LCD TV and computer monitor images require backlighting. Traditional LCD displays use cold cathode or compact florescent lighting (CCFL). This is basically white florescent lighting behind the LCD panel image.
LED backlighting replaces florescent lighting and involves a full array of LEDs behind the LCD panel image. LED backlighting has some advantages over CCFL backlighting. A screen image, whether moving or static can vary in color, brightness and intensity. Sections of the image having these different properties can be specifically backlit in those areas of the screen in the local color to enhance these characteristics giving a truer vibrant color gamut and contrast. Black image color would have little or no backlighting with LEDs turned off giving a richer black as there is no light escaping through the LCD in that area of the screen.
The combination of these factors give a remarkably bright, sharp image even in well lit rooms. LED backlighting can be adjusted, brightened or dimmed, to the lighting ambiance of a room environment. With some tweaking full LED backlighting arguably rivals the picture quality of a plasma TV with the added benefit of image brightness for well lit rooms.
Edge Lighting
Edge lighting is a form of LCD image background illumination that is provided by LEDs installed around the edge of the display behind the LCD panel. The LED edge lighting is diffused by an optical sheet spreading light throughout the full background of the LCD image. Edge lighting does not have the specific locally controlled backlighting of a full LED RGB backlighting array.
Edge lighting uses less power and makes for very thin display panels. Some panels may be only an inch or so thick.
Viewing Angles
The LED backlit TVs have less distorted viewing angles to rival plasma TVs.
Screen Refresh Rates
Screen refresh rates are expressed in cycles per second or Hertz (HZ). This number usually ranges between 60HZ to 240HZ in LCD classes and higher in Plasma and Laser classes. This means the screen image will refresh 60 to 240 or more times per second. It's kind of like shutter speed on a camera. The longer the shutter is open (lower refresh rate) the more likely there will be a blur in an image with a moving object. With emerging technologies we may see higher numbers. The higher this number the sharper the image will be especially in high motion video, action scenes and sporting events providing the media or incoming TV signal supports it.
Screen Glare
TV and monitor screens come in different finishes. A shiny high gloss finish may be prone to glare or reflection from a cross room window or light. A matte finish screen would subdue this effect. In either case consider sources and handling of glare and reflection in relation to room arrangement and display placement.
The term "LED TV" used in advertising can be confusing. Any LEDs used in backlighting can be called an "LED TV". Knowing the differences of LED backlit TV types will give you an advantage in choosing the right LED TV. The bottom line in choosing the right TV for you is what pleases your own discerning eye, your other needs and wants in this area, and your own pocket book.
