Abstract: The invention pertains to a phenylethanediol derivative having at least one polymerizable group, characterized in that the phenylethanediol derivative further comprises at least one photo-convertible group for adjusting the helical twisting power of the phenylethanediol derivative. According to a preferred embodiment the phenylethanediol has the formula wherein A stands for a bond or a p-phenylene group; B and B? are independently (O)p—CoH2o—O—CO—CR??CH2, o being 2-12, p being 0 or 1, and R? being H or CH3; P stands for a CH2 or a C?O group; Q and Q? are independently selected from H, C1-C3 alkyl, C1-C3 alkoxy, halogen, and CN; n is an integer from 1 to 3; and m is an integer from 0 to 2; and: wherein A stands for a bond or a p-phenylene group; B is (O)p—CoH2o—O—CO—CR??CH2, o being 2-12, p is 1, and R? being H or CH3; P stands for a CH2 or a C?O group; Q is selected from H, C1-C3 alkyl, C1-C3 alkoxy, halogen, and CN; and m is an integer from 0 to 2.

Abstract: A gas discharge lamp has a gas discharge vessel filled with a gas filling suitable for a gas discharge which emits VUV radiation, with a phosphor coating containing a downconversion phosphor. The downconversion phosphor has, in a host lattice, a pair of activators of a first lanthanoid ion and a second lanthanoid ion; a sensitizer selected from the group formed by the thallium(I) ion, lead(II) ion and bismuth(III) ion; and samarium(II) ion co-activator.

Abstract: The present invention relates to a cholesteric color filter (CCF) provided with a coating preventing the ingress of oxygen, and a method for making such a cholesteric color filter. It further relates to a device, such as a liquid crystal display (LCD), comprising a substrate provided with such a cholesteric color filter. The topcoat is preferably curable by electromagnetic radiation.