Liquid crystal lens driver electronics for eye protection, high speed shuttering with consistent performance

• US 5,751,258 A
• Filed: 09/04/1996
• Issued: 05/12/1998
• Est. Priority Date: 03/25/1991
• Status: Expired due to Term

• Current Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Original Assignee: OSD Envizion, Inc.
• Inventors: Fergason, John D., Fergason, Jeffrey K.
• Primary Examiner(s): BRIER, JEFFERY A
• Application Number:
  US08/707,269
• Time in Patent Office: 615 Days
• Field of Search: 359/84, 359/85, 250/205, 250/215, 250/229, 345/87, 345/89, 345/94, 345/7, 349/13, 349/14, 349/116, 2/8
• US Class Current: 345/7
• CPC Class Codes: A61F 9/067 with variable transmission
• CPC Class Codes: G01J 1/02 Details
• 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 1/44 Electric circuits for command of an exposure part G03B7/02
• CPC Class Codes: G01J 2001/0276 Protection
• CPC Class Codes: G02F 1/13306 Circuit arrangements or driving methods for the control of single liquid crystal cells G02F1/132, G02F1/133382 take precedence

Abstract

A power supply circuit for a liquid crystal welding lens or shutter provides a consistent and stable regulated power signal for driving or powering the liquid crystal shutter for maintaining stable performance over the life of the power supply and a battery level indicator feature to provide advance warning of degraded device performance.

Claims

1. A portable power supply for a protective optical lens system that has at least relatively greater and lesser light transmission characteristics, comprising

a regulated power supply for supplying substantially regulated power for driving such lens system from an unregulated power source,

said regulated power supply comprising a regulated voltage reference, a DC to DC oscillator, a voltage power input, and inductor and capacitor circuit with diode isolation to develop and to store in said capacitor a voltage of a magnitude greater than the voltage of said voltage power input, a switch for switching a connection between said inductor and capacitor, said oscillator being coupled to operate said switch to open and close state to accumulate charge and voltage in said capacitor, and a comparator circuit for comparing the voltage of said capacitor with said regulated voltage reference to control operation of said oscillator to develop a voltage in said capacitor in proportional relation to a comparison between said regulated voltage reference and the voltage in said capacitor,

output circuit means for coupling power from said regulated power supply to such lens system to cause such lens system to achieve greater and lesser light transmission characteristics.

2. The power supply of claim 1, said output circuit means comprising a level control means to adjust regulated power output level to achieve greater or lesser light transmission characteristics.

3. The power supply of claim 1, further comprising dark state adjust means for adjusting the darkness of the optical lens system in the lesser light transmission state over a prescribed range.

4. The power supply of claim 3, further comprising variable fine tuning adjustment means for further adjusting the darkness of the optical lens system in the lesser light transmission state over a range that is a percentage less than 100% of the range of said dark state adjust means.

5. The power supply of claim 1, further comprising an unregulated power supply comprising a depletable power source.

6. The power supply of claim 5, said unregulated power supply comprising a battery.

7. The power supply of claim 5, said unregulated power supply comprising a capacitor.

8. The power supply of claim 1, further comprising an unregulated power supply comprising a solar cell.

9. A portable power supply for a protective optical lens system that has at least relatively greater and lesser light transmission characteristics, comprising

input means for receiving an electrical input from a depletable power source,

circuit means coupled to said input means for converting such electrical input for use to operate such lens system,

monitor means for monitoring the power level of the electrical input received from such power source,

signal means coupled with respect to said monitor means for signaling that such power level has dropped below a prescribed level,

said monitor means comprising a comparator circuit for comparing the voltage of such electrical input with a regulated voltage, and said signal means being coupled to said comparator circuit to be energized thereby when a voltage proportionally representative of such electrical input drops below the voltage established by such regulated voltage.

10. The power supply of claim 9, said depletable power source comprises a battery.

11. The power supply of claim 9, said depletable power source comprises a capacitor.

12. The power supply of claim 9, said signal means comprising a light emitting diode.

13. The power supply of claim 9, said signal means comprising a series of light emitting diodes.

14. The power supply of claim 9, said signal means comprising a multicolor light emitting diode.

15. The power supply of claim 9, said signal means comprising a light.

16. The power supply of claim 9, said signal means comprising an audible indicator.

17. The power supply of claim 9, said monitor means comprising a comparator circuit for comparing the voltage of such electrical input with a regulated voltage, and said signal means being coupled to said comparator circuit to be energized thereby when a voltage proportionally representative of such electrical input drops below the voltage established by such regulated voltage.

18. A portable power supply for a protective optical lens system that has at least relatively greater and lesser light transmission characteristics, comprising

a regulated power supply for supplying substantially regulated power for driving such lens system in response to a power input from a power source,

circuit means coupled to said input means for converting such electrical input for use to operate such lens system,

output circuit means for coupling power from said regulated power supply to such lens system to cause such lens system to achieve greater and lesser light transmission characteristics,

monitor means for monitoring the power level of the electrical input received from such power source,

signal means coupled with respect to said monitor means for signaling that such power level has dropped below a prescribed level.

19. Protective eye gear for welding, comprising a variable shutter to control the amount of light transmitted to the eyes, the shutter being operable between relatively clear and relatively dark states, a power supply circuit for the shutter, mounting means for mounting the shutter, dark state adjusting circuit for determining the light transmission and blocking characteristics of the shutter when in the reduced transmission state, an adjustment device for adjusting said dark state adjusting circuit, said adjusting device being relatively inaccessible to a user wearing the protective eye gear, and variable fine tune adjusting means accessible while the eye gear is worn by a person for limited adjustment of the dark state over a range that is significantly smaller than the full range of the dark state adjusting circuit thereby to avoid accidental adjustment to the relatively clear state while welding is occurring and means for selectively connecting said variable fine tune adjusting means to the power supply.

20. The eye gear of claim 19, said eye gear comprising a welding helmet having a wall, and wherein at least part of said variable fine tune adjusting means is mounted in said wall.

31. The eye gear of claim 19, wherein the magnitude of the maximum change due to the fine tune adjustment is on the order of about 20% of the adjustment range achieved when using said adjusting device.

21. Protective eye gear, comprising:

a variable shutter to control the amount of light transmitted to the eyes, the shutter being operable between relatively clear and relatively dark states;

a power supply circuit for the variable shutter;

first adjusting means for adjusting the dark state; and

second adjusting means for adjusting the dark state.

22. The eye gear of claim 21, wherein the first and second adjusting means provide for adjustment of the dark state over a first and second adjustment range, respectively.

23. The eye gear of claim 22, wherein the second adjustment range is a fraction of the first adjustment range.

24. The eye gear of claim 21, further comprising a helmet having a wall, and wherein at least part of the second adjusting means is mounted to the wall.

25. The eye gear of claim 21, further comprising means for selectively connecting the second adjusting means to the power supply.

26. Protective eye gear, comprising:

a variable shutter to control the amount of light transmitted to the eyes, the shutter being operable between relatively clear and relatively dark states; and

means for selectively adjusting a time which it takes for the shutter to transition from the relatively dark state to the relatively clear state.

27. The eye gear of claim 26, said means for adjusting comprising a potentiometer.

28. A power supply for a protective optical shutter that is operable between relatively clear and relatively dark states, comprising:

power supply means for providing a driving signal to drive the optical shutter; and

frequency varying means for adjusting the frequency of said driving signal as a function of whether the optical shutter is to be driven in the relatively clear state or the relatively dark state, and

wherein the driving signal has a relatively low frequency when driving the optical shutter in the relatively dark state and a relatively high frequency when driving the optical shutter in the relatively clear state.

29. The power supply of claim 28, wherein the driving signal has a relatively large magnitude to drive the optical shutter in the relatively dark state and a relatively small magnitude to drive the optical shutter in the relatively clear state.

30. An energization circuit for a liquid crystal light shutter device, comprising

output means for supplying an output to the liquid crystal device for causing such device to produce at least two different optical responses, one output comprising a relatively low voltage level to cause relatively high light transmission optical response and a second output comprising a relatively high voltage level to cause a relatively low light transmission optical response.

driving means for driving said output means at one level to produce one optical response and at a second level to produce the second optical response,

said driving means including frequency means for changing the frequency at which said output means is driven whereby at such one relatively low voltage level the frequency is relatively higher than the frequency at such second level.