Pulse driving circuit

• US 20070252807A1
• Filed: 04/30/2007
• Published: 11/01/2007
• Est. Priority Date: 04/28/2006
• Status: Abandoned Application

• Current Assignee: InnoLux Corporation
• Original Assignee: Innolux Display Corporation (InnoLux Corporation)
• Inventors: Lu, Jian-Hui, Zhou, Tong
• Application Number:
  US11/796,881
• Publication Number:
  US 20070252807A1
• Time in Patent Office: Days
• US Class Current: 345/102
• CPC Class Codes: H05B 41/2824 using control circuits for the switching element H05B41/2822 takes precedence

Abstract

An exemplary pulse driving circuit (200) includes a pulse generator (210) configured for generating a pulse signal for driving the pulse driving circuit; a capacitor (220); an NMOS (negative metal-oxide semiconductor) transistor (230) comprising a gate electrode configured to be connected to the pulse generator via the capacitor, a drain electrode configured to be connected to a load circuit, and a source electrode configured to be connected to a DC (direct current) power supply (270); a current limiting resistor (240) connected between the gate electrode and the source electrode of the NMOS transistor; and a diode (250) comprising a positive terminal connected to the source electrode of the NMOS transistor and a negative terminal connected to the gate electrode of the NMOS transistor.

Claims

1. A pulse driving circuit comprising:

a pulse generator configured for generating a pulse signal for driving the pulse driving circuit;

a capacitor;

an NMOS (negative metal-oxide semiconductor) transistor comprising a gate electrode connected to the pulse generator via the capacitor, a drain electrode configured to be connected to a load circuit, and a source electrode configured to be connected to a DC (direct current) power supply;

a current limiting resistor connected between the gate electrode and the source electrode of the NMOS transistor; and

a diode comprising a positive terminal connected to the source electrode of the NMOS transistor and a negative terminal connected to the gate electrode of the NMOS transistor.

2. The pulse driving circuit as claimed in claim 1, further comprising a DC power supply connected to the source electrode of the NMOS transistor, wherein an output voltage of the DC power supply is approximately twelve volts.

3. The pulse driving circuit as claimed in claim 1, wherein a width of the pulse signal is in the range from 0˜

5 volts.

4. The pulse driving circuit as claimed in claim 3, wherein a frequency of the pulse signal is approximately equal to fifty-two thousand hertz.

5. The pulse driving circuit as claimed in claim 1, wherein a resistance “

R”

of the current limiting resistor and a capacitance “

C”

of the capacitor satisfy the following formula;

R·

C=2 milliseconds.

6. The pulse driving circuit as claimed in claim 5, wherein the resistance of the current limiting resistor is approximately equal to 2 KΩ

.

7. The pulse driving circuit as claimed in claim 5, wherein the capacitance of the capacitor is approximately equal to 1 μ

F.

8. The pulse driving circuit as claimed in claim 1, wherein an endurance of the diode is approximately equal to seventy-five volts.

9. The pulse driving circuit as claimed in claim 1, wherein the pulse generator is a pulse width modulation integrated circuit.

10. The pulse driving circuit as claimed in claim 1, wherein the load circuit is a coil of a transformer.

11. A liquid crystal display (LCD) device comprising:

an LCD panel;

at least one backlight configured for illuminating the LCD panel; and

an inverter configured for driving the at least one backlight, the inverter comprising a pulse driving circuit, the pulse driving circuit comprising;

a pulse generator configured for generating a pulse signal for driving the pulse driving circuit;

a capacitor;

an NMOS (negative metal-oxide semiconductor) transistor comprising a gate electrode connected to the pulse generator via the capacitor, a drain electrode configured to be connected to a load circuit, and a source electrode configured to be connected to a DC (direct current) power supply;

a current limiting resistor connected between the gate electrode and the source electrode of the NMOS transistor; and

a diode comprising a positive terminal connected to the source electrode of the NMOS transistor and a negative terminal connected to the gate electrode of the NMOS transistor.

12. The LCD device as claimed in claim 11, further comprising a DC power supply connected to the source electrode of the NMOS transistor, wherein an output voltage of the DC power supply is approximately twelve volts.

13. The LCD device as claimed in claim 11, wherein a width of the pulse signal is in the range from 0˜

5 volts.

14. The LCD device as claimed in claim 13, wherein a frequency of the pulse signal is approximately equal to fifty-two thousand hertz.

15. The LCD device as claimed in claim 11, wherein a resistance “

R”

of the current limiting resistor and a capacitance “

C”

of the capacitor satisfy the following formula;

R·

C=2 milliseconds.

16. The LCD device as claimed in claim 15, wherein the resistance of the current limiting resistor is approximately equal to 2 KΩ

.

17. The LCD device as claimed in claim 15, wherein the capacitance of the capacitor is approximately equal to 1 μ

F.

18. The LCD device as claimed in claim 11, wherein an endurance of the diode is approximately equal to seventy-five volts.

19. The LCD device as claimed in claim 11, wherein the pulse generator is a pulse width modulation integrated circuit.

20. The LCD device as claimed in claim 11, wherein the load circuit is a coil of a transformer.