Additive color electric paper without registration or alignment of individual elements

• US 6,128,124 A
• Filed: 10/16/1998
• Issued: 10/03/2000
• Est. Priority Date: 10/16/1998
• Status: Expired due to Fees

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Silverman, Alexander E.
• Primary Examiner(s): Epps, Georgia
• Assistant Examiner(s): Lester, Evelyn A.
• Application Number:
  US09/173,964
• Time in Patent Office: 718 Days
• Field of Search: 359/296, 359/298, 345/107, 427/214, 364/15, 364/4
• US Class Current: 359/296
• CPC Class Codes: G02B 26/026 based on the rotation of particles under the influence of an external field, e.g. gyricons, twisting ball displays based on orientable dipolar particles G02F1/172; based on electrophoresis G02F1/167
• CPC Class Codes: G09F 9/372 the positions of the elements being controlled by the application of an electric field

Abstract

Several variations in full-color additive gyricons are shown. Each gyricon shown has been designed for ease of construction by eliminating the need for precise placement of rotating elements, alignment between the gyricon layers, if any, and alignment between the gyricon sheet and the addressing device.

Claims

1. A gyricon sheet comprising:

a) a substrate having two opposed surfaces and at least two layers wherein one of the surfaces is a viewing surface, and

b) a collection of optically anisotropic light modulating elements capable of being made rotatable wherein each element is capable of producing at least two observable aspects to an observer favorably situated to observe the viewing surface wherein one aspect is being substantially optically transparent and the other aspect is associated with a first component color wherein at least some of said elements are associated with a first component color, at least some of said elements are associated with a second component color different from the first component color, and at least some of said elements are associated with a third component color different from both the first and second component colors, wherein the elements associated with one of the component colors are substantially contained in a different layer from the elements associated with the other component colors, and wherein the first, second, and third component colors are chosen such that when at least a portion of the elements associated with the first, second and third component colors are arranged to present the aspect associated with the component color to be observed simuftaneously by an observer situated favorably to observe the viewing surface the observer would approximately view white.

2. The gyricon sheet of claim 1 wherein the elements associate with the first and second component colors form a set of elements substantially contained in one layer wherein each element is capable of producing three observable aspects to an observer favorably situated to observe the viewing surface wherein one aspect is being substantially optically transparent, one aspect is associated with the first component color, and one aspect is associated with the second component color.

3. The gyricon sheet of claim 1 or claim 2 wherein the first, second and third component colors are chosen to be red, blue and green, respectively.

4. The gyricon sheet of claim 1 wherein the sheet has three layers, substantially all of the elements associated with a single component color are substantially contained within one layer, and wherein the elements associated with any one of the component colors are substantially contained in a different layer from the elements associated with the other component colors.

5. The gyricon sheet of claim 1 wherein the elements are rotatable.

6. The gyricon sheet of claim 1 wherein at least some of said elements are associated with a fourth component color different from all of the first, second, and third component colors.

7. The gyricon sheet of claim 6 wherein the elements associated with two of the component colors form a set of elements substantially contained in one layer wherein each element is capable of producing three observable aspects to an observer favorably situated to observe the viewing surface wherein one aspect is being substantially optically transparent, one aspect is associated with one of the component colors, and one aspect is associated with the other component color.

8. The gyricon sheet of claim 6 wherein the fourth component color is chosen from the set of black and white.

9. The gyricon sheet of claim 6 wherein at least some of said elements are associated with a fifth component color different from both the first, second, third, and fourth component colors.

10. The gyricon sheet of claim 6 wherein the elements associated with the fourth component color are also associated with a fifth component color different from all of the first, second, third, and fourth component colors and form a set of elements substantially contained in one layer which does not contain any elements associated with any of the other component colors, wherein each element is capable of producing three observable aspects to an observer favorably situated to observe the viewing surface, wherein one aspect is being substantially optically transparent, one aspect is associated with the fourth component color, and one aspect is associated with the fifth component color.

11. The gyricon sheet of claim 1 further comprising an additional set of elements substantially contained in one layer which does not contain any of the other elements wherein each element is capable of producing at least two observable aspects to an observer favorably situated to observe the viewing surface wherein one aspect is associated with a fourth component color and the other aspect is associated with a fifth component color wherein the fourth and fifth component colors are different from the first, second, and third component colors.

12. The gyricon sheet of either claim 10 or claim 11 wherein the fourth and fifth component colors are chosen to be black and white, respectively.

13. The gyricon sheet of claim 1 further comprising an opaque backing sheet adjacent to the surface that is not the viewing surface and is situated to be viewed by an observer situated favorably to observe the viewing surface when at least one element is arranged to present the aspect which is substantially optically transparent.

14. The gyricon sheet of claim 13 wherein the opaque backing sheet is selected to be viewed as a color and the color is chosen from the set of black and white.

15. The gyricon sheet of claim 1 wherein the elements produce the aspect associated with a component color by modulating at least some incident light.

16. The gyricon sheet of claim 15 wherein at least some of the elements modulate light by transmitting light.

17. The gyricon sheet of claim 15 wherein at least some of the elements modulate light by reflecting light.

18. The gyricon sheet of claim 1 wherein the viewing surface is capable of being divided into at least one area having an areal size with respect to the viewing surface wherein the area contains at least one element associated with each component color and approximately the same number of elements associated with each component color.

19. The gyricon sheet of claim 1 wherein the viewing surface is capable of being divided into a multiplicity of areas, each area having an areal size with respect to the viewing surface wherein the area contains at least one element associated with each component color and approximately the same number of elements associated with each component color.

20. The gyricon sheet of claim 1 wherein the viewing surface is capable of being divided into at least one area having an areal size with respect to the viewing surface wherein the area contains sufficient numbers of each element associated with each component color such that when they are arranged to present the aspect associated with the component color to be observed simultaneously by an observer situated favorably to observe the viewing surface the observer would approximately view white.

21. The gyricon sheet of either claim 18, 19, or 20 further comprising an addressing device having at least one addressable areal unit, the addressable areal unit being at least as large as the area of the viewing surface, the addressing device defining by virtue of its placement with respect to the viewing surface and actually addressed area having a boundary contiguous with that of the addressable areal unit of the addressing device.

22. The gyricon sheet of either claim 18, 19, or 20 further comprising an addressing device having at least one addressable areal unit, the addressable areal unit being at least as large as the area of the viewing surface, the addressing device defining by virtue of its placement with respect to the viewing surface and actually addressed area having a boundary contiguous with that of the addressable areal unit of the addressing device and the addressing device is removable.

23. The gyricon sheet of either claim 18, 19, or 20 further comprising an addressing device having at least one addressable areal unit, the addressable areal unit being at least as large as the area of the viewing surface, the addressing device defining by virtue of its placement with respect to the viewing surface and actually addressed area having a boundary contiguous with that of the addressable areal unit of the addressing device and the addressable areal unit is a unit cell of a rectilinear matrix.

24. The gyricon sheet of claim 1 wherein the portion of viewing surface is capable of being divided into at least one area having a minimum size wherein the distribution of elements in the area is substantially the same as the distribution of elements in the portion of the viewing surface.

25. The gyricon sheet of claim 1 wherein the elements are substantially spherical in shape.

26. The gyricon sheet of claim 1 wherein the elements are substantially cylindrical in shape.

27. A method of using a gyricon device comprising:

a) providing a light source having at least first, second, and third beams incident on a gyricon device having a substrate with two substantially parallel surfaces and containing at least two layers, wherein each layer comprises a plurality of optically and electrically anisotropic rotatable elements, at first, second, and third incidence locations, and

b) modulating each of the first, second and third rays with an element contained within one layer of the gyricon device, and

c) passing the first second, and third beams out of the gyricon device through a surface thereof substantially without further modulation from a modulating element situated in a different layer of the gyricon device such that a substantially full color gamut is provided while only modulating any one incident light beam by an element in any one layer.