LCD (liquid crystal display) is a term that most of us had heard –probably from the sales pitches for flat screen TV’s, computer monitors, laptops and gadgets like tablet PC’s and smart phones. We may also have noted that it is very hard to get anyone to tell what the real difference is between a plasma screen, an LED screen and an LCD screen? Possibly because the technology behind all three is somewhat complex and, maybe, the salesperson doesn’t understand it any better than you do; I am certainly not going to try and explain it here. Suffice to say that each type has its own pros and cons.
Light Emission
Both plasma and LED emit light when activated by electricity so there should be some sort of electrical logic to controlling how bright the image is on these display screens. An LCD on the other hand is a flat panel electronic visual display that operates on the light modulating properties of liquid crystals that do not directly emit light. For an LCD; segments are filled with liquid crystals and placed in front of a light source – this is known as backlighting and, for LCD use, this is normally provided by LED’s (light emitting diodes). To obtain a High Brightness on LCD screens, careful balance between the liquid crystals and the backlighting is required.
Liquid Crystals
These are just what their name suggests in so much as they exhibit properties that lie between those of conventional liquids and those of solid crystalline matter. They might flow like a liquid while having a crystalline molecular orientation. There are many different types which have differing optical properties which again makes it difficult for us laymen to comprehend their use as computer for TV display screens.
Need For Brightness
Some of the earliest LCD screens were somewhat lacking in brightness and only showed a sort of blackness to watchers positioned other than dead in front of the screen; additionally, their images were often impossible to see in direct sunlight. By and large, these obstacles have been overcome to a point where LCD TV’s of any size can be viewed from almost anywhere in the room and there is no need to draw drapes or turn off lights.
In fact, High Brightness LCD screens have developed to such a point that they have become a popular means of display for advertising and informational signs of all types both indoors and outside. High Brightness LCD signage can provide maximum impact to a large number of people in just about any location.