JPH05241468A - Thermal fixing device - Google Patents

Abstract

(57) [Abstract] [Object] The present invention relates to a heat fixing device used in a recording device such as an electrophotographic printer, a facsimile, and a copying machine, which does not require a pawl for separating recording paper and is capable of preventing a curl of a medium. An object is to provide a heat fixing device that does not generate. [Structure] The heat fixing device 11 includes a heat roller 12 and a backup roller 13 that is in pressure contact with the heat roller 12. The heat roller 12 and the backup roller 13 are made of rubber having a surface on which rubber layers 12a and 13a are formed. The heat roller 12 has a heat source 14 such as a halogen lamp built therein.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat fixing device used in recording devices such as electrophotographic printers, facsimiles and copying machines.

In recent years, this type of recording apparatus is required to have further improved performance and quality. Therefore, it is desired to improve the fixing property of a toner image, cope with various media, and prevent curl and wrinkles from occurring. There is.

[0003]

2. Description of the Related Art FIG. 2 is an explanatory view of a structure of a main part of a conventional electrophotographic recording apparatus (FIG. 2A is a side view, FIG. 2B is FIG.
(Detailed view of A portion of (A)), in the figure, 1 is a feed roller, 2 is a photosensitive drum, 3 is a transfer device, and 4 is a thermal fixing device. In addition to the transfer unit 3, a charger, an exposure unit, a developing unit, a cleaner, and a charge eliminator (not shown) are arranged around the photosensitive drum 2. The heat fixing device 4 includes a heat roller 6 having a halogen lamp (heat source) 5 built therein, a backup roller 7 made of a surface rubber in pressure contact with the heat roller 6, and a pawl 8 for separating recording paper. The heat roller 6 is formed by applying Teflon coating on the surface of an aluminum tube. The recording process by this device is as follows.

At the time of recording, the photosensitive drum 2 is shown in FIG.
The surface is rotated counterclockwise as indicated by the arrow in (A), the surface is uniformly charged by a pre-charger, and then the surface is exposed according to image information to form an electrostatic latent image. Form. This electrostatic latent image is developed by the developing device. By this development, a toner image is formed on the photosensitive drum 2.

On the other hand, a recording paper (medium) 100 stored in a recording paper storage portion (not shown) is fed out by a pick roller or the like, and conveyed by a feed roller 1 to a transfer position (a). At the transfer position (a), the transfer device 3 moves the photosensitive drum 2
The toner image formed on the photosensitive drum 2 as described above is transferred to the recording paper 100 by the transfer device 3.

After that, the recording paper 100 is caught between the heat roller 6 and the backup roller 7 of the heat fixing device 4, and the heat of the heat roller 6 heated by the halogen lamp 5 and the pressure of the backup roller 7 cause the toner. Image fixing is performed. After that, the recording paper is discharged to the stacker by a discharge roller (not shown). Further, the surface of the photosensitive drum 2 that has completed the transfer is cleaned by a cleaner,
The charge is removed by the static eliminator.

[0007]

In the above-mentioned conventional structure, the heat roller 6 is made of aluminum and is not crushed, and the backup roller 7 is made of rubber on the surface and crushes as shown in FIG. It becomes easy to wind around the roller 6. Therefore, conventionally, the pawl 8 is provided and the recording paper 1
00 was being separated. However, even if the separation is performed by the pawl 8, the recording paper 100 is rolled up by the time it reaches the pawl 8, so that the medium curl occurs.

It is an object of the present invention to provide a thermal fixing device which does not require a recording paper separating pawl and which does not cause a medium curl.

[0009]

In order to achieve the above object, the present invention comprises a heat roller having a built-in heat source and a surface rubber backup roller, and heat fixing for fixing a toner image transferred onto a medium. In the apparatus, the heat roller is made of rubber on the surface.

[0010]

Like the backup roller, the heat roller is also made of rubber on the surface, so that both rollers are uniformly crushed so that they are substantially flat at the pressure contact portion. Therefore, the medium conveyed by the planar pressure contact portion is not wound around the heat roller, and the medium curl which has been a problem in the related art is eliminated. Further, it is possible to remove the claw that was conventionally required to peel off the wound medium.

[0011]

Embodiments of the present invention will be described below with reference to FIG.

FIG. 1 is an explanatory view of the structure of the main part of the electrophotographic recording apparatus of this embodiment (FIG. 1 (A) is a side view, FIG. 1 (B) is FIG.
It is (B) detailed drawing of (A). In FIG. 1A, 1
Reference numeral 1 denotes a heat fixing device, and the heat fixing device 11 includes a heat roller 12 and a backup roller 13 that is in pressure contact with the heat roller 12. The other constituent members are the same as those in the related art, and the same reference numerals are used.

The heat roller 12 is made of a surface rubber having a rubber layer 12a such as silicon rubber formed on the surface thereof, and has a halogen lamp 14 built therein. The backup roller 13 is made of surface rubber having a rubber layer 13a such as silicon rubber formed on the surface thereof, and has a halogen lamp 15 built therein.

Recording by this recording device is performed in the same procedure as that of the conventional device described above. However, in the case of this example,
Since the heat roller 12 and the backup roller 13 both have a rubber layer formed on their surfaces,
Numerals 2 and 13 are pressure contact portions, which are uniformly flattened as shown in FIG. 1 (B). Therefore, the recording paper 100 conveyed by the flat pressure contact portion does not wind around the heat roller 12, and the medium curl which has been a problem in the past does not occur. In addition, the claw that was conventionally required to remove the wound recording paper is no longer necessary.

Further, in the case of this example, the backup roller 13 is of a heat roller type having a built-in heat source (halogen lamp) and is adapted to perform vertical heating, so that when the recording paper is a thick paper medium such as a postcard. However, the heat conduction by the rollers to the front and back of the recording paper is constant, and the fixing rate is improved.

[0016]

As described above, according to the present invention, since the heat roller also has the same surface rubber as that of the backup roller, the pressure contact portions of both rollers are flat and are conveyed by the pressure contact portion. The media will no longer wind around the heat roller. Therefore, the curl of the medium is eliminated, and it is possible to remove the claw that has been necessary to peel off the medium that has been wound up to now.

[Brief description of drawings]

1A and 1B are structural explanatory views of a main part of an electrophotographic recording apparatus according to an embodiment of the present invention, in which FIG. 1A is a side view and FIG. 1B is FIG.
It is a B section detail drawing of (A).

2A and 2B are explanatory views of a main part structure of a conventional electrophotographic recording apparatus, FIG. 2A is a side view, and FIG. 2B is A in FIG. 2A.
FIG.

[Explanation of symbols]

 11 Thermal Fixing Device 12 Heat Rollers 12a, 13a Rubber Layer 13 Backup Rollers 14 and 15 Halogen Lamp (Heat Source) 100 Recording Paper (Medium)

Claims (1)

[Claims] 1. A heat roller (12) having a built-in heat source.
And a surface rubber backup roller (13),
A heat fixing device for fixing a toner image transferred onto a medium (100), wherein the heat roller (12) is made of rubber on the surface.