Acer AL1913 Service Manual page 10

(1) Definition of Viewing Angle ( x, y):
= 90º x-
X-
6 o'clock
y-
= 90º
y-
(2) Definition of Contrast Ratio (CR):
The contrast ratio can be calculated by the following expression and figure
below.
Contrast Ratio (CR) = L255 / L0
L255: Luminance of gray level 255
L 0: Luminance of gray level 0
CR = CR (5)
CR (X) is corresponding to the Contrast Ratio of the point X at Figure in Note
(5).
Definition of luminance measured points and Brightness Uniformity:
Normal
x = y = 0º
y-
y
x-
x
Horizontal Line Number
0
320
0
256
1
512
768
3
1024
Horizontal Line Number [pixel]
10
12 o'clock direction
y+
= 90º
y+
x+
640
960
2
5
4
Active area
= 90º
X+
1280
: test point
X
X=1 to 5