JP2861540B2 - Developing 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 electrophotographic apparatus, and more particularly to a developing apparatus for a copier and a printer using a two-component developing system. Further, the present invention relates to a developing device suitable for a multi-color or color printer.

[0002]

2. Description of the Related Art In an electrophotographic system, there is a system using a two-component developer in which a carrier and a toner are mixed at a fixed ratio as a developing system for visualizing an electrostatic latent image on a photosensitive member. When such a two-component developing method is used, since only the toner is consumed by the development, the toner is appropriately replenished, and the toner density is kept constant for use. However, since the toner is used while being stirred and mixed in a developing device, the characteristics as a developer are deteriorated due to toner sticking to the carrier, pulverization of the carrier, mixing of foreign matter, and the like. That is, the developer also has a certain life. Generally, the life of the developer is much shorter than the life of the developing device main body which is an apparatus. Therefore, in the two-component developing method, a method of replacing a developer in a developing unit with a new developer when a predetermined number of images are developed is performed. However, the replacement of the developer is difficult because the developer is a mixture of the colored fine powder toner and the carrier of the fine powder magnetic material, and the developer is magnetically attracted to the developing magnet roller. It is extremely poor, and has drawbacks such as dirt on hands and clothes, and the fact that the developer is easily scattered inside and outside the main body of a copying machine or the like. For this reason, it is impossible for the user to replace the developer, and the maintenance is performed by a trained and specialized maintenance person. On the other hand, in the two-component developing method, a method of discarding the entire developing device at the end of the life of the developer and replacing the developing device with a new developing device in which a new developer is set has been attempted. Becomes unsuitable for practical use.

Further, in the case of a color printer, several multi-color developing units are arranged on one photosensitive drum or photosensitive belt, and each time a one-color toner image is formed, the toner image is transferred to a transfer drum and a color image is transferred. There is a way to get it. In this case, during the development of one color,
When a developer of another color is in contact with the photosensitive drum or the photosensitive belt, the image quality is deteriorated by mixing colors or disturbing the developed toner image, and another developer is contained in the developer of the developing device. Color toner is mixed in, and similarly causes image deterioration.
For this reason, a method has been attempted in which one developing unit is moved from a predetermined position during development of one color so as not to contact the photosensitive member. In this case, the driving device becomes large, and the gap accuracy between the photoconductor and the developing device during development during position control is difficult to be obtained.
Further, the toner may fall or scatter due to vibration during the movement.

As described above, in the two-component developing system, the exchangeability of the developer is extremely poor, and further, it is difficult for the user to exchange the developer which is a consumable. Further, in the case of a color printer or the like, it is necessary to move the developing device, which has a drawback that the apparatus becomes complicated and toner is scattered.

[0005]

The above prior art has a drawback that the exchangeability of the developer is extremely poor. Furthermore, there is a problem in user maintenance.

SUMMARY OF THE INVENTION It is an object of the present invention to make it possible to easily replace a developer in a two-component developing system without scattering the developer.
Further, it is another object of the present invention to allow a user to perform developer exchange at a practical cost.

Still another object of the present invention is to provide a structure for retracting the developer on the developing magnet roll.

[0008]

The feature of the present invention is that a plurality of
Different colored powders are attached to the photoreceptor surface by the developing device.
Forming a color image, wherein the plurality of
Each of the containers is placed in a hopper case,
Replenish the toner in the cartridge and the toner cartridge
A hopper having a toner supply roller to the case and
The developer and the toner replenishing unit are arranged in a guide base.
And a stirring roller for stirring the toner supplied from the roller.
Conveys developer and toner agitated by the agitation roller
The hopper has a stirring and conveying roller.
The agitation-reservoir formed and placed in the developing case,
Absorbs the developer and toner sent from the agitating and conveying rollers.
And a magnet roller for attaching and transferring to the photoreceptor.
Transport mug that attracts developer and toner remaining on the feed roller
Attracted by the net roller and the transfer magnet roller
To remove the developer and toner and return to the stirring-storage section.
The hopper section and the stirring-storage section having
Detachably configured developed - become more and the conveying section, it
At the end of the development, each of the developing devices has the stirring roller and the stirring device.
The drive of the stirring conveyance roller is stopped and the magnet
The developing roller by driving the roller and the conveying magnet roller.
-Return the developer and toner in the transport section to the stirring-reservoir section.
In the developing device.

[0009]

A stirring / conveying roller is provided in the stirring / storage section, and the developer in the stirring / storage section is supplied to the developing / conveying section by the stirring / conveying roller, and is attracted and conveyed by the developing magnet roller in the developing / conveying section. After developing, the developer is transferred to a conveying magnet roller, scraped off with a scraper, and returned to the stirring-storage section. At the end of development or during non-operation, first, the rotation drive of the stirring and conveying roller is stopped, and in this state, the developing magnet roller and the conveying magnet roller are driven to rotate for a certain period of time to stir the developer in the developing-conveying section. Collect in storage.

[0010]

An embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a full sectional view of a color printer device using a developing device according to one embodiment of the present invention. The recording belt 2 made of an organic photoconductor is driven by a belt driving roller 18 to rotate in the direction of the arrow. A first color (yellow) developing device, a second color (magenta) developing device 6b, a third color (cyan) developing device 6c, and a fourth color (black) developing device 6d are provided above the recording material belt 2. ing. Recording medium belt 2
Is first uniformly charged by the charger 4 and then exposed by the laser beam 20 from the laser beam generator 3 to form an electrostatic latent image on the recording material belt 2, and this is a first color (yellow) Develop with a developer. At this time, the respective developers of the second color (magenta) developing device 6b, the third color (cyan) developing device 6c, and the fourth color (black) developing device 6d are retracted by a method described later. Do not touch. The created yellow toner image is transferred to the transfer drum 1. The recording belt 2 is electrostatically discharged by the erase 5 and the residual toner is removed by the belt cleaner 21. Next, as the second color, the image is uniformly charged by the charger 4 and further exposed by the laser beam generator 3 in a pattern for the second color (magenta) to form an electrostatic latent image. Here, the developer of the first color (yellow) developing device 6a is retracted by a method described later, does not contact the recording material belt 2, and the second color (magenta) developing device 6b
Is in contact with the recording material belt 2 to perform development. Similarly, at this time, the developers of the third color (cyan) and the fourth color (black) are retracted, and the magenta toner image created by the development is transferred onto the transfer drum so as to be superimposed on the previous yellow toner image. . The same process is performed for the third color (cyan) and the fourth color (black), and a color toner image is obtained by superimposing the four color toner images on the transfer drum 1.

In synchronization with the timing when the four colors are superimposed and transferred on the transfer drum 1, the paper 8 stored in the paper feed cassette 7 is sent out to the registration roller 12 one by one by the paper feed roller 9 and the separation unit 10. The transfer timing with the toner image is set by the registration roller 12 and the transfer drum 1
, And the color toner image on the transfer drum 1 is transferred to the sheet 8 by the transfer device 13.

The paper 8 after the transfer is heat-fixed when passing through the fixing device 14 and is discharged onto a top cover 17 by a paper discharge roller 15.

The details of the present invention will be described with reference to FIGS. 2, 3 and 4 are sectional views of one embodiment of the developing device of the present invention. FIG. 2 is a diagram showing a state during operation, that is, a state during development, and FIG. 3 is a diagram showing a state at the time of collection, that is, a state in which development is completed and the developer is retracted and collected. FIG. 4 is a view showing a state where the developer is stopped, that is, a state where the developer is collected and retracted.

The developing device is mainly composed of three parts: a stirring-storage part, a developing-conveying part, and a hopper part. The structure of the stirring-storage section is formed in a box shape by a case 39, a guide base 37, and side plates (not shown) on both sides.
Reference numeral denotes a stirring roller, and reference numeral 40 denotes a paddle type stirring / conveying roller having a function of stirring and mixing and conveying the developer. 42 is a developer. Reference numeral 38 denotes a guide plate for flowing the developer obliquely. The configuration of the developing-conveying unit includes the developing case 31 and the scraper 3.
4 and a side plate (not shown) on both sides are formed in a box shape.
32 is a developing magnet roller, 33 is a conveying magnet roller, 35 is a guide base, and 36 is a doctor blade. The hopper part is a hopper case 43a, 43
b, a side plate (not shown) on both sides, and a toner cartridge 45 formed in a box shape with a lid 44 and having a discharge paddle 47.
Is installed. 46 is a toner, and 48 is a toner supply roller.

When the stirring / conveying roller 40 is driven to rotate in the direction of the arrow, the developer 42 of the stirring / conveying section is pumped to the upper portion of the guide base 35 by the rotation of the stirring / conveying roller 40, and falls on the guide base 35. Is attracted to the developing magnet roller 32. The developing magnet roller 32 is driven to rotate in the direction of the arrow, and the amount of the attracted developer is regulated to a certain height by the doctor blade 36, and the developer is spiked by the magnetic pole at the lower part, and comes into contact with the recording material belt 2, develop. Next, the developer 42 is suction-conveyed by the conveyance magnet roller 33 that is driven to rotate in the direction of the arrow, and the scraper 3
At 4, it is removed by the transfer magnet roller 33, falls on the guide base 37, and falls on the stirring roller 41.
In this way, during operation, the stirring roller 41 and the stirring and conveying roller 4
0, the developing magnet roller 32 and the conveying magnet roller 33 are driven to rotate, and the developer 42 is circulated to perform development. When the toner concentration in the developer decreases due to the development, the controller (not shown) rotates the toner supply roller 48 to supply the toner 46. If the developing device is stopped in this state when the development is completed or stopped, the developer remains adsorbed on the developing magnet roller 32 and the transporting magnet roller 33, and the developer remains in the other developing-transporting section. is there.

At the time of recovery in FIG. 3, the rotation of the stirring roller 41 and the stirring and conveying roller 40 is stopped, and the developing magnet roller 32 and the conveying magnet roller 33 are driven to rotate.
Therefore, the developer 42 in the stirring-storage section is not supplied to the developing-conveying section. Further, the developer adsorbed on the developing magnet roller 32 and the conveying magnet roller 33 and the other developer in the developing and conveying unit are sequentially collected by the rotation of both rollers 32 and 33 to the stirring and storing unit.

FIG. 4 shows a stopped state, in which the rotation of all the rollers is stopped, the developer on the developing magnet roll 32 is retracted, and most of the developer in the developing conveyance section is removed. Stir-collected in reservoir. When the development is resumed, the four rollers 41, 40, 32, and 33 are driven to rotate, and the operation state shown in FIG. 2 is established.

FIG. 5 shows that the developer has reached the end of its life and needs to be replaced.
FIG. 5 shows a state in which the stirring-storage unit, that is, the developer cartridge from which most of the developer has been recovered, has been removed from the developing device at the time of stoppage in FIG. 4.

FIG. 6 is a sectional view of the developer cartridge. When a predetermined number of sheets have been developed and the life has expired, the developing cartridge is discarded as it is, and a developing cartridge in which a new developer is set is mounted on the developing device. With this replacement, the developer can be replaced without touching the developer. Also, the portion of the device to be discarded and replaced as a developing cartridge is only a small part of the developing device as a whole, which is very advantageous in cost. Further, the size of the developing cartridge can be reduced as compared to the size of the entire developing device, and the hermetically sealed package for sealing the developer and preventing the developer from absorbing moisture in a stored state is simple and inexpensive.

FIG. 7 is a sectional view of the developing-transporting section.

[0021]

As described above, according to the present invention, the two-component developer can be easily replaced without touching the developer. Further, there is no practical problem with the cost. It can be exchanged by ordinary users as well as maintenance personnel with specialized training. Furthermore, the developer on the developing magnet roller can be retracted, and in a color printer, etc.
There is no need to move the entire developing device, and the configuration and driving can be simplified. The present invention also eliminates toner drop due to shock or vibration when the developing device is moved, color shift due to vibration during image formation, and the like.

Although the embodiment of the present invention has been described in the case of a color printer, even if the developing device of the present invention is applied to a black-and-white copying machine, the effect of simplifying the developer exchange and exchanging it without contamination can be obtained. Obviously obtained.

[Brief description of the drawings]

FIG. 1 is a full sectional view of an embodiment of a color printer using a developing device of an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the developing device according to the embodiment of the present invention, showing a state during operation.

FIG. 3 is a cross-sectional view of the developing device according to the embodiment of the present invention, illustrating a state in which the developer is collected.

FIG. 4 is a cross-sectional view of the developing device according to the embodiment of the present invention, illustrating a state when the developing device is stopped.

FIG. 5 is a cross-sectional view of the developing device according to the embodiment of the present invention, showing a state in which a developer cartridge is detached.

FIG. 6 is a sectional view of a developer cartridge of the developing device according to the embodiment of the present invention.

FIG. 7 is a cross-sectional view of a developing-conveying unit of the developing device according to one embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Transfer drum, 2 ... Recording belt, 3 ... Laser beam generator, 4 ... Charging device, 5 ... Erase, 6 ... Developing device, 7
... Paper feed cassette, 8 ... Paper, 9 ... Paper feed roller, 10 ... Separator, 11 ... Manual tray, 12 ... Register roller, 1
3 ... Transfer unit, 14 ... Fixing unit, 15 ... Discharge roller, 16 ...
Drum cleaning, 17: Top cover, 18: Belt drive roller, 19: Recording belt unit, 20: Laser beam, 21: Belt cleaner, 22: Support point, 23 ...
Open / close lever, 24: paper feed roller, 25: paper feed path,
26: body, 31: developing case, 32: developing magnet roller, 33: conveying magnet roller, 34: scraper, 35: guide base, 36: doctor blade,
37: guide base, 38: guide plate, 39: case,
40: stirring and conveying roller, 41: stirring roller, 42: developer, 43: hopper case, 44: lid, 45: toner cartridge, 46: toner, 47: discharge paddle, 48
... Toner supply roller, 50: Genzo side plate, 51: cartridge side plate, 52: hopper side plate.

Claims (1)

(57) [Claims] 1. The surface of a photoreceptor varies depending on a plurality of developing units.
A color image is formed by attaching colored powder.
Therefore , each of the plurality of developing devices is arranged in a hopper case.
And the toner cartridge and the toner cartridge.
A toner supply roller that supplies toner
And the developer and the toner placed in the case and the guide base.
Stirrer that stirs the toner supplied from the toner supply roller.
Roller and the developer and toner stirred by the stirring roller.
To the hopper section, which has
A stirring-storage unit configured to be detachable, and disposed in the developing case, and sent from the stirring-conveying roller.
A toner that absorbs the developer and toner that is transferred to the photoreceptor.
Developer remaining on gnet roller and magnet roller
Magnet roller for adsorbing toner and toner, and the conveyance
Remove the developer and toner adsorbed on the magnet roller
And a scraper for returning to the stirring-storage section
Current unit detachably configured in the hopper unit and the stirring-storage unit.
An image-conveying unit, and each developing unit is provided with the stirring roller and
When the drive of the stirring and conveying roller is stopped,
Drive the feed roller and the transfer magnet roller to
The developer and toner in the developing-conveying section are returned to the stirring-storage section.
Developed developing device.