Touch Screen Technology – Definition, Working, Types & Applications..

Touch screen technology is the direct manipulation type gesture based technology. Direct manipulation is the ability to manipulate digital world inside a screen. A Touch screen is an electronic visual display capable of detecting and locating a touch over its display area. This is generally refers to touching the display of the device with a finger or hand. This technology most widely used in computers, user interactive machines, smart phones, tablets etc to replace most functions of the mouse and keyboard.

Touch screen technology has been around for a number of years but advanced touch screen technology has come on in leaps and bounds recently. Companies are including this technology into more of their products. The three most common touch screen technologies include resistive, capacitive and SAW (surface acoustic wave). Most of low end touch screen devices contain on a standard printed circuit plug-in board and are used on SPI protocol. The system has two parts, namely; hardware and software. The hardware architecture consists of a stand-alone embedded system using an  8-bit microcontroller,  several type of interface and driver circuits. The system software driver is developed using an interactive C programming language.

Types of Touch Screen Technology:

The Touch screen is a 2-dimensional sensing device made of 2 sheets of material separated by spacers. There are four main touch screen technologies: Resistive, Capacitive, Surface Acoustical wave (SAW) and infrared (IR).

Resistive:

Resistive touch screen is composed of a flexible top layer made of polythene and a rigid bottom layer made of glass separated by insulating dots, attached to a touch screen controller. Resistive touch screen panels are more affordable but offering only 75% of light monitor and the layer can be damaged by sharp objects. Resistive touch screen is further divided into 4-, 5-, 6-, 7-, 8- wired resistive touch screen. The construction design of all these modules is similar but there is a major distinction in each of its method to determine the coordinates of touch.

Capacitive:

A capacitive touch screen panel is coated with a material that stores electrical charges. The capacitive systems can transmit up to 90% of light from the monitor. It is divided into two categories. In Surface-capacitive technology only one side of the insulator is coated with a conducting layer.

Whenever a human finger touches the screen, conduction of electric charges occurs over the uncoated layer which results in the formation of dynamic capacitor. The controller then detects the position of touch by measuring the change in capacitance at the four corners of the screen.

In projected capacitive technology, the conductive layer (Indium Tin Oxide) is etched to form a grid of multiple horizontal and vertical electrodes. It involves sensing along both the X and Y axis using clearly etched ITO pattern. For increasing the accuracy of the system, the projective screen contains a sensor at every interaction of the row and column.

Infrared:

In infrared touch screen technology, an array of X and Y axis is fitted with pairs of IR Leds and photo detectors. Photo detectors will detect any image in the pattern of light emitted by the Leds whenever the user touches the screen.

Surface Acoustic wave:

The surface acoustic wave technology contains two transducers placed along X-axis and Y-axis of the monitor’s glass plate along with some reflectors. When the screen is touched, the waves are absorbed and a touch is detected at that point. These reflectors reflect all electrical signals sent from one transducer to another. This technology provides excellent through put and quality.

Components and working of touch screen:

operation when using the touch screen panel

A basic touch screen is having a touch sensor, a controller, and a software driver as three main components. The touch screen is needed to be combined with a display and a PC to make a touch screen system.

Touch sensor:

The sensor generally has an electrical current or signal going through it and touching the screen causes a change in the signal. This change is used to determine the location of the touch of the screen.

Controller:

A controller will be connected between touch sensor and PC. It takes information from sensor and translates it for understanding of PC. The controller determines what type of connection is needed.

Software driver:

It allows computer and touch screen to work together. It tells OS how to interact the touch event information that is sent from the controller.

Application – Remote control using Touch screen technology:

Controlling of vehicles and robots using touch screen based remote

The touch screen is one of the simplest PC interfaces to use, for larger number of applications. A touch screen is useful for easily accessing the information by simply touching the display screen. The touch screen device system is useful in ranging from industrial process control to home automation.

Image Source – Edgefx Kits

In real time by simply touching the touch screen and with a graphical interface, everyone can monitor and control complex operations.

Image Source – Edgefx Kits

At the transmission end using a touch screen control unit, some directions will send to the robot for movinginto a specific direction like forward, backward, rotating left and rotating right. At the receiving end four motors are interfaced with the microcontroller. Two of them will be used for Arm and grip movement of the robot and other two are used for body movement.

Some remote operations can be done with touch screen technology using wireless communication for answering calls, locating and communicating with staff, and operating vehicles and robots. For this purpose RF communication or infrared communication may be used.

A real time Application: Controlling home appliances using Touch Screen Technology

It is possible to control the electrical appliances at home using touch screen technology. The whole system works by sending input commands from the touch screen panel through the RF communication which are received at the receiver end and control the switching of loads.

At the transmitter end, a touch screen panel is interfaced to the Microcontroller through a touch screen connector. When an area on the panel is touched, the x and y coordinates of that area are sent to the Microcontroller which generates a binary code from the input.

This 4 bit binary data is given to the data pins of the H12E encoder which develops a serial output. This serial output is now sent using a RF module and an antenna.

At the receiver end, the RF module receives the coded serial data, demodulates it and this serial data is given to the H12D decoder. This decoder converts this serial data into the parallel data which pertains to the original data sent by the microcontroller at transmission end. The microcontroller at the receiver end receiver end, receives this data and accordingly sends a low logic signal to the corresponding optoisolator which in turn switches on the respective TRIAC to allow AC current to the load and the respective load is switched on.

20 facts about technology that might surprise you !

The 4G Radiation Dangers!?30 Minutes of Exposure Affects Brain Activity..

The peer-reviewed journal Clinical Neurophysiology has just published research showing that 30 minutes of exposure to LTE cellphone radiation affects brain activity on both sides of the brain.

Researchers exposed the right ear of 18 participants to LTE radio frequency radiation for 30 minutes. The absorbed amount of radiation in the brain was well within international (ICNIRP) cell phone legal limits and the source of the radiation was kept 1 cm from the ear. 

To eliminate study biases the researchers employed a double blind, crossover, randomized design, exposing participants to real and sham exposures. 

The resting state brain activity of each participant was measured by magnetic resonance imaging (fMRI) twice, once after exposure to LTE radio frequency radiation, and then again after a sham exposure. 

The results demonstrate that radio frequency radiation from LTE 4G technology affects brain neural activity in both the closer brain region and in the remote region, including the left hemisphere of the brain. 

LTE Fastest Developing Mobile System Technology Ever

This study is important for two reasons. Firstly because it is the first one to be carried out on the short-term effects of Long Term Evolution (LTE), fourth generation (4G) cell phone technology. Secondly, because of the rapid rate of adoption of this technology. 

According to the Global mobile Suppliers Association “LTE is the fastest developing mobile system technology ever”. The United States is the largest LTE market in the world. By March 2013 the global total of LTE subscriptions was already 91 million subscribers. Over half of these, 47 million, were American 4G subscribers. 

Cell Phone Exposures and Disease 

This study establishes that short-term exposure to LTE radio frequency radiation affects brain activity. The long-term effects of these exposures have yet to be studied but there is already considerable evidence linking these exposures to a myriad of adverse biological effects including: 

• Sperm damage
• DNA breaks
• Increased glucose in the brain
• Weakened bones
• Genetic stress
• Immune system dysfunction
• Effects on unborn children

More worrying is the link between these exposures and a long list of diseases such as: 

• Alzheimer’s disease
• Autism
• Brain Tumors
• Breast cancer
• Brain cancer

More research is needed on the effects of LTE and other forms of cell phone radiation but the evidence is already compelling. Many scientific and medical experts are sounding the alarm. 

History Of Internet..!

Credit for the initial concept that developed into the World Wide Web is typically given to Leonard Kleinrock. In 1961, he wrote about ARPANET, the predecessor of theInternet, in a paper entitled “Information Flow in Large Communication Nets.” Kleinrock, along with other innnovators such as J.C.R. Licklider, the first director of the Information Processing Technology Office (IPTO), provided the backbone for the ubiquitous stream of emails, media, Facebook postings and tweets that are now shared online every day. Here, then, is a brief history of the Internet:

Partial map of the Internet based on the Jan. 15, 2005, data found on opte.org. Each line is drawn between two nodes, representing two IP addresses. The length of the lines are indicative of the delay between those two nodes.

Credit: Creative Commons The Opte Project

The precursor to the Internet was jumpstarted in the early days ofcomputing history, in 1969 with the U.S. Defense Department's Advanced Research Projects Agency Network (ARPANET). ARPA-funded researchers developed many of the protocols used for Internet communication today. This timeline offers a brief history of the Internet’s evolution:

1934: Belgian information expert named Paul Otlet imagined a “Radiated Library” that would use technology of the day — the telephone and radio — to create something very much like the Internet.

1965: Two computers at MIT Lincoln Lab communicate with one another using packet-switching technology.

1968: Beranek and Newman, Inc. (BBN) unveils the final version of the Interface Message Processor (IMP) specifications. BBN wins ARPANET contract.

A visualization of Internet connections in the United States. The lines represent connections between routers in major urban areas throughout the country.

Credit: NSF

1969: On Oct. 29, UCLA’s Network Measurement Center, Stanford Research Institute (SRI), University of California-Santa Barbara and University of Utah install nodes. The first message is “LO,” which was an attempt by student Charles Kline to “LOGIN” to the SRI computer from the university. However, the message was unable to be completed because the SRI system crashed.

1972: BBN’s Ray Tomlinson introduces network email. The Internetworking Working Group (INWG) forms to address need for establishing standard protocols.

1973: Global networking becomes a reality as the University College of London (England) and Royal Radar Establishment (Norway) connect to ARPANET. The term Internet is born.

1974: The first Internet Service Provider (ISP) is born with the introduction of a commercial version of ARPANET, known as Telenet.

1974: Vinton Cerf and Bob Kahn (the duo said by many to be the Fathers of the Internet) publish "A Protocol for Packet Network Interconnection," which details the design of TCP.

1976: Queen Elizabeth II hits the “send button” on her first email.

1979: USENET forms to host news and discussion groups.

1981: The National Science Foundation (NSF) provided a grant to establish the Computer Science Network (CSNET) to provide networking services to university computer scientists.

1982: Transmission Control Protocol (TCP) and Internet Protocol (IP), as the protocol suite, commonly known as TCP/IP, emerge as the protocol for ARPANET. This results in the fledgling definition of the Internet as connected TCP/IP internets. TCP/IP remains the standard protocol for the Internet.

1983: The Domain Name System(DNS) establishes the familiar .edu, .gov, .com, .mil, .org, .net, and .int system for naming websites. This is easier to remember than the previous designation for websites, such as 123.456.789.10.

1984: William Gibson, author of "Neuromancer," is the first to use the term "cyberspace."

1985: Symbolics.com, the website for Symbolics Computer Corp. in Massachusetts, becomes the first registered domain.

1986: The National Science Foundation’s NSFNET goes online to connected supercomputer centers at 56,000 bits per second — the speed of a typical dial-up computer modem. Over time the network speeds up and regional research and education networks, supported in part by NSF, are connected to the NSFNET backbone — effectively expanding the Internet throughout the United States. The NSFNET was essentially a network of networks that connected academic users along with the ARPANET.

1987: The number of hosts on the Internet exceeds 20,000. Cisco ships its first router.

1989: World.std.com becomes the first commercial provider of dial-up access to the Internet.

1990: Tim Berners-Lee, a scientist at CERN, the European Organization for Nuclear Research, develops HyperText Markup Language (HTML). This technology continues to have a large impact on how we navigate and view the Internet today.

1991: CERN introduces the World Wide Web to the public.

1992: The first audio and video are distributed over the Internet. The phrase “surfing the Internet” is popularized.

1993: The number of websites reaches 600 and the White House and United Nations go online. Marc Andreesen develops the Mosaic Web browser at the University of Illinois, Champaign-Urbana. The number of computers connected to NSFNET grows from 2,000 in 1985 to more than 2 million in 1993. The National Science Foundation leads an effort to outline a new Internet architecture that would support the burgeoning commercial use of the network.

1994: Netscape Communications is born. Microsoft creates a Web browser for Windows 95.

1995: Compuserve, America Online and Prodigy begin to provide Internet access. Amazon.com, Craigslist and eBay go live. The original NSFNET backbone is decommissioned as the Internet’s transformation to a commercial enterprise is largely completed.

1996: The browser war, primarily between the two major players Microsoft and Netscape, heats up. CNET buys tv.com for $15,000.

1997: PC makers can remove or hide Microsoft’s Internet software on new versions of Windows 95, thanks to a settlement with the Justice Department. Netscape announces that its browser will be free.

1998: The Google search engine is born, changing the way users engage with the Internet.

1999: AOL buys Netscape. Peer-to-peer file sharing becomes a reality as Napster arrives on the Internet, much to the displeasure of the music industry.

2000: The dot-com bubble bursts. Web sites such as Yahoo! and eBay are hit by a large-scale denial of service attack, highlighting the vulnerability of the Internet. AOL merges with Time Warner.

A newly expanded global Internet, to focus solely on science and education, now includes half of the world's countries. The high-speed fiber-optic network connects users at speeds of 10 Gbps.

Credit: GLORIAD.

2001: A federal judge shuts down Napster, ruling that it must find a way to stop users from sharing copyrighted material before it can go back online.

2003. The SQL Slammer worm spread worldwide in just 10 minutes. Myspace, Skype and the Safari Web browser debut.

2004: Facebook goes online and the era of social networking begins. Mozilla unveils the Mozilla Firefox browser.

2005: YouTube.com launches.

2006: AOL changes its business model, offering most services for free and relying on advertising to generate revenue. The Internet Governance Forum meets for the first time.

2009: The Internet marks its 40th anniversary.

2010: Facebook reaches 400 million active users.

2011: Twitter and Facebook play a large role in the Middle East revolts.