JP2003302859A - Electrophotographic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small, low-cost and highly reliable electrophotographic device. <P>SOLUTION: In the electrophotographic device using compressed air as a means for separating paper from a heat roll, a positioning pin having a compressed-air path is provided in the housing of the electrophotographic device, and a portion for receiving the pin having the compressed-air path is provided on a fixing device opposite to the pin. Thus, the position of the fixing device in the housing of the electrophotographic device is maintained highly accurately to obtain the low-cost electrophotographic device. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus having a fixing device.

[0002]

2. Description of the Related Art FIG. 3 is a schematic view of a conventional fixing device and casing of an electrophotographic apparatus.

In the fixing device 3 having the heating roll 1 and the pressure roll 2, a sheet (cut sheet) may be wound around the heating roll 1 or the pressure roll 2 contrary to normal sheet feeding. For the purpose of preventing this wrapping, a method is known in which compressed air is blown out from the nozzle 26 to separate the paper from the heating roll 1 or the pressure roll 2.

When paper remains in the fixing device due to paper jam or the like, the fixing device 3 mounted on the slide rails 5 and 6 is moved in the axial direction of the heating roll 1 and the pressure roll 2.
A method is known in which the paper is pulled out from the electrophotographic apparatus housing 4 and the paper is removed. Pins 9, 10, 15, 16 are provided on the electrophotographic apparatus housing 4 so as to be able to be drawn out and to accurately position the fixing apparatus 3 in the electrophotographic apparatus housing 4, and the holes of the frame of the fixing apparatus 3 can be provided. Each of them can fit into 12, 18, 19, 27.

The sheet peeling nozzle 26 of the fixing device 3 that can be pulled out from the compressed air supply source outside the fixing device.
A method is known in which a tube 28 wound in a coil shape and the joints 22 and 24 are used for connection in order to secure a path for sending compressed air.

[0006]

In the prior art, there is a problem that the storage space of the coiled tube is large and it is difficult to downsize the device.

In addition, if a shaft which serves as a guide for a coiled tube and parts for supporting the same are included, the number of parts is large and the structure is complicated, resulting in an expensive device. .

Further, since the path of the coiled tube becomes long, the resistance inside the tube increases, the compressed air blown out from the nozzle becomes weak, and it becomes difficult to peel the paper.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and provide a fixing device and an electrophotographic apparatus that are small in size, have a simple structure, are inexpensive, and have high reliability.

[0010]

In order to achieve the above object, in the present invention, a rear frame of an electrophotographic apparatus casing is provided with
A positioning pin having a compressed air path is provided, and a receiving portion for the pin having a compressed air path is provided on the rear frame of the fixing device which faces the positioning pin.

As a result, a storage space for the coiled tube is not required and a positioning mechanism is provided,
The size of the device can be reduced. Also, the structure is simplified,
It is possible to provide an inexpensive device. Furthermore, since the length of the compressed air path is shortened, the resistance inside the pipe is reduced, the compressed air blown out from the nozzle is not reduced, and stable paper peeling is realized, providing a highly reliable fixing device. Became.

[0012]

FIG. 1 shows a fixing device according to an embodiment of the present invention.

The fixing device 3 having the heating roll 1 and the pressure roll 2 is mounted on the movable portions of the slide rails 5 and 6 mounted on the casing 4 of the electrophotographic apparatus. Fixing device 3
The remaining paper can be easily taken out by unitizing the fixing device 3 and pulling it out from the electrophotographic apparatus housing 4.

Further, in order to carry the sheet with high reliability, it is necessary to accurately position the fixing device 3 in the casing 4 of the electrophotographic apparatus.

Therefore, when the fixing device 3 is pushed into the casing 4 of the electrophotographic apparatus, the pins 9 and 10 arranged with high precision on the rear frame 8 of the casing are mounted on the rear frame 11 of the fixing device 3. The holes 12 and the pin receiving portions 13 arranged with precision are fitted together. Similarly, the pins 15 and 16 arranged on the front frame 14 of the housing with high accuracy fit into the holes 18 and 19 of the front frame 17 of the fixing device 3, so that the fixing device 3 is mounted on the housing 4 of the electrophotographic apparatus. Positioned with high accuracy.

FIG. 2 shows the pin 9 and the receiving part 1 of the compressed air path.
FIG. 2 shows a cross section of a portion where 3 is fitted.

In the rear frame 8 of the electrophotographic apparatus housing 4,
The pin 9 assembled with the screw 20 is provided with a through hole serving as a compressed air path. Similarly, the pin receiving portion 13 assembled with the screw 21 is attached to the rear frame 11 of the fixing device 3.
There is also a through hole. The tube 23 connected to the joint 22 is connected to the compressed air supply source, and the tube 25 connected to the joint 24 is connected to the peeling nozzle 26.

The compressed air, which is appropriately supplied in accordance with the running of the paper, is supplied to the nozzle 26 through this path.

The fixing device unit is used as the casing 4 of the electrophotographic apparatus.
The path is opened when the paper is pulled out, but no inconvenience occurs because the paper is not running.

The O-ring 30 arranged in the groove of the fitting portion is for preventing leakage of compressed air.

FIG. 3 is a schematic view of an electrophotographic apparatus equipped with the fixing device 3. The surface layer of the photosensitive drum 41 is a charger 42.
Are uniformly charged by. The surface of the photosensitive drum 41 is
The light from the optical system 43 receiving the print data signal is emitted. The developer is stored in the developing machine 44. In the case of two-component development, the developer consists of toner and carrier. The toner adheres to the surface of the photosensitive drum 41 and is visualized. The toner image on the surface of the photosensitive drum 41 is transferred onto the paper 45 by the transfer device 46 and fixed by the fixing device 3. Toner remaining on the surface of the photosensitive drum 41 without being transferred is cleaned by the cleaner 47.

[0022]

According to the present invention, it is possible to provide an inexpensive apparatus having a small size and a simple structure while maintaining the position of the fixing device in the housing of the electrophotographic apparatus with high accuracy. Also,
Since the length of the compressed air path becomes short, the resistance inside the tube becomes low, the compressed air blown out from the nozzle does not decrease, and stable sheet peeling is realized, and a highly reliable electrophotographic apparatus can be provided.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of a fixing device and an electrophotographic apparatus casing according to the present invention.

FIG. 2 is a cross-sectional view of a fitting portion of FIG.

FIG. 3 is a schematic diagram of an electrophotographic apparatus that is an embodiment of the present invention.

FIG. 4 is a schematic diagram showing a conventional technique.

[Explanation of symbols]

1 ... Heating roll, 2 ... Pressure roll, 3 ... Fixing device, 4 ...
Electrophotographic device housing, 5, 6 ... Slide rails, 8 ... Rear frame of electrophotographic device housing, 9, 10 ... Pins, 11 ...
Rear frame of fixing device, 12 ... Hole, 13 ... Pin receiving portion, 14 ... Front frame of electrophotographic device, 15, 1
6 ... pin, 17 ... front frame of fixing device, 18,
19 ... Hole, 20, 21 ... Screw, 22, 24 ... Joint, 2
3, 25 ... Tube, 26 ... Nozzle, 27 ... Hole, 28 ...
Coiled tube, 29 ... Shaft, 30 ...
O-ring, 41 ... Photosensitive drum, 42 ... Charging device, 43 ... Optical system, 44 ... Developing device, 45 ... Paper, 46 ... Transfer device, 47
... cleaner.

Continued front page    (72) Inventor Masato Miwa             Hitachiko, 1060 Takeda, Hitachinaka City, Ibaraki Prefecture             Machine Co., Ltd. F-term (reference) 2H033 AA29 BA03 BA04 BA15 BA20                       BA21 BB01 BB38                 2H171 FA03 FA19 FA28 GA11 GA12                       GA13 JA12 JA48 KA05 KA16                       KA23 QC36 WA11

Claims (2)

[Claims] 1. An electrophotographic apparatus including a fixing device having a heating roll, a pressure roll, and a sheet peeling means using compressed air, a photosensitive drum, a charger, an optical system, a developing device, and a transfer device, An electrophotographic apparatus, wherein a connecting portion with a fixing device for receiving supply of compressed air from a compressed air supply source outside the fixing device has a positioning function of the fixing device. 2. The electrophotographic apparatus according to claim 1, further comprising a fixing device unit that can be pulled out from the casing of the electrophotographic apparatus in the direction of the central axis of rotation.