Information displays are the primary medium through which text and images generated by computer and other electronic systems are delivered to end-users. While early computer systems were designed and used for tasks that involved little interactions between the user and the computer, today's graphical and multimedia information and computing environments require information displays that have higher performance, smaller size and lower cost.
The market for display technologies also has been stimulated by the increasing popularity of hand-held computers, personal digital assistants and cellular phones; interest in simulated environments and augmented reality systems; and the recognition that an improved means of connecting people and machines can increase productivity and enhance the enjoyment of electronic entertainment and learning experiences.
For decades, the cathode ray tube has been the dominant display device. The cathode ray tube creates an image by scanning a beam of electrons across a phosphor-coated screen, causing the phosphors to emit visible light. The beam is generated by an electron gun and is passed through a deflection system that scans the beam rapidly left to right and top to bottom, a process called Rastering. A magnetic lens focuses the beam to create a small moving dot on the phosphor screen. It is these rapidly moving spots of light ("pixels") that raster or "paint" the image on the surface of the viewing screen. Flat panel displays are enjoying widespread use in portable computers, calculators and other personal electronics devices. Flat panel displays can consist of hundreds of thousands of pixels, each of which is formed by one or more transistors acting on a crystalline material.
In recent years, as the computer and electronics industries have made substantial advances in miniaturization, manufacturers have sought lighter weight, lower power and more cost-effective displays to enable the development of smaller portable computers and other electronic devices. Flat panel technologies have made meaningful advances in these areas. Both cathode ray tubes and flat panel display technologies, however, pose difficult engineering and fabrication problems for more highly miniaturized, high-resolution displays because of inherent constraints in size, weight, cost and power consumption. In addition, both cathode ray tubes and flat panel display are difficult to see outdoors or in other setting where the ambient light is brighter than the light emitted from the screen. Display mobility is also limited by size, brightness and power consumption.
As display technologies attempt to keep pace with miniaturization and other advances in information delivery systems, conventional cathode ray tube and flat panel technologies will no longer be able to provide an acceptable range of performance characteristics, particularly the combination of high resolution, high level of brightness and low power consumption, required for state-of-the-art mobile computing or personal electronic devices.