×

Liquid crystal display with phase difference plate having particular .DELTA . .DELTA.nxd at 45.degree. angle to surface

  • US 5,426,524 A
  • Filed: 04/11/1994
  • Issued: 06/20/1995
  • Est. Priority Date: 04/09/1990
  • Status: Expired due to Term
First Claim
Patent Images

1. A method of driving a liquid crystal display device which includes a twisted nematic liquid crystal display cell defining a display screen having a rear edge as viewed from the user and including a pair of spaced apart opposed substrates with electrodes selectively disposed thereon and a nematic liquid crystal material disposed in the space between the substrates;

  • a pair of polarizing plates disposed on opposite sides of the liquid crystal cell;

    at least one layer of an optically anisotropic substance disposed between said liquid crystal cell and one of said polarizing plates and serving as a phase difference plate; and

    a reflector disposed beneath the lower of the polarizing plates;

    the method comprising the steps of;

    selecting the value of k greater than or equal to 1.20, wherein the value of the ratio k is the ratio of the product Δ

    n1.d1, where Δ

    n1 is the optical anisotropy and d1 is the thickness in the vertical direction of said phase difference plate, to the product Δ

    n2.d2, where Δ

    n2 is the optical anisotropy and d2 is the thickness of said phase difference plate when inclined at 45°

    from the vertical direction of said phase difference plate in the direction of the optical axis;

    setting the optical axis of said phase difference plate at a predetermined angle in the range from about +30°

    to about +60°

    or in the range from about -30°

    to about -60°

    with respect to the observation direction the observation direction being the direction of the projection in the plane of the display screen of the direction from which a user of said display screen most frequently views said display screen, where the values of these angles are positive when measured clockwise from the observation direction; and

    applying a voltage to said liquid crystal display device.

View all claims
  • 0 Assignments
Timeline View
Assignment View
    ×
    ×