JPH07230224A - Image forming device - Google Patents

Abstract

PURPOSE:To prevent a transfer roller from pressing a photoreceptor over a long period when a device is stopped and to reduce the cost and size by providing a simple means for bringing and separating the transfer roller into contact with and from the photoreceptor. CONSTITUTION:The device is provided with a swing support-member 53 which supports the transfer roller 51 so that it can rotate, a spring 54 which energizes the support member 53 in the direction shown by the arrow B, a drive gear 10 which is driven by a main motor, a one-way clutch 11 provided on the swing central shaft 53a of the swing support-member and formed so that a connection gear 12, which meshes with the drive gear 10, is integrated with the circumference of the central shaft. The one-way clutch 11 transmits the swing central shaft 53a only a rotating drive force from the main motor, whose direction is opposite to that in a copying operation. After the copying operation, the main motor is reversely rotated only for the prescribed time, and the support member 53 is swung in the opposite direction to the direction shown by the arrow B against the energizing force of the spring 54, thereby separating the transfer roller 51. The transfer roller 51 may be driven by the gear 12 via an intermediate gear.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a facsimile or a printer, and more specifically, an image carrier and an image forming means for forming a visible image with a developer on the image carrier. The present invention relates to an image forming apparatus including a transfer device that transfers a visible image formed on the image carrier to a transfer material by using a transfer member that is in contact with the image carrier.

[0002]

2. Description of the Related Art In recent years, in this type of image forming apparatus, a transfer apparatus such as a transfer roller, a transfer belt, a transfer brush, or the like, in which a transfer member is arranged so as to contact an image carrier, is used because the generation of ozone is extremely small. Has been used. In a transfer device using such a transfer member, when the device is left for a long period of time, the transfer member is always in contact with the image carrier, so that the component of the substance forming the transfer member is image carrier. There is a problem that the image carrier oozes out to the body side and contaminates the image carrier, and as a result, an image defect occurs corresponding to the contaminated portion on the image carrier.

If a transfer member such as a transfer roller is left in pressure contact with the image carrier for a long period of time, the pressure contact portion of the transfer member is deformed and cannot return to its original state. as a result,
There is also a problem that unevenness in the rotational pitch of the transfer member occurs in the image feeding direction.

In order to solve the above problems, the transfer member may be separated from the image bearing member except when the image is formed, and at least the transfer member may be brought into contact with the image bearing member during the image forming. For example, in Japanese Unexamined Patent Publication (Kokai) No. 2-82278, the solenoid is energized to attract the movable shaft in synchronization with the start signal of one process from the charging process to the transfer process or the operation start signal of the fixing roller, and the movable shaft is moved. It is disclosed that a transfer roller as a transfer member connected to a shaft is brought into pressure contact with an image carrier. Further, for example, Japanese Patent Laid-Open No. 3-35
In Japanese Patent Laid-Open No. 276, in order to prevent the occurrence of permanent strain in the transfer member, a separating means for separating the transfer member from the material to be transferred is provided except when an image is formed, and the separating means is rotated around a fulcrum. A holding member that freely holds the transfer roller, which is a transfer member, a spring that urges the transfer roller so that the transfer roller is separated from the image carrier, a solenoid, and a movable shaft attracted by exciting the solenoid. It is disclosed that a transfer roller is provided with a link member and an elastic member that press the end portion of the holding member so that the transfer roller contacts with an appropriate pressure.

[0005]

However, a solenoid is used as a contact / separation means for a transfer member such as a transfer roller as disclosed in the above-mentioned JP-A-2-82278 and JP-A-3-35276. However, the manufacturing cost is high and the space for installing the solenoid is required, which hinders the downsizing of the device.

In Japanese Patent Laid-Open No. 3-107180, vibration is generated due to impact when the solenoid is operated.
In order to prevent the vibration and its adverse effect on the image carrier side, a cam receiver is axially supported coaxially with a transfer roller as a transfer member without using a solenoid, and the cam receiver and the control cam are formed by an elastic member. It is configured so as to be brought into pressure contact, and the rotation of the control cam causes the transfer roller to operate so that the recording paper comes into pressure contact with the photosensitive drum as an image carrier at the time of transfer, and is provided so as to be separated from the photosensitive drum at the time of non-transfer. It is disclosed that a transfer device is controlled via a cam so that the transfer material is operated so as to press the transfer material against the image carrier at the time of transfer.

However, the embodiment disclosed in Japanese Patent Laid-Open No. 3-107180 discloses a control cam having a relatively large diameter and further provided with a motor for rotating the control cam. However, in this case, it is disadvantageous in terms of downsizing the device. Further, instead of rotationally driving the control cam from a motor via a drive gear, a gear is provided on the drum shaft of the photosensitive drum, and the control cam is driven by meshing the gear with the gear provided on the control cam. In this case, since it is necessary to provide a speed reduction mechanism between the gear on the drum shaft side and the gear on the control cam side, it is also necessary to reduce the size and cost of the device. It is disadvantageous in terms of trying.

The present invention has been made in view of the above problems, and an object of the present invention is to avoid pressure contact of a transfer member with an image carrier for a long period during non-image formation, and
An object of the present invention is to provide an image forming apparatus equipped with a means for separating and contacting a transfer member with an image carrier, which can achieve cost reduction and size reduction.

[0009]

In order to achieve the above object, the invention of claim 1 provides an image carrier, an image forming means for forming a visible image on the image carrier by a developer, and the image. An image forming apparatus including a transfer device that transfers a visible image formed on the image carrier to a transfer material by using a transfer member that is in contact with the carrier, and the transfer member is rotatable and A rocking support member that supports the body so that it can come into contact with and separate from the body; a biasing unit that biases the rocking support member in the direction in which the transfer member contacts the surface of the image carrier; A one-way clutch that transmits only a rotational driving force in a separating direction in which the transfer member separates from the surface of the image carrier to the swing center axis, a driving member driven by a rotational driving source of the apparatus main body, and the one-way clutch. Between the connecting member and the one-way clutch when the image forming operation is completed. As the rotational driving force is transmitted and is characterized in that a control means for reversely rotating the rotary drive source for a predetermined time. Here, the predetermined time is set to at least the time when the transfer member is separated from the image carrier.

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, a drive gear is used as the drive member, and a bearing-shaped one-way clutch provided on the swing center shaft is used as the one-way clutch. The connecting member is a connecting gear integrally formed on the outer peripheral surface of the bearing-shaped one-way clutch so as to mesh with the drive gear.

According to a third aspect of the present invention, in the image forming apparatus according to the first aspect, drive transmitting means for transmitting a rotational drive force from the driving member or the connecting member to the transfer member is provided. is there. When a connecting gear is used as the connecting member as in claim 2, an intermediate gear may be provided as the drive transmitting means between the connecting gear and the gear provided on the rotation shaft of the transfer member. .

[0012]

According to the invention of claim 1, the transfer member is rotatably supported by the biasing means, and the transfer member is centered on the swing center axis so as to come into contact with and separate from the image carrier. The rocking support member that rocks is biased in the direction in which the transfer member contacts the image carrier. During the image forming operation, the one-way clutch does not transmit the rotational drive force from the drive member driven by the rotational drive source of the apparatus main body to the swing center shaft, so that the swing center shaft is rotatable. Therefore, the oscillating support member oscillates around the oscillating central axis by the urging force of the urging means, the transfer member comes into contact with the image carrier at a predetermined pressure, and The visible image of is ready to be transferred to the transfer material.

At the end of the image forming operation, the rotary drive source is reversed by the control means for a predetermined time. The rotational driving force from the driving member driven by the rotational driving source is transmitted to the swing center shaft through the connecting member and the one-way clutch, so that the urging force by the urging means is resisted. The swing support member swings, and the transfer member can be separated from the surface of the image carrier. After the rotation drive source is stopped, the one-way clutch between the rotation drive source and the swing center shaft is in the connected state for transmitting the rotation drive force. It is possible to prevent the swinging support member from swinging in a direction in which the transfer member comes into contact with the image carrier due to an urging force, and the separated state of the transfer member is rotated by the rotation drive source in the next image forming operation. Can be maintained until the beginning.

Particularly, in the invention of claim 2, during the image forming operation, the rotational driving force from the driving gear driven by the rotational driving source of the apparatus main body is formed on the outer peripheral surface of the bearing-shaped one-way clutch. However, this rotational driving force is not transmitted to the swing center shaft inside the one-way clutch, and the swing center shaft is rotatable, so that the biasing force is applied. The oscillating support member oscillates around the oscillating center axis by the urging force of the means, the transfer member comes into contact with the image carrier at a predetermined pressure, and the visible image on the image carrier is transferred to the transfer material. Ready to go.

At the end of the image forming operation, the rotary drive source is reversely rotated for a predetermined time by the control means. The rotational drive force from the drive gear driven by the rotational drive source is transmitted to the swing center shaft through the coupling gear and the one-way clutch, and therefore resists the urging force of the urging means. The swing support member can be swung to separate the transfer member from the surface of the image carrier.

Further, in the invention of claim 3 in particular, the drive transmission means causes the surface of the transfer member to move from the drive member or the connecting member to the transfer member in the same direction as the surface of the image carrier. It becomes possible to transmit various rotational driving force.

[0017]

Embodiments Embodiments in which the present invention is applied to an electrophotographic copying machine (hereinafter referred to as a copying machine) which is an image forming apparatus will be described below. FIG. 1 is a schematic configuration diagram of a copying machine according to this embodiment. This copying machine includes a photoconductor drum 1 as an image carrier, a charging device including a charging roller 2, an exposure device (not shown), an eraser 3, a developing device 4, a transfer roller 51 as a transfer member, and a transfer material. Transfer device 5 including guide member 52 that guides the transfer sheet and the like, photosensitive drum 1
The cleaning device 6 includes a cleaning blade 61 that comes into contact with the surface of the cleaning device 6, the static eliminator 7, and the like. The image forming means for forming a toner image on the photosensitive drum 1 is composed of the charging roller 2, the exposing device, the developing device and the like. The guide member 52 is configured to be swingable with a support shaft 52a as a fulcrum by a manual operation or the like as needed. The transfer roller 51 is disposed inside the guide member 52, and the opening 5 of the guide member 52 is provided.
It can be pressed against the photosensitive drum 1 through 2b.

During the copying operation by the copying machine, the photosensitive drum 1 is rotationally driven in the direction of the arrow by the main motor (not shown) of the apparatus main body as a rotational drive source, and the charging roller 2 uniformly charges the surface of the photosensitive drum 1. Is
The exposure device irradiates the surface of the photoconductor drum 1 with a light image L corresponding to the original to form an electrostatic latent image. Then, the developing device 4 supplies toner to the electrostatic latent image on the photosensitive drum 1 to form a toner image. Then, a transfer paper (not shown) as a transfer material is transferred by the registration roller 8 along the guide member 52 at a predetermined timing and a predetermined voltage is applied by a bias power source (not shown) to the transfer roller 51 and the photosensitive drum 1. The toner image on the photoconductor drum 1 is electrostatically transferred onto a transfer sheet by being conveyed to a pressure contacting part with. The transfer paper on which the toner image has been transferred is separated from the photosensitive drum 1 and conveyed to a fixing device, where it is subjected to a fixing process, and then discharged outside the machine. On the other hand, the photosensitive drum 1 after transfer
The residual toner on the surface of 1 is scraped off by the cleaning blade 61 and stored in the cleaning device 6. The surface of the photosensitive drum 1 after cleaning is subjected to predetermined light irradiation by the static eliminator 7 to remove residual charges, and is ready for the next image formation. When a jam occurs in the transfer device 5, the guide member 52 is swung in the direction of the arrow A with the support shaft 52a as a fulcrum to easily remove the transfer sheet causing the jam. be able to.

When the transfer roller 51 is left in contact with the surface of the photosensitive drum 1 for a long period after the copying operation is completed, the substance forming the transfer roller 51 seeps out to the photosensitive drum 1 side. Contamination of the photoconductor causes image defects corresponding to the contaminated portion, and the transfer roller 5
There is a possibility that the pressure contact portion of the first photosensitive drum 1 with the photosensitive drum 1 may be deformed and may not return to the original state, and unevenness may occur in the rotation pitch of the transfer roller 51 in the image feeding direction.

Therefore, in this embodiment, the transfer device 5 and the like are configured so that the transfer roller 51 is separated from the surface of the photosensitive drum 1 from the end of the copy operation to the start of the next copy. FIG. 2A is a perspective view showing a schematic configuration of the transfer device 5. The transfer roller 51 includes a metal cored bar 51a,
It is composed of a conductive elastic member 51b wound around the entire circumference of the core metal 51a. And the transfer roller 5
A swing support member 53 that rotatably supports the core metal 51a of the first core 51a so that it can be brought into contact with and separated from the photosensitive drum 1, and the swing support member 53 in the direction of arrow B with the swing center shaft 53a as a fulcrum. A pressure spring 54 is provided as a biasing means for biasing.

The end portion of the swing center shaft 53a is rotatably attached to the front and rear side plates 9 (not shown in FIG. 1A) of the apparatus body via bearings. Also, the swing center shaft 53
Swing side plates 53b, c for rotatably supporting the cored bar 51a of the transfer roller 51 are fixed to the front and rear ends of a by welding or the like. The swing center shaft 53 of each swing side plate 53b, c
Bearings 53d and e are attached to the end portion on the side opposite to the fixed portion to a, and the core metal 51a of the transfer roller 51 is inserted and attached to the bearings 53d and e.

The pressure spring 54 includes a pin 53f provided on an end of the swing center shaft 53a of the swing support member 53 and a pin 52 provided on a side plate of the guide member 52.
It is bridged between c and c and urges the swing center shaft 53a to rotate in the direction of arrow B.

The copying machine is shown in FIGS. 1 (a) and 1 (b).
As shown in FIG.
In addition, the bearing-shaped one-way clutch 11 attached to the end of the swing center shaft 53a so that the transfer member 51 transmits only the rotational driving force in the separating direction separating from the surface of the photosensitive drum 1.
And a connecting gear 12 as a connecting member between the drive gear 10 driven by the main motor and the one-way clutch 11,
At the end of the copying operation, the one-way clutch 11 is provided with a control unit that reversely rotates the main motor for a predetermined time so that the rotational driving force in the separating direction is transmitted. The connecting gear 12 is integrally formed on the outer peripheral surface of the one-way clutch 11. In addition, the one-way clutch 11 is shown in FIG.
When the connecting gear 12 in (b) rotates in the direction of arrow C, the rotational driving force of the connecting gear 12 is not transmitted to the swing center shaft 53a, while when rotating in the direction of arrow D, the connecting gear 12 is connected. The rotational driving force of the gear 12 is transmitted to the swing center shaft 53a. As the one-way clutch 11, for example, a commercially available HF
NTN one-way clutches (trade name) such as type, HFL type and NHF type can be used.

As the control means, a control unit 500 of the apparatus body as shown in the block diagram of FIG. 3 can be used. The control unit 500 includes a ROM 501 and a RAM 50.
2, I / O interface 503 and the like. By the control unit 500, the connection gear 12 is rotated in the direction of arrow C in FIG. 1B during the normal copy operation, while the connection gear 12 is rotated in the direction of arrow D for a predetermined time after the end of the copy operation. First, the rotation direction of the main motor 13 of the apparatus body is controlled.

As described above, during the normal copying operation of the copying machine having the above-described structure, the rotation driving force of the main motor 13 causes the rotation of the main motor shown in FIG.
As shown in (a), the drive gears 10 and 12 rotate in the arrow direction. At this time, the rotational driving force of the coupling gear 12 is not transmitted to the swing center shaft 53a of the swing support member 53, and the one-way clutch 11 and the swing center shaft 53a are in a free state. The swinging central shaft 53a is rotated in the direction of the arrow in the figure by the pressure spring 54. By this rotation,
Swing side plates 53b, c fixed to the swing center shaft 53a
Is oscillated, and the transfer roller 51 rotatably attached to the end portions of the side plates 53b and 53c is pressed against the photosensitive drum 1 at a constant pressure. The transfer roller 51 rotates together with the photoconductor drum 1 in the arrow direction by the frictional force with the photoconductor drum 1.

At the end of the copy operation, FIG.
As shown in (b), the main motor 13 is driven by the drive gear 1
0 and 12 are slightly reverse-rotated for a predetermined time so that they rotate in the direction of the arrow. For example, the surface of the photosensitive drum 1 is 5
It moves at least 10 mm, and at least the transfer roller 5
1 is reversely rotated until it is separated from the photosensitive drum 1. The reverse rotation drive of the main motor 13 may be performed in the related art in order to remove the toner attached to the tip of the cleaning blade 61 of the cleaning device 6. (Hereafter, margin)

Since the rotational driving force of the connecting gear 12 due to the reverse rotation of the main motor 13 is transmitted to the swing center shaft 53a of the swing support member 53, it swings against the biasing force of the pressure spring 54. The central shaft 53a rotates in the direction of the arrow in the figure. Due to this rotation, the swing side plates 53b and c fixed to the swing center shaft 53a swing, and the transfer roller 51 is separated from the photosensitive drum 1. After that, even if the rotation of the main motor 13 is stopped, since the one-way clutch 11 is in the connected state for transmitting the rotational driving force, the swing center shaft 53a does not rotate and the separated state is maintained. It

When the copying operation is performed again, the swing center shaft 53a becomes free as described above, and the transfer roller 51 is pressed against the photosensitive drum 1 at a predetermined pressure.

As described above, according to the present embodiment, the transfer roller 51 is separated from the photosensitive drum 1 at the end of the copying operation, and the separated state is maintained even when the apparatus main body is stopped. It is no longer left in contact with 1 for a long time. Therefore, it is possible to suppress the contamination of the photoconductor due to the exudation of the constituent material of the transfer roller 51 to the photoconductor, and the occurrence of the image defect corresponding to the contaminated part. It is possible to suppress the occurrence of uneven rotation of the transfer roller 51 due to the deformation of the pressure contact portion.

Further, according to this embodiment, the one-way clutch 11 and the coupling are provided between the swing center shaft 53a of the swing support member 53 and the drive gear 10 driven by the main motor 13 of the apparatus main body. The rocking support member 5 has a simple structure in which the gear 12 is provided and the rotation direction of the main motor 13 is controlled.
Since the contact / separation control of the transfer roller 51 can be performed via 3, there is no need to separately provide a drive mechanism such as a solenoid as in the conventional case, and the size and cost of the apparatus can be reduced.

Further, according to this embodiment, the drive gear 10 driven by the main motor 13 even during the copying operation.
Since the connecting gear 12 that meshes with can be kept rotating, it is necessary to separately provide a clutch mechanism or the like for turning on / off the drive transmission in the middle of the drive transmission system from the main motor 13 to the connecting gear 12. In addition, the size and cost of the device can be further reduced.

In the above embodiment, the transfer roller 51 is configured to rotate together with the surface of the photosensitive drum 1 in pressure contact with the copying operation, but the same direction as the moving direction of the surface of the photosensitive drum 1 is used. Alternatively, the transfer roller 51 may be driven so as to move the surface of the transfer roller 51.

FIGS. 5A and 5B are front views showing a schematic structure of the transfer device 5 which drives the transfer roller 51 at the time of the copy operation and at the end of the copy operation, respectively. In the present modification, the back side end of the core metal 51 of the transfer roller 51 is
The gear 51c is attached, and the gear 51c and the coupling gear 12 are attached.
An intermediary gear 14 is interposed between and, and the rotational driving force is transmitted from the coupling gear 12 to the transfer roller 51. Figure 5
As shown in (a), when the transfer roller 51 is independently driven without being driven by the photoconductor drum 1 during the copying operation, the transfer roller 51 is pressed against the photoconductor drum 1 and driven. Thus, the transfer roller 51 can be rotated more stably. Therefore, it is possible to prevent the transfer failure due to the slip of the transfer roller 51 which may occur when the transfer roller 51 is driven. Even at the end of the copy operation of this modification,
By rotating the main motor 13 in the reverse direction, as shown in FIG.
As shown in (b), the rotational driving force of the coupling gear 12 is transmitted to the swing center shaft 53a via the one-way clutch 11, and the swing support member 53 swings against the biasing force of the spring 54. The transfer roller 51 is separated from the photosensitive drum 1.

Further, as shown in FIG. 6, the transfer roller 51
Is rotated via a gear 1a integrally provided on a flange portion at an axial end portion of the photoconductor drum 1 and a gear 51c attached to an end portion of a core metal 51a of the transfer roller 51 so as to mesh with the gear 1a. You may drive. In the configuration of this modification, the diameter of the gear 1a and the diameter of the main body of the photosensitive drum 1 are substantially the same, and the diameter of the gear 51c and the diameter of the transfer roller 51 main body are substantially the same. In addition, the transfer roller 5
1 so that the gear 1a and the gear 51c are not disengaged from each other when the photosensitive drum 1 is separated from the photosensitive drum 1.
Of the gears 1a and 51c when the transfer roller 51 is pressed against the photosensitive drum 1.
Smaller than the meshing amount of. Particularly according to this modification,
The linear velocity difference between the transfer roller 51 and the photosensitive drum 1 is eliminated, and a better transferred image can be obtained.

Further, in the above embodiment, the rotational drive force from the main motor 13 is applied to the drive gear 10 and the connecting gear 1.
It is transmitted to the one-way clutch 11 via 2,
The drive shaft from the main motor 13 may be directly connected to the outer peripheral surface of the one-way clutch 11 without using a gear.

Further, in the above embodiment, the photoconductor drum 1 is used as the image bearing member and the transfer roller 51 is used as the transfer member, but the present invention is not limited to these examples. Can also be applied to the case where a belt-shaped photoreceptor or the like is used as the image carrier and the case where a belt-shaped member or the like is used as the transfer member.

Further, in the above embodiment, the case where the invention is applied to the electrophotographic copying machine is explained, but the invention is not limited to this, and the present invention is provided with the transfer member in contact with the image carrier. It can also be applied to other image forming apparatuses such as a facsimile and a printer.

[0038]

According to the first aspect of the present invention, when the image forming operation is completed, the rotary drive source of the apparatus main body is reversely rotated for a predetermined time, so that the drive member, the connecting member and the one-way clutch are used to perform the above-mentioned operation. With the rotational driving force transmitted to the swing center axis, the swing support member swings against the biasing force of the biasing means, the transfer member is separated from the surface of the image carrier, and this separated state is Is maintained until the start of the image forming operation. Therefore, the transfer member does not come into contact with the image bearing member for a long period of time, and the image bearing member is contaminated due to seepage of constituent substances of the transfer member onto the image bearing member and image defects corresponding to the contaminated portion. There is an effect that it is possible to prevent the occurrence of unevenness of rotation of the transfer member due to the deformation of the pressure contact portion of the transfer member with the image carrier.

Further, in addition to the above effects, a one-way clutch and a connecting member are provided between the swing center axis of the swing supporting member and a drive member driven by a rotary drive source of the apparatus body.
Since the separation / contact control of the transfer member can be performed with a simple configuration of controlling the rotation direction of the rotary drive source, in order to move the transfer member itself or its supporting member, a solenoid or the like is used as in the conventional case. There is an effect that it is not necessary to separately provide a drive mechanism, and the size and cost of the device can be reduced.

During the image forming operation, the rotational driving force in the direction in which the transfer member contacts the image carrier is transmitted from the rotational driving source to the one-way clutch. Since the transfer is not transmitted, the transfer member does not come into contact with the image carrier due to excessive pressure contact force, and stable transfer operation can be performed, and the drive transmission is turned on / off between the rotary drive source and the one-way clutch. Since it is not necessary to separately provide a clutch mechanism for turning off, there is an effect that the size and cost of the device can be further reduced.

In particular, according to claim 2, a drive gear is used as the drive member, a bearing-shaped one-way clutch provided on the swing center axis is used as the one-way clutch, and the drive member is used as the connecting member. By using the connecting gear integrally formed on the outer peripheral surface of the bearing-shaped one-way clutch so as to mesh with the gear, it is possible to further simplify the structure and reduce the size and cost of the device. The effect is that

According to the third aspect of the invention, the drive transmission means moves the connecting member on the one-way clutch to the transfer member in the same direction as the surface of the image carrier. By transmitting the rotational driving force, the transfer member can be rotated more stably as compared with the case where the transfer member is rotated with respect to the image carrier. There is an effect that it is possible to prevent transfer failure due to slip of the transfer member that occurs when the transfer member is rotated together.

[Brief description of drawings]

FIG. 1A is a perspective view of a transfer device of a copying machine according to an embodiment. (B) is an enlarged view of the rear side of the transfer device.

FIG. 2 is a front view showing a schematic configuration of the copying machine.

FIG. 3 is a block diagram of a control unit of the copying machine.

FIG. 4A is a front view of the transfer device during a copy operation. FIG. 6B is a front view of the transfer device at the end of the copying operation.

FIG. 5A is a front view of a transfer device during a copy operation of a copying machine according to a modification. (B) is a front view of the transfer device at the end of the copying operation of the copying machine.

FIG. 6 is a side view of a photosensitive drum and a transfer roller of a copying machine according to another modification.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor drum 1a Gear 2 Charging roller 4 Developing device 5 Transfer device 10 Driving gear 11 One-way clutch 12 Connecting gear 13 Main motor 14 Intermediate gear 51 Transfer roller 51a Core bar 51b Surface layer elastic member 51c Gear 52 Guide member 52a support Shaft 52b Opening 52c Pin 53 Swing support member 53a Swing center shaft 53b, c Swing side plate 53d, e Bearing 53f Pin 54 Pressure spring 500 Control unit

Claims (3)

[Claims] 1. A visible image formed on an image bearing member by using an image bearing member, an image forming means for forming a visible image on the image bearing member with a developer, and a transfer member in contact with the image bearing member. An image forming apparatus comprising: a transfer device for transferring a transfer material onto a transfer material; and a swing support member for supporting the transfer member rotatably and capable of coming into contact with and separating from the image carrier, and the swing support. Biasing means for biasing the member in the direction in which the transfer member contacts the surface of the image carrier, and a separating direction in which the transfer member separates from the surface of the image carrier on the center axis of the rocking of the rocking support member. The one-way clutch that transmits only the rotational drive force of the device, the connecting member between the drive member driven by the rotational drive source of the apparatus main body and the one-way clutch, and the one-way clutch to the one-way clutch when the image forming operation is completed. Turn the rotary drive source for a predetermined time so that the rotary drive force in the separating direction is transmitted. An image forming apparatus characterized in that a control means for rotating. 2. A drive gear is used as the drive member, a bearing-shaped one-way clutch provided on the rocking center axis is used as the one-way clutch, and the bearing is engaged with the drive gear as the connecting member. The image forming apparatus according to claim 1, wherein a coupling gear integrally formed on the outer peripheral surface of the bearing-shaped one-way clutch is used. 3. The image forming apparatus according to claim 1, further comprising drive transmission means for transmitting a rotational driving force from the driving member or the connecting member to the transfer member.