1. Field of the Disclosure
The present disclosure relates generally to toner cartridges used in electrophotographic image forming devices and, more particularly, to a toner cartridge having a pivoting exit port cover.
2. Description of the Related Art
In order to reduce the premature replacement of components traditionally housed within a toner cartridge for an image forming device, toner cartridge manufacturers have begun to separate components having a longer life from those having a shorter life into separate replaceable units. Relatively longer life components such as a developer roll, a toner adder roll, a doctor blade and a photoconductive drum are positioned in one replaceable unit (an “imaging unit”). The image forming device's toner supply, which is consumed relatively quickly in comparison with the components housed in the imaging unit, is provided in a reservoir in a separate replaceable unit in the form of a toner cartridge that mates with the imaging unit. In this configuration, the number of components housed in the toner cartridge is reduced in comparison with traditional toner cartridges. As a result, in systems utilizing a separate toner cartridge and imaging unit, the toner cartridge is often referred to as a “toner bottle” even though the toner cartridge is more complex than a mere bottle for holding toner.
To deliver toner from the toner cartridge to the imaging unit, an auger in the toner cartridge may be used to feed toner from an exit port on the toner cartridge into an entrance port on the imaging unit and into a second auger that disperses the toner within the imaging unit. As the toner is drawn out of the toner cartridge, it is augured through a shutter used for sealing the exit port of the toner cartridge when it is not inserted in the printer.
Image forming devices having a separate toner cartridge and imaging unit are susceptible to leakage of toner between the exit port of the toner cartridge and the entrance port of the imaging unit. Toner leakage is commonly experienced when the toner cartridge is separated from the imaging unit and removed from the image forming device. Toner leakage may be experienced even when the shutter is closed as a result of toner buildup outside the shutter, in and around the exit port. When this occurs, leaked toner may fall from the toner cartridge into the image forming device or onto surfaces surrounding the image forming device, such as a desktop or a user's clothing, resulting in uncleanliness. Further, when leaked toner falls into the internal portions of the image forming device, it can cause reliability issues and, in some cases, print defects.
One solution to the issue of toner leakage between the toner cartridge and imaging unit is to mask the problem by positioning the interface between the toner cartridge and the imaging unit in an area within the image forming device that the customer does not to interact with. However, this solution does not address the issues of reliability and print defects. Foam has also been used to soak up leaked toner. However, this solution is only useful where the foam is in a position to contact the leaked toner and where small amounts of toner are leaked. Otherwise, the foam is unable to soak up the leaked toner. A sliding cover has also been employed to cover the exit port of the toner cartridge in an attempt to trap any loose toner within the toner cartridge. The sliding cover is biased in the closed position.
When the toner cartridge is inserted into the image forming device and mated with the imaging unit, the sliding cover is engaged by a portion of the imaging unit that overcomes the bias and causes it to retract into an open position revealing the exit port of the toner cartridge. When the toner cartridge is separated from the imaging unit and removed from the image forming device, the cover slides into the closed position as a result of the bias. In some instances, the sliding cover contributes to toner leakage by pushing or skiving toner off the portion of the toner cartridge surrounding the exit port as the cover slides closed. Accordingly, it will be appreciated that an exit port cover that effectively prevents toner leakage is desired.