JP2000162879A - Image-forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image-forming device, adopting a paper sheet separating mechanism capable of improving performance for separating the paper sheet from a photoreceptor, and for preventing scratches on the photoreceptor, rolled-in of paper sheet, or the like. SOLUTION: This device is allowed to make a first separating member 8a for separating the paper sheet A from the photoreceptor 1 and the second separating member 8b for changing the transport direction of a leading end on the separated paper sheet fixed in one body, and to compose the first separating member 8a with a material which is at least, smaller than the thickness of the paper sheet A. The device is allowed to compose the second separating member 8b by the material being at least, larger than the thickness of the paper sheet A, and to arrange a free end of the first separating member 8a close to or in contact with the photoreceptor 1, and the free end of the second separating member 8b apart from the photoreceptor 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a separating mechanism for separating a sheet passing a transfer means from a photosensitive member during an electrophotographic process.

[0002]

2. Description of the Related Art In electrophotography using the Carlson process, a separating member is provided downstream of a transfer position in order to separate a sheet after transfer from a photosensitive member, and the separating member is wound around the photosensitive member. The paper is separated from the front end (free end) of the paper to be separated before. Such a separating member is made of a sheet-like material such as polyester, and is a single sheet separating unit.

[0003]

However, there are two contradictory problems with respect to a single sheet-like separating member. That is, if the thickness of the sheet is reduced in order to increase the separating property of the paper, the separating property is improved, but the strength as the separating member is reduced, and problems such as bending and bending occur.

[0004] On the other hand, when the thickness of the sheet is increased to increase the strength of the separating member, the strength is increased. However, since the thickness of the separating member is thicker, the separability of the sheet is reduced. May enter the gap between the leading end of the separation member and the photoconductor, causing a problem such as being wound around the photoconductor. Further, when the sheet is thick, the sheet is stiffened and the pressing force against the drum is increased, so that the drum is easily damaged.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to improve the performance of separating a sheet from a photoreceptor and to solve the above conflicting problems.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a sheet conveying means for feeding a sheet toward a transfer position, and a transfer for transferring the toner developed on the photoreceptor surface to the sheet at the transfer position. Means, and a paper separating means for separating the photoreceptor and the paper after passing through the transfer means, wherein the paper separating means comprises a first separating member for separating the paper from the photoreceptor. A second separating member for changing the conveying direction of the leading end of the separated sheet is integrally fixed, and the first separating member is formed at least thinner than the thickness of the sheet; The second separating member is formed at least of a thickness greater than the thickness of the sheet, and the free end of the first separating member is brought close to or in contact with the photosensitive member, and the free end of the second separating member is exposed to light. Farther than body It is not characterized by being configured to be positioned.

According to the structure of the present invention, the separation member suitable for separating from the photoreceptor is thinner than the thickness of the sheet, and the sheet is separated by the first separation member by using a good separation property. Since the leading end of the separated sheet is in contact with the second separating member which is thicker and stiffer than the sheet and is stronger than the sheet, the leading end of the sheet can be directed to the fixing roller without bending of the first separating member. This prevents the paper from wrapping around the photoreceptor.

[0008] In this case, the first and second layers formed in an overlapping manner.
Of the separation members, the first separation member is arranged so as to be positioned on the side of the sheet conveyance path for conveying the separated sheet, so that the first separation member conveys the leading end of the sheet to the second separation member. And the leading edge of the sheet can reliably contact the second separating member, and a good separating function can be performed.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic explanatory view of the image forming apparatus of the present invention. As shown in FIG. 1, reference numeral 1 denotes a photoconductor, and 2 denotes a corona charger. Reference numeral 3 denotes an exposure unit that irradiates light with a laser beam or an LED to reduce the charge on the surface of the photoconductor 1 charged by the corona charger 2, thereby forming a latent image.

Reference numeral 4 denotes a developing unit which carries toner on the surface and electrostatically attaches the toner to the latent image formed on the surface of the photoreceptor 1 to form a toner image. Reference numeral 5 denotes a registration roller, which aligns the leading edge of the sheet A to stand by, and drives the registration roller in accordance with the timing of forming a toner image. Thus, the sheet is conveyed toward the transfer section insertion guide 6. Reference numeral 7 denotes a transfer unit that transfers the toner image formed on the surface of the photoconductor onto the sheet A.

Reference numeral 9 denotes a cleaning unit, and the transfer unit 7
Cleans untransferred toner. Reference numeral 9a denotes a cleaning blade, and 9b denotes a polishing roller, which is configured to discharge the collected toner by a screw 9c. Reference numeral 10 denotes a fixing roller.

Next, the features of the present invention will be described in detail. Reference numeral 8 denotes a separating means which is a feature of the present invention. As shown in a partially enlarged view surrounded by a circle, 8a denotes a first separating member, which is formed by extending in the axial direction of the photosensitive member 1 (not shown). (Illustration). Similarly, reference numeral 8b denotes a second separating member, which is formed in the same size as the first separating member in the axial direction of the photoconductor.

The paper used in the present invention is, for example, 60 mm plain paper having a thickness of 0.1 mm.
Gram paper having a thickness of 0.2 mm is used.

The first separating member 8a is in contact with the free end after the sheet has passed through the transfer means 7 and at a position downstream from the transfer position in the rotation direction of the photosensitive member 1, and has a fulcrum 8c.
The side is held vertically on the second separating member, and a part of the surface is surface-bonded with an adhesive or the like (not shown). The first separating member 8a is made of a sheet-like material such as polyester film, polyimide, and stainless steel, and is formed thinner than the thickness of usable paper.
By forming the sheet smaller than the thickness of the sheet in this way, even if the sheet after transfer is physically or electrostatically adsorbed on the surface of the photosensitive member, it easily enters the boundary between the sheet and the surface of the photosensitive member 1 and separation is performed. Can promote. Although the present invention has been described as being in contact with the photoreceptor 1, the present invention is not limited to this, and includes a case in which the photoreceptor 1 is in proximity.
By setting the first separation member 8a to be thinner than the thickness of the sheet A, separation is promoted.

As the second separating member 8b, a member thicker than the thickness of the sheet A is used. For example, polyester film,
Examples thereof include polyimide, stainless steel, and polycarbonate. By using a member thicker than the thickness of the sheet in this way, the stiffness of the sheet A is generally stronger than that of the sheet, and the leading end of the sheet A can be laid down, and the sheet A can be directed toward the sheet transport guide 8d.

The free end of the second separating member 8b is formed apart from the photosensitive member 1. This is to prevent the free end of the second separating member 8b from contacting the photoreceptor 1 to cause a flaw or the like. If this interval is too large, the first separating member 8a may be cut or broken. Since it bends, the distance is preferably 1 to 10 times the thickness of the sheet.
In this case, it is preferable that the first separation member 8a is positioned closer to the sheet conveyance path 8d than the second separation member 8b. With this arrangement, after the paper A is separated,
The first separation member 8a can be guided to the second separation member 8b as a guide.
The paper A can be laid on the side.

[0017]

As described above, according to the configuration of the present invention, the paper separating performance can be improved and the strength of the mechanism for separating the paper can be ensured, so that the paper can be reliably separated. Further, even if the strength of the separation mechanism is increased, various effects such as the damage to the photoreceptor can be suppressed and the cost can be reduced for the separation member because it can be easily made of resin can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of an image forming apparatus of the present invention.

[Explanation of symbols]

 1: Photoreceptor 2: Charger 3: Exposure unit 4: Developing unit 5: Registration roller 6: Transfer unit insertion guide 7: Transfer unit 8: Separation unit 8a: First separation member 8b: Second separation member 8d: Paper transport guide 9: Cleaning means 10: Fixing roller

Claims (2)

[Claims] A transfer means for transferring toner developed on the surface of a photoconductor onto the paper at the transfer position; separating the paper from the photoconductor after passing through the transfer means; An image forming apparatus comprising: a first separating member configured to separate the sheet from the photoconductor; and a second unit configured to change a transport direction of a leading end of the separated sheet. The first separating member is formed with a thickness smaller than the thickness of the sheet, while the second separating member is formed with a thickness larger than the thickness of the sheet. And forming the first separation member such that the free end of the first separation member is close to or in contact with the photoconductor, and the free end of the second separation member is arranged so as to be separated from the photoconductor. Image forming apparatus. 2. The method according to claim 1, wherein the first and second separating members are arranged on a sheet conveying path for conveying the separated sheets. Item 2. The image forming apparatus according to Item 1.