| 摘要 |
PURPOSE:To eliminate dot-type impact forces, ensure favorable heat dissipation from magnetic coils and a uniform ink film thickness and contrive higher printing quality, by selectively driving a plurality of needles having tip parts located at a magnetic ink film formed in a magnetic field slit, and providing the magnetic coils on the upper side of magnetic poles. CONSTITUTION:When a needle magnet 11 is energized in a pulsed manner based on a printing command, a magnetic ink 22 adhered to a tip part 17 of a needle 15 driven is adhered to a recording paper, forming a dot. Upon returning to an original position, the tip part 17 is again located in a magnetic ink film 24, and is wetted by the ink 22. With the operations repeated, printing is conducted in a noiseless manner. A magnetic coil 18 is located on the upper side of a magnetic pole 20, so that the heat generated by the coil is dissipated into the surrounding air, and a rise in temperature can be made small. In this way, the thickness of the magnetic ink film 24 formed in a magnetic field slit 19 is fixed, printing quality is enhanced, line breakage accidents are prevented from occurring in the coil 18, and it is made easy to find deterioration or breakage of the coil. |
