JPH07219349A - Image forming device - Google Patents

Abstract

PURPOSE:To stably obtain an excellent quality image by providing a device separating foreign matter coexisting in used toner on a device main body side, removing the foreign matter from the used toner recovered by a cleaner and then, returning the used toner to a developing unit. CONSTITUTION:The process cartridge integrally housing an image carrier, the developing unit and the cleaner and freely attachable/detachable to/from an image forming device, is provided and the separating device 30 removing the foreign matter coexisting in the used toner recovered by the cleaner in the cartridge is provided on the image forming device main body side. The toner recovered by the cleaner is discharged from the cleaner by a carrying pipe 31 including a carrying screw and led into the separating device 30 from the opening of a shutter 32 through a discharging screw and the foreign matter coexisting in the toner is removed by a pair of magnet rollers and a mesh made of a nonmagnetic material in the separating device 30. The toner after the foreign matter is removed is carried to the developing unit through a carrying pipe 42 and reused to develop.

Description

Detailed Description of the Invention

[0001]

[Object of the Invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus using an electrostatic transfer process such as an electrostatic copying machine and a printer, and a used toner collecting apparatus for a cartridge used in the image forming apparatus.

[0002]

2. Description of the Related Art In the image forming apparatus using the process cartridge as described above, it is necessary to replace the cartridge when the toner in the developing device mounted in the cartridge is used up. By reusing the used toner for development, the life of the cartridge can be greatly extended. For this reason, there has already been proposed a method of returning the toner collected at the cleaner portion to the developing device as it is (for example, Japanese Patent Laid-Open Publication No. 6-58242).
(See JP-A-2-296258).

However, in the case where such used toner is conveyed to the developing device as it is, various foreign substances such as fine paper powder and dust are mixed in the toner, and such toner is developed. It is not easy to thoroughly mix and stir with the unused toner in the container.
There is a problem that image defects such as missing images are likely to occur.
The above-mentioned publication describes the case of a two-component type developer, but the same applies to the case of a one-component type developer, and avoids similar image deterioration when the used toner is reused as it is. There wasn't.

The present invention has been made in order to cope with such a situation, and in a process cartridge of an image forming apparatus, mixed foreign matters are removed from used toner collected from a cleaner, and then this toner is developed. It is an object of the present invention to provide a cartridge that is configured to be returned to a container, and an image forming apparatus that includes such a cartridge and that can stably obtain a high-quality image for a long period of time.

[0005]

[Constitution of the invention]

In order to achieve the above object, the present invention provides at least an image carrier, a developing device,
In an image forming apparatus equipped with a process cartridge in which a cleaner is integrally housed and detachably attached to the image forming apparatus main body, used toner collected by the cleaner in the cartridge is disposed on the apparatus main body side. Toner conveying means for conveying mixed foreign matter from used toner to a separating device for separation and removal, toner conveying driving means for transmitting driving force to the toner conveying means, and separated toner from which foreign matter is removed by the separating device in the cartridge The toner conveying means for conveying to the developing device, the image forming apparatus provided with the separated toner conveying driving means for transmitting the drive of the separated toner conveying means, or the above-mentioned cartridge has the collected toner conveying means, the collected toner conveying means on the cleaner side thereof. Conveying means Drive transmission means is provided, and the separated toner conveying means and the separated toner conveying are provided on the developing device side. A process cartridge for an image forming apparatus having a motion transmitting means, or in the above-mentioned image forming apparatus or its process cartridge, the used toner color detecting means provided in the cartridge is used to collect the recovered toner when a cartridge of a specific color toner is detected. The image forming apparatus stops the conveyance of the separated toner and the conveyance of the separated toner cartridge to the developing device.

With such a configuration, in the image forming apparatus having the cartridge for returning the toner collected by the cleaner to the developing device through the separating device and reusing the separating device, the separating device is always provided on the main body side of the device. It is possible to obtain a toner reusable image forming apparatus capable of reducing the cost of the cartridge.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic side sectional view of an image forming apparatus equipped with a cartridge according to the present invention. A process cartridge 1 is detachably mounted in a main body of the apparatus by a guide 9. In the illustrated case, the cartridge 1 integrally includes an image carrier 2, a primary charger 3, a developing device 5, and a cleaner 7. I am doing it.

The transfer material (not shown) is a transfer material supply tray 12
Supplied from the transfer roller 13, the transfer roller 13 and the registration roller 14, and then the transfer charger 6 passes through a transfer portion facing the image carrier 2. Then, the fixing device 1 passes through a separation stage 15 and a transfer path 16.
After passing through 7, the sheet reaches the sheet discharge tray 19. Since the series of image forming steps are well known, detailed description thereof will be omitted.

In such a cartridge type apparatus, in the illustrated apparatus, the cleaner 7 and the developing device 5 are connected by a pipe having a conveying screw therein, as will be described later. The toner side screw portion 7c and the developing device side screw portion 5a are shown.

FIG. 2 is a schematic plan view of the above device. As shown in the figure, the toner collected by the cleaner 7 is discharged from the transport pipe 31, passes through a separating device for separating foreign matter from the used toner, which is denoted by reference numeral 30, and is returned from the transport pipe 42 to the developing device 5. I shall. Reference numeral 46 is a motor for driving the separation device.

As described above, at the transfer site where the transfer charger 6 is arranged, the toner image formed on the image carrier 2 is transferred to the transfer site at a timing matched with that of the transfer material. However, at this time, a part of the toner does not contribute to the transfer and remains on the image carrier. The residual toner reaches the position of the cleaner 7 as the image carrier 2 rotates, and is removed by the cleaning blade.

The used toner collected in the cleaner 7 is discharged from the cleaner by the carrying pipe 31 including the carrying screw 7c, and is carried to the developing device 5 through the separating device 30 and the carrying pipe 42 as described above to be developed again. Is used for.

FIG. 3 is a perspective view of the separating device for removing foreign matters from the used toner collected from the cleaner 7, and FIG. 4 is a sectional view schematically showing the internal structure.

First, the construction and operation of the separation device will be briefly described with reference to FIG. The used toner discharged from the cleaner 7 is guided through the opening 32 a (“FIG. 3”) of the shutter 32 and the conveyance screw 33 into the separation device. Inside the apparatus, a pair of magnet rollers 37a and 37b rotating in the direction of the arrow in the figure, and a mesh 38 made of a non-magnetic material disposed between them are arranged.

The used toner introduced from the cleaner 7 is supplied to the magnet roller side in the lower part of the figure, so that it is adsorbed by the magnet roller 37a and conveyed with it, and approaches the mesh 38. In both of the magnet rollers 37a and 37b, [magnetic force of the magnet roller 37b]> [magnetic force of the magnet roller 37a] is set so that the polarities of the used magnet rollers are opposite to each other at a position close to the mesh. It has been done.

With this structure, the toner introduced to the side of the magnet roller 37a is conveyed by the magnet roller 37a in a manner similar to the separation portion in the vicinity of the mesh 38 and the magnet roller 37b, where the toner is the magnet roller. Invited by 37b. At this time, foreign matter such as paper dust, which is mostly composed of a non-magnetic substance, is sucked, and even if it moves with the toner, it is blocked by the mesh and falls to the magnet roller 37a side.

The foreign matter is carried on the magnet roller as it is, is brushed off by the brush 45 made of a non-magnetic material, and is collected in the reservoir.

The toner attracted by the magnet roller 37b to remove the foreign matter is scraped off by the scraping blade 39 and is transported leftward in the drawing by the transport blades 40 and 41, and the transport screw 42a in the transport pipe 42.
And is supplied to the developing device 5 through the opening 43a (“FIG. 3”) of the shutter 43.

FIG. 3 shows the external appearance of the separating device, and reference numeral 31 in the same drawing is a carrying pipe having a carrying screw for discharging the used toner from the cleaner 7, and a shutter 32 having an opening 32a is attached. Reference numeral 35 is a drive transmission holder for driving the cleaner-side carrying screw, 35a is a slitting portion, 36 is an electromagnetic clutch for switching the drive of the toner carrying screw, and 44 is a driving screw for the carrying screw 5a of the developing device 5 in the cartridge 1. A drive transmission holder for transmission, 43 is a shutter having an opening 43a, 44a is a slotted portion, and 36 is an electromagnetic clutch for switching the drive of the holders 35, 44.

FIG. 5 is a perspective view showing the external appearance of the process cartridge 1, showing the separation device 30 removed. Reference numeral 7e is a cleaner-side conveying pipe, and a shutter 23 having an opening 23a at the end thereof is arranged, and a tip end thereof is a bottle for receiving drive from the separating device side.

Reference numeral 27 is a conveying pipe on the side of the developing device, which is provided with a shutter 26 having an opening 26a at the step portion, and a drive receiving pin 25 is provided at the tip. Reference numeral 1a denotes a drive gear that drives the image carrier 2 by receiving drive from the apparatus main body side.

FIG. 6 is a side cross-sectional view of the toner carrying portion on the cleaner side. Reference numeral 1 indicates the cleaner side, and a pipe 7e for housing the carrying screw 7c is projectingly provided, and the toner is discharged to the end thereof. There is an opening 7d. Further, a shutter 23 having an opening 23a is provided, and this shutter is configured such that a spring 24 shifts the positions of the openings 7d and 23a. Reference numeral 22 is an end seal.

FIG. 7 is a sectional view showing a mode in which the cleaner side of the cartridge 1 and the separating device are combined. When the cartridge is set in the main body of the apparatus, the shutter 23 is pressed by the holder 35 on the separating apparatus side and moves as shown in the drawing, and the opening 23a is aligned with the opening 7d of the pipe 7e. Further, the shutter 32 of the transfer pipe 31 on the separation device side is pressed by the cartridge to take the position shown in the drawing, and the opening 31a,
32a matches.

Further, at the position shown in the figure, these four openings 7d, 23a, 31a, 32a are all aligned, so that the collected toner on the cleaner side reaches the pipe 31 through these openings and is separated by the conveying screw 33. It is supplied to the device 30.

FIG. 8 is a sectional view showing the structure of the toner replenishing portion on the developing unit side of the cartridge, and FIG. 9 is a sectional view showing the replenishing portion and the separating device connected to each other.

Reference numeral 1 indicates the developing device side, and the end portion of the conveying screw 5a of the developing device and the external protruding portion are pipes 27.
The shutter 26 mounted on the end of the shutter is normally biased to one side by the spring 24.
As a result, the opening 27a of the pipe 27 and the opening 26a of the shutter 26 are displaced. Reference numeral 28 is an end seal.

FIG. 9 shows the structure of the connecting portion when the separating device and the cartridge are connected. When the cartridge is set in the main body of the apparatus, the conveying screw on the developing device side is pushed by the holder 44 and driven. When the shutter 26 is in the transmission state, the shutter 26 moves against the spring 24 to move the opening 26.
Coincides with the opening 27a of the pipe 27. With this,
The shutter 43 attached to the conveying pipe 42 on the separating device side is moved by being pressed by the cartridge to move the opening 4 of the pipe 42.
2a coincides with the opening 43a of the shutter 43.

Further, as shown in the figure, at this time, the openings 26a, 27a, 42a, 43a are all in the same position, so that the toner in the separating device 30 is returned from the separating device to the developing device through these openings. It can contribute to development again.

FIG. 10 is a schematic plan view of the cartridge detecting portion. Reference numeral 56 is an appropriate number of protrusions provided on the cartridge side, and 57 is a corresponding microswitch or photosensor provided on the apparatus main body side. By separately detecting the cartridge using the color toner and the cartridge using the black toner, the electromagnetic clutch 36 is turned off when the color cartridge is detected, so that the mixture of the black toner and the color toner already accumulated in the separating device is detected. It can be prevented.

[0030]

As described above, according to the present invention,
In an image forming apparatus that uses a process cartridge, it is possible to repeatedly use the used toner of the cartridge without increasing the cost for the means for separating foreign matter from the used toner on the side of the cartridge to be replaced all the time, and to improve the life of the cartridge. It is possible to greatly extend and stably obtain a high-quality image, and it is possible to suitably prevent mixing with black or other toner when a color toner is used.

[Brief description of drawings]

FIG. 1 is a side view of an essential part of an image forming apparatus to which the present invention is applied.

FIG. 2 Same as above

FIG. 3 is a perspective view of the separation device.

FIG. 4 is a schematic side view showing the configuration of the above.

FIG. 5 is a perspective view of a process cartridge

FIG. 6 is a cross-sectional view of the toner transport unit on the cleaner side of the cartridge.

FIG. 7 is a cross-sectional view showing a state in which the transport unit is set in the separating device.

FIG. 8 is a cross-sectional view of a toner transport unit on the developing unit side of the cartridge.

FIG. 9 is a cross-sectional view showing a state in which the transport unit is set in a separating device.

FIG. 10 is a schematic plan view of a detection unit of a cartridge.

[Explanation of symbols]

 1 Process Cartridge 2 Image Carrier 3 Charging Device 5 Developing Device 5a Conveying Screw 6 Transfer Charging Device 7 Cleaner 7c Conveying Screw 30 Separation Device

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location G03G 21/10

Claims (3)

[Claims] 1. An image forming apparatus comprising a process cartridge in which at least an image carrier, a developing device, and a cleaner are integrally housed and detachably mounted on the main body of the image forming apparatus, and the process cartridge is collected by the cleaner in the cartridge. Toner conveying means for conveying the used toner to a separating device for separating and removing mixed foreign matters from the used toner arranged on the apparatus main body side, toner conveying driving means for transmitting a driving force to the toner conveying means, and the separating device An image forming apparatus comprising: a toner conveying unit that conveys the separated toner from which foreign matter is removed to a developing unit in a cartridge; and a separated toner conveying driving unit that transmits driving of the separated toner conveying unit. 2. A cartridge according to claim 1, wherein the cleaner side is provided with a collected toner carrying means and a collected toner carrying means drive transmission means, and the developing device side is provided with a separated toner carrying means and a separated toner carrying drive. A process cartridge for an image forming apparatus having a transmission means. 3. The image forming apparatus or the process cartridge thereof according to claim 1, wherein the used toner color detecting means provided in the cartridge stops the conveyance of the collected toner when the cartridge of a specific color toner is detected. An image forming apparatus that stops carrying of separated toner cartridges into a developing device.