JPH034279A - Fixing device - Google Patents

Abstract

PURPOSE:To carry without jamming even when the material to be fixed is thick by providing a guiding member protruding in a material to be transferred in a carrying path in the vicinity of one of a pair of fixing rollers with a harder surface in the down stream of the pair of the fixing rollers, correcting the curling of the material to be transferred. CONSTITUTION:The paper P on which an image is transferred is lead between heating rollers 63 and 64 through an entrance guiding roller 67, and the image is heated by the roller 63 and at the same time is pressured and fixed by the roller 64, and then ejected. On the other hand, at the time of fixing, the paper P which was passed through the rollers 63 and 64 is curled in the upper direction by heat and pressure. However, when this curled paper P is pushed down in the lower direction by a curved part 65 protruding in the lower direction of a separating pawl 65 and the curling is corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a fixing device provided in, for example, an electronic copying machine.

(Prior Art) As this type of fixing device, for example, one shown in FIG. 8 is known. That is, numeral 1 in the figure is a heat roller, and a press roller 2 is pressed against the lower side of the heat roller 1. Between the heat roller 1 and the press roller 2, a sheet of paper P with an image transferred thereon is passed through an entrance guide 3.
The image is fixed by being heated and pressurized by being introduced and passing through it.

Further, the paper P that has passed between the heat roller 1 and the press roller 2 is separated from the heat roller 1 by a separation claw 4, and is ejected from a pair of ejection rollers 6 via an exit guide 5. .

By the way, the press roller 2 normally has elasticity, so when it is pressed against the heat roller 1, its nip section is elastically deformed as shown in FIG. 9, and the paper P that has passed through the nip section is deformed. Forms a curl shape pointing upwards. This curl of the paper P is particularly noticeable when the paper is thick like a postcard.

Further, since the paper P introduced between the heat roller 1 and the press roller 2 via the population guide 3 is usually hygroscopic and thin, it is easily affected by humidity and the width direction of the leading edge is Wave-like unevenness is formed.

In such a state, if the paper P is simply introduced between the heat roller 1 and the press roller 2 with the entrance guide 3 at an angle as shown by the broken line as shown in FIG. 10, wrinkles will be formed. .

Therefore, by arranging the entrance guide 3 at an angle as shown by the solid line and bringing its tip close to the surface of the heat roller 1 to form a slit S, and introducing the paper P into the slit S, the paper P can be removed. It is introduced between the heat roller 1 and the press roller 2 to prevent wrinkles from forming.

(Problem to be Solved by the Invention) However, in the past, the lower end surface of the separating claw 4, that is, the contact surface with the paper P, was formed in a straight shape, so that curling of the paper P could not be corrected. However, there was a problem in that the paper could not be conveyed again and double-sided copying could not be performed.

In addition, the angle of the entrance guide 3 is fixed, and this angle is suitable for thin paper P, but for thick paper, especially for paper such as postcards that are not very long (between the pair of fixing rollers 1 and 2 and the registration rollers). (shorter than the distance), heat roller 1
It collides with the machine and stops, causing a jam.

Therefore, the present invention can correct the curl of the fixing material, and also
An object of the present invention is to provide a fixing device capable of conveying a material to be fixed without clogging even if the material is thick.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a method for heating and fixing an image on the fixing target material while nipping and conveying the fixing target material to which the image is attached. In a fixing device equipped with a pair of fixing rollers having different surface hardnesses, a fixing roller protruding into the conveying path of the to-be-fixed material on the conveying downstream side of the pair of fixing rollers and near the one of the pair of fixing rollers having a higher surface hardness. The invention is characterized in that a guide member is provided, and further, on the conveyance downstream side of the pair of fixing rollers,
Further, a separation member for separating the material to be fixed from the fixing roller is provided near the one of the pair of fixing rollers having a higher surface hardness, and the separation member is provided with a guide portion protruding into the transport path of the material to be fixed. The present invention is further characterized in that it includes a movable entrance guide for introducing the material to be fixed between the pair of fixing rollers, and the entrance guide is displaced depending on the type of material to be fixed.

(Function) A guide member protruding into the fixing material transport path, or a guide portion provided on a separation member that separates the fixing material from the fixing roller and protruding into the fixing material transport path, allows the fixing roller pair to be passed through the fixing roller pair. By pressing and straightening the curled material to be fixed, the material to be fixed can be conveyed again and double-sided copying is possible.

In addition, by displacing the population guide depending on the type of material to be fixed, the material to be fixed can be introduced between a pair of fixing members at an angle suitable for the type of material to be fixed, and jamming of the material to be fixed can be prevented. .

(Example) The present invention will be described below with reference to an example shown in the drawings.

Figure 2 shows the document holding cover open, and Figure 3 shows the internal structure of the entire device. An image forming process configuration means 2 is built-in, and an original tray (hereinafter referred to as a platen glass) 3 on which a document is set is provided on the top surface.

Further, on the rear edge of the apparatus main body 1, an original holding means 4 for holding down the original set on the platen glass 3 is attached, and on the front edge of the upper surface of the apparatus main body 1, a copy key 5, An operation panel 9 on which a clear/stop key 6, a numeric keypad 7, a display section 8, etc. are arranged is arranged.

Furthermore, a front cover 10 that can be opened and closed is provided on the front of the apparatus main body 1, and a paper P as a fixing material such as plain paper to be supplied to the image forming process configuration means 2 is provided at the lower part of the front. The paper feed cassette containing the paper is now inserted. Further, on the left side of the apparatus main body 1, there is a tray 12 for collecting fixed paper P and a power switch 13.
is provided.

The image forming process configuration means 2 has the following configuration. That is, a drum-shaped photoreceptor 20 serving as an image carrier is arranged approximately at the center of the apparatus main body 1.
Around this photoreceptor 20, along the rotation direction thereof, a charging device 21, an exposure section 22a1 of an exposure device 22, a developing device 2, etc.
3. Pre-transfer exposure device 24, transfer device 25. Peeling device 26
．． Cleaning device 27. Static eliminators 28 and the like are sequentially arranged.

Further, inside the main body 1 of the apparatus, paper P1 that is automatically fed from the paper feed cassette 11 or a manual paper feed tray 2 is provided.
The paper P manually fed through the photoreceptor 20
A paper transport path 31 that leads to the tray 12 provided on the left side of the apparatus main body 1 through an image transfer section 30 between the transfer device 25 and the transfer device 25.
is formed.

A pair of registration rollers 32 is arranged on the upstream side of the image transfer section 30 of the paper conveyance path 31, and a fixing device 3 is arranged on the downstream side.
3 and a pair of paper ejection rollers 34 are arranged. Further, a conveyor belt unit 35 is disposed between the peeling device 26 and the fixing device 33.

In addition, paper P
A take-out roller 36 that takes out the paper P one by one, and a transport roller and separation roller that receive the paper P taken out through the take-out roller 36 and send it into a first branch transport path that forms the upstream side of the paper transport path 31. Separation and conveyance means 3 consisting of
7 are arranged. Furthermore, a manual feeding feed roller 38 is disposed at the confluence of the first branched conveyance path and the second branched conveyance path for manual feeding.

Further, the exposure device 22 illuminates a document set on a platen glass 3 provided on the top surface of the main body 1 with an exposure lamp 41 whose back is surrounded by a reflector 40, and uses reflected light from the document document to The light is guided to a lens 45 as an optical element via a first mirror 42, a second mirror 43, and a third mirror 44 in order, and then the light transmitted through the lens 45 is guided to a fourth mirror 46 and a fifth mirror. 47, a sixth mirror 48, and a slit glass 49, and then the photoreceptor 20.
It is designed to lead to.

The exposure lamp 41 and the first mirror 42 surrounded by the reflector 40 are mounted on a first carrier body 50 that is movable back and forth along the lower surface of the platen glass 3. The second mirror 44 moves in the same direction at half the speed of the first carriage 50.
These first and second carriages 50.51 are mounted on a carriage shaft 52.
By moving from left to right in the state shown in FIG. 3 using guides such as those shown in FIG. It has become. Note that the fourth mirror 46 and the fifth mirror 47 are attached to the mirror support member 5.
3 and has become a unit.

Furthermore, the exposure apparatus 20 configured in this manner has a unit structure that is integrated into the frame 54.
The exposure device 20 can be handled alone.

Further, the apparatus main body 1 is divided into two parts, an upper unit IA and a lower unit IB, with the paper transport path 31 as the border. The upper unit IA can be opened approximately 25 degrees using the upper unit IA as a pivot point. The support shaft 55
is composed of a shaft portion of a torsion bar that constantly biases the upper unit IA in the direction of opening.

Further, in FIG. 3, 56 is a cooling fan disposed at the top of the fixing device, and 57 is a manual feed guide that guides the paper that is manually fed. 58 is a high-voltage transformer, and 59 is a scale that serves as a reference for setting an original.

Therefore, when making a copy, first, a document tray is set on the platen glass 3, and then the copy key 5 is depressed. As a result, the exposure lamp 41 is turned on, the first and second carriages 50, 51 are moved, and the original 1i4D is irradiated with light. The reflected light from the original is sent to the lens 45 via the first to third reflection mirrors 42, 43, 44, and then from this lens 45 to the fourth reflection mirror 42, 43, 44.
The images are formed on the photosensitive drum 20 through the sixth reflecting mirrors 46, 47, and 48. The surface of the photosensitive drum 20 is uniformly charged in advance by a charger 21,
An electrostatic latent image of the document is formed.

This electrostatic latent image is made visible by facing the developing device 23 and being supplied with developer. On the other hand, at this time, paper P is supplied from the paper feed cassette 11, aligned by the registration rollers 32, and then sent to the image transfer section 30. The developed image on the photosensitive drum 20 is transferred to the paper P by the action of the transfer charger 25 in the image transfer section 30 . The paper P on which the image has been transferred is transferred to the peeling charger 26.
The film is peeled off from the photoreceptor drum 20 by the action of . This peeled paper P is conveyed by the conveyor belt 35 and sent to the fixing bag F133. This fixing device 33 fixes the image on the paper P, and the image is transferred to the paper output tray 1 via the paper output roller 34.
2 is discharged on top.

Next, the fixing device 33 will be described in detail.

As shown in figure m1, the fixing device 33 has upper and lower units 61 and 62, and these upper and lower units 61 and 62
Inside, a heat roller 63 as a pair of constant volume members and a press roller 64 that rolls into contact with the heat roller 63 are rotatably attached.

Separation claws 65 as separation members are provided on the discharge side of the heat roller 63 and press roller 64. The tips of these separation claws 65 are brought into contact with the heat roller 63 to separate the paper P wound around the heat roller 63. A curved portion 65a serving as a guide portion projecting downward is integrally formed at the lower end portion of these separating claws 65.

Further, on the discharge side of the heat roller 63 and the press roller 64, exit guides 66 are arranged in parallel with the separation claws 65.

On the other hand, an entrance guide 67 is provided on the artificial side of the heat roller 63 and press roller 64. As shown in FIG. 5, this entrance guide 67 has one end with a shaft 68.
It is rotatably supported by and can be rotated in the vertical direction by an operating means 69.

The operating means 69 has a shaft 70 inserted into the device main body 1, and an operating arm 71 is attached to one end of the shaft 70.
is attached, and this operating arm 71 is in contact with the lower surface side of the other end of the guide body 67. Further, the other end of the shaft 70 projects outward from the device main body 1, and an operating lever 72 is attached to this projecting part.

Then, the paper P on which the image has been transferred is transferred to the heat roller 63.
and a press roller 64 via an entrance guide 67, and the image is heated by a heat roller 63 and fixed by being pressurized by a press roller 64, and then guided by an exit guide 71 and discharged. will be done.

By the way, during this fixing, the paper P that has passed between the heat roller 63 and the press roller 64 is curled upward by heat and pressure. However, this curled paper P
As shown in the figure, the curved portions 65a of the separating claws 65... push downward and the curl is corrected.

Therefore, the paper P can be conveyed again, and double-sided copying becomes possible.

Further, when the paper P is thick paper, for example, a postcard, the operating means 69 of the entrance guide 67 is operated to rotate the bar 72 downward. As a result, the entrance guide 67 is rotated downward, and its rotation end is connected to the heat roller 63 and the press roller 64.
It is opposed between.

Therefore, the leading edge of the paper P does not come into contact with the heat roller 63, and the heat roller 63 and press roller 64
It is introduced well between the two, and no jams occur.

In the above embodiment, the curved portion 65a is formed on the separation claw 65, but the present invention is not limited to this, and even if the exit guide 66 is formed with a curved portion 66a as shown in FIG. The same functions and effects as in the embodiment are achieved.

[Effects of the Invention] As explained above, according to the present invention, the curled material to be fixed that has passed between the pair of fixing rollers can be corrected by the guide member or the guide portion of the separating member, and the material to be fixed can be re-cured. Transport becomes possible, and double-sided copying becomes possible.

In addition, the entrance guide is displaceable, and since this entrance guide is displaced depending on the type of material to be fused, it can be introduced between the pair of fixing rollers at an angle suitable for the type of material to be fused, and jams of the material to be fused can be avoided. This has the effect of reliably preventing the problem.

[Brief explanation of drawings]

FIGS. 1 to 6 show an embodiment of the present invention, in which FIG. 1 is a configuration diagram showing a fixing device, and FIG. 2 is a schematic diagram showing the external appearance of the image forming apparatus with the document holding cover open. 3 is a schematic longitudinal sectional front view showing the electronic copying machine, FIG. 4 is a perspective view showing the operating means of the entrance guide, FIG. 5 is a side view thereof, and FIG. 6 is a paper curl correction FIG. 7 is a configuration diagram showing another embodiment of the present invention; FIG.
9 is an explanatory diagram showing a state in which paper curls, and FIG. 10 is a diagram showing a conventional entrance guide. 63... Heat roller (fixing member), 64... Press roller (fixing member) 65... Separation claw (separation member)
, 66... Exit guide, 65a, 66a... Curved part (guide part), 67... Entrance guide. 1 Figure 2 Figure 5

Claims (3)

[Claims] (1) In a fixing device equipped with a pair of fixing rollers having different surface hardnesses, the fixing roller pair heats and fixes the image on the fixing target material while nipping and conveying the fixing target material to which the image is attached, the conveyance of the fixing roller pair. A fixing device characterized in that a guide member protruding into the fixing material conveyance path is provided on the downstream side and near the one of the pair of fixing rollers having a higher surface hardness. (2) In a fixing device equipped with a pair of fixing rollers having different surface hardnesses, the fixing roller pair heats and fixes the image on the fixing target material while nipping and conveying the fixing target material to which the image is attached, the conveyance of the fixing roller pair. A separating member for separating the fixing material from the fixing roller is provided on the downstream side and near the one of the pair of fixing rollers having a higher surface hardness, and the separating member is provided with a guide portion protruding into the fixing material conveyance path. A fixing device characterized by: (3) In a fixing device comprising a pair of fixing rollers having different surface hardnesses, the fixing roller pair heats and fixes the image onto the fixing material while sandwiching and transporting the fixing material to which the image is attached. A fixing device comprising a movable entrance guide that is introduced between a pair of fixing rollers, and the entrance guide is displaceable depending on the type of material to be fixed.