摘要:
In an optical information recording/reproducing apparatus for recording/reproducing information on or from an optical disc, a laser beam is focused on the surface of a substrate of the optical disc so that the intensity or a high frequency component of a reflected laser beam is used to detect contaminants on the optical disc surface or a test signal containing a plurality frequency components and recorded on a specified track on the optical disc is reproduced and detected so that the difference between amplitudes of the frequency components is used to detect contaminants on the optical disc surface. Scattering of the laser beam can be prevented and recording/reproducing can be effected with a proper level of laser power.
摘要:
A deinterleaving and error correction system which is advantageously utilized in a playback system of an optical recording disk apparatus. As each block of sector data, encoded for example with the Reed-Solomon error correction code with block interleaving, is read from the disk, the positions within the data block at which drop-out of the playback signal occurs are respectively stored in a memory in which the data symbols are also stored, with these drop-out positions being stored as error position data. Error correction processing is executed using the error position data in conjunction with the code words, enabling the maximum number of correctable errors for each sector to be substantially increased using a simple system configuration.
摘要:
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 identification 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.
摘要:
In a read only type optical disk and a write type optical disk each thereof having a data recording area and a spare area, first encoded data for error detection and correction are recorded in the data recording area. In the case of the read only type optical disk, the spare area is used as a check sector in which second encoded data are recorded. When error correction by first error control means becomes impossible while sectors in the data recording area are reproduced, second error control means performs error correction by using the check sector corresponding to an associated error sector. In the case of the write type optical disk, the spare area is used as an alternate sector. A defective sector detected by defective sector detecting means is alternately recorded by being replaced by the alternate sector through sector alternating means.
摘要:
An optical disk duplicating apparatus comprises reproducing means for reproducing user's data recorded on a first optical disk, adding means for adding sector data identification information indicative of the state of using sectors in recording tracks on the first optical disk to the reproduced user's data, recording means for recording the user's data on a second optical disk, and transfer means for transferring the user's data and the sector data identification information to the recording means. The optical disk duplicating apparatus determines whether each of the sectors in the first optical disk has data properly recorded therein, a defective sector identifier portion, a defective data field portion, or no signal recorded therein, by using the sector data identification information and controls a signal supplied to the recording means, thereby producing duplicated sectors in a manner such that the sectors in the first optical disk correspond respectively to the sectors in the second optical disk on the sector-to-sector basis.
摘要:
This invention provides an erasable optical disk, on which information is recorded and reproduced repeatedly through the irradiation of laser beams, and an optical information recording/reproduction apparatus which records and reproduces information on the erasable optical disk. In erasing and then recording information on the erasable optical disk by using an erasing laser beam and a recording/reproduction laser beam, respectively, the tracking of both laser beams on the same track is detected so as to prevent erroneous erasing. The apparatus uses the optical disk having a mark signal disposed between a sector identifier and a data field, which mark signal is capable of determining the presence of the erasing laser beam on an adjacent track on the erasable optical disk, and the apparatus reproduces and detects the mark signal by using the erasing laser beam. The apparatus discriminates the position of the erasing laser beam depending on whether the mark signal has been detected or not, thereby preventing erroneous erasing of data on the adjacent track and simultaneously assuring the presence of the erasing laser beam on the same track along with the recording/reproduction laser beam.
摘要:
An information recording and reproducing apparatus detects deterioration in a recording medium. Structure is provided for recording information including an error correction code. A signal indicative of recorded information is received, and an error signal indicative of a number of errors that are detected is produced. This error signal is based on verification of the error correction code. The error correction code is verified using a strict clipping level, which is a level stricter than a usual level recognized as a particular signal level. This strict clipping level is compared with the signal indicative of reading areas, and error signals are produced thereby. When the error signal indicates a number of errors greater than a predetermined number, each sector is checked to determine if it is a bad sector. Each bad sector is recorded with a mark signal that indicates a bad sector. Before writing on the disk, each target sector is read verified using the strict clipping level, and mark signals indicative of a bad sector are recorded on any bad sectors. According to another aspect, the read verify operation is also carried out for a directory sector to ensure that the directory sector is correct.
摘要:
A data recording and reproducing apparatus is disclosed in which an optical disc for recording, reproducing or erasing data is radiated with an erasing light beam and a recording-reproducing light beam sequentially to record or reproduce the data with the recording-reproducing light beam and erase the data with the erasing light beam. In rewriting the data, the erasing light beam is radiated in advance of the recording-reproducing light beam on a data section of the disc, and the old data is erased by temperature increase and annealing by the erasing light beam, while new data is recorded by temperature increase and quenching with the recording-reproducing light beam set to the recording light intensity. After recording the new data, the light intensity of the erasing light beam is gradually decreased and turned off. In rewriting the sector data, the erasing light beam is radiated on the data section in advance of the recording-reproducing light beam, and by the temperature increase and annealing with the erasing light beam, the old data is erased, while new data is recorded by temperature increase and quenching with the recording-reproducing light beam set to the recording light intensity. After recording the new data, the light intensity of the erasing light beam is turned off after being modulated for a predetermined time. By doing so, the process of the temperature and quenching is eliminated which otherwise might be required at the time of turning off the erasing light beam, thereby preventing occurrence of a recording trace and a defect of the recording medium by a thermal shock.
摘要:
An information recording and reproducing apparatus for recording and reproducing information on and from a disk type information recording medium, wherein the information recording medium is used in which normal sectors (S1, Sn) each having an address formatted on an address area 12 in a sector ID field 9 and an alternative sector R1 having an address not yet recorded thereon are included on a same track. When a defective sector S3 is detected, first, the address of the defective sector is disabled to be reproduced by recording a delete signal 109 on the address area 12 of the defective sector S3, and at the same time, the address of the defective sector is recorded on an address area 13 in the unused alternative sector R1 located on the same track as the defective sector S3, and then, the data to be recorded on the defective sector is recorded within the alternative sector R1. Owing to such an operation for using an alternative sector, the alternative sector having the same address and data as the defective sector is formed on the same track as the defective sector. As a result, an information recording and reproducing apparatus which enables to access the alternative sector without an additional seek operation at the time of reproduction is provided.
摘要:
The apparatus includes a one-chip microcontroller, an error flag counter and an error comparison circuit to detect whether or not an optical disk or an internal optical head of the apparatus is fouled. Test data is recorded on a self-diagnostic area of the optical disk when the optical disk loaded in the apparatus is new and has not yet been used, and initial error information detected in the test data reproduced from the self-diagnostic area is registered on an error managing area of the optical disk. When an optical disk which has already been used is loaded, error information detected in the test data recorded on and reproduced from the self-diagnostic area of the optical disk is compared with the initial error information registered in the error managing area of the optical disk. When the comparison shows that the number of data errors is greater than a predetermined reference value, the optical disk or the internal optical head is fouled to such an extent that the recording and reproducing function cannot be satisfactorily performed.