Method and apparatus for driving printer head and image formation

An image forming apparatus, comprising:

• a printer head comprising printing elements;
• a data input unit for receiving image data of an image;
• and
• a control unit for providing control signals to sequentially drive the printing elements by dividing the printing elements into N driving groups according to the input image data,
• wherein the control unit comprises:
• a memory for storing image data;
• a line analyzer for reading the image data from the memory and calculating a number of driving groups among the N driving groups, wherein at least a first predetermined number of printing elements are driven for each line of print;
• a page analyzer for calculating a number of print lines wherein the calculated number of driving groups is not less than a second predetermined number;
• and
• a group determiner for increasing the number of N driving groups if the calculated number of print lines is not less than a third predetermined number.

A computer readable medium having stored thereon instructions for sequentially driving a plurality of printing elements of a printer head, the instructions comprising:

• dividing printing elements into N driving groups;
• calculating a number of driving groups among the N driving groups in which at least a first predetermined number of printing elements are driven for each line to be printed;
• calculating a number of print lines in which the calculated number of driving groups is at least a second predetermined number;
• and
• increasing the number of N driving groups if the calculated number of print lines is at least a third predetermined number.