JPH05210328A - Form guiding device for fixing device - Google Patents

Abstract

PURPOSE:To prevent a corner part of a form from being bent even when a curl is generated when the form is stripped from the heat roller system fixing device by a stripping claw member and guided toward an ejection path by the guiding member. CONSTITUTION:The guiding of the stripped paper is carried out by placing a multiple number of stripping claws 10, 10a,... in a part where the paper is stripped from a heat roller 2 and placing guide members 20,... between each of the stripping claw 10a to 10c and in a part outside the claw member placed in a position which is furthest from a reference line 6. Furthermore, a straight line state guides 22 are placed in positions in the vicinity of the claw members in guide members 20a to 20c, and in a position separated from the claw, a bending guide 23 is arranged. The bending guide 23 has a bending part 20 formed with its tip part faced to the straight line state guide, and by sliding the form against the paper guide surface formed on a bottom surface of that bending guide 23, the form is guided in a state where it is opened up toward outside and the curl is corrected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as an electronic copying machine which uses an electrophotographic system for fixing by using a heating roller type fixing device, and more particularly to a sheet discharged from the fixing device. On the other hand, the present invention relates to a guide member that guides the end portion of the sheet in the direction of expanding it outward.

[0002]

2. Description of the Related Art In an image forming apparatus using a dry toner such as an electronic copying machine, a toner image is formed on an image bearing member such as a photosensitive drum, the toner image is transferred onto a sheet, and the toner image is transferred. A means for making a copy by fixing a sheet carrying paper through a fixing device is used. In the image forming apparatus, a heating roller type device is often used as a fixing device. In the heating roller type fixing device, a heating roller provided with a heating source such as a halogen lamp and a heating source. A pressure roller not provided with the pressure roller is arranged in parallel, and the pressure roller is pressed against the heating roller. Then, when the paper carrying the toner image is passed between both rollers of the fixing device, heat and pressure are applied, and the toner melted by the heat is pressed against the paper to perform the fixing action. There is.

As described above, in the fixing device in which two fixing rollers are arranged to face each other, the heating roller has a metal core member coated with fluorine resin or the like, and melted toner is applied to the surface of the roller. Means are provided to prevent sticking. Further, in the pressure roller, the surface of the metal core member is coated with a thin elastic body, and the nip shape for the paper at the nip portion of both rollers can be set in a state where the coating is slightly deformed by pressure. I have to. In the pressure roller, a coating of fluororesin or the like may be formed in order to prevent paper from adhering to the surface of the elastic coating.

In the heating roller type fixing device, a peeling claw member is used when the fixed sheet is discharged from the nip portion of the roller. For example, JP-A-57-
In the fixing device disclosed in Japanese Laid-Open Patent Publication No. 104965, a peeling claw member is provided for each of the pressure roller and the heating roller to prevent the paper from being wound around the fixing roller.
A means for guiding toward the discharge path is used. The sheet discharged from the fixing device is discharged toward a discharge tray or the like through a discharge path set by upper and lower guide plates, as shown in Japanese Utility Model Laid-Open No. 63-126363. Further, in the guide plate disclosed in Japanese Utility Model Laid-Open No. 63-126363, a large number of long holes are provided in the guide plate in order to allow water vapor discharged from the paper heated by the fixing device to escape. The elongated hole formed on the sheet is formed in a shape that does not hinder the guidance of the sheet.

In the sheet guide means of the fixing device shown in the above-mentioned conventional example, after the sheet is peeled by the peeling claw, the sheet is guided by the guide member as shown in Japanese Patent Laid-Open No. 104965/1982. However, a system is used in which it is moved toward the discharge path set by the guide plate at the downstream portion thereof. Therefore, for example, a guide member 27 as shown in FIG. 6 is used as the guide means arranged in the discharge portion of the fixing device. In the example shown in FIG. 6, a plurality of peeling claws 10 to 10c are arranged at a predetermined interval, and vertical plate-shaped guides 27 to 2 are provided between the peeling claws.
7c are arranged respectively. The guide is configured by a member in which two linear guides 28 and 29 are arranged in parallel, and guides a sheet separated from the heating roller 2 by a separating claw by a sheet guide surface formed on the lower surface of the linear guide. I have to.

Among the plurality of peeling pawls, one peeling pawl 10c is arranged inside the paper feed reference line 6 of the fixing device, and the other peeling pawls are arranged at a predetermined interval according to the size of the paper. For the largest size paper used in the image forming apparatus, the peeling claw 10 farthest from the reference line is used.
To peel off. The peeling claw and the guide arranged as described above can guide the sheet peeled from the heating roller toward the discharge path.
In addition, since a space is formed between the linear guides that form the guide, water vapor discharged from the heated paper is discharged from the space between the guide members together with other exhaust gas, Prevent dew condensation on the guide plate.

[0007]

When the guide member as shown in FIG. 6 is used, the paper guide surface formed under each linear guide is arranged parallel to the moving direction of the paper. , Guide for the sheet peeled by the peeling claw. However, since the paper separated from the fixing roller is subjected to heating and pressurizing action, the paper may be curved in one direction in its entirety, and the edge of the paper is also largely curved in one direction. It may be discharged in a state. However, when the sheet separated from the heating roller is guided to the guide member in a state of being curved upward as shown in FIG. 7, the curl portion of the sheet is a linear guide sheet guide. When it slides on the surface, there is a problem that the curl is not corrected by the friction with the paper guide surface and the curl is sent out in a bent state.

Then, when the curl portion of the sheet is bent and nipped by the discharge roller at the downstream portion, the corner portion of the leading end portion of the sheet is completely bent, and the subsequent sheet processing and Problems occur in transportation, etc. For example, when the paper is sorted by a sorter, the paper is caught by a guide member inside the paper transport path of the sorter,
When the sheet is conveyed by the conveying roller device, an oblique feed state may occur.

In order to prevent the bending of the corner portion of the paper as described above, for example, the position of the linear guide is precisely positioned corresponding to the size of the paper, and the corner portion of the leading end of the paper is set. Even if the paper is curled, it is possible to guide the paper in a good condition. However, as the paper used in the electronic copying machine and the like, in addition to the paper of each size such as A series and B series, there are special sizes such as letter size. In addition to the size of the paper, paper called plain paper, thin paper such as tracing paper or Japanese paper, or thick paper may be used, and depending on the type and thickness of such paper, curling may occur. There is a problem that the arrangement position of the linear guide cannot be set corresponding to all the sheets because the degrees are different.

[0010]

SUMMARY OF THE INVENTION The present invention solves the problem of guiding a sheet discharged from a conventional fixing device as described above.
With respect to the linear guide provided on the guide member, a linear guide arranged at a position apart from the peeling claw and a bending guide for guiding the paper from the inside to the outside are arranged, and curl occurs at the edge of the paper. It is an object of the present invention to provide a device that guides the curled portion of the paper by the paper guide surface so as to spread the curled portion of the paper.

[0011]

According to the present invention, a heating roller provided with a heating source and a pressure roller pressed against the heating roller are arranged, and a toner image is carried between the rollers. The present invention relates to a guide member for a sheet discharged from a fixing device in an apparatus for fixing a sheet by passing heat through the sheet and applying heat and pressure. In the paper guide device of the fixing device of the present invention, a peeling claw member is arranged with respect to the heating roller at a predetermined interval, and a guide member for guiding the paper is arranged between the peeling claws, and the guide member is provided. Is a linear guide on the side of the reference line with respect to the peeling claw, and a bending guide on the outside of the reference line of the linear guide, and the tip of the bending guide on the fixing roller side is formed. To
It is formed as a bent portion toward the reference line side. Further, in the bending guide of the present invention, the paper guide surface that continues from the bending portion to the main body is with respect to the reference line of the paper transport path.
The sheet may be formed as an inclined surface facing outward, and may be configured to be guided while sliding in a state in which the leading end portion of the sheet is expanded outward.

As described above, in the guide member arranged between the peeling claws, the tip of one of the two guide members which is located away from the reference line is formed by bending the tip inward as a bent portion. The guide member can have a simple structure. Further, in the guide member of the present invention, even when the corner portion of the paper discharged from the nip portion of the fixing roller is curled, the leading end of the curled paper slides on the paper guide surface inclined outward. Force is applied in the direction of expanding the curl portion. Therefore,
In a state where the curl of the sheet is eliminated, the sheet can be guided toward the discharge path, and the sheet can be conveyed in the sheet conveying path and the post-processing can be performed in a good state.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A sheet guide device for a fixing device according to the present invention will be described with reference to the illustrated example. In the fixing device 1 shown in FIG. 1, the heating roller 2 including the heating source 3 such as a halogen lamp and the pressure roller 5 are opposed to each other, similar to those used in an image forming apparatus such as a general electronic copying machine. Let me arrange. In the fixing device 1, the pressure roller 5 is pressed against the heating roller 2 arranged at a fixed position by using a pressure mechanism (not shown) so that a nip pressure of a predetermined value is provided between both rollers. In this configuration, the sheet carrying the toner image is passed between the rollers to apply heat and pressure to fix the sheet.

In the fixing device, an upper peeling claw 10 and a lower peeling claw 15 are respectively arranged for the upper and lower fixing rollers 2 and 5 in order to guide the paper toward the discharge path.
The paper is peeled off. An upper guide plate 7 and a lower guide plate 8 are provided at a downstream portion of the peeling claw member,
A discharge path is configured, and a sheet formed as a copy is sent out by a discharge roller arranged in the discharge path. Further, in the upper and lower peeling claws 10 and 15,
The upper peeling claw 10 is supported by a guide member that is fixed to the support frame 9, and the lower peeling claw 15 is supported by a frame of a fixing device (not shown) so that each of them can rotate about a spindle. ..

The guide member 20 and the upper peeling claw 10 supported by the support frame 9 are arranged corresponding to the heating roller 2, as shown in FIG. In each member arranged in the discharge portion of the heating roller, as shown in FIG. 2, the peeling claw 1 is made to correspond to the reference line 6 for sheet conveyance.
0c is arranged, the peeling claw members are arranged at a predetermined interval from the claw 10c toward the other end, and the peeling claws 10 at the ends are arranged corresponding to the maximum size sheet. Further, the guide member 20 is provided between the peeling claws and outside the claw member 10.
.About.20c are arranged, and the paper peeled from the roller by the peeling claws is guided toward the discharge path along the lower surfaces of the two kinds of plate members forming the guide member.

As shown in FIGS. 3 and 4, the two plate members constituting the guide member 20 are formed in a downward U-shape when viewed from the front, and the plate members above them are formed. Is used as a fixed portion 21 for the support frame, and plate members hanging on both sides are provided with a linear guide 22 and a bending guide 23.
Is configured as. Of the two types of guides, the linear guide 22 is configured as a linear guide parallel to the moving direction of the paper, and the bending guide 23 has a tip portion as a bending portion 24 and is bent toward the linear guide. Composed as. The bending guide 23 has a lower surface as a paper guide surface 25, and is configured to guide the paper while sliding the paper. As shown in FIGS. The diagonal fold line 2
It is bent toward the side of the linear guide 22 via 4a. Then, the paper guide surface 2 of the folding portion 24.
The paper that slides on 5a is guided in a state of being pushed outwards.

Therefore, even if the side edge of the sheet is peeled away from the peeling claw member and the corner portion of the sheet is curled upward, the portion inside the corner portion of the sheet is The part with a small curl comes into contact with the paper guide surface first. Then, as the paper advances, the leading end of the paper slides along the paper guide surface 25a that is inclined in the direction away from the claw, so that the paper is pushed outward and expanded. , Guided by the guide member. Therefore, the sheet separated from the heating roller by the separation claw is guided toward the discharge path by the two guides without being affected by the curl.

In the guide member of the present invention configured as described above, as shown in FIG. 5, when the end portion of the paper opposite to the reference line is in the range C, the bending guide is used. By 23, it is possible to guide without being affected by the curl. That is, in the conventional linear guide, the outer guide can regulate the paper only when the edge portion of the paper is within the range A, but even in that case, the curl is generated on the curled paper. However, there was a problem of bending the corners. Further, when the edge of the sheet is located in the range B, the sheet is regulated only by the inner linear guide that is close to the peeling claw.

On the other hand, in the guide member of the present invention,
The range in which the sheet is guided by the folding guide 23 can be expanded to a range C including A and B, and the sheet positioned in the range C can be guided while curling is corrected. The action can be performed. Further, in the linear guide 22 close to the peeling claw, even if the sheet peeled by the claw member is curled, since the curl is not large, the problem of bending the corner of the sheet occurs. It's difficult. Therefore, the guide member can exert a very large effect on the sheet in a state where it does not reach the adjacent peeling claw.

In the paper guide member of the present invention as described above, in addition to disposing the two guides between the peeling claws, even when disposing one or a large number of guides, the bending guides A bent portion can be formed at the tip. Further, the peeling claw member to which the bending guide is applied may have any shape, and the shape and structure of the peeling claw are not particularly limited.
Further, the arrangement interval of the peeling claws can be set arbitrarily, and can be arbitrarily applied to a heating roller type fixing device using a conventional electrophotographic method.

[0021]

The paper guide device of the fixing device of the present invention is
Since the guide member arranged between the peeling claws has the above-described structure, the tip of one of the two guide members that is located away from the reference line is bent inward as a bending portion. The guide member can have a simple structure only by doing the above. Further, in the guide member of the present invention, even when the corner portion of the paper discharged from the nip portion of the fixing roller is curled, the leading end of the curled paper slides on the paper guide surface inclined outward. Force is applied in the direction of expanding the curl portion. Therefore, with the curl of the paper eliminated,
The paper can be guided toward the discharge path, and the paper can be transported in the paper transport path and the post-processing can be performed in a good state.

[Brief description of drawings]

FIG. 1 is a side view showing a sheet discharge mechanism of a fixing device of the present invention.

FIG. 2 is a plan view showing a configuration of a heating roller and a guide member.

FIG. 3 is a side view of the guide member of the present invention.

FIG. 4 is a front view in the DD direction of FIG.

FIG. 5 is an explanatory view showing a guide range of a sheet by the guide member of the present invention.

FIG. 6 is a plan view showing a configuration of a conventional heating roller and a guide member.

FIG. 7 is an explanatory diagram of a function of guiding a sheet by a conventional guide member.

[Explanation of symbols]

1 fixing device, 2 heating roller, 5 pressure roller, 6 reference line, 7.8 guide plate, 10
Upper peeling claw, 15 Lower peeling claw, 20 Guide member, 21 Fixing part, 22 Linear guide, 23
Bending guide, 24 Bending part, 25
Paper guide surface.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location G03G 15/20 106

Claims (1)

[Claims] 1. A heating roller provided with a heating source and a pressure roller pressed against the heating roller are arranged, and heat and pressure are passed between both rollers by passing a paper carrying a toner image. In the device for adding and fixing the peeling claw member to the heating roller with a predetermined gap, a guide member for the paper is arranged between the peeling claws, and the guide member is a peeling claw. On the other hand, the one on the reference line side that regulates the side surface of the paper in the paper transport path is configured as a linear guide, and the one outside the reference line is configured as a bending guide with respect to the linear guide, A sheet guide device of a fixing device, wherein a tip end portion of the bending guide on the fixing roller side is formed as a bending portion toward the reference line side.