JPH05232775A - Image forming device - Google Patents

Abstract

PURPOSE:To reduce influence of the fixing device of an electrophotographical image forming device upon its image formation process device and optical unit, lessen unevenness in the temp, distribution over the thrust direction of a heat roller of the fixing device, and prevent bedewing. CONSTITUTION:Air exhaust paths 12a, 12b of two-ply structure are furnished between a fixing device 9 and an image forming process device and optical unit 3, and a plurality of exhaust holes 13a-13e are formed in the air exhaust path 12b on the fixation device side in such an arrangement that their opening areas enlarge as positioning farther than an exhaust fan 11, and thereby the heat generated by the fixing device 9 can be shut off, and the exhausting amount in the thrust direction of the fixing device 9 be made constant, which allows making the exhaust amount uniform.

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 which reduces the amount of heat of a fixing device and the influence of the heat on other devices.

[0002]

2. Description of the Related Art In recent years, printers using electrophotography have made remarkable progress.

An image forming apparatus using a conventional electrophotographic method will be described below. As shown in FIGS. 3 and 4,
The image forming process apparatus includes a photosensitive drum 1, a charger 2,
Developing device 4, transfer device 5. It is composed of a cleaner 6 and a static eliminator 7. The air exhaust passage 14 is provided between the fixing device 9 and the image forming process device or the optical unit 3, and the exhaust fan 1 is provided via a filter (ozone removal filter) 10.
It communicates with 1. In the figure, 8 is a sheet and 9 is a fixing device.

The operation of the image forming apparatus having the above structure will be described below. The rotating photoconductor drum 1 is first charged with a uniform charge on its surface by the charger 2. Then, the light is exposed by the optical system unit 3 to remove the electric charge in the portion exposed to the light by the electrostatic latent image. Here, developing device 4
As a result, the toner having a charge opposite to the surface potential of the photosensitive drum 1 is attracted to the photosensitive drum 1. Then, it is transferred onto the sheet 8 by the transfer device 5. Then, the sheet 8 carrying the image is guided to the fixing device 9 and fixed by heat and pressure. The toner remaining on the surface of the photosensitive drum 1 is removed by the cleaner 6, and the charge is removed by the charge remover 7. Further, the dirty air containing ozone and nitrogen oxides generated by the charger 2 during the image forming process and the toner scattered from the developing device 4 passes through the air exhaust passage 14 and the filter 10 as indicated by the broken line arrow. The heat is exhausted outside the apparatus by the exhaust fan 11 as shown by the solid line arrow, and heat generated by the fixing apparatus 9 is insulated so as not to affect the image forming process apparatus and the optical unit 3.

[0005]

However, in the above-mentioned conventional structure, the heat generated in the fixing device 9 has an adverse effect on the image forming process device and the optical unit 3 (that is, toner blocking, thermal deformation of the device housing, etc.). ) Can be reduced, but the problem of heat buildup of the fixing device 9 itself is not eliminated, and there is a problem that uneven temperature distribution in the thrust direction of the heat roller of the fixing device 9 and dew condensation occur. Was there.

The present invention solves the above-mentioned conventional problems, and can reduce the adverse effects of heat of the fixing device on the image forming process device and the optical unit, and can also cause uneven temperature distribution in the thrust direction of the heat roller of the fixing device. Less,
An object of the present invention is to provide an image forming apparatus that prevents dew condensation.

[0007]

In order to achieve this object, an image forming apparatus of the present invention comprises a two-layer air exhaust passage provided between a fixing device and an image forming process device or an optical unit. In the air exhaust passage on the side of the fixing device, a plurality of exhaust holes having a larger opening area are formed so as to be arranged farther from the exhaust fan.

[0008]

With this structure, a heat insulating layer is formed between the fixing device and the image forming process device or the optical unit, and the exhaust amount of the fixing device in the thrust direction is kept constant so that the heat generated from the fixing device is discharged. The amount of heat is made uniform.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2 showing an embodiment of the present invention, the same parts as those of the conventional example are designated by the same reference numerals and the description thereof will be omitted.

The feature of this embodiment is that, as shown in FIG. 1, the air exhaust passage 14 of the conventional example is added to the conventional configuration described above.
Instead of this, an air exhaust passage 12a provided between the fixing device 9 and the image forming process device or the optical unit 3, and an air exhaust passage 12b adjacent to the air exhaust passage 12a on the fixing device 9 side.
Has been established. Further, as shown in FIG. 2, the air exhaust path 12b has a plurality of ventilation holes 13a to 13a each having an opening area increased so as to be arranged farther from the exhaust fan 11.
13e is formed.

With respect to the image forming apparatus including the above-mentioned components, the relationship and operation of each component will be described.

The description of the same operation as the operation described in the conventional example will be omitted. Dirty air generated in the apparatus during image formation passes through the air exhaust passage 12a and the filter 10
It is exhausted to the outside of the device by the exhaust fan 11 via the. At this time, the heat generated from the fixing device 9 is exhausted to the outside of the device by the exhaust fan 11 by the air exhaust passage 12b provided on the fixing device 9 side. When the heat generated from the fixing device 9 is released through the air exhaust passage 12b, the exhaust force becomes weaker as the distance from the exhaust fan 11 becomes longer. Therefore, the position away from the exhaust fan 11 in order to keep the exhaust heat amount accompanying the exhaust amount constant. The ventilation holes 13a to 13e having a larger opening area can be used to make the exhaust amount uniform, reduce uneven temperature distribution of the fixing device 9, and prevent dew condensation.

[0014]

As is apparent from the above description of the embodiments, the present invention has a two-layer air exhaust path provided between the optical unit of the fixing device and the image forming process device, and the fixing device side The air exhaust path has a structure in which a plurality of vent holes are formed with an opening area increased so that the air exhaust path is located farther away from the exhaust fan to prevent the heat of the fixing device from adversely affecting the image forming process device and the optical unit. It is possible to realize an excellent image forming apparatus which can reduce the temperature distribution unevenness in the thrust direction of the heat roller of the fixing device and prevent dew condensation.

[Brief description of drawings]

FIG. 1 is a schematic front cross-sectional view showing the concept of essential parts of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic plan view showing a concept of a main part of an air exhaust path of the image forming apparatus.

FIG. 3 is a schematic plan cross-sectional view showing the concept of essential parts of a conventional image forming apparatus.

FIG. 4 is a schematic front cross-sectional view showing the concept of a main part of the image forming apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor drum 3 Optical unit 4 Developing device 6 Cleaner 9 Stabilizer 12a, 12b Air exhaust path 13a, 13e Vent hole

Claims (1)

[Claims] 1. An electrophotographic process is applied to provide an image forming process device and an optical unit for carrying an image on a sheet, and a fixing device for the image, and the fixing device and the image forming process device and the optical unit are provided. An air exhaust passage having a two-layer structure disposed between them and having a plurality of ventilation holes formed so that the opening area is increased so as to be arranged farther from the exhaust fan on the side adjacent to the fixing device. Image forming apparatus provided.