JP3323251B2 - Color image forming equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention is used for a color printer, a color facsimile, a color copying machine, etc.
An intermediate transfer member, have one of the image carrier, the image carrier
An electrophotographic color image forming apparatus in which a plurality of developing devices are arranged around a body .

[0002]

2. Description of the Related Art Conventionally, various proposals have been made regarding the configuration of an electrophotographic color image forming apparatus having one intermediate transfer belt and one photosensitive belt. For example, in Japanese Patent Application Laid-Open No. 62-182766, the peripheral ratio of the photosensitive belt to the intermediate transfer belt is set to 2: 1, and a plurality of developing devices are installed on the upper surface where the photosensitive belt is horizontally arranged. There is disclosed a color image forming apparatus in which a transfer belt is disposed substantially perpendicular to one end surface of a photoreceptor belt, and a transfer path for transfer paper is placed below the intermediate transfer belt and the photoreceptor belt. In JP-A-4-5669, a photoreceptor belt is set up vertically, a multicolor developing device is provided on one side, and a black-and-white developing device and a discharging unit, a cleaner, and a writing unit are provided on the other side. There is disclosed a color image forming apparatus in which belts are arranged orthogonally and a transfer path of transfer paper is placed below the intermediate transfer belt. In Japanese Patent Application Laid-Open No. Sho 63-292156, a peripheral ratio of the photoreceptor belt to the intermediate transfer belt is set to 2: 1, and a plurality of developing devices are installed on the upper surface where the photoreceptor belt is arranged obliquely.
There is disclosed a color image forming apparatus in which an intermediate transfer belt is disposed at a lowermost end surface of a photoreceptor belt, and a transfer path of a transfer sheet is positioned below the intermediate transfer belt. In JP-A-3-249671, the peripheral ratio of the photosensitive belt to the intermediate transfer belt is set to 1: 1, the photosensitive belt is arranged vertically, and a plurality of developing devices are installed on one side of the photosensitive belt. And
There is disclosed a color image forming apparatus in which an intermediate transfer belt is arranged obliquely on the uppermost end surface of a photoreceptor belt, and a transfer path of a transfer sheet is placed below the intermediate transfer belt. further,
In U.S. Pat. No. 4,956,676, a photoreceptor belt is disposed vertically, a plurality of developing units are installed on one side of the photoreceptor belt, an intermediate transfer belt is disposed horizontally on the uppermost end surface of the photoreceptor belt, and transfer of transfer paper is performed. A color image forming apparatus in which a passage is placed above an intermediate transfer belt (also serving as a conveyance belt) is disclosed.

[0003]

However, in the above-described conventional color image forming apparatus, the size of the entire apparatus tends to increase as the structure of the apparatus becomes more complicated.
At the time of maintenance, there has been a problem in that operability is deteriorated such that the developer or the toner is scattered to cause color mixture, and it is not easy to replace the photosensitive member or the intermediate transfer belt. There is also a problem that transferability of transfer paper and operability at the time of paper jam (jam) are deteriorated. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a color image forming apparatus which solves the above-mentioned conventional problems, is easy in maintenance and processing in the case of paper jam, has high reliability, is more compact and has a simple configuration. I have.

[0004]

The gist of the present invention is that in a color image forming apparatus, an image forming apparatus main body, an image carrier, and an electrostatic latent image corresponding to each color image on the image carrier. A multicolor developing means for applying a plurality of color developing agents arranged around the image carrier on the image carrier, and a length of at least twice the circumference of the image carrier. of the <br/> intermediate transfer body detachable with respect to the image forming apparatus main body Chi lifting the circumference, and accommodating the transfer sheet for transferring the toner image detachable paper feed cassette to the image forming apparatus main body When, and a cover body versus pre Symbol intermediate transfer member by the opening is detachable, the before and Symbol intermediate transfer member and the sheet feed cassette detachably from the same surface of the image forming apparatus main body, In addition, the paper feed cassette does not exist on the open path of the cover. To, certain and pre-Symbol intermediate transfer member and the paper feed cassette that was placed at a predetermined vertical position. Also,
A transport path for transporting the transfer paper and a transport path cover for exposing the transport path are provided. The image forming apparatus further includes a fixing unit unitized for fixing the toner image on the transfer paper, and a fixing cover for opening and closing when the fixing unit is attached to and detached from the image forming apparatus main body. Further, the latent image forming means is provided below the multicolor developing means. Further, the latent image forming means is provided directly on the main body base of the image forming apparatus main body.

[0005]

The size of the image carrier can be reduced in the relation of an integer ratio as compared with the intermediate transfer member, so that the size and cost of the apparatus can be reduced.
In particular, by setting the ratio to an integer, the occurrence of displacement can be prevented. Before against the body's rating intermediate transfer member is removable by opening the cover. Detachably as before Symbol intermediate transfer member and the sheet feed cassette from the same surface of the image forming apparatus main body, and, as the paper feed cassette on the opening path of the cover is not present, the previous SL intermediate transfer member since the said paper feed cassette is disposed at a predetermined vertical position, it can be attached and detached in the middle between the transfer member without being bothered by the sheet feeding cassette, thereby facilitating the maintenance process. A transport path for transporting the transfer paper;
Since a transport path cover for exposing the transport path is provided, a paper jam can be easily handled. Further, since the fixing unit includes a unitized fixing unit for fixing the toner image on the transfer paper and a fixing cover for opening and closing when the fixing unit is attached to and detached from the image forming apparatus main body, maintenance of the fixing device is reduced. Easy to do. Further, since the latent image forming means is provided below the multicolor developing means, the apparatus becomes more compact. Further, since the latent image forming means is directly installed on the main body base of the apparatus main body, the latent image forming means is hardly affected by vibration from the developing device and other movable parts.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. It is widely known that there are one-component and two-component development systems as development systems. The one-component development method does not have a carrier, so that control of developer concentration and stirring are not required,
The device has the advantage of being simple and compact. There are two types of this one-component development system, a magnetic toner type and a non-magnetic toner type. For color, a non-magnetic toner type having excellent color reproducibility of the toner is used. It is not suitable for a high-speed machine or a device for a user who makes a large number of copies in a short time. The magnetic toner type is used for black and white.

On the other hand, the two-component developing system has a drawback that the apparatus becomes complicated and large, but is suitable for high-speed and large-volume copying. Therefore, the following examples all use a non-magnetic one-component developing system . FIG. 1 shows a basic configuration example of the present invention . In the figure, the main components are a writing unit 30 serving as a latent image forming unit for performing image exposure 3 by a laser beam on a photosensitive belt 1 serving as an image carrier, and a Y unit.
(Yellow) developing device 101Y, M (magenta) developing device 1
01M, C (cyan) developing device 101C, B (black)
The intermediate transfer belt unit 200 to re-transfer the color-developing-unit 100, to form a toner image on the intermediate transfer belt 201 is a medium between the transfer member transfer sheet 40 for multi-color developed by the developing unit 101B, to fix the toner image Fixing unit 3
00. The multicolor developing unit 100 is provided close to the vertical flat surface of the photoreceptor belt 1, and its developing units 101Y, 101M, 101C, and 101B have the same component configuration, and the developing sleeves 102Y, 102M, 1
02C, 102B, supply rollers 103Y, 103M,
103C, 103B and developing blades 104Y, 104
M, 104C, 104B and stirring members 105Y, 105
M, 105C and 105B.

The photoreceptor belt 1 includes a driving roller 7,
It is supported by the driven roller 8 and the supporting roller 4,
A static eliminator 6 and a charger 2 are provided near the periphery thereof, and a photosensitive member cleaner 5 as a cleaning means is provided integrally with the collected toner tank 207 at one end. An OPC system is usually used for the photosensitive belt 1. The intermediate transfer belt unit 2 is located above the photoreceptor belt 1.
And an intermediate transfer belt 201 constituting the intermediate transfer belt unit 200 includes a driving roller 205
a, a support roller 205b, and first bias rollers 202a and 202b, which are intermediate transfer means for applying a primary bias voltage.
02b (202 is a primary transfer unit), an intermediate transfer belt cleaner 206 that cleans the intermediate transfer belt 201 in the vicinity of the drive roller 205a, and a transfer unit that applies a secondary bias voltage , A second bias roller 204 (203 is a secondary transfer unit).

Further, the transfer paper 4
The transfer position at which the toner image is transferred to the drive roller 205 is an end roller that supports the intermediate transfer belt 201.
It is provided near a. The material of the intermediate transfer belt 201 has a surface resistivity of 1 based on polycarbonate, polyester, urethane rubber, non-plasticized vinyl chloride or the like.
It is desirable to have a resistance of 0 ⁸ to 10 ⁹ Ω, and seamlessness is advantageous for productivity of printing speed and compactness of the apparatus. Also, the circumference of the belt must be longer than the maximum print size. The circumferential length of the photoreceptor belt 1 and the circumferential length of the intermediate transfer belt 201 are the same, and the outer diameter of the drive roller 205a and the outer diameter of the drive roller 7 are the same. Has been prevented. The transfer paper 40 is stored in a paper feed cassette 41, and a paper feed roller 42 and a registration roller 43 are arranged to pull out the transfer paper 40 one by one. Also, a manual paper feed port 45 for performing manual paper feed,
A guide roller 44 is provided. The paper feed unit 510 is configured by the paper feed cassette 41, the paper feed roller 42, the registration rollers 43, and the like.

Further, the fixing unit 300 is provided with a fixing roller 301, a pressure roller 302, and a silicone oil applying member 305. The silicone oil applying member 305 is used to enhance the fixing property of the toner, and is used for color printing. A small amount of silicone oil is applied to the fixing roller 301 to ensure gloss and color reproducibility. Further, the fixing roller 301 is formed of a material such as silicon rubber or fluorine rubber having a high separability from the toner, and has a built-in heater. A paper discharge roller 400 for discharging the transfer paper after fixing to the outside of the apparatus is provided at the rear end of the fixing unit 300. Further, an upper cover 500 as an upper opening / closing lid is provided on the upper surface of the apparatus main body, and a lateral cover 501 as a side opening / closing lid is provided on the side surface so as to be openable and closable.

Since the contamination of the corona wire (or roller), the lamp and the like is the largest cause of image unevenness, the charge removing device 6 and the charging device 2 may be installed in the multicolor developing unit 100 or the photosensitive unit. It is preferable to install it at a position where toner, developer, dust and the like from the body cleaner 5 hardly reach. In this embodiment, a roller charger is used as the charger 2, but a corona charger may be used. Further, as the photoconductor cleaner 5 and the intermediate transfer belt cleaner 206,
The blade cleaner has the best overall cleaning performance, cost, reliability, etc. and removes materials (cleaned toner, dust such as paper dust, dust, etc.) in order to enhance the endurance of the cleaning performance. Install in a position where the maximum gravity of the can be used. The fixing unit 300, the intermediate transfer belt unit 200, and the photoconductor unit 530 (see FIG. 2) including the photoconductor belt 1, the photoconductor cleaner 5, and the collected toner tank 207 are flush with the cassette mounting / dismounting surface.
, Each is configured to be detachable from the apparatus main body. In the above configuration, the original image converted into an electric signal by the image processing / controller (not shown) is subjected to image exposure (3) on the photosensitive belt 1 by the writing unit 30, and an electrostatic latent image is formed on the photosensitive belt 1. After being formed,
This electrostatic latent image is developed by the multicolor developing unit 100. At this time, the yellow, magenta, cyan, and black toners are supplied to the developing sleeve 102 (Y, M, C) by the stirring member 105 (Y, M, C, B) and the supply roller 103 (Y, M, C, B). , B), and the toner is thinned by the developing blade 104 (Y, M, C, B) to perform development. (During non-development, the developing sleeve 102 is separated from the photoreceptor belt 1 and cannot be developed by a driving mechanism not shown.)
The upper toner image is the first bias roller 202a, 202
By applying a bias voltage to b, the toner images of each color are sequentially transferred to the intermediate transfer belt 201 (primary transfer).

On the other hand, the transfer paper 40 in the paper feed cassette 41 is conveyed to a registration roller 43 by a paper feed roller 42 so that the leading end of the transfer paper 40 and the toner image on the intermediate transfer belt 201 coincide with each other. Is controlled. Then, by applying a bias voltage to the second bias roller 204, the toner image on the intermediate transfer belt 201 is transferred to the transfer paper 40 (secondary transfer). The transfer paper 40 after the transfer is sent to the fixing unit 300, and passes between the fixing roller 301 and the pressure roller 302 to fix the toner image. At this time, an appropriate amount of silicone oil is applied to the fixing roller 301 by the silicone oil applying member 305, so that the fixing property is improved.
Thereafter, the sheet is discharged out of the apparatus via a sheet discharge roller 400.
Further, the intermediate transfer cleaner 206 is connected to the intermediate transfer belt 201.
The transfer residual toner and dust on the upper surface are cleaned, and the removed matter is removed by a transfer member (not shown).
Is transported to the used collected toner tank 207. By the way, when the maintenance of the color image forming apparatus of the first embodiment and the processing at the time of paper jam are performed, as shown in FIG. , Open the paper feed path, and fix the fixing unit 30
0 is taken out in the direction of arrow B. Further, by opening and closing the horizontal cover 501 in the direction of arrow C, the photoconductor unit 530 and the intermediate transfer belt unit 200 are taken out in the direction of arrow D. Further, the paper feeding unit 510 can slide in the direction of arrow E.

Next, an embodiment of the present invention will be described. The first embodiment shown in FIG. 3 has substantially the same configuration as the above-described basic configuration, but differs from the photoconductor belt 1 in the first embodiment.
The peripheral length ratio of the peripheral length of the intermediate transfer belt 201 to the peripheral length of the intermediate transfer belt 201 is the same in the basic configuration example, but is an integer specific peripheral length (the first embodiment, and the second, later described, In the third embodiment, the peripheral length ratio between the photosensitive belt 1 and the intermediate transfer belt 201 is set to 1: 2). Other basic structures
This means that the photoreceptor belt 1 is set horizontally, the intermediate transfer belt 201 is disposed on the photoreceptor belt 1, and the paper cassette is further placed thereon.
The multi-color developing unit uses a rotary multi-color developing unit 100 ′ in which developing units 101 y, 101 m, 101 c, and 101 b are arranged in a circle. The developing unit 100 ′ is disposed below the photoreceptor belt 1 , and further below the photoreceptor belt 1.
The difference is that 30 is arranged . As shown in FIG. 4, the maintenance and the processing at the time of paper jam in the first embodiment are the same as those in the case of the basic configuration example in FIG.

[0014] Next, a second embodiment shown in FIG. 5, the first
The second embodiment is similar to the first embodiment, but differs in that the photosensitive belt 1 and the intermediate transfer belt 201 thereon are arranged obliquely. The maximum print size of this embodiment is A3 size. As shown in FIG. 6, the maintenance and the processing at the time of paper jam in the second embodiment are the same as those in the basic configuration example shown in FIG.

[0015] The third embodiment shown in FIG. 7, the first
The second embodiment is similar to the first embodiment, except that the photosensitive belt 1 is disposed obliquely and the intermediate transfer belt 201 is horizontally disposed thereon. The maximum print size of this embodiment is A4 size. As shown in FIG. 8, the maintenance and the processing at the time of paper jam in the third embodiment are the same as those in the basic configuration example shown in FIG.

[0016]

As described above , according to the first aspect, the peripheral length of the intermediate transfer member is defined by the peripheral length of the image carrier.
To that two or more integral multiple, also transfer member and the sheet feeding cassette between China can be detachably attached to the same side of the image forming apparatus main body, and a cover for removable medium between transcripts opened locus since the paper feed cassette not present in the above can be attached and detached in the middle between the transfer member without being bothered by the sheet feeding cassette, thereby facilitating the maintenance process.

According to Claims 2, 3, 4, and 5 ,
In addition to the effect shown in FIG. 1, since a transport path for transporting the transfer material and a transport path cover for exposing the transport path are provided, a paper jam can be easily handled. Further, since the fixing unit includes a unitized fixing unit for fixing the toner image on the transfer paper and a fixing cover for opening and closing when the fixing unit is attached to and detached from the image forming apparatus main body, maintenance of the fixing device is reduced. Easy to do. Further, since the latent image forming means is provided below the multicolor developing means, the apparatus becomes more compact. Further, since the latent image forming means is directly installed on the main body base of the apparatus main body, the latent image forming means is hardly affected by vibration from the developing device and other movable parts.

[0018]

[0019]

[0020]

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a color image forming apparatus of a basic configuration example of the present invention.

FIG. 2 is an explanatory diagram showing attachment and detachment of each unit of the basic configuration example .

FIG. 3 is a schematic configuration diagram illustrating a color image forming apparatus according to a first embodiment of the present invention.

FIG. 4 is an explanatory diagram showing attachment and detachment of each unit of the first embodiment.

FIG. 5 is a schematic configuration diagram illustrating a color image forming apparatus according to a second embodiment of the present invention.

FIG. 6 is an explanatory diagram showing attachment and detachment of each unit according to the second embodiment.

FIG. 7 is a schematic configuration diagram illustrating a color image forming apparatus according to a third embodiment of the present invention.

FIG. 8 is an explanatory diagram showing attachment and detachment of each unit according to the third embodiment.

[Explanation of symbols]

1 image carrier 2 Charger 5,206 Cleaning means 6 Static eliminator 30 Latent image forming means 100 Multicolor developing unit 100 'Rotary multicolor developing unit 201 Intermediate transfer bodies 202a, 202b Intermediate transfer means 204 Transfer means

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-4-85575 (JP, A) JP-A-2-2037 (JP, A) JP-A-3-51863 (JP, A) JP-A-2-518 294673 (JP, A) JP-A-3-77973 (JP, A) JP-A-4-110871 (JP, A) JP-A-4-296784 (JP, A) JP-A-4-184361 (JP, A) JP-A-4-84159 (JP, A) JP-A-4-199165 (JP, A) JP-A-3-29971 (JP, A) JP-A-2-149858 (JP, A) JP-A-4-134377 (JP, A) JP-A-4-76563 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 15/01-15/01 117 G03G 15/16 G03G 15/00 550

Claims (5)

(57) [Claims] An image forming apparatus main body, an image carrier, a latent image forming means for forming an electrostatic latent image corresponding to each color image on the image carrier, and a latent image forming means disposed around the image carrier. a multi-color developing means for applying a plurality of colors of developing agent on the image bearing member, Chi lifting the circumferential length of more than twice the circumference of the image carrier, the image type
An intermediate transfer member detachably mountable to the main body of the forming apparatus; a paper feed cassette housing transfer paper for transferring a toner image and detachable relative to the main body of the image forming apparatus; Has a cover that can be attached and detached,
Wherein the intermediate transfer member and said paper feed cassette detachably from the same surface of the image forming apparatus main body, and, as the paper feed cassette on the opening path of the cover is not present, the
A color image forming apparatus, wherein an intermediate transfer member and the paper feed cassette are arranged at predetermined vertical positions. 2. The color image forming apparatus according to claim 1,
A transport path for transporting the transfer paper;
A color image forming apparatus , comprising: a conveyance path cover for exposing a path . 3. A color image forming apparatus according to claim 1, wherein
Device to fix the toner image on the transfer paper
A unitized fixing unit, and the fixing unit
A set for opening and closing when attaching to and detaching from the image forming apparatus main body.
A color image forming apparatus comprising a wearing cover . 4. The method according to claim 1 , wherein
In the color image forming apparatus, the latent image forming unit is
A color image forming apparatus, wherein the color image forming apparatus is provided below a multicolor developing unit . 5. The color image forming apparatus according to claim 4, wherein
Wherein the latent image forming means is a main body of the image forming apparatus main body.
A color image forming apparatus which is directly installed on a base .