| 摘要 |
PURPOSE:To prevent intervention of invalid shift action and to improve a printing efficiency of a serial printer by storing only the requirement for the exchange of a shift code and by receiving a shift requirement after the printing requirement of a character has arrived. CONSTITUTION:A code inputted into a register CREG of a serial dot printer is held, and when this code is a shift code, it is compared with a shift code being currently effective in a shift storage register SREG within a state storing part SECT in a shift state comparator SCOM. Further, when a newly inputted code value is different from a value of the register SREG, a signal set in an exchange storage register XREG is stored in a shift temporary storage register NREG, and if councide, the requirement for the exchange of the register XREG is erased. Still more, when in a shift code comparator CCOM, a shift requirement for a value inputted into printing character codes is received, an exchange trigger is sent to a state controlling circuit SCNT to prevent the intervention of invalid shift action. |
