High-brightness LEDs, used for automobile headlights and to backlight LCD screens, are an important application. The LCD panel is synchronized with the backlight. An OLED display works without a backlight because it emits visible light. Battery life is also extended through reduced usage of the LCD backlight. Most other manufacturers utilized an LCD screen that was not visible without backlight. An OLED display works without a backlight. More of a concern is the LCD backlight. LCDs that utilize a strobe backlight, such as nVidia's LightBoost, reduce crosstalk. "Mode" change occurs by varying the relative amounts backlight and ambient light. The chiclet-keys of backlight keyboard are matte black and feature a slightly concave surface area. In November 2008, Sony released the PRS-700BC, which incorporated a backlight and a touchscreen. Casio introduced their version of electroluminescent backlight technology in 1995. The grating splits the light from the white backlight into a spectrum. Powder or AC electroluminescence is found in a variety of backlight and night light applications. A control mechanism for the backlight is usually included on the same controller board.