As we complete the transition from CRT monitors to LCD monitors, we find that, in some cases, there is not an apples to apples comparison between specifications. The technology incorporated between these two architecture platforms is different and some of the specifications between the two platforms are no longer applicable.

To display an image, a CRT monitor redraws the entire screen with a new frame. This is known as the refresh rate specification of a CRT monitor. The higher the refresh rate (in terms of cycles/second or Hz), the more frequent the refresh rate resulting in a higher quality picture. Typical quoted CRT monitor refresh rates are 60 – 120 Hz.

LCD monitors do not display the picture using this technology. They simply change the color of the pixel on the screen as required. This spec is known as the response time of an LCD monitor. A lower response time implies that the pixels can change color state much faster, resulting in a higher quality picture. An LCD monitor does not publish a refresh rate specification, only a response time specification. Typical specified response times for LCD monitors purchased today are 5 ms, whereas they were more than double this when LCD monitors were first introduced.

So which technology is better? One can make arguments for both technologies but, in general, the marketplace has already chosen and LCD monitors are the only monitors that are currently available. Some of the major reasons LCD monitors have displaced CRT monitors are:

• Use less space
• More energy efficient
• Less eye strain due to reduced flicker
• Higher resolution monitors available
• More environmentally friendly – “green”

The one application where CRTs may have had an advantage over LCDs is in PC gaming applications. Because of the high speed required with PC games, CRTs may have had an initial advantage in these applications because the response time of the initial LCD monitors was not quick enough. As the LCD technology has progressed to achieve response times of 5 ms or less this disadvantage has all but been eliminated.

You can bet that there will be future enhancements to the LCD monitor technology going forward (increased resolutions, LED backlighting) which will make some of the topics discussed here obsolete. As the title states “Technology does not stand still.”

What changes to monitor technology do you see impacting the security industry? Please leave a comment below.