EL552.256-Q2 Operations Manual (OM410-00)
9
Optical
Table 5. Optical Specifications
Luminance
L
on
(areal), min
L
on
(areal), typ
L
off
(pixel), max
34.5 cd/m²
50 cd/m²
0.2 cd/m²
screen center, 120 Hz frame rate
screen center, 120 Hz frame rate
5 points: center plus four corners measured
1.0
±
0.025" from adjacent display edges, 120 Hz
Non-uniformity
All pixels fully lit
26%
Maximum difference two of five points, using
the formula:
LNU%=[1- (min_lum/max_lum)] x 100
Luminance Variation (Temperature)
Maximum
±
15%
Across operating temperature range
Luminance Variation (Time)
Maximum
<10%
15,000 hours at 25
°
C ambient
Viewing Angle
Minimum
>160
°
Contrast Ratio
Minimum
Typical
20:1
40:1
@ 500 lux ambient, 120 Hz frame rate
Generating Grayscales
Some applications may benefit by using grayscales. The Q2 has a maximum
frame rate frequency of 120 Hz. Using the higher frame rate, combined with
flat panel controllers designed for this faster display, it is possible to generate
usable grays through frame rate control and dithering. Video controllers from
manufacturers such as C&T, SMOS, and Cirrus Logic use these methods with
proprietary algorithms to generate grayscales.
The response time of electroluminescent displays is much faster than LCDs,
therefore not all possible grayscales generated by the video controller are
actually usable. Many of the grayscales may flicker or swim. Careful testing is
necessary to select appropriate grayscales for an application, especially when the
electroluminescent displays are driven at less than their maximum frame rate.
For additional information, refer to Planar Application Note 119,
Generating
Grayscales
, or contact Planar’s Application Engineering.
