1. Field of the Invention
The present invention relates to a developer replenishing cartridge, which is removably mountable to a developer replenishing apparatus and can be used in an image forming apparatus such as a copying machine, a facsimile, a printer, or a multifunction machine having two or more of functions of these apparatus, and a developer replenishing method.
2. Description of the Related Art
Hitherto, a particulate developer has been used in an electrophotographic image forming apparatus such as a copying machine, and the apparatus is configured to print an image while compensating for consumption of a developer in association with formation of the image through replenishment from a developer replenishing cartridge.
A developer replenishing container to be used in such related-art developer replenishing cartridge is, for example, a container described in Japanese Patent Application Laid-Open No. 2010-256894.
An apparatus described in Japanese Patent Application Laid-Open No. 2010-256894 adopts a system involving discharging a developer with a bellows pump provided in the developer replenishing container. A specific method is as described below. The bellows pump is expanded to bring an air pressure in the developer replenishing container into a state where the pressure is lower than the atmospheric pressure, whereby air is taken in the developer replenishing container to fluidize the developer. Further, the bellows pump is contracted to bring the air pressure in the developer replenishing container into a state where the pressure is higher than the atmospheric pressure, whereby the developer is extruded and discharged by a pressure difference between the inside and outside of the developer replenishing container. The apparatus is configured to discharge the developer stably by alternately repeating the two steps. However, there is a risk that the developer is tapped in the developer replenishing container to be excessively brought into a consolidated state by, for example, the vibration at the time of its transportation or storage state of the container. When the excessive consolidated state is established, a phenomenon called flushing in which a large amount of the developer is discharged all at once may occur in such system involving performing discharge control based on an internal pressure fluctuation as described above. In addition, the flowability of the developer fluctuates depending on a temperature and humidity of its storage environment. Accordingly, in order that the developer may be stably discharged with high replenishment accuracy even when exposed to an environmental fluctuation, matching property not only with the developer replenishing container but also with the developer needs to be improved.