Abstract: An image forming apparatus includes an engine unit to perform an image forming job; an engine control unit to control the operation of the engine unit; a brushless direct current (BLDC) motor to drive the engine unit; a sensor unit to sense electric angle information and driving velocity information of the BLDC motor; a communication interface to receive a digital control command with respect to the BLDC motor from the engine control unit; a driving signal unit to generate a driving signal to control the BLDC motor; and a digital control unit to control the operation of the driving signal unit in a digital phase locked loop (PLL) manner for feedback controls the BLDC motor, based on the received digital control command, the detected electric angle information and the driving velocity information and a digital gain value as a control factor with respect to the BLDC motor.

Abstract: A method for color registration includes determining if color registration is necessary, and if color registration is necessary, rotating an image forming medium and setting an optimum luminance of a registration sensor with respect to a rotating surface of the image forming medium, confirming an area with an undesirable surface condition on the image forming medium using luminance detected with respect to the rotating surface of the image forming medium during the setting of the optimum luminance, forming a preset mark for color registration adjustment excluding the area confirmed to have an undesirable surface condition, and carrying out color registration adjustment using the optimum luminance set with respect to the formed mark.

Abstract: A control method of a host device that avoids an error part through a user interface unit to use an image forming apparatus, an image forming system, an image forming apparatus and a host device employing the same, the control method including: requesting error information from the image forming apparatus in the host device; and displaying the error information of the image forming apparatus received from the image forming apparatus on a user interface unit of the host device.

Abstract: A method for color registration includes determining if color registration is necessary, and if color registration is necessary, rotating an image forming medium and setting an optimum luminance of a registration sensor with respect to a rotating surface of the image forming medium, confirming an area with an undesirable surface condition on the image forming medium using luminance detected with respect to the rotating surface of the image forming medium during the setting of the optimum luminance, forming a preset mark for color registration adjustment excluding the area confirmed to have an undesirable surface condition, and carrying out color registration adjustment using the optimum luminance set with respect to the formed mark.

Abstract: An image forming apparatus includes an engine unit used for performing an image forming job, an engine control unit which controls the operation of the engine unit, a brushless direct current (BLDC) motor which drives the engine unit, a sensor unit which senses the driving information of the BLDC motor, a communication interface unit which receives a digital control command with respect to the BLDC motor from the engine control unit, a driving signal unit which generates a driving signal to control the BLDC motor, and a digital control unit which controls the operation of the driving signal unit in a digital PLL manner, based on the received digital control command, the detected driving information and a digital gain value as a control factor with respect to the BLDC motor.

Abstract: A control method of a host device that avoids an error part through a user interface unit to use an image forming apparatus, an image forming system, an image forming apparatus and a host device employing the same, the control method including: requesting error information from the image forming apparatus in the host device; and displaying the error information of the image forming apparatus received from the image forming apparatus on a user interface unit of the host device.