Actively quenched lamp, infrared thermography imaging system, and method for actively controlling flash duration

• US 20050018748A1
• Filed: 07/24/2003
• Published: 01/27/2005
• Est. Priority Date: 07/24/2003
• Status: Abandoned Application

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Filkins, Robert John, Ringermacher, Harry Israel, Zhang, Richard S.
• Application Number:
  US10/627,206
• Publication Number:
  US 20050018748A1
• Time in Patent Office: Days
• US Class Current: 374/121
• CPC Class Codes: G01N 25/72 Investigating presence of flaws

Abstract

An actively quenched lamp includes a lamp and an active quenching means configured to quench the lamp. An infrared (“IR”) thermography imaging system includes at least one lamp configured to heat a surface of an object to be imaged, at least one active quenching means configured to quench the lamp, and an IR camera configured to capture a number of IR image frames of the object. A method, for actively controlling flash duration for IR thermography, includes generating an initial control signal T0, a lamp control signal T1, and a control signal T2. The method further includes activating a quenching means in response to initial control signal T0, to allow current I to flow to a lamp, activating the lamp in response to lamp trigger signal T1, and turning off the quenching means in response to control signal T2 to cut off the current I to the lamp.

Claims

1. An actively quenched lamp comprising:

a lamp; and

an active quenching means configured to quench said lamp.

2. The actively quenched lamp of claim 1, wherein said active quenching means is configured to receive a control signal T2 and to quench said lamp in response to the control signal T2.

3. The actively quenched lamp of claim 2, wherein said active quenching means comprises a high-voltage, high current switch, wherein said high-voltage, high current switch opens in response to the control signal T2.

4. The actively quenched lamp of claim 3, wherein said active quenching means is further configured to receive an initial control signal T0, and wherein said high-voltage, high current switch closes in response to the initial control signal T0.

5. The actively quenched lamp of claim 3, further comprising a timing generator configured to supply the control and initial control signals T2, T0 and to supply a lamp trigger signal T1, wherein said lamp is activated in response to the lamp trigger signal T1.

6. The actively quenched lamp of claim 3, wherein said timing generator comprises a computer.

7. The actively quenched lamp of claim 3, wherein said active quenching means further comprises a switch drive circuit configured to receive a logic level signal and to generate a switch-drive signal in response, wherein the control signal T2 is a logic level signal, and wherein said high-voltage, high current switch opens in response to the switch-drive signal TS2 that corresponds to the control signal T2.

8. The actively quenched lamp of claim 7, wherein the switch-drive signal TS2 is a switch-drive voltage signal TS2.

9. The actively quenched lamp of claim 3, wherein said high-voltage, high current switch comprises a power semiconductor switch.

10. The actively quenched lamp of claim 3, wherein said high-voltage, high current switch comprises an insulated gate bipolar transistor (IGBT).

11. The actively quenched lamp of claim 9, wherein the power semiconductor switch is selected from the group consisting of a silicon controlled rectifier, a gate turn-on thryristor, a MOSFET, a insulated gate commutated thyristor (“

IGCT”

), and combinations thereof.

12. The actively quenched lamp of claim 1, wherein said lamp comprises a halogen lamp.

13. The actively quenched lamp of claim 1, wherein said lamp comprises a flash lamp.

14. The actively quenched lamp of claim 1, wherein said lamp comprises an arc lamp.

15. An infrared (“

IR”

) thermography imaging system comprises;

at least one lamp configured to heat a surface of an object to be imaged;

at least one active quenching means configured to quench said at least one lamp; and

an IR camera configured to capture a plurality of IR image frames of the object.

16. The IR thermography imaging system of claim 15, wherein said active quenching means is configured to receive an initial control signal T0 and a control signal T2, and wherein said active quenching means is further configured to allow a current flow I to said lamp in response to the initial control signal T0 and to quench said lamp in response to the control signal T2.

17. The IR thermography imaging system of claim 16, wherein said active quenching means comprises a high-voltage, high current switch, wherein said high-voltage, high current switch closes in response to the initial control signal T0 and opens in response to the control signal T2.

18. The IR thermography imaging system of claim 17, further comprising a timing generator configured to supply the initial control signal T0 and the control signal T2 and to supply a lamp trigger signal T1, wherein said lamp is activated in response to the lamp trigger signal T1.

19. The IR thermography imaging system of claim 16, wherein said active quenching means further comprises a switch drive circuit configured to receive a logic level signal and to generate a switch-drive signal in response, wherein the control signal T2 is a logic level signal, and wherein said high-voltage, high current switch opens in response to the switch-drive signal that corresponds to the control signal T2.

20. The IR thermography imaging system of claim 19, wherein the switch-drive signal is a switch-drive voltage signal.

21. The IR thermography imaging system of claim 17, wherein said high-voltage, high current switch comprises a power semiconductor switch.

22. The IR thermography imaging system of claim 17, wherein said high-voltage, high current switch comprises an insulated gate bipolar transistor.

23. The IR thermography imaging system of claim 22, wherein said lamp comprises a halogen lamp.

24. The IR thermography imaging system of claim 22, wherein said lamp comprises a flash lamp.

25. A method for actively controlling a duration of a flash for infrared (“

IR”

) thermography, said method comprising;

generating an initial control signal T0, a lamp control signal T1, and a control signal T2;

activating a quenching means in response to the initial control signal T0 to allow current I to flow to a lamp;

activating the lamp in response to the lamp trigger signal T1; and

turning off the quenching means in response to the control signal T2 to cut off the current I to the lamp.

26. The method of claim 25, wherein the initial control signal T0 and the control signal T2 comprise logic level signals, and wherein said method further comprises:

generating a switch-drive signal TS2 in response to the control signal T2,

wherein said turning off the quenching means comprises opening a switch in response to the switch-drive signal TS2.

27. The method of claim 26, wherein the switch-drive signal TS2 is a switch-drive voltage signal TS2.