Patent Number: 6,167,012

Title: Information carrier, reading/writing device and reading device for writing and/or reading information blocks

Abstract: A disc-shaped information carrier has a track thereon which follows a helical or concentric path forming successive windings. For identifying each winding the information carrier also has a servo pattern thereon which includes position-information as well as synchronization elements. Such elements may be, for example, brief pulses in a continuous track wobble, and are distinguishable in adjacent windings based on a predetermined detectable parameter, such as alternating polarity or shifted relative phase positions. During recording by a read/write head a system control detects the synchronization elements and monitors whether a deviation has occurred signifying that the read/write head has wandered to an adjacent winding. In that event recording is interrupted. Thus, the least possible information in adjacent windings is overwritten in the case of disturbances resulting from shocks or defects of the information carrier. A read device is also described which interrupts reading if the winding identification provided by the synchronization elements signifies erroneous operation.

Inventors: Van Den Enden; Gijsbert J. (Eindhoven, NL), Spruit; Johannes H. M. (Eindhoven, NL)

Assignee: U.S. Philips Corporation

International Classification: G11B 27/30 (20060101); G11B 27/24 (20060101); G11B 27/19 (20060101); G11B 7/09 (20060101); G11B 7/007 (20060101); G11B 007/00 ()

Expiration Date: 12/26/2017