OSRAM ORBEOS Components - Manual (Page 11)

11
BINNING
OSRAM has established a fi ner resolution classifi cation and
has divided the ANSI-NEMA color boxes into smaller sub-bins
(so called “fi ne-bins”). In order to cover the full production
output, a row of sub-bins of similar size have been introduced
above and below the ANSI-NEMA boxes. The scheme is
shown in fi gure 9.
In this binning scheme, the size of one fi ne-bin box roughly
corresponds to a three-step MacAdam ellipse. According
to MacAdam, a one-step ellipse in the CIE 1931 diagram
represents an area where a homogeneous color impression
is perceived (MacAdam, D. L., Visual sensitivities to color dif-
ferences in daylight, J. Opt. Soc. Am., 32, 247 (1942)) and
where color differences are just noticeable to human observers.
The nomenclature of the fi ne-bins is set up as follows. The
resulting grid pattern is created by rows – enumerated from
4 to 8 (and 9, respectively) towards the top – and by columns
assigned from left to right with characters ranging from C to
X. The fi ne-bin is addressed via a combination of row num-
ber and column character. The example in fi gure 9 highlights
the bin 7H. The chromaticity coordinates of the fi ne-bins are
given in the appendix.
Since it is impossible to produce only one selected bin, an order
has to combine several fi ne-bins. The more parts are needed,
the more fi ne-bins have to be selected in order to ensure se-
curity of supply. Individual selections can be agreed upon in
close cooperation with each customer.
Fig. 9. OSRAM Opto Semiconductors’ fi ne binning scheme of white color.