Abstract: A plastic gear includes a hub disposed at a core portion, a gear ring disposed concentrically outside of the hub and having a plurality of teeth on an outer surface thereof, and a web that connects the hub and the gear ring. A plurality of ribs is formed on front and rear side surfaces of the web at a prescribed constant angular interval and each of the plurality of the ribs is located substantially at a middle angular position between a pair of neighboring ribs formed on the front side surface.

Abstract: An image forming apparatus has a driven image forming part for forming an image. A data supply device has at least one moving portion for supplying data to the image forming apparatus. For example, it may be a hard disk device or a toner sensor having an oscillator, both of which generate noise. A controller actuates the data supply device only during operation of the image forming part, and so the noise is not bothersome to the user.

Abstract: A device for driving a charge roller, charge belt, image transfer roller, image transfer belt or similar contact type charging member used to charge an image carrier of an image forming apparatus in contact with the image carrier. The charging member is driven by an exclusive motor independent of a motor for driving the image carrier. A drive gear and a driven gear are formed of metal and resin, respectively. A flywheel is mounted on a drive roller for causing the charging member to rotate. The drive side has greater rotation energy than the driven roller side. A flywheel is also mounted on the drive gear.

Abstract: An image forming apparatus having a first toner container storing a toner to be supplied to a developing device, and a second toner container storing a toner to be supplemented to the first toner container. A first and a second sensor are mounted on the wall of the first toner container at a comparatively high level and a comparatively low level, respectively. When the first sensor senses the absence of the toner, the toner is supplemented from the second toner container to the first toner container. When the second sensor senses the absence of the toner, the toner supplementing ability is increased to increase the amount of toner supplement from the second toner container to the first toner container.

Abstract: A fixing apparatus for fixing an image on a record sheet comprises a fixing roller in which a heater is disposed, a pressing roller urged against the fixing roller, heat pipes extending in either one of the fixing and pressing rollers in a longitudinal direction thereof, and a temperature detection / control device for detecting to control a temperature of the fixing roller. In a typical embodiment, the heat pipes are disposed in the fixing roller to extend both through an imaging portion, through which a record sheet passes, and through a non-imaging portion, through which no record sheet passes and the temperature detection / control device has a temperature detection device for detecting a temperature of the fixing roller in contact with the non-imaging portion. The temperature detection / control device is provided with a temperature regulating device for interrupting electricity to the heater when the fixing roller exceeds a predetermined temperature.

Abstract: A control method for an image recorder of the type transporting a recording medium substantially vertically from a lower portion to an upper portion inside the recorder. This type of recorder transfers a toner image from a photoconductive element to the medium, and has a toner density sensor for sensing the toner density of a reference density pattern. When the medium jams in the transport path while being transported in the vertical direction, whether it has slipped out of the transported path and dropped to a position where the toner density sensor is located is determined, the sensor is turned on when the operator starts on an operation for removing the medium and when the operator ends such an operation. When the resultant two consecutive outputs from the sensor are different from each other, it is determined that the medium has dropped and the jam is in the vicinity of the sensor.

Abstract: A toner supply device loaded with a removable toner cartridge for supplying a toner to a developing unit of an electrophotographic image forming apparatus. When the toner is fed from the toner cartridge to the toner supply device, an agitating member incorporated in the toner supply device is operated for a predetermined period of time to agitate the toner. The device supplies the toner evenly and rapidly to the developing unit after crushing hard masses of the toner or removing local concentration of the toner which are apt to occur in the cartridge.

Abstract: A developing roller for a developing unit of an image forming apparatus has at least a magnet with a transport pole, a magnet with a develop pole, and a magnet with a collect pole. These magnets are accommodated in a rotary sleeve and affixed to a support member. The magnet with the develop pole is dimensioned longer than the other magnets as measured in the axial direction of the roller. The developing roller surely collects a developer of a magnet brush remaining on the roller after development, and thereby frees the interior of the apparatus from contamination ascribable to the developer.

Abstract: A toner cartridge for use with a facsimile transceiver, printer or similar electrophotographic image forming apparatus for supplying a toner, or developer, to a developing unit of the apparatus. A first locking pawl fixes the casing and lid to each other in a condition wherein the toner has not been supplied to the developing unit, while a second locking pawl is caused into a position capable of fixing the casing and lid after the lid has been slid once relative to the casing. To supply the toner from the cartridge to the developing unit, the first pawl is pressed down to unlock the lid from the casing, and then the lid is slid along the casing. As the lid is so slid, the second pawl is brought to the condition for fixing the casing and lid. When the lid is returned along the casing after the supply of the toner, it is fixed to the casing by both of the first and second pawls.

Abstract: A fixing apparatus for fixing an image on a record sheet .?.comprises.!. .Iadd.includes .Iaddend.a fixing roller in which a heater is disposed, a pressing roller urged against the fixing roller, heat pipes extending in either one of the fixing and pressing rollers in a longitudinal direction thereof, and a temperature detection/control device for detecting .?.to control.!. .Iadd.and controlling .Iaddend.a temperature of the fixing roller. In a typical embodiment, the heat pipes are disposed in the fixing roller to extend both through .?.an imaging portion.!. .Iadd.a sheet passage area.Iaddend., through which a record sheet passes, and through a .?.non-imaging portion.!. .Iadd.sheet non-passage area.Iaddend., through which no record sheet passes and the temperature detection/control device has a temperature detection device for detecting a temperature of the fixing roller in contact with the .?.non-imaging portion.!. .Iadd.sheet non-passage area.Iaddend..