JPS6131459B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transfer sheet guide device that is attached to a transfer device used in an electrophotographic copying machine and the like, and that guides the progress of a transfer sheet as a transferred object.

The colored toner transferred from the photoreceptor is attached to the surface of the sheet immediately after transfer, and if another member touches this surface, the unfixed or undried image will be disturbed and the recorded image will no longer function. For this reason, the member that transports and guides the sheet after transfer is only allowed to contact the back side of the sheet or the edges that are not used for image formation, and if the surface of the sheet is unavoidably in contact with another member, In this case, the touch is limited to a light touch that does not disturb the image.

Therefore, the sheet after the transfer is generally peeled off from the photoreceptor by being guided or pinched by one end in the width direction of the sheet, a so-called lug on one side, and then sent out for the next process such as fixing.

Here, with reference to FIGS. 1 and 2, an example of a state in which a sheet as a transferred object advances in a transfer device will be described. A fed sheet S is held between a pair of conveying rollers. The photoreceptor 3 is first brought into contact with the transfer charger 2 and sent into the transfer device.
The image is electrostatically transferred to the peripheral surface of the
During the transfer, one side edge of the sheet S advances while being in sliding contact with the upper surface of the strip-shaped separation member 4 that contacts the circumferential surface of the photoreceptor 3.

Now, the sheet S which has completed the transfer and continues to move in close contact with the photoreceptor 3 then comes into contact with the turn roller 5, and at this time, the edge portion is regulated by the peeling plate 4a protruding from the separation member 4 and pulled from the photoreceptor 3. It is peeled off and drawn in between a rotating turn roller 5 and a belt 7 driven by a pulley 6.

In this way, the sheet S whose one edge is sent out from the delivery port 8 of the roller 5 passes over the guide member 10 provided on the side of the delivery port 8, reaches the discharge roller pair 9, and reaches the top of the delivery roller pair 9. The paper is lightly pressed by the rollers and sent to the lower feed roller, and then discharged from the transfer device to the next process mechanism.

By the way, the present invention relates to the above-mentioned guide member 10, and the illustrated embodiment of the guide member 10 is an embodiment of the present invention (described later), but the conventionally used guide member is the guide member shown in FIG. Member 20
It was formed into a flat plate like this.

Here, to describe the function and effect of this flat guide member 20, since the sheet S is pressed at one edge and sent out almost inverted, the other end in the width direction of the sheet S, the so-called opposite side (the upper left end in the drawing) part) rises from the guide member 20 due to the flatness of the sheet, and the surface of the sheet S on which the image is attached comes into contact with other members above and the image is easily rubbed.
There were drawbacks such as the tip of the paper was not guided uniformly and was liable to become jammed by the time it was caught between the pair of discharge rollers 9.

Particularly in low humidity conditions, the sheet S becomes strongly charged while it is traveling and is easily attracted to other nearby members, causing an accident where it sticks to other members above the sheet S and prevents the sheet S from advancing. be.

In order to prevent the free end of the sheet from lifting up, methods have been considered that use airflow or static electricity to suppress the lifting, but the lifting of the sheet is too large and is not recommended. The problem was that the side was too far away from the guide member 20, making it impossible to obtain a sufficient and reliable prevention effect.

Therefore, this invention devises the shape of the guide member,
Even when the edge of the sheet rises to the maximum,
To provide a transfer sheet guide device that reliably guides a sheet by solving the above-mentioned difficulties by forming the upper surface height of the guide member at a height that is aligned with the sheet and within the distance for attracting the sheet. The purpose is to

Hereinafter, the present invention will be explained with reference to an illustrated embodiment. As shown in FIGS. 1 and 2, after the sheet S is transferred, the peeling plate 4a of the separating member 4 first removes the edges of the sheet S from the turn roller. 5 and the belt 7 are fed into the contact surface as described above.

In this way, the sheet S that is in close contact with the photoreceptor 3 can be peeled off by using a claw that slides on the circumferential surface of the photoreceptor 3, in addition to using the peeling plate 4a, or by blowing air in the direction opposite to the direction of movement of the sheet S. There are also methods such as spraying or using a thread that slides across both the circumferential surfaces of the photoreceptor 3 and the turn roller 5, but these separation methods are unstable in operation, or may damage the members. Also, there were drawbacks such as a complicated mechanism.

Now, the guide member 10 through which the sheet S sent out from the turn roller 5 is guided is held in a fixed part by the mounting legs 11 parallel to the circumferential surface of the photoreceptor 3.
Its leading edge (right end in the drawing) is in contact with the side of the turn roller delivery port 8, and its rear edge faces five rows of discharge roller pairs 9 within each notch.

As shown in FIGS. 4 to 7, this guide member 10 has a fold 10a at the front edge and a flat part 10b at the rear edge horizontally, but the cross-sectional shape of the main surface 10c is shaped like a turn roller. It is flat at one end (Fig. 7), while the other end is raised into a thick wing shape (Fig. 6). Note that double rows of ribs 10d are formed over the entire surface of the member, and serve to reduce the conveyance resistance of the sheet S.

In a guiding device using such a guiding member 10, when the sheet S is sent out from the turn roller 5, even if the end of the sheet on the opposite side to the turn roller 5 rises, the guide member 10 is not moved toward one side. Since the upper surface is located high and close to the sheet, the sheet S is electrostatically drawn and reliably contacts the guide member, the inclination of the sheet S is corrected, and the leading end is correctly fed into the pair of discharge rollers 9. (Embodiment in Figure 2).

Note that the implementation structure of the guide member based on the present invention is not limited to the above-mentioned airfoil plate, for example, as shown in FIG.
A guide member 21 is provided with an air suction groove 21a inclined left and right, and the air in the inner cavity of this member 21 is pulled from the intake pipe 21b to create a negative pressure, thereby creating a so-called air curtain at the front edge of the guide member 21. to form. In devices where air is strongly blown onto the raised part of the transfer sheet on the side opposite to the separation side, or in a device where the image side of the transfer sheet is guided by a needle roller, the diameter corresponding to the raised part of the transfer sheet is increased and the diameter of that part is increased. Other well-known attraction methods other than electrostatics can be used, such as increasing the speed of the guide to ensure a more reliable guiding effect.

As described above, according to this transfer sheet guide device, the sheet after transfer is smoothly and reliably conveyed to the next process mechanism, and has the effect of improving the reliability of the sheet passing operation.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a transfer sheet guiding device showing one embodiment of the present invention, Fig. 2 is a perspective view thereof, Fig. 3 is a diagram illustrating a conventional guide member, and Fig. 4 is shown in Fig. 1. a plan view of the guide member as a partial view of the guide device;
Fig. 5 is a front view of the same, Fig. 6 is a sectional view of the same side (at the reference number - in Fig. 4), and Fig. 7 is a same front view of the same.
FIG. 8, which is indicated by the reference numeral ``-'', is a diagram illustrating another guide member embodying the present invention. S... Transfer sheet, 3... Photoreceptor, 4... Separation member, 5... Turn roller, 8... Turn roller delivery port, 9... Discharge roller, 10... Guide member.

Claims (1)

[Scope of Claims] 1. By grasping one end of the transfer sheet in the width direction after the transfer, the transfer sheet is removed from the photoreceptor with the other end of the transfer sheet rising to a higher position than the one end of the same width direction. A device for advancing the transfer sheet in the direction of separation, which is located at the front in the direction of movement of the transfer sheet, and a position facing the other end in the width direction of the transfer sheet from the back side of the transfer sheet is placed on the back side of the transfer sheet. A guide member having an asymmetrical surface in the width direction of the transfer sheet is provided so as to be closer to the other end of the sheet which is raised higher than the position facing one end of the sheet in the width direction. Characteristic transfer sheet guide device.