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US4348461A Expired / Lapsed US ⏱️ 0.0 years remaining

Recording member

Assignee: Hitachi Ltd
•
Filing: 1980-06-18
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Granted: 1982-09-07
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Expires: 2000-06-18
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Abstract

Abstract A recording member having a predetermined substrate, and a thin film which is formed on the substrate and which is formed with recesses or pits for recording information when irradiated with a working beam, characterized in that said thin film is formed of an inorganic material which contains at least arsenic, selenium and tellurium, and that a distribution of either of said Se and said Te decreases from a part near the surface of said thin film towards a central part thereof, while a distribution of said As increases from a part near the surface towards said central part, is disclosed. This recording member can afford a high signal-to-noise ratio and a long lifetime. It is preferable that the distribution of said Se decreases so as to be at least 50 atomic-% in terms of the content of said Se in a part being the closest to the surface of said thin film and to be at most 40 atomic-% in terms of the average content of said Se over the whole thin film, and that the distribution of said As increases so as to be at most 15 atomic-% in terms of the content of said As in the closest part and to be 5 to 35 atomic-% in terms of the average content of said As in said whole thin film. The Se-Te-As-based material may well be doped with at least one element selected from the group consisting of Ge, S, Tl, Sn, Pb, In and Ta, within a range of 2 to 15 atomic-%.

Inventors

  • 👤 Motoyasu Terao
  • 👤 Yoshio Taniguchi
  • 👤 Shinkichi Horigome
  • 👤 Masahiro Ojima
  • 👤 Kazuo Shigematsu
  • 👤 Keizo Kato
  • 👤 Yoshinori Miyamura
  • 👤 Seiji Yonezawa

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 20:36
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/242; G11B7/243; G03; G03C; G03C1/00; G03C1/705; G11B2007/24302; G11B2007/24314; G11B2007/24316; Y; Y10; Y10S; Y10S428/00; Y10S428/913; Y10S430/00; Y10S430/146; Y10S430/165; Y10T; Y10T428/00; Y10T428/31

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 177 words
A recording member having a predetermined substrate, and a thin film which is formed on the substrate and which is formed with recesses for recording information when irradiated with a working beam; said thin film being formed of an inorganic material containing at least arsenic, selenium and tellurium, with the concentration of the selenium decreasing from a part of the film near the surface of said thin film towards a central part thereof and the concentration of the arsenic increasing from a part of the film near the surface towards the central part of said film; the concentration of selenium being at lest 50 atomic-% in a part of said thin film that is the closest to said surface thereof with the average concentration of selenium being at most 40 atomic-% over the whole thin film, and the concentration of arsenic being at most 15 atomic-% in a part of said thin film that is the closest to said surface thereof with the average concentration of arsenic being 5 to 35 atomic-% over the whole thin film.
Claim 2
Dependent Claim 177 words
A recording member having a predetermined substrate, and a thin film which is formed on the substrate and which is formed with recesses for recording information when irradiated with a working beam; said thin film being formed of an inorganic material containing at least arsenic, selenium and tellurium, with the concentration of the selenium decreasing from a part of the film near the surface of said thin film towards a central part thereof and the concentration of the arsenic increasing from a part of the film near the surface towards the central part of said film; the concentration of selenium being at lest 50 atomic-% in a part of said thin film that is the closest to said surface thereof with the average concentration of selenium being at most 40 atomic-% over the whole thin film, and the concentration of arsenic being at most 15 atomic-% in a part of said thin film that is the closest to said surface thereof with the average concentration of arsenic being 5 to 35 atomic-% over the whole thin film.
Claim 3
Dependent Claim 48 words
A recording member as defined in claim 1, wherein said thin film is doped with at least one element selected from the group consisting of germanium, sulfur, thallium, tin, lead, indium and tantalum, in a range of 2 to 15 atomic-% in terms of a total quantity thereof.
Claim 4
Dependent Claim 21 words
A recording member as defined in claim 1, wherein said surface of said thin film is covered with a protective coating.
Claim 5
Dependent Claim 35 words
A recording member as defined in claim 1, wherein the average content of arsenic in said film is from 10 to 25 atomic-% and the average concentration of selenium is from 5 to 25 atomic-%.
Claim 6
Dependent Claim 32 words
A recording member as defined in claim 4, wherein the concentration of arsenic in the part of said thin film that is closest to said surface is from 2 to 10 atomic-%.
Claim 7
Dependent Claim 18 words
A recording member as defined in claim 1, wherein said thin film has a thickness from 200-1,000 A.
Claim 8
Dependent Claim 26 words
A recording member as defined in claim 1, wherein the concentration of arsenic varies with a gradient of 1/100 to 1/3 atomic-%/A in said thin film.

References Cited (Backward Citations)

US2822300A Cited
US3901996A Cited
US4214249A Cited
US3971874A Cited
US4032691A Cited
US4069487A Cited
US4238803A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1985-09-06 1986-03-08 1986-09-07 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1989-09-06 1990-03-08 1990-09-07 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1993-09-06 1994-03-08 1994-09-07 $7700.00 Window Closed / Lapsed

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