Ambient light processing system for controlling display device by sensing ambient light and method using the system

1. An ambient light processing system for controlling a display device by sensing ambient light, comprising:

a photo-detector outputting a sensed signal corresponding to a luminous intensity of the ambient light;

an amplification unit amplifying the sensed signal with a high amplification factor to output a first amplified signal and amplifying the sensed signal with a low amplification factor to output a second amplified signal;

an analog-to-digital converter respectively converting the first amplified signal and the second amplified signal into a first digital signal and a second digital signal; and

a controller outputting respectively a first control signal and a second control signal for controlling the display device in response to the first digital signal and the second digital signal.

2. The ambient light processing system of claim 1 , wherein the controller comprises:

a noise removal unit judging the first and second digital signals as noise when frequencies of the first and second digital signals vary and filtering the first and second digital signals to output a first noise-removed signal and a second noise-removed signal; and

a control signal generator respectively outputting the first and second control signals in response to the first and second noise-removed signals.

3. The ambient light processing system of claim 2 , wherein the noise removal unit judges the first digital signal as effective data only when results obtained by sampling the first digital signal continuously have a same value N times (where N is a natural number) and outputs the first noise-removed signal, and the noise removal unit judges the second digital signal as effective data only when results obtained by sampling the second digital signal continuously have a same value N times and outputs the second noise-removed signal.

4. The ambient light processing system of claim 1 , wherein the first control signal controls an LED driver.

5. The ambient light processing system of claim 1 , wherein the second control signal controls outdoor visibility of the display device.

6. The ambient light processing system of claim 2 , further comprising a low-pass filter filtering a high-frequency component of the sensed signal and outputting the filtered signal to the amplification unit.

7. The ambient light processing system of claim 1 , further comprising a hysteresis block classifying the first and second digital signals into predetermined sections divided in response to the luminous intensity of the ambient light and outputting the classified first and second digital signals to the controller.

8. The ambient light processing system of claim 7 , wherein the hysteresis block comprises:

a first hysteresis block classifying the first digital signal into the sections divided in response to the luminous intensity of the ambient light and outputting the classified first digital signal;

a second hysteresis block classifying the second digital signal into the sections divided in response to the luminous intensity of the ambient light and outputting the classified second digital signal; and

an arbitrator determining effective data in response to a luminous intensity difference between the output signals of the first and second hysteresis blocks.

9. The ambient light processing system of claim 8 , wherein the arbitrator determines one of the output signals of the first and second hysteresis blocks having lower luminous intensity as the effective data.

10. The ambient light processing system of claim 1 , wherein the amplification unit outputs the first amplified signal and then sequentially outputs the second amplified signal.

11. The ambient light processing system of claim 10 , wherein the amplification unit outputs the first amplified signal while the display device displays a frame and outputs the second amplified signal while the display device displays the next frame.

12. An ambient light processing method of controlling a display device by sensing ambient light, comprising:

outputting a sensed signal corresponding to a luminous intensity of the ambient light;

amplifying the sensed signal with a high amplification factor to output a first amplified signal and amplifying the sensed signal with a low amplification factor to output a second amplified signal;

respectively converting the first amplified signal and the second amplified signal into a first digital signal and a second digital signal; and

outputting a first control signal and a second control signal for controlling the display device respectively in response to the first digital signal and the second digital signal.

13. The ambient light processing method of claim 12 , wherein the outputting of the first control signal and the second control signal comprises judging the first and second digital signals as noise when frequencies of the first and second digital signals are varied and filtering the first and second digital signals to output a first noise-removed signal and a second noise-removed signal.

14. The ambient light processing method of claim 13 , wherein the filtering of the first and second digital signals comprises:

judging the first digital signal as effective data only when results obtained by sampling the first digital signal have a same value N times (N is a natural number) successively and outputting the first noise-removed signal; and

judging the second digital signal as effective data only when results obtained by sampling the second digital signal have a same value N times successively and outputting the second noise-removed signal.

15. The ambient light processing method of claim 12 , further comprising controlling an LED driver using the first control signal.

16. The ambient light processing method of claim 12 , further comprising controlling outdoor visibility of the display device using the second control signal.

17. The ambient light processing method of claim 12 , further comprising filtering a high-frequency component of the sensed signal the outputting of the first amplified signal and the second amplified signal comprising amplifying the signal from which the high-frequency component has been filtered with a high amplification factor to output the first amplified signal and amplifying the signal from which the high-frequency component has been filtered with a low amplification factor to output the second amplified signal.

18. The ambient light processing method of claim 12 , wherein the outputting of the first control signal and the second control signal comprises:

classifying the first and second digital signals into predetermined sections divided in response to the luminous intensity of the ambient light and outputting the classified first and second digital signals; and

outputting the first control signal and the second control signal in response to the classified first and second digital signals.

19. The ambient light processing method of claim 18 , further comprising determining effective data in response to a luminous intensity difference between the classified first and second digital signals.

20. The ambient light processing method of claim 19 , wherein the determining of the effective data comprises determining one of the classified first and second digital signals, which has lower luminous intensity, as the effective data.

21. The ambient light processing method of claim 12 , wherein the outputting of the first amplified signal and the second amplified signal comprises:

outputting the first amplified signal while the display device displays a frame; and

outputting the second amplified signal while the display device displays a next successive frame after outputting the first amplified signal.