| 摘要 |
PURPOSE:To print with a constant printing diameter at all times with respect to recording paper of various kinds and qualities and improve the printing quality of the system by a method wherein a detecting means to detect the degree of smoothness of the recording paper is provided to control the exciting voltage of a vibrator with the output signal thereof. CONSTITUTION:Light from a light source 10 is changed into parallel light beams to project the recording paper 6 and a photodetector 11 is disposed at the reflecting position of the light beams to detect the amount of reflection which is proper to the recording paper. On the other hand, the other photodetector 12 is disposed at the other position to detect the amount of irregular reflection to compare the output signals of both of the photodetectors 11, 12 with a differential amplifier and/or an analog comparator 13. If the degree of smoothness of the recording paper is bad, the output signal ratio of the photodetectors 12/11 becomes bigger in accordance with the badness thereof. Accordingly, the printing with the same diameter may be carried on at all times regardless of the kind of the recording paper by controlling a vibrator driving circuit 5 with said output signal to change the exciting voltage of the supersonic vibrator 2. |
