JP2899195B2 - Separation apparatus and image forming apparatus using this apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a separating apparatus for removing foreign matter from a mixture of developer and foreign matter, and an image forming apparatus using the same. The present invention relates to a separation device used in a forming device.

[0002]

2. Description of the Related Art From the viewpoint of effective use of resources and environmental protection, there are various apparatuses for separating a residue removed from the surface of an image carrier into a developer and other foreign matters and an apparatus for reusing the separated developer. Proposed.

As a separating device, a device using a mesh filter is particularly simple. Further, a filter that vibrates a mesh filter has been proposed in order to improve separation performance and prevent clogging of the mesh.

[0004]

However, when a vibration is applied to the mesh filter, the developer floats, and this developer enters between the mesh filter and the vibration applying means. As a result, the vibration state of the mesh filter becomes unstable, which may hinder stable separation.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a separating member for separating a developer from a mixture containing a developer, and a vibration applying means for applying a vibration by contacting the separating member. And a blocking unit for blocking the developer from entering between the separating member and the vibration applying unit, wherein the blocking unit is provided in non-contact with the separating member. It is characterized by being.

[0006]

[0007]

FIG. 1 is a schematic sectional view of a main body of an image forming apparatus to which the present invention is applied, FIG.
FIG. 3 is a detailed view of the mesh non-contact seal portion, and FIG. 4 is a side view of the separation device.

Reference numeral 1 denotes an image carrier for forming a latent image in an image forming unit; 2, a developing device for developing the latent image on the image carrier 1; 3, a new developer in the developing device 2 (the developer is a magnetic developer) 4 is a transfer separation charger, 5 is an image carrier 1
A cooler for recovering the developer remaining on the top, 6 is a pre-exposure, 7 is a primary charger for charging the image carrier 1, 8 is an optical system for reading a document image, and 8a is a latent image on the image carrier 1. An exposure unit for writing an image, 9 a document processing device for guiding a document to a reading unit, 10 a sheet feeding unit for feeding a sheet to the image forming unit, 11 a conveying table, and 12 a sheet for the sheet formed by the image forming unit. A fixing unit for fixing an image; 13, a sheet discharging unit for discharging a sheet on which image formation has been completed; 15, an intermediate tray for temporarily storing a sheet on which an image has been formed and fed to the image forming unit again; Intermediate tray 1 for sheets to be printed
A re-feeding sheet guiding section for guiding to 5, an intermediate tray 1 for 16
5 is a sheet re-feeding unit that feeds the sheets stored in the image forming unit 5 to the image forming unit again.

Next, the separation device will be described. Reference numeral 17 denotes an apparatus frame, which is a non-magnetic material (for example, a non-magnetic stainless steel wire,
A mesh 20, which is a separating member made of a non-magnetic brass wire or a nylon fiber, is disposed substantially horizontally, and a non-magnetic flexible sheet 21 (for example, a thin stainless steel leaf spring material, a thin phosphor bronze leaf spring) is disposed from above and below. Material). Further, sleeves 18 and 19 each containing a magnet are arranged above and below the mesh 20, and are rotationally driven by driving means (not shown) in the direction of the arrow. The magnetic forces N ₁₉ and S ₁₈ of the separation portion where the sleeves face each other are set so that N ₁₉ > S ₁₈ . Mesh 20
Vibration is applied to the flexible sheet 21 by a cam 24 connected to a drive motor 23 attached to a support member 22 for holding the mesh 2 and the mesh 2 via the flexible sheet 21.
Vibration is transmitted to zero. Reference numeral 25 denotes a magnet, on which a magnetic plate 26 is disposed on the opposite side of the mesh, and a concentrated magnetic field is formed across the mesh 20. 27, 30
Is a transport screw, 27 transports the developer collected from the cleaner from the back side to the front side, 30 transports the developer from the front side to the back side, and discharges it outside the device. (Including hopper). Reference numeral 28 denotes a doctor blade that regulates the thickness of the developer layer on the surface of the sleeve 18. Reference numeral 29 denotes a scraping blade that scrapes the developer from the surface of the sleeve 19. Numeral 31 denotes a non-magnetic brush for scraping non-magnetic substances remaining on and adhering to the sleeve 18 together with the residual developer to the collecting section 32, and is rotated at a low speed in the counter direction with respect to the sleeve 18.

Next, the operation of the image forming apparatus will be described. When a copy operation button (not shown) is pressed, the document in the document processing device 9 is guided to a reading unit, and then the image of the document is read by the optical system 8. The electric charge is charged to a predetermined potential by the charger 7, and then a latent image is written in the exposure section 8a. Next, the latent image on the image carrier 1 is developed by the developing device 2. At this time, if the developer is insufficient in the developing device 2, the developer is appropriately replenished from the hopper 3. When the sheet p is fed from the sheet feeding section 10 to the image forming section, the developed image on the image carrier 1 is transferred to the sheet p by the transfer separation charger 4.
The image is transferred to the fixing unit 12 by the transfer stand 11 and the image on the sheet is fixed. In the case of single-sided copying, the sheet is directly discharged to the sheet discharge unit 13. In the case of the double-sided mode or the multiplex mode, the sheet is not discharged as it is, but is stacked and stored on the intermediate tray 15 by the re-feeding sheet guiding unit 14, After being stored, the sheet re-feeding unit 16
The sheets are separated and fed one by one, and fed again to the image forming unit. Then, the next manuscript is the manuscript exchange device 9
Is formed on the platen to form a second image, the image is fixed by the fixing unit 12 and then the sheet discharging unit 1
It is discharged to 3.

The developer on the image carrier 1 that has not been transferred onto the sheet p by the transfer / separation charger 4 is scraped off by the cleaner 5 and cleaned. The developer that has been cleaned here is transported to the above-described separation device by a transport mechanism (not shown). The developer scraped off by the cleaner 5 is conveyed to the inside of the separation device by the screw 27 and supplied to the sleeve 18 side. Here, the developer adheres to the sleeve 18 by magnetic force, is conveyed upward with the rotation of the sleeve 18, and is regulated to a predetermined layer thickness by the doctor blade 28. Then the developer sent to the separation unit facing the sleeve 19 is effectively attracted by concentrated lines of magnetic force extending from S ₁₈ to N _19, the magnetic force N _19, S ₁₈ of the separation unit will be N _19> S ₁₈ As a result, the developer is more strongly attracted to N ₁₉ and is pulled upward through the mesh 20. However, the eyes of the mesh 20 have gaps several times as large as the particle size of the developer, so that the developer smoothly passes through the mesh in the initial clean state, but partially aggregates as the durability increases. The developer adheres to the gap of the mesh 20,
Further, when the environmental humidity is high, the degree of cohesion of the developer is further increased and a so-called clogging phenomenon in which the developer does not pass through the mesh is exhibited. However, in this embodiment, the non-magnetic thin flexible sheet 21 (preferably having a thickness of 0.0
(5 to 0.2 mm), and the vibration is applied to the mesh 20 via the flexible sheet 21.
The developer adhering to the mesh 20 breaks the aggregation by the vibration force, the clogging of the mesh 20 is eliminated, and the developer is easily separated. In addition, since the mesh 20 is sandwiched between the flexible sheets 21 from above and below, the flexible sheet 21 can be sufficiently restored even from bending due to vibration even though it is a very thin layer. Therefore, the flexible sheet 21 can transmit the vibration to the mesh 20 by fine vibration and can vibrate efficiently without deforming the mesh 20. In addition, the flexible sheet 2
1 is a thin layer having a thickness of about 0.05 to 0.2 mm, so that even if it vibrates, its vibration sound is very small and does not emit noise to the outside. Also, at this time, the magnetic developer separates and conveys the magnetic developer from the lower side to the upper side by the magnetic force, but the developer separated from the magnetic force during the conveyance floats in the container space, Sleeve 18,
The developer chamber does not leak outside since the storage chamber in which 19 is disposed is closed. Since the mesh 20 extends to the vibration applying part, the separation part and the vibration applying part are in spatial communication with each other. However, even if the developer floats in this space and moves toward the vibrating portion, the developer is formed by the magnet 25 and the magnetic plate 26, which are blocking means, disposed in the middle as shown in FIGS. The concentrated magnetic field captures the developer and the developer does not reach the vibration applying portion. Further, as the endurance progresses, the developer further adheres to the magnet 25 and the magnetic plate 26. Each of the adhered developers has a particle diameter of 10 μm.
Since the particles are of the order of magnitude, the connected state of each particle is flexible. Therefore, the particles adhered to the mesh 20
Does not attenuate the vibration of the mesh 20, and the vibration imparted by the vibration imparting means is efficiently transmitted to the separation unit.

Further, the separated developer is easily transported upward and adheres to the sleeve 19 by setting the magnetic force such that the gravity of the developer itself is small and the conveying force by the magnetic force is sufficiently large. In this embodiment, since the developer is set to be conveyed upward from the lower side in the direction of gravity and separated therefrom, the non-magnetic substance (foreign matter) separated from the developer adheres to the lower side of the mesh. Then, the vibration applied to the mesh loses the adhesive force to the mesh, and the mesh is knocked down by the gravity. Therefore, the developer and the foreign matter can be efficiently separated, and clogging of the mesh can be continuously prevented.
Further, the separated developer is further conveyed to the downstream side, is scraped off from the sleeve 19 by the scraping blade 29, and is conveyed out of the separation device by the screw 30. Then, the separated developer is transported to a developing system by a transport device (not shown) and supplied again for development. The foreign matter that has been separated by the separation unit falls on the sleeve 18 and is further transported together with the residual developer, and is once separated from the sleeve surface by the non-magnetic brush 31 set downstream of the separation unit. Since the non-magnetic brush 31 is in contact with the sleeve 18 by a small contact pressure, the sleeve 1
8 can be scraped off with a small force, but the developer that has not been completely separated at the separating portion and has remained is attracted to the sleeve by magnetic force. Cannot be scraped off, and is conveyed further downstream to obtain an opportunity for separation again.
Therefore, the developer is hardly collected in the collecting section 32, and most of the foreign matters made of non-magnetic material are stored in the collecting section 32.

As described above, the agglomeration of the developer is destroyed, and foreign matter adhering to the mesh is knocked off in the direction of gravity, whereby clogging of the mesh portion can be suppressed at all times and continuous and efficient separation can be achieved. . In addition, since the concentrated developer by the magnet and the magnetic plate can capture the floating developer without contacting the mesh as a sealing means for the space between the vibration applying part and the separation part, the vibration applying part applies the mesh to the mesh. The generated vibration is efficiently transmitted to the separation unit without being attenuated on the way, and the separation function can be continuously maintained.

(Other Embodiment) FIG. 5 is a sectional view of a separation apparatus according to an embodiment in which an air seal by an air suction duct is provided as a sealing means (blocking means).

Reference numeral 33 denotes a suction duct disposed between the vibration applying portion and the separation portion, and is suctioned by a suction fan 35 via a filter 34. Here, the suction force is not so strong, and is such that the flow of air flows into the suction duct 33. Since the mesh 20 extends to the vibration applying part, the separation part and the vibration applying part are in spatial communication with each other. However, even if the developer floats in this space and moves toward the vibration imparting portion, the developer is a particle having a particle size of about 10 μm, so that the developer flows into the air flow formed by the suction duct 33 arranged in the middle. It is sucked into the suction duct along. Therefore, the developer does not reach the portion of the vibration applying means. Also, mesh 2
Since there is nothing in contact with 0, the vibration applied to the mesh 20 by the vibration applying means is efficiently transmitted to the separation unit without being attenuated on the way.

The floating developer sucked into the suction duct 33 is further conveyed outward, captured by the filter 34, and only air is discharged to the outside.

In the above-described embodiment, the blocking means which does not come into contact with the mesh filter is shown. However, the present invention is not limited to this. For example, a malt plane which comes into contact with the mesh filter to prevent the intrusion of floating toner is provided. Alternatively, a sealing member such as the above may be used. However, in consideration of attenuation of the vibration of the mesh filter, a non-contact filter is preferable.

[0018]

As described above, the magnetic force generating means is rotatably disposed at the opposing positions via the mesh filter (mesh) vibrated by the vibration applying means, and the magnetic agent is provided on one magnetic force generating means. In the separation device, the magnetic agent is conveyed by rotating each magnetic force generating means to the other magnetic force generating means side on the opposite side through the mesh and separating the non-magnetic material mixed in the magnetic agent. Since the non-contact sealing means (magnetic seal, air seal) is disposed between the vibration applying part and the separation part via a mesh, the floating developer can be captured. It does not pollute. Further, since the sealing means is not in contact with the mesh, the separating ability of the collected developer can be continuously maintained without attenuating the vibration applied to the mesh.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a main body illustrating an image forming apparatus according to the present invention.

FIG. 2 is a cross-sectional view illustrating a configuration of a separation device.

FIG. 3 is a detailed view of a mesh non-contact seal portion.

FIG. 4 is a side view of the separation device.

FIG. 5 is a cross-sectional view illustrating a configuration of a separation device using an air seal unit.

FIG. 6 is a perspective view of FIG. 3;

[Explanation of symbols]

 2 Developing device 5 Cleaner 18 and 19 Sleeve with a magnet built in 20 Mesh 21 Flexible sheet 23 Vibration imparting motor 24 Vibration cam 25 Magnet 26 Magnetic plate 33 Suction duct 34 Filter 35 Suction fan

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) G03G 21/10-21/12 G03G 13/08 G03G 15/08-15/08 507

Claims (8)

(57) [Claims] A separating member that separates the developer from the mixture containing the developer; a vibration applying unit that abuts on the separating member to apply vibration; and a developer between the separating member and the vibration applying unit. And a blocking unit that blocks entry of the separating device, wherein the blocking unit is provided in non-contact with the separating member. 2. The separating apparatus according to claim 1, wherein said developer contains a magnetic toner, said blocking means includes a magnetic force generating means, and said magnetic force generating means forms a magnetic seal. 3. The separation device according to claim 1, wherein the separation member is a mesh filter. 4. The separating member separates the developer in a separating section, and the vibration applying section applies vibration by the vibration means. 2. The separation device according to claim 1, wherein the separation device blocks the ingress. 5. An image carrier for carrying a developer image, a cleaning unit for cleaning the image carrier, and separation for separating the developer from a mixture of the developer and foreign matter removed from the image carrier by the cleaning unit. A member, a vibration applying unit that applies vibration by contacting the separation member, and a blocking unit that blocks the developer from entering between the separation member and the vibration providing unit. The image forming apparatus is characterized in that the blocking unit is provided in non-contact with the separation member. 6. The image forming apparatus according to claim 5, wherein the developer contains a magnetic toner, the blocking unit includes a magnetic force generating unit, and the magnetic force generating unit forms a magnetic seal. 7. The image forming apparatus according to claim 5, wherein the separation member is a mesh filter. 8. The separating member separates the developer in a separating section, and a vibration is applied to the vibration applying section by a vibration applying section, and the blocking section applies the developer from the separating section to the vibration applying section. 6. The image forming apparatus according to claim 5, wherein the entrance is blocked.