Custom LED backlights

Thanks to advances in LED technology, it is possible to order a custom LED backlights not just in the color of your choice, but in the size, brightness, voltage and connection type you need. There was once a time when you could have any color car you like as long as it is black. Times have changed, not only for automobiles, but also for light-emitting diode (LED) technology.

Advances in LED technology:

LEDs were developed in 1927 by Oleg Vladimirovich Losev (a Russian who died in 1942 during the siege of Leningrad), but only recently have there been great advances in his technology. Advances such as reduced power consumption, more colors, brighter intensity and longer half-life are now available in full scale, low cost production.

In the last few years LEDs have become common place. This can be seen not only in backlights attached to Liquid Crystal Displays (LCDs), but in light bulbs, tail lights, spot lights and even flashlights.

I own a shaker flashlight with a LED light bulb, it‘s great, there are no batteries to replace or leak. You just shake it for a minute or two and it provides several minutes of bright light. It’s great for backpacking, power outages, hunting trips, and best of all… no more storing all those extra batteries!

The LED blub lasts much longer than the older incandescent light bulbs, also they require less power and are brighter. Not to mention you can use a red LED for night vision.

Custom LED Backlights: Panels

Although the majority of our business is the designing of LCD displays, we receive requests for custom LED backlights by themselves.

Applications for LEDs range from replacement backlights for LCDs, to camera flashes, portable reading lights, and lighting systems in concerts and movies.

For a one-time design (tooling fee) we can outline and build prototype samples for a large number of applications.

Focus Displays offers full custom LED backlighting. When ordering your custom LED backlights there are five options to consider:

OPTION #1: LED BACKLIGHT BRIGHTNESS:

How bright do you need your backlight?

LED backlight brightness is measured in candela-per-square-meter (cd/m2) or Nits. This is the amount of light one candle provides. Although both definitions mean about the same thing, I prefer to use Nits as it is much easier to spell.

The typical Nit values range from 200 Nits to over 1,500 Nits and higher. With a higher Nit count, the LED backlight is brighter and draws more electrical current. If your product is battery powered, we recommend a lower Nit count or implement Pulse Width Modulation (PWM) to provide a longer battery life.

As a general rule, LCD Displays with a Nit count of 700 or higher are classified as sunlight readable. It is possible however, to build a sun light readable product with a lower Nit count and a Transflective polarizer.

OPTION #2: HALF-LIFE

How long do you need the backlight to last?

LED, EL (electroluminescent) and CCFL (Cold cathode fluorescent lamp) backlights slowly dim over time. The half-life of a LED backlight is between 50,000 hours to 70,000 hours, verses EL backlights that average around 3,000 hours. CCFL backlights are shorter than LED and have pretty much become a legacy (legacy = no longer in production for LCD displays) technology for LCD applications.

Question: So, what is half-life? Is this something that has to do with radioactive waste?

Answer: No. Half-life for backlights is the time, in hours, of how long the backlight can operate before its brightness (Nits) is at half (or 50%) of what it originally was when first turned ON. This is not the amount of time it takes for the LED to burn out.

educing the amount of driving current will increase the half-life. A lower current will dim the light, but the backlight will last longer. This is a value judgment that needs to be made by the customer. One method to reduce the driving current is to incorporate a current limiting resistor. Below is a photo showing a LED array backlight with a built in current limiting resistor.

Additionally, if the backlight will operate in an excessively hot environment, like Phoenix, Arizona, the heat will shorten the half-life.

OPTION #3: LED OPERATING VOLTAGE

It is possible to choose your operating voltage on a custom backlight. The most common values are 3 volt, 5 volt and 12 volt:

3 volt backlights are popular in products that operate on batteries such as two AA batteries since one AA generates around 1.5V each.
5 volt backlights are popular on LCD displays that are not battery powered. (plugged into a wall outlet)
12V backlights are common in automotive, marine and some aviation applications.

We can design the backlight to work on the voltage you need.

OPTION #4: SIZE OF THE CUSTOM LED BACKLIGHTS

The nice thing about a custom backlight is that it fits into your design; you don’t have to modify your design to fit a standard size backlight. The one-time tooling cost for a LED backlight is much less than the tooling cost for a new case or injection molding.

With custom LED backlights, you can ‘have it your way’. (For those of you who are old enough to remember the Burger King ® commercials. If you are too young, check out this YouTube link.

Let us know length, width and height of the backlight and one of our coffee-drinking technical people will start your design.

OPTION #5: CONNECTION TYPE:

There are several methods to connect the custom LED backlights.

The most common method is to attach two discrete wires, also called a pig tail, as shown in the photo below. We can build this cable as long or as short as you need.

Note: LED’s are DC (Direct Current), so I suggest different color wires to recognize which one is power and which one is ground (or negative).

Custom LED backlights: lead times

By the way, custom LCD samples can be provided in a matter of a few weeks. When we ship your prototype samples, one of our coffee-drinking technical people can include some gourmet roasted coffee. You choose light or dark roast. The coffee will energize you; you need to provide your own power to energize the LED backlight.

Ready to start on your LCD design using custom LED backlights? Just click the little blue button below or call one of our coffee-drinking technical support people in Arizona at 480-503-4295.