Intelligent LCD brightness control system

In an electronic device having a liquid crystal display (LCD), an apparatus for automatically adjusting the brightness of the LCD in response to ambient lighting conditions, the apparatus comprising:

• brightness control circuitry including a microprocessor and a memory;
• means for manually adjusting the brightness of the LCD and generating a user-selected brightness level signal to the microprocessor;
• at least two photodetectors for detecting at least two levels of ambient light directed toward a front side and a back side of the LCD and for generating at least two ambient light signals to the microprocessor, wherein one of the at least two signals corresponds to the front side of the LCD and another of the at least two signals corresponds to the back side of the LCD;
• means for converting the at least two ambient light signals for input into the microprocessor;
• the brightness control circuitry further comprising artificial intelligence for learning over time user preferences with respect to said LCD brightness level in certain ambient lighting conditions as indicated by respective user-selected brightness level signals generated in response thereto, wherein the brightness control circuitry sets the LCD brightness level to a brightness level corresponding to a preferred LCD brightness level associated with said at least two ambient light signals, said preferred LCD brightness level not necessarily corresponding to a current user-selected brightness level signal.

In an electronic device having a liquid crystal display (LCD), a method of automatically adjusting the brightness of the LCD in response to ambient lighting conditions, the method comprising the steps of:

• manually adjusting the brightness level of the LCD and generating a selected brightness level signal to a microprocessor;
• detecting a level of ambient light directed toward a first side of the LCD and for generating a first ambient light signal to the microprocessor;
• detecting a level of ambient light directed toward a second side of the LCD opposite said first side of the LCD and for generating a second ambient light signal to the microprocessor;
• storing in a memory automatic brightness level signals indexed by the first and second ambient light signals;
• selecting one of automatic brightness level signals using said first and second ambient light signals;
• determining the lower value of the selected brightness level signal and the selected automatic brightness level signal;
• and
• setting the brightness level of the LCD to correspond to either the selected brightness level signal if the user has manually adjusted after the automatic brightness level signals have been indexed, or the lower value of the selected brightness level signal and the selected automatic brightness level signal.

In an electronic device having a liquid crystal display (LCD) and a microprocessor, a method of automatically adjusting the brightness of the LCD in response to ambient lighting conditions, the method comprising the steps of:

• detecting at least two levels of ambient light directed toward a front side and a back side of the LCD and for generating at least two ambient light signals to the microprocessor, wherein one of the at least two ambient light signals corresponds to the front side of the LCD and another of the at least two ambient light signals corresponds to the back side of the LCD;
• converting the at least two ambient light signals for input into the microprocessor;
• detecting a user-selected brightness level signal generated to the microprocessor;
• learning over time user preferences with respect to said LCD brightness level in certain ambient lighting conditions as indicated by respective user-selected brightness level signals generated in response thereto;
• and
• setting the LCD brightness level to a brightness level corresponding to a preferred LCD brightness level associated with said at least two ambient light signals, said preferred LCD brightness level not necessarily corresponding to a current userselected brightness level signal.