JP2002049243A - Image forming device - Google Patents

Abstract

(57) [Summary] In an image forming apparatus using a one-component developing method,
It is possible to avoid a decrease in density that occurs when the developing device is used for a long period of time without replacing the developing device, and at the same time, remove deposits on the surface of the image carrier. A developing device (10) is provided from a new toner container (31).
Before the toner is charged into the developing unit 10, control is performed such that the toner remaining in the developing device 10 is developed on the photoconductor 9 and collected by the cleaning blade 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer, a copying machine,
The present invention relates to an image forming apparatus such as a facsimile, and more particularly, to an image forming apparatus having a detachable toner cartridge.

[0002]

2. Description of the Related Art The one-component developing system is currently known as the most general developing system, as represented by a magnetic jumping developing system. Unlike the two-component developing method, this method is characterized in that the toner is agitated and the toner is charged in the gap between the blades, so that the control of the concentration of the carrier and the developer is unnecessary and the method is relatively inexpensive.

[0003]

However, since this developing method greatly depends on the characteristics of the toner, so-called selective development occurs in which the developing is preferentially performed depending on the charge amount and particle size of the toner. When this selective development occurs, the charge amount distribution and the particle size distribution of the toner in the developing device change, and if used for a long period of time, there is a problem that the density is reduced and fogging when replenishing the toner is caused. Was.

On the other hand, if the drum is used for a long period of time, the surface of the drum is contaminated with paper dust, toner, charge products, and the like, which may cause image blur and other image defects. there were.

As a method for avoiding these problems, there is a cartridge system in which the developing unit and the drum are replaced at a certain time. However, this system requires discarding usable members and purchasing a new one. This is not a desirable method in terms of quality.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has been developed by replacing only toner having changed physical properties in a developing unit without discarding usable members. It is an object of the present invention to provide an image forming apparatus capable of avoiding a decrease in density and a fog at the time of toner replenishment which occur when the toner is used for a long period of time and further removing foreign matter by polishing the surface of the image carrier.

Specifically, an image carrier, one-component developing means for developing toner on the image carrier, transfer means for transferring a developed image formed on the image carrier, and the image carrier And a cleaning unit that collects toner remaining in the image forming apparatus, wherein the developing unit includes a developing unit that stores the toner and develops the toner on the image carrier, and the developing unit is capable of filling the developing device with the toner. A toner container detachable from the developing device, and a detecting unit for detecting replacement of the toner in the developing device or an input unit for inputting replacement of the toner in the developing device. When an input is made by the input means, an image forming apparatus is controlled to execute a discharge mode in which toner remaining in the developing unit is developed on the image carrier and collected by the cleaning means. It is obtained by the apparatus.

Further, the discharge mode is an image forming apparatus which is used when the toner container is replaced.

Further, the toner contains an abrasive, and the cleaning means includes a polishing roll for performing polishing by contacting with the image carrier. After the image carrier is polished in the discharge mode, the toner is removed. Is an image forming apparatus that collects the images.

Further, after executing the discharge mode, the image is controlled to execute a filling / re-polishing mode in which the toner is charged from the toner container into the developing device and the image carrier is polished again. It is a forming device.

The transfer means may be a transfer roller, and the re-polishing may be performed by rotating the image carrier with a transfer material interposed between the image carrier and the transfer means. And an image forming apparatus for polishing the surface of the image carrier with a transfer material.

[0012]

Embodiments of the present invention will be illustratively described in detail below with reference to the drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention, but are merely illustrative examples. It's just

FIG. 1 shows an embodiment of an image forming apparatus to which the present invention is applied. The image forming apparatus 1 includes an a-Si photosensitive drum 9 rotating clockwise in FIG. A developing device 10, a transfer roller 19, a polishing roller 11 for cleaning, a cleaning blade 13, and a charging unit 8 are provided along the line.

A developing roller 32 is provided in the developing device 10, and the surface of the developing roller 32 is separated from the surface of the photosensitive member 9 by a predetermined distance. Then, the developing device 10 is used for the toner container 3.
It is configured to be able to supply a predetermined amount of toner from 1 as appropriate. The upper door 7 is disposed above the toner container 31 so as to be openable and closable about the base 7a in the direction of the arrow, and the toner container 31 is configured to be detachable.

An optical transmission mechanism 5 for forming image dots on the surface of the photoconductor 9 is provided above the photoconductor 9, and the optical transmission mechanism 5 includes a polygon mirror 2 for reflecting laser light from a laser light source (not shown), The optical system 3 is configured to form an image dot on the surface of the photoconductor between the charging unit 8 and the developing roller 32 via the reflection mirror 4 with the laser light.

At the lower part of the image forming apparatus 1, there is provided a base 54 in which a control circuit 71 for controlling the apparatus to be described later is housed. On the upper side of the base 54, a recording paper container 55 is detachably arranged from the outside. The recording paper container 55 is provided with a pre-transfer recording paper storage 14, and the recording paper placed on the pressing spring 52 is provided to face the auxiliary roller 30 through the passages 16 and 17 by the conveying rollers 53 and 15. It is configured to be able to be conveyed to the registered roller 18.

On the right side of the image forming apparatus 1, a front door 50 is provided.
When the front door 50 is opened as indicated by 50 ', the front door 50' is arranged so as to be openable and closable as indicated by a virtual line 50 '.
The recording paper placed on the paper is transported to the passage 17 by the transport roller 51.

On the left side of the image forming apparatus 1, a fixing roller 2
The fixing unit is constituted by 3 and 24, and the recording paper passing between the photosensitive member 9 and the transfer roller 19 is fixed by the fixing rollers 23 and 24.
The recording paper after fixing is transported by the transport rollers 25, 2
The recording paper stack 6 is configured to be accumulated on the transferred recording paper accumulation bin 6 by rollers 28 and 29 through a passage 27 by the cartridge 6.

A display unit 47 for displaying various information, an installation switch 48, and a power switch 49 are provided above the image recording apparatus 1.

The image recording apparatus 1 configured as above is
When the power switch 49 is closed, the main motor (not shown) starts driving, the photoconductor 9 is rotated clockwise by the start switch (not shown), and the optical transmission mechanism 5 forms an image on the surface of the photoconductor 9, Is developed by a developing roller 32 of the developing device 10, and the developed image is transferred to recording paper by a transfer roller 19, and is fixed to the fixing rollers 23 and 24.
, And are conveyed to and stacked by the stacker 6 by the rollers 25, 27, 28, and 29.

Next, each main part of the image forming apparatus 1 will be described. FIG. 2 is a sectional view showing the configuration of the developing device and the toner container, FIG. 3 is a perspective view showing the inside of the developing device, and FIG.
It is -A sectional drawing. In these figures, the developing device 10
Are storage chambers 10b and 10 in which magnetic one-component toner is stored.
c and a rotatable non-magnetic developing sleeve 32a
And a magnet 32 having a plurality of magnetic poles fixed therein.
b, the developing roller chamber 10e in which the developing roller 32 is disposed, and the surface of the developing roller is separated from the surface of the photoconductor 9 by a predetermined distance.

A wall 10a for separating the storage chambers 10b and 10c is provided along the longitudinal direction at the center of the developing device 10, and a piezoelectric sensor 39 is provided at the center of one wall 10g.
However, the pressing surface 39a is disposed so as to protrude slightly inside the wall surface 10g. The piezoelectric sensor 39 applies a predetermined voltage at a predetermined cycle under the control of a control circuit 71 described later,
The pressing surface 39a vibrates in the direction intersecting with the wall surface 10g in the cycle, and the vibration stops when the developer is filled with the toner, and the positive and negative voltages are input to the control circuit by the vibration of the piezoelectric sensor. The positive voltage is input to the control circuit by stopping the vibration.

At the center of the storage chambers 10b and 10c,
The first spiral shaft 41 and the second spiral shaft 42 are both provided so that the toner presses the spiral wrap toward the wall surface 10g, and the spiral shafts are respectively mounted on the wall surface via bearings 41a, 41a and 42a, 42a. 10g, and is disposed between the opposite wall 10h and rotatably clockwise. These spiral shafts are gears 45 provided on the outer wall surface of the developing device 10, respectively.
It is connected to a main motor 65 (FIG. 6) via 46.

Stir bars 43, 44 are mounted on the spiral shaft bearings 41a, 41a and 42a, 42a, respectively, so as to rotate and pass through positions deviated from each other by 180 °. And the stirring trajectory of the stirring rods 43 and 44 is the wall 1
0a, the toner in the storage chamber 10b can be easily moved to the next storage chamber 10c by the stirring rod 43, and the toner can be easily moved to the next storage chamber 10c by the stirring rod 43. When the toner is being moved to the storage room 10c, the stirring rod 44 in the storage room 10c
Is located at a position deviated by 180 °, the two stirring rods do not push the toner, and there is no hindrance to the transfer of the toner from the storage chambers 10b to 10c.

The deviation angle of both stirring rods is not limited to 180 °, but may be any angle as long as the transfer of the toner from the storage chambers 10b to 10c is not hindered. Further, a configuration without using the stirring cap 44 may be adopted.

A developing roller 32 is provided in a storage chamber 10e provided on the left hand side of the storage chamber 10c. The developing roller 32 has a developing sleeve 32a and a developing sleeve 32 which are rotatable to the outside in a direction indicated by an arrow. 32a and N on the photoconductor 9 side
The side seal 10d is provided at a predetermined interval from the surface of the developing sleeve 32a, and toner is supplied to the end of the side seal 10d toward the developing sleeve. The S pole 56 faces the opening 10j, and a regulating blade 40 for regulating the toner layer on the surface of the developing sleeve 32 is disposed on the left side of the S pole 56.

When the toner container 31 is mounted on the developing device 10, the developing sleeve 32a is connected to a main motor so as to be rotatable in the direction of the arrow. The photoreceptor 9 is disposed so that the surface of the photoreceptor 9 is located at a predetermined distance from the surface of the developing roller 32, and the toner agitated by the developing device 10 and regulated in the layer of the developing sleeve 32 a is developed by the developing roller 32. Magnetic spikes are formed by the N poles inside, and the image on the surface of the photoconductor 9 is developed.

An aperture 1 is provided on the upper surface of the developing device 10.
0f is opened, and when the toner container 31 is mounted on the developing device 10, the opening / closing door 38 having the toner discharge port 38a moves in conjunction with a mechanism (not shown) to move the aperture 10f.
, The toner discharge port 38a is opened.

The toner container 31 has an aperture 38.
a, a supply roller 33 for supplying toner through the a.
The supply rollers 33 and the stirring blades 36 and 37 are connected to a toner supply motor 67 (FIG. 6) when the toner container 31 is mounted on the developing device 10. It is configured.

Next, the operation of the developing device 10 and the toner container 31 configured as described above will be described. FIG. 5 is an explanatory diagram for exchanging the toner container 31. In the figure,
Opening the upper door 7 and raising it as shown in the drawing, removing the toner container 31 from the image forming apparatus 1 from the state of the toner container 31 shown by the solid line to the state shown by the virtual line 31 ', and inserting a new toner container. Can be used to replace the toner container.

As shown in FIG. 2, when the toner container 31 is mounted on the developing device 10, the opening / closing door 38 is opened, and the opening 38a and the aperture 10f of the developing device 10 are aligned. Developing unit 10 storage room 10
It falls into b. The piezoelectric sensor 39 receives positive and negative signals of a predetermined period from the control circuit, and the pressing surface 39a vibrates. However, toner is accumulated between the side walls 10g and 10h shown in FIG. When the piezoelectric sensors 39 accumulate so as to be pressed, the piezoelectric sensor 39 remains pressed to one side.

This signal indicates that a proper amount of toner has been accumulated in the developing device. On the other hand, the toner is agitated by the spiral shafts 41 and 42, charged, and sequentially sent to the storage chamber 10c. Then, the toner flies to the photoconductor 9 by the developing roller 32 to develop the surface of the photoconductor 9.

In FIG. 4, the total length L1 of the developing roller 32 is slightly shorter than the distance between the side walls 10g and 10h of the developing unit 10. However, the regulating blade 40 is provided between both side walls, and the developing roller end face is formed. And the scattering of toner between the side wall surfaces is minimized. Also, the wall 10a of the developing device 10
Is erected at the center, but the entire length L2 of the wall 10a is shorter than the entire length L1 of the developing roller 32 without the side wall of the developing device. The toner flow 57, 5 flowing by the spiral shaft 42
7 is formed.

The entire length L3 of the opening 38a provided on the toner storage chamber 10b side is shorter than the entire length L2 of the wall 10a as shown in FIG. 4, so that the toner dropped from the opening 28a is agitated. The storage room 1c directly by the rod 43
The toner is moved by the spiral shaft 41 in the direction of the arrow 58 and circulates outside the toner flow indicated by the arrow 58 near the spiral axis as the toner flows 59 and 57.

Further, in the storage chamber 10c, the toner enters the storage chamber 10c as a toner flow 57, or a small amount of the toner flows over the wall 10a from above by the stirring rod 43, and the toner flows into the storage chamber 1c.
Oc is circulated in the developing device as a toner flow 58, 57 or 58, 59.

As described above, the entire length of the developing roller 10, the entire length L2 of the wall 10a, and the entire length L3 of the toner receiving port are formed in the developing device 10 in a relationship of L1>L2> L3. When the toner is received from the container 31, the toner is not scattered and is not supplied to the developing roller side due to insufficient charging due to insufficient stirring.

Next, a control circuit for controlling the toner supply device will be described. As shown in FIG. 6, the control circuit 71 is mounted in the base 54 of the image forming apparatus 1. Control circuit 7
1 includes a CPU (central processing element), a counting circuit, and the like inside, a power switch 49 for supplying power to the image forming apparatus 1 at an input end, and an installation indicating that a user supplies toner to the apparatus for the first time. The switch 48, a recording sheet counting means 62, and information such as the state of the piezoelectric sensor 39 can be input, and a ROM 63 storing a control program and a RAM 64 storing measurement values and a calculation unit are connected. .

The output terminals include a main motor 65 for supplying power to the image forming apparatus 1, an electromagnetic clutch 66 connected to the main motor 65 to rotate the photosensitive member 9, a toner supply motor 67 for the toner container 31, Operating time control means 68 for controlling the operating time of the toner supply motor 67;
A motor speed control means 70 capable of variably controlling the rotation speed of the toner supply motor 67; a toner supply stop means 69 for stopping the motor even during the operation time of the toner supply motor depending on the toner supply state; The optical transmission mechanism 5 for transmitting image information to form an image, a display unit 47 for displaying various information, and a piezoelectric sensor (toner sensor) 39 composed of a piezoelectric sensor are connected.

Next, a configuration which is a feature of the present invention will be described. As the toner, a toner to which titanium oxide serving as an abrasive is externally added is used.
The surface of the photoconductor 9 is rubbed between the photoconductor 1 and the photoconductor 9. As a result, dust and the like on the photoconductor 9 can be removed, and in particular, when an a-Si photoconductor drum is used, a charged product that causes image flow can be removed. After passing through the polishing roller 1, the toner is scraped off by the cleaning blade 13 and collected as residual toner in a waste bottle (not shown).

The developing device 10 includes a toner container 31.
There is provided a detecting means (not shown) for detecting that the toner container 31 has been replaced, and the installation switch 48 acts as an input means for inputting by the user for notifying that the toner container 31 has been replaced. In this embodiment,
The means for detecting or inputting that the toner container 31 has been replaced as a detecting means or an input means has been described. With such detection means or input means, the charged toner can be discharged from the toner container 31 in the developing device 10 before replacement every time the toner container 31 is replaced. However, as another embodiment, a detection unit for detecting toner exchange in the developing unit 10 performed at an appropriate timing or an input unit for inputting replacement of the toner in the developing unit 10 may be provided.

In the control circuit 71, the toner container 31 is replaced, and the toner container 31 is
Before the toner is charged into the developing unit 10, the toner remaining in the developing unit 10 is developed on the photoreceptor 9, polished by the polishing roller 11, and then recovered by the cleaning blade 13.

Further, the control circuit 71 fills the developing unit 10 with toner from the replaced toner container 31 and, at the same time, sandwiches the transfer material between the photoconductor 9 and the transfer roller 19 with the registration roller 18 interposed therebetween. In this state, the photoconductor 9 can be controlled to rotate.

With this configuration, as shown in FIG. 7, a preparatory stage for mounting a new toner container 31 and an empty waste bottle, a developing bias is applied while rotating the photosensitive member 9 to remove the toner in the developing device 10 A discharging / polishing stage in which the toner is discharged while being developed on the photoconductor 9 and the surface of the photoconductor 9 is polished by the polishing roller 11 and then collected in a waste bottle, and new toner is charged from the toner container 31 into the developing device 10 and, at the same time, before transfer. When there is paper in the recording paper storage 14 (paper feed cassette), after passing through three stages of a filling and re-polishing stage in which the paper is sandwiched between the photosensitive member 9 and the transfer roller 19 and the drum surface is further polished, Normal printing processing can be performed. Note that the paper conveyance in the filling / re-polishing stage may be performed from the front door 50.

The operation of the three stages will be described below. First, as shown in FIG. 8, when the replacement mode is selected by the installation switch 48 when the toner container 31 is replaced, for example, “ADD NEWTON” is selected.
ER "is displayed (step 1). It is determined whether the toner is new toner (step 2).

Next, it is confirmed that the toner container 31 is mounted, and "REPLACE WASTE TONER" is checked.
"BOTTLE" is displayed (Step 3), and after confirming that the waste bottle is attached (Step 4), "PRE" is displayed.
"SS START BOTTON" is displayed (step 5), and the preparation stage is completed.

When the start button is pressed, the toner discharge / polishing mode shown in FIG. 9 starts at the timing shown in FIG. 11, and the time is measured by a built-in timer.

When a predetermined time has elapsed since the start of the toner discharge / polishing mode, the toner discharge / polishing mode is terminated (step 12). The discharging time at this time is preferably a time for discharging all of the toner in the developing device 10, and in this embodiment, it is set to 30 minutes. If the waste bottle is full during toner discharge (Yes in step 11), the “REPLACE WASTE TONER BOTT” is again displayed.
LE ”is displayed (step 3), and the process returns to the previous step.

The toner discharging operation and the surface polishing operation of the photosensitive member 9 will be described with reference to the timing chart of FIG. When the toner discharge / polishing mode starts, the main motor rotates, and thereafter, a developing bias is applied. At this time, since the charging bias is OFF, the surface of the photoconductor 9 is not charged, and the toner is developed on the surface of the photoconductor 9 by the potential difference between the photoconductor 9 and the developing sleeve 32a. Next, the toner developed on the surface of the photoreceptor 9 reaches the transfer roller 19. At this time, a bias voltage having a polarity opposite to that of the toner is applied to the transfer roller 19. It remains on the photoreceptor 9 without being soiled. After that, the toner on the photoreceptor 9 reaches the polishing roller 11 and the polishing roller 11
After the surface of the photoreceptor 9 is polished in the above, it is collected in a waste bottle.

FIG. 10 is a flowchart showing a mode for filling and repolishing the toner. When the toner filling / re-polishing mode starts, the toner supply motor 67 of the toner container 31 is driven, the toner in the toner container 31 is loosened by the stirring blades 36 and 37, and the toner is supplied to the developing device 10 by the supply roller 33. (Step 21). If the paper storage 14 is filled with paper (Yes in step 22), the paper feeding operation is performed (step 23), and the rotation of the registration rollers 18 is stopped after a certain time has passed after the paper passed the registration sensor. (Step 24) A state is set in which the sheet is sandwiched between the photosensitive member 9 and the transfer roller 19.

The operation time of the toner supply motor 67 is longer than that during normal toner supply, and is set to, for example, a first predetermined value of 600 seconds. If the toner sensor is at the H level within this predetermined value (the pressing surface of the piezoelectric sensor is depressed by pressing with toner) (Yes in step 25), the toner supply motor is stopped, and the toner stirring motor 70 is turned off. The toner in the developing device 10 is stirred by a spiral shaft for two seconds, and the refilling operation of the toner is completed. At this time, the registration roll is simultaneously rotated to discharge the sheet, and the normal printing can be performed. FIG. 12 shows a timing chart in the toner filling / re-polishing mode.

[0051]

As described above, according to the image forming apparatus of the present invention, the toner remaining in the developing device is removed from the image carrier at an appropriate timing, for example, before the toner is filled from a new toner container into the developing device. By executing the discharge mode in which the developing unit is developed and collected by the cleaning unit, it is possible to replace the toner having changed physical properties in the developing device without discarding usable members. An image forming apparatus can be provided which avoids a decrease in density that occurs in the image forming apparatus and fogging during toner replenishment.

Further, the toner contains an abrasive, and the cleaning means includes a polishing roll for polishing the image carrier in contact with the image carrier, and collects the toner after polishing the image carrier in the discharge mode. Accordingly, it is possible to provide an image forming apparatus that removes foreign matter by polishing the surface of the image carrier.

Further, at the same time as the toner is filled from the new toner container into the developing device, the image carrier is polished again, and more specifically, the transfer material is sandwiched between the image carrier and the transfer means. By re-polishing the image carrier with the transfer material, it is possible to provide an image forming apparatus that rubs the remaining toner even when the toner remains on and adheres to the image carrier in the discharge mode.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an image forming apparatus of the present invention.

FIG. 2 is a cross-sectional view illustrating a configuration of a developing device and a toner container in the image forming apparatus.

FIG. 3 is a perspective view showing the inside of a developing device in the image forming apparatus.

FIG. 4 is a sectional view taken along line AA of FIG. 2;

FIG. 5 is a diagram illustrating a state where a toner container is replaced.

FIG. 6 is a block diagram illustrating a control circuit in the image forming apparatus.

FIG. 7 is a schematic diagram of a replacement mode of the image forming apparatus.

FIG. 8 is a flowchart of a preparation stage of the image forming apparatus.

FIG. 9 is a flowchart of a toner discharging / polishing stage of the image forming apparatus.

FIG. 10 is a flowchart of a toner filling / re-polishing stage of the image forming apparatus.

FIG. 11 is a timing chart at the time of toner discharge / polishing stage of FIG. 9;

FIG. 12 is a timing chart at the time of a toner filling / re-polishing stage of FIG. 10;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Polygon mirror 5 Optical transmission mechanism 7 Upper door 9 Photoconductor 10 Developing device 11 Rubbing roller 31 Toner container 32 Developing roller 33 Supply roller 39 Toner sensor 47 Display part

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) G03G 21/00 510 G03G 21/00 326 372 F term (reference) 2H027 DA27 ED02 ED10 ED24 ED27 EE07 EF01 EG07 HB04 HB06 HB07 HB12 HB14 2H032 AA05 BA01 BA11 BA19 BA23 CA13 2H034 AA05 BC01 BC10 CA01 2H077 AA02 AC16 CA19 DA24 DA32 GA03

Claims (5)

[Claims] An image carrier; a one-component developing unit for developing toner on the image carrier; a transfer unit for transferring a developed image formed on the image carrier; and a transfer unit remaining on the image carrier. A cleaning unit that collects toner, wherein the developing unit includes a developing unit that stores the toner and develops the toner on the image carrier, and a developer that can fill the developing unit with the toner. A detachable toner container, and a detection unit for detecting replacement of the toner in the developing unit or an input unit for inputting replacement of the toner in the developing unit; and a detection by the detection unit or the input unit. When there is an input in (1), control is performed to execute a discharge mode in which the toner remaining in the developing unit is developed on the image carrier and collected by the cleaning unit. Image forming apparatus. 2. The image forming apparatus according to claim 1, wherein the discharge mode is performed when the toner container is replaced. 3. The image forming apparatus according to claim 1, wherein the toner contains an abrasive, and the cleaning means includes a polishing roll for performing polishing by contacting the image carrier with the image carrier. 2. The image forming apparatus according to claim 1, wherein the toner is collected after the operation. 4. The method according to claim 1, wherein after the discharge mode is executed, the charging and re-polishing mode for re-polishing the image carrier is performed at the same time as the toner is charged from the toner container into the developing device. The image forming apparatus according to claim 3, wherein 5. The image forming apparatus according to claim 5, wherein the transfer means is a transfer roller, and the re-polishing is performed by rotating the image carrier with a transfer material sandwiched between the image carrier and the transfer means. The image forming apparatus according to claim 4, wherein the surface of the body is polished.