JP2003330320A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device that forms an image of high image quality with toner of a small particle diameter by maintaining high cleaning performance which is not influenced by image formation hysteresis. <P>SOLUTION: An amount that images are formed is measured. According to the increase of the amount, an amount that a lubricant is applied to an image carrier is increased. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus, and more particularly to a cleaning for an image forming apparatus which forms an image of high quality in terms of resolution, gradation and the like by using a toner having a small particle size. Regarding technology.

[0002]

2. Description of the Related Art Due to improvements in resolution and gradation, it has become possible for image formation by electrophotography to form images of image quality comparable to plate-making printing. Although such improvement in image quality is a result of the development of many elemental technologies, there is development of a small particle size toner as an elemental technology that contributes to higher image quality. The development of small particle size toner has made it possible to increase the resolution, and not only the resolution but also the gradation and sharpness.

[0003]

(1) The small particle size toner greatly contributes to the improvement of the image quality as described above, but when the small particle size toner is used, it is important to secure the cleaning performance. That is, since the toner having a small particle diameter has a property of being more difficult to clean, a cleaning technique having a cleaning performance higher than that of the conventional one is required.

A technique of applying a lubricant to an image carrier on which a toner image is formed is used as a powerful means for improving cleaning performance. Lubricants generally consist of metal fatty acid salts and are loaded into the device as solid blocks. As described above, the volume of the lubricant block loaded in the apparatus has an upper limit naturally from the viewpoint of mounting the block and controlling the coating amount. Therefore, the lubricant becomes insufficient or it is necessary to replenish the lubricant frequently. There is a problem that it will occur.

It is an object of the present invention to eliminate poor cleaning and inconvenience caused by such a shortage of lubricant. (2) The small particle size toner greatly contributes to the improvement of the image quality as described above, but when the small particle size toner is used, it is important to secure the cleaning performance. That is, since the toner having a small particle diameter has a property of being more difficult to clean, a cleaning technique having a cleaning performance higher than that of the conventional one is required. A technique of applying a lubricant to an image carrier on which a toner image is formed is used as a powerful means for improving cleaning performance. Although the cleaning performance is improved by applying the lubricant, the cleaning performance may be insufficient under certain lubricant application conditions because the required cleaning performance changes depending on the amount of toner on the image carrier. The amount of toner on the image carrier to be cleaned is small in the part of the image carrier that has undergone the transfer process because the toner is transferred to the transfer member by transfer, but not in the part of the image carrier that is not subjected to the transfer process. Since the toner remains on the image carrier as it is transferred, the amount of toner increases.

The phenomenon in which the untransferred toner remains on the image carrier occurs at the start and end of the image forming process. That is, at the start and start of the image forming process, the image carrier, the charging unit, and the developing unit are in the unstable time of rising and falling, which causes a device failure such as carrier adhesion. The condition for attaching a large amount of toner is set for the purpose of avoiding the above, so that a large amount of toner attaches to the image carrier and
Since the transfer is not performed, a large amount of toner image remains on the image carrier.

In the case of image formation of a small number of sheets where the start and stop of the image forming step are frequently performed under such conditions in the image forming step, and in the case of continuous image formation of a large number of sheets with few start and stop of the image forming step There is a difference in the required cleaning performance between and. Conventionally, cleaning has not been sufficient because there has been no countermeasure against such fluctuations in cleaning performance.

It is an object of the present invention to provide an image forming apparatus which forms a high quality image with a toner having a small particle size by maintaining a high cleaning performance which is not affected by the image forming history. (3) When a cleaning blade generally used as a cleaning means is used, the contact portion of the photoconductor is worn and the cleaning performance is deteriorated. There is known a cleaning device that uses a cleaning brush or the like as a cleaning assisting means in order to improve the cleaning performance and applies a voltage to the cleaning brush. It has been confirmed that even in such a cleaning device, as the cleaning blade wears, the cleaning performance deteriorates and a problem arises in cleaning the small particle size toner. That is, when the blade temperature is low, the hardness of the cleaning blade is increased, so that the scraping force of the lubricant is increased and a large amount of the lubricant is removed, resulting in deterioration of the cleaning performance.

An object of the present invention is to solve such a problem. (4) In image formation using a toner having a small particle size, the hardness of the cleaning blade changes due to a change in temperature, and when the cleaning performance changes, cleaning failure occurs, resulting in image stains, background stains, and fog. May cause such as.

It is an object of the present invention to provide an image forming apparatus which forms a high quality image by preventing cleaning failure due to such a change in blade temperature. (5) It is known that the transfer rate changes due to the change of the water content of the transfer body such as recording paper due to the change of the environmental humidity and the difference of the thickness of the transfer body, and the transfer rate is corrected to maintain the image quality. Is being done. Even when such a correction is performed, it has been confirmed that the transfer rate remains unchanged and varies in the range of about 80 to 95%. It has been clarified that in the image formation using the small particle size toner, the cleaning failure may occur due to the fluctuation of the transfer rate.

An object of the present invention is to prevent a cleaning failure caused by a change in the properties of the transfer body or a difference in the type of the transfer body. (6) Japanese Patent Application Laid-Open No. 8-234642 proposes that the amount of lubricant applied is controlled according to the amount of toner carried into the cleaning means to maintain the cleaning performance constant. In this proposal, since the control is based on the toner amount calculated by statistically processing the entire image like the toner amount per image, the cleaning blade such as a line image or a small size image unevenly distributed at a specific position is used. There is a problem that cleaning failure occurs in the case of a toner image in which a large load is applied to the specific position.

It is an object of the present invention to solve such a problem and to provide an image forming apparatus which maintains good cleaning performance for all kinds of images. (7) The transfer rate changes depending on environmental conditions, that is, temperature and humidity. That is, the transfer rate decreases under high temperature and high humidity conditions.
Therefore, in order to maintain the transfer rate, when there is such a change in the conditions, the control for increasing the transfer current is performed. However, even with such control, the transfer rate is rarely completely corrected, and a change in the transfer rate cannot be avoided.
In the image forming process using the small particle size toner, cleaning failure may occur due to the change in the transfer rate remaining after such correction, and fogging may occur.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus which forms a high quality image by preventing a cleaning failure that occurs even when a change in environmental conditions is corrected. (8) In image formation using a toner having a small particle diameter, a technique of applying a lubricant is used to maintain high cleaning performance. Generally, the lubricant applying means is composed of a plurality of parts, but in order to maintain the uniform applying performance of the lubricant applying means, it is desirable to replace and use a part of parts such as a brush roller. . However, it has been clarified that when the parts are replaced, a part where the lubricant is not spread over the entire lubricant applying means causes uneven coating and causes poor cleaning.

An object of the present invention is to solve the above problems and to provide an image forming apparatus provided with a cleaning means for always applying a uniform lubricant and maintaining a high cleaning performance. (9) When an abnormality such as a jam of the transfer body occurs, it is general to immediately stop the apparatus at the time of the occurrence of the abnormality in order to prevent the failure of the apparatus. During such an abnormal stop, a large amount of toner is often left on the image carrier, and when restarting image formation after the abnormal stop, the cleaning of the image carrier, which is performed prior to the execution of the image forming process, is performed. In this case, a large amount of toner may be brought into the cleaning means.

In the image formation using the toner having a small particle diameter, it has been clarified that cleaning failure may occur and the image quality may be deteriorated due to a large load applied to the cleaning means due to the abnormal stop as described above. It was

An object of the present invention is to prevent defective cleaning due to such an abnormal stop and always maintain high cleaning performance.

[0017]

The above-mentioned object of the present invention is achieved by the following invention.

1. Image carrier, image forming means for forming a toner image on the image carrier, transfer means for transferring the toner image on the image carrier to a transfer body, and the image carrier after transfer is cleaned by a cleaning blade. In an image forming apparatus having a cleaning unit, the image forming unit forms a toner image using a toner having a volume average particle size of 4 to 6 μm, and a lubricant applying unit that applies a lubricant to the image carrier. An image characterized by having a control means for controlling the lubricant applying means, wherein the control means controls the lubricant applying means so as to increase the application amount in accordance with the progress of the wear degree of the cleaning blade. Forming equipment.

2. 2. The image forming apparatus as described in 1 above, further comprising a number counting unit for counting the number of images formed, the control unit controlling the lubricant applying unit based on the number counting result of the number counting unit.

3. 2. The distance measuring means for measuring the traveling distance of the image carrier is provided, and the control means controls the lubricant applying means based on the measurement result of the distance measuring means. Image forming apparatus.

4. Image carrier, image forming means for forming a toner image on the image carrier, transfer means for transferring the toner image on the image carrier to a transfer body, and the image carrier after transfer is cleaned by a cleaning blade. In an image forming apparatus having a cleaning unit, the image forming unit forms a toner image using a toner having a volume average particle size of 4 to 6 μm, and a lubricant applying unit that applies a lubricant to the image carrier. A control means for controlling the lubricant applying means, the control means controlling the lubricant applying means on the basis of information on the number of images formed between the start and stop of the image carrier. An image forming apparatus characterized by the above.

5. Image carrier, image forming means for forming a toner image on the image carrier, transfer means for transferring the toner image on the image carrier to a transfer body, and the image carrier after transfer is cleaned by a cleaning blade. In an image forming apparatus having a cleaning unit, the image forming unit forms a toner image by using a toner having a volume average particle diameter of 4 to 6 μm, and a lubricant applying unit that applies a lubricant to the image carrier. An image forming apparatus comprising: a power source for applying a voltage to the lubricant applying means; and a control means for controlling the power source to change the voltage.

6. 6. The image forming apparatus as described in 5 above, further comprising a number counting unit for counting the number of images formed, wherein the control unit controls the power source based on the number counting result of the number counting unit.

7. 6. The image forming apparatus as described in 5 above, further comprising: a distance measuring unit for measuring a traveling distance of the image carrier, wherein the control unit controls the power supply based on a measurement result of the distance measuring unit. .

8. 8. The image forming apparatus according to any one of 5 to 7 above, further comprising an environmental humidity detecting means for detecting environmental humidity, wherein the control means controls the power source according to the detected humidity.

9. Image carrier, image forming means for forming a toner image on the image carrier, transfer means for transferring the toner image on the image carrier to a transfer body, and the image carrier after transfer is cleaned by a cleaning blade. In an image forming apparatus having a cleaning unit, the image forming unit forms a toner image by using a toner having a volume average particle diameter of 4 to 6 μm, and a lubricant applying unit that applies a lubricant to the image carrier. It has a blade temperature detection means for detecting the temperature of the cleaning blade and a control means for controlling the lubricant application means, and the control means controls the lubricant application means according to the temperature detected by the blade temperature detection means. An image forming apparatus comprising:

10. Image carrier, image forming means for forming a toner image on the image carrier, transfer means for transferring the toner image on the image carrier to a transfer body, and the image carrier after transfer is cleaned by a cleaning blade. In an image forming apparatus having a cleaning unit, the image forming unit forms a toner image by using a toner having a volume average particle diameter of 4 to 6 μm, and a lubricant applying unit that applies a lubricant to the image carrier. A storage unit humidity detecting means for detecting the humidity of the transfer body storage part and a control means for controlling the lubricant applying means are provided, and the control means applies the lubricant based on the detection result of the storage part humidity detecting means. An image forming apparatus characterized by controlling means.

11. Image carrier, image forming means for forming a toner image on the image carrier, transfer means for transferring the toner image on the image carrier to a transfer body, and the image carrier after transfer is cleaned by a cleaning blade. In an image forming apparatus having a cleaning unit, the image forming unit forms a toner image by using a toner having a volume average particle diameter of 4 to 6 μm, and a lubricant applying unit that applies a lubricant to the image carrier. A transfer body setting means for setting the type of the transfer body and a control means for controlling the lubricant application means are provided, and the control means controls the lubricant application means based on the setting information of the transfer body setting means. An image forming apparatus comprising:

12. 12. The image forming apparatus as described in 11 above, wherein the transfer body setting unit sets the thickness of the transfer body.

13. Image carrier, image forming means for forming a toner image on the image carrier, transfer means for transferring the toner image on the image carrier to a transfer body, and the image carrier after transfer is cleaned by a cleaning blade. In an image forming apparatus including a cleaning unit and performing a front surface image forming step of forming an image on a front surface of a transfer body and a back surface image forming step of forming an image on a back surface of the transfer body, the image forming unit is a volume average particle. The toner image formation is performed using a toner having a diameter of 4 to 6 μm, and a lubricant applying unit for applying a lubricant to the image carrier and a control unit for controlling the lubricant applying unit are provided. The image forming apparatus controls the amount of lubricant applied in the front surface image forming step and the amount of lubricant applied in the rear surface image forming step.

14. Image carrier, image forming means for forming a toner image on the image carrier, transfer means for transferring the toner image on the image carrier to a transfer body, and the image carrier after transfer is cleaned by a cleaning blade. In an image forming apparatus having a cleaning unit, the image forming unit forms a toner image by using a toner having a volume average particle diameter of 4 to 6 μm, and a lubricant applying unit that applies a lubricant to the image carrier. A toner measuring unit and a control unit are provided for measuring the amount of toner forming the toner image formed on the image carrier at each coordinate position having a direction orthogonal to the moving direction of the image carrier as an axis. The control unit controls the lubricant applying unit based on the measurement result of the toner measuring unit.

15. 15. The image forming apparatus as described in 14 above, wherein the toner measuring unit measures the amount of the toner by processing image data.

16. Image carrier, image forming means for forming a toner image on the image carrier, transfer means for transferring the toner image on the image carrier to a transfer body, and the image carrier after transfer is cleaned by a cleaning blade. In an image forming apparatus having a cleaning unit, the image forming unit forms a toner image using a toner having a volume average particle size of 4 to 6 μm, and a lubricant applying unit that applies a lubricant to the image carrier. An image forming apparatus comprising: a control unit, the control unit controlling the lubricant applying unit according to a change of a transfer current in the transfer unit.

17. Image carrier, image forming means for forming a toner image on the image carrier, transfer means for transferring the toner image on the image carrier to a transfer body, and the image carrier after transfer is cleaned by a cleaning blade. In an image forming apparatus having a cleaning unit, the image forming unit forms a toner image using a toner having a volume average particle size of 4 to 6 μm, and a lubricant applying unit that applies a lubricant to the image carrier. In the image formation after the replacement of the replacement part in the lubricant applying means, the control means starts the image forming step after operating the lubricant applying means for a predetermined time. Image forming apparatus.

18. Image carrier, image forming means for forming a toner image on the image carrier, transfer means for transferring the toner image on the image carrier to a transfer body, and the image carrier after transfer is cleaned by a cleaning blade. In an image forming apparatus having a cleaning unit, the image forming unit forms a toner image using a toner having a volume average particle size of 4 to 6 μm, and applies a voltage to the conductive cleaning auxiliary unit and the cleaning auxiliary unit. An image forming apparatus, comprising: a power source and a control unit for controlling the power source to apply a voltage for enhancing the cleaning power of the cleaning assisting unit when returning from an abnormal stop.

19. The image forming means has a sphericity of 0.
19. The image forming apparatus according to any one of 1 to 18 above, wherein a toner image is formed using 94 to 0.98 toner.

20. The image forming means forms a toner image by using a polymerized toner.
The image forming apparatus according to claim 1.

21. The lubricant applying means has a solid lubricant supply body and a pressure contact member that is in pressure contact with the lubricant supply body, and the control means controls the pressure between the lubricant supply body and the pressure contact member. 21. The image forming apparatus according to any one of the items 1 to 4, 9 to 16, 19, and 20, which controls the coating amount.

22. The lubricant applying means has a solid lubricant supply body and a pressure contact member that is in pressure contact with the lubricant supply body, and the control means controls the application amount by controlling the rotation speed of the pressure contact member. 21. The image forming apparatus according to any one of the items 1 to 4, 9 to 16, 19, and 20.

[0040]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) Image Forming Apparatus FIG. 1 is a diagram showing an example of a monochrome image forming apparatus which is an image forming apparatus according to an embodiment of the present invention.

Reference numeral 1 is a photoconductor as an image bearing member, and OP
A C photoconductor, an a-Si photoconductor or the like is used. Reference numeral 2 is a charging means for uniformly charging the photoconductor 1, and a contact type charger such as a scorotron charger, a corotron charger or a roller charger is used. Reference numeral 3 denotes an exposure means for performing image exposure, and an exposure means for performing dot exposure with a light beam using a laser light source, a light emitting diode (LED) light source, or the like is used. Reference numeral 4 denotes a developing means, which uses a two-component developer containing a carrier and a toner as main components and which carries out reversal development or regular development. Reference numeral 5 is a transfer means, and a contact type transfer device such as a corotron charger or a transfer roller is used. 6
Is a lubricant applying means, which applies a lubricant evenly on the photoconductor 1 to assist cleaning. The lubricant and the lubricant applying means 6 will be described later. Reference numeral 7 denotes a cleaning unit that scrapes off the toner on the photoconductor 1, and a cleaning blade 71 scrapes off the adhered substances such as the toner. Denoted at 8 is a separation means, such as an electrostatic separation device such as a corotron static eliminator, a separation claw, a curvature separation (separating by utilizing the straightness of the recording material P by giving a strong bending to the photoconductor), and the like. Such a mechanical separating device is used. A fixing unit 9 fixes the toner image on the recording material P, and heats the toner by a heating member such as a heating roller, a heating belt, and a heating block to fix the toner on the recording material P. A paper discharge sensor 10 detects the discharge of the recording material P. Reference numeral 11 is a memory, and 12 is a control means. The recording material P as a transfer body is stored in a paper feed cassette 30 as a transfer body storage section.

An electrostatic latent image is formed on the photoconductor 1 rotating as indicated by an arrow W by charging by the charging means 2 and exposure by the exposing means 3, and a toner image is formed by the development by the developing means 4. The toner image formed on the photoconductor 1 is
The recording material P transferred to the recording material P by the transfer means 5 and having the toner image transferred thereto is separated from the photoconductor by the separating means 8 and fixed by the fixing means 9. The photoconductor 1 from which the recording material P is separated is cleaned by the cleaning means 7. The charging unit 2, the exposing unit 3, and the developing unit 4 form an image forming unit. The recording material P is supplied from a paper feed cassette 30 as a transfer body storage unit.

FIG. 2 shows an image forming apparatus according to the embodiment of the present invention, which is an example of a color image forming apparatus.

A yellow image forming section 10Y for forming a yellow image, a magenta image forming section 10M for forming a magenta image, and a cyan image forming section 10C for forming a cyan image.
The black image forming unit 10K for forming a black image has a photoconductor 1, a charging unit 2, an exposing unit 3, a developing unit 4, a transferring unit 5, a lubricant applying unit 6, and a cleaning unit 7, respectively.

The intermediate transfer member 40 is stretched around a plurality of rollers 41 and circulates as indicated by an arrow. 5A is an intermediate transfer member 4
Transfer means for transferring the toner image on 0 to the recording material P, 6A is a lubricant applying means for applying a lubricant to the intermediate transfer member 40, 7
A is a cleaning unit that cleans the intermediate transfer member 40.

The paper feed cassette 30 as a transfer body storage unit stores the recording material P. The paper feed unit including the paper feed unit 21, the transport rollers 22A to 22D, and the registration rollers 23 feeds the recording material P from the paper feed cassette 30 to a position where an image is formed and feeds the recording material P. The fixing unit 9 is a device that thermally fixes to the recording material P having a toner image, and the recording material P that has been subjected to the fixing processing is discharged to the discharge tray 26 by the discharge roller 25.

In the image forming process, the image forming unit 10
In Y, 10M, 10C and 10K, the monochromatic toner images formed on the photoconductor 1 by charging, exposing and developing are
The transfer unit 5 sequentially transfers the transferred images onto the intermediate transfer member 40 that moves in a circulating manner, and synthesizes them to form a full-color toner image.

The recording material P stored in the paper feed cassette 30.
Is fed by the paper feed unit 21, is conveyed to the transfer unit 5A via the plurality of conveyance roller rollers 22A, 22B, 22C, 22D and the registration roller 23, and the full color toner image is collectively transferred onto the recording material P. . Reference numeral 24 denotes a back side image forming conveyance section.

Recording material P on which a full-color toner image is transferred
Is subjected to a fixing process by the fixing unit 8 and discharged onto the discharge tray 26 by the discharge roller 25.

On the other hand, the intermediate transfer body 40 after the transfer is applied with the lubricant by the lubricant applying means 6A and cleaned by the cleaning means 7A.

In the image forming apparatus shown in FIG. 2, the lubricant applying unit 6 applies the lubricant to the photosensitive member 1 as the image bearing member, and the lubricant applying unit 6A applies to the intermediate transfer member 40 as the image bearing member. Apply lubricant. Photoreceptor 1 as image carrier
On the other hand, the charging unit 2, the exposing unit 3, and the developing unit are image forming units, and the image forming units 10Y, 10M, 10C, and 10K form the image forming unit with respect to the intermediate transfer member 40 as an image carrier.

The intermediate transfer member 40 is a transfer member in relation to the photoreceptor 1, the lubricant applying means 6 and the cleaning means 7, and is an image carrier in relation to the lubricant applying means 6A and the cleaning means 7A. (2) Toner In the present invention, a small particle size toner having a volume average particle size of 4 to 6 μm is used.

The volume average particle diameter is an average particle diameter on a volume basis, and "Coulter Counter TA equipped with a wet disperser.
-II "or" Coulter Multisizer "(both manufactured by Coulter, Inc.).

With such a small particle size toner, a high quality image having high resolution can be formed. With a toner having a volume average particle size of more than 6 μm, the characteristics of high image quality are weakened.

When a toner having a volume average particle size smaller than 4 μm is used, the image quality is apt to deteriorate due to fogging or the like.

Further, in the present invention, a spherical toner is desirable, and the degree of sphericity thereof is desirably 0.94 or more and 0.98 or less.

Spheroidization degree = (perimeter of a circle having the same area as the particle projection image) / (perimeter of the particle projection image) The sphericity is determined by a scanning electron microscope or a laser microscope for 500 resin particles. An image analyzer "SCANNI" was used to take a picture of resin particles magnified 500 times.
It can be calculated by analyzing the photographic image by using "NG IMAGE ANALYSER" (manufactured by JEOL Ltd.), measuring the circularity, and obtaining the arithmetic mean value thereof. In addition, as a simple measurement method, "FPIA-1
000 "(manufactured by Toa Medical Electronics Co., Ltd.).

When the sphericity is less than 0.94, the toner is crushed as a result of being subjected to strong stress without developing means, and fog and toner scattering are likely to occur. Further, the sphericity is 0.
If it is larger than 98, it may be difficult to maintain high cleaning performance.

It is desirable to use a polymerized toner for the toner having a small particle size and a high sphericity as described above.

The polymerized toner means a toner obtained by forming a binder resin for toner and forming a toner shape by polymerizing a raw material monomer or prepolymer of the binder resin and then performing a chemical treatment. More specifically, it means a toner obtained through a polymerization reaction such as suspension polymerization or emulsion polymerization and, if necessary, a step of fusing particles with each other. In the case of a polymerized toner, a raw material monomer or prepolymer is uniformly dispersed in an aqueous system and then polymerized to produce a toner, so that a toner having a uniform particle size distribution and shape can be obtained.

Specifically, those produced by the suspension polymerization method or emulsion polymerization of a monomer in a liquid of an aqueous medium to which an emulsion is added to produce fine polymer particles. It can be produced by a method of adding a solvent, a coagulant and the like to cause association. At the time of association, a method of preparing by mixing with a dispersion liquid such as a release agent or a colorant necessary for the constitution of the toner to allow association, or dispersing a toner constituent component such as a release agent or a colorant in a monomer Examples include the method of emulsion polymerization above. Here, the association means that a plurality of resin particles and colorant particles are fused. (4) Lubricant The lubricant is applied to the surface of the photoconductor mainly for the purpose of improving cleaning performance, and is generally composed of a fatty acid metal salt. Specific examples of the lubricant include zinc stearate, aluminum stearate, copper stearate, metal stearate such as magnesium stearate, zinc oleate, manganese oleate, iron oleate, copper oleate, magnesium oleate and the like. Metal salts of oleic acid, zinc palmitate, copper palmitate, magnesium palmitate, etc., metal linoleate such as zinc linoleate, zinc linoleate, metal ricinoleate such as zinc ricinoleate, lithium ricinoleate Salt etc. are mentioned. Zinc stearate is particularly preferred.

In the following description of the embodiments, the lubricant applying means 6 is the lubricant applying means 6 in FIG. 1, the lubricant applying means 6 in FIG. 2 and the lubricant applying means in FIG. 2 unless otherwise applicable. 6A, the cleaning means 7 will be described as including the cleaning means 7 in FIG. 1, the cleaning means 7 in FIG. 2, and the cleaning means 7A in FIG. (5) First Embodiment FIG. 3 shows a lubricant applying means 6 and a cleaning means 7 of the image forming apparatus according to the first embodiment of the present invention. The cleaning unit 7 has a cleaning blade 71 and a brush roller 62, and the lubricant applying unit 6 is a brush roller 62 as an application rotating member and an intermediate roller 6 as a pressure contact member.
3, a lubricant supply body 64, a cam 65, and a coil spring 66. The cleaning blade 71 scrapes and removes residual substances such as toner remaining on the photoconductor 1 after transfer, and is made of a rubber elastic body such as urethane rubber. The brush roller 62 is an application rotary member that applies a lubricant to the photoconductor 1 and a cleaning auxiliary unit that removes the deposits on the photoconductor 1. As the application rotary member or the cleaning auxiliary unit, a urethane foam or the like is used. A sponge can also be used. The brush forming the brush roller is preferably made of conductive fibers, and it is desirable to apply a voltage having the opposite polarity to the electric charge of the toner on the photoconductor 1 or to ground it. The intermediate roller 63 as a pressure contact member scrapes the lubricant from the lubricant supply body 64 and applies it to the brush of the brush roller 62, and is made of metal such as aluminum. The intermediate roller 63 also removes toner and the like from the brush roller 62, and the removed toner and the like is removed by a scraper 67 made of a PET film or the like.

Reference numeral 64 denotes a lubricant supply body composed of a solid block of the above-mentioned lubricant, which is brought into pressure contact with the intermediate roller 64 and supplies the lubricant to the intermediate roller 63.

Reference numeral 65 is a cam which constitutes the pressure switching means, and switches the pressure of the coil spring 66 which constitutes the pressure applying means. The pressure of the lubricant supply body 64 on the intermediate roller 63 is set by the coil spring 66, and this pressure changes as the rotational position of the cam 65 changes. Therefore, the lubricant is scraped off from the lubricant supply body 64 and the photosensitive member 1 The amount applied to is controlled by changing the angle of the cam 65.

Reference numeral 10 denotes a paper discharge sensor, and the paper discharge sensor 10
The number of formed images counted by is stored in the memory 11. The memory 11 is a non-volatile memory that holds the count number even when the power is turned off, and the number of image formed sheets is cumulatively counted.

Reference numeral 12 is a control means for changing the angular position of the cam 65 according to the cumulative count number stored in the memory 11 and changing the amount of lubricant applied to the photoconductor 1.

FIG. 4 is an enlarged view of the cleaning blade 71. As shown in FIG. 4 (a), the cleaning blade 71 has a blade-shaped photosensitive member contact portion EJ in the initial stage, but when used for a long period of time, it wears off and becomes smooth as shown in FIG. 4 (b). . Therefore, the cleaning blade 71 is shown in FIG.
In the initial stage shown in (a), it has a sufficient cleaning performance, and even if the amount of lubricant applied is small, good cleaning is performed in image formation using a small particle size toner. However, as a result of long-term use, the cleaning blade 71 shown in FIG. 4B has poor cleaning performance, and unless the coating amount of the lubricant is increased, sneaking of the small particle size toner occurs and cleaning failure easily occurs. .

In image formation using a toner having a small particle size, a means for applying a lubricant to maintain high cleaning performance is adopted in order to prevent the above-mentioned squeezing. It was consumed by and had to be replenished frequently. According to the present embodiment, by increasing the amount of lubricant applied in accordance with the increase in the amount of image formation to correct the deterioration in cleaning performance, an image using a toner having a small particle size while maintaining high cleaning performance can be obtained. The lubricant supply body 64 can be used for a long period of time in forming. The control unit 12 rotates the cam 65 in response to the increase in the number of image formations stored in the memory 11 for the above control, increases the pressing force of the coil spring 66, and increases the lubricant application amount.

As a result, the cleaning performance of the cleaning blade 71 is maintained at a high level for a long period of time while the amount of lubricant used is reduced as a whole, and cleaning of small particle size toner is enabled. The memory 11
The memory is initialized by replacing the cleaning blade 71.

In the example described above, the amount of lubricant applied is controlled according to the number of images formed, but other means is used for controlling the lubricant applied according to the degree of wear of the cleaning blade 71. It is also possible, for example, to provide an encoder in the drive system of the photoconductor 1, detect the travel distance of the photoconductor 1 from the detection of the rotation amount of the encoder, and apply the lubricant according to the accumulated value. Is. The amount of lubricant applied may be controlled by changing the rotation speed of the intermediate roller 63. (6) Second Embodiment The image forming apparatus shown in FIGS. 1 and 2 is the image forming apparatus according to the present embodiment, and the lubricant applying means shown in FIG. 3 is used.

FIG. 5 shows the relationship between the photoconductor surface potential and the developing bias potential when the photoconductor is started. V1 indicates the surface potential of the photoconductor, and V2 indicates the developing bias potential. In the steady state after the photoconductor is activated and a predetermined time has elapsed, the surface potential V1 is higher than the developing bias potential V2 by the blank sheet potential ΔV.
The developing bias potential V2 is maintained so as to be higher than that. The blank sheet potential ΔV is set to a value such that toner development and carrier development do not occur. On the other hand, during the rising period TA of the photoconductor, the developing bias potential V2 is much higher than the surface potential V1, toner development is performed, and a large amount of toner adheres to the photoconductor. Such a setting is for surely preventing carrier development in the rising period which is an unstable transition period. Moreover, since the transfer is not performed during the rising period,
A large amount of toner is brought into the cleaning means 7, and the load on the cleaning means 7 increases.

The image forming apparatus is designed so that the cleaning performance is not deteriorated even under such a large cleaning load at the time of start-up, but in the image formation using the toner having a small particle size, the excessive cleaning load causes It was discovered that poor cleaning may occur.

In the present embodiment, when the photosensitive member is frequently activated and a large cleaning load is frequently generated in the transition period as described above, that is, when the number of image forming sheets in one job is small. By controlling to increase the amount of lubricant applied, the cleaning failure is eliminated and high cleaning performance is always maintained.

The control means 12 controls the coating amount of the lubricant in accordance with the number of image formed sheets in the image forming process performed during the start and stop of the photosensitive member 1. That is, when the start-up and stop of the photoconductor 1 intervene between a small number of image-formed sheets, the amount of toner removed by cleaning increases, so the amount of lubricant applied is increased to improve cleaning performance. In continuous image formation in which a large number of images are formed without starting and stopping 1, the control unit 12 controls the amount of lubricant applied to reduce the cleaning performance.

Although there are various concrete methods of such control, for example, the following control is performed.

The control means 12 is an operation panel (not shown).
When the number of sheets set in (1) is smaller than the predetermined number, or when the number of print commands from the external device is smaller than the predetermined number, the cam 65 is controlled to increase the lubricant application amount.

By such control, the amount of lubricant applied is controlled in accordance with the number of image formed sheets in the image formation performed during the start-up and stop of the photosensitive member 1, and good cleaning is always guaranteed.

The amount of lubricant applied can be controlled by using the means described in the first embodiment. (7) Third Embodiment It has been clarified that in the image formation using the toner of small particle size, the cleaning may not be sufficiently performed only by the cleaning blade.
For this purpose, a cleaning assisting means such as a brush roller is used and a lubricant is applied.

In the present embodiment, an image using a toner having a small particle size is obtained by applying a lubricant, applying a cleaning voltage to the application rotor forming the lubricant applying means, and controlling the applied voltage. The cleaning performance in formation is improved.

FIG. 6 shows a main part of the image forming apparatus according to the third embodiment of the present invention. The same parts as those in FIG. 3 are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 6, reference numeral 62 denotes a brush roller as a cleaning assisting means, which has a brush made of a conductive fiber. The brush roller 62 removes a few percent to a few tens percent of the toner on the photoconductor 1 to reduce the cleaning load of the cleaning means 7 (shown in FIGS. 1 and 2). As the brush forming the brush roller 62, fibers having a resistance value of 10 ⁶ to 10 ⁸ Ω are used, the length of the brush bristles is about 3.5 mm, and the line thickness is about 6.25 d.
It is desirable that the density is about 60 k / 25.4 mm ² . Conductive acrylic or the like is used as the fiber material.
The brush roller 62 is a cleaning assisting device which will be described below, and also constitutes an application rotating member that applies the lubricant to the photoconductor 1 as described above. As the cleaning assisting means, a sponge roller such as urethane foam may be used instead of the brush roller.

68 is a power source for applying a voltage to the brush roller 62, and applies a voltage having the opposite polarity to the toner remaining on the photoconductor 1 (the same polarity as the power source 51 of the transfer means 5). In the present embodiment, since negatively charged toner is used, the power source 68 applies a positive voltage to the brush roller 62.

The control means 12 controls the power source 67 according to the number of image forming sheets counted by the paper discharge sensor 10 and accumulated in the memory 11. That is, in the initial stage, the brush roller 62 is maintained at the ground potential, and a positive voltage value is increased as the number of image forming sheets increases, or a positive voltage is applied in the initial stage, and the voltage value is increased as the number of image forming sheets is increased. To do. Control methods include continuous or stepwise methods.

Although the control means 12 controls the applied voltage according to the number of image forming sheets as described above, it can also be controlled according to the traveling distance of the photoconductor 1 as in the first embodiment. . The control unit 12 also performs the voltage control according to the environmental humidity in addition to the voltage control corresponding to the image forming amount. Reference numeral 13 is a humidity sensor as an environmental humidity detecting means for detecting environmental humidity, and the control means 12 is a humidity sensor 13
Based on the output of, the voltage is set high (high in absolute value) at low humidity to set the cleaning performance high. (8) Fourth Embodiment The image forming apparatus of FIGS. 1 and 2 is the image forming apparatus according to the present embodiment.

The cleaning blade 71 is generally made of a material having rubber elasticity such as urethane rubber, but its cleaning performance changes with temperature. That is, at a low temperature, since the hardness of the cleaning blade is high, the scraping force for scraping off the lubricant on the photoconductor 1 is strong, and the lubricant is scraped off much, so that the cleaning performance tends to decrease correspondingly. It has been clarified that in the image formation using the toner having a small particle diameter, the cleaning performance may be deteriorated due to such deterioration of the cleaning performance.

In the present embodiment, by controlling the application amount of the lubricant according to the temperature of the cleaning blade 71, it is possible to prevent defective cleaning and always maintain high cleaning performance. That is, by increasing the coating amount of the lubricant at low temperature, the deterioration of the cleaning performance at low temperature is prevented.

FIG. 7 shows a main part of the image forming apparatus according to the fourth embodiment of the present invention. The same parts as those in FIG. 3 are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 7, reference numeral 14 is a temperature sensor as a blade temperature detecting means for detecting the temperature of the cleaning blade 71. The temperature sensor 14 is composed of a thermistor or the like, and is arranged near the cleaning blade 71 as shown in the figure. Alternatively, the temperature sensor 14 may be attached to the cleaning blade 71.

Based on the output of the temperature sensor 14, the control means 12 controls the angle of the cam 65 so as to increase the lubricant application amount at low temperature and decrease it at high temperature.

The amount of lubricant applied can be controlled by using the means described in the first embodiment. (9) Fifth Embodiment The image forming apparatus of FIGS. 1 and 2 is the image forming apparatus according to the present embodiment.

The image forming apparatus is designed so that the transfer is performed without being affected by the water content or the thickness of the recording material P.
If the change of these conditions does not affect the transfer rate at all, that is not the case. In many cases, the transfer rate fluctuates within a range that does not affect the visually observed image, and the transfer rate is about 80 to 95%. Fluctuates within the range of. In addition, the transfer rate may vary greatly depending on the case. In the image forming process using the toner having a small particle diameter, the cleaning performance may be affected by such a change in the transfer rate, and cleaning failure may occur. In the present embodiment, in consideration of such a situation, control is performed to change the amount of lubricant applied in response to changes in the water content of the transfer body and the thickness of the transfer body. By this control, high cleaning performance is always maintained, and image stains and fogging are prevented.

FIG. 8 shows a main part of an image forming apparatus according to the fifth embodiment of the present invention. The same parts as those in FIG. 3 are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 8, reference numeral 15 denotes a humidity sensor as a storage unit humidity detecting means for detecting the humidity of the transfer member storage unit, which is disposed near the sheet feeding cassette 30. The water content of the recording material P corresponds to the humidity of the environment in which the recording material P is stored. Therefore, by detecting the humidity in the vicinity of the sheet feeding cassette 30 that is the transfer body storage unit and controlling the amount of lubricant applied based on the detected humidity, cleaning that is not affected by fluctuations in the water content of the recording material P can be performed. Will be done.

Reference numeral 16 is an operation panel as an operation unit,
The operator sets the thickness of the recording material P as a transfer body from the operation panel 16. As a setting method, for example, setting buttons of “thick paper”, “plain paper”, and “thin paper” are prepared on the operation panel 16, and the recording material P is selected by operating these buttons.
Thickness is set.

That is, the control means 12 controls the recording material P at high humidity.
When the water content is high and the transfer rate is low, and when thick paper is used as the recording material P and the transfer rate is low, control is performed to increase the amount of lubricant applied.

The amount of lubricant applied can be controlled by using the means described in the first embodiment. (10) Sixth Embodiment The image forming apparatus of FIGS. 1 and 2 is the image forming apparatus according to the present embodiment, and the lubricant applying means shown in FIG. 3 is used.

It is known that defective cleaning is likely to occur when the amount of toner carried into the cleaning means 7 is large, and it is proposed to detect the amount of toner and control the amount of lubricant applied based on the detection result. However, since the detected toner amount is a statistical toner amount detection result like the toner amount of the entire image, in the case of a line image There is a problem that cleaning failure occurs when there are many small-sized images unevenly distributed at specific positions.

In this embodiment, the cleaning load applied to the cleaning blade 71 is measured for each part of the cleaning blade 71 so that high cleaning performance is maintained for all kinds of images.

FIG. 9 shows the exposure means 3 according to the sixth embodiment of the present invention.
The processing system of the image data in FIG. In FIG. 9, the image data D1 is input to the image processing circuit 31, the image processing circuit 31 performs image processing such as gradation conversion, scaling, and multi-value conversion, and the processed image data D2 is the drive circuit 32. And the drive circuit 32 drives the semiconductor laser 33 to emit light. Reference numeral 34 is an integrating circuit as a toner measuring means for processing the image data D2 after the image processing to generate data for controlling the lubricant application. The integrating circuit 34 generates the data shown in FIG. In the graph of FIG. 10, the horizontal axis represents the position in the main scanning direction X, and the vertical axis DM represents the data amount of the image data D2. The data amount DM is a cumulative value of pixel values when the image data is multi-valued image data. That is,
In the integration circuit 34, integration calculation is performed as a black pixel cumulative value at each position in the main scanning direction X. A curve CV in FIG. 10 shows an example of the calculation result. The curve CV shown is
It is a calculation result obtained by performing the above calculation for each fixed number of image formations.

Since the load applied to the cleaning blade 71 is most accurately represented by the maximum toner amount at each position in the main scanning direction, the cleaning performance is controlled by controlling the lubricant application amount based on the peak value of the curve CV. Can be reliably prevented. In the present embodiment, as described above, the integrating circuit 34 detects the maximum toner amount in the main scanning direction, and the control unit 12 is based on the detected value.
Maintains the cleaning performance at a constant level by controlling the amount of lubricant applied.

The amount of lubricant applied can be controlled using the means described in the first embodiment. (11) Seventh Embodiment The image forming apparatus shown in FIGS. 1 and 2 is the image forming apparatus according to the present embodiment, and the lubricant applying means shown in FIG. 3 is used.

The transfer rate changes depending on environmental conditions, that is, temperature and humidity, or the characteristics of the transfer body. That is, high temperature,
The transfer rate decreases under high humidity conditions, and also when the transfer body has a high resistance value. Further, the transfer rate changes between the front surface image formation and the back surface image formation. Therefore, in order to keep the transfer rate constant, control is performed to change the transfer current when such a condition changes.
However, even with such control, the transfer rate is rarely completely corrected, and a change in the transfer rate cannot be avoided. In the image forming process using a small particle size toner, cleaning failure may occur and fogging may occur even when the transfer rate corrected by controlling the transfer current varies.

In this embodiment, when the control means 12 controls the transfer current for driving the transfer means 5, the cleaning performance is kept constant by changing the amount of lubricant applied. I am maintaining. Specifically, for example, the following control is performed. That is, the optimum transfer conditions are obtained for various parameters by experiments, the transfer current value and the transfer rate under each optimum condition are obtained, and when the transfer rate reaches a predetermined threshold value, standard lubricant application is performed. If not reached, increase the amount of lubricant applied. The amount of lubricant applied can be controlled using the means described in the first embodiment. FIG. 11 shows an image forming apparatus according to the seventh embodiment, in which the control means 12 controls the transfer current of the transfer means 5 and controls the lubricant applying means 6 in response to the control signal. (12) Eighth Embodiment The image forming apparatus of FIGS. 1 and 2 is the image forming apparatus according to the present embodiment, and the lubricant applying means shown in FIG. 3 is used.

The brush roller 62 which constitutes the lubricant applying means 6 is a part which is replaced due to deterioration. In the present embodiment, at the time of replacement, the brush roller 62 is rotated until the lubricant is spread over the entire brush roller 62, and the image forming process is started after the brush roller 62 is in a state where the lubricant can be applied uniformly. . Since the time required to apply the lubricant to the entire fibers of the brush roller 62 is substantially constant, the brush roller 62 is rotated for a predetermined time after the replacement, so that the lubricant is uniformly applied to the photoconductor 1. The purpose is achieved. (13) Ninth Embodiment FIGS. 1 and 3 show an image forming apparatus according to the ninth embodiment.

The image forming apparatus stops abnormally due to a jam of the transfer body or the like. When the apparatus normally stops, that is, when the apparatus stops due to the end of the image forming process, the stop timing of the charging unit 2 and the developing unit 4 is controlled so that the toner does not remain on the photoconductor 1. However, in the abnormal stop, there is a possibility that a large amount of toner will stop in the state where the toner adheres to the photoconductor 1. In such a case, a large amount of toner may be brought into the cleaning unit 7 at the start of the next image forming process, and cleaning failure may occur.

In the present embodiment, the control means 12
Controls the power supply 68 to increase the voltage applied to the brush roller 62 as a cleaning assisting means at the start of image formation after abnormal stop. Brush roller 62
Is grounded in the steady state or a voltage having the opposite polarity to the charge of the toner is applied. When grounded in a steady state, a voltage having a polarity opposite to that of the toner is applied to the brush roller 62, and when a voltage having a polarity opposite to that of the toner is applied in a steady state, the voltage value is increased. . In the present embodiment using the negatively charged toner,
Control is performed to apply a positive voltage to the brush roller 62 to increase its cleaning ability.

[0107]

Embodiments (1) Embodiment 1 Multifunction machine having copy function and print function Sitios
An image forming experiment using four types of cleaning blades was performed under the following conditions using 7065 (manufactured by Konica Corporation). -Toner: volume average particle diameter 5.4 μm, sphericity 0.96-Lubricant applying means: one having the structure shown in FIG. 3-Lubricant: zinc stearate-Spring load on the intermediate roller 63: PR1 of 0. 1N
/ Cm, PR2 0.2 N / cm-Cleaning blade: unused item as blade # 1, 50,000 printing blade # 2, 100,000 printing blade # 3, 200,000 blade # 4 When printing, the spring load in the following description and Tables 1 to 11 is the load per unit length in the axial direction of the intermediate roller 63 in FIG.

The results of the experiment are shown in Table 1. The experimental result is that 10 prints are prepared, and the defective cleaning is judged from the condition of image stain and background stain.

[0109]

[Table 1]

As is clear from Table 1, when 100,000 sheets were printed, cleaning failure occurred when the spring load was set low and the lubricant application amount was set low. If you set a large amount, 10
No defective cleaning occurred when printing 10,000 sheets or 200,000 sheets. (2) Example 2 Multifunction machine having copy function and print function Sitios
An image forming experiment was conducted using 7065 (manufactured by Konica Corporation) under the following conditions. -Toner: volume average particle diameter 5.4 μm, sphericity 0.96-Lubricant applying means: one having the structure shown in FIG. 3-Lubricant: zinc stearate-Spring load on the intermediate roller 63: PR1 of 0. 1N
/ Cm, 0.2 N / cm as PR2 ・ Cleaning blade: 100,000 prints ・ Environment: 10 ° C, relative humidity 20% ・ Image: Copying a document with a blackened area ratio of 6% Table 2 As shown in. The experimental result is 10
No. 0 print was used for experiment No. Printing is performed for each of 1 to 6 and the defective cleaning is determined based on the state of image stain and background stain.

[0111]

[Table 2]

As is clear from Table 2, in the print in which the photoconductor is stopped after every 50, 20 and 10 prints, no cleaning failure occurred, but the photoconductor was stopped after every 5 prints. In the print, the cleaning failure occurred when the spring load was set low and the amount of lubricant applied was set small. On the other hand, by increasing the spring load and setting a large coating amount, cleaning failure did not occur when the number of sheets per job was 5 and 2. (3) Example 3 Multifunction machine having copy function and print function Sitios
7065 (manufactured by Konica Corporation) was used to perform an image forming experiment using five types of cleaning blades under the following conditions. -Toner: Volume average particle diameter 5.4 μm, sphericity 0.96-Cleaning blade: unused blade # 1, blade # 2 with 50,000 prints, blade # 3 with 100,000 prints , Blade # 4 with 200,000 prints, blade # 5 with 50
Thousands of prints ・ Lubricant application means: Structure shown in Fig. 3 ・ Lubricant: Zinc stearate ・ Environment: 10 ° C, relative humidity 20% ・ Image: Copy original with blackened area ratio 6% Brush roller: the thickness of the fibers that make up the brush 6.25
d, flocking density 60 k / 24.5 mm ² , brush bristle length 3.5 mm, resistance value 10 ⁶ Ω-DC voltage of 0 V, +100 V, +300 V is applied to the brush roller. Shows the result of evaluation.

[0113]

[Table 3]

As shown in Table 3, when a voltage of 0 V was used and a cleaning blade was used at the time of 100,000 printing, cleaning failure occurred. However, by applying a voltage of +100 V to the brush roller, the cleaning failure was resolved. . Further, at a voltage of +100 V, cleaning failure occurred in the case of the cleaning blade at the time of printing 500,000, but by increasing the voltage to +300 V,
No defective cleaning occurred even when a cleaning blade was used for printing 0,000. (4) Example 4 Multifunction machine having copy function and print function Sitios
Using 7065 (manufactured by Konica Corporation), an image forming experiment was conducted under the following conditions while changing the blade temperature. -Toner: volume average particle diameter 5.4 μm, sphericity 0.96-Lubricant applying means: having the structure shown in FIG. 3-Lubricant: zinc stearate-Spring load on the intermediate roller 63: PR1 of 0. 1N
/ Cm, PR2 0.2N / cm ・ Cleaning blade: 100,000 prints ・ Image: Copying a document with a blackened area ratio of 6% 5 or more jobs in 5 prints at each temperature
100 prints were repeated and evaluated. The evaluation results are shown in Table 4.

[0115]

[Table 4]

As shown in Table 4, under the condition that the blade temperature was low, the cleaning failure occurred when the amount of the lubricant applied was small, but the cleaning failure was resolved by increasing the application amount. (5) Example 5 Under the same conditions as in Example 2, A4 size plain paper (64 g
20%, 50% of the relative humidity detected by a humidity sensor provided in the transfer body storage unit storing the plain paper.
For 80% and 80%, 100 sheets of images were formed by using a cleaning blade at the time of printing 100,000 sheets, and the occurrence of defective cleaning was examined. The moisture content of the plain paper at the humidity is 3.5% by mass, 5.5% by mass,
It was 10.0 mass%.

The experimental results are shown in Table 5.

[0118]

[Table 5]

As shown in Table 5, cleaning failure occurred when the humidity of the transfer member housing was high, but the cleaning failure was resolved by increasing the lubricant application amount. (6) Example 6 Plain paper (basis weight: 55 kg / m ² ) under the same conditions as in Example 2
An image forming experiment was conducted using a thick paper (basis weight 110 kg / m ² ) (however, low temperature and low humidity environment of 10 ° C. and 20% relative humidity). A job of 5 print units was repeated 20 times for each transfer member, and 100 prints were prepared and evaluated. The evaluation results are shown in Table 6.

[0120]

[Table 6]

As shown in Table 6, in the case of thick paper, the cleaning failure occurred at a low lubricant application amount, but the cleaning failure was resolved by increasing the application amount. (7) Example 7 Under the same conditions as in Example 2, A4 size plain paper (basis weight 5
5 kg / m ² ) at room temperature and humidity (20 ° C, relative humidity 50
%), 50 sheets of images were formed on each of the front and back sides using a cleaning blade at the time of 100,000 printing.
The experimental results are shown in Table 7.

[0122]

[Table 7]

As shown in Table 7, in the back side image formation, cleaning failure occurred under the same conditions as the front side.
The cleaning failure was resolved by increasing the lubricant application amount. (8) Example 8 Multifunction machine having copy function and print function Sitios
Using 7065 (manufactured by Konica Corporation), an image forming experiment was performed under the following conditions. -Toner: volume average particle diameter 5.4 μm, sphericity 0.96-Lubricant applying means: one having the structure shown in FIG. 3-Lubricant: zinc stearate-Spring load on the intermediate roller 63: PR1 of 0. 1N
/ Cm, PR2 0.2 N / cm-Image: copy of a document with a blackened area ratio of 6% -Environmental humidity, type and surface of recording material (transfer material) using an apparatus that performed 50,000 prints- With respect to each condition on the back surface, the condition was divided into 1 to 6 stages, the image was formed under each condition, and the transfer current under each condition was measured.

The image forming conditions 1 to 6 and the transfer current value under each condition are as shown in Table 8.

[0125]

[Table 8]

The transfer current is obtained by arranging the aluminum drum instead of the photosensitive drum so as to face the transfer means, applying the transfer voltage under each instructing condition, and measuring the current flowing through the aluminum drum.

Since the instruction conditions 4 to 6 were conditions in which the transfer rate was lowered, the pressure of the pressure contact member against the lubricant supply member was changed from PR1 to PR2 in the instruction conditions 4 to 6 to prevent the occurrence of defective cleaning. Examined. The status of occurrence of cleaning failure is shown in Table 9.

[0128]

[Table 9]

As shown in Table 9, the cleaning failure was resolved by increasing the lubricant coating amount even under the transfer condition where the transfer rate was low. (9) Example 9 Under the same conditions as in Example 2, copying was performed using a character image having a blackened area ratio of 6% and 30% and a vertical line (line in the sub-scanning direction) image of 10%. It was Further, an image forming experiment was conducted by changing the transfer current to set the transfer rates to 80% and 95%. The results are shown in Table 10.

[0130]

[Table 10]

As shown in Table 10, the blackened area ratio is high,
Although the cleaning failure occurred under the condition that the transfer rate is low, that is, the condition that the amount of toner sent to the cleaning means is large, the toner sent to the cleaning means is low when the blackened area ratio is low and the transfer rate is high. If the amount of toner is small, cleaning failure does not occur, and even if the amount of toner is large, cleaning failure is resolved by increasing the amount of lubricant applied. (10) Example 10 Multifunction machine having copy function and print function Sitios
An image forming experiment was conducted using 7065 (manufactured by Konica Corporation) under the following conditions. -Toner: volume average particle diameter 5.4 μm, sphericity 0.96-Cleaning blade: 100,000 printing-Lubricant applying means: having the structure shown in FIG. 3, provided that a brush roller is used as a cleaning assisting means Instead, a conductive urethane foam roller was used, and the urethane roller was rotationally driven in the forward direction at a linear velocity ratio of 1.05 with respect to the photosensitive member.-Applied voltage to the urethane roller: steady voltage 0 V-Restart after abnormal stop Applied voltage at the time of: Example 100V, Comparative example 0V-Lubricant: Zinc stearate-Environment: 10 ° C, relative humidity 20% -Image: During execution of a copy image forming process using a document having a blackened area ratio of 50% Then, the main power supply of the apparatus was turned off to stop the operation, and the apparatus was restarted to investigate the cleaning failure when image formation was performed.

The experimental results are shown in Table 11.

[0133]

[Table 11]

As shown in Table 11, when a voltage equal to that during steady operation is applied to the urethane roller at the time of restart after an abnormal stop, it occurred even if there was no cleaning failure during steady operation. By raising the voltage to 100 V, the cleaning failure was resolved.

[0135]

According to the first, second, third, twenty-first or twenty-second aspect of the present invention, the toner coating amount is controlled so as to increase the lubricant coating amount as the wear degree of the cleaning blade progresses. Even in high-quality image formation using, high-performance cleaning performance is ensured for a long period of time, and high-quality images can be formed. Even when the cleaning performance is maintained high as described above, the consumption amount of the lubricant can be suppressed to a low level, and the replenishment cycle of the lubricant supply body can be lengthened.

When the number of image forming sheets per image forming job is small, the ratio of the number of times the image carrier is started and stopped is high with respect to the number of image forming sheets. In such image forming, cleaning is performed. The amount of toner brought into the device increases, and cleaning failure easily occurs. According to the invention of claim 4, the application amount of the lubricant is controlled in accordance with the number of images formed between the start and stop of the image bearing member, so that even in the high quality image formation using the small particle size toner. High-performance cleaning performance is secured for a long period of time, and high-quality images can be formed.

In the image formation using the toner having a small particle size, when the lubricant applying means is used as the cleaning assisting means, if a constant voltage is applied to the cleaning assisting means, cleaning failure may occur. However, according to the fifth aspect of the invention, such cleaning failure can be effectively prevented, and good cleaning performance can be ensured even when a small particle diameter toner is used.

According to the sixth or seventh aspect of the invention, the cleaning failure that tends to occur as the amount of image formation increases is effectively prevented, and good cleaning performance is always maintained.

According to the invention of claim 8, good cleaning performance is always maintained without being affected by changes in environmental humidity.

In image formation using a toner having a small particle size, cleaning failure may occur due to a change in hardness of the cleaning blade depending on the temperature. According to the ninth aspect of the present invention, such cleaning failure is favorably prevented, and good cleaning performance is always maintained.

In the image formation using the toner having a small particle diameter, the change of the transfer rate due to the humidity of the transfer body, the change of the transfer rate due to the thickness of the transfer body, the front surface image formation and the back surface image formation When the transfer rate changes due to the change in the resistance value of the transfer body, such as the change in the transfer rate in step 1, the cleaning failure may occur. According to the invention of any one of claims 10 to 13, such defective cleaning is effectively prevented, and good cleaning performance is always maintained.

According to the fourteenth or fifteenth aspect of the invention, a statistical toner amount such as a ruled line image having many lines parallel to the moving direction of the image carrier or an image image in which a small size image is locally formed is Depending on the measurement, the undetected load of the cleaning blade is accurately measured, so that a high cleaning performance that is not affected by the shape or nature of the image is always maintained.

A means for controlling the transfer current is generally used in order to keep the transfer rate constant. However, even when such a control means is used, variations in the transfer rate are often not completely corrected. . In image formation using a toner having a small particle diameter, cleaning failure is likely to occur even with such a change in transfer rate. According to the sixteenth aspect of the invention, such defective cleaning is effectively prevented, and high cleaning performance is always maintained.

When the lubricant applying means is replaced, the cleaning performance changes temporarily due to the non-uniformity of the lubricant on the image bearing member. Is applied, so that good cleaning performance is always maintained.

According to the eighteenth aspect of the present invention, defective cleaning caused by the abnormal stop of the image forming apparatus is effectively prevented, and good cleaning performance is always maintained.

According to the invention of claim 19 or claim 20,
It is possible to form a high-quality image having excellent image characteristics such as high resolution, good gradation, and good sharpness.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a monochrome image forming apparatus, which is an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a color image forming apparatus, which is an image forming apparatus according to an embodiment of the present invention.

FIG. 3 is a diagram showing a lubricant applying unit and a cleaning unit of the image forming apparatus according to the embodiment of the present invention.

FIG. 4 is an enlarged view of a cleaning blade.

FIG. 5 is a graph showing a photosensitive member surface potential and a developing bias potential when the photosensitive member is activated.

FIG. 6 is a diagram showing a main part of an image forming apparatus according to a third embodiment of the present invention.

FIG. 7 is a diagram showing a main part of an image forming apparatus according to a fourth embodiment of the present invention.

FIG. 8 is a diagram showing a main part of an image forming apparatus according to a fifth embodiment of the present invention.

FIG. 9 is a diagram showing an image data processing system in an exposure unit according to a sixth embodiment of the present invention.

FIG. 10 is a graph showing the amount of measured image data.

FIG. 11 is a diagram showing a main part of an image forming apparatus according to a seventh embodiment of the present invention.

[Explanation of symbols]

1 photoconductor 2 charging means 3 exposure means 4 developing means 5, 5A transfer means 6,6A Lubricant application means 7,7A Cleaning means 8 Separation means 9 Fixing means 10 Paper ejection sensor 11 memory 12 Control means 13, 15 Humidity sensor 14 Temperature sensor 16 Operation panel 40 Intermediate transfer body 71 cleaning blade

Continued front page    F-term (reference) 2H005 AA15 AB06 DA07 EA05                 2H027 DA10 DA13 DA14 DA32 DA39                       DA45 DA46 DB01 DC02 DE04                       DE07 DE09 EA09 EB04 EC02                       EC06 EC07 EC15 EC18 EC19                       ED02 ED06 ED17 ED27 ED28                       EE01 EE04 EF09 EK04 FA13                       HB02 HB07 HB16 JA12 JC07                       ZA07                 2H134 GA01 GB02 HA01 HA09 HA13                       HA16 HA17 HB01 HB03 HB16                       HB18 HB19 HD01 HD19 KA05                       KA10 KA16 KA28 KA30 KA33                       KB03 KB04 KB05 KB09 KB14                       KD04 KD08 KF03 KG07 KG08                       KH01 KH04 KJ02 LA01 LA02

Claims (22)

[Claims] 1. An image carrier, image forming means for forming a toner image on the image carrier, transfer means for transferring the toner image on the image carrier to a transfer body, and the image carrier after transfer. In an image forming apparatus having a cleaning unit that cleans with a cleaning blade, the image forming unit forms a toner image using toner having a volume average particle size of 4 to 6 μm, and applies a lubricant to the image carrier. A lubricant applying unit and a control unit for controlling the lubricant applying unit are provided, and the control unit controls the lubricant applying unit so as to increase the application amount according to the progress of the wear degree of the cleaning blade. An image forming apparatus characterized by. 2. The method according to claim 1, further comprising a sheet number counting unit for counting the number of image formed sheets, wherein the control unit controls the lubricant applying unit based on a sheet number counting result of the sheet number counting unit. The image forming apparatus described. 3. A distance measuring means for measuring a traveling distance of the image carrier is provided, and the control means controls the lubricant applying means based on a measurement result of the distance measuring means. The image forming apparatus according to claim 1. 4. An image carrier, image forming means for forming a toner image on the image carrier, transfer means for transferring the toner image on the image carrier to a transfer body, and the image carrier after transfer. In an image forming apparatus having a cleaning unit that cleans with a cleaning blade, the image forming unit forms a toner image using toner having a volume average particle size of 4 to 6 μm, and applies a lubricant to the image carrier. A lubricant applying unit and a control unit for controlling the lubricant applying unit are provided, and the control unit controls the lubricant based on information on the number of images formed from the start to the stop of the image carrier. An image forming apparatus characterized by controlling a coating means. 5. An image carrier, image forming means for forming a toner image on the image carrier, transfer means for transferring the toner image on the image carrier to a transfer body, and the image carrier after transfer. In an image forming apparatus having a cleaning unit that cleans with a cleaning blade, the image forming unit forms a toner image using toner having a volume average particle size of 4 to 6 μm, and applies a lubricant to the image carrier. An image forming apparatus comprising: a lubricant applying unit; a power source for applying a voltage to the lubricant applying unit; and a control unit for controlling the power source to change the voltage. 6. The image according to claim 5, further comprising a sheet number counting unit for counting the number of image formed sheets, wherein the control unit controls the power supply based on a sheet number counting result of the sheet number counting unit. Forming equipment. 7. The distance measuring means for measuring the traveling distance of the image carrier is provided, and the control means controls the power source based on a measurement result of the distance measuring means. The image forming apparatus according to item 1. 8. The environmental humidity detecting means for detecting the environmental humidity, wherein the control means controls the power supply according to the detected humidity. Image forming device. 9. An image carrier, an image forming means for forming a toner image on the image carrier, a transfer means for transferring the toner image on the image carrier to a transfer body, and the image carrier after transfer. In an image forming apparatus having a cleaning unit that cleans with a cleaning blade, the image forming unit forms a toner image using toner having a volume average particle size of 4 to 6 μm, and applies a lubricant to the image carrier. Lubricant applying means, blade temperature detecting means for detecting the temperature of the cleaning blade, and control means for controlling the lubricant applying means, the control means performing the lubrication according to the temperature detected by the blade temperature detecting means. An image forming apparatus characterized by controlling an agent applying means. 10. An image carrier, image forming means for forming a toner image on the image carrier, transfer means for transferring the toner image on the image carrier to a transfer body, and the image carrier after transfer. In an image forming apparatus having a cleaning unit that cleans with a cleaning blade, the image forming unit forms a toner image using toner having a volume average particle size of 4 to 6 μm, and applies a lubricant to the image carrier. A lubricant applying unit, a storage unit humidity detecting unit for detecting the humidity of the transfer member storage unit, and a control unit for controlling the lubricant applying unit are provided, and the control unit is based on the detection result of the storage unit humidity detecting unit. An image forming apparatus is characterized by controlling the lubricant applying means. 11. An image carrier, image forming means for forming a toner image on the image carrier, transfer means for transferring the toner image on the image carrier to a transfer body, and the image carrier after transfer. In an image forming apparatus having a cleaning unit that cleans with a cleaning blade, the image forming unit forms a toner image using toner having a volume average particle size of 4 to 6 μm, and applies a lubricant to the image carrier. Lubricant applying means, transfer body setting means for setting the type of the transfer body, and control means for controlling the lubricant applying means, the control means performing the lubrication based on the setting information of the transfer body setting means. An image forming apparatus characterized by controlling an agent applying means. 12. The image forming apparatus according to claim 11, wherein the transfer body setting unit sets the thickness of the transfer body. 13. An image carrier, image forming means for forming a toner image on the image carrier, transfer means for transferring the toner image on the image carrier to a transfer body, and the image carrier after transfer. An image forming apparatus, comprising: a cleaning unit for cleaning with a cleaning blade, and performing a front surface image forming step of forming an image on a front surface of a transfer body and a back surface image forming step of forming an image on a back surface of the transfer body. Includes a lubricant applying means for applying a lubricant to the image carrier and a control means for controlling the lubricant applying means while forming a toner image using a toner having a volume average particle diameter of 4 to 6 μm. The image forming apparatus is characterized in that the control means controls the amount of lubricant applied in the front surface image forming step and the amount of lubricant applied in the rear surface image forming step. 14. An image carrier, image forming means for forming a toner image on the image carrier, transfer means for transferring the toner image on the image carrier to a transfer body, and the image carrier after transfer. In an image forming apparatus having a cleaning unit that cleans with a cleaning blade, the image forming unit forms a toner image using toner having a volume average particle size of 4 to 6 μm, and applies a lubricant to the image carrier. Lubricant applying means, toner amount measuring means for measuring the amount of toner forming a toner image formed on the image bearing member for each position on coordinates having a direction orthogonal to the moving direction of the image bearing member as an axis. An image forming apparatus comprising: and a control unit, the control unit controlling the lubricant applying unit based on a measurement result of the toner measuring unit. 15. The image forming apparatus according to claim 14, wherein the toner measuring unit measures the amount of the toner by processing image data. 16. An image carrier, image forming means for forming a toner image on the image carrier, transfer means for transferring the toner image on the image carrier to a transfer body, and the image carrier after transfer. In an image forming apparatus having a cleaning unit that cleans with a cleaning blade, the image forming unit forms a toner image using toner having a volume average particle size of 4 to 6 μm, and applies a lubricant to the image carrier. Having a lubricant application means and a control means,
The image forming apparatus, wherein the control unit controls the lubricant applying unit according to a change of a transfer current in the transfer unit. 17. An image carrier, image forming means for forming a toner image on the image carrier, transfer means for transferring the toner image on the image carrier to a transfer body, and the image carrier after transfer. In an image forming apparatus having a cleaning unit that cleans with a cleaning blade, the image forming unit forms a toner image using toner having a volume average particle size of 4 to 6 μm, and applies a lubricant to the image carrier. Having a lubricant application means and a control means,
The image forming apparatus, wherein the control means starts the image forming step after operating the lubricant applying means for a predetermined time in the image formation after replacement of the replacement part in the lubricant applying means. 18. An image carrier, image forming means for forming a toner image on the image carrier, transfer means for transferring the toner image on the image carrier to a transfer body, and the image carrier after transfer. In an image forming apparatus having a cleaning unit that cleans with a cleaning blade, the image forming unit forms a toner image using toner having a volume average particle diameter of 4 to 6 μm, and a conductive cleaning assisting unit and the cleaning assisting unit. An image, characterized in that it has a power supply for applying a voltage to the means and a control means, and the control means controls the power supply at the time of recovery from an abnormal stop to apply a voltage for enhancing the cleaning power of the cleaning auxiliary means. Forming equipment. 19. The image forming means has a sphericity of 0.9.
The image forming apparatus according to any one of claims 1 to 18, wherein a toner image of 4 to 0.98 is used to form a toner image. 20. The image forming unit forms a toner image using polymerized toner.
The image forming apparatus according to claim 1. 21. The lubricant applying means has a solid lubricant supply body and a pressure contact member that is in pressure contact with the lubricant supply body,
The control means controls the coating amount by controlling the pressure between the lubricant supply body and the pressure contact member, according to any one of claims 1 to 4, 9 to 16, 19, and 20. The image forming apparatus according to item. 22. The lubricant applying means has a solid lubricant supply body and a pressure contact member that is in pressure contact with the lubricant supply body,
The image forming according to any one of claims 1 to 4, 9 to 16, 19, and 20, wherein the control unit controls the coating amount by controlling a rotation speed of the pressure contact member. apparatus.