PRLog - Nov. 29, 2012 - Dispersive Signal Technology, specifically developed for interactive digital signage
NEC LED X401S
applications, sets new large-format touch standards for fast, accurate repeatable touch
response. In addition, Dispersive Signal Technology’s operation is unaffected by contaminants, static objects or other touches on the touch screen. Other key characteristics of this patented technology are exceptional optics, ease of integration, and input flexibility.
Key Technology Characteristics
• Fast, accurate and repeatable touch response
• Operation unaffected by surface damage,
• Input flexibility, accepting touch from finger, pencil,
credit card, fingernail, or almost any type of stylus
• Operates with static objects or other
touches on the screen
• Exceptional optical characteristics
• Scalable for sizes above 32” diameter
How it works Video: http://youtu.be/
How Dispersive Signal Technology Works
Dispersive Signal Technology determines a “touch point” by measuring the mechanical
energy (bending waves) within a substrate created by a finger or stylus touching the
surface of the glass. Bending waves differ from surface waves in that they traverse
through the thickness of the panel rather than the surface of the material, which provides
several important advantages including enhanced palm rejection and superior scratch
resistance. When the touch implement impacts the screen, bending waves are induced
that radiate away from the touch location. As the wave travels outwards, the signal
spreads out over time due to the phenomena of dispersion (explained below).
Piezoelectric sensors positioned in the corners on the backside of the glass convert this
smeared mechanical impulse into an electrical signal. The distance from each sensor
determines the extent to which the signal is dispersed. Namely, the further away the
“touch point” is from the sensor, the more the signal is smeared.
The Difference is “Through” the Substrate
Where other large-format touch technologies distribute an optical field, infrared beams,
or acoustic waves across the front surface of the touch screen and rely on a touch to
interrupt the field, Dispersive Signal Technology waits passively for a signal created by
a touch contact. This fundamentally different approach means that contaminants, such as
dirt, grease, and solids, can accumulate on the surface and around the edge of the screen
without a significant effect on the performance of the DST touch screen. Furthermore,
surface damage such as scratches or a gouge in the touch screen, will generally not affect touch performance.
Operates with Static Objects
Dispersive Signal Technology (DST) operates with static objects on the glass surface.
So, even when the user rests their other hand on the touch screen, or other users are
touching the screen, or when inanimate objects such as cups, cans or keys are left on the
touch screen, DST continues to respond to the user’s intended touch and ignores the
presence of these other objects. This unique touch capability helps avoid inadvertent
touches and overcome permanent surface damage.