Faça o download do xblacklight da loja de software do Ubuntu.
O Xbacklight é usado para ajustar o brilho da luz de fundo quando suportado. Ele encontra todas as saídas no servidor X que suportam o brilho da luz de fundo controlar e muda todos da mesma maneira.
-get Print out the current backlight brightness of each output with
such a control. The brightness is represented as a percentage of
the maximum brightness supported.
-set percent
Sets each backlight brightness to the specified level.
-inc percent
Increases brightness by the specified amount.
-dec percent
Decreases brightness by the specified amount.
-help Print out a summary of the usage and exit.
-time milliseconds
Length of time to spend fading the backlight between old and new
value. Default is 200.
-steps number
Number of steps to take while fading. Default is 20.