a technique for removing vertical stripe artifacts generated in a liquid crystal display panel , more particularly a technique for compensating for and removing an inter - channel offset voltage of a column driver , which causes the vertical stripe artifacts , is disclosed . an offset voltage generated in each channel for driving each pixel of the lcd panel is detected for a whole signal path and offset voltages detected for all channels are compared and extracted according to a given timing sequence by a common signal comparator , thereby preventing the offset of the detection comparator and reducing a chip size of the column driver in contrary to the prior art . moreover , an inter - channel offset voltage is detected in a digital circuit mode , thereby compensating for process variations in a semiconductor chip manufacturing process in circuit terms .