Control device having buttons with multiple-level backlighting

1. A control device comprising:

a backlighting circuit including a first light source, a second light source, and a third light source;

a first button having a first indicia configured to be illuminated by the first light source;

a second button having a second indicia configured to be illuminated by the second light source;

a third button having a third indicia configured to be illuminated by the third light source, the first button located between the second and third buttons; and

a control circuit responsive to actuations of the first, second, and third buttons, and electrically coupled to the first, second, and third light sources of the backlighting circuit, the control circuit configured to:

control the first light source to emit light at a first source illumination intensity to illuminate the first indicia on the first button;

control the second light source to emit light at a second source illumination intensity to illuminate the second indicia on the second button; and

control the third light source to emit light at a third source illumination intensity to illuminate the third indicia on the third button;

wherein the control circuit is configured to set both of the second and third source illumination intensities of the second and third buttons, respectively, using one or more correction factors so that the second and third source illumination intensities are both less than the first source illumination intensity and the first indicia on the first button is illuminated to a brighter intensity than the respective indicia on the second and third buttons, the control circuit further configured to set the second source illumination intensity to be less than the third source illumination intensity so that the second and third buttons are illuminated to the same intensity.

2. The control device of claim 1 , wherein respective correction factors of the second and third buttons are based on the relative positions of the second and third buttons with respect to the first button.

3. The control device of claim 2 , wherein the control circuit is configured to vary at least one of the correction factors based on the first, second, and third source illumination intensities.

4. The control device of claim 2 , wherein each of the correction factors is a constant percentage.

5. The control device of claim 2 , wherein the first indicia on the first button is located closer to the second button than the third button.

6. The control device of claim 1 , further comprising:

a communication circuit configured to receive digital messages;

wherein the control circuit is configured to receive the correction factors via the communication circuit.

7. The control device of claim 1 , further comprising:

a communication circuit configured to transmit digital messages;

wherein the control circuit is configured to transmit, via the communication circuit, a digital message for controlling an electrical load in response to an actuation of the first button, the second button, or the third button.

8. The control device of claim 1 , wherein the control circuit is configured to perform a closed-loop commission operation to determine the respective correction factors of the second and third buttons.

9. The control device of claim 1 , wherein the control device is electrically connected to an AC power source; and

wherein the control circuit is configured to control an amount of power delivered from the AC power source to an electrical load in response to an actuation of the first button, the second button, or the third button.

10. The control device of claim 1 , further comprising:

an ambient light detector configured to generate an ambient light detect signal;

wherein the control circuit is configured to receive the ambient light detect signal and to determine an ambient light level in a room in which the control device is installed based on the ambient light detect signal, and the control circuit is configured to adjust the first, second, and third source illumination intensities based on the ambient light level.

11. The control device of claim 1 , further comprising:

first, second, and third tactile switches electrically coupled to the control circuit;

wherein the first tactile switch is configured to be actuated in response to an actuation of the first button, the second tactile switch is configured to be actuated in response to an actuation of the second button, and the third tactile switch is configured to be actuated in response to an actuation of the third button.

12. A method of backlighting buttons of a control device, the control device comprising first, second, and third buttons, and first, second, and third light sources positioned to illuminate a respective one of the first, second, and third buttons, the method comprising:

controlling the first light source to emit light at a first source illumination intensity to illuminate first indicia on the first button;

controlling the second light source to emit light at a second source illumination intensity to illuminate second indicia on the second button;

controlling the third light source to emit light at a third source illumination intensity to illuminate third indicia on the third button;

setting both of the second and third source illumination intensities of the second and third buttons, respectively, using one or more correction factors so that the second and third source illumination intensities are both less than the first source illumination intensity and the first indicia on the first button is illuminated to a brighter intensity than the respective indicia on the second and third buttons; and

setting the second source illumination intensity to be less than the third source illumination intensity so that the second and third buttons are illuminated to the same intensity.

13. The method of claim 12 , further comprising:

setting respective correction factors of the second and third buttons are based on the relative positions of the second and third buttons with respect to the first button.

14. The method of claim 13 , wherein setting the respective correction factors further comprises varying at least one of the correction factors based on the first, second, or third source illumination intensities.

15. The method of claim 13 , wherein setting the respective correction factors further comprises setting each of the correction factors to be a constant percentage.

16. The method of claim 13 , wherein setting the respective correction factors further comprises performing a closed-loop commission operation to determine the respective correction factors of the second and third buttons.

17. The method of claim 12 , further comprising:

controlling an amount of power delivered from an AC power source to an electrical load in response to an actuation of the first button, the second button, or the third button.

18. The method of claim 12 , further comprising:

transmitting a digital message for controlling an electrical load in response to an actuation of the first button, the second button, or the third button.

19. The method of claim 12 , further comprising:

receiving a digital message including the correction factors.

20. The method of claim 12 , further comprising:

controlling the first light source to emit light at the first source illumination intensity to illuminate the first indicia on the first button to approximately a first surface illumination intensity;

controlling the second light source to emit light at the second source illumination intensity to illuminate the second indicia on the second button to approximately a second surface illumination intensity; and

controlling the third light source to emit light at the third source illumination intensity to illuminate the third indicia on the third button to approximately the second surface illumination intensity.