by the battery, and the initial value of the count value of the memory Me is 0 (zero).
[0037]
In the developing device Gy, when the maximum peripheral length of the toner particles is ML and the maximum value of the projected area of the toner particles is A, SF = 100π (ML) Two A toner having an average shape index SF expressed by / 4A of 100 to 140 is used. Further, the cleaning blade CBy is fixed to the container of the cleaner CLy in a state where the tip thereof abuts on the surface of the photoreceptor PRy in the counter direction (the direction opposite to the rotation direction).
Each of the toner image forming apparatuses Um, Uc, Uk (see FIG. 1) is configured in the same manner as the Y toner image forming apparatus Uy, and each of the photoconductor cleaners CLm, CLc, CLk is connected to each of the photoconductors PRm, PRc. , PRk (not shown) that contact cleaning blades CBm, CBc, and CBk in the counter direction.
[0038]
The toner images developed on the surfaces of the photoconductors PRy to PRk are conveyed to primary transfer areas Q3y, Q3m, Q3c, and Q3k that come into contact with the intermediate transfer belt (transfer member) B. In the primary transfer areas Q3y, Q3m, Q3c, and Q3k, the controller C controls the primary transfer rolls (photosensitive member surface toner image transfer members) T1y, T1m, T1c, and T1k disposed on the back side of the intermediate transfer belt B. At a predetermined timing, a primary transfer bias having a polarity opposite to the charge polarity of the toner is applied from a controlled power supply circuit E.
The toner images on the photoconductors PRy to PRk are primarily transferred to the intermediate transfer belt B by the primary transfer rolls T1y, T1m, T1c, and T1k. In FIG. 2, residual toner on the surfaces of the photoconductors PRy, PRm, PRc, and PRk after the primary transfer is scraped off by the elastic cleaning blades CBy, CBm, CBc, and CBk that are in contact with the photoconductor surface in the counter direction. , Cleaned.
[0039]
Above the photoconductors PRy to PRk, a belt module BM that can move up and down and can be pulled out forward is arranged. The belt module BM includes the intermediate transfer belt B, and belt support rolls (Rt, Rw, Rf, T2a) including a tension roll Rt, a walking roll Rw, an idler roll (free roll) Rf, and a backup roll T2a also serving as a drive roll. And the primary transfer rolls T1y, T1m, T1c, and T1k. The intermediate transfer belt B is rotatably supported by the belt support rolls (Rt, Rw, Rf, T2a). Therefore, the intermediate transfer belt driving device, that is, the intermediate transfer material conveyance for conveying the intermediate transfer belt B by the driving device for rotating and driving the backup roll T2a also serving as the driving roll and the belt supporting rolls (Rt, Rw, Rf, T2a). The devices (Rt, Rw, Rf, T2a) are configured.
[0040]
A secondary transfer roll T2b is arranged to face the surface of the intermediate transfer belt B in contact with the backup roll T2a, and the rolls T2a and T2b constitute a secondary transfer unit T2. A secondary transfer area Q4 is formed in an area where the secondary transfer roll T2b and the intermediate transfer belt B face each other.
The color toner images sequentially transferred on the intermediate transfer belt B by the transfer units T1y, T1m, T1c, and T1k in the primary transfer areas Q3y, Q3m, Q3c, and Q3k are conveyed to the secondary transfer area Q4. .
[0041]
Below the ROS, a pair of left and right guide rails GR, GR that support the paper feed trays TR1 to TR3 so that they can enter and exit in the front-rear direction (X-axis direction) are provided. The recording sheets (transferred objects) S of the paper feed trays TR1 to TR3 are taken out by a pickup roll Rp, separated one by one by a separation roll Rs, and then sent to a registration roll Rr by a plurality of transport rolls Ra. A plurality of the sheet transport rolls Ra are provided along a sheet transport path SH formed by a sheet guide, and a registration roll Rr is disposed upstream of the secondary transfer area Q4 in the sheet transport direction. The sheet conveying path (SH + Ra + Rr) includes the sheet conveying path SH, the sheet conveying roll Ra, the registration roll Rr, and the like.
[0042]
The registration roll Rr conveys the recording sheet S to the secondary transfer area Q4 at the same time that the color toner image formed on the intermediate transfer belt B is conveyed to the secondary transfer area Q4. When the recording sheet S passes through the secondary transfer area Q4, the backup roll T2a is grounded, and the secondary transfer roll T2b is connected to the toner charging polarity at a predetermined timing from a power supply circuit E controlled by the controller C. A secondary transfer voltage of the opposite polarity is applied. At this time, the color toner image on the intermediate transfer belt B is transferred to the recording sheet S by the secondary transfer device T2.
[0043]
A sheet transfer device (T1y to T1k + B + T2) for transferring the toner images formed on the surfaces of the photoconductors PRy to PRk to the recording sheet S by the primary transfer rolls T1y to T1k, the intermediate transfer belt B, the secondary transfer device T2, and the like. Is configured.
After the secondary transfer, the intermediate transfer belt B is cleaned by the cleaning blade of the belt cleaner CLb.
[0044]
The recording sheet S on which the toner image has been secondarily transferred is conveyed to a fixing area Q5 which is a pressure contact area between the heating roll Fh and the pressure roll Fp of the fixing device F, and is heated and fixed when passing through the fixing area Q5. Then, the sheet is discharged from the discharge roller Rh to the discharge tray TRh.
A releasing agent for improving the releasability of the recording sheet S from the heating roll Fh is applied to the surface of the heating roll Fh by a release agent applying device Fa.
[0045]
Above the belt module BM, there are arranged developer cartridges Ky, Km, Kc, and Kk that store Y (yellow), M (magenta), C (cyan), and K (black) developers. The developer contained in each of the developer cartridges Ky, Km, Kc, and Kk is supplied from the developer supply path (not shown) to each of the developer units Gy according to the consumption of the developer in the developer units Gy, Gm, Gc, and Gk. , Gm, Gc, Gk.
[0046]
In FIG. 1, the image forming apparatus U has an upper frame UF and a lower frame LF. The upper frame UF includes the ROS and members (photoconductors PRy, PRm, PRc, PRk, developing units Gy, Gm, Gc, Gk, belt module BM, etc.) are supported.
Further, on the lower frame LF, a guide rail GR supporting the paper feed trays TR1 to TR3 and the paper feed members (pickup roll Rp, separation roll Rs, sheet transport roll) for feeding paper from each of the trays TR1 to TR3 are provided. Ra etc. are supported.
[0047]
(Explanation of Control Unit of First Embodiment)
FIG. 3 is a block diagram (functional block diagram) illustrating each function provided in the control unit of the image forming apparatus U according to the first embodiment of the present invention.
In FIG. 3, the controller C stores an I / O (input / output interface) for inputting / outputting a signal to / from an external device and adjusting an input / output signal level, and programs and data for performing necessary processing. ROM (Read Only Memory), RAM (Random Access Memory) for temporarily storing necessary data, CPU (Central Processing Unit) for performing processing according to a program stored in the ROM, clock oscillator, etc. , And various functions can be realized by executing a program stored in the ROM.
[0048]
(Signal input element connected to the controller C)
The controller C receives signals from a UI (user interface), a temperature sensor SN1, a humidity sensor SN2, and other signal input elements.
The UI includes a copy start key UI1, a numeric keypad UI2, a copy number input key UI3, a display unit UI4, and the like.
[0049]
(Control elements connected to the controller C)
The controller C is connected to the laser drive circuit DL, the belt drive circuit DB, the photoconductor drive motors Dy to Dk, the power supply circuit E, and other control elements, and outputs operation control signals for them. The power supply circuit E includes development bias power supply circuits E1y to E1k, charging roll power supply circuits E2y to E2k, primary transfer roll power supply circuits E3y to E3k, a secondary transfer unit power supply circuit E4, and the like.
The CRU (cartridge unit) (see FIG. 2) is equipped with a photoconductor traveling cycle number counter (photoconductor traveling cycle number detecting means) ME1 and a latest cycle date / time storage memory (latest cycle date / time storage means) ME2. ing.
The laser drive circuit D1 drives a laser diode (not shown) of a ROS (exposure device).
The belt drive D2 rotationally drives the intermediate transfer belt B via a belt drive motor MB.
[0050]
ME1: photoconductor traveling cycle number counter (photoconductor traveling cycle number detecting means)
The photoconductor traveling cycle number counter ME1 has an accumulation counter ME1a and a reset counter ME1b.
ME1a: Cumulative counter
The accumulation counter ME1a continuously counts and stores the accumulated value of the respective running cycles (rotations) of the photoconductors PRy to PRk from the unused state of the photoconductors PRy to PRk.
ME1b: Reset counter
The reset counter ME1b counts the number of rotations q of each of the photoconductors PRy to PRk in order to detect that each of the rotation numbers q of the photoconductors PRy to PRk has reached the set traveling cycle number (set number of rotations) q1. Remember. Note that the count value q of the rotation speed (running cycle number) of each of the photoconductors PRy to PRk is reset each time the rotation speed reaches the set rotation speed q1.
[0051]
ME2: Latest cycle date / time storage memory (Latest cycle date / time storage means)
The latest cycle date / time storage memory ME2 is a memory for storing the latest cycle date / time (date / time at the end of the latest traveling cycle of the photoconductor), and the latest cycle date / time is written by the controller C having a clock function.
In the first embodiment, the traveling cycle counter ME1 and the latest cycle date / time storage memory ME2 are provided in a CRU (cartridge unit). However, the functions of the ME1 and ME2 may be provided in the controller C. . In that case, in order to determine whether or not the CRU is in an unused state, “0” is stored in the unused state, and “1” is written when a toner band is created once on the photoconductors PRy to PRk of the CRU. A non-volatile memory can be mounted on the CRU.
[0052]
The photoconductor drive motors Dy to Dk rotate the photoconductors PRy to PRk, the development rolls Gy to Gk, and the charging rolls CRy to CRk via the photoconductor drive motors My to Mk.
The developing bias power supplies E1y to E1k apply a developing bias voltage to the developing rolls GRy to GRk of the developing units Gy to Gk.
The charging roll power supply circuits E2y to E2k apply a charging bias to charging rolls (charge rolls) CRy to CRk.
The primary transfer roll power supply circuits E3y to E3k apply a primary transfer bias to the primary transfer rolls T1y to T1k.
The secondary transfer unit power supply circuit E4 applies a secondary transfer voltage (sheet transfer voltage) to the secondary transfer roll T2b.
[0053]
(Function of the controller C)
The controller C performs a process according to an output signal from each of the signal output elements UI, SN1, SN2, etc., and outputs a control signal to each of the control elements DL, DB, Dy to Dk, E, etc. (Control means). Next, the function (control means) of the controller C will be described.
C1: Laser drive control means
The laser drive control means C1 controls the operation of the laser drive circuit D1, thereby controlling the operation of the ROS (laser diode (not shown) of the exposure apparatus).
C2: belt rotation control means
The belt rotation control unit C2 controls the rotation of the belt drive motor MB and the intermediate transfer belt by controlling the operation of the belt drive circuit D2.
ROS (controls the operation of a laser diode (not shown) of the exposure apparatus).
[0054]
C3: Toner band creation start determination means
The toner band creation start time determination means C3 has a power-on time detection means C3a, an unused photoconductor detection means C3b, and a set traveling cycle storage means C3c, and determines whether or not it is time to create a friction reduction toner band. Is determined.
C3a: power-on detection means
The power-on detection unit C3a detects when the power of the image forming apparatus is turned on.
C3b: unused photoconductor detecting means
The unused photoconductor detecting unit C3b detects, when each of the photoconductors PRy to PRk mounted on the image forming apparatus is in an unused state, that fact.
C3c: Set running cycle number storage means
The set running cycle number storage means C3c stores the set running cycle number q1 for discriminating the start of toner band creation. The set traveling cycle number (set rotation number) q1 is used to determine whether or not it is time to execute the friction reduction processing. The toner band creation start determination means C3 determines that the toner band creation has started when the number of photoconductor travel cycles q described below has reached the set travel cycle number q1 at the time of the determination.
C3d: Long-term leaving state detection means
The long-term leaving state detecting means C3d detects that a long time has passed (for example, one week or more) from the latest date and time when the rotation of the photoconductor was performed. When the long-term leaving state detecting means C3d detects that one week or more has elapsed from the latest date and time when the rotation of the photoconductor has been performed, the toner band creation start determination means C3 determines whether or not the toner band creation has started. It is determined that there is.
[0055]
C4: Means for preparing toner band for reducing friction
The friction-reducing toner band creating means C4 creates a friction-reducing toner band when the toner-band creating start determining means C3 determines that it is time to create a friction-reducing toner band.
C5: Latest cycle date and time writing means
The latest cycle date and time writing means C5 writes the latest cycle date and time (date and time at the end of the latest running cycle of the photoconductor) into the latest cycle date and time storage memory ME2 mounted on the CRU (cartridge unit) (see FIG. 2).
The latest cycle date and time writing means C5 can be provided in the CRU (cartridge unit).
[0056]
C6: Power supply circuit control means
The power supply circuit controller C6 has a charging bias controller C6a, a developing bias controller C6b, a primary transfer bias controller C6c, a secondary transfer bias controller C6d, and the like.
C6a: charging bias control means
The charging bias control unit C6a controls the operation of the charging power supply circuits E1y to E1k to control the charging voltage or current applied to the charging rolls CRy to CRk. When the friction-reducing toner band is formed, the operation of the charging power supply circuits E1y to E1k is controlled so that the charging voltage is not applied to the charging rolls CRy to CRk.
C6b: developing bias control means
The developing bias controller C6b controls the operation of the developing power supply circuits E2y to E2k to control the developing bias applied to the developing rolls GRy to GRk. When a toner band for reducing friction is created, a developing bias is applied to the developing rolls GRy to GRk to move toner adhering to the surfaces of the developing rolls GRy to GRk to the photoreceptors PRy to PRk so that friction is applied to the photoreceptor surfaces. A reduction toner band is formed.
[0057]
C6c: primary transfer bias control means
The primary transfer bias control means C6c controls the operation of the primary transfer power supply circuits E3y to E3k to control the primary transfer bias applied to the primary transfer rolls (photosensitive member surface toner image transfer members) T1y to T1k. I do. In addition, the operation of the primary transfer power supply circuits E3y to E3k is controlled so that the primary transfer bias is not applied to the primary transfer rolls T1y to T1k when creating the friction reducing toner band.
C6d: secondary transfer bias control means
The secondary transfer bias controller C6d controls the operation of the secondary transfer power supply circuit E4 to control the secondary transfer bias applied to the secondary transfer roll T2b. Further, when the friction-reducing toner band is formed, the operation of the secondary transfer power supply circuit E4 is controlled so that the secondary transfer bias is not applied to the secondary transfer roll T2b.
[0058]
(Explanation of flowchart)
FIG. 4 is a flowchart of the photoconductor rotation number counting process of the image forming apparatus according to the first embodiment. The process of FIG. 4 is performed separately for each of the photoconductors PRy to PRk. The processing of each ST (step) in the flowchart of FIG. 4 is performed according to a program stored in the ROM of the controller C. This process is executed in multitask in parallel with other various processes of the image forming apparatus.
The flowchart of the photoconductor rotation number counting process shown in FIG. 4 is started when the power is turned on.
In ST1 (step 1) of FIG. 4, it is determined whether the PR (photoconductor) has made one rotation. If no (N), ST1 is repeatedly executed.
In ST2, p = p + 1 and q = q + 1. Here, p and q are the following values.
p: Count value of a photoconductor (PRy to PRk) rotation number integration counter (running cycle number counter).
q: The count value of the frictional resistance processing counter, which is the count value of the photoconductor (PRy to PRk) rotation speed integration counter (running cycle counter).
[0059]
In ST3, it is determined whether or not P ≧ 24000. If yes (Y), the process moves to ST4.
In ST4, q1 is set to 140.
q1 is a set value that determines when the friction reduction processing is executed. When q ≧ q1, the friction reduction processing is executed at the end of the job (see ST28 and ST29 in FIG. 5). Note that the initial value of q1 is 0.
After ST4, the process moves to ST12 (described later). In the case of No (N) in ST3, the process proceeds to ST5.
In ST5, it is determined whether or not P ≧ 8000. If yes (Y), the process moves to ST6.
In ST6, q1 is set to 130.
After ST6, the process moves to ST12 (described later). In the case of No (N) in ST5, the process proceeds to ST7.
[0060]
In ST7, it is determined whether or not P ≧ 2000. If yes (Y), the process moves to ST8.
In ST8, q1 is set to 120.
After ST8, the process moves to ST12 (described later). If no (N) in ST7, the process moves to ST9.
In ST9, it is determined whether or not P ≧ 500. If yes (Y), the process moves to ST10.
In ST10, q1 is set to 100.
After ST10, the process moves to ST12 (described later). In the case of No (N) in ST9, the process moves to ST11.
In ST11, q1 is set to 100. Next, the process moves to ST12.
In ST12, it is determined whether or not there is a reset signal for the count value of the q (friction reduction processing running cycle number counter. If no (N), the process returns to ST1. If yes (Y), the process proceeds to ST13.
In ST13, q = 0. Next, the process returns to ST1.
[0061]
FIG. 5 is a flowchart of the friction reduction process between the photoconductor and the cleaning blade. The process of FIG. 5 is performed separately for each of the photoconductors PRy to PRk and each of the cleaning blades CBy, CBm, CBc, and CBk for cleaning the photoconductors (only CBy is shown in FIG. 2). The processing of each ST (step) in the flowchart of FIG. 5 is performed according to a program stored in the ROM of the controller C. This process is executed in multitask in parallel with other various processes of the image forming apparatus.
The flowchart of the friction reduction process between the photoconductor and the cleaning blade shown in FIG. 5 is started when the power is turned on.
In ST21 (step 21) of FIG. 5, it is determined whether or not the power is on. This determination is made based on whether the value of the power-on determination flag FLa is “0”. Although the initial value of the power-on determination flag FLa is “0”, the flag FLa is set to “1” when the initialization process is performed. If yes (Y), the operation moves on to ST23, and if no (N), the operation moves on to C22.
In ST22, it is determined whether or not a door (a door provided in the image forming apparatus) for exchanging a CRU (a cartridge unit integrally assembled with a photoconductor, a charging roll, and a cleaner; see FIG. 2) has changed from an open state to a closed state. I do. If no (N), the process moves on to ST28, and if yes (Y), the process moves on to ST23.
[0062]
In ST23, it is determined whether or not the count value p of the photoconductor rotation speed integration counter is p = 0. If no (N), the process moves on to ST24, and if yes (Y), the process moves on to ST26.
In ST24, it is determined whether or not the image forming apparatus U has been left for a long period of time (a state in which the photoconductor has not been rotated for a long period of time). This determination is based on whether or not the current date and time stored in the latest cycle date and time storage memory ME2 has passed one week or more. If no (N), the process moves on to ST26, and if yes (Y), the process moves on to ST25.
In ST25, a first friction reduction process and an initialization process are performed. Details of the process of ST25 will be described later with reference to FIG. Next, the process moves to ST27.
In ST26, normal initialization processing (checking the rotation of the rotating member of the image forming apparatus, checking the power supply circuit, and the like) is executed. Next, the process moves to ST27.
In ST27, the power-on determination flag FLa is set to "1". The process moves to ST28 after ST27.
In ST28, it is determined whether the job has been completed. If no (N), the process returns to ST21, and if yes (Y), the process moves to ST29.
In ST29, it is determined whether or not q ≧ q1. If no (N), the process returns to ST21, and if yes (Y), the process moves to ST30.
In ST30, a second friction reduction process is performed. The details of ST30 will be described later with reference to FIG.
In ST31, a reset signal for q is output.
Next, the process returns to ST21.
[0063]
FIG. 6 is a detailed explanatory diagram of the process of ST25.
In FIG. 6, in ST25, the rotation drive system is rotated to start checking the rotation state of the rotation drive system (initialization work of the image forming apparatus is started. The initialization work is performed by a conventional image forming apparatus. It is possible to adopt various methods that have been performed.) At the same time, the first friction reduction processing is started.
In the first friction reduction processing, the following processing is executed while rotating the rotary drive system.
(1) No charging bias is applied. That is, the surface potential of the photoconductor is 0V.
(2) A developing bias is applied. The developing bias is set so that the toner density of the toner band moving (developed) to the photoreceptor surface is about 60% (area ratio).
In the case where charging and exposure are not performed, a potential difference is naturally generated if a potential is provided on the developing sleeve with a photosensitive member surface potential = 0 V and a developing bias. Thereafter, a toner image having a 60% density can be formed by adjusting the developing bias to control the amount of toner flying. If the potential difference is large when the developing bias is not adjusted, the carrier will fly together.
[0064]
(3) By setting the primary transfer bias to 0 V or a reverse bias, the cleaning blades CBy, CBm, CBc, and CBk (FIG. 2) without the toner adhered to the photoreceptor surface moving to the intermediate transfer belt B. (Only CBy is shown).
(4) The length of the toner band reaching the cleaning blades CBy, CBm, CBc, CBk (only CBy is shown in FIG. 2) in the sub-scanning direction (the circumferential length of the photoconductor) is 10 Four -10 6 The toner is supplied to the cleaning blade so as to be about mm.
[0065]
The following processing is also performed in the initialization processing performed in ST25.
(5) Check the energization of the heater of the fixing device.
(6) Check the rotation state of the rotary drive system while executing the first friction reduction processing.
(7) The surface of the photoreceptor is charged, exposed, and developed to form a toner patch for toner density detection, and the image density of the toner patch is detected.
(8) Set operation parameters (charging bias, current, developing bias, etc.) of the image forming apparatus according to the detected image density.
[0066]
FIG. 7 is a detailed explanatory diagram of the process of ST30.
In FIG. 7, in ST30, the following processing is performed while rotating the rotary drive system. Note that the process of ST30 in FIG. 7 performs only the process excluding the initialization process from the process of ST25 in FIG. 6 (friction reduction process of creating a friction reduction toner band and supplying it to the cleaning blade). The length of the toner band created in ST30 in the sub-scanning direction is about 3 mm. Four -10 6 It is set shorter than mm.
(1) No charging bias is applied. That is, the surface potential of the photoconductor is 0V.
(2) A developing bias is applied. The developing bias is set so that the toner density of the toner band moving (developed) to the photoreceptor surface is about 60% (area ratio).
(3) By setting the primary transfer bias to 0 V or a reverse bias, the cleaning blades CBy, CBm, CBc, and CBk (FIG. 2) without the toner adhered to the photoreceptor surface moving to the intermediate transfer belt B. (Only CBy is shown).
(4) The length of the toner band reaching the cleaning blades CBy, CBm, CBc, CBk (only CBy is shown in FIG. 2) in the sub-scanning direction (the length in the circumferential direction of the photoconductor) is about 3 mm. Then, the toner is supplied to the cleaning blade.
[0067]
(Operation of Embodiment 1)
In the image forming apparatus U of the first embodiment having the above-described configuration, the photosensitive member having the photosensitive layer provided on the conductive substrate of the toner image forming apparatuses Uy, Um, Uc, and Uk (only Uy is shown in FIG. 2) The surfaces of PRy to PRk are charged by charging rolls CRy to CRk. The exposure device ROS exposes the surfaces of the charged photoconductors PRy to PRk to form an electrostatic latent image on the photoconductor surface. The developing devices Gy to Gk develop the electrostatic latent images into toner images.
The photoreceptor surface toner image transfer members T1y, T1m, T1c, T1k transfer the toner images on the photoreceptors PRy to PRk to an intermediate transfer belt (transfer member) B.
The elastic cleaning blades CBy, CBm, CBc, and CBk (only CBy is shown in FIG. 2) of the cleaners CLy to CLk abut on the surfaces of the photoconductors PRy to PRk in the counter direction (the direction opposite to the rotation direction). The residual toner on the surfaces of the photoconductors PRy to PRk after the transfer is removed.
[0068]
In the following cases (1) and (2), the toner band creation start determining means C3, which determines whether or not the creation of the friction reducing toner band has started, determines that the toner band creation has started.
(1) When the unused state is detected by the unused photosensitive member detecting unit C3b that detects whether the photosensitive member mounted on the image forming apparatus U is in the unused state.
(2) The case where the running cycle number q of the photoconductors PRy to PRk detected by the reset counter ME1b at the end of the job has reached the set starting cycle number q1.
Then, when the toner band creation start determining means C3 determines that the toner band creation is started, the friction reducing toner band creating means C4 applies the friction reducing toner band having the toner density of 60% to the photoconductors PRy to PRk. Create on the surface.
[0069]
At the time of forming the friction reducing toner band, the charging bias control unit C6a does not apply a charging bias to the charging rolls (charging members) CRy to CRk. Therefore, the friction reducing toner band formed on the surface of the photoconductors PRy to PRk is formed (developed) only by the developing bias.
Before applying a discharge stress by the charging rolls CRy to CRk, a lubricating component such as a toner or an external additive is interposed between the photoconductors PRy to PRk and the cleaning blades CBy, CBm, CBc, and CBk, thereby increasing the initial torque, Edge damage can be suppressed, and cleaning maintainability can be ensured.
[0070]
When creating the friction-reducing toner band, the transfer bias control means C6d supplies the friction-reducing toner band to the contact portion between the cleaning blades CBy, CBm, CBc, and CBk and the photoconductors PRy to PRk. The transfer bias applied between the primary transfer rolls (toner image transfer members) T1y to T1k and the photoconductors PRy to PRk is controlled so that the friction reducing toner band is not transferred to the intermediate transfer belt (transfer member) B. I do. That is, the transfer bias is set to 0 (zero) or reverse bias.
By transferring as much toner and external additives as possible to the blade edge (the contact portion between the photoconductors PRy to PRk and the cleaning blade) without transferring the image developed to alleviate the blade edge damage. As a result, higher lubricity is created, blade damage is reduced, and high cleaning performance can be maintained.
[0071]
In the case of the above (1) (when the photoconductors PRy to PRk are not used), in the circumferential direction of the photoconductors PRy to PRk, 10 Four -10 6 mm of toner band is formed. The toner band is transported to a contact portion between the photoconductors PRy to PRk and the cleaning blades CBy, CBm, CBc, and CBk (only CBy is shown in FIG. 2). The toner forming the toner band is supplied to the contact portion and stays there, and reduces the frictional force between the photoconductors PRy to PRk and the cleaning blades CBy, CBm, CBc, and CBk (only CBy is shown in FIG. 2). be able to.
As shown in (1), when the photoconductors PRy to PRk are not used, the circumferential length = 10 Four -10 6 Since a relatively long toner band of mm is formed, a sufficient amount of toner can be supplied to the contact portion between the photoconductor and the cleaning blade.
[0072]
In the case of (2) above, when the toner band creation start determining means C3 executes the process of determining whether or not the toner band creation has started, the photoconductor running cycle number q of the reset counter ME1b determines the toner band creation start. When the set cycle number q1 has been reached, a toner band having a length of 3 mm is formed in the circumferential direction of the photoconductors PRy to PRk. The toner band is transported to a contact portion between the photoconductors PRy to PRk and the cleaning blades CBy, CBm, CBc, and CBk (only CBy is shown in FIG. 2). The toner forming the toner band is supplied to the contact portion and stays there, and reduces the frictional force between the photoconductors PRy to PRk and the cleaning blades CBy, CBm, CBc, and CBk (only CBy is shown in FIG. 2). be able to.
As shown in (2), when the photoconductors PRy to PRk are not unused, toner is already accumulated in the contact portions between the photoconductors PRy to PRk and the cleaning blades CBy, CBm, CBc, and CBk. Therefore, a relatively short toner band having a circumferential length of 3 mm is formed. Therefore, an appropriate amount of toner can be supplied to the contact portions between the photoconductors PRy to PRk and the cleaning blades CBy, CBm, CBc, and CBk without wasteful consumption of toner.
[0073]
As described in the above (1) and (2), by forming a friction reducing toner band, the friction reducing toner is supplied to the contact portions between the cleaning blades CBy, CBm, CBc, CBk and the photoconductors PRy to PRk. Therefore, the friction between the cleaning blades CBy, CBm, CBc, and CBk and the photoconductors PRy to PRk can be reduced. Therefore, abrasion and breakage due to excessive friction between the cleaning blades CBy, CBm, CBc, CBk and the photoconductors PRy to PRk are prevented, so that high cleaning performance can be maintained for a long period of time. That is, since the service life of the cleaning blades CBy, CBm, CBc, CBk and the photoconductors PRy to PRk can be extended, the image forming apparatus U can obtain high image quality over a long period of time.
[0074]
In the first embodiment, the set value (set cycle number) q1 of the count value (photoconductor run cycle number) q of the reset counter ME1b of the run cycle number counter ME1 that determines the execution time of the second friction reduction process is: The smaller the photosensitive member travel cycle number (cumulative travel cycle number) p, which is the count value of the cumulative counter ME1b, the smaller the value is set. For this reason, when the photoconductor is new and the toner is not sufficiently accumulated at the contact portion between the photoconductor and the cleaning blade, the second friction reduction process is frequently performed to remove the toner acting as a lubricant. It is supplied to the contact part. Also, the greater the value of the number p of photoconductor running cycles (the longer the use period of the photoconductor, and the more the toner acting as a lubricant is accumulated in the contact portion between the photoconductor and the cleaning blade). The interval at which the second friction reduction process is performed is made longer.
Therefore, the toner acting as a lubricant can be effectively consumed.
[0075]
(Embodiment 2)
In the description of the second embodiment, components corresponding to the components of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.
The second embodiment differs from the first embodiment in the following points, but has the same configuration as the first embodiment in other points. That is, the second embodiment has the configurations of FIGS. 8 and 9 instead of the configurations of FIGS. 3 and 5 of the first embodiment, and the other configurations (FIGS. 1, 2 and 4). , FIG. 6 and FIG. 7) are configured in the same manner as in the first embodiment.
[0076]
FIG. 8 is a block diagram (functional block diagram) illustrating functions provided in the control unit of the image forming apparatus U according to the second embodiment of the present invention.
In FIG. 8, the controller C has a job suspension request flag FL1 and a job suspension determination flag FL2. In other respects, it has the same configuration as that of the first embodiment shown in FIG.
FL1: Job suspension request flag
The job interruption request flag FL1 is set to FL1 = “1” when the program of the friction reduction process between the photoconductor and the cleaning blade executes the friction reduction process, and when the job execution program requests interruption of the image forming operation being executed. In other cases, the flag FL1 is "0".
FL2: Job interruption determination flag
In response to the job interruption request flag FL1 = "1", the job interruption determination flag FL2 becomes FL2 = "1" when the job execution program interrupts the job, and FL1 = "0" when the job execution program interrupts the job. FL2 = “0” when the job is restarted in response to the request of canceling the job suspension).
[0077]
FIG. 9 is a flowchart of the friction reduction process between the photoconductor and the cleaning blade according to the second embodiment of the image forming apparatus U of the present invention.
9, ST21 to ST27 execute the same processing as ST21 to ST27 of FIG. 5 of the first embodiment. Further, the following ST (step) is provided instead of ST28, ST29 and ST31 in FIG. 5 of the first embodiment.
(1) Instead of ST28 in FIG. 5, (STA28-1) and (STA28-2) in FIG. 9 are provided.
(2) (STA29-1) to (STA29-3) of FIG. 9 are provided instead of ST29 of FIG.
(3) Instead of ST31 in FIG. 5, STA31 'in FIG. 9 is provided.
In FIG. 9, in the case of Yes (Y) in ST22, and after ST27, the process moves to STA28-1.
In STA 28-1, it is determined whether or not the job has been started. If no (N), the process returns to ST21, and if yes (Y), the process proceeds to STA28-2.
In STA28-2, it is determined whether or not the job has been completed. If the determination is yes (Y), the process returns to ST21; if the determination is no (N), the process proceeds to STA29-1.
[0078]
The STA 29-1 determines whether or not q ≧ q1. If the determination is no (N), the process returns to the STA 28-2; if the determination is yes (Y), the process returns to the STA 29-2.
In STA29-2, the job suspension request flag FL1 is set to "1".
Next, in STA29-3, it is determined whether or not the job execution determination flag FL2 has become "1". If no (N), the STA 29-3 is repeatedly executed.
In the STA 29-2, when the job interruption request flag FL1 becomes "1", the job execution program (a flowchart of this program is not shown) transfers the image during the image forming operation to the recording sheet, fixes the image, and discharges the image. , The image formation for the next recording sheet is interrupted, and the job interruption determination flag FL2 is set to "1" to indicate that the job is interrupted.
When the job suspension flag FL2 is set to "1", the STA 29-3 turns to YES (Y). At this time, the process moves to STA30.
In the STA 30, a second friction reduction process is performed. Details of the processing of the STA 30 are as described with reference to FIG. 7 of the first embodiment.
[0079]
Next, the STA 31 'executes the following processing.
(1) A signal (reset signal) for resetting the value of the count value (number of running cycles) q of the reset counter ME1b is output.
(2) The value of the job suspension request flag FL1 is set to FL1 = "0".
Next, the process returns to ST21.
In the STA 31 ', when the job suspension request flag FL1 becomes FL1 = "0", the job execution program resumes the suspended job and simultaneously sets the job suspension determination flag FL2 to "0".
[0080]
(Operation of Embodiment 2)
In the image forming apparatus of the second embodiment having the above configuration, when q ≧ q1 during execution of a job, the job is interrupted and the second friction reduction process is executed.
That is, in the first embodiment, it is determined whether or not q ≧ q1 at the end of the job. Therefore, the second friction reduction process is always performed at the end of the job. Even in the middle, the second embodiment is different from the first embodiment in that the job is interrupted and the second friction reduction process is executed.
Other operations of the second embodiment are the same as those of the first embodiment.
[0081]
(Example of change)
As mentioned above, although the Example of this invention was described in full detail, this invention is not limited to the said Example, Various changes are made within the range of the gist of this invention described in the claim. It is possible. Modified embodiments of the present invention are exemplified below.
(H01) In the first or second embodiment, the following configuration requirement (A013) can be provided.
(A013) While the friction-reducing toner band passes through the transfer areas Q3y, Q3m, Q3c, and Q3k to the intermediate transfer belt (transfer member) B, the photosensitive members PRy to PRk and the transfer member B are non-conductive. It is possible to provide a transfer object position control means for controlling the position of the transfer object B so as not to be transferred to the transfer object B in contact therewith.
The transfer object position control means can be constituted by, for example, means for controlling the positions of the primary transfer rolls T1y to T1k. That is, in the first embodiment, when the primary transfer rolls T1y to T1k are moved downward, the intermediate transfer belt (transfer object) B is pressed by the lower photoconductors PRy to PRk, and the primary transfer rolls T1y to T1k are moved. When T1k is moved upward, the intermediate transfer belt (transfer object) B can be configured to be separated upward from the photoconductors PRy to PRk. In this case, the transfer object position control means is constituted by means for moving the primary transfer rolls T1y to T1k up and down.
[0082]
In the modified example (H01), while the friction-reducing toner band passes through the transfer area (primary transfer area) Q3y to Q3k to the transfer target B, the transfer target position control unit controls the photosensitive members PRy to PRy. Since the position of the transfer object B is controlled so that PRk and the transfer object B do not come into contact with each other, the toner of the friction reducing toner band formed on the surface of the photoconductors PRy to PRk is used as the toner of the transfer object B. The toner is supplied to the contact portions between the cleaning blades CBy to CBk and the photoconductors PRy to PRk without being transferred to the photoconductors PRy to PRk. Therefore, the toner can be efficiently supplied to the contact portion.
[0083]
(H02) The following components (A014) and (A015) can be provided in the first or second embodiment.
(A014) Use environment detecting members SN1, SN2 for detecting a use environment including temperature or humidity.
(A015) The higher the temperature detected by the use environment detecting members SN1 and SN2, or the higher the detected humidity, the lower the temperature or the lower the humidity. The friction-reducing toner band creating means C4 for creating the friction-reducing toner band such that the amount of toner supplied to the contact portions with the photoconductors PRy to PRk increases.
[0084]
When the usage environment of the image forming apparatus U is high temperature and high humidity, the frictional force between the cleaning blades CBy to CBk and the photoconductors PRy to PRk tends to be higher than when the usage environment is low temperature and low humidity. However, in the above modified example (H02), the friction-reducing toner band forming means (C4) uses the higher the detected temperature, the higher the detected humidity, the lower the temperature or the lower the humidity. The friction-reducing toner band is formed such that the amount of toner supplied to the contact portions between the cleaning blades CBy to CBk and the photoconductors PRy to PRk increases.
The increase in friction between the cleaning blades CBy to CBk and the photoconductors PRy to PRk is particularly remarkable under high-temperature and high-humidity conditions, and has a function of monitoring the use environment as described above. At least one of the rotation direction width and the image density of the unused photoconductors PRy to PRk are changed with respect to the start of use, so that the cleaning blades CBy to CBk and the photoconductors PRy to PRk can be lubricated with a minimum toner band. Can be controlled.
[0085]
(H03) The present invention is applicable to an image forming apparatus that directly transfers a toner image formed on a photoconductor to a recording sheet S without providing the intermediate transfer body B.
(H04) The present invention is applicable not only to a color image forming apparatus but also to a monochrome image forming apparatus.
(H05) In the first to fourth embodiments, the optical scanning unit is configured such that the optical scanning optical systems of four colors of Y, M, C, and K are supported by one base. , M, C, and K can be configured to be supported on separate substrates.
(H06) As the charging member, a charging blade may be used instead of the charging roll CR, or a discharge-type charging member such as Cotrotron may be used.
[0086]
【The invention's effect】
The above-described heating roll unit and image forming apparatus of the present invention can provide the following effect (E01).
(E01) It is possible to prevent the frictional force between the photosensitive member surface and the cleaning blade from becoming excessive, and to prevent the occurrence of cleaning failure.
(E02) It is possible to extend the life of the cleaning blade, the photosensitive member, and the like.
[Brief description of the drawings]
FIG. 1 is a front sectional view of an image forming apparatus according to a first embodiment of the present invention.
FIG. 2 is an enlarged explanatory view of a Y (yellow) toner image forming apparatus.
FIG. 3 is a block diagram (functional block diagram) illustrating functions provided in a control unit of the image forming apparatus U according to the first embodiment of the present invention;
FIG. 4 is a flowchart of a photoconductor rotation number counting process of the image forming apparatus according to the first embodiment.
FIG. 5 is a flowchart of a friction reduction process between a photoconductor and a cleaning blade.
FIG. 6 is a detailed explanatory diagram of the process of ST25.
FIG. 7 is a detailed explanatory diagram of the process of ST30.
FIG. 8 is a block diagram (functional block diagram) illustrating functions provided in a control unit of the image forming apparatus U according to the second embodiment of the present invention;
FIG. 9 is a flowchart of a process for reducing friction between the photoconductor and the cleaning blade according to the second embodiment of the image forming apparatus U of the present invention.
[Explanation of symbols]
B: Transfer object (intermediate transfer belt)
C3: toner band creation start determination means;
C3b: unused photoconductor detecting means,
C3c: Set traveling cycle number storage means,
C3d: means for detecting a long-term standing state,
C4: means for preparing a toner band for reducing friction;
ME1: photoconductor traveling cycle number detecting means (photoconductor traveling cycle number counter),
C6a: charging bias control means,
C6c: transfer bias control means,
CBy to CBk: cleaning blade,
CLy to CLk ... cleaner,
CRy to CRk: Charging member (charging roll, BCR)
Gy to Gk: developing device,
PRy to PRk: photoreceptor,
p, q: number of running cycles of the photoconductor (PRy to PRk),
q1... the set number of driving cycles for discrimination at the start of toner band creation;
Q3y, Q3m, Q3c, Q3k: transcription region (primary transcription region)
ROS: Exposure equipment,
SN1, SN2 ... usage environment detecting member,
T1y to T1k: toner image transfer member (primary transfer roll)
U: image forming apparatus,
Uy to Uk: toner image forming apparatus.

Claims (8)

  1. An image forming apparatus having the following components (A01) to (A07):
    (A01) Photoreceptor having a photosensitive layer provided on a conductive substrate, a charging member for charging the surface of the photoreceptor, and latent image formation for exposing the charged photoreceptor to form an electrostatic latent image Device, and a toner image forming apparatus having a developing device for developing the electrostatic latent image into a toner image,
    (A02) a toner image transfer member for transferring the toner image on the photoreceptor surface to a transfer-receiving member;
    (A03) a cleaner having an elastic cleaning blade in contact with the photoreceptor surface in a counter direction to remove residual toner on the photoreceptor surface after transfer;
    (A04) toner band creation start determining means for determining whether or not the creation of the friction reducing toner band has started;
    (A05) A friction having an image density of 10 to 100% having a maximum width developable in the axial direction of the photoreceptor and a predetermined length in the rotational direction of the photoreceptor when it is determined that the toner band for friction reduction is started. Friction-reducing toner band creating means for creating a reducing toner band on the photoreceptor surface,
    (A06) A transfer for controlling a transfer bias applied between the toner image transfer member and the photoconductor when the friction-reducing toner band is supplied so that the friction-reducing toner band is not transferred to the transfer-receiving member. Bias control means,
    (A07) An unused photoconductor detecting means for detecting whether or not the photoconductor mounted on the image forming apparatus is in an unused state is provided. The toner band creation start determining means for determining that there is the toner band
  2. An image forming apparatus having the following components (A01) to (A06), (A08), and (A09);
    (A01) Photoreceptor having a photosensitive layer provided on a conductive substrate, a charging member for charging the surface of the photoreceptor, and latent image formation for exposing the charged photoreceptor to form an electrostatic latent image Device, and a toner image forming apparatus having a developing device for developing the electrostatic latent image into a toner image,
    (A02) a toner image transfer member for transferring the toner image on the photoreceptor surface to a transfer-receiving member;
    (A03) a cleaner having an elastic cleaning blade in contact with the photoreceptor surface in a counter direction to remove residual toner on the photoreceptor surface after transfer;
    (A04) toner band creation start determining means for determining whether or not the creation of the friction reducing toner band has started;
    (A05) A friction having an image density of 10 to 100% having a maximum width developable in the axial direction of the photoreceptor and a predetermined length in the rotational direction of the photoreceptor when it is determined that the toner band for friction reduction is started. Friction-reducing toner band creating means for creating a reducing toner band on the photoreceptor surface,
    (A06) Since the friction-reducing toner band is supplied to the contact portion between the cleaning blade and the photosensitive member, the toner image transfer member and the photosensitive member are so protected that the friction-reducing toner band is not transferred to the transfer-receiving member. Transfer bias control means for controlling the transfer bias applied between
    (A08) a photoconductor traveling cycle number detecting means for detecting a traveling cycle number of the photoconductor mounted on the image forming apparatus;
    (A09) There is a set running cycle number storage means for storing a set running cycle number for determination at the start of toner band creation, and when the photoconductor running cycle number has reached the set running cycle number at the time of executing the determination process. The toner band creation start determining means for determining that the toner band creation has started.
  3. An image forming apparatus having the following components (A01) to (A06) and (A010);
    (A01) Photoreceptor having a photosensitive layer provided on a conductive substrate, a charging member for charging the surface of the photoreceptor, and latent image formation for exposing the charged photoreceptor to form an electrostatic latent image Device, and a toner image forming apparatus having a developing device for developing the electrostatic latent image into a toner image,
    (A02) a toner image transfer member for transferring the toner image on the photoreceptor surface to a transfer-receiving member;
    (A03) a cleaner having an elastic cleaning blade in contact with the photoreceptor surface in a counter direction to remove residual toner on the photoreceptor surface after transfer;
    (A04) toner band creation start determining means for determining whether or not the creation of the friction reducing toner band has started;
    (A05) A friction having an image density of 10 to 100% having a maximum width developable in the axial direction of the photoreceptor and a predetermined length in the rotational direction of the photoreceptor when it is determined that the toner band for friction reduction is started. Friction-reducing toner band creating means for creating a reducing toner band on the photoreceptor surface,
    (A06) Since the friction-reducing toner band is supplied to the contact portion between the cleaning blade and the photosensitive member, the toner image transfer member and the photosensitive member are so protected that the friction-reducing toner band is not transferred to the transfer-receiving member. Transfer bias control means for controlling the transfer bias applied between
    (A010) A charging bias control unit configured not to apply a charging bias to the charging member when forming the friction reducing toner image.
  4. The image forming apparatus according to any one of claims 1 to 3, comprising the following configuration requirement (A012):
    (A011) When the maximum peripheral length of the toner particles is ML and the maximum value of the projected area of the toner particles is A, the toner particles having an average shape index SF expressed by SF = 100π (ML) 2 / 4A of 100 to 140 are used. The developing device used.
  5. The image forming apparatus according to any one of claims 1 to 4, comprising the following constituent requirements (A012):
    (A012) The friction-reducing toner band having a length of 3 mm to 10 6 mm in the photoconductor rotation direction.
  6. The image forming apparatus according to any one of claims 1 to 5, comprising the following configuration requirements (A013):
    (A013) While the friction-reducing toner band passes through the transfer area to the transfer object, the photoconductor and the transfer object are kept out of contact with each other to prevent the transfer to the transfer object. Transfer object position control means for controlling the position.
  7. The image forming apparatus according to any one of claims 1 to 6, comprising the following constituent requirements (A014) and (A015):
    (A014) a use environment detecting member for detecting a use environment including temperature or humidity,
    (A015) As the temperature detected by the use environment detecting member is higher, or the detected humidity is higher, the contact between the cleaning blade and the photosensitive member is lower than when the temperature is low or low. The friction-reducing toner band creating means for creating the friction-reducing toner band such that the amount of toner supplied to the contact portion increases.
  8. The image forming apparatus according to any one of claims 1 to 7, comprising the following configuration requirement (A016):
    (A016) Long-term idle state detecting means for detecting that a long time has elapsed since the latest date and time when the photoconductor was rotated, performing the determination when the power is turned on, and determining whether or not the long-term idle state has occurred when the determination is performed The toner band creation start determining means for determining that the toner band creation start has started when
JP2002360754A 2002-12-12 2002-12-12 Image forming apparatus Withdrawn JP2004191737A (en)

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JP2010122468A (en) * 2008-11-19 2010-06-03 Canon Inc Image forming apparatus
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JP2014182308A (en) * 2013-03-19 2014-09-29 Canon Inc Image forming apparatus
JP2016095333A (en) * 2014-11-12 2016-05-26 ブラザー工業株式会社 Image forming apparatus, control method, and program
JP2016191787A (en) * 2015-03-31 2016-11-10 ブラザー工業株式会社 Image formation apparatus, control method and program of the same
JP2016194572A (en) * 2015-03-31 2016-11-17 ブラザー工業株式会社 Image forming apparatus, method of supplying developer, and program
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Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006154150A (en) * 2004-11-26 2006-06-15 Ricoh Co Ltd Image forming apparatus
JP2006251094A (en) * 2005-03-08 2006-09-21 Ricoh Co Ltd Image forming apparatus and process cartridge
JP2010122468A (en) * 2008-11-19 2010-06-03 Canon Inc Image forming apparatus
JP2011007905A (en) * 2009-06-24 2011-01-13 Konica Minolta Business Technologies Inc Image forming apparatus
JP2014182308A (en) * 2013-03-19 2014-09-29 Canon Inc Image forming apparatus
JP2016095333A (en) * 2014-11-12 2016-05-26 ブラザー工業株式会社 Image forming apparatus, control method, and program
JP2016191787A (en) * 2015-03-31 2016-11-10 ブラザー工業株式会社 Image formation apparatus, control method and program of the same
JP2016194572A (en) * 2015-03-31 2016-11-17 ブラザー工業株式会社 Image forming apparatus, method of supplying developer, and program
JP2017009760A (en) * 2015-06-19 2017-01-12 キヤノン株式会社 Image forming apparatus
US9891552B2 (en) 2015-06-19 2018-02-13 Canon Kabushiki Kaisha Image forming apparatus performing toner purge processing
US9927761B2 (en) 2016-02-08 2018-03-27 Canon Kabushiki Kaisha Image forming apparatus
US10261462B2 (en) 2016-10-04 2019-04-16 Canon Kabushiki Kaisha Image forming apparatus

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