JPH073418Y2 - Transfer roll of image output device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a transfer roll used in an image output device such as a copying machine or a printer, which includes a flexible support for adsorbing and supporting a transfer sheet.

[Conventional technology]

A copying machine using a transfer roll has a structure as shown in FIG.

Around the transfer roll 1, image forming units 21, 22, 23, 24 for forming a color image are arranged, and multiple transfer is performed on a transfer sheet a which is sucked and supported by the transfer roll 1 and conveyed. I am supposed to do it. Image forming unit 21,2
Reference numerals 2,23,24 denote photoconductors 201,202,203,204 and chargers 301,302,303,304 disposed around them, and developing devices 401,402,403,4.
04, transfer device 501,502,503,504 and cleaning device 601,6
It consists of 02,603,604.

Further, the image forming units 21, 22, 23, 24 are provided with an exposure device 10
1, 102, 103, 104 are provided respectively, and the exposure apparatus 10
Receiving the reflected light of the original from 1,102,103,104, photoconductor 201,2
An electrostatic latent image is formed on the exposed portions of 02, 203, and 204.

The electrostatic latent images formed on the surfaces of the photoconductors 201, 202, 203, 204 become toner images in the developing devices 401, 402, 403, 404. Then, the toner images of the respective photoconductors 201, 202, 203, 204 are transferred in multiple transfer onto the transfer sheet a in the respective transfer devices 501, 502, 503, 504.

The transfer sheet a is fed from the paper feed tray 26 of the paper feed unit 25 by the paper feed roll 27, the leading end of which is positioned by the sheet positioning rolls 28 and 29, and is transferred to a gripper (not shown) of the transfer roll 1 which rotates in the direction of the arrow in the figure. Grip and transfer device 501
Be transported to. Then, the transfer sheet a that has been transferred by the transfer device 501 moves according to the rotation of the transfer roll 1, and is sequentially transferred by the transfer devices 502, 503 and 504.

Here, the illustrated transfer device is a multiple transfer device for performing color copying, and the image forming units 21, 22, 23, 24 form respective color images by respective color developers. .

The transfer sheet a, which has been subjected to the multiple transfer by the transfer device 504, is peeled from the transfer roll 1 by the peeling claw 30, and the fixing device 31
The transfer image is fixed in (1), and is further discharged to the discharge tray 32.

The transfer roll 1 of such a copying machine is flexible for adsorbing and supporting the transfer sheet on the peripheral surface of the roll body formed by connecting two cylindrical members with a connecting member at a distance to form a roll. As a flexible support, a mesh or thin film made of a dielectric material is wound.

[Problems to be solved by the device]

When winding a mesh or a thin film around the roll body of the transfer roll 1, a double-sided adhesive tape is attached to a key part of the roll body, and the mesh or thin film is adhered to the double-sided adhesive tape. That is, as shown in FIG.
Inner peripheral edges of the cylindrical members 2a, 2b and peripheral edges of the connecting members 3a, 3b of the roll main body 1a formed by connecting two cylindrical members 2a, 2b with the connecting members 3a, 3b with a space therebetween. The double-sided adhesive tape 4 is adhered to, the mesh or thin film (not shown) is adhered to the double-sided adhesive tape 4, and the mesh or thin film is wound so as to cover the opening 5.

However, when the flexible support is wound around the roll body 1a as described above, when a mesh is used as the flexible support, the rigidity of the mesh itself is small and the entire mesh is easily deformed. It is difficult to wind the roll body 1a with high precision, and there are problems that the mesh is loosened, and the mesh is deformed by a slight impact to make it unusable.

On the other hand, when a thin film is used as the flexible support, the rigidity is greater than that of the mesh and it is less likely to be deformed.
It can be wound around 1a with high accuracy, and the degree of damage to impact is small, so that the problem as in the case of the mesh can be solved. However, in the case of a thin film, for example, when a polyethylene terephthalate sheet (hereinafter referred to as a PET sheet) is used as the thin film, the PET sheet has high rigidity, so that it does not follow the fluctuation of the gap between the transfer roll and the photosensitive drum at the transfer position. It has the drawback of being small. That is, when the gap between the transfer roll and the photoconductor drum becomes large for some reason, the rigidity of the mesh is small, so that the electrostatic attraction force attracts the photoconductor drum to the side between the photoconductor drum and the transfer sheet. There is no gap in. However, since the PET sheet has a high rigidity, it is not attracted to the photosensitive drum side, so that a gap is created between the photosensitive drum and the transfer sheet, and a transfer failure occurs. Further, when the transfer roll and the photosensitive drum are brought into close contact with each other for some reason, in the case of a mesh, the mesh is easily bent toward the opening 5 side of the roll main body 1a, so that the transfer sheet is strongly pressed against the photosensitive drum. There is no such thing. However, in the case of a PET sheet, since it is difficult to bend, the transfer sheet is strongly pressed against the photoconductor drum, resulting in transfer defects such as line image dropouts.

The present invention has been made to solve the above problems, and its purpose is to wind a thin film around an elastic member around a roll body of a transfer roll so that the transfer roll and the photosensitive drum are The object is to improve the followability with respect to the variation of the gap so that good transfer can be performed.

[Means for Solving the Problems]

The transfer roll of the present invention is designed to achieve the purpose.
In a transfer roll in which a flexible support for adsorbing and supporting a transfer sheet is wound around a peripheral surface of a roll body in which individual cylindrical members are connected by a connecting member at intervals, the flexible support is provided in the connecting member. A front end portion and a rear end portion of the flexible support body, and an adhesive portion for adhering a side edge portion of the flexible support body to each of the two cylindrical members. Portion and the rear end portion are continuously bonded to the bonding portion of the connecting member, and the side edge portion of the flexible support is bonded discontinuously in the circumferential direction of the bonding portion of the cylindrical member via the elastic member. It is characterized by having done.

Here, it is preferable that the bonding portion between the flexible support and the elastic member and the bonding portion at the bonding portion between the elastic member and the cylindrical member are different from each other. Further, the elastic member may be a strip-shaped flexible member. A sheet-like material is suitable as the flexible support.

[Operation] In the transfer roll of the present invention, since the flexible support for adsorbing and supporting the transfer sheet, for example, the PET sheet, is adhered to the roll main body through the elastic member, the PET sheet has a roll surface method. It is movable in the line direction, and has good followability to fluctuations in the gap between the transfer roll and the photosensitive drum.

〔Example〕

Hereinafter, the features of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view of a transfer roll according to an embodiment of the present invention. In addition, in the figure, the illustration of the flexible support is omitted.

The structure itself of the roll body 1a of the transfer roll 1 is basically the same as that of the conventional transfer roll shown in FIG. That is, the roll main body 1a is composed of two cylindrical members 2a and 2b and a connecting member 3a (and 3b not shown) that connects the cylindrical members 2a and 2b, and has an opening 5 on the peripheral surface thereof. A PET sheet as a flexible support is wound. And the roll body 1
In order to wind the PET sheet on a, the double-sided adhesive tape 4 is attached to the peripheral edges of the connecting members 3a and 3b, and the adhesive tape 4a is attached to the inner peripheral edge of the cylindrical members 2a and 2b.
A PET sheet is adhered to 4, 4a directly or through an elastic member.

FIG. 2 is a partial development view showing a situation in which the double-sided adhesive tape is attached to the roll body.

As shown in the figure, the double-sided adhesive tape 4 is continuously attached at the bonding portion of the connecting members 3a and 3b to form a cylindrical member.
A short double-sided adhesive tape 4a is attached discontinuously at the adhesive portions of 2a and 2b.

When the PET sheet is bonded, the bonding parts of the connecting members 3a and 3b are directly bonded to the bonding surface of the double-sided adhesive tape 4, and the bonding parts of the cylindrical members 2a and 2b are bonded via an elastic member. To do.

FIG. 3 is a partial cross-sectional view showing a method for adhering a PET sheet via an elastic member.

The figure is a cross-sectional view taken along the line II of FIG. 2, and as shown in the figure, a double-sided adhesive tape 4a is discontinuously attached to the adhesive portion of the cylindrical member 2a (2b) and a strip. One end of the elastic member 6 is adhered to and supported in a cantilever shape, the double-sided adhesive tape 4b is attached to the upper surface of the other end, and the PET sheet 7 is attached to the double-sided tape 4b.
Glue.

Here, the elastic member 6 may be made of the same material as the flexible support, for example, a PET sheet.

The PET sheet 7 is thus bonded to the bonding portion of the cylindrical member 2a via the elastic member 6. Therefore, the other end of the elastic member 6 supported in a cantilever shape can freely move up and down, so that the PET sheet 7 can also move up and down, that is, in the direction normal to the peripheral surface of the roll body 1a. Moreover, in the circumferential direction of the roll body 1a, the front end portion and the rear end portion of the PET sheet 7 are bonded at the bonding portions of the connecting members 3a, 3b,
Further, since it is supported by the elastic member 6, the roll body 1a
Movement of the peripheral surface in the tangential direction is restricted, and there is no displacement in the circumferential direction.

FIG. 4 is a partial cross-sectional view showing another example of a method for adhering a PET sheet via an elastic member.

In this example, a long elastic member 8 is circumferentially bonded to a double-sided adhesive tape 4a that is intermittently attached to the bonding portion of the cylindrical member 2a (2b), and the upper surface of this elastic member 8 is intermittently bonded. Stick the double-sided adhesive tape 4b, and then PET on this double-sided tape 4b.
Adhere the sheet 7.

Here, a double-sided adhesive tape to be attached to the upper surface of the elastic member 8
The attachment position of 4b is an intermediate position of the attachment position of the double-sided adhesive tape 4a on the lower surface side. In this way, double-sided adhesive tape 4a
The elastic member 8 can freely move up and down at the intermediate portion supported by the double-sided adhesive tape 4a by making the attaching positions of the and 4b different from each other. Therefore, in the PET sheet 7, the part supported by the double-sided adhesive tape 4b is moved up and down by the elastic member 8, and the intermediate part supported by the double-sided adhesive tape 4b is moved up and down by the PET sheet 7 itself. It can move in the vertical direction, that is, in the direction normal to the peripheral surface of the roll body 1a.

Moreover, the movement in the circumferential direction is restricted as described above.

In this way, the PET sheet 7 can move in the normal direction of the peripheral surface of the roll main body 1a, so that the PET sheet 7 having high rigidity
However, similar to the case of the mesh having low rigidity, the followability to the fluctuation of the gap between the transfer roll and the photosensitive drum at the transfer position becomes good.

That is, even if the gap between the transfer roll and the photoconductor drum becomes large for some reason, the electrostatic attraction force
Since the PET sheet 7 is sucked toward the photosensitive drum side, no gap is created between the photosensitive drum and the PET sheet 7, and good transfer is performed. Further, even if the transfer roll and the photosensitive drum are brought into close contact with each other for some reason, the PET sheet 7 bends toward the opening 5 side of the roll body 1a, so that the transfer sheet is not strongly pressed against the photosensitive drum. Good transfer is performed.

Table 1 shows an example in which the relationship between the quality of the transfer result and the gap between the transfer roll and the photosensitive drum and whether the transfer result is good or poor was investigated for the transfer roll of the present invention and the conventional transfer roll.

A PET sheet was used for both transfer rolls as the flexible support, and the transfer result was evaluated by the degree of image loss. In the table, the inter-drum distance t indicates the gap between the flexible support on the transfer roll and the photosensitive drum, and the symbol ◯ indicates good transfer, Δ indicates slight image loss, and x indicates image loss. In addition,
Each transfer current in color multiple transfer was sequentially increased for each color.

As shown in Table 1, in the case of the transfer roll of the present invention, good transfer results were obtained when the gap between the transfer roll and the photoconductor drum was in the range of 0.0 to 0.3 mm. No good transfer was obtained except when the gap was 0.1 mm. That is, the transfer roll of the present invention is
Since the followability to the variation of the gap between the transfer roll and the photosensitive drum is good, the allowable range of the variation of the gap is increased.

[Effect of device]

As described above, in the transfer roll of the present invention, the flexible support for attracting and supporting the transfer sheet, for example,
The side edges of the PET sheet are bonded to the roll body in the circumferential direction of the roll body via elastic members. For this reason, the PET sheet is movable in the direction of the normal line to the roll peripheral surface, and even with a flexible support having a high rigidity such as the PET sheet, it has good followability with respect to variations in the gap between the transfer roll and the photosensitive drum. In addition, good transfer can be obtained, and the allowable range of fluctuation of the gap can be made large.

[Brief description of drawings]

FIG. 1 is a perspective view of a transfer roll according to an embodiment of the present invention, FIG. 2 is a partially developed view showing a situation in which a double-sided adhesive tape is attached to a roll body, and FIG. 3 is a method for adhering a PET sheet through an elastic member. 4 is a partial cross-sectional view showing another example of a method for adhering a PET sheet via an elastic member, FIG. 5 is a side view showing a main structure of a copying machine, and FIG. FIG. 6 is a perspective view for explaining a method of adhering a flexible support of the transfer roll of FIG. 1: Transfer roll, 1a: Roll body 2a, 2b: Cylindrical member, 3a, 3b: Connecting member 4, 4a, 4b: Double-sided adhesive tape, 5: Opening 6,8: Elastic member, 7: PET sheet 21, 22,23,24: Image forming unit 101,102,103,104: Exposure device 201,202,203,204: Photosensitive member 301,302,303,304: Charger 401,402,403,404: Developing device 501,502,503,504: Transfer device 601,602,603,604: Cleaning device 25: Paper feed unit, 26: Paper tray 27: Paper roll 28 , 29: Sheet positioning roll 30: Release claw, 31: Fixing device 32: Paper ejection tray, a: Transfer sheet

Claims (4)

[Scope of utility model registration request] 1. A transfer roll in which a flexible support for adsorbing and supporting a transfer sheet is wound around a peripheral surface of a roll body in which two cylindrical members are connected by a connecting member with a gap therebetween. An adhesive portion for adhering a front end portion and a rear end portion of the flexible support body to each other, and an adhesive portion for adhering a side edge portion of the flexible support body to each of the two cylindrical members, The front end and the rear end of the flexible support are continuously bonded to the bonding portion of the connecting member, and the side edges of the flexible support are discontinuous in the circumferential direction of the bonding portion of the cylindrical member. A transfer roll for an image output device, wherein the transfer roll is adhered via an elastic member. 2. The adhesion part of the flexible support and the elastic member and the adhesion part of the adhesion part of the elastic member and the cylindrical member are different from each other. Transfer roll for image output device. 3. The transfer roll for an image output apparatus according to claim 1, wherein the elastic member is a strip-shaped flexible member. 4. The transfer roll for an image output apparatus according to claim 1, wherein the flexible support is sheet-shaped.