Servo pattern writing method, control circuit, and magnetic disk apparatus
View Patent ↗According to one embodiment, a servo pattern writing method includes: moving a head from a first one of innermost and outermost circumferences of a medium to the remainder other than the first one while controlling a position of the head in accordance with a temporary pattern preliminarily written on the medium; calculating a junction between a servo pattern to be written from the innermost circumference and a servo pattern to be written from the outermost circumference based on a movement distance of the head; first writing the servo pattern from a second one of the innermost and outermost circumferences to the junction, while controlling the position of the head in accordance with the temporary pattern; and second writing the servo pattern from the remainder other than the second one to the junction, while controlling the position of the head in accordance with the temporary pattern.
1. A servo pattern writing method comprising:
moving a head from a first one of an innermost circumference and an outermost circumference of a medium to the remainder other than the first one while controlling a position of the head in accordance with a temporary pattern indicating information for controlling the position of the head, the temporary pattern being preliminarily written on the medium;
calculating a junction between a servo pattern to be written from the innermost circumference and a servo pattern to be written from the outermost circumference based on a movement distance of the moved head;
first writing the servo pattern from a second one of the innermost circumference and the outermost circumference to the junction, while controlling the position of the head in accordance with the temporary pattern, after moving the head to the second one; and
second writing the servo pattern from the remainder other than the second one to the junction, while controlling the position of the head in accordance with the temporary pattern, after moving the head to the remainder other than the second one.
2. The servo pattern writing method of claim 1 , wherein
the temporary pattern is a spiral pattern which is not a concentrically written pattern but is a pattern written in a spiral fashion continuously from the innermost circumference to the outermost circumference.
3. The servo pattern writing method of claim 1 , wherein
the moving includes controlling the position of the head by using a relative position error between the temporary pattern and the head,
the first writing includes controlling the position of the head in accordance with the temporary pattern by using the relative position error, and
the second writing includes controlling the position of the head in accordance with the temporary pattern by using the relative position error.
4. The servo pattern writing method of claim 1 , wherein the medium is a perpendicular magnetic recording medium.