# US 5,335,197 A · Storage medium, storage method and stored information reading method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,335,197 A - Document ID: US5335197A - Status: Granted - Kind: A - Application number: 07/804,593 - Filed: 1991-12-10 - Granted: 1994-08-02 - Earliest claimed: 1989-03-28 - Assignees: Canon Kabushiki Kaisha - Inventors: Norio Kaneko; Katsuhiko Shinsho; Keisuke Yamamoto - Web page: https://patentgrep.com/patent/US5335197A ## CPC - G11B 7/004: Recording, reproducing or erasing methods; Read, write or erase circuits therefor {(magneto-optical systems G11B11/105)} - B82Y 10/00: Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic - G11B 7/24: Record carriers characterised by shape, structure or physical properties, or by the selection of the material (characterised by the arrangement of information on the carrier G11B7/007) - G11B 9/04: using record carriers having variable electric resistance; Record carriers therefor - G11B 9/1472: {characterised by the form} - G11B 9/1481: {Auxiliary features, e.g. reference or indexing surfaces} - G11B 9/149: {characterised by the memorising material or structure} - G11B 23/42: Marks for indexing, speed-controlling, synchronising, or timing - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES ## Abstract Disclosed are medium and methods for storage and reading of stored information. The storage medium comprises an oxide layer having a plurality of pits and projections on the oxide layer surface. Information storage is achieved by applying voltage or light, in accordance to information signals, to the oxide layer, to differentially heat said oxide layer and create a plurality of portions which contain different quantities of oxygen. Stored information is read by the application of voltage or light to the oxide layer containing a plurality of portions containing different quantity of oxygen and detection of the electrical resistance or light reflectivity of each of said plurality of portions. ## Claims ### Claim 1 A method for storing information comprising the following steps: (a) preparing a storage medium comprising an oxide layer; and (b) exposing portions of the oxide layer to light to heat the oxide layer in accordance with information signals; thereby forming a plurality of portions containing varying quantities of oxygen, wherein information is stored. ### Claim 2 (depends on 1) A storage method according to claim 1, wherein step (b) further comprises a step in which the light is applied to said oxide layer by a digital exposure. ### Claim 3 (depends on 1) A storage method according to claim 1, wherein step (b) further comprises a step in which the light is applied by an analog exposure. ### Claim 4 (depends on 1) A storage method according to claim 1, wherein step (a) further comprises a step wherein said oxide layer surface comprises a plurality of pits and projections. ### Claim 5 (depends on 4) A storage method according to claim 4, further comprising a step wherein the pits and projections are positioned such that the distance between said projections is in the rate of substantially 1 .mu.m to 4000 .ANG.. ### Claim 6 (depends on 4) A storage method according to claim 4, further comprising a step wherein said pits and projections are positioned such that a height of said projections is in the range of substantially 3 .mu.m to 2000 .ANG.. ### Claim 7 (depends on 1) A storage method according to claim 1, wherein step (a) further comprises a step in which said oxide layer is held between a substrate and a protection layer. ### Claim 8 (depends on 7) A storage method according to claim 7, further comprising a step wherein said protection layer comprises an oxygen permeable material. ### Claim 9 (depends on 7) A storage method according to claim 7, further comprising a step wherein said protection layer comprises an oxygen absorbable material. ### Claim 10 (depends on 7) A storage method according to claim 7, further comprising a step wherein said oxide layer surface comprises a plurality of pits and projections. ### Claim 11 (depends on 8) A storage method according to claim 8, further comprising a step wherein the pits and projections are positioned such that the distance between said projections is in the range of substantially 1 .mu.m to 4000 .ANG.. ### Claim 12 (depends on 8) A storage method according to claim 8, further comprising a step wherein said pits and projections are positioned such that a height of said projections is in the range of substantially 3 .mu.m to 2000 .ANG.. ### Claim 13 (depends on 1) A storage method according to claim 1, wherein step (a) further comprises a step in which said oxide layer comprises an oxide which changes crystalline structure in response to a change in a quantity of oxygen contained therein. ### Claim 14 A method for reading stored information comprising the following steps: (a) applying voltage to a medium comprising an oxide layer, wherein said oxide layer includes a plurality of portions containing varying oxygen concentrations; and (b) detecting an electrical resistance of each of said plurality of portions, wherein the electrical resistance of each of said plurality of portions relates to the oxygen concentration of the portion, whereby information is read. ### Claim 15 (depends on 14) A method for reading stored information according to claim 14, wherein step (a) further comprises a step wherein said oxide layer surface comprises a plurality of pits and projections. ### Claim 16 (depends on 14) A method for reading stored information according to claim 14, further comprising a step wherein said pits and projections are positioned such that a distance between said projections is in the range of substantially 1 .mu.m to 4000 .ANG.. ### Claim 17 (depends on 15) A method for reading stored information according to claim 15, further comprising a step wherein said pits and projections are positioned such that a height of said projections is in the range of substantially 3 .mu.m to 2000 .ANG.. ### Claim 18 (depends on 14) A method for reading stored information according to claim 14, wherein step (a) further comprises a step in which said oxide layer is held between a substrate and a projection layer. ### Claim 19 (depends on 18) A method for reading stored information according to claim 18, further comprising a step wherein said protection layer comprises an oxygen permeable material. ### Claim 20 (depends on 18) A method for reading stored information according to claim 18, further comprising a step wherein said protection layer comprises an oxygen absorbable material. ### Claim 21 (depends on 18) A method for reading stored information according to claim 18, further comprising a step wherein said oxide layer surface comprises a plurality of pits and projections. ### Claim 22 (depends on 21) A method for reading stored information according to claim 21, further comprising a step wherein said pits and projections are positioned such that the distance between said projections is in the range of substantially 1 .mu.m to 4000 .ANG.. ### Claim 23 (depends on 21) A method for reading stored information according to claim 21, further comprising a step wherein said pits and projections are positioned such that a height of said projections is in the range of substantially 3 .mu.m to 2000 .ANG.. ### Claim 24 (depends on 14) A method for reading stored information according to claim 14, wherein step (a) further comprises a step in which said oxide layer comprises an oxide which changes crystalline structure in response to a change in a quantity of oxygen contained therein. ### Claim 25 A method for reading stored information comprising the following steps: (a) applying light to medium comprising an oxide layer, wherein said oxide layer includes a plurality of portions containing varying oxygen concentrations; and (b) detecting a light reflectivity of each of said plurality of portions, wherein said light reflectivity of each of said plurality of portions relates to the oxygen concentration of the portion, whereby information is read. ### Claim 26 (depends on 25) A method for reading stored information according to claim 25, wherein step (a) further comprises a step wherein said oxide layer surface comprises a plurality of pits and projections. ### Claim 27 (depends on 26) A method for reading stored information according to claim 26, further comprising a step wherein said pits and projections are positioned such that a distance between said projections is in the range of substantially 1 .mu.m to 4000 .ANG.. ### Claim 28 (depends on 26) A method for reading stored information according to claim 26, further comprising a step wherein said pits and projections are positioned such that a height of said projections is in the range of substantially 3 .mu.m to 2000 .ANG.. ### Claim 29 (depends on 25) A method for reading stored information according to claim 25, wherein step (a) further comprises a step in which said oxide layer is held between a substrate and a protection layer. ### Claim 30 (depends on 29) A method for reading stored information according to claim 29, further comprising a step wherein said protection layer comprises an oxygen permeable material. ### Claim 31 (depends on 29) A method for reading stored information according to claim 29, further comprising a step wherein said protection layer comprises an oxygen absorbable material. ### Claim 32 (depends on 29) A method for reading stored information according to claim 29, further comprising a step wherein said oxide layer surface comprises a plurality of pits and projections. ### Claim 33 (depends on 32) A method for reading stored information according to claim 32, further comprising a step wherein said pits and projections are positioned such that a distance between said projections is in the range of substantially 1 .mu.m to 4000 .ANG.. ### Claim 34 (depends on 32) A method for reading stored information according to claim 32, further comprising a step wherein said pits and projections are positioned such that a height of said projections is in the range of substantially 3 .mu.m to 2000 .ANG.. ### Claim 35 (depends on 25) A method for reading stored information according to claim 25, wherein step (a) further comprises a step in which said oxide layer comprises an oxide which changes crystalline structure in response to a change in a quantity of oxygen contained therein.