JPH07230240A - Electrophotographic device - Google Patents

Abstract

PURPOSE:To smoothly feed used developer into a developing device, in an electrophotographic device which feeds the used developer into the developing device, thereby recycling it. CONSTITUTION:The device is equipped with a carrying device 45 which carries used developer from a cleaner 15 into the developing device 13. In the carrying device 45, one end of a carrying pipe 46 is connected to the cleaner 15, and a discharge opening 46a made at the other end communicates with the developer recovering opening 38b of the developing device 13. A carrying coil 47 for carrying the used developer, fed from the cleaner 15, to the discharge opening 46a is provided inside the carrying pipe 46 so that it turns freely. A pair of crushing rollers 53 which rotate in contact with each other to crush the large particles of the developer, carried by the carrying device 45, between them is provided under the discharge opening 46a of the carrying pipe 46.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention can be applied to an electrophotographic apparatus such as a laser copying machine, a laser printer or a laser facsimile which records on paper by an electrophotographic method. Specifically, in such an electrophotographic apparatus, the residual developer on the photoconductor after the image transfer is removed by a cleaning device and collected, and the collected used developer is conveyed into the developing device for reuse. Regarding what you do.

[0002]

2. Description of the Related Art In this type of electrophotographic apparatus, the used developer agglomerates into coarse particles, so that there is a problem that the image quality is deteriorated if the developer is used as it is.

Therefore, conventionally, in an electrophotographic apparatus, as shown in FIG. 7, for example, an auger 6 is rotatably provided in a developer carrying pipe 1, and at the outlet of the developer carrying pipe 1, a lower end is provided. There is also a configuration in which the mesh member 2 is provided and a small chamber 4 axially mounted with a rotating brush 3 for rubbing the mesh member 2 is provided.

When the used developer 5 is conveyed by the auger 6 into the developing device, the rotary brush 3 is driven to rotate, and the rotary brush 3 causes the coarse particles 5a to move into the mesh member 2.
It was rubbed against and pulverized, passed through the mesh member 2 and fed into the developing device.

[0005]

However, in such a conventional electrophotographic apparatus, since the mesh member 2 is used, there is a problem that clogging occurs to prevent the used developer from being fed into the developing apparatus. there were.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to smoothly feed a used developer into a developing device in an electrophotographic device for recovering and reusing the developer.

[0007]

Therefore, what is stated in claim 1 is, for example, as shown in the following illustrated embodiment,
A developing device 13 for developing the latent image on the photoconductor 11, a transfer device 14 for transferring the image on the photoconductor 11 developed by the developing device 13 to a sheet, and a transfer device 14 for transferring the image by the transfer device 14 A cleaning device 15 for removing and collecting the residual developer on the photoconductor 11, and a carrying device 4 for carrying the collected developer from the cleaning device 15 to the developing device 13.
5 and a pair of crushing rollers 53 that rotate in contact with each other and crush the developer conveyed by the conveying device 45 between them.

According to a second aspect of the present invention, for example, as shown in the following illustrated embodiment, in the electrophotographic apparatus of the first aspect, the linear velocities at the contact portions of the pair of crushing rollers 53 are made different. It is characterized by

According to a third aspect of the present invention, for example, as shown in the following illustrated embodiments, in the electrophotographic apparatus of the first aspect, the surface hardness of the pair of crushing rollers 53 is different. To do.

According to a fourth aspect of the present invention, for example, as shown in the following illustrated embodiments, in the electrophotographic apparatus of the first aspect, one or both surfaces of the pair of crushing rollers 53 are provided with the conveying device. It is characterized in that a concave portion for scraping the developer after conveyance by the pair 45 is formed between the pair of crushing rollers 53.

[0011]

In the present invention, at the time of recording, after the image on the photoconductor 11 is transferred to the paper, the residual developer on the photoconductor 11 is removed and collected by the cleaning device 15, and the collected developer is collected. It is conveyed by the conveying device 45 and passed through a pair of crushing rollers 53, where it is crushed and fed into the developing device 13.

In the second aspect of the invention, the conveyed developer is rubbed between the pair of crushing rollers 53 and crushed.

According to the third aspect, the length of the contact portion of the pair of crushing rollers 53 is increased.

In the fourth aspect, the developer after being conveyed is scraped between the pair of crushing rollers 53 in the recess.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 6 shows a schematic configuration of the entire internal mechanism of a laser printer which is an embodiment of the present invention.

Reference numeral 10 in the figure denotes a printer body. The printer body 10 includes a lower structure 10a and an upper structure 10b, and the upper structure 10b is attached to the lower structure 10a so as to be openable and closable around a fulcrum a.

A drum-shaped photosensitive member 11 is provided in the printer main body 10 substantially at the center thereof. Around the photoconductor 11, a charging device 12 is arranged on the lower side, a developing device 13 is arranged on the right side, a transfer device 14 is arranged on the upper side, and a cleaning device 15 is arranged on the left side. An optical writing device 16 is provided below the charging device 12 and the cleaning device 15. Below the optical writing device 16, a paper feed cassette 17 for storing the paper S is detachably attached.

On the right side of the developing device 13, that is, on the front side of the printer body 10 shown by the arrow A, there is provided a paper feed path 20 for guiding the fed paper S upward. A paper feed roller 21 is provided near the starting point of the paper feed path 20, and a transport path 23 common to the paper S inserted from the manual paper feed port 22 is provided in the front. In the middle of the transport path 23,
The registration roller pair 24 is arranged.

On the other hand, a fixing device 26 is provided on the side opposite to the registration roller pair 24 with the transfer device 14 interposed therebetween. Further, a paper discharge path 27 is provided on the left side of the fixing device 26, and a paper discharge receiver 28 is installed in front of it.

Therefore, at the time of recording, the paper feed roller 20 is rotationally driven to feed the paper S from the paper feed cassette 17, and the registration roller pair 24 conveys the paper S to the upper side of the photoconductor 11 at a timing. On the other hand, the photoconductor 11 is driven in the counterclockwise direction indicated by the arrow, and at that time, the surface thereof is uniformly charged by the charging device 12, and the surface is irradiated with the laser beam L from the optical writing device 16 so that the photoconductor 11 is irradiated. An electrostatic latent image is formed on the electrostatic latent image, and when the electrostatic latent image passes through the position of the developing device 13, the electrostatic latent image is sequentially visualized by a developer. Then, this visible image is transferred to the photoreceptor 11
The image is transferred by the transfer device 14 to the upper surface of the sheet S conveyed to the upper side of the sheet. After the image transfer, the sheet S is conveyed to the fixing device 26,
Therefore, the image on the paper S is fixed, then discharged and stacked on the paper discharge receiver 28.

On the other hand, after the image transfer, the residual developer on the photoconductor 11 is scraped off by the blade 29 of the cleaning device 15 to be collected in the cleaning case 30, and the surface of the photoconductor 11 after cleaning is destaticized (not shown). Use a device to eliminate static electricity.

By the way, the photoconductor 11, the charging device 12, the developing device 13, the cleaning device 15 and the like described above are shown in FIG.
As also shown in FIG. Reference numeral 33 in the figure denotes a main body case of the developing device 13, which is formed in a laterally long hollow shape in the axial direction of the photoconductor 11. Inside the main body case 33, a developing chamber 34 is provided on the left side in the drawing, and a developing roller 35 and a replenishing roller 36 are housed therein. Then, a part of the developing roller 35 is projected from the developing window 33a. An image wall portion 33b is provided on the right side of the developing chamber 34 in the drawing. A communication window 33c is opened in the picture wall portion 33b. The picture wall section 3
A storage chamber 3 is provided on the opposite side of the developing chamber 34 across the 3b.
7 is provided and the developer hopper 38 is housed therein.

The developer hopper 38 is formed in a horizontally long cylindrical shape, a developer supply port 38a is provided on the outer periphery, and an agitator 39 is rotatably provided inside. Then, the developer replenishing port 38a is attached so as to match the communication window 33c. Further, as shown in FIG. 4, the developer hopper 38 is provided with a developer recovery port 38b and a developer supply port 38c side by side at one end in the length direction, and these developer supply port 38c and developer recovery port 38b are provided. A conveying screw 40 is provided on the lower side in parallel with the agitator 39. The mouth 41a of the developer bottle 41 is connected to the developer supply port 38c. The developer bottle 41 is provided with spiral blades on its inner surface, and is supported so as to be rotatable.

On the other hand, the above-mentioned cleaning device 15 is
As shown in FIG. 4, a conveyance screw 43 is provided at the bottom of the cleaning case 30 in parallel with the photoconductor 11.

As shown in FIGS. 1 to 4, the laser printer of the illustrated embodiment includes a carrying device 45 for carrying the used developer from the cleaning device 15 to the developing device 13.

Reference numeral 46 in FIG. 4 is a carrier pipe. The transfer pipe 46 has one end side connected to the connection port of the cleaning case 30 and the other end side connected to the developer recovery port 38b of the developer hopper 38. A transfer coil 47 is housed inside the transfer tube 46. The carrying coil 47 is rotatably provided with one end fixed to a rotary shaft 48 shown in FIG. 4 and the other end fixed to a rotary shaft 49 shown in FIG.
A gear 50 is fixed to the rotary shaft 48. Then, the gear 50 is meshed with the gear 51 provided on one end side of the conveying screw 43. On the other hand, a gear 52 is fixed to the rotary shaft 49 shown in FIG.

As shown in FIG. 1, a discharge port 46a is provided downward at the other end of the carrier pipe 46. Its outlet 4
As shown in FIG. 2, a pair of crushing rollers 53 is provided under the 6a. The crushing rollers 53a and 53b having the same thickness and surface hardness are used. The crushing rollers 53a and 53b are provided in parallel with each other in contact with each other in the direction orthogonal to the discharging direction. Side wall portion 38d on the developer recovery port 38b shown
The roller shaft 55 is rotatably supported by a roller shaft 55, and a gear 57 is fixed to the roller shaft 55 and a gear 58 is fixed to the roller shaft 56, as shown in FIG. And the gear 52
The gear 57 of one of the crushing rollers 53a is engaged with the gear 57 of one of the crushing rollers 53a through the idle gear 59, and the gear 58 of the other crushing roller 53b is engaged with the gear 57 of the one crushing roller 53a.

Therefore, at the time of recording, when the driving force from a driving source (not shown) is transmitted to the gear 51 shown in FIG. 4 to drive it, the conveying screw 43 rotates. And
The used developer is sent out from the connection port of the cleaning case 30 by the carrying screw 43 to carry the carrying pipe 4
Put in 6.

At the same time as the conveyance screw 43 is rotated, the conveyance coil 47 is rotated through the gear 50, and the gear 52 shown in FIG. 3 is rotated. Then, the carrier pipe 46
The used developer inside the carrier coil 47 is used to discharge the used developer.
Transport to a side. Then, after being transported, the used developer is eventually discharged from the discharge port 46a to the pair of crushing rollers 53.
Fall on top.

On the other hand, when the gear 52 shown in FIG. 3 is rotated, the gear 57 and the gear 58 are sequentially rotated through the idle gear 59 to rotate the pair of grinding rollers 53. Then, the used developer dropped on the pair of crushing rollers 53 is scraped into the contact portion by the rotation of each of the crushing rollers 53a and 53b and passed through between them, and the coarse particles are crushed there. Then, the used developer after crushing is collected in the developer hopper 38 from the developer collecting port 38b.

Then, when the amount of the developer in the developer hopper 38 becomes less than a certain amount with the passage of time, it is detected by a developer end sensor (not shown). Then, the drive means is driven by the control means (not shown) to rotate the developer bottle 41 shown in FIG. 4, and the unused developer is sent to and pushed out by the spiral blade toward the mouth portion 41a, and the developer supply port 38c.
Through the developer hopper 38. Then, the carrying screw 40 carries the developer into the inside of the developer hopper 38.

In the illustrated embodiment described above, the linear velocities at the contact portions of the pair of crushing rollers 53 are the same. However, the linear velocities at the contact portions of the pair of crushing rollers 53 may be different. According to this structure, since the coarse particles are rubbed and crushed between the pair of crushing rollers 53, the coarse particles can be crushed efficiently.

In the illustrated embodiment described above, the surface hardness of the pair of grinding rollers 53 is the same. However, the surface hardness of the pair of crushing rollers 53 may be different. With this configuration, the length of the contact portion between the pair of crushing rollers 53 becomes long, and the crushing of coarse particles can be reliably performed.

Further, although not shown, on one or both surfaces of the pair of crushing rollers 53, a large number of recesses for scraping the developer after being transported by the transporting device 45 between the pair of crushing rollers 53 are formed. It may be configured. The recesses are 3 to 5 times the average particle size of the developer. According to this structure, the developer after conveyance is provided with a pair of crushing rollers 5 in the recesses.
Since the developer is scraped into the contact portion 3, it is possible to improve the feeding of the developer.

[0035]

As described above, according to the present invention, the developer after conveyance is crushed at the time of recording through a pair of crushing rollers, so that the mesh member is clogged as in the conventional case. The used developer can be smoothly fed into the developing device without being hindered from being conveyed.

When the transported developer is crushed through a pair of crushing rollers, the developer is rubbed and crushed between the pair of crushing rollers according to the second aspect of the invention.
According to the third aspect, since the length of the contact portion between the crushing rollers is long, it is possible to reliably crush the coarse particles.

According to the fourth aspect of the present invention, the developer after being conveyed is scraped between the pair of crushing rollers in the recess, so that the developer can be fed in well.

[Brief description of drawings]

FIG. 1 shows a laser printer according to an embodiment of the present invention,
It is a partially expanded schematic block diagram.

FIG. 2 is a vertical sectional view taken along the line EE in FIG.

FIG. 3 is a state explanatory view showing a meshed state of gears when viewed from a direction C in FIG.

FIG. 4 is a schematic plan view of a part of an image forming unit portion of the laser printer.

FIG. 5 is an enlarged schematic configuration diagram of an image forming unit portion thereof.

FIG. 6 is a schematic configuration diagram of an entire internal mechanism of the laser printer.

FIG. 7 is a partial cross-sectional view of a conventional electrophotographic apparatus.

[Explanation of symbols]

 11 Photoreceptor 13 Developing Device 14 Transfer Device 15 Cleaning Device 45 Conveying Device 53 Pair of Grinding Rollers

Claims (4)

[Claims] 1. A developing device for developing a latent image on a photoreceptor,
A transfer device for transferring the image on the photoconductor after development by the developing device to a sheet, a cleaning device for removing and collecting the residual developer on the photoconductor after the image transfer by the transfer device, and a cleaning device therefor An electrophotographic apparatus comprising: a conveying device that conveys the collected developer from the developing device to the developing device; and a pair of crushing rollers that rotate while coming into contact with each other and crush the developer after being conveyed by the conveying device between them. . 2. The electrophotographic apparatus according to claim 1, wherein the linear velocities of the contact portions of the pair of crushing rollers are different from each other. 3. The electrophotographic apparatus according to claim 1, wherein the pair of crushing rollers have different surface hardnesses. 4. The recess according to claim 1, wherein one or both surfaces of the pair of crushing rollers are provided with a recess for scraping the developer, which has been transported by the transport device, between the pair of crushing rollers. Electrophotographic device.