segun php.net
Código:
To the Editor's Note below:
It might be more efficient so use single quotes and might look nicer, but it does NOT work. (Not for me at least: Win 2K, Apache 1.3.27, PHP 5.0.1)
Error message says: "Printer \SERVERNAME\PRINTERNAME not found".
Using "\\\\SERVERNAME\\PRINTERNAME" does work perfectly and apart from the nanoseconds wasted for parsing the string I do not see why I should not use it. :-)
espero te sirva, si no, procura dar mas informacion acerca de tu dispositivo y el error que arroja