LED light output linearization

• US 7,586,274 B2
• Filed: 11/09/2007
• Issued: 09/08/2009
• Est. Priority Date: 11/09/2007
• Status: Active Grant

• Current Assignee: The Coca-Cola Company
• Original Assignee: The Coca-Cola Company
• Inventors: Primiano, Guy A.
• Primary Examiner(s): Owens; Douglas W
• Assistant Examiner(s): Chen; Jianzi
• Application Number:
  US11/937,551
• Publication Number:
  US 20090121654A1
• Time in Patent Office: 669 Days
• Field of Search: 315/291, 315/307, 315/360, 315/246, 315/247, 315/185.R, 315/294
• US Class Current: 315/291
• CPC Class Codes: G09G 2320/048 using evaluation of the usage time
• CPC Class Codes: H05B 45/18 using temperature feedback
• CPC Class Codes: H05B 47/20 Responsive to malfunctions or to light source life; for protection

Abstract

A system and method for producing a flattened characteristic for LED luminous output. The system may include an array containing one or more light emitted diodes, a power source connected to the LED array providing drive current to the LED array, a timer connected to a controller wherein the timer logs the on-time of the LED array and communicates the LED array on-time to the controller, and a controller connected to the power source wherein the controller adjusts the intensity of the drive current provided to the LED array based on the on-time data received from the timer such that the resultant relative luminous output is approximately equal to the initial relative luminous output.

Claims

1. A method for powering an array of LEDs, comprising:

powering an array containing one or more light emitted diodes with a power source connected to the LED array wherein the power source provides drive current to the LED array;

logging the on-time of the LED array with a timer connected to a controller;

communicating the LED array on-time data to the controller,

automatically adjusting the intensity of the drive current provided to the LED array based on the on-time data received from the timer such that the resultant relative luminous output is approximately equal to the initial relative luminous output.

2. The method of claim 1, wherein the power source powers the LED array using a pulse width modulation scheme.

3. The method of claim 1, wherein the power source is either supplying alternating current power supply voltage or direct current power supply voltage.

4. The method of claim 1, further including the step of mounting the power source on a flexible printed circuit board.

5. The method of claim 1, wherein the array of light emitting diodes comprises of one or more light emitted diodes serially connected.

6. The method of claim 1, wherein the luminous output is used to illuminate products contained in a product dispenser.