US5463609A
Expired / Lapsed
US
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Information recording and reproducing device and a method using the same
Assignee: Panasonic Holdings Corp
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Filing: 1993-10-20
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Granted: 1995-10-31
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Expires: 2013-10-20
Abstract
Abstract The information recording and reproducing apparatus includes: a recording medium including a plurality of concavo-convex pits; a light source for emitting laser light; a section for changing an optical characteristic value of the laser light, using interaction between the laser light and the recording medium; and a light detector for detecting the optical characteristic value of the laser light after the interaction occurs, and then outputting a signal in response to the detected optical characteristic value. The section for changing the optical characteristic value includes an evanescent wave generating section for generating an evanescent wave from the laser light. The evanescent wave generating section changes the optical characteristic value in accordance with how much the concavo-convex pits of the recording medium influences the evanescent wave. Multivalued data is reproduced on the basis of the signal from the light detector. The multivalued data corresponds to the dimension of the concavo-convex pits measured along the direction normal to the recording medium.
Inventors
- 👤 Tatsuhiko Inagaki
- 👤 Hiroshi Kohso
- 👤 Makoto Kuwamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 03:29
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/2407; G11B7/24085; G11B13/00; G11B13/04; G11B5/00; G11B5/48; G11B5/54; G11B5/55; G11B5/58; G11B7/004; G11B7/005; G11B7/0052; G11B7/12; G11B7/135; G11B7/1387
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
183 words
An information recording and reproducing apparatus comprising: a recording medium including a plurality of concavo-convex pits, a light source for emitting laser light, a means for changing an optical characteristic value of said laser light, using interaction between said laser light and said recording medium, and a light detector for detecting said optical characteristic value of said laser light after said interaction occurs, and then outputting a signal in response to said detected optical characteristic value; wherein said means for changing said optical characteristic value includes an evanescent wave generating means for generating an evanescent wave from said laser light, and said evanescent wave generating means changes said optical characteristic value in accordance with how much said concavo-convex pits of said recording medium influences said evanescent wave, the spacing between said evanescent wave and said concavo-convex pits being such that said concavo-convex pits substantially influence said evanescent wave; and multivalued data is reproduced on the basis of said signal from said light detector, said multivalued data corresponding to the dimension of said concavo-convex pits measured along the direction normal to said recording medium.
Claim 2
Dependent Claim
183 words
An information recording and reproducing apparatus comprising: a recording medium including a plurality of concavo-convex pits, a light source for emitting laser light, a means for changing an optical characteristic value of said laser light, using interaction between said laser light and said recording medium, and a light detector for detecting said optical characteristic value of said laser light after said interaction occurs, and then outputting a signal in response to said detected optical characteristic value; wherein said means for changing said optical characteristic value includes an evanescent wave generating means for generating an evanescent wave from said laser light, and said evanescent wave generating means changes said optical characteristic value in accordance with how much said concavo-convex pits of said recording medium influences said evanescent wave, the spacing between said evanescent wave and said concavo-convex pits being such that said concavo-convex pits substantially influence said evanescent wave; and multivalued data is reproduced on the basis of said signal from said light detector, said multivalued data corresponding to the dimension of said concavo-convex pits measured along the direction normal to said recording medium.
Claim 3
Dependent Claim
43 words
An information recording and reproducing apparatus according to claim 1, wherein said evanescent wave generating means includes a reflection surface so as to face said recording medium, and said laser light is totally reflected at the reflection surface, thereby generating said evanescent wave.
Claim 4
Dependent Claim
29 words
An information recording and reproducing apparatus according to claim 2, wherein said evanescent wave generating means includes a first lens for condensing said laser light onto said reflection surface.
Claim 5
Dependent Claim
34 words
An information recording and reproducing apparatus according to claim 3, wherein a medium having a reflectivity larger than that of the air is disposed between said reflection surface and said first lens at least.
Claim 6
Dependent Claim
31 words
An information recording and reproducing apparatus according to claim 4, wherein said evanescent wave generating means includes a second lens for collimating said laser light totally reflected at the reflection surface.
Claim 7
Dependent Claim
64 words
An information recording and reproducing apparatus according to claim 2, wherein said evanescent wave generating means includes a prism having a first surface, a second surface, and a third surface, said first surface receiving said laser light, said second surface functioning as said reflection surface for totally reflecting said laser light, said third surface emitting said laser light totally reflected at said second surface.
Claim 8
Dependent Claim
49 words
An information recording and reproducing apparatus according to claim 6, wherein said evanescent wave generating means includes a first lens for condensing said laser light onto said second surface of said prism, said first lens being located so as to be adjacent to said first surface of said prism.
Claim 9
Dependent Claim
51 words
An information recording and reproducing apparatus according to claim 7, wherein said evanescent wave generating means includes a second lens for collimating said laser light totally reflected on said second surface of said prism, said second lens being located so as to be adjacent to said third surface of said prim.
Claim 10
Dependent Claim
22 words
An information recording and reproducing apparatus according to claim 7, wherein said prism has a reflectivity larger than that of the air.
Claim 11
Dependent Claim
27 words
An information recording and reproducing apparatus according to claim 7, wherein said prism and said first lens are formed so as to be integrated with each other.
Claim 12
Dependent Claim
35 words
An information recording and reproducing apparatus according to claim 2, further comprising a mechanism for maintaining the distance from said reflection surface to said recording medium at a wavelength of said laser light or less.
Claim 13
Dependent Claim
44 words
An information recording and reproducing apparatus according to claim 1, wherein said recording medium further includes a magnetic recording layer, and said information recording and reproducing apparatus further comprises a magnetic means for recording and reproducing magnetic data recorded in said magnetic recording layer.
Claim 14
Dependent Claim
39 words
An information recording and reproducing apparatus according to claim 12, wherein the dimension of said concavo-convex pits measured along the direction normal to said recording medium is not more than one eighth of the wavelength of said laser light.
Claim 15
Dependent Claim
40 words
An information recording and reproducing apparatus according to claim 12, wherein a region provided with said magnetic data and a region provided with said concavo-convex pits are located in the same track on the same plane of said recording medium.
Claim 16
Dependent Claim
21 words
An information recording and reproducing apparatus according to claim 14, wherein said magnetic recording layer is laminated on said concavo-convex pits.
Claim 17
Dependent Claim
21 words
An information recording and reproducing apparatus according to claim 14, wherein said concavo-convex pits are formed on said magnetic recording layer.
Claim 18
Dependent Claim
25 words
An information recording and reproducing apparatus according to claim 14, wherein said concavo-convex pits are formed on a layer laminated on said magnetic recording layer.
Claim 19
Dependent Claim
60 words
An information recording and reproducing apparatus according to claim 1, wherein said recording medium records data having three or more values corresponding to change in the dimension of said concavo-convex pits measured along the direction normal to said recording medium; and said data having three or more values are reproduced on the bases of said signal from said light detector.
Claim 20
Dependent Claim
31 words
An information recording and reproducing apparatus according to claim 1, wherein said evanescent wave generating means includes an aperture having a size not more than the wavelength of said laser light.
Claim 21
Dependent Claim
26 words
An information recording and reproducing apparatus according to claim 1, wherein the surface of said concavo-convex pits of said recording medium is made of a metal.
Claim 22
Dependent Claim
20 words
An information recording and reproducing apparatus according to claim 20, wherein said concavo-convex pits are covered with a protective layer.
Claim 23
Dependent Claim
64 words
A recording medium comprising a plurality of concavo-convex pits, to which laser light is emitted, wherein said recording medium further comprises a magnetic recording layer for recording magnetic data by a magnetic head; and both a region provided with said magnetic data and a region provided with said concavo-convex pits are located in the same track on the same plane of said recording medium.
Claim 24
Dependent Claim
64 words
A recording medium comprising a plurality of concavo-convex pits, to which laser light is emitted, wherein said recording medium further comprises a magnetic recording layer for recording magnetic data by a magnetic head; and both a region provided with said magnetic data and a region provided with said concavo-convex pits are located in the same track on the same plane of said recording medium.
Claim 25
Dependent Claim
40 words
A recording medium according to claim 22, wherein a maximum value of the dimension of said concavo-convex pits measured along the direction normal to said recording medium is not more than one eighth of the wavelength of said laser light.
Claim 26
Dependent Claim
18 words
A recording medium according to claim 22, wherein said magnetic recording layer is laminated on said concavo-convex pits.
Claim 27
Dependent Claim
18 words
A recording medium according to claim 22, wherein said concavo-convex pits are formed on said magnetic recording layer.
Claim 28
Dependent Claim
22 words
A recording medium according to claim 22, wherein said concavo-convex pits are formed on a layer laminated on said magnetic recording layer.
Claim 29
Dependent Claim
139 words
An information recording and reproducing method, comprising: a first step for recording data into a recording medium as a plurality of concavo-convex pits, a second step for changing an optical characteristic value of said laser light, using interaction between said laser light and said recording medium, and a third step for detecting said optical characteristic value of said laser light after said interaction occurs, and then outputting a signal in response to said detected optical characteristic value; wherein, at said second step, an evanescent wave is generated from said laser light, and said optical characteristic value of said laser light is changed in accordance with how much said concavo-convex pits of said recording medium influences said evanescent wave, the spacing between said evanescent wave and said concavo-convex pits being such that said concavo-convex pits substantially influence said evanescent wave.
Claim 30
Dependent Claim
139 words
An information recording and reproducing method, comprising: a first step for recording data into a recording medium as a plurality of concavo-convex pits, a second step for changing an optical characteristic value of said laser light, using interaction between said laser light and said recording medium, and a third step for detecting said optical characteristic value of said laser light after said interaction occurs, and then outputting a signal in response to said detected optical characteristic value; wherein, at said second step, an evanescent wave is generated from said laser light, and said optical characteristic value of said laser light is changed in accordance with how much said concavo-convex pits of said recording medium influences said evanescent wave, the spacing between said evanescent wave and said concavo-convex pits being such that said concavo-convex pits substantially influence said evanescent wave.
Claim 31
Dependent Claim
39 words
An information recording and reproducing method according to claim 27, wherein, at said second step, elementary excitation is formed on the surface of said recording medium, and said evanescent wave and said elementary excitation are interacted with each other.
References Cited (Backward Citations)
JPS56140536A
Cited
JPS5936347A
Cited
US4985881A
Cited
US5144552A
Cited
US4978187A
Cited
US5249175A
Cited
JPH02179951A
Cited
JPH03201230A
Cited
JPH02308423A
Cited
JPH0414620A
Cited
JPH0426978A
Cited
JPH0462090A
Cited
US5125750A
Cited
JPH0534129A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-10-30 | 1999-05-01 | 1999-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-10-30 | 2003-05-01 | 2003-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-10-30 | 2007-05-01 | 2007-10-31 | $7700.00 | Window Closed / Lapsed |