Acoustic Diagnostics for Pivot Lift
Original Publication Date: 1985-Aug-01
Included in the Prior Art Database: 2005-Feb-19
Acoustically diagnosing armature pivot lift permits dynamic adjustment of the armature preload of assembled multiple actuators, such as printheads. Fig. 1 shows a schematic of a typical magnetic actuator, in which improper pivot preload W can be a failure mode, mounted in a test setup. Optimal pivot preload just prevents pivot lift during armature movement. Fig. 2 shows armature motion M, applied current I, and related acoustics with sufficient armature preload to prevent pivot lift. Note peaks at P1 and P2. Fig. 3 shows armature motion M, applied current I, and related acoustics with reduced armature preload. Note peak P3 which occurs at a relatively low frequency. Acoustic frequency spectrum changes transduce the pivot lift and may be analyzed to calculate preload adjustments.