Apparatus to measure an amount of toner consumed and method thereof

A toner consumption measuring apparatus having an effective signal generating unit to receive inputs of printing data and a video clock signal 'VCLK' to synchronize the printing data, and generating a count effective signal; a counting unit to count the generated count effective signal and to calculate a number of pixels of the printing data; a coefficient memory to store at least a toner consumption coefficient of a unit of pixel 'K' which is set in advance; and a printer control unit to determine an image pattern compensation coefficient by using the differences of numbers of the pixels of adjacent lines of a page in printing of every page, and calculating a toner consumption with applying a proper weight in accordance with the determined image pattern compensation coefficient. The image pattern compensation coefficient can be determined based on an average 'A', which is obtained by averaging the differences of numbers of pixels of adjacent lines in accordance with the number of pixels of a page 'Npixel', or based on an image pattern which is predetermined based on the mode of operation and the average 'A'. The image pattern compensation coefficient is determined as a plurality of image pattern compensation coefficients 'Kf' stored in the coefficient memory. By measuring the toner consumption with applying different weights in accordance with the average 'A' per page and/or varying modes of operation, errors in the toner consumption measurement can be prevented, and more accurate measuring can be provided.