1 Scope
This part of IEC 61747 gives details of the quality assessment procedures, the inspection requirements,
screening sequences, sampling requirements, and test and measurement procedures required
for the assessment of liquid crystal display modules.
This standard is restricted to reflective liquid crystal display-modules using either
segment, passive or active matrix and a-chromatic or colour type LCDs (see Note).
Furthermore, the reflective modes of transflective LCD modules with backlights OFF
and reflective LCD modules of front light type without its front-light-unit, are comprised
in this standard. A reflective LCD module with combination of a touch-key-panel or
a front-light-unit is out of the scope of this standard, because its measurements
are frequently inaccurate. Its touch-key-panel or front-light-unit should be removed
before it can be included in this scope.
NOTE Several points of view with respect to the preferred terminology on "monochrome",
"achromatic", "chromatic", "colour", "full-colour", etc. can be encountered in the
field amongst spectroscopists, (general-) physicists, colour-perception scientists,
physical engineers and electrical engineers. In general, all LCDs demonstrate some
sort of chromaticity (e.g. as function of viewing angle, ambient temperature or externally
addressable means). Pending detailed official description of the subject, the pre-fix
pertaining to the "chromaticity" of the display will be used so as to describe the
colour capability of the display that is externally (and electrically) addressable
by the user. This leads us to the following definitions (see also [19])
-
a) a monochrome display has NO user-addressable chromaticity ("colours"). It may or may
not be "black and white" or a-chromatic;
-
b) a colour display has at least two user-addressable chromaticities ("colours"). A 64-colour
display has 64 addressable colours (often made using 2 bits per primary for 3 primaries),
etc. A full-colour display has at least 6 bits per primary (≥ 260 thousand colours).
The purpose of this standard is to indicate and list the procedure-dependent parameters
and to prescribe the specific methods and conditions that are to be used for their
uniform numerical determination.