| 摘要 |
PURPOSE:To obtain high-contrast black-and-white display at a low cost by placing a cellulose acetate butyrate sheet or film formed by a flow extending method on the front or rear side of a liq. crystal cell or on both sides. CONSTITUTION:Incident light 1 becomes linearly polarized light by passing through a polarizing plate as a polarizer 2 and passes through a display panel 3 (liq. crystal cell). When no voltage is impressed on the panel 3, the light passing through the panel 3 becomes circularly polarized light and returns to the linearly polarized light by passing through a cellulose acetate butyrate film 4 or sheet as a phase plate for optical compensation. Finally the light reaches a polarizing plate as an analyzer 5 but does not pass through the analyzer 5 because the axis of polarization of the analyzer 5 meets at right angles to that of the polarizer 2, a completely black display is obtd. When voltage is impressed on the panel 3, the incident light passes through the polarizer 2, the panel 3 and the film 4, so completely white display is obtd. |
