Dear Good People

Our product is a class II laser scanning engine. The
original source of laser is from a laser diode. It
passes through a lens and strikes two subtended
mirrors before it goes out for scanning. According to
IEC 60825-1, AEL limit is defined as C6x10-3W where C6
is based on angular subtense (alpha). If alpha is less
than or equal to alpha min, C6 = 1. If alpha is
between min and max, C6 is alpha/alpha min where alpha
min is 1.5mrad.

The debate right now is how to define alpha value to
get C6. I was told to consider it is intrabeam viewing
so that alpha is always min and C6=1. I have no
objection that it is intrabeam viewing but I do not
accept that alpha is always min for intrabeam viewing.
In our case, I consider it is an enlarged source, not
a point source. Enlarged source will create enlarged
image at the retina of our eye. So alpha will be
greater than min value of 1.5mrad and C6 will be
greater than 1.

Anybody can shed the light on this topic? Or any
reference to a good info source?

Thanks in advance

Kyaw

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