| 摘要 |
PURPOSE:To obtain a printer capable of continuously varying the density gradation of characters or figures printed, by a construction wherein contact pressures of conical or pyramidal projections generated by locally energizing a piezoelectric plate are exerted on a printing surface of a printing medium to form on the printing surface dots each of which consists of a set of minute images each having an area corresponding to the contact area of each of the projections pressed against the printing surface. CONSTITUTION:A piezoelectric plate 2 is provided with a multiplicity of minute conical or pyramidal projections 5...5 over the entire surface of one side thereof. The plate 2 is locally expanded by applying a voltage. By applying a voltage to desired ones of electrode pins 3...3 and controlling the voltage, dots 8a-8c consisting of sets of minute images 7a... 7c... can be formed on a printing surface of a printing medium, and printing can be performed by forming a set of such dots. Since the printed density of the dots is varied by controlling the voltage, characters or figures having a continuous density gradation can be printed through varying the printed density of the dots themselves. |
