Archive for April, 2010
Touch screen LCD monitor – how does it work?
Touch screen monitors are a device by which we give inputs and take outputs as information without using any other external device. Instead of using a keyboard or mouse.
A touch screen is a display which can detect the presence and location of a touch within the display area. The term generally refers to touch or contact to the display of the device by a finger or hand. Touch screens can also sense other passive objects, such as a stylus.
The touch screen has two main qualities. First, it allows you to interact with what is displayed directly on the screen, where it is displayed, rather than indirectly with a mouse (computing) or touchpad. Secondly, it lets one do so without requiring any intermediate device, again, such as a stylus that needs to be held in the hand.
Touch screen monitors are used in a variety of different applications including POS (point of sale) cash registers, PDA’s (personal digital assistants), ATM’s, car navigation screens, cell phones, gaming consoles and any other type of appliance that requires you to input and receive information.
Types of technology available in Touch Screen. The commonly used are underneath:
- Resistive Touch monitors
A resistive touch screen monitor usually has a coat of very thin electrically conductive and resistive layer of metal. When pressed, the change in electrical current can be measured and the input processed by a computer. While very affordable they only offer about 75% clarity, they can also be easily damaged by objects that are sharp. Resistive touch screen monitors are the most popular types of touch screen monitors used today. They are usually not effected by dust or liquids which make them very reliable.
- Surface Wave Touch Screen Monitors
Surface wave touch screen monitors use ultrasonic waves to process inputs from the screen. Ultrasonic waves flow over the touch screen, when a person touches the pad at a specific location, the wave is absorbed and immediately processed by the computer. While not as common as resistive touch panels, they are used in certain applications. Dust and water can contaminate a surface wave touch screen so it is important to keep the screens properly maintained.
- Capacitive Touch Screen Monitors
Capacitive touch screens are coated with indium tin oxide. This material provides a continuous current across the screen. The current is precisely controlled throughout the touch pad and can be measured by the computer processor, when touched; the screen is able to send the processor specific coordinates to input information correctly. It is important to note that specific objects can only be used on capacitive touch screens. You can not use a stylus or a pencil for instance; usually you will need a bare finger. Capacitive touch screens have high clarity and are not affected by dust or liquids.
- Infrared Touch Screen Monitors
There are two types of Infrared touch screen monitor screens, the first reacts to infrared or thermal waves (heat), unfortunately this technology is slow and does not work well with cold hands or objects. The second type of Infrared touch screen monitors use vertical and horizontal infrared sensors around the perimeter of the touch screen. Creating a grid, the touch screen is able to pinpoint the exact location of where the screen has been touched and send that information to the computer for processing. Infrared touch screen monitors are very durable and are used for industrial and military applications.
How to Build Your Own Touch Screen Software
If you want to learn how to develop your very own touch screen applications, either for the iPhone or for the PC, the following quick guide should send you in the right direction.
1. Developing touch screen software for the iPhone
Beginning iPhone 3 Development: Exploring the iPhone SDK is the best book for anyone who wants to start developing for iPhone and iPod touch.
It delivers a clear picture of the entire development process from registering as an iPhone developer through creation of complete applications.
It is written in a fun and easy-to-follow style and you only need a minimal knowledge of Objective-C.
Best practice coding methodology is used throughout the book and there is a huge amount of code samples illustrating each feature of the iPhone.
Beginning iPhone Development is the definitive guide for iPhone development, and anyone aspiring to develop for the iPhone should get this invaluable reference.
2. Developing multi touch screen software for Windows 7 using Visual Studio and C++.
If want to use iPhone like events (pinch, flip, zoom) on Windows, the best place to start is this Windows 7 online training course.
This unit explains the basics of Windows 7 touch screen software and its APIs: Exercise 1: Build a Multitouch Application. A basic knowledge of C++ is required.
Prerequisites (click on the links to download directly from microsoft):
Touch-based interfaces are no longer just a matter of using larger buttons. Since Jeff Han’s demo at the 2006 TED conference and introduction of iPhone, gestural multi-touch software, has spread both on hand-held devices as well as net-books and desktop PC. It’s time for developers to start preparing for the touch screen era.
A fascinating UI experiment for iPad’s touch screen software.
This little girl likes playing with an iPhone, but this was her very first encounter with an iPad. Kids these days don’t know how good they have it.
A great demonstration of the play power of the iPad. And of the power of play.
She displays a very short attention span… I wonder, if this represents a problem with people in general or due to the fact that she’s a kid?
She can almost instinctively operate the thing without even really having to think about it much.
And what an amazing little speller she is!
The spelling apps she uses in the video are FirstWords Animals and FirstWords Vehicles (great games, IF you can figure out how to start them 😉 ).
On the downside, she had the same frustration as many adults, where touching the screen-edge with your thumb while holding the iPad blocks input to all home screen icons.
And she too wonders why it doesn’t have a camera…
Touch screen software was initially used in kiosk systems, POS terminals, ATM’s and on PDA’s.
With raising popularity of smart phones, modern PDA’s, GPS’s and portable game consoles (most notably Nintendo’s DS), the demand for touch screen technologies slowly increased.
Early touch screen displays could only sense a single point of input at a time and only a few of them were capable of detecting the strength of the pressure.
This was changed with Apples ongoing commercialization of the multi-touch technology with iPhone and iPod touch.
Multi-touch allows the user to interact with the screen with fingers, instead of a stylus. The movement of fingers creates gestures, which are then sent to the touch screen software.
Popularity of iPhone, has brought touch screen technology to many smart phones and hand-held devices.
Many companies have upgraded their products, either by adding a multi/touch support to the track-pad or by making their Tablet PC’s interact-able without the stylus.
Some companies specialize in production of large wall-mounted or table surfaces.
Most notable are Microsoft’s Surface and Perceptive Pixel’s Multi-Touch Collaboration Wall.
Both wall mounted and table mounted displays have had a few ergonomic problems.
“Gorilla arm” was a side effect, that destroyed wall mounted touch-screen as a mainstream.
Developers of touch screen systems, failed to notice, that humans are not built to hold their arms high for a long period of time, making small and precise motions at the same time.
Table mounted displays do not share this problem, however, users can develop neck pain after using it for a period of time and their view is obstructed by their arms.
Many modern operating systems include touch screen software, supporting multi-touch as well:
- Windows 7, Vista and XP Tablet PC Edition,
- Google’s Android,
- Palm’s webOS and Xandros
Windows 7 touch screen features:
With a combination of Windows 7 and a touch screen lcd monitor or laptop, you can just shuffle your files and folders, browse the web or flick trough your album, just with your fingers.
Limited one-finger touch screen capability has been available before, but Windows 7 is the first to deliver multi-touch. You can zoom in by placing your fingers on the screen and spread them apart. You can right “click” the file, by placing ane finger on the screen and tapping the screen with the other. Start menu and the taskbar now have bigger, finger-friendly icons.
All the programs included with windows are also touch ready. You can even finger paint in paint, with no additional touch screen software.
Many companies produce specialized touch screen software, either for specific devices or for general computers.
You can expect, from any decent touch screen software, to support multi-touch and gestures. However even more intuitive approaches are being invented all the time. BumpTop desktop, for example, a desktop replacement for Windows and Mac, goes beyond standard gestures such as pan and zoom.
A recent survey performed by Canalys (26. January 2010) shows, there is a significant rise in demand for touch screens computers, for both, users of laptops as well as home desktops.
New hand-held devices are being created all the time and new technologies are emerging.
Touch screen technology has had it’s share of troubles, but it is here to stay.
Blogroll – Cool Sites
- Touch Screen Applications from Corel on
- How to Build Your Own Touch Screen Software on
- How to Build Your Own Touch Screen Software on