Title: Thermoelectric display cell for recording images line by line

Do you think this is a good invention? Vote now:

Votes so far: For:(0) Against:(0)
Claims: What we claim is:

1. A display device for displaying images represented by a video signal comprising successive pluralities of successive portions, said device comprising:

a thermoelectric recordable layer having a characteristic such that erasure of a recorded image occurs at an erasure temperature;

means for heating above said temperature said layer along a plurality of lines corresponding respectively to said pluralities of successive portions of the video signal; said lines being heated temporarily one after the other and each line being heated simultaneously along its length;

means for applying a plurality of electrical fields respectively to a plurality of portions of said layer overlying parts of each line after the heating of one of said lines and until said one line reaches a temperature below said erasure temperature, said plurality of electrical fields representing one of said successive pluralities of successive portions of the video signal, thereby causing said plurality of successive portions of the video signal to be recorded in said layer at said parts of said one line.

2. A device as claimed in claim 1 wherein said layer is made with liquid crystal; said device further comprising a first and a second substrates for holding said layer.

3. A device as claimed in claim 1, wherein said liquid crystal has a smectic phase under said erasure temperature and an isomorphic phase above said erasure temperature, and said liquid crystal is capable to become light-diffusing in relation with said electrical field during the cooling from said isomorphic phase to said smectic phase.

4. A device as claimed in claim 3, wherein said first substrate has a first surface and said second substrate has a second surface, said first and second surfaces enclosing said layer, and said heating means comprise a plurality of electrical resisting lines deposited onto said first surface.

5. A device as claimed in claim 4, wherein said heating means further comprise first control means for applying successively to each of said electrical resisting lines a voltage under the control of first external synchronising signals, whereby said electrical heating lines are heated under the action of said voltage.

6. A device as claimed in claim 5, wherein said first control means are a first circuit integrated into said first substrate.

7. A device as claimed in claim 6, wherein said means for applying a plurality of electrical fields comprise a plurality of transparent conductive electrodes substantially perpendicular to said plurality of electrical resisting lines and deposited onto said second surface.

8. A device as claimed in claim 7, wherein said means for applying a plurality of electrical fields further comprises second control means for sampling successively said vedeo signal and applying simultaneously a plurality of samples of said video signal onto respectively said electrodes, under the control of second external synchronising signals.

9. A device as claimed in claim 8, wherein said second substrate is made of sapphire, and said second control means are a second circuit integrated into said second substrate.

10. A device as claimed in claim 8, wherein said second substrate is made of glass, and said second control means are a second circuit made with thin-film-transistors deposited onto said second substrate.

11. A device as claimed in claim 6, further comprising an isolating layer deposited onto said plurality of electrical resisting lines, and wherein said means for applying a plurality of electrical fields comprise a plurality of conductive electrodes substantially perpendicular to said plurality of electrical resisting lines and deposited onto said isolating layer.

12. A device as claimed in claim 11, wherein said means for applying a plurality of electrical fields further comprise second control means for sampling successively said video signal and applying simultaneously a plurality of samples of said video signal onto respectively said electrodes, under the control of second external synchronising signals.

13. A device as claimed in claim 12, wherein said second control means are a circuit integrated into said first substrate.

14. A device as claimed in claim 13, further comprising a plurality of interdigited light filtering lines deposited onto said conductive electrodes; said light filtering lines covering respectively said electrical heating lines; whereby said device may be used for displaying colour images.

15. A device as claimed in claim 13, further comprising a plurality of interdigited light filtering lines deposited onto said conductive electrodes; said light filtering lines covering respectively said conductive electrodes; whereby said device may be used for displaying colour images.

16. A device as claimed in any of claims 9, 10, and 13, further comprising means for inducing said crystal layer to spontaneously return to a non diffusing state.

Other info:

Inventors: Hareng, Michel (Paris, FR)
Le Berre, Serge (Paris, FR)

Application Number: 902112
Filing Date: 1978-05-02
Publication_date: 1980-05-06
Assignee: Thomson-CSF (Paris, FR)
Primary Class(es): 348/791 345/87, 349/7, 349/21, 349/106, 349/151, 349/158, 349/168
Other Classes:
US Patent Ref:

3410999	Nov, 1968	Fergason et al.	350/351.
3637291	Jan, 1972	Kessler et al.	350/351.

Other Refs:
Primary Examiner: Martin, John C.
Assistant Examiner:
Attorney: Cushman, Darby & Cushman