US4249800A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Display device
Assignee: US Philips Corp
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Filing: 1978-12-04
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Granted: 1981-02-10
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Expires: 1998-12-04
Abstract
Abstract In a display device having a liquid display medium, for example liquid crystal, the support plates must be kept accurately spaced apart. This is done by means of a monolayer of grains having a hard core and a thermoplastic envelope.
Inventors
- 👤 Aloysius M. J. M. Spruijt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 06:36
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1339; G02F1/13392; Y; Y10; Y10S; Y10S359/00; Y10S359/90
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
99 words
A method of making a display device with two support plates spaced apart by grains of a hard material having uniform diameters enveloped by a thermoplastic envelope comprising the steps of suspending the grains in a photosensitive lacquer on one of the plates, exposing the photosensistive lacquer to radiation through a patterned mask, developing the exposed photosensitive lacquer, whereby the grains are present only in the locations corresponding to the pattern of the mask, and pressing the plates together with the grains therebetween while raising the temperature of the thermoplastic envelopes to a temperature sufficiently to soften the same.
Claim 2
Independent Claim
99 words
A method of making a display device with two support plates spaced apart by grains of a hard material having uniform diameters enveloped by a thermoplastic envelope comprising the steps of suspending the grains in a photosensitive lacquer on one of the plates, exposing the photosensistive lacquer to radiation through a patterned mask, developing the exposed photosensitive lacquer, whereby the grains are present only in the locations corresponding to the pattern of the mask, and pressing the plates together with the grains therebetween while raising the temperature of the thermoplastic envelopes to a temperature sufficiently to soften the same.
Claim 3
Dependent Claim
19 words
A method as recited in claim 1, wherein the photosensitive lacquer is polyvinyl alcohol made photosensitive with ammonium bichromate.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-02-10 | 1984-08-11 | 1985-02-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-10 | 1988-08-11 | 1989-02-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-10 | 1992-08-11 | 1993-02-10 | $7700.00 | Window Closed / Lapsed |