JP3094250B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet recording paper feeder in an image forming apparatus such as a copying machine or a printer, and more particularly to an arrangement of a plurality of paper feed trays of a front loading type paper feeder. It is.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine or a printer, sheet-like recording paper stacked on a paper cassette which can be pulled out or a large-capacity recording paper feeding tray having a paper feeding table elevating means. A paper feeder is provided for sequentially taking out (transfer paper and the like) one sheet at a time from the top or bottom and sending it to an image recording unit or the like.

For example, in order to transfer a toner image formed on an image forming body onto a transfer material in a timely manner, recording paper conveyed from a paper feed cassette via a pickup roller and a feed roller is previously hit against a registration roller and loosened. The registration rollers are driven in synchronization with the scanning start operation of the optical system for reading the document information, and the recording paper is nipped and conveyed to the transfer area.

[0004] An automatic double-sided recording function (ADU) that enables image recording on both sides of a recording sheet, and an automatic multiple recording function (RAD).
In the image forming apparatus provided with U), an intermediate stack tray or a recording paper re-feeding device for temporarily storing recording paper on which one-side recording has been performed is generally provided below the image forming unit. The recording paper is fed, separated and fed, and conveyed. The paper feed cassette and the large-capacity recording paper feed tray are conventionally mounted on the side of the copying machine main body and can be detached or moved. For this reason, not only a large operation space is required on the side of the copying machine main body, but also there is a problem in operability.

[0005] In recent years, many front-loading-type sheet feeding devices that allow a sheet feeding cassette or the like to be pulled out from the near side of an operator have been put into practical use. In this type of paper feeder,
Although a plurality of paper cassettes are arranged in tandem below the main body of the copier, the height is limited due to the operability of the copier.
The number of paper feed cassettes is generally three or four.

On the other hand, according to user needs, a plurality of types of paper cassettes, a large-capacity recording paper feed tray (LCT), an automatic duplex recording function (ADU), and the like are provided to use recording papers of various sizes. There is a demand for a multifunctional copying machine.

[0007]

In order to meet the above-mentioned market demands for increasing the capacity of the paper feed tray and increasing the number of paper feed cassettes, the frequency of replacement of the paper feed cassettes is increased and the operability is reduced. There are problems such as a problem and an increase in the size of the copying machine body.

If a plurality of paper feed trays are to be arranged in tandem, a space for jam paper processing and a space for a vertical transport section necessary for each paper feed tray are required, and the size of the copying machine becomes large.

[0009]

According to the present invention, a plurality of paper cassettes which can be pulled out toward the front of the image forming apparatus main body and a large-capacity recording paper feed tray of the same type are provided below the main body of the image forming apparatus. By arranging them in two rows, the objective is to improve the operability of replenishing the recording paper, to integrate the various paper feed trays, to reduce the size of the image forming apparatus main body, and to facilitate the paper jam processing. It is.

The above object can be solved by the following constitution. (1) Image forming means for forming an image on recording paper, fixing means for fixing an image formed on recording paper,
In an image forming apparatus having a recording paper transport path and a plurality of recording paper storage means for storing recording paper, and capable of forming a double-sided image, the plurality of recording paper storage means is provided in a main body of the image forming apparatus. A first recording paper storage means and a second recording paper storage means are provided below the image forming means and arranged in two rows on the left and right, so that the first recording paper storage means and the second recording paper storage are provided. The recording papers stored in the first recording paper storage means and the second recording paper storage means are respectively disposed at the center of the apparatus. A paper feed mechanism is provided corresponding to each of the first recording paper storage means and the second recording paper storage means so that the recording paper can be sent out in the opposite direction. The first
A first conveyance path for guiding the recording paper sent from the recording paper storage means to the fixing means via the image forming means, and a recording paper sent from the second recording paper storage means via the image forming means; A second conveyance path for leading to the fixing unit, and a recording sheet on which an image formed on the front surface is fixed, the front and back of which are formed to form an image on the back surface,
A re-conveying path for conveying the sheet under the image forming means in a substantially horizontal direction, and then guiding the sheet to the fixing means again via the image forming means; the first conveying path and the second conveying path And a downstream side thereof is defined as a common transport path, and the common transport path is an upstream side in the transport direction of the recording paper from the image forming unit and a portion which is transported in a substantially horizontal direction of the re-transport path. And an image forming apparatus having a common downstream side.

(2) The image forming apparatus according to (1), wherein paper is fed from the plurality of recording paper storage units in a direction substantially perpendicular to a long side of the recording paper size. .

[0012]

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the accompanying drawings.

FIG. 1 is an overall configuration diagram including an optional device of an image forming apparatus (copier) to which the sheet feeding device of the present invention is applied. In the figure, reference numeral 1 denotes an automatic document feeder (AD
F), 2 is a scanning exposure optical system, 3 is an image forming unit, 4 is a recording paper supply unit (paper supply unit), 5 is a recording paper transportation unit, 6 is a fixing unit, 7 is a paper discharge reversal switching transportation unit, 8 Is a double-sided recording paper transport unit (ADU), 9 is a second recording paper supply unit,
A sorter 10 sorts and arranges recording paper discharged from the copying machine body. The dashed line in the figure indicates recording paper (transfer paper).
5 shows the transport path of S. FIG. 2 is an enlarged sectional view of a main part of the recording paper conveying means of the copying machine. The upper body of the copier includes a scanning exposure optical system 2 disposed below the platen glass 21;
Charger 32 around photoreceptor drum (image carrier) 31, developer 3
3, an image forming unit 3 including a transfer unit 34, a classifier 35, and a cleaning device 36; a recording sheet conveying unit 5 for conveying a recording sheet on which an image is formed by a belt; a fixing unit 6; And a double-sided recording paper transport unit (ADU). The lower main body of the copying machine is a paper supply unit in which a plurality of recording paper supply means (paper supply devices) 4A, 4B, 4C, and 4D are arranged. Note that the paper feeding devices 4A, 4B, 4
As shown in the plan view of FIG. 3, the recording papers S1 and S2 fed by C and 4D are all arranged so that the periphery of the recording paper is orthogonal to the arrowed paper feeding direction. 4A1 (4B1, 4C1) and the paper feed tray 4D1 are positioned and accommodated on one side reference (BL).

On the right side of the lower part of the copying machine main body, three-stage paper feeders 4A, 4B and 4C are provided. The paper feed cassette 4A1 can be pulled out to the operator's front side at the time of replenishing the recording paper in the upper paper feed device 4A. Similarly, a paper feed cassette 4B1 is mounted on the middle paper feed device 4B, and a paper feed cassette 4C1 is mounted on the lower paper feed device 4C so as to be able to be pulled out. These paper cassettes 4A1, 4B
1 and 4C1 have almost the same structure except that the height and the partition plate are different from each other according to the number of sheets of the recording paper S1 to be stored. The paper means will be described.

The upper paper feeder 4A is provided with a paper feed table 4A2 for storing the paper feed cassette 4A1 at a predetermined position and fixing it.
A cassette unit including a movable bottom plate 4A3 in the housing of the sheet feeding cassette 4A1, a push-up lever 4A4 for pushing up the movable bottom plate 4A3 so as to be able to vibrate, a vibration shaft 4A5 for driving the push-up lever 4A4 to vibrate, and driving means (not shown). And a paper feed mechanism including a pickup roller 4A6, a feed roller 4A7, a reverse roller 4A8, a transport roller 4A9, and the like. The middle sheet feeder 4B and the lower sheet feeder 4C have the same configuration as the above-mentioned upper sheet feeder. Since these sheet feeders are well-known sheet feed mechanisms, detailed description thereof will be omitted. The paper feeders 4A, 4B, and 4C store large-size recording paper of a maximum size A3 (or 11 ″ × 17 ″).

The feeding direction of the recording paper S1 by each of the paper feeding devices 4A, 4B, and 4C is directed to the center of the copying machine main body on the left side in the figure, and the recording paper S1 conveyed from each paper feeding device is , The guide plate 41 and the intermediate conveyance rollers R4 and R3 of the copying machine main body, the conveyance is carried out substantially vertically, and further, the intermediate stack tray in the double-sided recording paper conveyance means (ADU) 8 provided in the upper main body of the copying machine. It is conveyed horizontally to the right in the figure by conveying rollers R81, R82 and R83 provided below, and further rises again to follow the conveying path leading to the registration roller R1 via the intermediate conveying roller R2.

On the downstream side in the paper feeding direction by the three-stage paper feeding devices 4A, 4B, and 4C, further to the left in the drawing,
A large-capacity recording paper feed tray (LCT) 4D1 capable of storing 3000 sheets of recording paper S2 is positioned and arranged on the elevating paper feed table, and can be pulled out toward the operator when replenishing recording paper. The LCT has a maximum size A
4 size (or 8.5 "x 11") small size recording paper is stored.

A paper feed mechanism similar to the paper feed mechanism (4A6 to 4A9) is provided above the large-capacity recording paper feed tray 4D1, and the recording housed in the paper feed tray 4D1 is provided. The paper S2 is fed from the upper layer to the right side in the figure. The fed recording paper S2 rises vertically and joins the recording paper transport paths of the three-stage paper feeders 4A, 4B, and 4C, and thereafter, the above-described double-sided recording paper transport means (ADU). 8, a common transport path from the horizontal transport path formed by the transport rollers R81, R82 and R83 to the registration roller R1 via the intermediate transport roller R2.

On the right side of the copying machine main body, a second recording paper supply means 9 can be connected, and a three-stage paper supply device 9 is provided.
A, 9B and 9C make it possible to feed a large amount of about 4500 sheets. The three paper feed trays of these paper feeders can also be pulled out toward the operator when recording paper is replenished. The recording paper S3 sent out from the paper supply tray by the paper supply means is conveyed to the upper main body of the copying machine via the intermediate conveyance roller R9,
It reaches the registration roller R1 via the intermediate conveyance roller R2.

A paper feed passage formed by a pair of fixed / movable guide plates 41 and two pairs of intermediate transport rollers R3, R4 provided on the left side of the three-stage paper feeders 4A, 4B, 4C in the drawing. When the paper jam (jam) occurs in the recording paper S1, the movable guide plate 41 and the driven rollers R3 and R4 supported by the movable guide plate 41 are opened to the left to open the paper feed passage, and the jammed paper is removed. remove. When the movable guide plate is opened, an unobstructed space is formed on the left side of the lower body of the copying machine in the drawing, that is, on the right side of the large-capacity recording paper feed tray (LCT) 4D1. By sufficiently opening the plate 41, the inspection of the paper feed passage and the jam clearance can be easily performed.

The large-capacity recording paper feed tray (LC
T) 4D1 on the right side of the drawing shows that there is no need to provide an intermediate conveyance roller or a guide plate for the LCT.
D1 and the three-stage paper cassette 4A1, 4B1, 4C
Since the gap with 1 can be approached except for a common paper supply space, the copier body can be made compact.

[0023]

As described above, according to the present invention, a plurality of paper feed cassettes which can be pulled out toward the front of the image forming apparatus main body and a large capacity recording paper feed tray are provided below the main body of the image forming apparatus. , And the recording paper is sent out toward the center of the apparatus.
The size of the main body of the image forming apparatus and the simplification of paper jam processing are achieved.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an image forming apparatus to which a multi-sheet feeding device of the present invention is applied.

FIG. 2 is an enlarged cross-sectional view of a main part of a recording paper conveying unit of the image forming apparatus.

FIG. 3 is a plan view showing positioning of a recording sheet size and a conveying direction.

[Explanation of symbols]

3 Image forming means 31 Photoreceptor drums 4A, 4B, 4C, 4D Recording paper supply means (paper feeder) 4A1, 4B1, 4C1 Paper feed cassette 41 Guide plate 4D1 Large capacity recording paper feed tray (LCT) 8 Double-sided recording Recording paper transport means (ADU) 81 Intermediate stack tray 9 Second recording paper supply means 9A, 9B, 9C Paper feeder R1 Registration rollers R2, R3, R4, R81, R82, R83, R9 Intermediate transport rollers S, S1, S2, S3 recording paper

Claims (2)

(57) [Claims] An image forming means for forming an image on a recording sheet;
An image forming apparatus that includes a fixing unit that fixes an image formed on a recording sheet, a recording sheet conveyance path, and a plurality of recording sheet storage units that store the recording sheet, and that enables double-sided image formation; Recording paper storage means is provided with a first recording paper storage means and a second recording paper storage means arranged in two rows on the left and right below the image forming means so as to be accommodated in the main body of the image forming apparatus; The first recording paper storage means and the second recording paper storage means are configured to be independently pullable toward the front of the image forming apparatus main body, and the first recording paper storage means, the second recording paper A paper feed mechanism corresponding to each of the first recording paper storage means and the second recording paper storage means, so that the recording paper stored in the storage means can be sent out in a direction facing each other toward the center of the apparatus. Department is provided, The recording paper transport path includes a first transport path for guiding the recording paper sent from the first recording paper storage means to the fixing means via the image forming means, and a recording paper transport path which is sent from the second recording paper storage means. A second transport path for guiding the recording paper that has passed through the image forming unit to the fixing unit, and turning the recording paper on which the image formed on the front surface is fixed to form an image on the back surface. And a re-conveying path for conveying the sheet under the image forming unit in a substantially horizontal direction, and then guiding the sheet to the fixing unit again via the image forming unit. The first conveying path and the second conveying The paths merge and a downstream side thereof is used as a common transport path. The common transport path is an upstream side in the transport direction of the recording paper from the image forming unit and is transported in a substantially horizontal direction of the re-transport path. Merge into the part An image forming apparatus, wherein the downstream side is commonly configured. 2. The image forming apparatus according to claim 1, wherein the paper is fed from the plurality of recording paper storage units in a direction substantially perpendicular to a long side of the recording paper.