US4783041A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mold for molding optical disc
Assignee: Panasonic Holdings Corp
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Filing: 1987-02-04
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Granted: 1988-11-08
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Expires: 2007-02-04
Abstract
Abstract A mold for molding an optical disc includes a first mold member having a recess, and a second mold having a body and a plate-like sintered ceramic member secured to the body and having a flat seat surface. The recess and the flat seat surface jointly provides a mold cavity when the first and second mold members are mated together. A disc-shaped thin stamper is adapted to be seated on and detachably secured to the flat seat surface. The ceramic member is made of a ceramic material having Rockwell hardness (A-Scale) of not less than 90, so that the flat seat surface is not subjected to undue damage for a prolonged period of time.
Inventors
- 👤 Toshiaki Sakaida
- 👤 Yoshihiko Yuzawa
- 👤 Fumio Iriko
- 👤 Fumio Kagawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 16:14
CPC Classifications
B; B29; B29C; B29C45/00; B29C45/17; B29C45/26; B29C45/263; B29C45/2632; B29C33/00; B29C33/56; B29C45/37; B29D; B29D11/00; B29C2045/2634; B29K; B29K2909/00; B29K2909/02; B29L; B29L2011/00; B29L2017/00; B29L2017/001; B29L2017/003; Y; Y10; Y10S; Y10S425/00; Y10S425/81
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
97 words
A mold for molding an optical disc comprising a first mold member having a first cavity surface and a second mold member movable relative to said first mold member and having a second cavity surface, said first and second cavity surfaces jointly providing a mold cavity when said first and second mold members are mated together, said second cavity surface having a flat seat surface detachably holding a disc-shaped thin stamper thereon when molding said optical disc, said flat seat surface being made of a sintered ceramic material having Rockwell hardness (A-Scale) of not less than 90.
Claim 2
Dependent Claim
97 words
A mold for molding an optical disc comprising a first mold member having a first cavity surface and a second mold member movable relative to said first mold member and having a second cavity surface, said first and second cavity surfaces jointly providing a mold cavity when said first and second mold members are mated together, said second cavity surface having a flat seat surface detachably holding a disc-shaped thin stamper thereon when molding said optical disc, said flat seat surface being made of a sintered ceramic material having Rockwell hardness (A-Scale) of not less than 90.
Claim 3
Dependent Claim
34 words
A mold according to claim 1, in which said second mold member comprises a body and a separate ceramic member fixedly secured to said body, said separate ceramic member having said flat seat surface.
Claim 4
Dependent Claim
28 words
A mold according to claim 1, in which the density of said sintered ceramic material is not less than 85% of a theoretical density of said ceramic material.
Claim 5
Dependent Claim
16 words
A mold according to claim 1, in which said ceramic material is made of silicon carbide.
Claim 6
Dependent Claim
29 words
A mold according to claim 1, in which said flat seat surface has a surface roughness of about 0.05 S to 1.2 S according to Japanese Industrial Standard (JIS).
Claim 7
Dependent Claim
141 words
A mold for molding an optical disc comprising: (a) a first mold member having a first cavity surface; (b) a second mold member having a second cavity surface and movable relative to said first mold member so that said first and said second cavity surfaces jointly form a mold cavity when mated together, said second cavity surface having a flat seat surface being made of a sintered ceramic material having Rockwell hardness (A-Scale) of not less than 90; and (c) a disc-shaped thin stamper having a flat surface and an uneven surface on which information to be molded on said optical disc is patterned, said flat surface being in close adherence to said flat seat surface so that said uneven surface is in contact with said optical disc while molding it so as to mold said pattern on said optical disc.
Claim 8
Dependent Claim
141 words
A mold for molding an optical disc comprising: (a) a first mold member having a first cavity surface; (b) a second mold member having a second cavity surface and movable relative to said first mold member so that said first and said second cavity surfaces jointly form a mold cavity when mated together, said second cavity surface having a flat seat surface being made of a sintered ceramic material having Rockwell hardness (A-Scale) of not less than 90; and (c) a disc-shaped thin stamper having a flat surface and an uneven surface on which information to be molded on said optical disc is patterned, said flat surface being in close adherence to said flat seat surface so that said uneven surface is in contact with said optical disc while molding it so as to mold said pattern on said optical disc.
Claim 9
Dependent Claim
23 words
A mold according to claim 2, in which said separate ceramic member is fixedly secured to said body by means of an adhesive.
Claim 10
Dependent Claim
22 words
A mold according to claim 1, in which said flat surface has a maximum peak-to-peak surface irregularity between 0.05 and 1.2 μm.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-11-08 | 1992-05-09 | 1992-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-08 | 1996-05-09 | 1996-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-08 | 2000-05-09 | 2000-11-08 | $7700.00 | Window Closed / Lapsed |