Specifications

37
Alignment - The process of setting the spatial
relationship of the display’s coordinate
system to the touch coordinate system.
This facilitates the translation of touch
coordinates into display video
coordinates.
Calibration - The relationship between the
coordinate systems of the touch screen
and the video screen. The touch system
coordinate system is fixed, but the
position of the video image varies from
monitor to monitor and the two systems
must be synchronized with one another
before touches will be interpreted
properly.
Controller - The interface between the touch
system and the computer.
Drift - The gradual movement of the touch
active zones away from the graphic
targets representing them. Touch
technologies that are subject to drift
require periodic calibration to restore
the touch active zones to the correct
coordinates.
GUI - Graphical User Interface. Operating
systems, such as Windows
®
and
Macintosh
®
, that provide an intuitively
simple interface, such as icons and pull-
down menus, as opposed to an operating
system that is accessed via a command
line interface.
Invasive integration - A type of permanent
installation of the touch system to the
display that requires actual disassembly
of the display.
MTBF - Mean Time Between Failures. A
statistical estimate of how long a
component or a system is expected to
perform before a failure occurs.
NEMA 4/12 compliance - National Equipment
Manufacturers Association. NEMA 4
compliance indicates that a device can
withstand hose-directed water and still
operate. NEMA 12 compliance
indicates that a device is for industrial
use.
Optical bonding - Permanent attachment of the
touch sensor to the display with a silicon
laminate. Used in invasive integrations.
Parallax - An optical phenomena in which a
touch zone registers slightly off of the
graphical target. Parallax is caused by
space between the display surface and
the plane of the touch sensor, and varies
according to the type and architecture of
the touch technology. Parallax tends to
be unnoticeable on flat displays and
increases relative to the curvature of the
display.
Resolution - The physical spacing between the
adjacent touch coordinates.
Response time - The time required by the touch
system to locate the touch and transmit
the coordinates to the host system.
Sealability - The ability of a touch system to be
sealed for use in surgical,
pharmaceutical, and other sterile and
clean-room applications.
Static Graphic - Hard-copy photograph(s) or
illustration(s), mounted behind a touch
frame. Touch coordinates correspond to
the graphic instead of targets on a CRT
or other digital display. Touching the
graphic activates a touch event.
Section 8. Glossary