Nokia 445PRO, Руководство по обслуживанию, Страница: 25 / 67

445N 23
6.3 White Uniformity
Measurement conditions:
--- Full screen picture size, Brightness in middle 100 nit
--- Magnetic field horizontal 0 Gauss
vertical 0.45 Gauss
--- Warming up time 1 hour
Maximum variation between colour coordinates between any measurement points shall not vary
more than d(x),d(y) below.
d(x) = ± 0.015
d(y) = ± 0.015
6.4 Colour Purity
There should not be visual discoloration with each of the red, green and blue beams after the tube is
moved to any directions.
Measurement conditions: same as spec. 6.3
6.5 Luminance
Definition:
The following methodology and definition of luminance shall be applicable throughout this specifica-
tion
Luminance shall be measured on 1600 x 1280@85 Hz pixel format at five areas, using two different
pictures:
--- 1. In the center of the screen white field 50*50 mm
--- 2. Full white field.
The five areas are defined as:
L0 Center of the screen
L1 L2
L1 Upper left of the screen
L2 Upper right of the screen L0
L3 Lower left of the screen
L4 Lower right of the screen L3 L4
Requirements:
Maximum contrast luminance:
With the brightness control set so that background brightness is 1 nit and the contrast control set to
maximum.
L0 = 140
30 nits (40.9Ft---L) 50*50 mm white field
L0 = 110 10 nits (29.4 Ft---L) Full white field
Minimum luminance:
Using full white picture, with the brightness and contrast controls in minimum, the foreground full
white field (L0) < 5 nits.
Background luminance:
The luminance of the background, measured at center of the screen without active video and in the
absence of significant ambient illumination, brightness at maximum must be:
1 nit.
±
L0
±
10 nits
The background shall be extinguished before brightness control reaches its end.
Luminance uniformity:
With the brightness control set so that the background raster is just extinguished the contrast con-
trol set for L0 = 100 nits, ( 29.2 Ft---L), luminance on areas L1, L2, L3 and L4 shall be greater than
(80 %) of L0.(80 nits, 23 Ft---L)