Title:
PHASE DIFFERENCE PLATE AND LIQUID CRYSTAL DISPLAY DEVICE FORMED BY USING THE SAME
Document Type and Number:
Japanese Patent JP3206177
Kind Code:
B2
Abstract:
PURPOSE: To provide the liquid crystal display device which has a wide visual angle and is less colored by using such phase difference plates that make a double refractive index zero at a certain wavelength of visible light.
CONSTITUTION: This liquid crystal display device is constituted of an upper polarizing plate 1, the first phase difference plate 2, the second phase difference plate 3, a liquid crystal cell 4, a lower polarizing plate 5 and an upper substrate 6, lower substrate 7, transparent electrodes 8 and nematic liquid crystal 9 of the liquid crystal cell. A PC (polycarbonate) film of 2.00μm retardation to 589nm light is used for the first phase difference plate 2 and a PMMA (polymethyl methacrylate) film likewise of 2.02μm is used for the second phase difference plate 3. The PC film is higher in the dependency of the refractive index on wavelength than the PMMA film. The phase difference plate which makes the retardation zero exactly at 550nm is obtd. if both are laminated by unifying uniaxial stretching axes. The PC is positive in photoelastic constant and conversely the PMMA is negative. This combination is more advantageous in terms of visual angle characteristic than the combination of positive and positive or negative and negative.
Inventors:
Osamu Okumura
Application Number:
JP1491993A
Publication Date:
September 04, 2001
Filing Date:
February 01, 1993
Export Citation:
Assignee:
Seiko Epson Corporation
International Classes:
G02B5/30; G02F1/1335; G02F1/13363; (IPC1-7): G02F1/13363; G02B5/30
Domestic Patent References:
| JP313916A | ||||
| JP313917A | ||||
| JP4116603A | ||||
| JP329921A | ||||
| JP592010A | ||||
| JP592004A | ||||
| JP3263013A |
Attorney, Agent or Firm:
Kisaburo Suzuki (1 outside)