JPH08123275A - Toner recovery device for electrophotographic device - Google Patents

Abstract

PURPOSE: To eliminate the need to increase the size of a device and to add large stress on used toner, in the toner recovery device of an electrophotographic device which transports the used toner in a cleaner to a recovering part. CONSTITUTION: The cleaning device 15 and a developing device as the recovering part are connected by a toner carrying pipe 35. Inside the toner carrying pipe 35 a driving roller 40 and a follower roller 41, are arranged, between which an endless belt 43 is stretched. On the periphery of the endless belt 43, elastic fins 44 are provided with their front ends pressed against the internal surface of the toner carrying pipe 35. The endless belt 43 is rotated by the transmission of rotation to the driving roller 40, and the used toner in the toner carrying pipe 35 is transported to the developing device by means of the elastic fins 44.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus, such as a laser copying machine, a laser printer, a laser facsimile, which records on paper by using an electrophotographic system. More specifically, the present invention relates to a toner recovery device for transferring the residual toner on the photoconductor after the image transfer, which is removed by the cleaning device, to the recovery unit through the toner transport pipe in such an electrophotographic apparatus.

[0002]

2. Description of the Related Art Conventionally, for example, in a laser copying machine,
The collected toner on the photoconductor after the image transfer, which is removed by the cleaning device, is conveyed to the developing device, which is a collecting part, through the toner collecting device, and the collected toner in the developing device is attached to the surface of the photoconductor and reused. There is a type to do.

In such a laser copying machine, conventionally, in a toner recovery device, a cleaning device and a developing device are connected by a toner carrying pipe, and a coil spring is rotatably provided in the toner carrying pipe. There is something.

At the time of driving, the residual toner on the photosensitive member after the image transfer removed by the cleaning device is transferred to the developing device by the rotation of the coil spring.

Further, in the toner collecting device of the laser copying machine, as shown in FIG. 7, the outer diameter of the rotary shaft 2 of the photosensitive drum 1 is slightly smaller than the outer diameter of the photosensitive drum 1. Then, a non-magnetic rotating body 4 provided with a plurality of permanent magnets 3 ... There is also a configuration in which the tension roller 7 works to make the tension state.

At the time of driving, the non-magnetic rotating body 4 is rotated together with the photosensitive drum 1, and the endless belt 6 is rotated in the direction of the arrow in the figure. Then, when passing through the developing device 8, the toner on the developing roller 9 is attracted by the permanent magnet 3 to form the ears A of the toner on the endless belt 6, and when passing through the cleaning device 10, from the discharge port 10a. When the used toner sent out is sucked by the brush A and passes through the position of the idler gear 5, the toner having no attraction by the permanent magnet 3 is dropped to the inlet 8a of the developing device 8 (Japanese Patent Laid-Open No. 57-136674). (See the official gazette).

[0007]

However, among the above-mentioned laser copying machines, the former one (not shown) has a problem that the toner is pressed against the inner surface of the toner carrying pipe, so that the stress on the toner is great. for that reason,
The toner may have a high degree of aggregation, or the surface film of the toner may be scraped off to change the characteristics, which may cause inconvenience when it is reused. In the latter case shown in FIG. 7,
Since a plurality of permanent magnets 3 are used, there is a problem that the device becomes large.

Therefore, an object of the present invention is to increase the size of the toner collecting device of the electrophotographic device for transferring the used toner in the cleaning device to the collecting part,
It is to prevent the toner from being greatly stressed.

[0009]

Therefore, in the toner collecting device of the electrophotographic apparatus of the present invention, the residual toner on the photoconductor 11 after the image transfer is removed by the cleaning device 15 as shown in the following illustrated embodiments. In the electrophotographic apparatus for transferring the removed used toner through the toner transport pipe 35 to a recovery unit such as the developing device 13, a driving roller 40 and a driven roller 41 are provided in the toner transport pipe 35. And the endless belt 43 is hung between the rollers, and the elastic fins 44 are provided on the outer circumference of the endless belt 43 by pressing the tip end against the inner surface of the toner transport pipe 35. And

According to a second aspect of the present invention, as shown in the following illustrated embodiment, in the toner collecting device A of the electrophotographic apparatus according to the first aspect, the elastic fins 44 are provided on the inner surface of the toner conveying pipe 35. Of the elastic fins 4 along with the rotation of the endless belt 43.
When the engaging member 4 is disengaged, the projecting portion 37d that bounces off with the elastic fin 44 and sends the used toner to the collecting portion
Is formed.

According to a third aspect of the present invention, as shown in the following illustrated embodiment, in the toner collecting apparatus A of the electrophotographic apparatus according to the first aspect, the outside of the driven roller 41 on the collecting section side is provided. It is characterized in that the diameter is made larger than the outer diameter of the drive roller 40 on the cleaning device 15 side to increase the amount of bending of the elastic fins 44.

According to a fourth aspect of the present invention, the endless belt 43 and the elastic fins 44 are made of the same material in the toner collecting device A of the electrophotographic apparatus according to the first aspect as shown in the following illustrated embodiments. The endless belt 43 is thinner than the elastic fins 44.

According to a fifth aspect of the present invention, as shown in the following illustrated embodiments, in the toner collecting apparatus A of the electrophotographic apparatus according to the first aspect, the endless belt 43 is provided with a long hole 43a, and It is characterized in that the drive roller 40 is provided with pins 40a and 40b which enter into the elongated hole 43a and intermittently feed the endless belt 43.

[0014]

During driving, the rotation is transmitted to the driving roller 40 to rotate the endless belt 43, and the used toner having entered the toner conveying pipe 35 is transferred to the collecting portion by the elastic fin 44.

According to the second aspect of the present invention, the elastic fins 44 are provided with protrusions 37d as the endless belt 43 rotates.
When the engagement with is released, the elastic fin 44 bounces off the used toner and sends the used toner into the collecting portion.

According to the third aspect of the present invention, the elastic fins 44 are largely bent on the collecting portion side to strengthen the repulsive force, and the elastic fins 44 engage with the inner surface of the toner conveying pipe 35 as the endless belt 43 rotates. When is released, the elastic fins 44 bounce off by the large repulsive force and send the used toner to the collecting portion.

According to the fourth aspect, the drive roller 4 is
The endless belt 43 is bent between 0 and the driven roller 41 to reduce the amount of bending of the elastic fins 44.

According to the fifth aspect, the drive roller 4
When 0 is rotationally driven, the pins 40a and 40b are elongated holes 43a.
It goes inside and intermittently feeds the endless belt 43.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 5 shows a schematic configuration of the entire internal mechanism of a laser printer provided with a toner recovery device according to an embodiment of the present invention.

Reference numeral 50 in the drawing denotes a printer main body. Inside the printer main body 50, a drum-shaped photosensitive member 11 is provided substantially in the center. Around the photoconductor 11, the charging device 12 and the developing device 1 in the driving direction shown by the arrow.
3, the transfer / separation device 14 and the cleaning device 15 are arranged. An optical writing device 16 is arranged above the charging device 12. Then, on the right side of the printer body 10 in the drawing, a paper feed cassette 17 accommodating the paper S is detachably provided.

When recording on the paper S, the paper feed roller 18 is rotationally driven to feed the paper S from the paper feed cassette 17 in the direction of the arrow, and the paper S is timed by the registration roller pair 19. And conveys it to the lower side of the photoconductor 11.

The photoconductor 11 is rotationally driven in the clockwise direction indicated by the arrow, at which time the surface is uniformly charged by the charging device 12, and then the laser beam from the optical writing device 16 is irradiated to the photoconductor 11. Form an electrostatic latent image on top. This latent image is visualized by toner when passing through the position of the developing device 13. Then, this visible image is transferred by the transfer / separation device 14 onto the upper surface of the sheet S conveyed to the lower side of the photoconductor 11, and after the transfer, is separated from the photoconductor 11.

After separation, the sheet S is conveyed to the fixing device 20, and the fixing image is fixed by the fixing device 20. After the fixing, the sheet S discharged from the fixing device 20 is conveyed, discharged by the pair of discharge rollers 21, and stacked on the discharge tray 22.

On the other hand, the residual toner on the surface of the photoreceptor 11 after the image transfer is removed by the cleaning device 15,
The electricity is removed by the electricity removing device 23 to prepare for the next use.

By the way, the cleaning device 15 is
As shown in FIG. 4, one end portion of the cleaning case 25 projects outside the side end of the photoconductor 11 and a toner delivery port 25a is provided there.

The cleaning case 25 has a toner carrying screw 26 housed in the bottom thereof. As shown in FIG. 2, the toner carrying screw 26 is provided with screw blades 28 on the outer circumference of the rotary shaft 27.
One end 27a of the above is projected from the toner delivery port 25a to the outside. A drive roller 40 is attached to one end 27a side of the rotary shaft 27. The drive roller 40 is provided with two pins 40a and 40b on the outer circumference. The other end of the rotary shaft 27 penetrates the side plate of the cleaning case 25 and projects to the outside, and a drive gear 29 is attached thereto. A driving force from a driving source (not shown) is transmitted to the driving gear 29.

On the other hand, in the developing device 13 which is the "collecting portion" in the present invention, one end portion of the developing case 32 projects outside the side end of the photoconductor 11 and the toner collecting port 3 is located there.
2a is provided and the transfer coil 33 is rotatably housed inside.

Now, the cleaning device 15 and the developing device 13 are connected to each other to provide a toner carrying pipe. The toner transport pipe 35 is composed of a U-shaped upper half portion 36 having a downward opening and a U-shaped lower half portion 37 having an upward opening for detachably covering the U-shaped portion. It is attached to the outlet 25a, and the other end, which is the outlet, is attached to the toner recovery port 32a of the developing device 13. Recesses 37a are provided on both sides of the lower half 37 so as to face the toner delivery port, and recesses 37b.3 are provided near the outlet.
7c are provided facing each other.

The drive roller 40 is inserted in the lower half 37, and the other end 27a of the rotary shaft 27 is inserted in the recess 37a. Then, the endless belt 43 is wound around the driving roller 40 and the driven roller 41. The driven roller 41 is formed to have the same diameter as the driving roller 40, and the lower half 37
Both ends of the roller shaft 42 are placed in the recesses 37b and 37c.

The endless belt 43 is formed of an elastic member such as a rubber material, and a plurality of elastic fins 44 ... Are integrally formed on the outer periphery at equal intervals, and long holes 43a are formed between the elastic fins 44. ... is provided. And FIG.
When the length dimension of the long hole 43a is a, the diameter dimension of the drive roller 40 is b, and the length dimension from one long hole 43a to the next long hole 43a is c, as shown in FIG. , And their relationship is c <b · π <a + c. Then, the pins 40a, 4 are inserted in the two long holes 43a, 43a.
Enter 0b.

Therefore, the upper half 3 is attached to the lower half 37.
6 and the state shown in FIG.
The endless belt 43 is rotatably provided by pressing the tips of the elastic fins 44 against the inner surface of the.

By the way, in the illustrated embodiment, the developing device 13
On the inner surface of the lower half portion 37 that is close to the side, a protrusion 37d having a mountain shape that gradually increases the amount of bending of the elastic fin 44 is formed.

During driving, therefore, the driving force from a driving source (not shown) is transmitted to the driving gear 29 to rotate it, thereby rotating the toner carrying screw 26 and simultaneously rotating the driving roller 40. To rotate the endless belt 43. Then, by rotating the toner carrying screw 26, the used toner in the cleaning device 15 is sent out from the toner sending port 25a and put into the toner carrying pipe 35.

On the other hand, when the drive roller 40 is rotated, the one pin 40a engages with the hole edge of the elongated hole 43a to rotate the endless belt 43, and eventually the one pin 40a comes out of the elongated hole 43a. At this time, the other pin 40b enters the intermediate position of the next long hole 43a. The endless belt 43 does not rotate until the driving roller 40 further rotates and the other pin 40b engages with the hole edge of the elongated hole 43a. After that, when the other pin 40b engages with the edge of the long hole 43a, the endless belt 43 is again engaged by the pin 40b.
To rotate. Eventually, the other pin 40b becomes the long hole 43.
When the pin 40a comes out of the "a", one pin 40a moves to the next long hole 43a
Re-enter The endless belt 43 does not rotate until the driving roller 40 further rotates and one pin 40a engages with the hole edge of the elongated hole 43a. After that, when one pin 40a engages with the edge of the long hole 43a, the end 40 is rotated again by the pin 40a. By intermittently feeding the endless belt 43 in this manner, the used toner is transferred to the recovery port 32a side by the elastic fins 44. Then, when the elastic fins 44 are largely bent by the protrusions 37d and the engagement of the elastic fins 44 is released as the endless belt 43 rotates, the elastic fins 44 are used by being bounced off. The toner is sent into the developing device 13.

Then, the used toner sent into the developing device 13 is carried further inside the carrying coil 33.

In the illustrated embodiment described above, the drive roller is
The la 40 is driven to rotate, and the pins 40a and 40b are elongated holes 43a.
The endless belt 43 was intermittently fed into the inside.
By doing so, it is possible to prevent blocking of the toner in the toner transport pipe. However, if such advantages are not expected, although not shown, the endless belt 43 may be rotated by the frictional force between the drive roller 40 and the endless belt 43 without intermittently feeding the endless belt 43. OK, drive low
The endless belt 43 may be rotated by the engagement of the unevenness between the la 40 and the endless belt 43.

In the illustrated embodiment described above, the drive roller 40 is arranged near the cleaning device 15 and the driven roller 41 is arranged near the developing device 13. However, although not shown, the driven roller 41 may be arranged near the cleaning device 15 and the drive roller 40 may be arranged near the developing device 13.

In the illustrated embodiment described above, the protrusion 37d is provided on the inner surface of the toner transport pipe 35 to provide the elastic fin 4.
The bending amount of 4 was increased. However, although not shown, for example, the driven roller 41 on the developing device 13 side is provided without providing the protrusion 37d on the inner surface of the toner transport pipe 35.
The outer diameter of the elastic roller 44 may be larger than the outer diameter of the driving roller 40 to increase the amount of bending of the elastic fins 44.

Further, in the illustrated embodiment described above, the endless belt 43 and the elastic fins 44 have the same thickness.
However, as shown in FIG. 6, the endless belt 43 may be formed to be thinner than the elastic fins 44. In this way, as shown in the figure, the drive roll
Since the endless belt 43 bends between the roller 40 and the driven roller 41, the amount of bending of the elastic fins 44 can be reduced to further reduce the stress applied to the toner.

Furthermore, in the illustrated embodiment described above, the example in which the developing device 13 is used as the recovery section is shown. However, although not shown, for example, a waste toner tank that discards the conveyed toner as it is may be used as the collecting unit.

[0041]

As described above, according to the present invention, during driving, the rotation is transmitted to the driving roller to rotate the endless belt, and the elastic fin is scratched to collect the used toner in the cleaning device. Since the toner is transferred to, the toner is not pressed against the inner surface of the toner transfer pipe, and the stress applied to the toner can be reduced and transferred. Therefore, it is possible to prevent the occurrence of inconveniences due to an increase in the aggregation degree of the toner and a change in the characteristics due to the surface film of the toner being scraped. Moreover, since a plurality of permanent magnets are not used as in the conventional case, the device can be downsized.

According to a second aspect of the present invention, when the elastic fin is pressed against the protrusion to be largely bent and the elastic fin is disengaged from the protrusion as the endless belt rotates, the third aspect of the present invention is also preferable. In the one described in (1), when the elastic fin is pressed against the inner surface of the toner transport pipe to be largely bent, and when the elastic fin disengages from the inner surface of the toner transport pipe with the rotation of the endless belt, the large elastic fin Since the toner is bounced off by the repulsive force and sent into the collecting unit, the toner can be reliably transferred to the inner part of the collecting unit without being retained in the vicinity of the collecting port.

According to the fourth aspect of the present invention, the endless belt side bends between the driving roller and the driven roller,
The amount of bending of the elastic fin can be reduced to further reduce the stress applied to the toner.

According to the fifth aspect of the present invention, when the drive roller is rotationally driven, the pin enters into the elongated hole and intermittently feeds the endless belt. Therefore, when the pin engages with the hole edge of the elongated hole. Impact can be applied to the toner to prevent blocking of the toner in the toner transport pipe.

[Brief description of drawings]

FIG. 1 illustrates a toner recovery device according to an embodiment of the present invention,
It is a front view cut and shown at a toner transport pipe position.

FIG. 2 is an exploded perspective view of the drive transmission system.

FIG. 3 is a partially enlarged view thereof.

FIG. 4 is a plan view showing a schematic configuration of the toner collecting device.

FIG. 5 is a schematic configuration diagram showing a configuration of a laser printer including the toner recovery device as viewed from the front.

FIG. 6 is a front view showing a toner recovery device according to another embodiment of the present invention, cut at a toner transport pipe position.

FIG. 7 is a front view showing a schematic configuration of a conventional toner recovery device.

[Explanation of symbols]

 11 Photoreceptor 13 Developing Device 15 Cleaning Device 35 Toner Conveying Pipe 37d Projection 40 Drive Roller 41 Driven Roller 43 Endless Belt 44 Elastic Fin

Claims (5)

[Claims] 1. An electrophotographic apparatus in which residual toner on a photoconductor after image transfer is removed by a cleaning device, and the removed used toner is transferred to a collecting section through a toner transport pipe, and the inside of the toner transport pipe. Drive to
La and a driven roller are provided, an endless belt is spanned between those rollers, and the outer circumference of the endless belt is
A toner recovery device for an electrophotographic apparatus, wherein an elastic fin is provided by pressing the tip end against the inner surface of the toner transport pipe. 2. The amount of flexure of the elastic fins is increased on the inner surface of the toner carrying pipe, and when the elastic fins are disengaged as the endless belt rotates, the elastic fins bounce off the toner and the toner is transferred. The toner recovery device for an electrophotographic apparatus according to claim 1, wherein a projection is formed to be sent to the recovery unit. 3. The elasticity of the drive roller or the driven roller on the recovery section side is made larger than the outer diameter of the driven roller or the drive roller on the cleaning device side. The toner recovery device for an electrophotographic apparatus according to claim 1, wherein the amount of bending of the fin is increased. 4. The electrophotographic apparatus according to claim 1, wherein the endless belt and the elastic fin are integrally formed of the same material, and the thickness of the endless belt is thinner than the thickness of the elastic fin. Toner recovery device. 5. The electrophotographic apparatus according to claim 1, wherein the endless belt is provided with a long hole, and the drive roller is provided with a pin which is inserted into the long hole to intermittently feed the endless belt. Toner recovery device.