Transfer position controlling apparatus, image forming device having the same and transfer position controlling method thereof

An image forming device comprising:

• a photoconductor to form a developer image;
• a transfer belt to transfer the developer image from the photoconductor to the transfer belt;
• a transfer position controlling unit to control a transfer position at which the developer image is transferred to the transfer belt,
• wherein the transfer position controlling unit comprises:
• an encoding part having a plurality of first encoding elements formed in a longitudinally spaced apart relation on a transfer belt, the plurality of first encoding elements moving along a moving path when the transfer belt rotates;
• a sensing part having a first detecting sensor for detecting the plurality of first encoding elements, the sensing part being disposed on the moving path of the plurality of first encoding elements;
• and
• a controller to determine a transfer start position at which a developer image is transferred to the transfer belt on the basis of a detection signal generated by the first detecting sensor when the first detecting sensor detects one of the plurality of first encoding elements after a printing command is input, and to control the device to form a developer image on the photoconductor according to the transfer start position.

A transfer position controlling method of an image forming device comprising the steps of:

• initiating the image forming device;
• detecting a second encoding element formed on a transfer belt with a second detecting sensor while initiating the image forming device;
• counting a number of detection signals generated by a first detecting sensor when the first detecting sensor detects a plurality of first encoding elements formed on the transfer belt, from a time when the second detecting element is detected;
• determining whether a printing command is input;
• controlling a transfer start position at which a first developer image of a plurality of developer images is transferred to the transfer belt on the basis of a position of the transfer belt corresponding to a first encoding element detected when the printing command is input;
• and
• controlling transfer start positions at which the remaining developer images of the plurality of developer images are transferred to the transfer belt on the basis of the number of detection signals generated by the first detecting sensor counted from the time when the second detecting element is detected through a time when the printing command is input.