HDSP-2301 HP [Agilent(Hewlett-Packard)], HDSP-2301 Datasheet - Page 44

• Manufacturer Part Number: HDSP-2301
• Description: Four Character 5.0 mm (0.20 inch) 5 x 7 Alphanumeric Displays
• Manufacturer: HP [Agilent(Hewlett-Packard)]

Figure 32. Contrast Enhancement Filters
www.semiconductor.agilent.com
Data subject to change.
Copyright © 1999 Agilent Technologies, Inc.
5953-7787 (11/99)
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Contrast Enhancement
Another important consideration
for optimum display appearance
and readability is the contrast be-
tween the display “ON” elements
and the background. High con-
trast can be achieved by placing a
filter over the display. The filter, if
properly chosen, will transmit the
luminance of the light emitting
elements while attenuating the
luminance of the background.
Filter choice is dependent upon
the LED display package, ambient
lighting conditions and the de-
sired front panel appearance. For
alphanumeric displays in indoor
lighting ambients a plastic or glass
wavelength filter can be used. In
sunlight ambients a neutral den-
sity circular polarizer sandwiched
between two pieces of optically
coated glass is recommended.
Figure 32 lists the filter materials
recommended for each particular
display color. For further informa-
tion please see Application Note
1015 on Contrast Enhancement
for LED Displays.