Variably Transmittive, Electronically-Controlled Eyewear

• US 20090317773A1
• Filed: 06/24/2008
• Published: 12/24/2009
• Est. Priority Date: 06/24/2008
• Status: Active Grant

• Current Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Original Assignee: The United States of America As Represented By The Secretary of Agriculture
• Inventors: Glaab, Louis J., Schott, Timothy D., Chapman, John J., Howell, Charles T., Fleck, Vincent J.
• Granted Patent: US 8,411,214 B2
• Time in Patent Office: Days
• US Class Current: 434/36
• CPC Class Codes: G09B 9/30 Simulation of view from aircraft
• CPC Class Codes: G09B 9/307 by helmet-mounted projector or display G09B9/36 takes precedence; optical parts of head-up displays G02B27/01
• CPC Class Codes: G09B 9/36 Simulation of night or reduced visibility flight

Abstract

A system and method for flight training and evaluation of pilots comprises electronically activated vision restriction glasses that detect the pilot'"'"'s head position and automatically darken and restrict the pilot'"'"'s ability to see through the front and side windscreens when the pilot-in-training attempts to see out the windscreen. Thus, the pilot-in-training sees only within the aircraft cockpit, forcing him or her to fly by instruments in the most restricted operational mode.

Claims

1. A system for selectively obscuring a user'"'"'s vision, the system comprising:

a head position detection element for detecting a position of the user'"'"'s head;

eyewear having variably transmittive lenses; and

a controller configured to receive user head position information from the head position detection element and further configured to control the transmittivity of the lenses based on the user head position information by varying an electrical signal applied to the lenses.

2. The system of claim 1, wherein the user head position information comprises information regarding an up and down position of the user'"'"'s head relative to a predetermined point in space in front of the user, wherein the controller is configured to reduce the transmittivity to darken the lenses and thereby obscure the user'"'"'s vision when the user'"'"'s up and down head position is above the predetermined point in space, and wherein the controller is configured to increase the transmittivity to lighten the lenses and thereby not obscure the user'"'"'s vision when the user'"'"'s up and down head position is below the predetermined point in space.

3. The system of claim 2, wherein the predetermined point in space is at a border between a windscreen and an instrument panel of an aircraft.

4. The system of claim 1, wherein the user head position information comprises information regarding a left and right position of the user'"'"'s head relative to a predetermined point in space in front of the user, wherein the controller is configured to reduce the transmittivity to darken the lenses and thereby obscure the user'"'"'s vision when the user'"'"'s left and right head position is more than a predetermined distance from the predetermined point in space.

5. The system of claim 1, wherein the head position detection element comprises at least one near-infrared light emitting diode and an associated collimated detector mounted on the user'"'"'s head.

6. The system of claim 5, wherein the head position detection element comprises three near-infrared light emitting diodes, wherein one light emitting diode is mounted in front of the user to detect an up and down position of the user'"'"'s head and one light emitting diode is mounted on each side of the user to detect a left and right position of the user'"'"'s head.

7. The system of claim 1, further comprising:

a gaze direction detection element for detecting a direction of the user'"'"'s gaze;

wherein the controller is further configured to receive user gaze direction information from the gaze direction detection element and further configured to control the transmittivity of the lenses based on the user head position information and the gaze direction information.

8. The system of claim 1, wherein the controller is configured to control the transmittivity of the lenses by varying at least one of an amplitude or a duty cycle of the electrical signal applied to the lenses.

9. The system of claim 1, wherein the system is further configured to receive aircraft altitude information and wherein the system is configured to increase the transmittivity to lighten the lenses and thereby not obscure the user'"'"'s vision when the aircraft altitude information indicates that the aircraft is below a predetermined altitude.

10. The system of claim 1, wherein each variably transmittive lens comprises two stacked variable attenuation optical cells sandwiching a half-wave plate, and

wherein each optical cell comprises (1) a transparent substrate, (2) an optically transparent electrically conductive layer on the substrate, (3) a transmissive type twisted nematic liquid crystal polymer layer on the electrically conductive layer, (4) a first linear polarization layer on the substrate opposite the electrically conductive layer, and (5) a second linear polarization layer on the liquid crystal polymer layer, the second polarization layer having a transmission axis oriented 90 degrees apart from a transmission axis of the first polarization layer.

11. A method of selectively obscuring a user'"'"'s vision, the method comprising the steps of:

providing a head position detection element for detecting a position of the user'"'"'s head;

providing eyewear having variably transmittive lenses; and

providing a controller configured to receive user head position information from the head position detection element and further configured to control the transmittivity of the lenses based on the user head position information by varying an electrical signal applied to the lenses.

12. The method of claim 11, wherein the user head position information comprises information regarding an up and down position of the user'"'"'s head relative to a predetermined point in space in front of the user, wherein the controller is configured to reduce the transmittivity to darken the lenses and thereby obscure the user'"'"'s vision when the user'"'"'s up and down head position is above the predetermined point in space, and wherein the controller is configured to increase the transmittivity to lighten the lenses and thereby not obscure the user'"'"'s vision when the user'"'"'s up and down head position is below the predetermined point in space.

13. The method of claim 12, wherein the predetermined point in space is at a border between a windscreen and an instrument panel of an aircraft.

14. The method of claim 11, wherein the user head position information comprises information regarding a left and right position of the user'"'"'s head relative to a predetermined point in space in front of the user, wherein the controller is configured to reduce the transmittivity to darken the lenses and thereby obscure the user'"'"'s vision when the user'"'"'s left and right head position is more than a predetermined distance from the predetermined point in space.

15. The method of claim 11, wherein the head position detection element comprises at least one near-infrared light emitting diode and an associated collimated detector mounted on the user'"'"'s head.

16. The method of claim 15, wherein the head position detection element comprises three near-infrared light emitting diodes, wherein one light emitting diode is mounted in front of the user to detect an up and down position of the user'"'"'s head and one light emitting diode is mounted on each side of the user to detect a left and right position of the user'"'"'s head.

17. The method of claim 11, further comprising the steps of:

providing a gaze direction detection element for detecting a direction of the user'"'"'s gaze;

wherein the controller is further configured to receive user gaze direction information from the gaze direction detection element and further configured to control the transmittivity of the lenses based on the user head position information and the gaze direction information.

18. The method of claim 11, wherein the controller is configured to control the transmittivity of the lenses by varying at least one of an amplitude or a duty cycle of the electrical signal applied to the lenses.

19. The method of claim 11, further comprising the steps of:

receiving aircraft altitude information, and

increasing the transmittivity to lighten the lenses and thereby not obscure the user'"'"'s vision when the aircraft altitude information indicates that the aircraft is below a predetermined altitude.

20. The method of claim 11, wherein each variably transmittive lens comprises two stacked variable attenuation optical cells sandwiching a half-wave plate, and

wherein each optical cell comprises (1) a transparent substrate, (2) an optically transparent electrically conductive layer on the substrate, (3) a transmissive type twisted nematic liquid crystal polymer layer on the electrically conductive layer, (4) a first linear polarization layer on the substrate opposite the electrically conductive layer, and (5) a second linear polarization layer on the liquid crystal polymer layer, the second polarization layer having a transmission axis oriented 90 degrees apart from a transmission axis of the first polarization layer.

21. A system for selectively obscuring a user'"'"'s vision, the system comprising:

a laser detection element for detecting laser light;

eyewear having variably transmittive lenses; and

a controller configured to receive information from the laser detection element and further configured to control the transmittivity of the lenses based on a detection of laser light by the laser detection element.

22. The system of claim 21, wherein each variably transmittive lens comprises two stacked variable attenuation optical cells sandwiching a half-wave plate, and

wherein each optical cell comprises (1) a transparent substrate, (2) an optically transparent electrically conductive layer on the substrate, (3) a transmissive type twisted nematic liquid crystal polymer layer on the electrically conductive layer, (4) a first linear polarization layer on the substrate opposite the electrically conductive layer, and (5) a second linear polarization layer on the liquid crystal polymer layer, the second polarization layer having a transmission axis oriented 90 degrees apart from a transmission axis of the first polarization layer.