| 摘要 |
PURPOSE:To easily perform contrast adjustment without using fixed and variable resistors by setting contrast adjusting voltage by an output of a D/A converter, using an existing key switch part of an operating part in the case of setting, and storing a preset value in a non-volatile memory. CONSTITUTION:An existing key switch part 23 in an operating part 22 is used, and a contrast adjusting preset value is fed to a transceiving interface part 29 through a controller 14. A CPU28 in a printer control part 15 writes contrast information, interrupted relating to a non-volatile memory 32, through a non- volatile memory interface part 31. In a D/A converter 33, in the case of reading a contrast control data stored in the non-volatile memory 32 by receiving a command from the CPU28, the data is converted into analog voltage to determine contrast of a display character in a liquid crystal display part 24 as contrast adjusting voltage Vo through an analog interface part 34. In this way, adjustment is facilitated with no contrast setting fixed and variable resistors required. |
