JPS63177184A - Image forming device - Google Patents

Abstract

PURPOSE:To eliminate a transfer deviation at a transfer position even when vibration occurs by arranging the position where an abutting member abuts on a transfer material support body nearly symmetrically with the transfer position where the transfer material support body contacts an image carrier about the center axis of the transfer material support body. CONSTITUTION:The abutting position S of a positioning roll 13 is arranged nearly symmetrically with the transfer position T of a transfer material 8 about the center axis O of a transfer drum 15. The transfer position T and abutting position S are therefore arranged on a line extending in a radial direction of a photosensitive drum 1. Then the positioning roll 13 of a paper feed guide 12 is abutted against a position S which is nearly 180 deg. away from the transfer position T about the center of the drum. Vibrations in rigid body mode, therefore, become radial vibrations at the transfer position T to not only allow the photosensitive drum 1 to serve as a suppressing member, but also make the vibrations into up-down vibrations for an image. Consequently, a transfer deviation caused principally by horizontal vibrations is precluded.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is directed to a color copying machine, etc., in which a transfer material is supported on a transfer material support, and images on an image carrier (i.e., The present invention relates to an image forming apparatus.

(Prior Art) Conventionally, as this type of image forming apparatus, there are those shown in FIGS. 3 and 4, for example. That is, lOO is a drum-shaped transfer material support that rotates in synchronization with the image carrier 101, and each color (for example, , yellow, magenta, cyan) toner images are sequentially transferred in multiple layers. Transfer material 1 to transfer material support 100
The winding of 02 is as shown in FIG. The timing of the transfer material 102 fed by the paper feed roller 105 is determined by the second register rollers 103 and 104, and the transfer material 102 is guided to the surface of the transfer material support 100 via the paper feed guide lO6. It is gripped by a provided gripper 107. Further, the transfer material 102 is transferred to the transfer material support 10
As the image bearing member 101 and the transfer material support 100 are in contact with each other, the image carrier 101 is conveyed while being wound around the image bearing member 101 .

1- The paper feed guide 106 is arranged around the transfer material support 100 and is swingable about a pin 108, and its positioning rollers 109 move toward and away from the transfer material support 100.

By abutting the positioning roller 109 against the outer peripheral surface of the transfer material support lOO, the paper feed guide 106 is accurately positioned relative to the transfer material support 100 (paper feeding position), and the transfer material 102 is reliably placed. It's gripping. On the other hand, when the grip is parked, the paper feed guide 106 is moved to the transfer material support 1.
00 to the position indicated by the dotted line in the figure to prevent the tip of the paper feed guide 106 from interfering with the transfer material 102.

1. Although not shown, during the transfer process, when the tip of the transfer material is gripped, the part that is not held by the gripper rolls. When the transfer material is electrostatically held on the screen of the material support, the transfer material is rolled 1+J material support. The squeezing roller that abuts against the body to improve the suction property is also a member that comes into contact with and separates from the transfer material support, and is retracted except when pressing the transfer material against it.

(Problems to be Solved by the Invention) However, the conventional example 1- has the following problems. That is, when forming images continuously, while the toner image of the closest color is being transferred to one transfer material 102 at the transfer position T, the operation of gripping the next transfer material 102 may be repeated. At this time, the paper feed guide 106 mentioned above swings from the retracted position to the paper feed position, and its positioning rollers 109 abut against the transfer material support 100, but the vibrations generated at this time cause the transfer There was a problem in that transfer unevenness occurred at position T, resulting in image unevenness and blurring.

Also, regarding the contact and separation of the ironing roller described in I-.

Similar to the paper feed guide 106, there is a problem in that vibrations generated in the transfer material support 100 cause uneven transfer and impair image quality.

The invention was made in order to solve the problems of the prior art mentioned above, and its purpose is to improve the structure of contact members that come into contact with and separate from transfer material supports such as paper feed guides and ironing rollers. Prevents transfer misalignment at the transfer position even if vibration occurs during contact 1! - To provide an image forming bag 2 with high image quality free from uneven transfer and blur.

(Means for solving the problem) 1-Remarks] In order to achieve the objective, in the present invention, the image IBh rotates in synchronization with the body, and the surrounding surface of the image is supported. A drum-shaped transfer material support is provided to transfer images formed on a bipedal image carrier in multiple layers, and the transfer material is brought into contact with and separated from the transfer material support around the transfer material support. Chi Jti
In the image forming apparatus in which the member is submerged, 1; the contact position of the distributing contact member with the transfer material support; 1 - the central axis of the distributing transfer material support; 1; the distributing transfer material support and the image carrier It was placed at a position approximately symmetrical to the transfer position where it is in contact with the transfer position.

(Function) Even if the abutting member contacts the transfer material support and vibrates during transfer, the transfer position is symmetrical with respect to the central axis of the transfer material support, so the information is transmitted. Vibrations are also damped.

(Embodiment) The present invention will now be described with reference to the illustrated embodiment. The photosensitive drum 1 is rotatably supported by a shaft 2, rotates in the direction of the arrow, and is charged with negative charges 7 and +3, and then exposed with light 8!14. The electrostatic latent image is visualized into a toner image of the required color by the operation of a designated developer among yellow developer Y, magenta developer M, and cyan developer C.

On the other hand, the transfer material 8 in the cassette 7 is fed into the machine by the paper feed roller 9, and the rough timing is taken by the second register roller 11, and then the accurate timing is taken by the second register roller 11, and the material comes into contact with the machine. The paper feeding guide 12 as a member is gripped by a gripper 151 on a transfer drum l 5 as a transfer material support, and is further conveyed while being wrapped around the drum 15 as the transfer drum 15 rotates, and is transferred to a transfer discharger 16 and a photosensitive drum. While the transfer material 8 passes between the photosensitive drums 1 and 1, the toner image on the photosensitive drum 1 is transferred onto the transfer material 8.

The transfer drum 15 is constructed by cutting out both ends of a cylindrical rigid body, leaving a part connecting the two ends, and covering the outer circumferential surface with a dielectric insulating sheet or screen. . Then, a transfer discharger 16 is installed in the transfer drum 15 so as to face the photosensitive drum 15 at a transfer position in contact with it.
is provided to apply a charge of opposite polarity to the toner from the back side of the recording sheet, etc., and transfer the toner image on the photosensitive drums 1-L to the transfer material 8.

On the other hand, the paper feed guide 12 is disposed between the second registration roller 11 and the transfer roller 1.15, as in the conventional example, and
The end portion on the side of the registration roller 11 is swingably supported by a pin 14, and a positioning roller 13 provided at the tip can freely approach and separate from the peripheral surface of the transfer drum 15. That is, when feeding paper, the paper feed guide 12 rotates clockwise in the figure, the positioning roller 13 comes into contact with the transfer drum 15, and the tip of the paper feed guide 12 is positioned close to the outer peripheral surface of the transfer drum 15. Transfer material 8 by holding green and pa 151
This ensures that the tip can be gripped reliably.

The contact position S after this positioning roller 13 is located at a position approximately symmetrical with respect to the transfer position T of the L2 transfer material 8 and the central axis 0 of the transfer drum 15, and is located at a position separated by 180@fi in this embodiment. There is. Therefore, the line 1- extending in the radial direction of the photosensitive drum l! - The rotation position T and the contact position S are arranged, so that the contact position S of the first positioning roller 13 is arranged on the back side of the transfer drum 15 with respect to the photosensitive drum l.

In addition, the first and second registration rollers 1 are provided from the L cassette 7.
0, 11 and the paper feed guide 12 are arranged in a substantially straight line F.

After the transfer, the surface of the photosensitive drum 1 is cleaned by a cleaning device 123 composed of a blade 23a, and the transfer drum 15 is moved to the next cycle.
51, the transfer material 8 is rotated by a required number of rotations while gripping the leading end thereof, and an image of the required number of colors is transferred.

Immediately after the transfer is completed, the transfer material 8 is neutralized by a static eliminator 17° 18 disposed downstream of the transfer position 21T around the transfer drum 15, released from adsorption to the transfer drum 15, and moved to the gripper 1.
51 rides on the cam 19 and opens. At the same time, the transfer material 8 is released from the gripper 51, guided by the separation claw 20 to the conveyance bell 21, fixed by the fixing device 22, and discharged.

In the image forming apparatus having the configuration L, during the continuous sequence, the transfer drum 15 performs the primary transfer at the position of the paper feed guide 12 within the same rotation as the transfer material 8 is separated from the transfer drum 15. Grip the material.

At this time, the paper feeding kite 12 is moved around the pin 14 from the retracted position indicated by the broken line to the paper feeding position indicated by the solid line, and the positioning roller 13 is brought into contact with the transfer drum 15 to generate vibration. The vibrations generated in the transfer drum 15 at this time are roughly classified into the following two types. One is the vibration due to the rigid body mode, that is, the vibration with the roller drum 15 as the mass (in the direction of the arrow in FIG. 2), and the other is the surface wave ( Conventionally, this vibration causes transfer unevenness in the image being transferred (immediate separation), but according to the device configuration of the present invention, transfer 1, gargle n)j +I- can be achieved.

To explain this in detail, move the positioning roller 13 of the paper feed guide 12 to the transfer position i? Almost 18 for IT and drum center
It hits position S of 00. First, the vibration due to the rigid body mode mentioned earlier becomes a radial vibration at the transfer position T, and not only does the photosensitive drum 1 act as a suppressing member, but this vibration is caused by the [-downward direction] with respect to the image (transfer material). It becomes vibration, 1
: Transfer deviation caused by vibration in the direction of the water layer is prevented.

Furthermore, the surface waves (Rayleigh waves) propagating on the outer peripheral surface of the transfer drum 15 are attenuated during propagation. In other words, the transfer position T is independent of the magnitude of the impact force of the positioning roller 13 mentioned above.
Since the distance to the transfer position T is maximum at the abutting position S at approximately 180° from the position S, it is most advantageous to obtain this attenuation effect.

The surface waves generated at the time of abutment are sufficiently attenuated so that the image being transferred is not influenced by vibration, and rotation of the center of the image is prevented.

In this embodiment, the paper feed guide is used as an example of the abutting member, but the present invention can also be applied to a squeezing roller that abuts the transfer material 8 against the transfer drum 15 to improve suction performance. be.

In addition, although a color copying machine was explained in the wood example,
It goes without saying that the present invention is not limited to those that form color images, but can also be applied to those that transfer images in a single color in multiple layers using a transfer drum.

OP:, bright effect) The present invention consists of the above-described structure and operation, and the contact member contacts the transfer material support at a position t that is approximately symmetrical to the transfer position with respect to the center of the transfer material support. By arranging the positions, even if vibration occurs during contact, it is possible to prevent transfer misalignment at the transfer position, and it is possible to obtain high-quality images without transfer unevenness or blurring. can get.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a schematic configuration of an image forming apparatus according to an embodiment of the present invention, FIG. 2 is a front view showing main parts around the transfer drum of the apparatus shown in FIG. 1, and FIG. FIG. 4 is a front view showing a schematic configuration of the image forming apparatus, and FIG. 4 is a front view of the main parts around the transfer material support of the apparatus shown in FIG. Explanation of symbols 1... Photosensitive drum (image carrier) 12... Paper feed guide (contact member) 15... Transfer drum (transfer material support) T... Transfer position S...・Contact position 0...Central axis Fig. 2

Claims (3)

[Claims] (1) A drum-shaped transfer material support that rotates in synchronization with the image carrier and transfers images formed on the image carrier multiple times to a transfer material that is wound and supported around the circumferential surface of the image carrier; , in an image forming apparatus provided with an abutting member that contacts and separates from the peripheral surface of the transfer material support around the transfer material support, the contact position of the abutment member with the transfer material support is determined by adjusting the contact position of the abutment member with the transfer material support to An image forming apparatus characterized in that the image forming apparatus is arranged at a position substantially symmetrical to a transfer position where the transfer material support and the image carrier are in contact with each other with respect to the central axis of the image forming apparatus. (2) The image forming apparatus according to claim 1, wherein the contact member is a paper feed guide for guiding the transfer material to the transfer material support. (3) The abutment member is a squeezing roller that presses the transfer material that is electrostatically attracted to the transfer material support and is wound and supported against the transfer material support. The image forming apparatus according to item 1.