US4042526A
Expired / Lapsed
US
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Non-crystalline substance having an optical memory effect
Assignee: Hoya Glass Works Ltd
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Filing: 1975-04-08
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Granted: 1977-08-16
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Expires: 1995-04-08
Abstract
Abstract A non-crystalline substance for use in an optical memory device which consists of an As-Se system non-crystalline material and the additional third component(s) Zn, Au, or Ag and/or Cu. The substance is characterized by its transmission ability in the visible region as well as in the I.R. region and its extreme reduction of transmittance upon irradiation with, e.g., a laser beam.
Inventors
- 👤 Yoshiyuki Asahara
- 👤 Tetsuro Izumitani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:36
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/242; G11B7/243; G03; G03C; G03C1/00; G03C1/705; G11B2007/24302; G11B2007/24304; G11B2007/24308; G11B2007/24314; G11B2007/24316
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
156 words
A method of storing information in an optically sensitive non-crystalline substance which comprises: a. irradiating the non-crystalline substance with a high intensity light source to change its transmittance from one value to a second value, said non-crystalline substance comprising 25-65 atomic % of As, 25-65 atomic % of Se and additionally at least one of 0.1-10 atomic % of Zn, 0.1-8 atomic % of Au, and 0-32 atomic % of Ag and 0-25 atomic % of Cu, the total amount of Cu + Ag being 0.1-35 atomic %; the total being 100 atomic % in all; b. discontinuing the irradiation of Step (a) so that said non-crystalline substance can retain said second value of transmittance and thereby act as a memory device for storing information, and c. heating said non-crystalline substance to a temperature of 170°-200° C. to cause said second value of transmittance to return to said first value and thereby erase said stored information.
Claim 2
Independent Claim
156 words
A method of storing information in an optically sensitive non-crystalline substance which comprises: a. irradiating the non-crystalline substance with a high intensity light source to change its transmittance from one value to a second value, said non-crystalline substance comprising 25-65 atomic % of As, 25-65 atomic % of Se and additionally at least one of 0.1-10 atomic % of Zn, 0.1-8 atomic % of Au, and 0-32 atomic % of Ag and 0-25 atomic % of Cu, the total amount of Cu + Ag being 0.1-35 atomic %; the total being 100 atomic % in all; b. discontinuing the irradiation of Step (a) so that said non-crystalline substance can retain said second value of transmittance and thereby act as a memory device for storing information, and c. heating said non-crystalline substance to a temperature of 170°-200° C. to cause said second value of transmittance to return to said first value and thereby erase said stored information.
Claim 3
Dependent Claim
24 words
The method of claim 1, wherein said additional component is employed in an amount of at least 1.0 atomic % of said non-crystalline substance.
Claim 4
Dependent Claim
15 words
The method of claim 2, wherein said additional component is 0.1-10 atomic % of Zn.
Claim 5
Dependent Claim
15 words
The method of claim 2, wherein said additional component is 0.1-8 atomic % of Au.
Claim 6
Dependent Claim
15 words
The method of claim 4, wherein said additional component is 1.0-8 atomic % of Au.
Claim 7
Dependent Claim
15 words
The method of claim 2, wherein said additional component is 0.1-32 atomic % of Ag.
Claim 8
Dependent Claim
15 words
The method of claim 2, wherein said additional component is 1.0-32 atomic % of Ag.
Claim 9
Dependent Claim
20 words
The method of claim 2, wherein said additional component is 0.1-35 atomic % Ag + Cu, both elements being present.
Claim 10
Dependent Claim
21 words
The method of claim 2, wherein said additional component is 1.0-35 atomic % of Ag + Cu, both elements being present.
Claim 11
Dependent Claim
23 words
The method of claim 2, wherein said additional component is more than one of Zn, Au and a mixture of Ag plus Cu.
Claim 12
Dependent Claim
24 words
The method of claim 1, wherein said additional component is present in an amount of at least 1.0 atomic % of Cu + Ag.
Claim 13
Dependent Claim
24 words
The method of claim 1, wherein said additional component is present in an amount of at least 5-20 atomic % of Cu + Ag.
Claim 14
Dependent Claim
14 words
The method of claim 1 wherein said high intensity light source is a laser.
References Cited (Backward Citations)
US3720921A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-08-15 | 1981-02-14 | 1981-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-15 | 1985-02-14 | 1985-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-15 | 1989-02-14 | 1989-08-16 | $7700.00 | Window Closed / Lapsed |