TFT Guide - Part 2 - Viewing Angle Technologies

Introduction

Part 1: Flat Panel Displays of the TFT Guide discussed the basics of flat panel displays and the general market situation for them. This part of the report is dedicated to our more technically-minded readers as it covers the latest technologies used to improve the viewing angle and response times of the displays.

The Current Situation

TFT flat panel displays have two decisive disadvantages when you compare them with conventional cathode ray tube monitors:

(1) When you view a TFT display from the side, you will quickly notice a dramatic loss of screen brightness and a characteristic change of displayed colors. Older flat panel displays typically have a viewing angle of 90 degrees, i.e. 45 degrees to each side. As long as there is only one viewer this isn't a problem. As soon as you invite a second viewer, for example a customer you want to show something to, or an additional player for an action game at home - then you won't have to wait too long to hear a complaint about bad display quality.

(2) Quick scene changes, which are commonplace for video playback and games, demand performance that is just too much for today's slow liquid crystals. Slow response times result in distorted or streaked images. Classic examples of streak distortion can be seen when a stock exchange ticker is displayed, or when a jet fighter flies through a valley in an action game.

The flat panel manufacturers are not resting on their laurels and have recently introduced the first models with improved technology to the market. The most important technologies available are TN+Film, IPS (or 'Super-TFT') and MVA, all of which are explained in the following sections of this article.