JPS6460878A - Method for detecting reference position of head - Google Patents

Abstract

PURPOSE:To accurately move a head to a reference position in an error within a quantity of travel by one pulse of a stepping motor, by using a rotary position sensor and a home position sensor. CONSTITUTION:At the time of returning the head 42 from an arbitrary position to the reference position, a first detecting means (rotary position sensor) 64 which rotates the stepping motor 34 at every constant angle by a weak exciting pattern of one cycle which sets a prescribed excitation phase as reference discriminates whether or not it detects the part to be detected of a rotary member, and executes such operation repeatedly until the part to be detected is detected. Next, the stepping motor 34 is rotated at every constant rotation, and the head 42 is moved in the direction of the reference position track by track, and also, a second detecting means (home position sensor) 69 discriminates whether or not it detects the movement of the head 42 to a prescribed position at every movement of track, and executes such operation repeatedly until the movement to the prescribed position is detected. And the position of the head after that is set as the reference position. In such a way, it follows that the head 42 can be positioned at an arbitrary track on a recording medium.