| 摘要 |
PURPOSE:To widen a gradation range while reducing the lowering of a recording speed, by applying a plurality of drive pulses to an electromechanical converter in coincidence with a head inherent vibration cycle shorter than a min. response cycle corresponding to a density signal. CONSTITUTION:The light from a light source 2 is reflected from a manuscript 1 to enter a light detector 3 and the analogue density signal Da of the output from the light detector 3 is converted to a digital signal by an A-D converter 4 and the digital signal is set to a subtraction counter 5 where the clock signal CL with a pulse amplitude Tp and a cycle Tr outputted from a clock generating circuit 6 is counted. The clock signal CL corresponding to the density signal is applied to the base of a transistor 7 as a pulse line Dd and applied to a piezoelectric element 9 through charging resistance 8 to perform driving. By applying a plurality of drive pulses coincided with a head inherent vibration cycle shorter than a min. response cycle Tm in order to perform stable recording to the piezoelectric element, stable gradation recording is enabled without too much increasing the substantial response cycle Tm. |
