Specifications

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One such display under consideration, the Lumex LDD-A5004RI is commonly
used in portable electronic devices, including personal breathalyzer units
developed by competing companies in the breath-alcohol measurement industry.
Figure 2.9.1-1 shows a mechanical drawing of these displays, demonstrating
how they can be manufactured into extremely small packages, as small as 20mm
wide for a two character display, including decimal point lights for potentially
representing greater numerical accuracy if necessary. Being such a mature,
mass produced technology, these displays are on the extreme end of the supply-
demand curve, and as such are incredibly inexpensive. Due to their limited
functionality, these display types are ineffective at communicating anything more
than timing or statistical information to the user, which in the case of the hand
held breathalyzer, would be sufficient for the very basic level of human
interaction needed.
Figure 2.9.1-1 Lumex LDD-A5004RI Seven-Segment Display Mechanical
Characteristics, reprinted with permission granted by Lumex Inc.
2.9.2 Dot-Matrix Display
More complex in design than the previously evaluated seven-segment style
display, dot-matrix displays use a series of row-aligned and column-aligned light
emitting dots, spaced at a constant pitch, to display letters, numbers, and even