(19)
(11) EP 0 420 129 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
22.04.1992 Bulletin 1992/17

(43) Date of publication A2:
03.04.1991 Bulletin 1991/14

(21) Application number: 90118351.7

(22) Date of filing: 24.09.1990
(51) International Patent Classification (IPC)5: G09G 3/36, G02F 1/137
(84) Designated Contracting States:
DE FR GB

(30) Priority: 25.09.1989 JP 248731/89

(71) Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
Atsugi-shi Kanagawa-ken, 243 (JP)

(72) Inventors:
  • Fukui, Takashi
    Atsugi-shi, Kanagawa-ken 243 (JP)
  • Watanabe, Toshio
    Atsugi-shi, Kanagawa-ken 243 (JP)

(74) Representative: Grünecker, Kinkeldey, Stockmair & Schwanhäusser Anwaltssozietät 
Maximilianstrasse 58
80538 München
80538 München (DE)


(56) References cited: : 
   
       


    (54) Liquid crystal electro-optical device and method for driving the same


    (57) A liquid crystal electro-optical device and a method for driving the same are disclosed. The liquid crystal electro-optical device comprises a pair of substrates and nematic liquid crystals disposed between said pair of substrates in a helical structure. In the present invention the liquid crystal electro-optical device having a duty number of 200 or more is driven at a frame frequency of 200 to 280Hz, and thereby high contrast can be obtained.







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