APPARATUS AND METHOD FOR CONTROLLING LIGHTING BRIGHTNESS THROUGH PULSE FREQUENCY MODULATION

• US 20090160360A1
• Filed: 03/07/2008
• Published: 06/25/2009
• Est. Priority Date: 12/21/2007
• Status: Abandoned Application

• Current Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Kwon, Yong Il, Hong, Kyung Hee, Kim, Myeung Su, LIM, Joon Hyung
• Application Number:
  US12/044,734
• Publication Number:
  US 20090160360A1
• Time in Patent Office: Days
• US Class Current: 315/294
• CPC Class Codes: H05B 41/3925 by frequency variation H05B41/3922 takes precedence

Abstract

Provided is an apparatus for controlling lighting brightness through PFM, the apparatus including a lighting control unit that generates a control signal for controlling the brightness of a plurality of lightings; a PFM signal generating unit that is controlled by the control signal so as to generate a plurality of PFM signals having a different frequency from each other; and a driving voltage generating unit that composes the generated PFM signals in accordance with a preset combination, thereby generating driving voltages for driving the lightings.

Claims

1. An apparatus for controlling lighting brightness through pulse frequency modulation (PFM), comprising:

a lighting control unit that generates a control signal for controlling the brightness of a plurality of lightings;

a PFM signal generating unit that is controlled by the control signal so as to generate a plurality of PFM signals having a different frequency from each other; and

a driving voltage generating unit that composes the generated PFM signals in accordance with a preset combination, thereby generating driving voltages for driving the lightings.

2. The apparatus according to claim 1, wherein the PFM signal generating unit includes a plurality of PFM signal generating sections of which the number is equal to the number of the lightings.

3. The apparatus according to claim 2, wherein each of the PFM signal generating sections includes a plurality of PFM signal generating elements which are controlled by the control signal so as to generate a plurality of PFM signals having a different frequency from each other.

4. The apparatus according to claim 3, wherein the driving voltage generating unit includes a plurality of driving voltage generating sections of which the number is equal to the number of the lightings.

5. The apparatus according to claim 4, wherein each of the driving voltage generating sections combines the plurality of PFM signal, generated from the PFM signal generating sections, in accordance with a preset combination to thereby generate driving voltages with a non-periodic property.

6. The apparatus according to claim 5, wherein the PFM signals are combined in such a manner that when the duty-on interval of any one of the PFM signals ends, the duty-on interval of the next PFM signal begins.

7. The apparatus according to claim 1, wherein the plurality of lightings are light emitting diodes (LEDs).

8. A method for controlling lighting brightness through PFM, comprising the steps of:

(a) generating a control signal for controlling the brightness of a plurality of lightings;

(b) generating a plurality of PFM signals having a different frequency from each other, in accordance with the control signal;

(c) combining the PFM signals in accordance with a preset combination so as to generate driving voltages; and

(d) supplying the generated driving voltages to the lightings, thereby adjusting the brightness of the lightings.

9. The method according to claim 8, wherein in step (c), the PFM signals are combined in such a manner that when the duty-on interval of any one of the PFM signals ends, the duty-on interval of the next PFM signal begins.

10. The method according to claim 8, wherein in step (c), the driving voltages have a non-periodic property.

11. The method according to claim 8, wherein the plurality of lightings are LEDs.