| 摘要 |
PURPOSE:To move an information reading part to a correct access position of desired information to set the recording sequence of the desired recording information, and to assure an accurate and high-speed access of the recording information, by securing a high-speed shift with no contact for the reading part after setting a set band code, repeating the alternate reading of the extracted band code, and then controlling the high-speed shift of the reading part on the basis of the result of comparison between both band codes. CONSTITUTION:The head band codes (1)-(10) of recording information are positioned as shown in a diagram along with the total reading time set at 60min and a pickup (1) set at a point A. Under such conditions, the 9th band code is set to an address setting circuit 6b. Then 30min are set to a comparator 5c via a route function as shown by solid line arrows. Thus the pickup (1) moves at a high speed to a point B with no contact. When the measuring time information at the reading position which is delivered to the circuit 5c from an arithmetic circuit 10 is coincident with 30min, the information has a contact with a disk (2) to extract a band code of a point B by the route function shown by double-line arrows. Then the 9th band code is compared with the 7th and code, and a forward mode is indicated to a control circuit 7c. The time information of 45min is set to the circuit 5c with a high-speed shift again with no contact. Repeating the same operations, the information is shifted with contact at the place near the desired position to approximate to gradually to the set position based on the result of comparison between the set and extracting band codes. |
