Infrared (IR) Touch Panels
Infrared touch screen monitors do not overlay the display with an additional screen or screen sandwich.
Instead, infrared monitors use IR emitters and receivers to create an invisible grid of light beams across the
screen. This ensures the best possible image quality. When an object interrupts the invisible infrared light
beam, the sensors are able to locate the touch point.
Advantages:
• Highest image clarity and light transmission of all touch technologies
• Unlimited “touch-life”
• Impervious to surface scratches
Disadvantages:
• Accidental activation may occur because the infrared beams are actually above the glass surface
• Dust, oil, or grease buildup on screen or frame could impede light beam causing malfunction
• Sensitive to water, snow, rain
• May be sensitive to ambient light interference
• Higher cost
SAW Touch Panels
Advantages:
• Excellent image clarity
• Even better scratch resistance than capacitive
• High “touch-life”
Disadvantages:
• Will not activate with hard items (pen, credit card, or fingernail)
• Water droplets may cause false-triggering
• Solid contaminants on the screen can create non-touch areas until they are removed
Projected Capacitive Touch Panels
Projected Capacitive similar to Surface Capacitive, but it offers two primary advantages: in addition to a bare finger, it can also be activated with surgical gloves or thin cotton gloves; and it enables multi-touch activation (simultaneous input from two fingers). A projected capacitive is composed of a sheet of glass with embedded transparent electrode films and an IC chip, which creates a three dimensional electrostatic field. When a finger comes into contact with the screen, the ratios of the electrical currents change and the computer is able to detect the touch points.Advantages:
• Excellent image clarity
• More resistant to scratching than Surface Capacitive
• Resistant to surface contaminants and liquids (dust, oil, grease, moisture)
• Multi-touch (two-touch)
Disadvantages:
• Sensitive to EMI/RFI
• Must be activated via exposed finger, or thin surgical or cotton gloves
Surface Capacitive Touch Panels
Surface Capacitive are the second most popular type of touch screens on the market. In a surface capacitive touch screen monitor, a transparent electrode layer is placed on top of a glass panel, and covered by a protective cover. When an exposed finger touches the monitor screen, it reacts to the static electrical capacity of the human body; some of the electrical charge transfers from the screen to the user. This decrease in capacitance is detected by sensors located at the four corners of the screen, allowing the controller to determine the touch point. Capacitive touch screens can only be activated by the touch of human skin or a stylus holding an electrical charge.
Advantages:
• Better image clarity than Resistive Touch
• Durable screen
• Excellent resistance to surface contaminants and liquids (dust, oil, grease, water droplets)
• High scratch resistance
Disadvantages:
• Requires bare finger or capacitive stylus for activation
• Sensitivity to EMI/RFI
Resistive Film Touch Panels
Advantages:
• Can be activated with virtually any object (finger, stylus, gloved hand, pen, etc.)
• Has tactile feel
• Lowest cost touch technology
• Low power consumption
• Resistant to surface contaminants and liquids (dust, oil, grease, moisture)
Disadvantages:
• Lower image clarity compared to other touch technologies
• Outer polyester film is vulnerable to damage from scratching, poking and sharp objects
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