LCD – For the Novice and the Expert
by Kristopher Kubicki on September 4, 2003 12:13 AM EST- Posted in
- Displays
In the beginning
LCD stands for Liquid Crystal Display. Incredibly, this technology has its roots in 1888 when Friedrich Reinitzer melted cholesteryl benzoate. It became a cloudy liquid which then turned into a blue opaque substance when cooled. Almost 80 years later, RCA began to tinker with the idea of using these liquid crystals in watches. Then, in 1968, the RCA team created a working liquid crystal timepiece, albeit they were still some years off from creating large scale devices.To briefly go over how LCDs are possible, we have to understand Reinitzer’s discovery 115 years ago. Cholesteryl benzoate is a very tightly packed fibrous material. Typically, it arranges itself in a tight helix pattern that is “twisted” together. Although LCDs today don’t use cholesteryl benzoate, the materials used today share some similar properties. Modern LCDs are composed of a pool of twisted liquid crystals in front of every sub-pixel on the display. Applying various degrees of current to the liquid crystals untwists them ever slightly (enough to allow light to pass).
This very important principal in LCD technology is called the twisted nematic field effect. The important thing to understand is that LCDs do not generate light; they simply allow or inhibit light from passing through a certain place on a substrate.
When the liquid crystal is untwisted, light from the backlight passes it. There are no white sub-pixels on the display, so the color of the red, blue or green sub-pixel shines through. We no longer use cholesteryl benzoate, but rather Ferroelectric liquid crystals. These crystals are arranged in a very tight helix arrangement, which allows them to twist and untwist very rapidly. Even further advances in LCDs have brought us surface-stabilized ferroelectric liquid crystals, which form a slightly different natural pattern, but still allows for an electrical current to untwist the crystal.
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Anonymous User - Sunday, September 7, 2003 - link
http://www.anandtech.com/showdoc.html?i=1730Its ok from what I hear.
Anonymous User - Saturday, September 6, 2003 - link
Great article - typical AnandTech coverage/information! I have a question though - I would like to get a 17" LCD with DVI and S-Video inputs (for playing console games). The Samsung MP series has VGA and S-Video, but no DVI. Albatron has a one with some nice specs - the L17AT.http://www.albatron.com.tw/english/ia/pro_view.asp...
The only problem is that I have seen no reviews of them. I am a little leery of spending $500+ on a monitor sight unseen. Any suggestions?
KristopherKubicki - Saturday, September 6, 2003 - link
#49, Ill add that into Part II then.#50, perhaps down the line I will try to do that. It would not really fit into part II right now.
Cheers,
Kristopher
artifex - Saturday, September 6, 2003 - link
Also, I'd really like to own an LCD because of the weight and size issues (I want larger than my current 16" viewable CRT, 17 or 19 maybe), but also because of the expected power savings. Would you consider adding a comparison of the power consumption in future roundups?artifex - Saturday, September 6, 2003 - link
I am disgusted to discover that many manufacturers using the 262000 color panels are lying and claiming 16.7 million. I challenge Anandtech to clearly identify these manufacturers in future product reviews, because if they can't tell the truth about this simple spec, how can we trust them on things like warranties?KristopherKubicki - Saturday, September 6, 2003 - link
#47 - Yes, SamsungUSA anyway. Computex is around the corner, maybe we can find out something new there =)Anonymous User - Friday, September 5, 2003 - link
Hi Kristopher, is Samsung still denying/not talking about their X line of 16ms panels?KristopherKubicki - Friday, September 5, 2003 - link
Hi Dan,The Apple 23" monitor is OK, but its more bark than bite (Apple does these amazing things with advertising). I would be very hesitant to judge a monitor by its contrast ratio.
In fact, one monitor we reviewed a few months ago, the Samsung 192T claimed a 500:1 contrast ratio when we recieved. Now, the specifications claim 750:1 even though nothing has changed on the monitor.
In any case, do remember that the Cinematic Displays are expensive as well. Samsung has done some very neat things in the 21 and 23" area, and in my opinion they are better than apples. To further sweeten the deal you wont need a seperate adaptor to convert the signal.
If you use graphics heavily (as in professionally) CRT is still your only option.
As for your question about DVI, there are actually about 3 versions of the technology. However, almost all hardware on the PC uses the DVI-I format. This format is backwards compatible with the other two, so you'll be just fine.
Cheers,
Kristopher
Anonymous User - Friday, September 5, 2003 - link
Hi my old 17" CRT is dying, and I'll need to replace it very soon. I have found that when working in PhotoShop, my old 17" monitor is just to small, and my eyes get quit sore. I think I would like to get and LCD of around 19". I am a PC user and am running Windows 98se.In my research "the Monitor to which all others is compaired" is the Apple 23" Cinem HD Display Having a resolution of 1920 by 1200, 170 viewing angle, brightness of only 200 cd/m2, lowsey 350:1 contrast ratio, and a half decient pixel pitch of 0.258.
Here in Australia coumptor stores aren't at all helpful in showing you their monitors in real world sisutions. So I've only been able to read the technical specs found on the internet. It seems a number of monitors have hit the 700 to 1 mark, and Planar offer a 19" with a pixel pitch of 0.242mm at 1600 x 1200 while most offer a auful 0.290mm at 1280 x 1024.
Going on specifications alone, I think I would like a 19" LCD with 1600 x 1200 resolution, 300 CD/m2 brightness, 700 to 1 contrast ratio, 25ms or less response time, 170 degree horizonal and vertical viewing angle, 0.242 mm pixel pitch, and of course a DVI coennection. I am not a gamer.
Is this reasonable and practical, or is a CRT a better option, and if so which one would best suit the graphics environment?
I recently read something about there being two kinds of DVI, DVI and DVI-D, is this a concern?
Thank You for any help you can give me, my e-mail address is danandrews@optusnet.com.au
Sincerely, Dan Andrews
Anonymous User - Friday, September 5, 2003 - link
What's the deal with all the misleading and irrelevant hypertext links in the article (e.g. "computer", "connection", "solution", etc?)