Systems and methods for providing a storage medium
First Claim
1. A storage medium for storing an image, comprising:
- a pair of substrates; and
a plurality of display layers between the pair of substrates, the plurality of display layers being configured such that there are no electrodes between any two of the plurality of display layers, wherein each display layer comprises material that exhibits a well-type electro-optical response and each display layer has a texture change characteristic, and wherein the storage medium stores the image when a voltage is applied to the storage medium causing at least one of the plurality of display layers to change texture.
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Accused Products
Abstract
This invention provides a storage medium, method of writing images to a storage medium, method of forming a storage medium and a storage medium formed using the method of forming a storage medium. The storage medium provides a display which has memory capability without power, allows images to be updated quickly by external equipment, and is capable of a full-color display. The storage medium includes three display layers having cholesteric liquid crystals which selectively reflect blue, green, and red, respectively, and are different from each other in texture change threshold voltage. The display layers are stacked between substrates and a light absorption layer is provided. An image writing apparatus is formed separately from the storage medium and provides write electrodes sandwiching the storage medium. A write signal is applied between the electrodes with a voltage, wherein the voltage is selected from seven levels of voltage which are produced based on the respective texture change threshold voltages of the cholesteric liquid crystal display layers.
79 Citations
35 Claims
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1. A storage medium for storing an image, comprising:
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a pair of substrates; and
a plurality of display layers between the pair of substrates, the plurality of display layers being configured such that there are no electrodes between any two of the plurality of display layers, wherein each display layer comprises material that exhibits a well-type electro-optical response and each display layer has a texture change characteristic, and wherein the storage medium stores the image when a voltage is applied to the storage medium causing at least one of the plurality of display layers to change texture. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31)
a first display layer selectively reflecting colors having a peak wavelength in a range of approximately 400 to 500 nm;
a second display layer selectively reflecting colors having a peak wavelength in a range of approximately 500 to 600 nm; and
a third display layer selectively reflecting colors having a peak wavelength in a range of approximately 600 to 700 nm.
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5. The storage medium according to claim 1, wherein the material for each of the plurality of display layers includes cholesteric liquid crystals.
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6. The storage medium according to claim 5, wherein each of the plurality of display layers have a PNLC structure.
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7. The storage medium according to claim 6, wherein the PNLC structure is formed by phase-separating a polymer and a cholesteric liquid crystal.
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8. The storage medium according to claim 5, wherein each of the plurality of display layers have a PDLC structure.
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9. The storage medium according to claim 8, wherein the PDLC structure is formed by phase-separating a polymer and a cholesteric liquid crystal.
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10. The storage medium according to claim 1, wherein each of the plurality of display layers comprise two display layers which selectively reflect a mutually identical color and are opposite in a helical twisting direction to each other.
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11. The storage medium according to claim 1, wherein the pair of substrates are flexible.
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12. The storage medium according to claim 1, wherein the storage medium stores an image comprised of at least one of characters, graphics and data.
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13. The storage medium according to claim 1, wherein a common electrode is provided in one substrate.
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14. The storage medium according to claim 1, wherein neither one of the pair of substrates includes an electrode.
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15. The storage medium according to claim 1, wherein each of the plurality of display layers reflects electromagnetic radiation when the texture of the display layer is changed to a reflecting texture.
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16. The storage medium according to claim 1, wherein the substrates have large dielectric constants.
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17. The storage medium according to claim 1, wherein the plurality of display layers are comprised of at least one of cholesterol derivatives doped with a chiral dopant, nematic liquid crystals doped with a chiral dopant, cholesterol derivative mixtures doped with a chiral dopant, and nematic liquid crystal mixtures doped with a chiral dopant.
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18. The storage medium according to claim 17, wherein the cholesteric liquid crystals are doped with a plurality of chiral dopant which have differing twisting direction or exhibit reverse temperature dependence.
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19. The storage medium according to claim 1, wherein the plurality of display layers comprise:
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a first display layer selectively reflecting blue light;
a second display layer selectively reflecting green light; and
a third display layer selectively reflecting red light.
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20. The storage medium of claim 1, further comprising a light absorption layer, wherein light is transmitted through the plurality of display layers and is absorbed by the absorption layer.
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21. A method of writing images to the storage medium of claim 1, comprising:
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applying a write signal over a normal operating range of the write signal to the plurality of display layers from an external image writing apparatus; and
changing a texture of the plurality of display layers by controlling a select stage voltage of the write signal.
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22. The method of claim 21, wherein the select stage voltage is greater than a refresh stage voltage of the write signal.
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23. An apparatus in combination with the storage medium of claim 1, the apparatus comprising:
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at least one electrode in proximity to the storage medium; and
a writing device, wherein the writing device applies a write signal over a normal operating range of the write signal to the plurality of display layers from outside the storage medium, the write signal having a select stage voltage that causes one or more of the display layers of the storage medium to change texture.
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24. The apparatus of claim 23, wherein the select stage voltage is greater than a refresh stage voltage of the write signal.
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25. The apparatus of claim 23, wherein the texture state is one of a planar texture and a focal conic texture.
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26. The apparatus of claim 23, wherein the texture is one of a selective reflection texture and a transmission texture.
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27. The apparatus of claim 23, wherein the writing device is one of a pen-type device, a line scan writing type device, a surface writing device.
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28. The apparatus of claim 23, wherein the write signal causes the plurality of display layers to change to one of the following states:
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(1) each of the plurality of display layers have a planar texture;
(2) each of the plurality of display layers have a focal conic texture;
(3) one of the plurality of display layers has a planar texture and the other of the plurality of display layers have a focal conic texture; and
(4) two of the plurality of display layers have a planar texture and the other of the plurality of display layers have a focal conic texture.
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29. The apparatus of claim 23, wherein the plurality of display layers comprise a first display layer having a high threshold voltage, a second display layer having a medium threshold voltage, and a third display layer having a low threshold voltage, and wherein the write signal causes the plurality of display layers to change to one of the following states:
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(1) a state in which the first, second and third display layers each have a planar texture;
(2) a state in which the first, second and third display layers each have a focal conic texture;
(3) a state in which the first display layer has a planar texture and the second and third display layers have a focal conic texture;
(4) a state in which the second display layer has a planar texture and the first and third display layers have a focal conic texture;
(5) a state in which the third display layer has a planar texture and the first and second display layers have a focal conic texture;
(6) a state in which the first and second display layers have a planar texture and the third display layer has a focal conic texture; and
(7) a state in which the second and third display layers have a planar texture and the first display layer has a focal conic texture.
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30. The apparatus of claim 29, wherein the first display layer selectively reflects blue light, the second display layer selectively reflects green light, and the third display layer selectively reflects red light.
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31. The storage medium according to claim 1, wherein the storage medium continues to store the stored image after the voltage applied to the storage medium is removed from the storage medium.
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32. A storage medium comprising:
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a first film;
a first color mixed solution that includes cholestic liquid crystals that exhibit a well-type electro-optical response and texture change characteristic disposed on the first film;
a second film disposed on the first film;
a second color mixed solution that includes cholestic liquid crystals that exhibit a well-type electro-optical response and texture change characteristic disposed on the second film;
a third film disposed on the second film;
a third color mixed solution that includes cholestic liquid crystals that exhibit a well-type electro-optical response and texture change characteristic disposed on the third film; and
a fourth film disposed on the third film.
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33. A storage medium for storing an image, comprising;
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a pair of substrates;
a plurality of layers between the pair of substrates, each of the plurality of layers comprising a cholesteric liquid crystal that exhibits a well-type electro-optical response and texture change characteristic, wherein each one of the plurality of layers changes texture when a predetermined voltage is applied from outside the storage medium. - View Dependent Claims (34, 35)
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Specification