JP3434492B2 - Image forming device - Google Patents

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 for forming an image by developing an electrostatic latent image formed on the surface of a photoconductor into a toner image.

[0002]

2. Description of the Related Art In an electrophotographic image forming apparatus, an electrostatic latent image corresponding to an image to be formed is formed by exposing the surface of a photoconductor, and this electrostatic latent image is converted into a toner image by a developing device. It is developed. A printed matter is obtained by transferring this toner image onto a sheet and further fixing it. For example, the photoconductor is formed in a drum shape, and while the photoconductor is rotated around the axis, the electrostatic latent image is formed, the toner image is developed, and the toner image is transferred. On the other hand, the developing device includes a developing roller that supplies toner to the surface of the photoconductor, and the toner agitated in the housing of the developing device is supplied to the surface of the photoconductor by the developing roller.

Therefore, the image forming apparatus is provided with a photosensitive member driving mechanism for driving the photosensitive member, and similarly with a developing driving mechanism for driving the developing device. Since the photoconductor and the developing device are arranged close to each other, the photoconductor drive mechanism and the developing drive mechanism are often configured as a common drive unit. To form a color image, for example, a toner image of four colors is formed,
It is necessary to transfer the toner images of the four colors on the paper in an overlapping manner. One form of an image forming apparatus for forming such a color image is a tandem type in which four photoconductor drums are arranged along a paper transport path. In this case, a developing device is provided for each of the four photoconductor drums.

Conventionally, even in such a tandem type image forming apparatus, the photosensitive member driving mechanism and the developing driving mechanism are constituted as one driving unit.

[0005]

However, if the photoconductor drive mechanism and the developing drive mechanism are configured as one drive unit, a large vibration occurs in the drive unit. Especially,
Since the tandem drive unit has a configuration in which the plurality of photoconductors and the plurality of developing devices are driven by one drive unit, the drive load is large, and accordingly, the vibration generated in the drive unit is also large.

Since the vibration generated in the drive unit is transmitted to the photoconductor, an electrostatic latent image is formed on the surface of the photoconductor.
It adversely affects the development and transfer processes. This hinders the formation of a high-quality image, and there is a problem that blurring or unevenness of the image remarkably appears particularly in a high-definition image. Therefore, an object of the present invention is to provide an image forming apparatus which can solve the above-mentioned technical problems and reduce the vibration transmitted to the photoconductor, thereby contributing to the improvement of the image quality. That is.

[0007]

Means for Solving the Problems and Effects of the Invention In order to achieve the above-mentioned object, the invention according to claim 1 is a photoconductor (28) on which an electrostatic latent image is formed, and a photoconductor (28) of this photoconductor. Developing device (30) for developing the electrostatic latent image on the surface into a toner image
And a photoconductor drive unit (77) equipped with a photoconductor drive mechanism (70) for driving the photoconductor, and a developing drive mechanism which is formed separately from the photoconductor drive unit and drives the developing device. (80) is seen containing a on-board development drive unit (88), the photosensitive member driving mechanism is connected to each other
The pair of support plates (71, 72) thus formed are used as drive sources.
Motor (73), the driving force from this motor is transmitted
The gear mechanism (74) and the rotation by this gear mechanism.
Photoreceptor drive shaft (75B, 75C, 75M, 75Y)
The above-mentioned developing drive mechanism
Is a pair of support plates (81, 82) connected to each other,
Motor (83) as a drive source, drive from this motor
Gear mechanism (84) to which force is transmitted, and this gear mechanism
Development drive shaft rotated by (85C, 85M, 85
Y) is attached and integrated, and
The vibration unit and the development drive unit are
Vibration transmission than the support plate (71, 72, 81, 82) of the unit (77, 88)
Attached to the body frame (90)
The image forming apparatus is characterized in that However,
The alphanumeric characters in parentheses represent corresponding components in the embodiments described later. The same applies in this section below.

According to the above arrangement, since the photoconductor drive unit and the developing drive unit are separate bodies, the drive load on each drive unit is small. Therefore, vibrations in the individual drive units are reduced. In addition, the vibration generated by driving the developing device is not directly transmitted to the photoconductor. As a result, the vibration transmitted to the photoconductor can be reduced, and the image quality can be improved. In addition, the vibration-damping main body frame
Frame (for example, resin body frame)
Of vibration between the photoconductor drive unit and the development drive unit.
Transmission is suppressed. As a result, the vibration transmitted to the photoconductor is
Motion can be reduced more effectively.

According to a second aspect of the present invention, a plurality of photoconductors (28) on the surface of which electrostatic latent images are formed respectively, and a plurality of photoconductors provided corresponding to the plurality of photoconductors are provided. A plurality of developing devices (30) for developing the electrostatic latent images formed on the surface into toner images, and a plurality of photoconductors (a part or all of the plurality of photoconductors) The photoconductor drive unit (77) equipped with the photoconductor drive mechanism (70) and the photoconductor drive unit are configured separately, and a plurality of developing devices (a part or all of the plurality of developing devices are included). And a developing drive unit (88) equipped with a developing drive mechanism (80) for driving
The above-mentioned photoconductor drive mechanism includes a pair of supports connected to each other.
The holding plate (71, 72) has a motor (7
3), a gear mechanism to which the driving force from this motor is transmitted
(74), and the photosensitivity rotated by this gear mechanism
Attach body drive shaft (75B, 75C, 75M, 75Y)
The developing drive mechanisms are mutually integrated.
A pair of support plates (81, 82) connected to the
Motor (83) and the driving force from this motor is transmitted
Gear mechanism (84), and by this gear mechanism
Remove the rotating development drive shaft (85C, 85M, 85Y)
It is mounted on the photoconductor drive unit and integrated.
And the drive unit for developing
Lower vibration transmission than (77,88) support plate (71,72,81,82)
An image forming apparatus characterized by being attached to a main body frame (90) of material . It is preferable that the plurality of developing devices develop the electrostatic latent images on the corresponding photoconductors with toners of different colors.

With this configuration, the same effect as that of the first aspect can be achieved. In particular, according to the present invention, since the plurality of photoconductors and the plurality of developing devices are used, the vibration reducing effect is large because the photoconductor driving unit and the developing driving unit are separated. Thereby, for example, when a color image is formed with a plurality of color toners, a color image with good image quality can be formed .

[0011]

[0012]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram of a color printer as an image forming apparatus according to an embodiment of the present invention. The color printer 2 has four image forming units 5B, 5C, 5M and 5Y arranged along a linearly formed sheet conveying path, and transfers toner images of four colors of black, cyan, magenta and yellow to a transfer body. The sheet member (paper) 3 as
It has a tandem type configuration.

This color printer 2 has a sheet member 3
A sheet feeding unit 4 for feeding sheets one by one, a conveying unit 6 for conveying the sheet member 3 fed from the sheet feeding unit 4, the plurality of image forming units 5B, 5C, 5M, 5Y described above, and the image forming unit 5
A transfer unit 7 for transferring the toner image formed of B, 5C, 5M, 5Y to the sheet member 3, a fixing unit 8 for fixing the toner image of the sheet member 3 transferred by the transfer unit 7, and the fixing Paper discharge unit 10 that receives the sheet member 3 discharged from the unit 8
And an optical unit 11.

The paper feeding unit 4 includes a first paper feeding unit 15 for feeding the sheet members 3 stacked on the first paper feeding tray 12 one by one to a downstream side by a paper feeding roller 13 and a retard roller 14,
The manual feed tray 16 includes a second paper feed unit 18 that feeds the sheet members 3 one by one to the downstream side by a paper feed roller 17. The conveyance unit 6 guides the conveyance of the sheet member 3 sent from the first paper feed unit 15 or the second paper feed unit 18, and a conveyance roller 21 disposed in the middle of the conveyance path 20. The sheet member 3 is received from the conveying roller 21, the leading end portion of the sheet member 3 is temporarily stopped, and the oblique feeding is regulated (corrected), and the image forming units 5B, 5C, 5 on the downstream side are provided.
It is composed of a pair of registration rollers 22 for feeding to M and 5Y, and a manual feed path 23 connected to the path 20 upstream of the registration roller pair 22.

The image forming units 5B, 5C, 5M and 5Y form images with black toner, cyan toner, magenta toner and yellow toner, respectively. Each of the image forming units 5B, 5C, 5M and 5Y includes a drum-shaped photoconductor 28.
A developing device 30 for developing the electrostatic latent image on the photoconductor 28 into a toner image; a cleaning device 33 having a fur brush 31 and a cleaning blade 32 for removing residual toner on the photoconductor 28; Charging device 3 for uniformly charging the surface of the photoconductor 28 by applying an electric charge to the surface of the photoconductor 28.
4 and.

The transfer section 7 is a transfer belt 37 made of a fluororesin material, a driving roller 38 and a tension roller 40 for driving the transfer belt 37, and a transfer roller arranged at a position opposed to each photoconductor 28. Roller 41a,
41b, 41c, 41d, and also has a function of conveying the sheet member 3 to the downstream side. The transfer rollers 41a, 41b, 41c, 41d and the photoconductors 2
8 and the transfer belt 37 are sandwiched between them. The guide roller 4 is provided at an appropriate position on the inner peripheral side of the transfer belt 37.
2, 43 are arranged.

When only a black and white image is formed, the transfer section 7 uses only the black transfer roller 41a and other magenta, cyan, and yellow transfer rollers 41b, 41c, and 41b.
41 d is separated from the photoconductor 28. The fixing unit 8 is
A heating roller 44 having a built-in heater and a fixing roller 45
A metal endless belt 46 wound around the heating roller 44 and the fixing roller 45, and the fixing roller 45.
And a pressure roller 47 that is pressed against. Then, an oil application roller 48 for applying silicone oil to the outer surface of the endless belt 46, a cleaning roller 51 for cleaning the surface of the oil supply roller 50 and the oil supply roller 50 for supplying oil to the oil applying roller 48 is It is arranged.

The paper discharge unit 10 receives the sheet member 3 discharged from the fixing unit 8 and stacks the first paper discharge unit 52 for stacking with the image forming surface upward and the sheet member 3 discharged from the fixing unit 8. The image forming apparatus main body 36 is guided to the upper part of the image forming apparatus main body 36 via the discharge path 53, and has a second sheet discharge section 54 for stacking with the image forming surface facing downward. The first paper discharge unit 52 is housed in the image forming apparatus main body 36 when not in use.
The optical unit 11 includes a polygon mirror 55 and a lens 5.
6, 57 and a mirror 58 are arranged corresponding to each photoconductor 28, and the laser light is emitted from each slit 61 formed in the optical unit support plate 60 toward each photoconductor 28. There is. As a result, an electrostatic latent image corresponding to the image to be formed is formed on the surface of each photoconductor 28.

In the color printer 2 having the above-described structure, the sheet member 3 is fed from the first paper feeding unit 15 or the second paper feeding unit 18.
When the sheet is fed, the sheet member 3 is sequentially fed by the conveying section 6 between the photoconductor 28 of the image forming sections 5B, 5C, 5M and 5Y and the transfer belt 37 of the transfer section 7. The sheet member 3 includes the photoconductor 28 and the transfer roller 41.
The black, magenta, cyan, and yellow toner images formed on each photoconductor 28 are sequentially transferred onto the surface of the photoconductor 28 while being conveyed by the transfer belt 37 among the a, 41b, 41c, and 41d. Sheet member 3 after transfer of color image
Is further conveyed by the transfer belt 37 and is fed between the fixing roller 45 and the pressure roller 47 of the fixing unit 8, where the color image is fixed. After fixing, the sheet member 3
Is discharged to the first paper discharge unit 52 or the second paper discharge unit 54.

FIG. 2 shows the image forming sections 5B, 5C, 5M and 5
A photoconductor drive mechanism 70 for driving a plurality of (four) Y photoconductors 28, and a developing drive mechanism 80 for driving a plurality (four) development devices 30 of the image forming units 5C, 5M, and 5Y. FIG. 3 is a perspective view for explaining the configuration, and FIG. 3 is a perspective view seen from the direction of arrow A in FIG. 2. Photoconductor driving mechanism 70
The developing drive mechanism 80 is arranged on the rear portion of the color printer 2 (on the back side of the paper surface of FIG. 1).

The photoconductor drive mechanism 70 includes metal support plates 71 and 72 connected to each other and a motor 7 as a drive source.
3, a gear mechanism 74 to which the driving force from the motor 73 is transmitted, and four photoconductor drive shafts 75B, 75C, 75M, and 75Y rotated by the gear mechanism 74, and these components are exposed. Body drive unit 77
Is integrated as. Photoreceptor drive shaft 75B, 7
The image forming units 5B, 5
A coupling mechanism for coupling the shafts of the C, 5M, and 5Y photoconductors 28 is provided. This coupling mechanism may be, for example, a pin that fits in a cross-shaped groove formed on the end surface of the shaft of the photoconductor 28.

The developing drive mechanism 80 includes metal support plates 81 and 82 connected to each other and a motor 8 as a drive source.
3, a gear mechanism 84 to which the driving force from the motor 83 is transmitted, and three developing drive shafts 85C, 85M, 85Y rotated by the gear mechanism 84 are attached.
These components are integrated as a developing drive unit 88. In this embodiment, the developing drive mechanism of the image forming section 5B that forms a black toner image is a unit different from the developing drive mechanism 80, and the developing drive mechanism for the black toner image forming section 5B. Development drive shaft 8 from
5B is adapted to be inserted through an insertion hole 76 formed in the support plate 72 of the photoconductor drive unit 77.

Developing drive shafts 85B, 85C, 85M, 85
At the tip of Y, a coupling mechanism for coupling the image forming units 5B, 5C, 5M and 5Y to the drive input shaft of the developing device 30 is provided. This coupling mechanism may be, for example, a pin that fits in a cross-shaped groove formed on the end surface of the drive input shaft. The photoconductor drive unit 77 and the developing drive unit 88 are attached and fixed to a resin main body frame 90. In the assembly process of the color printer 2, the photoconductor drive unit 77 is attached to the main body frame 9
By mounting it on the photoconductor drive shafts 75B, 75
C, 75M, 75Y and image forming units 5B, 5C, 5M, 5
The Y axis of the photoconductor 28 is coupled by the coupling mechanism described above. Similarly, by attaching the developing drive unit 88 to the main body frame 90, the developing drive shaft 85
C, 85M, 85Y and the drive input shaft of the developing device 30 of the image forming sections 5C, 5M, 5Y are coupled via the above coupling mechanism.

As described above, according to this embodiment, the photoconductor drive unit 77 and the developing drive unit 88 are separately configured and separated. As a result, the load on each drive unit 77, 88 can be reduced. Accordingly, the vibration generated in each drive unit 77, 88 can be suppressed. Moreover, since it is a separate unit, the vibration generated in the developing drive unit 88 is not directly transmitted to the photoconductor 28 via the photoconductor drive unit 77.

Further, the photoconductor driving unit 77 and the developing driving unit 88 are mounted on a resin main body frame 90 having a vibration damping property. As a result, it is possible to prevent the vibration generated in the developing drive unit 88 from being transmitted to the photoconductor drive unit 77. In this way
Since the vibration transmitted to the photoconductors 28 of the image forming sections 5B, 5C, 5M and 5Y can be remarkably reduced, blurring and unevenness of the image can be effectively prevented and the image quality can be remarkably improved. .

Although one embodiment of the present invention has been described, the present invention can be implemented in other forms. For example, in the above-described embodiment, the photoconductor driving mechanism 7
0 is configured to drive the photoconductors 28 of all the image forming units 5B, 5C, 5M and 5Y.
You may provide two drive units which drive one photoreceptor. However, in order to prevent color misregistration (displacement of the positions of toner images of different colors), it is necessary to completely synchronize the rotations of the four photoconductors 28.
The configuration of the above-described embodiment in which one is driven by one photosensitive member drive unit 77 is preferable.

Further, in the above embodiment, the developing drive unit 88 has four image forming sections 5B, 5C, 5M and 5Y.
Of the three, the developing device 30 is configured to be driven,
All image forming sections 5B, 5 with one developing drive unit
The C, 5M, and 5Y developing devices 30 may be driven. Further, in the above-described embodiment, the color printer 2 including the plurality of image forming units 5B, 5C, 5M, and 5Y that form toner images of different colors is taken as an example, but one color (for example, black) toner image is used. Even in an image forming apparatus provided with only one image forming section for forming the image, vibration of the photosensitive member can be reduced by improving the image quality by separating the photosensitive member driving unit and the developing driving unit. it can.

Further, in the above embodiment, an example in which the drum-shaped photoconductor is used has been described, but the configuration of the present invention may be adopted even when the belt-shaped photoconductor is used. In addition, various design changes can be made within the scope of the matters described in the claims.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a color printer as an image forming apparatus according to an embodiment of the invention.

FIG. 2 is a perspective view for explaining a configuration of a photoconductor driving mechanism and a developing driving mechanism.

FIG. 3 is a perspective view as seen from the direction of arrow A in FIG.

[Explanation of symbols]

2 color printer 5B, 5C, 5M, 5Y Image forming unit 7 Transfer part 8 fixing section 11 Optical unit 28 photoconductor 30 developing device 70 Photoreceptor drive mechanism 71,72 Support plate 73 motor 74 Gear mechanism 75B, 75C, 75M, 75Y Photoreceptor drive shaft 77 Photoreceptor drive unit 80 Development drive mechanism 81,82 Support plate 83 motor 84 gear mechanism 85C, 85M, 85Y Development drive shaft 88 Development drive unit 90 body frame

─────────────────────────────────────────────────── --Continued from the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G03G 15/00 550 G03G 21/16-21/18 G03G 15/01-15/01 117 G03G 21/00 345 -352 G03G 15/08-15/08 507

Claims (2)

(57) [Claims] 1. A photoconductor on which an electrostatic latent image is formed, a developing device for developing the electrostatic latent image on the surface of the photoconductor into a toner image, and a photoconductor driving mechanism for driving the photoconductor. a mounting photoreceptor drive unit, this is a photosensitive member driving unit is formed separately, viewed contains a developing drive unit development driving mechanism for driving the developing device is mounted, the photosensitive member driving mechanism, A pair of support plates connected to each other
The motor as the drive source, and the driving force from this motor
Transmission gear mechanism and rotation by this gear mechanism
The photoconductor drive shaft is attached and integrated.
Ri, the development driving mechanism includes a pair of support plates which are connected to each other
The motor as the drive source, and the driving force from this motor
Transmission gear mechanism and rotation by this gear mechanism
The developing drive shaft is integrated with the developing drive shaft, and the photoconductor drive unit and the developing drive unit vibrate.
An image forming apparatus characterized by being attached to a buffer main body frame . 2. A plurality of photoconductors on which electrostatic latent images are respectively formed on the surface, and electrostatic latent images formed on the surfaces of the photoconductors provided corresponding to the plurality of photoconductors, respectively. A developing device for developing each of the toner images into a toner image, a photoconductor driving unit equipped with a photoconductor driving mechanism for driving a plurality of photoconductors, and the photoconductor driving unit are configured separately. and a developing drive unit developing drive mechanism is mounted for driving a plurality of developing devices seen including, the photosensitive member driving mechanism includes a pair of support plates which are connected to each other
The motor as the drive source, and the driving force from this motor
Transmission gear mechanism and rotation by this gear mechanism
The photoconductor drive shaft is attached and integrated.
Ri, the development driving mechanism includes a pair of support plates which are connected to each other
The motor as the drive source, and the driving force from this motor
Transmission gear mechanism and rotation by this gear mechanism
The developing drive shaft is integrated with the developing drive shaft, and the photoconductor drive unit and the developing drive unit vibrate.
An image forming apparatus characterized by being attached to a buffer main body frame .