Dynamic information storage or retrieval – Storage medium structure – Optical track structure
Patent
1998-01-28
2000-07-04
Dinh, Tan
Dynamic information storage or retrieval
Storage medium structure
Optical track structure
369 14, 369 94, G11B 724
Patent
active
060848502
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention concerns a method for optical data storage with high density, wherein there are employed as a data carrying medium a number of flat thin memory components in the form of cards or disks, wherein each component comprises one or more information carrying layers, wherein each memory component has one or more data carrying areas which are including one or more of the information carrying layers and adapted for optical data storage, and wherein the method comprises arranging two or more of the memory components in a stack, thus enabling each individual memory component to be maneuvered in relation to the other memory components by means of a maneuvering device. The invention also concerns a data carrying medium for use with the method for optical data storage with high density, wherein the data carrying medium comprises a number of flat, thin memory components in the form of cards or disks, wherein each memory component comprises one or more information carrying layers, and wherein each memory component comprises one or more data carrying areas which are including one or more of the information carrying layers and being adapted for optical storage of data.
2. Description of the Prior Art
In to-day's digital, optical data storage media information is stored in a flat layer on a disk, a card or tape. Circular disks or a rectangular card format are normally used. Even though the data density per area unit in the storage layer is very high, the effective volumetric storage density is not correspondingly high. Each disk or each card has only one or two data storage layers at the most and is typically 0.7-2 mm thick in order to provide the necessary rigidity and flatness for write/read operations. Moreover, when such media are placed in a protective cassette, there is a further increase in the volume. Even in the case of so-called "floppy" optical Bernoulli disks which have recently been proposed, the volumetric density is limited by the still substantial volume of the actual floppy disk's substrate, as well as the requirement for a protective housing or sleeve to cover the disk. The limiting effect of the packing on the volumetric density in connection with filing is particularly obvious in libraries which store CD cassettes.
The information carrying layer on present optical data storage media is thin, typically much less than 1 .mu.m. Thus only a small fraction of the volume of the disk or card is used directly for the data storage process. This is also the case even if the protective housing or sleeve is disregarded.
If it were possible to use the entire volume in a typical disk or a card for optical data storage, with a density which corresponded to that which at present can be achieved per area unit, this would be of substantial importance. By extrapolating from an area density which for example corresponds to a bit spacing of 1 .mu.m, the volumetric density could be 10.sup.9 bit/mm.sup.3. In a number of countries considerable efforts have been made to achieve digital, optical data storage within the volume of a data medium. A number of different methods have been proposed for this purpose: read in the bulk material; within a bulk material, selective positioning being, achieved by means of sharp focusing of a laser beam, a non-linear response in the medium or an excitation on several wavelengths, another in a uniform structure which may be a simple bulk material or a number of thin substrates which are attached to one another in order to form a sandwich structure.
Of these above-mentioned methods, (a) and (b) appear to have the potential for the highest volumetric data density, but at the present time they are far from being capable of practical implementation, not least in equipment which should not be too expensive. In connection with the method described under (c), several different techniques are the subject of research and development, cf. the examples mentioned in the following. Even though these techniques appear to have the potential to
REFERENCES:
patent: 3731060 (1973-05-01), Weinstein
patent: 3800942 (1974-04-01), Hirata et al.
patent: 5317556 (1994-05-01), Tsuboi et al.
patent: 5371730 (1994-12-01), Maeda et al.
patent: 5825404 (1998-10-01), Konno et al.
JP-A-56-129989, Patent Abstracts of Japan, vol. 6, No. 5, P-97, IKEHARA.
Gudesen Hans Gude
N.ae butted.ringsrud Thormod
Nilsen Rolv M.o slashed.ll
Dinh Tan
Thin Film Electronics ASA
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