JPH0733246Y2 - Transfer drum separation device for sheet paper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a separating device that facilitates separation of transfer paper from a transfer drum in a copying machine having a transfer drum. It is available.

[Prior Art] In a conventional copying machine, a separation claw is generally used as a separation method of transfer paper after image transfer by a transfer drum.

For example, as shown in FIG. 5, the transfer paper 2 which is in contact with the photosensitive drum 1 and on which the image is transferred is separated from the drum by the separation claw 4 by the front paper fold 3 attached to the front end side in advance. Further, when the transfer paper is roll paper, the curl of the roll paper is used to facilitate the separation from the drum, and the separation paper is used for separation.

However, in the above-mentioned conventional technique, the leading edge paper fold remains to the end, and a conveyance failure occurs in the conveyance path after separation. Also,
With sheet paper, there is almost no curl and the "waist" of the paper cannot be used, so the paper was picked into a direction that was difficult to bend and sent to the drum for use.

[Problems to be Solved by the Present Invention] The present invention aims to improve the separation performance of the transfer drum and the transfer paper by providing a device having a simple structure so that the tip of the transfer paper is easily separated by the transfer drum. It is something to try.

[Means for Solving the Problem] In the present invention, air is blown to one side of the leading edge of the transfer paper in the transfer paper transport path to cause a difference in water content between the front and back surfaces, and the paper is curled in a direction away from the transfer drum. The purpose is to improve the separation performance of the transfer paper from the transfer drum.

[Operation] By blowing air on the back side of the transfer paper tip, the back side dries from the surface, and the difference in moisture between the front and back surfaces causes the transfer paper tip to bend outward with respect to the transfer drum surface. Is improved.

[Example] Hereinafter, a specific description will be given based on an example of the present invention.

First, FIG. 1 shows an outline of the first embodiment.

A roller pair 5 for transferring the transfer paper is provided at the entrance of the transfer paper transport path, and the sheet paper enters the transport path 6 and blows out from the outlet 7.
After passing through the position sensor 8 and the resist pair 9, they are transferred and separated by the drum 10. Further, the air blown from the outlet 7 is generated by the fan 12 and sent by the duct 11.

Next, the operating state of the device will be described with reference to FIGS. First, in FIG. 2A, when the sheet paper 13 sent by the roller pair 5 passes through the transport path 6 and the leading edge 14 of the sheet comes to the position sensor 8, the rotation of the roller pair 5 is stopped.
Transport is interrupted.

Next, as shown in FIG. 2B, the fan 12 rotates at the same time as the conveyance is interrupted, and the wind 15 passes through the duct 11 and comes out from the outlet 7.

Then, as shown in FIG. 2 (c), the wind 15 hits the back side 16 of the sheet paper 13 to cause a difference in water content from the front side 17, and the sheet paper
A curved portion 18 is generated at 13. The duct 11 is provided at an angle of 10 ° to 60 ° from the transfer paper traveling direction so as not to obstruct the transfer paper.

After a certain period of time after the air is blown, the roller pair 5 starts to rotate and the sheet paper 13 is conveyed by the resist pair 9 in synchronization with the drum 10. When the trailing edge 19 of the sheet passes the position sensor 8,
The fan 12 stops. Then, the sheet paper 13 is transferred by the drum 10, and the leading end 14 of the sheet paper 13 is, as shown in FIG. 2D, curved so as to be separated from the transfer drum, so that the sheet paper 13 is easily separated. ing.

Next, a second embodiment will be described with reference to FIG. The members corresponding to those in FIGS. 1 and 2 are designated by the same reference numerals.

The second embodiment differs from the first embodiment in that a curved conveyance path 6a is provided between the roller pair 5 and the resist pair 9.

As shown in FIG. 3, the sheet paper 13 is curved by the curved conveyance path 6a, and the wind 15 from the outlet 7 is curved on the curved surface 20.
Therefore, the effect of the present invention can be easily obtained.

Next, a third embodiment will be described with reference to FIG. The members corresponding to those in FIGS. 1, 2, and 3 are designated by the same reference numerals.

The difference from the first and second embodiments described above is that the heater 21 is provided in the duct 11.

As shown in FIG. 4, the warm air 15a heated by the heater 21 hits the sheet surface 13 of the curved conveyance path 6a against the curved surface 20, and the normal temperature air 1
The decrease in water content is greater than when 5 hits, the "hip" becomes stronger, and good curl is obtained.

[Advantages of the Invention] As described above, according to the present invention, due to the difference in dryness between the front and back of the transfer paper leading edge, a curl is applied to the transfer paper leading edge in the direction that facilitates separation from the transfer drum. The effect of is obtained.

It is possible to add a curve to the leading edge of the sheet to facilitate separation, regardless of the direction in which the paper is made.

When used in combination with the separation claw, the separation current by the separation charger can be reduced and fatigue of the photosensitive drum can be reduced.

 Since there is no breakage at the leading edge of the paper, it is unlikely that conveyance defects will occur.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a schematic configuration of a first embodiment according to the present invention, FIG. 2 is an explanatory view showing an operating state in the first embodiment shown in FIG. 3, and FIG. 3 is a partial side view showing a second embodiment. Sectional view, 4th
FIG. 5 is a partial side sectional view showing a third embodiment, and FIG. 5 is an explanatory view showing a conventional example of a separation system. 6 ... conveyance path, 7 ... blowout port, 8 ... position sensor, 9
...... Registration roller pair, 10 ...... Transfer drum, 11 ...... Duct, 12 ...... Fan, 13 ...... Sheet paper (transfer paper), 14 ......
Tip, 15 …… wind, 16 …… back side, 17 …… front side, 18 …… curved part, 20 …… curved surface, 21 …… heater.

Claims (1)

[Scope of utility model registration request] 1. An air outlet is provided facing a back surface of a transfer sheet passing through a transfer sheet conveying path for a transfer sheet drum by a transfer roller pair, and a front end position of the transfer sheet is detected at a position in front of the air outlet. A transfer paper leading edge position detection sensor that temporarily stops the transfer paper transport roller pair is provided, and air is blown to the back surface of the temporarily stopped transfer paper leading edge to cause a difference in water content between the front and back of the transfer paper leading edge. A transfer drum separating device for sheet paper, characterized in that it is configured to impart a curl in the opposite direction to the transfer drum surface.