Head-mounted display unit with adaptable facial interface

1. A facial interface for a head-mounted display to be worn on a head of a user, the facial interface comprising:

an upper portion that engages an upper facial region above eyes of the user; and

a lower portion that engages a lower facial region below the eyes of the user;

wherein the lower portion has a lower shear compliance that is greater than an upper shear compliance of the upper portion to provide a low restriction to movement of the lower facial region as compared to the upper facial region,

wherein the upper portion has an upper shear range of displacement that is at most seventy-five percent of a lower shear range of displacement of the lower portion.

2. The facial interface according to claim 1 , further comprising a light seal that engages a face below the lower portion;

wherein the lower portion includes a lower facial support having a pivot mechanism that provides the lower shear compliance, the pivot mechanism including one of an elongated roller, a spherical roller, or a multi-axis gimbal and a spring that provides normal compliance in a normal direction; and

wherein the lower portion has a lower normal compliance in the normal direction that is greater than an upper normal compliance of the upper portion in the normal direction, and the lower normal compliance is greater than the upper normal compliance by having at least one of a lesser stiffness or a greater range of displacement in the normal direction.

3. The facial interface according to claim 1 , wherein the lower shear compliance is greater than the upper shear compliance by having at least one of a lesser stiffness or a greater shear range of displacement.

4. The facial interface according to claim 3 , wherein the lower portion has a lower normal compliance in a normal direction that is greater than an upper normal compliance of the upper portion in the normal direction.

5. The facial interface according to claim 4 , wherein the lower normal compliance is greater than the upper normal compliance by having at least one of a lesser stiffness or a greater range of displacement.

6. The facial interface according to claim 1 , wherein the lower portion includes a lower facial support having a pivot mechanism that provides the lower shear compliance.

7. The facial interface according to claim 6 , wherein the pivot mechanism includes one of an elongated roller, a spherical roller, or a multi-axis gimbal.

8. The facial interface according to claim 7 , wherein the pivot mechanism further includes a spring that provides normal compliance in a normal direction.

9. The facial interface according to claim 1 , further comprising a light seal that engages a face of the user below the lower portion of the facial interface.

10. The facial interface according to claim 1 , further comprising an upper facial support in the upper portion, a lower facial support in the lower portion, and one or more selective stiffness devices each associated with one or more of the upper facial support or the lower facial support, wherein the one or more selective stiffness devices are electronically operable to vary the upper shear compliance or the lower shear compliance.

11. The head-mounted display according to claim 1 , further comprising a chassis, an upper facial support coupled to the chassis and forming the upper portion, a lower facial support coupled to the chassis and forming the lower portion, and one or more normal position adjustment devices each associated with one or more of the upper facial support or the lower facial support, wherein the one or more normal position adjustment devices are electronically operable to change a position of one or more of the upper facial support or the lower facial support relative to the chassis in a normal direction.

12. A head-mounted display to be worn on a head of a user comprising:

a display assembly having a display; and

a facial interface coupled to the display assembly for supporting the display assembly on a face of the user, the facial interface including a first facial support that engages an upper facial region above eyes of the user with a first stiffness, a second facial support that engages a lower facial region below the eyes of the user with a second stiffness, and a third facial support that engages a nose of the user with a third stiffness;

wherein first stiffness is at least two times stiffer than the second stiffness in a shear direction and the third stiffness is less than the first stiffness in the shear direction to limit movement of the head-mounted display based on movement of the lower facial region and the nose.

13. The head-mounted display according to claim 12 , wherein the second stiffness is less than the first stiffness in a normal direction;

wherein the first facial support, the second facial support, and the third facial support are different types selected from a group consisting of a sprung load spreader, an elongated roller, a spherical roller, and a gimbal.

14. The head-mounted display according to claim 12 , wherein the second stiffness is less than the first stiffness in a normal direction.

15. The head-mounted display according to claim 12 , wherein the first facial support, the second facial support, and the third facial support are each a type selected from a group consisting of a sprung load spreader, an elongated roller, a spherical roller, and a gimbal.

16. The head-mounted display according to claim 15 , wherein the first facial support, the second facial support, and the third facial support are different types selected from the group.

17. The head-mounted display according to claim 12 , further comprising a movement sensor for measuring movement of the user, a controller, and one or more selective stiffness devices each associated with one or more of the first facial support, the second facial support, or the third facial support, wherein the controller operates the one or more selective stiffness devices according to the movement sensor to vary one or more of the first stiffness, the second stiffness, or the third stiffness.

18. The head-mounted display according to claim 12 , further comprising a position sensor for measuring a position of the display relative to an eye of the user, a controller, and one or more normal position adjustment devices, wherein the controller operates the one or more normal position adjustment devices to change a position of one or more of the first facial support, the second facial support, or the third facial support in a normal direction relative to the display.

19. A facial interface for a head-mounted display to be worn on a head of a user, the facial interface comprising:

an upper portion that engages an upper facial region above eyes of the user; and

a lower portion that engages a lower facial region below the eyes of the user; and

a central portion located between the upper portion and the lower portion that engages a central facial region located between the upper facial region and the lower facial region,

wherein the central portion has a central shear compliance that is greater than an upper shear compliance of the upper portion to provide a low restriction to movement of the central facial region as compared to the upper facial region,

wherein the upper portion has an upper shear range of displacement that is at most seventy-five percent of a central shear range of displacement of the central portion.

20. The facial interface according to claim 19 , wherein central portion has a central normal compliance in the normal direction that is greater than an upper normal compliance of the upper portion in the normal direction, and the central normal compliance is greater than the upper normal compliance by having at least one of a lesser stiffness or a greater range of displacement in the normal direction.

21. The facial interface according to claim 19 , wherein the central shear compliance is greater than the upper shear compliance by having at least one of a lesser stiffness or a greater shear range of displacement.

22. The facial interface according to claim 19 , wherein the central portion includes a central facial support having a pivot mechanism that provides the central shear compliance.