stated differently it is divided into sections each having two columns and two dots are formed in every other section at the next row dot forming sections and dot non forming sections are located at opposite positions to the positions at the one row that is dots are not formed in a section having a dot forming section immediately above and dots are formed in a section having a dot non forming section immediately above for example at the 195th row dots are formed at the 1st and 2nd columns not formed at the 3rd and 4th columns and formed at the 5th and 6th columns at the next 196th row dots are not formed at the 1st and 2nd columns formed at the 3rd and 4th columns and not formed at the 5th and 6th columns likewise at the 197th row dots are formed at the 1st and 2nd columns not formed at the 3rd and 4th columns and formed at the 5th and 6th columns even with this arrangement dots are more prone to overlap with each other in the main scanning direction than in the auxiliary scanning direction therefore the column interval a can be set longer than the row interval b the row interval b is controlled by a signal that is supplied to the lf motor drive circuit 41 which controls the lf motor 40 the column interval a is controlled by a signal that is supplied to the cr motor drive circuit 39 which controls the cr motor 16.