Flat Panel Feature Comparisons

The table below provides a feature comparison between a 13.5in passive matrix LCD (PMLCD) and active matrix LCD (AMLCD) and a 15in CRT monitor:

Display Type Viewing Angle Contrast Ratio Response Speed Brightness Power Life
PMLCD 49-100 degrees 40:1 300ms 70 – 90 45 watts 60K hours
AMLCD > 140 degrees 140:1 25ms 70 – 90 50 watts 60K hours
CRT > 190 degrees 300:1 n/a 220 – 270 180 watts Years

Contrast ratio is a measure of how much brighter a pure white output is compared to a pure black output. The higher the contrast the sharper the image and the more pure the white will be. When compared with LCDs, CRTs offer by far the greatest contrast ratio.

Response time is measured in milliseconds and refers to the time it takes each pixel to respond to the command it receives from the panel controller. Response time is used exclusively when discussing LCDs, because of the way they send their signal. An AMLCD has a much better response time than a PMLCD. Conversely, response time doesn’t apply to CRTs because of the way they handle the display of information (an electron beam exciting phosphors).

There are many different ways to measure brightness. The higher the level of brightness (represented in the table as a higher number), the brighter the white displays. When it comes to the life span of an LCD, the figure is referenced as the mean time between failures for the flat panel. This means that if it is runs continuously it will have an average life of 60,000 hours before the light burns out. This would be equal to about 6.8 years. On the face of it, CRTs can last much longer than that. However, while LCDs simply burn out, CRT’s get dimmer as they age, and in practice don’t have the ability to produce an ISO compliant luminance after around 40,000 hours of use.