US4818648A
Expired / Lapsed
US
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Optical memory element
Assignee: Sharp Corp
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Filing: 1986-11-25
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Granted: 1989-04-04
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Expires: 2006-11-25
Abstract
Abstract An optical memory element comprising a substrate with grooves functioning as grooves for, for example, controlling the position of a laser beam, wherein said substrate is composed of a glass containing SiO 2 in the range of 51 to 71% by weight, Na 2 O in the range of 10 to 18% by weight, K 2 O in the range of 0 to 8% by weight, Al 2 O 3 in the range of 12 to 22% by weight, and B 2 O 3 in the range of 0 to 9% by weight.
Inventors
- 👤 Kenji Ohta
- 👤 Akira Takahashi
- 👤 Tetsuya Inui
- 👤 Hiroyuki Katayama
- 👤 Junji Hirokane
- 👤 Yoshiteru Murakami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:27
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; C; C03; C03C; C03C3/00; C03C3/04; C03C3/076; C03C3/083; C03C3/089; C03C3/091; G11B7/241; G11B7/252; G11B7/253; G11B7/2531; G11B7/26; G11B7/261; G11B7/242; G11B7/243; G11B2007/24302; G11B2007/24304; G11B7/2533; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24479; Y10T428/2457
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
93 words
In an optical memory element comprising a substrate with grooves from which signals are read out, and recording medium disposed on said substrate, said substrate is composed of a glass containing SiO 2 in the range of 51 to 71% by weight, Na 2 O in the range of 10 to 18% by weight, K 2 O in the range of 0 to 8% by weight, Al 2 O 3 in the range of 12 to 22% by weight, and B 2 O 3 in the range of 0 to 9% by weight.
Claim 2
Dependent Claim
93 words
In an optical memory element comprising a substrate with grooves from which signals are read out, and recording medium disposed on said substrate, said substrate is composed of a glass containing SiO 2 in the range of 51 to 71% by weight, Na 2 O in the range of 10 to 18% by weight, K 2 O in the range of 0 to 8% by weight, Al 2 O 3 in the range of 12 to 22% by weight, and B 2 O 3 in the range of 0 to 9% by weight.
Claim 3
Dependent Claim
107 words
An optical memory element according to claim 1, wherein said grooves are formed by disposing a photoresist film on said glass substrate; disposing a masking board, on which groove information is patterned, on said photo-resist film; applying light to said masking board to form a guide groove pattern latent image on said photo-resist film; developing said guide groove pattern latent image formed on said photoresist film to form the grooves in the photo-resist film; subjecting said glass substrate covered with said photo-resist film containing the grooves to an etching treatment to form the grooves in said glass substrate; and removing said photo-resist film from said glass substrate.
Claim 4
Dependent Claim
25 words
An optical memory element according to claim 2, wherein said etching treatment is conducted by either a dry etching technique or a wet etching technique.
Claim 5
Dependent Claim
89 words
In an optical memory element comprising a substrate with grooves from which signals are read out, the element wherein said substrate is composed of a glass comprising: SiO 2 in the range of 51 to 71% by weight, Na 2 O in the range of 10 to 18% by weight, K 2 O in the range of 0 to 8% by weight, Al 2 O 3 in the range of 12 to 22% by weight, and B 2 O 3 in the range of 0 to 9% by weight.
Claim 6
Dependent Claim
89 words
In an optical memory element comprising a substrate with grooves from which signals are read out, the element wherein said substrate is composed of a glass comprising: SiO 2 in the range of 51 to 71% by weight, Na 2 O in the range of 10 to 18% by weight, K 2 O in the range of 0 to 8% by weight, Al 2 O 3 in the range of 12 to 22% by weight, and B 2 O 3 in the range of 0 to 9% by weight.
Claim 7
Dependent Claim
107 words
An optical memory element according to claim 4, wherein said grooves are formed by: disposing a photo-resist film on said glass substrate; disposing a masking board, on which groove information is patterned, on said photo-resist film; applying light to said masking board to form a guide groove pattern latent image on said photo-resist film; developing said guide groove pattern latent image formed on said photo-resist film to form the grooves in the photo-resist film; subjecting said glass substrate covered with said photo-resist film containing the grooves to an etching treatment to form the grooves in said glass substrate; and removing said photo-resist film from said glass substrate.
Claim 8
Dependent Claim
24 words
An optical memory element according to claim 5 wherein said etching treatment is conducted by a technique selected from dry etching and wet etching.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1992-04-03 | 1992-10-03 | 1993-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-03 | 1996-10-03 | 1997-04-04 | $3760.00 | Window Closed / Lapsed |
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