Information recording and reproducing apparatus with detection and management of defective sectors

• US 4,774,700 A
• Filed: 03/07/1986
• Issued: 09/27/1988
• Est. Priority Date: 03/12/1985
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Fukushima, Yoshihisa, Satoh, Isao
• Primary Examiner(s): PSITOS, ARISTOTELIS
• Application Number:
  US06/837,171
• Time in Patent Office: 935 Days
• Field of Search: 369/53, 369/54, 369/58, 360/31, 360/60, 360/53
• US Class Current: 369/47.14
• CPC Class Codes: G11B 20/1883 Methods for assignment of alternate areas for defective areas
• CPC Class Codes: G11B 2220/20 Disc-shaped record carriers

Abstract

An information recording and reproduction apparatus for recording and reproduction of information in a recording medium having an information recording area divided into a plurality of sectors, in which a defective sector is replaced for recording and a signal for identifying the defective sector is recorded. Each sector includes a preformatted sector identification section ID and a data field for recording data therein. A defective sector is replaced by a sector at another position. When the sector identification section ID and/or data field DF has a defect, a first signal is recorded in addition to the data in the data field DF, followed by writing a second signal overlapped in the sector identification section ID of the same sector which causes an address data read error thereby to attach a defect mark to the defective sector. By detecting the first signal at the time of recording or reproduction, the sector involved is known to be defective, and at the same time, the data therein is transferred to another (replacement) sector, or a sector is detected where the data is recorded. A defective sector never fails to be identified by the second signal overwritten in the sector identification section ID. A defective sector is thus detected in real time at the time of data recording or reproduction, and therefore the defective sector replacing operation is performed in a minimal access time. Further, the storage capacity has no loss since a defective sector is identified by a signal recorded in the data field section DF.

Claims

1. In an information recording and reproduction apparatus comprising an optical disc including a plurality of sectors comprising at least one replacement sector, each of said sectors having a sector identification section ID having address data recorded therein and a data field section DF for recording data, and recording/reproducing means for recording and reproducing data in each of said sectors of the optical disc, the improvement further comprising defective sector marking means including (i) means for detecting a defective sector having a defect in at least one of said sector identification section ID and said data field section DF and generating a defect indicating signal, (ii) means, responsive to said defect indicating signal, for recording a first signal different from the data in the data field section DF of said defective sector independently of whether said defect is in said sector identification section ID or said data field section, DF, (iii) means, responsive to said defect indicating signal, for overwriting a second signal, independently of whether said defect is in said sector identification section ID or said data field section, DF, in the sector identification section ID of said defective sector that causes a read error of the address information, and (iv) means for detecting the first signal recorded in said defective sector and thereafter accessing a replacement sector to enable said recording/reproducing means to record and reproduce data in said replacement sector.

2. The apparatus as in claim 1, wherein said first signal contains information designating said replacement sector and is recorded in the data field section DF of said defective sector.

3. The apparatus as in claim 1 or 2, wherein said first signal has a lower frequency than that of a signal recording data in said data field section DF.

4. The apparatus as in claim 1, further comprising means for detecting a dropout in said data field section DF of an unrecorded one of said sectors, and wherein said means for detectors a defective sector includes means for detecting said unrecorded one of said sectors as a defective sector by detection by said dropout exceeding a predetermined criteria.

5. The apparatus as in claim 1, wherein said data field section DF of said sectors includes rewritable sections, and said apparatus further comprises means for recording and reproducing test data inclusive of error detection and correction codes on and from said sectors, and said means for detecting a defective sector includes means for detecting an error flag exceeding a given criterion from data reproduced by said means for recording and reproducing to determine whether the sector from which said data has been reproduced is a defective sector.