JP2001034031A - Sheet material carrying device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain image forming speed and quality of an image for various kinds of sheet material by making a carrying means in a 2nd carrying path function as an intermediate transfer body transferring an image to the sheet material in a 1st carrying path. SOLUTION: After a toner image is formed on photoreceptor drums 111 to 141, it is not transferred to the sheet material but to a carrying belt 150 functioning as the intermediate transfer body. The image successively transferred from the lower drum 111 and formed on the belt 150 is transferred to the sheet material fed from a manual paper feeding tray 161 at a transfer roller 155, and the sheet material passes through a fixing device 170 so that the toner image may be fixed, and is ejected to a paper ejection tray 162. As for carrying in a paper path 21 where a consecutive flow of the sheet material is set as the 1st carrying path, special paper such as cardboard or an envelope is suitably mentioned as the kind of the sheet material where the image is formed, because the sheet material is supplied from the tray 161 installed at an part and the carrying path is almost linear.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet conveying apparatus and an image forming apparatus, and more particularly to a color image forming apparatus employing an electrophotographic system and a sheet conveying apparatus applied to such an image forming apparatus. Related to the device.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus employing an electrophotographic system, a photosensitive drum is charged by a charger, and a light image corresponding to image information is applied to the photosensitive drum to form a latent image. A series of image forming processes, such as transferring an image (toner image) obtained by developing a latent image by a developing device onto a sheet material such as paper, are performed.

On the other hand, with the colorization of images, a plurality of photosensitive drums to be subjected to each of these image forming processes are prepared, and a yellow image, a magenta image, a cyan image, and a color image of a black image are prepared for each photosensitive drum. There is also proposed an image forming apparatus which forms a color image by forming the color image on the sheet material at the transfer position of each photosensitive drum by superposing and transferring the color image on the sheet material.

[0004] Such a color image forming apparatus has an image forming section (image forming station) for each color, which is advantageous for speeding up. In addition, since the conveying path of the sheet material can be configured in a straight line, it can be used for thick paper. It has the advantage of being adaptable to sheet materials such as paper and OHT paper, but has the disadvantage that it requires a toner cartridge for each color, a photosensitive drum, etc., which makes the device larger. Can be

To solve this problem, by arranging the cartridges of each color, the photosensitive drums, and the like vertically so as to be stacked vertically, it is possible to reduce the installation area and achieve a compact configuration. However, in this case, the linearity of the sheet material conveyance path is reduced.

Here, an example of a conventional image forming apparatus will be described with reference to the drawings. First, FIG. 4 shows a structural diagram of a first example of an inline printer as a conventional image forming apparatus.

In the image forming apparatus shown in FIG. 4, a sheet material is conveyed along a paper path 403 by a conveying device 401 in an arrow direction, and a yellow (Y) photosensitive drum 405, a magenta (M) photosensitive drum 407, and a cyan After the image is transferred to the sheet material by the photosensitive drum 409 of (C) and the photosensitive drum 411 of black (Bk), respectively, the fixing device 4
The image is fixed by 13 and discharged.

[0008] As described above, the image forming apparatus shown in FIG. 4 is an example of an in-line color laser printer configured vertically. In this example, the linearity of the transport path (paper path 403) is lost.

On the other hand, as a vertical composition in which the linearity is not lost, a configuration using an intermediate transfer member as shown in FIG. 5 can be considered. FIG. 5 shows a structural diagram of a second example of an inline printer as a conventional image forming apparatus.

In the image forming apparatus shown in FIG. 5, a photosensitive drum 405 for yellow (Y), a photosensitive drum 407 for magenta (M), a photosensitive drum 409 for cyan (C), and a photosensitive drum 411 for black (Bk) are intermediate. Transfer body 50
After the image is temporarily transferred to the sheet transfer member 1, the image on the intermediate transfer body 501 is transferred to a sheet material conveyed along the paper path 503, and then fixed by the fixing device 413.

As described above, in the image forming apparatus shown in FIG. 5, by using the intermediate transfer member 501, the paper path 5
03 linearity is secured.

[0012]

However, in the above-described conventional image forming apparatus, there is a problem that the linearity of the conveying path may be inconsistent with the image forming speed and the image quality of the formed image. have.

That is, for example, the prior art shown in FIG. 4 is an inline color laser printer in which each toner cartridge, photosensitive drum, and the like are vertically arranged, which is advantageous in terms of installation area and image forming speed. Since the linearity of the road is low, it is difficult to ensure stable conveyance of thick paper such as postcards and envelopes. In order to secure this, it is necessary to increase the height of the entire apparatus.

On the other hand, in the prior art shown in FIG. 5, although the linearity of the conveyance path is improved, the intermediate transfer member 501 can be applied to a sheet material such as paper which does not require much linearity.
Therefore, there is a problem that it is difficult to maintain an image forming speed and a high image quality because an image is formed using the image forming method.

The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide a sheet conveying apparatus and an image forming apparatus capable of maintaining the image forming speed and the image quality of an image formed on various sheet materials while securing the linearity of a conveying path. .

[0016]

In order to achieve the above object, a sheet conveying apparatus according to the present invention includes a first conveying path and a second conveying path for conveying a sheet material. Wherein the conveying means for conveying the sheet material in the first conveying path is an intermediate transfer member for transferring an image to the sheet material conveyed in the first conveying path.

Further, the present invention is characterized in that the first transport path is a substantially linear transport path.

Further, image forming means for forming an image directly on the sheet material conveyed in the second conveying path and forming a toner image on the conveying means serving as the intermediate transfer member may be a different type of toner. It is characterized by comprising at least two or more image forming units for forming an image.

Further, the first transport path extends in a substantially horizontal direction, and the second transport path extends in a substantially vertical direction.

Further, in a second transport path which is a transport path for transporting the sheet material in a substantially vertical direction, a transport means for transporting the sheet material, and a sheet abutting on the transport means and stacked along the vertical direction. Further, at least two or more image forming means for directly forming an image on the sheet material conveyed in the second conveyance path, and a substantially straight first conveyance in contact with a substantially vertical end of the conveyance means And a path, wherein the image forming unit transfers the image to the transporting unit, and the transporting unit serves as an intermediate transfer member, and transfers the image to the sheet material being transported in the first transporting path. It is characterized by doing.

Further, the image forming apparatus according to the present invention is characterized in that it comprises fixing means for fixing an image on the sheet material conveyed by the sheet material conveying device.

Therefore, according to the sheet conveying apparatus and the image forming apparatus of the present invention, the first conveying path, which can be a substantially linear conveying path, and the second conveying path, and the second conveying path Since the conveyance unit that conveys the sheet material on the path is an intermediate transfer body that transfers an image to the sheet material conveyed on the first conveyance path, the sheet material conveyed on the second conveyance path includes: The image is directly transferred by the image forming unit, and on the other hand, for a sheet material such as cardboard that requires linearity in the conveyance path, the image is transferred on the first conveyance path by the conveyance means as an intermediate transfer body. Therefore, it is possible to stably perform appropriate image formation on various sheet materials, and to avoid an increase in installation area, a decrease in image formation speed, a decrease in image quality, and the like.

Further, since the image forming means is constituted by at least two or more image forming sections each forming different types of images, it is easy to apply the present invention to, for example, color image formation.

Further, since the substantially straight first transport path extends substantially horizontally and the second transport path extends substantially vertically, the installation area of the apparatus can be effectively reduced. be able to.

[0025]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the dimensions of the components described in this embodiment,
The materials, shapes, relative arrangements, and the like are not intended to limit the scope of the present invention only to them unless otherwise specified.

(First Embodiment) First, a first embodiment of a sheet conveying apparatus according to the present invention will be described with reference to FIG. FIG. 1 shows a structural diagram of a first embodiment of a sheet material conveying device according to the present invention. The sheet material conveying device shown in FIG. 1 is a sheet material conveying device applied to a color laser printer.

However, the sheet conveying apparatus shown in FIG. 1 is also a sheet conveying apparatus provided in the first embodiment of the image forming apparatus according to the present invention. Therefore, hereinafter, the description of the first embodiment of the image forming apparatus according to the present invention also serves as the description of the first embodiment of the sheet material transporting apparatus according to the present invention.

In FIG. 1, reference numerals 110, 120, 130 and 140 denote yellow (Y), magenta (M), cyan (C) and black (Bk) toner cartridges, and 111, 121, 131 and 141, respectively. Photosensitive drums 112, 122, 132 and 1
Reference numeral 42 denotes a sleeve roller that supplies toner to the photosensitive drum of each color. Each of these constitutes an image forming unit.

Further, 113, 123, 133 and 143
Are transfer rollers of each color for transferring toner onto a sheet material, 1
50 is a conveyor belt as a conveying means, 151, 152,
153 and 156 are conveying belt support rollers.

Reference numeral 154 denotes a paper feed roller; 155, a transfer roller for transferring the sheet from the conveyor belt 150 to a thick sheet material;
0 is a cassette for plain paper, 161 is a manual paper feed tray,
162 is a paper discharge tray, and 170 is a fixing device as fixing means.

In the example shown in FIG. 1, the manual paper feed tray 161 is always mounted. However, the present invention is not limited to such a constantly mounted manual paper feed tray 161. A good manual tray may be used.

Next, the operation when the image forming apparatus shown in FIG. 1 forms an image will be described. As a first image forming procedure, first, a toner adhesion pattern latent image is formed on each of the photosensitive drums 111, 121, 131, and 141 by a semiconductor laser.

The sleeve rollers 112, 122, 1
32 and 142 are developed by adhering the toner supplied thereto, and a cassette 160 for plain paper is further provided.
The toner image is transferred onto the sheet material conveyed onto the conveyor belt 150 through the paper feed roller 154 from the printer.

An image formed by transferring images sequentially from the lower photosensitive drum 111 is fixed to a sheet material through a fixing device 170. The sheet material on which the image has been fixed is discharged to a discharge tray 162.

At this time, the transfer roller 155 is
50. A series of flows of the sheet material is set as a paper path 11 as a second conveyance path.

Next, as a second image forming procedure, each of the photosensitive drums 111 and 12 is formed in the same manner as in the first image forming procedure.
After the toner images are formed on 1, 131 and 141, the toner images are transferred onto the transport belt 150 instead of onto the sheet material. That is, the transport belt 150 plays the role of an intermediate transfer member.

An image formed on the transport belt 150 by sequentially transferring images from the lower photosensitive drum 111 is transferred to a sheet material coming from a manual paper feed tray 161 by a transfer roller 155. Then, the image on the sheet material is fixed to the sheet material through the fixing device 170. This sheet material is discharged to a discharge tray 162. A series of flows of the sheet material is used as a first conveyance path, and is referred to as a paper path 21.

The conveyance in the paper path 11 is suitable for plain paper (for example, paper of about 80 g paper) because the sheet material is supplied from a paper feed cassette 160 provided at the lower part.

In the paper path 21, the sheet material is supplied from a manual paper feed tray 161 provided on the upper side,
As shown in FIG. 1, since the transport path has substantially linearity, the type of sheet material on which an image can be formed is suitable for special paper such as thick paper and envelopes.

At the time of printing, the user operates the manual paper feed tray 1
By designating the cassette 61 or the plain paper cassette 160, an image can be formed on a desired sheet material.

As described above, in the first embodiment of the sheet conveying apparatus and the image forming apparatus according to the present invention, the reduction of the installation area is maintained by using the vertical path. The image forming speed and image quality are maintained by forming an image on the path 11, and the image forming is performed on the thick paper by forming the image on the paper path 21 using the transport belt 150 as an intermediate transfer member. Images can be reliably and stably formed on various sheet materials while maintaining speed and image quality.

(Second Embodiment) Next, a second embodiment of the sheet conveying apparatus according to the present invention will be described with reference to FIG. FIG. 2 is a structural view of a second embodiment of the sheet conveying apparatus according to the present invention. The sheet conveying apparatus shown in FIG. 2 is a sheet conveying apparatus applied to a color laser printer.

However, the sheet conveying apparatus shown in FIG. 2 is also a sheet conveying apparatus included in the second embodiment of the image forming apparatus according to the present invention. Accordingly, in the following, the description of the second embodiment of the image forming apparatus according to the present invention also serves as the description of the second embodiment of the sheet material conveying apparatus according to the present invention.

The image forming apparatus shown in FIG. 2 has substantially the same configuration as that of the image forming apparatus shown in FIG. 1, but the positions of the manual paper feed tray 261 and the paper discharge tray 262 are the same as those of the first embodiment. The second embodiment is different from the first embodiment in that the position of the fixing device 270 as a fixing unit is moved to the cartridge side accordingly.

The operation when the image forming apparatus according to the second embodiment forms an image will be described. First, as a first image forming procedure, the toner adhesion pattern latent image is formed by the above-described semiconductor laser into the photosensitive drums 211, 221, and 231 of yellow (Y), magenta (M), cyan (C), and black (Bk). , And 241.

In addition, the toner cartridges 210 and 22
0, 230 and 240 to the sleeve rollers 212 and 22
Develop by depositing the toner provided by 2,232 and 242. Each of these constitutes an image forming unit.

213, 223, 233 and 243
Are transfer rollers of each color for transferring toner onto the sheet material, 2
50 is a conveyor belt as a conveying means, 251, 252,
253 and 156 are conveying belt support rollers.

Then, from the plain paper cassette 260, through the paper feed roller 254, the transport belt 2 as transport means
The toner image is transferred onto the sheet material conveyed onto 50.

Then, an image formed by transferring images sequentially from the lower photosensitive drum 211 is fixed through a fixing device 270. The sheet material on which the image has been fixed is discharged to a discharge tray 262. A series of flows of the sheet material is set as a paper path 281 as a second conveyance path.

Next, as a second image forming procedure, each of the photosensitive drums 211 and 22 is formed in the same manner as in the first image forming procedure.
After forming the toner images on 1, 231 and 241, the toner images are transferred onto the transport belt 250 instead of onto the sheet material.

The last part of the image on the conveyor belt 250 formed by sequentially transferring images from the lower photosensitive drum 211 is
After temporarily stopping near the transfer roller 255, a reverse rotation operation is performed. At this time, the image is transferred to the sheet material synchronously conveyed from the manual paper feed tray 261 by the transfer roller 255. Then, this sheet material is used as the fixing device 2
70, the image is fixed, and
2 is discharged. A series of flows of the sheet material is set as a paper path 291 as a first conveyance path.

The conveyance in the paper path 281 is suitable for plain paper (for example, paper of about 80 g paper) since the sheet material is supplied from the inside of the paper feed cassette 260 provided at the lower part.

In the paper path 291, as shown in FIG. 2, the sheet material is supplied from a manual feed tray 261 provided on the upper side due to its linearity. Suitable for special paper such as.

As described above, according to the second embodiment of the sheet conveying apparatus and the image forming apparatus according to the present invention, the same as the above-described first embodiment of the sheet conveying apparatus and the image forming apparatus according to the present invention. Is obtained, and the user can form an image on a desired sheet material by designating the manual paper feed tray 261 or the plain paper cassette 260 at the time of image formation. It is possible to realize an apparatus that stably forms an image having an optimum image quality on all types of sheet materials while maintaining the area.

(Third Embodiment) Next, a third embodiment of the sheet conveying apparatus according to the present invention will be described with reference to FIG. FIG. 3 shows a structural diagram of a third embodiment of the sheet conveying apparatus according to the present invention. The sheet material conveying device shown in FIG. 3 is a sheet material conveying device applied to a color laser printer.

However, the sheet conveying apparatus shown in FIG. 3 is also a sheet conveying apparatus included in the third embodiment of the image forming apparatus according to the present invention. Therefore, in the following, the description of the third embodiment of the image forming apparatus according to the present invention also serves as the description of the third embodiment of the sheet material conveying apparatus according to the present invention.

A third embodiment of the image forming apparatus according to the present invention will be described with reference to FIG. The main structure is such that the first embodiment is upside down.

More specifically, the positions of the manual paper feed tray 361, the paper discharge tray 362, and the fixing device 370 as a fixing unit move from the upper part to the lower part, and the cassette 360 for plain paper moves from the bottom part to the upper part. The point at which the rotation direction of 350 is in contact with the photosensitive drums 311, 321, 331, and 341 is downward rotation.

Accordingly, the toner cartridge 310,
The order of 320, 330 and 340 is also yellow (Y), magenta (M), cyan (C) and black (Bk) from the top, and the sleeve rollers 312, 322, 33
The rotation directions of the photosensitive drums 2 and 342 and the photosensitive drums 311, 321, 331, and 341 are also determined by the transport belt 350.

313, 323, 333 and 343
Are transfer rollers of each color for transferring toner onto the sheet material, 3
50 is a conveying belt as a conveying means, 351, 352,
353 and 356 are conveying belt support rollers.

Next, the image forming operation of the image forming apparatus shown in FIG. 3 will be described. First, as a first image forming procedure, a toner adhesion pattern latent image is formed on each of the photosensitive drums 311, 321, 331, and 341 by a semiconductor laser.

The sleeve rollers 312, 322, 3
32 and 342 are developed by adhering the supplied toner, and further, the toner image is transferred from the plain paper cassette 360 onto the sheet material conveyed onto the transport belt 350 through the paper feed roller 354. .

An image formed by transferring images sequentially from the upper photosensitive drum 311 is fixed to a sheet material through a fixing device 370. Then, this sheet material is supplied to the discharge tray 3
62 is discharged. At this time, the transfer roller 355 is separated from the transport belt 350. A series of flows of the sheet material is set as a paper path 381 as a second conveyance path.

Next, as a second image forming procedure, each of the photosensitive drums 311 and 32 is formed in the same manner as in the first image forming procedure.
After forming the toner images on 1, 331 and 341, the toner images are transferred not on the sheet material but on the transport belt 350. That is, the transport belt 350 plays the role of an intermediate transfer member.

Then, the image on the transport belt 350 formed by performing the transfer sequentially from the upper photosensitive drum 311 is
The image is transferred to the sheet material coming from the manual feed tray 361 by the transfer roller 355. After the transferred sheet material passes through the fixing device 370 and the image is fixed, the sheet material is discharged to a discharge tray 362. A series of flow of the sheet material is set as a paper path 391 as a first conveyance path.

The conveyance in the paper path 381 is suitable for plain paper (for example, paper of about 80 g paper) because the sheet material is supplied from the inside of the paper supply cassette 360 provided at the upper part.

In the paper path 391, as shown in FIG. 3, due to its linearity, the sheet material is supplied from a manual paper feed tray 361 provided at the lower part, and the type of sheet material on which an image can be formed is as follows. Suitable for special paper such as cardboard and envelopes.

At the time of image formation, the user can form an image on a desired sheet material by designating the manual paper feed tray 361 or the cassette 360 for plain paper.

As described above, according to the third embodiment of the sheet conveying apparatus and the image forming apparatus according to the present invention, the same effects as those of the first embodiment can be obtained, and the image forming speed can be maintained. In addition, it is possible to stably form an image having an optimum image quality on various types of sheet materials.

[0070]

As described above, according to the present invention,
In the conveying means for conveying the sheet material in the second conveying path,
By giving the characteristics of the intermediate transfer member, the thick sheet material is transported through the first transport path which can be a substantially linear transport path,
For sheet materials that do not require linearity in the transport path, the second
Can be conveyed, and without sacrificing image formation speed and installation area, maintaining the linearity of the conveyance path and stabilizing the image quality of images for various types of sheet materials. A sheet material conveying device and an image forming device that can be formed can be provided.

[Brief description of the drawings]

FIG. 1 is a structural diagram of a first embodiment of a sheet conveying apparatus according to the present invention.

FIG. 2 is a structural diagram of a second embodiment of the sheet conveying apparatus according to the present invention.

FIG. 3 is a structural diagram of a third embodiment of a sheet conveying apparatus according to the present invention.

FIG. 4 is a structural diagram of a first example of an inline printer as a conventional image forming apparatus.

FIG. 5 is a structural diagram of a second example of an inline printer as a conventional image forming apparatus.

[Explanation of symbols]

 11, 21 Paper path 110, 120, 130, 140 Toner cartridge 111, 121, 131, 141 Photosensitive drum 112, 122, 132, 142 Sleeve roller 113, 123, 133, 143 Transfer roller 150 Conveying belt 151, 152, 153 Conveying Belt support roller 154 Feed roller 155 Transfer roller 156 Conveyor belt support roller 160 Cassette 161 Manual feed tray 162 Discharge tray 170 Fixing device 210, 220, 230, 240 Toner cartridge 211, 21, 21, 231, 241 Photosensitive drum 212, 222 , 232, 242 Sleeve roller 213, 223, 233, 243 Transfer roller 250 Conveying belt 251, 252, 253 Conveying belt support roller 254 Feed roller 255 Transfer roller 25 Conveyor belt support roller 260 Cassette 261 Manual feed tray 262 Discharge tray 270 Fixing device 281,291 Paper path 310,320,330,340 Toner cartridge 311,321,331,341 Photosensitive drum 312,322,332,342 Sleeve roller 313, 323, 333, 343 Transfer roller 350 Conveyor belt 351, 352, 353 Conveyor belt support roller 354 Paper feed roller 355 Transfer roller 356 Conveyor belt support roller 360 Cassette 361 Manual feed tray 362 Paper discharge tray 370 Fixing device 381, 391 Paper path 401 Transport device 403 Paper path 405, 407, 409, 411 Photosensitive drum 413 Fixing device 501 Intermediate transfer body 503 Paper path

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H030 AA06 AB02 AD05 BB23 BB42 BB44 BB46 BB53 2H032 AA05 BA09 BA18 BA19 BA23 CA12 2H072 AA36 AB06 BA01 CA07 3F049 BA00 DA04 LA02 LB03

Claims (6)

[Claims] A first conveying path for conveying the sheet material and a second conveying path for conveying the sheet material;
Wherein the conveying means for conveying the sheet material in the second conveying path is an intermediate transfer member for transferring an image to the sheet material conveyed in the first conveying path. Sheet material transport device. 2. The sheet conveying apparatus according to claim 1, wherein the first conveying path is a substantially linear conveying path. 3. An image forming means for forming an image directly on a sheet material conveyed in the second conveyance path and forming a toner image on a conveying means serving as the intermediate transfer body, wherein each of the image forming means comprises a different type of toner. 3. The sheet conveying apparatus according to claim 1, wherein the sheet conveying apparatus includes at least two image forming units that form an image. 4. The apparatus according to claim 1, wherein the first transport path extends in a substantially horizontal direction, and the second transport path extends in a substantially vertical direction. The sheet material conveying device according to the item. 5. A transporting means for transporting the sheet material in a second transporting path, which transports the sheet material in a substantially vertical direction, and the transporting means is in contact with the transporting means and is stacked along the vertical direction. Further, at least two or more image forming means for directly forming an image on the sheet material conveyed in the second conveying path, and a substantially linear first contacting a substantially vertical end of the conveying means.
Wherein the image forming means transfers an image to the conveying means, and the conveying means serves as an intermediate transfer member, and the image is transferred to a sheet material conveyed in the first conveying path. A sheet material conveying device for transferring a sheet. 6. An image forming apparatus comprising a fixing unit for fixing an image on the sheet material conveyed by the sheet material conveying apparatus according to claim 1. Description: