of the tracking pattern generator 410 in a case like this this circuit obviates the need for a frequency divider for dividing the frequency of a block in synchronism with the bd signal which is necessary in the above example a tracking pattern mixed in this example is in synchronism with the vdo signal 6 as an image signal so the printed state is as shown in fig1 although a preferred embodiment of the present invention has been described above the present invention naturally includes arbitrary combinations of some of the abovementioned arrangements also both the forced on dot and the forced off dot are smaller than one dot in the above embodiment however these dots can be larger than one dot e g can be 11 8 dots or 5 4 dots furthermore pclk output from the frequency divider 435 can be entirely different from the image transfer rate if this is the case the size and interval of tracking pattern dots are not integral multiples of an image dot this is established because not absolute dimensions but a printing interval ratio is used to extract codes from the positions of tracking pattern dots the use of a clock signal of a quartz oscillator by another circuit makes any additional quartz oscillator unnecessary this can realize an inexpensive arrangement in the above embodiment after the frequency of the output clock from the quartz oscillator 413 is raised by the frequency multiplier 434 the clock is synchronized with the horizontal sync signal to set the phase jitter of a tracking.