| 摘要 |
PURPOSE:To prevent the lowering in printing quality and the damage of a magnetic medium by always holding a constant air gap, by contacting the roller attached to a multihead support member through a leaf spring with the magnetic medium and measuring the strain quantity or load applied to the leaf spring and moving a multihead to a direction negating the difference with a reference value. CONSTITUTION:Now, when a multihead support member 13 is moved to the direction shown by an arrow X by a drive system 18, rollers 14, 14' are contacted with a magnetic medium 11. At this time, the air gap between the magnetic medium 11 and a multihead 12 is set to an initial gap delta. When the multihead support member 13 is further moved to the direction X, the spring part of roller support metal fittings 15, 15' are bent and the air gap comes to a set gap delta1. In this case, because the relation between the strain measured values by the strain gauges 16, 16' adhered to the roller support metal fittings 15, 15' and the air gaps is almost proportional relation, the variation in the air gaps can be measured if strain quantity is measured. Because strain quantity can be measured by voltage, feedback control can be performed by comparing the strain quantity with reference voltage corresponding to the set gap delta1. |
