This application claims priority under Korean Patent Application No. 10-2009-0060838, filed on Jul. 3, 2009, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
One or more embodiments of the present general inventive concept relate to a developing device and an electrophotographic image forming apparatus employing the development device.
2. Description of the Related Art
Electrophotographic image forming apparatuses print an image on a recording medium by irradiating light, which is modulated to correspond to image information, onto a photoconductor in order to form an electrostatic latent image on a surface of the photoconductor, supplying toner to the electrostatic latent image in order to develop the electrostatic latent image into a visible toner image, and then, transferring and fixing the toner image onto the recording medium. Electrophotographic image forming apparatuses include a developing device containing toner.
The photoconductor and the toner may be provided via a cartridge which may be referred to as a ‘developing device’. When the toner contained in the developing device is completely consumed, the developing device is removed from the electrophotographic image forming apparatus, and a new developing device is inserted into the electrophotographic image forming apparatus.
A developing device may be divided into a toner container and a developing unit. Before the developing device is inserted into an image forming apparatus, the toner container and the developing unit are isolated from each other by disposing a blocking film therebetween. The blocking film is removed in order to connect the toner container and the developing unit with each other before the developing device is inserted into the image forming apparatus. When the toner container is not completely isolated from the developing unit, toner may leak to the developing unit during delivery of the developing device. If toner leaks to the developing unit, it may be difficult to remove the blocking film.
One or more embodiments of the present general inventive concept provide a developing device in which toner contained in a toner container is prevented from leaking to the developing unit, and an electrophotographic image forming apparatus employing the same.
One or more embodiments of the present general inventive concept also provide a developing device in which a blocking film disposed between a toner container and a developing unit is easily removed, and an electrophotographic image forming apparatus employing the same.
Additional aspects and utilities of the present general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the general inventive concept.
Features and/or utilities of the present general inventive concept may be realized by a developing device including a housing including a toner container containing toner, and a developing unit, wherein the developing unit includes a developing roller and a photoconductive drum; a barrier member including a toner supply window, wherein the barrier member is combined with the housing to separate the toner container and the developing unit from each other; and a blocking film that is attached to the barrier member to block the toner supply window, wherein an end of the blocking film is exposed outside the housing through an opening formed in a sidewall of the housing, wherein a bottom surface and first and second side surfaces of the barrier member are attached to a bottom surface and first and second side surfaces of the housing by using a welding process, and a distance between the first and second side surfaces of the barrier member and a distance between the first and second side surfaces of the housing increase from bottom to top.
The first and second side surfaces of the barrier member may be disposed at an angle of about 75 to about 81 degrees with respect to a horizontal plane.
The developing device may further include a plurality of fusion protrusions protruding from the bottom surface and the first and second side surfaces of the barrier member, and fusion grooves formed in the bottom surface and the first and second side surfaces of the housing, into which the plurality of fusion protrusions are inserted. An overlapping distance, constituting a measure of how much the fusion protrusions overlap the fusion grooves, respectively, may be about 0.3 to about 0.5 mm.
The blocking film may be attached to an attachment surface of the barrier member, the attachment surface facing the developing unit.
A lower end of the toner supply window may be disposed to be higher than a bottom surface of the developing unit. The developing unit may include a supply roller attaching toner to the developing roller, and the lower end of the toner supply window may be disposed to be higher than a center of the supply roller.
The barrier member may include a reinforcing rib having a multi-rib structure, the reinforcing rib being disposed on an upper portion of the toner supply window.
The barrier member may include a plurality of window reinforcement ribs crossing the toner supply window, wherein each of the window reinforcement ribs may be disposed such that an upper surface of each of the window reinforcement ribs is lower than the attachment surface, thereby forming a step between each of the window reinforcement ribs and the attachment surface.
A lower end of the opening may be disposed to be higher than a lower end of the toner supply window.
The developing device may include an elastic sealing unit that is combined with the sidewall of the housing in which the opening is formed, to cover the opening. A length of the sealing unit may be greater than a length of the opening. The developing device may further include a pressurizing unit pressing the sealing unit toward the sidewall of the housing. The housing may include a lower frame forming a lower frame of both the toner container and the developing unit; a receiving frame receiving remnant toner removed from the photoconductive drum; and a side frame that is combined with side surfaces of the lower frame and the receiving frame to connect the lower frame and the receiving frame, wherein the pressurizing unit is disposed at the side frame.
The housing may include a lower frame forming a lower structure of both the toner container and the developing unit; and an upper frame covering an upper portion of the lower frame, wherein a front end of the upper frame is fused with a top surface of the barrier member. A location at which the bottom surface of the barrier member is fused with the lower frame may be disposed closer to the toner container than a location at which the top surface of the barrier member is fused with the front end of the upper frame.
Features and/or utilities of the present general inventive concept may also be realized by an electrophotographic image forming apparatus including the developing device described above, an optical scanning unit scanning light, which is modulated according to an image signal, onto the photoconductive drum; a transfer device transferring a toner image formed on the photoconductive drum onto a recording medium; and a fixing unit fixing the toner image to the recording medium by applying heat and pressure to the recording medium.
The above and other features and advantages of the present general inventive concept will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:
Reference will now be made in detail to the embodiments of the present general inventive concept, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below to explain the present general inventive concept by referring to the figures.
The developing unit 20 includes a photoconductive drum 1, a charging roller 2, and a developing roller 3. The photoconductive drum 1 is manufactured by forming a photoconductive layer around an outer circumference of a cylindrical metal pipe. The charging roller 2 is an example of a charger that charges a surface of the photoconductive drum 1 to a uniform potential. A charging bias voltage is applied to the charging roller 2. A corona charger (not shown) may be used instead of the charging roller 2. The developing roller 3 supplies the toner from the toner container 10 to an electrostatic latent image formed on a surface of the photoconductive drum 1 in order to develop the electrostatic latent image. In the current embodiment, the developing device 100 employs a contact developing technique based on a principle that the developing roller 3 and the photoconductive drum 1 contact each other to form a developing nip D. In this case, the developing roller 3 may consist of an elastic layer (not shown) formed around an outer circumference of a conductive metal core (not shown). When a developing bias voltage is applied to the developing roller 3, the toner is transferred and attached to the electrostatic latent image, which is formed on the surface of the photoconductive drum 1, via the development nip D. If the developing device 100 employs a non-contact developing technique, a surface of the developing roller 3 and a surface of the photoconductive drum 1 are spaced about several hundreds of microns apart from each other. The development unit 20 may further include a supply roller 4 that attaches the toner supplied from the toner container 10 to the developing roller 3. A supply bias voltage may be applied to the supply roller 4 so as to attach the toner to the developing roller 3. Reference numeral 5 denotes a cleaning roller that removes foreign substances or toner attached to the charging roller 2. Reference numeral 6 denotes a regulator that regulates an amount of toner that is attached to a surface of the developing roller 3 to be supplied to the development nip D. Reference numeral 7 denotes a cleaning unit that removes remnant toner and foreign substances from a surface of the photoconductive drum 1 before charging is performed. The remnant toner and foreign substances removed from the photoconductive drum 1 via the cleaning unit 7 are contained in the waste toner container 30.
The toner container 10 may include an agitator 8 that supplies the toner to the development unit 20. The agitator 8 may agitate the toner contained in the toner container 10 in order to charge the toner to a predetermined electric potential. Although
Referring to
Referring to
As indicated by dotted lines in
As described above, the first and second side surfaces 442 and 443 of the barrier member 40 and the first and second sidewalls 61 and 62 of the lower frame 60 are determined to be inclined at the angle E with respect to a horizontal plane, thereby allowing the first and second side surfaces 442 and 443 of the barrier member 40 to be firmly fused with the first and second sidewalls 61 and 62 of the lower frame 60. When the first and second side surfaces 442 and 443 of the barrier member 40 are firmly fused with the first and second sidewalls 61 and 62 of the lower frame 60, it is possible to prevent the toner contained in the toner container 10 from leaking to the developing unit 20.
During fusing of the barrier member 40 with the lower frame 60, if the fusion jig 901 pressurizes the entire top surface 431 of the barrier member 40, then the barrier member 40 may be deformed. If the barrier member 40 is deformed, a part of the blocking film 50 may be separated from the attachment surface 421 of the barrier member 40. To prevent this, during the fusing operation, the fusion jig 901 applies pressure to only parts of the top surface 431 of the barrier member 40 that are adjacent to the first and second side surfaces 442 and 443 of the barrier member 40 instead of to the entire top surface 431 of the barrier member 40, as illustrated in
Referring to
Referring to
Referring to
After the toner container 10 is filled with toner, the upper frame 80 is combined with the lower frame 60 and the barrier member 40. The upper frame 80 may be combined with the lower frame 60 and the barrier member 40 according to the ultrasonic welding process is performed on the barrier member 40. A plurality of fusion grooves (not shown) are formed at a bottom surface of the upper frame 80 to surround the toner container 10. Also, a plurality of fusion protrusions (not shown) are formed on the lower frame 60 to surround the lower frame 60 except for a region where the barrier member 40 is located. The top surface 431 of the barrier member 40 includes an upper fusion groove 452 into which a fusion protrusion (not shown) at a front end of the upper frame 80 and protruding toward the developing unit 20 is inserted. A location at which the lower frame 60 is fused with the bottom surface 441 of the barrier member 40 is closer to the toner container 10 than a location at which the front end of the upper frame 80 is fused with the top surface 431 of the barrier member 40. That is, the lower fusion protrusion 401 is closer to the toner container 10 than the upper fusion groove 452.
When the lower frame 60 and the receiving frame 70 are combined via the side frame 95, an end of the blocking film 50 is exposed to the outside via a slit 96 illustrated in
In the developing unit 20, a small amount of toner (which is referred to as “initial toner”) is contained in order to test the performance of the developing device 100 of
In other words, as illustrated in
Also, a pressurizing unit 650 may further be installed to push the sealing unit 640 so that the sealing unit 640 is not separated from the first sidewall 61 when the blocking film 50 is removed. The pressurizing unit 650 may be disposed, for example, at an inner side of the side frame 95 that connects the lower frame 60 and the receiving frame 70 with each other. When the side frame 95 is combined with the lower frame 60 and the receiving frame 70, the pressurizing unit 650 presses the sealing unit 640 not to be separated from the lower frame 60. In this case, the pressurizing unit 650 presses a location on the sealing unit 640 close to the opening 610. If the pressurizing unit 650 presses a location on the sealing unit 640 closest to the opening 610, then the blocking film 50 is extremely firmly pressed by the sealing unit 640 and thus cannot be easily removed. For example, the pressurizing unit 650 may press a location on the sealing unit 640 about 0.5 mm to 1 mm away from the opening 610.
The optical scanning unit 200 scans light, which is modulated according to image information, onto the photoconductive drum 1 which has been charged to a uniform potential. For example, a laser scanning unit (LSU) that scans light emitted from a laser diode onto the photoconductive drum 1 by deflecting the light in a main scanning direction by using a polygon mirror, may be used as the optical scanning unit 200.
The transfer roller 300, which is an example of a transfer device, is disposed to face a surface of the photoconductive drum 1, which is exposed through an opening 9b, in order to form a transfer nip. A transfer bias voltage is applied to the transfer roller 300 so as to transfer a toner image developed on the surface of the photoconductive drum 1 onto a recording medium P. A corona transfer device may be used instead of the transfer roller 300.
The toner image transferred onto the recording medium P by the transfer roller 300 remains adhered to the recording medium P due to electrostatic attraction. A fixing unit 400 applies heat and pressure onto the toner image in order to fix the toner image on the recording medium P, thereby forming a permanent printed image on the recording medium P.
A method of forming an image by using the electrophotographic image forming apparatus having the above configuration will now be briefly described. When a charging bias voltage is applied to the charging roller 2, the photoconductive drum 1 is charged to a uniform potential. The optical scanning unit 200 forms an electrostatic latent image on the photoconductive drum 1 by scanning light, which is modulated according to image information, onto the photoconductive drum 1 through the optical window 9a of the developing device 100. The toner contained in the toner container 10 is supplied to the development unit 20 by the agitator 8 and is then attached to the developing roller 3 by the supply roller 4. The regulator 6 forms a toner layer having a uniform thickness on the developing roller 3. A developing bias voltage is applied to the developing roller 3. The toner is moved to the development nip D as the developing roller 3 rotates and is then transferred and attached to the electrostatic latent image on the photoconductive drum 1, due to the developing bias voltage. Thus, a visible toner image is formed on the photoconductive drum 1. The recording medium P picked up from a recording medium tray 501 by a pick-up roller 502 is transported to the transfer nip between the transfer roller 300 and the photoconductive drum 1 by a transporting roller 503. When a transfer bias voltage is applied to the transfer roller 300, the toner image is transferred onto the recording medium P by electrostatic attraction. If the fixing unit 400 applies heat and pressure onto the toner image transferred onto the recording medium P, then the toner image is fixed to the recording medium P, thereby completing printing. The recording medium P is externally discharged by a discharge roller 504. Toner remaining on the surface of the photoconductive drum 1 which has not been transferred to the recording medium P is removed by the cleaning unit 7 and is collected in the waste toner container 30.
While the present general inventive concept has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present general inventive concept as defined by the following claims.
Number | Date | Country | Kind |
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2009-60838 | Jul 2009 | KR | national |
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03-279983 | Dec 1991 | JP |
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Number | Date | Country | |
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20110002708 A1 | Jan 2011 | US |