| 摘要 |
PURPOSE:To detect the head height position with a high precision by making a magnetic head opposite to the fixed magnetic head in the reference height position so that their magnetic gaps may be rectangular to each other and by detecting the leak magnetic flux from one magnetic head by the other. CONSTITUTION:Detecting head 18 is fixed and installed in the reference height with a form by which magnetic gap gb is rectangular to magnetic gap ga of head 15 such as a rotary head of a VTR, and the leak magnetic flux dependent upon the recording current of opposite head 15 is detected by head 18. The head height position is detected with a high precision by the detection signal which changes the amplitude and the phase according to the positional slippage quantity and the vertical direction of height of head 15, and this detection signal is processed by a level detection circuit, a phase detection circuit, a polarity decision circuit, a polarity determining circuit, etc., to control the bimorph voltage, thereby controlling the height position of the head with a high precision. Then, even if the rotary head is used to perform preproducing in a speed different from the speed of recording, the head performs accurately tracking of tracks at a recording time. |
