The capacitive touch screens: complete record of writing (operation, applications, advantages, disadvantages, quality).
The touch screen technology has been deployed widely to the public in recent years. If at first glance some may consider the tactile interfaces like science-fiction dreamers computer savvy, it is clear that they are truly part of our daily lives.
A touch interface is nothing magic behind every interactive device hidden advanced techniques. One of the most common technology is based on the model of capacitive touch screen.
Operation of the capacitive
The first question one can ask is how a capacitive screen?
The capacitive touch screen technology is based on a solid surface like glass, which is traversed by an electrically charged grid and almost invisible to the naked eye. The accumulation of electrical charges on the glass plate upon contact of the fingers of the user transfers a portion of these charges in the fingers, causing a deficit that can then locate to process information.
The information processing is done using a calculation algorithm integrated directly into the device. It determines the point or points of impact (in the case of multi touch), the direction of movement, sometimes the pressure, and acts accordingly.
diagram of capacitive touch screen
In slightly less technical terms, or the fingers on a screen creates an electrical disturbance, the grid under glass localizes to identify actions and movements. She then related what is displayed on the screen at that time, to reflect the effects of the user and act just as does a mouse on a screen "normal."
Technology applications for capacitive screens
What are the capacitive screens and what applications are used?
The first prototypes of touchscreens have emerged in the 1970s, since they are discreetly integrated into our habits.
There are over 10 years of aircraft using the general-capacitive screens: ATMs, kiosks and book train tickets are some familiar examples.
The computer is also using these technologies, we think including graphic tablets and touchpads unavoidable (touchpad) that replace the traditional mouse on some laptops.
In recent years, it is undoubtedly the appearance and development of solid smartphones that have mediated capacitive screens.
It is clear that the Apple iPhone has played a key role at this level since 2007 thanks to ease of use for both new and instinctive, attractive design and marketing titanic work, Apple has managed to democratize use of capacitive touch screens on mobile phones. the vast majority of current touch phones now use capacitive screen technology.
For more information: applications for touch screens .
Advantages and disadvantages of capacitive
Capacitive technology offers a range of benefits which are often the top compared to other techniques to implement a touch screen.
First, the interface of a device with a capacitive screen is much more robust due to its support: the glass is a hard surface which fears that shocks less flexible coating (used for resistive screens )
On the other hand, treatment of the material are possible for a scratch-pad effectively.
Another significant point: the capacitive touch screens are brighter and guarantee transparency very interesting (more than 90% against 75% for resistive screens), a benefit resulting from the thinness of the glass support. The sensitivity of the screen is more interesting, simply touch the touch screen to get an immediate response.
The technology of multi touch (recognition of multiple contact points and simultaneous) seems logically more appropriate for the resistive capacitive screens. Indeed, it is simpler to use his 10 fingers simultaneously, rather than requiring several pens each with several fingers for a good grip ...
The capacitive however suffers from a number of constraints.
In comparison, there is a higher rate for capacitive screens which are not accessible to all budgets. There is also a high sensitivity of the screen to the presence of water and moisture. It is important to take great care: avoid the rain and cleaning with wet sponge!
The principle of capacitive technology makes it difficult to use these screens other than bare hands, a conductive body is capital to the reactivity of the slab. Have you ever tried to fly an iPhone with a surface other than your finger?
Gloves and stilettos are not permitted, although over the years there has been an increase in their consideration.
Determine the quality of a capacitive touch screen
This video compares the quality of the capacitive touch screen of three mobile phones using a simple test: the faithful reproduction of a line on the finger. Two scenarios were considered: a light support on the screen, with the edge of the finger and support more pronounced with the finger. The first case evaluates the path with a weak signal and can lead to a more hazardous route.
We note that the implementation of a capacitive screen (choice of components, display controller, etc.). Is not sufficient to provide a high quality user experience, the algorithm signal processing plays a predominant role .
This is what we can say at this time of writing this file, the technology of capacitive screens. Innovation helps, manufacturers of capacitive screens are changing their techniques, and find solutions to improve some weak points.
Sources pictures: Etronics, Digitalworld, Wikipedia.
