Abstract: A display presenting an image having enhanced contrast has a screen which switches between a bright, image-presenting state and a dark, image-less state, to minimize glare from ambient light reflections. Alternatively, a shutter which switches between a substantially transparent state and a dark, light absorbing state is placed over a conventional screen.

Abstract: A liquid crystal display comprises (a) a first transparent base; (b) a plurality of first picture electrodes on the first transparent base; (c) a plurality of data lines for supplying electrical signals to the first picture electrodes; (d) a second transparent base, parallel to and spaced apart from the first transparent base; (e) a plurality of second picture electrodes on the second transparent base; (f) a plurality of varistor elements made of a varistor material comprising zinc oxide as a primary metal oxide and cobalt and praseodymium oxides as additive metal oxides, in amounts of between 0.1 and 8.0 atom % cobalt and between 0.08 and 8.0 atom % praseodymium, one varistor element being associated with and in electrical contact each second picture electrode; (g) a plurality of scan lines for supplying electrical signals to the second picture electrodes via the respective associated varistor elements; and (h) electrooptically active liquid crystal material between the first and second picture electrodes.

Abstract: A display presenting an image having enhanced contrast has a screen which switches between a bright, image-presenting state and a dark, image-less state, to minimize glare from ambient light reflections. Alternatively, a shutter which switches between a substantially transparent state and a dark, light absorbing state is placed over a conventional screen.

Abstract: Poly(arylene ether ketones) are prepared by a Friedel-Crafts polymerization wherein a gelled reaction mixture is produced, by permitting the polymerization to proceed in a first reactor until substantial partial polymerization has occurred, but before substantial gelation of the reaction mixture; transferring the partially polymerized reaction mixture into a piston-equipped second reactor; permitting polymerization to continue in the second reactor until a gelled, polymerized reaction mixture has been obtained; and discharging the polymerized reaction mixture from the second reactor by stroking the piston.

Abstract: A method of preparing a poly(arylene ether ketone) by a Friedel-Crafts polymerization wherein a gelled reaction mixture is produced, comprising the steps of:(A) forming, in a first reactor, a reaction mixture for polymerization comprising(I) a monomer system comprising(a) (i) phosgene or an aromatic dicarboxylic acid dihalide and (ii) a substantially stoichiometric amount of a polynuclear aromatic comonomer having two active hydrogen atoms or(b) a polynuclear aromatic carboxylic acid halide having an active hydrogen atom; and(II) a Lewis acid in an amount of at least one equivalent per equivalent of carbonyl groups in the monomer system, plus an amount effective to act as a catalyst for the polymerization;(B) permitting the reaction mixture to polymerize in the first reactor until substantial partial polymerization has occurred, but before substantial gelation of the reaction mixture;(C) transferring the partially polymerized reaction mixture into a second reactor having a nozzle at one end thereof and a pist