JP2003167413A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase the capacity of a container for a toner that is used in large amount by effectively utilizing a space in an apparatus. <P>SOLUTION: In the image forming apparatus 10 in which four image forming units 20Y, 20M, 20C, and 20K are arranged along an intermediate transfer belt 12 and toners are supplied to the developing units 30 of the image forming units from corresponding toner containers 44Y, 44M, 44C, and 44K, a paper delivery tray 11 provided on the apparatus is inclined upward from a paper delivery roller pair 40 toward the downstream side in the direction of paper delivery, the toner containers 44Y, 44M, 44C, and 44K corresponding to the toners of a plurality of colors are arranged in the apparatus, right below the paper delivery tray 11, and in the direction of paper delivery. Of the four toner containers, the black toner container 44K disposed furthest downstream in the direction of paper delivery has the largest capacity. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tandem type image forming apparatus in which a plurality of image forming portions are arranged along a transfer body such as an intermediate transfer belt.

[0002]

2. Description of the Related Art Conventionally, a tandem type full-color image forming apparatus is known in which four image forming units respectively corresponding to toners of yellow, magenta, cyan and black are arranged side by side along an intermediate transfer belt.

In such a tandem type image forming apparatus, each image forming unit is provided with a developing device, and each developing device is supplied with toner from toner containers of respective colors provided inside the device. There is.

On the other hand, even full-color image forming apparatuses are often used in monochrome mode rather than in color mode. In this case, since the amount of black toner used is larger than that of toner of other colors, it is preferable to make the container for black toner larger than the toner containers of other colors to increase the capacity.

[0005]

However, the space in which each color toner container can be arranged is very limited inside the miniaturized device, and in such a situation, a large toner container can be provided without increasing the size of the device. It is not easy to secure a space for placement.

[0006]

In order to solve the above problems, the present invention provides a plurality of image forming units arranged along a transfer body, and the developing units of the image forming units respectively correspond to the developing units. In an image forming apparatus in which a developer is replenished from a developer container, a paper discharge tray provided on an upper portion of the apparatus is inclined upward from a paper discharge unit toward a downstream side in a paper discharge direction. A plurality of developer containers respectively corresponding to developers of a plurality of colors are arranged side by side in the paper discharge direction inside the device immediately below the paper discharge tray, and the most downstream side of the plurality of developer containers in the paper discharge direction. It is characterized in that the one arranged in the maximum capacity is the maximum capacity.

In the image forming apparatus of the present invention, the maximum capacity developer container may be for black developer.

[0008]

In the image forming apparatus of the present invention, the space under the inclined sheet discharge tray is effectively used to secure the space for arranging, for example, the black developer container having the maximum capacity. This makes it possible to increase the size of the developer container that is used the most without increasing the size of the device. As a result, the frequency of replacement of the developer container that is used the most can be reduced, and Printing cost can be reduced.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a schematic configuration of an image forming apparatus 10 of this embodiment. Image forming apparatus 10
Has an intermediate transfer belt (transfer body) 12 inside. The intermediate transfer belt 12 is laid between two rollers 14 and 16 and is rotationally driven in the direction of arrow A.

Below the intermediate transfer belt 12, four toners (developers) of yellow (Y), magenta (M), cyan (C), and black (K) are respectively provided.
Image forming unit (image forming unit) 20Y, 20M, 20
C and 20K are arranged side by side along the intermediate transfer belt 12.

Each image forming unit 20Y, 20M, 20C,
Each of the photoconductors 20K has a drum-shaped photoconductor 22 that is driven to rotate. Around the photoconductor 22, a cleaning roller 24 for cleaning the surface of the photoconductor 22, a charging roller 26 for uniformly charging the surface of the photoconductor 22, and a uniformly charged photoconductor 22 are arranged in this order along the rotation direction. A developing device 30 that develops an electrostatic latent image formed by exposure 28 with toner to form a toner image on the surface is arranged.
The photoconductor 22, the cleaning roller 24, the charging roller 26, and the developing device 30 are integrated to form the image forming unit 2.
0Y, 20M, 20C and 20K are configured, and the image forming units 20Y, 20M, 20C and 20K are detachable from the image forming apparatus 10, respectively.

A transfer roller 32 is arranged so as to face the photoconductor 22 with the intermediate transfer belt 12 interposed therebetween. The toner image formed on the surface of the photoconductor 22 is primarily transferred onto the intermediate transfer belt 12 by the transfer roller 32.

A secondary transfer roller 34 is pressed against the portion of the intermediate transfer belt 12 supported by the roller 14.
The paper transport path 36 indicated by the alternate long and short dash line starts from a paper feed unit (not shown), and then the secondary transfer roller 34 and the intermediate transfer belt 1
2 through the nip portion between the fixing device 38 and the roller pair of the fixing device 38, and extends to the sheet discharge roller pair (sheet discharge portion) 40.

The paper discharged from the paper discharge roller pair 40 in the paper discharge direction shown by the arrow B is accommodated on the paper discharge tray 11 provided at the upper part of the apparatus. The paper discharge tray 11 has a shape that is inclined upward from the paper discharge roller pair 40 toward the downstream side in the paper discharge direction. Since the paper discharge tray 11 has such a shape, a space 42 that is wider toward the downstream side in the paper discharge direction is formed inside the device below the paper discharge tray 11.

In a space 42 inside the apparatus immediately below the paper discharge tray 11, four toner containers corresponding to yellow (Y), magenta (M), cyan (C), and black (K) toners, respectively. (Developer container) 44Y, 44
M, 44C and 44K are arranged side by side in the paper discharge direction. Cylindrical toner bottle-shaped toner containers 44Y, 44M,
44C and 44K are detachably attached in a lying state, and the corresponding image forming units 20Y and
The developing devices 30 of 20M, 20C, and 20K communicate with each other. Thereby, the toner containers 44Y, 44M, 44
The toners contained in C and 44K are supplied to each developing device 30.

Four toner containers 44Y, 44M, 44
Among the C and 44K, the black toner container 44K disposed on the most downstream side in the paper discharge direction is the other toner container 44Y and 44K.
The bottle has a larger diameter than the M and 44C, and has the maximum capacity. The black toner container 44K, which is larger than the other containers, is used for the inclined sheet discharge tray 1
It can be arranged by utilizing the widened portion of the lower space 42 of No. 1.

Each toner container 44Y, 44M, 44
C and 44K are not limited to cylindrical ones,
The black toner container 44K is replaced by another toner container 44Y, 4
It is sufficient if the capacity is larger than 4M and 44C.

Subsequently, the image forming apparatus 1 having the above structure
The operation of 0 will be described. In the color mode, each image forming unit 20Y, 20M, 20C, 20K operates,
Four-color toner images are formed on the intermediate transfer belt 12 in an overlapping manner. The four-color toner image formed on the intermediate transfer belt 12 is secondarily transferred to the sheet conveyed from the sheet feeding section by the action of the secondary transfer roller 34. Then, the sheet passes through the fixing device 38 to fix the toner image, and then the sheet is discharged onto the sheet discharge tray 11 from the pair of discharge rollers 40.

On the other hand, in the monochrome mode, only the image forming unit 20K operates to form a black toner image on the intermediate transfer belt 12. The black toner image formed on the intermediate transfer belt 12 is secondarily transferred to the sheet conveyed from the sheet feeding section by the action of the secondary transfer roller 34. Then, the sheet passes through the fixing device 38 to fix the toner image, and then the sheet is discharged onto the sheet discharge tray 11 from the pair of discharge rollers 40.

As described above, in the image forming apparatus 10 of this embodiment, the lower space 42 of the inclined paper discharge tray 11 is used effectively to secure the space for disposing the black toner container 44K having the maximum capacity. ing. This makes it possible to increase the size of the black toner container 44K that is used most without increasing the size of the apparatus. As a result, the black toner container 44K needs to be replaced less frequently, and the black toner container 44K can be used in a monochrome mode. Printing cost can be reduced.

In this embodiment, the image forming unit 20
Although the image forming apparatus 10 in which Y, 20M, 20C, and 20K are arranged below the intermediate transfer belt 12 has been described, the present invention is directed to the image forming units 20Y, 20M, 20C, and 2.
The present invention is also applicable to an image forming apparatus in which 0K is arranged on the intermediate transfer belt 12 or an image forming apparatus arranged on both sides of the intermediate transfer belt 12 in between.

In this embodiment, the image forming apparatus 10 using the intermediate transfer belt 12 as the transfer body has been described, but the present invention is applicable to the image forming units 20Y, 20M, 20.
It is also applicable to an image forming apparatus in which a sheet conveyed along C and 20K serves as a transfer body.

[Brief description of drawings]

FIG. 1 is a partial schematic configuration diagram of an image forming apparatus of the present embodiment.

[Explanation of symbols]

10 ... Image forming device, 11 ... Paper discharge tray, 12 ... Intermediate transfer belt (transfer body), 20Y, 20M, 20C, 2
0K ... Image forming unit (image forming section), 22 ... Photoconductor, 2
4 ... Cleaning roller, 26 ... Charging roller, 30 ... Developing device, 32 ... Transfer roller, 40 ... Paper discharging roller pair (paper discharging unit), 44Y, 44M, 44C, 44K ... Toner container (developer container), 46 ... Supply route.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kyoichi Yoshizawa             2-3-3 Azuchi-cho, Chuo-ku, Osaka-shi, Osaka Prefecture             Osaka International Building Minolta Co., Ltd. F term (reference) 2H030 AA06 AB02 AD05 BB38 BB42                       BB63                 2H071 BA27 DA08 DA15 DA24 EA18                 2H077 AA14 AD06 BA10 DB01 DB14                       EA24 GA13

Claims (2)

[Claims] 1. An image forming apparatus in which a plurality of image forming units are arranged along a transfer body, and a developing device of each image forming unit is replenished with a developer from a corresponding developer container. The paper discharge tray provided at the top of the device is inclined upward from the paper discharge section toward the downstream side in the paper discharge direction. A plurality of corresponding developer containers are arranged side by side in the paper discharge direction, and the one of the plurality of developer containers arranged on the most downstream side in the paper discharge direction has the maximum capacity. apparatus. 2. The image forming apparatus according to claim 1, wherein the maximum capacity developer container is for a black developer.