JP3154757B2 - Color image forming equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image forming apparatus, and more particularly to a color image forming apparatus which is reduced in size by providing a cleanerless image forming unit.

[0002]

2. Description of the Related Art A plurality of image forming units are continuously arranged, and a toner image formed for each image forming unit is formed.
2. Description of the Related Art A color image forming apparatus that forms a color image by sequentially transferring the transferred material to a transfer material surface by a transfer unit is known. FIG. 3 shows a main part of the configuration of this type of color image forming apparatus, that is, a scanner section for reading a document provided in the main body of the color image forming apparatus, and an image signal output from the scanner section as a digital signal. An image processing unit that performs electrical processing, and a cross-sectional view of a configuration of a color image forming unit among a color image forming unit that copies and reproduces a required image based on image information of each color by the image processing unit. is there. The color image forming unit includes, for example, an image forming unit 1 for black, an image forming unit 2 for yellow, an image forming unit 3 for magenta, and an image forming unit 4 for cyan.

In addition, each of these image forming units 1
Each of the configurations 2, 3, and 4 includes a latent image carrier (for example, a photosensitive drum) 1a, 2a, 3a, 4a, and the latent image carrier 1a, 2a, 3a, 4
charging means (e.g., corona chargers) 1b, 2b, 3b, 4b for uniformly charging the surface a; surfaces of the latent image holders 1a, 2a, 3a, 4a charged based on image information from the image processing unit; Electrostatic latent image forming means 1c, 2c, 3c, 4c for forming a required electrostatic latent image, developing means 1d, 2d for supplying toner to the electrostatic latent image surface to convert the electrostatic latent image into a toner image , 3d, 4d, transfer means (transfer chargers) 1e, 2e, 3e, 4e for transferring the toner image onto the transfer material surface, and transfer residual toner remaining in the transfer to the latent image holders 1a, 2
cleaning means 1f, 2f, 3f,
4f. In other words, although a different color toner is used, a general image forming apparatus (unit) having a so-called cleaning means is continuously arranged (Japanese Patent Laid-Open No. 1-112267). According to this color image forming apparatus, first, an electrostatic latent image of a black component color is formed on the latent image holding member 1a in the image forming unit 1, developed into a black toner image, and transferred to the transfer material surface. Next, in the image forming unit 2, an electrostatic latent image of a yellow component color is formed on the latent image holding member 1a, developed into a yellow toner image, and transferred in a stacked manner to a transfer material surface conveyed. Thereafter, the required color image is copied and recorded through the same process.

[0004]

However, the color image forming apparatus having the above configuration has the following practical problems. That is, even in the case of this type of color image forming apparatus, while having excellent image forming functions, it is desired to reduce the size of the color image forming apparatus including the image forming section. However, in the case of the color image forming apparatus having the above configuration, each of the plurality of image forming units 1, 2, 3, and 4 constituting the image forming unit, which is a main part, includes the cleaning units 1f, 2
Since the image forming units 1, 2, 3, and 4 also have relatively large occupied volumes with f, 3f, and 4f, it is an obstacle to downsizing. That is, the cleaning means 1f, 2f, 3f, 4f
In order to collect and clean the residual transfer toner remaining on the surface of the latent image holding member (drum) 1a and the like after transfer, a relatively large transfer residual toner collection and storage tank is provided. Inevitably, the cleaning means 1f, 2f, 3f, 4f are inevitably downsized.
In particular, when a large number of images are continuously copied and formed, or when the transfer to the transfer material surface is affected by the humidity of the external environment and the like, the transfer residual toner becomes relatively large. There is also a limit to the size of the collection and storage tank, which is a bottleneck in making the image forming unit compact.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a color image forming apparatus which is not only functionally highly reliable and can always form a high quality image but also can be made compact. Aim.

[0006]

Color image forming apparatus according to the present invention SUMMARY OF THE INVENTION may, latent image bearing member, an electrostatic latent image forming means for forming an electrostatic latent image on the surface of the latent image holding member, the electrostatic latent image A plurality of image forming units each having a developing unit for forming a toner image by attaching toner to a surface thereof and a transfer unit for transferring the toner image to a transfer material; and a toner formed for each image forming unit. a color image forming apparatus for forming successively transferred color image by transfer means onto the transfer material surface which is conveyed to an image, the image forming units plurality of, one holding a latent image after transfer even without least a cleanerless image forming unit configured to transfer residual toner remaining on the body surface to cleaning by the developing means, and at least one is viewing with a separate cleaning device and the developing means A forming unit, the chestnut
Printer with a cleaning device
From the direction of flow of the transfer material for the image forming unit
It is characterized by being arranged on the upstream side .

[0007]

According to the present invention, at least one of the image forming units is a cleaner-less image forming unit configured to clean transfer residual toner remaining on the surface of the latent image holding member after transfer by developing means. Accordingly, the image forming unit can be made compact, and the color image forming apparatus itself can be downsized. In other words, at least one of the image forming units has a configuration of developing and simultaneous cleaning and does not have a separate cleaning unit, so that the spatial volume occupied by the cleaning unit can be omitted. In addition, in the cleanerless image forming unit, the transfer residual toner is also collected and reused in the toner storage tank, so that the toner can be efficiently used.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a cross-sectional view showing an example of a main part (image forming unit) of a color image forming apparatus according to the present invention, and FIG. 2 is an enlarged view of one image forming unit (cleanerless image forming unit). FIG. The image forming unit includes, for example, a cleanerless image forming unit 5 for yellow,
It comprises a cleanerless image forming unit 6 for magenta, a cleanerless image forming unit 7 for cyan, and a cleanerless image forming unit 8 for black. Each of the cleanerless image forming units 5, 6, 7, and 8 has a latent image holding member (for example, a photosensitive drum) 5a, 6a, 7a, 8a, and a latent image holding member 5a, 6a,
Charging means (for example, a corona charger) 5b, 6b, 7b, 8b for uniformly charging the surfaces 7a, 8a, and a latent charged on the basis of image information from a separately provided image processing unit (not shown). Electrostatic latent image forming means (print head) 5c, 6c, 7c, 8c for forming a required electrostatic latent image on the surface of the image carriers 5a, 6a, 7a, 8a; Developing means 5d, 6d, 7d, 8d for supplying a magnetic toner to convert the electrostatic latent image into a toner image, and transfer means (transfer chargers) 5e, 6 for transferring the toner image onto a transfer material surface
e, 7e, 8e, and after the transfer of the toner image by the transfer means 5e, 6e, 7e, 8e, a static elimination lamp 5f for removing (erasing) charges remaining on the surfaces of the latent image holders 5a, 6a, 7a, 8a. 6f, 7f, 8f and the residual toner remaining after the transfer are transferred to the latent image holders 5a, 6a, 7a, 8
The surface a is dispersed to contribute to uniform charging by the charging means 5b, 6b, 7b, 8b, and the developing means 5d, 6d, 7
In this configuration, transfer residual toner dispersing means 5g, 6g, 7g, and 8g for facilitating the cleaning action in d and 8d are provided. In other words, the color toner used is different,
So-called cleanerless image forming apparatus (unit) 5,
6, 7, and 8 are continuously arranged.

In FIG. 1, reference numeral 9 denotes a transfer material conveying means for conveying a transfer material for transferring a toner image, which substantially conveys transfer paper supplied from a paper feed roller 10 in conjunction with the image formation. Transparent endless belt
9a, a rotating mechanism (such as a roller) 9b for running the belt 9a endlessly, a belt cleaner 9c for cleaning the surface of the running belt 9a, and a belt charger 9d for applying a required charge to the running belt 9a. Reference numeral 11 denotes a fixing unit for fixing the toner image transferred onto the transfer paper to the surface of the transfer paper, and reference numeral 12 denotes a partition between the respective cleanerless image forming units 5, 6, 7, and 8.

The cleanerless image forming units 5, 6, 7, and 8 constituting the components of the color image forming apparatus according to the present invention.
The configuration and function of the developing means 5d, 6d, 7d, 8d will be described below. A roller type toner carrier carrying a toner layer on a peripheral surface arranged opposite to the surface of the latent image holding members 5a, 6a, 7a, 8a 5d ₁ , 6d ₁ , 7d ₁ , 8d ₁ , toner carrier 5
_{d 1, 6d 1, 7d 1} , 8d 1 toner supplying member for supplying the toner to the surface _{5d 2, 6d 2, 7d 2} , 8d 2, wherein the toner carrying member 5 of the
_{d 1, 6d 1, 7d 1} , 8d toner layer regulating blade 5d ₃ for regulating the thickness of the toner layer carried on _one side, 6d _3, 7d _3, 8d
₃ , the toner carriers 5d ₁ , 6d ₁ , 7d ₁ , 8d ₁ after supplying toner to the electrostatic latent image surfaces of the latent image carriers 5a, 6a, 7a, 8a
Toner collecting blade 5d _4, 6d ₄ for collecting the toner surface,
While wearing 7d _4, 8d ₄ and these are provided with a toner storage tank _{5d 5, 6d 5, 7d 5} , 8d 5 for storing the toner.

Next, the development and simultaneous cleaning in the cleanerless image forming units 5, 6, 7, and 8 will be schematically described. When an electrostatic latent image is formed on the surface of the latent image holding member 5a, 6a, 7a, 8a by the electrostatic latent image forming means 5c, 6c, 7c, 8c, the electrostatic latent image exists in the charged portion (that is, the unexposed portion or the non-image portion). The remaining transfer toner to be transferred is reliably charged by the charging means 5b, 6b, 7b, 8b, so that the toner carriers 5d ₁ , 6d
_1, 7d _1, 8d ₁ from the latent image holding member 5a, 6a, 7a, suppresses the to 8a faces the toner 2 is transferred electric field, i.e. the charged portion potential and the toner carrying member _{5d 1, 6d 1, 7d 1} , The toner carriers 5d ₁ , 6d ₁ , and 7d are caused by an electric field caused by a potential difference from the potential of 8d _1.
1 , 8d Transfer to ₁ side. Uncharged portion simultaneously, that transfer residual toner present on the exposed portion or image portion, the toner carrying member _{5d 1, 6d 1, 7d 1} , 8d 1 from the latent image holding member 5a, 6a,
The latent image holding members (photoconductors) 5a, 6a,
It remains on the 7a and 8a surfaces. New toner is transferred from the toner carriers 5a ₁ , 6a ₁ , 7a ₁ , 8a ₁ to the non-charged portion, and cleaning is performed simultaneously with development.

According to the color image forming apparatus having the above configuration,
First, a required electrostatic latent image pattern is formed on the surface of the latent image holding member (photoreceptor) 5a by information corresponding to the yellow image,
In the next stage of the developing means 1d, development and simultaneous cleaning are performed according to the above-described operation principle, and a toner image corresponding to the electrostatic latent image pattern is formed on the surface of the latent image holding member 5a. The toner image thus formed is transferred from the surface of the latent image holding member 5a to the surface of the transfer material conveyed synchronously by the transfer means 5e. After the transfer, the surface of the latent image holding member 5a is irradiated with a static elimination lamp 5f to remove the charge, and is then substantially uniformly dispersed by the transfer residual toner dispersing means 5g.
The surface of the latent image holding member 5a is made uniform, and formation of an electrostatic latent image pattern corresponding to the yellow image, development, simultaneous cleaning, and the like are repeated again.

On the other hand, the transfer material onto which the yellow image has been transferred is conveyed to the next cleaner-less image forming unit 6 for magenta, and the operation or operation is the same as in the case of the cleaner-less image forming unit 5 for yellow. Accordingly, a required magenta image is transferred in a laminated manner on the transfer material surface on which the yellow image has been transferred. Thereafter, in a cleaner-less image forming unit 7 for cyan and a cleaner-less image forming unit 8 for black, a corresponding color image is formed into a toner image and transferred, and then fixed by a fixing unit 11 to obtain a required color. An image is obtained.

In the image forming process in each of the image forming units 5, 6, 7, and 8, no so-called cleaning means is separately provided, but the latent image is developed by the developing and simultaneous cleaning by the developing means 5d, 6d, 7d, and 8d. Image carrier 5a, 6a, 7a, 8
Since the untransferred toner on the a-side is easily and surely removed, the color mixture of the toner images of each color and the image shift are eliminated, and a clear (sharp) high-quality color image is always formed.

In the above-described color image forming apparatus, all of the image forming units are the cleanerless image forming units 5, 6, 7, and 8. However, in the present invention, at least one of the image forming units is the cleanerless image forming unit. It may be set to 5. For example, the image forming unit located at the most upstream side in the flow direction of the transfer material may be a cleanerless image forming unit 5 for yellow, and the other may be an image forming unit with a dedicated cleaning means. Can be more effectively avoided. Alternatively, the image forming unit located on the most downstream side in the flow direction of the transfer material is the cleaner-less image forming unit 8 for black, and the other is an image forming unit with a dedicated cleaning unit (or an image forming unit with a dedicated cleaning unit). the image forming unit and may be a cleanerless image forming units), it may be used to form a monochrome image by leaving a relatively large capacity of the toner reservoir 8d ₅ cleanerless image forming unit 8 for black in this arrangement . Further, the image forming unit located at the most downstream side in the flow direction of the transfer material is an image forming unit with a cleaning unit for yellow or an image forming unit with a cleaning unit for cyan, and the other is also a cleanerless image forming unit. Often, even in this configuration, the effect of color mixing can be avoided more effectively.

In any case, in the color image forming apparatus according to the present invention, the arrangement and position of each image forming unit are appropriately selected and set in consideration of the proper use (single color or color) or the characteristics of the toner to be used. However, it is necessary to provide at least one cleanerless image forming unit. That is, the initial purpose cannot be achieved in terms of the function of forming a color image and the compactness.

In the color image forming apparatus having the above structure,
Although the static elimination lamps 5f, 6f, 7f, 8f are arranged inside the substantially transparent endless belt 9a, the present invention is not limited to this configuration, and the static elimination lamps 5f, 6f, 7f, 8f are not limited to this configuration. The endless belt 9a may be opaque by being arranged outside the endless belt 9a. However, by employing the above-described configuration, efficient arrangement using the inside of the endless belt 9a becomes possible, and the color image forming apparatus can be made more compact.

[0019]

As described above, according to the color image forming apparatus of the present invention, the cleaning means for the transfer residual toner can be omitted, and the configuration can be simplified and compacted. In addition, since the electrostatic latent image formation / simultaneous development and the toner recovery / cleaning of the non-image area can be performed accurately or appropriately, a sharp or clear and high quality color image can always be formed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration example of a main part of a color image forming apparatus according to the present invention.

FIG. 2 is an enlarged sectional view showing a cleanerless image forming unit in a configuration example of a main part of the color image forming apparatus according to the present invention.

FIG. 3 is a cross-sectional view illustrating a configuration of a main part of a conventional color image forming apparatus.

[Explanation of symbols]

1, 2, 3, 4 ... Image forming units 1a, 2a, 3a, 4a, 5
a, 6a, 7a, 8a… Latent image carrier 1b, 2b, 3b, 4b, 5b, 6b, 7b, 8b
... Charging means 1c, 2c, 3c, 4c, 5c, 6c, 7c, 8c ... Electrostatic latent image forming means 1d, 2d, 3d, 4d, 5d, 6d, 7d, 8d ... Developing means
1e, 2e, 3e, 4e, 5e, 6e, 7e, 8e… Transfer means 1f, 2f, 3f, 4f
... Cleaning means 5f, 6f, 7f, 8f ... Electric discharge lamp
5g, 6g, 7g, 8g ... Transfer residual toner dispersing means 5,
6, 7, 8 ... the cleaner-less image forming unit 5d _1,
6d ₁ , 7d ₁ , 8d ₁ ... toner carrier 5d ₂ , 6d ₂ , 7d ₂ , 8d
₂ … Toner supply body 5d ₃ , 6d ₃ , 7d ₃ , 8d ₃ … Toner layer regulating blade 5d ₄ , 6d ₄ , 7d ₄ , 8d ₄ … Toner collection blade 5d ₅ , 6d ₅ , 7d ₅ , 8d ₅ … Toner storage tank
9: transfer material conveying means 9a: belt 9b: rotating mechanism
9c… Belt cleaner 9d… Belt charger 10…
Paper feed roller 11: Fixing unit 12: Partition body between cleanerless image forming units

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yukihiro Osugi 6-78 Minamimachi, Mishima-shi, Shizuoka Tokyo Electric Company, Ltd. (56) References JP-A-55-40404 (JP, A) JP-A-3 JP-A-26971 (JP, A) JP-A-3-4283 (JP, A) JP-A-63-96675 (JP, A) JP-A-2-15288 (JP, A) JP-A-62-247379 (JP, A) JP-A-62-170989 (JP, A) JP-A-62-151365 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 21/10-21/12 G03G 15 / 01-15/01 117 G03G 15/08 507

Claims (1)

(57) [Claims] A latent image holder, an electrostatic latent image forming unit for forming an electrostatic latent image on the surface of the latent image holder, a developing unit for forming a toner image by attaching toner to the electrostatic latent image surface; And a plurality of image forming units having transfer means for transferring the toner image onto a transfer material are successively arranged, and the toner images formed for each of the image forming units are sequentially transferred to the surface of the transferred transfer material by the transfer means. a color image forming apparatus for forming a color image by transferring, said image forming units plurality of, such that one even without less is cleaned by the toner remaining developing means remaining on the latent image bearing member surface after transfer And at least one is an image forming unit with a cleaning device separate from the developing means , wherein the cleanerless image forming unit is Knit front
Transfer to image forming unit with cleaning device
A color image forming apparatus, which is disposed on the upstream side when viewed from the direction of material flow .