(19)
(11) EP 0 778 558 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
04.02.1998 Bulletin 1998/06

(43) Date of publication A2:
11.06.1997 Bulletin 1997/24

(21) Application number: 96308500.6

(22) Date of filing: 25.11.1996
(51) International Patent Classification (IPC)6: G09G 3/36
(84) Designated Contracting States:
CH DE ES FR GB IT LI NL

(30) Priority: 27.11.1995 GB 9524193

(71) Applicants:
  • VARINTELLIGENT (BVI) LIMITED
    Tortola, British Virgin Islands (VG)
  • JOHNSON, Terence Leslie
    London WC2A 1SD (GB)

(72) Inventor:
  • Ho, Kai Pui, c/o Varitronix Limited
    Kwun Tong, Kowloon (HK)

(74) Representative: Johnson, Terence Leslie 
Edward Evans & Co. Chancery House 53-64 Chancery Lane
London WC2A 1SD
London WC2A 1SD (GB)

   


(54) A column driver for LCD using frame duty cycle control


(57) A driver for a liquid crystal display has fixed preset drive voltage levels and means for varying an ON:OFF ratio over a number of cycles, whereby effectively to present variable driving voltage levels for driving a liquid crystal display.






Search report