Multiple-shutter flat-panel display having individually controlled pixels and method for making same

• US 5,600,459 A
• Filed: 12/20/1993
• Issued: 02/04/1997
• Est. Priority Date: 12/20/1993
• Status: Expired due to Fees

• Current Assignee: Howard S. Roy, Narinder P. Singh
• Original Assignee: Howard S. Roy, Narinder P. Singh
• Inventors: Roy, Howard S., Singh, Narinder P.
• Primary Examiner(s): Crane, Sara W.
• Assistant Examiner(s): Abraham, Fetsum
• Application Number:
  US08/169,229
• Time in Patent Office: 1,142 Days
• Field of Search: 359/53, 359/59
• US Class Current: 349/42
• CPC Class Codes: G02F 1/13471 in which all the liquid crystal cells or layers remain transparent, e.g. FLC, ECB, DAP, HAN, TN, STN, SBE-LC cells G02F1/13475 takes precedence
• CPC Class Codes: G02F 1/1362 Active matrix addressed cells G02F1/134336, G02F1/134363 take precedence

Abstract

A display having a plurality of pixel locations includes first and second display layers, each including a cell at each pixel location, wherein each cell includes a liquid-crystal layer for modulating light passing through the display and a capacitor for controlling the liquid-crystal layer. Also disclosed are a method of making a display in accordance with the present invention and a method of displaying a composite image.

Claims

1. A display having a plurality of pixel locations, comprising:

first and second display layers, each including a cell at each pixel location, wherein each cell includes means for modulating light passing through the display and means for controlling the modulating means of the cell;

wherein the controlling means of a cell at a pixel location operates independently of the controlling means of another cell at the pixel location.

2. The display of claim 1, wherein at least one of the display layers comprises a flat panel display.

3. The display of claim 1, wherein the pixel locations are arranged in an array.

4. The display of claim 1, wherein the pixel locations are arranged in a regular array.

5. The display of claim 1, wherein each cell of each display layer may be in a first state wherein light is substantially permitted to pass through the display layer at the cell and a second state wherein light is substantially prevented from passing through the display layer at the cell.

6. The display of claim 1, wherein each cell at each pixel location may be in first and second states, and wherein the display has a first appearance at a particular pixel location when all of the cells at the particular pixel location are in the first state, and the display has a second appearance at the particular pixel location when a cell at the particular pixel location is in the second state.

7. The display of claim 1, wherein each modulating means at each of the pixel locations may be in first and second states, and wherein light is substantially permitted to pass through the display at a particular pixel location when all of the modulating means at the particular pixel location are in the first state, and light is substantially blocked at the particular pixel location when a modulating means at the particular pixel location is in the second state.

8. The display of claim 1, wherein each modulating means at each of the pixel locations may be in first and second states, and wherein the display has a first appearance at a particular pixel location when all of the modulating means at the particular pixel location are in the first state, and the display has a second appearance at the particular pixel location when a modulating means at the particular pixel location is in the second state.

9. The display of claim 1, wherein at least one of the modulating means at a pixel location variably attenuates light passing through the display at the pixel location.

10. The display of claim 1, wherein each controlling means comprises a capacitor and a thin-film transistor associated with the capacitor.

11. The display of claim 10, wherein each controlling means further includes means for selectively charging and discharging at least one of the capacitors at a pixel location.

12. The display of claim 10, wherein each controlling means further includes means for selectively charging and discharging each of the capacitors at a pixel location.

13. The display of claim 10, wherein each capacitor at each of the pixel locations may be in first and second states, and wherein light is substantially permitted to pass through the display at a particular pixel location when all of the capacitors at the particular pixel location are in the first state, and light is substantially blocked at the particular pixel location when a capacitor at the particular pixel location is in the second state.

14. The display of claim 10, wherein each capacitor at each of the pixel locations may be in first and second states, and wherein the display has a first appearance at a particular pixel location when all of the capacitors at the particular pixel location are in the first state, and the display has a second appearance at the particular pixel location when a capacitor at the particular pixel location is in the second state.

15. The display of claim 10, wherein each controlling means further includes means for selectively charging and discharging a capacitor at a pixel location.

16. The display of claim 1, wherein each of the display layers comprises a plurality of cells at each pixel location, each including means for modulating light passing through the display and means for controlling the modulating means, and wherein the display further comprises an optical filter associated with at least one of the cells at each pixel location.

17. The display of claim 1, wherein each modulating means comprises a liquid-crystal layer.

18. The display of claim 1, wherein each modulating means is selected from a group consisting of active-matrix liquid-crystal displays, passive-matrix liquid-crystal displays, mechanical-shutter displays, plasma displays, and deformable-mirror displays.

19. A display having a plurality of pixel locations, comprising:

first and second display layers, each including a cell at each pixel location, wherein each cell includes means for modulating light passing through the display and means for controlling the modulating means;

wherein each controlling means comprises a capacitor and a thin-film transistor associated with the capacitor, and

wherein at least one of the capacitors at a particular pixel location stores a variable charge enabling the modulating means at the particular pixel location to variably attenuate light passing through the display at the particular pixel location.

20. A display having a plurality of pixel locations, comprising:

first and second display layers, each including a cell at each pixel location, wherein each cell includes means for modulating light passing through the display and means for controlling the modulating means;

wherein each modulating means comprises a mechanical shutter, and wherein the controlling means at a particular pixel location comprises means for opening and closing the mechanical shutter at the particular pixel location.

21. A flat panel display having a plurality of pixel locations arranged in a regular array, comprising:

first and second display layers, each including a cell at each pixel location wherein the cells of the first display layer are aligned with corresponding cells of the second display layer;

each cell of each display layer including a liquid-crystal layer which may be in a first state wherein light is substantially permitted to pass through the display layer at the cell and a second state wherein light is substantially prevented from passing through the display layer at the cell; and

causing means for each cell for causing the liquid-crystal layers to be in one of the first and second states;

wherein the causing means of the cells at each pixel location operate independently of one another.

22. The display of claim 21, wherein each cell includes a capacitor and wherein the liquid-crystal layer of a cell is in one state when the capacitor of the cell is charged and is in the other state when the capacitor of the cell is uncharged.

23. The display of claim 21, wherein at least one of the liquid-crystal layers at a particular pixel location variably attenuates light passing through the display at the particular pixel location.

24. The display of claim 21, wherein each of the display layers comprises a plurality of cells at each pixel location, each including a liquid-crystal layer for modulating light passing through the display and means for controlling the liquid-crystal layer, and wherein the display further comprises an optical filter associated with at least one of the cells at each pixel location.

25. A flat panel display having a plurality of pixel locations arranged in a regular array, comprising:

first and second display layers, each including a cell at each pixel location, wherein the cells of the first display layer are aligned with corresponding cells of the second display layer;

each cell including a liquid-crystal layer which may provide attenuation of light passing through the cell in a range of levels between a first level and a second level greater than the first level, wherein at a particular cell, light is substantially blocked at the particular cell when the liquid-crystal layer at the particular cell provides the second level of attenuation; and

means for causing the liquid-crystal layers to provide a particular level of attenuation.

26. A flat panel display having a plurality of pixel locations arranged in a regular array, comprising:

first and second display layers, each including a plurality of cells at each pixel location, wherein each cell of each display layer includes a liquid-crystal layer which may be in a first state wherein light is substantially permitted to pass through the display layer at the cell and a second state wherein light is substantially prevented from passing through the display layer at the cell, wherein the state of the first display layer is independent of the state of the second display layer; and

an optical filter associated with at least one of the cells at each pixel location.

27. A method of displaying a composite image, comprising the steps of:

providing first and second display layers, each having a plurality of pixel locations and a cell at each of the pixel locations, wherein each cell includes means for modulating light passing through the display at the cell and means for independently controlling the modulating means;

combining the first and second display layers so that the pixel locations of the first display layer are aligned with the pixel locations of the second display layer; and

operating the controlling means to selectively control the modulating means of at least one of the cells at each of the pixel locations.

28. A method of making a display for modulating light at each of a plurality of pixel locations of the display, comprising the steps of:

providing first and second display layers, each having a plurality of pixel locations and a cell at each of the pixel locations;

providing independent means at each cell for modulating light passing through the display at the cell; and

combining the first and second layers so that the pixel locations of the first layer are aligned with the pixel locations of the second layer.

29. A flat panel display having a plurality of pixel locations arranged in a regular array, comprising:

first and second display layers, each including a cell at each pixel location, wherein the cells of the first display layer are aligned with corresponding cells of the second display layer;

each cell including a liquid-crystal layer for providing attenuation of light passing through the cell in a range of levels between a first level and a second level greater than the first level, wherein at a particular cell, light is substantially blocked at the particular cell when the liquid-crystal layer at the particular cell provides the second level of attenuation; and

causing means for each cell for causing the liquid-crystal layers to provide a particular level of attenuation;

wherein the causing means of the cells at each pixel location operate independently of one another.