Lighting apparatus

1. A lighting apparatus comprising:

a plurality of light source units comprising at least three light source units, wherein the light source units emit lights having different color temperatures from each other and different color coordinates from each other;

a plurality of optical exciters disposed on the light source units, all of which convert light emitted from the light source unit into lights having different color temperatures and different color coordinates;

a sensor sensing each of the light quantities of the R (red) component, G (green) component and B (blue) component of light mixed with lights emitted from a plurality of the optical exciters, wherein the sensor outputs an R component signal, a G component signal and a B component signal, each of which respectively corresponds to light quantities of the R component, the G component and the B component;

a memory having a standard color coordinate located within an area formed by the color coordinates of the light output from the optical exciters; and

a controller receiving the R component signal, the G component signal and the B component signal, wherein the controller generates a comparative color coordinate,

wherein the controller compares the comparative color coordinate with the standard color coordinate and wherein the controller controls light quantities of the light source units in such a manner as to reduce an error value between the standard color coordinate and the comparative color coordinate, and

wherein the standard color coordinate or the comparative color coordinate is calculated by tristimulus values of X, Y and Z by using the R component signal, the G component signal and the B component signal.

2. The lighting apparatus of claim 1 , wherein the standard color coordinate is coordinates are set according to a black body locus, MacAdam curve or Ansi bin curve.

3. The lighting apparatus of claim 1 , wherein at least two light source units emit white light.

4. The lighting apparatus of claim 1 , wherein at least one light source unit emits greenish white light.

5. The lighting apparatus of claim 1 , wherein the light quantities are controlled by supplying alternating current voltage having a controlled duty ratio to the light source units.

6. The lighting apparatus of claim 1 , wherein color distribution at respective color temperatures of lights emitted from the optical exciters is within 3-step MacAdam ellipse.

7. The lighting apparatus of claim 1 , wherein the optical exciters comprises a first optical exciter, a second optical exciter and a third optical exciter, wherein a first color coordinate of light emitted from the first optical exciter and a second color coordinate of light emitted from the second optical exciter are disposed on a black body locus, and wherein a third color coordinate of light emitted from the third optical exciter is spaced from the black body locus.

8. The lighting apparatus of claim 7 , wherein the optical exciters comprises a fourth optical exciter, wherein a fourth color coordinate of light emitted from the fourth optical exciter is spaced from the black body locus, and wherein the black body locus is disposed between the third color coordinate and the fourth color coordinate.

9. The lighting apparatus of claim 1 , wherein the R component signal, the G component signal and the B component signal are digital signals.

10. The lighting apparatus of claim 1 , wherein the plurality of optical exciters comprises a first exciter disposed on the light source units, a second optical exciter and a third optical exciter, wherein the second optical exciter and the third optical exciter are arranged adjacently to the first optical exciter, and wherein the second optical exciter and the third optical exciter are alternately arranged.

11. The lighting apparatus of claim 1 , wherein the plurality of optical exciters comprises a first exciter disposed on the light source units, a second optical exciter disposed on the first exciter and a third optical exciter disposed on the second exciter.

12. A lighting apparatus comprising:

a plurality of light source units comprising at least four light source units;

a plurality of optical exciters disposed on the light source units and comprising at least three optical exciters, wherein the optical exciters comprises a first optical exciter, a second optical exciter and a third optical exciter, wherein a first color coordinate of light emitted from the first optical exciter and a second color coordinate of light emitted from the second optical exciter are disposed on a black body locus, and wherein a third color coordinate of light emitted from the third optical exciter is spaced from the black body locus;

a sensor sensing each of the light quantities of the R (red) component, G (green) component and B (blue) component of light mixed with lights emitted from a plurality of the optical exciters, wherein the sensor outputs an R component signal, a G component signal and a B component signal, each of which respectively corresponds to light quantities of the R component, the G component and the B component;

a memory having a standard color coordinate located within an area formed by the color coordinates of the light output from the optical exciters; and

a controller receiving the R component signal, the G component signal and the B component signal, wherein the controller generates a comparative color coordinate,

wherein the controller compares the comparative color coordinate with the standard color coordinate and wherein the controller controls light quantities of the light source units in such a manner as to reduce an error value between the standard color coordinate and the comparative color coordinate, and

wherein the standard color coordinate or the comparative color coordinate is calculated by tristimulus values of X, Y and Z by using the R component signal, the G component signal and the B component signal.

13. The lighting apparatus of claim 12 , wherein the optical exciters comprises a fourth optical exciter, wherein a fourth color coordinate of light emitted from the fourth optical exciter is spaced from the black body locus, and wherein the black body locus is disposed between the third color coordinate and the fourth color coordinate.

14. The lighting apparatus of claim 12 , wherein the light source units emit lights having different color temperatures from each other and different color coordinates from each other.

15. The lighting apparatus of claim 12 , wherein the light source units emit lights having the same color temperature.

16. The lighting apparatus of claim 12 , wherein the standard color coordinate is coordinates are set according to a black body locus, MacAdam curve or Ansi bin curve.

17. The lighting apparatus of claim 12 , wherein at least two light source units emit white light, and wherein at least one light source unit emits greenish white light.

18. The lighting apparatus of claim 12 , wherein the light quantities are controlled by supplying alternating current voltage having a controlled duty ratio to the light source units.

19. The lighting apparatus of claim 12 , wherein color distribution at respective color temperatures of lights emitted from the light source units is within 3-step MacAdam ellipse.

20. The lighting apparatus of claim 12 , wherein the R component signal, the G component signal and the B component signal are digital signals.