[sane-standard] Disabling of the internal Light Source of Epson 1680 sane-epson 2

[Hans Parkmann]

Hello,

i own a Epson 1680 Pro without TPU. I want to build my own TPU to scan 
negatives. The Problem is the main light source of the scanner must be 
disabled and the focus point must be set to : right above the glas.

Is there a way to disable the internal light source while using the 
scanner in the flatbed mode?

Best regards
Simon