Abstract: A color laser printer includes a transfer belt unit including a transfer belt with reference marks, and a drive mechanism for the transfer belt, wherein the transfer belt unit includes a data storage unit (EEPROM) that stores color correction data and position correction data. When the transfer belt unit is new or replaced, corrections for color difference and position difference are performed based on the color correction data and the position correction data.

Abstract: An image forming apparatus of the present invention includes a pair of support plates supporting the rotary shaft of a photoconductive drum at axially opposite ends of the drum. One of the support plates is openable away from the body of the apparatus and loaded with a contact forming member including a current feed path for feeding a current from a high-tension power supply for charging to a charge roller, a wiring forming a current return path that allows a current to flow from the photoconductive drum to the ground of the power supply, and a plurality of contacts where the wiring and drum contact each other. A current flowing through the current return path is sensed to execute feedback control to the output of the high-tension power supply.

Abstract: An electrophotographic image forming apparatus includes a device to set a temperature correspondence electrifying duty ratio relative to a fixing heater of a fixing device according to a detected temperature. A device is included to set a power corresponding electrifying duty ratio relative to the fixing heater, according to a detected voltage; along with a device to compare the temperature correspondence electrifying duty ratio and the power correspondence electrifying duty ratio. When the temperature correspondence electrifying duty ratio is equal to or larger than the power correspondence electrifying duty ratio, it is restricted to obtain a restricted electrifying duty ratio. Electrifying control is then performed using the restricted ratio. When electrifying the fixing heater immediately after the power has been turned on, a power correspondence electrifying duty ratio is set according to a first voltage. Electrifying control is then performed using the set power correspondence electrifying duty ratio.

Abstract: An image forming apparatus of the present invention includes a pair of support plates supporting the rotary shaft of a photoconductive drum at axially opposite ends of the drum. One of the support plates is openable away from the body of the apparatus and loaded with a contact forming member including a current feed path for feeding a current from a high-tension power supply for charging to a charge roller, a wiring forming a current return path that allows a current to flow from the photoconductive drum to the ground of the power supply, and a plurality of contacts where the wiring and drum contact each other. A current flowing through the current return path is sensed to execute feedback control to the output of the high-tension power supply.

Abstract: An image forming apparatus including an image bearing member configured to bear an electrostatic latent image; a charging device configured to charge the image bearing member by applying a DC voltage overlapped with an AC voltage to the image bearing member; an AC current detector configured to detect an AC current flowing through the image bearing member on a ground side of the image bearing member; a light irradiating device configured to irradiate the charged image bearing member with imagewise light to form the electrostatic latent image on the image bearing member; a developing device configured to develop the electrostatic latent image with a developer comprising a toner to form a toner image on the image bearing member; a transferring device configured to transfer the toner image onto a receiving material; and a cleaning device configured to clean a surface of the image bearing member.

Abstract: A charging apparatus, process cartridge, and image forming apparatus with which current fluctuation values in the charging current can be suppressed, and image defects caused by filming and the like can be prevented, by specifying a permissible gap fluctuation value by quantitatively ascertaining the relationship between the fluctuation value in charging current and the fluctuation value in the gap between the photosensitive body and the charging roller. In a charging apparatus equipped with a charging roller provided at a minute gap away from a photosensitive body, for performing charging, the relationship Gmax?Gmin?30 (?m) is satisfied when the gap (?m) between the charged side of the photosensitive body and the charging side of the charging roller has a maximum value Gmax (?m) and a minimum value Gmin (?m).

Abstract: An electrophotographic image forming apparatus includes a device to set a temperature correspondence electrifying duty ratio relative to a fixing heater of a fixing device according to a detected temperature of the fixing device. A device is included to set a power corresponding electrifying duty ratio relative to the fixing heater, according to a detected voltage of the commercial power source. A device is additionally included to compare the temperature correspondence electrifying duty ratio and the power correspondence electrifying duty ratio. When the temperature correspondence electrifying duty ratio is equal to or larger than the power correspondence electrifying duty ratio, it is restricted with the power correspondence electrifying duty ratio to obtain a restricted electrifying duty ratio. Electrifying control relative to the fixing heater is then performed using the restricted ratio.

Abstract: A color laser printer includes a transfer belt unit including a transfer belt with reference marks, and a drive mechanism for the transfer belt, wherein the transfer belt unit includes a data storage unit (EEPROM) that stores color correction data and position correction data. When the transfer belt unit is new or replaced, corrections for color difference and position difference are performed based on the color correction data and the position correction data.

Abstract: There is provided an ink-type recording apparatus in which an intensity of light emitted by a photoelectric sensor is controlled to fall within an appropriate range so as to detect an ink-end mark at an appropriate sensitivity. A light-emitting element emits light toward a recording paper. A light-receiving element converts an intensity of the received light into an output current having a level corresponding to the intensity of the light. A current/voltage converting unit converts the output current into a voltage. A digitizing unit digitizes a level of the voltage into a digital value which is one of consecutive numbers from 0 to a predetermined maximum number. A ratio of the digital value to the predetermined maximum number is calculated. An input current supplied to the light-emitting element is varied so that an intensity of the light emitted by the light-emitting element is varied in accordance with the ratio.