The Different Types of Touchscreen Technology

The tech that makes your TV screen light up is a key part of the image quality you get to see. Screens use several different display technologies, with IPS, TN, and VA/VAM being the most common.

There's also a newer technology called MicroLED, which uses millions of tiny LEDs to create screens with better black levels and wider-gamut color. It can also avoid burn-in.

Touch screens

Touch screens can be found in many places, from self-serve kiosks at airports to tablets and smartphones. Despite their simplicity, however, touchscreens are sophisticated pieces of screen technology. There are four different types of touchscreens, each with unique capabilities.

The earliest touchscreens used opaque conductive copper tracks to sense touch. But in 1984, projected capacitance was introduced, and it allowed a single wire to replace about 30 of these tracks, allowing more precise sensing.

Other forms of touchscreens include optical imaging and infrared. Optical imaging sensors use light strips that emit invisible grid beams across the screen and photodetectors around the edges to detect touch. When a finger or stylus touches the screen, it interrupts the beams and triggers the sensors, which locate the touch point. Infrared-based systems also record heat from the touch to identify the intended command. These technologies are ideal for industrial applications that require high reliability and consistent behavior. The most common uses of these displays, says Udupa, are in warehouse and logistics, manufacturing and healthcare.

Digitizer screens

Screen digitizers, which are also known as touch screens or interactive displays, convert analog inputs like drawing and writing into digital data. They enable users to interact with devices using their fingers or styluses and provide a more intuitive experience that’s less dependent on hand-eye coordination.

They also make it easier for individuals with physical limitations to use computers and other electronic devices. Digitizer screens are a crucial part of the touchscreen ecosystem and work in tandem with LCD screens to maximize device performance and user experience.

Digitizer screens utilize a grid of sensors beneath the display surface to detect pressure and position. They then convert this data into a digital signal that’s transmitted to the device’s processor. These sensors can be based on resistive technology, capacitance, or SAW (surface acoustic wave). A resistive touchscreen digitizer, for example, uses two layers of conductive material separated by an air gap to register touch. When the screen is touched, it disrupts the natural electrical flow of the device and registers a change in current.

Diagnostic displays

Medical imaging equipment like X-rays, Magnetic Resonance Imaging (MRI), and Computerized Tomography scans produce diagnostic images that physicians use to make diagnoses. Those images need to be displayed on monitors that meet strict medical-grade performance criteria.

The best medical monitors are light-emitting diode (LED) and feature a wide viewing angle for easy positioning of the image. They also offer high brightness, excellent contrast ratio, and low noise. They require less power than CCFL displays and generate much lower heat.

A growing trend in radiology is the use of multi-modality displays that allow different modalities to be viewed on one screen. Such displays are able to display X-rays, CTs, and MRIs simultaneously.

In a recent study, it was found that the diagnostic quality of high-performance monochrome medical-grade LCDs is often similar to color display devices, especially in comparison to COTS color LCDs. However, the same has not been proven for medical-grade LED displays.

Displays on real-world surfaces

Currently, touch screens are used in mobile devices, laptops, computer monitors and car infotainment systems. They are also used in educational settings, point of sale systems and public information kiosks.

Displays on real-world surfaces provide greater accessibility, better ergonomics and enhanced user experience for a wide variety of users. They are also a key technology for augmented reality (AR) and virtual reality (VR) applications.

Emissive electronic displays such as LCDs and OLEDs are widely used as stand-ins for real reflective surfaces in e-commerce, appearance design and other applications. Despite the resemblance of these images to their real-world counterparts, they do not produce the same visual responses as real reflective surfaces.

A recent study has developed a surface display system that simulates the color and texture of physical objects using off-the-shelf laptop technology. By integrating an accelerometer and a webcam, the orientation of the screen and position of the observer can be tracked in real-time. This allows realistic surface material properties, illuminated by environment-mapped lighting to be rendered on the display at interactive rates.