US3636526A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Information-recording system employing amorphous materials
Assignee: Energy Conversion Devices Inc
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Filing: 1970-06-08
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Granted: 1972-01-18
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Expires: 1990-06-08
Abstract
Abstract The systems disclosed herein record information on an amorphous thin film by applying light to selected regions of the film. The temperature in these regions increases to the point where the film softens. Upon removal of the light the film returns to the solid phase leaving enclosed voids in the film. The information can be read from the amorphous film by irradiating the film with light of a wavelength in the order of magnitude of the size of the voids. The light is scattered or absorbed by multiple reflections produced by the voids allowing the selected regions to be readily detected. In order to erase the information the amorphous film is heated to the softening point, but not to a temperature as high as the temperature reached during recording. The softened amorphous film flows into the voids erasing the stored information.
Inventors
- 👤 Julius Feinleib
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:32
CPC Classifications
G; G11; G11C; G11C13/00; G11C13/04; G11C13/048; G03; G03C; G03C1/00; G03C1/705; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/242; G11B7/243; G11B2007/24302; G11B2007/24316; G11B2007/24318; G11B2007/24324; G11B7/004; G11B7/0045; G11B7/00452; G11B7/252; G11B7/253; G11B7/2531; G11B7/257; G11B7/2572
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
46 words
The system as defined in claim 1 wherein said amorphous film expands in response to heat produced by application of said electromagnetic energy and contracts after said electromagnetic energy is removed thereby leaving said voids in those selected regions wherein said certain threshold temperature is exceeded.
Claim 2
Dependent Claim
42 words
The system as defined in claim 1 further characterized by the addition of a layer of material in contact with a surface of said amorphous film upon which said electromagnetic energy is applied, and which material is transparent to said electromagnetic energy.
Claim 3
Dependent Claim
56 words
The system as defined in claim 3 wherein said amorphous film and layer of material exhibit a surface adhesion at the interface therebetween prior to heating above said certain threshold temperature, and exhibit a reduction in said adhesion at said interface after being heated above said certain threshold temperature, thereby producing said voids at said interface.
Claim 4
Dependent Claim
132 words
An information-recording system comprising: a source of electromagnetic energy; an amorphous film capable of being softened and vaporized in response to heat produced by application of said electromagnetic energy; writing means for applying to selected regions of said film, said electromagnetic energy in sufficient amount to heat said film, softening and vaporizing portions thereof, and forming vapor pressure bubbles at said selected regions; means for preventing the escape of said vapor bubbles from said film thereby causing said vapor to condense inside said bubbles leaving voids in said film; reading means for detecting said selected regions of said film in which said voids reside; and erasing means for applying to said film energy in sufficient amount to soften but not vaporize said film, whereby said softened film collapses to fill said voids.
Claim 5
Dependent Claim
48 words
The system as defined in claim 5 wherein said means for preventing the escape of said vapor bubbles includes a layer of material in contact with a surface of said amorphous film upon which said electromagnetic energy is applied, and which material is transparent to said electromagnetic energy.
Claim 6
Dependent Claim
31 words
The system as defined in claim 6 further characterized by the addition of a plastic undercoating sandwiched between said film and material, and which plastic is transparent to said electromagnetic energy.
Claim 7
Dependent Claim
59 words
The system as defined in claim 5 wherein said means for preventing the escape of said vapor bubbles includes a focusing means for converging said electromagnetic energy at a point within said film which is sufficiently distant from any outer surfaces of said film to prevent said vapor bubbles from flowing through said film to an outer surface thereof.
Claim 8
Dependent Claim
18 words
The system as defined in claim 1 wherein said amorphous film is composed of an amorphous semiconductor material.
Claim 9
Dependent Claim
14 words
The system as defined in claim 9 wherein said amorphous semiconductor material includes selenium.
Claim 10
Dependent Claim
16 words
The system as defined in claim 1 wherein said amorphous film exhibits a high refractive index.
Claim 11
Dependent Claim
15 words
The system as defined in claim 1 wherein said amorphous film is a chalcogenide glass.
Claim 12
Dependent Claim
13 words
The system as defined in claim 1 wherein said electromagnetic energy is light.
Claim 13
Dependent Claim
26 words
The system as defined in claim 12 wherein the diameter of said vapor bubbles is in the order of magnitude of the wavelength of said light.
Claim 14
Dependent Claim
17 words
The system as defined in claim 1 wherein said source of variable electromagnetic energy is a laser.
Claim 15
Dependent Claim
49 words
The system as defined in claim 1 wherein said writing means includes means for directing said electromagnetic energy into discrete ares of said film, each area being separated sufficiently to provide thermal isolation so that the operation of said writing means and erasing does not overlap on said film.
Claim 16
Dependent Claim
25 words
The system as defined in claim 16 wherein said erasing means includes means for directing said electromagnetic energy into selected ones of said discrete areas.
Claim 17
Dependent Claim
37 words
The system As defined in claim 16 wherein said writing means includes means for shaping said electromagnetic energy into a plurality of pulses of energy, each pulse being directed into a different discrete area of said film.
Claim 18
Dependent Claim
28 words
The system as defined in claim 18 wherein said erasing means includes means for directing a pulse of said electromagnetic energy into selected ones of said discrete areas.
Claim 19
Dependent Claim
36 words
The system as defined in claim 19 wherein the pulses applied to said film by said writing means contain a greater amount of electromagnetic energy than the pulses applied to said film by said erasing means.
Claim 20
Dependent Claim
49 words
The system as defined in claim 1 wherein said reading means includes means for directing said electromagnetic energy on selected regions of said film, and sensing means for determining changes produced in said electromagnetic energy by the relative difference in the index of refraction between said film and voids.
Claim 21
Dependent Claim
13 words
The system as defined in claim 21 wherein said electromagnetic energy is light.
Claim 22
Dependent Claim
19 words
The system as defined in claim 22 wherein said light is scattered upon striking a void in said film.
Claim 23
Dependent Claim
18 words
The system as defined in claim 22 wherein said light is absorbed by multiple reflections within said voids.
Claim 24
Dependent Claim
21 words
The system as defined in claim 23 wherein changes in said light are sensed by observing light reflected from said film.
Claim 25
Dependent Claim
27 words
The system as defined in claim 24 wherein changes in said light are sensed by observing the amount of absorption of said light transmitted through said film.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-17 | 1975-07-19 | 1976-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-17 | 1979-07-19 | 1980-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-17 | 1983-07-19 | 1984-01-18 | $7700.00 | Window Closed / Lapsed |