JP2002362807A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of carrying sheets toward a post-processing device while preventing the decrease in the quantity of the stackable sheets. SOLUTION: This image forming device is provided with a sheet discharge member 2 discharging the sheet S after forming the image and a sheet discharge tray 3 storing the discharged sheets S. An image forming part 1 is disposed in a device body 4, while the sheet discharge member 2 and the sheet discharge tray 3 are disposed in a discharge unit 5 detachably attached to the device body 4. A transport unit 6, which is provided with a sheet feed member 7 discharging the sheet S after the image formation, a sheet discharge part 8 storing the discharged sheets S, a transport carrier passage 10 carrying the sheets S toward the post-processing device 9, and a carrier passage changeover member 11 changing over the carrier direction of the sheets S between the side of the sheet feed member 7 and the side of the transport carrier passage 10, is installed replaceably with the discharge unit 5.

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 such as a copying machine, a printer, and a facsimile, and more particularly to an improvement in an image forming apparatus in which a sheet after image formation is discharged upward.

[0002]

2. Description of the Related Art Conventionally, a recording paper discharge section (discharge tray) is provided above an image forming section by, for example, an electrophotographic system, and an image reading section (scanner) is provided above the recording paper discharge section.
There is known an image forming apparatus (for example, a digital electrophotographic copying machine) in which the image forming apparatus is provided. Such an image forming apparatus has an advantage that the arrangement space of the apparatus can be reduced as compared with a mode in which a discharge tray is provided on the side of the apparatus main body.

However, in the case of the type in which the discharge tray is provided above, the sheet discharge port is provided in the upper part of the apparatus, so that the type in which the discharge tray is provided on the side, ie, the sheet discharge port is provided on the side. In comparison with the apparatus, it is difficult to mount a post-processing device such as a sorter, a stapler, a finisher, and the like.

Therefore, for example, Japanese Patent Laid-Open No. 10-69137 proposes a technique in which a sheet material transport unit is mounted on the discharge tray. Here, the sheet material transport unit includes a stack unit for stacking sheets discharged from a discharge port provided in the image forming apparatus main body, and a stack transport unit that transports the discharged sheet material to the stack unit. A post-processing conveying means provided at a lower portion of the stack section for conveying the sheet material to a post-processing apparatus; and a conveying direction for the sheet material discharged from the discharge port, the stack conveying means or the post-processing conveying means. And a branching means for switching to

[0005]

However, according to the above-described technique, the branching means is disposed downstream of the discharge port provided in the upper portion of the image forming main body, so that the height of the sheet conveying unit is reduced. It has to be set to a certain high level, and accordingly, the amount of sheets that can be stacked on the stack unit is reduced, or the space formed between the image reading unit and the stack is narrowed, There was a technical problem that it was difficult to take out the sheet.

SUMMARY OF THE INVENTION The present invention has been made to solve the above technical problems, and an image forming apparatus capable of conveying a sheet to a post-processing apparatus while preventing a decrease in the amount of sheets that can be stacked is provided. To provide.

[0007]

That is, according to the present invention, as shown in FIGS. 1A and 1B, an image forming section 1 for forming an image on a sheet S and a sheet S after the image formation are discharged. A sheet discharge member 2 and a sheet discharge tray 3 that is provided above the image forming unit 1 and stores a sheet S discharged by the sheet discharge member 2; The sheet discharge member 2
And an image forming apparatus in which the sheet discharge tray 3 is disposed in a discharge unit 5 that is detachable from the apparatus main body 4, and includes a transport unit 6 that can be replaced with the discharge unit 5. A sheet feeding member 7 for discharging the sheet S after image formation, a sheet discharging section 8 for accommodating the sheet S discharged by the sheet feeding member 7, a sheet discharging section 8 provided below the sheet discharging section 8, and A transport path 10 for transporting the sheet S toward the processing device 9; and a transport path switching member 11 for switching the transport direction of the sheet S on the sheet sending member 7 side or the transport path 10 side. It is characterized by. FIG. 1A shows a discharge unit 5 in the image forming apparatus.
FIG. 1B shows a state in which the transport unit 6 is mounted on the image forming apparatus and the post-processing apparatus 9 is mounted.
Is connected.

In such technical means, if the image forming section 1 forms an image on the sheet S, it is appropriately selected from various image forming methods such as an electrophotographic method, an electrostatic recording method and an ink jet method. I don't mind.

Further, the sheet discharge member 2 transfers the sheet S on which an image is formed by the image forming section 1 to a sheet discharge tray 3.
Any material may be used as long as it is discharged upward, and usually, for example, a pair of roll members is used. Further, the discharge unit 5 in which the sheet discharge member 2 and the sheet discharge tray 3 are disposed,
It is provided detachably from the apparatus main body 4 and is replaceable with a transport unit 6 described later.

The transport unit 6
Is a sheet sending member 7 for discharging the sheet S after image formation.
A sheet discharging section 8 for storing the sheet S discharged by the sheet sending member 7, and a transport path 10 provided below the sheet discharging section 8 and configured to convey the sheet S toward the post-processing device 9. And a transport path switching member 11 for switching the transport direction of the sheet S on the sheet sending member 7 side or the transport transport path 10 side.

Here, the sheet delivery member 7 may be any member as long as it discharges the sheet S on which an image has been formed by the image forming section 1 onto the sheet discharge tray 3 in the same manner as the sheet discharge member 2. For example, a pair of roll members is used.
Regarding the disposition position of the sheet sending member 7, from the viewpoint of preventing the phenomenon of the sheet stacking amount, the sheet S discharged by the sheet discharging member 2 of the discharging unit 5, the sheet discharging tray 3, It is preferable to set the arrangement position such that the height difference between the sheet and the sheet S delivered by the sheet delivery member 7 of the transport unit 6 and the sheet delivery unit 8 are substantially the same. .

The sheet discharge section 8 preferably has substantially the same shape as the sheet discharge tray 3 of the discharge unit 5 to be replaced. Further, in a type in which the transport member 12 for transporting the sheet S is provided on the transport transport path 10, from the viewpoint of simplification of the configuration, the drive member 12 is provided in the post-processing device 9. It is preferably driven by a source.

The transport unit 6 may be formed integrally, but may be disassembled into a plurality of units.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on an embodiment shown in the accompanying drawings. FIG. 2 is an explanatory diagram showing an embodiment of an image forming apparatus (tandem image forming apparatus) to which the present invention is applied. However, FIG. 2 shows a normal image forming apparatus without a post-processing unit (not shown). In the figure, an image forming apparatus according to the present embodiment includes an image forming unit 22 (specifically, 22a to 22a) of four colors (yellow, magenta, cyan, and black in the present embodiment) in a main body housing 21.
a) a belt unit (belt transport device) including an intermediate transfer belt 230 that is circulated and transported along the direction in which the image forming units 22 are arranged.
23, a recording material supply cassette 24 for accommodating recording materials (sheets, not shown) such as paper sheets is provided below the main body housing 21, and recording from the recording material supply cassette 24 is performed. A recording material conveyance path (conveyance path) 25 serving as a material conveyance path is arranged in the vertical direction.

In this embodiment, the image forming units 22 (22a to 22d) are arranged in order from the upstream side in the circulation direction of the intermediate transfer belt 230, for example, for yellow, magenta, cyan, and black (the arrangement is not limited to this. The toner image is formed in any order (not limited to the order), and includes each photoconductor unit 30, each developing unit 33, and one common exposure unit 40. Here, the photoconductor unit 30 includes, for example, a photoconductor drum 31, a charger (a charging roll in this example) 32 for pre-charging the photoconductor drum 31, and a cleaner 34 for removing residual toner on the photoconductor drum 31. Are integrated into a cartridge.

The developing unit 33 develops the electrostatic latent image formed by exposure on the charged photosensitive drum 31 by the exposure unit 40 with a corresponding color toner (for example, negative polarity in this embodiment). Is what you do. Further, reference numeral 35
(35a to 35d) are toner cartridges for replenishing the respective developing units 33 with the respective color component toners.

On the other hand, the exposure unit 40 includes, for example, four semiconductor lasers (not shown), one polygon mirror 42, an imaging lens (not shown), and each of the photoconductor units 30 in a unit case 41. (Not shown), the light from the semiconductor laser for each color component is deflected and scanned by the polygon mirror 42, and the light image is formed at the corresponding exposure point on the photosensitive drum 31 via the imaging lens and the mirror. Is to lead.

In the present embodiment, the belt unit 23 has an intermediate transfer belt 230 stretched between a plurality of stretching rolls 231 to 234, and corresponds to the photosensitive drum 31 of each photosensitive unit 30. A primary transfer device (primary transfer roll in this example) 51 is provided on the back surface of the intermediate transfer belt 230, and a voltage having a polarity opposite to the charging polarity of the toner is applied to the primary transfer roll 51, so that the photosensitive drum The toner image on the transfer belt 31 is electrostatically transferred to the intermediate transfer belt 230 side.

Further, a secondary transfer device 52 is disposed at a position corresponding to the tension roll 234 on the downstream side of the most downstream image forming unit 22d of the intermediate transfer belt 230, and the primary transfer on the intermediate transfer belt 230 is performed. The image is secondarily transferred (collectively transferred) to a recording material. In the present embodiment, the secondary transfer device 52 includes a secondary transfer roll 521 that is disposed in pressure contact with the toner image bearing surface of the intermediate transfer belt 230.
And a backup roll (also used as a stretching roll 234 in this example) disposed on the back surface side of the intermediate transfer belt 230 and serving as a counter electrode of the secondary transfer roll 521.
Then, for example, the secondary transfer roll 521 is grounded, and a bias having the same polarity as the charged polarity of the toner is applied to the backup roll (stretch roll 234) via a power supply roll (not shown). . Further, a belt cleaner 53 is disposed upstream of the intermediate transfer belt 230 from the uppermost stream image forming unit 22a so as to remove residual toner on the intermediate transfer belt 230.

The recording material supply cassette 24 is provided with a feed roll (not shown) for picking up the recording material. Immediately after this feed roll, a takeaway roll 62 for feeding the recording material is provided. A registration roll (registration roll) 63 for supplying a recording material to the secondary transfer portion at a predetermined timing is disposed in the recording material transporting path 25 located immediately before the secondary transfer portion. On the other hand, a fixing device 66 is provided in the recording material conveying path 25 located downstream of the secondary transfer portion.
A discharge roll (sheet discharge member) 67 for discharging the recording material is provided on the downstream side of the main body 21 so that the discharge recording material is stored in a storage tray (sheet discharge tray) 68 formed on the upper part of the main body housing 21. It has become. In the present embodiment, the discharge roll 67 and the storage tray 68 are provided in the discharge unit 60 that is detachable from the main body housing 21, and a transport unit 70 described later is used.
(See FIG. 3).

FIG. 3 shows a state in which the discharge unit 60 is removed from the image forming apparatus shown in FIG. 2 and the transport unit 70 is mounted. In the present embodiment, as shown in FIGS. 3 and 4, the transport unit 70 includes a paper discharge tray unit (sheet discharge unit) 71 for discharging a recording material after image formation, instead of the storage tray 68. A transport transport path (transport transport path) 72 provided below the discharge tray section 71 and connected to a post-processing device (not shown);
, A feeding roll (sheet sending member) 74 for discharging the recording material provided downstream of the fixing device 66 in place of the discharging roll 67, and the recording material conveying path 25 or The transport transport path 72 has a gate 75 for switching the transport direction of the recording material. Here, each transport roll pair 73 and delivery roll 74
Are driven to rotate by a motor provided in a post-processing device (not shown).

Next, an image forming process of the image forming apparatus according to the present embodiment will be described. Each image forming unit 2
2 (22a to 22d) form the respective color component images (toner images) on the photosensitive drum 31 and sequentially and primarily transfer the respective color component images onto the intermediate transfer belt 230 by the primary transfer roll 51. On the other hand, the recording material is supplied from the recording material supply cassette 24, and is conveyed to the secondary transfer portion via the registration roll 63 at a predetermined timing. Then, the intermediate transfer belt 2
The multi-transferred image primarily transferred onto 30 is conveyed to a secondary transfer portion, and is collectively transferred to a recording material by a secondary transfer device 52. In each image forming unit 22, the residual toner on the photosensitive drum 31 is cleaned by the cleaner 34, while the residual toner on the intermediate transfer belt 230 is cleaned by the belt cleaner 53.

On the other hand, the recording material to which the image has been transferred is discharged after fixing the image which has been collectively transferred via the fixing device 66. Here, in the image forming apparatus illustrated in FIG. 2, the recording material is discharged to the storage tray 68 through the discharge roll 67. On the other hand, in the image forming apparatus shown in FIG.
The conveying direction of the recording material is switched, and the recording material is discharged to the paper discharge tray unit 71 through the sending roll 74, or when not performing post-processing, is not illustrated via the transport conveying path 72 by each conveying roll pair 73. It is transported to a post-processing device.

In this embodiment, when the post-processing device is connected, the discharge unit 60 is detached and the transport unit 70 is mounted.
The height of the apparatus can be reduced as compared with a mode in which a gate is provided on the downstream side of 7. As a result, the recording material can be conveyed toward a post-processing device (not shown) while preventing the phenomenon of the storage amount of the recording material. Further, in a mode in which the scanner unit is mounted above the image forming apparatus according to the present embodiment and used as a copying machine, the space between the scanner and the upper part of the image forming apparatus can be increased,
It is possible to easily take out the recording material.

Further, in the present embodiment, the main paper amount hardly changes before and after the transport unit 70 is mounted. FIG. 5A shows the height difference h between the recording material discharge height (discharge position from the discharge roll 67) of the image forming apparatus (see FIG. 2) to which the discharge unit 60 is mounted and the storage tray 68.
Shows the relationship. FIG. 5B shows a transport unit 70 (and a discharge tray unit 7 attached thereto).
3 shows a relationship between a recording material discharge height (a discharge position from the delivery roll 74) of the image forming apparatus (see FIG. 3) mounted with 1) and a height difference h between the discharge tray unit 71. Reference numeral 100 indicates a post-processing device. In the present embodiment, the delivery roll 7
4 is higher than the height of the discharge rolls 67 so that the height difference h is substantially the same, so that the loading amount of the recording material P is substantially the same in both cases. can do.

In the present embodiment, the transport unit 70 is formed integrally. However, the present invention is not limited to this. For example, as shown in FIG. The first unit 70a having the passage 72 and the second unit 70b having the delivery roll 74 and the gate 75 may be disassembled.

[0027]

As described above, according to the present invention,
Since the discharge unit and the transport unit are exchanged when the post-processing unit is connected, the height of the apparatus can be reduced as compared with a mode in which a transport path switching member is provided downstream of the discharge member. As a result, it is possible to obtain an image forming apparatus capable of conveying a sheet toward a post-processing apparatus while preventing a decrease in the amount of sheets that can be stacked.

[Brief description of the drawings]

FIGS. 1A and 1B are explanatory diagrams illustrating an outline of an image forming apparatus according to the present invention.

FIG. 2 is an explanatory diagram of an embodiment of an image forming apparatus (when a discharge unit is mounted) to which the present invention is applied.

FIG. 3 is an explanatory diagram of an embodiment of an image forming apparatus (when a transport unit is mounted) to which the present invention is applied.

FIG. 4 is an enlarged view of a transport unit and a switching unit.

FIGS. 5A and 5B are schematic diagrams illustrating a relationship between a recording material discharge height before and after a transport unit is mounted and a height difference between a storage tray or a discharge tray unit.

FIG. 6 is an explanatory diagram of a modification of the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Image forming part, 2 ... Sheet discharge member, 3 ... Sheet discharge tray, 4 ... Device main body, 5 ... Discharge unit, 6 ... Transport unit, 7 ... Sheet sending member, 8 ... Sheet discharge part, 9 ... Post-processing Apparatus, 10: transport transport path, 11: transport path switching means, 12: transport member, S: sheet

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) G03G 21/16 H04N 1/00 D 3F054 H04N 1/00 108C 5C062 108 108L G03G 15/00 554 (72) Inventor Yasuo Nakamura 2274 Hongo, Ebina-shi, Kanagawa Prefecture F-Xerox Co., Ltd. F-term (reference) 2C061 AQ06 AR01 AS02 HJ04 HN18 2H071 AA20 AA35 AA39 BA03 BA13 BA27 BA29 CA05 DA23 DA26 2H072 CA01 CB01 FB01 JA02 JA08 3F0LA3A05 LA12 LA12 DA03 EA04 EA05 EC02 ED16 LA02 LA05 LA07 LB03 3F054 AA01 AC02 AC03 AC05 BA04 BC11 DA13 5C062 AA02 AA05 AB32 AB35 AC15 AD06 BA04

Claims (4)

[Claims] An image forming unit that forms an image on a sheet; a sheet discharging member that discharges the sheet after the image is formed; and a sheet that is provided above the image forming unit and that receives the sheet discharged by the sheet discharging member. A sheet discharge tray, wherein the image forming unit is disposed in the apparatus main body, and the sheet discharge member and the sheet discharge tray are disposed in a discharge unit detachable from the apparatus main body. A transport unit that is interchangeable with the discharge unit, the transport unit includes a sheet delivery member that discharges a sheet after image formation, and a sheet that stores the sheet discharged by the sheet delivery member. A discharge section, a transport path provided below the sheet discharge section and configured to convey a sheet toward a post-processing apparatus; An image forming apparatus characterized in that is provided a timber-side or transport path switching member to the transport conveyor path side switches the conveying direction of the sheet. 2. The image forming apparatus according to claim 1, wherein a height difference between a sheet discharged by a sheet discharge member of the discharge unit and the sheet discharge tray, and a sheet discharge member of the transport unit. Wherein the height difference between the sheet discharged from the sheet discharge unit and the sheet discharge unit is set to be substantially the same. 3. The image forming apparatus according to claim 1, wherein
An image forming apparatus in which a transport member that transports a sheet is provided in the transport transport path, wherein the transport member is driven by a driving source provided in a post-processing device. 4. The image forming apparatus according to claim 1, wherein the transport unit can be disassembled into a plurality of units.