AUTOMATED SENSITIVITY SETTING FOR AN AUTO-DARKENING LENS IN A WELDING HELMET

• US 20090094721A1
• Filed: 10/03/2008
• Published: 04/16/2009
• Est. Priority Date: 10/11/2007
• Status: Abandoned Application

• Current Assignee: Illinois Tool Works Inc.
• Original Assignee: Illinois Tool Works Inc.
• Inventors: Becker, William J.
• Application Number:
  US12/245,522
• Publication Number:
  US 20090094721A1
• Time in Patent Office: Days
• US Class Current: 2/8.8
• CPC Class Codes: A61F 9/067 with variable transmission
• CPC Class Codes: G01J 1/02 Details
• CPC Class Codes: G01J 1/0219 Electrical interface; User interface
• CPC Class Codes: G01J 1/0228 Control of working procedures; Failure detection; Spectral bandwidth calculation
• CPC Class Codes: G01J 1/04 Optical or mechanical part supplementary adjustable parts
• CPC Class Codes: G01J 1/0411 using focussing or collimating elements, i.e. lenses or mirrors; Aberration correction
• CPC Class Codes: G01J 1/18 using comparison with a reference electric value
• CPC Class Codes: G01J 1/26 adapted for automatic variation of the measured or reference value regulation of light intensity G05D25/00
• CPC Class Codes: G01J 1/4204 with determination of ambient light solar light G01J2001/4266
• CPC Class Codes: G01J 1/46 using a capacitor
• CPC Class Codes: G01J 2001/0276 Protection
• CPC Class Codes: G02F 1/13318 Circuits comprising a photodetector

Abstract

There are provided systems and methods for automatic adjustment of sensitivity threshold settings in an auto-darkening lens. For example, a user may initiate an automatic sensitivity setting process by activating a user interface (e.g., a button, a switch, a slider, etc.). The automatic sensitivity setting process may proceed to gradually increase the sensitivity threshold voltage until it exceeds an optical voltage based on the ambient light. The process may then be terminated. In some embodiments, a hysteresis may be added to the sensitivity threshold voltage to prevent lens flicker. The automatic sensitivity setting process may be implemented in a digital or analog system. These automatic sensitivity setting processes and systems may save time and provide for more precise sensitivity adjustment.

Claims

1. A welding helmet, comprising:

an auto-darkening lens, comprising;

one or more optical sensors configured to sense optical energy;

optical sensing circuitry configured to convert the sensed optical energy into an electrical voltage;

sensitivity circuitry configured to automatically adjust a threshold sensitivity voltage based on the electrical voltage; and

a user input configured to initiate automatic adjustment of the threshold sensitivity voltage.

2. The helmet of claim 1, wherein the threshold sensitivity voltage is adjustable only when initiated by the user input.

3. The helmet of claim 1, wherein the user input comprises a button, a switch, a slider, or a knob.

4. The helmet of claim 1, wherein the user input comprises a power or reset control of the auto-darkening lens.

5. The helmet of claim 1, wherein the user input is electrically connected to the auto-darkening lens.

6. The helmet of claim 1, wherein the user input is wirelessly connected to the auto-darkening lens.

7. The helmet of claim 1, wherein the user input is accessible to a user while wearing the welding helmet.

8. The helmet of claim 1, comprising a comparator configured to compare the electrical voltage to the threshold sensitivity voltage and output a digital signal indicative of the comparison.

9. The helmet of claim 8, wherein the sensitivity circuitry is configured to adjust the threshold sensitivity voltage at least until the digital signal from the comparator changes.

10. The helmet of claim 9, wherein the sensitivity circuitry is configured to adjust the threshold sensitivity voltage by an amount of hysteresis after the digital signal from the comparator changes.

11. The helmet of claim 10, wherein the amount of hysteresis is adjustable.

12. The helmet of claim 1, wherein the sensitivity circuitry comprises a microprocessor.

13. The helmet of claim 12, comprising an analog-to-digital converter configured to convert the electrical voltage from the optical sensing circuitry to a digital signal, wherein the microprocessor is configured to adjust the threshold sensitivity voltage based on the digital signal.

14. The helmet of claim 1, wherein the sensitivity circuitry comprises an integrated circuit counter.

15. The helmet of claim 1, comprising a device configured to alert a user of the automatic adjustment to the threshold sensitivity voltage.

16. The helmet of claim 1, comprising override circuitry configured to enable override of the automatic adjustment to the threshold sensitivity voltage.

17. The helmet of claim 16, wherein the override circuitry enables manual adjustment of the threshold sensitivity voltage relative to the automatically adjusted threshold sensitivity voltage.

18. A method for automatically adjusting sensitivity in an auto-darkening lens, comprising:

detecting ambient light intensity;

converting the ambient light intensity to an optical voltage;

comparing the optical voltage to a sensitivity voltage and outputting a digital signal based on the comparison; and

automatically adjusting the sensitivity voltage stepwise until the digital signal changes value.

19. The method of claim 18, comprising adjusting the threshold sensitivity voltage by an amount of hysteresis after the digital signal from the comparator changes.

20. The method of claim 18, comprising forcing the lens to a darkened state upon first applying power to the lens, restarting the lens, resetting the lens, and/or reinitializing the lens.

21. The method of claim 18, comprising forcing the lens to a darkened state while the sensitivity threshold is being adjusted.

22. An auto-darkening lens, comprising:

a user interface configured to initiate an automatic sensitivity setting process;

sensitivity setting circuitry configured to set a sensitivity voltage to an initial value upon initiation of the automatic sensitivity setting process;

one or more optical sensors configured to detect light intensity;

an optical sensing circuit configured to convert the light intensity to an optical voltage; and

a comparator configured to compare the sensitivity voltage to the optical voltage and output a digital signal indicative of the comparison;

wherein the sensitivity setting circuitry is configured to alter the sensitivity voltage until the digital signal from the comparator changes.

23. The lens of claim 22, wherein the user interface comprises a button, a switch, a slider, or a knob.

24. The lens of claim 22, wherein the sensitivity setting circuitry comprises a microprocessor.

25. The lens of claim 22, wherein the sensitivity setting circuitry comprises an integrated circuit counter.

26. The lens of claim 22, wherein the sensitivity setting circuitry is configured to adjust the sensitivity voltage with hysteresis after the digital signal from the comparator changes.