JP2001312111A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device in which transfer paper can be inverted without exposing transfer paper to outside and an inverting part is easily mounted and inspected for maintenance. SOLUTION: In the image forming device in which the transfer paper fed from a paper feeding cassette 17 is fed to a transfer roller 14 by passing the side of a front frame 8 and is ejected to the outside of a device from a pair of paper ejecting rollers 81a and 81b after fixing is performed by a fixing device 80, it is provided with a feeding part 50, an inverting part 60 and a paper ejecting part 40 having a changeover lever 41 to switch whether the transfer paper is ejected to the outside of the device or is fed to the feeding part 50 to transfer an image on the second surface of the transfer paper, and the feeding part 50, the inverting part 60 and the paper ejecting part 40 are respectively utilized, and the housed in a feeding main body 55 attachable/detachable to/from a device main body, a transfer main body and a paper ejecting main body 49.

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 suitable for a copying machine, a printer, a facsimile, and the like.

[0002]

2. Description of the Related Art As an image forming apparatus used in a copying machine, a printer, a facsimile or the like, an electrophotographic apparatus such as a PPC or an LBP is known. Such an electrophotographic apparatus forms an electrostatic latent image on a photoreceptor, develops the image by a developing device to obtain a toner image, and transfers the toner image onto transfer paper. As the transfer paper, plain paper can be used. Therefore, it has been widely spread, and with the spread, a reduction in size and weight has been demanded. In response to this request, the front side can be operated, and a paper feed unit is located at the bottom, and a fixing / discharge unit is located at the top to shorten the transfer paper transport path length and improve operability such as jam clearance. Image forming apparatus that employs a substantially vertical conveyance path
Used in small and medium models.

In recent years, demand for so-called double-sided printing for forming images on both sides of a transfer sheet has been increasing, and the size of the transfer sheet has been reduced by employing the above-described front-side operation and employing a substantially vertical conveyance path. 2. Description of the Related Art An image forming apparatus has been proposed in which double-sided printing is enabled by adding a double-sided apparatus for transferring an image to the reverse side of the reverse side, as disclosed in, for example, JP-A-6-110274. Japanese Patent Application Laid-Open No. Hei 6-110
In the image forming apparatus disclosed in Japanese Patent No. 274, a double-sided apparatus is mounted from the upper part of the apparatus main body to the front front side. In addition, a transfer switching mechanism is provided in front of the paper discharge unit, and the transfer paper re-fed for double-sided printing is conveyed to the upper part of the normal paper discharge unit, where it is switched back and passed through the front of the apparatus. The paper is fed again. At the time of switchback, the transfer paper has a structure in which a part of the transfer paper comes out of the machine.

[0004]

As described above, the image forming apparatus employing the front operation / substantially vertical transport path has a structure in which the front is opened and the operation is performed in the case of jam clearance or supply replacement. In many cases, an operation panel and the like are naturally provided on the front surface. For this reason, Japanese Patent Application Laid-Open
If the double-sided device is mounted on the front side as in the image forming apparatus described in JP-A-110274, the double-sided device may be obstructed when the front side is opened, or may interfere with the above operation. In the image forming apparatus disclosed in JP-A-6-110274, when a part of the transfer paper comes out of the machine at the time of switchback, the user may erroneously make an error because the paper is particularly close to the paper discharge part. There is a concern that a jam may be caused by grasping the transfer sheet that is being reversed, or that the transfer sheet may be caught or pushed out of the sheets stacked on the sheet discharge unit.

[0005] The present invention has been made in view of such a situation of the prior art, and an object of the present invention is to make it possible to reverse the transfer paper without exposing the transfer paper to the outside, and to facilitate image mounting and maintenance inspection of the reversing unit. It is to provide a forming device.

[0006]

In order to achieve the above object, a first means is to transfer a transfer sheet fed from a sheet stacking section located below the apparatus body to an operation section side (front side) of the apparatus body. ), The paper is fed to a printing unit, the transfer paper on which the image is transferred in the printing unit is fixed in a fixing unit located above the apparatus main body, and the paper is discharged from a discharge port above the apparatus main body. In the image forming apparatus, a transport unit that is located substantially perpendicular to a non-operation unit side (back side) of the apparatus main body and transports the transfer paper downward from above, and the transfer paper that is located below the apparatus main body and A reversing mechanism having a reversing mechanism for reversing the transfer paper from the transport unit, and a reversing unit having a transport path for re-transporting the transfer paper to the printing unit; and a reversing unit provided at the discharge port, wherein the transfer from the fixing unit is performed. Eject the paper out of the machine or A paper discharge unit having switching means for switching whether to convey the image to the conveyance unit to transfer the image to the second surface, wherein the conveyance unit, the reversing unit, and the paper discharge unit are respectively detachable from the apparatus main body. It is characterized by being stored in. As described above, since each unit is divided into units such as a paper discharge unit, a conveyance unit, and a reversing unit, which constitute the duplex apparatus, it is easy to mount the image forming apparatus on the main body, and some trouble occurs. When it is done, it can be easily replaced.

[0007] To achieve the above object, a second means is as follows.
The paper discharge unit of the first means includes a cover means whose upper surface serves as a paper discharge tray for the transfer paper, and one end of the cover means is rotatably supported by a housing of the paper discharge unit and rotates. Thereby, the transport path from the paper discharge port to the transport unit is opened, and the operability of the paper jam of the paper discharge unit can be improved by the cover unit.

[0008] To achieve the above object, a third means is as follows.
The paper discharge unit in the first means includes a cover means whose upper surface serves as a paper discharge tray for the transfer paper. The cover means includes the switching means and the paper discharge tray for discharging the transfer paper to the paper discharge tray. One end of the cover means is rotatably supported by a housing of a paper discharge unit, and the rotation of the cover means opens a transport path from the paper discharge port to the transport unit. When the cover unit is rotated, the switching unit and the paper discharge roller are also lifted, so that the jam processing of the paper discharge unit can be performed more efficiently.

In order to achieve the above object, a fourth means is as follows:
The cover means in the second or third means is characterized in that a lower surface thereof constitutes an upper surface of a transport path from the paper discharge port to the transport section. By also using the cover, the number of parts can be reduced and the size of the apparatus can be reduced.

[0010] To achieve the above object, the fifth means includes:
The fixing unit in the first to fourth means is provided with a fixing cover that can be opened and closed at an upper portion on the discharge port side.
Jams generated in the fixing section can be easily removed.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

First, a basic configuration of a color image forming apparatus will be described with reference to FIGS. FIG. 1 is a vertical sectional side view for explaining a basic configuration of a color image forming apparatus according to an embodiment of the present invention, and FIG. 2 is a vertical side view for explaining an upper configuration of the color image forming apparatus of FIG. It is.

In FIG. 1, reference numeral 1 denotes an endless photosensitive belt which is a flexible image bearing member.
It is bridged between the rotating rollers 2 and 3 and is conveyed in the direction of arrow A (clockwise) in the figure by the rotation of the rotating roller 2. In the vicinity of the lower side of the photoreceptor belt 1, a charging charger 4 as charging means for uniformly charging the surface of the photoreceptor belt 1 is provided. The photoreceptor belt 1 further includes a laser optical device 5 of a laser writing system unit serving as an electrostatic image exposure unit, and four developing devices having yellow, magenta, cyan, and black developers (toners) described later. Are provided.

Above the photosensitive belt 1, an intermediate transfer belt 10, which is an intermediate transfer member, is provided. The intermediate transfer belt 10 is laid between rotating rollers 11 and 12,
The paper is conveyed in the direction of arrow B (counterclockwise) in the figure by the rotation of the rotation roller 11. The photosensitive belt 1 and the intermediate transfer belt 10 are in contact with each other at a portion of the rotating roller 3 of the photosensitive belt 1. A conductive bias roller 13 is provided on the intermediate transfer belt 10 side of the contact portion.
Under the predetermined condition.

Thus, after the photosensitive belt 1 is uniformly charged by the charging charger 4, the laser optical device 5
Is scanned and exposed based on the image information, thereby forming an electrostatic latent image on the surface. The image information to be exposed is monochromatic image information obtained by decomposing a desired full-color image into yellow, cyan, magenta, and black color information, and is generated by a semiconductor laser (not shown) in the laser optical device 5 based on this information. The laser beam has been scanned and optical path adjusted by an optical device (not shown).

The electrostatic latent image formed by the photosensitive belt 1 is
Each color image is formed on the photoreceptor belt 1 in order by a single color development using predetermined yellow, cyan, magenta, and black toners by a color developing device 6 which is a rotary developing device described later. That is, each single-color image formed on the photoreceptor belt 1 rotating in the direction of arrow A is synchronized with the photoreceptor belt 1 on the intermediate transfer belt 10 rotating in the direction of arrow B in FIG. Magenta,
For each single color of black and black, transfer is sequentially performed by a predetermined transfer bias applied to the bias roller 13.

The yellow, cyan, magenta, and black images superimposed on the intermediate transfer belt 10 are collectively transferred to transfer paper by a transfer roller 14 serving as a transfer unit. The transfer paper is provided in a bottom portion of the unattended main body, and is stacked in a paper feed cassette 17 which can be pulled out to the front side, that is, the front frame 8 side which is the operator side. Paper cassette 17
A paper feed roller 18 for pulling out transfer papers one by one from the paper feed cassette 17 is disposed above the front frame 8 side. The transfer paper from the reversing unit 60, which will be described later, is placed on the front frame 8 side of the paper feed cassette 17 by the pair of transport rollers 2.
A transport path (not shown) for passing through 1a and 21b is provided.

The transfer paper sent from the paper feed roller 18 is transferred to a pair of transport rollers 21 attached to the front frame 8.
a, 21b, a pair of registration rollers 20a, 20b, and a pair of conveying rollers 19a, 19b, and the sheet is conveyed to the transfer roller 14, which is a transfer section. The transfer roller 14 also has the front frame 8
When the front frame 8 is set so as to cover the front surface of the apparatus main body, it is mounted so as to be in pressure contact with the intermediate transfer belt 10. After the transfer, the transfer paper is fixed by passing between the pair of fixing rollers 80a and 80b in the fixing device 80, and the transfer paper on which the transfer of the full-color image is completed on one side is discharged from the pair of discharge rollers 81a and 81b. You. As described above, the front frame 8 holds the pair of registration rollers 20a and 20b, the pair of conveyance rollers 19a and 19b, the transfer roller 14, and the like, which are part of the conveyance path. Thus, when the front frame 8 is opened, the transfer path of the transfer paper from the paper feed cassette 17 to the transfer roller 14 is opened, and the paper jam can be performed.

As shown in FIG. 2, a cover 82 is provided on the upper portion of a pair of paper discharge rollers 81a and 81b, which are paper discharge ports of the fixing device 80, so as to be openable and closable. This cover 82
Is mounted with one roller 81a of a pair of paper discharge rollers 81a and 81b. When the cover 82 is opened, the space between the pair of paper discharge rollers is opened, and the jam processing in the fixing device 80 can be easily performed. .

A double-sided device is provided after the pair of paper discharge rollers 81a and 81b. In such a double-sided device, the transfer paper discharged from the pair of paper discharge rollers 81a and 81b is discharged to the outside of the apparatus, or the transfer roller is again transferred. 14, the image forming / transferring / fixing step is performed on the second side of the transfer sheet in the same manner as the first side. This double-sided device includes a paper discharge unit 40 provided in the rear of the fixing device 80 in the conveyance direction, that is, an upper rear of the left main body, a conveyance unit 50 provided to extend substantially vertically behind the main body of the device, and a device. It is composed of three units of a reversing part 60 provided so as to extend below the main body, that is, along the bottom.

The paper discharge section 40 includes a pair of paper discharge rollers 81a, 81
b at the outlet side and behind the upper part of the apparatus main body. The paper discharge unit 40 discharges the transfer paper discharged from the pair of paper discharge rollers 81a and 81b through the fixing device 80, and discharges the paper to the paper discharge stack unit 43 or transfers the paper to the second surface. A switching lever 41 for switching the transport direction so that the transport direction is sent to the transport unit 50 for performing
A pair of discharge rollers 42a and 42b for discharging transfer paper from the switching lever 41 to a paper discharge stack 43 formed on the upper surface of the paper discharge unit 40, and the transport unit 50 transports the transfer paper from the switching lever 41. Roller pair 44 for
a, 44b, 56a, 56b, and a guide plate 45 for guiding the transfer paper from the switching lever 41 to the transport section 50 through the transport roller pairs 44a, 44b, 56a, 56b.

The discharge stack 43 is rotatably supported by a pin A, and can be opened as shown in FIG. 1 by turning in the counterclockwise direction. The paper discharge stack 43 is provided at the outlet of the paper discharge unit 40,
A paper ejection tray 43a located almost at the upper rear of the apparatus main body.
A slidable auxiliary tray 43b located below the paper discharge tray 43a, and a guide plate 4 when set.
5 and a lower surface 43c which constitutes the upper part of the transport path to the transport unit 50. A switching lever 41 and a discharge roller pair 42a,
42b and the transport rollers 44b and 56b are attached, and by opening the paper discharge stack section 43, the transport path from the outlet of the pair of paper discharge rollers 81a and 81b to the transport section 50 is opened, and the transfer paper is placed in this transport path. Can be easily removed even if a jam occurs. On the other hand, during use, the auxiliary tray 43b is pulled out from the lower side of the paper discharge tray 43a to the rear outside the apparatus, and the discharge tray 43a and the auxiliary tray 43b hold the entire transfer paper. When not in use, the auxiliary tray 43b is pushed below the paper discharge tray 43a so that the tip of the auxiliary tray 43b does not protrude from the rear of the apparatus. The transport roller 44
The a and 56a and the guide plate 45 are attached to a paper discharge main body 49 of the paper discharge section 40, and the paper discharge main body 49 is detachably mounted to the apparatus main body. The transport unit 50 is a paper discharge unit 40
A transfer main body 55 attached to the apparatus main body, and a transfer cover 54 provided so as to cover the outside, that is, the rear of the transfer main body 55. Three transport roller pairs 52a, 5 for transporting the transfer paper from the paper output unit 40 to the reversing unit 60
2b, 58a, 58b, 59a, 59b,
Therefore, these three pairs of transport rollers 52a, 52b, 58
a, 58b, 59a, 59b, and guide plates 51a, 51b for guiding the transfer paper to the reversing section 60. The lower portion of the transport cover 54 is rotatably attached to a reversing main body 70 of a reversing section 60 described later by a support shaft 53, and the rear opening of the transport main body portion 55 is opened by rotating the support shaft 53 about a fulcrum. Or cover. In the transport cover 54, transport rollers 52a, 58a, 59a and a guide plate 51a are mounted, and in the transport main body 55, the transport rollers 52b, 58b, 59b and the guide plate 51a are mounted.
b is attached. The transport main body 55 is detachable from the apparatus main body, whereby the transport unit 50 is unitized, and only the transport unit 50 can be detached. When the transport cover 54 is opened, the transport rollers 52a,
Roller 52 in which 58a, 59a and guide plate 51a face each other
b, 58b, 59b and the guide plate 51b,
Even if a jam occurs in the transport unit 50, the transfer paper can be easily removed.

The rear part of the transport cover 54 is a discharge tray 43a.
Is located so as to project slightly rearward from the rear end.
Further, in order to prevent interference with the discharge tray 43a and the auxiliary tray 43b when opening and closing the transport cover 54, a slight gap is provided between the upper end of the transport cover 54 and the lower surface of the discharge tray 43a. Is provided. Each transport roller pair 52a, 52b, 58a, 58b, 59a, 59b
Of the transfer rollers 5 attached to the transfer main body 55
At least one of the rollers 2b, 58b and 59b may be constituted by a driving roller.

The reversing unit 60 includes three pairs of transport rollers 6 for transporting the transfer paper from the transport unit 50 to the front frame 8 side.
2a, 62b, 67a, 67b, 68a, 68b and the transfer paper from the transport section 50
2b, 67a, 67b, 68a, 68b, a pair of upper and lower guide plates 61a, 61b, a reversible reversing roller 63, and a pair of upper and lower reversals positioned substantially parallel below the guide plates 61a, 61b. Guide plate 66a,
66b, and a pair of transport rollers 64a and 64b for transporting the transfer paper sent from the reversing roller 63 to the transport path 17b of the paper feed cassette 17. A transport guide plate 65 is elastically pressed against the reversing roller 63, and the transfer paper transported from the transport unit 50 by the transport guide plate 65 is sent out to the reversal guide plates 66a and 66b, and the reversal guide plate 66a , 66b, and guides the transfer paper to be sent to a pair of transport rollers 64a, 64b.

A drive roller 6 capable of reversing rotation is provided in a transfer path of transfer paper between the pair of transfer rollers 68a and 68b and the reversing roller 63.
The driven roller 69a is in contact with the upper portion of the driving roller 69, and the driven roller 69b is also in contact with the lower portion of the driving roller 69. The transfer roller 69 has passed through the guide plates 61a and 61b by the driven roller 69a. The paper is transported to the reversing roller 63, and the transfer paper from the guide plates 66a, 66b is transported to the reversing roller 63 by the driving roller 69 and the driven roller 69b. The components of the above-described reversing unit 60 are housed in the reversing main body 70, and the reversing main body 70 is detachable from the apparatus main body, whereby the reversing unit 60 is also unitized, and only the reversing unit 60 can be detached. It has become. Note that the reversing roller 63 and the driving roller 69 also rotate and their rotation directions are, of course, synchronized.
Further, the transport roller 67a may be a driving roller.

Therefore, the transfer paper conveyed from the conveyance section 50 includes guide plates 61a and 61b, and conveyance roller pairs 62a and 62b, 67a, 67b, 68a and 68b.
Through the drive roller 69 and the driven roller 69a,
Then, the sheet is conveyed to the near side (operator side) through the reversing roller 63. A transfer guide plate 65 is in contact with the reversing roller 63, and the transfer paper is sent to the reversing guide plates 66a and 66b by the transfer guide plate 65 and the reversing roller 63.
When the trailing edge of the transfer sheet passes over the conveyance guide plate 65, the reversing roller 63 and the driving roller 69 are reversed. As a result, the transfer paper, which has been the rear end, is now set as the front end, and the conveyance roller pair 64a, 64
b, and passes through a conveyance path 17b provided on the front side of the sheet feeding cassette 17, and passes through a pair of conveyance rollers 19a, 19a.
b, the sheet is guided to the pair of registration rollers 20a and 20b, and thereafter, the image is transferred to the second surface of the transfer paper through the same process as the first surface, and the transfer paper is discharged so as to be stacked on the discharge stack 43.

As described above, the double-sided device for reversing the transfer paper is provided with the paper discharge section 40 at the upper rear of the apparatus main body, the transport section 50 at the rear of the apparatus main body, and the reverse at the bottom of the apparatus main body. The front frame 8 can be freely opened and closed even when this double-sided device is attached, and jam processing and the like can be easily performed even if the double-sided device is attached. Further, since the paper discharge unit 40, the transport unit 50, and the reversing unit 60 are unitized, by attaching them to the apparatus main body, there is no need to improve the internal structure of the color image forming apparatus as a single-sided machine. It is very easy to change to a color image forming apparatus as a double-sided machine, and maintenance and inspection of each part can be performed very easily.

The timing of the switching of the switching lever 41 and the reverse rotation of the reversing roller 63 and the driving roller 69 in the above-described embodiment may be determined, for example, by using a sensor near the switching lever 41 or the reversing roller 63 and the driving roller 69.
And when the passage of the transfer paper is detected.

[0029]

As is apparent from the above description, according to the first aspect of the present invention, the transporting unit, the reversing unit, and the sheet discharging unit that constitute the double-sided apparatus are unitized, so that the apparatus body is formed. In addition to being easy to mount on the device, even if any portion fails, the portion can be easily replaced, and operability can be improved.

According to the second aspect of the present invention, the transport path from the paper discharge port to the transport section can be opened by rotating the cover means, so that the operability of the paper discharge section during jam clearance is improved. Can be.

According to the third aspect of the present invention, since the switching means and the paper discharge roller are attached to the cover means, the conveyance path from the paper discharge port to the conveyance section can be formed simply by rotating the cover means. The paper discharge section is opened, and the paper discharge section can be processed more efficiently.

According to the fourth aspect of the present invention, the lower surface of the cover means constitutes the upper surface of the transport path from the sheet discharge port to the transport section, and one component is used for multiple functions, so that it can be saved. Cost reduction can be realized by increasing space and reducing the number of parts.

According to the fifth aspect of the present invention, since the fixing portion is provided with the fixing cover which can be opened and closed at the upper portion on the discharge port side, a jam which occurs during the conveyance from the fixing portion to the sheet discharging portion can be easily performed. Can be eliminated.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view for explaining a basic configuration of a color image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a vertical sectional side view for explaining an upper configuration of the color image forming apparatus of FIG. 1;

[Explanation of symbols]

 Reference Signs List 1 photoreceptor belt 5 laser optical device 6 color developing device 8 front frame 10 intermediate transfer belt 14 transfer roller 17 paper feed cassette 40 paper discharge unit 41 switching lever 42a, 42b discharge roller pair 43 paper discharge stack 43a paper discharge tray 43c bottom surface Unit 49 sheet discharging main body 50 conveying unit 51a, 51b guide plate 54 conveying cover 54a supporting member 55 conveying main unit 60 reversing unit 63 reversing roller 70 transfer main unit 80 fixing device 81a, 81b discharging roller pair 82 cover

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Masafumi Takiguchi 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Hirotaka Hatta 1-3-6 Nakamagome, Ota-ku, Tokyo Stock (72) Inventor Hideyuki Takemoto 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh F-term (reference) 2H028 BA06 BA09 BA16 2H071 AA22 AA35 AA38 BA05 BA13 BA27 DA22 DA23 DA24 EA18 3F049 AA04 DB02 LA02 LB03 3F100 AA02 BA23 CA11 CA12

Claims (5)

[Claims] 1. A transfer sheet fed from a sheet stacking section located below the apparatus main body is fed to a printing section through an operation section side of the apparatus main body, and the transfer section on which an image is transferred in the printing section. In an image forming apparatus in which a transfer sheet is fixed in a fixing unit located above the apparatus main body, and is discharged from a discharge port above the apparatus main body, the image forming apparatus is located substantially vertically on a side opposite to the operation unit of the apparatus main body, A transport unit that transports the transfer paper from above to below, and a reversing mechanism that is located below the apparatus main body and reverses the transfer paper. After the transfer paper from the transport unit is reversed, the printing unit is again turned on. A reversing unit having a conveyance path for conveying the transfer paper to the discharge port, and the conveyance unit for discharging the transfer paper from the fixing unit to the outside of the apparatus or transferring an image to a second surface of the transfer paper. To switch to transport to An image forming apparatus comprising: a paper discharge unit having a unit; wherein the transport unit, the reversing unit, and the paper discharge unit are each formed as a unit. 2. The paper discharge section includes cover means whose upper surface serves as a paper discharge tray for the transfer paper, and one end of the cover means is rotatably supported by a housing of the paper discharge section, and is rotatable. The image forming apparatus according to claim 1, wherein a conveyance path from the paper discharge port to the conveyance unit is opened by doing. 3. The discharge unit includes a cover having an upper surface serving as a discharge tray for the transfer paper. The cover includes a switching unit and a discharge tray for discharging the transfer paper to the discharge tray. One end of the cover means is rotatably supported by a housing of a paper discharge unit, and the rotation of the cover means opens a transport path from the paper discharge port to the transport unit. The image forming apparatus according to claim 1, wherein: 4. The image forming apparatus according to claim 2, wherein the lower surface of the cover unit forms an upper surface of a transport path from the sheet discharge port to the transport unit. 5. The image forming apparatus according to claim 1, wherein the fixing unit is provided with a cover capable of opening and closing an upper portion on the discharge port side.