JP2003043781A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently reduce the number of motors in an image forming device. SOLUTION: This image forming device is provided with a plurality of photoreceptor drums corresponding to respective color toner images developing rollers installed corresponding to the respective photoreceptor drums, an intermediate transfer belt on which the respective color toner images developed on the photoreceptor drums are superposed on each other and transferred so as to form a color toner image, a 1st motor 23 for generating rotational force, a 1st transmission system 25 for transmitting the rotational force from the 1st motor 23 to a 1st driven system being the photoreceptor drums on which an electrostatic latent image corresponding to the toner image other than the black image is formed and the developing rollers corresponding to the photoreceptor drums, a 2nd motor 24 for generating rotational force, and a 2nd transmission system 26 for transmitting the rotational force from the 2nd motor 24 to a 2nd driven system including the photoreceptor drum on which an electrostatic latent image corresponding to the black toner image is formed and the developing roller corresponding to the photoreceptor drum and excluding the 1st driven system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus having an endless intermediate transfer member.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus adopting an electrophotographic system, a photoconductor, which is an image carrier, is charged by a charger, and the charged photoconductor is irradiated with light according to image information. An image is formed, the latent image is developed by a developing device, and the developed toner image is transferred to a recording medium to form the image.

On the other hand, there are provided a plurality of image forming stations for executing the above-mentioned image forming processes in accordance with colorization of images, and toner images of respective colors of cyan image, magenta image, yellow image, and preferably black image are respectively provided. A tandem-type color image forming apparatus has also been proposed which forms a full-color image by superposing these toner images on an intermediate transfer member having an endless shape at the transfer position of each photosensitive member.

Since such a tandem type color image forming apparatus has an image forming section for each color,
It is advantageous for speeding up.

Here, in the conventional image forming apparatus, for driving the photoconductors for the respective colors of yellow, magenta, cyan and black, for driving the developing means for the respective colors, for driving the intermediate transfer member, for driving the transfer roller, and for driving the fixing roller. Motors are individually provided for each of the driven bodies, such as for driving the paper feed roller, driving the transport roller, and supplying toner.

Therefore, for example, four motors are used only for driving the photoconductor.

[0007]

In the prior art as described above, motors are required for the number of driven bodies, and the size of the apparatus increases.

Furthermore, since a large number of motors are required in this way, the cost of the device increases.

On the other hand, simply reducing the number of motors cannot achieve efficient cost reduction.

Therefore, an object of the present invention is to provide an image forming apparatus capable of efficiently reducing the number of motors.

[0011]

In order to solve this problem, the image forming apparatus of the present invention is arranged in a line so that the central axes of rotation thereof are parallel to each other, and rotates in the circumferential direction, so that black toner is obtained. Image and electrostatic latent images corresponding to toner images other than black are formed on each of the plurality of photoconductors, and the electrostatic latent images formed on the photoconductors are visualized. Developing means for converting into a toner image,
An endless type that is provided so as to be able to contact the photoconductor, is supported by a plurality of rollers in a band and rotates, and the toner images of the respective colors developed on the photoconductor are superimposed and transferred to each other to form a color toner image. Of the intermediate transfer member, the first motor for generating a rotational force, the rotational force from the first motor, and the photoconductor on which an electrostatic latent image corresponding to a toner image other than black is formed, A first transmission system that transmits to a first driven system that is a developing unit, a second motor that generates a rotational force, and an electrostatic latent image corresponding to a black toner image that rotates the rotational force from the second motor. A structure having a photoconductor on which an image is formed and a second transmission system that includes a developing unit corresponding to the photoconductor and transmits the photoconductor to a second driven system other than the first driven system. is there.

As a result, the first driven system, which is involved in the formation of the color toner image, and the second driven system, which is the other driven system, are driven by separate motors, respectively, so that it is efficient. It is possible to reduce the number of motors.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is arranged in a row so that the central axes of rotation thereof are parallel to each other and rotated in the circumferential direction, and a black toner image and a non-black toner are formed. A plurality of photoconductors on which electrostatic latent images corresponding to the images are respectively formed, and the photoconductors are installed corresponding to the respective photoconductors, and the electrostatic latent images formed on the photoconductors are visualized to form toner images. And a developing means for contacting the photosensitive member, and is supported by a plurality of rollers in a belt-like manner to rotate around,
The endless intermediate transfer member on which the toner images of the respective colors developed on the photoconductor are superposed and transferred on each other to form a color toner image, a first motor for generating a rotational force, and a first motor The rotational force is transmitted to the photoconductor on which an electrostatic latent image corresponding to a toner image other than black is formed and the first driven system which is the developing means corresponding to these, and the rotational force. A first driven system including a second motor generated, a photoconductor on which an electrostatic latent image corresponding to a black toner image is formed by the rotational force from the second motor, and a developing unit corresponding to the photoconductor. An image forming apparatus having a second transmission system for transmitting to a second driven system configured by other than the first driven system and the other driven systems involved in forming a color toner image. A second driven system is driven by separate motors Because, such an action is possible to efficiently reduce the number of motors.

According to a second aspect of the present invention, in the first aspect of the invention, the photoreceptor on which an electrostatic latent image corresponding to a toner image other than black is formed is yellow, magenta and cyan toner. An image forming apparatus which is a photoconductor on which an image is formed respectively, and a second driven system which is a first driven system involved in the formation of a color toner image and a second driven system other than the first driven system.
Since the driven system and the driven system are driven by separate motors, the number of motors can be efficiently reduced.

According to a third aspect of the present invention, in the invention according to the first or second aspect, the first motor and the second motor are rotated when performing color printing, and the first motor is performed when performing monochrome printing. An image forming apparatus in which a first motor is stopped and a second motor is rotated, and driving of a photosensitive drum and a developing roller involved in toner image formation other than black, which is unnecessary in monochrome printing, can be stopped. It is possible to prevent the mechanical deterioration.

The invention according to claim 4 of the present invention is the second aspect of the invention according to claim 3 when monochrome printing is performed.
Is an image forming apparatus in which the rotation speed of the motor is higher than the rotation speed when performing color printing, and has an effect of enabling high-speed processing in monochrome printing.

FIG. 1 shows an embodiment of the present invention.
And it demonstrates using FIG. In addition, in these drawings, the same members are denoted by the same reference numerals, and duplicate description is omitted.

FIG. 1 is an explanatory view showing the configuration of an image forming apparatus according to an embodiment of the present invention, and FIG. 2 is a first and second driven system and first and second driven systems in the image forming apparatus of FIG. It is a conceptual diagram which shows a transmission system.

As shown in FIG. 1, the image forming apparatus of the present embodiment has four image forming stations Pa, Pb, P.
c and Pd are arranged, and each image forming station P
Each of a, Pb, Pc, and Pd has a photoconductor drum (photoconductor) 1a, 1b, 1c, and 1d that rotates in the circumferential direction as an image carrier. The photosensitive drums 1a, 1b, 1c, 1d
Are arranged in a row so that their rotation center axes are parallel to each other.

Around the photosensitive drums 1a, 1b, 1c, 1d, charging means 3a, 3b for uniformly charging the surfaces of the photosensitive drums 1a, 1b, 1c, 1d to a predetermined potential.
3c, 3d, charged photosensitive drums 1a, 1b, 1
Exposure light beam 4 corresponding to image data of a specific color on c and 1d
Exposure means 4 for irradiating K, 4C, 4M and 4Y to form an electrostatic latent image, and electrostatic latent images formed on the photoconductor drums 1a, 1b, 1c and 1d are visualized to form a toner image. The developing roller (developing means) 5a, 5b, 5c, 5d, the driving roller 9a, and the driven roller 9b are belt-supported so that the toner images of the respective colors visualized on the photosensitive drums 1a, 1b, 1c, 1d are mutually transferred. An endless intermediate transfer belt (intermediate transfer member) 8 on which a color toner image is formed by superposing and transferring onto the intermediate transfer belt 8 and a transfer means 6 for transferring the toner image to the intermediate transfer belt 8.
a, 6b, 6c, 6d, photoconductor drums 1a, 1b, 1
Cleaning means 7a, 7b, 7 for removing the residual toner remaining on the photosensitive drums 1a, 1b, 1c, 1d after transferring the toner image from the intermediate transfer belts c, 1d to the intermediate transfer belt 8.
c and 7d are arranged respectively.

Here, the photosensitive drums 1a, 1b, 1c,
The intermediate transfer belt 8 provided so as to be capable of contacting 1d is rotated in the direction of arrow A by the drive roller 9a in the illustrated case. The image forming stations Pa, Pb,
In Pc and Pd, a black image, a cyan image,
A magenta image and a yellow image are formed. Then, the monochromatic images of the respective colors formed on the photoconductor drums 1a, 1b, 1c, 1d are sequentially superposed and transferred onto the intermediate transfer belt 8 to form a full-color image. Here, the image is formed in the order of the yellow image, the magenta image, the cyan image, and the black image. Therefore, the yellow image is first transferred onto the intermediate transfer belt 8, and the magenta image, the cyan image, and the yellow image are transferred to the yellow image. Black images are transferred one after another.

At the bottom of the apparatus, there is provided a paper feed cassette 12 in which a sheet material 11 such as printing paper is stored.
Then, the sheet material 11 is sent from the sheet feeding cassette 12 by the sheet feeding roller 10 to the sheet conveying path one by one.

On the paper conveyance path, the outer peripheral surface of the intermediate transfer belt 8 is contacted for a predetermined amount, and the intermediate transfer belt 8 is contacted.
A sheet material transfer roller 13 that transfers the color image formed on the sheet material 11, and a fixing that fixes the color image transferred on the sheet material 11 to the sheet material 11 by pressure and heat associated with the rotation of nip of the roller. The container 14 is arranged.

In the image forming apparatus having such a structure,
First, the latent image of the yellow component color of the image information is formed on the photosensitive drum 1d by the charging device 3d and the exposure device 4 of the image forming station Pd. This latent image is visualized as a yellow toner image by the developing roller 5d having yellow toner, and is transferred by the transfer means 6d to the intermediate transfer belt 8.
It is transferred as a yellow toner image on top.

On the other hand, while the yellow toner image is being transferred to the intermediate transfer belt 8, a latent image of a magenta component color is formed at the image forming station Pc, and then a magenta toner image of magenta toner is developed on the developing roller 5c. To be imaged. Then, the magenta toner image is transferred by the transfer means 6c of the image station Pc to the intermediate transfer belt 8 where the transfer of the yellow toner image is completed at the previous image station Pd, and is superimposed on the yellow toner image.

Thereafter, the cyan toner image and the black toner image are similarly formed, and when the superimposing of the four color toner images on the intermediate transfer belt 8 is completed, the paper is fed from the paper feeding cassette 10 by the paper feeding roller 10. The toner images of four colors are collectively transferred onto the fed sheet material 11 by the sheet material transfer roller 13. Then, the transferred toner image is heated and fixed on the sheet material 11 by the fixing device 14, and a full-color image is formed on the sheet material 11.

The photosensitive drums 1a, 1b, 1c and 1d, which have been transferred, have cleaning means 7a,
The residual toner is removed by 7b, 7c, and 7d, and the toner is prepared for the next image formation to be performed subsequently.

In such an image forming apparatus, as shown in FIG. 2, the photoconductor driving gears 15a, 15b, 15c and 15 are coaxially arranged on the photoconductor drums 1a, 1b, 1c and 1d.
d is the developing roller drive gears 16a, 16b, 16c, 16d on the same axis as the developing rollers 5a, 5b, 5c, 5d.
Are installed respectively. Further, a drive roller drive gear 17 is coaxial with the drive roller 9a, a transfer roller drive gear is coaxial with the sheet material transfer roller 13, and a paper feed roller drive gear 19 is coaxial with the paper feed roller 10.
A transport roller drive gear is coaxial with the transport roller, and a pressure roller drive gear 21 is coaxial with the pressure roller of the fixing device 14.
However, a toner supply roller drive gear 22 is mounted coaxially with the toner supply roller for supplying toner to the developing rollers 5a, 5b, 5c, 5d.

Then, the photosensitive drums 1b, 1c, 1d on which electrostatic latent images corresponding to toner images other than black are formed.
A first driven system is constituted by the driven members such as the developing rollers 5b, 5c and 5d corresponding thereto. Further, the photosensitive drum 1a on which an electrostatic latent image corresponding to the black toner image is formed, and the developing roller 5 corresponding to the photosensitive drum 1a.
The second driven system is constituted by a, a driven roller 9a, the sheet material transfer roller 13, the paper feed roller 10, the conveyance roller, the pressure roller, and the toner supply roller.

Further, the first motor 23 for generating a rotational force
And a second motor 24 is provided.

The members constituting the second driven system are
As long as the photosensitive drum 1a and the developing roller 5a are included, they are not limited to those shown in the present embodiment. That is, the second driven system may include various driven bodies other than those shown here, and may not include some or all of the driven bodies shown here.

Further, in the present embodiment, yellow, magenta and cyan are selected as the toner image other than black, but colors other than these may be used.

As shown in the figure, a first transmission system 25 is arranged to transmit the rotational force from the first motor 23 to the first driven system, and the rotational force from the second motor 24 is arranged. Is transmitted to the second driven system.

Therefore, the first driven system and the second driven system, which are the other driven systems involved in the formation of the color toner image, and the second driven system which are the other driven systems, are separate motors. The motors 24 are driven respectively, and the number of motors can be efficiently reduced.

Since the number of motors is reduced in this way, the size of the device can be reduced and the cost of the device can be reduced.

Here, when performing color printing, the first motor 23 and the second motor 24 are rotated, and when performing monochrome printing, the first motor 23 is stopped and the second motor 24 is rotated. By doing so, the photosensitive drums 1b, 1c, 1d and the developing rollers 5b, 5c, which are involved in the formation of toner images other than black, which are unnecessary in monochrome printing,
It is possible to stop the driving of 5d and prevent mechanical deterioration.

If the rotation speed of the second motor 24 during monochrome printing is set higher than the rotation speed during color printing, high speed processing in monochrome printing becomes possible.

The arrangement of the gears and belts forming the first transmission system 25 and the second transmission system 26 in the present embodiment is merely an example, and various other arrangements can be adopted.

The gears used in the first and second transmission systems 25 and 26 are not limited to spur gears, but helical gears, helical gears, or two gears having different diameters are arranged coaxially. Various gears such as a coaxial gear can be appropriately used as necessary.

[0040]

As described above, according to the present invention, the first driven system which is involved in the formation of the color toner image and the second driven system which is the other driven system are separately provided. Since the motors are used for driving, it is possible to effectively reduce the number of motors, which is an effective effect.

Since the number of motors is reduced as described above, an effective effect that the device can be downsized can be obtained.

Since the number of motors is reduced,
An effective effect that the cost of the device can be reduced can be obtained.

When performing color printing, the first motor and the second motor are rotated, and when performing monochrome printing, the first motor is stopped and the second motor is rotated. It is possible to stop the driving of the photoconductor drum and the developing roller that are involved in the formation of an unnecessary toner image other than black, and it is possible to prevent mechanical deterioration, which is an effective effect.

This is an image forming apparatus in which the rotation speed of the second motor during monochrome printing is faster than the rotation speed during color printing, and the effective effect of enabling high-speed processing in monochrome printing is obtained. To be

[Brief description of drawings]

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

FIG. 2 is a conceptual diagram showing first and second driven systems and first and second transmission systems in the image forming apparatus of FIG.

[Explanation of symbols]

23 First motor 24 Second motor 25 First transmission system 26 Second transmission system

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 15/16 G03G 21/00 384 21/00 384 15/08 507H (72) Inventor Yukitaka Muto Kadoma Osaka Prefecture 1006 City Kadoma Matsushita Electric Industrial Co., Ltd. (72) Inventor Kazuhiko Tajima Osaka Kadoma City 1006 Kadoma Matsushita Electric Industrial Co., Ltd. F term (reference) 2H027 ED01 ED08 EE03 EE04 FA28 2H030 AA05 AB02 AD08 AD16 AD19 BB32 BB42 BB71 2H077 BA01 DA05 DB14 DB18 GA13 GA15 2H200 GA12 GA23 GA29 GA47 JC03 LA27 LA29 PA11 PA26

Claims (4)

[Claims] 1. A plurality of units are arranged in a row so that their central axes of rotation are parallel to each other and are rotated in the circumferential direction to form electrostatic latent images corresponding to a black toner image and a non-black toner image, respectively. And a developing unit which is installed corresponding to each of the photoconductors, and which develops the electrostatic latent image formed on the photoconductors to form a toner image, and contacts the photoconductors. An endless intermediate transfer member which is movably provided and is supported by a plurality of rollers to rotate around, and the toner images of respective colors developed on the photoconductor are superposed on each other and transferred to form a color toner image. A first motor that generates a rotational force; the rotational force from the first motor; and the photoconductor on which an electrostatic latent image corresponding to a toner image other than black is formed, and the development corresponding to these. First driven means A first transmission system for transmitting a rotational force to the system; a second motor for generating a rotational force; and a photoconductor on which an electrostatic latent image corresponding to a black toner image is formed by the rotational force from the second motor. And a second transmission system including the corresponding developing means and transmitting to a second driven system other than the first driven system. 2. The photoconductor on which an electrostatic latent image corresponding to a toner image other than black is formed is a photoconductor on which yellow, magenta, and cyan toner images are formed, respectively. 1. The image forming apparatus according to 1. 3. When performing color printing, the first motor and the second motor are rotated, and when performing monochrome printing, the first motor is stopped and the second motor is rotated. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. 4. The image forming apparatus according to claim 3, wherein the rotation speed of the second motor during monochrome printing is higher than the rotation speed during color printing.