Abstract: An image forming apparatus includes a skew correcting unit that performs skew correction by dividing an input image that has undergone a halftone process into image data in a predetermined skew correction area in a main scanning direction and by shifting the image data in the skew correction area in a sub-scanning direction; an edge detecting unit that detects whether a pixel at a division position is an edge pixel based on concentrations of a set of pixels including the pixel at the division position; a correction area determining unit that, if detected that the pixel at the division position is the edge pixel, determines a correction area that is an area of pixels including the edge pixel to be subjected to concentration correction within the skew correction area; and an edge correcting unit that corrects concentrations of the pixels within the correction area.

Abstract: An image forming apparatus capable of minimizing degradation in density correction as a part of skew correction includes a noise-occurrence determining unit, a correction-target-pixel selecting unit, a density correcting unit, and a phase correcting unit. When the noise-occurrence determining unit determines that noise would appear, the density correcting unit performs density correction on a correction target pixel that is determined by the correction-target-pixel selecting unit. The phase correcting unit corrects an output point in time of image data of the density-corrected correction target pixel in a pixel period during which the image data can be output so as to output the image data at a position displaced away from a shift position or toward a shift position.

Abstract: An image forming apparatus, includes a transferring belt where a color image is formed; a conveyance belt transferring a recording medium where a monochrome image is transferred; a velocity difference detecting part detecting a velocity difference between the transferring belt and the conveyance belt; a determining part determining whether the velocity difference detected by the velocity difference detecting part is equal to or greater than a designated value; a velocity adjusting part adjusting the velocity difference so that the velocity difference becomes lower than the designated value in a case where the velocity difference is determined to be the designated value or more by the determining part; and a color correcting part correcting a shift of colors between the color image and the monochrome image by using the transferring belt and the conveyance belt whose velocities are adjusted by the velocity adjusting part.

Abstract: An image forming apparatus, includes a transferring belt where a color image is formed; a conveyance belt transferring a recording medium where a monochrome image is transferred; a velocity difference detecting part detecting a velocity difference between the transferring belt and the conveyance belt; a determining part determining whether the velocity difference detected by the velocity difference detecting part is equal to or greater than a designated value; a velocity adjusting part adjusting the velocity difference so that the velocity difference becomes lower than the designated value in a case where the velocity difference is determined to be the designated value or more by the determining part; and a color correcting part correcting a shift of colors between the color image and the monochrome image by using the transferring belt and the conveyance belt whose velocities are adjusted by the velocity adjusting part.

Abstract: A pattern generating unit generates correction patterns on a transfer belt. Detection sensors detect the correction patterns, and amounts of magnification correction, amounts of misregistration in the main- and the sub-scanning direction are calculated. The amount of skew between each of colors is then calculated, and a position where an image is divided and a direction for shifting a divided image are determined. Possible dividing-positions are also determined, and a calculated dividing position and each of the possible dividing positions are compared with one another. Then, a possible dividing position closest to the calculated dividing position is set as an actual dividing position.

Abstract: An image forming apparatus includes a skew correcting unit that performs skew correction by dividing an input image that has undergone a halftone process into image data in a predetermined skew correction area in a main scanning direction and by shifting the image data in the skew correction area in a sub-scanning direction; an edge detecting unit that detects whether a pixel at a division position is an edge pixel based on concentrations of a set of pixels including the pixel at the division position; a correction area determining unit that, if detected that the pixel at the division position is the edge pixel, determines a correction area that is an area of pixels including the edge pixel to be subjected to concentration correction within the skew correction area; and an edge correcting unit that corrects concentrations of the pixels within the correction area.

Abstract: An image forming apparatus includes a rotating member that is rotatable, a communication medium, and a receiving unit. The communication medium that is attached to an outer circumference of the rotating member stores therein information on the rotating member and relays the information on the rotating member via wireless communication. The receiving unit receives the information on the rotating member from the communication medium.

Abstract: An image forming apparatus capable of minimizing degradation in density correction as a part of skew correction includes a noise-occurrence determining unit, a correction-target-pixel selecting unit, a density correcting unit, and a phase correcting unit. When the noise-occurrence determining unit determines that noise would appear, the density correcting unit performs density correction on a correction target pixel that is determined by the correction-target-pixel selecting unit. The phase correcting unit corrects an output point in time of image data of the density-corrected correction target pixel in a pixel period during which the image data can be output so as to output the image data at a position displaced away from a shift position or toward a shift position.

Abstract: A pattern generating unit generates correction patterns on a transfer belt. Detection sensors detect the correction patterns, and amounts of magnification correction, amounts of misregistration in the main- and the sub-scanning direction are calculated. The amount of skew between each of colors is then calculated, and a position where an image is divided and a direction for shifting a divided image are determined. Possible dividing-positions are also determined, and a calculated dividing position and each of the possible dividing positions are compared with one another. Then, a possible dividing position closest to the calculated dividing position is set as an actual dividing position.

Abstract: An image forming apparatus includes a rotating member that is rotatable, a communication medium, and a receiving unit. The communication medium that is attached to an outer circumference of the rotating member stores therein information on the rotating member and relays the information on the rotating member via wireless communication. The receiving unit receives the information on the rotating member from the communication medium.

Abstract: A communication apparatus comprising a semiconductor DAA, a system unit and a modem is provided. The DAA has a line control unit connected to a communication line network and a serial IF unit connected to the line control unit via an isolating circuit, and controls the communication line network and transmits and receives data. The modem modulates and demodulates the transmitted and received data. The system unit controls the semiconductor DAA and the modem. The line control unit includes a line current detector for detecting a line current and a line voltage detector for detecting a line voltage. The system unit obtains line impedance based on the line current and the line voltage, and adjusts the transmission level of the modem in accordance with the obtained line impedance.

Abstract: An image forming apparatus is disclosed that is capable of automatically acquiring thickness variation data of a transfer belt newly installed in the image forming apparatus without manual operation of setting the thickness variation data, and capable of controlling the moving speed of the newly installed transfer belt to be constant based on the acquired data so as to output images of high quality constantly. The transfer belt includes a belt information mark recorded with information used for creating rotational speed correction data, and the rotational speed control unit includes a storage unit configured to store the rotational speed correction data. A rotational speed control unit is provided that includes a belt information reading unit for reading the belt information mark to obtain the belt information, and a correction data updating unit for updating and storing the rotational speed correction data based on the obtained belt information.

Abstract: A belt driver includes a belt having a constant number of regions dividing the belt in the perimeter direction thereof. A plurality of marks have different widths in the perimeter direction and are formed in the respective regions of the belt. A sensor detects the marks on the belt. A storage part stores in advance the relationship between position information of the belt and speed variation of the belt for one rotation of the belt. Speed variation of the belt is reduced by correcting the drive speed of the belt based on the relationship. The position of the belt is detected from a time required for one of the marks to pass the sensor, and speed correction control of the belt is performed in accordance with the detected position.

Abstract: An image forming apparatus is disclosed that is capable of automatically acquiring thickness variation data of a transfer belt newly installed in the image forming apparatus without manual operation of setting the thickness variation data, and capable of controlling the moving speed of the newly installed transfer belt to be constant based on the acquired data so as to output images of high quality constantly. The transfer belt includes a belt information mark recorded with information used for creating rotational speed correction data, and the rotational speed control unit includes a storage unit configured to store the rotational speed correction data. A rotational speed control unit is provided that includes a belt information reading unit for reading the belt information mark to obtain the belt information, and a correction data updating unit for updating and storing the rotational speed correction data based on the obtained belt information.

Abstract: A belt driver includes a belt having a constant number of regions dividing the belt in the perimeter direction thereof. A plurality of marks have different widths in the perimeter direction and are formed in the respective regions of the belt. A sensor detects the marks on the belt. A storage part stores in advance the relationship between position information of the belt and speed variation of the belt for one rotation of the belt. Speed variation of the belt is reduced by correcting the drive speed of the belt based on the relationship. The position of the belt is detected from a time required for one of the marks to pass the sensor, and speed correction control of the belt is performed in accordance with the detected position.

Abstract: A communication apparatus comprising a semiconductor DAA, a system unit and a modem is provided. The DAA has a line control unit connected to a communication line network and a serial IF unit connected to the line control unit via an isolating circuit, and controls the communication line network and transmits and receives data. The modem modulates and demodulates the transmitted and received data. The system unit controls the semiconductor DAA and the modem. The line control unit includes a line current detector for detecting a line current and a line voltage detector for detecting a line voltage. The system unit obtains line impedance based on the line current and the line voltage, and adjusts the transmission level of the modem in accordance with the obtained line impedance.