JPS6310425B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a peeling mechanism for peeling a transfer material from an image carrier. Specifically, it is an image bearing member such as a photoreceptor, an insulator, or a magnetic thin film that carries a toner image, an electrostatic latent image, a magnetic latent image, etc., and an image carrier placed between the transfer material for transferring the image on the image bearing member. However, the present invention relates to a separation mechanism having a fixed separation belt.

As a transfer material separation mechanism, an electrophotographic copying apparatus using a drum-shaped photoreceptor as an image carrier will be described as an example.

Generally, an electrophotographic copying apparatus includes a rotating photosensitive drum, an electrostatic latent image forming means arranged sequentially in the rotation direction around the photosensitive drum, a means for developing the electrostatic latent image, and a means for transferring the developed image onto a transfer material. and means for cleaning the surface of the photosensitive drum. In such electrophotographic copying devices, the transfer material is pressed against the photosensitive drum by a corona discharger or a transfer roller during transfer, but at this time, the transfer material is strongly electrostatically attracted and cannot be easily peeled off. become. For this purpose, it is necessary to take some sort of separation means, and one known method is to guide the end surface of the transfer material with a separation belt and separate it with a separation roll or the like. This method is highly reliable and preferred.

Here, the conventional peeling mechanism described above will be explained with reference to FIG. In the figure, from the front of the transfer roller 2,
A peeling belt 5 is stretched in substantially the same direction as the tangent line A-A at the contact point between the roller and the photosensitive drum 1, and a peeling roller 6 that rotates immediately after the transfer roller 2 is provided to expose the peeling belt 5 to light at a contact angle α. It is guided in a direction away from drum 1. Then, the peeling belt guides the widthwise end of the transfer material P without contacting the photosensitive drum 1 before the transfer, and after passing the transfer roller position, the transfer material is guided in a direction away from the photosensitive drum 1 with a constant tension. It is configured to be peeled off from the photosensitive drum 1.
Note that 3 is a conveying roller and 4 is a guide that guides the transfer material P to the surface of the drum 1.

However, in the above configuration, the peeling belt 5 must constantly be in pressure contact with the peeling roller 6 with a contact angle α. That is, pressure contact between the peeling belt 5 and the peeling roller 6 is unavoidable. Moreover, since the peeling belt 5 is fixedly stretched, only a specific portion of the belt is always in contact with the rotating peeling roller, and this specific portion is damaged due to wear. In addition, this phenomenon is particularly noticeable because a material with a large abrasion coefficient, such as rubber, is used for the peeling roller to prevent slipping with the transfer material and to strengthen the conveying force. Of course, if the stripping belt is damaged, the stripping function of the apparatus will cease and the operation must be stopped until the belt is replaced or refurbished, which is extremely uneconomical. Moreover, in the current peeling mechanism that employs a peeling belt, the longer the life of the photosensitive drum is extended, the more it becomes necessary to prevent the photosensitive drum from being damaged by the peeling belt. For this reason, the surface hardness of the photosensitive drum is made as strong as possible, but the material of the peeling belt that comes into contact or sliding contact with the drum surface is selected to be more likely to wear out compared to the normal drum surface strength. In other words, it is preferable to design the peeling belt as a consumable item rather than a permanent concept. However, in this case, the lifespan of the peeling belt is short compared to the original lifespan of the copying device, so it must be replaced periodically before it breaks, and the settings and settings at the time of replacement must be changed. There are many problems such as time and effort. As described above, it is important to select the material for the peeling belt that comes into contact with the photosensitive drum.If the peeling belt is made to have durability and wear resistance, the contact portion of the photosensitive drum is undesirably prone to roughening of the surface of the drum due to friction. On the other hand, if a weak material is selected for the belt, deterioration will occur from the surface end of the belt, resulting in the damage described above. For this reason,
The peeling belt must be replaced before it reaches its limit of use and breaks.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a transfer material peeling mechanism that increases the durability of a peeling belt and performs its peeling function over a long period of time.

That is, the present invention that achieves the above object has the following advantages:
A peeling belt is provided along the transport direction of the transfer material from upstream to downstream of the transfer means, and a peeling belt is provided on the downstream side of the transfer means, and the transfer material is guided and conveyed between the peeling belt and transferred from the image carrier. A rotating peeling roller for peeling off the material, and this peeling roller is provided independently, is located within the width of the peeling belt, is adjacent to the outer end of the transfer material width of the peeling roller, and is located within the width of the peeling belt. and a guide pulley having a diameter larger than the peeling roller so as to guide and convey one end side of the transfer material between the peeling roller and the peeling roller.

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 2 and 3 are diagrams showing an embodiment of the present invention. FIG. 2 is a front view thereof, and FIG. 3 is a side view thereof. In the figure, 7 is a peeling roller made of a material with a large friction coefficient, such as rubber. Then, on the mounting shaft 8 of this peeling roller 7,
Furthermore, a peeling belt guide pulley 9 is arranged.
This guide pulley 9 is made of a material with a small friction coefficient such as plastic, has a larger outer diameter than the peeling roller 7, and is rotatable with respect to the shaft 8.
It is attached near the peeling roller 7. That is, even if the peeling roller 7 is rotated by the drive of the shaft 8, the guide pulley 9 does not rotate.

Therefore, the peeling belt 14 made of mylar or the like, which is held at both ends by the shafts 10 and 11, is
It is stretched along the outer periphery of the guide pulley 9, and has a gap between it and the peeling roller 7 by the difference in the outer diameters of both rollers 7 and 9. That is, the peeling belt 14 is separated from the circumferential surface of the peeling roller and does not touch it. Therefore, the transfer material P guided onto the surface of the drum 1 by the conveyance roller 12 and the guide 13 is separated from the surface of the drum 1 by the belt 14 at one side edge, and is transferred to the corona discharger 15. The image formed on the drum is transferred by the drum. Thereafter, the transfer material P is guided by the belt 14 toward the rotating peeling roller 7, is conveyed between the belt 14 and the circumference of the roller 7, and is peeled off from the surface of the drum 1. Moreover, in this embodiment, the peeling belt 14
Although there is a small gap between the transfer material P and the peeling roller 7, the transfer material P obtains sufficient conveying force due to the frictional force with the circumferential surface of the peeling roller 7 on its back surface, and the surface of the transfer material P is Since the transfer material P is pressed against the peeling roller 7 side by the peeling belt 14, the transfer material P is reliably peeled off from the surface of the drum 1 and conveyed. Moreover, the belt 14 is a peeling roller 7 with a large coefficient of friction.
It is pressed toward the drum 1 by the pulley 9 without contacting the peripheral surface. Therefore belt 1
4 can be prevented from being damaged due to wear, and the belt 1
4 durability can be increased. Furthermore, as shown in FIG. 2, in this embodiment, the width of the guide pulley 9 is made equal to the width of the peeling roller 7, thereby increasing the width of the belt 14 guided by the guide pulley 9. The precision of the gap between the peeling roller 7 and the belt 14 is increased, and the gap is kept uniform. Furthermore, since the transfer material P passes through this gap, the transfer material P is peeled off and guided without receiving any impact when it is held between the peeling rollers 7. Moreover, even if the transfer material P deviates from the normal conveyance path within the width of the peeling roller 7 and is forced to pass between the guide pulley 9 and the peeling belt 14, the transfer material P will come into contact with the guide pulley 9. As a result, the guide pulley 9 rotates, so that delays, jams, etc. of the transfer material P can be prevented.

Still other embodiments will be described using FIGS. 4 to 6. FIG. 4 is a plan view of this embodiment, FIG. 5 is a side view thereof, and FIG. 6 is a perspective view thereof. In this embodiment, rollers 16 and 17 are further added to the above embodiment. That is, a portion of the peeling belt 18 located above the peeling roller 7 is partially cut out, and the rollers 16, which are in pressure contact with the peeling roller 7, are placed in the cutout portion.
17. The rollers 16 and 17 are made of high-molecular polyethylene or the like, and are rotated by the peeling roller 7 due to frictional force with the peeling roller 7. With the above configuration, the transfer material P is guided toward the peeling roller 7 by the peeling belt 18, is held in pressure contact with the peeling roller 7 by the rollers 16 and 17, and is reliably peeled off from the surface of the drum 1. Furthermore, since the peeling belt 18 is disposed between the rollers 16 and 17 with a gap from the surface of the peeling roller 7, the transfer material P can be reliably guided. Therefore, the rollers 16, 1 of the transfer material P can be easily moved without taking the trouble of providing a guide section for the transfer material P using a separate member.
This will allow us to guide you for 7 days. In FIG. 6, reference numeral 32 denotes a peeling roller drive gear, which rotates the shaft 8 to which the peeling roller 7 is attached when driven by a drive source (not shown) such as a motor. In addition, the peeling belt does not only cut out
Only the portion where the rollers are delivered may be provided with punched holes, or furthermore, the portion separated from the peeling roller may be provided with double holes. This further increases the strength of the belt.

According to this embodiment, the width of the peeling roller 7 is 10 mm,
By setting the diameter to 31 mm, the width of the guide pulley to 10 mm, the diameter to 31.2 to 31.4 mm, and the width of the peeling belt to 20 mm, the transfer material (thickness 0.07 to 0.09 mm)
It has been confirmed that peeling is possible.

Furthermore, using Fig. 7, attach the roller 1 to the housing.
An example in which 6 and 17 are provided is shown. The rollers 16 and 17 are held by a housing 19. The housing 19 is coupled to the housing 21 via a shaft 20 and is swingable about the shaft 20 provided on the side plate 24. Furthermore, housing 2
1 is swingable around a shaft 22 and has one end pulled by a spring 23. Also spring 2
The other end of 3 is hung on the side plate 24. Therefore, the rollers 16 and 17 are brought into pressure contact with the peeling roller 7 due to the tensile force of the spring 23. Further, the peeling belt 18 is fixed at one end to a shaft 10 and at the other end to a shaft 11, and the shaft 11 is fixed to a tension plate 25. Also, the spring 26 is connected to the tension plate 2
5 and is hung on the side plate 24. Therefore, a certain tension is always applied to the peeling belt 18 by the spring 26. Note that 27 is a peeling belt guide plate that guides the peeling belt 18 in the direction of the peeling roller 7.

Furthermore, the shape of the housing for holding the rollers may be as shown in FIG. That is, the lower side of the housing 28 is shaped like a circular arc and runs along the circumferential surface of the peeling roller 7, thereby preventing the peeling belt 18 from lifting when the transfer material P passes. By doing so, the transfer material is more reliably guided to the peeling belt, so that it is more reliably peeled off from the drum surface. In addition, instead of Koro,
Of course, it may also be a belt suspended on a pulley.

Note that each of the above embodiments shows an example in which the separation belt and the separation roller are separated by providing a guide pulley having a diameter slightly larger than that of the separation roller. The examples are not limited. For example, as shown in FIG. 9, a separating piece 30 having an arc-shaped curved portion 29 may be attached by fixing its vertical portion 31 to a tilted plate. It is also possible to adjust the gap width between the peeling belt and the peeling roller by arranging the curved portion 29 near the side of the peeling roller and adjusting the installation height thereof. Alternatively, the belt may be separated from the circumferential surface of the roller by simply attaching a rod-shaped member to the inverted plate.

As described above, the peeling mechanism of the present invention separates the peeling roller from the peeling belt by providing, for example, a guide pulley with a larger diameter than the peeling roller as a separating member, thereby preventing the peeling belt from being damaged due to wear. By preventing this, the durability of the peeling belt is significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a side view of a conventional peeling mechanism, FIG. 2 is a front view of a peeling mechanism using an embodiment of the present invention, and FIG.
4 is a front view of a peeling mechanism using another embodiment, FIG. 5 is a side view thereof, FIG. 6 is a perspective view thereof, and FIG. 7 is a peeling mechanism equipped with a housing. FIG. 8 is a side view showing another housing shape, and FIG. 9 is a perspective view showing another embodiment of a separating member. In the figure, 1... photosensitive drum, 7... peeling roller, 8...
Mounting shaft, 9... Guide pulley, 10, 11...
Shaft, 14... Peeling belt, 16, 17... Roller,
18... Peeling belt, 19, 21... Housing, 30... Separation piece.

Claims (1)

[Scope of Claims] 1. A peeling belt provided along the transfer direction of the transfer material from upstream to downstream of the transfer means on the side of the transfer position of the image carrier that supports the toner image; and a peeling belt provided on the downstream side of the transfer means. a rotating peeling roller disposed on the peeling belt for guiding and transporting the transfer material between the peeling belt and peeling the transfer material from the image carrier; a guide pulley located within the width of the peeling roller, adjacent to the outer edge of the transfer material width of the peeling roller, and having a diameter larger than that of the peeling roller to guide and convey one end of the transfer material between the peeling belt and the peeling roller; A peeling device comprising: and