| 摘要 |
<p>A device for controlling an access operation of an information recording and reproducing device to a target position for rough access in a disk-shaped recording medium (102) prior to a precision access to a final target position. The access control device has a controller (209), which determines whether an access distance for rough access is long or short by comparing it with a reference value. The device has first and second reference velocity tables (205). The first table is used to generate first reference velocity when the access distance is long, and the second table is used to generate second reference velocity whose gradient is smaller than that of the first reference velocity when the access distance is short. An actual travel velocity of a head or other recording/reproducing portion (102) is detected by a velocity detector. While the head is traveling, a scale (203) emits pulses and a counter (204) counts them. A midpoint detector (210) detects an actual midpoint of the access distance based on the output from the counter (204) and the access distance. The head (102) is accelerated till the midpoint and then decelerated according to the first or second table. The travel velocity of the head is always regulated by a head drive mechanism (103, 208, 201) based on a comparison result by a comparator (207) which compares the output from the first or second table with the actual travel velocity of the head.</p> |
