How does the touch screen work?
Touch screens are becoming more and more popular because they make the user interface more exciting and intuitive for people who are new to modern technological devices. Touch screen technology was first developed for specialized research products in the 1970s, but are now found in everyday devices including Automation, Medical, Computer Screens, Cell Phones, Point of Sale, GPS, etc. But have you ever stopped to think about how these devices recognize the remains of your finger, pen or stylus? We have some answers.
Currently, there are four basic systems used in touch screens to recognize your touch:
- Resistive
- capacitive
- Infrared
- acoustic wave surface
How does the resistive touch screen work?
When you press your finger on a resistive screen, the upper flexible layer touches the lower one, and the device detects the interruption of electrical current and calculates the precise location of the point of contact. Depending on which button is under your finger, the software records the coordinates and executes the command. they respond to pressure, you can activate them with bare fingers, gloves, or stylus (remember the PalmPilot?), but you can’t swipe or use multi-touch gestures, because the electrical current locked inside them can only successfully register one point of contact at once.
How does the capacitive touch screen work?
iPhones, iPads, Samsung Galaxy smartphones, and Amazon Kindle Fire, to name a few, use the “capacitive” method. These electronic devices monitor changes in electrical currents running through the screens. Touch screens include a layer of capacitive or electrical storage material. The screen capacitors are arranged according to a coordinate system, creating a grid. The circuitry inside the screen can detect changes in electrical charge at each point along the grid. As a result, each individual grid point generates its own signal when touched, which is then transmitted to the device’s processor, allowing the device to recognize multiple touch points.
How does infrared touch screen technology work?
In infrared touch screen technology, a series of X and Y axes are equipped with pairs of IR LEDs and photodetectors. The photodetectors detect any change in the light pattern emitted by the LEDs each time the user touches the monitor/screen.
How does surface acoustic wave technology work?
Surface Acoustic Wave touchscreen technology contains two transducers (transmitter and receiver) positioned along the X-axis and Y-axis of the monitor’s glass plate along with some reflectors. The waves propagate through the glass and are reflected back to the sensors. When the screen is touched, the waves are absorbed and a touch is detected at that point. These reflectors reflect all electrical signals sent from one transducer to another. This technology provides excellent performance and image clarity.
Sean is a professional touch screen HMI and operator panel keyboard engineer. And Sean also likes to write on the touch screen and membrane keyboard Product knowledge and points, precautions, etc. You can view these articles at https://www.vicpas.com/faq.htm