UNRECORDED AREA DETECTING SYSTEM OF REINSTALLING DISK IN OPTICAL INFORMATION RECORDING DEVICE,申请号JP19820174576-传众专利搜索

UNRECORDED AREA DETECTING SYSTEM OF REINSTALLING DISK IN OPTICAL INFORMATION RECORDING DEVICE

申请公布号：JPS5965935(A)

申请号：JP19820174576

申请日期：1982.10.06

申请公布日期：1984.04.14

申请人：

HITACHI SEISAKUSHO KK

发明人：OKAZAKI KICHIZAEMON;FUJISHIMA TOORU;MIURA YOSHIO;YAMASHITA TADASHI;NISHIJIMA TATSUMI

分类号：G11B7/00;G11B7/0045;G11B19/04

主分类号：G11B7/00

摘要：PURPOSE:To prevent information from being written doubly by executing a detection of a non-recorded area of the outside circumferential part from the final track by detecting a cross signal of an information track by a focus signal, when a partially recorded disk is reinstalled and additional recording is executed to its unrecorded area. CONSTITUTION:When an information recording disk 1 is detached from a recording device once and is installed again, a recording pickup part 10 is in a set position of the innermost circumferential side of the disk, and the disk 1 rotates at a high speed. Therefore, by moving the pickup part 10 in the radial direction of the disk 1, a cross signal 41 of a nearly sinusoidal waveform is inputted to a detecting circuit 40 through a focus signal detecting circuit 20 when a minute spot of an optical beam 12 crosses information recording track loci 50, 51. Subsequently, the detecting circuit 40 counts the time from the time point of the end of the signal 41, namely, the time point when the minute spot passes through the information recording track loci 50, 51, stops the pickup part 10 when the signal 41 is not inputted within a constant interval of time t0, and detects its position as a start point of a non-recorded area of the information recording disk 1 at the time of reinstallation.