Principles of Cathode-Ray Tube and Liquid Crystal Display Devices

摘要

The effectiveness of digital diagnostic imaging modalities that rely on display devices for interpretation, review, or consultation is determined by the performance of individual system components, from the image acquisition device through image processing and transmission, until the image is displayed and a diagnosis is determined. When human observers are in charge of or involved in the diagnostic decision-making process, the quality of the display system has important effects on overall system performance and the ability of the observer to make an accurate diagnosis. Current display offerings for diagnostic radiology systems are based on two competing technologies, the cathode-ray tube (CRT) and the active-matrix liquid crystal display (AMLCD). The CRT is a half-century-old mature technology that is based on the excitation of cathodoluminescent phosphors by focused energetic electron beams. Light is generated in an emissive structure, where it diffuses in a controlled manner until it emerges toward the viewer, forming the displayed image. The AMLCD, which is based on active-matrix liquid crystal (LC) modulators, is the result of 25 years of engineering advances.