JPH06161168A - Image forming device - Google Patents

Abstract

PURPOSE:To provide an image forming device of such structure as to prevent the mixing of colors caused by the scatter or fall of a developer and an adverse effect to write failure. CONSTITUTION:One end in the stretched direction of a belt like photosensitive body 2 with a part stretched in the horizontal direction of an image forming device is brought into contact with a belt like transfer body 5A stretched along the height direction of the image forming device so as to provide a secondary transfer part 5B at the upper end of the belt like transfer body 5A. Developing means 4 (4A-4D) are then placed opposedly to the lower face of the belt like photosensitive body 2 so as to provide such structure as to prevent toner, falling scatteringly from the developing means 4, from being stuck to the belt like photosensitive body 2 and onto transfer paper at least.

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,
In particular, it relates to an image forming apparatus capable of forming a full-color image.

[0002]

2. Description of the Related Art Generally, in an image forming apparatus such as a copying machine or a printer capable of obtaining a full-color image by an electrophotographic method, a toner image of a color selected from color separation or color information is formed on a recording paper in an overlapping manner. There is a need to. Therefore, conventionally, for example, a transfer drum arranged so as to face the photoconductor is used, recording paper is wound on the transfer drum, and the recording paper is formed on the photoconductor, for example, There is a structure in which a toner image corresponding to each color separation or in accordance with color information is transferred and superimposed to form a full-color image.

However, since one end of the recording paper wound on the transfer drum needs to be clamped, the image forming range on the recording paper is narrowed, or the photosensitive member and the clamp mechanism are combined. In many cases, the structure of the device is complicated due to the necessity of a driving method for avoiding interference.

Therefore, before the transfer to the recording paper, the toner image carried on the photosensitive member is temporarily primary-transferred directly to the intermediate transfer member, and then successively transferred onto the intermediate transfer member, and then the recording is performed. A structure has been proposed in which a secondary transfer process is set in which toner images that have been superposed and transferred onto a sheet are collectively transferred.

[0005]

By the way, in an image forming apparatus for obtaining a full-color image, there is a problem of color mixing because the visible image processing of the electrostatic latent image is performed by the developers of a plurality of colors. That is, in order to improve the opposition to the developing device containing the developer for each color, when the photoconductor is composed of a belt, the developing devices are arranged along the extended portion. Then, the developing device supplies the developer by moving the developing device accommodating the developer of the selected color toward the belt-shaped photoconductor to face them. At this time, the developer contained in the developing device is
In some cases, the developer supply unit may be scattered from the opening of the developing device where the developer supply unit is exposed due to inertial force or impact when the device moves. Therefore, the developer leaked from the developing device may float or fall inside the image forming device and enter the adjacent developing device, thereby causing color mixing between the developing devices. Further, the location where the color mixing occurs is on the photoreceptor or the transfer paper, and the location where adverse effects are caused by the contamination of the dropped or scattered developer is the exposure or writing optical device which is the electrostatic latent image forming means. .

Therefore, an object of the present invention is, in view of the above-mentioned problems in the image forming apparatus for forming a conventional full-color image, it is possible to prevent color mixture and further adverse effects due to scattering or dropping of the developer. An object is to provide an image forming apparatus having a structure.

[0007]

In order to achieve this object, the invention described in claim 1 forms a toner image on a photoconductor in accordance with each color separation or in accordance with color information, and the toner image is transferred to an intermediate transfer body. In the image forming apparatus that forms an image of at least two colors or more by performing a primary transfer step of sequentially overlappingly transferring to an image forming apparatus and a secondary transfer step of collectively transferring from the intermediate transfer member to a recording sheet, A belt-shaped transfer member that constitutes an intermediate transfer member that is expanded along the height direction of the belt-shaped transfer member, and one end of the belt-shaped transfer member in the expansion direction is brought into contact with the expanded portion. A belt-shaped photoconductor that is extended in the horizontal direction of the apparatus main body and can be interlocked with the belt-shaped transfer body, a unit that forms an electrostatic latent image corresponding to each color on the belt-shaped photoconductor, and the belt-shaped photoconductor. Facing the underside of the body extension A plurality of developing units that are arranged to perform visible image processing with developers of different colors, and a secondary transfer unit that is provided opposite to the upper end side of the belt-shaped transfer body and that performs a secondary transfer process. A sheet feeding device for feeding the transfer sheet toward the secondary transfer portion, and the developing means is arranged at least below the belt-shaped photoreceptor and the sheet feeding device.

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the developing device is composed of a plurality of developing portions arranged along the extending direction of the belt-shaped photoreceptor. It has a feature.

According to a third aspect of the present invention, in the image forming apparatus according to the first aspect, the developing device is rotatably provided on the lower surface of the belt-shaped photoconductor, and a plurality of developing devices are provided along the rotation direction. It is characterized in that it is constituted by a rotary developing means in which a developing portion in which a toner of a selected color is accommodated among the toner accommodating portions is opposed to one position in the circumferential direction of the photosensitive drum.

According to a fourth aspect of the present invention, there is provided a primary transfer step in which a toner image is formed on the photoconductor in accordance with each color separation or in accordance with color information, and the toner image is sequentially transferred onto the intermediate transfer body.
In an image forming apparatus that forms an image of at least two colors by executing a secondary transfer step of collectively transferring from the intermediate transfer body to a recording sheet, the image forming apparatus is spread along the height direction of the apparatus body. A belt-shaped transfer member that constitutes an intermediate transfer member having a primary transfer portion, and one end of the belt-shaped transfer member in the expansion direction is brought into contact with the expanded portion of the belt-shaped transfer member so that A belt-shaped photosensitive member which is extended at an angle directed in the horizontal direction and can be interlocked with the belt-shaped transfer member, and means for forming an electrostatic latent image corresponding to each color on the belt-shaped photosensitive member, A plurality of developing means arranged to face the lower surface of the stretched portion of the belt-shaped photoconductor and processing visible images with developers of different colors respectively, and provided to face the upper end side of the belt-shaped transfer body. The secondary transfer that performs the secondary transfer process And a sheet feeding device that feeds a transfer sheet toward the secondary transfer portion, and the developing means is arranged at least below the belt-shaped photoreceptor and the sheet feeding device. There is.

[0011]

According to the present invention, the secondary transfer portion is provided on the upper end side of the belt-shaped transfer member extended along the height direction of the apparatus main body, and one end of the belt-shaped transfer member is attached to the extension portion. A developing device is provided on the lower surface of the belt-shaped photoconductor that is in contact with the developing device. Therefore, since the developing device is located below the secondary transfer portion and the photoconductor, even if the developer drops, color mixing on the transfer paper and the photoconductor does not occur.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the drawings. The present embodiment is characterized in that the developing means is arranged in the interior of the main body of the image forming apparatus, further below the sheet feeding section located at the uppermost position and the photoconductor located below the sheet feeding section.

FIG. 1 is a schematic layout diagram showing the overall structure of the image forming apparatus of the present invention.
The side wall 1A and the upper wall 1B of the device body are formed so as to be openable and closable by, for example, being hinged to the device body. In such a structure of the apparatus main body, for example, the side wall 1A is opened at the time of replacement of the photoconductor unit which will be described later, and the upper wall 1B is cleared of the jam at the sheet feeding unit which will be described later. It is open to the public.

On the other hand, a belt-shaped photoreceptor 2 is arranged inside the apparatus, and the belt-shaped photoreceptor 2 is a pair of pulleys 2A arranged along the horizontal direction of the main body of the image forming apparatus 1. It is adapted to be hung around 2B and move in the direction of the arrow shown. Therefore, the spreading surface of the belt-shaped photoconductor 2 is in a state along the horizontal direction of the image forming apparatus 1. An electrostatic latent image forming unit 3, a rotary developing unit 4, a primary transfer unit 5, and a photosensitive member cleaning unit 6 are arranged around the belt-shaped photosensitive member 2 along the moving direction. The electrostatic latent image forming means 3 uses, for example, a writing laser beam according to the image information color-separated in the image reading unit DR attached to the upper surface of the image forming apparatus 1. Similar to the structure used in the adopted image forming apparatus, a structure for performing exposure scanning on the photosensitive drum 2 is provided. Therefore, the belt-shaped photoreceptor 2
A charging device 3A, a writing device 3B, and an eraser 3C are arranged in the vicinity of. Among these constituent members of the electrostatic latent image forming means 3, the writing device 3B is located on the bottom side of the main body of the apparatus, and uses a laser light from a built-in laser light source as a polygon mirror and a plurality of optical path setting mirrors. Irradiation is performed in the main scanning direction on the belt-shaped photoconductor 2 via.

Further, the developing means 4 has a structure provided with a developer supplying portion facing the lower surface of the lower extending portion of the extending portion of the belt-shaped photosensitive member 2. The developer supply unit 4A contains, for example, non-magnetic one-component toners of yellow, magenta, cyan, and black, which are complementary colors to the three primary colors of subtractive color mixture, The developing units 4B, 4C, and 4D are configured so that the developing unit, which stores the toner of the selected color, of the developer supplying unit can be opposed to the Baltic photosensitive member 2. As described above, the developer supplying section of the developing means 4 uses the non-magnetic one-component toner, but such a one-component toner is well known, and in the present embodiment, the developing section is also provided. Similar to the apparatus of this type, the structure includes a developing sleeve 40 which is a toner supply member, a supply roller 41 which is a toner conveying member, a developing blade 42 which is a toner thinning member, and a stirring screw 43 which is a toner conveying member. ing. It should be noted that in FIG. 1, one of the developing units is cited to show the configuration of the developing unit. Further, the developer to be used is not limited to the non-magnetic one as far as the above-mentioned one-component system is concerned, and a magnetic toner may be used, and a two-component system is used instead of the one-component system. It is also possible. Then, the belt-shaped photosensitive member 2 having each of the above structures, the developing unit 4 facing the photosensitive member 2 and a part of the writing device 3B are
For example, it is supported by a module M1 (see FIG. 2) unitized by one support. For this reason, the module M1 is slidably supported with respect to the image forming apparatus 1, so that the above-mentioned members supported by the module M1 can be pulled out as shown in FIG.

On the other hand, the primary transfer portion 5 is composed of the belt-shaped photoreceptor 2
It is a portion where the toner image carried thereon is directly transferred onto the surface thereof, and is provided with a belt-shaped transfer body 5A and a bias roller 5B as main parts. Belt-shaped transfer body 5A
Are extended along the height direction of the image forming apparatus 1 with a length set to an integer ratio with the peripheral length of the photosensitive drum 2. Therefore, the belt-shaped transfer member 5A is set to have a perpendicular relationship with respect to the Baltic photosensitive member 2.
The belt-shaped transfer body 5A includes a drive pulley 5C and a driven pulley 5D whose ends in the extending direction form a belt supporting member.
It can be moved around in the direction of the arrow shown in the figure. The outer diameter of the drive pulley 5C is set to have an integer ratio relationship with the outer diameter of the photoconductor drum 2 to ensure the alignment of the transferred image positions. The bias roller 5B is arranged in front of and behind the position facing the photosensitive drum 2 in the moving direction of the belt-shaped transfer body 5A, and applies a transfer bias in the front. Further, in the belt-shaped transfer member 5A, one of the extending portions is in contact with the belt-shaped photosensitive member 2, and this position is pressed toward the belt-shaped photosensitive member 2 by the bias roller 5B. Also, this belt-shaped transfer member 5A
A transfer body cleaning device 5E is arranged on the other side of the extending portion of the transfer body cleaning device 5E. The transfer body cleaning device 5E includes a recovery tank that can contact and separate from the belt-shaped transfer body 5A.
Among them, the recovery tank is connected to the tank of the photoconductor cleaning means by a communication means such as a recovery pipe 5E1 as shown by a dashed line in FIG. On the other hand, the photoconductor cleaning means 6 arranged around the belt-shaped photoconductor 2 has a toner scraping structure including a blade that comes into contact with the peripheral surface of the belt-shaped photoconductor 2, and is scraped by the blade. It is equipped with a tank for storing toner.
Further, the arrangement position of the photoconductor cleaning means 6 has no components which are contaminated by the toner when the toner scraped from the surface of the belt-shaped photoconductor 2 or dust such as paper dust naturally drops due to gravity. In the case of this embodiment, it is located closer to the side wall 1A of the apparatus main body than the position of the belt-shaped photoconductor 2. The toner recovery tank of the photoconductor cleaning means 6 is set in a shape that allows one end of the belt-shaped transfer member 5A in the extending direction to be positioned.

The photosensitive member cleaning means 6
Is supported by the module M1 which supports the belt-shaped photoreceptor 2 and the developing means 4, and can be pulled out from the image forming apparatus 1 together with the belt-shaped photoreceptor 2 and the developing means 4.

A secondary transfer portion 8 is provided at the upper end of the belt-shaped transfer member 5A in the extending direction. The secondary transfer section 8 is composed of a transfer bias roller which is vertically displaceable in the drawing and is capable of coming into contact with and separating from the belt-shaped transfer body 5A, and recording which passes through a sheet feeding section described later. A transfer bias is applied when the paper is pressed and brought into contact with the belt-shaped transfer body 5A.

The sheet feeding section 9 is arranged above the belt-shaped transfer member 5A and the belt-shaped photosensitive member 2 and the rotary developing means 4 above the inside of the apparatus main body. . Since there is no interfering component below the paper feed unit 9, a recording paper conveyance path that is substantially horizontal and crosses the secondary transfer unit 8 is formed.
A paper feed cassette 9A that is attachable to and detachable from the apparatus main body is arranged on one side of the extension direction of the conveyance path, and the above-mentioned fixing device 7 is arranged on the other side of the extension direction. This fixing device 7
It has a well-known structure in which a heating roller and a pressure roller are combined, and is provided with a release agent coating device for preventing offset. Paper feed cassette 9 in paper feed unit 9
From A, one sheet of recording paper is delivered by the delivery roller 9A1, and the delivered recording sheet is conveyed by the registration roller 9A2 after alignment with the image position on the belt-shaped transfer body 5A is set, and the secondary recording sheet is conveyed. The image on the belt state transfer body 5A is transferred by being pressed by the transfer bias roller 8 and being applied with a bias from the transfer bias roller when the position of the transfer bias roller forming the transfer portion 8 is reached, and the fixing device 7 The image carried on the belt-state transfer member 5A is transferred by being pressed by the fixing means 7 and biased by the transfer bias roller, and the fixing device 7 fixes the carried image. In the paper feeding unit 9, the image transfer is performed on the lower surface of the recording paper fed from the paper feeding cassette 9A. Therefore, the primary transfer from the photosensitive drum 2 to the belt-shaped transfer body 5A is performed. Are sequentially transferred from the first page of the document.

Next, the operation will be described. Inside the image forming apparatus, the belt-shaped photoreceptor 2 is stretched in the horizontal direction of the apparatus main body, and one end in the stretching direction faces one of the stretched portions of the belt-shaped transfer body 5. Further, the developing means 4 is arranged on one lower surface of the extending portion of the belt-shaped photosensitive member 2, and above the other extending portion of the belt-shaped photosensitive member 2, that is, the upper end position of the belt-shaped transfer member 5A in the extending direction. The paper feed unit 9 is located at. Therefore, the developing means 4 is located below the respective positions of the belt-shaped photoconductor 2, the belt-shaped transfer body 5A, and the conveyance path of the transfer paper fed from the paper feed section 9, so that the developer supply section It is possible to prevent the toner scattered and dropped from adhering to the above-mentioned parts. Further, the developer supply section in the developing means 4 is
Since the belt-shaped photoconductors 2 are arranged in parallel in the horizontal direction along the extending direction, it is possible to prevent the toner from being mixed into the adjacent developer supply portions due to dropping.

On the other hand, when forming a full-color image, the belt-shaped photoreceptor 2 forms an electrostatic latent image through scanning by the writing device 3B for each color separation or for each color information, and this electrostatic latent image is colored. A developer supply unit containing a toner of a color corresponding to information faces the belt-shaped photoconductor 2 to perform a visible image processing. Then, the toner image carried on the belt-shaped photosensitive member 2 is transferred to the belt-shaped transfer member 5A in the primary transfer portion 5, and the transfer is repeated and repeated for each color. Then, the images that have been overlaid and transferred are collectively transferred to the recording paper fed from the paper supply unit 9 in the secondary transfer unit 8. Further, the belt-shaped transfer body 5 that has completed the batch transfer
The belt-shaped photoconductor 2 after the transfer of the toner images of A and colors is cleaned after the transfer, and the toner and paper dust scraped off by this cleaning are introduced into the recovery tank of the belt-shaped photoconductor cleaning means 6. It

On the other hand, replacement of the belt-shaped photoconductor 2 or
When a jam occurs in the paper feeding unit 9, the side wall 1A or the upper wall 1B of the apparatus main body is opened as shown in FIG. Therefore, when the side plate 1A or the upper wall 1B is opened, the unitized module M1 including the belt-shaped photoconductor 2 can be pulled out to the side of the apparatus main body, and the transport path of the sheet feeding unit 9 is exposed. .

According to the present embodiment, the arrangement position of the photoconductor cleaning means 6 is set to a position where the toner scraped from the belt-shaped photoconductor is not contaminated by the natural drop of the toner or paper powder, and the photoconductor cleaning device 6 is scratched from the transfer body. Since the taken toner is collected on the side of the photoconductor cleaning means 6, it is possible to prevent the internal components from being contaminated due to the natural fall of the toner or paper powder.

Further, since the paper feeding unit 9 is arranged at the position corresponding to the highest position inside the image forming apparatus 1, it is possible to set the position with good visibility when replacing the paper feeding cassette and the operability. Can be better.

Further, since the paper feeding section 9 is arranged at a position where there is no interference in the vicinity, the transfer paper transport path can be set to a substantially horizontal line. Therefore, since it is not necessary to provide a bent path or the like on the transfer paper conveyance path, the shortest distance can be set, and the probability of jam occurrence can be suppressed.

In the above-described embodiment, the structure of the electrostatic latent image forming means is, for example, the bottom surface side of the image forming apparatus, in other words, the structure in which the scanning portion is arranged below the belt-shaped photoconductor 2. However, the present invention is not limited to such a structure. For example, as shown in FIG. 3, by setting the optical path to the belt-shaped photoconductor 2 at an appropriate position, the belt-shaped photoconductor 2 can be positioned above the belt-shaped photoconductor 2. The writing device 3B may be arranged. In this case, in addition to the case of the embodiment shown in FIG. 1, it is possible to prevent the toner from dropping to the optical path setting portion formed in the writing device 3B.

Further, in the present invention, as the structure of the above-mentioned developing means, the structure in which the developer supplying portions are arranged in parallel along the extending direction of the belt-shaped photosensitive member is mentioned, but it is not limited to this structure. For example, as shown in FIG. 4, a rotary developing device 400 may be configured in which a plurality of developer supply units are arranged along the circumferential direction of the rotary support.

That is, the rotary developing means 400 in this case
Is provided with a rotatable casing which is arranged so as to face the lower surface of the lower stretched portion of the belt-shaped photoreceptor 2. Then, along the circumferential direction of the casing, for example, a developer supply unit 400A containing non-magnetic one-component toners of yellow, magenta, cyan, and black, which are complementary colors to the three primary colors of subtractive color mixture. Four
00B, 400C, and 400D, and the developer supply portion containing the toner of the selected color among these developer supply portions can be made to face the lower extension portion of the belt-shaped photoreceptor 2. ing. As described above, the developer supply unit of the rotary developing unit 4 uses a non-magnetic one-component toner, but such a one-component toner is well known, and the developing unit is also used in this embodiment. As in the structure of this type of apparatus, the developing sleeve 40, which is a toner supply member, the supply roller 41, which is a toner conveying member, the developing blade 42, which is a toner thinning member, and the stirring screw 43, which is a toner conveying member, have the same structure. Is equipped with. Note that FIG.
In FIG. 1, one of the developing units is cited to show the configuration of the developing unit.

Further, the developing means 4 or 400 needs to be located at least below the belt-shaped photosensitive member 2 and the paper feeding section 9, as is apparent from the above-mentioned embodiments. For this reason, in the belt-shaped photoconductor 2, the position facing the developing means 4 or 400 needs to be set in the horizontal direction of the image forming apparatus 1. However, this horizontal portion is set between the pulleys. It is not limited to targeting the entire area. That is, the example shown in FIG. 5 is an example of this case, in which the belt-shaped photosensitive member 2 is wound around a plurality of pulleys, and a part of the extending portion between the pulleys is horizontal in the image forming apparatus 1. Is set to the direction. The developing means, in this case the rotary developing means 400, is arranged on the lower surface of the portion that is horizontally extended. With such a structure of the belt-shaped photosensitive member 2, it is possible to incline the range other than the horizontal portion of the belt-shaped photosensitive member 2 with respect to the horizontal direction while ensuring the peripheral length required for image formation. become. Therefore, the belt-shaped transfer body 5A is also tilted along the height direction of the image forming apparatus 1 to reduce the horizontal size occupied by the belt-shaped photoconductor 2 and at the same time, the belt-shaped transfer body 5A. It is possible to reduce the size of the image forming apparatus 1 in the height direction. In FIG. 5, reference numeral 500 indicates a developing device that contains a black developer for forming a monochrome image. In the developing device 500, a large amount of two-component toner that can be supplied is stored.

[0030]

As described above, according to the present invention,
The photoconductor on which the image is formed and the paper feed unit for feeding the transfer paper on which the formed image is transferred can be located above the developing means. Therefore, it is possible to prevent the toner scattered and dropped from the developing unit from dropping and adhering to the photoconductor or the transfer paper. For this reason, it is possible to substantially completely prevent color mixture on the image bearing the photoconductor or the transfer paper.

Further, according to the present invention, a belt-shaped photoreceptor is used as the photoreceptor, the belt-shaped photoreceptor is provided with a stretched portion along the horizontal direction of the image forming apparatus 9, and the developing means is provided along the stretched portion. It is possible to arrange a plurality of developer supply units. Therefore, the toner scattered and dropped from each developer supply section does not intrude into the adjacent developer supply section, whereby the color mixture of the dynamic motion of the developer is prevented in advance.

Further, the developing means can be located below the belt-shaped photosensitive member including the writing device and the paper feeding section. Therefore, not only the belt-shaped photoconductor and the paper feeding unit, but also the scattering and dropping of the toner to the optical path forming opening in the writing device can be eliminated.
It is possible to prevent the occurrence of adverse effects such as writing failure on image formation.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an overall configuration of an image forming apparatus according to the present invention.

FIG. 2 is a schematic diagram for explaining a module withdrawn state during maintenance of the image forming apparatus shown in FIG.

FIG. 3 is a schematic diagram showing a partially modified example of the image forming apparatus shown in FIG.

FIG. 4 is a schematic diagram showing another modification of a part of the image forming apparatus shown in FIG.

5 is a schematic view showing still another modification of a part of the image forming apparatus shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image forming apparatus 1A Side wall 1B Upper wall 2 Belt-shaped photoreceptor 3 Electrostatic latent image forming means 4 Rotational development means 5 Primary transfer section 5A Belt-shaped transfer body 5B Transfer body support member 5C Transfer body support member 6 Photoconductor cleaning means 8 Secondary transfer section 9 Paper feeding section 400 Rotational developing means M1 Module on belt side photoreceptor

Claims (4)

[Claims] 1. A primary transfer process in which a toner image is formed on a photosensitive member for each color separation or in accordance with color information, and the toner images are sequentially transferred to an intermediate transfer member, and a primary transfer process is performed from the intermediate transfer member to a recording sheet. An image forming apparatus that forms an image of at least two or more colors by executing a secondary transfer step of collectively transferring the image, and is provided with a primary transfer unit that is extended along the height direction of the apparatus main body. The belt-shaped transfer member that constitutes the intermediate transfer member and one end of the belt-shaped transfer member in the expansion direction are brought into contact with each other, and the belt-shaped transfer member is expanded in the horizontal direction of the apparatus main body and can be interlocked with the belt-shaped transfer member. A belt-shaped photoconductor, a means for forming an electrostatic latent image corresponding to each color on the belt-shaped photoconductor, and a different surface of the belt-shaped photoconductor. Of visible image processing with the developer A number of developing means, a secondary transfer section for performing a secondary transfer step, which is provided on the upper end side of the belt-shaped transfer body so as to face it, and a paper feed for feeding a transfer sheet to the secondary transfer section. An image forming apparatus, wherein the developing unit is arranged at least below the belt-shaped photosensitive member and the sheet feeding device. 2. The image forming apparatus according to claim 1, wherein the developing device is composed of a plurality of developer supply units arranged along the extending direction of the belt-shaped photoconductor. 3. The image forming apparatus according to claim 1, wherein the developing device is rotatably provided on the lower surface of the belt-shaped photosensitive member, and among the plurality of toner containing portions provided along the rotation direction. 2. An image forming apparatus comprising a rotary developing means in which a developing section accommodating toner of the selected color is opposed to one position in the circumferential direction of the photosensitive drum. 4. A primary transfer process in which a toner image is formed on a photoconductor for each color separation or in accordance with color information, and the toner images are sequentially superposed and transferred onto an intermediate transfer member, and from this intermediate transfer member to a recording sheet. An image forming apparatus that forms an image of at least two or more colors by executing a secondary transfer step of collectively transferring the image, and is provided with a primary transfer unit that is extended along the height direction of the apparatus main body. The belt-shaped transfer member forming the intermediate transfer member and one end of the belt-shaped transfer member in the expansion direction are brought into contact with each other so that an angle of the belt-shaped transfer member in the horizontal direction of the apparatus main body is set to be larger than that of the belt-shaped transfer member. A belt-shaped photoconductor that is expanded with the belt-shaped photoconductor and is operable to form an electrostatic latent image corresponding to each color on the belt-shaped photoconductor, and the belt-shaped photoconductor is expanded. Located opposite the underside of the part, A plurality of developing units that perform visible image processing with developers of different colors; a secondary transfer unit that performs a secondary transfer process that is provided so as to face the upper end side of the belt-shaped transfer body; An image forming apparatus, comprising: a sheet feeding device that feeds a transfer sheet toward a secondary transfer portion, wherein the developing unit is disposed at least below the belt-shaped photoreceptor and the sheet feeding device. .