Philips 298P4QJEB/00 Service Manual page 108

108 Meridian 3
Factory requirements
Factory requirements are taken into account.
It needs to do calibration to make sure the same detection distance.
Service requirements
Service requirements are taken into account.
In the factory mode, it needs to reserve the max. distance adjustment value to adjust
distance ranges.
3.21 Webcam :
Follow Wbcam spec , video transfer at USB HUB.
VISUAL CHARACTERISTICS
Test conditions
Unless otherwise specified, this specification is defined
under the following conditions.
(1) Input signal : As defined in 3.3, follow panel resolution, signal sources must have 75 ohm
(2) Luminance setting : controls to be set to 300 nits with full screen 100 % duty cycle white signal
(3) Warm up: more than 30 minutes after power on with signal supplied.
(4) Ambient light: 400 -- 600 lux.
(5) Ambient temperature: 20 ± 5 C
Brightness
Follow Panel specification.
Image size
Actual display size
Brightness uniformity
Set contrast at 100% and turn the brightness to get average above 300 nits at centre of the
screen.
Apply the Fig 1, it should comply with the following formula:
Where B_max = Maximum brightness
Check Cross talk (S)
Apply Pattern 2. Set contrast and brightness at 100 %.
Measure YA. Then output Pattern 3 and measure YB.
the cross talk value :
Color temperature adjustment
There are six factory preset white color 11500K,9300K,8200K,7500K 6500K,5000K
Apply full white pattern, with brightness in 100 % position and the contrast control at 50 % position.
output impedance.
: Follow panel spec.
( B_max - B_min )
B_max
B_min = Minimum brightness
ABS ( YA - YB )
X 100% > 75%
X 100%
YA
< 1.5 %