JPH0624598A - Conveyer roller of electronic photograph type image forming device - Google Patents

Abstract

PURPOSE:To convey a copying and fixing belt stably without generating a meandering and a bending, and to prevent generation of a disorder in the copied image on the copying and fixing belt, by providing belt guide wheels to guide the copying and fixing belt and to rotate integrally with a roller main body, to both ends of the roller main body. CONSTITUTION:In an electronic photograph type image forming device, sprockets 3 as guide wheels are press-fitted to both ends of an aluminum shaft 2 of a straight conveyer roller 1, and a copying and fixing belt 4 is conveyed with sprocket pins 3a by rotating the sprockets 3 integrally together with the conveyer roller 1. Or in the other way, the roller main body 1 and the belt guide wheels 3 are rotated separately. And the roller main body 1 is formed in a drum form, an hour-glass form, or a taper form. Consequently, the copying and fixing belt 4 can be conveyed stably without generating a meandering, and no disorder is generated in the copied image on the copying and fixing belt 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic printer, and more particularly to a carrying roller for an electrophotographic printer that simultaneously performs transfer and fixing (transfer fixing).

[0002]

2. Description of the Related Art FIG. 9 is a sectional view showing the structure of a conventional electrophotographic printer. The photoconductor 34 from which the untransferred developer has been cleaned through the cleaning device 33 is uniformly charged by the primary charging device 35, and an electrostatic latent image is formed on the photoconductor 34 by the exposure device 36.
The formed latent image is visualized on the photoconductor 34 by the developing device 37, and the above-mentioned visible image is transferred by the transfer charging device 40 to the transfer / fixing belt 39 which is conveyed through the conveying roller 38. The transfer image on 39 is the conveyance roller 3
It is conveyed to the fixing device 41 by 8. Thereafter, in the fixing device 41, the transfer image on the transfer fixing belt 39 is fixed on the medium 43 conveyed from the paper feeding hopper 42. In this conventional electrophotographic printer, the transport roller 38 has a simple structure including only the roller 44 and the shaft 45, as shown in the cross section of FIG.

[0003]

The transfer roller of this conventional electrophotographic printer has a simple structure of only a roller and a shaft and has no belt guide wheels at both ends. There is a problem that the image transferred on top is disturbed.

[0004]

The transport roller of the electrophotographic image forming apparatus of the present invention has a cleaning device, a charging device, an exposure device, a developing device, and a transfer device arranged around the image carrier as a center. An image formed on the image carrier through a series of electrophotographic processes is transferred and formed on a transfer fixing belt passing between the image carrier and the transfer device,
In an electrophotographic image forming apparatus in which the transfer fixing belt is conveyed to a fixing device by a conveying roller, and the image on the transfer fixing belt is transferred and fixed onto a medium and discharged, the conveying roller is a straight roller body, and the roller is a roller body. Belt transfer wheels are provided at both ends of the main body to guide the transfer and fixing belt and rotate integrally with the roller main body.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

1 to 8 are sectional views showing the first to eighth embodiments of the present invention, and FIG. 9 is a sectional view showing the structure of a general electrophotographic printer for simultaneously performing transfer and fixing. .

First, the construction and operation of this type of printer will be described with reference to FIG. Cleaning device 3
Photoreceptor 34 from which the untransferred developer has been cleaned after 3
Are uniformly charged by the primary charging device 35, and an electrostatic latent image is formed on the photoconductor 34 by the exposure device 36. The formed latent image is visualized on the photoconductor 34 by the developing device 37, and the above-mentioned visible image is transferred by the transfer charging device 40 to the transfer / fixing belt 39 which is conveyed through the conveying roller 38. The transfer image on 39 is conveyed to the fixing device 41 by the conveying roller 38. After that, in the fixing device 41, the medium 43 conveyed from the paper feeding hopper 42.
Then, the transfer image on the transfer fixing belt 39 is fixed. In this embodiment, by improving the structure of the carrying roller 38,
This is intended to stabilize the conveyance of the transfix belt.

The present invention provides first to eighth embodiments as the structure of the conveying roller. In the first embodiment, a straight conveying roller 1 and a sprocket 3 as a belt guide wheel provided at both ends of the conveying roller 1 for guiding the transfer fixing belt 4 and rotating integrally with the conveying roller 1 are provided. It is done. Also in the second to fourth embodiments, the conveying rollers 5, 9, 13 and the sprockets 7, 11,
It is integrated with 15. However, in the fifth to eighth embodiments, the conveying rollers 17, 21, 25, 29 and the sprockets 19, 23, 27, 31 are rotated separately. Regarding the shape of the transport roller, the first and fifth embodiments have a straight cylindrical shape,
The second and sixth embodiments are drum-shaped, the third and seventh embodiments are drum-shaped, and the fourth and eighth embodiments are tapered. It is assumed that all of the above-mentioned sprockets have a plurality of sprocket pins planted on the outer periphery thereof. That is, by way of example, in the first embodiment, a plurality of sprocket pins 3a are planted on the outer periphery of the sprocket 3 and are engaged with holes (not shown) provided in the transfix belt 4 correspondingly. The transfer / fixing belt 4 is conveyed.

Each embodiment will be described below with reference to the drawings. In the first embodiment shown in FIG. 1, sprockets 3 are press-fitted into both ends of an aluminum shaft 2 of a straight conveying roller 1, and the sprocket 3 rotates integrally with the conveying roller 1 via a sprocket pin 3a. And the transfer fixing belt 4 is conveyed. In the second embodiment shown in FIG. 2, sprockets 7 are pressed into both ends of the aluminum shaft 6 of the drum-shaped transport roller 5,
Rotates integrally with the drum-shaped transport roller 5 and transports the transfer fixing belt 8 via the sprocket pin 7a. In the third embodiment shown in FIG. 3, sprockets 11 are press-fitted on both ends of the aluminum shaft 10 of the drum-shaped carrier roller 9, and the sprocket 11 rotates integrally with the drum-shaped carrier roller 9 and the sprocket pin is rotated. The transfer fixing belt 12 is conveyed via 11a. In the fourth embodiment shown in FIG. 4, the sprocket 15 is press-fitted to the end of the transport roller 13 on the side where the roller diameter is smaller in the aluminum shaft 14 of the tapered transport roller 13. The sprocket 15 rotates together with the tapered conveying roller 13 and conveys the transfer fixing belt 16 via the sprocket pin 15a.

In the fifth embodiment shown in FIG. 5, sprockets 19 are rotatably arranged at both ends of an aluminum shaft 18 of a straight conveying roller 17, and the sprocket 19 rotates with the rotation start of the conveying roller 17 to rotate the sprocket pin 1.
The transfer fixing belt 20 is conveyed via 9a. In the sixth embodiment shown in FIG. 6, sprockets 23 are rotatably arranged at both ends of an aluminum shaft 22 of a drum-shaped carrier roller 21, and the sprocket 23 rotates when the drum-shaped carrier roller 21 starts to rotate to rotate a sprocket pin. The transfer fixing belt 24 is conveyed via 23a. In a seventh embodiment shown in FIG. 7, sprockets 27 are rotatably arranged at both ends of an aluminum shaft 26 of a drum-shaped carrier roller 25, and the sprocket 27 rotates with the rotation start of the drum-shaped carrier roller 25 and a sprocket pin. The transfer fixing belt 28 is conveyed via 27a.

In the eighth embodiment shown in FIG. 8, a sprocket 31 is rotatably arranged on the end of the conveying roller 29 on the side where the roller diameter is small on the aluminum shaft 30 of the tapered conveying roller 29. . Sprocket 31
Rotates with the start of rotation of the tapered conveying roller 29, and the transfer fixing belt 3 is rotated through the sprocket pin 31a.
2 is conveyed.

As described above, in the first to eighth embodiments of the present invention, the sprocket as a guide wheel for guiding the transfer and fixing belt is provided at both ends of the conveying roller, so that the transfer and fixing belt does not meander. It can be stably transported. In the above-described embodiment, the sprocket pin is provided on the sprocket. However, the present invention is not limited to this, and a protrusion is provided over the entire circumference of the sprocket to form a wall shape to guide the transfer fixing belt so that it does not meander. You may do it.

[0013]

As described above, according to the present invention, the transfer guide belt is provided on the conveying roller and the shape of the roller is devised so that the transfer fixing belt can be stably conveyed without meandering and bending. Therefore, it has an effect of preventing the transfer image on the transfer fixing belt from being disturbed.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing a second embodiment of the present invention.

FIG. 3 is a sectional view showing a third embodiment of the present invention.

FIG. 4 is a sectional view showing a fourth embodiment of the present invention.

FIG. 5 is a sectional view showing a fifth embodiment of the present invention.

FIG. 6 is a sectional view showing a sixth embodiment of the present invention.

FIG. 7 is a sectional view showing a seventh embodiment of the present invention.

FIG. 8 is a sectional view showing an eighth embodiment of the present invention.

FIG. 9 is a cross-sectional view showing the structure of a general electrophotographic printer that simultaneously performs transfer and fixing.

FIG. 10 is a sectional view showing an example of a conventional conveying roller.

[Explanation of symbols]

1, 5, 9, 13, 17, 17, 21, 25, 29 Conveying rollers 2, 6, 10, 14, 18, 22, 26, 30 Aluminum shaft 3, 7, 11, 15, 19, 23, 27, 31 Sprocket 4,8,12,16,20,24,28,32 Transfer fixing belt 33 Cleaning device 34 Photoconductor 35 Primary transfer device 36 Exposure device 37 Developing device 38 Conveying roller 39 Transfer fixing belt 40 Transfer charging device 41 Fixing device 42 Supply Paper hopper 43 Medium 44 Roller 45 Shaft

Claims (4)

[Claims] 1. A cleaning device, a charging device, an exposure device, a developing device, and a transfer device are arranged around the image carrier, and an image formed on the image carrier is subjected to a series of electrophotographic processes. The image is transferred and formed on a transfer fixing belt that passes between the image carrier and the transfer device, the transfer fixing belt is conveyed to a fixing device by a conveying roller, and the image on the transfer fixing belt is transferred and fixed on a medium and discharged. In the electrophotographic image forming apparatus, the transport roller includes a straight roller body, and belt guide wheels provided at both ends of the roller body to guide the transfer and fixing belt and rotate integrally with the roller body. A conveyance roller for an electrophotographic image forming apparatus, characterized by: 2. The transport roller for an electrophotographic image forming apparatus according to claim 1, wherein the roller body and the belt guide wheel rotate separately. 3. The transport roller for an electrophotographic image forming apparatus according to claim 1, wherein the roller body is drum-shaped, drum-shaped, or tapered. 4. The belt guide wheel is provided with a sprocket pin on the outer circumference.
Alternatively, a conveyance roller of the electrophotographic image forming apparatus described in 3.