Transmission type liquid crystal display device having capacitance ratio of ...

United States Patent [w]

Shimada et al.

US005953084A [ii] Patent Number: [45] Date of Patent:

5,953,084 Sep. 14,1999

[54] TRANSMISSION TYPE LIQUID CRYSTAL DISPLAY DEVICE HAVING CAPACITANCE RATIO OF 10% OR LESS AND CHARGING RATE DIFFERENCE OF 0.6% OR LESS

[75] Inventors: Takayuki Shimada, Yamatokoriyama;

Masaru Kajitani, Osaka; Masaya
Okamoto, Soraku-gun; Naofumi
Kondo; Mikio Katayama, both of
Ikoma; Yoshikazu Sakuhana,
Yamatokoriyama; Akihiro Yamamoto,
Tenri; Yukinobu Nakata, Tenri;
Hirohiko Nishiki, Tenri; Yoshinori
Shimada, Yamatokoriyama, all of Japan

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

[21] Appl. No.: 09/110,151 [22] Filed: Jul. 6, 1998

Related U.S. Application Data

[63] Continuation of application No. 08/695,632, Aug. 12, 1996.

[30] Foreign Application Priority Data

Aug. 11, 1995 [JP] Japan 7-206367

Sep. 29, 1995 [JP] Japan 7-254043

[51] Int. CI.6 G02F 1/1343; G02F 1/136

[52] U.S. CI 349/38; 349/39; 349/42

[58] Field of Search 349/38, 39, 42

[56] References Cited

U.S. PATENT DOCUMENTS

3.602.782 8/1971 Klein 317/235 R

4,688,896 8/1987 Castleberry 350/333

4,759,610 7/1988 Yanagisawa 350/334

4,857,907 8/1989 Koden 340/784

4,923,948 5/1990 Matsuki et al 528/26

5,166,085 11/1992 Wakai et al 437/40

5,182,661 1/1993 Ikeda et al 359/54

5.314.783 5/1994 Koibuchi et al 430/191

5,335,102 8/1994 Kanemori et al 359/59

5,378,585 1/1995 Watanabe 430/176

(List continued on next page.)

(List continued on next page.)

OTHER PUBLICATIONS

Patent Abstracts of Japan, vol. 016, No. 218, May 21, 1992 & JP-A-04 042214, Feb. 12, 1992.

"Application of a Wide Viewig Angle Technique Essential for a Large-Area Display to Mass Production Panel of TFT Starts", Flat-Panel Display '94, p. 166, Dec. 10, 1993. "Mass Production of CMP is Full-Fledged to be Applied to ASIC and DRAM", Nikkei Microdevices, pp. 50-57, 1994. "Backlight", Flat-Panel Display '94, p. 217, Dec. 10, 1993.

(List continued on next page.)

Primary Examiner—-William L. Sikes
Assistant Examiner—Tarifur R. Chowdhury
Attorney, Agent, or Firm—Nixon & Vanderhye PC.

The transmission type liquid crystal display device of this invention includes: gate lines; source lines; and switching elements each arranged near a crossing of each gate line and each source line, a gate electrode of each switching element being connected to the gate line, a source electrode of the switching element being connected to the source line, and a drain electrode of the switching element being connected to a pixel electrode for applying a voltage to a liquid crystal layer, wherein an interlayer insulating film formed of an organic film with high transparency is provided above the switching element, the gate line, and the source line, and wherein the pixel electrode formed of a transparent conductive film is provided on the interlayer insulating film.

22 Claims, 13 Drawing Sheets

U.S. PATENT DOCUMENTS

5,396,353 3/1995 Takahashi et al 349/51

5,402,141 3/1995 Haim et al 349/42

5,446,562 8/1995 Sato 359/59

5.483.082 1/1996 Takizawa et al 257/59

5,517,342 5/1996 Kim et al 359/59

5,526,014 6/1996 Shiba et al 345/96

5,573,978 11/1996 Cho 437/192

5,585,951 12/1996 Noda et al 349/122

5,641,974 6/1997 den Boer et al 257/59

5,658,679 8/1997 Lin 430/7

5,661,579 8/1997 Takahashi 349/42

5,675,159 10/1997 Oku et al 257/284

5^679,596 10/1997 Lu 437/52

5,682,211 10/1997 Yao et al 349/38

5,688,366 11/1997 Ichinose et al 156/662.1

5,688,410 11/1997 Kajitani et al 216/64

5,695,906 12/1997 Nishi et al 430/190

5,757,453 5/1998 Shin et al 349/39

5.771.083 6/1998 Fujihara et al 349/39

5,818,407 10/1998 Selichiro et al 349/42

5,822,027 10/1998 Shimada et al 349/39

5,831,708 11/1998 Hiraishi et al 349/39

FOREIGN PATENT DOCUMENTS

4-307521 10/1992 Japan .

4-74714 11/1992 Japan .

6- 230422 8/1994 Japan .
7-36043 2/1995 Japan .

7- 122719 12/1995 Japan .

OTHER PUBLICATIONS

Fujita et al, "Colorless Polyimide", Nitto Giho, Vo. 29, No. 1, pp. 20-28, 1991.

Sakamoto et al "27.3: A High-Aperture-Ratio 3-in.-Diagonal VGA a-Si Light Valve with Pixel/Data and Pixel/Gates Lines Overlapping", SID 96 Digest, pp. 681-684, 1996. Kim et al "4:3: High-Aperture and Fault-Tolerant Pixel Structures for TFT-LCDs", SID 95 Digest, pp. 15-18,1995. Patent Abstracts of Japan, vol. 017, No. 428 (P-1588), Aug. 9, 1993 & JP-A-05 088199 (Sanyo Electric Co. Ltd.), Apr. 9, 1993.

Patent Abstracts of Japan, vol. 018, No. 532 (P-1810), Oct. 7, 1994 & JP-A-06 186580 (Seiko Epson Corp.), Jul. 8, 1994.