LCD Panel Technology Overview (122701)



December 27, 2001; 5:27pm

http://www6.tomshardware.com/display/99q3/990707/index.html

Amy (and mom) had mentioned they were interested in buying LCD flat panel displays... I had mentioned to Amy at Carl's Jr. on the way back that you needed to potentially buy a new video card as well... This is an explanation of why...

There are analog VGA flat panels, but just think about what it has to do... it takes the original digital signal from the graphics card, and the graphics card converts it to analog to transmit to normal monitors (an analog signal is what you get sent to your monitors normally). Then, with the flat panel displays which accept analog, it has to convert the analog back to digital by trying to guess where the pixels are in the analog signal. It may work, but it will lead to much lower quality of display, etc.

Anyhow, take a look at this article to under more. :-)

Michael. :-)



December 27, 2001; 5:48pm

A brief look through the article showed that there are currently 4 possible ways to connect to an LCD panel:
- analog
- P&D
- DFP
- DVI

Analog, as we said before, has the lowest entry cost, BUT it has an inherent technological flaw that doesn't make sense if you are trying to purchase equipment for the long term. It requires an additional A-to-D (analog-to-digital) conversion. What are the problems? 1) the need to detect pixel edges from the analog signal, 2) potential problems with color since they may not use an A-to-D converter with a large enough bit width (from the article, they seemed to suggest some LCD manufacters used an 18-bit wide converter whereas True Color is 24-bit (anyone who has had me play around on your computer has already had me tune your Windows display to True Color... :-)).

P&D seemed like it was the original standard with VESA. But apparently it has fallen out of favor since it has a higher implementation cost. (it tried to include USB and Firewire and audio in the same cable).

DFP was originally backed by ATI, etc. But apparently it has a max resolution of 1280x1024. This means a limited upgrade path.

DVI is the defacto "standard" that people are riding behind since it has a higher resolution (1900x??), has an analog signal riding next to it if you want to connect to a regular monitor, and the potential to convert back to DFP or P&D.

My suggestion? Buy a digital flat panel that supports DVI. And then buy a video card that supports DVI output. (for Amy's computer, does she have AGP? Or only PCI slots? This will be important in making a video card decision... if possible, buy AGP...).

Okay, enough "soapbox" talking... :-) This was an interesting lesson for me in flat panel technology. :-) I hope it was interesting for everyone else. :-)



December 27, 2001; 5:57pm

One further interruption... :-) You could potentially get an LCD panel similar to this one... it accepts both DVI and analog... so you buy it first and see how the quality is... if the quality isn't good enough, get a DVI card... now, understand that LCD panels are fixed resolution... for example, if it is 1280x1024, you shouldn't run it below that or above that since the pixels are discrete... anyhow, if you get one and have problems we can work it out later... :-)

http://www.sonystyle.com/vaio/displays/sdm_m51d.shtml

Now, actually looking through www.bestbuy.com , I couldn't figure out what LCD panels were digital DVI. Anyhow, my main point with these last emails is just to remain informed about your purchasing decisions... :-) Price isn't the only aspect to technology buys. :-)



December 27, 2001; 6:24pm

Okay, I lied... :-) one more interruption... :-)

So, some people on newsgroups are okay with the quality they get from analog... I suspect for the lower resolutions, the difference is less... (like below 1024x768). For myself, personally, I like to avoid that extra A-to-D conversion since it just seems inefficient and error prone... But you can give it a try if you wish... :-) I currently don't have plans to start playing with LCD panels quite yet... :-) But when I do, I plan to go the pure-digital DVI route. :-)


Last updated: 122801