LED vs OLED

LED TVs really are still just LCD TVs the only thing which has changed is the backlight which used to be based on flourescent lights and are now moving over to LEDs allowing thinner TVs with lower power consumption. As such LED TVs that just replace the white flourescent light with white LEDs do not offer any significant increase in picture quality. However those using more complex LED backlights that use a feature called 'localised dimming' essentially selectively lowering or tunrning off the backlight in areas of the screen can significantly increase black levels and contrast, even more so if the LED backlight uses a mix of red, green and blue (RGB LED) leds allowing the selective diming of each individual colour. The Sony x4500 series which use this system claim a 1,000,000:1 contrast ratio as a result.







OLED screens use organic leds small enough to replace each individual pixel with an RGB led, as such there is no layer of liquid crystal and the screen is a pure LED system. This has the potential to massively increase picture quality, but is still very expensive and largely at the prototype stage. I think the one small non HD sony is the only retail model, and the largest manufacturer protype shown is a 40" Samsung I think. But the short version is it will probably be a good few years at least yet before we see a large HD consumer version and probably more years on that before they are affordable.






Essentially you could consider and LED backlight TV to become equivalent to an OLED when you reach the point where the backlight has an RGB LED for every pixel of the display, of course at that point you no longer need the LCD layer but current LEDs are to big to do this, (certain stadium displays actually work like this using a pixel that contains an RGB LED of course the pixel is an inch across so it's only good for really large size screens viewed at a distance).