JP2002258626A - Image forming device - Google Patents

Abstract

(57) [Problem] To provide an image forming apparatus capable of cleaning a fiducial mark without providing a new member and having excellent cost and quality stability. SOLUTION: An intermediate transfer member 501 capable of transferring a visible image formed on an image carrier 100, and a brush member 505 for applying or cleaning a lubricant capable of coming into contact with and separating from an image transfer surface of the intermediate transfer member 501. A reference mark 519 outside the image transfer area on the image transfer surface of the intermediate transfer body 501;
In the image forming apparatus that controls image formation based on a detection signal from the detection unit 803, a contact area of the brush member 505 with respect to the intermediate transfer body 501 is determined by a reference mark 519. An image forming apparatus is proposed, wherein the range includes the provided portion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a printer, and a facsimile, and more particularly, to an image forming apparatus using an intermediate transfer member.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus using a belt-shaped member as an intermediate transfer member has been known. In such an image forming apparatus, a toner image formed on an image carrier is transferred to a belt-shaped intermediate transfer member, and the toner image on the belt-shaped intermediate transfer member is transferred to a transfer member such as transfer paper (recording paper). You. Further, in an image forming apparatus in which a color image can be formed by using a multicolor toner, the toner image formed on the image carrier is prevented from being displaced with respect to the intermediate transfer body including a belt-shaped member. A reference mark made of a sheet-like reflective member is attached to the outside of the image transfer area of the intermediate transfer body in order to transfer the image over multiple times, and the image forming operation is controlled based on the detection signal of the detection means for detecting the reference mark. Some are configured to do so.

However, in the image forming apparatus, if the reference mark is contaminated by scattered toner in the apparatus, dust from the outside air, dust, etc., the detection means may not be able to detect the reference mark accurately. In such a case,
In particular, at the time of color image formation using a multicolor toner, the transfer timing from the image carrier to the intermediate transfer member is shifted for each color, resulting in a color-shifted image. An image having a color shift has a problem that the image appears blurred, color reproducibility is reduced, and image quality is significantly reduced. For this reason, in this type of image forming apparatus, it is necessary to appropriately clean the reference mark before the reference mark becomes undetectable due to dirt, but it is necessary to provide a cleaning member only for cleaning the reference mark. However, there is a problem in that a large burden is imposed in terms of cost, and it is not possible to cope with sudden contamination of the fiducial mark by relying on cleaning by a technician such as a service engineer for regular maintenance.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned problems.
An object of the present invention is to provide an image forming apparatus which can clean a reference mark without providing a new member, and is excellent in cost and quality stability.

[0005]

Means for Solving the Problems In order to achieve the above object, the invention according to claim 1 comprises: an intermediate transfer member capable of transferring a visible image formed on an image carrier; A brush member for applying or cleaning a lubricant that can be brought into contact with or separated from the image transfer surface, a reference mark outside the image transfer area of the image transfer surface of the intermediate transfer body, and detection means for detecting the reference mark An image forming apparatus that controls an image forming operation based on a detection signal from a detecting unit.
The image forming apparatus is configured such that the contact range of the brush member with the intermediate transfer member is a range including a portion where the reference mark is provided. According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, when the intermediate transfer member is stopped,
An image forming apparatus is provided in which a reference mark is stopped at a contact position of a brush member, and the brush member is kept in contact with the intermediate transfer member. The invention described in claim 3 is the invention described in claim 1 or 2
Wherein the blade member for cleaning the intermediate transfer member is provided, and the blade member portion corresponding to the reference mark portion has a shape that does not contact the reference mark.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an electrophotographic color copying machine (hereinafter referred to as "color copying machine") as an image forming apparatus will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of an image forming unit which is a main part of the color copying machine according to the embodiment. The color copying machine includes, in addition to the image forming unit shown in FIG. 1, a color image reading unit (hereinafter, referred to as a “color scanner”), a paper feeding unit, and a control unit that controls the driving of these units.

A color scanner reads color image information of a document for each color separation light of, for example, red, green, and blue (hereinafter, referred to as “R”, “G”, and “B”), and outputs an electrical image signal. Convert to Then, based on the intensity levels of the R, G, and B color separation image signals obtained by this color scanner, a color conversion process is performed by an image processing unit (not shown), and black, cyan, magenta, and yellow (hereinafter, respectively) “Bk”, “C”, “M”, “Y”) are obtained.

The image forming section shown in FIG. 1 includes a photosensitive drum 100 as an image carrier and a charger 2 as a charging unit.
00, a photoconductor cleaning device 300 including a cleaning blade and a fur brush, a writing optical unit (not shown) as an exposure unit, a revolver development unit 400 as a development unit, an intermediate transfer unit 500, a secondary transfer unit 600, and a fixing roller pair 701. And a fixing unit 700 using the same. The photoreceptor drum 100 rotates counterclockwise as indicated by the arrow in the figure, and around the charger 100, the photoreceptor cleaning device 300, the selected developing machine of the revolver developing unit 400, and the intermediate transfer unit 500. And an intermediate transfer belt 501 as an intermediate transfer member.

The writing optical unit converts the color image data from the color scanner into an optical signal, and applies a laser beam corresponding to the image of the document on the surface of the photosensitive drum 100 uniformly charged by the charger 200. Light L
To perform optical writing to form an electrostatic latent image on the surface of the photosensitive drum 100. The writing optical unit includes, for example, a semiconductor laser as a light source, a laser emission drive control unit, a polygon mirror and its rotation motor, f / θ
It can be constituted by a lens, a reflection mirror or the like.

Also, the revolver developing unit 400
B developer 401 using k toner, C developer 402 using C toner, M developer 403 using M toner, Y
The image forming apparatus includes a Y developing device 404 using toner, a developing revolver driving unit that rotates the entire unit counterclockwise, and the like. Each of the developing machines 401 to 404 installed in the revolver developing unit 400 is a developing device as a developing material carrier which rotates by bringing a spike of the developing material into contact with the surface of the photosensitive drum 100 in order to develop an electrostatic latent image. Sleeve and
It comprises a developer paddle that rotates to pump up and agitate the developer, and a developing sleeve drive unit that rotates the developing sleeve clockwise as indicated by the arrow. In this embodiment, the toner in each of the developing devices 401 to 404 is negatively charged by stirring with the ferrite carrier, and a negative DC voltage is applied to each developing sleeve by a developing bias power source (not shown) as a developing bias applying unit. Vdc
A developing bias voltage in which an AC voltage Vac (AC component) is superimposed on the (DC component) is applied, and each developing sleeve is biased to a predetermined voltage with respect to the metal base layer of the photosensitive drum 100.

In a stand-by state of the main body of the color copying machine, the revolver developing unit 400 is stopped at the home position where the Bk developing machine 401 is located at the developing position, and when the copy start key is pressed, the original starts reading image data. Then, based on the color image data, the optical writing by the laser beam L, that is, the formation of the electrostatic latent image starts (hereinafter, referred to as an electrostatic latent image).
The electrostatic latent image based on the Bk image data is called “Bk electrostatic latent image”. The same applies to C, M, and Y). In order to enable development from the front end of the Bk electrostatic latent image, before the front end of the electrostatic latent image reaches the Bk development position, the rotation of the Bk developing sleeve is started to convert the Bk electrostatic latent image into Bk toner. Develop with. And
Thereafter, the developing operation of the Bk electrostatic latent image is continued, but when the trailing end of the Bk electrostatic latent image passes the Bk developing position, the revolver developing unit is immediately operated until the next color developing machine comes to the developing position. 400 rotates. This is completed at least before the leading end of the electrostatic latent image based on the next image data reaches the developing position.

The intermediate transfer unit 500 includes an intermediate transfer belt 501 which is an intermediate transfer member stretched over a plurality of rollers described later. This intermediate transfer belt 50
1, a secondary transfer belt 601 as a transfer material carrier of the secondary transfer unit 600, a secondary transfer bias roller 605 as a secondary transfer charge applying unit, and a belt cleaning blade 504 as an intermediate transfer body cleaning unit. ,
A lubricant application brush 505 serving as a lubricant application means is disposed so as to face the lubricant application brush 505. This intermediate transfer belt 50
Reference numeral 1 is stretched around a primary transfer bias roller 507, a belt drive roller 508, a belt tension roller 509, a secondary transfer opposed roller 510, a cleaning opposed roller 511, and an earth roller 512 as primary transfer charge applying means. . Each roller is formed of a conductive material, and each roller other than the primary transfer bias roller 507 is grounded.

The primary transfer bias roller 507 is supplied with a primary transfer power supply 801 controlled by a constant current or a constant voltage.
A transfer bias controlled at a predetermined current or voltage according to the number of superimposed toner images is applied. The intermediate transfer belt 501 is driven by a drive motor (not shown) in a direction indicated by an arrow.
8 is driven in the direction of the arrow. The intermediate transfer belt 501 is made of a semiconductor or an insulator and has a single-layer or multilayer structure. A reference mark 519 for detecting the position of the belt is provided at a part of the end of the image transfer surface of the intermediate transfer belt 501. In order to detect the reference mark 519, a mark sensor 803 is attached to a stationary member in a predetermined passage area where the reference mark 519 passes. As the mark sensor 803, a reflection type photo sensor is used. A reflective seal piece and a reference mark 519 are attached to a part of the intermediate transfer belt 501, and the reference mark 51 is applied from a low-reflective surface of the belt member by a reflective photosensor.
9 or a change from the reference mark 519 to the surface of the intermediate transfer belt 501 with low reflectivity.

A lubricant applying brush 505 grinds a plate-shaped lubricant 506 of zinc stearate as a lubricant.
The polished fine particles are applied to the intermediate transfer belt 501. The lubricant application brush 505 is also configured to be adjacent to the intermediate transfer belt 501, and is controlled so as to contact the intermediate transfer belt 501 at a predetermined timing. The axial length of the lubricant application brush 505 is not limited to the image transfer area of the intermediate transfer belt 501,
The length is such that it covers the area of the reference mark 519 (see FIG. 2). Accordingly, when the lubricant applying brush 505 applies the lubricant to the intermediate transfer belt 501, the lubricant also serves to clean the reference mark 519.

When the rotation of the intermediate transfer belt 501 is stopped, the intermediate transfer belt 501 is constantly moved after the mark detection sensor 803 detects a mark.
5 to be stopped. At that time,
The lubricant applying brush 505 is kept in contact with the intermediate transfer belt 501. Of course, when stopping the intermediate transfer belt 501 at the end of the image forming job, the intermediate transfer belt 5
Since the operation of applying the lubricant to 01, that is, the operation of cleaning the reference mark 519, is stopped, the reference mark 519 is protected under the lubricant application brush 519 in a cleaned state. This makes it possible to prevent dirt from sticking to the reference mark 519 before the machine stops for a long time. Further, the belt cleaning blade 504 includes an intermediate transfer member 501.
And has a function of removing unnecessary residual toner from the intermediate transfer body 501. The axial length of the belt cleaning blade 504 is sufficient if the image transfer area of the intermediate transfer body 501 can be covered with a margin of several [mm] to several tens [mm], and the area of the reference mark 519 needs to be in contact. There is no. In particular, as described above, the fiducial mark 51
In the case where a seal piece is used for the reference mark 9, the reference mark 519 is prevented from being peeled off by the belt cleaning blade 504, and the belt cleaning blade 504 is entangled with the reference mark 519. In terms of prevention, it is preferable that the belt cleaning blade 504 has a shape that does not contact the reference mark 519 (see FIG. 3).

The secondary transfer unit 600 includes a secondary transfer belt 601 stretched over three support rollers 602, 603, and 604, and a stretched portion between the support rollers 602 and 603 of the intermediate transfer belt 501 is formed. The secondary transfer opposing roller 510 can be pressed against the roller. One of the three support rollers 602, 603, and 604 is a driving roller that is rotationally driven by a driving unit (not shown), and the driving roller drives the secondary transfer belt 601 in a direction indicated by an arrow in the drawing. The secondary transfer bias roller 605 is
A secondary transfer means, which is disposed so as to sandwich the intermediate transfer belt 501 and the secondary transfer belt 601 between the secondary transfer opposing roller 510 and a secondary transfer power source 8 controlled at a constant current.
02, a transfer bias of a predetermined current is applied. Further, the supporting roller 602 and the secondary transfer bias roller 605 are arranged such that the secondary transfer belt 601 and the secondary transfer bias roller 605 can take a position where the secondary transfer belt 601 and the secondary transfer bias roller 605 are pressed against the secondary transfer opposed roller 510 and a position where the secondary transfer bias roller 605 is separated. An unillustrated separation / contact mechanism that is driven in the direction of the arrow is provided. The secondary transfer belt 601 and the support roller 602 at the separated position are shown by two-dot chain lines in FIG.

Reference numeral 650 denotes a registration roller pair, which is an intermediate transfer belt 501 and a secondary transfer belt 6 sandwiched between a secondary transfer bias roller 605 and a secondary transfer opposing roller 510.
01, the transfer paper P which is a transfer material at a predetermined timing.
Send. Fixing roller pair 70 of secondary transfer belt 601
A transfer sheet discharging charger 606 serving as a transfer material discharging unit and a belt discharging charger 607 serving as a transfer material carrier discharging unit are provided on a portion stretched around the first support roller 603.
Are opposed to each other. A cleaning blade 608, which is a transfer material carrier cleaning unit, is in contact with a portion of the secondary transfer belt 601 that is stretched around the lower support roller 604 in the drawing.

The transfer paper discharging charger 606 discharges the electric charges held in the transfer paper so that the transfer paper can be satisfactorily separated from the secondary transfer belt 601 by the strength of the transfer paper itself. is there. The belt static elimination charger 607 eliminates electric charges remaining on the secondary transfer belt 601. The cleaning blade 6
Reference numeral 08 denotes a device that removes and adheres to the surface of the secondary transfer belt 601 for cleaning.

In the color copying machine constructed as described above, when the image forming cycle is started, the photosensitive drum 1
Reference numeral 00 denotes a counterclockwise rotation indicated by an arrow by a drive motor (not shown), and the intermediate transfer belt 501 is rotated clockwise by an arrow by a belt driving roller 508. As the intermediate transfer belt 501 rotates, primary transfer is performed by a transfer bias by a voltage applied to the primary transfer bias roller 507 to form a Bk toner image, a C toner image, an M toner image, and a Y toner image. Then, a toner image is finally formed on the intermediate transfer belt 501 in the order of Bk, C, M, and Y. For example, Bk toner image formation is performed as follows. The charging charger 200 uniformly charges the surface of the photosensitive drum 100 to a predetermined potential with negative charges by corona discharge. Then, raster exposure using laser light is performed by a writing optical unit (not shown) based on the Bk color image signal. When this raster image is exposed, in the exposed portion of the surface of the photosensitive drum 100 that is initially uniformly charged, the charge proportional to the amount of exposure light disappears, and a bk electrostatic latent image is formed.

When the negatively charged Bk toner on the Bk developing roller of the Bk developing device 401 comes into contact with the Bk electrostatic latent image, toner adheres to a portion of the photosensitive drum 100 where the charge remains. Instead, the toner is attracted to a portion having no charge, that is, an exposed portion, and a Bk toner image similar to the electrostatic latent image is formed. The Bk toner image formed on the photosensitive drum 100 is transferred onto the surface of the intermediate transfer belt 501 that is driven at a constant speed in a state of contact with the photosensitive drum 100. Hereinafter, the transfer of the toner image from the photosensitive drum 100 to the intermediate transfer belt 501 is referred to as “belt transfer”. A small amount of untransferred residual toner remaining on the surface of the photoconductor drum 100 after the belt transfer is cleaned by the photoconductor cleaning device 300 in preparation for reuse of the photoconductor drum 100. On the photosensitive drum 100 side, the process proceeds to the C image forming step after the Bk image forming step, and reading of the C image data by the color scanner starts at a predetermined timing. A C electrostatic latent image is formed on the surface.

After the trailing end of the previous Bk electrostatic latent image has passed and before the leading end of the C electrostatic latent image has arrived, the rotation operation of the revolver developing unit 400 is performed, and the C developing device 402 is set to the development position, and the C electrostatic latent image is developed with the C toner. Thereafter, the development of the C electrostatic latent image area is continued, but when the rear end of the C electrostatic latent image passes, the revolver developing unit rotates as in the case of the Bk developing machine 401, and Is moved to the developing position. This is also completed before the leading end of the next M electrostatic latent image reaches the developing position. Note that, for the M and Y image forming steps, the respective color image data reading,
The operations of forming and developing the electrostatic latent image are the same as those of the above-described steps Bk and C, and thus the description thereof is omitted. On the intermediate transfer belt 501, Bk, which are sequentially formed on the photosensitive drum 100,
The C, M, and Y toner images are sequentially aligned and transferred to the same surface by image forming control based on a detection signal of the reference mark 519. As a result, a toner image in which a maximum of four colors are superimposed on the intermediate transfer belt 501 is formed.

At the time when the image forming operation is started, the transfer paper P is fed from a paper feed unit such as a transfer paper cassette or a manual feed tray (not shown) and stands by at the nip of the pair of registration rollers 650. When the leading end of the toner image on the intermediate transfer belt 501 approaches the secondary transfer portion where the nip is formed by the secondary transfer opposing roller 510 and the secondary transfer bias roller, the leading end of the transfer paper P is just the leading end of the toner image. The registration roller pair 650 is driven so as to match the registration of the transfer sheet P and the toner image. Then, the transfer paper P is superimposed on the toner image on the intermediate transfer belt 501 and passes through the secondary transfer portion. At this time, 2
The secondary transfer bias roller 60 is driven by the secondary transfer power source 802
The four-color superimposed toner image on the intermediate transfer belt 501 is collectively transferred onto the transfer paper by the transfer bias caused by the voltage applied to the transfer belt 5. The transfer paper P is neutralized when passing through a portion facing the transfer paper neutralization charger 606 disposed downstream of the secondary transfer portion in the moving direction of the secondary transfer belt 601, and is separated from the secondary transfer belt 601. Fixing roller pair 7
Sent to 01. The toner image is fused and fixed at the nip portion of the pair of fixing rollers 701, sent out of the apparatus body by a pair of discharge rollers (not shown), and stacked face-up on a copy tray (not shown) to obtain a full-color copy.

On the other hand, the photosensitive drum 100 after the belt transfer
Is cleaned by the photoreceptor cleaning device 300 and is uniformly discharged by a discharge lamp (not shown). Further, the toner remaining on the surface of the intermediate transfer belt 501 after the transfer of the toner image onto the transfer paper P is cleaned by a belt cleaning blade 504 pressed against the intermediate transfer belt 501 by a separation / contact mechanism (not shown).
At the same time as the belt cleaning operation, the lubricant application brush 505 is pressed against the intermediate transfer belt 501 and rotated to perform lubricant application and cleaning of the reference mark. At the end of all image forming operations, the intermediate transfer belt 501 is stopped at a position where the reference mark 519 contacts the lubricant application brush 505, and the lubricant application brush maintains the contact state.

Here, at the time of the repeat copy, the operation of the color scanner and the image formation on the photosensitive drum 100 are as follows.
After the fourth color (Y) image forming process of the first sheet, the process proceeds to the second color (Bk) image forming process at a predetermined timing. Further, the intermediate transfer belt 501 transfers the second Bk toner image to the area of the front surface cleaned by the belt cleaning blade 504, following the batch transfer process of the first four-color superimposed toner image onto the transfer paper. Is transferred to the belt. Thereafter, the operation is the same as that of the first sheet. The above is the copy mode for obtaining a four-color full-color copy. However, in the three-color copy mode and the two-color copy mode, the same operation is performed for the designated color and the number of times. In the case of the single color copy mode,
Until the predetermined number of sheets is completed, the revolver developing unit 4
Only the developing device of the predetermined color No. 00 is set in the developing operation state, and the copying operation is performed with the belt cleaning blade 504 and the lubricant application brush 505 kept pressed against the intermediate transfer belt 501.

Next, a more specific embodiment of the color copying machine according to the embodiment will be described. As the intermediate transfer belt 501, an intermediate transfer belt having a thickness of 0.15 mm, a width of 368 mm, and an inner peripheral length of 565.5 mm was used, and the moving speed of the intermediate transfer belt 501 was set to 200 mm / sec. The surface layer 501a of the intermediate transfer belt 501 is formed of an insulating layer having a thickness of about 1 μm, and the intermediate layer 501b is formed of PV.
An insulating layer made of DF (polyvinylidene fluoride) having a thickness of about 75 μm (volume resistivity: about 10 ¹³ Ωcm)
The base layer 501c is made of PVDF (polyvinylidene fluoride)
And a medium resistance layer (volume resistivity: 10 ⁸ to 10 ¹¹ Ωcm) of about 75 μm in thickness and made of titanium oxide.

When the volume resistivity of the entire intermediate transfer belt formed of such a material was measured, it was 10 ⁹ to 10 ¹⁴ Ω.
cm. Each volume resistivity is measured by applying a voltage of 100 V for 10 seconds using a measuring method described in JIS K 6911. Further, the surface resistivity of the surface of the intermediate transfer belt 501 on the surface layer 501a side is expressed by:
It was found to be 10 ⁹ to 10 ¹⁴ Ω / □ when measured with a resistance meter “High Lester IP” manufactured by Mitsubishi Yuka. The surface resistivity can be measured by using a resistance measuring instrument and JIS K6911.
Can also be measured by the surface resistance measurement method described in (1).

A nickel-plated metal roller was used as the primary transfer bias roller 507, a metal roller was used as the belt discharging roller 512, and a metal roller or a conductive resin roller was used as the other rollers. The primary transfer bias roller 507 has, for example, 1.5 kV for the first color toner image, 1.7 kV for the second color toner image, and 1.9 kV for the third color toner image. A DC transfer bias of an appropriate magnitude such as 2.1 kV was applied to the fourth color toner. Further, as the secondary transfer bias roller 605,
A roller having a surface layer made of conductive sponge or conductive rubber and a core layer made of metal or conductive resin was used, and a transfer bias controlled at a constant current of 10 to 40 μA was applied to this roller. As the secondary transfer belt 601, a belt material made of PVDF (polyvinylidene fluoride) having a thickness of 100 μm and a volume resistivity of 10 ¹³ Ωcm was used. The lubricant-applied brush 505 was a brush of carbon-containing acrylic fiber (10 ⁸ Ω or less) and had an axial length of 365 mm. The brush diameter is 16mm
And the contact width at the time of contact with the intermediate transfer belt 501 is about 5 m.
m width.

Further, the belt cleaning blade 504
Used a polyurethane having a hardness of about 68 degrees and a length of 354.
mm and the end 5 mm overlapping the area of the reference mark 519
The width portion was cut out by about 2 mm so as not to contact the reference mark 519. Further, in the present embodiment, an example in which the intermediate transfer belt 501 is used as the intermediate transfer body has been described, but the present invention can be applied to an apparatus using an intermediate transfer body having another shape. The electrical characteristics (volume resistivity, surface resistivity, etc.), thickness, structure (single-layer, two-layer,...), Material, material, etc. of the intermediate transfer belt 501 should be appropriate depending on the imaging conditions. Various selections can be made.

In this embodiment, an example in which a primary transfer bias roller is used as the primary transfer charge applying means has been described. However, the present invention relates to an apparatus employing a primary transfer charge applying means having another shape. Can also be applied. In the present embodiment, the primary transfer bias roller 50
The values of the voltage and current applied to the charge applying means such as 7 and the secondary transfer bias roller 605 are not limited to those in the above embodiment, but may be set to appropriate values according to various image forming conditions. Can be. In the present embodiment, 2
The values of the contact time and timing of the next transfer bias roller 605 with respect to the intermediate transfer belt 501 are not limited to the above-described embodiment, but can be set to appropriate values according to various image forming conditions. Further, in the present embodiment, the example in which the secondary transfer bias roller is used as the secondary transfer charge applying means has been described. It can also be applied to things. Further, in the present embodiment, the secondary transfer belt 601 is used as the transfer material carrier for supporting the transfer material in the secondary transfer unit. The present invention can be applied to those using. Further, in the present embodiment, the case where the charging potential of the photosensitive drum 100 is negative and the developing device adopting the reversal developing method using the two-component type developer is described. The present invention is not limited to the one in which the charging potential of the body drum 100 is negative, and is also applicable to those using a one-component developer or those employing a regular development system.

[0030]

As described above, according to the image forming apparatus of the first aspect, the contact area of the existing brush member for applying or cleaning the lubricant is determined by setting the area where the reference mark is provided. By setting the range to be included, the reference mark can be cleaned simultaneously with the lubricant application operation. Thus, there is an excellent effect that a high-quality image free from color misregistration can be provided at low cost. According to the image forming apparatus of the present invention, when the intermediate transfer member is stopped, the reference mark is stopped at the contact position of the brush member, and the brush member is kept in contact with the intermediate transfer member. , Which prevents dirt from accumulating and sticking to the fiducial marks, and as a result, it is possible to continue to provide stable image quality without color shift even when using a machine for a long period of time. There is. According to the image forming apparatus of the third aspect, even when a blade member for cleaning the intermediate transfer member is provided,
Since the blade member does not contact the fiducial mark, it is possible to prevent the fiducial mark and the blade member from being damaged, and as a result, it is possible to continue to provide a stable image quality without color shift.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a color copying machine showing an embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a schematic configuration diagram of a brush member according to the present invention.

FIG. 3 is a schematic configuration diagram of a blade member according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 photoconductor drum (image carrier) 200 charging charger 300 photoconductor cleaning device 400 revolver developing unit 500 intermediate transfer unit 501 intermediate transfer belt (intermediate transfer member) 505 lubricant coating brush 507 primary transfer bias roller 508 belt drive roller 519 Intermediate transfer belt mark (reference mark) 550 Intermediate transfer unit movable section 600 Secondary transfer unit 601 Secondary transfer belt 602 to 604 Support roller 605 Secondary transfer bias roller 650 Registration roller pair 700 Fixing unit 701 Fixing roller pair 801 Primary transfer Power supply 802 Secondary transfer power supply 803 Mark sensor (detection means)

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 2H030 AA01 AD16 BB02 BB24 BB34 BB42 BB53 BB56 BB63 2H200 FA02 GA14 GA23 GA34 GA45 GA47 GA50 GA53 GA57 GA59 GB02 GB12 GB13 GB25 HA02 HA12 HB03 HB12 HB22 JA02 JA46 J46 JA30 JB49 JB50 JC12 JC15 JC16 JC19 JC20 KA07 LA24 LB12 LB13 LB35 LB36 MA01 MA04 MA12 MA14 MA20 MB04 PA03 PA06 PA12 PA29 PA30 PB05 PB15 PB39

Claims (3)

[Claims] An intermediate transfer member capable of transferring a visible image formed on an image carrier; a brush member for applying or cleaning a lubricant capable of coming into contact with and separating from an image transfer surface of the intermediate transfer member; An image forming apparatus comprising: a reference mark outside an image transfer area of an image transfer surface of a transfer body; and detection means for detecting the reference mark, and controlling an image forming operation based on a detection signal from the detection means. An image forming apparatus, wherein a contact range of a brush member with an intermediate transfer member is a range including a portion where a reference mark is provided. 2. The image forming apparatus according to claim 1, wherein when the intermediate transfer member is stopped, the reference mark is stopped at a contact position of the brush member, and the brush member is kept in contact with the intermediate transfer member. An image forming apparatus comprising: 3. The image forming apparatus according to claim 1, further comprising a blade member for cleaning the intermediate transfer member, wherein a blade member portion corresponding to the reference mark portion has a shape not in contact with the reference mark. An image forming apparatus comprising: