JPS587993B2 - Master paper holding mechanism in electrostatographic copying machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a master paper holding mechanism in an electrophotographic copying machine, and its purpose is to facilitate attachment or replacement of master paper to a photoreceptor drum, and to To provide a master paper holding mechanism which can securely bring the master paper into close contact with a drum especially during copying to obtain clear copies without image unevenness.

In some conventional copying machines, a master paper roll is placed inside a photoreceptor drum, and the master paper pulled out from the roll is wound around the outer periphery of the photoreceptor drum and held at both ends. In this conventional device, once the master paper is wound, it becomes sagging due to the rotation of the photoreceptor drum during copying or due to the effects of humidity, etc., and the sagging causes the image to blur during copying (during exposure and transfer). I couldn't get a clear copy.

The present invention has been made to eliminate such conventional drawbacks and achieve the above objects.

An embodiment of the apparatus of the present invention will be described below with reference to the drawings.

In FIG. 1, a master paper roll 1 is inserted into a master paper roll accommodating portion 3 provided in a photosensitive drum (hereinafter referred to as drum) 2 through an opening 3a thereof, and is held by a support shaft 4. As shown in FIG.

As shown in FIG. 5, both ends of the support shaft 4 are rotatably inserted into guide grooves 5 (see FIG. 5) provided on the required portions of the inner surface of the side plate 2a of the drum 2. It is supported so that it can move in the direction.

Furthermore, a master presser roller 6 that comes into contact with a holder 41 of the master paper roll 1 is rotatably held by a side plate 40 of a support member 39, which will be described later.

Further, on the lower surface of the master paper roll 1, a master feed roller 7 has a gear 16 fixed to its shaft 7a and is rotatably provided on a tension arm 17.

Furthermore, as shown in FIGS. 2 and 3, an idle gear 18 that engages with the gear 16 and a delivery gear 15 that is pivotally attached to the drive shaft 8 are rotatably attached to the arm 17.

Both ends of the drive shaft 8 are rotatably supported by the side plate 2a of the drum 2, and the arm 17 can swing around the drive shaft 8 as a fulcrum.

Further, a tension spring 19 is stretched between the free end of the arm 17 and a pin provided on the side plate 2a of the drum 2, so that the roller 7 is always pulled toward the master paper roll 1, Thereby, the master delivery roller 7 is always in contact with the master paper roll 1 with appropriate pressure.

As shown in Figures 4-A and 4-B, one end of the drive shaft 8 protrudes from the drum side plate 2a, and a drive gear 9 is pivotally attached to the protruding portion.

At one end of the drum rotating shaft 10 that rotatably supports the drum 2, a gear 11 that meshes with the drive gear 9, and a sprocket 12 that is integrally formed with the gear 11 and a connecting sleeve 13 are provided with a bearing. It is attached to the frame 38 via.

Further, a drum driving gear 14 is rotatably attached to the frame 38 at the other end of the drum rotating shaft 10 via a bearing.

Furthermore, as shown in FIG. 5, a roller 3 which guides the master paper drawn out from the master paper roll 1 to the circumferential surface of the drum 2 and is rotatable is provided near the storage section 3.
In addition, a master unwinding roller 20 and a master unwinding idle roller 22 are provided to wrap around the entire circumference of the master pH drum 2 and to clamp the tip thereof.

As shown in FIG. 6, the idle roller 22 and the presser roller 6 are attached to a support member 3 that can be freely inserted into and removed from the housing portion 3.
It is rotatably supported by the side plate 40 of 9.

As shown in Figures 4-A and 4-B, the roller shaft 20a of the roller 20 is rotatably supported on the drum side plate 2a by a bearing, and one end of the shaft 20a protrudes outside the drum side plate 2a. A gear 21 is attached thereto via a one-way bearing so that it engages with the shaft 20a only in the direction of winding up the master paper.

The gear 21 is operatively connected to the gear 11 via intermediate gears 23 and 24 which are pivotally supported on the outside of the drum side plate 2a.

Furthermore, when replacing the master paper, the sprocket 26 that is engaged with the chain 42 that receives power from a drive system provided in the machine body to rotate the sprocket 12, and the sprocket 26 that is integral with the sprocket 26. A clutch 2γ is provided at one end, and a sprocket 2 is provided at the other end.
A drive shaft 25 having a fixed number 8 is provided.

As will be described later, the clutch 27 is activated during the master exchange operation to transmit the drive of the chain 42 to the drive shaft 25, and on the other hand, it is not activated when the drum is rotating during copying, so that no transmission occurs. There is.

Furthermore, a chain 29 is stretched between the sprocket 28 and the sprocket 12, so that the rotation of the drive shaft 25 is transmitted from the sprocket 28 to the sprocket 12 and the master gear 11 via the chain 29. There is.

Furthermore, a sprocket 30 that engages with the chain 42 in order to rotate the drum 2 during copying, and a clutch 31 that is integral with the sprocket 30 and is activated by the copying operation are provided. ,
A gear 32 that meshes with the drive gear 14 is fixed.

Therefore, during copying, the clutch 31 operates, and the chain 42 is driven by the sprocket 30, the clutch 31,
It is transmitted to the gear 14 via the gear 32, and causes the drum 2 to rotate.

Next, the operation will be explained.

When setting the master paper roll anew When setting the master paper roll 1 anew, first pull out the master presser roller 6 and master unwinding idle roller 22 from inside the drum 2 along with the support member 39. Then, insert a new master paper roll 1 into the master storage section 3, engage both ends of the roll support shaft 4 with predetermined positions of the guide groove 5, and then store the support member 39 inside the storage section 3 and press it down. The roller 6 is brought into contact with the holder 41.

Then, while pulling out the master paper from the roll 1 and holding the tip by hand, the clutch 31 is activated to drive the gear 32 and the drum 2 is rotated once in the counterclockwise direction as shown in FIG. The master paper is pulled out by a predetermined dimension and attached to the circumferential surface of the drum 2.

Next, the leading edge of the master paper is moved to the unwinding roller 20.
and the idle roller 22 so that both 20.32
hold it in place.

As a result, the master paper is held under tension on the circumferential surface of the drum 2.

Incidentally, the extra master paper is cut off at the edge of the opening 3a of the master accommodating section 3 or with a cutter, and the setting of the master paper is completed.

When replacing the master paper attached to the drum circumference Next, when replacing the master paper attached to the drum circumference, first turn on the master paper exchange switch (not shown) and operate the clutch 31. , the drum 2 is stopped at a predetermined position, and the master clutch 37 is operated to move the chain 42.
The drive of the master drive shaft 25 is transmitted to the master drive shaft 25.

Due to the rotation of the master drive shaft 25, the sprocket 28,
The sprocket 12 and the master gear 11 are rotated via the chain 29.

The rotation of the master gear 11 directly rotates the drive gear 9 and intermediate gear 24 that are meshed with the master gear 11.

Therefore, due to the rotation of the drive gear 9, the drive shaft 8 and the gear 1
5. In other words, it rotates in the direction of the arrow in FIG.

On the other hand, due to the rotation of the intermediate gear 24, the intermediate gear 23
The roller 20 rotates via the roller 1, and the idle roller 22 rotates as a slave.

Therefore, a new master paper is delivered by the delivery rotation of the master paper delivery roller 7 and the rotation of the master paper delivery roller 20 and idle roller 22 which hold the master paper, for a time period in which the master paper replacement switch or clutch 27 is actuated.

Thereafter, the replacement switch is turned OFF to stop feeding out the master paper, and the used master paper sent out to the outside of the drum 2 is cut, thereby completing the replacement of the master paper.

During the copying period, the clutch 27 is deactivated to stop the driving of the drive shaft 25, thereby causing the master gear to
1 in a non-rotating state.

Then, the clutch 31 is activated by a switch linked to the copy operation.
is operated to drive the chain 42 and rotate the gear 32 and drum drive gear 14.

This causes the drum 2 to rotate together with the drum shaft 10.

This rotation of the drum 2 causes the arm 17 and the gear 1 to
5,18.16 Drive shaft 8, roller 7 are drum rotation shaft 1
It revolves around 0.

Therefore, the master delivery roller driving gear 9 revolves along the master gear 11 which is in a non-rotating state while rotating itself in the opposite direction to the arrow direction in FIG. 1 (that is, in the opposite direction to when replacing the master paper). Rotate to.

Due to this rotation of the gear 9, the master feed roller 7 also rotates in the direction opposite to the direction of the arrow in FIG. The master paper roll 1, which is rotating in accordance with the roller 7, receives a rotational force in a direction to wind up the master paper via a rotatable idle roller 33.

In this case, since the roller 7 is in contact with the back surface of the master paper, no trouble (damage to the surface of the master paper) caused by the rotational force occurs.

On the other hand, the master unwinding gear 21 rotates via the intermediate gear 23 due to the rotation of the intermediate gear 24 (rotation in the direction opposite to the arrow direction in FIG. 1) which is meshed with the master gear 11 similarly to the gear 9. However, since a one-way bearing is provided on the shaft 20a of the master unwinding roller 20 to which this unwinding gear 21 is attached, only the unwinding gear 21 rotates, the master unwinding roller 20 does not rotate, and the master paper is rotated. It is held by a master unwinding roller 20 and an idle roller 22.

As a result, the tip of the master paper wrapped around the circumferential surface of the drum 2 is attached to the roller 2 while the drum 2 is rotating for copying.
The other end is held under tension by the winding action of the master feed roller 7 (rotating in the opposite direction to the feed direction), and the wound master paper is held as the drum 2 rotates. It is possible to completely adhere to the circumferential surface of the drum 2.

Further, even if the diameter of the master paper roll 1 is reduced due to copying, the feed roller 7 is supported by the arm 17 and the spring 19 keeps the feed roller 7 and the master paper roll 1 in contact with each other at all times. Therefore, the above action can be carried out without any problem.

According to the apparatus of the present invention as described above, during copying, the master feeding roller rotates in the direction opposite to the feeding direction of the master paper roll, that is, in the direction of winding up the master paper, so that the master paper roll is not attached to the drum circumference. Even if the master paper that is being used has wrinkles or walnuts before copying starts, the rotation of the copy keeps it under tension, so the rotation of the drum can remove the wrinkles and walnuts that tend to occur on the master paper when the humidity is high. You can always get clear images without blur.

Furthermore, by using the master paper, the master delivery roller can be kept in contact with the master paper at all times.

[Brief explanation of the drawing]

Figure 1 is a perspective view showing one embodiment of the present invention, Figures 2 and 3 are side and perspective views showing the supporting state of the master feed roller, and Figures 4-A and B are front views showing the transmission system. Figures and Side Views FIG. 5 is a side view showing the state in which the master paper is wound, and FIG. 6 is a perspective view of the support member. 1... Master paper roll, 2...
・Photoreceptor drum, 2a...Drum side plate, 6...
...Master presser roller, 7...Master feed roller, 8...Feed roller drive shaft,
9...Feeding roller drive gear, 10...
...Drum rotation axis, 11...Master gear, 1
7... Tension arm, 19... Tension spring, 20... Master unwinding roller, 22... Master unwinding idle roller.

Claims (1)

[Claims] 1. In a master paper holding mechanism in which a master paper roll is housed in a photoreceptor drum, the end of the master paper pulled out from the roll is held, and the master paper is attached to the outer peripheral surface of the photoreceptor drum. The master paper roll is supported so as to be movable in the radial direction relative to the photoreceptor drum, and further includes a presser member that defines the master paper roll in a predetermined position, and a presser member that is in constant contact with the master paper roll and that presses the master paper roll when replacing the master paper. What is claimed is: 1. A master paper holding mechanism for an electrophotographic copying machine, characterized in that a master paper holding mechanism is provided for rotating a master paper roll in a feeding direction, and a master feeding roller that applies rotational force in a winding direction to a master paper roll during copying.