JP2002244431A - Developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the leaking of developer from the toner replenishing opening of a developing device even when the developing device is inclined or brought down by mistake when the developing device is detached from an image forming device main body. SOLUTION: In the developing device utilizing a dry type 2-component developer consisting of a magnetic powder carrier and toner, and carrying out opening and closing of a toner replenishing opening by a shutter that is solid on the inner surface of a case, it is characterized in that a magnetic body is installed below the sliding surface of the shutter and the case. One more item is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing apparatus using a dry two-component developer comprising a magnetic powder carrier and a toner.

[0002]

2. Description of the Related Art In recent years, an image forming apparatus using a downsized developing device or a process cartridge equipped with the developing device has become mainstream. Some of the developing devices in such an image forming apparatus perform maintenance such as replacement by a serviceman, and others perform maintenance by a user himself. In any case, if a serviceman or user accidentally tilts or knocks down the device during maintenance,
The developer may leak from the toner supply port or the developer supply port which is a path outside the apparatus, and may cause a serious problem.

As a conventional example which solves such a problem, there is known a shutter provided in a toner supply port or the like so as to prevent the developer from leaking outside. For example, a sealing member such as a sponge made of foamed polyurethane or a brush is provided between the housing and the shutter to improve the sealing performance. However, the toner gradually penetrates into the sponge and the brush while the opening and closing operations of the shutter are repeated many times and even in a normal use state due to vibration of the developing device itself.
Further, even when the developing device is tilted or tilted as described above, the developer instantaneously enters the sliding portion of the shutter and penetrates the sealing member to cause clogging, thereby causing a malfunction of the shutter. At times, there is a problem that the liquid leaks out of the apparatus at a stretch.

On the other hand, as disclosed in Japanese Patent Application Laid-Open No. 8-334977, a magnet is provided between a shutter and a housing. However, since the magnet is provided around the opening of the developer supply port, it is possible to prevent leakage around the opening of the developer supply port. Can not. Further, since the magnet is provided around the opening, if the developer adheres to the magnet, the area of the opening serving as a supply path of the developer becomes small, so that not only the efficiency of the developer supply is reduced but also blocking occurs. There is.

[0005]

Therefore, in the present invention,
A first object is to prevent the developer from leaking from the toner supply port of the developing device when the developing device is detached from the image forming apparatus main body even if the developing device is accidentally tilted or tilted.

Further, even if the developing device is removed from the image forming apparatus main body and the developing device is accidentally tilted or falls down, even if the developer adheres to the magnet provided on the lower surface of the shutter, the magnet is integrated with the shutter. The second configuration is such that the toner can be smoothly supplied without causing a decrease in the opening area due to the developer adhering to the vicinity of the toner supply port by being configured to move and move away from the toner supply port. Aim.

[0007]

The above object of the present invention is achieved by the following means. According to a first aspect of the present invention, there is provided a developing device that uses a dry two-component developer including a magnetic powder carrier and a toner and that opens and closes a toner supply port with a shutter that slides on an inner surface of the housing. The most important feature is a developing device in which a magnetic material is arranged below the moving surface.

According to a second aspect, in the developing device according to the first aspect, the magnetic material is fixed to a lower surface of a shutter.
The main feature is a developing device that operates integrally with the shutter.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram illustrating a schematic configuration of a main part of a laser copying machine as an example of an image forming apparatus to which the present invention is applied. In the figure, reference numeral 10 denotes a drum-shaped photoconductor serving as an image carrier. Around the photoconductor 10, a roller-shaped charging device 11, a developing device 12, a transfer device 13, a paper separating device 14, a cleaning device 15, and the like are provided in order in the rotation direction indicated by the arrow 0 of the photoconductor 10. .

When a copy is to be taken, 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 reader (not shown), and at the same time, the sheet 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 then the surface is irradiated with laser light L from an optical writing device (not shown) to perform writing. An electrostatic latent image is formed, and subsequently toner is adhered when passing through the position of the developing device 12 to sequentially visualize the electrostatic latent image. Then, the toner image formed by the visualization is
As described above, the image is transferred by the transfer device 13 onto the sheet P conveyed between the photoconductor 10 and the transfer device 13.

After the transfer, the paper P is separated from the electrostatically adhered photoreceptor 10 by a paper separating device 14, and is conveyed to a fixing device (not shown) where the transferred image is fixed there. Discharge to Separating claw 14a instead of paper separating device 14
May be provided and mechanically separated from the photoconductor 10.

On the other hand, the photoreceptor 10 after image transfer scrapes residual toner remaining on the surface with a cleaning blade 17 provided in a cleaning device 15 and cleans the surface.
The surface potential is initialized by removing charges with a removing lamp (not shown).

In such a laser copying machine, the photosensitive member 10, the charging device 11, the developing device 12, the cleaning device 15 and the like are integrated in one unit case 19 as shown in FIG. Is generally constructed. Although not shown, the photoreceptor unit 20 is attached between side plates provided to face each other in the main body of the laser copying machine, and is detachable and replaceable.

Now, in such a laser copying machine,
As shown in FIG. 1, the above-described developing device 12 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 has a first stirring member 23 and a second stirring member 24 for accommodating a two-component developer therein and conveying the developer while stirring the developer. Although illustration and detailed description are omitted, a toner density sensor for detecting a mixture ratio of the toner and the carrier in the developer is provided.

Before use, the space between the developer accommodating portion 21 and the developer carrying portion 22 is sealed by a seal member (not shown). As shown in FIG. 3, the developer accommodating section 21 is provided with a new toner supply port 25 and a recycle toner supply port 26 on one side thereof, each opening upward. And those supply ports 25 and 2
3 is conveyed by the first stirring member 23 and the second stirring member 24 so as to circulate in the arrow direction Q in FIG.

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

In the cleaning device 15, a conveying screw 30 for conveying the residual toner scraped by the cleaning blade 17 is arranged in the axial direction of the photoconductor 10. As shown in FIG. 2, the transport screw 30 has one end 31 a of the shaft 31 and the front plate 19 of the unit case 19.
It is provided so as to enter the fall path 35 from the fall path entrance 33 provided on the upper side of a. The falling path 35 is provided on the outer surface of the front plate portion 19a so as to be surrounded by the peripheral wall 36, and is formed so as to hermetically cover a front side thereof with a cover 38 described later with reference to FIG. The falling path 35 has a bottom surface 36 of a peripheral wall 36.
a shows the recycled toner supply port 2 of the developing device 12 described above.
The peripheral wall 36 is partially inclined between the falling path exit 37 and the falling path entrance 33 leading to 6, 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 rotate the stirring members 23 and 24 to stir the developer. The toner and the carrier are transported to the developing roller 28 while being frictionally charged. On the other hand, the developing roller 28
A predetermined bias is applied to the photosensitive member 1 to apply toner in the developer.
0 electrostatically adheres to the surface of the surface, thereby visualizing the latent image on the surface.

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 to remove the toner. Collect in front of you. Next, as shown by the arrow in FIG. 2, the developer is dropped onto the falling surface 36 b from the falling path entrance 33, and further slid down on the falling surface 36 b as shown by the arrow, and the developer is stored through the recycled toner supply port 26 from the falling path exit 37. Part 2
Collect in 1.

Next, the toner supply device 120 will be described with reference to FIGS. As shown in FIGS. 1 and 4, the toner replenishing device 120 includes a toner bottle 55 as a toner storage container, a receiving tray 57 that integrally has the toner hopper 56 and stores the toner bottle 55, and a toner hopper 56. , A bottle holding member 58 that rotates integrally with the toner bottle 55 is provided, and the bottle holding member 58 has a plurality of toner pushing members 59. As shown in FIG. 1, an opening 60 is formed in the toner hopper 56, and an outer surface of the opening 60 is provided with a replenishment regulating member 61 having elasticity to make the toner replenishment amount appropriate. A toner introduction cover 62 is attached outside the opening 60, and a lower end of the introduction cover 62 is formed with a toner supply port 63 that opens horizontally. The supply restricting member 61 is formed of a mylar material such as a PET film, and has an opening 61 a as shown in FIG. 1 from which the toner is scraped out by the pushing member 59. By changing the width of the opening 61a, the amount of the extruded toner can be controlled to an appropriate amount by one scraping.

FIG. 4 illustrates the toner replenishing device 120 in further detail. As illustrated, the toner bottle 55 is driven to rotate by a driving unit 65 fixed to the rear plate of the apparatus main body. The driving unit 65 includes a joint 66 and a spring 6
7. It is composed of a case 68 containing a motor and a shaft. On the other hand, a handle 69 is attached to the front of the toner replenishing device 120, and the operation shown by the arrow F opens and closes the cap of the toner bottle, and attaches and detaches the toner replenishing device from the main body of the device, and removes the toner bottle. Make a replacement. The rotation of the toner bottle 55 is obtained by the engagement between the joint 66 and the bottom of the toner bottle.
As shown in FIG. 4, when the joint of the drive unit rotates in the direction of arrow E, the toner bottle 55 also rotates in the same direction. The toner bottle is engaged with the above-described bottle holding member 58 by a claw or the like, and when the toner bottle 55 rotates, the holding member 58 also rotates simultaneously with the rotation of the toner bottle 55.

The toner supply port 63 of the toner replenishing device 120 is connected to the tip of the shutter support member 72 when the PCU is not mounted in the apparatus main body or when the toner replenishing device 120 is taken out of the apparatus main body. It is closed by the provided elastic member 72a. This is spring 7
3 is urged downward. On the other hand, when the photoreceptor unit 20 is mounted in the apparatus main body, the protruding portion 42 provided on the photoreceptor unit 20 and the protruding portion 72b integral with the shutter 72 are engaged, and the toner supply port 63 is open. Further, the toner replenishing device 120 is configured to be detachable in a direction indicated by an arrow X on a guide rail 71 provided on the apparatus main body. The fixing member of the toner supply device with respect to the apparatus main body is 70.

The state of toner supply will be described with reference to FIGS. When the toner bottle 55 rotates as described above, as shown by an arrow A from the opening 55a,
The toner flows out to the toner hopper section 56 in FIG. This toner is pushed up in the direction of arrow B by the pushing member 59 of the bottle holding member 58 along with the rotation of the toner bottle 55, and advances through the opening 60 in the direction of arrow C as shown in FIG. Then, the toner is supplied to the developing device 12 through the toner supply port 63 and the toner receiving port 25 in the communicating state as shown by an arrow D.

Next, the appearance of the photosensitive unit 20 will be described with reference to FIG. Reference numeral 41 denotes a seal member for preventing toner from leaking between the toner supply port 63 and the toner receiving port 40. The photoconductor unit 20 is also similar to the toner replenishing device 120,
A guide rail (not shown) provided on the apparatus main body is configured to be detachable in the arrow Y direction. The fixing member (stopper) of the photoconductor unit 20 to the apparatus main body is formed by a claw 39 provided integrally with the front cover 38 of the photoconductor unit.

An embodiment in which a shutter and a magnet, which are features of the present invention, are applied to a laser copying machine having the above configuration will be described with reference to FIG. Reference numeral 74 denotes a shutter for opening and closing the toner receiving port 40 shown in FIG. Reference numeral 76 denotes a spring for constantly applying a biasing force to the shutter 74 in the Z direction. One end of the spring 76 is press-fitted into a boss 74b integral with the shutter 74, and the other end abuts the inside of the front cover 38 shown in FIG.

Next, the portion of the magnet 75 indicated by hatching is adhered to the lower surface of the shutter 74 as shown by an arrow R with an adhesive or a double-sided tape. This shutter with magnet is inserted and assembled in the direction of arrow S shown in FIG. FIG. 9 shows the positional relationship of the shutter with magnet in the photoconductor unit. The magnet 75 is provided below the sliding surface 77 of the shutter and the housing. In other words, it protrudes below each sliding surface.

Next, when the photosensitive member unit is mounted on the image forming apparatus main body, a projection 74a provided integrally with the shutter abuts on a projection provided on the image forming apparatus main body side (not shown). The shutter slides in the direction of arrow L as shown in FIG. The position of L1 indicates that the photoconductor unit is outside the image forming apparatus main body, and the toner receiving port 4
0 is closed. Reference numeral 40 'denotes a position corresponding to the toner receiving port 40 of the shutter 74.

When the photoconductor unit is mounted on the image forming apparatus main body, the shutter 74 moves to the position L2, and the toner receiving port 40 is opened. This open state is a state in which toner is replenished in the image forming apparatus main body as described above, and there is no fear that the photoconductor unit is inclined or falls as a matter of course, so that there is no leakage of the developer.

On the other hand, FIG. 10 shows the state of the developer near the toner receiving port 40 when the photoreceptor unit is turned upside down and turned upside down. FIG. 10A shows a case where the magnet 75 is not attached to the shutter 74, the developer wraps around the gap between the shutter and the sliding surface of the housing, and the developer leaks from the toner receiving port 40. On the other hand, FIG. 10B shows a case where a magnet 75 is attached to the shutter 74, and the developer adheres to the magnet, and the attached developer enters the gap between the shutter and the sliding surface of the housing.
It prevents wraparound. That is, it is sealed with the developer attached to the magnet.

By providing the magnet below the sliding surface of the shutter and the housing, the developer does not leak even when the photosensitive unit is tilted or tilted outside the image forming apparatus main body. Also, even if the photoconductor unit is knocked down outside the image forming apparatus main body and the developer is attached to the magnet, and the magnet is attached to the image forming apparatus main body as described above, the magnet slides integrally with the shutter. , The developer is not attached to the receiving port at all, and the size of the receiving port does not change at all. Therefore, toner replenishment is performed smoothly.

[0031]

According to the first aspect of the present invention, there is provided a developing device which uses a dry two-component developer composed of a magnetic powder carrier and a toner, and opens and closes a toner supply port with a shutter sliding on the inner surface of the housing. Since the magnet is provided below the sliding part of the housing, if the developing device is removed from the main body of the image forming apparatus, even if the developing device is accidentally tilted or tilted down, the developing device is developed from the toner supply port of the developing device. It is possible to prevent the agent from leaking.

According to a second aspect of the present invention, in a developing device using a dry two-component developer composed of a magnetic powder carrier and a toner, a toner supply port is opened and closed by a shutter sliding on the inner surface of the housing. Since the magnet moves integrally with the shutter, even if the developer adheres to the magnet by accidentally tilting or tilting the developing device, the developer adheres near the toner supply port, and the opening is reduced. The toner can be smoothly replenished without performing the above operation.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a main configuration of an image forming apparatus to which the present invention is applied.

FIG. 2 is a perspective view illustrating an example in which a photoconductor unit to which the present invention is applied is integrated as one unit.

FIG. 3 is a perspective view illustrating a developer accommodating section to which the present invention is applied.

FIG. 4 is a perspective view of a toner supply device to which the present invention is applied.

FIG. 5 is a perspective view illustrating how toner is supplied in a toner supply device to which the present invention is applied.

FIG. 6 is an external view illustrating a photoreceptor unit to which the present invention is applied.

FIG. 7 is a perspective view of an essential part for explaining an embodiment of the present invention.

FIG. 8 is an essential part perspective view for explaining an operation state of the embodiment of the present invention.

FIG. 9 is an explanatory diagram in which the embodiment of the present invention is applied to a photoreceptor unit.

FIG. 10 is an explanatory diagram of a state in which the embodiment of the present invention is applied to a photoconductor unit and is turned upside down.

[Explanation of symbols]

 Reference Signs List 10 photoconductor 11 charging device 12 developing device 13 transfer device 14 separation device 14a separation claw 15 cleaning device 17 cleaning blade 19 unit case 19a front plate portion 20 photoconductor unit 21 developer storage portion 22 developer holding portion 23 first stirring member Reference Signs List 24 Second stirring member 25 New toner supply port 26 Recycled toner supply port 27 Developing window 28 Developing roller 29 Developing doctor 30 Conveyor screw 31 Shaft 31a One end 33 Drop path entrance 35 Drop path 36 Perimeter wall 36a Bottom 36b Drop surface 37 Drop path Outlet 38 Cover 39 Claw portion 40 Toner receiving port 40 ′ Position corresponding to toner receiving port 40 41 Seal member 42 Projecting portion 55 Toner bottle 55 a Opening portion 56 Toner hopper portion 57 Receiving stand 58 Bottle holding member 59 Toner pushing member 60 Mouth 61 Replenishment regulating member 61a Opening 62 Toner introduction cover 63 Toner supply port 65 Drive 66 Joint 67 Spring 68 Case 69 Handle 70 Fixing member 71 Guide rail 72 Shutter support member 72a Elastic member 72b 73 Spring 74 Shutter 74a Projection 74b Boss 75 Magnet 76 Spring 77 Sliding surface 120 Toner supply device P Paper L Laser beam

Claims (2)

[Claims] 1. A developing device that uses a dry two-component developer composed of a magnetic powder carrier and a toner and that opens and closes a toner supply port with a shutter that slides on an inner surface of the housing. A developing device, wherein a magnetic material is disposed below the developing device. 2. The developing device according to claim 1, wherein said magnetic material is fixed to a lower surface of a shutter, and operates integrally with said shutter.