Question

a sensor is to be designed and deployed under the screen panel of the mobile phone.the purpose of the sensor is to turn the backlight when the user touches his finger on the screen.what type of sensor will you suggest for this purpose and why

Answer 1

I suggest to use CAPACITVE TOUCH SENSOR for this purpose.

Why? Because capacitive touch sensor works on the principle of electric disturbance. They are places on the opposite side of viewing angle/viewing side. Whenever a conducting material such as human skin tissue comes in contact with the glass of screen which is further connected with the sensor produce a signal which leads to any operation according to our need.

Capacitve touch sensor include conducting coating on one side and printed circuit board on another side of sheet of glass. The PCB is used to create the charge on the outer surface of glass i.e. conducting material and when it comes in contact with the skin tissue, charge gets disturbed and hence signal is generated.

Since, the sensor is built on the sheet itself so we don't need to apply high preassure even a very small for is significant for the working.