US4423137A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Contact printing and etching method of making high density recording medium
Assignee: Quixote Corp
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Filing: 1981-07-31
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Granted: 1983-12-27
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Expires: 2001-07-31
Abstract
Abstract A process for making a radiation-reflecting record carrier, such as a video disc, is provided on which video and/or audio information is stored in an optically readable track in which reflective areas alternate with non-reflective areas, the two areas having different effects on a reading beam in a playback machine so that the information recorded on the carrier may be recovered. The non-reflective areas are formed as apertures in the reflective areas and the underlying substrate is preferably translucent. The disclosed process uses photographic techniques to form a master negative or positive, and to form record carrier replicas from the master. In one disclosed embodiment of the method and apparatus of this invention, a two-sided recording medium comprises two transparent substrates, each of which supports a perforated metallic, reflecting layer. The two substrates are held together by a layer of adhesive disposed between the two reflecting layers.
Inventors
- 👤 Marshall D. Rester
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:01
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/26; G11B7/261; G11B7/252; G11B7/256; G11B7/258; G11B7/2585
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
213 words
A method for fabricating a high density recording medium comprising the following steps: (a) providing a substrate having a first surface covered by a reflecting layer; (b) coating at least a portion of the reflecting layer with a masking layer of a radiation sensitive material, said masking layer having a thickness less than about 0.1 microns; (c) exposing a microscopic pattern on the masking layer by a contact printing step such that a first patterned plurality of microscopic regions of the masking layer, each having a minimum dimension of less than about 0.6 microns, is exposed to a radiation to a different extent than is a second region of the masking layer; (d) then selectively removing the first plurality of microscopic regions of the masking layer to expose a plurality of corresponding regions of the underlying reflecting layer, each corresponding region having a minimum dimension of less than about 0.6 microns; (e) selectively removing the plurality of corresponding regions of the reflecting layer by an etching step to expose a plurality of corresponding regions of the underlying substrate, the second region of the masking layer acting to mask and protect the corresponding region of the underlying reflecting layer during the etching step; and then (f) removing the second region of the masking layer.
Claim 2
Independent Claim
213 words
A method for fabricating a high density recording medium comprising the following steps: (a) providing a substrate having a first surface covered by a reflecting layer; (b) coating at least a portion of the reflecting layer with a masking layer of a radiation sensitive material, said masking layer having a thickness less than about 0.1 microns; (c) exposing a microscopic pattern on the masking layer by a contact printing step such that a first patterned plurality of microscopic regions of the masking layer, each having a minimum dimension of less than about 0.6 microns, is exposed to a radiation to a different extent than is a second region of the masking layer; (d) then selectively removing the first plurality of microscopic regions of the masking layer to expose a plurality of corresponding regions of the underlying reflecting layer, each corresponding region having a minimum dimension of less than about 0.6 microns; (e) selectively removing the plurality of corresponding regions of the reflecting layer by an etching step to expose a plurality of corresponding regions of the underlying substrate, the second region of the masking layer acting to mask and protect the corresponding region of the underlying reflecting layer during the etching step; and then (f) removing the second region of the masking layer.
Claim 3
Dependent Claim
10 words
The method of claim 1 wherein the substrate is translucent.
Claim 4
Dependent Claim
34 words
The method of claim 1 wherein the etching step of the removing step (e) comprises the step of bringing the plurality of corresponding regions of the reflecting layer into contact with an etching solution.
Claim 5
Dependent Claim
12 words
The method of claim 1 wherein the masking layer comprises a photoresist.
Claim 6
Dependent Claim
66 words
The method of claim 1 wherein the coating step (b) comprises the following steps: applying a mixture of a photoresist and a carrier to the reflecting layer, said mixture having a solids content of less than about 5%; baking the applied mixture to drive off a major portion of the carrier; and then cooling the baked mixture at a relative humidity in excess of about 40%.
Claim 7
Dependent Claim
22 words
The method of claim 5 wherein the cooling step is conducted at a relative humidity in the preferred range of about 45-55%.
Claim 8
Dependent Claim
16 words
The method of claim 6 wherein the solids content of the applied mixture is about 1-1/2%.
Claim 9
Dependent Claim
14 words
The method of claim 1 wherein the recording medium is a replica video disc.
Claim 10
Dependent Claim
14 words
The method of claim 1 wherein the recording medium is a replica audio disc.
Claim 11
Independent Claim
243 words
A method for fabricating a high density recording medium comprising the following sequential steps: (a) providing a translucent substrate having a first surface covered by a reflecting layer; (b) applying a mixture of a photosensitive material and a carrier to the reflecting layer, said mixture having a solids content of less than about 5%; (c) baking the applied mixture to drive off a major portion of the carrier, the remaining photosensitive material having a thickness less than about 0.1 microns; (d) cooling the baked mixture; (e) exposing a microscopic pattern on the cooled photosensitive material by a contact printing step such that a first patterned plurality of microscopic regions of the photosensitive material, each having a minimum dimension of less than about 0.6 microns, is exposed to a radiation to a different extent than is a second region of the photosensitive material; (f) then selectively removing the first plurality of microscopic regions of the photosensitive material to expose a plurality of corresponding regions of the underlying reflecting layer, each corresponding region having a minimum dimension of less than about 0.6 microns; (g) selectively removing by etching the plurality of corresponding regions of the reflecting layer to expose a plurality of corresponding regions of the underlying substrate, the second region of the photosensitive material acting to mask and protect the corresponding region of the underlying reflecting layer during the removing by etching step; and then (h) removing the remaining portion of the photosensitive material.
Claim 12
Independent Claim
243 words
A method for fabricating a high density recording medium comprising the following sequential steps: (a) providing a translucent substrate having a first surface covered by a reflecting layer; (b) applying a mixture of a photosensitive material and a carrier to the reflecting layer, said mixture having a solids content of less than about 5%; (c) baking the applied mixture to drive off a major portion of the carrier, the remaining photosensitive material having a thickness less than about 0.1 microns; (d) cooling the baked mixture; (e) exposing a microscopic pattern on the cooled photosensitive material by a contact printing step such that a first patterned plurality of microscopic regions of the photosensitive material, each having a minimum dimension of less than about 0.6 microns, is exposed to a radiation to a different extent than is a second region of the photosensitive material; (f) then selectively removing the first plurality of microscopic regions of the photosensitive material to expose a plurality of corresponding regions of the underlying reflecting layer, each corresponding region having a minimum dimension of less than about 0.6 microns; (g) selectively removing by etching the plurality of corresponding regions of the reflecting layer to expose a plurality of corresponding regions of the underlying substrate, the second region of the photosensitive material acting to mask and protect the corresponding region of the underlying reflecting layer during the removing by etching step; and then (h) removing the remaining portion of the photosensitive material.
Claim 13
Dependent Claim
22 words
The method of claim 10 wherein the cooling step is conducted at a relative humidity in the preferred range of about 45-55%.
Claim 14
Dependent Claim
16 words
The method of claim 10 wherein the solids content of the applied mixture is about 1-1/2%.
Claim 15
Dependent Claim
12 words
The method of claim 10 wherein the photosensitive material comprises a photoresist.
Claim 16
Dependent Claim
14 words
The method of claim 10 wherein the recording medium is a replica video disc.
Claim 17
Dependent Claim
14 words
The method of claim 10 wherein the recording medium is a replica audio disc.
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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) | 1986-12-26 | 1987-06-27 | 1987-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-26 | 1991-06-27 | 1991-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-26 | 1995-06-27 | 1995-12-27 | $7700.00 | Window Closed / Lapsed |