LED Backlight vs CCFL Backlight in a LCD Display Module
We have received many requests for LCD’s that contain a CCFL backlight (aka: cold-cathode fluorescent lamps backlight). We are finding it more and more difficult to supply a CCFL backlight.
The Liquid crystal displays we talk about in this article are monochrome LCD displays; this includes alphanumeric LCD displays and graphic displays. We do not cover TFT LCD’s or OLED’s in this discussion.
When a customer contacts us for an application that needs a CCFL backlight, we recommend switching over to an LED backlight or LED edge lit display.
Below is a break down on the advantages and disadvantages of LED backlight vs CCFL backlight.
LED Backlight Advantages
- Longer life time (An estimated 60K to 100K hours depending on the customers driving current)
- DC, there is no need for an inverter and there is no noise produced to interfere with external circuits
- Easier to control dimness
- Faster on and off response time
- Can operate at extreme cold temperatures. See what to expect when operating an monochrome display at cold temperatures (click here)
LED Backlight Disadvantages
- Does not provide as even light on larger displays as a CCFL. On a larger display it may be possible to see hot and cold spots. (Although a diffuser can help to reduce this)
- Many times the thickness of the display is thicker then a CCFL or EL version
CCFL Backlight Advantages
- A more even light. This is even more true over a lager size LCD
- In many cases less heat than an LED backlight, although as technology of the LED changes this is becoming less and less true
CCFL Backlight Disadvantages
- They contain mercury; many countries are limiting or banning CCFL
- Shorter life time then LED. An estimated 20K to 30K hours
- CCFL backlight requires a higher voltage
- CCFL backlight requires an inverter
For additional information on LED vs CCFL backlight ( click here)
Character LCD module (aka alphanumeric LCD display, character LCD, numeric LCD displays) The majority of character LCD modules listed below are STN but can be supplied in TN or FSTN.
An estimated 80% of our character LCD displays are supplied with LED backlight or LED edge lit. 15% of alphanumeric LCD displays are supplied with no backlight. The last 5% of numeric LCD displays are supplied with EL backlight.
8×1 LCD display, 8×2 LCD display, 16×1 LCD display, 16×2 LCD display, 16×4 LCD display, 20×2 LCD display, 20×4 LCD display, 24×2 LCD display, 40×1 LCD display, 40×2 LCD display, 40×4 LCD display.
Segment Display (aka static LCD displays, seven segment display, glass only LCD display) The majority of segment displayslisted below are TN, but they can be ordered in STN and even FSTN.
Segment Display’s do not contain a backlight as a standard option. It is possible to order a separate backlight. This would need to be ordered as a custom LCD module. See custom LCD displays for more details.
7(seven) segment LCD display, 14(fourteen) segment LCD display, 16(sixteen) segment LCD displays, multiplex, mux, common mode LCD.
Graphic Displays (aka Monochrome Graphic LCD Displays, dot matrix LCD module) The majority of graphic displayslisted below are FSTN, but can be order in STN. We do not recommend TN on these displays.
122 x 32 graphic LCD display, 128 x 128 graphic LCD display, 128 x 64 graphic LCD display, 240 x 64 graphic LCD display.
In the past 70% of the LCD monochrome displays we offered came with the CCFL backlight. At the current time we see this number dropping to 0%.