| 摘要 |
PURPOSE:To judge abnormality of a head gap simply by an inclination of an upper frame based on defects of locking by a method wherein the head gap is detected at both end parts in a moving range of a head carrier, and a difference between respective detected values is compared with a difference between corresponding set values. CONSTITUTION:Under a state wherein an upper frame 1 and a lower frame 2 are locked by using lock levers 6, 6' and a reinforcing shaft 7, a head carrier 4 is moved along a carrier sliding shaft 3, and a head gap is detected at positions point A, point B of both ends. The head gaps of respective points A, B when the upper and lower frames 1, 2 are certainly locked are preliminarily detected to be stored as set values SA, SB. A difference (DA-DB) between detected values and a difference (SA-SB) between the set values are obtained. Further, a difference between those differences is obtained. Then, when that value exceeds a tolerable value C, abnormality of the head gap by defects of locking is considered to be present and execution of printing is forbidden. Further, issue of an error alarm and others are carried out. |
