JPS63271382A - Fixing device - Google Patents

Abstract

PURPOSE:To prevent the generation of paper wrinkles and to improve the quality of copied paper by arranging a suction means for sucking the entering tip part of a substance to be fixed so as to lift it into a round shape on the guide face of a guide member. CONSTITUTION:The suction means 106 for sucking the entering tip part of substance to be fixed like a projection is arranged on the guide face of the guide member 103. The entering tip part of the substance p to be fixed which is carried while being curled can be straightened by lifting the leading tip part of the substance P to be fixed into a round shape by means of the suction means 106 formed on the guide face 104 of the guide member 103. Consequently, the entering tip part of the substance P to be fixed can be surely guided and carried to a fixing part arranged between a fixing roller 101 and a press roller 102, so that the generation of paper wrinkles in the carrying direction on the fixing part can be prevented and the quality of copied paper can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a fixing device installed in an image forming apparatus such as a dry type electronic copying machine or a printer.

(Prior Art) Generally, for example, a heated roller type fixing device conveys a recording sheet, which is an object to be fixed, onto which a developer image has been transferred, to a fixing section between a heated fixing roller and a pressure roller. , fixing the image of the developer onto the recording paper by heat fusing,
After fixing, the recording paper is peeled off via a peeling means and conveyed to the paper ejection roller side for ejection.

Conventionally, in this type of fixing device, 1, for example,
As disclosed in Japanese Utility Model Publication No. 123955, Japanese Utility Model Publication No. 60-9806, or Japanese Utility Model Publication No. 60-14284, a guide member is provided on the entrance side of the fixing section between the fixing roller and the pressure roller, and Some guide members have an elliptical guide surface formed into a chevron-shaped curved surface to prevent wrinkles from forming on the recording paper.

(Problems to be Solved by the Invention) However, such a fixing device with a conventional structure, in particular,
Regarding the shape of the guide surface of the guide member.

If the leading edge of the recording paper is curled in the transport direction,
It is often difficult to reliably guide the leading edge of the recording paper along the guide surface of the guide member using only the weight of the recording paper. When fusing (copying) is performed twice, the first fusing has already caused a large curl at the leading edge of the recording paper, which can cause jams (JAMs) at the fusing section between the fusing roller and the pressure roller. There was a problem in that paper wrinkles were likely to occur and the quality after copying was degraded.

The present invention has been made under the above circumstances, and an object thereof is to reliably guide a fixing object to a fixing section with a simple structure and prevent the occurrence of paper wrinkles in the conveying direction. Another object of the present invention is to provide a fixing device that can improve the quality after copying.

[Structure of the invention] (Means for solving problems) In order to solve the above-mentioned problems, the present invention has been made.

, 7 A fixing device in which an object to be fixed enters and is conveyed to a fixing section between a fixing roller and a pressure roller and is thermally fixed, and the object to be fixed is guided and conveyed to the fixing section via a guide member, The guide surface of the guide member is provided with a suction means for suctioning the leading end of the object to be fixed so as to lift it into a chevron shape.

(Function) That is, by having the above configuration, the present invention has the following features:
Since the suction means provided on the guide surface of the guide member lifts the leading end of the object to be fixed into a chevron shape,
This is because it is possible to straighten the leading edge of the curled object to be fixed.

The leading edge of the object to be fixed can be reliably guided and conveyed to the fixing section between the fixing roller and the pressure roller, thereby preventing paper wrinkles in the conveyance direction at the fixing section and preventing copying. It becomes possible to improve the subsequent quality.

(Embodiment) Hereinafter, one embodiment of the present invention will be explained in detail with reference to the drawings.

FIG. 1 schematically shows the overall configuration of an electronic copying machine, which is an image forming apparatus equipped with a fixing device according to the present invention.
This electronic copying machine is provided with a photoreceptor drum 2 rotatably supported approximately at the center of the apparatus main body 1, and the photoreceptor drum 2 is uniformly charged by a charging charger 3. In addition, there is a document table 4 made of transparent glass.
An unillustrated original image placed on the exposure lamp 5a, and first, second, and third reflecting mirrors 5b, 5c, and 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 photoreceptor drum 2 via a developing device 6, and a developer is applied to the electrostatic latent image to develop it, and the image is sent to the transfer charger 7 side. In this transfer charger 7, a paper feed roller 9 and a pair of registration rollers 1 are fed from a paper feed cassette 8, which is automatically or manually fed.
A toner image T is transferred onto a copy paper P made of plain paper as a recording paper fed through a 0.10 mm, and is peeled off by a peeling charger 11 using an AC corona discharge.
'It's turning.

In this way, the developer remaining on the photoreceptor drum 2 after the transfer and peeling off of the developed image onto the copy paper P is cleaned by the cleaning device 12, and the potential on the photoreceptor drum 2 is kept constant by the static elimination lamp 13. The copy paper P after the transfer is peeled off from the photosensitive drum 2 and transferred to the conveying path 14.
The toner image T is then conveyed to a fixing device 100 according to the present invention, which will be described later, and after the toner image T is melted and fixed by this fixing device 100, it is discharged onto a paper discharge tray 17 by a pair of upper and lower discharge rollers 15 and 16. This is what has become.

As shown in FIGS. 2 to 4, the above-described fixing device 100 of the present invention transfers the recording paper P conveyed onto the conveyance path 14 between the fixing roller 101 and the pressure roller 102. The guide member 103 has a flat guide surface 104 made of a sheet metal material, and its tip is pressed against the fixing port line '101. Fixing section 1 between roller 102
05 is located close to the contact point (the prong point).

Further, a large number of suction ports 107 constituting a suction means 106 are formed through the guide surface 104 near the tip end side of the guide member 103, and in the lower part of the guide member 103 corresponding to the suction ports 107, A suction machine 108 is installed.

That is, this suction device 108 includes a fan 109 and a pair of left and right suction nozzles 110 and 110.

When the recording paper P conveyed onto the conveyance path 14 slides on the guide surface 104 of the guide member 103, the width perpendicular to the conveyance direction X of the leading edge of the recording paper P curled in the conveyance direction X. By suctioning both ends of the recording paper P and correcting it so that the leading edge of the recording paper P, especially the center thereof, is lifted up into a chevron shape, it is made easier to get caught in the fixing unit 105. In this case, the fixing roller 101 is provided with an inverted crown or taper of about 80 to 200 μm, so that the conveyance speed of the recording paper P is faster at both ends than at the center of the recording paper P.
A tensile force is applied in the width direction of the fabric to smooth out wrinkles.

By the way, the suction machine 108 that constitutes the suction means 106
The suction force can at least stop the conveyance of the recording paper P,
The strength is set and adjusted to such an extent that the recording paper P does not bend in the transport direction. Furthermore, if the position of the suction device 108 is made movable and interlocked with a paper size detection means, it can be adapted to a variety of paper sizes.

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 object to be fixed enters and is conveyed to the fixing section between the fixing roller and the pressure roller and is thermally fixed. A fixing device that guides and conveys an object to a fixing section via a guide member, wherein a suction means is provided on the guide surface of the guide member to suck the advancing end of the object to be lifted up in a chevron shape. Therefore, it is possible to straighten the leading edge of the curled and conveyed object due to the suction action of the suction means, so that the leading edge of the curled object can be moved between the fixing roller and the pressure roller. The fixing device has the excellent effect of being able to reliably guide and convey the paper to the fixing section, thereby preventing the occurrence of paper wrinkles in the conveyance direction at the fixing section, and improving the quality after copying. It is something that can be provided.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing an embodiment in which a fixing device according to the present invention is installed in an electronic copying machine as an image forming device, and FIG. 2 is a main part showing the fixing device as seen from the side. FIG. 3 is a schematic front view of the fixing device viewed from the upstream side in the conveyance direction, and FIG. 4 is a schematic plan view of the guide member. DESCRIPTION OF SYMBOLS 100... Fixing device, 101... Fixing roller, 102... Pressure roller, 103... Guide member, 104... Guide surface, 105... Fixing part. 106... Suction means, 107... Suction port, 108
...Suction machine, 109...Fan, 109...Suction nozzle, X...Transportation direction. P: Object to be fixed (recording paper). Applicant's agent Patent attorney Takehiko Suzue Figure 2 Figure 8 I03 Figure 4

Claims (2)

[Claims] (1) In a fixing device in which an object to be fixed enters and is conveyed to a fixing section between a fixing roller and a pressure roller and is thermally fixed, and the object to be fixed is guided and conveyed to the fixing section via a guide member. 2. A fixing device, characterized in that the guide surface of the guide member is provided with suction means for sucking the advancing end of the object to be fixed so as to lift it into a chevron shape. (2) The fixing device according to claim 1, wherein the suction means sucks both ends in the width direction perpendicular to the conveying direction of the leading end of the object to be fixed.