![• Eric Johnson, of the Royal Radar Establishment, England, described his work on
capacitive touchscreens in 1965
• Frank Beck and Bent Stumpe, developed a transparent touchscreen in the early
1970s, based on Stumpe's work at a television factory in the early 1960s ; it was
put to use in 1973
The prototype[2]
x-y mutual capacitance touchscreen
(left) developed at CERN[3][4]
in 1977 by Bent Stumpe,
a Danish electronics engineer, for the control room
of CERN’s accelerator SPS (Super Proton Synchrotron).
This was a further development of the self-capacitance screen
(right), also developed by Stumpe at CERN[5]
in 1972.](https://image.slidesharecdn.com/touchsensor-181125080248/85/Touch-sensor-5-320.jpg)
Touch sensor
- 4. • a clear glass panel with a touch responsive surface • an electrical signal passes through their surface, by touching a point of the signals, the signal is changed and this change can be determined by the location of the touch.
- 5. • Eric Johnson, of the Royal Radar Establishment, England, described his work on capacitive touchscreens in 1965 • Frank Beck and Bent Stumpe, developed a transparent touchscreen in the early 1970s, based on Stumpe's work at a television factory in the early 1960s ; it was put to use in 1973 The prototype[2] x-y mutual capacitance touchscreen (left) developed at CERN[3][4] in 1977 by Bent Stumpe, a Danish electronics engineer, for the control room of CERN’s accelerator SPS (Super Proton Synchrotron). This was a further development of the self-capacitance screen (right), also developed by Stumpe at CERN[5] in 1972.
- 6. A basic Touchscreen has three main components: • A Touch sensor • A Controller • A Software driver.
- 7. 2. Controller • The controller is a small PC card that connects between the touch sensor and the PC. It takes information from the touch sensor and translates it into information that PC can understand. • The controller is usually installed inside the monitor for integrated monitors or it is housed in a plastic case for external touch add- ons/overlays. • The controller determines what type of interface/connection you will need on the PC. Specialized controllers are also available that work with DVD players and other devices.
- 8. 3. Software Driver • allows the touchscreen and computer to work together. It tells the computer's operating system how to interpret the touch event information that is sent from the controller. • Most touch screen drivers today are a mouse-emulation type driver. This makes touching the screen the same as clicking your mouse at the same location on the screen.
- 9. There are basically six types of touch screen technologies: •Resistive •Capacitive •Projected Capacitive (PCAP) •Infra Red •Optical •Surface Acoustic Wave (SAW)
- 10. Resistive Touchscreen Technology • is the most widely used touch technology today • consists of two thin flexible metallic layers with a gap in between • These two layers have an electric current running through them • When touched the top flexible layer touches the bottom one, interrupting the electrical current
- 11. • The device notices this and detects the point of contact by the change in electrical flow • responds to pressure and doesn't care what object applies the pressure • Swiping and multi touch do not work, because this technology only registers one touch point doesn't work on smartphones or tablets
- 12. Advantages •Use pretty much any object to touch - finger, stylus, pen, gloved hand, etc. •Solid feel •Lowest cost •Low power consumption •Resistant to surface contaminants and liquids - dust, oil, grease, water, etc. Disadvantages •Image clarity not as great as other technologies •Outer touch layer is vulnerable to damage - scratching, poking with sharp objects, etc.
- 13. Capacitive Touchscreen Technology • uses a transparent electrode layer is placed on top of a glass panel and covered by a protective layer • When a finger touches the touchscreen some of the electrical charge transfers from the screen to the user • Sensors in all four corners of the screen detect the decrease of electric current The controller then determines the touch point • can only be activated when touched by human skin or a stylus holding an electrical charge
- 14. Advantages •Great image clarity (better than resistive touch) •Durable screen •Excellent resistance to surface contaminants and liquids - dust, grease and water •High scratch resistance Disadvantages •Only works with bare finger or special capacitive stylus •Sensitive to EMI (Electromagnetic Interference) and RFI (Radio Frequency Interference)
- 15. Projected Capacitive (PCAP) • works very similar to regular capacitive touchscreens but They do offer two great advantages Next to a bare finger, they also work with surgical gloves or thin cotton gloves they make multi touch possible • Multi touch means when two fingers simultaneously activate the touchscreen
- 16. • consists of a sheet of glass with embedded transparent electrode films and an IC chip This creates a three dimensional electrostatic field • A change in the electrical currents is noticed when a finger touches the screen A touch point is then detected • They are generally chosen over regular capacitive touchscreens because of their durability
- 17. Advantages •Excellent image clarity •More resistant to scratching than capacitive touch •Resistant to surface contaminants and liquids •Multi touch possible Disadvantages •Sensitive to EMI (Electromagnetic Interference) and RFI (Radio Frequency Interference) •Only activates using an exposed finger, thin surgical gloves or cotton gloves
- 18. Infra Red touchscreen • Unlike other technologies, infra red touchscreens don't overlay the screen with an extra layer • based on light beam interruption technology • uses infra red emitters and receivers create an invisible grid of infra red light beams across the screen • No extra film or layer the best possible image quality and clarity. • A sensor detects the touch when an object interrupts the light beams
- 19. Advantages •Best image quality of all touch technologies •Unlimited 'touch life‘ •Unaffected to surface scratches Disadvantages •Accidental touches may occur when the light beams are accidentally above the glass surface. •Grease, dust or other contaminants could block light beam •Sensitive to water, snow and rain •May be sensitive to ambient light •More expensive
- 20. Optical touchscreen • use multiple optical sensors to detect the touch • The sensors actually detect the touch just before the user makes physical contact with the screen you don't evenhave to completely touch the screen • or can touch it very lightly. • don't use electrical currents they can be activated using any object
- 21. Advantages •Enables multi touch •No pressure needed to register a touch •100% light transmission •Scratches do not affect the touchscreen •Use any object to touch Disadvantages •Direct sunlight can affect the touchscreen •Depth of monitor increases by frame
- 22. Surface Acoustic Wave Touchscreen • works a little different than resistive and capacitive touchscreens • use transducers mounted to the edge of a glass panel create an invisible grid of ultrasonic waves on the surface which are received by sensors • can be activated using a finger, gloved hand or stylus
- 23. Advantages •Good optical clarity •Even better scratch resistance than capacitive touch •High 'touch life' • Disadvantages • Cannot be activated with hard objects - pens, credit cards or fingernails • False touches are an option - like by water droplets • Solid contaminants on the screen can create non- touch areas until removal
- 24. • Resistive: at the ATM, supermarket check outs or kiosks • Capacitive: Navigation devices, car monitors, mobile phones, lanyards and pcs, smartwatches, cameras, etc. • Infra Red ATM, medical devices, carrier tracking systems