How does the touch screen work?
Touchscreens are becoming more popular because they make the user interface more exciting and intuitive for people new to modern technology devices. Touch screen technology was first developed for specialized research products in the 1970s, but they are now found in everyday devices such as automation, medical, computer screens, cell phones, product sales, GPS, etc. But have you ever stopped to think about How do these devices recognize your finger, stylus or stylus? We have some answers.
Currently, there are four basic systems used by touchscreens to recognize your touch, including:
- Resistive
- Capacitive
- Infrared
- Surface acoustic wave
How does the resistive touch screen work?
When you press your finger on a resistive screen, the flexible top layer touches the bottom one, and the device senses the interruption of electrical current and calculates the precise location of the contact point. Depending on the button under your finger, the software records the coordinates and executes the command. They respond to pressure, you can activate them with your bare fingers, gloves, or stylus pens (remember the PalmPilot?), but you can’t swipe or use multi-touch gestures, because the electrical current locked inside can only successfully register one point of contact at once.
How does the capacitive touch screen work?
iPhones, iPads, Samsung Galaxy smartphones, and Amazon’s Kindle Fire, to name a few, use the “capacitive” method. These electronic devices monitor changes in electrical currents that flow through screens. Touchscreens include a layer of capacitive or electricity-storing material. The capacitors on the screen are arranged according to a coordinate system, creating a grid. The circuits within the screen can detect changes in electrical load at each point in the network. As a result, each individual point on the network generates its own signal when touched, which is then relayed to the device’s processor, allowing the device to recognize multiple points of contact.
How does infrared touch screen technology work?
In infrared touch screen technology, a series of X and Y axes are equipped with pairs of infrared LEDs and photodetectors. The photodetectors detect any change in the light pattern emitted by the LEDs each time the user presses the monitor / screen.
How does Surface Acoustic Wave technology work?
Surface Acoustic Wave touchscreen technology contains two transducers (transmit and receive) positioned along the X-axis and Y-axis of the monitor glass plate along with some reflectors. The waves travel through the glass and are reflected off the sensors. When the screen is touched, the waves are absorbed and a touch is detected at that point. These reflectors reflect all the electrical signals sent from one transducer to another. This technology provides excellent image clarity and performance.
Sean is a professional HMI touch screen and operator panel keypad engineer. And Sean also likes to write about the touch screen and membrane keyboard, product knowledge and points, cautions, etc. You can view these articles at https://www.vicpas.com/faq.htm