Patent Application
20070065196
Image forming devices form images through a toner transfer process that transfers toner particles to a media sheet. The process includes forming a latent image on a photoconductive member with a laser device. The toner particles originally stored in a reservoir are attracted to the latent image and transferred from the reservoir to the photoconductive member. The toner particles on the photoconductive member are than passed either directly to the media sheet, or transferred to an intermediate member and then transferred to the media sheet. During the toner transfer process, some toner particles are not transferred and remain on the photoconductive member or intermediate member. These particles should be removed prior to forming the next toner image.
The removed toner particles, also referred to as waste toner, may be transported within the image forming device and stored for disposal. Alternatively, the waste toner may be recycled and re-introduced back into the reservoir for forming a subsequent toner image. In either event, the waste toner should be transported in a leak-free system. The transport system may include conduits that lead from one section of the image forming device to a second section of the device. Further, the transport system may pass or hand-off the waste toner from a first conduit to a second conduit.
The waste toner has the consistency of a fine powder that is prone to leak from the transport system. Small cracks or openings in the transport system, such as at the hand-off areas of one conduit to a second conduit, may result in toner leakage. Waste toner that leaks from the transport system gathers within the interior of the image forming device. The leaked toner may attach to a media sheet moving through the device resulting in a print defect. Alternatively, the leaked toner may attach to a user, such as when the user is replacing a cartridge or other internal component. Either leakage situation is problematic and should be kept to a rare occasion, or completely eliminated.
The present application is directed to embodiments of a device to move waste toner within an image forming device. In one embodiment, waste toner is formed during the image formation process. The waste toner is captured and moved through a first conduit. The conduit includes an outlet for passing the waste toner to a second conduit. The door is positionable between an open orientation for the waste toner to discharge into the second conduit, and a closed orientation. The second conduit includes an inlet for receiving the waste toner. The interface between the first and second conduits allows the door to move between the open and closed orientations. The interface also greatly reduces or prevents the waste toner from leaking as it passes from the first conduit into the second conduit.
The present application is directed to embodiments for moving waste toner within an image forming device.
The present embodiments are better understood within the context of the workings of an image forming device.
The media sheet with loose toner is then moved through a fuser 181 that adheres the toner to the media sheet. Exit rollers 190 rotate in a forward or a reverse direction to move the media sheet to an output tray 191 or a duplex path 192. The duplex path 192 directs the inverted media sheet back through the image formation process for forming an image on a second side of the media sheet.
During image formation, the device 110 forms a latent image on a photoconductive member 141 that is within each of the cartridges 20. Each photoconductive member 141 rotates past a toner reservoir and the toner is attracted to the latent image. The photoconductive member 141 with toner then rotates further and transfers the toner image onto the media sheet that is passing along on the transfer belt 130. Residual toner, referred to as waste toner, that remains on the photoconductive drum 141 after toner transfer is removed by a removal mechanism 142. The removal mechanism 142 includes a channel 145 (
The transfer of the waste toner from the cartridge 20 into the waste toner chute 30 occurs with no leakage.
A door 25 is movably positioned over the port 21 and behind the shield 40. The door 25 is movable between a closed orientation as illustrated in
Shield 40 is positioned on the exterior of the door 25 to protect the door 25. Shield 40 is positioned a distance from the cartridge 20 forming a gap for housing the door 25. Opening 41 aligns with the port 21 and may be substantially the same size as the port 21. The shield 40 is statically mounted and does not move as the door 25 moves between the open and closed orientations.
The toner chute 30 includes an opening 31 for receiving the waste toner from the cartridge 20 as illustrated in
Seal 32 is positioned between the shield 40 and toner chute 30 when the cartridge 20 is mounted to the toner chute 30. Both the shield 40 and toner chute 30 are statically positioned and do not move as the door 25 moves between the open and closed orientations. The static contact forms a barrier to prevent toner leakage as the waste toner moves through the hand-off between the cartridge 20 and the chute 30. If the moving door 25 were to directly contact the seal 32, the movement may allow toner to leak, and the moving door 25 may also cause damage to the seal 32 as it moves between the open and closed orientations.
Door 25 is positioned between the cartridge housing 146 and shield 40. Door 25 includes an opening 29 that is positioned away from opening 41 and the outlet port 21 in the closed orientation as illustrated in
As illustrated in
The placement of the cartridge 20 relative to the toner chute 30 allows for transfer of the waste toner and reduces the possibility of toner clogs.
To alleviate and/or prevent clogging, opening 29 is positioned such that the path of the waste toner exiting the cartridge 20 is roughly horizontal. This path is chosen to minimize the distance between the cartridge 20 and the sweep range A (the size D of the potential clog area increases the farther from horizontal the opening 29 is positioned). To further reduce the likelihood of a toner clog, opening 31 in the toner chute 30 has a larger vertical opening size from horizontal H. Opening 31 has an opening angle β defined between the horizontal H and a lower edge of the opening 31. Opening 29 has an opening angle α defined between the horizontal H and a lower edge of opening 29. To reduce clogging, angle β is greater than the outlet port opening α. In one embodiment, angle β is about 80° and angle α is about 30°. The angular placement below horizontal also allows for any waste toner on the toner chute side of the door 25 to fall into the toner chute 30 after the door is closed. The horizontal size of the opening 31 may also be greater than opening 29.
Door 25 is closed when the cartridge 20 is removed from the device 110. The door 25 may also close depending upon the position of the device 110 as illustrated in
The opening 41 on the shield 40 and the outlet port 21 may have the same size, or may have different sizes. In one embodiment, door 25 is substantially cylindrical and attaches to an end of the cartridge housing 146. The door 25 may have other configurations, and may have other attachments.
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, a biasing mechanism biases the door 30 towards the closed orientation. 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.
