Subtractive color LCD utilizing circular notch polarizers and including a triband or broadband filter tuned light source or dichroic sheet color polarizers

• US 5,751,385 A
• Filed: 06/07/1994
• Issued: 05/12/1998
• Est. Priority Date: 06/07/1994
• Status: Expired due to Fees

• Current Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Original Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Inventors: Heinze, William C.
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): Malinowski, Walter J.
• Application Number:
  US08/255,031
• Time in Patent Office: 1,435 Days
• Field of Search: 359/53, 359/65, 359/63, 359/73, 359/37, 349/1, 349/74, 349/78, 349/80, 349/98, 349/117, 349/61, 349/97
• US Class Current: 349/61
• CPC Class Codes: G02F 1/133533 Colour selective polarisers G02F1/1347 takes precedence
• CPC Class Codes: G02F 1/13473 for wavelength filtering or for colour display without the use of colour mosaic filters
• CPC Class Codes: G02F 2201/343 cholesteric liquid crystal reflector
• CPC Class Codes: G02F 2203/34 Colour display without the use of colour mosaic filters

Abstract

A subtractive color liquid crystal display employing circular polarizers. In the subtractive color display each picture element has three liquid crystal switching elements. Adjacent to each liquid crystal switching element are a circular polarizer and 1/4 wave retarder plate combination. The circular polarizer and 1/4 wave retarder plate combination create a linear notch polarizer for an isolated and steep polarization band for each of the primary colors (red, green blue). The notch polarizes are tuned to the particular backlight of the display in order to provide increased light transmittance and color gamut.

Claims

1. A subtractive color liquid crystal display comprising:

tuned illumination means comprising a triband tuned light source; and

a plurality of picture elements, each of said picture elements comprising;

first, second, and third active switching elements aligned relative to said illumination means, which selectively rotate polarization of incident light from said illumination means;

a first entrance notch polarizer adjacent to the first switching element which polarizes a narrow band of light of the first primary color (red, green, and blue);

a first exit notch polarizer adjacent to the first switching element which blocks or passes light of the first primary color depending on the rotation imparted on the light by the first switching element;

a second entrance notch polarizer adjacent to the second switching element which polarizes a narrow band of light of a second primary color;

a second exit notch polarizer adjacent to the second switching element which blocks or passes light of the second primary color depending on the rotation imparted on the light by the second switching element;

a third entrance notch polarizer adjacent to the third switching element which polarizes a narrow band of light of the third primary color; and

a third exit notch polarizer adjacent to the third switching element which blocks or passes light of the third primary color depending on the rotation imparted on the light by the third switching element;

and wherein the entrance and exit notch polarizers are comprised of a circular notch polarizer and a quarter wave retarder plate, said circular notch polarizer being constructed of tuned crosslinked cholesteric liquid crystal silicons.

2. The subtractive liquid crystal display of claim 1 wherein the triband light source is a trio of lasers each of which emits light of a narrow bandwidth and high intensity for each of the primary colors.

3. A subtractive color liquid crystal display comprising:

tuned illumination means comprising a filter tuned broadband light source; and

a plurality of picture elements, each of said picture elements comprising;

first, second, and third active switching elements aligned relative to said illumination means, which selectively rotate polarization of incident light from said illumination means;

a first entrance notch polarizer adjacent to the first switching element which polarizes a narrow band of light of the first primary color (red, green, and blue);

a first exit notch polarizer adjacent to the first switching element which blocks or passes light of the first primary color depending on the rotation imparted on the light by the first switching element;

a second entrance notch polarizer adjacent to the second switching element which polarizes a narrow band of light of a second primary color;

a second exit notch polarizer adjacent to the second switching element which blocks or passes light of the second primary color depending on the rotation imparted on the light by the second switching element;

a third entrance notch polarizer adjacent to the third switching element which polarizes a narrow band of light of the third primary color; and

a third exit notch polarizer adjacent to the third switching element which blocks or passes light of the third primary color depending on the rotation imparted on the light by the third switching element;

and wherein the entrance and exit notch polarizers are comprised of a circular notch polarizer and a quarter wave retarder plate, said circular notch polarizer being constructed of tuned crosslinked cholesteric liquid crystal silicons.

4. The subtractive liquid crystal display of claim 3 wherein the filter tuned illumination means is tuned by a plurality of the notch polarizers which filter predetermined portions of the spectrum between the primary colors.

5. A subtractive color liquid crystal display comprising:

tuned illumination means; and

a plurality of picture elements, each of said picture elements comprising;

first, second, and third active switching elements aligned relative to said illumination means, which selectively rotate polarization of incident light from said illumination means;

a first entrance notch polarizer adjacent to the first switching element which polarizes a narrow band of light of the first primary color (red, green, and blue);

a first exit notch polarizer adjacent to the first switching element which blocks or passes light of the first primary color depending on the rotation imparted on the light by the first switching element;

a second entrance notch polarizer adjacent to the second switching element which polarizes a narrow band of light of a second primary color;

a second exit notch polarizer adjacent to the second switching element which blocks or passes light of the second primary color depending on the rotation imparted on the light by the second switching element;

a third entrance notch polarizer adjacent to the third switching element which polarizes a narrow band of light of the third primary color; and

a third exit notch polarizer adjacent to the third switching element which blocks or passes light of the third primary color depending on the rotation imparted on the light by the third switching element;

and wherein;

the entrance and exit notch polarizers are comprised of a circular notch polarizer and a quarter wave retarder plate, said circular notch polarizer being constructed of tuned crosslinked cholesteric liquid crystal silicons; and

the notch polarizers are further comprised of a combination of dichroic sheet color polarizers making a broad notch polarizer or black filter polarizer which would be employed with broad band lamps.

6. The subtractive liquid crystal display of claim 5 wherein the circular notch polarizer is tuned to efficiently polarize light inefficiently polarized or not polarized by the dichroic sheet color polarizers.

7. A subtractive color liquid crystal display comprising:

illumination means comprising a triband tuned light source; and

a plurality of stacked liquid crystal color filters each subtracting a particular primary color (red, green, blue), each filter includes a plurality of picture elements which are comprised of;

at least one entrance circular notch polarizer tuned relative to said illumination means to polarize one of the primary colors;

a liquid crystal switching element to selectively rotate light from the illumination means through a known angle; and

at least one exit circular notch polarizer tuned relative to said illumination means to either block or pass the same one of the primary colors depending on the rotation selectively imparted on the light by the liquid crystal switching element;

and wherein the entrance and exit notch polarizers are comprised of a circular notch polarizer and a quarter wave retarder plate, said circular notch polarizer being constructed of tuned crosslinked cholesteric liquid crystal silicons.

8. The subtractive liquid crystal display of claim 7 wherein the triband light source is a trio of lasers each of which emits light of a narrow bandwidth and high intensity for each of the primary colors.

9. A subtractive color liquid crystal display comprising:

illumination means comprising a filter tuned broadband light source with tuned lamp peaks; and

a plurality of stacked liquid crystal color filters each subtracting a particular primary color (red, green, blue), each filter includes a plurality of picture elements which are comprised of;

at least one entrance circular notch polarizer tuned relative to said illumination means to polarize one of the primary colors;

a liquid crystal switching element to selectively rotate light from the illumination means through a known angle; and

at least one exit circular notch polarizer tuned relative to said illumination means to either block or pass the same one of the primary colors depending on the rotation selectively imparted on the light by the liquid crystal switching element;

and wherein the entrance and exit notch polarizers are comprised of a circular notch polarizer and a quarter wave retarder plate, said circular notch polarizer being constructed of tuned crosslinked cholesteric liquid crystal silicons.

10. The subtractive liquid crystal display of claim 9 wherein the filter tuned illumination means is tuned by a plurality of cross linked notch polarizer pairs which filter predetermined portions of the spectrum to define the bandwidth and location of the primary colors.

11. A subtractive color liquid crystal display comprising:

illumination means; and

a plurality of stacked liquid crystal color filters each subtracting a particular primary color (red, green, blue), each filter includes a plurality of picture elements which are comprised of;

at least one entrance circular notch polarizer tuned relative to said illumination means to polarize one of the primary colors;

a liquid crystal switching element to selectively rotate light from the illumination means through a known angle; and

at least one exit circular notch polarizer tuned relative to said illumination means to either block or pass the same one of the primary colors depending on the rotation selectively imparted on the light by the liquid crystal switching element;

and wherein;

and wherein the entrance and exit notch polarizers are comprised of a circular notch polarizer and a quarter wave retarder plate, said circular notch polarizer being constructed of tuned crosslinked cholesteric liquid crystal silicons; and

the notch polarizers are further comprised of dichroic sheet color polarizers.

12. The subtractive liquid crystal display of claim 11 wherein the circular notch polarizer is tuned to efficiently polarize light inefficiently polarized or unpolarized by the dichroic sheet color polarizers.

13. A subtractive color liquid crystal display comprising:

tuned illumination means comprising a triband tuned light source; and

a plurality of picture elements, each of said picture elements comprising;

first, second, and third active switching elements aligned relative to said illumination means, which selectively rotate polarization of incident light from said illumination means;

a first entrance notch polarizer adjacent to the first switching element which polarizes a narrow band of light of the first primary color (red, green, and blue);

a first exit notch polarizer adjacent to the first switching element which blocks or passes light of the first primary color depending on the rotation imparted on the light by the first switching element;

a second entrance notch polarizer adjacent to the second switching element which polarizes a narrow band of light of a second primary color;

a second exit notch polarizer adjacent to the second switching element which blocks or passes light of the second primary color depending on the rotation imparted on the light by the second switching element;

a third entrance notch polarizer adjacent to the third switching element which polarizes a narrow band of light of the third primary color; and

a third exit notch polarizer adjacent to the third switching element which blocks or passes light of the third primary color depending on the rotation imparted on the light by the third switching element.

14. The subtractive liquid crystal display of claim 13 wherein the triband light source is a trio of lasers each of which emits light of a narrow bandwidth and high intensity for each of the primary colors.

15. A subtractive color liquid crystal display comprising:

tuned illumination means comprising a filter tuned broadband light source; and

a plurality of picture elements, each of said picture elements comprising;

first, second, and third active switching elements aligned relative to said illumination means, which selectively rotate polarization of incident light from said illumination means;

a first entrance notch polarizer adjacent to the first switching element which polarizes a narrow band of light of the first primary color (red, green, and blue);

a first exit notch polarizer adjacent to the first switching element which blocks or passes light of the first primary color depending on the rotation imparted on the light by the first switching element;

a second entrance notch polarizer adjacent to the second switching element which polarizes a narrow band of light of a second primary color;

a second exit notch polarizer adjacent to the second switching element which blocks or passes light of the second primary color depending on the rotation imparted on the light by the second switching element;

a third entrance notch polarizer adjacent to the third switching element which polarizes a narrow band of light of the third primary color; and

a third exit notch polarizer adjacent to the third switching element which blocks or passes light of the third primary color depending on the rotation imparted on the light by the third switching element.

16. The subtractive liquid crystal display of claim 15 wherein the filter tuned illumination means is tuned by a plurality of the notch polarizers which filter predetermined portions of the spectrum between the primary colors.

17. A subtractive color liquid crystal display comprising:

illumination means comprising a triband tuned light source; and

a plurality of stacked liquid crystal color filters each subtracting a particular primary color (red, green, blue), each filter includes a plurality of picture elements which are comprised of;

at least one entrance circular notch polarizer tuned relative to said illumination means to polarize one of the primary colors;

a liquid crystal switching element to selectively rotate light from the illumination means through a known angle; and

at least one exit circular notch polarizer tuned relative to said illumination means to either block or pass the same one of the primary colors depending on the rotation selectively imparted on the light by the liquid crystal switching element.

18. The subtractive liquid crystal display of claim 17 wherein the triband light source is a trio of lasers each of which emits light of a narrow bandwidth and high intensity for each of the primary colors.

19. A subtractive color liquid crystal display comprising:

illumination means comprising a filter tuned broadband light source with tuned lamp peaks; and

a plurality of stacked liquid crystal color filters each subtracting a particular primary color (red, green, blue), each filter includes a plurality of picture elements which are comprised of;

at least one entrance circular notch polarizer tuned relative to said illumination means to polarize one of the primary colors;

a liquid crystal switching element to selectively rotate light from the illumination means through a known angle; and

at least one exit circular notch polarizer tuned relative to said illumination means to either block or pass the same one of the primary colors depending on the rotation selectively imparted on the light by the liquid crystal switching element.

20. The subtractive liquid crystal display of claim 19 wherein the filter tuned illumination means is tuned by a plurality of cross linked notch polarizer pairs which filter predetermined portions of the spectrum to define the bandwidth and location of the primary colors.