| 摘要 |
PURPOSE:To prevent a printing operation from being continued in a misprinting condition, by stopping the printing operation on detecting an abnormal condition such as breakage or bending of a spoke of a daisy type wheel. CONSTITUTION:A light-emitting element 9 and a light-receiving element 10 are so arranged that only when a type 5b is accurately positioned on the line of the moving direction P of a hammer in a hammer mechanism part 6, light from the light-emitting element 9 is reflected by a reflector 8 provided on the lower side of the type 5b to reach the light-receiving element 10. Therefore, even when the wheel spoke 5a fitted with the type selected is brought to a printing position (hammer striking position) and is stopped there, if the spoke 5a is broken or bent, the light from the element 9 is not detected by the element 10, so that the abnormal condition in the daisy type wheel 5 can be detected. Based on the detection signal, it is judged by a microprocessor whether a normal printing operation can be performed after the selected spoke 5a is stopped at the hammer striking position, and an alarm is issued when the normal printing operation can not be performed. |
