08-02-2013, 12:10 PM
TOUCH SCREEN TECHNOLOGY
[attachment=50157]
INTRODUCTION
Works with the principle of CRT (Cathode Ray Tube) technology.
Input device --> Operates a PC by simply touching the display screen.
Made of sensitive glass overlay & desired inputs can be given by touching it.
Inputs --> External (light pen) or an internal device (touch overlay and controller) .
TOUCH SENSORS
Touch sensor --> In between clear glass panels.
Responsive area --> Entire viewable area of the display screen.
Sensors --> Detects electrical current or signal.
Touching -->causes a voltage or signal change, thereby the location can be determined.
SOFTWARE DRIVER
Acts as a bridge --> Screen and processor.
Makes the operating system --> To interpret the touch event information.
Touch screen drivers today --> Mouse-emulation type driver ( like touching the screen the same as clicking mouse)
Recent research --> To make it as PNP
TYPES OF TOUCH SCREEN
Resistive Touch screen
Surface wave Touch screen
Capacitive Touch screen
Surface capacitive
Projected capacitive
Infrared Touch screen
WORKING OF RESISTIVE SENSORS
Resistive touch screen monitor composed of :
Flexible top layer
Rigid bottom layer
Insulating dots
Along with touch screen controller.
Top & Bottom layers --> transparent metal oxide coating.
Pressure over the flexible top sheet --> Makes electrical contact between the resistive layers & the switch closing in the circuit.
Controller --> Alternating voltages & converts them into the digital X and Y coordinates.
WORKING OF CAPACITIVE TOUCHSCREEN
Uniform conductive coating on a glass panel.
Operation --> Electrodes around the panel's edge evenly distribute a low voltage across the conductive layer & creates an uniform electric field.
Finger touch --> Draws current from each corner.
Controller --> Measures ratio of the current flow from the corners & calculates the touch location.
Capacitance --> Finger and the sensor grid.
conclusion
Though the Touch screen technology contains some limitations it’s
user friendly.
Fast.
Accurate.
easy to operate.
It has been widely accepted and a little modification can replace the mouse and key board completely in near future.
[attachment=50157]
INTRODUCTION
Works with the principle of CRT (Cathode Ray Tube) technology.
Input device --> Operates a PC by simply touching the display screen.
Made of sensitive glass overlay & desired inputs can be given by touching it.
Inputs --> External (light pen) or an internal device (touch overlay and controller) .
TOUCH SENSORS
Touch sensor --> In between clear glass panels.
Responsive area --> Entire viewable area of the display screen.
Sensors --> Detects electrical current or signal.
Touching -->causes a voltage or signal change, thereby the location can be determined.
SOFTWARE DRIVER
Acts as a bridge --> Screen and processor.
Makes the operating system --> To interpret the touch event information.
Touch screen drivers today --> Mouse-emulation type driver ( like touching the screen the same as clicking mouse)
Recent research --> To make it as PNP
TYPES OF TOUCH SCREEN
Resistive Touch screen
Surface wave Touch screen
Capacitive Touch screen
Surface capacitive
Projected capacitive
Infrared Touch screen
WORKING OF RESISTIVE SENSORS
Resistive touch screen monitor composed of :
Flexible top layer
Rigid bottom layer
Insulating dots
Along with touch screen controller.
Top & Bottom layers --> transparent metal oxide coating.
Pressure over the flexible top sheet --> Makes electrical contact between the resistive layers & the switch closing in the circuit.
Controller --> Alternating voltages & converts them into the digital X and Y coordinates.
WORKING OF CAPACITIVE TOUCHSCREEN
Uniform conductive coating on a glass panel.
Operation --> Electrodes around the panel's edge evenly distribute a low voltage across the conductive layer & creates an uniform electric field.
Finger touch --> Draws current from each corner.
Controller --> Measures ratio of the current flow from the corners & calculates the touch location.
Capacitance --> Finger and the sensor grid.
conclusion
Though the Touch screen technology contains some limitations it’s
user friendly.
Fast.
Accurate.
easy to operate.
It has been widely accepted and a little modification can replace the mouse and key board completely in near future.