Abstract: An image forming apparatus includes an image former configured to perform printing using an LPH (LED Print Head) that emits light to a photosensitive drum based on a sync signal; a sensor configured to sense a cyclical speed of the photosensitive drum; and an LPH controller configured to adjust a generation gap of the sync signal using the sensed cyclical speed.

Abstract: An image forming apparatus includes an image former configured to perform printing using an LPH (LED Print Head) that emits light to a photosensitive drum based on a sync signal; a sensor configured to sense a cyclical speed of the photosensitive drum; and an LPH controller configured to adjust a generation gap of the sync signal using the sensed cyclical speed.

Abstract: An image forming apparatus includes a plurality of photosensitive media, a light source unit which comprises a plurality of light sources, a polygon mirror which deflects a plurality of beams output from the plurality of light sources into the plurality of photosensitive media using a plurality of reflective surfaces, a beam detector which receives beams reflected from the polygon mirror during a rotating process of the polygon mirror, and outputs a beam detection signal, and a horizontal sync signal generator which receives the beam detection signal and counts beam reflecting times during which the beams are reflected from the plurality of reflective surfaces, and compares the plurality of counted beam reflecting times with the compensation values calculated for the reflective surfaces, respectively, generates a horizontal sync signal for a corresponding reflective surface, and provides the horizontal sync signal to the light source unit.

Abstract: An image forming apparatus includes a plurality of photosensitive media, a light source unit which comprises a plurality of light sources, a polygon mirror which deflects a plurality of beams output from the plurality of light sources into the plurality of photosensitive media using a plurality of reflective surfaces, a beam detector which receives beams reflected from the polygon mirror during a rotating process of the polygon mirror, and outputs a beam detection signal, and a horizontal sync signal generator which receives the beam detection signal and counts beam reflecting times during which the beams are reflected from the plurality of reflective surfaces, and compares the plurality of counted beam reflecting times with the compensation values calculated for the reflective surfaces, respectively, generates a horizontal sync signal for a corresponding reflective surface, and provides the horizontal sync signal to the light source unit.

Abstract: An inkjet printer having a wide array head and an image forming method for use in the inkjet printer having the wide array head includes a nozzle group setting unit for grouping nozzles of the wide array head into N (N is an integer larger than 1) groups and grouping the N groups into K groups (K is an integer between 1 and N); a printing media sensing unit determining whether a rear edge of a current printing medium passes the nozzles of one of the K groups; and a printing media convey controller conveying a front edge of a next printing medium to the nozzles of the group K if the rear edge of the current printing medium passes the nozzles of the one of the K groups. Therefore, the nozzles of the wide array head are classified into groups, and the beginning and completion of the printing operation can be identified by the nozzle group unit, and thus, the printing can be performed at high speed.

Abstract: An image forming apparatus includes an array head part which includes a plurality of printer heads arranged to have a head gap and to print a line of print data, a partition part to partition the line of print data into predetermined sections based on a number of nozzles of the respective printer heads, a storage unit in which the print data partitioned into the predetermined sections are read out and written corresponding to a memory block, and a controller to generate a write pointer or a read pointer of the memory block based on the head gap of the respective printer heads.

Abstract: An array head type printer and a printing method using an array head type printer are provided. The array head type printer includes an array head with a plurality of unit heads for spraying ink according to received printing data, and a head control unit for distinguishing between used unit heads and unused unit heads and converting the printing data to data to be received by the unit heads determined to be in use. Since unit heads are inactivated in the inkjet array head printer when they do not correspond to a printing area, it is possible to reduce the power consumption for driving the unit heads.

Abstract: An inkjet printhead that enables a controller to determine whether or not refilled ink is qualified ink, an inkjet image forming apparatus that includes the inkjet printhead and a controller for controlling the operation of the printhead, and a method for performing maintenance operations in an inkjet image forming apparatus according to whether refilled ink is qualified ink or not are provided. The printhead includes an ink tank for storing ink, a plurality of nozzles for forming an image on a printing medium by ejecting the ink stored in the ink tank to the printing medium, and a memory for storing identity information for determining whether the ink stored in the ink tank is qualified ink or not. The controller determines whether the ink stored in the ink tank is qualified ink based on the identity information and controls the inkjet printhead to perform maintenance operations according to a mode for qualified ink or non-qualified ink based on the result of the determination.