JP2603132B2 - Image forming device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for supporting a transfer material on a rotatable transfer material carrier, such as a photosensitive drum, so that an image can be transferred onto the transfer material. The present invention relates to an image forming apparatus provided with a transfer device for transferring a toner image on a carrier.

2. Description of the Related Art As an image forming apparatus provided with this type of transfer device, a color copying device as shown in FIG. 6 is known.

In FIG. 6, reference numeral 2 denotes a photosensitive drum as an image carrier. The photosensitive drum 2 is uniformly charged by a primary charger 38, and is irradiated with a light image 54 corresponding to image information to form a latent image. The latent image is formed and developed with a developer by the developing device 40 to visualize the latent image.

In the case of a color copying apparatus, the developing device 40 includes developing units 40M and 40M that separately store four colors of a magenta color developer, a cyan color developer, a yellow color developer, and a black color developer.
C, 40Y, and 40B, and color reproduction is performed by superimposing the four color developers.

For this reason, a method has been proposed in which a color image is visualized with four color developers on the photosensitive drum 2 and transferred to the transfer agent P. However, a method of charging the photosensitive drum 2 on which a toner image has been formed has been proposed. Developing is repeated, resulting in poor color reproducibility. For this reason, the transfer drum 1 as a transfer material carrier of the transfer device 100 is usually used as an intermediate carrier for supporting the transfer material P, and the toner image is transferred every time a toner image is formed on the photosensitive drum 2. A method of repeating transfer to the material P is adopted.

The transfer drum 1 is rotated in synchronization with the photosensitive drum 2,
The toner image on the photosensitive drum 2 is transferred onto the transfer material P supported on the peripheral surface. The transfer material P is supplied from the cassette 41 to the transfer drum 1. When the transfer is completed, the residual developer on the photosensitive drum 2 is removed by the cleaner 37, and the developing device 40 rotates in the direction of arrow G to replace the developing unit. Then, the developing process for the next color is started. By repeating the development and transfer steps four times, a color image is formed on the transfer material P on the transfer drum 1.

The transfer material P after the transfer is separated from the transfer drum 1 by a charge remover 43 and a separation claw 44 for removing and releasing the electrostatic attraction force to and from the transfer drum 1, and a fixing device 46 by a transport device 45.
And the image is fixed there, and then discharged out of the copying apparatus.

 Next, the transfer device 100 will be described.

As shown in FIG. 7, the photosensitive drum 2 has its rotating shaft 47
Are rotatably supported in the direction of arrow H by front and rear support members 48 (only the front support member is shown in the figure). The transfer drum 1 has its center rotating shaft 6 rotatably supported by support plates 5 and 49 in the front and rear of the transfer drum 1, and is rotated in the direction of arrow K by a driving device (not shown). The drum support plate 5,
A swing shaft 4 is provided at one end of the photosensitive drum 2 on the side of the photosensitive drum 2, and the swing shaft 4 swings on the front and rear side plates 13 and 50 of the copier body in the normal direction of the photosensitive drum 2 (the direction of arrow J). It is movably engaged. Also, parts 13a, 50a of the main body side plates 13, 50
A release arm 14 having a sliding roller 15 at its tip is attached to a release lever shaft 27 rotatably supported at both ends thereof at a position facing the drum support plates 5 and 49. A release lever 3 is fixed to a front end (front side of the apparatus main body).

The other end of each of the drum supporting plates 5 and 49 is in contact with the cam follow surface 52 with which the sliding roller 15 of the release arm 14 comes into contact, and when the transfer drum 1 is in the contact position with the photosensitive drum 2. The setting latch section R1 and the transfer drum 1 are the photosensitive drum 2
The release arm R2 and the sliding roller 15 swing together with the operation of the release lever 3 to move the transfer drum 1 to the position where the transfer drum 1 is released. The transfer force of the transfer drum 1 to the photosensitive drum 2 is realized by the spring 51 at the lower end for urging the drum support plates 5 and 49 downward.

A transfer sheet 58 for electrostatically adsorbing and supporting a transfer material is wound between the front and rear drum flanges 1a and 1c of the transfer drum 1, and the front and rear drum flanges 1a and 1c do not affect an image. Supported by a minimum of struts 59. For this reason, a pressing sheet 57 that comes into contact with the transfer sheet 58 is provided inside the transfer drum 1 so as to be inclined in the rotation direction K so as not to affect the rotation of the transfer drum 1. The curvature is maintained. Further, inside the transfer drum 1, a transfer charger 42 for moving the toner image on the photosensitive drum 2 to the transfer material on the transfer drum 1, and a charge remover for removing and releasing the electrostatic attraction force of the transfer material 43 and are included.

However, in the above-described conventional example, since the transfer drum 1 adopts a configuration that presses the support column 59 to a minimum as described above, the rotation center is not at the center of the rotation shaft 6 and is eccentric. Therefore, when the contact force on the photosensitive drum 2 is released, the transfer drum 1 rotates by itself in an attempt to stabilize.

Therefore, when a paper jam (paper jam) occurs on the transfer drum 1, the release lever 3 is operated to operate the photosensitive drum 1.
When the contact with the transfer drum 1 is released, paper jams and the like are deteriorated due to the rotation of the transfer drum 1, and there is a disadvantage that the processing cannot be performed.

Therefore, an object of the present invention is to prevent the transfer-bearing member from rotating even if a paper jam or the like occurs on a transfer material carrier such as a transfer drum of a transfer device, and to easily process the paper without deterioration. It is an object of the present invention to provide an image forming apparatus which is enabled.

Means for Solving the Problems The above object is achieved by the image forming apparatus of the present invention. In summary, the present invention is directed to a method of supporting a transfer material on a transfer material carrier that is freely contactable and rotatable with respect to an image carrier, and transfers a toner image on the image carrier to the transfer material. In the image forming apparatus provided with the transfer device, when the transfer material carrier in contact with the image carrier is released from contact, the transfer material carrier is brought into contact with the transfer material carrier and stopped, and the transfer to the image carrier is performed. An image forming apparatus, wherein the transfer device is provided with a brake means for the transfer material carrier that releases the contact with the transfer material carrier when the material carrier is in contact with the transfer material carrier. is there. According to one aspect of the present invention, a manual rotating unit is provided which abuts on the transfer material carrier and allows the transfer material carrier to be manually rotated when the transfer material carrier is stationary. According to another aspect of the present invention, the functions of the brake unit and the manual rotation unit are integrally provided.

Embodiments Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.

1 to 3 show a transfer device in an embodiment of the image forming apparatus of the present invention.

The image forming apparatus according to the present invention is characterized in that the transfer device 100 is provided with a brake unit and a manual rotation unit on the transfer drum 1 as a transfer material carrier. Other configurations are basically the same as those of the conventional image forming apparatus shown in FIGS. 6 and 7, and the same reference numerals as those shown in FIGS. 6 and 7 in FIGS. .

1A shows a state in which the transfer drum 1 is in contact with the photosensitive drum 2, and FIG. 1B shows a state in which the release lever 3 is operated in the direction of arrow A to swing the transfer drum 1. Axis 4
In the direction of arrow B about the center of rotation. This state is set when the transfer material jammed on the transfer drum 1 is removed or when the transfer drum 1 is pulled out of the apparatus. FIG. 2A shows an enlarged view of the brake means, and FIG. 2B shows a plan view of the brake means. FIG. 3 shows a manual rotating means of the transfer drum 1.

 The details of the present embodiment will be described below.

The transfer drum 1 has a center rotating shaft 6 rotatably supported by a support plate 5 in front of the transfer drum 1 and a support plate (not shown) after. The front support plate 5 and the rear support plate of the drum 4
The relative position between the transfer drum 1 and the photosensitive drum 2 is determined by the engagement of the swinging shaft 4 with the centering plate 24.

Further, a release arm 14 having a sliding roller 15 at the tip is provided on a release lever shaft 27 whose both ends are supported by a front side plate 13 and a rear support plate (not shown) of the apparatus main body. The release lever 3 is fixed to the front end of the release lever shaft 27. Further release arm
The other end of 14 is formed in a shape to engage with the link shaft 17 of the link 16.

On the other hand, a cam follow surface 52 with which the sliding roller 15 contacts the drum front support plate 5, a contact setting latch portion R1 and a transfer drum 1 when the transfer drum 1 is in a contact position with the photosensitive drum 2. A contact release latch R2 is formed when the transfer drum 1 is at a position separated from the photosensitive drum 2. The release arm 14 and the sliding roller 15 swing in conjunction with the operation of the release lever 3, and the transfer drum 1 is moved. The transfer drum 1 swings around the swing shaft 4.
Is in contact with the photosensitive drum 2 (FIG. 1 (a)) and in a contact release position where it has been separated from the photosensitive drum 2 (FIG. 1 (b)).
Position.

In addition, in the lower part of the drum front support plate 5, FIG.
Brake means as shown in (b) are provided. The brake means has a roller (for example, rubber roller) 7 having a high coefficient of friction, and the roller 7 is connected by a parallel pin 26 to a brake shaft 8 having a torque limiter 53 on the shaft. One end of a pair of brake support plates 12 that swing about the brake swing shaft 11 is engaged with end bearings (with rotation stoppers) at both ends of the torque limiter 53. At the other end of the brake support plate 12, an engagement shaft 9 that engages with the main body front side plate 13 is provided.

The contact spring 10 attached between the main body front side plate 13 and the brake support plate 12 applies a contact force to the roller 7 in the direction of the transfer drum 1, that is, in the direction of arrow C. Roller 7 is
By setting the slip torque (T2) of the torque limiter 53 (a torque that does not cause rotation at a torque lower than this) to be larger than the rotation torque (T2) of the transfer drum 1 (T2> T1), the roller 7 is transferred. Flange in front of drum 1
The rotation of the transfer drum 1 is prevented when it comes into contact with 1a.

A manual rotating means for the transfer drum 1 as shown in FIG. The manual rotating means has a swing arm 20 that swings around a knob shaft 25 having a knob 21 at one end. At one end of the swing arm 20, a rotating gear 22 that engages with the transfer drum 1b has a rotating shaft 23.
, And is rotatable via a knob gear 55 at the other end of the knob shaft 25. Swing arm 20
Is provided with a shaft 19 at the other end thereof, and the shaft 19 is engaged with the link 16. The link shaft 17 at the lower end of the link 16 is fitted in the elongated hole 13c formed in the main body front side plate 13, and the above-described release arm 14 is engaged. A spring 18 for pulling up the link shaft 17 is connected between the link 16 and the link shaft 17.

In this configuration, when removing the transfer material jammed from the transfer drum 1, the following operation may be performed.

That is, in order to separate the transfer drum 1 from the photosensitive drum 2, the release lever 3 is operated in the direction of arrow A as shown in FIGS.

When the release lever shaft 27 rotates by the operation of the release lever 3, the release arm 14 swings, and the sliding roller 15 at the tip thereof slides on the cam follow surface 52, and is positioned on the contact release latch portion R2. The drum front support plate 5 swings about the swing shaft 4 in the direction of arrow B, and the contact of the transfer drum 1 with the photosensitive drum 2 is released.

On the other hand, since the engagement shaft 9 of the brake means is engaged with the main body front side plate 13 in the contact state, the roller 7
Is located away from the front flange 1a of the vehicle. As the drum front support plate 5 swings as described above, the engagement shaft 9
Separates from the main body front side plate 13. Therefore, the roller 7 is pressed against the front flange 1a of the transfer drum 1 by the reaction force of the contact spring 10, and the rotation of the transfer drum 1 due to the eccentricity of the rotation center is prevented. Therefore, when the transfer material jammed on the transfer drum 1 is removed, the processing can be performed without deteriorating the jam.

On the other hand, since the release arm 14 pushes down the link shaft 17,
The swing arm 20 of the manual rotating means swings via the link 16, and the rotating gear 22 at the other end engages with the transfer drum gear 1b. As a result, by manually turning the knob shaft 25 with the knob 21, the stationary transfer drum 1 can be arbitrarily rotated by the brake means. Therefore, when the transfer material jammed on the transfer drum 1 is removed, the removal is facilitated.

Conversely, in order for the transfer drum 1 to contact the photosensitive drum 2,
When the release lever 3 is operated in the direction opposite to the direction of the arrow A, the link shaft 17 having been released from the restriction of the release arm 14 is pushed upward by the reaction force of the spring 18. As a result, the rotation gear 22 is separated from the transfer drum gear 1b via the link 16 and the swing arm 20. Further, when the drum front support plate 5 swings in conjunction with the movement of the release lever 3, the engagement shaft 9 of the brake means is pressed against the main body front side plate 13. As a result, the brake support plate 12 swings about the brake swing shaft 11, and the roller 7 separates from the flange 1a of the transfer drum 1.

As described above, according to the present embodiment, the rotation of the transfer drum 1 can be prevented by the brake means only by operating the release lever 3, and the stationary transfer drum 1 is manually rotated by the manual rotation means. be able to. Further, by providing the brake means in the unit of the transfer apparatus 100, the rotation of the transfer drum 1 can be prevented even when the unit is detached from the apparatus body as a single unit.

 Next, another embodiment of the present invention will be described.

4 and 5 show a transfer device according to another embodiment of the image forming apparatus of the present invention. The present embodiment is characterized in that the function of the brake means is integrated with the manual rotation means.

4 (a) shows a state in which the transfer drum 1 is in contact with the photosensitive drum 2, and FIG. 4 (b) operates the release lever 3 in the direction of arrow A to swing the transfer drum 1. A state of swinging in the direction of arrow B with the shaft 4 as the center of rotation is shown. In FIG. 4B, the centering plate 24 shown in FIG.
Has been removed. FIG. 5 is a detailed view of a manual rotating means having a function of a brake means. FIG. 5 (a) is an enlarged view thereof, FIG. 5 (b) is a horizontal sectional view thereof, and FIG. 5 (c). FIG. 4 is an explanatory diagram showing the rotation direction.

 The details of the present embodiment will be described below.

The transfer drum 1 has a center rotating shaft 6 rotatably supported by a support plate 5 in front of the transfer drum 1 and a support plate (not shown) after. The front support plate 5 and the rear support plate of the drum 4
The relative position between the transfer drum 1 and the photosensitive drum 2 is determined by engaging the swing shaft 4 with the centering plate 24.

Further, a release arm 14 having a sliding roller 15 at the tip is provided on a release lever shaft 27 whose both ends are supported by a front side plate 13 and a rear support plate (not shown) of the apparatus main body. The release lever 3 is fixed to the front end of the release lever shaft 27. Further release arm
The other end of 14 is formed in a shape to engage with the link shaft 17 of the link 16.

On the other hand, a cam follow surface 52 with which the sliding roller 15 contacts the drum front support plate 5, a contact setting latch portion R1 and a transfer drum 1 when the transfer drum 1 is in a contact position with the photosensitive drum 2. A contact release latch R2 is formed when the transfer drum 1 is at a position separated from the photosensitive drum 2. The release arm 14 and the sliding roller 15 swing in conjunction with the operation of the release lever 3, and the transfer drum 1 is moved. The transfer drum 1 swings around the swing shaft 4.
At the contact position with the photosensitive drum 2 (FIG. 4A) and the contact release position at which the contact is released from the photosensitive drum 2 (FIG. 4B).
Position.

The centering plate 24 is provided with a manual rotating means for the transfer drum 1 as shown in FIGS. 5 (a) to 5 (c). The manual rotating means has a rotating shaft 29 attached to a fixed support plate 34 on the box, and the fixed support plate 34 is centered so as to be swingable through a swing support plate 33 by a step screw 36. Attached to plate 24. A rotating gear 22 that engages with the gear 1b of the transfer drum 1 and imparts rotation to the rotating shaft 29 has a parallel pin.
It is attached so as to rotate integrally with the rotation shaft 29 by 26. Furthermore, in order to guarantee the distance between the gear pitch between the drum gear 1b and the rotating gear 22, a contact roller 28 that is in contact with the drum flange 1b is attached to the rotating shaft 29. Pivot axis
A knob 21 is attached to the other end of 29.

Between the swing support plate 33 and the fixed support plate 34, there is provided a one-way bearing 30 shaft having a built-in one-way clutch receiving the rotation shaft 29, as shown in FIG. 5 (c). In addition, the knob 21 does not rotate in the clockwise direction, but functions so as to be rotatable in the counterclockwise direction. Also fixed support plate
A rotation bearing 32 is mounted on the rotation shaft 29 so as to rotate integrally with the rotation shaft 29 via a parallel pin 26, and a one-way bearing
Between the rotation bearing 30 and the rotation bearing 32, a torque spring 31 that provides rotation resistance is fitted to a rotation shaft 29. That is, the torque spring
Due to the reaction force of 31, the swing support plate 33 and the one-way bearing 30
The rotation resistance torque (T3) is generated by the frictional force generated at the contact surface between the rotating shaft 32 and the fixed support plate 34 and the rotating bearing 32.

The rotating means is pulled in a counterclockwise direction by a spring 35 attached between the swing support plate 33 and the centering member 24. On the centering plate 24, the transfer drum 1 to the photosensitive drum 2
An opening 56 is provided for restricting the drum gear 1b and the rotating gear 22 of the rotating means from engaging with each other when the contact is made.

In the above configuration, when the release lever 3 is operated to release the contact of the transfer drum 1 with the photosensitive drum 2, the gear 1b of the transfer drum 1 and the opening gear 22 are engaged, and the transfer drum 1
The rotation due to the eccentricity of the center of rotation is restricted. That is, when the transfer drum 1 attempts to rotate in the direction of arrow D in FIG. 5A, the transfer drum 1 is not rotated because it is regulated by the one-way bearing 30.

When the transfer drum 1 attempts to rotate in the direction of arrow E, the one-way bearing 30 is not restricted, but the torque spring 31
By setting the rotation resistance torque (T3) generated by the above to be larger than the rotation torque (T1) of the transfer drum 1 (T3> T1), the transfer drum 1 is braked,
Stop without rotating. However, when the knob 21 is operated, the transfer drum 1 rotates only in the direction of the arrow E due to the function of the one-way bearing 30, and does not affect the pressing sheet inside the transfer drum 1.

When the release lever 3 is operated to bring the transfer drum 1 into contact with the photosensitive drum 2, the engagement between the drum gear 1b and the rotating gear 22 is released, and the rotation of the rotating means is released.

As described above, according to this embodiment, the mechanism can be simplified by providing the centering plate 24 with the rotating means integrally having the function of the braking means.

As described above, in the image forming apparatus of the present invention, when the contact of the transfer material carrier such as the transfer drum that is in contact with the image carrier such as the photosensitive drum is released, the image forming apparatus interlocks with the transfer material carrier. When the transfer device is provided with a brake means for the transfer material carrier that abuts and releases the contact with the transfer material carrier when the transfer material carrier contacts the image carrier, the transfer device has Even if a paper jam or the like occurs on the body, it is possible to prevent deterioration of processing or an accident against paper jam or the like due to rotation of the transfer-bearing member.

Further, by further providing a manual rotating means in the transfer device, it is possible to further facilitate the processing such as removal of the paper jammed transfer material, and to have the functions of the brake means and the sliding rotating means integrally. Thereby, it can be simplified easily.

[Brief description of the drawings]

FIGS. 1A and 1B are side views showing a transfer device according to an embodiment of the image forming apparatus of the present invention, showing a state where the transfer drum abuts on the photosensitive drum and a state where the abutment is released. 2 (a) and 2 (b) are a side view and a plan view, respectively, showing a brake means provided in the transfer device shown in FIGS. 1 (a) and 1 (b). FIG. 3 is a plan view showing a manual rotation mechanism provided in the transfer device shown in FIGS. 1 (a) and 1 (b). FIGS. 4 (a) and 4 (b) show a transfer device according to another embodiment of the image forming apparatus of the present invention, in which a transfer drum is brought into contact with and released from a photosensitive drum, respectively. FIGS. 5 (a), (b) and (c) are a side view, a horizontal sectional view and an operation explanation showing a manual rotating means provided in the transfer device shown in FIGS. 4 (a) and (b), respectively. FIG. FIG. 6 is a configuration diagram showing a conventional image forming apparatus. FIG. 7 is a perspective view showing the periphery of a transfer device provided in the image forming apparatus shown in FIG. 1: Transfer drum 2: Photosensitive drum 3: Release lever 7: Roller 22: Rotating gear 30: One-way bearing

Claims (3)

(57) [Claims] A transfer member configured to transfer a toner image on the image carrier to the transfer material by supporting the transfer material on a transfer material carrier rotatable and rotatable against the image carrier; In the image forming apparatus provided with the image forming apparatus, when the transfer material carrier in contact with the image carrier is released from contact, the transfer material carrier is brought into contact with the transfer material carrier and stopped, and the transfer material carrier is held in the image carrier. The image forming apparatus according to claim 1, wherein the transfer device is provided with brake means for the transfer material carrier, which is rotatable by releasing the contact with the transfer material carrier when the body comes into contact. 2. The image forming apparatus according to claim 1, wherein the transfer device includes a manual rotating unit that abuts on the transfer material carrier and allows the transfer material carrier to be manually rotated when the transfer material carrier is stationary. . 3. The image forming apparatus according to claim 2, wherein the functions of said brake means and manual rotation means are integrally provided.