What's this? (retroilluminated mobile phone screen)

[Pajarico]

Hi, I've savaged an old mobile phone (an LG, about 5-7 years old, I'm not sure really). There's a plastic sheet of yellow-greenish color behind the LCD which is for illuminating the LED

 

[gsmaster1]

Thats "EL foil Backlight"
These usually need a high voltage inverter to work

 

[Pajarico]

Thanks. Could you point me to a circuit that you know is working? Most of the high voltage inverters I found use some transistors and a transformer (I doubt there was a transformer in there).

EDIT: Now I have the name I'm doing a bit of research. Technicaly an EL panel is a capacitor which if has to be feed with a alternate sginal would make it a unpolarized capacitor. But wikipedia doesn't talk about inverting the DC and my panel is polarized....
The only thing that's clear is that it requires high voltage.

EDIT 2: Nevermind. It needs an inverter as you pointed out. I've found a manufacturer page with information:
http://www.seiko-precision.com.hk/html/el-catalogue.html

However I want to know how can I drive the panel without a transformer.... (cause there wan't none)