This application claims priority under 35 USC ยง119 to Japanese Patent Application No. 2000-039843 filed on Feb. 17, 2000, and its internal priority claiming application number of which is not yet known, the entire contents of which are herein incorporated by reference.
1. Field of the Invention
The present invention generally relates to an image forming apparatus, such as a printer, a copier, a facsimile, etc., and in particular relates to a toner replenishing device capable of replenishing a developing device with toner stored in a toner storage container.
2. Discussion of the Background
In known image forming apparatuses, such as printers, copiers, facsimiles, etc., a toner storage container such as a toner bottle or a toner cartridge is disposed within or in the vicinity of a unit which mounts a developing device. The developing device generally is replenished directly or via a toner hopper with toner conveyed from the toner storage container. In such a construction, conveyance of the toner from the toner storage container to the developing device generally is performed by a mechanical auger such as a screw, a paddle, etc.
However, when the mechanical auger conveys the toner, since the screw, for example, can only be arranged substantially straight, the toner storage container and the toner replenishing device are necessarily integrated with, or in the vicinity of, the developing device. Thus, the construction of the toner replenishing device is complex, costly and has low productivity and a low machine maintenance performance. In addition, protection and maintenance of toner quality characteristics are burdensome. In addition, it is generally difficult for a user to exchange a toner storage container.
Japanese Patent Application Laid Open No. 04-9082A has proposed a toner replenishing device capable of suppressing such problems. Specifically, the toner replenishing device conveys toner using suction generated by a suction device, and has an advantages that toner can be replenished, whatever positional relationship exists between a toner storage container and a developing device or the like.
However, toner utilized in an image forming apparatus which employs an electrophotographic system generally has greatly poor fluidity, and it is typically noted that conveyance of such toner is difficult. Accordingly, there are problems in the above noted toner replenishing device that toner clogging easily arises at a leading end or a middle portion of a suction pipe, and as a result, toner is not smoothly replenished.
Accordingly, it is an object of the present invention to address the above and other problems and provide a new image processing apparatus. The above and other objects are achieved according to the present invention by providing a novel toner replenishing device including a toner conveyance path extending from a toner storing device to a developing device, a toner conveying device for conveying toner from the toner storing device to the developing device along the toner conveyance path, and an air supplying device connected to the toner conveyance path via an air supply path for supplying the toner storing device with air from a bottom of the toner storing device so as to agitate the toner pooling in the toner storing device.
In yet another embodiment, the toner storing device includes an evacuation section at a top thereof so as to evacuate and receive air.
In yet another embodiment, the evacuation section is made of a breathable filter so as to efficiently evacuate the air.
In yet another embodiment, a multicolor image forming apparatus includes an air supply control device for controlling supplying of air to a plurality of toner storing devices and a fewer number of air generation sources than the plurality of toner storing devices so as to efficiently supply the air to the plurality of toner storing devices.
In yet another embodiment, the air supply control device controls both the driving of the air generation source and the opening and closing of a plurality of openable valves provided in a plurality of toner conveyance paths in such a manner that the plurality of toner storing devices is supplied with air one after another when the air generation sources are driven, so that an amount of air supplied to each of the toner storing devices can independently be supervised.
In yet another embodiment, the toner conveyance path is configured to receive at its middle portion user toner collected by a cleaning device so as to recycle the toner and protect the used toner from needless stress.
A more complete appreciation of the present invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout several views.
As noted from
A full color image forming process executed by the color laser printer illustrated in
A sheet designated as a transfer member may be fed from the sheet feeding section 2, and may strike against, and temporarily stop at, a register roller 23 provided upstream of the transfer belt 20. The sheet may then fed onto the transfer belt 20 in synchronism with the visualized image, and may arrive at a transfer position opposing the PC drum 5 as transferred by the transfer belt 20. The image having the magenta toner may be transferred onto the sheet at the transfer position by operation of the transfer roller 24 engaged with the backside of the transfer belt 20.
Other mono color toners may also visualize a plurality of remaining mono color images, respectively, on the surface of respective ones of the PC drums 5 of the respective image formation units 4C, 4Y, and 4Bk. Each of these visualized images may be transferred and superimposed every time the sheet arrives at each of the transfer positions. Thus, the color laser printer can quickly transfer and superimpose a full color image as a monochrome image. The sheet may then be separated from the transfer belt 20 and fixed by the fixing device 30. The sheet may be ejected outside the color laser printer after completing the fixing. Otherwise, the sheet may be inverted and ejected onto an ejection tray 40 which is constituted by an upper surface of the apparatus body 1 with its backside facing upward. Such backside ejection may be an essential condition for a printer when arranging the sheets in order of pages.
A toner replenishing device for replenishing each of image formation units 4M, 4C, 4Y, and 4Bk with applicable toner contained in each of toner storage containers 100M, 100C, 100Y, and 100Bk is now described with reference to
A uniaxial eccentric screw pump as a powder pump 110 of a suction type may be provided in a body or in the vicinity of the developing device 10. The powder pump 110 may be constructed with a rotor 142 which is made of rigid material such as metal and is formed in an eccentric screw shape, a stator 143 which is made of elastic material such as rubber and is formed in a two rowed screw shape, and a holder 144 which is made of plastic and encloses these devices, thereby forming a conveyance path for powder. The rotor 142 may be driven via a gear 146 connected in a body to a driving shaft 145 via a pin joint. An electromagnet clutch 147 controls an operation of the powder pump 110.
At the leading end of the holder 144 (i.e., at a right end in
A set portion 200 (see
The air connection opening 164 may be connected to an air pump 151 as an air supply source via an air transfer pipe 152. When the air pump 151 operates, some of air may gush out into the toner storage container 100 from the lower side thereof via the air transfer pipe 152 and the air supply route. This air may then agitate and thereby fluidize the toner while passing through a toner pool.
The toner storage container 100 may be a bag in a box type and is constructed by an external box 101 as a protection case, and a toner bag 102 of a bag shape, which is detachably installed and has flexibility so as to be deformed. The external box 101 may be made of rigid material such as paper, corrugated paper, plastic, etc., and has a prescribed internal dimension that is capable of accepting the toner bag 102 substantially without creating a gap therebetween. Thus, the toner storage container 100 may have advantages of easy handling and sorting during storage, in addition to protection of the flexible toner bag 102.
Further, a bag portion of the toner bag 102 may be constructed by a single layer or a plurality of layers of a flexible sheet like material having thickness of from 80 to 125 m. The flexible material may be made of polyester, polyethylene, etc. A mouthpiece member 103 made of plastic such as polyethylene, nylon, etc., may be secured to the toner bag 102 and include, at substantially the center of the bottom section, a toner ejection hole 104. In the mouthpiece member 103, there may be provided a seal member 105 which is constituted by a single or a plurality of layers and made of stiff elastic material such as expanded sponge, etc. The seal member 105 may function as a shut-in valve. The toner bag 102 may have an a tapered shape narrowing to the toner ejection hole 104 so that toner hardly remains therein. Accordingly, a nozzle 160 may be inserted into the toner storage container 100 in the vertical direction from the lower side thereof (i.e., right down side) when the toner storage container 100 is set onto the set portion 200.
With the above described image forming apparatus, when toner is suctioned by the powder pump 110 and if an angle of a slope of the toner bag towards its bottom is small, since the toner hardly drops in the vicinity of the nozzle 160 by gravity, the toner remains in the bag. Since the remaining toner may become readily suctioned if sufficiently agitated and fluidized while the toner storage container 100 is supplied with extensive air, an amount of the remaining toner can be greatly minimized (in such situation). However, since an amount of air supplied to the toner storage container 100 is limited to a capacity of the toner storage container 100, the toner may probably be insufficiently agitated, due to insufficient supply of air.
In such a situation, so as to decrease interior pressure, the toner storage container 100 may be provided with an opening 106 as an evacuation section, as illustrated in
If constructed in the above-described manner, since air supplied to the toner storage container 100 can partially be evacuated outside thereof through the breathable filter 107, the toner storage container 100 can be supplied with air substantially in the limitless manner. Thus, since toner in the toner storage container 100 can be sufficiently agitated by extensively supplied air, the toner can smoothly be suctioned by the powder pump 110, and an amount of remaining toner in the toner storage container 100 can be greatly decreased.
As described above, if a toner storage container 100 is provided with a breathable filter 107, the storage container 100 can be supplied with extensive air. Since extensive air is supplied by the air pump 151 and the full color image forming apparatus includes four toner storage containers 100M, 100C, 100Y, and 100Bk, four units of an air supplying device are necessarily required. However, it is typically costly and needs a large setting space to provide a plurality of air pumps 151.
To this end, the present invention may be constructed in a manner as illustrated in
With a color image forming apparatus constituted in the above-described manner, since one or more air pumps 151 having a fewer number than the toner storage containers 100 are employed, the color image forming apparatus can be compact and its cost can be lowered.
The second embodiment will be now described with reference to
With such a construction, the color image forming apparatus can be compact and a cost thereof can be lowered as in the earlier described embodiment. In the first and second embodiments of
Then, the plurality of openable valves 154M, 154C, 154Y, and 154Bk illustrated in
Thus, if the plurality of openable valves is controlled in the above-described manner, an amount of air supplied to each of the toner storage containers 100M, 100, 100Y, and 100Bk can readily be recognized from the capacity of the air pump 151 and its operation time period. As a result, the amount of air can easily be supervised.
Due to such a construction, the image forming apparatus can be compact and its cost can be lowered as in the above-described embodiments. In addition, since the valve-cum-surge tanks 155M, 155C, 155Y and 155Bk are provided to the air transfer pipes 152M, 152C, 152Y, and 152Bk, air can simultaneously be supplied to a plurality of toner storage containers 100. In addition, since the powder pump 110 ejects toner in the toner storage container 100 after air is supplied, it rarely remains therein. As a result, the image forming apparatus can be economical, and a used toner storage container 100 can safely and sanitarily be discarded or recycled.
Control of air supply to each of the toner storage containers 100M, 100C, 100Y, and 100Bk performed in the color laser printer illustrated in
A toner replenishing process will be now described with reference to
Considering air supply efficiency or the like, air may be supplied when image formation is repeated for an odd number. To this end, it may initially be determined if current image formation repetition is related to an odd number (in step S1). Subsequently, when image formation repetition is related to the odd number, it is determined if a development clutch (not shown) is turned ON (in step S2). When the development clutch is turned ON (Yes, in step S2), it is determined if a clutch 147 of the powder pump 110 is turned ON (in step S3). When the clutch 147 is turned ON (Yes, in step S3), a developing device may be supplied with toner. It is then determined whether the clutch 147 is turned OFF (in step S4). When the clutch 147 is deactivated, and as a result toner supply is stopped, the air may be supplied (in step S6). In this instance, since the air is independently supplied to respective ones of toner storage containers 100M, 100C, 100Y and 100Bk as illustrated in
Specifically, when a latent image is developed by the magenta developing unit (Yes in step S51), which initially develops the latent image, air supply for the magenta toner container may start (in step S6). If the image is subsequently developed by the cyan developing unit (No, in step S51, Yes, in step S52), and the air supply to the magenta toner container is turned OFF (Yes, in step S56) as illustrated in
Whenever the air supply has not yet been completed in the previous color developing process, the present air supply may wait for termination thereof (No, in steps S54, S55, and S56). The air supply may be stopped when the clutch 147 is turned ON (Yes, in step S7), or a prescribed preset air supply tome period has elapsed after air supply start (Yes, in step S8).
The third embodiment will now be described with reference to
According to the third embodiment of the present invention of
Thus, since fresh toner stored in the toner storage container 100 is conveyed to the developing device 10 via the collected toner ejection outlet 150, the fresh toner can be mixed with the collected toner from the middle of a toner conveyance process. In addition, since toner conveyance by the powder pump 140 substantially does not impose needless stress, and new toner is conveyed while being mixed with air along the toner conveyance members, mechanical stresses substantially are not imposed on collected toner mixed with the fresh toner.
Thus, if collected toner is reused, since a toner conveyance process substantially does not impose needless stress on the collected toner, an image formed by using such collected toner can substantially surely prevent generation of spots or the like in an image.
The mechanisms and processes set forth in the present invention may be implemented using one or more conventional general purpose microprocessors and/or signal processors programmed according to the teachings in the present specification as will be appreciated by those skilled in the relevant arts. Appropriate software coding can readily be prepared by skilled programmers based on the teachings of the present disclosure, as will also be apparent to those skilled in the relevant arts. However, as will be readily apparent to those skilled in the art, the present invention also may be implemented by the preparation of application-specific integrated circuits by interconnecting an appropriate network of conventional component circuits or by a combination thereof with one or more conventional general purpose microprocessors and/or signal processors programmed accordingly. The present invention thus also includes a computer-based product which may tee hosted on a storage medium and include, but is not limited to, any type of disk including floppy disks, optical disks, CD-ROMs, magnet-optical disks, ROMs, RAMs, EPROMS, EEPROMs, flash memory, magnetic or optical cards, or any type of media suitable for storing electronic instructions.
Numerous additional modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described herein.
Number | Date | Country | Kind |
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2000-039843 | Feb 2000 | JP | national |
Number | Date | Country | |
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Parent | 10434174 | May 2003 | US |
Child | 10830223 | Apr 2004 | US |
Parent | 09785234 | Feb 2001 | US |
Child | 10434174 | May 2003 | US |
Number | Date | Country | |
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Parent | 10830223 | Apr 2004 | US |
Child | 11312568 | Dec 2005 | US |