Color matching of guest-host liquid crystal displays

A bright reflective LCD without a backlight is a key device for portable information systems. The guest-host LCDs use absorption effect of dichroic dyes and have a wide viewing angle cone. So that, complicated designs of optical compensation in birefringence or optical rotatory power modes have no use of the GH-LCDs. Black and white color of the GH-LCDs works as a light shutter of a full color display with micro-color filters and achromatic color must be displayed precisely. Then it is necessary to mix dyes for achromatic display in the GH-LCDs. In this work, the design was carried out with the Newton-Raphson method in order to obtain the optimum dye concentration. As a result, the relationship between the dye concentration and the optical property was clarified. The process gives us a helpful guideline in fabrication of the reflective color LCD and it is expected that the precise color matching improves the quality of GH-LCDs.