| 摘要 |
PURPOSE:To make an operator to exchange the paper at a proper time point possible, by displaying the residue of paper after a paper shortage signal is produced. CONSTITUTION:An electronic cash register is provided with a keyboard 1, a display 2, a printer 3, a paper shortage detector 4, A CPU5, a memory 6, etc. The detector 4 transmits the paper shortage signal to the CPU5 when the residue of the printing paper is less than a prescribed level. The CPU5 sets the paper shortage flag in a memory 6 at 1 and then calculates the printable line number of the printing paper to store it in the printable area of the memory 6. Then the contents of the printable area is used to display a paper shortage message at the display 2. If the contents of the printable area is not 0, the printing is still possible. Thus the printing is carried out, and the contents of the printable area is subtracted by 1. In such way, the effective use of the printing paper is attained, and at the same time the paper shortage occurring in the course of printing can be avoided. |
