Abstract: A DMA controller capable of employing a plurality of data transfer modes and a data transferring method for the same. A preprocessor generates a designating packet in accordance with a specific data transfer mode, and provides the designating packet for a memory/peripheral device transfer engine and a peripheral device/memory transfer engine. The designating packet includes a transfer direction identification parameter, a transfer start memory address, an address increment/decrement flag, a tag identification flag, a tag transfer identification flag and a transfer word count. In accordance with this designating packet, the transfer engines transfer data between the memory and the peripheral device.

Abstract: A toner density control method wherein a change in a toner density when a developer of a standard density is stirred, a correction coefficient is calculated from the change, and a toner density of the developer of the standard density under stable condition is calculated from the toner density of the developer which has been stirred and from the correction coefficient, in order to control the toner density.

Abstract: A toner cartridge for supplying a toner to a photo-copy machine and collecting a waste portion of the toner after a copy operation with the photo-copy machine, comprising; a cylindrical body for providing a supplement toner containing room and a waste toner collecting room by means of a separating wall inside, the separating wall for dividing the supplement toner containing room and the waste toner collecting room, an outlet being located on the wall of the cylindrical body at the side of the supplement toner containing room for supplying the toner contained in the room into the photo-copy machine, and an inlet being located on the wall of the cylindrical body at the side of the waste toner collecting room for collecting the waste portion of the toner from the photo-copy machine, in which the separating wall is angled so that its surface is leaned toward the supplement toner containing room or the waste toner collecting room.

Abstract: Disclosed is a developing unit equipped with a shaft supporting mechanism for slidably supporting a photosensitive drum, thereby the photosensitive drum can be pressed onto the developing sleeve with an elastic force. The unit has a balancing mechanism for eliminating a thrust force caused by the driving mechanism.

Abstract: The invention provides a toner recovery device for collecting toner from a cleaning device into a recovery toner container. The device includes a toner conveyance, an operating lever and a shutter. The tone conveyance has a conveyance pipe whose base end portion is rotatably connected to the cleaning device and tip end portion with an outlet opening is detachably coupled to an inlet opening of the recovery toner container so that the tip end portion is pivotted around the base end portion so as to take the coupled position and the detached position. The operating lever is linked to the conveying pipe for pivotting the tip end portion between the coupled position and the detached position. The shutter is adapted to move on the conveying pipe interlockingly with the movement of the operating lever so that the shutter closes the outlet opening of the conveying pipe on the detached position and opens the outlet opening on the coupled position.