JPS6385669A - electrophotographic equipment - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electrophotographic apparatus using the Carlson process;
In detail, it includes a transfer and conveyance unit that transfers and conveys images to copy paper, and can always obtain stable copy images and good paper passing performance regardless of environmental changes, and maintenance such as parts replacement. This invention relates to an electrophotographic device n with improved performance.

BACKGROUND OF THE INVENTION In recent years, electrophotographic devices have become smaller and more sophisticated, but improvements in reliability and simplification of maintenance have become important issues.

An example of a conventional electrophotographic apparatus will be described below with reference to the drawings.

FIG. 9 shows a schematic sectional view of a conventional electrophotographic apparatus. In the figure, reference numeral 10 denotes a cylindrical photoreceptor as an electrostatic latent image carrier, which rotates at a constant speed in the direction of arrow a. Reference numeral 12 denotes a charger, which is installed so as to face the photoreceptor 10. Reference numeral 14 denotes an optical section that exposes the photoreceptor 10 to light on the downstream side of the photoreceptor 10 with respect to the charger 12 . A developing device 16 is installed further downstream from the exposure position of the photoreceptor 10 and adjacent to the photoreceptor 10 . 18 is copy paper as a transfer material. Reference numeral 20 denotes a paper feed section that supplies the copy paper 18. Reference numeral 22 indicates a transfer charger, and reference numeral 24 indicates a separation charge eliminator, which are installed so as to face the photoreceptor 10 in close proximity to each other. 26 is a conveying section, which is composed of a conveying belt 28, a driving roller 30, a driven roller 32, and a suction section 34,
The copy paper 18 is conveyed. 36 is a supporting and fixing part, which is connected to the conveying part 2.
6 is supported and fixed. A fixing device 38 fixes the toner image onto the copy paper 18.

The operation of the electrophotographic apparatus configured as described above will be described below.

First, the photoreceptor 10 has an optical semiconductor layer such as Se on its surface and rotates at a constant speed in the direction of arrow a. After the surface is uniformly positively charged by the charger 12, the optical part 1
4, exposure is performed to form an electrostatic latent image corresponding to the original. The developing device 16 performs development using negatively charged toner to form a toner image corresponding to the electrostatic latent image on the surface of the photoreceptor 10. Here, the formation of a toner image on the surface of the photoreceptor 10 is performed by an electrostatic force acting between the positive charge on the surface of the photoreceptor 10 and the negative charge of the toner. The toner image formed on the surface of the photoconductor 10 is transferred to the photoconductor 10 by the paper feeding section 20.
The transfer charger 2 is transferred onto the copy paper 18 that is supplied in synchronization with the rotational speed of the transfer charger 2, which discharges a positive charge.
Step 2 is performed by positively charging the copy paper 18 passing over the transfer charger 22, and the positively charged copy paper 18 attracts negatively charged toner on the surface of the photoreceptor 10 by electrostatic force. . In order to always obtain stable transfer performance, the electrostatic force acting between the copy paper 18 and the toner must always be greater than the electrostatic force acting between the surface of the photoreceptor 10 and the toner (
To achieve this, the amount of charge on the copy paper 18 may be increased. Furthermore, the copy paper 18 charged by the transfer charger 22 not only attracts the toner, but also has an electrostatic force between it and the photoreceptor 10 and is attracted to the photoreceptor 10, so that the toner is not transferred onto the copy paper 18. A need arises to separate the copy paper 18 from the photoreceptor 10 without disturbing the toner image. Therefore, transfer charger 2
Copy paper 1 due to AC discharge of separation static eliminator 24 adjacent to
8, the adhesion force between the copy paper 18 and the photoreceptor 10 is weakened, and the curvature of the cylindrical photoreceptor 10 and the rigidity of the copy paper 18 are used. The copy paper 18 is separated from the photoreceptor 10 by using the force of the copy Wc 18 trying to separate from the photoreceptor 10. Now, increasing the amount of discharge of the transfer charger 22 in order to increase the amount of charge on the copy paper 18, and increasing the amount of discharge of the separation charge remover 24 in order to sufficiently eliminate the charges on the copy paper 18, directly results in the following: It is known that transfer performance 1 does not improve separation performance, but this is because the transfer charger 22 and separation static eliminator 24 are installed adjacent to each other and have contradictory effects. This is because they influence each other. For example, if the amount of discharge is increased in order to increase the static elimination ability of the separation static eliminator 24, the separation performance for separating the copy paper 18 from the photoreceptor 10 will certainly improve; As a result, the amount of charge on the copy paper 18 by the transfer charger 22 is removed and reduced (reducing the transfer performance. Also, in order to increase the charging ability of the transfer charger 22, the amount of discharge is increased. This increases the amount of charge on the copy paper 18 and certainly improves the transfer performance, but on the other hand, the adhesion force between the copy paper 18 and the photoreceptor 10 also increases, requiring greater charge removal ability and lowering the separation performance. Therefore, the discharge amount of the transfer charger 22 and the separation static eliminator 24 must be controlled to balance the copying performance and separation performance obtained in each discharge state, and the setting of the discharge amount is difficult. difficult.

By the way, as described above, the transfer charger 22 and the separation static eliminator 2
4, the toner image on the photoreceptor 10 is transferred to the photoreceptor 1.
The copy paper 18 separated from the copy paper 1
In order to obtain a conveyance force of 8, the copy paper 18 is transferred to the conveyor belt 28.
The sheet is conveyed to a fixing device 38 by a conveying section 26 including a suction section 34 for suctioning the toner image, heated and pressurized, the toner image is fixed thereon, and then the sheet is discharged.

Now, considering the paper path through which the copy paper 18 passes, the copy paper 18 is supplied by a paper feed section 20, has a toner image transferred to it by a transfer charger 22, and is transferred to a photoreceptor 10 by a separation charge eliminator 24. The sheet is separated from the sheet, transported by the transport section 26, fixed by the fixing device 38, and ejected. The conveyance force of the copy paper 18 on the conveyance section 26 is solely due to the suction section 34 sucking the copy paper 18 from inside the vehicle conveyance belt 28, so it is not possible to obtain a large conveyance force, and the shape The conveyance force for small copy paper 18 or curled copy paper 18 is even smaller. Also,
Because the adsorption force of the copy paper 18 to the conveyor belt 28 is not sufficient, most copy paper 18 is is in a free state, and furthermore, since each part is independent, it is not possible to control how the copy paper 18 behaves. Therefore, the copy paper 18 vibrates or an impact force is applied to the copy paper 18, causing the copy paper 18 to
The toner image on the top is disturbed, the copy paper 18 rushes into the transfer charger 222, the separation static eliminator 24, etc., and paper jams occur.
When the copy paper 18 enters the conveyance section 26 and the fixing device 38, it does not enter the copy paper 18 in a specified manner, and paper jams are likely to occur.

Therefore, the conveyance section 26 strictly controls the settings of the separation static eliminator 24 and the fixing device 38 so that paper jams of the copy paper 18 are less likely to occur at the joints with the separation static eliminator 24 and the fixing device 38. In addition, in order to increase the area that the suction unit 34 suctions, the suction unit 34 has a large-scale structure.
The transport section 26 also has a thick structure (because it is thick, the transport section 26 is fixed by the support and fixing section 36, and the paper feed section 20 and the fixing device 38 are
(It is impossible to attach and detach the conveyance section 26 alone as a unit. Also, since the conveyor belt 28 does not have a place where it comes into contact with the toner, the conveyor belt 28 is generally not cleaned. However, in reality, the conveyor belt 2 is damaged by floating toner or toner falling from the copy paper 18 being conveyed, the photoreceptor 10 being rotated, etc.
8 may get dirty and stain the copy paper 18. (Reference Japan Society for the Promotion of Science; Recording Materials and Photosensitive Materials Gakkai Publishing Center 23-32, etc.) Problems to be Solved by the Invention However, the above structure has the following point J. .

(1) The toner image is transferred to the il copy paper 18 using the copy paper 1.
The transfer performance is largely dependent on the amount of charge on the copy paper 18 because the transfer is performed using an electrostatic force acting between the charge on the copy paper 18 and the toner. The amount of charge on the copy paper 18 varies depending on the physical properties such as the resistance of the copy paper 18, so it is sufficient if the physical properties of the copy paper 18 can be kept constant at all times. There are many types of copy paper, each with its own unique physical properties.Furthermore, even if the copy paper 18 of the same type has the same physical properties, if the environment changes (particularly a change in humidity), the copy paper 18 will change accordingly. Because the physical properties of the transfer charger 22 also change, various types of copy paper 18 can be used under various environments without changing the discharge amount of the transfer charger 22.
The amount of charge on the copy paper 18 cannot be kept constant. However, in order to keep the band and electric charge of the copy paper 18 constant, it is possible to some extent to change the discharge amount of the transfer charger 22 according to the physical properties of the copy paper 18, but the structure becomes complicated.
This is not actually done because it is expensive and there are cases where it is not possible to keep up with it. the result,
Transfer performance changes due to changes in the copy paper 18 and environmental conditions,
The problem is that stable transfer performance cannot always be obtained.

(2) The separation force that separates the photo paper 18 from the photoreceptor 10 is
Since the separation performance is obtained by the rigidity of the copy paper 18, the separation performance is greatly affected by the rigidity of the copy paper 18.The stiffness of the copy paper 18 varies depending on the type of copy paper 18, and in the case of a copy paper 18 with high rigidity. However, if the copy paper 18 has low rigidity, it will not be possible to obtain sufficient separation force to separate the copy paper 18 from the photoreceptor 10, resulting in poor separation.
There is a problem in that separation performance changes as the copy paper 18 changes, resulting in poor separation.

(3) The transfer charger 22 and the separation static eliminator 24 are installed adjacent to each other, and since they have contradictory actions, they influence each other's actions. Therefore, the amount of discharge of the transfer charger 22 and the separation static eliminator 24 must be controlled to balance the transfer performance and separation performance obtained in each discharge state. This balance point depends on the type of copy paper 18.

Since conditions such as changes in environmental conditions also overlap, the range of balance is very narrow, and it is extremely difficult to adjust the discharge amount of the transfer charger 22 and the separation static eliminator to a balance point, and it requires a lot of adjustment skills and The problem is that it requires a lot of adjustment time.

(4) The copy paper 18 on the conveyance unit 26 does not have sufficient conveyance force, so it is rigid such as official postcards (requires a large conveyance force when entering the fixing device 38, and the copy paper 18 is small in shape and conveyed The problem is that the copy paper 18, which can only be conveyed by the belt 28, cannot be conveyed to the fixing device 38.

(5) On the paper path through which the copy paper 18 passes, the copy paper 18
is supplied by the paper feed section 20 and is mostly in a free state until it is fixed by the fixing device 38. Furthermore, since the transfer, separation, and conveyance sections are independent, it is not possible to control the behavior of the copy paper 18, which may cause disturbances in the toner image on the copy paper 18 or the copy paper. There is a problem that 18 paper jams occur.

(6) The conveyance section 26 is fixed by the support fixing section 36, and the conveyance section 26 alone cannot be attached or detached without attaching or detaching anything other than the conveyance section 26. Therefore, for example, when replacing parts such as the conveyance belt 28, The problem is that maintainability is very poor.

(7) Since the conveyor belt 28 is not cleaned, there is a problem in that the conveyor belt 28 soiled with floating toner etc. stains the copy paper 18.

In particular, the present invention solves the above-mentioned problems.
In view of the problems that the toner image on the copy paper 8 is easily disturbed and the copy paper 18 gets jammed, and the copy paper 18 becomes dirty, it is difficult to maintain the copy paper 18. During the process, the toner image on the copy paper 18 is not disturbed, the copy paper 18 is not jammed, and the copy paper 18 is not soiled (stable paper passing performance can always be obtained, and parts can be replaced. The present invention provides an electrophotographic apparatus with improved maintainability.

Means for Solving the Problems In order to solve the above problems, the electrophotographic apparatus of the present invention includes:
An electrostatic latent image carrier, a charging means for charging the surface of the electrostatic latent image carrier, and an exposure for exposing the surface of the electrostatic latent image carrier charged by the charging means to form an electrostatic latent image. means and
A developing means for visualizing the electrostatic latent image using toner and forming a toner image on the surface of the electrostatic latent image carrier, and a transfer conveyance means for transferring the toner image onto a transfer material and conveying the transfer material. at least t]1010 to 1013 for directly supporting and conveying the transfer material by electrostatic electricity, contacting the electrostatic latent image carrier, and transferring the toner image to the transfer material.
A transfer conveyance belt having a semiconductor layer formed of a semiconductor material having a resistivity of Ωcm, a drive means for driving the transfer conveyance belt, a transfer conveyance belt and a drive means supported, and an electrostatic latent electrostatic electrostatic coating that supports the transfer conveyance belt and the drive means. It is constituted by a transfer conveyance unit having a support means for press-contacting the image bearing member and a belt cleaning means for cleaning the transfer conveyance belt, and a belt charging means for applying electric charge to the transfer conveyance belt, and The transfer conveyance unit is configured to be detachable.

According to the above-described structure, the belt charging means is attached to a portion of the transfer conveyance belt made of a semiconductor material having an electrical resistance of 1010 to 1013 Ωcm in the vicinity of the vicinity of the electrostatic latent image carrier and the transfer conveyance belt. By applying an electric charge, the transfer material fed by the transfer material supplying means is transferred by the electrostatic attraction between the polarized charge caused by electrostatic induction of the transfer material and the true charge of the transfer conveyance belt, without directly applying an electric charge to the transfer material fed by the transfer material supply means. The material is attracted and conveyed onto the transfer conveyance belt. The toner is transferred by the belt charging means applying an electric charge to the transfer conveyance heald to a polarity opposite to that of the toner on the electrostatic latent image bearing member. That is, the toner is attracted toward the transfer conveyance belt by the electrostatic attraction between the charges on the transfer conveyance belt and the charges on the toner, and is transferred onto the transfer material adsorbed on the transfer conveyance belt.

In addition, since the transfer material does not have a true charge and is attracted onto the transfer conveyance belt by polarized charges, there is no need to remove static electricity from the transfer material when separating the electrostatic latent image carrier from the transfer material, and in addition, the above-mentioned The electrostatic adsorption force between the transfer material and the transfer conveyance belt acts as a forcing force that separates the transfer material from the electrostatic latent image carrier, making it difficult for conventional electrophotographic devices that rely only on the rigidity of the transfer material. The separation of the transfer material is more stable compared to the conventional method.

Further, the present invention integrates various parts that perform the transfer, separation, and conveyance functions of transferring the toner image on the electrostatic latent image carrier to a transfer material, and separating and conveying the transfer material from the electrostatic latent image carrier. By using a transfer conveyance unit, the passage of the transfer material can be simplified, and the behavior of the transfer material on this transfer conveyance unit can be controlled, so that the toner image on the transfer material is not disturbed on this passage. , it is possible to always obtain stable conveyance performance without causing poor conveyance of the transfer material.

Furthermore, since the transfer conveyance belt is well cleaned by the belt cleaning means, the transfer conveyance belt does not stain the transfer material supported and conveyed by the transfer conveyance belt, so that the transfer material is always in good condition. Conveyance performance can be obtained.

EXAMPLE Hereinafter, an electrophotographic apparatus according to an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a schematic cross-sectional view of an electrophotographic apparatus according to an embodiment of the present invention. In the figure, reference numeral 10 denotes a cylindrical photoreceptor as an electrostatic latent image carrier, which rotates at a constant speed in the direction of arrow a. Reference numeral 12 denotes a charger, which is installed so as to face the photoreceptor 10. Reference numeral 14 denotes an optical section that exposes the photoreceptor 10 to the charging 2fr12 on the downstream side of the photoreceptor 10. 1
A developing device 6 is installed further downstream from the exposure position of the photoreceptor 10 and adjacent to the photoreceptor 10 . 18 is copy paper as a transfer material. Reference numeral 20 denotes a paper feed section that supplies the copy paper 18. 48 is a transfer conveyance unit. Reference numeral 50 denotes a transfer conveyance belt, which is brought into pressure contact with the photoreceptor 10 and driven in one direction. 52 is a drive shaft, and 54 is a separation shaft, which is a driving means for stretching and driving the transfer conveyance belt 50. The separation shaft 54 also eliminates static electricity from the transfer conveyance belt 50.

Reference numeral 56 denotes a transfer shaft, which is located near the position where the photoreceptor 10 and the transfer conveyance heald 50 come into contact (hereinafter referred to as the transfer position). 58 is 2
This is a charger, and is installed so as to sandwich the transfer conveyance belt 50 and face the photoreceptor 10 at the transfer position. 60
61 is a transport board serving as a support means, and 61 is a moving board serving as a support means. 62 is a cleaning section;
Clean the transfer conveyance belt. A support plate 64 is provided on the main body side and supports the transfer conveyance unit 48. 38 is a fixing device, which is installed on the downstream side of the transfer conveyance unit in the transfer path 18.

The operation of the electrophotographic apparatus configured as described above will be described below with reference to FIGS. 1 to 8.

First, an explanation will be given with reference to FIG.
It rotates at a constant speed in the direction.

After the surface is uniformly positively charged by the charger 12, exposure is performed by the optical section 14 to form an electrostatic latent image corresponding to the original. The developing device 16 performs development using negatively charged toner to form a toner image corresponding to the electrostatic latent image on the surface of the photoreceptor 10. Here, the formation of a toner image on the surface of the photoreceptor 10 is performed by an electrostatic force acting between the positive charge on the surface of the photoreceptor 10 and the negative charge of the toner. The copy paper 18 is fed by the paper feed section 20 toward the transfer conveyance belt 50 in synchronization with the rotational speed of the photoconductor 1o, and after reaching the transfer conveyance belt 50, it is transferred to the photoconductor 10 along the transfer conveyance belt 50. It is supplied to the transfer position where the conveyor belt 50 is in contact. The transfer conveyance unit 48 transfers the toner image formed on the surface of the photoconductor 10 to the copy paper 18 that has reached the transfer position, separates the copy paper 18 from the photoconductor 10, and further conveys the copy paper 18. This section explains the principles of transfer, separation, and transportation.

The transfer conveyance belt 50 has a resistivity of 1010 to 1013Ω.
It is an endless belt made of a semiconductor material, which is a cam, and is stretched by a drive shaft 52 supported by a conveyance board 60 and a moving board 61, a separation shaft 54, and a transfer shaft 56. , and is driven by the driving force of the drive shaft 52 , and a positive charge is injected onto the No. 2 charger 58 by discharge of the No. 2 charger 58 . The transfer conveyance heald 50 injected with a positive charge forms an electric field due to the electric charge, generates polarization in the copy paper 18 supplied between the transfer conveyance belt 50 and the photoreceptor 10, and transfers and conveys the copy paper 18. Negative charges are polarized on the belt 50 side and positive charges are polarized on the photoreceptor 10 side. Here, the positive polarized charges of the 10 photoreceptors of the copy paper 18 attract the negative charges of the toner on the surface of the photoreceptor 10 by electrostatic force, and the toner image is transferred onto the copy paper 18. In order to always obtain stable transfer performance, it is necessary to adjust the polarization charge of the copy paper 18 so that the electrostatic force acting between the copy paper 18 and the toner is always greater than the electrostatic force between the surface of the photoreceptor 10 and the toner. The amount of polarized charge on the copy paper 18 is determined by the resistance value of the copy paper 18,
It is always constant regardless of the physical properties such as thickness, the amount of charge injected into the transfer conveyance belt 50, the adhesion between the copy paper 18 and the transfer conveyance belt 50, and the difference in the physical properties of the copy paper 18.

In other words, stable transfer performance can always be obtained regardless of the environment in which the copy paper 18 (fl type or m copy paper 18) is placed. Further, an electrostatic force acts between the positive polarized charge on the photoreceptor 10 side of the copy paper 18 and the photoreceptor 10,
The copy paper 18 tries to adhere to the photoreceptor 10. Conversely, an electrostatic force also acts between the negative polarized charge of the copy paper 18 on the transfer conveyance heald 50 and the positive injection charge injected into the transfer conveyance belt, causing the copy paper 18 to adhere to the transfer conveyance belt 50. try to. Therefore, copy paper 18 and transfer conveyance belt 50
In order to always make the electrostatic force larger than the electrostatic force between the copy paper 18 and the photoreceptor 10, it is possible to
This is possible by ensuring close contact with the transfer conveyor belt 50, so that the copy paper 18 can be separated from the photoreceptor 10 and conveyed while remaining attached to the transfer conveyance belt 50. In other words,
This means that stable separation performance can always be obtained regardless of the rigidity of the copy paper 18. Furthermore, since the copy paper 18 is electrostatically attracted to the transfer conveyance belt 50, the behavior of the copy paper 18 on the transfer conveyance belt 50 is such that it remains in close contact with the transfer conveyance belt 50, and The copy paper 18 does not vibrate on the transfer conveyance belt 50, no impact force is applied to the copy paper 18, and the toner image on the copy paper 18 is not disturbed. Furthermore, since the copy paper 18 is in close contact with the transfer conveyance belt 50, a very large force can be obtained to convey the copy paper 18, making it possible to convey official postcards and the like. When the copy paper 18 is conveyed from the transfer position to the fixing device 38, it must be separated from the transfer conveyance belt 50 before the fixing device 38. (1) Since the transfer conveyance belt 50 is made of a semiconductor material, the amount of charge at the separation position is higher than the amount of charge at the transfer position when it is injected by the No. 2 charger 58 due to electrical leakage. Therefore, the adhesion force due to electrostatic force between the transfer conveyance belt 50 and the copy paper 10 is weakened.■ At the separation position, the transfer conveyance belt 50 is in contact with the separation shaft 54, and the surface of the separation shaft 54 is has conductivity and is grounded, so the transfer conveyance belt 50 is neutralized, and the electrostatic adhesion between the transfer conveyance belt 50 and the copy paper 10 is weakened.■ Transfer on the downstream side of the separation position. The conveyor belt 50 has a thick curvature (
Therefore, using the rigidity of the copy paper 18, the copy paper 18
It is possible to obtain a separation force that separates the transfer belt 50 from the transfer conveyance belt 50. The above actions ■ to ■ work, and the transfer conveyance belt 50
At the same time, the adsorption force of the copy paper 10 becomes weaker, and a separation force acts to separate the copy paper 18 from the transfer conveyance belt 50 (
Therefore, the copy paper 18 is naturally separated from the transfer conveyance belt 50 and conveyed to the fixing device 38. Here, before the separation position, the force with which the transfer conveyance belt 50 attracts the copy paper 18 is weaker, but it is still sufficiently strong, so the copy paper 18
There is no effect on the behavior of 8 or the conveyance force. Then, the copy paper 18 conveyed to the fixing device 38 is fixed and discharged. The transfer conveyance unit 48 also includes a transfer conveyance belt 50 , a drive shaft 52 that stretches and drives the transfer conveyance belt 50 , a separation shaft 54 that stretches the transfer conveyance belt 50 and removes static electricity, and a transfer conveyance belt 50 . A transfer shaft 56 for stretching, eliminating static electricity, and ensuring a state of pressure contact between the transfer conveyance belt 50 and the photoreceptor 10, and a No. 2 charger 5 for injecting charge into the transfer conveyance belt 50.
8, a cleaning section 62 for cleaning the transfer conveyance belt 50, and a cleaning section 62 for cleaning the transfer conveyance belt 50, and a cleaning section 62 for cleaning the transfer conveyance belt 50.
A push-up section 63 that pushes up the transfer conveyance unit 48 in order to press the transfer conveyance unit 48 , supports the transfer conveyance belt 50 , the drive shaft 52 , the separation shaft 54 , the transfer shaft 56 , the No. 2 charger 58 , the cleaning section 62 , and the push-up section 63 . It is composed of a transport board 60 and a moving board 61, and is configured to transport the photoreceptor 1 to the copy paper 18.
0 toner image is transferred, and the copy paper 18 is transferred to the paper feed section 2.
It is an integrated unit that conveys the copy paper 18 from when it is supplied by the fuser 38 until it is fixed by the fuser 38.
It is supported in a removable manner. And photoreceptor 1
0 rotates to perform a copying operation and supply the copy paper 18, the push-up portion 63 uses the pushing force received from the main body to push up the transfer conveyance unit 48 so that the transfer conveyance belt 50 comes into contact with the photoreceptor 10. After the copying operation is completed and the copy paper 18 is conveyed, the transfer conveyance belt 50
leaves the photoreceptor 10. This is to keep the photoreceptor 10 and transfer conveyance belt 50 as far apart as possible, since if the transfer conveyance belt 50 is in constant contact with the photoconductor 10, the surface of the photoconductor 10 may be deteriorated due to mechanical damage caused by compression. It is. Further, when removing the transfer conveyance unit 48 from the support plate 64 supporting the main body, the fulcrum 10
After opening the photoreceptor 10, the developing device 16, etc. in an alligator manner centering on the photoreceptor 10, the transfer conveyance unit 48 can be removed.

Next, a detailed explanation of each part will be given with reference to FIGS. 1 to 8.

First, regarding the support method of supporting the transfer conveyance unit 48 with the support plate 64, there is shown a schematic cross-sectional view in FIG. 1, a detailed view of the transfer conveyance unit 48 in FIG. 2, and FIG. 3.

This will be explained with reference to a detailed view of the support portion of the transfer conveyance unit 48 in FIG. Here, the transfer conveyance unit 48 includes a support bearing 11 to support the separation shaft 58 to the moving substrate 61.
This support bearing 112 has a flange portion and an H-cut portion having an H-shaped outer circumference. The support plate 64 is provided with the H of the support bearing 112.
A hole has the same diameter as the long side of the cut part, and a groove is cut from this hole with a width that passes through the short side but not on the long side. Further, the support bearing 112 is attached obliquely to the moving board 61. Here, with the alligator opened (dotted chain line in FIG. 1), the short width part of the support bearing 112 can be inserted into the support plate 64 in the direction of the arrow while tilting the transfer conveyance unit 48. After finishing, transfer transfer unit 48 centering on the hole of support plate 64 (concentric with support bearing 112).
When the drive shaft 52 side is rotated in the direction of pushing down, the groove of the support plate 64 and the H-cut part of the support bearing 112 become diagonal, and the support bearing 112 cannot be removed even if it is pushed up in the opposite direction of the arrow. , the transfer conveyance unit 48 is transferred to the support plate 64.
The support can be fixed. If the transfer conveyance unit 48 is to be removed here, the process may be performed in the reverse order. By supporting and fixing the transfer conveyance unit 48 as described above, the transfer conveyance unit 48 can be easily attached and detached, and can be easily and securely attached.

Next, regarding the method of attaching the No. 2 charger 58 and the No. 2 charger 58 to the transfer conveyance unit 48, the schematic sectional view in FIG. 1, the detailed view of the transfer conveyance unit 48 in FIG. 2, and the method shown in FIG. This will be explained with reference to a cross-sectional view of the No. 2 charger 58 when it is installed.

The No. 2 charger 58 is a charger that injects positive charge into the transfer conveyance belt 50, and includes a wire 160 for corona discharge, block (1) 162, block (2) 164, and wire 160 for fixing the wire 160. A positioning spring 170 pushes up the house 166 vertically upward on the block (1) 162 side and grounds the house 166. Further, a block receiver 178 for positioning the block (2) 164 is installed on the transfer board 60. Here, the No. 2 charger 58 can be easily attached and detached from the transfer conveyance unit 48 so that cleaning can be easily performed when the wire 160 becomes dirty. When removing the No. 2 charger 58 from the installed state (Fig. 7), first remove the block (1) 162.
Push down in the direction of arrow C.

Then, the positioning spring 170 is compressed, and the removal stop formed by the transfer board 6° and the house 166 is released, allowing the No. 2 charger 58 to be pulled out in the direction of arrow d.
8 can be removed from the transfer conveyance unit 48.

However, even if the No. 2 charger 58 is pulled in the direction of arrow d without pushing down the block (1) 162 in the direction of arrow C, it cannot be pulled out due to the stopper. Next, the uninstalled state (
When installing the No. 2 charger 58 from FIG. enters the hole made in the block receiver 178 attached to the transfer board 60, and the block (2) 1
64 is positioned vertically and horizontally. When inserted further, the positioning spring 170 pushes it vertically upward, and the 2
The removal stop provided in the house 166 of the number charger 58 is engaged, and the installation is completed. Although the second charger 58 can be easily attached and detached from the transfer conveyance unit 48 by a so-called two-wheel slide attachment method, it is firmly attached when attached.

Next, regarding the cleaning section 62 and the method of attaching the cleaning section 62 to the transfer conveyance unit 48, the schematic sectional view in FIG. 1, the detailed view of the transfer conveyance unit 48 in FIG. 2, and the transfer conveyance unit in FIG. The explanation will be given with reference to a schematic cross-sectional view of the transfer unit 48 and a side view of the transfer conveyance unit 48 in FIG.

The cleaning section 62 is for cleaning foreign matter such as toner on the transfer conveyance belt 50, and includes a blade 130 that directly cleans the transfer conveyance belt 50 and a cleaning substrate 132 that holds the blade 130 so as to be able to move toward and away from the transfer conveyance belt 50. The blade lever 1 moves in conjunction with the movement of the blade 130 toward and away from the transfer conveyance bell h50.
34, a spring 136 that always applies pressure to the blade lever 134 so that the blade 130 comes into pressure contact with the transfer conveyance belt 50, a discharge toner box 138 that stores the toner cleaned by the blade 130, and the toner removed from the cleaning section 62. Pad 1 to prevent scattering
A back pad 142 that is in contact with the back surface of the transfer conveyance belt (the side opposite to the blade 130) and attached to the conveyance substrate 60; It is configured to face a back plate 144 via a transfer conveyance belt. Here, the blade 130, which receives the pressing force constantly applied by the spring 136 via the blade lever 134, is constantly pressed against the transfer conveyance belt 50 and cleans the transfer conveyance belt 50. Here, in order to prevent the blade 130 from biting into the transfer conveyance belt 50 too much, the amount of biting is controlled by a stopper constituted by a blade lever 134 and a cleaning board 132, so that the blade 130 does not bite into the transfer conveyance belt 50 more than a specified amount. The toner cleaned by the blade 130 is sent to a discharge toner box 138 provided at the bottom of the blade 130.
It falls inside and accumulates. The waste toner box 138 can be slidably attached to and removed from the cleaning board 132, and when the waste toner box 138 is full of toner, etc., it can be removed from the cleaning board 132.
The waste toner box 138 after discarding the toner and the new waste toner box 138 are returned to the cleaning board 132.
All you have to do is attach it to. blade 130
The toner cleaned by the blade 1 does not all fall into the discharge toner box 138 instantly.
It floats around 30 and scatters outside. Therefore, by closing the gap between the cleaning section 62 and the outside with the pad 140, the toner is prevented from scattering to the outside. In addition, the pack pad 142 presses the transfer conveyance belt 50 from the back side of the transfer conveyance belt 50 toward the blade 130 side, and has the effect of improving cleaning performance and suppressing abnormal noise generated by sliding between the blade 130 and the transfer conveyance belt 50. It is intended to prevent Back plate 14
4, the blade 13 moves the transfer conveyance belt 50 from the back side of the transfer conveyance belt 50 immediately upstream of the pressure contact position of the blade 130.
By pressing toward the 0 side, the cleaning performance is improved by increasing the drag force against the blade 130 on the transfer conveyance belt 50 at the pressure contact position of the blade 130. The cleaning section 62 can be easily attached and detached from the transfer conveyance unit 48 for purposes such as replacing the blade 130. First, in order to remove the cleaning part 62 from the attached state a (FIG. 6), the moving board 61 is rotated in the direction of the arrow g on the transport board 60.
Thereafter, it can be removed by moving the cleaning section 62 in the direction of arrow i. When installing, with the movable board 61 rotated in the direction of the arrow g relative to the transport board 60, the cleaning part 62 is inserted in the groove provided in the cleaning board 132 into the hook provided on the transport board 60 in the direction indicated by the arrow i. It is inserted in the opposite direction and fixed to the transfer conveyance unit 48, and then the movable substrate 61 is rotated in the direction opposite to the arrow g with respect to the conveyance substrate 60 to prevent removal. In this way, the cleaning section 62 can be easily attached and detached from the transfer conveyance unit 48.

Next, details of the push-up portion 63 will be described with reference to the schematic cross-sectional view in FIG. 1, the detailed view of the transfer conveyance unit 48 in FIG. 2, and the schematic diagram of the push-up portion 63 of the main body in FIG.

In order to prevent deterioration of the surface of the photoreceptor 10, when the photoreceptor 10 rotates to perform a copying operation and copy paper 18 is supplied, the push-up portion 63 pushes up the transfer conveyance unit 48, and causes the transfer conveyance belt 50 to touch the photoreceptor 10. After the copying operation is completed and the copy paper 18 is conveyed, the transfer conveyance belt 50 is brought into contact with and separated from the photoreceptor lO. The push-up part 63 is installed in the transfer transport unit 48, with an electromagnetic plunger 182 installed in the main body, a push-up lever 184 that rotates in conjunction with the electromagnetic plunger 182, and a push-up spring 186 that constantly pushes up the transfer transport unit 48. Push-up plate (1) that receives the force of push-up lever 184
188 and a push-up plate (2) 190 that receives the force of the push-up spring 186. Here, when starting a copying operation, a signal is input to the electromagnetic plunger 182, and the electromagnetic plunger 182 is turned on. In conjunction with this, the push-up lever 184 rotates, transmits its rotational force to the push-up plate (1) 188, and transfers and conveys unit 48
is pushed up, and the transfer conveyance belt 50 is positioned at the push-up position where it is brought into pressure contact with the photoreceptor 10. Push-up spring 18
6 is the transfer conveyance unit 4 to the push-up plate (2) 190
However, since the pushing up force by the pushing up spring 186 is a pushing up force that balances with the weight of the transfer conveyance unit 48, the pushing up force of the pushing up spring 186 alone cannot push up the transfer carrying unit 48. However, there is an advantage in that the pushing up force by the pushing up lever 184 can be reduced.Also, compared to the stroke required to push up the transfer conveyance unit 48 to the pushing up position, the stroke that can be pushed up by the pushing up lever 184 is sufficiently large ( This is done to ensure that the transfer and conveyance unit 48 can always be pushed up completely even if there is a dimensional error in the parts. The push-up plate (1) 188 absorbs the pressure, so that the transfer conveyance unit 48 can always be reliably pushed up to the push-up position.

Next, regarding the procedure for replacing the transfer conveyance belt 50,
This will be explained with reference to a schematic cross-sectional view in FIG. 1, a detailed view of the transfer conveyance unit 48 in FIG. 2, and a side view of the transfer conveyance unit 48 in FIG. Here, the transfer conveyance belt 50 is normally used as shown in FIGS. 1 and 2.

As shown in FIG. 6, a drive shaft 52, a separation shaft 54, a transfer shaft 56
However, it may need to be replaced at the end of its service life. Here, when the movable substrate 61 is rotated in the direction of arrow g with respect to the transfer substrate 60, the retainer for removing the cleaning section 62 is released and the cleaning section 62 is removed from the transfer transfer unit 48.
In addition, it is possible to remove the tension on the transfer conveyance belt 50 that has been subjected to tension until now.Then, the transfer conveyance belt 50 that has no longer tension can be easily removed from the transfer conveyance unit 48. On the other hand, when attaching the transfer conveyance belt 50 to the transfer conveyance unit 48, the transfer conveyance unit 48 is inserted into the transfer conveyance belt 50 while the movable substrate is rotated in the direction of arrow g with respect to the conveyance substrate 60. After that, the movable substrate 61 is rotated in the direction opposite to the arrow g with respect to the transfer substrate 60, and tension is applied to the transfer conveyance belt 50.The tension applied to the transfer conveyance belt 50 in this way is This is done by rotating the movable substrate 61 with respect to the transfer conveyance unit 48, so that the transfer conveyance belt 50 can be easily attached and detached from the transfer conveyance unit 48.

As described above, according to this embodiment, the photoreceptor 10, the charger 12 for charging the surface of the photoreceptor 10, and the surface of the photoreceptor 10 charged by the charger 12 are exposed to light to form an electrostatic latent image. an optical section 14 for visualizing the electrostatic latent image using toner and forming a toner image on the surface of the photoreceptor 10; 1
8, the transfer conveying means directly supports and conveys the copy paper 18 using static electricity, contacts the photoreceptor 10, and transfers the toner image onto the copy paper 18. A transfer conveyance belt 50 having a semiconductor layer formed of a semiconductor material having a resistivity of 1010 to 1013 ΩcI11, a drive shaft 52 for stretching and driving the transfer conveyance belt 50, a separation shaft 54, and a transfer conveyance belt 50 It is composed of a transfer conveyance unit 48 having a conveyance substrate 60 and a moving substrate 61 that support the belt 50, the drive shaft 52, and the separation shaft 54, and a No. 2 charger 58 for applying electric charge to the transfer conveyance belt 50, In addition, the transfer conveyance unit 48 is configured to be detachable. 1. After the copy paper 18 is fed by the paper feed section 20, it is transferred to the fixing device 38.
The paper passing path of the copy paper 18 to which the toner image on the surface of the photoconductor 10 is transferred, separated from the photoconductor 10, and conveyed until it is fixed by the transfer conveyance unit 48, which is an integrated unit. and a copy paper 1
8, a transfer conveyance belt 50 is moved by electrostatic force on the paper passing path.
Since the copy paper 18 is attracted to Stable paper passing performance can be obtained. Further, since the integrated transfer conveyance unit 48 can be made compact, the transfer conveyance unit 48 can be easily attached and detached, and maintenance efficiency such as parts replacement can be improved.

Note that the transfer conveyance heald 50 has a resistivity of 1010 to 10.
Although the endless belt was made of a semiconductor material having a resistance of 13 ΩcIm, the surface of the belt preferably has low surface roughness, low coefficient of friction, and excellent wear resistance in order to clean adhered toner.

Therefore, the base material on the No. 2 charger 58 side is set to 1010 to 1013Ω.
cam semiconductor layer, and the surface layer of the photoreceptor 10 (!
It is also possible to have a multilayer structure made of nylon resin or the like, and in such a case, the cleaning performance of the transfer conveyance belt 50 can be reliably improved. In addition, it is desirable to have appropriate elasticity so that strong wrinkles do not occur during drive rotation by the drive shaft 52 or the like. This is because if the rigidity is too strong and wrinkles occur, the wrinkled portion may not be able to maintain close contact with the copy paper 18. Further, in view of running performance of the transfer conveyance belt 50, it is more preferable that the transfer conveyance belt 50 has appropriate elasticity in order to prevent meandering.

The drive shaft 52 must transmit the driving force transmitted from the drive transmission section 104 to the transfer conveyance belt 50 and drive the transfer conveyance belt 50. The driving force is transmitted through the drive shaft 52.
This is done by the frictional force between the front surface and the back surface of the transfer conveyance belt 50.

Here, in order to perform sufficient transmission, it is desirable that the surface of the drive shaft 52 has a large friction coefficient. However, the drive shaft 52
If the friction coefficient is large, the transfer conveyance belt 50 is likely to meander when a meandering force is generated.
It is desirable that the surface of the drive shaft 52 has so-called roll marks, which have a small coefficient of friction in the meandering direction. In addition, in order to make it difficult to generate meandering force as much as possible, the drive shaft 52
It is also possible to use a drum shape in which the shaft diameters at both ends are smaller than the central shaft diameter, or to use a drive shaft 52 having a plurality of drum shapes.

The separation shaft 54 has a small surface (both surfaces are made of a conductive material,
Electricity is removed from the transfer conveyance belt 50 at a portion that is grounded by an earth plate spring 114 and is in contact with the transfer conveyance belt 50. Further, since the portion in contact with the transfer conveyance belt 50 is also the separation position where the copy paper 18 is separated from the transfer conveyance belt, the smaller the radius of curvature of the separation shaft 54, that is, the diameter of the separation shaft 54, the more the copy paper is removed from the transfer conveyance belt 50. However, if the diameter of the separation shaft 54 is 20 mm or less, preferably 16 mm or less, more reliable separation can be ensured.

The transfer shaft 56 contacts the transfer conveyance belt 50 immediately upstream of the transfer position where the transfer conveyance belt 50 and the photoreceptor 10 contact. The surface of the transfer shaft 56 is made of a conductive material and is grounded, so that the transfer conveyance belt 50 is neutralized immediately upstream of the transfer position, and the toner on the surface of the photoreceptor 10 is transferred to the photoreceptor 10 and the copy paper 18. The transfer conveyor belt 50
This prevents so-called toner flying, which is flying toward the charge on the copy paper 18. Further, the transfer conveyance belt 50 is connected to the photoreceptor 10.
, the pressure area and pressure between the transfer conveyance belt 5o and the photoreceptor 10 are increased, and the copy paper 18 is pressed against the transfer conveyance belt 50.
This is used to ensure close contact between the copy paper 18 and the transfer conveyance belt 50 when the copy paper 18 is supplied between the photoreceptor 10 and the copy paper 18 . Although the transfer shaft 56 is installed upstream of the transfer position in order to ensure close contact between the copy paper 18 and the transfer conveyance belt 50, the same close contact can also be achieved by installing the transfer shaft 56 instead on the downstream side of the transfer position. It is possible to ensure sex. Furthermore, by installing it on both the upstream and downstream sides, the adhesion can be further increased.

In order to easily attach and detach the No. 2 charger 58 from the transfer conveyance unit 48, a two-wheel chair sliding type is used, but it is not necessarily necessary to attach and detach it in this manner. In addition, No. 2 charger 5
Since there is a transfer conveyance belt 50 on top of 8, the second charger 5
No. 8 is less likely to get dirty, so the No. 2 charger 58 may be completely fixed to the transfer conveyance unit 48.

Further, although the transfer conveyance belt 50 is cleaned by the blade 130 here, the blade 130 is not necessarily used to clean the transfer conveyance belt 50.
It does not have to be the same, and any material may be used as long as it cleans the transfer conveyance belt 50 well. For example, blade 1
In addition to 30, there are fur brushes, woven fabrics, etc. Further, although the blade 130 is pressed by a spring 136 and a stopper is attached to prevent digging, it is not necessary to use the spring 136 and a stopper, and even a completely fixed type can be sufficiently cleaned. Although the method of attaching and detaching the discharge toner box 138 is a sliding type, the discharge toner box 1
This is to facilitate the processing of the toner accumulated in 38, and it is not necessarily necessary to attach or detach it. Also, the sliding attachment/detachment method does not necessarily have to be a sliding type.
Other methods such as a built-in type may be used as long as the discharge toner box 138 can be easily attached and detached. The back pad 142 has the effect of improving cleaning performance and preventing abnormal noise, and the material is thick due to its elastic modulus (
For example, if the base material is made of a material such as foamed sponge, and the surface on which the back side of the transfer conveyance belt 50 contacts is made of a material with a low coefficient of friction and good wear resistance, such as fluororesin, the sliding with the transfer conveyance belt 50 will be improved. Dynamic resistance is also small, and very good leaning performance and noise prevention effects can be obtained, but it is not necessarily necessary because a good leaning performance can be obtained even without the back pad 142. The back plate 144 has the effect of improving cleaning performance. In particular, if the surface on which the back surface of the transfer conveyance belt 50 contacts and slides is made of a surface with a small coefficient of friction and excellent wear resistance, such as a surface made of fluororesin, etc. Although the back plate 144 has little sliding resistance with the transfer conveyance belt 50 and can obtain very good leaning performance, it is not necessarily necessary because the back plate 144 can provide good leaning performance even without the back plate 144. The cleaning section 62 fits the hook provided on the transfer substrate 60 into the groove provided on the cleaning substrate 132, rotates the movable substrate 61, and removes the cleaning section 62 from the transfer transfer unit 48 as a stopper to prevent it from coming off. Although it is assumed that the cleaning section 62 can be easily attached and detached, it is not necessarily necessary to attach the cleaning section 62 to the transfer conveyance unit 48 using this method, and any method that allows for easy attachment and detachment may be used.

Further, the earth coil spring 110 is for earthing the transfer shaft 56, and does not necessarily have to be the earth coil spring 110 as long as it earths the transfer shaft 56.

Further, the ground plate spring 114 is for grounding the separation shaft 54, and does not necessarily need to be the ground plate spring 114 as long as it is used to ground the separation shaft 54.

Furthermore, the meandering prevention roller 154 is provided to suppress meandering when the transfer conveyance belt 50 meanders, but it is not necessarily necessary.

Effects of the Invention As described above, the present invention includes an electrostatic latent image carrier, a charging means for charging the surface of the electrostatic latent image carrier, and a method for exposing the surface of the electrostatic latent image carrier charged by the charging means. , an exposure means for forming an electrostatic latent image, a developing means for visualizing the electrostatic latent image using toner and forming a toner image on the surface of the electrostatic latent image carrier, and transferring the toner image. The transfer conveyance means directly supports and conveys the transfer material using static electricity, contacts the electrostatic latent image carrier, and transfers the toner image to the transfer material. To transfer to a small (
A transfer conveyance belt having a semiconductor layer formed of a semiconductor material having a resistivity of 1010 to 1013 Ω, a drive means for driving the transfer conveyance belt, and a transfer conveyance belt and a drive means supporting the transfer conveyance belt and the drive means. a transfer conveyance unit having a support means for pressing the belt against the electrostatic latent image carrier; a belt cleaning means for cleaning the surface of the transfer conveyance belt; a belt charging means for applying electric charge to the transfer conveyance belt; In addition, the transfer conveyance unit is configured to be detachable, so that the conveyance path for the transfer material until it is supplied and fixed is formed by an integrated unit called the transfer conveyance unit. This makes it possible to prevent the toner image on the transfer material from being disturbed or the transfer material to become stuck on the transfer material transport path (an excellent feature that allows stable transfer material transport performance to be obtained at all times). In addition to this, it is also possible to obtain the effect that maintenance efficiency such as parts replacement can be improved.

Furthermore, since the transfer conveyance belt is not soiled, the transfer material supported and conveyed by the transfer conveyance belt is not contaminated.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of an electrophotographic apparatus according to an embodiment of the present invention, FIG. 2 is a detailed view of the transfer conveyance unit of this embodiment, and FIGS. 3 and 4 are details of the support portion of the transfer conveyance unit. Figure 5 is the same (schematic sectional view of the transfer conveyance unit, Figure 6 is the same).
The figure is a side view of the transfer conveyance unit, FIG. 7 is a sectional view of the No. 2 charger when the device is in use, FIG. 8 is a schematic diagram of the push-up section, and FIG. 9 is a schematic diagram of an example of a conventional electrophotographic device. FIG. 10... Photoreceptor, 12... Charger, 1
4...Optical section, 16...Developer, 18
... Copy paper, 20 ... Paper feed section, 22.
...Transfer charger, 24... Separation static eliminator,
26... Conveyance section, 28... Conveyance belt, 30... Drive roller, 32... Driven roller, 34... Suction section, 36... Support fixing part, 38... Fixing device, 48...
Transfer conveyance unit, 50...Transfer conveyance belt,
52... Drive shaft, 54... Separation shaft, 5
6... Transfer shaft, 58... No. 2 charger,
60... Transfer board, 61... Moving board, 62... Cleaning section, 63...
Push-up portion, 64...Support substrate, 100...
...Fully point, 110...Earth coil spring, 1
12...Support bearing, 114...Earth leaf spring, 130...Blade, 132...
... Cleaning board, 134 ... Blade lever, 136 ... Spring, 138 ... Discharge toner box, 140 ... Pad, 142 ...
... Pack pad, 144 ... Back plate, 154 ... Meandering prevention roller, 160.
...Wire, 162...Block (1
), 164...Block (2), 166...
...House, 170...Position ゛Determining spring,
178...Block received, 182...
Electromagnetic plunger, 184... Push-up lever, 186... Push-up spring, 188...
・Push-up plate (1), 190...Push-up plate (
2). Agent's name Patent attorney Toshio Nakao 1 stupid person 10 - 11 sense body Shoichi Transfer unit 50 - Transfer 4 belts 5z - Drive shaft % - J & vertical axis 56 - Transfer axis Hu - 2nd tea t1S bo - * d Reishoku 61 - Collar Kanki Ying 62 - Cleaning part 112... - Friendship reception → God b Ma /, * Public - 1 upper raising fIS t82 - gutter plunge Y - 184・- (〒 raising Lever 186---↑〒Shinigeba Base Figure 8

Claims (2)

[Claims] (1) An electrostatic latent image carrier, a charging means for charging the surface of the electrostatic latent image carrier, and the surface of the electrostatic latent image carrier charged by the charging means is exposed to light to form an electrostatic latent image. an exposure means for forming the electrostatic latent image, a developing means for visualizing the electrostatic latent image using toner and forming a toner image on the surface of the electrostatic latent image carrier, and transferring the toner image to a transfer material. and a transfer conveyance means for conveying the transfer material, and the transfer conveyance means directly supports and supports the transfer material by electrostatic force.
at least 10^1^0 for conveying, contacting the electrostatic latent image carrier, and transferring the toner image to the transfer material.
A transfer conveyance belt having a semiconductor layer formed of a semiconductor material having a resistivity of ~10^1^3 Ωcm, a driving means for driving the transfer conveyance belt, and supporting the transfer conveyance belt and the driving means. a transfer conveyance unit having a support means for pressing the transfer conveyance belt against the electrostatic latent image carrier; and a belt cleaning means for cleaning the surface of the transfer conveyance belt; 1. An electrophotographic apparatus comprising: a belt charging means for applying electrification. (2) The electrophotographic apparatus according to claim (1), wherein the transfer conveyance unit is configured to be detachable.