Feature: Tru-Focus™ Lenses

Benefit: Improved resolution with no compromise in brightness or focus.

Explanation: Just as in photography, the optics in a projection television system is one of the key elements in determining image quality. Even when the best quality, high-grain film and most precise shutter system are part of a camera's design, you simply won't get good pictures without great lenses. The same is true for projection televisions, particularly with high-definition programs where the display system must meet the higher quality now available from the incoming signal. Mitsubishi has long been a leader in optical design for projection televisions, and their Tru-Focus™ lenses are the latest in their long line of high quality lens systems.

First, some background information: Within the dimensions of a slim projection TV cabinet, no lens system can be "textbook perfect". That would require a much deeper cabinet. Therefore, all rear projection TVs have lenses with carefully balanced compromises. Simple spherical lenses, shaped like those in typical "magnifying glasses", would result in a bright and well-focused center image, but the edges and corners of the screen would be both dark and out of focus. Given the limits of the lens materials and their manufacturing processes, the optical engineer must give up some of the center image brightness and focus in order to make improvements in the edges and corners. In other words, in optics, as in many other areas, there is no free lunch.

However, Mitsubishi's Tru-Focus™ optical design and manufacturing technology has dramatically extended these limits. New sophisticated equations that describe how the shape of each lens element affects a lens's overall performance allows for theoretical improvements in brightness and resolution not only in the center, but throughout the screen area. These, coupled with revised manufacturing methods that provide tighter tolerances, actually allow these improvements to be materialized.

The result, in qualitative terms, is a smaller beam spot size and reduced "flare" (the soft edge around the spot), with no loss in brightness. The benefits of Tru-Focus™ lenses are particularly noticeable when viewing high quality HDTV content- an added sense of depth and realism.