JPS5651374A - Printing pressure control device - Google Patents

Abstract

PURPOSE: To provide a uniform density of printing even if a style of printing characters is changed by a method wherein there are provided a change-over mechanism for a group of the printing pressures, control means for producing a printing pressure by shifting a printing pressure, and means for changing over said output to a plurality of steps and varying a printing pressure.

CONSTITUTION: For example, there are provided a resistance line change-over decoder analog switch 23 for changing over a printing pressure to 8 steps, micro computer control circuit 20 for setting a printing pressure to 6 steps and a change- over switch 26 for a group of printing pressures. Then, when signals of eight levels of binary data are fed, the switch 23 selects one of the separated eight lines to feed an electric current to one of the resistors R₁WR₈ to vary an input voltage of an amplifier 22. Transistor 24 transmits the variation to a hammer control circuit HMC to vary a printing pressure. If the group of printing pressure selects a high printing pressure level, six steps of printing pressure are produced for each of the levels under a high printing pressure. Because there is no combination of any analog elements, simplification of the constitution can be achieved.

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