Converting CCFL to LED backlight on your LCD may require tooling
Converting CCFL to LED backlight on your LCD display module may require tooling for a custom glass display. CCFL backlights are becoming a thing of the past for smaller LCD modules such as Graphic monochrome LCD displays. There are several reasons why these LCD backlights are being discontinued. But we will not cover that in this article.
CCFL (Cold Cathode Fluorescent Lamp) backlights are a backlight with low power consumption and a very bright light. CCFL’s are most commonly produced as an edge lit backlight. This backlight uses a diffuser (similar to a lamp shade) to distribute the light evenly across the viewing area. CCFL’s do require an inverter to convert DC to AC. This is to supply the 270 to 300 VAC @ 35KHz that is used by the CCFL tube. CCFL backlights are used primarily in graphic displays. They have a (half-life) lifespan of 10K to 20K hours which is longer than an EL but shorter than an LED backlight.
The biggest hang up with CCFL backlights is that the light output can be lowered by as much as 60% in cold weather. They require inverters to generate the 350VAC and inverters do not work well in cold temperatures. Another issue is the display is either ON or OFF, the brightness cannot be varied. CCFL’s also handle vibration poorly, vibrations can reduce the life expectancy of the backlight by up to 50%.
Converting CCFL to LED
Customers are finding that their current LCD’s are becoming legacy and their supplier is asking for a last-time buy. If the customer needs to continue production of their product they will need to switch over to an LED backlight.
As a general rule it is easier to design a custom LCD screen to convert from CCFL to LED backlight then to redesign the customer’s product. If you have questions or need to help converting CCFL to LED on your LCD display just call FocusLCDs.com at 480-503-4295. We’re ready to assist you.
Smaller character displays such as a 16×1 display, 20×2 display and 40×4 display do not make use of a CCFL backlight.
What is the Expected Lifetime for LED Backlights?
The short answer: 50,000 to 70,000 hours for most colors except blue and white (5.7 to 8 years of continuous running). Blue and white are rated at 30K hours (3.4 years of continuous running).
The long answer: There are two definitions in the industry for “lifetime”
- Half-life: this is when the LED will be half as bright as when the LED was first turned on.
- MTBF (Mean-time between failures). This is when there is a 50% chance that the LED will fail.
There are many studies on the subject of ‘lifetime”. Each study claims a different number of hours. One thing to take into account is that as technology improves, the lifetime of the LED’s will become longer.
For questions on customized displays, please contact us at (480) 503-4295.