What is Multi-touch?
The early technologies used resistive or capacitive touch technology. However, other technologies such as infrared and acoustic wave are also used. Recent years have seen a significant amount of technological advancement, and many new multi-touch display units have appeared on the market, most of them using advanced capacitive technologies. However, there is a wide variety of choices when it comes to choosing a touch screen. The prices of these units can vary widely, depending on their specifications and features.
Let's take a look at some of these different types of touch-screen units
Capacitive technology uses one or more electric conductors along with an analog sensor to sense a touch. This system allows the user to interact with the unit without actually touching the screen itself. By applying pressure on the sensitive surface area, a signal is generated which is interpreted by the system. The most common application of this type of multi-touch unit is on a laptop. Because of its high level of accuracy, it is suitable for applications where the users will not be interacting directly with the unit. For example, it is commonly found in digital signage, industrial machinery, medical equipment, gaming systems, and the like.
One of the major drawbacks of capacitive multi-touch units is their slow response time, which makes it difficult to react to quick movements. In addition, because of the slow response time, there is often a delay between the actual touch on the screen and the sign appearing on the screen. As a result, users may have to wait for a long time before their desired information appears. The other common problem associated with this type of unit is that it can produce only a single image.
A resistive multi-touch screen uses one or more resistors along with an LED or magnet. Instead of an LED or magnet, the resistors are used to determine whether or not a particular touch has been detected. In many instances, the unit includes a graphic user interface, although it may also include a physical keypad as well. In addition, resistive units are typically designed for LCD displays.
An image-switching multi-touch unit switches between two images based on whether the cursor is currently located on the screen. For example, if the finger is currently located on the lower half of the touch screen, then the display will rotate around the lower half of the screen and display the lower image. In addition, the images can be switched based on whether the finger has actually touched the surface area or not. These types of multi-touch screens are extremely useful for providing a visual representation of the location of various items, such as pictures or computer forms.
Capacitive multi-touch screens use capacitance to detect the physical touch. Capacitance is measured in terms of capacitance multiplied by the conductivity of the device. Because a very low threshold level is required for the capacitance to be active, this type of multi-touch screen is suitable for use with a variety of devices that do not require high levels of resolution but instead only need to be sensitive to very small changes in physical surface areas. On the other hand, because the capacitance is generally very low, these units are also very expensive. Some manufacturers bundle additional technologies such as a resistive touch layer into their multi-touch screens to reduce the cost.
A resistive multi-touch screen is based on the same principles of capacitance and resistivity. Instead of requiring a very sensitive and exacting material, the resistive multi-touch screen uses a layer of resistors to determine the presence and absence of a finger on the surface. When a finger is detected, the screen is sensitive to the electrical signal. This technology is ideal for making mobile computing more convenient since it is convenient to use. It is also useful in tablet computers since the screen can be used as a stylus, which makes it easier to point and click.
In computer science, multi-touch is a computing technology which allows a flat surface to detect the presence of more than one-touch point on the surface at once. The first prototypes of such technology were developed at CERN, MIT, University of Toronto University of California, Carnegie Mellon University and Bell Labs located in the early 1970's.