JPH0887151A - Image forming device - Google Patents

Abstract

PURPOSE: To obtain an image forming device excellent in maintainability by inclining a carrying path to a horizontal direction. CONSTITUTION: Driving rollers 14A and 14B are provided near a paper feeding roller 12 and a fixing device 13 in a housing 11, and a transfer belt 15 is laid over the driving rollers 14A and 14B. The inclined carrying path 16 for an image transfer medium is formed of the driving rollers 14A and 14B and the transfer belt 15. Paper 17 being the image transfer medium supplied from a paper supply port 11A in the housing 11 is carried on the carrying path 16 and ejected from a paper ejection port 11B in the housing 11. The carrying path 16 is provided to be inclined at an angle 20 deg. to the base of the housing 11. Since the carrying path 16 is inclined to the horizontal direction, large space for arrangement is secured on the downstream side of the carrying path 16 by inclining the downstream side of the carrying path 16 downward. Therefore, a large-capacity toner hopper and an image forming means having a photoreceptive drum whose diameter is large are arranged on the downstream side, and the maintenance is facilitated.

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 such as a printer.

[0002]

2. Description of the Related Art There are various methods for forming an image on a printing apparatus such as a printer that forms an image on an image transfer medium such as paper. For example, an electrophotographic method in which an electrostatic image is formed on a photosensitive drum, which is an image recording medium, is visualized with toner and transferred to paper, an inkjet method in which ink droplets are directly sprayed on the paper to form an image, and a photosensitive color material is used. A typical example is a silver salt photographic method in which an image is exposed and recorded.

When a color image is formed by a printing apparatus using an electrophotographic system, the following system is adopted. (1) 3 to form a color image on the photosensitive drum
A method of forming a toner image of one of the primary colors yellow, magenta, and cyan and transferring the toner image onto a sheet is repeated for three colors (in some cases, four colors including black are repeated).

(2) A method of forming toner images of three primary colors on a photosensitive drum and transferring them to a sheet at a time. (3) A method in which an image forming unit that forms a single-color toner image is formed by arranging only black and three primary color toners in the paper direction and sequentially superposing the single-color images on the paper to form a color image.

Among these methods, the method of arranging a plurality of image forming units in (3) in the paper conveying direction is called a tandem method, which is superior in that the printing recording speed is higher than other methods, and the apparatus is small. This is one of the most suitable methods to realize.

A configuration example of a tandem type color image forming apparatus by an electrophotographic method will be described with reference to FIG. The housing 1 is provided with a paper supply port 1A on one side and a paper discharge port 1B on the other side. A paper feed roller 2 is provided near the paper supply port 1A in the housing 1, and a fixing device 3 is provided near the paper discharge port 1B. Further, drive rollers 4A and 4B are provided near the paper feed roller 2 and the fixing device 3 in the housing 1, and a transfer belt 5 is stretched around the drive rollers 4A and 4B. A conveyance path 6 for the image transfer medium is formed by the drive rollers 4A and 4B and the transfer belt 5, and the paper 7 which is the image transfer medium supplied from the paper supply port 1A in the housing 1 along the conveyance path 6. Is transported on the transport path 6 and discharged from the paper discharge port 1B in the housing 1. The transport path 6 is provided in parallel to the bottom side of the housing 1, and therefore the transport path 6 is configured to extend substantially in the horizontal direction.

Image forming units 8A and 8A for forming monochrome images of yellow, magenta, cyan and black are provided on the conveying path 6.
B, 8C, and 8D are sequentially arranged along the paper transport direction from the paper supply port 1A on the upstream side of the transport path 6 to the paper discharge port 1B on the downstream side of the transport path 6 so as to be separated from each other.
The image forming units 8A, 8B, 8C, 8D are
It is composed of a toner hopper, a photosensitive drum, a charging device, a line optical head, a developing device, a transfer roller, a charge eliminating lamp, a memory removing brush and the like. Here, each toner hopper, each photosensitive drum, each charging device, each line optical head, each developing device, each transfer roller, each charge eliminating lamp, and each memory removing brush in each image forming unit 8A, 8B, 8C, 8D is a toner type. Except for, it has substantially the same shape, volume and function.

Since such an image forming apparatus is provided with a plurality of image forming units 8A, 8B, 8C and 8D,
It has an advantage that the time for forming a color image on the paper 7 is shorter than other methods. In the electrophotographic tandem color image forming apparatus, as shown in FIG. 4, generally, image forming units 8A, 8B, 8 for forming light-colored yellow, magenta, cyan, and black monochromatic images.
The color images are formed by arranging them in the order of C and 8D horizontally with respect to the paper conveyance direction.

In general, in terms of the frequency of use of the printer device, a black-and-white image forming a black image forming a monochrome image is much larger than a full-color image forming a black-and-white image in a ratio of 3: 7. The toner consumption amount is increased as compared with other toner colors, the number of times of black toner replenishment is increased, and there is a problem in maintainability.

This is because the capacity of each toner hopper provided in each image forming unit is constant. Therefore, in order to increase only the capacity of the black toner hopper of the image forming unit 8D that forms the black monochromatic image disposed on the most downstream side, only the one of the image forming unit 8D that forms the black monochromatic image has a large capacity toner hopper. It is conceivable to equip it, but this will increase the size of the entire device.
When forming only a black and white image, only the image forming unit 8D that forms a black monochromatic image is operated, and the other color image forming units 8A, 8B and 8C stop only the drive circuit of the developing device and the photosensitive drum. Then, the contact between the photosensitive drum surface and the transfer belt is released.

On the other hand, the photosensitive drum of the image forming unit 8D for forming a black monochromatic image has an overwhelmingly larger unit area than the photosensitive drums of the image forming units 8A, 8B, 8C for forming other color images. Frequent use.

An organic photoconductor (OPC) or the like is often used for the photosensitive layer on the surface of the photosensitive drum, and the functional life of the photosensitive layer is generally defined by the frequency of use per unit area. That is, even with a color image forming apparatus, the frequency of output of monochrome images is high due to the usage pattern of general users. From this, in the image forming apparatus in which the photosensitive drum of the image forming unit that forms a black monochrome image and the photosensitive drum of the color image forming unit have the same diameter, the difference in the frequency of use per unit area of the photosensitive drum There is a problem that the photosensitive drum of the image forming unit that forms a black monochromatic image is replaced more frequently than the photosensitive drums of other color image forming units.

Further, in the image forming apparatus, an electronic control board for controlling these is incorporated in addition to the image forming unit, the fixing device and the conveying path which are the main elements of image formation.
The electronic control board is often arranged in an empty space in a housing that houses the image forming unit, the fixing device, and the transport path. Therefore, the high voltage, noise, and high heat generated by the high voltage source, the noise source, the image forming unit that is the high heat source, the fixing device, and the transport system may affect the electronic control board and cause the device to malfunction. Met. In order to prevent such malfunctions, it is preferable to electrically and thermally shield the electronic control board.
Not only the complexity of the structure but also the size of the device is increased.

[0014]

As described above, in the conventional image forming apparatus, when forming a black and white image, the toner hopper for storing the toner has a constant capacity, so that a black monochromatic image compared with other toner colors is formed. The amount of black toner that forms the toner increases, the number of times black toner is replenished increases, and the diameter of the photosensitive drum, which is the image transfer medium, is constant. Due to the difference, the photosensitive drum for forming a black and white image must be frequently replaced, which causes a problem in maintainability.

Further, in the conventional image forming apparatus, there is a risk of malfunction due to high voltage, noise and high heat. Therefore,
An object of the present invention is to provide an image forming apparatus having excellent maintainability. Another object of the present invention is to provide an image forming apparatus capable of reducing the occurrence of malfunction.

[0016]

In order to achieve the above-mentioned one object, an image forming apparatus according to the present invention comprises a plurality of image transfer media arranged along a predetermined conveying path with respect to an image transfer medium conveyed along the predetermined conveying path. An image forming apparatus configured to form a multicolor image by an image forming unit is characterized in that the conveying path is inclined with respect to a horizontal direction.

In order to achieve the above-mentioned other objects, an image forming apparatus according to the present invention has an image forming section for transferring a toner image onto an image transfer medium conveyed along a predetermined conveying path, and an image forming section for transferring the toner image. In an image forming apparatus including a fixing unit that fixes the toner image to the image transfer medium, and a control unit that controls at least the image forming unit and the fixing unit, the image forming unit and the fixing unit include The conveyance path is provided between at least one of them and the control unit.

[0018]

According to the present invention, since the conveying path is inclined in the horizontal direction, for example, if the downstream side of the conveying path is inclined downward, a large arrangement space is secured on the downstream side of the conveying path. An image forming unit having a large-capacity toner hopper and a large-diameter photosensitive drum can be arranged on the downstream side.

As described above, if the large-capacity toner hopper accommodates the black toner, which is particularly frequently used,
It is possible to extend the replacement maintenance life of the toner hopper, and by making the size of the toner hopper different for each color, it is possible to prevent a mistake in mounting each color when the toner hopper is replaced.

Further, since the conveying path is provided between at least one of the image forming section and the fixing section and the control section, the conveying path has a space between at least one of the image forming section and the fixing section and the control section. And the influence of high voltage, noise, and high heat on the control unit can be reduced.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a tandem type color image forming apparatus will be described below with reference to FIGS. As shown in FIG. 1, the housing 11 of the tandem color image forming apparatus 10 has a sheet supply port 11 on one side thereof.
A is provided, and a paper discharge port 11B is provided on the other side. As shown in FIG. 1, the paper supply port 11A is provided at a high position with respect to the bottom side of the housing 11, and the paper discharge port 11B is provided at a low position with respect to the bottom side of the housing 11. There is. A paper feed roller 12 is provided near the paper supply port 11A, and a fixing device 1 is provided near the paper discharge port 11B.
3 is provided.

Driving rollers 14A and 14B are provided near the paper feed roller 12 and the fixing device 13 in the housing 11.
Is provided, and the transfer belt 15 is stretched around the drive rollers 14A and 14B. This drive roller 14A, 1
An inclined conveyance path 16 for the image transfer medium is formed by 4B and the transfer belt 15. Paper supply port 1 in housing 11
The sheet 17 which is the image transfer medium supplied from 1A is conveyed on the inclined conveyance path 16 and the sheet discharge port 1 in the housing 11 is conveyed.
Emitted from 1B. The inclined transport path 16 is provided in the housing 11
Is inclined with a predetermined angle with respect to the bottom side (generally along the horizontal plane). In this embodiment, the inclination angle is set to 20 degrees, for example.

In the present embodiment, the conveying path is lowered and inclined toward the downstream side, but it may be reversed, that is, it may be inclined upward from the upstream side toward the downstream side. Image forming units 18, 19, 2 for forming monochrome images of yellow, magenta, cyan, and black are provided on the conveying path 16.
Nos. 0 and 21 are sequentially arranged along the sheet conveying direction from the sheet supply port 11A on the upstream side of the inclined conveyance path 16 to the sheet ejection port 11B on the downstream side of the inclined conveyance path 16.

Each image forming unit 18, 19, 20, 2
Reference numeral 1 denotes a toner hopper 18 that stores yellow, magenta, cyan, and black nonmagnetic toners TY, TM, TS, and TB.
a, 19a, 20a, 21a, photosensitive drums 18b, 19b, 20b, 21b which are image recording media, and chargers 18c, 19c, 20c, 21c for uniformly charging the surfaces of the photosensitive drums 18b, 19b, 20b, 21b. And line optical heads 18d, 19d, 2 for forming electrostatic latent images on the surfaces of the photosensitive drums 18b, 19b, 20b, 21b.
0d, 21d, developing rollers 18e, 19e, 20e, 21e for developing the electrostatic latent image into a toner image, and the photosensitive drum 1.
The toner images on 8b, 19b, 20b, and 21b are printed on the paper 17
Transfer rollers 18f, 19f, 20f, 21f for transferring to
And the photosensitive drums 18b, 19b, 20b, 21 after transfer
Static elimination lamps 18g, 19g, 20 for eliminating static electricity on the surface of b
g, 21g, and memory removal brushes 18h, 19h, 20h, 21h for averaging transfer residual toner, developing roller 1
8i, 19i, 20i, 21i, developing blade 18j,
It is composed of 19j, 20j, 21j and the like.

Then, each image forming unit 18, 19,
Toner hoppers 18a, 19a, 20 in 20, 21
a, 21a and the photosensitive drums 18b, 19b, 20b, 2
1b, chargers 18c, 19c, 20c, 21c, line optical heads 18d, 19d, 20d, 21d, developing rollers 18e, 19e, 20e, 21e, transfer rollers 18f, 19f, 20f, 21f, static elimination lamps. 18
g, 19g, 20g, 21g and memory removal brush 18
h, 19h, 20h, 21h and developing rollers 18i, 1
9i, 20i, 21i, developing blades 18j, 19j,
20j and 21j have substantially the same function except for the toner type, but the toner hoppers 18a, 19a, 20
a, 21a and the photosensitive drums 18b, 19
The diameters of b, 20b and 21b are different.

In this embodiment, the toner hopper 21a of the image forming unit 21 arranged on the most downstream side of the inclined conveying path 16 is the other toner hoppers 18a, 19a, 20a.
It has a large volume compared to. In the example shown in FIG. 1, the toner hoppers 18a, 19a, 20a, and 21a of the image forming units 18, 19, 20, and 21 are gradually increased in volume from the upstream side to the downstream side of the inclined conveyance path 16.

The diameter of the photosensitive drum 21b of the image forming unit 21 arranged on the most downstream side of the inclined conveying path 16 is larger than the diameter of the other photosensitive drums 18b, 19b, 20b.

In this embodiment, an electronic control board 30 is incorporated in the lowermost part of the inclined conveyance path 16 of the housing 11 on the most upstream side. Here, the inclined conveyance path 16 is configured between the image forming units 18, 19, 20, 21 and the fixing device 13 and the electronic control board 30, and with this configuration, in the housing 11. Image forming unit 18,
19, 20, 21 and fixing device 13, and electronic control board 30
And are spatially separated. Next, the operation of this embodiment configured as described above will be described. That is, the toner images formed by the image forming units 18, 19, 20, and 21 are adhered onto the transfer belt 15 by electrostatic force and transferred onto the conveyed paper 17 while being sequentially superposed, and the toner is fixed by the fixing device 13. Is melt-pressed to form a color image.

The recording principle will be described in detail with reference to FIG. FIG. 2 is a schematic view of a one-component non-magnetic developing roller represented by the yellow image forming unit 18. Of course,
Similar operations are performed in the other image forming units 19, 20, and 21. That is, the photosensitive drum 18a of the image forming unit 18 is negatively charged by the charger 18c. An electrostatic latent image is formed on the surface of the charged photosensitive drum 18a by the line optical head 18d. The electrostatic latent image is developed into a toner image by a one-component non-magnetic developing method which does not require a magnetic carrier and a magnet roller. The toner image is transferred onto the sheet 17 which is an image transfer medium by the transfer roller 18f, and the toner TY is transferred by a fixing device (not shown).
Is melt-pressed to form a color image.

In the example shown in FIG. 2, since the transfer leakage toner TYa on the photosensitive drum 18a is directly returned to the developing roller 18e by the simultaneous developing cleaning, the transfer residual toner TYa is collected by the developing roller 18i, This eliminates the need for a dedicated cleaner. The memory removal brush 18h
The transfer residual toner TYa can be averaged to improve the reliability of the cleanerless process. Static elimination lamp 18g
Erases the surface of the photosensitive drum 18b after transfer,
The memory removing brush 18h is arranged in front of the memory removing brush 18h in order to promote averaging of toner.

A one-component non-magnetic developing system will be described with reference to FIG. 3 in addition to FIG. That is, the non-magnetic toner TY is sent to the developing roller 18e by the toner supply roller 18i made of a conductive sponge. Toner supply roller 1
8i rotates counterclockwise while contacting the developing roller 18e. The developing roller 18e is a roller in which conductive paint is applied to the surface of conductive urethane rubber, and
Rotate counterclockwise while contacting b. The developing blade 18j made of silicone rubber is pressed against the surface of the developing roller 18e, and the toner TY adheres to the surface of the developing roller 18e in a thin layer by frictional charging with the developing roller 18e.

Next, from the developing roller 18e to the photosensitive drum 1
The transfer process to 8b will be described with reference to FIG. That is, the line optical head 18 is formed on the surface of the charged photosensitive drum 18b.
An electrostatic latent image is formed by d. The surface potential of the electrostatic latent image is charged to about 0 V, and the surface other than the surface of the electrostatic latent image is about −.
It is charged to 500V.

Approximately -200 V is applied to the developing roller 18e by the negative biases R and E, and the toner TY on the surface of the developing roller 18e is attracted to and adheres to the potential difference between it and the electrostatic latent image portion. develop. Photosensitive drum 1
The untransferred toner TYa remaining on the surface of 8b is attracted to the developing roller 18e and cleaned at the same time as the developing, because it is charged to -500V by the charger 18c.

As shown in FIG. 1, the image forming units 18, 19, 20, 21 for forming a color image have a predetermined angle with respect to the slanted conveyance path 16, that is, the bottom side of the housing 11 (generally along the horizontal plane). Is installed with an inclination. In this embodiment, the inclination angle is set to 20 degrees, a predetermined inclination angle is provided, and yellow, magenta, cyan, and black are arranged at equal intervals along the inclination line in the sheet conveying direction (the arrow direction in the drawing), and the Toner hopper 18 of developing rollers 18e, 19e, 20e, and 21e for developing an electrostatic latent image into a toner image
The volumes of a, 19a, 20a, and 21a can be deformed according to the inclination angle, whereby the amount of toner can be increased. In particular, the image forming unit 21 located at the bottom is formed to form a black image, and the angle of inclination is increased to, for example, 2
By securing about 0 °, the space on the upper side of the inclined line can be wide, and the volume of the black toner hopper 21a can be about 1.5.
The black toner T can be deformed largely by a factor of two to two.
The amount of B can be increased, which is effective when forming a monochrome image.

The same applies to the photosensitive drum, which is the image recording medium of the image forming unit, and the inclined conveying path 16 is used.
Image forming units 18, 19, 20, depending on the inclination angle of
Photosensitive drums 18b, 19b, which are 21 image recording media,
The diameter of 20b and 21b can be enlarged. In particular, since the photosensitive drum 21b, which is the image recording medium of the image forming unit 21 that forms a black image, can have a large inclination angle, the space above the inclination line can be wide, and the photosensitive drum conventionally used. The diameter of 40φ can be increased to 60φ. Therefore, since the diameter of the photosensitive drum 21b of the image forming unit 21 that forms a black image can be increased, the frequency of use of the photosensitive drum 21b per unit area can be reduced, and the replacement time of the photosensitive drum 21b can be extended. You can

Further, since the toner hopper 21a having an increased capacity and the image forming unit 21 having a large diameter of the photosensitive drum 21b as an image recording medium are provided at the lowermost portion,
Replenishment of the toner TB and replacement of the photosensitive drum 21b can be reduced. This is particularly effective when forming a black and white image.

Since the size of the toner hopper or the photosensitive drum can be made different for each color, it is possible to prevent the replacing person from mistakenly installing the wrong color when replacing the toner hopper or the photosensitive drum.

On the other hand, in this embodiment, the electronic control board 3 is used.
0 is placed in an empty space formed in the lowermost portion of the inclined transport path 16 of the housing 11 on the most upstream side. That is, the inclined conveyance path 16 has a configuration in which the image forming units 18, 19, 20, 21 and the fixing device 13 are spatially separated in the housing 11, and the inclined conveyance path 16 of the housing 11 is included. An empty space is formed in the lowermost part on the most upstream side. By arranging the electronic control board 30 in this empty space, not only the space is effectively used but also the electronic control board 3 is used.
It is possible to reduce the influence of high voltage, noise, and high heat from the image forming units 18, 19, 20, and 21 and the fixing device 13 on zero.

The above-described embodiments have been described with respect to the image forming apparatus capable of reducing the maintainability and the occurrence of malfunctions. In the following, a flat photoconductor is used to achieve high accuracy in image color matching. An image forming apparatus capable of performing the above will be described.

First, a conventional technique of an image forming apparatus capable of highly accurately performing color matching of images by using a flat photoconductor will be described. That is, in a full-color image printer, conventionally, when a full-color image is printed on a sheet, a four-series tandem type image forming apparatus is known as shown in FIG.

In this type of image forming apparatus, there are respective image forming units 44 (44-1, 44-2, 44-3, 44-4) for yellow, cyan, magenta and black. The printing process of the image forming apparatus will be described for the yellow image forming unit 44-1 as the operation of the image forming unit 44. The photosensitive drum 41 removes the toner remaining after the transfer with the cleaner 46, and is uniformly charged by the charging roller 42.

Next, the phosphor head 43 changes the charging state on the photosensitive drum 41, and the toner in the image forming unit 44 adheres to the surface of the photosensitive drum 41 at the changed portion. The sheet of paper 49 is inserted from the insertion port of the image printer, conveyed by the transfer belt 47, and the photosensitive drum 41 to which toner adheres also rotates,
The toner is transferred onto the sheet 49 by the transfer charger 45. This transfer is performed by the image forming unit 44 (44-1, 4).
4-2, 44-3, 44-4) is repeated for four colors, and the paper 49 on which the four colors are transferred is fixed by the fixing device 48.

However, in the four-series random image forming apparatus, the photosensitive drum 41 of the image forming unit 44 for each color has eccentricity of the driving mechanism and load variation of contact development, and the peripheral speed of each photosensitive drum 41 is not constant. Instead, the image printed on the paper 49 appeared as a color shift.

Further, due to the lack of parallelism of the transfer belt 47 conveyance mechanism, the sheet was meandered and conveyed, which also appeared as a color misregistration of the image. In order to eliminate these color misregistrations, a method for controlling the peripheral speed of the photosensitive drum 41 with high accuracy and a method for preventing color misregistration even if there is a rotation fluctuation have been required. Further, when the parallelism of the paper transport mechanism is insufficient, it is necessary to improve the parts and assembling accuracy so as not to cause meandering or to correct the meandering.

A color image forming apparatus which solves the above problems and is capable of highly accurately performing color matching of images by using a flat photosensitive member has the following configuration. That is, a flat photoconductor on which an image is formed, a plurality of image forming units movable along the flat photoconductor, a flat transfer plate for transferring the image formed on the flat photoconductor to a sheet, and a sheet are conveyed. It is provided with a belt and a conveyance roller, and a roller for fixing the image transferred on the paper.

Further, the flat photoconductor is configured to be movable between an image forming position and an image transfer position. Further, the image forming unit includes a cleaner for removing the toner remaining on the surface of the flat photoconductor, a means for forming an electrostatic latent image on the surface of the flat photoconductor, and the electrostatic latent image developed into a toner image. It is configured to include means for performing.

Further, the image forming unit is movable only in one direction, and the alignment of the plurality of image forming units is detected by a detector in the image forming unit to detect a mark provided in the movable direction. By doing so, the alignment is performed.

That is, in this embodiment, an image is formed on the flat photoconductor surface. In forming an image, main scanning is performed by moving the image forming unit, and sub-scanning is performed by exposing a flat photoconductor by a phosphor head inside the image forming unit. Toner is attached to the surface of the flat photoconductor exposed by the phosphor head, and the toner adhering to the surface of the flat photoconductor is transferred to a sheet using a flat transfer plate. The toner transferred to the paper is fixed by the fixing roller.

A plurality of forming units are provided for the color components forming an image, and the image transfer position on the paper is
The marks on the rails arranged in the main scanning direction in which the image forming unit moves are read by a detector in the image forming unit.

Using a flat photoconductor as the photoconductor,
Each image forming unit moves in the main scanning direction to form an image on the surface of the coplanar photoconductor. The sub-scanning start position of each image forming unit is set by reading a mark attached in the main scanning direction in which the image forming unit moves. Also, when transferring toner to paper, stop the paper,
Done on the transfer plate.

To explain the preferred embodiment of the present invention based on the above-described principle of the invention, FIG. 6 is a perspective view of the present embodiment, in which the flat photoconductor 51 on which an image is formed is a motor for moving the flat photoconductor. A guide 6 is provided so that the flat photosensitive member 51 does not move left and right and front and back.
0 is attached.

In the image forming unit 53, the toner 84 is
Four are prepared to output a full color using four colors of yellow, cyan, magenta, and black. As shown in FIG. 7, the image forming unit 53 mainly cleans the surface of the flat photoconductor 51 by uniformly removing the toner remaining on the surface of the flat photoconductor 51. A charging device 82, an LED head 83 that removes a charged portion of the flat photosensitive member 1 by exposure depending on the content of the image, and a toner 84 on the exposed and uncharged portion of the surface of the flat photosensitive member 51. It is composed of a conductive rubber roller attached to the surface of 51.

Further, these image forming units 53 are
It can be moved in the main scanning direction, and as shown in FIG. 8, a dependent roller 87 is attached along a guide 59 and is moved by a drive roller 86. The linear encoder 63 detects the moving position at this time.

In the color image forming process, the paper insertion port 56
The sheet 54 inserted from is conveyed by the sheet conveying belt 58 and stopped on the plane transfer plate 52. Next, the first toner 84 is attached to the surface of the flat photoconductor 51 while the image forming unit 53 moves. Flat photoconductor 5
When the toner 84 of the first color is completely attached to the surface of No. 1, the planar photoconductor moving motor 61 lowers the planar photoconductor 51, and the planar transfer plate 52 causes the toner 84 on the paper 54.
Is transcribed. When the transfer is completed, the flat photoconductor 51 is again used.
Is lifted by the planar photoconductor moving motor 61,
The toner 84 adheres to the surface of the flat photoconductor 51 while the second color image forming unit 53 moves.

In this way, the four colors of yellow, cyan, magenta, and black are transferred to the paper 4, and when the transfer is completed, the transport roller 57 rotates again and the paper transport belt 58 fixes the paper 54 to the fixing device. It is conveyed to 55 and fixing is completed.

As described above with reference to the illustrated embodiment, according to the present embodiment, a plane photosensitive member is used as the photosensitive member, and a unit of each color component is formed as an image on the surface of this one photosensitive member. To form. In addition, since the reference of the movement of the image forming unit is read by reading the mark arranged in the main scanning direction, color matching of the image formed on the photoconductor can be performed with high accuracy. Further, since the transfer of the toner to the paper is stopped on the transfer plate, the color misregistration due to the meandering of the paper conveyance is eliminated.

[0057]

As described above, in the present invention, since the conveying path is inclined with respect to the horizontal direction, a large arrangement space is secured on the downstream side or the upstream side of the conveying path, and the downstream side or An image forming unit having a large-capacity toner hopper and a large-diameter photosensitive drum can be arranged on the upstream side.

Therefore, according to the present invention, it is possible to provide an image forming apparatus excellent in maintainability. Further, in the present invention, since the conveyance path is provided between at least one of the image forming section and the fixing section and the control section, the conveyance path includes at least one of the image forming section and the fixing section and the control section. They can be spatially separated, and the influence of high voltage, noise, and high heat on the control unit can be reduced. Therefore, according to the present invention, it is possible to provide an image forming apparatus capable of reducing the occurrence of malfunction.

[Brief description of drawings]

FIG. 1 is a schematic side view of an electrophotographic tandem color printer that is an embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a one-component non-magnetic development cleanerless process diagram.

FIG. 3 is a process diagram of simultaneous cleaning with development.

FIG. 4 is a schematic side view of a conventional electrophotographic tandem color printer.

FIG. 5 is a diagram showing a conventional color image forming apparatus.

FIG. 6 is a perspective view showing the configuration of a color image forming apparatus according to the present invention.

FIG. 7 is a diagram showing a configuration of an image forming unit.

FIG. 8 is a diagram showing movement of a linear encoder and an image forming unit.

[Explanation of symbols]

11 ... Housing, 12 ... Paper feed rollers 1, 13 ... Fixing device 1
3, 14A, 14B ... Driving roller, 15 ... Transfer belt,
16 ... Inclined transport path, 17 ... Paper (image transfer medium) 18, 19, 20, 21 ... Image forming unit, 18a,
19a, 20a, 21a ... Toner hopper, 18b, 19
b, 20b, 21b ... Photosensitive drum, 18c, 19c, 2
0c, 21c ... Charger, 18d, 19d, 20d, 21
d ... Line optical head, 18e, 19e, 20e, 21e
... development roller, 18f, 19f, 20f, 21f ... transfer roller, 18g, 19g, 20g, 21g ... static elimination lamp, 18h, 19h, 20h, 21h ... memory removal brush, 18i, 19i, 20i, 21i ... development roller, 1
8j, 19j, 20j, 21j ... Developing blade, 30 ...
Electronic control board.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masao Takanashi No. 1 Komukai Toshiba-cho, Sachi-ku, Kawasaki City, Kanagawa Prefecture, Corporate Research & Development Center, Toshiba Corporation (72) Minor Ishikawa Komukai Toshiba, Kawasaki-shi, Kanagawa Prefecture Town No. 1 Incorporated company Toshiba Research & Development Center (72) Inventor Koji Suzuki Komukai Toshiba Town No. 1, Komukai Toshiba Town, Kawasaki City, Kanagawa Prefecture Incorporated company Toshiba Research & Development Center

Claims (4)

[Claims] 1. An image forming apparatus configured to form a multi-color image on an image transfer medium conveyed along a predetermined conveying path by a plurality of image forming means arranged along the conveying path. An image forming apparatus in which a road is inclined with respect to a horizontal direction. 2. Each of the plurality of image forming means has a toner hopper, and among the plurality of image forming means, the volume of the toner hopper of the image forming means arranged on the downstream side of the conveying path and the upstream side of the conveying path. The image forming apparatus according to claim 1, wherein a volume of the toner hopper of the image forming unit disposed in the image forming unit is different from that of the toner hopper. 3. Each of the plurality of image forming means has a photosensitive drum, and the diameter of the photosensitive drum of the image forming means disposed on the downstream side of the conveying path among the plurality of image forming means, and the diameter of the conveying path. 3. The image forming apparatus according to claim 1, wherein the diameter of the photosensitive drum of the image forming means arranged on the upstream side is different. 4. An image forming section for transferring a toner image onto an image transfer medium conveyed along a predetermined conveying path, and a fixing for fixing the toner image transferred by the image forming section onto the image transfer medium. An image forming apparatus including a control unit and a control unit that controls at least the image forming unit and the fixing unit, wherein the conveyance path is provided between at least one of the image forming unit and the fixing unit and the control unit. An image forming apparatus comprising: