US3637291A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Display device with inherent memory
Assignee: NCR Voyix Corp
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Filing: 1970-02-11
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Granted: 1972-01-25
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Expires: 1990-02-11
Abstract
Abstract A visual display device utilizing encapsulated liquid crystals as the image-containing medium, the encapsulated liquid crystals evidencing two chromatic states; i.e., a first translucent state and a second opaque state. The encapsulated liquid crystals serve as the image-containing medium (display screen) of the display device, and writing is accomplished by first rendering the encapsulated liquid crystals translucent by the application of a momentary electrostatic field and the erasing of selected areas of translucency by raising the temperature of selected areas of the encapsulated liquid crystals by the selective application of heat and allowing the subsequent cooling thereof, thereby transposing the selected translucent areas into opaque areas. The temperature must be sufficient to cause the transition of the encapsulated liquid crystals into an isotropic liquid. The point at which this transition occurs is known as the clear point. The images manifest themselves in the eyes of a viewer as a color, the color being determined by the wavelength of the incident light reflected by the opaque areas.
Inventors
- 👤 Clarence W Kessler
- 👤 Theodore T Trzaska
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:56
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/132; G02F1/133; G02F1/1333; G02F1/1334
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
170 words
A visual display device with memory, comprising: a layer of electrostatically and thermally sensitive material having the property of being rendered translucent when subjected momentarily to an electrostatic field and the property of being rendered opaque when subjected to heat and subsequent cooling thereof; a plurality of first and second field electrodes, with at least one field electrode intimately positioned on either side of said layer of electrostatically and thermally sensitive material; an array of high-resistance thermal heating elements positioned immediately adjacent to said first field electrode; means for energizing said field electrodes, thereby establishing an electrostatic field for rendering said electrostatically and thermally sensitive material translucent; means for establishing a current in selected ones of said thermal heating elements for raising the temperature level thereof and thereby altering the light-reflecting properties of those portions of said electrostatically and thermally sensitive material which are in close proximity to said selected heating elements; and heat stabilizing means for maintaining said electrostatically and thermally sensitive material at a substantially constant reference temperature.
Claim 2
Dependent Claim
170 words
A visual display device with memory, comprising: a layer of electrostatically and thermally sensitive material having the property of being rendered translucent when subjected momentarily to an electrostatic field and the property of being rendered opaque when subjected to heat and subsequent cooling thereof; a plurality of first and second field electrodes, with at least one field electrode intimately positioned on either side of said layer of electrostatically and thermally sensitive material; an array of high-resistance thermal heating elements positioned immediately adjacent to said first field electrode; means for energizing said field electrodes, thereby establishing an electrostatic field for rendering said electrostatically and thermally sensitive material translucent; means for establishing a current in selected ones of said thermal heating elements for raising the temperature level thereof and thereby altering the light-reflecting properties of those portions of said electrostatically and thermally sensitive material which are in close proximity to said selected heating elements; and heat stabilizing means for maintaining said electrostatically and thermally sensitive material at a substantially constant reference temperature.
Claim 3
Dependent Claim
18 words
The device as described in claim 1 wherein said electrostatically and thermally sensitive material comprises encapsulated liquid crystals.
Claim 4
Dependent Claim
14 words
The device as described in claim 1 wherein said second field electrode is transparent.
Claim 5
Dependent Claim
48 words
The device as described in claim 1 wherein a said heat stabilizing means comprises a temperature-sensing element in contact with said visual display device, a display heating element, and a temperature controller operated by said temperature-sensing element and capable of selectively applying current to said display heating element.
Claim 6
Dependent Claim
202 words
A visual display device with memory, comprising: a substrate; a plurality of high-resistance thermal heating elements positioned on said substrate; a thin layer of dielectric material overlying said thermal heating elements; a first field electrode overlying said dielectric material; a layer of electrostatically and thermally sensitive material, overlying said field electrode, having the property of being rendered translucent when subjected momentarily to an electrostatic field and the property of being rendered opaque when raised to a temperature at least equal to the clear point of said material and the subsequent cooling thereof; a transparent field electrode overlying said layer of electrostatically and thermally sensitive material; a transparent protective covering overlying said transparent field electrode; means for energizing said field electrode, thereby establishing an electrostatic field for rendering said electrostatically and thermally sensitive material translucent; means for establishing a current in selected ones of said thermal heating elements for raising the temperature level of those portions of said electrostatically and thermally sensitive material which are in close proximity to said selected heating elements, thereby altering the light-reflecting properties of said electrostatically and thermally sensitive material; and heat stabilizing means for maintaining said electrostatically and thermally sensitive material at a substantially constant reference temperature.
Claim 7
Dependent Claim
202 words
A visual display device with memory, comprising: a substrate; a plurality of high-resistance thermal heating elements positioned on said substrate; a thin layer of dielectric material overlying said thermal heating elements; a first field electrode overlying said dielectric material; a layer of electrostatically and thermally sensitive material, overlying said field electrode, having the property of being rendered translucent when subjected momentarily to an electrostatic field and the property of being rendered opaque when raised to a temperature at least equal to the clear point of said material and the subsequent cooling thereof; a transparent field electrode overlying said layer of electrostatically and thermally sensitive material; a transparent protective covering overlying said transparent field electrode; means for energizing said field electrode, thereby establishing an electrostatic field for rendering said electrostatically and thermally sensitive material translucent; means for establishing a current in selected ones of said thermal heating elements for raising the temperature level of those portions of said electrostatically and thermally sensitive material which are in close proximity to said selected heating elements, thereby altering the light-reflecting properties of said electrostatically and thermally sensitive material; and heat stabilizing means for maintaining said electrostatically and thermally sensitive material at a substantially constant reference temperature.
References Cited (Backward Citations)
US3322485A
Cited
US3529156A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-24 | 1975-07-26 | 1976-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-24 | 1979-07-26 | 1980-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-24 | 1983-07-26 | 1984-01-25 | $7700.00 | Window Closed / Lapsed |