We have found that when customers are using a display from another manufacture that has 14 pins and we send them a sample of an exact cross, they find that our displays have 16 pins.  There is no difference between the two displays other than the 2 additional pins.

Most displays come with three backlight options.

   Option 1:  LED

   Option 2:  EL

   Option 3:  No backlight

On the PCB, pins 15 and 16 are used to power up the LED or EL backlight.  

I do not have a backlight:    If you do not use a backlight, there is no need for pins 15 and 16. Some manufactures use a PCB with 14 pins on the displays that have no backlight and 16 pins on displays that have a backlight. This means they carry two different types of PCBs in stock. 

We find that it lowers the manufacturing cost to manufacture one PCB that has 16 pins. If you do not have a backlight, then pins 15 and 16 are not connected. They are just two holes that were drilled out of the PCB.  

I have an LED backlight:   If you have an LED backlight, then you need to draw your power from some other location than pins 15 and 16. You have two options.

Option 1:  You can draw this power from pins 1 and 2.  Note, this is only possible if your LCD voltage is the same as your LED backlight voltage. Some customers may have a 3.3V LCD and a 5V LED. If this is the case, do not draw the LED power from pins 1 and 2.

Option 2:  You can draw the power from pins A and K on the side of the PCB.  

 I have an EL backlight:   If you have an EL backlight, then you will have to draw the power from the A and K on the side of the PCB.   

This is a condition where OFF pixels, dots or segments are partially activated, producing faint images.  The segments or letters that should not be “on” are a light gray.  See the example below:

      ON

      OFF (ghosting)

The example below is a good illustration between positive and negative modes:

Focus Display Solutions ®                                                       © 2010 Focus Display Solutions

The most likely cause is that the polarity is reversed. A LED backlight operates on DC (Direct Current). The backlight must be connected correctly. The positive side of the backlight must be connected to the positive side of the power supply.

The positive side is called “A”. The other connection is called “K”, this is normally ground.  If the polarity is reversed then the backlight will not work. The solution is to reverse the polarity. How?

LCD’s that come with the LED backlight integrated into the display  normally have pin 15 set as positive and pin 16 as ground. Please see diagram below.

Your product may require pin 15 to be ground and pin 16 to be positive. If this is the case there are two jumper settings on the back of the LCD that allow the user to reverse the polarity.

Please contact us for information on which jumper settings to reverse the polarity.

Focus Display Solutions ®                                                              © 2010 Focus Display Solutions

Focus Display's Process for Custom LCDs

A trace, sometimes referred to as a track, is a strip of copper that runs from one connection on the PCB to another connection. The trace is used to carry the voltage/current from one area of the PCB to another.

Below are two photos showing a trace.

Many PCB’s have more then one layer. This is referred to as a multilayer board. If the PCB has more then two layers, some of these layers will be placed between the top and bottom layer. Making it difficult or impossible to see the trace.

Note, cutting a trace is equivalent to cutting a wire. This will disrupt the flow of voltage/current from one area of the PCB to another.

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.

EL backlights have a half life of 5,000 hours (7 months of continuous running) Half Life is when the brightness of the backlight is ½ of what is was when it was first turned on.