JP4655686B2 - Developing device and image forming apparatus - Google Patents

Description

The present invention relates to a developing device, and images forming device, in particular, a developing device having a plurality of developing devices to adhere the toner to a plurality of image charge of bearing member to the electrostatic latent image on the image responsible lifting body, and field The present invention relates to an image forming apparatus.

  In recent years, image forming apparatuses such as color printers and color copiers have, for example, a photoconductor and a developing unit corresponding to each color of yellow (Y), magenta (M), cyan (C), and black (Bk), and are used for intermediate transfer. In general, a quadruple tandem method in which an image in which four colors are superimposed on each other is transferred to an image forming medium at once.

In such an image forming apparatus, various proposals have been made to improve unevenness in image formation due to periodic vibration or the like, and Patent Document 1 discloses a source of banding of an image forming apparatus main body or an output image. For example, a piezoelectric element such as a laminated piezo is provided in at least one place such as a motor , a photosensitive drum , a paper feed roller , a conveyance roller , a polygon mirror , and an exposure element, and vibration is controlled by a voltage applied to the piezoelectric element. Thus, for example, there is described a technique that suppresses periodic vibration due to resonance in the image forming apparatus and gives an output image without banding by giving random vibration to the image forming apparatus.
JP 11-194570 A

  However, the configuration described in Patent Document 1 described above is complicated in configuration and increases in cost.

  SUMMARY An advantage of some aspects of the invention is that it provides a developing device, a process cartridge, and an image forming apparatus that can prevent banding with a simple configuration.

The invention of claim 1 includes a plurality of image charge of lifting body, and a plurality of developing units to be provided for each image in charge bearing member of said plurality of toner to adhere to the electrostatic latent image on the image bearing member ,
For each plurality of developing devices, a developing device including a developing roller and a developing roller driving gear for driving the developing roller,
The developing roller driving gear, Te developing apparatus odor that is dynamic drive rotation meshes with device gear main body of the driving force for transfer of the image forming apparatus using the developing device,
The number of teeth of the developing low la drive gear of the developing unit adjacent among the plurality of developing units shall all common, and the developing unit adjacent among the plurality of developing units
A developing device according to claim Rukoto dispersing the mesh frequency by changing one another the number of teeth of the reduction gear of the driving force for transmission for.

According to a second aspect of the present invention, in the developing device according to the first aspect, the plurality of developing devices have compatibility .

According to a third aspect of the present invention, there is provided an image forming apparatus comprising the developing device according to the first or second aspect.

According to a fourth aspect of the present invention, the developing device according to any one of the first to third aspects can form a full-color image with toners for respective colors of yellow (Y), magenta (M), cyan (C), and black (Bk). The image forming apparatus is characterized by having a large number .

The invention of claim 5 includes a plurality an image charge of lifting body, and the present image unit that by adhering toner to the electrostatic latent image on the Zo担lifting member, a process cartridge that have a and the current image roller, the An image forming apparatus having a developing roller driving gear for driving the developing roller for each of a plurality of process cartridges , wherein the developing roller driving gear is used for transmitting a driving force on the apparatus main body side of the image forming apparatus using the process cartridge. in the image forming apparatus is driven to rotate in mesh with the gear, mutually meshing frequency with the teeth of the developing roller drive gear of the process cartridge with the teeth of the gear of the driving force for transmission adjacent in the plurality of process cartridges The image forming apparatus is characterized by being different .

According to a sixth aspect of the present invention, in the image forming apparatus of the fifth aspect, the plurality of process cartridges have compatibility .

A seventh aspect of the present invention is the image forming apparatus according to the fifth or sixth aspect, wherein a common drive source side gear for meshing with the driving force transmission gears of the plurality of process cartridges to rotationally drive the developing roller is used. characterized in that the reduction.

The invention according to claim 8 is the image forming apparatus according to any one of claims 5 to 7, wherein the process cartridge is a toner for each color of yellow (Y), magenta (M), cyan (C), and black (Bk). characterized by comprising the number capable of forming a full-color image by.

  According to the developing device, the process cartridge, and the image forming apparatus according to the present invention, it is possible to prevent the occurrence of banding with a simple configuration.

  Embodiments as the best mode for carrying out the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic cross-sectional view of a tandem type indirect transfer type copying apparatus to which the present invention is applied. In the figure, 100 is a copying machine body, 110 is a paper feed table, 120 is a scanner, and 130 is an automatic document feeder (ADF). The copying machine main body 100 is placed on the paper feed table 110,
A scanner 120 is mounted on the copying machine main body 100, and an ADF 130 is mounted thereon. Reference numeral 200 denotes a developing device arranged in the copying machine main body 100.

  The copying machine main body 100 is provided with an endless belt-like intermediate transfer member 10 in the center and is wound around three support rollers 14, 15 and 16 so that it can be rotated and conveyed clockwise in the figure. In this example, an intermediate transfer body cleaning device 17 for removing residual toner remaining on the intermediate transfer body 10 after image transfer is provided on the left side of the second support roller 15 among the three support rollers.

Further, yellow (Y) along the conveyance direction of the intermediate transfer member 10 so as to be positioned on the intermediate transfer member 10 between the first support roller 14 and the second support roller 15 of the three support rollers. ) , Magenta (M) , cyan (C) , and black (Bk) , the four image forming means 18 are arranged side by side to constitute the tandem imaging device 20. An exposure device 21 is provided above the tandem image forming device 20 as shown in the figure.

  On the other hand, a secondary transfer device 22 is provided on the opposite side of the tandem image forming device 20 with the intermediate transfer member 10 interposed therebetween. In the illustrated example, the secondary transfer device 22 is configured such that a secondary transfer belt 24, which is an endless belt, is stretched between two rollers 23, and is connected to the third support roller 16 via the intermediate transfer body 10. The secondary transfer belt 24 is disposed so as to be pressed against it, and the image on the intermediate transfer body 10 is transferred to a sheet as a transfer material.

  Next to the secondary transfer device 22, a fixing device 25 for fixing the transferred image on the sheet is provided. The fixing device 25 is configured by pressing a pressure roller 27 against a fixing belt 26 that is an endless belt. The secondary transfer device 22 described above has a sheet transport function for transporting the sheet after image transfer to the fixing device 25. Of course, a transfer roller or a non-contact charger may be disposed as the secondary transfer device 22, but in such a case, it is difficult to provide this sheet conveyance function together.

  In the example shown in the figure, a sheet for reversing the sheet in order to record an image on both sides of the sheet in parallel with the tandem image forming device 20 described above below the secondary transfer device 22 and the fixing device 25. A reversing device 28 is provided.

  The operation when making a copy using this color electrophotographic apparatus will be described. The document is set on the document table 30 of the automatic document feeder 130, or the automatic document feeder 130 is opened and the document is set on the contact glass 32 of the scanner 120. The automatic document feeder 130 is closed and pressed by it.

  When a start switch (not shown) is pressed, when the document is set on the automatic document feeder 130, the document is transported and moved onto the contact glass 32, and then the document is set on the other contact glass 32. When this occurs, the scanner 120 is immediately driven to cause the first traveling body 33 and the second traveling body 34 to travel. Then, the first traveling body 33 emits light from the light source and further reflects the reflected light from the document surface toward the second traveling body 34, and is reflected by the mirror of the second traveling body 34 and passes through the imaging lens 35. The document is placed in the reading sensor 36 and the original content is read.

  When a start switch (not shown) is pressed, one of the support rollers 14, 15 and 16 is also rotated by a drive motor (not shown) and the other two support rollers are driven to rotate. 10 is rotated and conveyed. At the same time, the photoconductors 40 are rotated by the individual image forming means 18 to form black, yellow, magenta, and cyan monochrome images on the photoconductors 40, respectively. Then, along with the conveyance of the intermediate transfer member 10, the single color images are sequentially transferred to form a composite color image on the intermediate transfer member 10.

  On the other hand, when a start switch (not shown) is pressed, one of the paper feed rollers 42 of the paper feed table 110 is selected and rotated, and the sheet is fed out from one of the paper feed cassettes 44 provided in the paper bank 43 in multiple stages and separated. The paper is separated one by one by the roller 45 and put into the paper feed path 46, conveyed by the transport roller 47, led to the paper feed path 48 in the copying machine main body 100, abutted against the registration roller 49 and stopped. When paper is fed from the manual feed tray 51, the paper feed roller 50 is rotated to feed out the sheets on the manual feed tray 51, separated one by one by the separation roller 52, and put into the manual feed path 53. Stop by hitting.

  Then, the registration roller 49 is rotated in synchronization with the composite color image on the intermediate transfer member 10, the sheet is fed between the intermediate transfer member 10 and the secondary transfer device 22, and transferred by the secondary transfer device 22. A color image is recorded on the sheet.

  The sheet after the image transfer is conveyed by the secondary transfer device 22 and sent to the fixing device 25. The fixing device 25 applies heat and pressure to fix the transferred image, and then the switching roller 55 is used to switch the discharge image. The paper is discharged at 56 and stacked on the paper discharge tray 57. Alternatively, it is switched by the switching claw 55 and put into the sheet reversing device 28, where it is reversed and guided again to the transfer position, and an image is recorded also on the back surface, and then discharged onto the discharge tray 57 by the discharge roller 56.

  On the other hand, the intermediate transfer member 10 after the image transfer is removed by the intermediate transfer member cleaning device 17 to remove residual toner remaining on the intermediate transfer member 10 after the image transfer, so that the tandem image forming device 20 can prepare for another image formation. Here, the registration roller 49 is generally used while being grounded, but it is also possible to apply a bias in order to remove paper dust from the sheet.

  FIG. 2 shows a developing device of an image forming apparatus according to an embodiment of the present invention. In this embodiment, the developing device is a tandem type image forming apparatus having four photoconductors 201a to 201d, and from the right, the black photoconductor 201a, the magenta photoconductor 201b, the cyan photoconductor 201c, and the yellow photoconductor 201d. It is. The toner images formed by the developing rollers 202a to 202d on the photoreceptors 201a to 201d are sequentially transferred to the intermediate transfer belt 203 and transferred from the secondary transfer roller 204 to the transfer paper.

  Each of the photoconductors 201a to 201d has the same shape and is supported in the process cartridges 205a to 205d, respectively. The process cartridges 205a to 205d have the same structure, and, as shown in FIG.

  Next, the drive system of the developing device 200 of the image forming apparatus of this embodiment will be described. 3 is a perspective view illustrating a process cartridge according to the embodiment, FIG. 4 is a perspective view illustrating a drive system of the image forming apparatus according to the embodiment, FIG. 5 is a perspective view of a main part of the process cartridge according to the embodiment, and FIG. FIG. 7 is a front view showing the drive system of the image forming apparatus according to the embodiment, FIG. 7 is a graph showing the rotation unevenness of the drum of the image forming apparatus according to the embodiment, and the rotation unevenness of the drum of the conventional image forming apparatus. 6 is a table showing meshing frequencies of the image forming apparatus according to the example.

Drive system, reduction gear 207a~20 7 d than the motor 206a~206d as a driving source as shown in FIG. 4, idler gear 208A～208d, driving of the developing clutches 209a~209d coaxially through the developing clutches 209a~209d The gears 210a to 210d transmit to the idler gear 212 and the developing roller driving gear 213 in the process cartridge 205 via the idler gears 211a to 211d to drive the developing roller 202.

FIG. 7 shows a meshing frequency table of the development drive system of this embodiment. The meshing frequencies of the developing units are 130 Hz for black and cyan, and 123 Hz for magenta and yellow, and the frequencies are shifted.

That is, in this example, the developing roller driving gears 213a to 213d have the same number of teeth as 20 and the reduction gears 207a to 208d and the driving gears 210a to 210d that transmit the rotational driving to the developing roller driving gears 213a to 213d. The number of teeth is black and cyan common (85 and 39), magenta and yellow are common (90 and 39), and the reduction ratios are different.

Thus, in this example, black, 130 Hz a mesh frequency of the developing drive gear stations cyan, magenta, by the 123Hz the meshing frequency of the developing drive gear of the yellow station, a vibration due to developing gear mesh frequency Reduce and disperse to suppress banding.

  On the other hand, conventionally, the same meshing frequency is set for all stations, but in this case, when the meshing vibration phases of the respective colors are matched, the vibration may be amplified.

  When the rotation unevenness of the conventional drum is measured, a peak of 130 Hz is amplified as shown in FIG. 8, and banding is generated on the image. On the other hand, in the case of this embodiment, as shown in FIG. 8, the occurrence of banding can be prevented without amplifying the peak by dispersing the meshing frequency of the developing unit to 123 Hz and 130 Hz.

In the above example, the developing roller driving gear has two different meshing frequencies, but may have three or four different meshing frequencies.

  Further, in this example, all the process cartridges 205a to 205d are configured in common, and the meshing frequency is dispersed by the drive gear on the main body side. Therefore, it is not necessary to distinguish the process cartridges by color, and the process cartridges can be shared.

1 is a cross-sectional view illustrating a structure of an image forming apparatus according to an embodiment. 1 is a diagram illustrating a developing device of an image forming apparatus according to an embodiment. It is a perspective view which shows the process cartridge which concerns on an Example. 1 is a perspective view illustrating a drive system of an image forming apparatus according to an embodiment. It is a perspective view of the principal part of the process cartridge which concerns on an Example. 1 is a front view illustrating a drive system of an image forming apparatus according to an embodiment. 6 is a table showing meshing frequencies of the image forming apparatus according to the example. 6 is a graph showing the rotation unevenness of the drum of the image forming apparatus according to the example and the rotation unevenness of the drum of the conventional image forming apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Intermediate transfer body 14 ... 1st support roller 15 ... 2nd support roller 16 ... 3rd support roller 17 ... Intermediate transfer body cleaning apparatus 18 ... Image forming means 20 ... Tandem image forming device 21 ... Exposure device 22 ... Secondary transfer device 23 ... Roller 24 ... Secondary transfer belt 25 ... Fixing device 26 ... Fixing belt 27 ... -Pressure roller 28 ... Sheet reversing device 30 ... Document table 32 ... Contact glass 33 ... First traveling body 34 ... Second traveling body 35 ... Imaging lens 36 ... Sensor 40 ... Photoconductor 42 ... Paper feed roller 43 ... Paper bank 44 ... Paper feed cassette 45 ... Separation roller 46 ... Paper feed path 47 ... Conveying roller 48 ... Paper feed path 49... Registration roller 50. -Manual feed tray 52 ... Separation roller 53 ... Paper feed path 55 ... Switching claw 56 ... Discharge roller 57 ... Paper discharge tray 100 ... Copier body 110 ... Paper feed table 120 ... Scanner 130 ... Automatic document feeder 200 ... Developer 201 ... Photoreceptor 201a ... Black photoreceptor 201b ... Magenta photoreceptor 201c ... Cyan photoreceptor 201d ... Yellow Photoconductors 202a to 202d ... developing roller 203 ... intermediate transfer belt 205 ... process cartridges 205a to 205d ... process cartridges 206a to 206d ... motors 207a to 208d ... reduction gears 208a to 208d ..Idler gears 209a to 209d ... developing clutches 210a to 210d ... drive gears 211a to 21 d ... idler gear 212 ... idler gear 213 ... developing roller drive gear 213A～213d ... developing roller drive gear

Claims (8)

Includes a plurality of image charge of lifting body, and a plurality of developing units to be provided for each image in charge bearing member of said plurality of toner to adhere to the electrostatic latent image on the image bearing member,
For each plurality of developing devices, a developing device including a developing roller and a developing roller driving gear for driving the developing roller,
The developing roller driving gear, Te developing apparatus odor that is dynamic drive rotation meshes with device gear main body of the driving force for transfer of the image forming apparatus using the developing device,
The number of teeth of the developing low la drive gear of the developing unit adjacent among the plurality of developing units shall all common, and the developing unit adjacent among the plurality of developing units
A developing device according to claim Rukoto dispersing the mesh frequency by changing one another the number of teeth of the reduction gear of the driving force for transmission for. The developing device according to claim 1, wherein the plurality of developing devices have compatibility . An image forming apparatus comprising the developing device of 請 Motomeko 1 or 2. 4. The developing device according to claim 1, wherein the developing device includes a number capable of forming a full-color image with toner for each color of yellow (Y), magenta (M), cyan (C), and black (Bk). An image forming apparatus. A plurality an image charge of lifting body, and the present image unit that by adhering toner to the electrostatic latent image on the Zo担lifting member, a process cartridge that have a and the current image roller,
Each said plurality of process cartridges, an image forming apparatus having a developing roller drive gear that drives the developing roller,
In the image forming apparatus in which the developing roller driving gear meshes with a driving force transmission gear on the apparatus main body side of the image forming apparatus using the process cartridge and is driven to rotate.
The meshing frequencies of the teeth of the developing roller driving gear and the teeth of the driving force transmission gear in adjacent process cartridges among the plurality of process cartridges are different from each other.
An image forming apparatus . 6. The image forming apparatus according to claim 5, wherein the plurality of process cartridges have compatibility . The image forming apparatus according to claim 5 or 6, characterized in that the common drive source side of the gear for rotating the developing roller meshes with the gear for the driving force transmission of the plurality of process cartridges. 8. The process cartridge according to claim 5, wherein the process cartridge is provided with a number capable of forming a full color image with toners for each color of yellow (Y), magenta (M), cyan (C), and black (Bk) . Any image forming apparatus .