Image forming apparatus

An image forming apparatus comprising:

• a plurality of image carriers;
• a plurality of polygonal mirror drive motors each configured to drive a polygonal mirror to scan each image carrier with a laser beam emitted from a light source image;
• an intermediate transfer member configured to transfer thereto a toner image formed on each image carrier;
• a drive roller configured to drive the intermediate transfer member, wherein a perimeter of the intermediate transfer member is substantially an integral multiple of a perimeter of each of the plurality of image carriers and the drive roller;
• an intermediate transfer member position detection unit configured to detect a position of the intermediate transfer member to output an image forming operation start signal;
• a pattern detection unit configured to detect a registration correction pattern formed on the intermediate transfer member based on the image forming operation start signal;
• a misregistration variation detection unit configured to read the registration correction pattern detected by the pattern detection unit based on the image forming operation start signal and to generate a reference clock signal based on the read registration correction pattern;
• and
• a polygonal mirror drive motor control unit configured to adjust a rotation speed of each of the plurality of polygonal mirror drive motors based on the reference clock signal generated by the misregistration variation detection unit.

An image forming apparatus comprising:

• an image carrier;
• a polygonal mirror drive motor configured to drive a polygonal mirror to scan the image carrier with a laser beam emitted from a light source;
• a transfer material conveying member;
• a drive roller configured to drive the transfer material conveying member, wherein a perimeter of the transfer material conveying member is substantially an integral multiple of a perimeter of each of the image carrier and the drive roller;
• a transfer material conveying member position detection unit configured to detect a position of the transfer material conveying member to output an image forming operation start signal;
• a pattern detection unit configured to detect a registration correction pattern formed on the transfer material conveying member based on the image forming operation start signal;
• a misregistration variation detection unit configured to read the registration correction pattern detected by the pattern detection unit based on the image forming operation start signal and to generate a reference clock signal based on the read registration correction pattern;
• and
• a polygonal mirror drive motor control unit configured to adjust a rotation speed of the polygonal mirror drive motor based on the reference clock signal generated by the misregistration variation detection unit.

An image forming apparatus comprising:

• a plurality of image carriers;
• a plurality of polygonal mirror drive motors each configured to drive a polygonal mirror to scan each image carrier with a laser beam emitted from a light source image;
• a transfer material conveying member;
• a drive roller configured to drive the transfer material conveying member, wherein a perimeter of the transfer material conveying member is substantially an integral multiple of a perimeter of each of the plurality of image carriers and the drive roller;
• an transfer material conveying member position detection unit configured to detect a position of the transfer material conveying member to output an image forming operation start signal;
• a pattern detection unit configured to detect a registration correction pattern formed on the transfer material conveying member based on the image forming operation start signal;
• a misregistration variation detection unit configured to read the registration correction pattern detected by the pattern detection unit based on the image forming operation start signal and to generate a reference clock signal based on the read registration correction pattern;
• and
• a polygonal mirror drive motor control unit configured to adjust a rotation speed of each of the plurality of polygonal mirror drive motors based on the reference clock signal generated by the misregistration variation detection unit.