| 摘要 |
A printer mounted on an electronic cash register (ECR) performs printing on printing paper by moving a print head left to right and right to left, i.e. bidirectionally. The printer uses right (RR) and left reset signals (RL) to determine the print start position and printing direction of the print head, the right (RR) and left reset signals (RL) being fed alternately and regularly to the driving circuit (16) for the print head for performing bidirectional printing, thereby assuring correct bidirectional printing. The right (RR) and left reset signals (RL) are constantly monitored. If the reset signals (RR,RL) of the same kinds are successively detected, it is judged that trouble has occured, hampering correct bidirectional printing, and notice is issued accordingly. |
