is preferably at least equal to that of the recording elements in the recording head the output of said sensor 35 is used for detecting the presence of discharge failure in the recording head and whether the unevenness of printing exceeds a predetermined level and the aforementioned discharge recovery operation is conducted if necessary now the normal recording sequence will be explained with reference to fig1 and 2 referring to fig1 when a recording material sensor not shown positioned in front of the transport rollers 5 detects a recording material fed from the roll 2 or the cassette 7 the transport rollers 5 and the sub scanning roller 6 advances the recording material by a predetermined amount until the leading end thereof reaches the sub scanning roller 6 when the leading end of the recording material 22 reaches the sub scanning roller 6 in fig2 the carriage 9 and the ink supply system 11 are respectively driven by the motors 13 17 in the scanning direction to the right in fig2 at the same time the recording heads 9c 9m 9y 9bk effect recording with a width i according to image signals after recording of a line the carriage 9 and the ink supply system 11 are returned to a predetermined position at the left side in fig2 and the recording material 22 is simultaneously advanced by the motor 21 by an amount precisely corresponding to said printing width i after the above explained sequence of recording and recording material transportation by a predetermined number of cycles the recording material 22 is discharged from the apparatus in the following an explanation will be given on.