Display apparatus

United States Patent [i9]

Yamaguchi et al.

1HIIIIIIIIIIIII

US005627557A [li] Patent Number: [45] Date of Patent:

5,627,557 May 6,1997

[54] DISPLAY APPARATUS

[75] Inventors: Akira Yamaguchi, Soraku-gun; Yutaka Ishii, Nara; Yoshitaka Yamamoto. Yamatokoriyama; Tomoaki Toichi, Tenri, all of Japan

[73] Assignee: Sharp Kabushiki Kaisha, Osaka, Japan

[21] Appl. No.: 107,895

[22] Filed: Aug. 18,1993

[30] Foreign Application Priority Data

Aug. 20, 1992 [JP] Japan 4-221774

Aug. 20, 1992 [JP] Japan 4-221775

Aug. 20, 1992 [JP] Japan 4-221776

Jul. 26, 1993 [JP] Japan 5-184189

[51] IntCl.6 G09G3/36

[52] U.S. CI 345/90; 345/92; 345/96

[58] Field of Search 345/87, 90, 92,

345/96, 205; 359/55, 57, 59

[56] References Cited

U.S. PATENT DOCUMENTS

4,432,610 2/1984 Kobayashi et al 345/90

4,471,347 9/1984 Nakazawa et al. .

4,532,506 7/1985 Kitazima et al 345/90

4,781,437 11/1988 Shields etal 359/57

4,870,396 9/1989 Shields 345/90

5,111,195 5/1992 Fukuokaetal 345/94

5,165,075 11/1992 Hirokietal 345/92

5,194,974 3/1993 Hamadaetal 359/59

FOREIGN PATENT DOCUMENTS

0079496 5/1983 European Pat. Off. .
55-62480 10/1980 Japan.

A display apparatus according to this invention includes a plurality of pixels, each of which is supplied with a pixel data; a pixel capacitance for accumulating an electric charge in accordance with the pixel data; a holding capacitance provided to each of the pixels to hold the pixel data; and a buffer amplifier for supplying the electric charge to the pixel capacitance in accordance with the voltage of the holding capacitance. Another display apparatus of this invention includes a plurality of pixels, each of which is supplied with a pixel data; a pixel capacitance for accumulating an electric charge in accordance with the pixel data; a first holding capacitance provided to each of the pixels in order to hold the pixel data; a display changing circuit which is controlled to be turned on/off by a display changing signal; a second holding capacitance which is supplied with the electric charge by the first holding capacitance via the display changing circuit; and a buffer amplifier for supplying the electric charge to the pixel capacitance in accordance with the voltage of the second holding capacitance.

20 Claims, 21 Drawing Sheets