JP4579394B2 - Intermediate transfer unit and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a configuration of an intermediate transfer body unit in an image forming apparatus such as a copying machine or a printer using an electrophotographic system.
[0002]
[Prior art]
An image forming apparatus using an electrophotographic system forms an image by developing a latent image with toner as a developer, and transferring and fixing the latent image on a sheet. In such an electrophotographic image forming apparatus, in order to form a color image in particular, it is generally known that a plurality of color toner images are primarily transferred onto an intermediate transfer member in a superimposed manner, and then transferred onto a sheet in a secondary transfer. ing.
[0003]
For example, as shown in FIG. 10, a conventional color image forming apparatus using an intermediate transfer member has a cartridge configuration in which an image carrier unit 100 and an intermediate transfer unit 101 are independent of each other. A large movable frame 102 is provided on the front surface (left side of the drawing) of the apparatus, and the image carrier unit 100 and the intermediate transfer unit 101 are detachably attached by rotating and opening the frame 102.
[0004]
The image carrier unit 100 is provided above the intermediate transfer body unit 101, and integrally includes a photosensitive drum 103 and a waste toner storage box. Waste toner on the photosensitive drum 103 is scraped off by the cleaning blade 104 and stored in the waste toner storage box 105 on the back surface.
[0005]
Waste toner on the intermediate transfer belt 106 of the intermediate transfer unit 101 is also scraped off by a cleaning blade (not shown), conveyed to the lower part of the first conveyance pipe by a conveyance coil, and further by a screw in the first conveyance pipe. It is conveyed to above the waste toner storage box 105. Thereafter, the toner is transported by the transport coil through the second transport pipe and finally stored in the waste toner storage box 105. Note that the connecting portion between the second transport pipe and the waste toner box is configured as a separate unit and is detachable, so that the waste toner is not spilled during detachment.
[0006]
In the above configuration, the image carrier unit 100 and the intermediate transfer body unit 101 are independently positioned on the image forming apparatus main body, and the drive transmission couplings of the photosensitive drum 103 and the intermediate transfer belt 106 are also independent. Thus, it is configured to be coupled to the coupling on the image forming apparatus main body side.
[0007]
Here, the cleaning blade itself for scraping the waste toner on the intermediate transfer belt 106 is provided in the intermediate transfer body unit 101, but the driving means for contacting and separating the cleaning blade from the intermediate transfer belt 106 is provided in the apparatus main body. Yes. In addition, a driving unit for bringing the secondary transfer unit 107 that collectively transfers the toner images on the intermediate transfer belt 106 onto the sheet to and away from the surface of the intermediate transfer belt 106 is also provided on the apparatus main body side.
[0008]
FIG. 11 shows conventional cam drive transmission means. As shown in the figure, an ICL contact / separation cam 108 for contacting and separating the cleaning blade is attached to an ICL contact / separation cam shaft 109. The ICL contact / separation cam shaft 109 extends over the right side plate 100a and the left side plate 100b of the apparatus main body. It is supported. Then, the ICL contact / separation cam 108 urges the cleaning blade to contact and separate from the intermediate transfer belt 106 by rotating the ICL contact / separation cam shaft 109 by a predetermined angle.
[0009]
Similarly, the apparatus main body includes a secondary transfer device contact / separation cam 110 for making the secondary transfer unit 107 contact and separate from the intermediate transfer belt 106, a secondary transfer device contact / separation cam shaft 111 for rotating the secondary transfer device 107, and a photosensitive drum 103. A DB contact / separation cam 112 and a DB contact / separation cam shaft 113 for contacting and separating the intermediate transfer belt 106 are provided from the right side plate 100a to the left side plate 100b.
[0010]
[Problems to be solved by the invention]
However, in the configuration according to the above conventional example, the cleaning blade that scrapes off the waste toner on the intermediate transfer belt 106 and the cam drive transmission means for bringing the secondary transfer means 107 into and out of contact with the surface of the intermediate transfer belt. Since it is provided on the main body side and the rotational driving force is also transmitted from the drive source in the apparatus main body via the gear train 114, the drive transmission path in the apparatus main body is complicated.
[0011]
Further, the mechanism for contacting and separating the cleaning blade and the secondary transfer means 107 to and from the intermediate transfer belt 106 requires levers and cams 108, 110, and 112, respectively, and requires through shafts 109, 111, and 113 across the width of the apparatus body. There is a problem that a large space is required in the apparatus main body and the configuration is complicated. For this reason, there existed a problem of causing the enlargement of a unit, the complexity and enlargement of an apparatus main body, and the raise of production cost.
[0012]
Furthermore, in the configuration in which the image carrier unit 100 and the intermediate transfer member unit 101 are provided separately, there is a problem that the entire apparatus becomes large. Further, the opening for attaching and detaching the unit is large and complicated, leading to an increase in cost. Furthermore, the presence of the two types of process cartridges may cause a predetermined attachment / detachment procedure, which may reduce the operability for the user.
[0013]
SUMMARY OF THE INVENTION An object of the present invention is to provide an intermediate transfer body unit and an image forming apparatus which minimize the drive transmission path from the apparatus main body and reduce the apparatus size and production cost.
[0014]
[Means for Solving the Problems]
  In order to solve the above-described problems, a typical configuration of the intermediate transfer unit according to the present invention is detachable from the apparatus main body.An intermediate transfer body unit comprising: an endless intermediate transfer belt; and a driving roller that stretches the intermediate transfer belt and rotates the intermediate transfer belt.Intermediate transferbeltaboveToner primarily transferred from image carrierSecondary transfer means for secondary transfer of the image to the sheet is the intermediate transfer.Belt outer surfaceSecondary transfer means for contacting and separating fromThe secondary transfer means contacting / separating means is pivotally supported on the inner surface side of the intermediate transfer belt.It is characterized by that.
  In another exemplary configuration of the image forming apparatus according to the present invention, a photoreceptor on which a toner image is formed, an endless intermediate transfer belt, the intermediate transfer belt is stretched, and the intermediate transfer belt is A driving roller that rotates, a primary transfer unit that primarily transfers a toner image from the photoconductor to the intermediate transfer belt, a secondary transfer unit that secondarily transfers the toner image transferred onto the intermediate transfer belt to a sheet, A cleaning unit for cleaning toner remaining on the intermediate transfer belt, which is not transferred to the sheet by the secondary transfer unit, from the intermediate transfer member; and the secondary transfer unit is brought into contact with and separated from the outer surface of the intermediate transfer belt. And a secondary transfer unit contacting / separating unit. The driving roller is provided at a position facing the secondary transfer unit via the intermediate transfer belt. The secondary transfer contact / separation means has a cam supported on the same axis as the drive roller, and has cam drive transmission means for transmitting a driving force to the cam, and the cam is the drive The secondary transfer unit is rotatable with respect to the roller, and the cam is rotated independently from the rotation of the drive roller by transmitting a driving force from the cam drive transmission unit, It is characterized in that it contacts and separates from the outer surface of the intermediate transfer belt.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of an intermediate transfer member unit and an image forming apparatus according to the present invention will be described with reference to the drawings. In this embodiment, the image forming apparatus is a four-color full-color laser beam printer that employs an electrophotographic system.
[0016]
(Image forming device)
FIG. 1 is a longitudinal sectional view illustrating a schematic configuration of an image forming apparatus. The image forming apparatus A has a process cartridge B that is detachable as an intermediate transfer body unit having an intermediate transfer body and secondary transfer means contact / separation means or cleaning contact / separation means. The process cartridge B will be described later.
[0017]
When forming an image, the photosensitive drum 1 as an image carrier is rotated in the direction of the arrow (counterclockwise) in the drawing while the surface is uniformly charged by a charging roller 2 as a charging unit, and light is irradiated by an exposure unit 3. By doing so, an electrostatic latent image is formed. Simultaneously with the formation of the electrostatic latent image, the developing device 4 is driven to first place the yellow developing device 4Y at the developing position, and the electrostatic latent image on the photosensitive drum 1 is developed with yellow toner. A voltage having the same polarity and substantially the same potential as the charging polarity of the photosensitive drum 1 is applied to the toner so that the yellow toner adheres to the electrostatic latent image.
[0018]
The toner image formed on the photosensitive drum 1 is transferred to an intermediate transfer belt 5 that is an intermediate transfer member that rotates in synchronization with the photosensitive drum 1 by a primary transfer roller 6 that is a primary transfer unit. A voltage having a polarity opposite to that of the toner is applied to the primary transfer roller 6 to attract the toner image on the photosensitive drum 1. When the yellow toner image is primarily transferred, the developing device 4 is rotated, and similarly, electrostatic latent image formation, development, and primary transfer are sequentially performed for each color of magenta, cyan, and black, and four colors are formed on the intermediate transfer belt 5. The toner images are superimposed.
[0019]
At this time, a secondary transfer roller 7 described later is in a non-contact state with the intermediate transfer belt 5. The charging roller 8 as a cleaning unit for the intermediate transfer belt 5 is also in a non-contact state with the intermediate transfer belt 5.
[0020]
On the other hand, a feeding cassette 10 that stacks and supplies sheets is disposed below the apparatus main body A, and is fed to the registration roller pair 13 by a feeding roller 11. A pre-registration sensor 12 that detects the sheet is provided upstream of the registration roller pair 13. The rotational driving force of the registration roller pair 13 is cut off by detecting the leading edge of the sheet, and the sheet S waits at a predetermined position. Let
[0021]
After the four color toner images are formed on the intermediate transfer belt 5, the secondary transfer roller 7 is pressed against the intermediate transfer belt 5 (state shown in FIG. 1). Further, in synchronization with the rotation of the intermediate transfer belt 5, the conveyance of the sheet waiting at a predetermined position in the vicinity of the registration roller pair 13 serving as a sheet conveyance unit is started, and the nip between the intermediate transfer belt 5 and the secondary transfer roller 7 is started. Sent to the department. A voltage having a polarity opposite to that of the toner is applied to the secondary transfer roller 7, and the toner image on the intermediate transfer belt 5 is secondarily transferred collectively onto the surface of the conveyed sheet.
[0022]
The sheet onto which the toner image has been secondarily transferred reaches the fixing means 15 via the conveyance belt unit 14, and is fixed with the heat and pressure applied thereto. Then, the sheet is conveyed along the discharge guide 17 by the fixing discharge roller 16, and discharged and stacked on the discharge tray 19 provided on the upper surface of the apparatus by the discharge roller pair 18, thereby completing the image formation.
[0023]
On the other hand, a charging roller 8 as a cleaning unit is pressed against the intermediate transfer belt 5 after the secondary transfer is completed, and the residual toner remaining on the intermediate transfer belt 5 is given a charge opposite to that at the time of transfer. The residual toner on 5 is electrostatically attached to the photosensitive drum 1. A cleaning blade 9 is brought into contact with the photosensitive drum 1 as a cleaning means, and residual toner scraped off from the surface is collected and accumulated in a waste toner storage box 20 through a waste toner conveying means described later.
[0024]
(Intermediate transfer unit)
Next, the process cartridge B that is an intermediate transfer body unit will be described. 2 and 3 are side views of the intermediate transfer body unit viewed from the left side, FIGS. 4 and 5 are side views of the intermediate transfer body unit viewed from the right side, and FIG. 6 is an intermediate transfer body. 7 is a top view of the unit, FIG. 7 is a view for explaining the operation of the waste toner conveying means, FIG. 8 is a view showing a state where the secondary transfer means and the cleaning means are in contact with the intermediate transfer member, and FIG. It is a figure explaining.
[0025]
As shown in FIG. 2, in the process cartridge B, an image carrier 21 having the photosensitive drum 1 is disposed above the projection of the intermediate transfer member 22 including the intermediate transfer belt 5, and the projection of the intermediate transfer member 22 is performed. A waste toner storage box 20 is disposed below.
[0026]
In the image carrier 21, both ends of the photosensitive drum 1 are rotatably supported by the right bearing 1 a and the left rotation shaft 1 b, and the main body of the apparatus via a drive transmission coupling 58 which is a drive bearing at the right end. A predetermined rotational driving force is transmitted from (see FIG. 6). Further, the image carrier 21 is also provided with a drum shutter 25 that opens and closes in conjunction with an operation of attaching to and detaching from the image forming apparatus main body.
[0027]
A charging roller 2 is pressed against the photosensitive drum 1 with a predetermined force by a compression spring 24 via bearings 23 at both ends, and is configured to rotate following the photosensitive drum 1. At least one of the bearings 23 is made of a conductive member, and the surface of the photosensitive drum 1 is uniformly charged by applying a predetermined charging bias voltage to the charging roller 2. Such a contact charging type charging device is disclosed in Japanese Patent Laid-Open No. 63-149669.
[0028]
In the intermediate transfer member 22, the intermediate transfer belt 5 is an endless belt, and is stretched around an intermediate transfer member frame 35 including a handshake part 35a by a driving roller 26 and a driven roller 27. The driven roller 27 is given a predetermined tension by a compression spring 29 provided on the bearings 28 at both ends. Both ends of the drive roller 26 are rotatably supported by a right bearing 26a and a left bearing 26b, and a predetermined rotational driving force is transmitted from the apparatus main body via a drive transmission coupling 59 which is a drive bearing portion at the right end. It has become so.
[0029]
A primary transfer roller 6 is provided at a position facing the photosensitive drum 1 across the intermediate transfer belt 5, and is pressed by a predetermined force by a compression spring 31 through bearings 30 at both ends, and is driven to rotate by the intermediate transfer belt 5. It is configured to At least one of the bearings 30 is formed of a conductive member, and a toner image on the surface of the photosensitive drum 1 is primarily transferred onto the intermediate transfer belt 5 by applying a predetermined charging bias voltage to the primary transfer roller 6.
[0030]
The driving roller 26 of the intermediate transfer member 22 is provided with a cleaning charging roller 32 which is a cleaning means (hereinafter referred to as ICL), and has an integral structure. The charging roller 8 disposed in the cleaning charging roller section 32 is configured to be pressed by the compression spring 34 with a predetermined force through the bearings 33 at both ends and to be driven to rotate. At least one of the bearings 33 is composed of a conductive member, and a voltage reverse to that at the time of transfer is applied to the charging roller 8 to apply a charge opposite to that at the time of transfer to the residual toner on the intermediate transfer belt 5. As a result, the waste toner on the intermediate transfer belt 5 is electrostatically adsorbed and collected on the surface of the photosensitive drum 1.
[0031]
The photosensitive drum 1 is provided with a cleaning blade 9 as a cleaning unit at a predetermined position. The residual toner on the photosensitive drum 1 and the residual toner on the intermediate transfer belt 5 attracted and collected on the photosensitive drum 1 described above. It is configured to scrape off. The scraped waste toner is prevented from falling onto the intermediate transfer belt 5 by the squeeze sheet 36 and falls into the image carrier frame 37. Waste toner collected on the bottom of the image carrier frame 37 is conveyed to the right side as viewed from the front of the apparatus by the rotation of the screw 38 (in the direction of arrow C in FIG. 6).
[0032]
As shown in FIG. 4, the waste toner is transported to the right side as viewed from the front of the process cartridge B by the screw 38 and slides down the waste toner passage 39 (in the direction of arrow D in FIG. 4). Further, a wire 40 having a U-shaped configuration as shown in FIG. 6 is provided inside the waste toner passage 39, and one end thereof is rotated to a position eccentric from the rotation center of the screw 38 as shown in the drawing. The other end is a free end, and is inserted into a hole 41 that connects the waste toner passage 39 and the waste toner storage box 20.
[0033]
Thus, when the screw 38 rotates in the direction of arrow C, the wire 40 traces the inner wall surface of the waste toner passage 39 while swinging as shown in FIGS. 7 (a) to (d). At this time, since the U-shape of the wire 40 moves back and forth in the waste toner transport direction, the waste toner can be prevented from being clogged and transported. Further, in the hole 41 connecting the waste toner passage 39 and the waste toner storage box 20, the end of the wire 40 rotates around the outer periphery of the hole 41 as shown in FIGS. 7 (a) to 7 (d). Clogging can also be prevented.
[0034]
Waste toner that has fallen into the waste toner storage box 20 from the hole 41 is acclimatized and accumulated by the stirring plate 42. Similar to the screw 38, the stirring plate 42 is rotated by a rotational driving force transmitted from the main body of the image forming apparatus.
[0035]
(Contact / separation means)
Here, the contact / separation means of the secondary transfer means and the cleaning means (ICL), which is a feature of the present invention, will be described. As shown in FIG. 6, ICL contact / separation cams 45a and 45b and secondary transfer roller contact / separation cams 46a and 46b are provided at both ends of the drive roller 26 of the intermediate transfer belt 5, respectively. Further, cam drive gears 47a and 47b are respectively disposed between the ICL contact / separation cam 45 and the secondary transfer roller contact / separation cam 46. The ICL contact / separation cam 45 and the secondary transfer roller contact / separation cam 46 are cam drive gears. 47 is fixed with a predetermined phase.
[0036]
The ICL contact / separation cam 45, the secondary transfer roller contact / separation cam 46, and the cam drive gear 47 are integrally provided to be rotatable with respect to the drive roller 26. The left and right cam phases are matched with each other, and the left and right cam drive gears 47a and 47b mesh with drive transmission gears 49a and 49b, which are cam drive transmission means provided at both ends of the through shaft 48, respectively. The cams at both ends are configured to rotate in synchronization. As shown in FIG. 5, the rotational driving force transmitted from the apparatus main body is transmitted from the gear 50 through idler gears 51 and 52 to the right drive transmission gear 49a. As a result, the driving force is transmitted from the drive transmission gears 49a, 49b provided at the left and right ends to the cam drive gears 47a, 47b, respectively, and the ICL contacting / separating cams 45a, 45b and the secondary transfer roller contacting / separating cams 46a, 46b rotate. To do.
[0037]
Here, the charging roller 8 for cleaning is rotatably held by the left and right bearings 33 as described above, and along the bearing slide portion 35b (see FIG. 4) of the intermediate transfer member frame 35 by the left and right compression springs 34. The drive roller 26 of the intermediate transfer belt 5 is urged. In the state shown in FIGS. 3 and 4, the tips 33 a of the left and right bearings 33 are in contact with the ICL contact / separation cams 45 a and 45 b, and the cleaning charging roller 8 is separated from the surface of the intermediate transfer belt 5.
[0038]
The secondary transfer roller 7 provided on the apparatus main body side is also rotatably held by the left and right bearings 54, and the intermediate transfer belt 5 is driven along the bearing slide guide portion 57 of the apparatus main body frame 56 by the compression spring 55. The roller 26 is energized. 3 and 4, the front ends 54 a of the left and right bearings 54 are in contact with the secondary transfer roller contact / separation cam 46 and are separated from the surface of the intermediate transfer belt 5. Here, a protrusion 57a for preventing the bearing 54 from coming off is provided at the tip of the bearing slide guide portion 57 on the apparatus main body frame 56 side, and the secondary transfer roller 7 does not fall out even if the process cartridge B is extracted from the apparatus main body. It is like that.
[0039]
In the above configuration, the cleaning contact / separation means includes an ICL contact / separation cam 45, a drive transmission gear 49, a compression spring 34, and a bearing 33. Similarly, the secondary transfer means contact / separation means includes a secondary transfer roller contact / separation cam 46, a drive transmission gear 49, a compression spring 55, and a bearing 54.
[0040]
The state where the charging roller 8 and the secondary transfer roller 7 are separated from the intermediate transfer belt 5 is a state where a toner image is formed on the intermediate transfer belt 5 or a state where the image forming apparatus main body itself is at rest. . The ICL contact / separation cam 45 and the secondary transfer roller contact / separation cam 46 are also the same when the process cartridge B is detached from the apparatus main body and when the process cartridge B is mounted on the apparatus main body. The transfer roller 7 is positioned in a phase that holds the transfer roller 7 in a separated state.
[0041]
When a toner image is formed on the intermediate transfer belt 5 and is secondarily transferred onto the sheet, the driving force is transmitted to the gear 50, whereby the driving transmission gear 49 is rotationally driven. As shown in FIG. The contact / separation cam 45 and the secondary transfer roller contact / separation cam 46 are rotated together by 180 °. As a result, the ICL contacting / separating cam 45 has a phase with a small diameter with respect to the bearing tip 33 a of the charging roller 8, and the charging roller 8 is biased to the intermediate transfer belt 5 by the biasing force of the compression spring 34. Exactly in the same manner, the secondary transfer roller contact / separation cam 46 is in a phase with a small diameter with respect to the bearing tip 54a of the secondary transfer roller 7, so that the secondary transfer roller 7 is subjected to an intermediate transfer belt by the biasing force of the compression spring 55. It is energized to 5.
[0042]
In this way, the bearing of the secondary transfer roller 7 or the charging roller 8 is urged and brought into contact with the cam provided coaxially with the drive roller, and the secondary transfer roller 7 or the charging roller 8 is contacted and separated by rotating the cam. With this configuration, the contact / separation means can be provided in the intermediate transfer body unit with a very simple configuration, and the drive transmission path can be minimized.
[0043]
(Cam drive transmission means)
Next, the configuration of the cam drive transmission means for transmitting drive from the image forming apparatus main body to the cam drive transmission means will be described. In FIG. 5, the gear ratio between the gear 50 directly connected to the coupling and the cam drive gears 47a and 47b is 1: 2, and the cam is configured to make a half rotation by one rotation of the coupling.
[0044]
As shown in FIG. 9A, one of the D cut portions at both ends of the cam drive shaft 60 is inserted into the gear 50, and the D cut portion at the other end is inserted into the coupling 61. Two holes 61a are provided in the coupling 61, and a groove 61b is formed on the outer periphery. A slide ring 62 for inserting the cam drive shaft 60 is provided between the coupling 61 and the gear 50 and is urged toward the coupling 61 by a compression spring 63. At this time, the two claw portions 62 a of the slide ring 62 are inserted into the holes 61 a of the coupling 61. Further, the protrusion 62b, which is a locking means provided on the outer periphery of the slide ring 62, passes through the groove 61b provided on the outer periphery of the coupling 61 and fits into the groove 43a provided on the right side cover 43. Match.
[0045]
When connecting the drive, as shown in FIG. 9B, the drive coupling 64 is slid and protrudes from the image forming apparatus main body. Then, the claw portion 64a of the drive coupling 64 is inserted into the hole 61a of the coupling 61 on the process cartridge B side, and the claw portion 62a of the slide ring 62 presses the entire slide ring 62 against the compression spring 63.
[0046]
At this time, the protrusion 62b provided on the outer peripheral portion of the slide ring 62 is detached from the groove 43a of the right side cover 43, and the lock is released. When the driving coupling 64 on the image forming apparatus main body side rotates in this state, the rotational driving force is transmitted through the claw portion 64a of the driving coupling 64 and the hole 61a of the coupling 61, and further, the gear 50, idler gears 51, 52 are transmitted. Rotational driving force is transmitted to the ICL contact / separation cam 45 and the secondary transfer roller contact / separation cam 46 via the.
[0047]
The drive coupling 64 on the image forming apparatus main body side is controlled by one rotation and is configured to stop at the same phase. Since the gear ratio between the gear 50 and the cam drive gears 47a and 47b is 1: 2, the ICL contact / separation cam 45 and the secondary transfer roller contact / separation cam 46 rotate 180 ° for each rotation of the drive coupling 64. . The state of these cams can be determined by looking at the current values of the intermediate transfer belt 5, the secondary transfer roller 7, and the charging roller 8.
[0048]
【The invention's effect】
As described above, the intermediate transfer body unit and the image forming apparatus according to the present invention are configured as an intermediate transfer body unit having the intermediate transfer body and the secondary transfer means contact / separation means or the cleaning contact / separation means. Thus, the drive transmission path in the image forming apparatus main body can be minimized.
[0049]
The contact / separation means is attached to the roller by a cam that is supported on the same axis as the roller that stretches the intermediate transfer member, a cam drive transmission means that transmits drive to the cam, and a secondary transfer means or a cleaning means. By comprising the biasing means for biasing and the bearing that pivotally supports the secondary transfer means or the cleaning means and contacts the cam, the contact / separation means can be provided in the intermediate transfer body unit with a very simple configuration. Also, the drive transmission path can be minimized in the intermediate transfer unit.
[0050]
Since the intermediate transfer body unit is small and can be configured with a small number of drive transmission paths, the entire image forming apparatus can be reduced in size, and the cost of the apparatus can be reduced.
[0051]
In addition, by configuring the image carrier and the intermediate transfer member as an integrated unit, even a color printer can be made as small and low-cost as a conventional black-and-white developing means and an image carrier-integrated process cartridge. Can do. In addition, since the opening for attaching and detaching the unit can be made small and simple, the cost of the apparatus can be further reduced.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view illustrating a schematic configuration of an image forming apparatus.
FIG. 2 is a side view of the intermediate transfer body unit viewed from the left side with respect to the front surface.
FIG. 3 is a side view seen from the left side with respect to the front surface of the intermediate transfer body unit.
FIG. 4 is a side view of the intermediate transfer body unit viewed from the right side with respect to the front surface.
FIG. 5 is a side view of the intermediate transfer body unit viewed from the right side with respect to the front surface.
FIG. 6 is a top view of an intermediate transfer body unit.
FIG. 7 is a diagram illustrating an operation of a waste toner conveying unit.
FIG. 8 is a diagram illustrating a state where the secondary transfer unit and the cleaning unit are in contact with the intermediate transfer member.
FIG. 9 is a diagram illustrating cam drive transmission means.
FIG. 10 is a diagram illustrating a conventional image forming apparatus.
FIG. 11 is a diagram for explaining conventional cam drive transmission means.
[Explanation of symbols]
A: Image forming apparatus
B ... Process cartridge
S ... Sheet
1 ... Photoconductor drum
1a: Right side bearing
1b: Left rotation axis
2 ... Charging roller
3 Exposure means
4 ... Developing device
5 ... Intermediate transfer belt
6 ... Primary transfer roller
7: Secondary transfer roller
8 ... Charging roller
9 ... Cleaning blade
10 ... Feed cassette
11… feed roller
12… Sensor before cash register
13… Registration roller pair
14… Conveyor belt unit
15: Fixing means
16… Fixing discharge roller
17… discharge guide
18… discharge roller pair
19… discharge tray
20 ... Waste toner storage box
21 ... Image carrier
22… Intermediate transfer member
23… Bearing
24… Compression spring
25… Drum shutter
26… Drive roller
26a… Right side bearing
26b… Left side bearing
27… driven roller
28… Bearing
29… Compression spring
30… Bearing
31… Compression spring
32… Cleaning charging roller
33… Bearing
33a ... tip
34… Compression spring
35 ... Intermediate transfer frame
35a ... handshake part
35b ... Bearing slide part
36… Squeesheet
37… Image carrier frame
38 ... Screw
39… Waste toner passage
40 ... Wire
41… hole
42… Stirring plate
43… Right side cover
43a ... Groove
44… Left side cover
45 ... ICL contact / separation cam
46… Secondary transfer roller contact cam
47… Cam drive gear
48… through shaft
49… Drive transmission gear
50… Gear
51… idler gear
52… idler gear
53… Bearing
54… Bearings
54a ... tip
55… Compression spring
56… System unit frame
57… Bearing slide guide
57a ... Projection
58… Drive transmission coupling
59… Drive transmission coupling
60… Cam drive shaft
61… Coupling
61a… hole
61b ... groove
62… Slide ring
62a ... nail part
62b ... Projection
63… Compression spring
64… Drive coupling
64a ... nail part

Claims (9)

An intermediate transfer unit that is detachable from an apparatus main body, and includes an endless intermediate transfer belt, and a driving roller that stretches the intermediate transfer belt and rotates the intermediate transfer belt. In
Has a secondary transfer unit moving means for contacting and separating the secondary transfer means for secondarily transferring the toner image primarily transferred from the image carrier to the intermediate transfer belt onto a sheet against the outer surface of the intermediate transfer belt ,
The intermediate transfer member unit , wherein the secondary transfer means contacting / separating means is pivotally supported on the inner surface side of the intermediate transfer belt . The drive roller is provided at a position facing the secondary transfer unit via the intermediate transfer belt, and the secondary transfer contact / separation unit has a cam supported on the same axis as the drive roller. 2. The cam according to claim 1, wherein the cam is rotatable with respect to the drive roller, and the secondary transfer means is brought into contact with and separated from the outer surface of the intermediate transfer belt by the rotation of the cam. The intermediate transfer member unit described. Cam drive transmission means for transmitting drive force to the cam, wherein the cam rotates independently of rotation of the drive roller by transmitting drive force from the cam drive transmission means. The intermediate transfer member unit according to claim 2. A cleaning unit for cleaning the intermediate transfer belt in contact with an outer surface of the intermediate transfer belt, and a cleaning contact / separation unit for bringing the cleaning unit into contact with or separated from the outer surface of the intermediate transfer belt. The intermediate transfer member unit according to claim 1 . The intermediate transfer member unit according to claim 4, wherein the cleaning unit is provided at a position facing the driving roller via the intermediate transfer belt . 6. The intermediate according to claim 1 , further comprising: a photoconductor on which a toner image is formed; and a waste toner storage box that stores toner collected from the photoconductor. Transfer body unit. A photoreceptor on which a toner image is formed, an endless intermediate transfer belt, a driving roller that stretches the intermediate transfer belt and rotates the intermediate transfer belt, and a toner image from the photoreceptor to the intermediate transfer belt. A primary transfer means for primary transfer, a secondary transfer means for secondary transfer of the toner image transferred onto the intermediate transfer belt to the sheet, and a toner image remaining on the intermediate transfer belt without being transferred to the sheet by the secondary transfer means. An image forming apparatus comprising: a cleaning unit for cleaning toner from the intermediate transfer member; and a secondary transfer unit contacting / separating unit for contacting and separating the secondary transfer unit with respect to an outer surface of the intermediate transfer belt.
The drive roller is provided at a position facing the secondary transfer unit via the intermediate transfer belt, and the secondary transfer contact / separation unit has a cam supported on the same axis as the drive roller. A cam drive transmission means for transmitting a driving force to the cam; the cam is rotatable with respect to the drive roller; and the secondary transfer means is driven by the cam from the cam drive transmission means. An image forming apparatus, wherein the image forming apparatus contacts and separates from the outer surface of the intermediate transfer belt by rotating independently of the driving roller by transmitting force. The cam drive transmission means includes a first coupling and a second coupling that is fitted to the first coupling and transmits a driving force from the first coupling, The image forming apparatus according to claim 7, wherein when the first coupling stops, the first coupling stops at the same phase. The image forming apparatus according to claim 7, further comprising a cleaning contact / separation unit that contacts and separates the cleaning unit with respect to an outer surface of the intermediate transfer belt.

Images