Controlling the gray scale of plasma display devices

(19)

(11)

EP 0 887 785 A3

(12)	EUROPEAN PATENT APPLICATION

(88)	Date of publication A3:
	29.03.2000 Bulletin 2000/13

(43)	Date of publication A2:
	30.12.1998 Bulletin 1998/53

(21)	Application number: 98203252.6

(22)	Date of filing: 31.01.1994

(51)	International Patent Classification (IPC)⁷: G09G 3/28

(84)	Designated Contracting States:
	DE FR GB

(30)

Priority:

17.11.1993 JP 28834593

(62)	Application number of the earlier application in accordance with Art. 76 EPC:
	94300695.7 / 0653740

(71)	Applicant: FUJITSU LIMITED
	Kawasaki-shi, Kanagawa 211-8588 (JP)

(72)	Inventors:
	Nagaoka, Keishin Nakahara-ku, Kawasaki-shi, Kanagawa 211 (JP) Tajima, Masaya Nakahara-ku, Kawasaki-shi, Kanagawa 211 (JP) Awata, Yoshimasa Nakahara-ku, Kawasaki-shi, Kanagawa 211 (JP) Kanazawa, Yoshikazu Nakahara-ku, Kawasaki-shi, Kanagawa 211 (JP) Ueda, Toshio Nakahara-ku, Kawasaki-shi, Kanagawa 211 (JP)

(74)	Representative: Stebbing, Timothy Charles et al
	Haseltine Lake & Co., Imperial House, 15-19 Kingsway London WC2B 6UD London WC2B 6UD (GB)

(54)	Controlling the gray scale of plasma display devices

(57) A method of controlling the gray scale of a plasma display device, comprising the steps of: forming a frame for an image by a plurality of subframes each having a specific weight value; and displaying an image on the plasma display device by optionally combining gray levels of the subframes. A ratio of brightnesses of each gray level is calculated so as to substantially correspond with a ratio of the specific weight values of each gray level, a ratio of numbers of sustain emissions of each gray level being not coincident with the ratio of the specific weight values of each gray level. Therefore, an enhancement of the display quality of the plasma display device can be realized.

Search report