Quato iColor Display 3.7, User Manual

Page: 37 / 73

37
WARNING:
Your display is a high-voltage component
and should not be opened for any reason (the back-
light inverter uses up to 3.000V), even when it is un-
plugged. There are no user-serviceable parts inside.
Opening the unit will void the warranty.
TFT Pixel failure criteria
Although TFT technologies have been constantly
improved in the past few years, single pixel defects
can still not be completely avoided in the production
process of TFT panels.
There are typically millions of these subpixels on an
LCD display. For example, the LCD panel used in the
Intelli Proof 240 is made up of 2.3 million pixels and
6.9 million red, green, and blue subpixels. Occasi-
onally, a transistor does not work perfectly, which
may result in the affected subpixel being turned
on (bright) or turned off (dark). With the millions of
subpixels on a display, it is quite possible to have
a low number of faulty transistors on an LCD. The-
refore, a certain number of subpixel anomalies is
considered acceptable. Rejecting all but perfect LCD
panels would significantly increase the retail price
for products using LCD displays. These factors apply
to all manufacturers using LCD technology.
ISO standard 13406 defines pixel defect classes I to
IV, whereas only devices of the defect classes I,II and
III are sold to the „public“. Class I devices are distri-
buted for military and clinical purposes only. Accor-
ding ISO 13406-II, a 24“ display with 1.920x1.200
pixel resolution is allowed to have up to 12 defective
pixels.
However, QUATO has defined special acceptance
criteria which go far beyond the demands of the ISO
standard 13406-2.
Pixel failure criteria for Intelli Proof/Color monitors:
- Zero defective pixels in the center area (DIN
A6 landscape)
- max. 2 defective pixels in the remaining
area