Mobile Phone Faulty Screens.
Part of our research at Datlabs is “why products fail “. If determined from our analysis there is a likelyhood that failures of specific product types are to become commonplace then this assists us in forward planning.
A recent “look see” into common smart phone failures revealed a pattern of non-responsive or broken mobile smart phone touch screens, so why is this?
In attempting to answer this question we first considered the underlying touch screen technology used in the various products.
The two most common technologies used in the manufacture of touch screens (not specifically mobile phones) are “resistive” and “capacitive”.
Resistive Touch Screen
This technology from a smart phone perspective is now defunct but worth a mention as the technology is still used in basic products, typically ATM’s; and here’s why:
These screens literally “resist” your touch; if you press hard enough you can feel the screen bend slightly. This is what makes resistive screens work – two electrically conductive layers bending to touch one another. One of the layers is resistive and the other is conductive and they are separated by a gap of tiny dots called spacers to keep the two layers apart until you touch it. An electrical current runs through the resistive layer and when your finger hits the screen the two are pressed together and the electrical current changes at the point of contact. The software recognizes a change in the current at the specific coordinates and executes the function that corresponds with that particular point reference on the screen image. These touch screens are robust and consistent but are very limited in that the technology can only deal with a single co-ordinate function at a time. The screen material layers also reflect considerable amounts of light making them difficult to read in bright daylight.
Capacitive Mobile Phone Screen Technology.
Capacitive mobile phone touch screens use the electrical characteristics of your finger (skin) or a similar material to hold an electrical charge. Capacitive touch screens are constructed from materials that store electrical charges in an electrostatic grid of tiny wires, each smaller than a human hair. When your finger hits the screen a tiny electrical charge is transferred from the screen to your finger and completes an electric circuit producing a voltage drop on the specific co-ordinate reference on the screen. This is why your screen refuses to function when you wear gloves. Capacitive screens don’t work when you wear everyday ordinary gloves for example. There are two main types of capacitive touch screens – surface and projective. Surface capacitive uses sensors at the corners and a thin evenly distributed film across the surface, whereas projective capacitive uses a grid of rows and columns with a separate chip for sensing.
Mobile Phone Screen Damage.
In both cases mentioned above vigorous poking at the screen when it fails to respond tends to cause damage to the screen technology. Touch screens can also become faulty if in contact with liquids and water. When using a smart phone touch screen it is well to keep in mind that the screen itself is an electrical component and is not to be treated in an inappropriate manner.
Touchscreen responsiveness can be adversely affected by skin oils deposited by your fingertips. The visible effects of fingerprint oils can be seen on most smartphones. Developments to reduce oil residue include matte-finish anti-glare screen protectors that do not retain smudges.
Alternative and New Technology.
In response to new requirements of accuracy and responsiveness manufacturers are developing new or complementary technologies i.e. Infrared grid, Infrared acrylic projection, optical imaging, dispersive signal technology, acoustic pulse recognition and notably 3D Touch used in the iPhone 6. (we will keep an eye out for any problems that develop ).
Mobile Phone Screen Protectors.
There is a good case for using good quality, compatibility approved screen protectors.
If you have a failed smart phone screen and need your files and folders then contact our customer service team here.