Abstract: An image forming apparatus includes: a plurality of photosensitive bodies disposed along a moving direction of a recording medium; a drive mechanism for driving and rotating the plurality of photosensitive bodies; a plurality of exposure units, each exposure unit being associated with a respective one of the photosensitive bodies, the each exposure unit configured to expose the respective photosensitive body; a determining unit for determining an exposure-starting phase that is a rotation phase at an exposure-starting timing with respect to one photosensitive body among the plurality of photosensitive bodies; and a varying unit for varying a exposure-starting time difference between the exposure-starting timing of the one photosensitive body and an exposure-starting timing of an other photosensitive body disposed at a downstream side of the one photosensitive body in the moving direction of the recording medium, based on the exposure-starting phase.

Abstract: An image forming apparatus is provided. A development cartridge having a first memory storing therein cartridge information is detachably mountable to the image forming apparatus. The image forming apparatus includes: an apparatus casing and an exposure unit having plural light emitting portions. The exposure unit is supported by the apparatus casing so that the light emitting portions face a photosensitive member rotatably supported by the apparatus casing. The image forming apparatus further includes a reader unit disposed on the exposure unit and configured to read the cartridge information from the first memory when the development cartridge is mounted to the image forming apparatus.

Abstract: A printer controller includes: a selecting unit that selects authentication information from among a plurality of authentication information; a first transmitting unit that transmits the authentication information selected by the selecting unit to a printer connected to the printer controller via a network; and a second transmitting unit that transmits print data to be printed to the printer. The authentication information selected by the selecting unit is used for authentication for allowing the printer to print an image based on the print data.

Abstract: The image forming apparatus preferably includes a process unit, an acquisition unit, a detection unit, and a selection unit. The process unit executes processes in a plurality of modes corresponding to identification information for identifying a user. The acquisition unit acquires identification information for identifying a user. The detection unit detects presence or absence of an object to be used in at least any one of the plurality of modes. The selection unit selects a mode corresponding to the presence or absence of the object detected by the detection unit from the plurality of modes corresponding to the identification information acquired by the acquisition unit.

Abstract: An image forming apparatus is provided. A development cartridge having a first memory storing therein cartridge information is detachably mountable to the image forming apparatus. The image forming apparatus includes: an apparatus casing and an exposure unit having plural light emitting portions. The exposure unit is supported by the apparatus casing so that the light emitting portions face a photosensitive member rotatably supported by the apparatus casing. The image forming apparatus further includes a reader unit disposed on the exposure unit and configured to read the cartridge information from the first memory when the development cartridge is mounted to the image forming apparatus.

Abstract: An image forming apparatus includes: a plurality of photosensitive bodies disposed along a moving direction of a recording medium; a drive mechanism for driving and rotating the plurality of photosensitive bodies; a plurality of exposure units, each exposure unit being associated with a respective one of the photosensitive bodies, the each exposure unit configured to expose the respective photosensitive body; a determining unit for determining an exposure-starting phase that is a rotation phase at an exposure-starting timing with respect to one photosensitive body among the plurality of photosensitive bodies; and a varying unit for varying a exposure-starting time difference between the exposure-starting timing of the one photosensitive body and an exposure-starting timing of an other photosensitive body disposed at a downstream side of the one photosensitive body in the moving direction of the recording medium, based on the exposure-starting phase.

Abstract: A printer controller includes: a selecting unit that selects an authentication information from among a plurality of authentication information; a first transmitting unit that transmits the authentication information selected by the selecting unit to a printer connected to the printer controller via a network; and a second transmitting unit that transmits print data to be printed to the printer. The authentication information selected by the selecting unit is used for authentication for allowing the printer to print an image based on the print data.

Abstract: The image forming apparatus preferably includes a process unit, an acquisition unit, a detection unit, and a selection unit. The process unit executes processes in a plurality of modes corresponding to identification information for identifying a user. The acquisition unit acquires identification information for identifying a user. The detection unit detects presence or absence of an object to be used in at least any one of the plurality of modes. The selection unit selects a mode corresponding to the presence or absence of the object detected by the detection unit from the plurality of modes corresponding to the identification information acquired by the acquisition unit.

Abstract: A heater temperature control circuit for controlling a temperature of, for example, a heater incorporated in a laser printer for fixing a toner image on a recording material includes a voltage divider circuit delivering an output voltage divided by a thermistor changing a resistance value thereof in response to temperature changes with generation of heat by a heater and a resistance having a predetermined resistance value, and a heater control circuit comparing the output voltage of the voltage divider circuit with a reference voltage, thereby delivering a control signal for controlling an amount of heat generated by the heater on the basis of results of comparison.

Abstract: A host based printer has a control unit on which an external RAM can be optionally mounted. Whether or not the external RAM is mounted thereon is determined. When affirmative, image data received from a host computer is temporarily stored in the external RAM serving as a reception buffer. The image data retrieved from the reception buffer is sent to a decoding circuit to produce dot image data which in turn is sent to a line buffer for printing. When the external RAM is not mounted, the print control is implemented with a buffer-less configuration in which the received image data is directly sent to the decoding circuit and the decoded data is sent to the line buffer for printing. Accordingly, the host based printer can operate with a buffer-less configuration while preserving operability of general host based printers.

Abstract: A host based printer has a control unit on which an external RAM can be optionally mounted. Whether or not the external RAM is mounted thereon is determined. When affirmative, image data received from a host computer is temporarily stored in the external RAM serving as a reception buffer. The image data retrieved from the reception buffer is sent to a decoding circuit to produce dot image data which in turn is sent to a line buffer for printing. When the external RAM is not mounted, the print control is implemented with a bufferless configuration in which the received image data is directly sent to the decoding circuit and the decoded data is sent to the line buffer for printing. Accordingly, the host based printer can operate with a buffer-less configuration while preserving operability of general host based printers.

Abstract: In order that the reception buffer of a host based printer is unlikely to become full with image data transmitted from a host computer and to reduce the number of print interruptions caused by the fullness of the reception buffer, it is determined whether the reception buffer is in a first buffer-full state or in a second buffer-full state. The first buffer-full state is a state in which the reception buffer is full with image data and a page end code. The second buffer-full state is a state in which the reception buffer is full with image data but no page end code is contained therein. In the first buffer-full state, printing has already been started upon detection of the page end code and so an interruption signal for interruting the printing procedure will not be generated. In the second buffer-full state, an interruption signal is issued to start an in-advance printing if printing has not yet been started.