US3749828A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for improving the centering of stamping matrices for sound and video discs
Assignee: TELDEC Telefunken Decca Schallplatten GmbH
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Filing: 1971-11-23
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Granted: 1973-07-31
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Expires: 1991-11-23
Abstract
Abstract The care and accuracy of centering the negative, e.g. the master or stamping matrix, used in the production of sound and video record discs is improved by preparing the original lacquer foil record so that the negative will have a profile which extends centrically to the record groove spiral. This is accomplished by inserting a centering core, which is adapted to the spindle of the playback system and has a laterally extending flange defining a galvanically reproducible centering edge, into a centering hole in the foil prior to the cutting of the spiral groove containing the recorded information into the lacquer foil.
Inventors
- 👤 W Rohwer
- 👤 H Knothe
- 👤 K Roschmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 03:08
CPC Classifications
B; B29; B29C; B29C43/00; B29C43/02; B29L; B29L2017/00; B29L2017/001; B29L2017/003
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
141 words
In a method for producing a negative from a lacquer foil original for the manufacture of record discs containing sound or video recordings, wherein the negative, i.e., a master or a stamping matrix,is formed from the lacquer foil original recording, in a known manner, either chemically or galvanically, the improvement comprising the steps of: providing the lacquer foil with a centering hole; inserting a hollow centering core, which is adapted to the spindle of the playback system and which is provided with a laterally extending flange defining a galvanically reproduceable centering edge, into said centering hole; cutting a groove spiral containing the recording into the lacquer foil; and then forming the negative from the lacquer foil whereby the negative will include the profile of the laterally extending flange which profile can then be used to center the negative during subsequent processing.
Claim 2
Dependent Claim
141 words
In a method for producing a negative from a lacquer foil original for the manufacture of record discs containing sound or video recordings, wherein the negative, i.e., a master or a stamping matrix,is formed from the lacquer foil original recording, in a known manner, either chemically or galvanically, the improvement comprising the steps of: providing the lacquer foil with a centering hole; inserting a hollow centering core, which is adapted to the spindle of the playback system and which is provided with a laterally extending flange defining a galvanically reproduceable centering edge, into said centering hole; cutting a groove spiral containing the recording into the lacquer foil; and then forming the negative from the lacquer foil whereby the negative will include the profile of the laterally extending flange which profile can then be used to center the negative during subsequent processing.
Claim 3
Dependent Claim
55 words
The method for producing negatives for the manufacture of video or sound record discs as defined in claim 1 including the step of simultaneously cleansing and sensitizing the lacquer foil and centering core in a combined bath after the step of cutting of a spiral groove and prior to thee step of forming the negative.
Claim 4
Dependent Claim
32 words
The method for producing negatives for the manufacture of video and sound record discs as defined in claim 2 wherein the cleansing and sensitizing is additionally effected by means of ultrasonic cleaning.
Claim 5
Dependent Claim
168 words
In a method for producing a negative from a lacquer foil original recording for the manufacture of record discs containing sound or video recordings, wherein the negative, i.e., a master or a stamping matrix, is formed from the lacquer foil original recording, in a known manner, either chemically or galvanically, the improvement comprising the steps of: providing the lacquer foil with a centering hole; providing a hollow centering core having an inner diameter which corresponds to the diameter of the spindle of the playback system and a laterally extending flange defining a concentric galvanically reproducible centering edge; inserting the centering core into the centering hole with the flange extending along the surface of the lacquer foil on which the recording is to be made; cutting a groove spiral containing the recording into the lacquer foil; and then forming the negative from the original, whereby the negative will include the profile of the laterally extending flange which profile can then be used to center the negative during subsequent processing.
Claim 6
Dependent Claim
168 words
In a method for producing a negative from a lacquer foil original recording for the manufacture of record discs containing sound or video recordings, wherein the negative, i.e., a master or a stamping matrix, is formed from the lacquer foil original recording, in a known manner, either chemically or galvanically, the improvement comprising the steps of: providing the lacquer foil with a centering hole; providing a hollow centering core having an inner diameter which corresponds to the diameter of the spindle of the playback system and a laterally extending flange defining a concentric galvanically reproducible centering edge; inserting the centering core into the centering hole with the flange extending along the surface of the lacquer foil on which the recording is to be made; cutting a groove spiral containing the recording into the lacquer foil; and then forming the negative from the original, whereby the negative will include the profile of the laterally extending flange which profile can then be used to center the negative during subsequent processing.
References Cited (Backward Citations)
US1253374A
Cited
US1755743A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-30 | 1977-01-29 | 1977-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-30 | 1981-01-29 | 1981-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-30 | 1985-01-29 | 1985-07-31 | $7700.00 | Window Closed / Lapsed |