Computer Input Output Questions Medium
There are several different types of touchscreens commonly used in computer input-output systems. These include:
1. Resistive Touchscreens: These touchscreens consist of two layers with a small gap between them. When pressure is applied to the screen, the layers make contact at the specific point, and the touch is registered. Resistive touchscreens are durable and can be operated with any object, including fingers, stylus, or gloves. However, they may not provide as accurate touch recognition as other types.
2. Capacitive Touchscreens: Capacitive touchscreens use a layer of capacitive material that stores electrical charges. When a conductive object, such as a finger, touches the screen, it disrupts the electrical field, and the touch is detected. Capacitive touchscreens offer excellent touch accuracy and multi-touch capabilities, but they require a conductive object to register the touch.
3. Surface Acoustic Wave (SAW) Touchscreens: SAW touchscreens use ultrasonic waves that pass over the screen's surface. When the screen is touched, some waves are absorbed, and others are reflected. The touch position is determined by analyzing the pattern of reflected waves. SAW touchscreens provide high image clarity and durability, but they can be affected by environmental factors like dust or moisture.
4. Infrared Touchscreens: Infrared touchscreens use an array of infrared light-emitting diodes (LEDs) and photodetectors placed around the screen's edges. When the screen is touched, the interruption of the infrared beams is detected, and the touch position is determined. Infrared touchscreens are highly durable and can be used with any object, but they may be affected by ambient light interference.
5. Optical Touchscreens: Optical touchscreens use infrared light sources and sensors placed on opposite sides of the screen. When the screen is touched, the light beams are interrupted, and the touch position is calculated. Optical touchscreens offer high touch accuracy and can support multi-touch gestures, but they may be affected by external light sources.
6. Projected Capacitive Touchscreens: Projected capacitive touchscreens use a grid of micro-fine wires embedded in the screen. When a conductive object, such as a finger, approaches the screen, it creates a change in the electrical field, and the touch is registered. Projected capacitive touchscreens provide excellent touch accuracy, multi-touch support, and are highly durable.
These are some of the commonly used types of touchscreens in computer input-output systems, each with its own advantages and limitations. The choice of touchscreen technology depends on factors such as the intended application, desired touch accuracy, durability requirements, and budget considerations.