JPH11161128A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent much toner from flowing out even when a toner carrying function is lowered or the toner can not be carried by providing a part for shifting toner from a 1st toner carrying means to a 2nd toner carrying means. SOLUTION: Apertures 51 and 50 which are aligned with each other are formed on the adjacent wall parts of the toner receiving case 46 of the 1st toner carrying means 44 and the hollow case 47 of the 2nd toner carrying means 45, and both cases 46 and 47 communicate with each other through the apertures 51 and 50. When the means 44 breaks down and the toner carrying function is lowered or gets impossible, the toner dropping from a toner discharge tube 42 to a 1st toner carrying tube 62 is accumulated on the tube 62. When the quantity of the accumulated toner is large, the toner is shifted to the 2nd toner carrying tube 53 of the means 45 through the apertures 51 and 50 and carried to a waste toner container by a 2nd toner carrying member 54. Thus, failure that the inside of the tube 62 is clogged with the toner and the toner overflows to the outside is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating image carrier, a developing device for forming a toner image on the surface of the image carrier, and a transfer material on which a toner image on the surface of the image carrier is transferred. A transfer belt for conveying, a carrier cleaning device for removing the transfer residual toner adhered to the surface of the image carrier after transferring the toner image to the transfer material from the surface of the image carrier, and cleaning the surface of the image carrier; A belt cleaning device that cleans the transfer belt surface by removing toner adhered to the surface of the transfer belt from the transfer belt surface; and a toner cleaning device that reuses the toner discharged from the carrier cleaning device in the developing device. A first toner conveying unit that conveys the toner to the developing device; and a second toner conveying unit that conveys the toner discharged from the belt cleaning device to a waste toner container. An image forming apparatus comprising Te.

[0002]

2. Description of the Related Art In an image forming apparatus of the above-mentioned type configured as a copier, a printer, a facsimile or a multifunction machine having at least two of these functions, toner discharged from a carrier cleaning device is used as a toner. Since the toner can be conveyed to the developing device by the one toner conveying unit and the toner can be reused in the developing device, the toner consumption of the image forming apparatus can be reduced, and the economic burden on the user can be reduced. On the other hand, the toner collected from the transfer belt can be conveyed to the waste toner container by the second toner conveying means, and the toner can be stored in the waste toner container.

The untransferred toner adhering to the surface of the image carrier is
Since the quality of the toner is maintained so that it can be reused in the developing device, the toner is transported to the developing device by the first toner transport means. On the other hand, the quality of the toner recovered from the transfer belt becomes poor. Therefore, the toner is conveyed to the waste toner container by the second toner conveying means, and is not used in the developing device.

In this case, the amount of toner discharged from the cleaning device for the carrier is much larger than the amount of toner discharged from the cleaning device for the belt.
If the toner transport function is reduced or the toner cannot be transported due to failure of the first toner transport unit, the first toner transport unit is clogged with toner, and the toner finally flows out. However, this may be scattered in the main body of the image forming apparatus, and the inside of the main body may be contaminated with toner.

[0005]

SUMMARY OF THE INVENTION The present invention has been made based on the above-described novel recognition, and an object of the present invention is to reduce the toner conveying function of the first toner conveying means. Another object of the present invention is to provide an image forming apparatus of the type described at the beginning, which can prevent a large amount of toner from flowing out of the first toner conveying means even when the toner conveying means becomes unable to convey toner. .

[0006]

According to the present invention, in order to achieve the above object, in the image forming apparatus of the type described at the beginning, the toner transport function of the first toner transport means is reduced or the first toner transport function is reduced. When the first toner conveying means is in a state in which the toner cannot be conveyed, the second toner conveying means can transfer the toner in the first toner conveying means into the second toner conveying means. The present invention proposes an image forming apparatus characterized in that a toner transfer section is provided to the means.

At this time, it is advantageous to provide the waste toner container with a toner amount detecting means for detecting that the toner in the waste toner container has reached a predetermined amount.

Further, in the image forming apparatus according to the second aspect, it is time to replace the waste toner container while maintaining the normal state of the first and second toner conveying means, or to shorten the life of the image forming apparatus. It is advantageous to set the capacity of the waste toner container so that the toner amount detecting means does not detect that the amount of toner in the waste toner container has reached a predetermined amount even when the toner amount has reached (claim 3).

Further, in the image forming apparatus according to claim 2, a measuring means for measuring an operation time of the image forming apparatus after a new waste toner container is set in the image forming apparatus main body, and a toner amount detecting means. Determining that the toner in the waste toner container has reached a predetermined amount, and determining that the first toner conveying means is abnormal when the operating time is equal to or shorter than a predetermined time. It is advantageous to have it (claim 4).

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic sectional view showing an image forming apparatus to which the present invention is applied, viewed from the front side. FIG. 2 shows a state in which an outer cover of the image forming apparatus is removed and a part of the image forming apparatus is removed. FIG. 2 is a perspective view showing only the elements of FIG. The image forming apparatus shown here functions as a copying machine, is configured to read a document image and form an image by an electrophotographic method based on the document image.

In FIG. 1, an original (not shown) is placed on a contact glass 2 fixedly mounted on an upper portion of an image forming apparatus main body 1, and the original is illuminated by a light source 3 moving rightward in FIG. The reflected light image is reflected by the first mirror 4 moving rightward together with the light source 3,
After being reflected by the second and third mirrors 5 and 6 moving rightward at half the speed of the light, the light enters the reading device 7. The reading device 7 includes an image sensor (not shown) formed of, for example, a CCD for reading a reflected light image from a document,
It also has an imaging lens (not shown) for forming an optical image on this sensor.

On the other hand, a drum-shaped photosensitive member 14 which is an example of a latent image carrier rotatably supported by the frame 1A and the side plate 1B of the image forming apparatus main body 1 shown in FIG. 1 by a drive motor 61 supported by a rear side plate 1B via a transmission (not shown).
It is driven to rotate clockwise in FIG. At this time, the surface of the photoconductor 14 is uniformly charged to a predetermined polarity by the charging device 15, and the charged surface is irradiated with the light-modulated laser light L emitted from the exposure device 8, thereby An electrostatic latent image is formed on body 14. The drive motor 61 also serves as a drive source for other elements for forming an image in addition to the photoconductor 14, and also serves as a drive source for first and second toner conveying units described later.

An exposure apparatus 8 shown in FIG. 1 is a scanning image forming lens system 1 including a rotary polygon mirror 9 for reflecting a laser emitted from a laser light source (not shown), an fθ lens, and the like.
0, mirror 1 that reflects the laser that has passed through lens system 10
The laser beam L is formed on the photoreceptor 14. The laser light is optically modulated in accordance with the image signal read by the reading device 7, and an electrostatic latent image corresponding to the original image is formed on the surface of the photoconductor 14 irradiated with the laser light L. Is done.

The electrostatic latent image described above is
Is visualized as a toner image. The developing device 16 shown in FIG.
8 and a developing roller 17 rotatably supported therein.
The developer is carried and conveyed on the circumferential surface of the developing roller 17 that is driven to rotate, and the electrostatic latent image formed on the photoreceptor 14 is visualized as a toner image by the conveyed developer. . In the developing device 16 of the present example, as the developer D,
Although a powdery two-component developer having a toner and a carrier is used, a one-component developer not containing a carrier can also be used. Further, the developing case 18 is provided with a toner supply container 18A, in which the toner T is stored.
When the toner concentration of the developer D in the developing case 18 decreases, the toner supply roller 19 rotates, and the toner T in the toner supply container 18A is supplied into the developer in the developing case 18.

On the other hand, a plurality of paper feed cassettes 20, 20A,
Transfer paper P, which is an example of a transfer material, is fed in the direction of arrow A from one of the cassettes 20B, and at the timing when the transfer paper P is aligned with the toner image on the photoconductor 14 by the registration roller pair 21, The sheet is fed to a transfer position T between the photoconductor 14 and the transfer belt 22.

The endless transfer belt 22 is driven by the drive roller 2.
3 and is driven in the direction of arrow B, and is in contact with the surface of the photoconductor 14 at the transfer position T. The transfer paper P sent out by the registration roller pair 21 is conveyed by the transfer belt 22,
The sheet passes through a transfer position T between the transfer belt 22 and the photoconductor 14. At this time, a voltage having a polarity opposite to that of the toner of the toner image on the photoreceptor 14 is applied to the bias roller 25 disposed on the back side of the transfer belt 22, whereby the photoreceptor 14 is
The upper toner image is electrostatically transferred to the surface of the transfer paper P.

FIG. 3 is an exploded perspective view showing the components of the image forming apparatus obliquely from the rear. As shown in FIG. 3, the rollers 23 and 24 around which the transfer belt 22 is wound
The case 27 is rotatably supported, and these constitute a transfer unit.

The transfer paper P on which the toner image has been transferred is subsequently carried on the transfer belt 22 and is conveyed there.
2, the toner image passes through the fixing device 30, and at this time, the toner image is fixed on the transfer paper P by the action of heat and pressure. Then
The transfer paper P is discharged onto a discharge tray 32 as copy paper by a discharge roller pair 31.

The transfer residual toner that has not been transferred to the transfer paper P adheres to the surface of the photoreceptor after the transfer of the toner image. The transfer residual toner is removed by the cleaning device 33 for the carrier, and the surface of the photoreceptor is removed. Is cleaned. The surface of the photoreceptor after cleaning is initialized by receiving a charge removing action by a charge removing device 37 composed of a lamp, and the above-described operation is continuously performed.
The toner image is transferred onto the next transfer paper.

The carrier cleaning device 33 of the present embodiment comprises:
The cleaning device includes a cleaning member including a cleaning blade 34, a cleaning case 35, and a toner discharging member 36 disposed at the bottom of the case 35. The cleaning blade 34 is made of an elastic material such as rubber,
The image area in the axial direction of the photoconductor 14, that is, the entire area to which the transfer residual toner adheres, extends in parallel with the photoconductor 14, and its base end is fixed to the cleaning case 35, The leading edge presses against the surface of the photoreceptor 14 to scrape off and remove transfer residual toner attached to the surface.

The toner discharging member 36 is configured as a screw conveyor having a rotation center axis and a spiral blade fixed therearound (see FIG. 5). It is rotatably arranged and driven to rotate about its central axis.
The toner discharge member 36 extends substantially in parallel with the photoconductor 14 and in the longitudinal direction of the cleaning case 35 (a direction perpendicular to the paper surface of FIG. 1), and as shown in FIGS. It protrudes into a toner discharge pipe 42 fixed to the side wall on the back side of the case 35.

The transfer residual toner scraped and removed from the surface of the photoreceptor 14 by the cleaning blade 34 shown in FIG. 1 falls to the bottom of the cleaning case 35, and the dropped toner is deposited on the bottom of the cleaning case 35. The carrier cleaning device 3 is conveyed toward the back side by the toner discharge member 36 that is arranged and driven to rotate, and passes through the toner discharge pipe 42 from the toner discharge port at the tip thereof.
3 is discharged outside. As described above, the carrier cleaning device 33 has the toner discharging member 36 that transports the toner removed from the surface of the image carrier to the outside of the carrier cleaning device and discharges the toner.

In the illustrated image forming apparatus, the photoreceptor 14, the charging device 15, the cleaning device 33 for the carrier and the neutralizing device 37 are incorporated in the unit case 41 shown in FIG. The cleaning case 35 is constituted by a part of the unit case 41.

On the other hand, a small amount of toner adheres to the surface of the transfer belt 22, and if the toner is left unattended, the toner adheres to the back surface of the transfer paper P sent to the transfer belt 22, and the transfer paper is washed with toner. The toner adhering to the surface of the transfer belt is contaminated, so that the belt cleaning device 26
Removed by

The belt cleaning device 26 of the present embodiment comprises:
A cleaning member comprising a cleaning blade 28 pressed against the surface of the transfer belt 22; a cleaning case 26A formed by a part of the case 27;
And a toner discharging member 29 disposed at the bottom thereof.

The cleaning blade 28 is made of an elastic material such as rubber and extends in parallel with the transfer belt 22 over the entire area of the transfer belt 22 to which toner adheres, and its base end is connected to the cleaning case 26A. The transfer belt 22 is fixed, and the leading edge on the opposite side is pressed against the surface of the transfer belt 22 to scrape and remove the transfer residual toner adhered to the surface.

The cleaning blades 28 and 3 of the belt cleaning device 26 and the carrier cleaning device 33 are provided.
Instead of 4, a cleaning member such as a fur brush, a cleaning roller, or a magnetic brush roller may be used, or a plurality of cleaning members may be used.

The toner discharge member 29 is configured as a screw conveyor having a rotation center axis and a helical blade fixed therearound similarly to the toner discharge member 36 described above (see FIG. 5). The member 29 is rotatably arranged at the bottom of the cleaning case 26A, and is driven to rotate around its central axis. The toner discharge member 29 also extends in the longitudinal direction of the cleaning case 26A (the direction perpendicular to the plane of FIG. 1), and is fixed to the inner side wall of the cleaning case 26A as shown in FIGS. It protrudes into the inside of the provided toner discharge pipe 43.

As a toner discharging member of the belt cleaning device 26 and the carrier cleaning device 33, for example, a toner discharging member of a type in which a linear body such as a wire is wound in a coil shape and driven to rotate to convey toner. Etc. can also be used.

The toner scraped and removed from the surface of the transfer belt 22 by the cleaning blade 28 is
The toner that has fallen to the bottom of the cleaning case 26 </ b> A is conveyed toward the back by a toner discharge member 29 that is disposed at the bottom of the cleaning case 26 </ b> A and is driven to rotate. It is discharged from the outlet to the outside of the belt cleaning device 26. Thus, the belt cleaning device 26 is also
A toner discharging member 29 is provided to transport the toner removed from the surface of the transfer belt 22 to the outside of the belt cleaning device 26 and discharge the toner.

As described above, the image forming apparatus shown in FIG.
An image carrier composed of a photoconductor 14 driven in rotation, a developing device 16 for forming a toner image on the surface of the image carrier, and a transfer material composed of transfer paper P on which the toner image on the surface of the image carrier is to be transferred. A transfer belt 22 to be conveyed; and a carrier cleaning device 33 for removing the transfer residual toner attached to the surface of the image carrier after transferring the toner image onto the transfer material to clean the surface of the image carrier. And a belt cleaning device 26 for removing the toner adhered to the surface of the transfer belt 22 from the surface of the transfer belt and cleaning the surface of the transfer belt.

Here, the transfer residual toner adhering to the surface of the photoreceptor after the transfer of the toner image is discharged from the carrier cleaning device 33 since the quality thereof is maintained so that the residual toner can be reused in the developing device 16. The toner is conveyed to the developing device 16 by the first toner conveying means 44 shown in FIGS. 2 to 5 and is reused. On the other hand, the transfer belt 2
2 is generally of poor quality, and it is inappropriate to reuse it in the developing device 16.
For this reason, the toner discharged from the belt cleaning device 26 is supplied to the waste toner container 3 shown in FIGS. 1 and 2 by the second toner conveying means 45 shown in FIGS.
8 and is housed therein.

The toner discharge pipe 42 connected to the cleaning case 35 of the carrier cleaning device 33 and the cleaning case 26A of the belt cleaning device 26
Are protruded toward the back of the main body of the image forming apparatus, and extend through the side plate 1B on the back side of the main body of the image forming apparatus and extend to the back. The toners discharged from the cleaning devices 33 and 26 are both discharged in the same direction on the back side of the image forming apparatus main body. And
First and second toner conveying means 44 and 45 are provided in the image forming apparatus main body further deeper than the rear side plate 1B of the image forming apparatus main body 1, and these toner conveying means are arranged as follows. It is configured as follows.

As shown in FIGS. 2 to 5, the first toner conveying means 44 has a box-shaped first toner receiving case 46, and the first toner receiving case 46 is provided at the lower end thereof.
A first toner conveying pipe 62 that communicates with the
A first toner conveying member 72 is provided in the toner conveying pipe 62.
(See also FIG. 6), but is disposed over substantially the entire length of the toner conveying pipe 62.

On the other hand, the second toner conveying means 45 also has a box-shaped second toner receiving case 52, and at the lower end thereof,
A second toner conveying pipe 53 communicating with the second toner receiving case 52 is integrally connected, and a second toner conveying member 54 is connected to the second toner conveying pipe 53 with a toner conveying pipe 62 of the second toner conveying pipe 53. It is arranged over almost the entire length. Further, the second toner conveying pipe 53 is provided with the toner conveying pipe 5.
A hollow case 47 communicating with the third toner receiving case 3 is integrally fixed, and the hollow case 47 and the above-described first toner receiving case 46 are adjacent to each other in the front-rear direction.

The toner discharge pipe 42 protruding from the cleaning case 35 of the above-described carrier cleaning device 33.
Penetrates through holes 48 and 49 formed in the upper part of the hollow case 47 and the first toner receiving case 46, and the tip end protrudes into the upper space of the first toner receiving case 46. Similarly, the toner discharge pipe 43 protruding from the cleaning case 26A of the belt cleaning device 26 fits into a hole 53 formed at the upper part of the second toner receiving case 52, and the tip thereof is the second toner receiving case 52. It protrudes into the upper space of the toner receiving case 52. The first and second toner conveying pipes 62 and 53 are integrally assembled with each other, and are fixed to the rear side plate 1B of the image forming apparatus main body 1 by screws (not shown).

The first and second toner conveying members 7 of this embodiment
Similarly to the toner discharge members 36 and 29, the screw conveyors 2 and 54 are configured as screw conveyors having a rotation center axis and spiral blades fixed therearound. A wound toner conveying member may be used.

The first toner conveying member 72 is connected to a pulley 59 via an electromagnetic clutch 57, and a timing belt 58 is wound around the pulley 59. The timing belt 58 is connected to the drive motor 6 described above.
1 and is wound around a pulley 63 that is driven to rotate. The pulley 59 is integrally provided with a gear 60 concentric therewith, and this gear 60 meshes with a gear 67 fixed to the second toner conveying member 54. The second toner transport pipe 53 is, as shown in FIG.
8 and the outlet of the conveying pipe 53 is connected to the waste toner container 38.
Is connected to the entrance of the connection pipe 38A fixed to the connection pipe 38A.

A downstream end of the first toner conveying pipe 62 is connected to a toner pump 54, which is fixedly disposed inside a holder 70 as shown in a cross section in FIG. It has a cylindrical stator 69 made of an elastic body, and a rotor 68 rotatably fitted inside the stator 69, and the downstream end of the first toner conveying member 72 is fixed to the rotor 68. ing. The rotor 68 has a first
Is concentrically connected to the toner conveying member 72 and is rotationally driven by the rotation of the toner conveying member 72. 2, one end of a tube 56 is connected to the air inlet 73 of the holder 70, and the other end of the tube 56 is connected to an air supply device 64. Air supply device 6
Reference numeral 4 is operated by a DC motor (not shown) to supply external air into the holder 70 via the tube 56. This DC motor is the same as the electromagnetic clutch 57 described above.
Are turned on and off at a predetermined timing with respect to the operation timing. At the toner outlet 71 of the holder 70,
One end of the toner transport tube 55 is connected, and the other end of the tube 55 is connected to the toner supply container 18A of the developing device 16 shown in FIG. 1 and opens inside the container 18A.

The rotation of the first toner conveying member 72 drives the rotation of the rotor 68 and the air supply device 6.
4, the outside air is introduced into the holder 70, so that the toner sent from the first toner conveying pipe 62 into the stator 69 is mixed with the air.
5 and is conveyed into the toner supply container 18A.
The toner pump itself is conventionally known. For example, Japanese Patent Application Laid-Open No. 7-219329 discloses a pump similar to the pump 54.

First and second toner conveying means 44, 45
Is as described above, and details of its operation are as follows.

As described above, the toner removed from the surface of the photosensitive member 14 by the cleaning blade 34 of the carrier cleaning device 33 is discharged out of the carrier cleaning device by the toner discharging member 36. As shown by a reference numeral T1 in FIG. 5, the first toner receiving case 46
Through the first toner conveying pipe 62. At this time, since the drive motor 61 shown in FIG. 2 is operating, the rotation is transmitted to another pulley 59 via the pulley 63 and the timing belt 58. At this time,
If the electromagnetic clutch 57 is in the ON state, the rotation of the pulley 59 is transmitted to the first toner conveying member 72, which rotates. For this reason, the toner T1 that has fallen into the first toner conveying pipe 62 is sent to the toner pump 44 by the first toner conveying member 72, and the toner is further urged by the operation of the toner pump 44, and the flexibility is increased. Tube 55
Through the toner supply container 18A of the developing device 16. The direction of toner conveyance at this time is indicated by an arrow C in FIG.
Indicated by The toner returned to the toner replenishing container 18A is replenished into the developing case 18 by the rotation of the toner replenishing roller 19, as described above, for visualizing the electrostatic latent image formed on the photoreceptor 14. Used for A foreign matter removing device that removes foreign matter such as paper dust mixed in the toner in the toner carrying path of the first toner carrying means 44;
For example, a filter (not shown) can be provided.

Since the amount of the toner T1 discharged from the carrier cleaning device 33 is smaller than the toner conveying capacity of the toner pump 54, in this embodiment, the electromagnetic clutch 57 is intermittently turned on and off. The toner that has fallen into the first toner conveying pipe 62 is conveyed to the developing device 16 only when it is turned on. The electromagnetic clutch 57 may be eliminated, and the first toner conveying member 72 and the toner pump 54 may always be operated.

On the other hand, the toner removed from the surface of the transfer belt 22 by the cleaning blade 28 of the belt cleaning device 26 is discharged to the outside of the belt cleaning device 26 by the toner discharging member 29. , The second toner receiving case 52 from the outlet at the end of the toner discharge pipe 43.
And falls into the second toner transport pipe 53 through At this time, the rotation of the drive motor 61 is directly transmitted to the gear 60 via the pulleys 63 and 59 and the timing belt 58 without passing through the electromagnetic clutch 57, and therefore, the second toner conveying member 54 is constantly rotated. As a result, the toner T2 dropped into the second toner transport pipe 53
The waste toner container 3 by the second toner conveying member 54
8 and stored and stored here. The direction of toner conveyance at this time is indicated by an arrow E in FIG. The toner stored in the waste toner container 38 is usually finally disposed of. This toner can be regenerated and reused.

As described above, the first toner conveying means 44
, The toner pump 54 and the flexible tube 55
Is used to transport the toner to the developing device 16. This is because the toner is transferred from the carrier cleaning device 33 to the developing device 16.
This is because the toner conveyance path up to the end is complicated, and it is difficult to convey the toner only by the toner conveyance member such as a screw conveyor. Depending on the layout of each element of the image forming apparatus, the toner discharged from the carrier cleaning device 33 may be conveyed to the developing device 16 only by a toner conveying member such as a screw conveyor.

As described above, in the image forming apparatus of the present embodiment, the first toner that conveys the toner discharged from the carrier cleaning device 33 to the developing device 16 is reused in the developing device 16. The image forming apparatus includes a conveying unit 44 and a second toner conveying unit 45 that conveys the toner discharged from the belt cleaning device 26 to the waste toner container 38. With this configuration, the relatively high-quality toner discharged from the carrier cleaning device 33 is reused in the developing device 16 and the belt cleaning device 2 is used.
The inferior quality toner discharged from 6 can be conveyed to a waste toner container 38 and discarded.

However, when this configuration is adopted, as described above, the amount of toner discharged from the carrier cleaning device 33 is reduced by the belt cleaning device 26.
Much more than the amount of toner
Since the former toner amount may be ten times or more than the latter toner amount, for example, a failure of the toner pump 54 of the first toner conveying means 44 causes a decrease in the conveying function, When it becomes impossible to transport
For example, there is a possibility that the toner may clog in, for example, the first toner conveying pipe 62 of the first toner conveying means 44 and may eventually flow out to stain the inside of the image forming apparatus main body with the toner.

Therefore, in the image forming apparatus of this embodiment,
The toner transport function of the first toner transport unit 44 decreases,
Alternatively, when the first toner conveying unit 44 is in a state where the toner cannot be conveyed, the toner in the first toner conveying unit 44 can be transferred to the second toner conveying unit 45.
From the first toner conveying means 44 to the second toner conveying means 4
5 is provided.

More specifically, as shown in FIGS. 4 and 5, a first toner receiving case 46, which is a component of the first toner conveying means 44, and a second toner conveying means 4
Openings 51 and 50 that match each other are formed in adjacent walls of the hollow case 47, which is a component of the fifth case, and the two cases 46 and 4 are formed through these openings 51 and 50, respectively.
7 are in communication with each other. The first toner transport pipe 62 and the second toner transport pipe 53 connected to the lower portions of the cases 46 and 47 are separated by a partition wall 74 formed below the openings 50 and 51 by walls of the toner transport pipes. It is partitioned.

When the first toner conveying means 44 is operating normally, the toners T1 and T2 which have fallen into the first toner conveying pipe 62 and the second toner conveying pipe 53, respectively.
Since these toner transport pipes 62 and 53 are separated from each other, they are transported to the developing device 16 and the waste toner container 38, respectively, as described above.

Here, when the toner pump 54 of the first toner conveying means 44 breaks down and its toner conveying function is reduced or becomes impossible, for example, the first toner conveying pipe is connected to the toner discharging pipe 42. The toner dropped to 62 is accumulated here. When the amount increases, the toner moves to the second toner conveying pipe 53 of the second toner conveying means 45 through the openings 51 and 50, and is conveyed to the waste toner container 38 by the second toner conveying member 54. Is done.

As described above, even if the first toner conveying means 44 fails, the toner discharged from the carrier cleaning device 33 is conveyed to the waste toner container 38 by the second toner conveying means 45. Therefore, there is no problem that the toner is clogged in the first toner transport pipe 62 of the first toner transport means 44 and overflows the outside. Moreover, the second toner conveying means 45 for conveying the toner discharged from the belt cleaning device 26 and the waste toner container 38 for storing the toner are used to carry the toner when the first toner conveying means fails. Since the toner discharged from the body cleaning device 33 is processed, a dedicated means for processing the toner is not required, and a problem that the cost of the image forming apparatus increases can be prevented.

In the example shown in FIGS. 4 and 5, the opening 5 formed in the first toner receiving case 46 and the hollow case 47 is formed.
1, 50, the first toner conveying means 44
The transfer section of the toner to the toner conveying means 45 is constituted.

The above is the first configuration of the image forming apparatus of the present embodiment. In the illustrated image forming apparatus, in addition to the first configuration, as shown in FIGS.
A toner level sensor 39, which is an example of a toner amount detecting unit that detects that the amount of toner in the toner container 8 has reached a predetermined amount, is provided at an upper portion of the waste toner container 38. This is the second configuration of the present example, in which the sensor 39 detects that the waste toner container 38 is full or nearly full of toner. A detecting means including such a sensor is generally called a full detecting means. Hereinafter, the fact that the waste toner container 38 is full of toner or that the amount of toner has increased to a state close to this is simply referred to as full.

When the first toner conveying means 44 breaks down,
As described above, the toner discharged from the carrier cleaning device 33 is also transported to the waste toner container 38 together with the toner discharged from the belt cleaning device 26. At this time, since the amount of toner discharged from the carrier cleaning device 33 is large, the first toner conveying means 44
A large amount of toner is sent to the waste toner container 38 as compared with the case where the normal operation is performed, and the container is quickly filled up. For this reason, if the amount of toner in the waste toner container 38 is left as it is without being detected, the user does not notice it,
There is a possibility that the toner may overflow from the waste toner container 38 and contaminate the inside of the image forming apparatus main body with the toner.

Therefore, a toner level sensor 39 is provided in the waste toner container 38, and when the waste toner container 38 becomes full at an early stage due to a failure of the first toner conveying means 44, this is detected by the level sensor 39. Then, as shown in FIG. 7, the control device 80 including the CPU recognizes from the detection signal that the waste toner container 38 is full, stops the image forming operation, and sets the waste toner container 38 to an empty state. It is configured to display on the operation display unit that it should be replaced with a new waste toner container. In this way, according to the second configuration of the present example, even if the first toner conveying unit 44 fails, it is possible to prevent the toner from overflowing from the waste toner container 38 without the user's knowledge.

By providing the toner level sensor 39, the above-described advantages can be obtained. However, with the second configuration alone, it is difficult to know the fact even when the first toner conveying means 44 breaks down. It is. If the toner cannot be transported due to the failure of the first toner transport unit 44, and if the cause is solidification of blocking of the toner, the failure can be relatively easily detected by an abnormal noise of the drive system. When the cause is partial cross-linking of the toner, there is little information for recognizing a failure such as appearance and sound, and the failure cannot be easily found. Even if the toner level sensor 39 detects that the waste toner container 38 is full of toner, it is determined whether the toner container 38 is in a normal state in which only the toner discharged from the belt cleaning device 26 is full. It is impossible to determine whether the toner discharged from the cleaning device 33 is also sent to the waste toner container 38 and is in an abnormal state in which the toner is full.

Therefore, in the third configuration of the present embodiment, in addition to the above-described second configuration, the waste toner container 38 is replaced while the first and second toner conveying units 44 and 45 maintain the normal state. The toner level sensor 39, which is an example of a toner amount detecting unit, does not detect that the toner in the waste toner container 38 has reached a predetermined amount even at the time when the image forming apparatus has reached the end of its life. Waste toner container 38
Is set.

Usually, the number of times of image formation is a predetermined number, for example, 10
The waste toner container 38 is to be replaced with an empty new container when the number of times has reached 10,000 times. When it is time to replace the waste toner container 38, When the first toner conveying means 44 normally operates until the end of the service life of the toner, and only the toner discharged from the belt cleaning device 26 is stored in the waste toner container 38, the toner The capacity of the waste toner container 38 is set so that the level sensor 39 does not detect that the toner is full.

In this way, the toner level sensor 39 detects the fullness of the toner in the waste toner container 38 before the time to replace the waste toner container 38 or before the life of the image forming apparatus expires. In this case, the reason is that the toner sent to the waste toner container 38 becomes abnormally large due to the failure of the first toner conveying means 44, and the waste toner container 38 is quickly filled with the toner. Is shown. In this manner, it can be determined that the toner discharged from the belt cleaning device 26 is usually a part of the toner that is stained between the images on the photoreceptor 14, and the cleaning device for the carrier. This is based on the fact that the amount is very small, for example, 1/10 or less of the amount of toner discharged from the printer 33. Therefore, when the toner level sensor 39 detects fullness as described above, as shown in FIG.
The control device 80 including the CPU determines that the first toner conveying means 44 has failed, stops the image forming operation, and controls the operation display section 81 to display "error". Thus, according to the third configuration,
The failure of the first toner conveying means 44 can be determined only by the detection of the fullness of the toner level sensor 39, and appropriate measures such as subsequent repair can be reliably performed.

However, according to the third configuration described above,
When the periodic replacement of the waste toner container 38 is necessary, the replacement operation is performed manually. Therefore, if the periodic replacement of the waste toner container 38 is neglected, the first toner conveying unit Even if 44 is not out of order, the waste toner container 38 becomes full, and the fact is detected by the toner level sensor 39.
Is detected, it is determined that the first toner conveying means 44 has failed. In the third configuration,
When the toner level sensor 39 detects a full state, it is determined that the first toner conveying means 44 has failed even if it has not failed.
Before the full state of the waste toner container 38 is detected, the waste toner container must be replaced with a new one, thereby avoiding the possibility that the above-mentioned problem occurs.

Therefore, in the fourth configuration of the present embodiment, the following configuration is added to the above-described second configuration, whereby the failure of the first toner conveying means 44 can be reliably determined.

First, a new article detecting means for detecting that the waste toner container 38 when set in the image forming apparatus main body 1 is empty and new is provided.
0 shows an example of the new article detecting means.

In FIGS. 9 and 10, the waste toner container 3
8, a hollow box-shaped holder 65 is fixedly mounted on the rear side (see also FIG. 2), and the base of the operating member 66 is fitted and held in the holder 65. On the other hand, a stopper 75 is provided on the rear side plate 1C (not shown in FIG. 2) of the image forming apparatus main body.
Are projected, and the light transmission sensor 76 is supported.

The new waste toner container 38 is inserted from the front side to the back side of the image forming apparatus main body 1 and set in the image forming apparatus main body.
Moves together with the operating member 66 in the direction indicated by the arrow in FIG. During this movement, the operating member 66 is
The light transmission sensor 76 reacts at this time, and then the tip of the operating member 66 strikes the stopper 75. Thereby, as shown in FIG. 11, the operating member 66 is detached from the holder 65 by the external force received from the stopper 75 and falls into the holder 65.

As can be seen from the above operation, when the empty new waste toner container 38 is pushed into the image forming apparatus main body 1 and set, the light transmitting sensor 76 first reacts, and the operating member 66 is moved to the holder at the next moment. Since it falls into 65, the reaction of the light transmission sensor 76 disappears. By a series of these operations and the reaction of the light transmission sensor 76, as shown in FIG.
The control device 80 including the CPU includes a new waste toner container 38.
Is set in the image forming apparatus main body 1.
The new article detecting means detects that the waste toner container 38 immediately after being set in the image forming apparatus main body 1 is in a new article state, and that information is input to the control device 80.

The waste toner container 38 once set in the image forming apparatus main body 1 has the operating member 66 dropped into the holder 65. Therefore, it is assumed that the waste toner container 38 is set in the image forming apparatus main body 1 again. Are not considered new. In this way, when the new waste toner container 38 is set in the image forming apparatus main body 1, the control device 80 determines that the new waste toner container 38 is new. 9 to 11 function as input means for inputting information to the control device 80 that an empty new waste toner container 38 has been set in the image forming apparatus main body 1.

Next, from the detection of a new product of the waste toner container 38,
Fullness is detected by the toner level sensor 39, and the first
The process up to the determination of the failure of the toner conveying means 44 will be described based on the block diagram shown in FIG. 12 and the flowchart shown in FIG.

First, as described above, a new waste toner container 38 is set in the image forming apparatus main body, and a new product detection operation of the waste toner container 38 is performed (S1).
When input to the control device 80 including U, the counter value W
Is set to 0 (S2). In this state, the image forming operation is performed as described above.
The value W of the counter is counted up in accordance with the operation time of the image forming apparatus (for example, the operation time of the drive motor 61) since 8 is set in the image forming apparatus main body 1, and the operation time is measured.

Thereafter, when it is detected by the toner level sensor 39 that the toner in the waste toner container 38 is full (S3), the detection of the fullness is determined based on the failure of the first toner conveying means 44. Whether the full state is detected or the normal full state detection based on the failure is determined by the value of W in the control device 80 (S4).
That is, the first toner conveying means 44 is not out of order, and the belt cleaning device 26 is
When only the toner discharged from the printer is stored, the capacity of the waste toner container 38 is set so as to correspond to the operation amount of the image forming apparatus for a predetermined time (1000 hours in this example). Waste toner container 38
If the value of W exceeds 1000 hours when the full state is detected, the controller 80 determines that the full state is detected (S5), and replaces the waste toner container 38 with the operation display section 81. (S6), prompting the user to replace the waste toner container, and prohibiting the image forming operation. And
When the waste toner container 38 is replaced with a new one, the above-described new product detection operation is performed (S1), the value of W becomes 0, and the image forming apparatus is enabled.

When the toner level sensor 39 detects that the waste toner container 38 is full when the operation time of the image forming apparatus, that is, the value of W is 1000 hours or less, is abnormally short. So that
In this case, it is determined that the abnormality is full, that is, it is determined that the first toner transport unit 44 has failed (S6), and an error of the toner transport system of the toner transport unit 44 is displayed on the operation display unit 81.
(S7), prompting the user to request a repair,
The image forming operation is prohibited. When the repair and inspection of the first toner conveying means 44 are completed and the waste toner container 38 is replaced with a new one, the new article detecting operation is performed as described above, the value of W becomes 0, and the image forming operation is possible. Becomes

As described above, the fact that the new waste toner container 38 is set in the image forming apparatus main body 1 in an empty state is input to the control device 80 from the input means including the new product detection means, The operation time of the image forming apparatus is measured, and the operation amount of the image forming apparatus until the toner amount in the waste toner container 38 reaches a predetermined amount is detected by the toner amount detecting means including the toner level sensor 39. The control device 80 determines whether the toner is normal or abnormal, and determines a failure of the first toner conveying unit. The failure of the first toner conveying means is determined based on the operation time of the image forming apparatus until the empty waste toner container 38 becomes full. Therefore, the failure of the first toner conveying means can be correctly determined without replacing the waste toner container 38 before the waste toner container 38 becomes full. As described above, the failure state of the first toner conveying means can be determined based on the operation amount of the image forming apparatus until the full state of the waste toner container 38 is detected because the toner discharge amount from the belt cleaning device 26 is as follows. This is because the amount of toner discharged from the carrier cleaning device 33 is smaller than, for example, 1/10 or less.

As described above, the image forming apparatus of the fourth configuration is different from the image forming apparatus of the second configuration in that a new waste toner container 38 is set in the image forming apparatus main body 1. When the toner amount in the waste toner container 38 is detected to have reached a predetermined amount by the measuring means including a counter for measuring the operating time of the , First
And a determination unit for detecting that the toner transport unit 44 is abnormal. In the illustrated example, the determination unit is configured by the control device 80.

Instead of the new article detecting means shown in FIGS. 9 to 11, other suitable new article detecting means or input means to the control device can be adopted. For example, when the waste toner container 38 is replaced, the operator operates a button on the operation input unit or operates a maintenance switch to notify that the waste toner container has been replaced with a new one.
In this case, the information indicating that a new waste toner container has been set in the main body of the image forming apparatus can be controlled by operating input means such as an operation input unit and a maintenance switch. It is input to device 80 and performs the same operations as described above. Also in this example, input means is provided for inputting information to the control device that a new waste toner container has been set in the image forming apparatus main body, and this input means constitutes a new article detection means. Further, a container presence / absence sensor for detecting whether or not the waste toner container 38 is set in the image forming apparatus main body is provided, and when the waste toner container 38 is detected to be full, the waste toner container 38 is pulled out from the image forming apparatus main body 1. Then, when a new empty waste toner container is set, a method of turning on / off the container presence / absence sensor and detecting that the waste toner container has been replaced with a new one can be adopted from these conditions. . In this case, the container presence / absence sensor and the toner level sensor 39 detect that a new waste toner container has been set in the main body of the image forming apparatus, and transmit the information to the control device 80.
The input means or the new article detecting means for inputting the information to the user is constituted.

The present invention can be widely applied to various image forming apparatuses other than the illustrated type.

[0077]

According to the image forming apparatus of the first aspect, when the toner transport function of the first toner transport unit is reduced or when the first toner transport unit is in the toner transport disabled state, Since the toner of the first toner conveying means can be transferred to the second toner conveying means, it is possible to prevent the toner conveying path of the first toner conveying means from being clogged with the toner and preventing the toner from flowing out to a large amount outside.

Further, when the transport function of the first toner transport unit is reduced or becomes impossible, a larger amount of toner is sent to the waste toner container than in the normal state. According to this, since the waste toner container is provided with the toner amount detection means,
The problem that the toner overflows from the waste toner container can be prevented.

According to the image forming apparatus of the third aspect,
When the toner amount detecting means detects that the amount of toner in the waste toner container has reached a predetermined amount, it is possible to know that an abnormality has occurred in the first toner conveying means.

According to the image forming apparatus of the fourth aspect,
It is possible to more accurately know that an abnormality has occurred in the first toner conveying means.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an image forming apparatus from the front side.

FIG. 2 is a perspective view showing only some of the components of the image forming apparatus as viewed obliquely from behind.

FIG. 3 shows the first and second toner conveying units separated from a main body of the image forming apparatus and a transfer unit including a transfer belt and a carrier unit separated from the main body of the image forming apparatus in an oblique rear direction. FIG.

FIG. 4 is a perspective view showing the first and second toner conveying units in a state where they are separated.

FIG. 5 is a schematic vertical sectional view of first and second toner conveying pipes.

FIG. 6 is a sectional perspective view of the toner pump.

FIG. 7 is a block diagram of first and second configurations.

FIG. 8 is a block diagram of a third configuration.

FIG. 9 is a perspective view showing an example of a new article detecting means.

FIG. 10 is a cross-sectional view illustrating a state of a new article detection unit when the waste toner container is set in the image forming apparatus main body.

FIG. 11 is a cross-sectional view illustrating a state of a new article detection unit when the waste toner container is set in the image forming apparatus main body.

FIG. 12 is a block diagram of a fourth configuration.

FIG. 13 is a flowchart illustrating the operation of the fourth configuration.

[Explanation of symbols]

 1 Image Forming Apparatus Main Body 16 Developing Device 22 Transfer Belt 26 Cleaning Device for Belt 33 Cleaning Device for Carrier 38 Waste Toner Container 44 First Toner Conveying Means 45 Second Toner Conveying Means

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hiroshi Saito 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd.

Claims (4)

[Claims] An image carrier that is driven to rotate, a developing device that forms a toner image on the surface of the image carrier, a transfer belt that conveys a transfer material onto which the toner image on the surface of the image carrier is transferred, A cleaning device for a carrier that cleans the surface of the image carrier by removing the transfer residual toner adhered to the surface of the image carrier after transferring the toner image to the transfer material, and adheres to the surface of the transfer belt. A cleaning device for a belt that cleans the surface of the transfer belt by removing the collected toner from the surface of the transfer belt; and transporting the toner to the developing device so that the toner discharged from the cleaning device for the carrier is reused in the developing device. An image forming apparatus comprising: a first toner conveying means for performing the operation; and a second toner conveying means for conveying the toner discharged from the belt cleaning device to a waste toner container. The toner transport function of the first toner transport unit is reduced,
Alternatively, when the first toner conveying means is in a state where toner conveyance is impossible, the toner in the first toner conveying means
An image forming apparatus provided with a toner transfer section from the first toner conveying means to the second toner conveying means so that the toner can be transferred into the toner conveying means. 2. The image forming apparatus according to claim 1, wherein a toner amount detecting unit that detects that the toner in the waste toner container has reached a predetermined amount is provided in the waste toner container. 3. When the waste toner container is replaced or the image forming apparatus reaches the end of its life while the first and second toner conveying means are maintained in a normal state, the toner amount detecting means is capable of detecting the toner amount. 3. The image forming apparatus according to claim 2, wherein the capacity of the waste toner container is set so as not to detect that the toner in the waste toner container has reached a predetermined amount. 4. A measuring means for measuring an operation time of the image forming apparatus after a new waste toner container is set in the image forming apparatus main body, and the toner in the waste toner container reaches a predetermined amount by a toner amount detecting means. 3. The image forming apparatus according to claim 2, further comprising: a determination unit configured to detect that the first toner conveying unit is abnormal when the operation time is equal to or shorter than a predetermined time when the operation is detected. apparatus.