United States Patent [19]
Van Sprang
[54] REFLECTIVE LIQUID CRYSTAL DISPLAY DEVICE WITH TWIST ANGLE BETWEEN 50° AND 68° AND THE POLARIZER AT THE BISECTRIX
[75] Inventor: Hendrik A. Van Sprang, Eindhoven, Netherlands
[73] Assignee: U.S. Philips Corporation, New York, N.Y.
[21] Appl. No.: 141,433
[22] Filed: Oct. 21, 1993
Related U.S. Application Data
[63] Continuation of Ser. No. 898,988, Jun. 15,1992, abandoned. [30] Foreign Application Priority Data
Jun. 28, 1991 [EP] European Pat. Off. 91201665
[51] Int. CI.6 G02F 1/13
[52] U.S. CI 359/63; 359/102; 359/7 0
[58] Field of Search 359/41, 63, 64,
359/78, 93, 72, 102, 70, 65
[56] References Cited
U.S. PATENT DOCUMENTS 4,019,807 4/1977 Boswell et al 359/93
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US005490003A
[ii] Patent Number: 5,490,003 [45] Date of Patent: Feb. 6, 1996
4,378,955 4/1983 Blehu, Jr. et al 359/93
4,896,947 1/1990 Leenhouts 359/102
4,999,619 3/1991 Te Velde 359/63
5,105,289 4/1992 Sonehara et al 359/93
5,139,340 8/1992 Okumura 359/63
5,249,071 9/1993 Yoshimizo et al 359/63
FOREIGN PATENT DOCUMENTS
0377757 7/1990 European Pat. Off. .
2154616 8/1985 United Kingdom.
OTHER PUBLICATIONS
Sonehara et al., "A New Twisted Nematic Electrically Controlled Bisefringent (TN-ECB) Made for a Reflective Light Valve", Proceedings of the SID, vol. 31/2, 1990.
Primary Examiner—William L. Sikes
Assistant Examiner—Kenneth Parker
Attorney, Agent, or Firm—Norman N. Spain
[57] ABSTRACT
To obtain a monotonic transmission/voltage characteristic curve in a reflective display having a small twist angle, the polarizer in a cell with crossed polarizer and analyzer is arranged parallel to the dividing line of the directions of orientation (23, 24) determining the twist angle a, the cell being optimized for a and d.An.
7 Claims, 3 Drawing Sheets
