Systems and methods for controlling brightness of an avionics display

A method of controlling the brightness of an avionics display comprising a plurality of LEDs operating in an aircraft cockpit, the method comprising:

• detecting light generated by at least one of said plurality of LEDs;
• determining a pulse width modulated wave control signal having a given duty cycle and a current control voltage signal having a given voltage level to control at least partially light generated by said plurality of LEDs;
• and
• adjusting one or both of said duty cycle of said pulse width modulated wave and said voltage level of said current control voltage signal based on the light detected in the detecting step to be generated from said one of said plurality of LEDs.

An apparatus for controlling the brightness of an LED matrix providing backlight to an avionics display operating in an aircraft cockpit, comprising:

• a sensor for detecting an amount of light emitted by said LED matrix and generating an input signal based thereon;
• a processor that receives said input signal and that provides a first output digital signal and a second output digital signal based on said input signal;
• a pulse width modulator controller that receives said first output digital signal and provides a pulse width modulated control signal wherein said pulse width modulated control signal is of a fixed periodic frequency and having a duty cycle based on said first output digital signal;
• and
• a current controller that receives said second output digital signal and provides a current control voltage signal based on said input signal.

An apparatus for controlling the brightness of an LED matrix, comprising:

• an LED matrix that receives a brightness control signal and comprises a plurality of light-emitting-diodes arranged in a planar array affixed to a substrate with a first side and a second side where substantially all of the LEDs are affixed to said first side of said substrate and the remaining LEDs are affixed to said second side of said substrate;
• a sensor that detects light generated by said LEDs to said second side of said substrate and generates an input signal;
• and
• a control unit that receives said input signal and provides said brightness control signal based on at least in part on said input signal.

A system for backlighting a display in the presence of ambient light, comprising:

• a first sensor arranged to sense the ambient light, and generating a first light intensity signal based thereon;
• a second sensor arranged to sense intensity of light used to backlight the display, and generating a second light intensity signal based thereon;
• a controller operatively connected to receive the first and second light intensity signals from said first and second sensors, respectively, and generating at least one control signal based on the first and second intensity signals;
• and
• a light source matrix comprising a plurality of LEDs arranged proximate to the display and operatively connected to receive at least one intensity control signal, said light source matrix generating the light used to backlight the display based on the control signal.