JPH11160937A - Transfer paper carrying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent a transfer paper from floating at a carrying time and to simplify structure by eliminating the need of a mechanism for opening and closing an clamping part. SOLUTION: Since one end of the champing part 46 is fixed to the first layer 38 of a belt 36, a gap 60 is formed between the layer 38 and the clamping part 46 when the layer 38 is curved by a first roller 32. When the belt 36 becomes horizontal on a condition that the transfer paper 14 is inserted in the gap 60, the leading edge of the paper 14 is interposed between a belt main body 38 and the clamping part 46. Thus, the leading edge of the paper 14 does not float in a carrying path.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer paper transport device, and more particularly, to a transfer paper transport device having a belt for transporting a transfer paper to a photoreceptor in an image forming apparatus such as an electrophotographic printer or a copying machine. .

[0002]

2. Description of the Related Art An example of this type of conventional transfer paper transport apparatus is disclosed in Japanese Patent Application Laid-Open No. 8-305181 [G03G 15/1.
6]. In this conventional technique, a transfer paper is electrostatically attracted onto a transfer belt by applying a transfer bias voltage to a transfer belt composed of two layers, an inner layer and a surface coat layer, and the transfer belt is rotated in that state. Transfer paper.

[0003]

The magnitude of the electrostatic force for electrostatically attracting the transfer paper to the transfer belt varies depending on environmental conditions such as the thickness, surface condition, resistance value and temperature of the transfer paper. Therefore, in the related art, depending on environmental conditions, the leading end of the transfer paper may easily float from the transfer belt, and the transfer paper may be jammed in the transport path, or the jammed transfer paper may damage the photoconductor.

As one means for solving this problem, there is known a transfer drum system in which the leading end of the transfer paper is held on the transfer drum by a claw that is mechanically opened and closed.
This method has another problem that the structure is complicated because a special mechanism for opening and closing the claws is required. SUMMARY OF THE INVENTION Therefore, a main object of the present invention is to provide a transfer paper transport device that can reliably prevent the transfer paper from being lifted with a simple structure.

[0005]

According to the present invention, there is provided a transfer paper transporting apparatus provided with a belt for transporting a transfer paper to a photoreceptor, wherein the belt has an annular belt body rotated by a rotating means, and one end of the belt body. A transfer sheet transport device including a fixed plate-shaped holding portion, wherein the transfer sheet is held between the belt body and the holding portion.

[0006]

[Function] Since one end of the holding portion is fixed to the belt body,
When the belt body is bent, the other end of the holding portion rises from the belt body due to the rigidity of the holding portion, and a gap is formed between the belt body and the other end of the holding portion. When the curvature of the belt body is returned to the original state in a state where the leading end of the transfer paper is inserted into the gap, the leading end of the transfer paper is clamped by the belt body and the clamping portion. In addition, as a gap forming unit that forms a gap by bending the belt main body, for example, a roller that rotationally drives the belt or the like can be used.

[0007]

According to the present invention, the leading end of the transfer sheet is held between the belt body and the holding portion, so that the transfer sheet can be reliably prevented from floating. Further, since there is no need to separately provide a mechanism for opening and closing the holding portion, the structure can be simplified. The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG.
Is for transporting transfer paper 14 onto which a toner image is transferred in an image forming apparatus 12 such as an electrophotographic printer or a copying machine. The image forming apparatus 12 includes four photoconductor units 16a, 16b, 16c, and 16d, which are arranged side by side in the horizontal direction and form toner images of different colors. Each photoconductor unit 16a to 16d
Each includes a photoconductor drum 18 that is driven to rotate by a motor (not shown). Around the photoconductor drum 18, the chargers 20 and LS are arranged in the rotation direction (the direction of the arrow).
An exposure device 22, such as a U (laser scanning unit), a developing device 24, a transfer roller 26, a cleaning device 28, and a static eliminator 30 are arranged. Then, the transfer paper transport device 10 is provided so as to sequentially supply the transfer paper 14 to the photoconductor drums 18 of the respective photoconductor units 16a to 16d.

The transfer paper transport device 10 includes an annular belt 36 rotated by a first roller 32 and a second roller 34.
And the belt 36 includes
16d passes between the photosensitive drum 18 and the transfer roller 26. As shown in FIG. 2, the belt 36 has a first layer 38 as a belt body and a second layer 4 laminated on the outer surface thereof.
0, and the first layer 38 and the second layer 40 are adhered by the adhesive 44 except for a part (the non-adhered portion 42). The non-adhesive portion 42 is formed over the entire length in the width direction of the belt 36, and the continuity of the second layer 40 is cut off at the rear end of the non-adhesive portion 42 in the rotation direction (the arrow direction in FIG. 2)
A substantially plate-shaped holding portion 46 is formed. This holding portion 46
In the horizontal portion (FIG. 2) of the belt 36, the belt 36 approaches the first layer 38, but when the first layer 38 is curved by the first roller 32 or the second roller 34, as shown in FIG. 3 or FIG. Due to its rigidity, it rises from the first layer 38. The holding portion 46 may be formed at only one place in the circumferential direction of the belt 36, or may be formed at two or more places.

As shown in FIG. 1, in addition to the photoreceptor units 16a to 16d, around the belt 36, a paper feed unit 48, a discharge unit 50, a discharge unit 52 also serving as a fixing unit, and a charging unit are provided. The container 54 and the like are arranged. The paper feeding device 48 includes a pair of paper feeding rollers 56 and a guide portion 58 for guiding the transfer paper 14 fed by the paper feeding rollers 56 to the belt 36, and the guide portion 58 is, as shown in FIG. Roller 3
In order to insert the transfer paper 14 into the gap 60 between the first layer 38 and the holding portion 46 generated on the
2 is arranged in the vicinity. On the other hand, as shown in FIG. 1, the paper discharge device 52 includes a guide portion 62 for guiding the transfer paper 14 and a paper discharge roller 64 for fixing and discharging the toner image on the transfer paper 14. , So that the transfer paper 14 separated from the belt 36 can be taken off.
4 is arranged in the vicinity.

In operation, when the image forming process in the image forming apparatus 10 is started, the photosensitive unit 16
a to 16d, a single color toner image is formed on the photosensitive drum 18 and each photosensitive drum 18
The transfer paper 14 is sequentially conveyed, and the color toner image on the photosensitive drum 18 is sequentially transferred to the transfer paper 14. In each of the photoconductor units 16a to 16d, first, the surface of the photoconductor drum 18 is uniformly charged by the charger 20, and then the surface is irradiated with laser light from the exposure device 22 to form an electrostatic latent image. You. Then, this electrostatic latent image is
4 for toner development. When the developed toner image is moved to a position facing the belt 36, the toner image on the photosensitive drum 18 is transferred to the transfer paper 14 by the transfer roller 26. The toner remaining on the photosensitive drum 18 without being transferred to the transfer paper 14 is
Is scraped off by the inner blade 28a. The toner that has not been scraped off by the blade 28a is removed by the charge remover 30.

On the other hand, in the transfer paper transport device 10, the belt 36 is rotated by the first roller 32 and the second roller 34. When the holding portion 46 formed on the belt 36 is moved and comes on the first roller 32, as shown in FIG.
The first layer 38 is curved by the roller 32,
A gap 60 is formed between the holding member 46 and the holding portion 46. Nipping part 4
When the sensor (not shown) detects that the sheet 6 comes on the first roller 32, the sheet feeding roller 56 of the sheet feeding device 48 is rotated, and the transfer sheet 14 is sent out from the guide portion 58, and the transfer sheet 1 is transferred.
4 are inserted into the gap 60. When the belt 36 is further rotated and passes through the first roller 32, as shown in FIG. 4, the gap 60 between the first layer 38 and the holding portion 46 is closed, and the leading end of the transfer paper 14 is held. At this time, the transfer paper 14 is electrostatically attracted to the belt 36 by the static electricity generated by the charger 54. Therefore,
In the subsequent transfer step, the leading end of the transfer paper 14 does not rise.

When the holding section 46 has passed the transfer step, the electrostatic attraction between the belt 36 and the transfer paper 14 is weakened by the neutralizer 50. When the holding portion 46 comes on the second roller 34, the first layer 38 is bent by the second roller 34 as shown in FIG. 5, and the gap 60 is again formed between the first layer 38 and the holding portion 46. Is formed. Then, the leading end of the transfer paper 14 is released and floats from the first layer 38 due to its rigidity. Accordingly, when the belt 36 is further rotated, as shown in FIG. 6, the transfer paper 14 is guided by the guide portion 62, is taken up by the paper discharge roller 64, and is conveyed by the paper discharge roller 64 also serving as a fixing device. .

According to this embodiment, since the leading end of the transfer paper 14 is conveyed between the first layer 38 of the belt 36 and the holding portion 46, the leading end of the transfer paper 14 is transferred. Floating from the belt 36 can be reliably prevented.
Further, since the belt 36 only needs to be provided with the holding portion 46, the structure is not complicated. In the above-described embodiment, the entire belt 36 has a two-layer structure. However, for example, only a part of the belt 36 has a two-layer structure, and the holding portion 46 is formed by the second layer 40 in that portion. It may be. Alternatively, the holding portion 46 may be formed by a member different from the second layer 40, and this may be fixed at one end to the outer surface of the first layer (belt body) 38.

In the above-described embodiment, the case where the present invention is applied to the image forming apparatus 12 which performs color development with the plurality of photoreceptor units 16a to 16d has been described.
The present invention can be applied to any image forming apparatus in which the transfer paper 14 is transported by using the belt 36. For example, the present invention is applicable to an apparatus having only one photoconductor unit 16.

[Brief description of the drawings]

FIG. 1 is an illustrative view showing one embodiment of the present invention;

FIG. 2 is an illustrative view showing a belt used in the embodiment in FIG. 1;

FIG. 3 is an illustrative view showing a state in which transfer paper is supplied to a belt;

FIG. 4 is an illustrative view showing a state in which transfer paper is held between a first layer and a holding section.

FIG. 5 is an illustrative view showing a state in which a leading end of a transfer sheet is released;

FIG. 6 is an illustrative view showing a state in which transfer paper is pulled from a belt;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Transfer paper conveying apparatus 12 ... Image forming apparatus 14 ... Transfer paper 16a-16c ... Photoconductor unit 36 ... Belt 38 ... First layer 40 ... Second layer 46 ... Nipping part 48 ... Sheet feeding apparatus 52 ... Sheet discharging apparatus

Claims (4)

[Claims] 1. A transfer paper transport device comprising a belt for transporting a transfer paper to a photoreceptor, wherein the belt has an annular belt main body rotated by rotating means, and a plate-shaped one end fixed to the belt main body. A transfer sheet transport device, comprising: a holding portion; wherein the transfer sheet is held between the belt body and the holding portion. 2. A first gap forming means for forming a gap between the belt body and the other end of the holding portion by bending the belt body, and formed by the first gap forming means. The transfer paper transport device according to claim 1, further comprising a paper feeding unit that inserts the transfer paper into the gap. 3. A release means for releasing the transfer paper held between the belt body and the holding portion by bending the belt body, and a take-off means for taking off the transfer paper released by the release means. The transfer paper transport device according to claim 1, further comprising: 4. The belt according to claim 1, wherein the belt includes a first layer and a second layer laminated on an outer surface of the first layer, and the holding portion is formed by the second layer. A transfer paper transport device according to any one of the above.