| 摘要 |
PROBLEM TO BE SOLVED: To provide a picture forming device capable of discriminating abnormality related to a controlled part and abnormality caused by external noise, and thereby urging to cope with the abnormality of the controlled part. SOLUTION: This picture forming device detects a state and its level in which external noise is applied to the harness 25, 29 between a board of a main control part and that of a sub-control part. It detects the state of the pulse signal line 29 from the time of turning on a power source. Ta is defined as a minimum time of T2-T1 (Fig. 3: H-level signal), and Tb is defined as a maximum time of T2-T1 (Fig. 3: H-level signal), and (1) Ta<T2-T1<Tb is defined as a state wherein the external noise (S11) is not applied, and (2) Ta<T2-T1, Tb<T2-T1 are defined as a state wherein the external noise (S12) is applied. In the case of (2), strong external noise is picked up at the level H, the level H instantaneously causes a state of L-level signal (Fig. 3: V1). Thus, it is possible to detect whether or not the external noise is applied to the Internet harness between the board of the main control part 30 and that of the sub-control part 31. |
