Specifications

50
an arrangement of various other symbols to the target audience. The clarity of
these characters is a function of the dot-density of the individual display, which
means the more columns and rows on the display, the more resolution each
potential character can have. However, due to the size limitations of the design, it
would be necessary to have a dot-matrix display with a very small pitch size.
Because of the nature of a dot-matrix display, it is necessary to have separate
drivers for both the rows and the columns, so that individual dots within a
particular row-column pair can be driven when necessary, adding to the
complexity of the design necessary for its use. Because of the ability to
individually define the resolution of each character, a dot-matrix display would
offer a greater level of clarity than a seven-segment display, while consuming
nearly the same level of current, and requiring a minimal amount of additional
hardware to support.
2.9.3 Liquid Crystal Display
LCDs are the most complex display being evaluated for use in this design. They
are constructed using thin, flat panels. The panels consist of layers of light
filtering film, liquid crystal, glass panels with electrode film to display shapes, and
either a reflective surface or backlight for making the images viewable to the
audience. These types of displays are extremely lightweight and can be
produced at a very small scale, as seen in Figure 2.9.3-1, making them ideal for
portable electronics devices.
Figure 2.9.3-1 Matrix Orbital LCD0821 Display Module w/ approximate size reference,
reprinted with permission granted by Matrix Orbital, Inc.
LCDs allow for the greatest possible range of image and character resolution,
and even allow the developer to design their own custom characters and images,
based on the display resolution of the device. Because of the complexity of the
display driving, as well as the resolution of the displays themselves, modules that