JPH1165194A - Image forming device - Google Patents

Abstract

(57) Abstract: An apparatus for forming an image forming means is integrated to reduce the pitch between image carriers as much as possible, thereby shortening the entire apparatus in the longitudinal direction and reducing costs. Provided is an image forming apparatus that contributes. Kind Code: A1 A plurality of image forming means for forming an image of a predetermined color by processing photosensitive drums 1a to 1d in the order of charge-exposure-developing-transfer-cleaning-discharge are arranged in series, In an image forming apparatus for forming a multicolor image by sequentially transferring visible images of a predetermined color by passing through P,
An image forming unit S is provided in which a developing device 4 for a predetermined color and a cleaning device 6 on one upstream side are integrated.

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 and an image forming unit used in an electrophotographic color electronic copying machine and a color printer.

[0002]

2. Description of the Related Art FIG. 4 shows a schematic configuration of a conventional color image forming apparatus. Four photoconductor drums 1a to 1d as image carriers are provided, and charging devices 2a to 1d are arranged around each photoconductor drum along the rotation direction.
2d, exposure devices 3a to 3d, developing devices 4a to 4d, transfer devices 5a to 5d, cleaning devices 6a to 6d, and charge removing devices 7a to 7d in this order.

That is, first to fourth image forming units Ya to Yd, which are image forming means of a predetermined color, are constituted by devices arranged along the periphery of each of the photosensitive drums 1a to 1d. You.

[0004] These first to fourth image forming units Ya to Yd are yellow (yellow) image forming units Y.
a, magenta (magenta) image forming unit Yb,
A total of four image forming units Yc for cyan (blue-green) and Yd for black (black) are provided.

[0005] First to fourth image forming units Ya to
In Yd, the surface of each of the photoconductor drums 1a to 1d is processed in the order of charging-exposure-development-transfer-cleaning-discharge elimination. Then, the visible images of a predetermined color formed by the respective image forming units are successively transferred, and finally fixed by a fixing device (not shown) adjacent to the fourth image forming unit Yd, and A multicolor image is formed.

[0006]

In such a color image forming apparatus, only four units, which are conventionally used image forming means constituting a so-called monochrome copying machine, are arranged in series. Absent.

The cleaning devices 6a to 6c except for the cleaning device 6d of the fourth image forming unit Yd and the developing devices except for the developing device 4a of the first image forming unit Ya are provided between the photosensitive drums 1a to 1d. 4b to 4d are interposed.

Each of the cleaning devices 6a to 6c and the developing devices 4b to 4d has a predetermined volume, and it is necessary to secure a minimum necessary gap for mounting and adjusting each volume.

Therefore, the pitch between the photosensitive drums 1a to 1d viewed from the lateral direction (hereinafter referred to as the longitudinal direction) needs to be a predetermined length, and at present, the pitch in the longitudinal direction of the entire color image forming apparatus is required. Reduction is not possible.

In addition, since the frequency of use of each color is not actually uniform, it is necessary to replace each image forming unit Ya-Yd in an independent state, and to have a structure capable of adjustment and maintenance. there were.

Each of the image forming units Ya to Yd is composed of a plurality of devices as described above, and since four sets of these devices must be prepared, the production and management of each component device are complicated and cost is reduced. Has had a negative impact.

The bottleneck in downsizing the image forming units Ya to Yd is the photosensitive drums 1a to 1d.
In consideration of this, the photosensitive performance of d is taken into consideration, and when trying to increase the process speed in order to copy a large number of sheets, the distance between exposure and development becomes strict, and there is naturally a limit in consideration of the paper transport portion. For example, usually 0.15 between exposure and development.
Due to the necessity of sec, it is impossible to make the diameter of the photosensitive drum smaller than the present.

After all, in order to shorten the longitudinal dimension of the entire color image forming apparatus of this type, the photosensitive drums 1a to 1d are required.
It is effective to reduce the size in the longitudinal direction between the developing devices 4a to 4d and the cleaning devices 6a to 6d arranged on the left and right of the photosensitive drums 1a to 1d. .

The present invention has been made based on the above circumstances, and it is an object of the present invention to integrate the devices constituting the image forming means to reduce the pitch between the image carriers as much as possible. It is an object of the present invention to provide an image forming apparatus which can shorten the longitudinal direction of the entire apparatus and contribute to cost reduction.

[0015]

SUMMARY OF THE INVENTION In order to satisfy the above object, a first aspect of the present invention provides a first image carrier that rotates in a predetermined direction and a first image carrier downstream of the first image carrier in the rotational direction. A second image carrier, which is arranged side by side, and a first opening,
A removing unit that is disposed to face the first opening with respect to the first image carrier, and that removes a developer adhered on the first image carrier; A developing unit having a second opening at a position opposite to the first opening, and developing by supplying a developer to the uniformly charged area of the second image carrier; And a unit comprising:

According to a fifth aspect of the present invention, a charging device, an exposing device, a developing device, a transfer device, a cleaning device, and a charge removing device are sequentially disposed along the peripheral surface of the image carrier, and the surface of the image carrier is charged. A plurality of image forming units that form an image of a predetermined color by performing processing in the order of exposure-development-transfer-cleaning-static elimination are arranged in series, and the image-receiving unit sequentially passes the image-receiving material to each image. In an image forming apparatus for sequentially transferring visible images of a predetermined color formed by a forming unit to form a multicolor image, a developing device in the image forming unit of a predetermined color, and one of the image forming units of the predetermined color 7. The image forming apparatus according to claim 6, further comprising an image forming unit in which a cleaning device in the upstream image forming unit is integrated, a charging device, an exposure device, a developing device, Transfer device, A cleaning device and a static eliminator are sequentially arranged, and an image forming means for forming an image of a predetermined color in order of charging-exposure-development-transfer-cleaning-static elimination on the surface of the image carrier and forming a predetermined color image is connected in series. In the image forming apparatus that sequentially passes the material to be transferred to these image forming means and sequentially transfers the visible images of a predetermined color formed by the respective image forming means to form a multicolor image, A developing device formed as a single unit in the first color image forming unit, a developing device in the second, third, and fourth color image forming units; and an image forming unit upstream of one of the image forming units. A plurality of image forming units, each of which is integrated with the cleaning device of (1), and a cleaning device configured as a single unit in the fourth color image forming means.

According to a seventh aspect of the present invention, a charging device, an exposing device, a developing device, a transfer device, a cleaning device, and a static eliminator are sequentially disposed along the peripheral surface of the image carrier to charge the surface of the image carrier. -Exposure-development-transfer-cleaning-de-electrification, and image forming means for forming an image of a predetermined color for four colors are arranged in series. In the image forming apparatus for sequentially transferring the visible images of a predetermined color formed by the image forming means to form a multi-color image, a developing device in the first color image forming means to the fourth color image forming means is provided. A plurality of image forming units each integrating a cleaning device in an image forming unit on the upstream side of one of the image forming units; and a cleaning unit configured as a single unit in the fourth color image forming unit. Characterized by comprising and.

According to an eighth aspect of the present invention, as an image forming unit, a developing means for developing a latent image on an image carrier by supplying a developer and the image forming unit are provided integrally with the developing means, and It is characterized by comprising only a removing means for removing the developer adhered on the carrier.

As described above, according to the first aspect of the present invention, the first opening in which the removing section is arranged facing the first image carrier, and the developing section in which the removing section is arranged facing the second image carrier. By arranging the unit having the second opening, the pitch between the image carriers can be reduced as much as possible, and thus the entire apparatus can be shortened in the longitudinal direction.

According to a fifth aspect of the present invention, there is provided an image forming unit in which a developing device for an image forming means of a predetermined color and a cleaning device for the image forming means on one upstream side are provided in an integrated manner. The volume of the case and the gap for attaching and adjusting each can be omitted.

According to the sixth aspect of the present invention, the developing device in the first color image forming means and the cleaning device in the fourth color image forming means are provided as a single unit, and the developing devices in the second, third and fourth color image forming means are separated. By providing a plurality of image forming units in which a developing device and a cleaning device for one upstream image forming unit are integrated, the pitch between the image carriers can be reduced, and the length of the device in the longitudinal direction can be reduced. .

According to a seventh aspect of the present invention, there are provided a plurality of image forming units in which a developing device in the image forming means of the first to fourth colors and a cleaning device in the image forming means on one upstream side are integrated. By providing the cleaning device in the color image forming means, the mounting interval of each image forming unit is reduced. Although the cleaning device in the image forming unit for the first color is extra, a dedicated developing device for the first color is not required, which greatly contributes to cost reduction.

According to the eighth aspect of the present invention, since the image forming unit includes the developing means and the removing means, the structure can be simplified and the length can be reduced by combining with other components.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described.
This will be described with reference to the drawings. As shown in FIG. 1, the photosensitive drum 1, which is an image bearing member, is formed of a cylindrical body having a diameter of about 30 mmφ, and is provided so as to be rotatable in the direction of the arrow in the figure. The following devices are arranged around the photosensitive drum 1 along the rotation direction.

At a predetermined position, a charging device 2 which contacts the surface of the photosensitive drum 1 and uniformly charges the photosensitive drum 1 to a predetermined negative potential is arranged. An exposure device 3 that irradiates a document and exposes the charged image to a charged photosensitive drum to form an electrostatic latent image on the drum rotation direction side of the charging device 2
Is arranged.

On the drum rotation side of the exposure device 3, a developing device 4 for reversing developing the electrostatic latent image by supplying a developer to the electrostatic latent image formed on the photosensitive drum is arranged. The developing device 4 is configured such that the opening 41 is connected to the photosensitive drum 1 on the downstream side.
b. On the drum rotation direction side of the developing device 4, a transport belt T as a transport unit that transports the sheet P as a transfer material is disposed.

A transfer device 5 is arranged on the rear side of the conveyor belt opposite to the contact position between the photosensitive drum 1 and the conveyor belt T, and transfers an original image formed on the photosensitive drum 1 onto paper P. On the drum rotation direction side of the transfer device 5, a cleaning device 6 and a charge removing device 7 are arranged.

The cleaning device 6 has an opening 61 facing the photosensitive drum 1a on the upstream side, and the opening 61 has a blade b.
Scrape off the toner remaining on the surface of the.

The collected toner is collected in a toner collecting device (not shown), and is discarded every time a predetermined amount is reached. The residual potential remaining on the photosensitive drum 1 after the toner is removed by the cleaning device 6 is removed by the above-described charge removing device 7 which comprises a charge removing lamp and uniformly irradiates the surface of the photosensitive drum.

As described above, the charging device 2, the exposure device 3, the developing device 4, the transfer device 5, and the cleaning device 6 are provided around one photosensitive drum 1 along the rotation direction of the drum.
The configuration in which the static eliminators 7 are sequentially arranged, and a means for forming an image of a predetermined color using these components is not changed in the present invention.

However, as a feature of the present invention, at least
A developing device 4 between adjacent photosensitive drums 1 and 1;
And an image forming unit S in which the cleaning device 6 on the upstream side is integrated.

FIG. 2 schematically shows the structure of an actual color image forming apparatus. On the transport belt T, the paper P
The first to fourth photosensitive drums 1a
To 1d are arranged at predetermined intervals. Around the photoreceptor drums 1a to 1d, all of the devices constituting the image forming means described above are arranged, and a plurality (four sets) of image forming means for a predetermined color are arranged in series. You.

That is, the charging devices 2a to 2d, the exposure devices 3a to 3d, the developing devices 4a to 4d, and the transfer devices 5a are arranged around the photosensitive drums 1a to 1d along the rotation direction.
To 5d, cleaning devices 6a to 6d, static eliminator 7a to
7d is arranged. Yellow (yellow) in developing device 1a
, A magenta (red-purple) developer is stored in the developing device 1b, a cyan (blue-green) developer is stored in the developing device 1c, and black (black) is stored in the developing device 1d. Is stored.

On the other hand, a paper feeding device (not shown) for supplying the paper P toward the photosensitive drum 1a is arranged at the right end of the transport belt T in the drawing. The sheet P taken out from the sheet feeding device is sent to a transport belt, and further, the photosensitive drum 1
a to 1d.

A fixing device (not shown) is disposed at the left end of the conveyor belt T in the drawing. The fixing device functions to fix the toner transferred onto the sheet P by heating / pressing the toner onto the sheet. At a position adjacent to the fixing device, a discharge tray (not shown) for discharging the sheet P on which the developer image is fixed is provided.

The image forming unit S in which the developing device 4 and the upstream cleaning device 6 described above are integrated is disposed between the first photosensitive drum 1a and the second photosensitive drum 1b. A first image forming unit Sa, a second image forming unit Sb disposed between the second photosensitive drum 1b and the third photosensitive drum 1c, and a third photosensitive drum 1c.
And a third image forming unit Sc disposed between the image forming unit and the fourth photosensitive drum 1d.

Accordingly, in the first image forming unit Sa, the cleaning device 6a cleans the first photosensitive drum 1a, and the developing device 4b of the unit Sa operates in the second image forming unit Sa.
The electrostatic latent image on the photosensitive drum 1b is developed.

Similarly, in the second image forming unit Sb, the cleaning device 6b cleans the second photosensitive drum 1b, and the developing device 4c of the unit Sb uses the electrostatic latent image on the third photosensitive drum 1c. Is developed.

Further, in the third image forming unit Sc, the cleaning device 6c cleans the third photosensitive drum 1c, and the developing device 4d of the same unit Sc removes the electrostatic latent image on the fourth photosensitive drum 1d. Develop.

Each of the image forming units Sa to Sc provided in the actual color image forming apparatus is a developing device for developing an electrostatic latent image formed on the photosensitive drums 1b to 1d in the predetermined color image forming means. 4b to 4d and cleaning devices 6a to 6c for cleaning the photosensitive drums 1a to 1c in the image forming means on one upstream side are integrally provided.

In this apparatus, the developing device 4a constituting the first color image forming means is formed as a single unit similarly to the conventional one, and the cleaning device 6d constituting the fourth color image forming means is also the same as the conventional one. It is configured as a single unit.

Thus, the electrostatic latent image formed on the photosensitive drum 1a is opposed to the developing device 1a, is supplied with the developer, and is visualized to form a yellow (yellow) developer image. On the other hand, the sheet P taken out of the sheet cassette is transported by the transport belt T, and the yellow developer image on the surface of the photosensitive drum 1a is transferred onto the sheet P at a position facing the transfer device 5a.

Further, when the sheet P is conveyed to the transfer device 5b, the magenta developer image on the surface of the photosensitive drum 1b is transferred onto the yellow P developer image on the sheet P in a superimposed manner. When transported to the transfer device 5c, the cyan developer image is transferred so as to overlap the developer image already transferred. When transported to the transfer device 5d, the black developer image is multiplex-transferred onto the developer image already transferred.

The sheet P on which the developer images of the respective colors are transferred in a multiplex manner is conveyed to a fixing device (not shown), and the developer images are fixed on the sheet P to form a color image. The fixed paper P is sequentially discharged to a discharge tray.

In each of the photosensitive drums 1a to 1d, the toner remaining on the surface is scraped off by the blade b of each of the cleaning devices 6a to 6d, and the remaining potential is reduced by uniform light irradiation by each of the charge removing devices 7a to 7d. Static electricity is removed.
Then, the charging devices 2a to 2d uniformly charge the surfaces of the uncharged photosensitive drums 1a to 1d again, and the above-described operation is repeated.

In the present invention, the photosensitive drums 1a to 1a
d, the first to third image forming units Sa to Sc in which the developing devices 4b to 4d and the cleaning devices 6a to 6c for one color, which is one upstream, are integrated. It is possible to avoid the overlap of the thicknesses of the frames constituting these components and to eliminate the gap for mounting and adjusting, thereby shortening the longitudinal direction of the apparatus.

More specifically, the unit per color can be reduced by about 6 mm as compared with the conventional color image forming apparatus, and the total length of four colors can be reduced by about 20 mm.

In order to maintain high image quality, the photosensitive drums 1a to 1d must be
The positions of the developing devices 4a to 4d must be set with reference to the photosensitive drums 1a to 1d so that the gap between the developing devices 4a to 4d and the magnet roller m becomes a designated value.

By using the image forming units Sa to Sc of the present invention, the positions of the developing devices 4b to 4d with respect to the photosensitive drums 1b to 1d can be correctly set within a specified value range and assembled.

However, by adjusting the positions of the developing devices 4b to 4d with respect to the photosensitive drums 1b to 1d for each of the image forming units Sa to Sc, these image forming units Sa to S can be adjusted.
The positions of the cleaning devices 6a to 6c provided for the photoconductor drums 1a to 1c opposed to each other vary.

Therefore, these cleaning devices 6a
6c is fixed, the contact state of the doctor blade b with the photosensitive drums 1b to 1d depends on the result of adjusting the gap between the photosensitive drums 1b to 1d and the developing devices 4b to 4d. There is a possibility that the cleaning effect may be affected by a large fluctuation.

Therefore, at least the cleaning devices 6a to 6c provided in the image forming units Sa to Sc, respectively.
For example, it is necessary to employ a constant pressure type in which the doctor blade b is elastically pressed and urged toward the photosensitive drums 1a to 1c by a spring body.

A color image forming apparatus as shown in FIG. 3 may be used. Here also, the first image forming unit Sa is provided between the first photosensitive drum 1a and the second photosensitive drum 1b.
Are arranged, and the second image forming unit Sb is arranged between the second photosensitive drum 1b and the third photosensitive drum 1c.
In addition to disposing the third imaging unit Sc between the photosensitive drum 1c and the fourth photosensitive drum 1d,
The fourth image forming unit Sd is provided upstream of the photosensitive drum 1a.
Is arranged.

The cleaning device 6d relating to the fourth photosensitive drum 1d is configured as a single unit, as described above. In addition, the same components as those described in FIG. 2 are denoted by the same reference numerals, and a new description will be omitted.

In the fourth image forming unit Sd disposed on the upstream side of the first photosensitive drum 1a, the developing device 4a
Only the first photosensitive drum 1a has a predetermined action, and the cleaning device 6 provided in the image forming unit Sd has no action on the photosensitive drum 1a.

Therefore, although the cleaning device 6 provided in the fourth image forming unit Sd is redundant, the developing device 4a for the first-color photosensitive drum 1a as described above with reference to FIG. This eliminates the need to do so, thus contributing to significant cost reduction.

[0057]

As described above, the first aspect of the present invention is:
By arranging a unit having a first opening in which a removing section is arranged opposite to the first image carrier and a second opening in which a developing section is arranged opposite to the second image carrier. This has the effect of shortening the pitch between the image carriers as much as possible, thereby shortening the entire apparatus in the longitudinal direction.

According to a fifth aspect of the present invention, there is provided an image forming unit in which the developing device of the image forming means of a predetermined color and the cleaning device of the image forming means on one upstream side are integrated. There is an effect that it is possible to omit the volume of the case and the gap for attaching and adjusting each case.

According to a sixth aspect of the present invention, the developing device of the first color image forming means and the cleaning device of the fourth color image forming means are provided as a single unit, and the developing devices of the second, third, and fourth color image forming means are separated from each other. Since there are provided a plurality of image forming units in which the cleaning device of the image forming means on the upstream side is integrated, the pitch between the image carriers can be reduced, and the length of the device in the longitudinal direction can be reduced.

According to a seventh aspect of the present invention, there is provided an image forming unit in which a developing device in the first to fourth color image forming means and a cleaning device in the one upstream image forming means are integrated, Since the cleaning device for the image forming means is provided, the interval between each image forming unit is reduced.
Although the cleaning device for the first color image forming unit is unnecessary, a dedicated developing device is not required, and the effect of contributing to a significant cost reduction can be obtained.

According to the invention of claim 8, since the image forming unit includes the developing means and the removing means, the structure can be simplified and the length can be reduced by combination with other components.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an image forming unit according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of an image forming apparatus according to the embodiment;

FIG. 3 is a schematic configuration diagram of an image forming apparatus according to another embodiment.

FIG. 4 is a schematic configuration diagram of a conventional image forming apparatus.

[Explanation of symbols]

 1a to 1d: image carrier (first to fourth photosensitive drums), 2a to 2d: charging device, 3a to 3d: exposure device, 4a to 4d: developing device, 5a to 5d: transfer device, 6a to 6d ... cleaning device, 7a to 7d ... static eliminator, P ... transfer material (paper), Sa to Sd ... (first to fourth) image forming units.

Continued on the front page (72) Inventor Kazuhisa Kimura 70 Yanagicho, Saiwai-ku, Kawasaki City, Kanagawa Prefecture Inside Toshiba Intelligent Technology Co., Ltd.

Claims (9)

[Claims] A first image carrier that rotates in a predetermined direction; a second image carrier that is arranged side by side in the rotation direction of the first image carrier; and a first opening. A removing unit disposed to face the first opening with respect to the first image carrier, and removing a developer adhered to the first image carrier; and a removing unit. Supplying a developer to the uniformly charged area of the second image carrier having a second opening at a position opposite to the first opening; An image forming apparatus comprising: 2. An image forming apparatus according to claim 1, further comprising: an upstream side of said first image carrier and said second side.
2. The image forming apparatus according to claim 1, wherein the unit is further disposed downstream of the image carrier. 3. A developing means provided upstream of the first image carrier and developing by supplying a developer to the uniformly charged surface of the first image carrier. The image forming apparatus according to claim 1, wherein: 4. The image forming apparatus according to claim 1, further comprising a developing means provided downstream of said second image bearing member for removing a developer which has been developed by a developing section of said unit and has adhered to said second image bearing member. The image forming apparatus according to claim 1, wherein: 5. A charging device, an exposure device, a developing device, a transfer device, a cleaning device, and a static eliminator are sequentially arranged along the peripheral surface of the image carrier, and the surface of the image carrier is charged, exposed, developed, and charged. A plurality of image forming units that perform processing in the order of transfer-cleaning-static elimination and form an image of a predetermined color are arranged in series,
In an image forming apparatus that sequentially passes a transfer material through these image forming units and sequentially transfers visible images of a predetermined color formed by the respective image forming units to form a multicolor image, an image of a predetermined color An image forming apparatus comprising: an image forming unit in which a developing device in a forming unit and a cleaning device in an image forming unit upstream of the image forming unit of a predetermined color are integrated. 6. A charging device, an exposure device, a developing device, a transfer device, a cleaning device, and a static eliminator are sequentially arranged along the peripheral surface of the image carrier, and the surface of the image carrier is charged, exposed, and developed. Image forming means for performing processing in the order of transfer-cleaning-static elimination and forming an image of a predetermined color are arranged in series for four colors, and the material to be transferred is sequentially passed through these image forming means.
An image forming apparatus for sequentially transferring visible images of a predetermined color formed by the respective image forming means to form a multi-color image, comprising: a developing device formed as a single unit in the first color image forming means; A plurality of image forming units each integrating a developing device in the image forming means for the second color, the third color and the fourth color, and a cleaning device in the image forming means on the upstream side of one of the image forming means; An image forming apparatus comprising: a cleaning device that is configured as a single unit in a color image forming unit. 7. A charging device, an exposing device, a developing device, a transfer device, a cleaning device, and a static eliminator are sequentially arranged along the peripheral surface of the image carrier, and the surface of the image carrier is charged, exposed, developed, and charged. Image forming means for performing processing in the order of transfer-cleaning-static elimination and forming an image of a predetermined color are arranged in series for four colors, and the material to be transferred is sequentially passed through these image forming means.
In an image forming apparatus for sequentially transferring visible images of a predetermined color formed by respective image forming means to form a multi-color image, a developing device in a first color image forming means to a fourth color image forming means A plurality of image forming units each integrating a cleaning device in the image forming unit on the upstream side of one of the image forming units; and a cleaning device configured as a single unit in the fourth color image forming unit. An image forming apparatus comprising: 8. A developing means for developing the latent image on the image carrier by supplying the developer, and a developer provided integrally with the developing means and removing the developer adhered on the image carrier. An image forming unit comprising only removing means for removing the toner. 9. An image forming unit according to claim 8, wherein said image forming unit is detachable between two image carriers arranged side by side.