Backlights: Which Is Better, LED or CCFT?
‘Better’ may depend on your requirements however it seems reasonably clear that LED provides a number of benefits over CCFT backlights. A few of the issues:
- Availability: Now many of the panels meeting other specification requirements are likely to have LED backlights, this factor alone may be the end of discussion.
- Robustness: LED is solid-state whereas CCFT backlights are narrow tubes made of thin glass. Having said that the LCD itself is made of thin glass and I have seen more LCD panels broken than I have heard of CCFT tubes breaking. (Note: LCD panels can be ‘strengthened’ by bonding with toughened glass)
- Price: If there is a choice then CCFT backlit panels appear to still be lower cost but the difference is reducing.
- Brightness: In terms of absolute brightness this is not an issue as either can be used to make very bright panels. However LED may be an easier choice to work with for low light brightness control.
- Lifetime: Backlight lifetimes for both LED and CCFT are generally around 50,000 hours as defined by the time to half brightness. Toshiba current catalogue is all LED and shows most panels with 70,000 hours and one model with 100,000 hours.
- Power: Generally LED use less power and the rate of improvements suggest this will develop into a clear lead in the near future.
- Future: LED’s are getting massive development investment and likely to continue to see more improvements than CCFT.
The bottom line is that depending on the LCD panel requirements there may not be too much choice as to whether the backlight is CCFT or LED. Increasingly the panels will be LED backlit.
So what next? LED needs to watch out for OLED, this upcoming display technology doesn’t use a backlight as the OLED is the light source.