Holographic Multicolor optical elements for use in liquid crystal displays and methods of making the elements

• US 5,930,011 A
• Filed: 09/17/1996
• Issued: 07/27/1999
• Est. Priority Date: 06/10/1994
• Status: Expired due to Term

• Current Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Mackara, Steven Robert, Weber, Andrew Michael, Gambogi, William John Jr., Martin, Paul James, Trout, Torence John
• Primary Examiner(s): Spyrou, Cassandra
• Assistant Examiner(s): CHANG, AUDREY Y
• Application Number:
  US08/718,688
• Time in Patent Office: 1,043 Days
• Field of Search: 359/1, 359/15, 359/22, 349/105, 349/106, 430/1, 430/2
• US Class Current: 359/15
• CPC Class Codes: G02B 5/203 having holographic or diffractive elements diffraction gratings per se G02B5/18; holographic elements per se G02B5/32; generating the spectrum using diffraction elements G01J3/18
• CPC Class Codes: G02B 5/32 Holograms used as optical elements
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G03H 1/0248 Volume holograms
• CPC Class Codes: G03H 1/26 Processes or apparatus specially adapted to produce multiple sub- holograms or to obtain images from them, e.g. multicolour technique

Abstract

The present invention relates to holographic multicolor optical elements for use as multicolor filters in liquid crystal displays and methods of making the elements. The elements can be used as multicolor reflective or transmission filters The elements can have one, two, three or more holographic recording film layers Each layer comprises at least first and second pixel volumes containing holographic mirrors and preferably third pixel volumes containing a holographic mirror.

Claims

1. A volume holographic optical element, comprising:

a photohardened holographic recording film element comprising a first plurality of pixel volumes, a second plurality of pixel volumes, and a third plurality of pixel volumes;

each one of the first pixel volumes including a first volume holographic mirror that reflects only light with a first color wavelength band and passes light with at least a second color wavelength band and a third color wavelength band;

each one of the second pixel volumes including a second volume holographic mirror that reflects only light with the second color wavelength band and passes light with at least the first color wavelength band and the third color wavelength band; and

each one of the third pixel volumes including a third volume holographic mirror that reflects only light with the third color wavelength band and passes light with at least the first color wavelength band and the second color wavelength band.

2. The element of claim 1, wherein the first color wavelength band has a width of at least 5 nanometers and includes 612 nanometer, the second color wavelength band has a width of at least 5 nanometers and includes 545 nanometer, and the third color wavelength band has a width of at least 5 nanometers and includes 436 nanometer.

3. The element of claim 1, wherein the film element comprises a single photohardened holographic recording film layer.

4. The element of claim 1, wherein the film element comprises two photohardened holographic recording film layers.

5. The element of claim 1, wherein the film element comprises three photohardened holographic recording film layers.

6. In a reflective liquid crystal display apparatus, comprising, in order:

a first light polarizer for passing ambient light having a first polarization;

a liquid crystal display element for selectively modifying the polarization of the light passing through an array of cells such that the polarization of light passing through a first set, a second set or a third set of the cells can be changed to a second polarization;

a second light polarizer for passing light from the liquid crystal display element having the second polarization; and

a holographic multicolor reflection filter comprising a first plurality of pixel volumes, a second plurality of pixel volumes, and a third plurality of pixel volumes;

each one of the first pixel volumes including a first volume holographic mirror that reflects only light with a first color wavelength band and passes light with at least a second color wavelength band and a third color wavelength band;

each one of the second pixel volumes including a second volume holographic mirror that reflects only light with the second color wavelength band and passes light with at least the first color wavelength band and the third color wavelength band; and

each one of the third pixel volumes including a third volume holographic mirror that reflects only light with the third color wavelength band and passes light with at least the first color wavelength band and the second color wavelength band;

such that (1) when the liquid crystal display element modifies the polarization of the light passing through the first set of cells to the second polarization, the light passes through the second polarizer into the first pixel volumes in which the first volume holographic mirrors reflect light with the first color wavelength band back to a viewer, (2) when the liquid crystal display element modifies the polarization of the light passing through the second set of cells to the second polarization, the light passes through the second polarizer into the second pixel volumes in which the second volume holographic mirrors reflect light with the second color wavelength band back to the viewer, and (3) when the liquid crystal display element modifies the polarization of the light passing through the third set of cells to the second polarization, the light passes through the third polarizer into the third pixel volumes in which the third volume holographic mirrors reflect light with the third color wavelength band back to the viewer.

7. A method for making a first volume holographic optical element, comprising:

a holographic recording film element comprising a first plurality of pixel volumes, a second plurality of pixel volumes, and a third plurality of pixel volumes;

each one of the first pixel volumes including a first volume holographic mirror that reflects only light with a first color wavelength band and passes light with at least a second color wavelength band and a third color wavelength band;

each one of the second pixel volumes including a second volume holographic mirror that reflects only light with the second color wavelength band and passes light with at least the first color wavelength band and the third color wavelength band; and

each one of the third pixel volumes including a third volume holographic mirror that reflects only light with the third color wavelength band and passes light with at least the first color wavelength band and the second color wavelength band;

the method comprising;

(A) holographically exposing the film element with coherent or substantially coherent light to record the first volume holographic mirrors in the first pixel volumes;

(B) holographically exposing the film element with coherent or substantially coherent light to record the second volume holographic mirrors in the second pixel volumes; and

(C) holographically exposing the film element with coherent or substantially coherent light to record the third volume holographic mirrors in the third pixel volumes.

8. The method of claim 7, wherein steps (A), (B) and (C) are performed simultaneously.

9. The method of claim 7, wherein the step (A) comprises:

directing coherent or substantially coherent light through a photomask having a first plurality of pixels which block light and a second plurality of pixels which allow light to pass and then through the film element onto a reflector which reflects the coherent or substantially coherent light back through the film element holographically forming the first volume holographic mirrors in the first pixel volumes.

10. The method of claim 9, further comprising:

before step (A), positioning a first index matching fluid layer on the reflector, a glass support on the first index matching fluid layer, the film element on the glass support, a second index matching fluid layer on the film element, the photomask on the second index matching fluid layer, and an anti-reflection layer on the photomask.

11. The method of claim 9, wherein the step (B) is after step (A) and comprises:

shifting the photomask one pixel in a first direction; and

directing coherent or substantially coherent light through the photomask and then the film element onto the reflector which reflects the coherent or substantially coherent light back through the film element holographically forming the second volume holographic mirrors in the second pixel volumes.

12. The method of claim 11, wherein the step (C) is after step (B) and comprises:

shifting the photomask one pixel in the first direction; and

directing coherent or substantially coherent light through the photomask and then the film element onto the reflector which reflects the coherent or substantially coherent light back through the film element holographically forming the third volume holographic mirrors in the third pixel volumes.

13. The method of claim 7, further comprising curing the holographic recording film element by exposing it to actinic radiation to substantially polymerize any monomer and fix the holographic mirrors in the film element.

14. The method of claim 7, further comprising heating the holographic recording film to increase the refractive index modulation, efficiency and bandwidth of the holographic mirrors.

15. The method of claim 7, further comprising forming the film element with a single, substantially solid, holographic recording film.

16. A volume holographic optical element, comprising:

a photohardened holographic recording film element comprising a first plurality of pixel volumes, a second plurality of pixel volumes, and a third plurality of pixel volumes;

each one of the first pixel volumes including a first volume holographic mirror that passes light with a first color wavelength band and reflects light with at least a second color wavelength band and a third color wavelength band;

each one of the second pixel volumes including a second volume holographic mirror that passes light with the second color wavelength band and reflects light with at least the first color wavelength band and the third color wavelength band; and

each one of the third pixel volumes including a third volume holographic mirror that passes light with the third color wavelength band and reflects light with at least the first color wavelength band and the second color wavelength band, wherein;

the film element comprising a first holographic recording layer, a second holographic recording layer, and a third holographic recording layer;

each one of the first pixel volumes, the second pixel volumes and the third pixel volumes comprises a first layer volume, a second layer volume and a third layer volume;

each of the first volume holographic mirrors comprising;

a fourth volume holographic mirror that passes light with the first color wavelength band and the second color wavelength band and reflects light with the third color wavelength band, the fourth mirrors in the third layer volumes of the first pixel volumes; and

a fifth volume holographic mirror that passes light with the first color wavelength band and the third color wavelength band and reflects light with the second color wavelength band, the fifth mirrors in the second layer volumes of the first pixel volumes; and

each of the second volume holographic mirrors comprising;

one of the fourth mirrors in the third layer volumes of the second pixel volumes; and

a sixth volume holographic mirror that passes light with the second color wavelength band and the third color wavelength band and reflects light with the first color wavelength band, the sixth mirrors in the first layer volumes of the second pixel volumes; and

each of the third volume holographic mirrors comprising;

one of the fifth mirrors in the second layer volumes of the third pixel volumes; and

one of the sixth mirrors in the first layer volumes of the third pixel volumes.

17. A volume holographic optical element, comprising:

a photohardened holographic recording film element comprising a first plurality of pixel volumes, a second plurality of pixel volumes, and a third plurality of pixel volumes;

each one of the first pixel volumes including a first volume holographic mirror that passes light with a first color wavelength band and reflects light with at least a second color wavelength band and a third color wavelength band;

each one of the second pixel volumes including a second volume holographic mirror that passes light with the second color wavelength band and reflects light with at least the first color wavelength band and the third color wavelength band; and

each one of the third pixel volumes including a third volume holographic mirror that passes light with the third color wavelength band and reflects light with at least the first color wavelength band and the second color wavelength band, wherein;

the film element comprising a first holographic recording layer and a second holographic recording layer on the first layer;

each one of the first pixel volumes, the second pixel volumes and the third pixel volumes comprises a first layer volume and a second layer volume;

each of the first volume holographic mirrors comprising;

a fourth volume holographic mirror that passes light with the first color wavelength band and the second color wavelength band and reflects light with the third color wavelength band, the fourth mirrors in the first layer volumes of the first pixel volumes; and

a fifth volume holographic mirror that passes light with the first color wavelength band and the third color wavelength band and reflects light with the second color wavelength band, the fifth mirrors in the second layer volumes of the first pixel volumes; and

each of the second volume holographic mirrors comprising;

one of the fourth mirrors in the second layer volumes of the second pixel volumes; and

a sixth volume holographic mirror that passes light with the second color wavelength band and the third color wavelength band and reflects light with the first color wavelength band, the sixth mirrors in the first layer volumes of the second pixel volumes; and

each of the third volume holographic mirrors comprising;

one of the fifth mirrors in the second layer volumes of the third pixel volumes; and

one of the sixth mirrors in the first layer volumes of the third pixel volumes.

18. In a transmission liquid crystal display apparatus, for use with a light source having narrowband discrete spectral power peaks at a first color, a second color and a third color, comprising, in order:

a light assembly which emits light with a first color wavelength band, a second color wavelength band and a third color wavelength band;

a first light polarizer for passing light from the light assembly having a first polarization;

a liquid crystal display element for selectively modifying the polarization of the light passing through an array of cells such that the polarization of light passing through a first set, a second set or a third set of the cells can be changed to a second polarization;

a volume holographic optical element comprising a photohardened holographic recording film element comprising a first plurality of pixel volumes, a second plurality of pixel volumes, and a third plurality of pixel volumes;

each one of the first pixel volumes including a first volume holographic mirror that passes light with a first color wavelength band and reflects light with at least a second color wavelength band and a third color wavelength band;

each one of the second pixel volumes including a second volume holographic mirror that passes light with the second color wavelength band and reflects light with at least the first color wavelength band and the third color wavelength band; and

each one of the third pixel volumes including a third volume holographic mirror that passes light with the third color wavelength band and reflects light with at least the first color wavelength band and the second color wavelength band, wherein;

the film element comprising a first holographic recording layer, a second holographic recording layer, and a third holographic recording layer;

each one of the first pixel volumes, the second pixel volumes and the third pixel volumes comprises a first layer volume a second layer volume and a third layer volume;

each of the first volume holographic mirrors comprising;

a fourth volume holographic mirror that passes light with the first color wavelength band and the second color wavelength band and reflects light with the third color wavelength band, the fourth mirrors in the third layer volumes of the first pixel volumes; and

a fifth volume holographic mirror that passes light with the first color wavelength band and the third color wavelength band and reflects light with the second color wavelength band, the fifth mirrors in the second layer volumes of the first pixel volumes; and

each of the second volume holographic mirrors comprising;

one of the fourth mirrors in the third layer volumes of the second pixel volumes; and

a sixth volume holographic mirror that passes light with the second color wavelength band and the third color wavelength band and reflects light with the first color wavelength band, the sixth mirrors in the first layer volumes of the second pixel volumes; and

each of the third volume holographic mirrors comprising;

one of the fifth mirrors in the second layer volumes of the third pixel volumes; and

one of the sixth mirrors in the first layer volumes of the third pixel volumes;

a second light polarizer for passing light having a second polarization,

such that (1) when the liquid crystal display element modifies the polarization of the light passing through the first set of cells to the second polarization, the light passes into the first pixel volumes in which the first volume holographic mirrors pass light with the first color wavelength band through the second polarizer to a viewer, (2) when the liquid crystal display element modifies the polarization of the light passing through the second set of cells to the second polarization, the light passes into the second pixel volumes in which the second volume holographic mirrors pass light with the second color wavelength band through the second polarizer to the viewer, and (3) when the liquid crystal display element modifies the polarization of the light passing through the third set of cells to the second polarization, the light passes into the third pixel volumes in which the third volume holographic mirrors pass light with the third color wavelength band through the third polarizer to the viewer.

19. A method for making a second volume holographic optical element from a first volume holographic optical element, the first volume holographic optical element comprising:

a first holographic recording film element comprising a first plurality of pixel volumes, a second plurality of pixel volumes, and a third plurality of pixel volumes;

each one of the first pixel volumes including a first volume holographic mirror that reflects light with a first color wavelength band and passes light with at least a second color wavelength band and a third color wavelength band;

each one of the second pixel volumes including a second volume holographic mirror that reflects light with the second color wavelength band and passes light with at least the first color wavelength band and the third color wavelength band; and

each one of the third pixel volumes including a third volume holographic mirror that reflects light with the third color wavelength band and passes light with at least the first color wavelength band and the second color wavelength band;

the method comprising;

directing coherent or substantially coherent light including the first color wavelength band, the second color wavelength band and the third color wavelength band through the first volume holographic optical element and then a second holographic recording film element;

reflecting the coherent or substantially coherent light off a reflector back through the second film element; and

holographically forming the second volume holographic optical element comprising;

the second film element comprising a first plurality of pixel volumes, a second plurality of pixel volumes, and a third plurality of pixel volumes;

each one of the first pixel volumes including a first volume holographic mirror that passes light with a first color wavelength band and reflects light with at least a second color wavelength band and a third color wavelength band;

each one of the second pixel volumes including a second volume holographic mirror that passes light with the second color wavelength band and reflects light with at least the first color wavelength band and the third color wavelength band; and

each one of the third pixel volumes including a third volume holographic mirror that passes light with the third color wavelength band and reflects light with at least the first color wavelength band and the second color wavelet band.

20. The method of claim 19, further comprising:

before the directing step, positioning the second film element on the reflector, a glass support on the second film element, and the first film element on the glass support.

21. The method of claim 19, further comprising:

removing the first film element; and

curing the second film element by exposing it to actinic radiation to substantially polymerize any monomer and fix the holographic mirrors in the second film element.

22. The method of claim 21, further comprising, after the removing step and before the curing step, laminating a cover sheet to the second film element.

23. The method of claim 22, further comprising heating the second film element to increase the refractive index modulation, efficiency and bandwidth of the holographic mirrors.

24. The method of claim 22, further comprising:

removing the reflector; and

laminating the second film element to a second glass support.

25. The method of claim 19, further comprising forming the film element with a single, substantially solid, holographic recording film.

26. The method of claim 19, forming the film element with a first holographic recording layer sensitized to the third color wavelength band, a second holographic recording layer sensitized to the second color wavelength band on the first layer, and a third holographic recording layer sensitized to the first color wavelength band on the second layer.

27. A method for making a second volume holographic optical element from a first volume holographic optical element, comprising:

a first holographic recording film element comprising a first plurality of pixel volumes, a second plurality of pixel volumes, and a third plurality of pixel volumes;

each one of the first pixel volumes including a first volume holographic mirror that passes light with a first color wavelength band and reflects light with at least a second color wavelength band and a third color wavelength band;

each one of the second pixel volumes including a second volume holographic mirror that passes light with the second color wavelength band and reflects light with at least the first color wavelength band and the third color wavelength band; and

each one of the third pixel volumes including a third volume holographic mirror that passes light with the third color wavelength band and reflects light with at least the first color wavelength band and the second color wavelength band;

the method comprising;

directing coherent or substantially coherent light including the first color wavelength band, the second color wavelength band and the third color wavelength band through a laminate comprising a second holographic recording film element and then the first volume holographic optical element;

reflecting the second color wavelength band and the third color wavelength band off the first mirrors back through first pixel volumes of the second film element;

reflecting the first color wavelength band and the third color wavelength band off the second mirrors back through second pixel volumes of the second film element;

reflecting the first color wavelength band and the second color wavelength band off the third mirrors back through third pixel volumes of the second film element; and

holographically forming the second volume holographic optical element.

28. The method of claim 27, further comprising:

before the directing step, positioning the first film element on a light absorbing layer, a glass support on the first film element, the second film element on the glass support, an index matching fluid layer on the second film element, and an anti-reflection layer on the index matching fluid layer.

29. The method of claim 28, further comprising:

removing the light absorbing layer, the first film element, the glass support, the index matching fluid layer and the anti-reflection layer; and

curing the second film element by exposing it to actinic radiation to substantially polymerize any monomer and fix the holographic mirrors in the second film element.

30. The method of claim 29, further comprising heating the second film element to increase the refractive index modulation, efficiency and bandwidth of the holographic mirrors.

31. The method of claim 30, further comprising laminating the second film element to a second glass support.

32. The method of claim 27, further comprising forming the film element with a single, substantially solid, holographic recording film.

33. The method of claim 27, forming the film element with a first holographic recording layer sensitized to the third color wavelength band, a second holographic recording layer sensitized to the second color wavelength band on the first layer, and a third holographic recording layer sensitized to the first color wavelength band on the second layer.

34. A method for making a multi-layer volume holographic optical element, comprising:

a photohardened holographic recording film element comprising a first plurality of pixel volumes, a second plurality of pixel volumes, and a third plurality of pixel volumes;

each one of the first pixel volumes including a first volume holographic mirror that passes light with at least a first color wavelength band and reflects only light with a second color wavelength band and a third color wavelength band;

each one of the second pixel volumes including a second volume holographic mirror that passes light with at least the second color wavelength band and reflects only light with the first color wavelength band and the third color wavelength band; and

each one of the third pixel volumes including a third volume holographic mirror that passes light with at least the third color wavelength band and reflects only light with the first color wavelength band and the second color wavelength band;

the film element comprising a first holographic recording layer sensitized to the third color wavelength band, a second holographic recording layer sensitized to the second color wavelength band on the first layer, and a third holographic recording layer sensitized to the first color wavelength band on the second layer;

each one of the first pixel volumes, the second pixel volumes and the third pixel volumes comprises a first layer volume, a second layer volume and a third layer volume;

each of the first volume holographic mirrors comprising;

a fourth volume holographic mirror that passes light with the first color wavelength band and the second color wavelength band and reflects light with the third color wavelength band, the fourth mirrors in the third layer volumes of the first pixel volumes; and

a fifth volume holographic mirror that passes light with the first color wavelength band and the third color wavelength band and reflects light with the second color wavelength band, the fifth mirrors in the second layer volumes of the first pixel volumes; and

each of the second volume holographic mirrors comprising;

one of the fourth mirrors in the third layer volumes of the second pixel volumes; and

a sixth volume holographic mirror that passes light with the second color wavelength band and the third color wavelength band and reflects light with the first color wavelength band, the sixth mirrors in the first layer volumes of the second pixel volumes; and

each of the third volume holographic mirrors comprising;

one of the fifth mirrors in the second layer volumes of the third pixel volumes; and

one of the sixth mirrors in the first layer volumes of the third pixel volumes;

the method comprising;

imagewise exposing the film element to actinic radiation to polymerize monomer in selected first layer volumes, second layer volumes and third layer volumes to make the exposed volumes holographically inactive; and

holographically imaging the film element with coherent or substantially coherent light consisting essentially of the first color wavelength band, the second color wavelength band and the third color wavelength band to record the multi-layer volume holographic optical element.

35. A method for making a two-layer volume holographic optical element, comprising:

a photohardened holographic recording film element comprising a first plurality of pixel volumes, a second plurality of pixel volumes, and a third plurality of pixel volumes;

each one of the first pixel volumes including a first volume holographic mirror that passes light with a first color wavelength band and reflects light with at least a second color wavelength band and a third color wavelength band;

each one of the second pixel volumes including a second volume holographic mirror that passes light with the second color wavelength band and reflects light with at least the first color wavelength band and the third color wavelength band; and

each one of the third pixel volumes including a third volume holographic mirror that passes light with the third color wavelength band and reflects light with at least the first color wavelength band and the second color wavelength band;

the film element comprising a first holographic recording layer at least sensitized to the first color wavelength band and the third color wavelength band, and a second holographic recording layer at least sensitized to the second color wavelength band and the third color wavelength band on the first layer;

each one of the first pixel volumes, the second pixel volumes and the third pixel volumes comprises a first layer volume and a second layer volume;

each of the first volume holographic mirrors comprising;

a fourth volume holographic mirror that passes light with the first color wavelength band and the second color wavelength band and reflects light with the third color wavelength band, the fourth mirrors in the first layer volumes of the first pixel volumes; and

a fifth volume holographic mirror that passes light with the first color wavelength band and the third color wavelength band and reflects light with the second color wavelength band, the fifth mirrors in the second layer volumes of the first pixel volumes; and

each of the second volume holographic mirrors comprising;

one of the fourth mirrors in the second layer volumes of the second pixel volumes; and

a sixth volume holographic mirror that passes light with the second color wavelength band and the third color wavelength band and reflects light with the first color wavelength band, the sixth mirrors in the first layer volumes of the second pixel volumes; and

each of the third volume holographic mirrors comprising;

one of the fifth mirrors in the second layer volumes of the third pixel volumes; and

one of the sixth mirrors in the first layer volumes of the third pixel volumes;

the method comprising;

imagewise holographically exposing the second layer with coherent or substantially coherent light consisting essentially of the third color wavelength band to record the fourth volume holographic mirrors in the second layer volumes of the second pixel volumes;

imagewise holographically exposing the second layer with coherent or substantially coherent light consisting essentially of the second color wavelength band to record the fifth volume holographic mirrors in the second layer volumes of the first pixel volumes and the third pixel volumes;

laminating the first holographic recording layer adjacent the second layer;

imagewise holographically exposing the first layer with coherent or substantially coherent light consisting essentially of the third color wavelength band to record the fourth volume holographic mirrors in the first layer volumes of the first pixel volumes;

imagewise holographically exposing the first layer with coherent or substantially coherent light consisting essentially of the first color wavelength band to record the sixth volume holographic mirrors in the first layer volumes of the second pixel volumes and the third pixel volumes.

36. A volume holographic optical element, comprising:

a photohardened holographic recording film element comprising at least a first plurality of pixel volumes and a second plurality of pixel volumes arranged in rows and columns;

each one of the first pixel volumes including a volume holographic mirror that passes light with at- least one first color wavelength band and reflects light with at least a second color wavelength band;

each one of the second pixel volumes including a volume holographic mirror that passes light with at least the second color wavelength band and reflects light with at least the first color wavelength band;

a substantially optically transparent mask surrounding each first and second pixel volumes, that transmits light with at least the first color wavelength band and the second color wavelength band; and

an optical absorber that is substantially nonreflective and optically opaque such that light which passes through the mask between the first pixel volumes and the second pixel volumes is substantially absorbed by the optical absorber.

37. In a liquid crystal display apparatus having a multicolor filter comprising (i) at least a first plurality of pixel volumes that pass light with at least a first color wavelength band and block light with at least a second color wavelength band and (ii) a second plurality of pixel volumes that passes light with at least a second color wavelength band and blocks light with at least the first color wavelength band, wherein the improvement comprises the filter being a photohardened holographic recording film element having an integral substantially transparent mask surrounding the first and second pixel volumes.

38. In a reflective liquid crystal display apparatus, comprising, in order:

a first light polarizer for passing ambient light having a first polarization;

a liquid crystal display element for selectively modifying the polarization of the light passing through an array of cells such that the polarization of light passing through a first set, a second set or a third set of the cells can be changed to a second polarization;

a second light polarizer for passing light from the liquid crystal display element having the second polarization; and

a holographic multicolor reflection filter comprising a first plurality of pixel volumes, a second plurality of pixel volumes, a third plurality of pixel volumes, and an integral transparent mask comprising a fourth plurality of mask volumes;

each one of the first pixel volumes including a first volume holographic mirror that reflects light with a first color wavelength band and passes light with at least a second color wavelength band and a third color wavelength band;

each one of the second pixel volumes including a second volume holographic mirror that reflects light with the second color wavelength band and passes light with at least the first color wavelength band and the third color wavelength band;

each one of the third pixel volumes including a third volume holographic mirror that reflects light with the third color wavelength band and passes light with at least the first color wavelength band and the second color wavelength band;

each one of the fourth mask volumes that transmits light with first color wavelength band, the second color wavelength band, and the third color wavelength band; and

an optical absorber that is substantially nonreflective and optically opaque;

such that (1) when the liquid crystal display element modifies the polarization of the light passing through the first set of cells to the second polarization, the light passes through the second polarizer into the first pixel volumes in which the first volume holographic mirrors reflect light with the first color wavelength band back to a viewer, (2) when the liquid crystal display element modifies the polarization of the light passing through the second set of cells to the second polarization, the light passes through the second polarizer into the second pixel volumes in which the second volume holographic mirrors reflect light with the second color wavelength band back to the viewer, (3) when the liquid crystal display element modifies the polarization of the light passing through the third set of cells to the second polarization, the light passes through the third polarizer into the third pixel volumes in which the third volume holographic mirrors reflect light with the third color wavelength band back to the viewer, and (4) light which passes through the mask between the first pixel volumes, the second pixel volumes and the third pixel volumes is substantially absorbed by the optical absorber.

39. A wide bandwidth volume holographic optical element, comprising:

a photohardened holographic recording film element comprising at least a first plurality of pixel volumes and a second plurality of pixel volumes arranged in rows and columns;

each one of the first pixel volumes including a first volume holographic mirror in a first layer that passes light with at least one first color wavelength band and reflects light only with a first wavelength sub-band of a second color wavelength band and a second volume holographic mirror in a second layer that passes light with at least one first color wavelength band and reflects light only with a second wavelength sub-band of the second color wavelength band, the first sub-band of the second color wavelength band being immediately adjacent in wavelength to the second wavelength sub-band of the second color wavelength band; and

each one of the second pixel volumes including a first volume holographic mirror in the first layer that passes light with at least the second color wavelength band and reflects light only with a first wavelength sub-band of the first color wavelength band and a second volume holographic mirror in the second layer that passes light with at least the second color wavelength band and reflects light only with a first wavelength sub-band of the first color wavelength band, the first sub-band of the first color wavelength band being immediately adjacent in wavelength to the second wavelength sub-band of the first color wavelength band.

40. In a liquid crystal display apparatus having a multicolor filter comprising (i) at least a first plurality of pixel volumes that pass light with at least a first color wavelength band and block only light with a second color wavelength band and (ii) a second plurality of pixel volumes that passes light with at least a second color wavelength band and blocks only with the first color wavelength band, wherein the improvement comprises the filter being a photohardened holographic recording film element, comprising:

a photohardened holographic recording film element comprising at least a first plurality of pixel volumes and a second plurality of pixel volumes arranged in rows and columns;

each one of the first pixel volumes including a first volume holographic-mirror in a first layer that passes light with at least one first color wavelength band and reflects light only with a first wavelength sub-band of a second color wavelength band and a second volume holographic mirror in a second layer that passes light with at least one first color wavelength band and reflects light only with a second wavelength sub-band of the second color wavelength band, the first sub-band of the second color wavelength band being immediately adjacent in wavelength to the second wavelength sub-band of the second color wavelength band; and

each one of the second pixel volumes including a first volume holographic mirror in the first layer that passes light with at least the second color wavelength band and reflects light only with a first wavelength sub-band of the first color wavelength band and a second volume holographic mirror in the second layer that passes light with at least the second color wavelength band and reflects light only with a first wavelength sub-band of the first color wavelength band, the first sub-band of the first color wavelength band being immediately adjacent in wavelength to the second wavelength sub-band of the first color wavelength band.

41. A wide-bandwidth volume holographic optical element for use as a multicolor reflection filter in a liquid crystal display apparatus, the volume holographic optical element comprising:

a plurality of first pixel volumes which each include a volume holographic mirror in a first layer and a volume holographic mirror in a second layer, the volume holographic mirror in the first layer reflecting light in a first wavelength sub-band of a first color wavelength band and passing at least a second and a third color wavelength band, and the volume holographic mirror in the second layer reflecting light in a second wavelength sub-band of a first color wavelength band and passing at least a second and a third color wavelength band, the first sub-band of the first color wavelength band being immediately adjacent in wavelength to the second wavelength sub-band of the first color wavelength band;

a plurality of second pixel volumes which each include a volume holographic mirror in a first layer and a volume holographic mirror in a second layer, the volume holographic mirror in the first layer reflecting light in a first wavelength sub-band of a second color wavelength band and passing at least a first and a third color wavelength band, and the volume holographic mirror in the second layer reflecting light in a second wavelength sub-band of a second color wavelength band and passing at least a first and a third color wavelength band, the first sub-band of the second color wavelength band being immediately adjacent in wavelength to the second wavelength sub-band of the second color wavelength band;

a plurality of third pixel volumes-which each include a volume holographic mirror in a first layer and a volume holographic mirror in a second layer, the volume holographic mirror in the first layer reflecting light in a first wavelength sub-band of a third color wavelength band and passing at least a first and a second color wavelength band, and the volume holographic mirror in the second layer reflecting light in a second wavelength sub-band of a third color wavelength band and passing at least a first and a second color wavelength band, the first sub-band of the third color wavelength band being immediately adjacent in wavelength to the second wavelength sub-band of the third color wavelength band.

42. The element of claim 41, wherein the first color wavelength band has a width of at least 20 nanometers and includes 612 nanometer, the second color wavelength band has a width of at least 20 nanometers and includes 545 nanometer, and the third color wavelength band has a width of at least 20 nanometers and includes 436 nanometer.

43. The element of claim 41, wherein the film element comprises three photohardened holographic recording film layers.

44. In a reflective liquid crystal display apparatus, comprising, in order:

a first light polarizer for passing ambient light having a first polarization;

a liquid crystal display element for selectively modifying the polarization of the light passing through an array of cells such that the polarization of light passing through a first set, a second set or a third set of the cells can be changed to a second polarization;

a second light polarizer for passing light from the liquid crystal display element having the second polarization; and

a holographic multicolor reflection filter comprising a first plurality of pixel volumes, a second plurality of pixel volumes, and a third plurality of pixel volumes;

each one of the first pixel volumes including a volume holographic mirror in a first layer and a volume holographic mirror in a second layer, the volume holographic mirror in the first layer reflecting light in a first wavelength sub-band of a first color wavelength band and passing at least a second and a third color wavelength band, and the volume holographic mirror in the second layer reflecting light in a second wavelength sub-band of a first color wavelength band and passing at least a second and a third color wavelength band, the first sub-band of the first color wavelength band being immediately adjacent in wavelength to the second wavelength sub-band of the first color wavelength band;

each one of the second pixel volumes including volume holographic mirror in a first layer and a volume holographic mirror in a second layer, the volume holographic mirror in the first layer reflecting light in a first wavelength sub-band of a second color wavelength band and passing at least a first and a third color wavelength band, and the volume holographic mirror in the second layer reflecting light in a second wavelength sub-band of a second color wavelength band and passing at least a first and a third color wavelength band, the first sub-band of the second color wavelength band being immediately adjacent in wavelength to the second wavelength sub-band of the second color wavelength band; and

each one of the third pixel volumes including a volume holographic mirror in a first layer and a volume holographic mirror in a second layer, the volume holographic mirror in the first layer reflecting light in a first wavelength sub-band of a third color wavelength band and passing at least a first and a second color wavelength band, and the volume holographic mirror in the second layer reflecting light in a second wavelength sub-band of a third color wavelength band and passing at least a first and a second dolor wavelength band, the first sub-band of the third color wavelength band being immediately adjacent in wavelength to the second wavelength sub-band of the third color wavelength band;

such that (1) when the liquid crystal display element modifies the polarization of the light passing through the first set of cells to the second polarization, the light passes through the second polarizer into the first pixel volumes in which the first volume holographic mirrors reflect light with the first color wavelength band back to a viewer, (2) when the liquid crystal display element modifies the polarization of the light passing through the second set of cells to the second polarization, the light passes through the second polarizer into the second pixel volumes in which the second volume holographic mirrors reflect light with the second color wavelength band back to the viewer, and (3) when the liquid crystal display element modifies the polarization of the light passing through the third set of cells to the second polarization, the light passes through the third polarizer into the third pixel volumes in which the third volume holographic mirrors reflect light with the third color wavelength band back to the viewer.

45. A wide-viewing angle volume holographic optical element for use as a multicolor reflection filter in a liquid crystal display apparatus, the volume holographic optical element comprising:

a holographic recording film element comprising a first plurality of pixel volumes, a second plurality of pixel volumes, and a third plurality of pixel volumes;

each one of the first pixel volumes including a first volume holographic mirror that reflects, in a diverging manner within a predetermined cone angle, only light with a first color wavelength band and passes light with at least a second color wavelength band and a third color wavelength band;

each one of the second pixel volumes including a second volume holographic mirror that reflects, in a diverging manner within a predetermined cone angle, only light with the second color wavelength band and passes light with at least the first color wavelength band and the third color wavelength band; and

each one of the third pixel volumes including a third volume holographic mirror that reflects, in a diverging manner within a predetermined cone angle, only light with the third color wavelength band and passes light with at least the first color wavelength band and the second color wavelength band.

46. A method for making a first volume holographic optical element, comprising:

a holographic recording film element comprising a first plurality of pixel volumes, a second plurality of pixel volumes, and a third plurality of pixel volumes;

each one of the first pixel volumes including a first volume holographic mirror that reflects, in a diverging manner within a predetermined cone angle, only light with a first color wavelength band and passes light with at least a second color wavelength band and a third color wavelength band;

each one of the second pixel volumes including a second volume holographic mirror that reflects, in a diverging manner within a predetermined cone angle, only light with the second color wavelength band and passes light with at least the first color wavelength band and the third color wavelength band; and

each one of the third pixel volumes including a third volume holographic mirror that reflects, in a diverging manner within a predetermined cone angle, only light with the third color wavelength band and passes light with at least the first color wavelength band and the second color wavelength band;

the method comprising;

(A) holographically exposing the film element with coherent or substantially coherent light to record the first volume holographic mirrors in the first pixel volumes;

(B) holographically exposing the film element with coherent or substantially coherent light to record the second volume holographic mirrors in the second pixel volumes; and

(C) holographically exposing the film element with coherent or substantially coherent light to record the third volume holographic mirrors in the third pixel volumes.

47. The method of claim 46, wherein steps (A), (B) and (C) are performed simultaneously.

48. The method of claim 46, wherein the step (A) comprises.

directing coherent or substantially coherent light through a photomask having a first plurality of pixels which block light and a second plurality of pixels which allow light to pass and then through the film element onto a reflector comprising an array of concave reflector elements corresponding to the first plurality of pixels, the reflector elements reflecting the coherent or substantially coherent light back through the film element, in a diverging manner within a predetermined cone angle to holographically form the first volume holographic mirrors in the first pixel volumes.

49. The method of claim 48 wherein the reflector elements are substantially spherically concave.

50. The method of claim 48 wherein the reflector elements are substantially cylindrically concave.

51. The method of claim 50, wherein the step (C) is after step (B) and comprises:

shifting the photomask one pixel in the first direction; and

directing coherent or substantially coherent light through the photomask and then the film element onto a reflector comprising an array of concave reflector elements corresponding to the third plurality of pixels, the reflector elements reflecting the coherent or substantially coherent light back through the film element holographically forming the third volume holographic mirrors in the third pixel volumes.

52. The method of claim 48, further comprising:

before step (A), positioning a first index matching fluid layer on the reflector, a glass support on the first index matching fluid layer, the film element on the glass support, a second index matching fluid layer on the film element, the photomask on the second index matching fluid layer, and an anti-reflection layer on the photomask.

53. The method of claim 48, wherein the step (B) is after step (A) and comprises:

shifting the photomask one pixel in a first direction; and

directing coherent or substantially coherent light through the photomask and then the film element onto a reflector comprising an array of concave reflector elements corresponding to the second plurality of pixels, the reflector elements reflecting the coherent or substantially coherent light back through the film element, in a diverging manner within a predetermined cone angle, holographically forming the second volume holographic mirrors in the second pixel volumes.

54. The method of claim 46, further comprising curing the holographic recording film element by exposing it to actinic radiation to substantially polymerize any monomer and fix the holographic mirrors in the film element.

55. The method of claim 46, further comprising heating the holographic recording film to increase the refractive index modulation, efficiency and bandwidth of the holographic mirrors.

56. The method of claim 46, further comprising forming the film element with a single, substantially solid, holographic recording film.

57. A wide viewing angle volume holographic optical element, comprising:

a photohardened holographic recording film element comprising a first plurality of pixel volumes, a second plurality of pixel volumes, and a third plurality of pixel volumes;

each one of the first pixel volumes including a first volume holographic mirror that passes light, in a diverging manner, with a first color wavelength band and reflects light, within a predetermined acceptance cone angle, with at least a second color wavelength band and a third color wavelength band;

each one of the second pixel volumes including a second volume holographic mirror that passes light, in a diverging manner, with the second color wavelength band and reflects light, within a predetermined acceptance cone angle, with at least the first color wavelength band and the third color wavelength band; and

each one of the third pixel volumes including a third volume holographic mirror that passes light, in a diverging manner, with the third color wavelength band and reflects light with at least the first color wavelength band within a predetermined acceptance cone angle and the second color wavelength band, wherein;

the film element comprising a first holographic recording layer and a second holographic recording layer on the first layer;

each one of the first pixel volumes, the second pixel volumes and the third pixel volumes comprises a first layer volume and a second layer volume;

each of the first volume holographic mirrors comprising;

a fourth volume holographic mirror that passes light with the first color wavelength band and the second color wavelength band and reflects light, within a predetermined acceptance cone angle, with the third color wavelength band, the fourth mirrors in the first layer volumes of the first pixel volumes; and

a fifth volume holographic mirror that passes light with the first color wavelength band and the third color wavelength band and reflects light, within a predetermined acceptance cone angle, with the second color wavelength band, the fifth mirrors in the second layer volumes of the first pixel volumes; and

each of the second volume holographic mirrors comprising;

one of the fourth mirrors in the second layer volumes of the second pixel volumes; and

a sixth volume holographic mirror that passes light with the second color wavelength band and the third color wavelength band and reflects light, within a predetermined acceptance cone angle, with the first color wavelength band, the sixth mirrors in the first layer volumes of the second pixel volumes; and

each of the third volume holographic mirrors comprising;

one of the fifth mirrors in the second layer volumes of the third pixel volumes; and

one of the sixth mirrors in the first layer volumes of the third pixel volumes.

58. In a transmission liquid crystal display apparatus, for use with a light source having narrow bandwidth discrete spectral power peaks at a first color, a second color and a third color, comprising, in order:

a light assembly which emits light with a first color wavelength band, a second color wavelength band and a third color wavelength band;

a first light polarizer for passing light from the light assembly having a first polarization;

a liquid crystal display element for selectively modifying the polarization of the light passing through an array of cells such that the polarization of light passing through a first set, a second set or a third set of the cells can be changed to a second polarization;

a holographic multicolor transmission filter comprising a first plurality of pixel volumes, a second plurality of pixel volumes, and a third plurality of pixel volumes;

each one of the first pixel volumes including a first volume holographic mirror that passes, in a diverging manner, at least light with a first color wavelength band and reflects light, within a predetermined acceptance cone angle, with only a second color wavelength band and a third color wavelength band;

each one of the second pixel volumes including a second volume holographic mirror that passes light, in a diverging manner, with at least the second color wavelength band and reflects light, within a predetermined acceptance cone angle, with only the first color wavelength band and the third color wavelength band; and

each one of the third pixel volumes including a third volume holographic mirror that passes light, in a diverging manner, with at least the third color wavelength band and reflects light, within a predetermined acceptance cone angle, with only the first color wavelength band and the second color wavelength band;

a second light polarizer for passing light having a second polarization,

such that (1) when the liquid crystal display element modifies the polarization of the light passing through the first set of cells to the second polarization, the light passes into the first pixel volumes in which the first volume holographic mirrors pass light with the first color wavelength band, in a diverging manner, through the second polarizer to a viewer, (2) when the liquid crystal display element modifies the polarization of the light passing through the second set of cells to the second polarization, the light passes into the second pixel volumes in which the second volume holographic mirrors pass light with the second color wavelength band, in a diverging manner, through the second polarizer to the viewer, and (3) when the liquid crystal display element modifies the polarization of the light passing through the third set of cells to the second polarization, the light passes into the third pixel volumes in which the third volume holographic mirrors pass light with the third color wavelength band, in a diverging manner, through the third polarizer to the viewer.

59. A volume holographic optical element, comprising:

a photohardened holographic recording film element comprising at least a first plurality of pixel volumes and a second plurality of pixel volumes;

each one of the first pixel volumes including a volume holographic mirror that passes light with at least one first color wavelength band and reflects light with at least a second color wavelength band;

each one of the second pixel volumes including a volume holographic mirror that passes light with at least the second color wavelength band and reflects light with at least the first color wavelength band; and

a substantially optically opaque mask volume surrounding each first and second pixel volumes, comprising a third volume holographic mirror that reflects light with at least the first color wavelength band and the second color wavelength band.

60. In a liquid display apparatus having a multicolor filter comprising (i) at least a first plurality of pixel volumes that pass light with at least a first color wavelength band and block light with at least a second color wavelength band and (ii) a second plurality of pixel volumes that passes light with at least a second color wavelength band and blocks light with at least the first color wavelength band, wherein the improvement comprises the filter being a photohardened holographic recording film element having an integral substantially optically opaque mask volume surrounding the first and second pixel volumes the mask volume comprising a third volume holographic mirror that reflects light with at least the first color wavelength band and the second color wavelength band.

61. In a reflective liquid crystal display apparatus, comprising, in order:

a first light polarizer for passing ambient light having a first polarization;

a liquid crystal display element for selectively modifying the polarization of the light passing through an array of cells such that the polarization of light passing through a first set, a second set or a third set of the cells can be changed to a second polarization;

a second light polarizer for passing light from the liquid crystal display element having the second polarization; and

a holographic multicolor reflection filter comprising a first plurality of pixel volumes, a second plurality of pixel volumes, a third plurality of pixel volumes, and an integral opaque mask volume comprising a fourth plurality of mask volumes;

each one of the first pixel volumes including a first volume holographic mirror that reflects light with a first color wavelength band and passes light with at least a second color wavelength band and a third color wavelength band;

each one of the second pixel volumes including a second volume holographic mirror that reflects light with the second color wavelength band and passes light with at least the first color wavelength band and the third color wavelength band;

each one of the third pixel volumes including a third volume holographic mirror that reflects light with the third color wavelength band and passes light with at least the first color wavelength band and the second color wavelength band; and

each one of the fourth mask volumes including a fourth volume holographic mirror that reflects light with first color wavelength band, the second color wavelength band and the third color wavelength band;

such that (1) when the liquid crystal display element modifies the polarization of the light passing through the first set of cells to the second polarization, the light passes through the second polarizer into the first pixel volumes in which the first volume holographic mirrors reflect light with the first color wavelength band back to a viewer, (2) when the liquid crystal display element modifies the polarization of the light passing through the second set of cells to the second polarization, the light passes through the second polarizer into the second pixel volumes in which the second volume holographic mirrors reflect light with the second color wavelength band back to the viewer, and (3) when the-liquid crystal display element modifies the polarization of the light passing through the third set of cells to the second polarization, the light passes through the third polarizer into the third pixel volumes in which the third volume holographic mirrors reflect light with the third color wavelength band back to the viewer.

62. A method for making a first volume holographic optical element, comprising:

a holographic recording film element comprising a first plurality of pixel volumes, a second plurality of pixel volumes, a third plurality of pixel volumes, and a fourth plurality of mask volumes;

each one of the first pixel volumes including a first volume holographic mirror that reflects light with a first color wavelength band and passes light with at least a second color wavelength band and a third color wavelength band;

each one of the second pixel volumes including a second volume holographic mirror that reflects light with the second color wavelength band and passes light with at least the first color wavelength band and the third color wavelength band; and

each one of the third pixel volumes including a third volume holographic mirror that reflects light with the third color wavelength band and passes light with at least the first color wavelength band and the second color wavelength band;

each one of the fourth mask volumes including a fourth volume holographic mirror that reflects light with first color wavelength band, the second color wavelength band and the third color wavelength band;

the method comprising;

(A) holographically exposing the film element with coherent or substantially coherent light to record the first volume holographic mirrors in the first pixel volumes and a first portion of the fourth volume holographic mirrors in the fourth mask volumes;

(B) holographically exposing the film element with coherent or substantially coherent light to record the second volume holographic mirrors in the second pixel volumes and a second portion of the fourth volume holographic mirrors in the fourth mask volumes; and

(C) holographically exposing the film element with coherent or substantially coherent light to record the third volume holographic mirrors in the third pixel volumes and a third portion of the fourth volume holographic mirrors in the fourth mask volumes.