Patent ID: 7569258

Claim:
A liquid crystal compound represented by one of formulas (a) to (d): wherein Ra and Rb are independently hydrogen or linear alkyl having 1 to 10 carbons, provided that in the alkyl, —CH 2 — may be replaced by —O—, —(CH 2 ) 2 — may be replaced by —CH═CH—, and hydrogen may be replaced by a halogen; rings A 1 , A 2 , B and C are independently trans-1,4-cyclohexylene or 1,4-phenylene; Z 11 , Z 12 , Z 2 and Z 3 are independently a single bond or alkylene having 2 or 4 carbons, provided that in the alkylene, —CH 2 — may be replaced by —O— and —(CH 2 ) 2 — may be replaced by —CH═CH—; and X 1 is fluorine, and X 2 is chlorine, provided that: in a case where: in formula (a), rings B and C are trans-1,4-cyclohexylene, and Z 2 and Z 3 are a single bond, in formula (b), rings A 1 and B are trans-1,4-cyclohexylene, Z 11 is a single bond, and Z 2 is —CH 2 O—, and in formula (d), rings A 1 , A 2 and B are trans-1,4-cyclohexylene, Z 11 and Z 12 are a single bond, and Z 2 is a single bond or —CH 2 O—, Rb is one of linear alkoxy having 1 to 9 carbons, linear alkoxyalkyl having 2 to 9 carbons, linear alkenyl having 2 to 10 carbons, linear alkenyloxy having 2 to 9 carbons.