Feature: QuadField Focus™

Benefit: Improved corner focus for projection televisions

Explanation: The "HD" in HDTV stands for "High Definition", as the system has the capability to deliver more than six times the resolution of conventional analog television technology. The electronics within an HDTV display is always capable of receiving HDTV signals. However, in order to display HDTV images with all their innate quality, it is critical to have a high quality optical system that delivers these images to the screen without loss of that resolution along the optical path. The optical path begins with the cathode ray tubes (CRTs), which convert the electrical signals into the light that eventually reaches the screen. A critical part of the CRTs in selected Mitsubishi models is the QuadField Focus™ system that helps to deliver the tightest on-screen focus in the industry.

QuadField Focus™ uses an additional passive magnetic yoke on the neck of the CRT to correct both the corner and edge focus of the electron beam. It makes this correction as the beam travels from the electron gun at the back of the tube to the phosphor coated face plate at the front of the tube. By magnetically compressing the beam as it progresses through the neck of the CRT, the beam spot size is kept in tighter focus. Tighter focus within the tube means that the TV's electronic focus system doesn't have to correct as many errors in CRT performance. That, in turn, means that the corrections it does make will be made more accurately.

The end result? QuadField Focus™ delivers crisp images right out of the CRT, enabling the lenses and dynamic focus system to better do their jobs. What does this translate to when you look at the picture on a Mitsubishi projection television? Images that are sharper in focus not only in the critical center viewing area, but at the harder to focus corners and edges, as well. HDTV has the power to deliver the best video images possible. QuadField Focus™ is one part of the total technology package that lets Mitsubishi deliver the quality promise of HDTV.