JPH03171071A - Transfer device using transfer drum - Google Patents

Abstract

PURPOSE:To prevent the occurrence of the misregistration of a transfer image and paper jamming etc., caused by an impact at the time of releasing a transfer paper by engaging an engaging part with a push-up member by means of a clipper energized by an energizing means and pressing the push-up member on the side of a transfer drum. CONSTITUTION:The clipper 3 is energized by the energizing member 7 and engages the engaging part 3a with the push-up member 4 while it clamps the transfer paper P, whereby the push-up member 4 is pressed on the side of the transfer drum 1 by the engaging part 3a. Consequently, since the push-up member 4 can be energized through the clipper 3 by the energizing member 7 energizing the clipper 3, the need for an energizing means 4 for directly energizing the push-up member 4 is eliminated. Therefore, the need for the energizing means for directly energizing the release of the transfer paper 1 can be eliminated. Therefore, the misregistration of the transfer image and the paper jamming etc., is prevented from generating caused by the impact at the time of releasing the transfer paper, and a construction can be simplified.

Description

[Detailed description of the invention] Industrial application field> This invention forms a transferred image by superimposing toner of multiple colors carried on a photoreceptor drum on a transfer paper wound around a transfer drum. The present invention relates to a transfer device using a transfer drum, which is attached to an image forming device such as a color image forming device.

Conventionally, as shown in FIGS. 4 and 5, the above-mentioned transfer device has been known to place the leading end Pa of the transfer paper P in a recess 81 on the circumference of the transfer drum 80. It was equipped with a clipper 82 for gripping upward, and a push-up member 83 for pushing up the tip Pa from the recess 81.

These clippers 82 and push-up members 83 are arranged in plurality (for example, four ) is provided. Also, clipper 8
2 and the push-up member 83 are each pressed against the transfer drum 80 by biasing means 85 and 86 provided independently from each other.
biased toward the side. Furthermore, the clipper 82 and the push-up member 83 are pushed up against the biasing means 85, 86 when necessary by the operating cam 87, and this push-up is released.

In the above-described transfer device, after the transfer paper P whose leading end is gripped by the clipper 82 is transferred onto the transfer paper P while being wound around the transfer drum 80, the operation cam 87 moves the paper P to the clipper 82. 82 is pushed up against the urging means 85 to release the grip on the transfer paper P, and the push-up member 83 is pushed up against the urging means 86.
As a result, the leading end Pa of the transfer paper P is pushed up, and the leading end Pa is peeled off from the transfer drum 80.

By the way, in the above-mentioned transfer device, each of the plurality of clippers 82 and the push-up members 83 has biasing means 85 and 86.
, the total number of biasing means 8586 is equal to the total number of clippers 82 and push-up members 83.

Therefore, when the operating cam 87 pushes up the clipper 82 and the push-up member 83 that have received the biasing force of the biasing means 85 and 86, the transfer drum 80 receives a strong impact, and this impact is transmitted to the photosensitive drum, causing the transfer There was a problem in that the toner inside shifted, causing color shift, making it impossible to obtain a good transferred image. In addition, the impact causes the transfer drum 80 and the photosensitive drum to not rotate smoothly, causing paper jams.

In view of the above-mentioned problems, it is an object of the present invention to provide a transfer device that can prevent image shift and jamming caused by impact when the transfer paper is opened, and that can simplify the structure. purpose.

Means for Solving the Problems> In order to achieve the above object, a transfer device using a transfer drum according to the present invention is installed in an image forming device that forms a transferred image on a transfer paper wound around the transfer drum. , a clipper that is biased by a biasing means to grip the leading edge of the transfer paper within the recess on the circumference of the transfer drum, and a pusher that pushes the leading edge of the transfer paper released from the grip by the clipper out of the recess. In the transfer device comprising a member, the clipper includes:
The device is characterized in that it includes an engaging portion that presses the push-up member toward the transfer drum while holding the transfer paper.

According to the transfer device configured as described above, the clipper urged by the urging means engages the engaging portion with the push-up member while gripping the transfer paper, thereby causing the engaging portion to engage with the push-up member. The push-up member can be pressed against the transfer drum by the urging means that urges the clipper.
Since the push-up member can be biased via the clipper, a biasing means for directly biasing the push-up member can be made unnecessary, and the total number of biasing means can be reduced.

Example Embodiments will be described in detail below with reference to the accompanying drawings showing embodiments.

1 and 2 are a perspective view and a schematic side view of a main part of a transfer device using a transfer drum as an embodiment of the present invention. includes a transfer drum 1, a clipper 3 for gripping transfer paper and a push-up member 4 for peeling off the transfer paper, which are disposed in a recess 2 on the circumference of the transfer drum 1; and these clippers 3 and push-up members. 4 and an operating means 5 for operating the main part.

The clipper 3 and the push-up member 4 are rotatably attached to a shaft 6 attached within the recess 2. The clipper 3 includes a cam follower 3 for driving the clipper 3.
1 and is formed in an angular shape integrally with the push-up member 4.
is a cam follower 4 for driving the push-up member 4;
It is shaped like an angle and is integrated with 1. Further, an extending portion 3a is formed at an end of the clipper 3 as a retaining portion that engages with the push-up member 4 and presses the push-up member 4 toward the transfer drum 1 side.

Further, the clipper 3 and the push-up member 4 are biased toward the transfer drum 1 by a torsion coil spring 7 serving as biasing means. Both ends 7a and 7b of the torsion coil spring 7 are locked to a shaft 71, and the middle part 7c urges the clipper 3 downward by a repulsive force against torsion.

The operating means 5 includes a solenoid 51 as a driving means, an arm 53 that is rotated around a shaft 52 by the solenoid 51, and shafts 54a and 54b that are rotated by the arm 53.
The main part is constituted by a pair of cam members 55a and 55b which are rotated around , and are brought into contact with and separated from the cam followers 31.41. The cam member 55a has a cam surface 55
c operates only the clipper 3, and the cam member 55b operates the clipper 3 with the cam surface 55d, and the cam member 55b operates the clipper 3 with the cam surface 55d.
The push-up members 4 are each operated by 5e.

Next, the operations of the clipper 3 and the push-up member 4 will be explained. Then, the arm 53 is set to the second position by the solenoid 51.
By rotating clockwise in the figure, the cam member 55a is rotated counterclockwise, thereby pushing up the clipper 3 and causing it to escape from the recess 2. Then, the leading edge Pa of the transfer paper P that has been conveyed in synchronization with the rotation of the transfer drum 1 is received by the clipper 3 that has escaped. Then, by rotating the arm 53 counterclockwise, the push-up by the cam member 55a is released.
The clipper 3 is biased by a torsion coil spring 7 and grips the leading end Pa of the transfer paper P on the circumference of the transfer drum 1.

In this gripped state, the transfer paper P is wound around the transfer drum 1,
As the transfer drum 1 rotates, toner of each basic color is transferred from the photosensitive drum to the transfer paper P.

After the transfer is completed, the arm 53 is rotated clockwise by the solenoid 51 again, and the cam member 5
5b is rotated counterclockwise, and both the clipper 3 and the push-up member 4 are pushed up against the biasing force of the torsion coil spring 7. Then, the clipper 3 releases the gripping of the leading end Pa of the transfer paper P, which has already been transferred, and the leading end Pa is pushed up by the push-up member 4, so that the leading end Pa is peeled off from the transfer drum 1. As the transfer drum 1 rotates, the separated transfer paper P is removed by the separation claw 8.
While being separated from the transfer drum 1, it is guided to the downstream side of the conveyance path.

When the separation of the transfer paper P is completed, the arm 53 is rotated counterclockwise by the solenoid 51, and the cam member 55b is rotated counterclockwise by the solenoid 51.
The push-up caused by
Return within.

According to this embodiment, the push-up member 4 can be pressed against the transfer drum 1 side via the clipper 3 by the torsion coil spring 7 that urges the clipper 3 toward the transfer drum 1 side. Therefore, there is no need to provide an independent biasing means for pressing the push-up member 4. In other words, the torsion coil spring 7 can be used commonly for biasing the clipper 3 and the push-up member 4, which The total number of biasing means can be reduced compared to.

Therefore, when the transfer paper is released, the impact when the cam member 55b comes into contact with the cam follower 31.41 is small, and as a result, the impact exerted on the transfer drum 80 and the photosensitive drum can be reduced. , it is possible to prevent misalignment of transferred images, paper jams, etc. that would otherwise occur due to strong impact when the transfer paper P is opened. Furthermore, since the number of biasing means is small, the structure on the transfer drum 1 side can be simplified.

In the above embodiment, the engagement side of the clipper 3 is formed as an extension part, but by forming an extension part on the engaged side of the push-up member 4, the clipper 3 and the push-up member 4 can be connected. In addition, the present invention is not limited to the above-mentioned embodiment, and various design changes can be made without changing the gist of the present invention.

Effects of the Invention> As described above, according to the present invention, the clipper urged by the urging means engages the engaging portion with the push-up member and presses the push-up member against the transfer drum side. Since the clipper and the push-up member can be attached to each other, it is possible to reduce the total number of bias means by eliminating the need for a biasing means to directly bias the push-up member. A unique effect is that it can weaken the impact on the transfer drum and photoreceptor drum when it is pushed up, and can prevent misalignment of transferred images and paper jams that would otherwise occur due to the strength of the impact. play. 4.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the main parts of a transfer device using a transfer drum as an embodiment of the present invention, Fig. 2 is a schematic side view of the transfer drum showing a state in which transfer paper is gripped, and Fig. 3 is a transfer device. FIG. 4 is a schematic side view of the transfer drum showing a state in which paper grip is released; FIG. 4 is a perspective view of essential parts of a conventional transfer device; FIG. 5 is a schematic side view of the conventional transfer device. DESCRIPTION OF SYMBOLS 1... Transfer drum, 2... Recessed part, 3... Clipper, 3a... Extension part (retention part), 4...
...Push-up member, 7...Tension recoil spring (biasing means), P...Transfer paper, Pa...Tip portion.

Claims (1)

[Claims] 1. Transfer the image onto the transfer paper wound around the transfer drum attached to an image forming device that forms an image; A biasing force is applied in the recess on the circumference of the transfer drum. The leading edge of the transfer paper is biased by means and a clipper that grips this clipper. Hold the leading edge of the transfer paper that has been released from the grip. Equipped with a push-up member that pushes up outside the recess. In the transfer device, the clipper is While holding the transfer paper, push up the push-up member. It has an engaging part that presses against the transfer drum side. Using a transfer drum characterized by Transfer device.