JP2000227744A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase flexibility in design, to prevent a toner clogging, and to prevent scatter of recovered toner of a small particle-diameter, by adjusting an amount of carried proper-toner according to the detected density of an image to be formed. SOLUTION: A control means 110 monitors a detection signal from an image density reading means 109, and when judging that image density is higher than a specific threshold, it drives a motor so as to reduce an area where each hole of a first net member and each hole of a second net member communicate with each other, and makes adjustment so that an amount of proper toner carried by a proper-toner carrying means 40 is such a degree that a toner clogging does not occur in an exhaust tube 8. Also, a detection signal from a toner flow rate detection means 64 is monitored, and when an amount of light received by a light receiving element 63 is smaller than a specific threshold, in order to lessen an amount of proper toner flowing in the exhaust tube 8, the motor is driven so as to reduce the area where each hole of the first net member and each hole of the second net member communicate with each other, and adjustment is made in the same manner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a printer, an electrophotographic copying machine, a facsimile, etc., and more particularly to an image forming apparatus having a toner recycling apparatus for reproducing and recycling collected toner.

[0002]

2. Description of the Related Art In the above-described image forming apparatus, toner collected by removing a latent image carrier after transfer by a cleaning device is returned to a developing device as described in JP-A-9-230770. Is being recycled, and resources are being used effectively. If the collected toner is returned to the developing device as it is, there is a problem that the quality of an image formed by the toner is inferior. Therefore, the collected toner is classified, foreign matters are removed and reproduced, and the quality is reusable. After returning to the developing device, a technique has been proposed in JP-A-6-308828. Means for transporting the collected toner is disclosed in, for example,
219349, JP-A-7-210047,
JP-A-5-249820, JP-A-9-31922
No. 0 publication.

[0003]

However, in the techniques disclosed in each of the above publications relating to the regeneration and transport of the collected toner, the cleaning device is used because the collected toner is conveyed by gravity or by a screw conveyor. The device and the developing device need to be provided adjacent to or close to each other, and there is a problem that the degree of freedom in design is extremely low. Although it is conceivable to convey the recovered toner by using a mechanical drive such as an agitator other than the screw conveyor, it is not suitable for a device aiming at miniaturization. Further, there is a problem that toner clogging is likely to occur in a portion where the recovered collected toner is returned to the developing device. Recovered toner contains more water than new toner and easily aggregates. Once the toner is clogged, the recycling system is completely down, shutting down the equipment and performing maintenance involving difficult work. Must be done, causing user distrust.

[0004] The amount of collected toner varies depending on the density of an image to be formed. Specifically, as the amount of toner supplied to the latent image carrier increases, the amount of toner remaining on the latent image carrier after transfer increases, and the amount of collected toner increases.
Therefore, when the density of the image to be formed is high, the amount of the collected toner is large, and the toner clogging at the portion where the recovered collected toner is returned to the developing device is more likely to occur. Further, when the recovered toner having an excessively small particle diameter is reproduced and reused, the collected toner having the small particle diameter leaks from a developing device or the like, causing toner scattering and contaminating the inside of the image forming apparatus. There is a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus having a small-sized toner recycling apparatus which has a high degree of freedom in design, can prevent toner clogging, and prevents scattering of collected toner having a small particle diameter. .

[0006]

In order to achieve the above object, according to the present invention, there is provided a developing device for developing a latent image on a latent image carrier, and removing residual toner on the latent image carrier. An image forming apparatus comprising: a cleaning unit that performs cleaning; and a toner recycling device that conveys the removed toner removed by the cleaning unit to the developing unit.
The toner recycling device includes a toner regenerating unit that regenerates the removed toner by separating the removed toner into a proper toner suitable for development and an inappropriate toner not suitable for development.
There is a proper toner conveying means for conveying the proper toner separated and reproduced by the toner reproducing means to the developing means, and a conveying toner amount adjusting means for adjusting an amount of the proper toner conveyed by the proper toner conveying means. The proper amount of toner to be conveyed by the proper toner conveying unit is adjusted by the conveyed toner amount adjusting unit in accordance with the density of the image to be formed, detected by the image density detecting unit.

According to a second aspect of the present invention, in the image forming apparatus of the first aspect, the toner regenerating means allows the removed toner to pass from one end to the other end thereof.
A first horizontally disposed first toner that allows proper toner to pass through the mesh on the peripheral surface and discharges inappropriate toner from the other end.
A cylindrical mesh body, and a rotary transport body disposed in the first cylindrical mesh body for transporting the removed toner from the one end to the other end, wherein the transport toner amount adjusting means includes: A first and second net member disposed substantially horizontally below the cylindrical net, and a drive for driving at least one of the first and second net members in a substantially horizontal direction. Means,
The driving means adjusts the area where the hole of the first mesh member and the hole of the second mesh member communicate with each other, and adjusts the amount of fall of the proper toner that has passed through the cylindrical mesh body. It is characterized in that an appropriate amount of toner to be conveyed by the conveying means is adjusted.

According to a third aspect of the present invention, in the image forming apparatus according to the second aspect, a mesh is smaller at the one end side on the same axis as the first cylindrical mesh body than at the first cylindrical mesh body. A second cylindrical mesh body through which inappropriate toner is transmitted is provided.

According to a fourth aspect of the present invention, in the image forming apparatus of the second or third aspect, the first cylindrical mesh body passes through the first cylindrical mesh body from the one end to the other end. It is characterized by having air flow generating means for generating an air flow.

[0010] The invention according to claim 5 is the invention according to claims 2 to 4.
The image forming apparatus according to any one of the above, further comprising a vibration unit that applies vibration to the first cylindrical net.

[0011] The invention according to claim 6 is the invention according to claims 1 to 5.
In the image forming apparatus according to any one of the above, the appropriate toner conveying means has a tubular tube member for conveying the appropriate toner toward the developing unit, and determines an appropriate amount of toner flowing through the tube member. It has a toner flow detecting means for detecting,
The proper toner amount conveyed by the proper toner conveying means is adjusted by the conveyed toner amount adjusting means in accordance with the proper toner amount flowing in the pipe member detected by the toner flow detecting means.

[0012]

FIG. 1 shows a toner recycling apparatus 1 to which the present invention is applied and an image forming apparatus 100 having the same. The image forming apparatus 100 includes a photoconductor 101 as a latent image carrier.
A charging device 102 for charging the photosensitive member 101; and an exposure device 106 for forming a latent image corresponding to an image to be formed on the charged photosensitive member 101 by optical scanning with a laser beam 103.
Developing device 2 as a developing means for developing a latent image on photoconductor 101 after exposure, and photoconductor 1 obtained by development
Transfer device 104 for transferring the toner image on the sheet 01 to the paper P
Cleaning device 3 as cleaning means for removing untransferred toner remaining on photoconductor 101 after transfer
A static eliminator 105 for eliminating static before charging by the charging device 102, and an optical reading of an original 111 placed on the contact glass 107 as an image to be formed, and a laser beam corresponding to the read image information. The image forming apparatus includes a reading device 108 as reading means for causing the exposure device 106 to generate 103, and the toner recycling device 1.

The toner recycling apparatus 1 regenerates the toner by classifying the removed toner disposed near the cleaning device 3 and removed by the cleaning device 3 into a proper toner suitable for development and an inappropriate toner not suitable for development. A toner regenerating device 4 as a toner regenerating device, and a pump 5 serving as a first air flow generating device for generating an air flow for transporting appropriate toner classified and regenerated by the toner regenerating device 4 to the developing device 2. , A waste toner bottle 13 serving as an inappropriate toner collecting device that stores the inappropriate toner generated in the toner regenerating device 4 and conveyed through the pipe 33, and the connection unit 9 and the like. The cleaning device 3 has a well-known rotatable cleaning roller 6 that comes into contact with the photoconductor 101.
As a result, the residual toner that is not transferred to the sheet P after the transfer by the transfer device 104 and adheres to the photoconductor 101 is removed. The removed toner is separated by a blade (not shown) in contact with the cleaning roller 6 and falls by gravity, and the dropped toner is collected and collected by the screw conveyor 30 at the back side in FIG. Be guided.

The pump 5 is connected to one end of an intake tube 7 for taking in air and one end of an exhaust tube 8 as a tubular pipe member for discharging air. The other end of each of these tubes is connected to a substantially rectangular parallelepiped connection unit 9 communicating with the developing device 2. The toner recycling device 4 is connected to the exhaust tube 8 by a tube 32. The air flow in the exhaust tube 8 generated by the pump 5 is regenerated by the regenerating device 4 according to the principle of the Venturi tube, and the reusable proper toner is sucked from the tube 32 and conveyed to the connection unit 9. The tube 32 and the exhaust tube 8 form an appropriate toner conveying unit 40. The appropriate toner conveyed to the connection unit 9 is mixed with the new toner supplied from the toner bottle 10 by the stirring screw 11 serving as stirring means in the developing device 2, supplied to the developing roller 12 side, and The above electrostatic latent image is developed.

As shown in FIG. 2, the toner reproducing device 4
In the process of passing the removed toner guided to the pipe 31 from the receiving port 16 at one end thereof to the discharge port 17 at the other end, classification is performed, and appropriate toner is allowed to pass through the mesh on the peripheral surface thereof, and inappropriate toner is removed. A mesh pipe 15 as a cylindrical net disposed in a substantially horizontal direction and discharged from the other end, and a mesh pipe 15 disposed in the mesh pipe 15 for transporting the removed toner from the receiving port 16 to the discharging port 17. A coil-shaped pitch screw 18 as a rotary conveyance body, a chamber 20 having a mesh tube 15 therein for collecting proper toner,
Conveying toner amount adjusting means 19 for adjusting an appropriate amount of toner to be conveyed by the tube 32 and the exhaust tube 8; An air flow generator 26 serving as a second air flow generation means for generating an air flow passing through the air flow generator; and an air flow generator 2 disposed at a position facing the air flow generator 26 on the wall surface of the pipe 33.
It mainly has a louver 35 for letting the air flow generated by 6 escape outside the pipe 33 and an ultrasonic vibrator 21 as a vibration means for applying ultrasonic vibration to the mesh tube 15.

The mesh tube 15 has its receiving port 16 side held by a ring 22 and its discharge port 17 side held by a ring 23. The ring 3 has a pipe 3
One end of the pipe 33 is fitted to the ring 23 at one end, and the mesh pipe 15 is rotatably supported by the pipes 31 and 33. Both ends of the pitch screw 18 are locked to a rotating shaft 25 that is rotationally driven by a driving shaft 36 provided on a pitch screw motor 24 as a driving means for the rotary conveyance body. Is driven to rotate. Pipe 31
Is vented at an appropriate angle just before the part to be engaged with the chamber 20, in this embodiment, almost perpendicularly, and is joined almost perpendicularly to the chamber 20, and the pitch screw motor 24 is arranged at the vented part. Has been established. The pitch screw 18 has a diameter such that it does not slide on the inner peripheral surface of the mesh tube 15. Ring 23
The mesh screen 3 as a mesh having a coarser mesh than the mesh of the mesh pipe 15 and closing the discharge port 17 is provided on the inner peripheral edge of the mesh screen 3.
4 is fixed, whereby the end face of the mesh tube 15 on the discharge port 17 side is closed to the extent that the inappropriate toner can be discharged.

The air flow generator 26 is an axial fan having fins 37 fixed on a drive shaft 36, and is capable of sending an air flow evenly to the center of the mesh tube 15. However, it is possible to use a sirocco fan with less unevenness in the flow velocity distribution of the generated air current. Louver 35
The pipe 33 moves the airflow generated by the airflow generation device 26 as indicated by an arrow b without leaking inappropriate toner to the outside.
Discharge outside. The mesh tube 15 is gently driven to rotate in a direction opposite to the rotation direction of the pitch screw 18 by driving means (not shown). Pitch screw 18
Has a brush on the peripheral edge thereof in sliding contact with the inner peripheral surface of the mesh tube 15. The brush has a fibrous shape, and the fiber has a length sufficient to rub the inner peripheral surface of the mesh tube 15 and is made of nylon, which is a material having a small tendency to triboelectrically charge. The ultrasonic vibrator 21 is fixed to the rings 22 and 23, and operates periodically at predetermined time intervals.
5 is vibrated by ultrasonic waves, and the operation may be performed when a predetermined number of copying operations are performed. The vibrating means is not limited to the ultrasonic vibrator, but may be a means for hitting the rings 22, 23, the mesh tube 15, etc., as long as it vibrates the mesh tube 15. A part of the exhaust tube 8 is a transparent wall 61, and the LE is sandwiched by the transparent wall 61.
The light emitting element 62 and the light receiving element 63 made of D are arranged so as to face each other. Light emitting element 62 and light receiving element 63
Constitutes a toner flow detecting means 64 for detecting an appropriate amount of toner flowing in the exhaust tube 8. Light emitting element 6
2 emits a certain amount of light by emitting light. The light receiving element 63 receives the light, and if the appropriate amount of toner flowing in the exhaust tube 8 increases, the light receiving element 6
3, the amount of light received is reduced.

As shown in FIG. 3, the chamber 20 has a rectangular parallelepiped part 27 and a funnel-shaped part 28 provided continuously below the rectangular parallelepiped part 27 and having a narrowed tip. The ends of the pipes 31 and 33 are joined to the
Is located inside the cylindrical portion 27. The conveying toner amount adjusting unit 19 includes a first net member 41 and a second net member 42 disposed substantially horizontally below the mesh tube 15, a support frame 43 supporting the first net member, and a A support frame 44 for supporting the second net member 42, and a first net member 41 via the support frame 43.
And a driving means 53 for driving the driving means in a substantially horizontal direction.
The driving means 53 includes an arm 45 fixed to the support frame 53.
Eccentric cam 48 engaged with arm 45, eccentric cam 4
And a tension spring 51 having one end fixed to the arm 45 and the other end fixed to the housing 52 of the main body of the image forming apparatus 100, and for urging the arm 45 to always contact the eccentric cam 48. And Arm 45
Has two elongated holes 46 and 47 formed in the horizontal direction. When a fixed shaft (not shown) slides in each of the elongated holes 46 and 47, the arm 45 is displaced substantially in the horizontal direction. The first mesh member is displaced in a substantially horizontal plane.

As shown in FIG. 4, the reading device 108 (FIG. 1) has an image density detecting means 109 for detecting the density of an image to be formed. The image density reading unit 109 measures the density of the image to be formed as an average image density of the document 111 and outputs the average image density to the control unit 110.
The toner flow detecting unit 64 outputs an appropriate amount of toner flowing in the exhaust tube 8 to the control unit 110. The control means 110 drives the motor 5 to rotate the eccentric cam 48, displaces the first net member 41, and the hole of the first net member 41 communicates with the hole of the second net member. Adjusting the area, the proper toner that has passed through the peripheral surface of the mesh tube 15 is
The proper amount of toner to be conveyed by the proper toner conveying means 40 is adjusted by adjusting the amount of the toner that falls toward the tube 32. Specifically, the control unit 110 monitors the detection signal from the image density reading unit 109, and when it is determined that the image density is higher than a predetermined threshold, the control unit 110 normally has the maximum value. The motor 50 is driven so as to reduce the area where the hole of the first mesh member 41 and the hole of the second mesh member communicate with each other, and the proper amount of toner conveyed by the proper toner conveying means 40 is reduced within the exhaust tube 8. Adjust so that toner clogging does not occur.
The detection signal from the toner flow detecting means 64 is monitored, and when the amount of light received by the light receiving element 63 is smaller than a predetermined threshold value, the maximum value is normally set to reduce the appropriate amount of toner flowing into the exhaust tube 8. The motor 50 is driven to reduce the area where the hole of the first mesh member 41 and the hole of the second mesh member
Is adjusted so that toner clogging does not occur. The control unit 110 includes an image density detection unit 109
The toner flow rate detecting means 6
The determination based on the signal from No. 4 is prioritized. Control means 110
In, the threshold value for the image density and the appropriate toner flow rate may not be set, and the communication area may be adjusted by a function using these as parameters. When the area is reduced, the area may be set to zero.

Since the image forming apparatus 100 has the above configuration, the photosensitive member 101 charged in the charging step by the charging device 102 is rotated in the direction of arrow A in the exposure step by the laser beam 103 emitted from the exposure apparatus 106. After the latent image formation corresponding to the document 111, the development process by the developing device 2, the transfer process by the transfer device 104, the cleaning process by the cleaning device 3, and the static elimination process by the static elimination device 105, the process proceeds to the charging process again. The toner image transferred on the sheet P in the transfer step is fixed on the sheet P by a transfer step in a well-known fixing device (not shown). The sheet P on which the toner image has been fixed is discharged outside the apparatus.

On the other hand, the residual toner remaining on the photoreceptor 101 after the transfer is removed by the cleaning device 3 and is conveyed to the toner reproducing device 4 through the pipe 31 as the removed toner. In the toner regenerating device 4, the removed toner is conveyed in the mesh pipe 15 from the receiving port 16 side to the discharging port 17 side by the pitch screw 18 rotating in a certain direction and the air flow generated by the air flow generating means 26. Is done. In a process in which the removed toner passes through the inside of the mesh tube 15, of the removed toner, an appropriate toner having a relatively small particle size suitable for development passes through the mesh on the peripheral surface of the mesh tube 15 and falls downward. As described above, the removed toner is classified into the proper toner and the inappropriate toner by the mesh tube 15. When the toner enters the mesh tube 15 from the receiving port 16, even if the removed toner has a relatively large particle size due to adsorption of impurities such as dust, dust, talc, and moisture, and adhesion to each other, While being mechanically conveyed and agitated by the pitch screw 18, impurities are cleaned by being separated or crushed, and if the proper toner having a particle size suitable for development is obtained, the impurities are originally contained in the removed toner. Along with the proper toner that has been passed, the proper toner passes through the mesh on the peripheral surface of the mesh tube 15 as shown by an arrow a. The airflow generated by the airflow generation means 26 contributes to the collection of the waste toner bottle 13 by passing the toner having an excessively small particle diameter contained in the removed toner through the mesh screen 34 by passing the toner on the flow. ing. The mesh screen 34 keeps the removed toner guided into the mesh tube 15 in the mesh tube 15 for a certain period of time to increase the efficiency of cleaning and classification, and to reuse more removed toner as proper toner. Has contributed.

Since the mesh tube 15 rotates in the direction opposite to the direction of rotation of the pitch screw 18, the removed toner not only acts on the pitch screw 18 in the axial direction of the mesh tube 15 but also in the radial direction of the mesh tube 15. Also receives efficient agitation, promotes the sedimentation of the appropriate toner having a relatively small particle size downward, and can perform the classification efficiently, and the peripheral surface for receiving the removed toner is always changed. The clogging of the tube 15 and the adhesion of toner are reduced. A fibrous brush made of a material having a low tendency to triboelectrically slidably contacts the inner peripheral surface of the mesh tube 15. Even if toner adheres to the inner peripheral surface of the mesh tube 15, it can be removed by the brush. In addition, the toner is prevented from re-adhering since frictional charging does not occur. Since the mesh tube 15 is rotating in the direction opposite to the rotation direction of the pitch screw 18, the relative speed between the brush 29 and the mesh tube 15 is high, and the toner is effectively separated by the brush.

Since the ultrasonic vibration is applied to the mesh tube 15 intermittently by the ultrasonic vibrator 21, toner is prevented from adhering to the inner peripheral surface of the mesh tube 15 regardless of human means. Even if it adheres, it is peeled off by vibration,
In addition, the stirring effect is improved by breaking up the weir of the toner, which tends to move upward with the rotation of the mesh tube 15, and further promotes the sedimentation of the appropriate toner having a relatively small particle size downward to classify the toner. It can be performed efficiently. The peeling action of the toner by the ultrasonic vibrator 21 is based on the mesh tube 1.
5 is more effective for toner adhering to the upper portion of 5, that is, toner that is affected by gravity in the peeling direction.

The proper toner that has passed through the mesh on the peripheral surface of the mesh tube 15 falls through the portion where the hole of the first mesh member 41 and the hole of the second mesh member 42 communicate, and drops. Shape 2
8, the air flow in the exhaust tube 8 as the exhaust of the pump 5 passes through the pipe 32 according to the Venturi tube principle, is sucked to the exhaust tube 8 side, and is connected to the connection unit 9 together with the air flow in the exhaust tube 8. Transported to The proper toner conveyed to the connection unit 9 falls downward due to airflow and gravity in the exhaust tube 8, and
The toner is supplied to the developing device 2, mixed with new toner supplied from the toner bottle 10 by the stirring screw 11, supplied to the developing roller 12, and used again for developing the electrostatic latent image on the photoconductor 101. At this time, if the control unit 110 determines that the image density is high and that the appropriate toner flow rate flowing through the exhaust tube 8 is large, the transport toner amount adjusting unit 19 causes the hole of the first mesh member 41 to be in the second position. The area of the portion communicating with the hole of the mesh member 42 is reduced, and the appropriate amount of toner flowing in the exhaust tube 8 is reduced so that the exhaust tube 8 does not cause toner clogging. When the area of the portion where the hole of the first net member 41 and the hole of the second net member 42 communicate decreases, the proper toner is deposited on the first net member 41 and the second net member 42. However, when the image formation is completed, when the image density to be formed is low, or when the appropriate toner flow rate flowing through the exhaust tube 8 decreases, the first
The area of the portion where the hole of the mesh member 41 and the hole of the second mesh member 42 communicate with each other is maximized, the normal state is established, and the accumulated appropriate toner is supplied to the developing device 2.

The removed toner which has a relatively large particle size due to adsorption of impurities or adhesion to each other, and which has not been cleaned, or inappropriate toner consisting of the impurities themselves, passes through the mesh screen 34. That is, the waste toner bottle 13 passes through the mesh tube 15 and passes through the pipe 33 and is collected in the waste toner bottle 13. In the mesh tube 15,
In the conveying direction of the removed toner by the pitch screw 18,
Since the airflow generated by the airflow generator 26 flows, very small toner rides on the airflow, passes through the mesh screen 34, and is collected in the waste toner bottle 13. This airflow also contributes to prevention of toner clogging and toner aggregation in the mesh tube 15. Waste toner bottle 13
Is detachable, and when it is filled with the improper toner, the improper toner inside is discarded and reused. However, the entire waste toner bottle 13 may be discarded and replaced with a new waste toner bottle.

The same amount of air discharged into the connection unit 9 through the exhaust tube 8 is sucked into the pump 5 from the connection unit 9 through the suction tube 7. As a result, since the exhaust and the intake are performed in the connection unit 9, the airflow is efficiently used. It is desirable that all of the proper toner conveyed into the connection unit 9 by the exhaust tube 8 be deposited in a stable state in the developing device 2. However, due to an air current generated by being sucked out by the intake tube 7, Some of them float in the atmosphere. If the floating toner is sucked into the intake tube 7, it causes clogging of the intake tube 7 and failure of the pump 5. However, since a mesh-shaped filter (not shown) is provided in the connection unit 9, the connection unit 9 can be used only for the toner without obstructing the air flow.
Since the internal space is partitioned, only clean air flows into the intake tube 7 and no toner enters.

FIG. 5 shows another embodiment of the toner reproducing apparatus to which the present invention is applied. In this embodiment, parts different from the above-described toner reproducing apparatus will be mainly described, and the same components will be denoted by the same reference numerals. The toner regenerating apparatus 4 according to the present embodiment is configured such that the mesh pipe 15 is coaxial with the mesh pipe 15
It has a mesh tube 72 as a second cylindrical net having a smaller mesh. Mesh tube 15 and mesh tube 72
Are connected by a ring 71, and a receiving port 75 for the removed toner of the mesh tube 72 is held by the ring 76. The ring 76 is rotatably supported by the pipe 31. The pitch screw 18 is connected to the mesh tube 1
5 and mesh tube 72. Mesh tube 7
In No. 2, the size of the mesh is such that only an excessively small particle size toner that is not suitable for development can pass therethrough, and a part thereof is present in the chamber 20 and is tightly connected to the chamber 20. It is provided in the chamber 73.
One end of a tube 74 is connected to the lower part of the chamber 73, and the other end of the tube 74 is connected to the pipe 33. Since the toner regenerating device 4 in this embodiment has such a configuration, the removed toner is first supplied to the mesh tube 72.
When passing, the toner having an excessively small particle diameter falls as an unsuitable toner through the mesh on the peripheral surface of the mesh tube 72 to form a chamber 7 having a constricted shape.
3 are collected along the inner wall surface of the tube 74, the pipe 3
After that, the toner is collected in the waste toner bottle 13. The mesh pipe 15 is meshed with the pitch screw 18 through the mesh pipe 72.
The removed toner that has entered the toner has almost completely separated the toner having an excessively small particle diameter, and the proper toner that has passed through the mesh on the peripheral surface of the mesh tube 15 hardly contains the small particle toner. There is no scattering of small particle size toner.

The embodiment has been described above.
It is not always necessary to provide a driving means for driving the rotation. When the driving means is not provided, the entire peripheral surface of the mesh tube 15 does not need to be formed of a mesh, and the lower surface necessary for transmitting the proper toner is not required. It is sufficient to make only the facing part a net,
Further, the portion other than the surface facing the pitch screw 18 necessary for transporting the removed toner may not be arc-shaped. The connection unit 9 is not always necessary, and the exhaust tube may be directly connected to the developing device 2. If the developing device 2 is provided with an exhaust hole and the pump 5 is provided with an intake hole, the intake tube 7 is not necessarily required. As is apparent from FIG. 3, in the embodiment, the directions in which the first net member and the second net member are laid are the same, but they may be laid diagonally to each other. , The displacement direction of the mesh member is
You may make it face diagonally with respect to the direction which laid the net. In order to adjust the area where the hole of the first mesh member and the hole of the second mesh member communicate with each other, at least one of these mesh members may be displaced with respect to the other. Thus, the present invention is not limited to displacing only the first mesh member. The number of net members may be three or more. Further, instead of the mesh member, a plate-like member provided with a large number of holes may be used. It has been confirmed that the static pressure in the tube 8 sharply increases immediately before the toner clogging occurs. Therefore, the toner flow rate detecting means measures the static pressure in the tube 8 instead of the light emitting element and the light receiving element. Sensor or a light emitting element and a light receiving element. The image density detecting means may be provided as a device for reading a document separately from the reading device, or may be provided around the latent image carrier. When the data of the image to be formed is not the data read by the reading unit but the data read or created outside the image forming apparatus 100, the data is processed by the image forming apparatus 100 to process the image. A density detecting means may be provided.

[0029]

According to the first aspect of the present invention, the developing means for developing the latent image on the latent image carrier, the cleaning means for removing residual toner on the latent image carrier, and the cleaning means An image forming apparatus comprising: a toner recycling device configured to transport the removed toner to the developing unit; and an image density detecting unit configured to detect a density of an image to be formed. A toner regenerating unit that regenerates the removed toner by separating into a proper toner suitable for the toner and an improper toner not suitable for the development, and a conveying unit for conveying the proper toner separated and regenerated by the toner regenerating unit to the developing unit. A proper toner conveying means; and a conveying toner amount adjusting means for adjusting an amount of proper toner conveyed by the proper toner conveying means. According to the density of the image to be formed, which is detected by the density detecting means, the appropriate amount of toner to be transported by the appropriate toner transporting means is adjusted by the transported toner amount adjusting means. Even when the amount of toner is large, it is possible to prevent the proper toner conveying means from excessively increasing the conveying amount of the proper toner. Therefore, it is possible to prevent toner clogging in the proper toner conveying means and to have a high degree of freedom in design and to be compact The present invention can provide an image forming apparatus with high user reliability, which can perform high-quality image formation by returning only reusable proper toner to the developing unit.

According to a second aspect of the present invention, in the image forming apparatus of the first aspect, the toner regenerating means allows the removed toner to pass from one end to the other end thereof.
A first horizontally disposed first toner that allows proper toner to pass through the mesh on the peripheral surface and discharges inappropriate toner from the other end.
A cylindrical mesh body, and a rotary transport body disposed in the first cylindrical mesh body for transporting the removed toner from the one end to the other end, wherein the transport toner amount adjusting means includes: A first and second net member disposed substantially horizontally below the cylindrical net, and a drive for driving at least one of the first and second net members in a substantially horizontal direction. Means,
The driving means adjusts the area where the hole of the first mesh member and the hole of the second mesh member communicate with each other, and adjusts the amount of fall of the proper toner that has passed through the cylindrical mesh body. Since the appropriate amount of toner to be transported by the transport unit is adjusted,
Since a proper amount of toner to be conveyed by the proper toner conveying means can be properly adjusted, a small toner recycling device capable of preventing toner clogging in the proper toner conveying means is provided, and only reusable proper toner is returned to the developing means. Accordingly, it is possible to provide an image forming apparatus that can form high-quality images and has high user reliability.

According to a third aspect of the present invention, in the image forming apparatus according to the second aspect, a mesh is smaller than the first cylindrical net on the one end side on the same axis as the first cylindrical net. Since the second cylindrical mesh that transmits the inappropriate toner is disposed,
Since the recovered toner having an excessively small particle diameter that passes through the second cylindrical mesh body can be separated from the appropriate toner to be reused for the development as an inappropriate toner, the small particle toner leaks from the developing unit or the like. Accordingly, it is possible to provide an image forming apparatus having a toner recycling apparatus that can prevent toner scattering and contamination of the inside of the image forming apparatus.

According to a fourth aspect of the present invention, in the image forming apparatus according to the second or third aspect, the first cylindrical net passes through the first cylindrical net from the one end to the other end. Since the air flow generating means for generating the air flow is provided, the removed toner can be smoothly transported in the first cylindrical mesh, and the removed toner is prevented from aggregating in the first cylindrical mesh. In addition to this, the toner having an excessively small particle diameter contained in the removed toner can be separated by being put on the flow of the toner. It has a toner recycling device that can prevent the inside of the image forming apparatus from being contaminated and can satisfactorily separate removed toner into proper toner and inappropriate toner, and returns only reusable proper toner to the developing unit. And in can be carried out high-quality image formation, it is possible to provide a user of the reliable image forming apparatus.

The invention according to claim 5 is the invention according to claims 2 to 4
The image forming apparatus according to any one of the above, further comprising vibrating means for applying vibration to the first cylindrical net, so that toner adhesion to the first cylindrical net and the net In addition to being able to prevent toner agglomeration in the body, it is possible to remove the adhered toner, and to promote the sedimentation of the appropriate toner having a relatively small particle size downward, thereby efficiently classifying the toner. Provided is an image forming apparatus that has a toner recycle that can reuse more removed toner as proper toner, and can form a high-quality image by returning only reusable proper toner to a developing unit. can do.

[0034] The invention according to claim 6 is the invention according to claims 1 to 5.
In the image forming apparatus according to any one of the above, the appropriate toner conveying means has a tubular tube member for conveying the appropriate toner toward the developing unit, and determines an appropriate amount of toner flowing through the tube member. It has a toner flow detecting means for detecting,
The proper amount of toner conveyed by the proper toner conveying means is adjusted by the conveyed toner amount adjusting means according to the appropriate amount of toner flowing through the pipe member detected by the toner flow rate detecting means. The proper amount of toner flowing is monitored, and even if the amount of proper toner flowing in the pipe member increases, it is possible to prevent the excessive amount of proper toner being conveyed by the proper toner conveying means. User reliability with high degree of design freedom, small toner recycling device, and high quality image formation by returning only reusable toner to developing means. Image forming apparatus can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an image forming apparatus including a toner recycling apparatus to which the present invention is applied.

FIG. 2 is a side view showing the toner reproducing unit shown in FIG.

FIG. 3 is a schematic perspective view showing a conveying toner amount adjusting unit shown in FIG. 2;

FIG. 4 is a block diagram showing a control mode of a conveying toner amount adjusting unit shown in FIG. 3;

FIG. 5 is a schematic side view showing another embodiment of the toner reproducing unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Toner recycling apparatus 2 Developing means 3 Cleaning means 4 Toner regenerating means 8 Appropriate toner conveying means, pipe member 15 First cylindrical net 18 Rotary conveying body 19 Conveyed toner amount adjusting means 21 Vibrating means 26 Air flow generating means 32 Toner conveying means 41 First net member 42 Second net member 53 Driving means 64 Toner flow rate detecting means 72 Second cylindrical net 100 Image forming apparatus 101 Latent image carrier 109 Image density detecting means

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H027 DB01 DD07 DE07 DE10 EA06 ED10 EE10 EF09 JB02 JB03 JC06 2H034 BC00 CB01 CB02 2H077 AA01 AA37 AB02 AB14 AC11 AC16 AD06 CA01 CA02 CA16 DA10 DA12 DA31 DB02

Claims (6)

[Claims] A developing means for developing the latent image on the latent image carrier; a cleaning means for removing residual toner on the latent image carrier; and a toner removed by the cleaning means to the developing means. An image forming apparatus comprising: a toner recycling device for transporting the toner; and an image density detection unit for detecting a density of an image to be formed. A toner regenerating means for regenerating the removed toner by separating the toner from the improper toner;
There is a proper toner conveying means for conveying the proper toner separated and reproduced by the toner reproducing means to the developing means, and a conveying toner amount adjusting means for adjusting an amount of the proper toner conveyed by the proper toner conveying means. An image forming apparatus that adjusts an appropriate amount of toner to be conveyed by the appropriate toner conveying unit by the conveyed toner amount adjusting unit in accordance with a density of an image to be formed detected by the image density detecting unit. . 2. An image forming apparatus according to claim 1, wherein said toner regenerating means passes the removed toner from one end to the other end thereof, thereby allowing the proper toner to pass through a mesh on the peripheral surface thereof, A first cylindrical net disposed in a substantially horizontal direction for discharging inappropriate toner from the other end, and a removed toner disposed in the first cylindrical net toward the one end to the other end; A rotating carrier for transporting the toner, the transport toner amount adjusting means comprising: first and second mesh members disposed substantially horizontally below the cylindrical mesh; and at least a first mesh. A driving unit for driving one of the member and the second net member in a substantially horizontal direction, whereby the hole of the first net member communicates with the hole of the second net member. Adjusting the area and adjusting the amount of fall of the proper toner that has passed through the cylindrical mesh Ri, the image forming apparatus characterized by appropriate conveying means adjusts the proper amount of toner conveyance. 3. The image forming apparatus according to claim 2, wherein the mesh is smaller than the first cylindrical mesh at the one end side on the same axis of the first cylindrical mesh, and the inappropriate toner is transmitted. Second
An image forming apparatus, comprising: a cylindrical reticulated body. 4. An image forming apparatus according to claim 2, wherein said air generates an airflow passing through said first cylindrical mesh from said one end to said other end of said first cylindrical mesh. An image forming apparatus comprising a flow generating unit. 5. The image forming apparatus according to claim 2, further comprising a vibration unit that applies vibration to the first cylindrical net. 6. The image forming apparatus according to claim 1, wherein said proper toner conveying means has a tubular tube member for conveying proper toner toward said developing means. And a toner flow detecting means for detecting an appropriate amount of toner flowing in the pipe member. The toner is conveyed by the appropriate toner conveying means in accordance with the appropriate toner amount flowing in the pipe member detected by the toner flow detecting means. An image forming apparatus wherein an appropriate amount of toner is adjusted by the toner amount adjusting means.