LIQUID CRYSTAL DISPLAY WITH A FLUORESCENT BACKLIGHT EMITTING POLARISED LIGHT

• US 20110216271A1
• Filed: 08/13/2009
• Published: 09/08/2011
• Est. Priority Date: 09/10/2008
• Status: Active Grant

• Current Assignee: Merck Patent GmbH (Merck & Co., Inc.)
• Original Assignee: Merck Patent GmbH (Merck & Co., Inc.)
• Inventors: Fujiwara, Naoya, Suzuki, Masayoshi, Manabe, Atsutaka
• Granted Patent: US 8,879,024 B2
• Time in Patent Office: Days
• US Class Current: 349/71
• CPC Class Codes: G02F 1/133543 Cholesteric polarisers
• CPC Class Codes: G02F 1/133557 Half-mirrors
• CPC Class Codes: G02F 1/133614 using photoluminescence, e.g. phosphors illuminated by UV or blue light
• CPC Class Codes: G02F 1/13362 providing polarized light, e.g. by converting a polarisation component into another one
• CPC Class Codes: G02F 1/133621 providing coloured light G02F1/133617, G02F1/133533 take precedence
• CPC Class Codes: G02F 2201/086 UV absorbing

Abstract

The instant invention relates to electro-optical switching elements and displays comprising them. In particular, it relates to electro-optical switching elements comprising one or more light conversion means capable to convert light (e.g. ambient light and/or light from a backlight system), wherein each of said light conversion means o is capable to convert the state of polarization of the light from non-polarized light either to linear polarized light or to circular polarized light and, at the same time, o optionally is capable to shift the wavelength of the light to longer values and—at least one of said conversion means o is capable to shift the wavelength of the light to longer values and—a liquid crystal material, which is capable of switching, —one or more means to polarize light, and—optionally a means for illumination such as e.g. a backlight.

Claims

1. An electro-optical switching element comprising

one or more light conversion means capable to convert light (e.g. ambient light and/or light from a backlight system), each of said light conversion means

is capable to convert the state of polarization of the light from non-polarized light either to linear polarized light or to circular polarized light and, at the same time,

optionally is capable to shift the wavelength of the light to longer values and

at least one of said conversion means

is capable to shift the wavelength of the light to longer values and

a liquid crystal material, which is capable of switching,

one or more means to polarize light and optionally a polarizer, and

optionally a means for illumination, as e.g. a backlight.

2. An electro-optical switching element, according to claim 1, wherein

a back light system capable to emit blue light,

one light conversion means capable to convert the light from said backlight system, which is

capable to convert the state of polarization of the light and

optionally, at the same time, capable to shift the wavelength of the blue light to longer values,

at least one additional light conversion means capable to convert the light from said backlight system, which is, respectively which are,

capable to convert the state of polarization of the light and

at the same time, capable to shift the wavelength of the light to longer values.

3. An electro-optical switching element, according to claim 1, wherein the light conversion means has or have the form of a layer or of layers.

4. An electro-optical switching element, according to claim 1, wherein the light conversion means comprises or consists of an aligned liquid crystal material.

5. An electro-optical switching element, according to claim 4, wherein the light conversion means comprises or consists of linearly aligned liquid crystal material.

6. An electro-optical switching element, according to claim 4, wherein the light conversion means comprises or consists of cholesteric liquid crystal material.

7. An electro-optical switching element, according to claim 1, wherein the light conversion means comprises one or more dichroic dyes.

8. An electro-optical switching element, according to claim 1, wherein the a liquid crystal material capable of switching comprises a dichroic dye.

9. An electro-optical switching element, according to claim 1, wherein the a liquid crystal material capable of switching has a negative dielectric anisotropy.

10. An array of electro-optical switching elements, according to claim 1, comprising a set of three electro-optical switching elements or a multitude of said sets of three electro-optical switching elements, the switching elements in each of said sets having different colours from each other.

11. An array of electro-optical switching elements according to claim 10, wherein the light conversion means has the form of a layer of laminated layers.

12. An array of electro-optical switching elements according to claim 10, wherein the light conversion means has the form of a spatially structured/patterned layer having separate areas for the three colours red, green and blue, respectively.

13. A liquid crystal display comprising an array of electro-optical switching elements according to claim 10.

14. Use of an electro-optical switching element according to claim 1 or of an array of such electro-optical switching elements for the display of information.

15. Use of an electro-optical switching element according to claim 1 or of an array of such electro-optical switching elements in an electro-optical display.