Patent Application
20080226331
The present disclosure relates generally to imaging units and method of insertion into an image forming device and, more specifically, to imaging units that provide for accurate alignment within the image forming device and methods of accurately aligning the imaging units.
Image forming devices include copiers, laser printers, facsimile machines, and the like. These devices may include multiple imaging stations that are completely or partially removed and replaced when necessary. In particular, color devices may require up to four imaging stations. The imaging stations may include a developer unit, photoconductor unit, and a toner cartridge. The developer unit may include a developer roll, a doctor blade, and a toner adder roll. The photoconductor unit may include a photoconductive (PC) drum, charge roll, and PC drum cleaner. The toner cartridge may include a reservoir to contain the toner.
The toner is consumed during the image forming process whereby the amount of toner is reduced during each successive image forming process. Once all of the toner has been distributed, the user removes all or part of the imaging station and inserts a replacement. The imaging forming device and the imaging unit should be constructed to provide access to the imaging stations to facilitate the removal. Further, the device should provide for accurate replacement and realignment within the imaging unit and/or the image forming device.
Current imaging forming devices include imaging station designs with various negative aspects. In image forming devices that use multiple cartridges, each imaging station should be capable of being inserted into the image forming device, located, and electrically connected independently from the other stations. These stations may also require significantly more mechanical interfaces with the image forming device, including mechanical hold-downs, electrical contacts, guide rails, and datum surfaces. The independent stations may also require extra space within the interior of the image forming device to facilitate insertion and removal. This results in an increase in the overall size of the image forming device.
The present application is directed to an imaging unit for an image forming device. In one embodiment, the imaging unit includes a frame that includes brace members that are connected together to form a central opening. The imaging unit may also include separate mounting locations positioned on the frame in a side-by-side orientation. Each of the mounting locations may be adapted to receive an imaging station that may include a developer unit, photoconductor unit, and a toner cartridge. The frame may also include locating features to align the frame within the image forming device. Electrical contacts may be operatively connected to the frame. The electrical contacts may operatively connect with the image forming device to provide electrical communication to each of the plurality of imaging stations.
The present application is directed to an imaging unit that is mounted within an image forming device. The imaging unit includes two or more separate imaging stations that are mounted together as a single element for insertion into the image forming device.
As illustrated in
A first toner transfer area 160 includes one or more imaging stations 300 that are aligned horizontally extending from the front 110 to the back 111 of the body 101. Each imaging stations 300 includes a photoconductor unit 310 and a developer unit 330. Each of the imaging stations 300 is mounted such that photoconductive (PC) drums 312 are substantially parallel. For purposes of clarity, the units 310, 330 are labeled on only one of the imaging stations 300. In one embodiment, each of the imaging stations 300 is substantially the same except for the color of toner.
The developer unit 330 includes a toner reservoir 331 to contain the toner. One or more agitating members may further be positioned within the reservoir 331 to move the toner. Developer unit 330 further includes a toner adder roll 332 that moves the toner supplied from the reservoir 331 to a developer roll 333. The photoconductor unit 310 includes in part a charging roll 311 and a PC drum 312. The units 310, 330 include additional elements that are explained below with reference to
The charging roll 311 forms a nip with the PC drum 312, and charges the surface of the PC drum 312 to a specified voltage such as −1000 volts, for example. A laser beam from a printhead 126 is directed to the surface of the PC drum 312 and discharges those areas it contacts to form a latent image. In one embodiment, areas on the PC drum 312 illuminated by the laser beam are discharged to approximately −300 volts. The developer roll 333, which also forms a nip with the PC drum 312, then transfers toner to the PC drum 312 to form a toner image. The toner is attracted to the areas of the PC drum 312 surface discharged by the laser beam from the printhead 126.
An intermediate transfer mechanism (ITM) 129 is disposed adjacent to each of the imaging stations 300. In this embodiment, the ITM 129 is formed as an endless belt trained about drive roll 131, tension roll 132 and back-up roll 133. During image forming operations, the ITM 129 moves past the imaging stations 300 in a clockwise direction as viewed in
The ITM 129 rotates and collects the one or more toner images from the imaging stations 300 and then conveys the toner images to a media sheet at a second transfer area. The second transfer area includes a second transfer nip 140 formed between the back-up roll 133 and a second transfer roll 141.
A media path 144 extends through the device 100 for moving the media sheets through the imaging process. Media sheets are initially stored in the input tray 130 or introduced into the body 101 through a manual feed 148. The sheets in the input tray 130 are picked by a pick mechanism 143 and moved into the media path 144. In this embodiment, the pick mechanism 143 includes a roll positioned at the end of a pivoting arm. The roll rotates to move the media sheets from input tray 130 towards the second transfer area. In one embodiment, the pick mechanism 143 is positioned in proximity (i.e., less than a length of a media sheet) to the second transfer area with the pick mechanism 143 moving the media sheets directly from the input tray 130 into the second transfer nip 140. For sheets entering through the manual feed 148, one or more rolls are positioned to move the sheet into the second transfer nip 140.
The media sheet receives the toner image from the ITM 129 as it moves through the second transfer nip 140. The media sheets with toner images are then moved along the media path 144 and into a fuser area 150. Fuser area 150 includes fusing rolls or belts 151 that form a nip to adhere the toner image to the media sheet. The fused media sheets then pass through exit rolls 145 that are located downstream from the fuser area 150. Exit rolls 145 may be rotated in either forward or reverse directions. In a forward direction, the exit rolls 145 move the media sheet from the media path 144 to an output area 147. In a reverse direction, the exit rolls 145 move the media sheet into a duplex path 146 for image formation on a second side of the media sheet.
In one embodiment as illustrated in
The imaging unit 350 may also include a toner cartridge 90 to supply toner to the developer unit 330.
In one embodiment, an electrical connector 98 is positioned at the bottom side 92 and engages with a connector in the body 101 or in the imaging unit 350. Electrical connector 98 may be associated with computing hardware for storing parameters including but not limited to pages printed, toner color, first use date, and toner cartridge. The computing hardware may include one or more processors, logic devices, and memory. The computing hardware may further comprise integrated circuits, including for example application specific integrated circuits and digital signal processors, in which embedded program code may be stored and executed.
Examples of toner cartridges are disclosed in U.S. patent application Ser. Nos. 11/554,157 and 11/554,117 each filed on Oct. 30, 2006, and 11/556,863 filed on Nov. 6, 2006, each of which are incorporated herein by reference.
As previously explained, two or more imaging stations 300 are mounted together to form the imaging unit 350.
In one embodiment as illustrated in
As best illustrated in
The imaging unit 350 further includes various locating features for positioning during insertion into the body 101. As illustrated in
The frame 301 may also include locating features to accurately position the PC drums 312 of the photoconductor units 310. In one embodiment, the PC drums 312 are mounted on a central shaft 319. As illustrated in FIGS. 7 and 8A-C, apertures 420 extend through the second brace member 303 to receive the shafts 319. Bushings 421 may be mounted in the apertures 420 and include an opening 426 to receive the shafts 319.
In one embodiment as illustrated in
A path to ground may be created by positioning of the PC drum shaft 319 within the aperture 420 in the second brace member 303. In one embodiment, the bushing 421 is constructed of an oil-impregnated sintered bronze material that forms a portion of the ground path.
The imaging unit 350 is positioned as a single assembly into the body 101.
Locating studs 803, 804 are positioned towards a front section of the interior 103. Stud 803 is contacted by flat feature 403 (
The near and far walls of the interior 103 may include hold-downs 802 that couple the imaging unit 350 to the body 101 and provide forces necessary for the internal function of the imaging unit 350. Sets of drive couplers 809, 810 may be positioned at the far wall and engage with each imaging station 300 respectively for transferring rotary motion to the photoconductor units 310 and developer units 330.
A high voltage electrical interface 820 is positioned to engage with the electrical traces 410 on the imaging unit 350. In one embodiment, the electrical interface 820 includes a single contact block with one or more contacts that interface with the traces 410. Data communication electrical contacts 821 are positioned to interface with the electrical contacts 415 for data communication between the imaging stations 300 and the body 101. In one embodiment, the electrical contacts 821 are reduced to a single contact block.
As illustrated in
Once the imaging unit 350 is mounted within the body 101, the toner cartridges 90 are aligned vertically under the door 121 on the top side 114. This positioning provides for the toner cartridges 90 to be vertically removed and replaced without removing the imaging unit from the body 101. As explained above with reference to
In one embodiment, each of the toner cartridges 90 is approximately the same shape and size. In another embodiment as illustrated in
As disclosed with reference to
In one embodiment, the imaging stations 300 include independent photoconductor units 310 and developer units 330. These units may be separated from each other, and removed separately from the imaging unit 350. In another embodiment, the units 310, 350 are both contained within a single cartridge and cannot be separated from each other, or removed separately from the imaging unit 350.
As illustrated best in
The embodiments disclosed above are directed to image forming devices 100 with a secondary-transfer area. These devices include a first transfer of the toner image to an intermediate member, and a second transfer from the intermediate member to the media sheet. The present application may also be used in a direct transfer device that transfers the toner image directly to the media sheet (i.e., there is no intermediate member or second transfer).
Spatially relative terms such as “under”, “below”, “lower”, “over”, “upper”, and the like, are used for ease of description to explain the positioning of one element relative to a second element. These terms are intended to encompass different orientations of the device in addition to different orientations than those depicted in the figures. Further, terms such as “first”, “second”, and the like are also used to describe various elements, regions, sections, etc and are also not intended to be limiting. Like terms refer to like elements throughout the description.
As used herein, the terms “having”, “containing”, “including”, “comprising” and the like are open ended terms that indicate the presence of stated elements or features, but do not preclude additional elements or features. The articles “a”, “an” and “the” are intended to include the plural as well as the singular, unless the context clearly indicates otherwise.
The present invention may be carried out in other specific ways than those herein set forth without departing from the scope and essential characteristics of the invention. In one embodiment, the guide rails 305 on the frame 301 are substantially parallel with the PC drums 312 in each of the imaging stations 300. In one embodiment, brace member 302 includes openings to receive a shaft from each of the PC members 312. In one embodiment, bushings are positioned in the openings in the brace member 302. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.
