US4723903A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stamper for replicating high-density data recording disks
Assignee: Hitachi Ltd
•
Filing: 1985-06-18
•
Granted: 1988-02-09
•
Expires: 2005-06-18
Abstract
Abstract Herein disclosed are a stamper for replicating a high-density data recording disk, wherein there is formed on a substrate a multi-layered metal film, in which a plurality of metals of different kinds are laminated and which has a thickness equal to the depth of a pit, by an etching technique having a selectivity for the kinds of metals and a process for producing that stamper. Since one or more pits having different depths are formed very precisely, the recording density is increased, and the quality of a readout data signal is improved while dispensing with the plating step. As a result, there can be attained an effect that the productivity and economy can be improved.
Inventors
- 👤 Shinji Okazaki
- 👤 Masaru Ito
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:02
CPC Classifications
G; G11; G11B; G11B23/00; G11B23/0057; Y; Y10; Y10S; Y10S425/00; Y10S425/03; Y10S425/81; Y10T; Y10T428/00; Y10T428/12; Y10T428/12389
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
114 words
A stamper for replicating a high-density data recording disk, which is recorded with data in pit-shaped and track-shaped undulating patterns, comprising: a substrate; and a plurality of metal films on said substrate, said plurality of metal films including two layers, a first layer on the substrate and a second layer on the first layer, the second layer being formed with track-shaped undulating pattern and the first and second layers being formed with the pit-shaped undulating pattern, and wherein said track-shaped undulating pattern has a depth substantially equal to the thickness of said second layer, the depth of the pit-shaped undulating pattern being substantially equal to the total thickness of the first and second layers.
Claim 2
Dependent Claim
114 words
A stamper for replicating a high-density data recording disk, which is recorded with data in pit-shaped and track-shaped undulating patterns, comprising: a substrate; and a plurality of metal films on said substrate, said plurality of metal films including two layers, a first layer on the substrate and a second layer on the first layer, the second layer being formed with track-shaped undulating pattern and the first and second layers being formed with the pit-shaped undulating pattern, and wherein said track-shaped undulating pattern has a depth substantially equal to the thickness of said second layer, the depth of the pit-shaped undulating pattern being substantially equal to the total thickness of the first and second layers.
Claim 3
Dependent Claim
25 words
A stamper for replicating a high-density data recording disk according to claim 1, wherein said track-shaped undulating pattern is a guide track for pickup drive.
Claim 4
Dependent Claim
21 words
A stamper for replicating a high-density data recording disk according to claim 1, wherein said substrate is made of a metal.
Claim 5
Dependent Claim
15 words
A stamper for replicating a high-density data recording disk according to claim 3, wherein the
Claim 6
Dependent Claim
26 words
A stamper for replicating a high-density data recording disk according to claim 4, wherein said metal of the substrate and said another metal are different metals.
Claim 7
Dependent Claim
34 words
A stamper for replicating a high-density data recording disk according to claim 4, wherein the another metal coated on the surface of said substrate and the metal of said first layer are different metals.
Claim 8
Dependent Claim
25 words
A stamper for replicating a high-density data recording disk according to claim 1, wherein said pit-shaped undulating pattern is a pit for an address signal.
Claim 9
Dependent Claim
25 words
A stamper for replicating a high-density data recording disk according to claim 2, wherein said pit-shaped undulating pattern is a pit for an address signal.
Claim 10
Dependent Claim
24 words
A stamper for replicating a high-density data recording disk according to claim 1, wherein the pit-shaped undulating pattern is a pit for a signal.
Claim 11
Dependent Claim
24 words
A stamper for replicating a high-density data recording disk according to claim 2, wherein said pit-shaped undulating pattern is a pit for a signal.
Claim 12
Dependent Claim
25 words
A stamper for replicating a high-density data recording disk according to claim 1, wherein the pit-shaped undulating patterns are spaced from the track-shaped undulating patterns.
Claim 13
Dependent Claim
133 words
A stamper for replicating a high-density data recording disk which is recorded with data in pit-shaped and track-shaped undulating patterns, made by a process comprising: the step of coating a substrate with a plurality of metal films, the plurality of metal films including two layers, a first layer on the substrate and a second layer on the first layer; and the step of forming the pit-shaped and track-shaped undulating patterns, the second layer being formed with the track-shaped undulating pattern and the first and second layers being formed with the pit-shaped undulating pattern, such that the depth of the track-shaped undulating pattern is substantially equal to the thickness of said second layer, and the depth of the pit-shaped undulating pattern is substantially equal to the total thickness of the first and second layers.
Claim 14
Dependent Claim
133 words
A stamper for replicating a high-density data recording disk which is recorded with data in pit-shaped and track-shaped undulating patterns, made by a process comprising: the step of coating a substrate with a plurality of metal films, the plurality of metal films including two layers, a first layer on the substrate and a second layer on the first layer; and the step of forming the pit-shaped and track-shaped undulating patterns, the second layer being formed with the track-shaped undulating pattern and the first and second layers being formed with the pit-shaped undulating pattern, such that the depth of the track-shaped undulating pattern is substantially equal to the thickness of said second layer, and the depth of the pit-shaped undulating pattern is substantially equal to the total thickness of the first and second layers.
Claim 15
Dependent Claim
29 words
A stamper for replicating a high-density data recording disk according to claim 12, wherein the undulating patterns are patterns formed by removing portions of the plurality of metal films.
Claim 16
Dependent Claim
20 words
A stamper for replicating a high-density data recording disk according to claim 13, wherein the removing is performed by etching.
References Cited (Backward Citations)
US3532587A
Cited
US4259433A
Cited
DE3019189A1
Cited
US4482511A
Cited
US4495026A
Cited
EP0108258A1
Cited
US4519872A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-02-08 | 1991-08-10 | 1992-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-02-08 | 1995-08-10 | 1996-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-02-08 | 1999-08-10 | 2000-02-09 | $7700.00 | Window Closed / Lapsed |