Replacement LED backlights for LCD Modules
Replacement LCD modules
This article covers the wide spectrum replacement LED backlights (including LED, EL and CCFL), replacement backlights for obsolete LCD displays; and custom LED backlights with a current limiting resistors.
Although the majority of new custom LCD designs we support are slated for new product development, we also receive a fair number of request for replacement LCD Displays. Liquid Crystal Display manufactures either discontinue production of a specific LCD and push it to an EOL (End Of Life) status or some LCD suppliers, such as Standish displays and Seiko LCD Displays, have completely discontinued production of all their LCD products.
This creates a need by many OEM and Repair customers to locate an exact equivalent LCD.
Replacement backlights for obsolete LCD Displays
In many cases when the LCD module has been discontinued, the LCD is still operating, but the backlight has burned out or become too dim. The customer does not need to replace the entire LCD module, but only the backlight that fits behind the LCD polarizer.
There are three major types of backlights in use with LCD modules with the most popular being LED, so we will start with this.
Replacement LED backlight
LED (Light Emitting Diode) backlights are the most popular backlight technology in use today; one reason is that they have a rated half-life between 30K to 70K hours of operation. Half-life is not when the display burns out or goes dark, but instead when the brightness of the display is half as bright as when it was first turned on.
Several factors can reduce the half-life of a LED backlight including:
- Excessive current (IF)
- Excessive vibration
- Extreme operating and storage temperatures
When it is time to locate a replacement LED backlight, send us the LED module (working or not), we will reverse engineer and then offer you options for a drop-in equivalent backlight.
There will be a one-time tooling fee, with this you will receive
- Prototype Samples
- Data sheets
- US based support and inventory
- Your exclusive rights to this backlight design. (We will not sell this design to anyone else without your permission)
Custom LED backlights with a current limiting resistor
In many cases, the replacement LED backlight that Focus Display Solutions designs for you may require a current limiting resistor.
The function of a current limiting resistor is to use a resistance value that either dims the light (extending the half-life) or increase the brightness (decreasing the half-life)
If the backlight is powered from the A and K pins, and not through the PCB, the current limiting resistor will need to be attached to the backlight. The image to the right is an example of a custom LED backlight with built in current limiting resistors.
EL and CCFL replacement backlights
The other two less popular backlight technologies are
This technology has fallen far behind in volume due to its short half-life (an estimated 3K hours) and its need for an inverter. Also, some applications cannot accept the noise generated by its AC signal.
Focus Displays can still supply EL backlights, although the MOQ has increased to 1K units or more.
COLD-CATHODE FLUORESCENT BACKLIGHT
CCFL backlights for use in LCD modules, such as larger graphic displays, are a thing of the past. Environmental issues have reduced their availability. We no longer design LCD products that integrate a CCFL. If your current display contains a CCFL and you need a replacement, your best option may be to replace this with a DC powered LED backlight.
Since CCFL is AC driven and LED is DC driven, the swap of technologies will require additional work and design.
Is it possible? Yes
Need help replacing the backlight on your LCD module? Contact us at 480-503-4295.