課文主文、單字與專業術語
Touchscreens are common in devices such as game consoles, all-in-one computers, tablet computers, and smartphones. They also play a prominent role in digital appliances such as personal digital assistants and satellite navigation devices. A touchscreen is an electronic visual display that users input through simple or multi-touch gestures by touching the screen with one or more fingers. Some touchscreens also detect objects such as a stylus or ordinary or specially coated gloves. Users can use touchscreens to react to what is displayed and to control how it is displayed, for example to zoom the text size.
The popularity of smartphones, tablets, and many types of information appliances has driving the demand and acceptance of common touchscreens for portable and functional electronics. Touchscreens are popular in both medical and heavy industries, as well as in kiosks such as museum displays or room automation. In those industries and locations, keyboards and mouse systems normally do not allow a suitably intuitive, rapid, or accurate interaction between users and content of the display.
Historically, touchscreen sensors and their accompanying controller-based firmware have been made available by a wide array of system integrators, and not by display, chip, or motherboard manufacturers. Display manufacturers and chip manufacturers worldwide have acknowledged the trend toward acceptance of touchscreens as a highly desirable user interface component and have begun to integrate touchscreens into the fundamental design of their products.
Resistive and capacitive touches are the two major touchscreen technologies. A resistive touchscreen panel is comprised of two thin, transparent electrically-resistive layers. These layers are separated by a thin space. The two layers face each other with a thin gap between. The top screen, or the one that is touched, has a coating on the underside surface. Just beneath it is a similar resistive layer on top of its substrate. A voltage is applied to one layer, and sensed by the other. When an object, such as a fingertip or stylus tip, presses down on the outer surface, the two layers touch to become connected at that point. The panel then behaves as a pair of voltage dividers, one axis at a time. By rapidly switching between each layer, the position of a pressure on the screen can be read.
Resistive touch is used in public locations such as restaurants, factories and hospitals due to its high resistance to liquids and contaminants. A major benefit of this technology is its low cost. Additionally, as only sufficient pressure is necessary for the touch to be sensed, they may be used with gloves on, or by using anything rigid as a finger/stylus substitute. The disadvantages of this technology include the need to press down and a risk of damage by sharp objects. Due to having additional reflections from the extra layer of material placed over the screen, resistive touchscreens also have poorer contrast.
A capacitive touchscreen panel consists of an insulator such as glass, coated with a transparent conductor. As human body is an electrical conductor, touching the surface of the screen results in a distortion of the screen's electrostatic field, measurable as a change in capacitance. Unlike a resistive touchscreen, one cannot use a capacitive touchscreen through most types of electrically insulating material, such as gloves. This disadvantage affects usability in consumer electronics, such as touch tablets and capacitive smartphones in cold weather. It, however, can be overcome with a special capacitive stylus, or a special-application glove with an embroidered patch of conductive thread passing through it and contacting the user's fingertip.