Display backlight modulation

摘要

An apparatus may include a backlight for illuminating a liquid crystal display and a control module for controlling the illumination of the backlight. The control module may alternate between turning the backlight on and off at a first frequency and turning the backlight on and off at a second frequency.

主权项

1. An apparatus to degrade a portion of recorded images of copyrighted material, the apparatus comprising:
a control module to degrade only a portion of recorded images at a time by selectively controlling the illumination of a first backlight to illuminate a first portion of a liquid crystal display and a second backlight to illuminate a second portion of the liquid crystal display, wherein in an enabled state, the control module is configured to turn the first backlight on and off at a first frequency during a first period while the second backlight is not being turned on and off at a second frequency and turn the second backlight on and off at a second frequency during a second period while the first backlight is not being turned on and off at the first frequency where the first frequency is a non-harmonic frequency associated with known recording frequencies of recording devices and the second frequency is a non-harmonic frequency associated with known recording frequencies of recording devices, the second frequency being different than the first frequency, wherein the control module is in the enabled state in response to receiving an indication that recorded image degradation is desired.