I expected such a dumb question from someone pretending to be the expert around here.
He has an AD7260 which is manufactured by NEC and sold through the channels of the Sony-NEC-joint venture called Optiarc.
The green zone represent the ability of the burner to read damaged sectors (it includes here the "repaired" sectors), the red ones are the unreadable ones.
There is a concentration of NECs at the bottom and one of LGs at the top