Liquid Crystal Display Technology

Abstract

As the display in most imaging systems is the final medium through which an image is rendered for manipulation and verification, an understanding of display technologies is essential to the imaging process. Because individuals working in the field of imaging science and technology may spend more time looking at a display screen than at anything else in their office or laboratory, it is imperative that it be comfortable to use and appropriate for the particular context. Twenty years ago, system manufacturers often integrated the electronic display directly into the system to provide a complete package for a specified imaging application. Although this approach does not afford much flexibility, the display could be closely matched to a specific application because user requirements were well defined. This custom design approach enabled optimizing the graphics controller, system software, and user interface for the display, user, and application requirements. Despite the positive attributes of this “black‐box” approach, such as high performance and superior application specific image quality, closed architecture platforms tend to be more expensive and suffer from incompatibility with peripheral add‐ons and software packages not supported by the system manufacturer. Today, the situation is dramatically different due to the continual evolution of the graphics controller interface. By mixing images with text and graphics, software developers require more from the display to support moving images without diminishing display performance for static images. The graphical capability of today's standard computer platforms has now made it unprofitable for vendors of imaging systems to develop their own displays for system‐specific tasks. End users now typically purchase a computer platform, display, and a variety of other peripherals from multiple vendors and integrate them with ease (i.e., a plug‐and‐play philosophy). In such a marketplace, one must be well educated to match display technology to application needs. This article provides the reader with a fundamental knowledge of working principles of liquid crystal displays (LCDs), their capabilities, and their limitations.