MiniDisc Patent Abstracts

MiniDisc Patent Abstracts
(from the US Patent Database)

The newer IBM Patent Server is an excellent source of patent information. It has complete patent text and figures from 1971 to present. Both servers give links to patents of prior art. These are useful for seeing what technology a particular device is comprised of.

Daewoo has a patent on a Disc player for reproducing both MiniDisc and a Compact Disc with a single drive mechanism.
The Sony MZ-R2 Patent.
5,392,265 Recording and reproducing apparatus which calculates and displays management information of recorded segments
[Sony, 1993, a recent MiniDisc system patent that has links to most of the original MD technology]
A recording and/or reproducing apparatus records and/or reproduces a recording medium on which musical information is recorded discretely together with management information for managing the recorded musical information. The apparatus calculates, based on the management information, a playing time of each musical piece, a total playing time of all of the musical pieces recorded on the recording medium, a remaining time for which the recording medium can be further recorded, and a remaining number of musical pieces which can be further recorded onto the recording medium, and displays the result of the calculation.
5,400,316 High density small-diameter magnetic optical disk
[Sony, 1991, recent patent for the MD disc itself, has links to original MD disc technology]
A magnetic optical disc comprising a magnetic optical recording layer on a transparent substrate. The disc measures less than 80 millimeters in outer diameter and is capable of recording at least 130 megabytes of compressed digital signals. The extreme storage density of the disk is achieved by the suppression of double refraction characteristics near the center area of the disk, whereby the minimum diameter of the recording area can be made smaller. This allows a small-diameter magnetic optical disc to provide a recording area of sufficient storage capacity. In combination with a novel magnetic optical recording system, the disc may illustrative accommodate at least 60 minutes of the user's audio signals while measuring smaller than any other conventional discs of comparable storage capacity.
5,274,617 Method and device for data management in an optical recording medium
[Sharp, 1990]
A recording and reproducing device, which records and reproduces information on and from a rewritable recording medium having absolute addresses and including an information recording area wherein information entered from external devices is recorded and a Table of Contents area wherein additional address information with respect to the information recorded in the information recording area is recorded. The TOC area contains the absolute addresses of the recording positions of each information recorded in the information recording area. A display section graphically and independently displays the recorded and unrecorded ranges of the information recording area according to the absolute addresses recorded in the TOC area with respect to the recording positions of each piece of information. A warning device alerts the user that a position on the disc is occupied by referring TOC area when it is instructed to record new information in the position of the information recording area where another information has already been recorded.
5,243,588 Method and apparatus for reading digital data bursts comprising data clusters and cluster linking sectors
[Sony, 1991]
There is provided a disc recording apparatus for recording digital data by an optical unit in such a manner that time compressed digital data are arranged into a plurality of clusters at an interval of a predetermined number of sectors, a cluster-linking sector having a length longer than an interleaving length is provided at each linking part of each cluster, and the digital data are subsequently interleaved and recorded on a disc-shaped recording medium so that interleaving at the time of data recording on the cluster-by-cluster basis is within the range of the cluster-linking sector. There is also provided a disc reproducing apparatus for reproducing digital data by an optical unit in which playback data are obtained by reproducing record data recorded on a disc-shaped recording medium in such a manner that a cluster-linking sector longer than an interleaving length is provided in a linking section of each cluster composed of a predetermined number of sectors, the resulting data is interleaved and recorded on the disc-shaped recording medium, and the playback data are deinterleaved and freed of the cluster-linking sectors so as to be stored transiently in a storage unit. Playback data are written in the storage unit when the data volume of playback data stored in the storage unit becomes smaller than a predetermined volume to maintain a readout space in the storage unit which is in excess of the predetermined data volume.
5,224,087 Apparatus for recording compressed digital information to an optical disc
[Sony, 1991]
An apparatus for recording compressed digitized information to an optical disc by reading the digital data into a memory for transient storage. The digital input data thus written into the memory are sequentially read out of the memory and into an encoder at a transfer rate faster than the input transfer rate where the digital data are arranged in discrete clusters of record units including cluster-linking groups such that each record unit can be interleaved independently and without affecting other record units. The interleaved record units are then recorded onto an optical disc. Reproduction of the record units from the optical disk is carried out by reversing the process.
5,214,631 Disc recording/reproducing apparatus having a servo system capable of successively recording and reproducing tracks on a disc irrespective of turbulence of the servo system due to a disturbance
[Sony, 1991]
During recording the inputted data are sequentially written into a memory at one transfer rate and are read out at a second, higher transfer rate for recording on a record medium. The reading of the memory is such that data in a preset first amount are successively read from the memory to always ensure a write space in the memory which has a capacity which is higher than a predetermined second amount when the amount of the inputted data stored in the memory exceeds the first amount. During playback, the recorded data are reproduced at a second transfer rate, which is higher than a first transfer rate required for outputting the reproduced data, and are written in the memory. The thus written data are successively read out of the memory as reproduced output data at the first transfer rate. The writing of the reproduced data to the memory is controlled so that a second amount of the reproduced data is written into the memory and an amount of reproduced data, not less than a first amount, is always stored in the memory when the amount of the reproduced data stored in the memory becomes not higher than the first given amount.
5,153,861 Recording/reproducing device
[Sharp, 1989]
In a recording/reproducing device in accordance with the present invention, recording or reproducing positions are recognized by using absolute address parts which are predeterminately formed in a rewritable recording medium. Moreover, the device is composed so that the user can easily edit reproducing procedures stored in memory means with respect to each information in the recording medium by using the recording or reproducing positions read from above-mentioned absolute address parts and he/she can also rewrite above-mentioned reproducing procedures edited by him/her in the lead-in region of the above-mentioned recording medium. Accordingly, the user can save trouble to re-enter those reproducing procedures every time he/she places the recording medium in the recording/reproducing device, and once the recording medium having the edited reproducing procedure information recorded in the lead-in area is placed in the recording/reproducing device, successive reproductions of each information according to desired reproducing procedures are easily performed, thereby resulting in an improved operability.
5,142,521 Recording/reproducing device
[Sharp, 1990, Address in PreGroove]
A recording/reproducing device performs the recording/reproduction on a recording medium having an information recording area and a table of contents area. The recording medium is provided with guiding grooves that snake in cycles corresponding to values of absolute addresses. The device divides the information recording area into a plurality of domains. Each domain corresponds to a single sampling frequency with respect to the information being recorded. An electromagnet and an optical head record information in the domain that corresponds to its sampling frequency and records additional information concerning the division in the table of contents. A spindle motor drives the disk which is adjusted such that the velocity of the disk is changed for each domain during recording and reproduction. A demodulator obtains the absolute addresses through demodulation by comparing frequencies determined from the snaking cycles of the guiding grooves with a reference frequency. An operational circuit converts the demodulated absolute addresses in accordance with the velocity of the disk into corrected absolute addresses that represented the period of time which has elapsed since the starting time. As a result, the burden imposed on the spindle motor is relieved, the demodulation of the absolute addresses may be executed accurately even when the rotational speed of the disk varies, and the time elapsed since the start of the recording/reproduction may be determined.
4,862,439 Recording device that identifies recordable areas of a disk record
[Sony, 1988]
A disk recording device records blocks of data such as musical information on a recordable disk where absolute addresses have been previously recorded. Address data indicating the starting and ending address of each block is recorded in a lead-in section, and recordable areas of the program area, such as unrecorded parts or unnecessarily recorded parts, are detected on the basis of the address data of each block. The respective lengths of the recordable areas are indicated. Hence the user can easily identify unrecorded or unnecessarily recorded areas that are long enough for further recording.
5,309,421 Recording and/or reproducing apparatus for optical disk
[Sony, 1991, Recent MD drive mechanism technology, many links to original patents.]
An optical disk recording and/or reproducing apparatus employing a disk cartridge having accommodated therein an optical disk not more than 80 mm in diameter as a recording medium, the apparatus including an outer casing having a length not larger than 112 mm, a width not more than 89 mm and a height not more than 31 mm which encompasses a cartridge loading section, a driving unit for rotationally driving the optical disk, an optical pickup unit and means for transporting the optical pickup unit across inner and outer peripheries of the optical disk driven rotationally by the disk driving unit for recording information signals on or reproducing information signals from a recording surface on the optical disk, a magnetic head unit for generating an external magnetic field based on information signals to be recorded, the magnetic head unit and the optical pickup unit being connected together for movement in unison therewith and arranged facing each other on opposite sides of the optical disk, controlling means for controlling a movement of the magnetic head unit perpendicular to the recording surface of the optical disk as a function of the types of the disks loaded into the apparatus, and a disk loading unit for loading the disk cartridge onto the cartridge loading section and loading the optical disk accommodated in the disk cartridge onto the disk driving unit.
5,461,597 Mastering apparatus for producing compact disk and minidisk master disks
[Sony, 1993, MD mastering equipment]
A mastering apparatus which can produce both a format signal for a compact disk and another format signal for a minidisk. Most of the components of a mastering processing system for a compact disk are common to a mastering processing system for a minidisk. An address generator for generating an address upon mastering processing for a minidisk is provided. The operation condition of the address generator is controlled by controlling a digital signal processor of the address generator. When a compact disk format signal is to be produced, the address generator is controlled to a no-operation mode so that the apparatus operates as a compact disk mastering apparatus. On the other hand when a minidisk format signal is to be produced, the address generator is controlled to an operation mode so that the apparatus operates as a minidisk mastering apparatus.
MD-Data drive with a SCSI interface.
5,475,537 Optical system for use in recording and reading information on an optical information medium
[Konica 1994]
5,469,961 Combined minidisc box
[C. Chang, Taipei, 1994, Stackable, lockable MD cases]
5,320,221 Transport and protective case for information medium
[Kurz Kunstoffe GmbH, 1993, MD carrying case]

ATRAC Patents (all Sony)

Other Audio Compression related Patents

5,394,473 Adaptive-block-length, adaptive-transforn, and adaptive-window transform coder, decoder, and encoder/decoder for high-quality audio
[This looks like Dolby Labs' patent of the prior art for ATRAC]
5,263,088 Adaptive bit assignment transform coding according to power distribution of transform coefficients
[NEC]
5,235,623 Adaptive transform coding by selecting optimum block lengths according to variatons between successive blocks
[NEC]
5,222,189 Low time-delay transform coder, decoder, and encoder/decoder for high-quality audio
[Dolby Labs -- 192kbps coder for 44.1kHz audio!]
5,166,686 Variable length block coding with changing characteristics of input samples
[NEC patent]
5,142,656 Low bit rate transform coder, decoder, and encoder/decoder for high-quality audio
[Dolby patent covering adaptive bit allocation]
5,109,417 Low bit rate transform coder, decoder, and encoder/decoder for high-quality audio
[Dolby patent covering block floating point format]
4,516,258 Bit allocation generator for adaptive transform coder
[AT&T patent for novel bit allocation]

MiniDisc Patent Abstracts (from the US Patent Database)

ATRAC Patents (all Sony)

Other Audio Compression related Patents

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MiniDisc Patent Abstracts
(from the US Patent Database)