Backlight and ambient light sensor system

A machine readable non-transitory medium storing instructions which when executed cause a method of operating a device which includes a display having a touch screen input device, the method comprising:

• operating the display, while the touch screen input device receives one or ore inputs, at a brightness level controlled by an ambient light sensor (ALS) that takes measurements of ambient light around the device;
• determining that the device has become inactive;
• entering an inactivity dim state in response to determining that the device has become inactive, wherein during inactivity dim state the display is operated at a dim brightness level and a plurality of different ambient light levels do not effect control of the brightness level of the display and the touch screen input device does not accept inputs until after a wake input which causes the device to exit the inactivity dim state;
• receiving the wake input which is one or more touches on the touch screen input device, wherein the touch screen input device is a multi-touch input device;
• adjusting the brightness level of the display in response to receiving the wake input which causes the device to exit the inactivity dim state, wherein the brightness level is adjusted with the ALS such that a plurality of different ambient light levels measured by the ALS do effect control of the brightness level after receiving the wake input.

A device comprising:

• a display;
• an ambient light sensor (ALS);
• a touch screen input device which is a multi-touch input device;
• a memory;
• a processing system coupled to the display and to the ALS and to the touch screen input device and to the memory, the memory storing instructions which configure the processing system to:
• operate the display, while the touch screen input device receives one or more inputs, at a brightness level controlled by an ambient light sensor (ALS) that takes measurements of ambient light around the device;
• determine that the device has become inactive;
• enter an inactivity dim state in response to determining that the device has become inactive, wherein during the inactivity dim state the display is operated at a dim brightness level and a plurality of different ambient light levels do not effect control of the brightness level of the display and the touch screen input device does not accept inputs until after a wake input which causes the device to exit the inactivity dim state;
• receive the wake input which is one or more touches on the touch screen input device, wherein the touch screen input device is a multi-touch input device;
• adjust the brightness level of the display in response to receiving the wake input which causes the device to exit the inactivity dim state, wherein the brightness level is adjusted with the ALS such that a plurality of different ambient light levels measured by the ALS do effect control of the brightness level after receiving the wake input.