摘要:
A magnetic-tape cassette apparatus having a deck for magnetic-tape cassettes with a reel drive mechanism for transporting a tape with a first and an opposite, second tape transport direction. The change-over from the first tape transport direction to the opposite second tape transport direction is affected by a switching mechanism which switches the reel-drive mechanism between a play mode in the forward direction and a play mode in the reverse direction. The switching mechanism includes a switching lever moveable from a first position for the first playing direction to a second position for the opposite second play direction. The switching lever is moved by a pair of switching wheels, whose teeth are engageable with associated teeth of adjacent flywheels for changing over the switching lever from the predetermined position for one playing direction to the predetermined position for the opposite other playing direction by actuating elements provided on the switching wheels.
摘要:
Supertwist liquid-crystal displays having excellent properties are obtained using a nematic liquid-crystal mixture based on component A which contains one or more compounds of the formula IIa or IIb: ##STR1## on or more compounds of the formulae IIc to IIe: ##STR2## and one or more compounds of the formula IIf to IIh: and one or more compounds of the formula IIf to IIh: ##STR3## wherein R, R.sup.1, R.sup.2, L, Y, X and n are as defined herein.
摘要:
Compounds of the formula IR.sup.1 --A.sup.1 --Z.sup.1 --A--O--R.sup.2in whichR.sup.1 and R.sup.2, independently of one another, are each alkyl having 1 to 9 C atoms, in which, in addition, one or two CH.sub.2 groups may be replaced by --O--, --CO--, --O--CO--, --CO--O-- and/or --CH.dbd.CH--, where two O atoms are not linked directly to one anther, or one of the two groups R.sup.1 and R.sup.2 is alternatively H,Z.sup.1 is --CH.sub.2 --O--, --OCH.sub.2 --, --CH.sub.2 CH.sub.2 -- or a single bond,A.sup.1 is trans-1,4-cyclohexylene in which, in addition one or two nonadjacent CH.sub.2 groups may be replaced by O and/or S, or 1,4-cyclohexenylene, andA is unsubstituted or fluorine-substituted 1,4-phenylene, can be used as components of liquid-crystalline dielectrics containing at least three liquid-crystalline compounds for shortening the switch-on time T.sub.on of electrooptical display elements based on a TN cell on switching the voltage from a first voltage below or approximately at the threshold voltage to a second voltage on the increase of the electrooptical characteristic line.
摘要:
The invention relates to a matrix liquid crystal display containing integrated non-linear elements and a liquid crystal mixture which has a particularly high resistivity.
摘要:
Ethyne derivatives of the formula IR.sup.1 --(A.sup.1 --Z.sup.1).sub.m --A.sup.3 --C.tbd.C--A.sup.4 -(Z.sup.2 -A.sup.2).sub.n --R.sup.2 Iwherein R.sup.1, A.sup.1, Z.sup.1 m, A.sup.3, A.sup.4, Z.sup.2, A.sup.2, n and R.sup.2 have the meaning given in claim 1 are suitable as components of liquid crystal phases.
摘要:
A pressure for a belt grinding machine includes an elongated carrier with a base plate facing the grinding belt and having a plurality of bores arranged in a matrix, a plurality bolt shaped pressure members supported in the bores for free axial movement and which are adapted to engage the grinding belt with their free ends and which with their other ends are urged toward the grinding belt by a hose inflatable by a pressure fluid. The hose is surrounded by a plurality of frame shaped pressure shoes arranged next to one another in the longitudinal direction of the carrier, each of which pressure shoes is adjustable vertically relative to the base plate by a positioning device. The pressure shoes each have a frame side facing the base plate provided with bores registering with the base plate bores for receiving the pressure members, and inside of each pressure shoe and between the hose and the adjacent ends of the pressure members is a flexible pressure distribution element having a higher stiffness than that of the hose material.
摘要:
2,3-Difluorophenol derivatives of the formula ##STR1## wherein R.sup.1 and R.sup.2, in each case independently of one another, are an alkyl group having 1 to 15 C atoms in which, in addition, one or two nonadjacent CH.sub.2 groups may be replaced by --O--, --CO--, --CH.dbd.CH-- and/or --C.tbd.C--;A is 1,4-phenylene which is unsubstituted or substituted by one or two fluorines, or is trans-1,4-cyclohexylene or a single bond; andL.sup.1 and L.sup.2, in each case independently of one another, are H or F,are suitable as components of liquid-crystalline media.
摘要:
Liquid crystalline fluorine-containing pyrimidine compounds have the formula I ##STR1## wherein R.sup.1 and R.sup.2 are H, R, OR or OCOR, and one of them can also be CN or F, or, if A is a covalent bond, also one or both of R.sup.1 and R.sup.2 can be 4-R.sup.4 -phenyl or 4-R-cyclohexyl, wherein R.sup.4 is R, OR, cyano, f or OCOR; wherein R is an alkyl group of 1 to 12 C atoms; R.sup.3 is F or, if one of the radicals R.sup.1 or R.sup.2 is F or 4-fluorophenyl, also H; Z is 1,3-pyrimidin-2,5-diyl; and A is 1,4-phenylene, 1,4-cyclohexylene or a covalent bond.Fluorine-containing pyrimidine compounds are useful components of liquid crystal dielectrics for electro-optical display devices.
摘要翻译:液晶含氟嘧啶化合物具有式I的化合物,其中R 1和R 2是H,R,OR或OCOR,它们之一也可以是CN或F,或者如果A是共价键,也可以是一个或 R 1和R 2可以是4-R 4 - 苯基或4-R-环己基,其中R 4是R,OR,氰基,F或OCOR; 其中R是1至12个C原子的烷基; R 3为F,或者如果基团R 1或R 2中的一个为F或4-氟苯基,则为H; Z是1,3-嘧啶-2,5-二基; A是1,4-亚苯基,1,4-亚环己基或共价键。 含氟嘧啶化合物是用于电光显示装置的液晶电介质的有用组分。
摘要:
Compounds of the formula IR.sup.1 --A.sup.1 --Z.sup.1 --A.sup.2 --R.sup.2 IwhereinR.sup.1 and R.sup.2 are each H, an alkyl, alkoxy, alkanoyl, alkanoyloxy or alkoxycarbonyl group with in each case 1-10 C atoms, F, Cl, Br, CN or R.sup.3 --A.sup.3 --Z.sup.2 --,A.sup.1 is --A--, --A.sup.4 --A--or --A--A.sup.4 --,A is a 1,3-dioxane-2,5-diyl or a 1,3-dithiane-2,5-diyl group,A.sup.2, A.sup.3 are each a 1,4-cyclohexylene, 1,3-dioxane-2,5-diyl,and A.sup.4 1,3-dithiane-2,5-diyl, piperidine-1,4-diyl or 1,4-bicyclo(2,2,2)octylene group, or a 1,4-phenylene, pyrimidine-2,5-diyl or pyridazine-3,6-diyl group which is unsubstituted or substituted by one or two F and/or Cl atoms and/or CH.sub.3 groups and/or CN groups,Z.sup.1 and Z.sup.2 are each --CO--O--, --O--CO--, --CH.sub.2 CH.sub.2 --, --OCH.sub.2 --, --CH.sub.2 O or a single bond andR.sup.3 is H, an alkyl, alkoxy, alkanoyl, alkanoyloxy or alkoxycarbonyl group with in each case 1-10 C atoms, F, Cl, Br or CN, with the proviso that(a) at least one group A.sup.2, A.sup.3 and/or A.sup.4 contains lateral substituents,(b) 1,3-dioxane-2,5-diyl and 1,3-dithiane-2,5-diyl groups are not substituted by alkoxy, alkanoyl, alkanoyloxy, alkoxycarbonyl, F, Cl, Br, CN or R.sup.3 --A.sup.3 --Z.sup.2 in the 2-position and piperidine-1,4-diyl groups are not substituted by these radicals in the 1-position,(c) Z.sup.1 is not --CH.sub.2 CH.sub.2 --if A.sup.1 is --A--and(d) Z.sup.1 is not --CO--O--if A.sup.1 is --A--A.sup.4 --and --A.sup.2 --R.sup.2 is 3-chloro-4-cyanophenyl and(e) all lateral substituents on pyrimidine-2,5-diyl and pyridazine-3,6-diyl groups are attached to C-atoms,can be used as components of liquid crystal phases.
摘要:
New decalin-carbonitriles of the formula I ##STR1## wherein R.sup.1 is an alkyl group with 1-10 C atoms, it being possible for up to two CH.sub.2 groups to be replaced by O atoms, Z is --CH.sub.2 CH.sub.2 --, --CO--O--, --O--CO--, --O--CH.sub.2 --, --CH.sub.2 O-- or a single bond, A is 1,4-phenylene, 1,4-cyclohexylene, 1,3-dioxane-2,5-diyl, 1,4-bicyclo(2,2,2)octylene, pyrimidine-2,5-diyl or a single bond, and R.sup.2 is an alkyl group with 1 to 10 C atoms, it being possible for up to two CH.sub.2 groups to be replaced by O atoms, or is F, Cl, Br, CN, --O--COR.sup.3 or --COOR.sup.3, or, if at least one of the groups Z and A is not a single bond, can also be H and R.sup.3 is alkyl of 1 to 6 C atoms, and the acid addition salts of basic compounds of this type, are suitable for use as components of liquid crystal dielectrics.