(19)
(11) EP 0 238 113 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
17.07.1991 Bulletin 1991/29

(43) Date of publication A2:
23.09.1987 Bulletin 1987/39

(21) Application number: 87200221.7

(22) Date of filing: 12.02.1987
(51) International Patent Classification (IPC)4: G09G 1/16
(84) Designated Contracting States:
DE FR GB IT SE

(30) Priority: 17.02.1986 GB 8603850

(71) Applicants:
  • PHILIPS ELECTRONICS UK LIMITED
    Croydon CR9 3QR (GB)

    GB 
  • Philips Electronics N.V.
    5621 BA Eindhoven (NL)

    DE FR IT SE 

(72) Inventor:
  • Penna, David Edward
    Redhill Surrey RH1 5HA (GB)

(74) Representative: White, Andrew Gordon et al
Philips Electronics UK Limited, Patents and Trade Marks Department, Cross Oak Lane
Redhill, Surrey RH1 5HA
Redhill, Surrey RH1 5HA (GB)


(56) References cited: : 
   
       


    (54) Data display


    (57) A logic processor-controlled data display apparatus having a display memory in which pixel data representing text for display is stored in bit-map form. The pixel data is produced for each display from character data stored in a background memory. When the character data is stored in bit-map form it can be read directly from the background memory bit-by-bit and written into the display memory as the pixel data. However, this process takes a large number of programme steps, so that the transfer of the data is relatively slow. The present invention provides for the storage in the background memory of character data in the form of machine code sub-routines. The sub-routine for a character contains instructions for identifying the shape-defining pixels (dots) of the character relative to a base dot position and the sub-routine is run to write these pixels into the display memory following location of the base dot position in the display memory. Figures 2 and 4 exemplify the invention.










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