JP3839979B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrophotographic or electrostatic recording image forming apparatus such as a copying machine or a printer.
[0002]
[Prior art]
In an image forming apparatus such as a copying machine or a laser beam printer, a toner image is formed on the surface of a photosensitive drum as an image carrier, and this toner image is transferred to a transfer material such as paper. Thereafter, residual toner remaining on the surface of the photosensitive drum is removed by a cleaning device.
[0003]
Further, in a color copying machine, even in a model equipped with an intermediate transfer member in order to improve the selectivity of a transfer material, untransferred toner remaining on the intermediate transfer member is removed by a cleaning device for the intermediate transfer member.
[0004]
The cleaning device has, for example, a cleaning blade in which an elastic member such as urethane rubber is formed in a plate shape, and the edge of this cleaning blade is brought into contact with the surface of the photosensitive drum with a predetermined pressure and adhered to the surface of the photosensitive drum. The residual toner is scraped off. A cleaning device using this cleaning blade has a relatively simple structure, is small in size, and is advantageous in terms of cost, but has an advantage of excellent toner removal performance, and thus has been widely put into practical use.
[0005]
Also, in high-quality color image forming devices that require high-speed and high-quality images, a simple light pressure type brush cleaner or cleaning is used to reduce vibration and damage to the intermediate transfer member as much as possible. There are some models that have introduced the less type.
[0006]
[Problems to be solved by the invention]
However, in the above-described image forming apparatus, since the cleaning blade is in contact with the surface of the photosensitive drum, with the long-term use of the image forming apparatus, residual toner adheres firmly to the cleaning blade, and so-called filming occurs. And the subsequent image quality is degraded.
[0007]
Further, in recent image forming apparatuses, after image formation is performed on the front surface (first surface) of the transfer material, the transfer material is turned upside down in the image forming apparatus and is transferred again to the back surface (second surface). An image forming apparatus having a so-called double-sided image forming function is often used.
[0008]
In such an image forming apparatus, when a general fixing device configured to pass a transfer material through a nip portion of a pair of rollers is used for fixing a toner image, in order to prevent toner from adhering to the roller, Apply silicone oil to the roller surface. This silicon oil adheres to the transfer material when the toner image on the first surface is fixed, and adheres to the intermediate transfer member when forming the image on the second surface. The silicon oil adhering to the surface of the intermediate transfer member is partially transferred to and adhered to the photosensitive drum in contact with the intermediate transfer member, so that not only image defects due to oil contamination of the intermediate transfer member but also charging defects due to oil contamination of the surface of the photosensitive drum. In addition, there is a problem that a cleaning defect occurs due to mixing with toner present on the edge of the cleaning blade and rubbing through the edge of the cleaning blade.
[0009]
In addition, in order to achieve high image quality with the structure provided with the intermediate transfer member, it is necessary to prevent damage from the cleaning member to the intermediate transfer member as much as possible. Furthermore, cleaner-less operation based on the use of toner having high transfer efficiency is being put into practical use.
[0010]
In this case, the ability to remove the charged product remaining on the intermediate transfer member, the above-mentioned transfer oil, paper dust, dust, etc. inevitably tends to be reduced.
[0011]
Also, if the contact pressure of the member for cleaning the toner on the intermediate transfer member is forcibly increased, damage to the intermediate transfer member will increase, and defects in image formation such as poor conveyance of the intermediate transfer member may become noticeable. is there.
[0012]
In addition, there are models that use auxiliary means such as non-contact charging before cleaning to simplify and lighten the cleaning on the intermediate transfer member. Of course, there is a problem that the deterioration of the rubber material in the machine is promoted and the life of the entire machine is reduced.
[0013]
In addition, deterioration of the electrical performance of the intermediate transfer member due to charging and retention of the electrical memory are factors that hinder image defects and long-term stabilization of image quality.
[0014]
Therefore, the object of the present invention is to prevent the occurrence of filming due to long-term use and the prevention of poor cleaning due to the adhesion of silicon oil during fixing, without the complexity of the structure, and the cleaning property of the simple intermediate transfer member cleaning device. It is an object of the present invention to provide an image forming apparatus that achieves securing simultaneously and prevents deterioration of image quality.
[0015]
[Means for Solving the Problems]
  The above object is achieved by the image forming apparatus according to the present invention.The
[0016]
  In summary,First of the present invention1According to this aspect, the image bearing member having a movable surface, the toner image forming means for forming a toner image on the surface of the image bearing member, and the image bearing member that is always in contact with the surface of the image bearing member. In an image forming apparatus comprising: an intermediate transfer body that transfers a toner image on a body surface; and a transfer unit that transfers a transfer toner image on the intermediate transfer body onto a transfer material.
  When the contact pressure of the intermediate transfer member to the image carrier during image formation is P1, and the contact pressure at the time of non-image formation is P2, P1 = P2> 0 is satisfied, and at the time of non-image formation The intermediate transfer member rotates in a forward direction with the image carrier with a relative speed difference from the image carrier, and has means for detecting temperature and humidity in the image forming apparatus main body. An image forming apparatus is provided that changes the rotational speed of the image carrier or the intermediate transfer member in response to a change in temperature and humidity in the main body of the image forming apparatus.
  First of the present invention2According to this aspect, the image bearing member having a movable surface, the toner image forming means for forming a toner image on the surface of the image bearing member, and the image bearing member that is always in contact with the surface of the image bearing member. In an image forming apparatus comprising: an intermediate transfer body that transfers a toner image on a body surface; and a transfer unit that transfers a transfer toner image on the intermediate transfer body onto a transfer material.
  When the contact pressure of the intermediate transfer member to the image carrier during image formation is P1, and the contact pressure at the time of non-image formation is P2, P1 = P2> 0 is satisfied, and at the time of non-image formation The intermediate transfer member rotates in a forward direction with the image carrier with a relative speed difference from the image carrier, and has means for detecting temperature and humidity in the image forming apparatus main body. An image forming apparatus is provided in which the rotation time of the image carrier or the intermediate transfer member is changed in response to a change in temperature and humidity in the main body of the image forming apparatus.
  First of the present invention3According to this aspect, the image bearing member having a movable surface, the toner image forming means for forming a toner image on the surface of the image bearing member, and the image bearing member that is always in contact with the surface of the image bearing member. In an image forming apparatus comprising: an intermediate transfer body that transfers a toner image on a body surface; and a transfer unit that transfers a transfer toner image on the intermediate transfer body onto a transfer material.
  When the contact pressure of the intermediate transfer member to the image carrier during image formation is P1, and the contact pressure at the time of non-image formation is P2, P1 = P2> 0 is satisfied, and at the time of non-image formation The intermediate transfer member rotates in the forward direction with the image carrier with a relative speed difference from the image carrier, and has means for detecting temperature and humidity in the image forming apparatus main body. An image forming apparatus is provided in which the rotation speed or the rotation time of the image carrier or the intermediate transfer member is changed in response to a change in temperature and humidity in the main body of the forming apparatus.
  First of the present invention4According to this aspect, the image bearing member having a movable surface, the toner image forming means for forming a toner image on the surface of the image bearing member, and the image bearing member that is always in contact with the surface of the image bearing member. In an image forming apparatus comprising: an intermediate transfer body that transfers a toner image on a body surface; and a transfer unit that transfers a transfer toner image on the intermediate transfer body onto a transfer material.
  When the contact pressure of the intermediate transfer member to the image carrier during image formation is P1, and the contact pressure at the time of non-image formation is P2, P1 = P2> 0 is satisfied, and at the time of non-image formation The intermediate transfer member rotates in the forward direction with the image carrier with a relative speed difference from the image carrier, and has means for detecting temperature and humidity in the image forming apparatus main body. An image forming apparatus is provided that changes the rotation speed and rotation time of the image carrier or the intermediate transfer member in response to a change in temperature and humidity in the main body of the forming apparatus.
[0017]
  According to one embodiment of the present invention, during non-image formation, the rotation speed of the image carrier and the intermediate transfer body is higher than the rotation speed during image formation.
  According to another embodiment of the present invention, during the non-image formation, the conveyance rotation of the intermediate transfer member is stopped while the image carrier is rotating. Here, according to another embodiment, during the non-image formation, the rotation speed of the image carrier during the period in which the intermediate transfer member stops carrying rotation is V1, and the rotation speed during image formation is V2. V1> V2.
  According to another embodiment of the present invention, during the non-image formation, the intermediate transfer member is transported and rotated during a period when the rotation of the image carrier is stopped. According to another embodiment, during the non-image formation, the rotation speed of the intermediate transfer member is V3 and the rotation speed of the image transfer is V4 during the period when the rotation of the image carrier is stopped. V3> V4.
  According to another embodiment of the present invention, during non-image formation, the rotation speed of the image carrier during a period in which the intermediate transfer member stops carrying rotation is V1, and the rotation speed during image formation is V2. V1> V2.
  According to another embodiment of the present invention, during the non-image formation, during the period in which the image carrier stops rotating, the conveyance rotation speed of the intermediate transfer member is set to V3, and the conveyance rotation speed during image formation is set to V3. When V4, V3> V4.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
The image forming apparatus according to the present invention will be described below in more detail with reference to the drawings.
[0019]
Example 1
FIG. 1 is a block diagram showing a first embodiment of an image forming apparatus according to the present invention. The image forming apparatus shown in FIG. 1 is a four-color full-color copying machine, and is located inside the image forming apparatus main body (hereinafter referred to as “apparatus main body”) 100 and downstream from the upstream side along the rotational conveyance direction A of the image carrier 1. Four image forming units, that is, a first image forming unit 4a, a second image forming unit, a third image forming unit 4c, and a fourth image forming unit 4d are provided in this order.
[0020]
As shown in FIG. 1, the first to fourth image forming units 4 a to 4 d include a drum-type electrophotographic photosensitive member (hereinafter referred to as “photosensitive drum”) 1 as an image carrier. As the photosensitive drum 1, a photosensitive layer having a carrier generation layer (CGL) and a carrier transport layer (CTL) on the surface of a cylindrical aluminum substrate is coated with a coating 1 and a JIS surface roughening so that the CTL thickness is 40 μm. Rz (10 points average) which is (B0601) was 2 μm or less in the initial state. The photosensitive drum 1 is rotatably supported by the apparatus main body 100 and is rotationally driven in the direction of arrow A at a process speed of 120 mm / sec by a driving unit (not shown). The photosensitive drum 1 having an outer diameter of 80 mm was used.
[0021]
Above the photosensitive drum 1, a primary charger (toner image forming means) 2 is disposed close to the photosensitive drum 1, and the surface of the photosensitive drum 1 is uniformly charged by the primary charger 2. The charged surface of the photosensitive drum 1 is exposed to an optical system (toner image forming unit) disposed above the image forming unit to form an electrostatic latent image, and then exposed to the blank exposure unit 3.
[0022]
Subsequently, the toner in the developer is attached to the electrostatic latent image by the developing devices (toner image forming means) 4a to 4d, and is developed as a toner image. As the developer, a two-component developer mainly composed of silicon toner and ferrite carrier was used.
[0023]
This toner image is pressurized at 5 gr / cm with the photosensitive drum 1 and the linear pressure (the member pressure applied in the thrust direction by the length in the drum thrust direction) applied to the photosensitive drum 1. When the intermediate transfer belt 11, which is an intermediate transfer body that rotates in the forward direction, arrives at a transfer portion that abuts and faces the intermediate transfer belt 11, the intermediate transfer belt is exposed from the surface of the photosensitive drum 1 by the action of an electric field formed by the precharged intermediate transfer belt 11. 11 in the form of electrostatic adsorption.
[0024]
Here, when the contact pressure of the intermediate transfer belt 11 to the photosensitive drum 1 during image formation is P1, and the contact pressure during non-image formation is P2, P1 = P2> 0 is satisfied.
[0025]
In the intermediate transfer belt 11 described above, EPDM rubber, chloroprene rubber, epichlorohydrin rubber, silicon rubber, NBR rubber, or a modified rubber thereof is used as a base layer material. Further, as the surface layer material, a material containing a fluororesin (for example, a material containing PVDF, PTFE, ethylene tetrafluoride, or the like) is used from the viewpoint of high releasability and a low friction coefficient.
[0026]
In this embodiment, as shown in FIG. 2, EPDM rubber is used for the base layer 11a constituting the intermediate transfer belt 11, and the base layer 11a is coated with a paint in which PVDM resin is dispersed to form a surface layer 11b. .
[0027]
The intermediate transfer belt 11 is moved in the direction of arrow B to a primary transfer bias roller 8 facing the photosensitive drum 1, a support roller 9, a facing roller 10 facing the secondary transfer bias roller 12, and a facing roller 19 facing the cleaning blade 16. It is stretched so that it can be rotated.
[0028]
Further, a cleaning blade 16 as a cleaning means for the intermediate transfer belt 11 is brought into contact with the forward transfer direction of the intermediate transfer belt 11 in the forward direction. Note that polyurethane rubber was used as the material of the cleaning blade 16.
[0029]
After the toner image is transferred, the residual toner remaining on the surface of the photosensitive drum 1 that has not been transferred to the transfer material P is scraped off and removed by the cleaning blade 17 of the cleaning device 5, and the residual charge is further removed by the pre-exposure lamp 15. After being removed, it is used for the next image formation.
[0030]
As described above, the photosensitive drum 1 on which the first toner image is formed by the first image forming unit 4a is conveyed and rotated, and the second image forming unit 4b, the third image forming unit 4c, and the fourth image forming unit 4a. As in the case of the first image forming unit 4a, the toner image is multiple developed by the image forming unit 4d. However, the toner colors of the toner images developed in the first to fourth image forming units 4a to 4d are different from each other, and the four color toner images are collectively collected on the intermediate transfer member 11 in the primary transfer bias roller 8 unit. The transfer material P is transferred to the transfer bias roller 12 so as to be synchronized with the toner composite image on the intermediate transfer belt 11, and the toner composite image is collectively transferred to the transfer material P. The transfer material P is conveyed to a fixing unit 14 for fixing a toner image through a transfer material conveyance path 18 and is fixed by receiving heat and pressure from the fixing unit 14 to obtain a copy image.
[0031]
At this time, for example, silicon oil is applied to the surface of the fixing roller of the fixing unit 14 as a release agent so that the toner on the transfer material P does not adhere to the surface of the fixing roller.
[0032]
The transfer material P on which the toner image is formed on the front surface (first surface) passes over the flapper and is discharged onto the paper discharge tray when the image formation is on one side. On the other hand, when the image is formed on both sides, the transfer material P having the toner image fixed on the first side is not discharged to the discharge tray by the switching of the flapper, but is guided to the lower refeed means. It is burned. Then, after the front and back are reversed by the reversing device, the toner image is transferred again to the second surface, and then fixed by the fixing unit 14, and is discharged onto the paper discharge tray through the upper side of the flapper, thereby forming an image. Is completed.
[0033]
Thereafter, the photosensitive drum 1 performs an idle rotation operation three times, and at the same time, the intermediate transfer belt 11 that is in contact with the photosensitive drum 1 in the forward direction also performs a predetermined rotation operation.
[0034]
Here, the rotational process speed of the photosensitive drum 1 was increased from 120 mm / sec to 160 mm / sec in order to generate a rotational speed difference between the photosensitive drum 1 and the intermediate transfer belt 11 which is a characteristic part of the present invention.
[0035]
Due to the difference in relative speed, a rubbing polishing force is generated between the photosensitive drum 1 and the intermediate transfer belt 11, and an operation in which the photosensitive drum 1 and the intermediate transfer belt 11 polish each other is performed. Accordingly, it is possible to remove foreign matters (charged products, paper powder, oil, toner, dust, etc.) that adhere to and accumulate on the surfaces of the photosensitive drum 1 and the intermediate transfer body 11, and achieve high image quality and high stability. I was able to.
[0036]
Incidentally, in this embodiment, the contact linear pressure of the cleaning blade 17 contacting the photosensitive drum 1 is 40 gr / cm and the contact linear pressure of the cleaning belt 16 contacting the intermediate transfer belt 11 is 10 gr / cm. As a result of endurance experiments in an environmental test chamber at 32 ° C. and 75%, image defects (image flow) and oil streak cleaning defects that have been observed due to charged products have occurred at the time of 20,000 sheets. It was confirmed that the good state was maintained even after passing 30,000 sheets. In this experiment, as an endurance mode, evaluation was performed by continuously copying an image with an image ratio of about 25% by A4 size horizontal feed.
[0037]
In this embodiment, the case where the intermediate transfer belt 11 is adopted as the intermediate transfer member has been described. However, as shown in FIG. 3, the cylindrical intermediate transfer drum 20 as shown in FIG. The effect was confirmed. The intermediate transfer drum 20 is endless. By including a rubber, elastomer, or sponge layer in any of the layers, the surface of the intermediate transfer drum 20 can have appropriate elasticity. A device for suppressing an increase in damage to the photosensitive drum 1 as compared with the intermediate transfer body 11 of the system was added.
[0038]
Example 2
Next, a second embodiment of the present invention will be described.
[0039]
The purpose of this embodiment is to improve the polishing ability by utilizing the relative speed difference, which is the main focus of the first embodiment, at a certain number of copies, avoiding the continuous introduction of the sequence of the first embodiment during non-image formation. To achieve high image quality and stability.
[0040]
However, since the number of times of polishing is naturally reduced with respect to the first embodiment, and this reduction must be covered by another means, in this embodiment, the photosensitive drum 1 at the time of non-image formation is used. The rotation process speed is increased to 200 mm / sec from 120 mm / sec during image formation, and at the same time, the rotation process speed of the intermediate transfer belt 11 is increased from 120 / sec to 150 mm / sec. This was achieved by increasing the number of polishings between 11.
[0041]
This embodiment is particularly effective in an image forming apparatus that does not have a double-sided continuous copy version. In the executed sequence, the sequence of this embodiment is input at a rate of once every 5,000 copies, which is unnecessary. Thus, it was attempted to extend the life of the photosensitive drum 1 and the intermediate transfer belt 11 and to extend the life of the drum cleaning blade 17 and the intermediate transfer member cleaning blade 16 without increasing the number of times of polishing.
[0042]
Incidentally, in the prior art, image flow (image blur due to charging failure) occurred at 32 ° C. and 75% under a high temperature and high humidity environment, but in this embodiment, A4 size side feed on one side, It was confirmed that the cleaning performance was maintained up to 35,000 sheets by intermittent intermittent copying of one sheet.
[0043]
Example 3
Next, a third embodiment of the present invention will be described.
[0044]
The purpose of this embodiment is the same as that of the second embodiment described above. However, this embodiment is particularly effective for an image forming apparatus that uses toner on the photosensitive drum 1 that is very strong and easily melts. is there.
[0045]
As an experimental evaluation of this example, it is an external additive in the toner used in the first and second examples (particularly, it is used as a cleaning aid to serve as a lubricant and an abrasive). In the system in which twice the amount of strontium titanate was added, a strong fusing substance (commonly called filming) was generated in the non-image forming portion as the number of copies was accumulated. The number of generated sheets was 10,000 or less in a high temperature and high humidity 32 ° C. and 75% environment.
[0046]
For this reason, in order to make the abrasiveness stronger than that of the second embodiment, the intermediate transfer drum 20 is stopped before image formation and during non-image formation after image formation, and only the photosensitive drum 1 has a process speed of 120 mm / sec. Thus, the polishing force between the photosensitive drum and the intermediate transfer member 20 in the first and second embodiments or more was generated, and the filming firmly adhered on the photosensitive drum 1 could be removed. At this time, it was single-sided, A4 size lateral feed, and one-sheet intermittent copy.
[0047]
In the present embodiment, a sequence that operates every 5,000 sheets in consideration of avoiding damage to the photosensitive drum 1 and the intermediate transfer drum 20 is used.
[0048]
Example 4
Next, a fourth embodiment of the present invention will be described.
[0049]
This embodiment further improves the effects of the third embodiment, and particularly corresponds to a high-speed color copier having a higher process speed than the image forming apparatus described in the third embodiment.
[0050]
The present embodiment was applied to a high speed copying machine having a process speed as high as 160 mm / sec. A drum with a diameter of 180 mm was used corresponding to the increase in speed.
[0051]
As an experimental evaluation, the same evaluation mode as in the third embodiment was performed. In the conventional technique, filming was observed when the number of copies was 3,000, but in this embodiment, during non-image formation. The process speed of the photosensitive drum 1 is set to V2 = 180 mm / sec, which is larger than the process speed at the time of image formation (V1 = 120 mm / sec), and the intermediate transfer drum 20 is stopped more firmly than in the third embodiment. The attached filming can be removed.
[0052]
Incidentally, the sequence of this embodiment was introduced every 2000 sheets, and the copy number target of 10,000 sheets could be achieved. At this time, it was A4 size lateral feed and 1 sheet intermittent copy.
[0053]
Further, as a form in which exactly the same effect has been confirmed, in a system in which the intermediate transfer member that is in contact with the photosensitive drum 1 is the intermediate transfer drum 20, the photosensitive drum 1 is stopped and the intermediate transfer is performed during non-image formation. Even when the process speed of the drum 20 is set to V4 = 180 mm / sec, which is larger than the process speed at the time of image formation (V3 = 120 mm / sec), it is possible to obtain substantially the same effect as described above. The images used were those with a duty ratio of 25%.
[0054]
Here, when the photosensitive drum 1 is stopped rotating during non-image formation, V3> V4 when the conveyance rotation speed of the intermediate transfer drum 20 is V3 and the conveyance rotation speed during image formation is V4. It is.
[0055]
Example 5
Next, a fifth embodiment of the present invention will be described.
[0056]
The purpose of the present embodiment is to suppress the occurrence of image defects particularly in an image forming apparatus of an image forming apparatus which has a process design in which the external additive component in the toner is reduced so as to reduce the occurrence of filming and the like. The main focus is to do.
[0057]
Reducing external additive components (especially abrasives) in the toner suppresses damage to the photoreceptor (durability, rubbing scratches, etc.) and delays the occurrence of image defects such as vertical defects due to scratches. However, on the other hand, the amount of shaving of the photoconductor is reduced, causing a reduction in the removal capability of the charged product that hinders the charging performance of the surface of the photoconductor, especially when the charged product is at high temperature and high humidity. The water absorption phenomenon in the case leads to a reduction in the charge holding ability of the photosensitive drum, and causes an image defect called so-called image flow (image blur).
[0058]
Here, in this embodiment, as an image flow countermeasure, a polishing power-up sequence between the photosensitive drum 1 and the intermediate transfer belt 11 found in the above-described first embodiment and the like is incorporated particularly in a high temperature and high humidity environment. In order to improve the polishing power over a sequence other than in a high-temperature and high-humidity environment, a sequence for changing the polishing power in conjunction with the environmental conditions in the apparatus is introduced. On the contrary, the polishing force that does not require much polishing force, for example, in a low temperature and low humidity environment, prevents the polishing force from operating more than necessary, and unnecessarily decreases the life of the members around the photosensitive drum 1. I tried not to.
[0059]
As an embodiment, environmental conditions are divided into three sections, I (in-machine temperature 20 ° C. to less than 30 ° C., humidity 10% to less than 60%), II (in-machine temperature 30 ° C. to less than 45 ° C., humidity 60% to 80% %) And III (in-machine temperature 45 ° C. or higher, humidity 80% or higher). Other combinations were assigned to categories with humidity values.
[0060]
Under the environmental conditions of Category I, the process speed during non-image formation of the photosensitive drum 1 in the first example was 140 mm / sec. In Section II, the sequence was the same as that in the first example. In section III, the process speed of the photosensitive drum 1 during non-image formation of the photosensitive drum 1 in the first embodiment was set to 180 mm / sec. This makes it possible to increase the polishing force between the photosensitive drum 1 and the intermediate transfer belt 11 in conjunction with environmental conditions for an image flow that is likely to occur due to high temperature and high humidity, and an efficient image quality stabilization sequence. It became possible to build up.
[0061]
Also, the same effect as described above could be achieved by creating a sequence corresponding to different environmental conditions.
[0062]
Corresponding to the environmental division in the image forming apparatus described above, in division I, the rotational speed of the photosensitive drum 1 in the first embodiment was set to three. In Category II, the rotational speed of the photosensitive drum 1 in the first embodiment was set to 4 rotations. In section III, the rotational speed of the photosensitive drum 1 in the first embodiment was set to 5 rotations.
[0063]
As described above, the same effect as described above is achieved by making the number of rotations of the photosensitive drum 1, that is, the time of contact and polishing with the intermediate transfer belt, correspond to the environmental conditions.
[0064]
Incidentally, according to the conventional example, in a high-temperature and high-humidity environment or at 32 ° C./75%, the amount of the external additive strontium titanate in the toner is 0.2% (weight%). In the case of the number of copies, the image flow occurred when the power was turned on at the start of work, but both the image flow of 20,000 or more in both cases due to the increase in the relative speed difference and the rotation speed of the photosensitive drum (the polishing time increased) in this embodiment. We were able to confirm that At this time, A4 landscape feed, image duty ratio 6%, and one-sheet intermittent copy were performed.
[0065]
Here, in accordance with the environment, the rotational speed or the rotational speed of the photosensitive drum 1 during non-image formation is controlled by a control circuit (not shown). As a control transmission system, conditions detected by a temperature / humidity sensor disposed in a paper feed section of the image forming apparatus (not shown) are converted into signals and transmitted to the control circuit arithmetic circuit described above. It is sent to a drum drive motor control circuit to control the rotation of the photosensitive drum.
[0066]
【The invention's effect】
  As is apparent from the above description, according to the present invention, when the contact pressure of the intermediate transfer member to the image carrier during image formation is P1, and the contact pressure during non-image formation is P2. Further, P1 = P2> 0 is satisfied, the intermediate transfer member rotates in a forward direction with respect to the image carrier with a relative speed difference with the image carrier during non-image formation, and,
(1)Means for detecting temperature and humidity in the image forming apparatus main body, and at the time of non-image formation, the rotational speed of the image carrier or the intermediate transfer body is adjusted in response to changes in temperature and humidity in the image forming apparatus main body. Change or
(2) It has means for detecting the temperature and humidity in the image forming apparatus main body, and the rotation time of the image carrier or the intermediate transfer body is set in response to the change in temperature and humidity in the image forming apparatus main body during non-image formation. Change or
(3) Having means for detecting the temperature and humidity in the image forming apparatus main body, and at the time of non-image formation, the rotation speed of the image carrier or intermediate transfer body in accordance with the change in temperature and humidity in the image forming apparatus main body or Change the rotation time or
(4) Having means for detecting the temperature and humidity in the image forming apparatus main body, and at the time of non-image formation, the rotational speed of the image carrier or intermediate transfer body in accordance with the change in temperature and humidity in the image forming apparatus main body Change the rotation time,
By adopting a structure, without complicated structures, it is possible to prevent filming caused by long-term use and to prevent cleaning failure due to adhesion of silicon oil during fixing, and to ensure cleaning performance in a simple intermediate transfer member cleaning device. At the same time, it is possible to prevent deterioration of image quality.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram illustrating a multicolor image forming apparatus according to first, second, and fifth embodiments.
2 is a partial enlarged cross-sectional view showing an intermediate transfer belt of the multicolor image forming apparatus of FIG. 1. FIG.
FIG. 3 is a schematic configuration diagram illustrating a multicolor image forming apparatus according to third and fourth embodiments.
[Explanation of symbols]
1 Photosensitive drum (image carrier)
11 Intermediate transfer belt (intermediate transfer member)
12 Transfer means
20 Intermediate transfer drum (intermediate transfer member)

Claims (11)

An image carrier having a movable surface, a toner image forming means for forming a toner image on the surface of the image carrier, and a toner image on the surface of the image carrier while being in constant contact with the surface of the image carrier. In an image forming apparatus comprising: an intermediate transfer body to be transferred; and transfer means for transferring a transfer toner image on the intermediate transfer body onto a transfer material.
When the contact pressure of the intermediate transfer member to the image carrier during image formation is P1, and the contact pressure at the time of non-image formation is P2, P1 = P2> 0 is satisfied, and at the time of non-image formation The intermediate transfer member rotates in a forward direction with the image carrier with a relative speed difference from the image carrier, and has means for detecting temperature and humidity in the image forming apparatus main body. An image forming apparatus characterized in that the rotational speed of the image carrier or the intermediate transfer member is changed in response to a change in temperature and humidity in the main body of the image forming apparatus. An image carrier having a movable surface, a toner image forming means for forming a toner image on the surface of the image carrier, and a toner image on the surface of the image carrier while being in constant contact with the surface of the image carrier. In an image forming apparatus comprising: an intermediate transfer body to be transferred; and transfer means for transferring a transfer toner image on the intermediate transfer body onto a transfer material.
When the contact pressure of the intermediate transfer member to the image carrier during image formation is P1, and the contact pressure at the time of non-image formation is P2, P1 = P2> 0 is satisfied, and at the time of non-image formation The intermediate transfer member rotates in a forward direction with the image carrier with a relative speed difference from the image carrier, and has means for detecting temperature and humidity in the image forming apparatus main body. An image forming apparatus, wherein the rotation time of the image carrier or the intermediate transfer member is changed in response to a change in temperature and humidity in the main body of the image forming apparatus. An image carrier having a movable surface, a toner image forming means for forming a toner image on the surface of the image carrier, and a toner image on the surface of the image carrier while being in constant contact with the surface of the image carrier. In an image forming apparatus comprising: an intermediate transfer body to be transferred; and transfer means for transferring a transfer toner image on the intermediate transfer body onto a transfer material.
When the contact pressure of the intermediate transfer member to the image carrier during image formation is P1, and the contact pressure at the time of non-image formation is P2, P1 = P2> 0 is satisfied, and at the time of non-image formation The intermediate transfer member rotates in the forward direction with the image carrier with a relative speed difference from the image carrier, and has means for detecting temperature and humidity in the image forming apparatus main body. An image forming apparatus, wherein the rotation speed or the rotation time of the image carrier or intermediate transfer member is changed in response to a change in temperature and humidity in the main body of the forming apparatus. An image carrier having a movable surface, a toner image forming means for forming a toner image on the surface of the image carrier, and a toner image on the surface of the image carrier while being in constant contact with the surface of the image carrier. In an image forming apparatus comprising: an intermediate transfer body to be transferred; and transfer means for transferring a transfer toner image on the intermediate transfer body onto a transfer material.
When the contact pressure of the intermediate transfer member to the image carrier during image formation is P1, and the contact pressure at the time of non-image formation is P2, P1 = P2> 0 is satisfied, and at the time of non-image formation The intermediate transfer member rotates in the forward direction with the image carrier with a relative speed difference from the image carrier, and has means for detecting temperature and humidity in the image forming apparatus main body. An image forming apparatus, wherein a rotation speed and a rotation time of the image carrier or the intermediate transfer body are changed in response to a change in temperature and humidity in the main body of the forming apparatus. The non-image-forming, the rotation speed of the image bearing member and the intermediate transfer member, one of the image forming apparatus of claims 1 to 4 is greater than the rotational speed at the time of image formation. The non-image-forming, during the rotation of the image bearing member The image forming apparatus according to claim 1 to 4 conveying the rotation of the intermediate transfer body is stopped. The non-image-forming, the rotation speed of the image bearing member of the period in which the intermediate transfer member has stopped conveyance rotation V1, when the rotational speed of the image formation was V2, according to claim 6 which is V1> V2 Image forming apparatus. The non-image-forming, during a period in which the image bearing member has stopped rotating, one of the image forming apparatus of claim 1, wherein the intermediate transfer body is conveyed rotates. 5. In a period in which rotation of the image carrier is stopped during non-image formation, V3> V4, where V3 is a conveyance rotation speed of the intermediate transfer member and V4 is a conveyance rotation speed during image formation. 8 is an image forming apparatus; 2. When V1 is a rotation speed of the image carrier and V2 is a rotation speed during image formation when the intermediate transfer member is stopped from rotating during non-image formation, V1> V2 . The image forming apparatus according to any one of 4 . 5. In a period in which rotation of the image carrier is stopped during non-image formation, V3> V4, where V3 is a conveyance rotation speed of the intermediate transfer member and V4 is a conveyance rotation speed during image formation. The image forming apparatus of any one of 1-4 .

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