JPS63113574A - Image forming device - Google Patents

Abstract

PURPOSE:To exactly separate an image supporting body from the latent image surface of an image carrying body, by forming a separating means by a separating claw member having a sharp tip part consisting of a synthetic resin elastic body brought into contact with the latent image surface by a suitable timing. CONSTITUTION:A separating device 20 turns a turning link 22 by bringing a turning lever 23 to a pressure operation by ON of a solenoid 24, opens one end 22a engaged to the rear end part 21b of a separating claw member 21 and turns it by the dead weight of the separating claw member 21, and allows the sharp tip part 21a of the separating claw member 21 to bring into contact with the latent image surface 2a of a photosensitive body 2. On the other hand, the turning lever 23 and the turning link 22 are operated in a reverse direction by OFF of the solenoid 24, the rear end part 21b of the separating claw member 21 is depressed against the dead weight, and the tip part 21a of the separating claw member 21 is separated from the latent image surface 2a. In such a way, an image supporting body after the transfer and peeling-off can be separated exactly from the latent image surface.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention relates to a means for separating an image support from an image carrier after transfer and peeling of a developed image in, for example, an electronic copying machine or the like. The present invention relates to an improved image forming apparatus.

(Prior Art) Conventionally, in this type of image forming apparatus, for example, an electronic copying machine, an image support after a copying operation in which a developed image is transferred and peeled off on a latent image surface on a photoreceptor as an image carrier; That is, a means for separating the recording paper using a separating claw member installed on the way to the cleaning device is provided.

As the separation claw member constituting such separation means, ABS resin, hardening plastic such as Delrin, flexible film such as Mylar (trade name), etc. are normally used, and the sharp tip of the material is used. , by contacting the occult blood surface of the photoconductor at an appropriate timing, the recording paper is separated from the photoconductor after transfer and peeling, and at the same time assists in preventing the occurrence of a jam due to the recording paper entering the cleaning device. It is a mechanism.

(Problems to be Solved by the Invention) However, the above-mentioned conventional separating claw members, especially AB
Plastics such as S-resin have high hardness, so when they come into contact with the photoreceptor.

The latent image surface of a photoreceptor made of selenium (Se) or the like, which has relatively low hardness, is easily damaged, resulting in defects that impair image quality or cause failure of the photoreceptor.

In addition, in order to compensate for the above-mentioned problems, if a flexible film such as Mylar (trade name) is used as the separation claw member, it is difficult to maintain the precision and shape of the contact part with the photoreceptor. The composite structure uses a hard material as the base material, which not only easily scratches the latent image surface of the photoreceptor, but also causes the recording paper to become static when the pressure in contact with the latent image surface of the photoreceptor is weakened. Since it is electrically separated, it is easier to enter the cleaning device without being separated from the photoreceptor.

There was a problem with the cleaning equipment breaking down.

The present invention has been made under the above circumstances, and its purpose is to reliably separate recording paper from the 'M' image surface of the photoreceptor without damaging the latent image surface of the photoreceptor. An object of the present invention is to provide an image forming apparatus that can perform the following operations.

[Structure of the Invention (Means for Solving the Problems)] In order to solve the above-mentioned problems, the present invention provides a method to solve the problems described above. Separating means for separating the image support from the image carrier on the way to the cleaning device, the separating means comprising a synthetic resin elastic body brought into contact with the latent image surface of the image carrier at an appropriate timing. The structure is formed by a separating claw member having a sharp tip.

(Function) That is, by having the above configuration, the present invention has the following features:
Since the separating claw member is made of an elastic synthetic resin such as polyurethane resin, the material itself of the separating claw member is soft, so it does not damage the latent image surface of the image carrier. The structure can be simplified to maintain the precision and shape necessary for contacting the latent image surface of the image carrier, and this allows the image support to be transferred and peeled off to the latent image surface of the image carrier. It becomes possible to reliably separate it from the surface.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 schematically shows the internal mechanism of an electronic copying machine which is an image forming apparatus according to the present invention, and numeral 1 in the figure is the main body of the apparatus. A drum-shaped photoreceptor 2 serving as an image carrier is rotatably supported approximately at the center of the apparatus main body 1, and the photoreceptor 2 is uniformly charged by a charger 3. At the same time, an exposure lamp 5a,
1st. second and third reflecting mirrors 5b, 5c, 5d;

Optical system 5 consisting of lens 5e and fourth reflection mirror 5f
An electrostatic latent image is formed by forming an image on the latent image surface 2a of the photoreceptor 2 through the electrostatic latent image, and a developer is applied to this electrostatic latent image by a developing device 6 to develop it, and the image is sent to the transfer charger 7 side. On the other hand, this transfer charger 7 transfers the copy paper P made of plain paper as a recording paper fed from a paper feed cassette 8 which is automatically or manually fed via a paper feed roller 9 and a pair of aligning rollers 10. Transfer the developed image and AC
It is designed to be peeled off by a peeling charger 11 using corona discharge.

The copy paper P after the transfer and peeling is peeled off from the photoreceptor 2 by a separating device to be described later, passes through a conveying path 12, and a fixing device 13 melts and fixes the developed image. It is something that is discharged upwards.

Furthermore, the developer remaining on the latent image surface 2a of the photoconductor 2 after the transfer and peeling off of the developed image onto the copy paper P is cleaned by the cleaning device 16, and the photoconductor 2 is cleaned by the static elimination lamp 17.
The upper potential is lowered below a certain level to enable the next copy operation.

The above-mentioned separation device 2o is installed at one or more locations in the longitudinal direction of the photoreceptor 2 on the way from the peeling charger 11 to the cleaning device 16, and this separation device 20 includes: As shown in FIG. 2, a sharp tip 21a is rotatably supported on the latent image surface 2a of the photoreceptor 2 so as to be able to come into contact with it due to its own weight.
A separating claw member 21 made of polyurethane resin with a standard rubber hardness of 90° and a thickness of 1.5 mm; and this separating claw member 2.
a rotary link 22 whose one end 22a side is engaged with the rear end 21b of the rotary link 22; a rotary lever 23 whose one end 23a is brought into contact with the other end 22b side of this rotary link 22; The solenoid 24 rotates the lever 23.

That is, as shown by the solid line arrow in FIG. 2, the separation device 20 presses the rotation lever 23 by turning on the solenoid 24 to rotate the rotation link 22, thereby releasing the rear end portion 21b of the separation claw member 21. The one end 22a that engages with the photoreceptor 2 is opened to allow the separation claw member 21 to rotate due to its own weight.
The third latent image surface 2a is brought into contact with the third latent image surface 2a.
As shown by the solid arrow in the figure, the OF of the solenoid 24 is
F operates the rotary lever 23 and the rotary link 22 in the opposite direction to push up and rotate the rear end portion 21b of the separation claw member 21 against its own weight, thereby sharpening the tip of the separation claw member 21. The tip end 21a is connected to the latent image surface 2 of the photoreceptor 2.
It is released so as to be separated from a.

By the way, the shape of the contact surface of the sharp tip 21a of the separation claw member 21 when it starts contacting the wIa surface 2a of the photoreceptor 2 is as shown in FIG. Let the tangent X passing through the contact starting point A to be the 15 quasi of Oo,
With respect to this reference tangent line
Two lines Y passing through each fulcrum after advancing by ' and 60',
It is set so that both sides are included in the angle O formed by Z, and the angle O formed by both sides is within an acute angle range of 20 to 60', for example, 35 degrees, and the reason for this setting is 0 to 20 degrees
If the angle range is 60' or more, the recording paper may not be separated due to so-called contact, whereas if it is 60' or more, the photoconductor 2 may be damaged due to bounding. Furthermore, at least a portion of the surface of the contact area of the sharp tip 21a with the latent image surface 2a of the photoreceptor 2 is coated with Teflon-based lubricant having a particle diameter of 2 to 3 μm, as shown by diagonal lines in FIG. It is coated with a powder layer 30.

This makes it possible to reduce the coefficient of friction when the photoreceptor 2 contacts the latent image surface 2a as much as possible.

On the other hand, the timing at which the sharp tip 21a of the separation claw member 21 contacts the latent image surface 2a of the photoreceptor 2 is determined by the timing when the recording paper P
Based on the starting timing of the aligning roller pair 10 in the paper feeding section of the apparatus main body 1 that feeds the recording paper P to the transfer section of the photoreceptor 2, when the aligning roller pair 10 starts and the recording paper P is sent out, the recording paper P After a period of time corresponding to a position several tens of millimeters before the tip of the latent image surface of the photoreceptor 2 passes the contact start point A, the solenoid 24 of the separation device 20 is turned on to bring the tip into contact with the recording paper P. After passing the contact start point A, the solenoid 24 of the separating device 20 is turned off after a period of time corresponding to a position of several tens of mm has elapsed. The contact time with the latent image surface of the photoreceptor 2 is shortened to the minimum time necessary to separate the recording paper, and the probability that the latent image surface of the photoreceptor 2 is damaged due to contact with the separating claw member 21 is lowered. This is what we are doing.

It should be noted that the present invention is not limited to the above embodiments, and it goes without saying that various changes can be made without departing from the gist of the present invention.

[Effects of the Invention] As is clear from the above description, according to the present invention, the image support after the copying operation, in which the developed image has been transferred and peeled off on the latent image surface on the image carrier, is transferred to the cleaning device. Image formation comprising a separating claw member that separates the image carrier from the image carrier midway through the process, and the separating member includes a separating claw member whose sharp tip is brought into contact with the latent image surface of the image carrier at an appropriate timing. In the device, since the separating claw member is made of an elastic synthetic resin such as polyurethane resin, the material of the separating claw member itself is soft, so it does not damage the latent image surface of the image carrier. In addition, it is possible to simplify the structure for maintaining the precision and shape necessary for contacting the latent image surface of the image carrier, and thereby, the image support after transfer and peeling can be transferred to the image carrier. Therefore, it is possible to provide an image forming apparatus having an excellent effect of being able to reliably separate the latent image from the latent image surface.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing one embodiment of an electronic copying machine as an image forming apparatus according to the present invention, FIGS. 2 and 3 are schematic explanatory diagrams showing the operating state of the separating device, and FIG. This figure is also a schematic explanatory diagram showing the shape of the separating claw member, and FIG. 5 is an explanatory diagram of the tip end of the separating claw member. 1... Apparatus main body, 2... Image carrier (photoreceptor). 2a...Latent image surface, 3...Electrostatic charger. 4...M bridge abutment, 5...optical system, 6...
...Developing device, 7...Transfer charger, 11.
...Peeling charger, 16...Cleaning device, 20...
Separation device, 21... Separation claw member, 21a...
Tip, P... Image support (recording paper). Applicant's agent Patent attorney Takehiko Suzue Figure 4 Figure 5 Procedure Neichi - iF Book Showa 6412. June 3rd, Commissioner of the Japan Patent Office, Kuro 1) Akira Tono 1, Indication of the case, Patent Application No. 1988-259724 2, Name of the invention Image forming device 3, Relationship with the person who overturns the amendment case Patent applicant (307) Co., Ltd. Toshiba 4, agent uBE Building 6, 3-7-2 Kasumigaseki, Chiyoda-ku, Tokyo, drawings subject to amendment 7, details of amendment

Claims (5)

[Claims] (1) A separating means is provided for separating the image support after the copying operation, in which the developed image has been transferred and peeled off on the latent image surface on the image carrier, from the image carrier on the way to the cleaning device; An image forming apparatus characterized in that the means is formed by a separation claw member having a sharp tip made of a synthetic resin elastic body and brought into contact with the latent image surface of the image carrier at an appropriate timing. (2) The image according to claim 1, characterized in that a lubricating powder layer is formed on at least a part of the contact area of the sharp tip of the separating claw member with the latent image surface of the image carrier. Forming device. (3) The shape of the sharp tip of the separation claw member at the time when it starts contacting the latent image surface of the image carrier is based on a tangent passing through the point where it starts contacting the latent image surface of the image carrier as a reference of 0°. 2 passing through each fulcrum that is 20° and 60° in the direction opposite to the rotational direction of the image carrier with respect to the reference tangent with this contact start point as the fulcrum.
Claims 1 or 2, characterized in that both sides are included within the angle formed by the line of the book, and the angle formed by both sides is within an acute angle range of 20 to 60 degrees. The image forming apparatus described above. (4) The timing at which the sharp tip of the separation claw member contacts the latent image surface of the image carrier is at a position before the tip of the image support passes through the point where it starts contacting the latent image surface of the image carrier. Claims 1 to 3 are characterized in that the image support member is brought into contact and released at a position where the tip of the image support member is assumed to have passed a contact start point with the latent image surface of the image support member. The image forming apparatus according to any one of the items. (5) The image forming apparatus according to any one of claims 1 to 4, wherein the sharp tip of the separating claw member has a hardness of 85 degrees or more.