Head mounted display with micro-display alignment mechanism

1. A head mounted display device comprising:

a structural frame arranged generally along a X-axis and a Y-axis for viewing along a Z-axis, the X, Y, and Z axes being mutually perpendicular;

a micro-display coupled to the structural frame, and configured to project visual content in a substantially forward direction along the Z-axis away from a user,

a group of one or more optical elements with reflective optical surfaces coupled to the structural frame and respectively positioned on a front side of the micro-display to reflectively guide a light ray bundle from the micro-display to a user's eye; and

a micro-display alignment mechanism mounted to the structural frame and configured to align and control the reflectively guided light ray bundle from the micro-display to the user's eye by positioning the micro-display along the X and Z axes, the micro-display alignment mechanism comprising:

a micro-display holder configured to hold the micro-display; and

a carriage configured to couple to and constrain motion of the micro-display holder to motion along the X and Z axes and restraining rotational motion of the micro-display holder about the X and Z axes,

wherein the micro-display alignment mechanism fits into an envelope having dimensions of less than 40 mm in X, less than 30 mm in Y, and less than 20 mm in Z.

2. The head mounted display device of claim 1 , wherein the micro-display alignment mechanism is configured to adjust interpupillary distance by linearly displacing the micro-display along the X-axis while constraining against rotational motion about the X-axis and the Z-axis.

3. The head mounted display device of claim 1 , wherein the micro-display alignment mechanism is configured to adjust a focal point in a Z dimension of the reflectively guided light ray bundle by linearly adjusting the position of the micro-display along the Z-axis while constraining against rotational motion about the X-axis and the Z-axis.

4. The head mounted display device of claim 1 , wherein the micro-display alignment mechanism fits into an envelope having dimensions of less than 35 mm in X, less than 20 mm in Y, and less than 15 mm in Z.

5. The head mounted display device of claim 1 , wherein the micro-display alignment mechanism fits into an envelope having dimensions of less than 30 mm in X, less than 19 mm in Y, and less than 14 mm in Z.

6. The head mounted display device of claim 1 , wherein the carriage is configured to constrain user-manipulated motion of the micro-display holder to motion along the X and Z axes.

7. The head mounted display device of claim 1 , wherein the micro-display alignment mechanism comprises:

a X-gear including a user-manipulation portion attached to a shaft configured to be received in a first opening in the carriage; and

a Z-gear including a user-manipulation portion attached to a shaft configured to be received in a second opening in the carriage.

8. The head mounted display device of claim 7 , wherein:

the micro-display holder includes upwardly extending teeth; and

the X-gear shaft is configured to insert into the first opening of the carriage along the Z-axis and includes radially extending teeth to engage the upwardly extending teeth of the micro-display holder.

9. The head mounted display device of claim 8 , wherein engagement of the radially extending teeth of the X-gear shaft to the upwardly extending teeth of the micro-display holder translates rotational motion of the X-gear shaft to linear motion of the micro-display along the X-axis.

10. The head mounted display device of claim 7 , wherein:

the micro-display holder includes downwardly extending teeth; and

the Z-gear shaft is configured to insert into the second opening of the carriage along the X-axis and includes radially extending teeth to engage the downwardly extending teeth of the micro-display holder.

11. The head mounted display device of claim 10 , wherein engagement of the radially extending teeth of the Z-gear shaft to the downwardly extending teeth of the micro-display holder translates rotational motion of the Z-gear shaft to linear motion of the micro-display along the Z-axis.

12. A head mounted display device comprising:

a structural frame arranged generally along a X-axis and a Y-axis for viewing along a Z-axis, the X, Y, and Z axes being mutually perpendicular;

a micro-display coupled to the structural frame, and configured to project visual content in a substantially forward direction along the Z-axis away from a user;

a group of one or more optical elements with reflective optical surfaces coupled to the structural frame and respectively positioned on a front side of the micro-display to reflectively guide a light ray bundle from the micro-display to a user's eye, wherein the group of optical elements comprise:

a first mirror with reflective optical surface facing in a substantially rearward direction along the Z-axis;

a second mirror with a reflective optical surface facing in a substantially forward direction along the Z-axis; and

a third mirror with reflective optical surface facing in a substantially rearward direction along the Z-axis; and

a micro-display alignment mechanism mounted to the structural frame and configured to align and control the reflectively guided light ray bundle from the micro-display to the user's eye by positioning the micro-display along the X and Z axes, wherein the micro-display alignment mechanism fits into an envelope having dimensions of less than 40 mm in X, less than 30 mm in Y, and less than 20 mm in Z.

13. The head mounted display device of claim 12 , wherein the reflective optical surface of the first and third mirrors is a concave reflective optical surface and the reflective optical surface of the second mirror is a convex reflective optical surface.

14. A micro-display alignment mechanism configured to be mounted to a structural frame of a head mounted display device, the structural frame arranged generally along a X-axis and a Y-axis for viewing along a Z-axis, the X, Y, and Z axes being mutually perpendicular, the micro-display alignment mechanism comprising:

a micro-display holder configured to hold a micro-display; and

a carriage configured to couple to and constrain motion of the micro-display holder to motion along the X and Z axes and restraining rotational motion of the micro-display holder to align and control a reflectively guided light ray bundle from the micro-display to a user's eye by positioning the micro-display along the X and Z axes,

wherein the micro-display holder includes a tab that is received into a slot in the carriage wherein the tab and slot cooperate to restrain the motion to the X and Z axes.

15. The micro-display alignment mechanism of claim 14 , comprising:

a X-gear including a user-manipulation portion attached to a shaft configured to be received in a first opening in the carriage; and

a Z-gear including a user-manipulation portion attached to a shaft configured to be received in a second opening in the carriage.

16. The micro-display alignment mechanism of claim 15 , wherein:

the micro-display holder includes upwardly extending teeth; and

the X-gear shaft is configured to insert into the first opening of the carriage along the Z-axis and includes radially extending teeth to engage the upwardly extending teeth of the micro-display holder to translate rotational motion of the X-gear shaft to linear motion of the micro-display along the X-axis.

17. The micro-display alignment mechanism of claim 15 , wherein:

the micro-display holder includes downwardly extending teeth; and

the Z-gear shaft is configured to insert into the second opening of the carriage along the X-axis and includes radially extending teeth to engage the downwardly extending teeth of the micro-display holder to translate rotational motion of the Z-gear shaft to linear motion of the micro-display along the Z-axis.

18. A method of assembling a micro-display mechanism configured to be mounted to a structural frame of a head mounted display device, the structural frame arranged generally along a X-axis and a Y-axis for viewing along a Z-axis, the X, Y, and Z axes being mutually perpendicular, the method comprising:

attaching a micro-display to a first portion of a micro-display holder,

assembling a second portion of the micro-display holder to a carriage configured to couple to and constrain motion of the micro-display holder to motion along the X and Z axes and restraining rotational motion of the micro-display holder to align and control a reflectively guided light ray bundle from the micro-display to a user's eye by positioning the micro-display along the X and Z axes, wherein the micro-display holder includes a tab that is received into a slot in the carriage wherein the tab and slot cooperate to restrain the motion to the X and Z axes;

providing a X-gear including a user-manipulation portion attached to a shaft;

inserting the X-gear shaft into a first opening in the carriage;

providing a Z-gear including a user-manipulation portion attached to a shaft; and

inserting the Z-gear shaft into a second opening in the carriage.