LED Light Output Linearization

• US 20090121654A1
• Filed: 11/09/2007
• Published: 05/14/2009
• 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.
• Granted Patent: US 7,586,274 B2
• Time in Patent Office: Days
• US Class Current: 315/307
• 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 system for powering an array of LEDs, comprising:

an array containing one or more light emitted diodes;

a power source connected to the LED array wherein the power source provides 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 data to the controller,

the 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.

2. The system of claim 1, wherein the power source provides current to the LED array using a pulse width modulation scheme.

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

4. The system of claim 1, wherein the power source is mounted on a flexible printed circuit board.

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

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

13. The system of claim 1, farther comprising:

a sensor connected to the controller, wherein the sensor logs operating temperature data and communicates the operating temperature data to the controller, and

wherein the controller is farther adapted to adjust the intensity of the drive current provided to the LED array based at least in part on the on-time data received from the timer and the operating temperature data received from the sensor such that the resultant relative luminous output is approximately equal to the initial relative luminous output.

7. 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,

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.

8. The method of claim 7, wherein the power source powers the LED array using a pulse width modulation scheme.

9. The method of claim 7, wherein the power source is either supplying alternating current power supply voltage or direct current power supply voltage.

10. The method of claim 7, further including the step of mounting the power source on a flexible printed circuit board.

11. The method of claim 7, wherein the array of light emitting diodes comprises of one or more light emitted diodes serially connected.

12. The method of claim 7, wherein the luminous output is used to illuminate products contained in a product dispenser.

14. The method of claim 7 further comprising:

logging the operating temperature data of the LED array with a sensor connected to the controller;

communicating the operating temperature data of the LED array to the controller; and

adjusting the intensity of the drive current provided to the LED array based at least in part on the operating temperature data received from the sensor such that the resultant relative luminous output is approximately equal to the initial relative luminous output.