JP2000155513A - Electrophotographic image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent toner bridging at a drop path without increasing the number of parts, as for an electrophotographic image forming device for removing the residual toner on an image carrier after transferring an image to a paper, and then, recovering the toner through the drop path. SOLUTION: A carrying screw 30 for carrying the residual toner removed from the photoreceptor to the entrance of the drop path 35 is arranged in a cleaning device. An eccentric part 31b is formed on the shaft 31 of the carrying screw, and the eccentric part is fitted into the drop path 35, and a hook 40c is hung on the eccentric part 31b so to arrange a toner bridge preventing member 40 in the drop path 35. And, the rotation of the carrying screw 30 is converted to the reciprocative movement so as to be transmitted to the toner bridge preventing member 40, then, the toner bridge preventing member 40 is reciprocatively moved in the toner direction, and also, the member is moved vertically and horizontally in a direction vertical to the drop direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for transferring an image formed on an image carrier by using an electrophotographic method, such as a copying machine, a printer, a facsimile, and a multifunction machine using a laser, for example, for paper. The present invention relates to an image forming apparatus that performs recording on a recording medium.

[0002]

2. Description of the Related Art Conventionally, in this type of image forming apparatus, a residual toner remaining on an image carrier after image transfer is removed by a cleaning member such as a blade or a brush, and the removed toner is shown in FIG. As described above, the toner is collected at one end of the cleaning device 3 by the transport screw 2 as a rotary transport member through the transport path 1a of the cleaning case 1, and falls by its own weight through the vertical drop path 4 from the downward opening 1b of the cleaning case 1 to be horizontal. The toner is conveyed through the conveyance path 5 and further conveyed through the conveyance path 5 by the conveyance screw 6, and is collected, for example, by entering a waste toner collection tank for disposal or returning to the developing device for recycling.

However, particularly when the temperature is high and humid, the toner passing through the falling path 4 adheres to the inner surface 4a of the falling path on the way, and aggregates to form a first step a, a second step b, and a third step as shown in the figure. c, the toner gradually accumulates and gradually narrows the passage to cause toner crosslinking, which hinders the recovery of the toner.

Therefore, in order to prevent such toner cross-linking, a conventional agitator 7 is provided in the falling path 4 and rotates with a driving force from the outside, as shown in FIG. In some cases, the agitator 7 is rotated to scrape off the toner adhering to the inner surface 4a of the falling path (see JP-A-7-319245).

[0005] Although not shown, there is a type in which a sphere is provided in contact with a conveying screw in a falling path, and the sphere is moved by rotation of the conveying screw to drop toner adhered to the inner surface of the falling path (JP-A-Hei. 7-92875).

[0006]

However, the former FIG.
In the image forming apparatus shown in FIG. 3, parts such as gears and belts for transmitting the drive are separately required to rotate the agitator 7, and there is a problem that the number of parts increases and the cost increases.

Further, in the latter image forming apparatus (not shown), although toner bridging below the falling path can be prevented, there is a problem that it is not possible to drop the toner that has accumulated gradually from near the middle stage to above.

Accordingly, an object of the present invention is to remove a residual toner remaining on an image carrier after an image is transferred by a cleaning member, transport the removed residual toner to a falling path by a rotary transporting member, and pass through the falling path. It is an object of the present invention to provide an electrophotographic image forming apparatus which drops by its own weight and collects it, by reducing the number of parts and making it inexpensive, and reliably preventing toner crosslinking on a falling path.

[0009]

Accordingly, the present invention provides
An electrophotographic image in which the residual toner remaining on the image carrier after the image transfer is removed by a cleaning member, the removed residual toner is transported to a falling path by a rotary transport member, and falls by its own weight through the falling path to be collected. Related to forming equipment
The inventions according to claims 1 to 4 are configured as follows.

According to the first aspect of the present invention, a fall surface on which the collected toner slides is provided on the fall path, and a toner bridging prevention member is provided on the fall surface, and the rotational movement of the rotary conveying member is provided on the toner bridging prevention member. Is converted into a reciprocating motion and transmitted, and the toner cross-linking prevention member slides on the falling surface to reciprocate in the toner dropping direction and move up and down in a direction perpendicular to the dropping direction. Features.

According to the first aspect of the present invention,
When the residual toner is collected, the rotational movement of the rotary conveying member is converted into a reciprocating motion and transmitted to the toner crosslinking preventing member, and the toner crosslinking preventing member slides on the falling surface to reciprocate in the toner falling direction. As it moves, it moves up and down in a direction perpendicular to the falling direction.

According to a second aspect of the present invention, a fall surface on which the collected toner slides is provided on the fall path, and a toner bridge preventing member is provided on the fall surface, and the rotation movement of the rotary conveying member is provided on the toner bridge preventing member. Is converted into a reciprocating motion and transmitted, and the toner cross-linking prevention member slides on the falling surface to reciprocate in the toner dropping direction and move left and right in a direction perpendicular to the dropping direction. Features.

In the invention according to claim 2,
When the residual toner is collected, the rotational movement of the rotary conveying member is converted into a reciprocating motion and transmitted to the toner crosslinking preventing member, and the toner crosslinking preventing member slides on the falling surface to reciprocate in the toner falling direction. As well as moving right and left in the direction perpendicular to the falling direction.

According to a third aspect of the present invention, in the electrophotographic image forming apparatus according to the second aspect, an engaging portion which engages when the toner crosslinking preventing member reciprocates and moves it in the left-right direction is provided. It is formed in a falling path.

According to a fourth aspect of the present invention, a fall surface on which the collected toner slides is provided on the fall path, and a toner bridging prevention member is provided on the fall surface, and the rotation movement of the rotary conveyance member is provided on the toner bridging prevention member. Is converted into a reciprocating motion and transmitted, and the toner cross-linking prevention member slides on the falling surface to reciprocate in the toner dropping direction, and simultaneously moves up and down in a direction perpendicular to the dropping direction and simultaneously moves left and right. It is characterized by that.

In the invention according to claim 4,
When the residual toner is collected, the rotational movement of the rotary conveying member is converted into a reciprocating motion and transmitted to the toner crosslinking preventing member, and the toner crosslinking preventing member slides on the falling surface to reciprocate in the toner falling direction. As well as moving up and down in a direction perpendicular to the falling direction, it also moves left and right.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a main part of a laser copying machine according to the present invention.

Reference numeral 10 in the figure denotes a drum-shaped photosensitive member serving as an image carrier. Around the photoreceptor 10, a developing device 12, a transfer device 13, a paper separating device 14, and a cleaning device 15 are provided in order from a roller-shaped charging device 11 provided beside the photoreceptor 10 in the rotation direction indicated by the arrow A of the photoreceptor 10. .

When a copy is to be made, a document is set on a contact glass (not shown) and a copy switch is pressed, as is well known. Then, the image of the document is read by an optical reading device (not shown), and at the same time, the paper P is transported between the photoconductor 10 and the transfer device 13.

On the other hand, the surface of the photoreceptor 10 is uniformly charged by the charging device 11 with its rotation, and the surface is irradiated with laser light L from an optical writing device (not shown) to perform writing. An electrostatic latent image of the read document image is formed thereon, and subsequently toner is adhered when passing the developing device 12 to sequentially visualize the electrostatic latent image. Then, the toner image formed by the visualization is transferred by the transfer device 13 onto the sheet P conveyed between the photoconductor 10 and the transfer device 13 as described above.

After the transfer, the paper P is discharged by the paper separating device 14, separated from the photoreceptor 10 to which the electrostatically adheres, conveyed to a fixing device (not shown), and the transferred image is fixed there. To the paper discharge section. A separating claw may be provided in place of the sheet separating device 14 so as to be mechanically separated from the photoconductor 10.

On the other hand, the photoreceptor 10 after image transfer is cleaned of the surface by scraping off the residual toner remaining on the surface with a cleaning blade 17 provided in a cleaning device 15 and then neutralizing with a static elimination lamp (not shown). Initialize the surface potential.

In this laser copying machine, the photosensitive member 10, the charging device 11, the developing device 12, the cleaning device 15 and the like are integrated into one unit case 19 shown in FIG. I do. Although not shown, the photoconductor unit 20 is replaceable by being attached between side plates provided to face each other in the main body of the copying machine.

Now, in such a laser copying machine,
As shown in FIG. 1, the developing device 12 described above has a configuration in which a developer accommodating section 21 is provided on a lower side and a developer carrying section 22 is provided on an upper side. The developer accommodating section 21 is provided with a first agitating member 23 and a second agitating member 24 for accommodating a two-component developer and transporting the developer while agitating the developer. Although not shown, a toner concentration sensor for detecting a mixing ratio between the toner and the carrier in the developer is provided. Before use, the space between the developer holding portion 22 and the developer carrying portion 22 is sealed with a seal member (not shown).

As shown in FIG. 3, a new toner supply port 25 and a recycled toner supply port 26 are provided on one side of the developer accommodating section 21 so as to open upward. Then, the toner entering from the supply ports 25 and 26 is conveyed by the first stirring member 23 and the second stirring member 24 so as to circulate in the direction indicated by the arrow in FIG.

On the other hand, as shown in FIG.
2, a developing roller 28 is provided at a position facing the photoreceptor 10 through the developing window 27. Further, a developing doctor 29 for controlling the supply amount of the developer to the photoconductor 10 is provided.

The cleaning device 15 is provided with a transport screw (“rotary transport member” in the present invention) 30 for transporting the residual toner scraped off by the cleaning blade 17 into a case 15 a of the cleaning device 15. Place in the direction. As shown in FIG. 2, the transfer screw 30 is provided with one end 31 a of the shaft portion 31 inserted into a drop passage 35 from a drop passage entrance 33 provided above the front plate portion 19 a of the unit case 19.

The fall path 35 is provided with a peripheral wall 36 provided on the outer surface of the front plate portion 19a so as to surround the fall path 35, and a front side thereof is airtightly covered with a front cover which is removed and omitted in FIG. The falling path 35 includes a bottom surface 36 a of the peripheral wall 36.
The recycled toner supply port 2 of the developing device 12 described above
A fall path exit 37 leading to 6 is provided. Further, the peripheral wall 36 is partially inclined between the falling path exit 37 and the falling path entrance 33, and a falling surface 36b of the residual toner is formed on the inner surface of the inclined portion.

In the developing device 12, at the time of copying, a drive motor (not shown) is driven, and the drive is transmitted to rotate the developing roller 28 and to rotate the stirring members 23 and 24 to stir the developer. The toner and the carrier are conveyed to the developing roller 28 while being frictionally charged. On the other hand, the developing roller 2
The toner in the developer is electrostatically attached to the surface of the photoreceptor 10 by applying a predetermined bias to 8, and the latent image on the surface is visualized.

On the other hand, in the cleaning device 15, the rotation of the photoconductor 10 is transmitted via a gear to drive the transport screw 30 to rotate, and the residual toner removed from the photoconductor 10 is transported by the transport screw 30 and the cleaning case 15 a Gathered in front of the inside, as shown by the arrow in FIG.
3 and fall on the falling surface 36b, and further slide down on the falling surface 36b as shown by the arrow, and are collected into the developer accommodating section 21 from the falling path exit 37 through the recycled toner supply port 26.

In such a laser copying machine, when the temperature and humidity are high, the toner passing through the falling path 35 tends to adhere to the falling surface 36b on the way, and the toner is agglomerated with time and gradually deposited, and gradually falls. 35 may be blocked and toner crosslinking may occur, which may hinder toner recovery.

Therefore, the above-described illustrated copying machine is additionally configured as follows in order to prevent the occurrence of such toner crosslinking.

For example, the above-described transfer screw 30 is formed by integral molding using a resin material, and as shown in FIG.
A toner crosslinking preventing member 40 is provided on one end 31a side of the shaft portion 31.
Is eccentrically provided.

The toner crosslinking preventing member 40 is made of, for example, AB
Using a resin material such as S / PC or a metal material such as SUS,
A rectangular toner receiving plate portion 40a made of a thin plate having elasticity, bent in a rectangular shape, and the toner receiving plate portion 40a
An elongated hook 40b extending from one end of the frame is provided. A hook 40c is provided at the tip of the hook 40b.
The hook portion 40c is formed so as to be curved such that the dimension D obtained by doubling the radius of curvature is at least 0.5 mm larger than the shaft diameter d of the eccentric shaft portion 31b, and ds (d
>S> 0).

Then, the eccentric shaft 31b is inserted into the hook 40c through the opening p, and the hook 40c is connected to the eccentric shaft 3c.
1b, the toner receiving plate portion 40a is placed on the falling surface 36b as shown in FIG. 5, and the toner crosslinking prevention member 40 is disposed in the falling path 35. In this case, as shown in FIG. 6, even when the eccentric shaft portion 31b has reached the distance Lmax farthest from the falling surface 36b, the uppermost portion 40d of the toner receiving plate portion 40a of the toner crosslinking prevention member 40 is in contact with the falling surface 36b. Make contact.

When the residual toner is collected, most of the residual toner entering the fall path 35 from the fall path entrance 33 falls on the toner receiving plate portion 40a of the toner cross-linking prevention member 40, and weighs itself thereabove. Fall at exit 3
7 will be discharged.

At this time, the rotational movement of the conveying screw 30 is transmitted to the toner cross-linking preventing member 40 so that the eccentric shaft portion 31 b
Reciprocating with a stroke twice the eccentricity e of
With the rotation of the eccentric shaft 31b, the toner receiving plate 40a sequentially rotates and moves up and down with the uppermost portion 40d as a fulcrum as shown in FIGS.

That is, when the transport screw 30 rotates clockwise with the state shown in FIG. 6 as an initial state, the toner receiving member 40a rotates about the uppermost portion 40d as a fulcrum, and first, as shown in FIG. Rises slightly from the falling surface 36b, and then the transport screw 30 further rotates to bring the eccentric shaft 31b closest to the falling surface 36b.
As shown in FIG. 7 (b), it rises most, and when it further rotates, it starts approaching the falling surface 36b again as shown in FIG. 7 (c).
It returns to almost the initial state as shown in FIG.

As described above, with one rotation of the conveying screw 30, the toner crosslinking preventing member 40 slides on the falling surface 36b to reciprocate one time in the toner falling direction, and
Move up and down one direction at right angles to the drop direction. As a result, the residual toner on the toner receiving plate portion 40a is shaken off and discharged through the falling path exit 37 without adhering onto the toner receiving plate portion 40a.

FIGS. 8 to 11 show another embodiment of the present invention. In this example, as shown in FIG. 8, an engaging portion h is provided to protrude from the front plate portion 19a of the unit case 19 in the falling path 35.

On the other hand, the toner crosslinking preventing member 40
As shown in FIG. 7, both sides of the toner receiving plate portion 40b are bent to form opposed bent edges 40e, and a projection i is provided on the outer surface of one of the bent edges 40e. In the toner crosslinking prevention member 40 of this example, a plurality of small protrusions 40f are further provided between the bent edge portions 40e, and the small protrusions 40f are provided.
A rectangular relief hole 40g is provided between them.

Then, similarly to the above-described example, the hook portion 4
0c on the eccentric shaft 31b of the transfer screw 30,
The bent edge 40e is placed on the falling surface 36b and disposed in the falling path 35 as shown in FIG.

In the illustrated example, when the residual toner is collected, most of the residual toner entering the fall path 35 from the fall path entrance 33 falls on the fall surface 36b, and further falls on the fall surface 36 by its own weight. And is discharged from the drop exit 37.

At this time, the toner crosslinking preventing member 40 reciprocates by transmitting the rotational movement of the conveying screw 30. At the same time, when reciprocating, the engaging portion h and the projection i are not engaged as shown in FIG. 11A, and the toner crosslinking preventing member 40 is rotated as the transport screw 30 rotates.
Moves downward, the inclined surface of the projection i is engaged with the inclined surface of the engaging portion h, and the state shown in FIG. 11A is changed to the state shown in FIG. 11B. When it is in the lower position, the state shown in FIG. And
When the toner crosslinking prevention member 40 returns to the upper position again, the state shown in FIG. 11C is returned to the state shown in FIG. 11A through the state shown in FIG. 11B.

Thus, the toner crosslinking preventing member 40 is
Sliding on the falling surface 36b, it reciprocates in the toner drop direction, and moves left and right in a direction perpendicular to the drop direction.
The folded edge 40e and the small protrusion 40f slide on the falling surface 36b to scrape off the toner adhering thereon, and discharge the toner through the falling path exit 37.

As in the above-described example, the diameter D of the hook 40c is 0.5 mm larger than the diameter d of the eccentric shaft 31b.
Since it is made large as described above, there is no fear that the toner crosslinking prevention member 40 will rotate due to the rotational force of the transport screw 30 even if it moves left and right.

When the toner falls between the bent edges 40e of the toner crosslinking preventing member 40, a part of the toner is released from the relief hole 40g, so that the falling surface 36b and the toner crosslinking preventing member 40 It is possible to prevent the toner from being sandwiched between them and causing the toner to crosslink.

[0048]

According to the present invention, therefore, the rotational movement is directly obtained from the rotary conveying member for conveying the residual toner to the falling path, and the toner cross-linking preventing member is moved to cause the toner cross-linking in the falling path. This eliminates the need for a separate drive transmission component such as a gear or a belt as in the related art, and can reduce the number of components and cost.

Further, the toner crosslinking preventing member slides on the falling surface to reciprocate in the toner dropping direction, and according to the first aspect of the present invention, the toner crosslinking preventing member moves up and down in a direction perpendicular to the dropping direction. According to the second aspect of the present invention, the movable body moves right and left in a direction perpendicular to the falling direction, and according to the fourth aspect of the present invention, the movable body moves up and down in a direction perpendicular to the falling direction and simultaneously moves left and right. Thus, it is possible to reliably prevent the toner from bridging on the falling path.

According to the third aspect of the present invention, the reciprocating toner crosslinking prevention member is engaged with the engaging portion in the falling path and moves in the left-right direction. Can move left and right.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a main part of a laser copying machine according to the present invention.

FIG. 2 is an external perspective view of a photoconductor unit provided in the laser copying machine.

FIG. 3 is a perspective view of a developer accommodating portion of a developing device provided in the photoconductor unit.

FIG. 4 shows a transfer screw provided in the developer storage section,
FIG. 9 is a perspective view showing a toner crosslinking prevention member to be hung thereon.

FIG. 5 is an external perspective view of the photoconductor unit to which the toner crosslinking preventing member is attached.

FIG. 6 is an explanatory front view thereof.

FIGS. 7A to 7D are explanatory front views illustrating the movement of the toner crosslinking prevention member in FIGS.

FIG. 8 is a partial perspective view of a photoconductor unit provided in a laser copying machine according to another embodiment of the present invention.

FIG. 9 is a perspective view showing a toner cross-linking prevention member provided in the photoconductor unit as viewed from the back side.

FIG. 10 is an external perspective view of the photoconductor unit shown in FIG. 8 to which the toner crosslinking prevention member is attached.

FIGS. 11A to 11C are explanatory front views illustrating the movement of the toner crosslinking prevention member in FIGS.

FIG. 12 is an explanatory cross-sectional view illustrating a toner cross-linking state on a falling path in a conventional image forming apparatus.

FIG. 13 is an explanatory cross-sectional view showing the vicinity of a drop path of a conventional image forming apparatus in which an agitator is provided on a drop path in order to prevent the occurrence of toner crosslinking.

[Explanation of symbols]

Reference Signs List 10 photoconductor (image carrier) 15 cleaning device 17 cleaning blade (cleaning member) 19 unit case 19a front plate 20 photoconductor unit 30 transport screw (rotary transport member) 31 shaft 31a one end 31b eccentric shaft 33 drop path Inlet 35 Falling path 36b Falling surface 37 Falling path exit 40 Toner bridging prevention member 40a Toner receiving plate 40b Hook 40c Hook 40d Top 40e Bend edge 40f Small protrusion 40g Relief hole h Engagement part i Projection

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Jiji Mizuishi 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company, Ltd. (72) Inventor Noriyuki Usui 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Hideki Yoshinami 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Toshitaka Yamaguchi 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (72) Inventor Mayumi Ohori 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (72) Inventor Hiroshi Mizusawa 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (72) Invention Person Ken Amamiya 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Co., Ltd. 2H034 CA00 CA02 CB00 CB01 2H077 AA37 AB02 AB18 AC02 AC16 CA02 CA05 EA01

Claims (4)

[Claims] 1. A cleaning device for removing residual toner remaining on an image carrier after image transfer, transporting the removed residual toner to a falling path by a rotary transport member, and dropping and collecting by its own weight through the falling path. In the electrophotographic image forming apparatus, a fall surface on which the collected toner slides is provided on the fall path, and a toner bridge preventing member is provided on the fall surface, and the toner bridge preventing member controls the rotational movement of the rotary conveyance member. It is converted into reciprocating motion and transmitted, and the toner cross-linking prevention member slides on the falling surface to reciprocate in the toner falling direction and moves up and down in a direction perpendicular to the falling direction.
Electrophotographic image forming apparatus. 2. A cleaning device for removing residual toner remaining on an image carrier after image transfer, transporting the removed residual toner to a falling path by a rotary transport member, and dropping and collecting by its own weight through the falling path. In the electrophotographic image forming apparatus, a fall surface on which the collected toner slides is provided on the fall path, and a toner bridge preventing member is provided on the fall surface, and the toner bridge preventing member controls the rotational movement of the rotary conveyance member. It is converted into a reciprocating motion and transmitted, and the toner cross-linking prevention member slides on the falling surface to reciprocate in the toner dropping direction, and moves left and right in a direction perpendicular to the dropping direction.
Electrophotographic image forming apparatus. 3. The electrophotographic image according to claim 2, wherein an engaging portion which engages when the toner crosslinking prevention member reciprocates and moves it in the left-right direction is formed in the falling path. Forming equipment. 4. A cleaning member removes residual toner remaining on the image carrier after image transfer, transports the removed residual toner to a falling path by a rotary transport member, and drops by its own weight through the falling path to collect. In the electrophotographic image forming apparatus, a fall surface on which the collected toner slides is provided on the fall path, and a toner bridge preventing member is provided on the fall surface, and the toner bridge preventing member controls the rotational movement of the rotary conveyance member. It is converted into reciprocating motion and transmitted, and the toner cross-linking prevention member slides on the dropping surface to reciprocate in the toner dropping direction, and simultaneously moves up and down in a direction perpendicular to the dropping direction and simultaneously moves left and right. An electrophotographic image forming apparatus.