Composite optical disc having both a data read-only area and a data ...

Related U.S. Application Data

[60] Continuation of Ser. No. 353,171, May 17, 1989, Pat. No. 5,023,354, Division of Ser. No. 7,641, Jan. 28, 1987, abandoned.

[30] Foreign Application Priority Data

Feb. 7, 1986 [JP] Japan 61-26374

Feb. 7, 1986 [JP] Japan 61-26376

Feb. 13, 1986 [JP] Japan 61-29256

Feb. 24, 1986 [JP] Japan 61-38839

Mar. 4, 1986 [JP] Japan 61-46533

May 19, 1986 [JP] Japan 61-113934

Jun. 3, 1986 [JP] Japan 61-128669

[51] Int. Cl.s G11B 7/085

[52] U.S. CI 369/32; 369/44.29;

369/44.36; 369/48; 369/54; 369/58; 369/116;

369/275.2.275.3

[58] Field of Search 369/14-15,

369/32, 44.29, 44.31, 44.36, 44.39, 47-50, 54, 58, 100, 106, 116, 124, 275.1-275.5, 283, 13, 44.28; 358/335, 342

[56] References Cited

U.S. PATENT DOCUMENTS

4,229,808 10/1980 Hui 369/48

4,269,917 5/1981 Drexler et al 346/135.1 X

4,296,491 10/1981 Jerome 369/275 X

4,301,486 11/1981 Brown et al 360/99

4,385,372 5/1983 Drexler 369/275 X

(List continued on next page.)

FOREIGN PATENT DOCUMENTS

0089020 9/1983 European Pat. Off. .

0164131 12/1985 European Pat. Off. .

59- 154652 9/1984 Japan .
60-38735 2/1985 Japan .

60- 237682 11/1985 Japan .

60- 261041 12/1985 Japan .
61-5442 1/1986 Japan .

61- 222033 10/1986 Japan .

OTHER PUBLICATIONS

IBM Technical Disclosure, "Video Disk With Updating Feature", Bruce, C. A. et al., vol. 22, No. 3, Aug./1979.

(List continued on next page.)

Primary Examiner—Wayne R. Young

Attorney, Agent, or Firm—Stevens, Davis, Miller &

Mosher

A composite read-only and rewritable type optical disc, and a disc drive apparatus for reading/writing data into the disc. The optical disc has a plurality of sectors forming a data read-only area and a write/read area. The disc includes a recording film formed over its entire surface by which data can be recorded on the disc. Each area has track sectors each having a sector identifier portion in which address information is recorded and a data field portion to record data. Data-field identi

'fication flags indicative of the read-only area and the write/read area are recorded in the respective identifier portions. On reading or writing this optical disc, the data field identification flag is detected to identify the kind of related area, i.e., whether it is a read-only area or a write/read area. Thus, it is possible to avoid erroneous recording of data into the read-only area. Upon executing a reading operation, waveform equalization and binary-clipping level of reproduction signals can be well controlled. The gain of the servo loop can be

. switched. The track searching operation can be stably performed. The reading and writing of data with respect to the data write/read area can be improved.

1 Claim, 11 Drawing Sheets

U.S. PATENT DOCUMENTS

4,417,330 11/1983 Hazel et al 369/100 X

4,467,383 8/1984 Ohta et al 369/275 X

4,484,319 11/1984 Koishi et al. .

4,507,763 3/1985 Kato 369/275 X

4,509,161 4/1985 Vande Leest et al 369/275

4,523,304 6/1985 Satoh et al 358/335 X

4,527,263 7/1985 Nakagawa 369/58 X

4,546,462 10/1985 Koishi et al 369/54 X

4,561,082 12/1985 Gerard et al 369/275 X

4,570,251 2/1986 Yokota et al 369/116 X

4,580,255 4/1986 Inoue et al 369/48 X

4,583,208 4/1986 Verboom 369/44 X

4,592,036 5/1986 Furuya et al 369/48 X

4,594,701 6/1986 Earman et al 369/44 X

4,599,718 7/1986 Nakagawa et al 369/275 X

4,607,358 8/1986 Maeda et al 369/44

4,611,314 9/1986 Ogata et al 369/48 X

4.611.316 9/1986 Takeuchi et al 369/44

4.611.317 9/1986 Takeuchi et al 369/50 X

4,663,751 5/1987 Kaku et al 369/46

4,669,077 5/1987 Gerard et al 369/275