Solutions For Demanding Applications
Volume 2
Issue 4
April 2003

LCD Characteristics:
Advantages and Disadvantages

LCDs have many characteristics that have caused their demand to increase over the past several years. They are lightweight, aesthetically appealing, energy efficient and long-term cost effective. Some of the disadvantages are that they are not suitable for dimly lit applications, can require frequent adjustments throughout the day, have limited viewing angles, and their purchase cost is relatively expensive.

LCD Advantages
Brightness Produces very bright images due to high peak intensity. Very suitable for environments that are brightly lit .
Emissions Produce considerably lower electric, magnetic and electromagnetic fields than CRTs.
Geometric Distortion No geometric distortion at the native resolution. Minor distortion can occur for other resolutions.
Power Consumption Energy efficient. Consume less than 1/3 the power of a comparable CRT. Consume less electricity than a CRT and produce little heat.
Physical Aspects Take up about 40% less desk space. LCDs are thin and compact.
Screen Shape Completely flat screen.
Sharpness At the native resolution, the image is perfectly sharp. Adjustments are required at all other resolutions which can result in measurable degradation to the image.
LCD Disadvantages
Aspect Ratio The aspect ratio and resolution are fixed.
Black-Level Not proficient at producing black and very dark grays. In a "standard" configuration, not appropriate for use in dimly lit and dark conditions.
Contrast Lower contrast than CRTs due to a poor black-level.
Color and Gray-Scale Accuracy Color saturation is reduced at low intensity levels due to a poor black-level. Images are satisfactory, but not accurate due to problems with black-level, gray-scale and Gamma.
Cost Considerably more expensive purchase price than comparable CRTs . (Cheaper lifetime cost: lasts about 13,000 - 15,000 more hours than a typical CRT.)
Gray-Scale Have an irregular intensity scale and typically produce fewer than 256 discrete intensity levels. For some LCDs portions of the gray-scale may be dithered.
Motion Artifacts Slow response times and scan rate conversion result in severe motion artifacts and image degradation for moving or rapidly changing images.
Resolution Works best at the native resolution. The native resolution can not be changed. All other resolutions require adjusting procedures which can cause considerable deterioration of the image.
Viewing Angle Restricted viewing angles. Viewing angles affect the brightness, contrast and colors shown. Wide angles can lead to contrast and color reversal.
White Saturation Saturation and compression can occur due to the bright-end of the intensity scale becoming overloaded. Contrast control must be carefully adjusted.
Other LCD Characteristics
Bad Pixels Can have many weak or stuck pixels, which are permanently on or off. Some pixels may be improperly connected to adjoining pixels, rows or columns.
Interference May require frequent readjustments throughout the day due to timing drift and jitter. Analog input requires careful modification of pixel tracking / phase to decrease or eliminate digital noise in the image.

 

VarTech Systems Inc.
Solutions for Demanding Applications
11301 Industriplex Blvd · Suite 4 · Baton Rouge · Louisiana · 70809 · U.S.A
U.S./Canada Toll Free: 800.223.8050 · International Phone: 001.225.298.0300
Fax: 225.297.2440 · E-mail: sales@vartechsystems.com