Steerable near-to-eye display and steerable near-to-eye display system

A steerable near-to-eye display is provided and may include, but is not limited to, a first curved support arm configured to rotate about a first axis, a second curved support arm configured to rotate about a second axis, and an ocular assembly coupled to at least one of the first curved support arm and the second curved support arm, the ocular assembly configured to display an image and configured to substantially maintain a position where the first curved support arm crosses the second curved support arm.

TECHNICAL FIELD

The following relates to display systems, and more particularly to a steerable near-to-eye display.

BACKGROUND

Near-to-eye (NTE) display systems are used to display an image to a user at a close proximity to a user's eye. However, typical NTE displays often have a narrow field of view, especially when a compact and lightweight assembly is desired. Field of regard for typical displays is also limited unless the user's head is rotated. Accordingly, it is desirable to provide a NTE display system with a large field of regard without the need to rotate the head each time the instantaneous field of view is moved within the field of regard.

SUMMARY

In accordance with one embodiment, a steerable near-to-eye display is provided. The steerable near-to-eye display may include, but is not limited to, a first curved support arm configured to rotate about a first axis, a second curved support arm configured to rotate about a second axis, and an ocular assembly coupled to at least one of the first curved support arm and the second curved support arm, the ocular assembly configured to display an image and configured to substantially maintain a position where the first curved support arm crosses the second curved support arm.

In accordance with another embodiment, a near-to-eye display system is provided. The near-to-eye display system may include, but is not limited to, a first circular support arm configured to rotate about a first axis, a second circular support arm configured to rotate about a second axis, and an ocular assembly coupled to at least one of the first circular support arm and the second circular support arm, the ocular assembly configured to display an image and configured to substantially maintain a position where the first circular support arm crosses the second circular support arm.

In accordance with yet another embodiment, a near-to-eye display system is provided. The near-to-eye display system may include, but is not limited to, a first partially circular support arm configured to rotate about a first axis, a second partially circular support arm configured to rotate about a second axis, an ocular assembly coupled to at least one of the first partially circular support arm and the second partially circular support arm, the ocular assembly configured to display an image and configured to substantially maintain a position where the first partially curved support arm crosses the second partially curved support arm, a first motor coupled to the first partially circular support arm and configured to rotate the first partially circular support arm about the first axis, a second motor coupled to the second partially circular support arm and configured to rotate the second partially circular support arm about the second axis, and a controller coupled to the first and second motors and configured to control a rotation of the first partially circular support arm and the second partially circular support arm.

DETAILED DESCRIPTION

According to various exemplary embodiments, a steerable near-to-eye display system is provided. The steerable near-to-eye display system may be used in any near-to-eye display application. In some embodiments, for example, the steerable near-to-eye display system may be utilized by a pilot of an aircraft.

FIG. 1is a block diagram of an exemplary steerable near-to-eye (NTE) display100, in accordance with an embodiment. The NTE display100includes at least two support arms110and120, an ocular assembly130and a controller140. The ocular assembly130produces an image to be displayed to a user and is supported by the support arms110and120.

The controller140may be any type of controller. In one embodiment, for example, the controller140is a processor. The processor may be, for example, a central processing unit (CPU), a graphical processing unit (GPU), a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a microcontroller, or any other type of logic device or any combination thereof. The controller140may utilize any combination of hardware, software and firmware to control the NTE display100.

The support arms110and120can be any curved shape. In one embodiment, for example, the support arms110and120are substantially circular. In other embodiments, the support arms110and120may be partially circular where there is a gap to provide clearance for a user's head. In other embodiments, for example, the support arms could be substantially elliptical or partially elliptical in shape.

The support arms110and120can be mounted on a helmet, visor, goggles, or the like. The support arms110and120are positioned to cross each other, as discussed in further detail below. The ocular assembly130is mounted to the support arms110and120such that the ocular assembly130substantially maintains a position where the support arms cross regardless of the respective positions of the support arms110and120. In one embodiment, for example, a sliding mechanism may be used to substantially maintain a position of the ocular assembly130, as discussed in further detail below. The center of curvature for the curved support arms110and120is preferably situated approximately at the center of rotation of the user's eye. One benefit of this configuration is that the eyebox (generally related to the exit pupil) of the ocular assembly130can be minimized.

The support arms110and120each rotate about an axis. In one embodiment, for example, each support arm110or120is rotated about its respective axis by motors150. The motors150may be, for example, servo motors. In other embodiments, the motors150may use a combination of actuators and belts to move the curved support arms110and120. The motors150may move their respective support arms110and120in discrete steps or continuously, depending upon a mechanical drive configuration. The support arms110and120could include optical encoder markings such that a sensor included with the ocular assembly130can provide positional feedback. The positional feedback provided by the sensor can be transmitted to a controller140. The controller140is electrically coupled to the motors150and can instruct the motors to rotate the support arms110and120, as discussed in further detail below. In another embodiment, a linear resistance system could be used to provide positional feedback. Each support arm110or120could include an electrode which traverses a length of a respective support arm110or120. The resistance of each electrode will change depending upon where the support arms110and120cross each other. The resistance of each electrode can be received by the controller140and then translated into a position of each support arm110or120based upon the resistance. The controller can then use the position information to control the movement of the support arms110and120via the motors150. The position information can also be used to control the information displayed, independent of what, if any, servo system is present.

In one embodiment, for example, the controller140instructs the motors150to move the support arms110and120to follow the movement of an eye of a user. A camera160can be coupled to the ocular assembly and be positioned to receive a view of a user's eye. In one embodiment, for example, the camera may be mounted to focus directly on a user's eye. In another embodiment, for example, the camera160could be directed toward a reflective surface of the ocular assembly130which is positioned to reflect an image of the user's eye. The image data is sent to the controller140which processes the image data to determine where the user is looking. The controller140may then send instructions to motors150to move the support arms110and120such that the ocular assembly is positioned in the user's field of view.

In one embodiment, for example, the controller140may be communicatively coupled to the ocular assembly130through the support arms110and120. In this embodiment, the support arms110and120can each include an electrically conductive path from the ocular assembly130to the controller140. The electrically conductive paths on the support arms110and120can act as a two-wire interface between the controller140and ocular assembly130, allowing the components of the NTE display100to pass power, video and/or control signals therebetween. One advantage of using the support arms110and120to pass signals is that bulky cabling can be omitted from the system which could otherwise partially block the user's view.

In some embodiments the support arms110and120may be manually moveable allowing a user to position the ocular assembly130at a desired location. The user could also manually move the support arms110and120to a position out of the user's field of view such that the NTE display100does not block the user's field of view. In one embodiment, for example, the controller140turns off the NTE display100when the NTE display100is manually moved outside the user's field of view, and turns on the NTE display100when the NTE display100is manually moved into the user's field of view. In still other embodiments, the support arms110and120could be moved both manually and automatically, via the motors150.

FIGS. 2-4illustrate perspective views of an exemplary NTE display100. As discussed above, the NTE display100includes two support arms110and120. In the embodiment illustrated inFIG. 2, the support arm110is positioned substantially vertical and the support arm120is positioned substantially horizontally. Accordingly, in the embodiment illustrated inFIG. 2, the support arms110and120are positioned substantially perpendicular to each other. The support arms110and120may be positioned in various other orientations. The support arm geometry can be thought of as controlling the crossing point in the sense of a dual-longitude style angular coordinate system. One example of such a coordinate system might have a north-south polar axis in combination with an east-west polar axis. While distinct from a traditional latitude-longitude coordinate pair, the dual-longitude description still describes each possible orientation. Furthermore, the two axes need not be orthogonal. The relative angle between the axes can be considerably less than ninety degrees, for example by tilting the axis of rotation of support arm110to be closer to the axis of rotation of support arm120inFIG. 2. It is preferred, however, that the geometries swept by rotation of both arm110and arm120remain substantially spherical as well as concentric or identical.

As discussed above, the support arms110and120may each rotate about an axis. The support arm110illustrated inFIG. 2, for example, is rotatable about an axis112as illustrated by the arrow114and the support arm120is rotatable about an axis122as illustrated by the arrow124.FIG. 3illustrates the NTE display100ofFIG. 2where the support arm110has been rotated to the right, from the perspective of the user. As discussed above, the ocular assembly130is coupled to the support arms110and120such that the ocular assembly130substantially maintains a position at the crossing of the support arms110and120. Accordingly, the image produced by the NTE display would be visible when the user is looking to the right and substantially horizontally.FIG. 4illustrates the NTE display100ofFIG. 2where the support arm120has been rotated upwards. Accordingly, the image produced by the NTE display100would be visible when the user is looking to up and straight ahead. WhileFIGS. 3 and 4only illustrated one of the support arms110and120being rotated, both support arms110and120can be rotated to provide a large field of regard to a user. The ocular130is shown as being positioned at the intersection of support arms110and120, but could also be offset a distance from one or both, in any of the four quadrants of the intersection.

While the NTE display100discussed herein uses multiple support arms110and120, in other embodiments only a single support arm may be used when only a single axis of motion is needed. In other embodiments, the second support arm120may be quite short and mounted only to the first support arm, and configured to slide along the length of the first support arm while maintaining a consistent angle with respect to the first support arm. If an actuator is used for moving the second support arm (including optical assembly130) along the length in this case, that actuator could include a motor in combination with a flexible belt or other coupling mechanism.

Returning toFIG. 1, the ocular assembly130includes an image source. The image produced by the ocular assembly can be conformal, non-conformal or a combination thereof. The image may supplement what the user would see without the ocular assembly, overlay an entirely new image or a combination thereof. In one embodiment, for example, the ocular assembly130also includes at least one reflective or semi-reflective surface to direct the image towards a user's eye. The reflective or semi-reflective surface can be made of glass, plastic or the like which allows an image to be reflected therefrom while also allowing the user to see through the reflective or semi-reflective surface. Further, in one embodiment, the support arms110and120may also be made of a transparent or semi-transparent material (e.g., glass, plastic or the like), thereby minimally obstructing a user's field of view.

FIG. 5illustrates a side view of an exemplary NTE display100. The ocular assembly130illustrated inFIG. 5includes an image source510, a beam splitter520and a collimating mirror530. It should be noted that the figure is not necessarily drawn to scale.

The image source510is preferably a small micro display. In some embodiments, for example, an active-matrix liquid crystal display (AMLCD), a liquid crystal on silicon (LCOS) display, an organic light-emitting-diode (OLED) display or other light modulating or light emitting display devices may be used. In other embodiments, where size is less of a concern, larger display devices could be used. In one embodiment, for example, a transparent or semi-transparent OLED or other see-though micro display may be used as the image source510. In another embodiment, for example, when the image source is transparent, or semi-transparent, the image source510can be positioned in front of the collimating mirror, eliminating the need for the beam splitter520.

The image output by the image source510is projected or directed towards the beam splitter520which reflects the image to the collimating mirror530. The collimating mirror530reflects the image to the user's eye540. In another embodiment, for example, one of the support arms110and120may also be used as the collimating mirror to focus the image to the user. In yet another embodiment, for example, the collimating mirror may be replaced with a larger fixed spherical mirror (not illustrated), thereby reducing the amount of mass to be dynamically adjusted when the ocular assembly130is moved. The display location and any intervening optics can be adjusted to match the effective focal length of the spherical mirror. In some of the embodiments discussed herein, where the spherical mirror radius matches the radius of the support arms, the total effective path length between the image source510and the reflector (either a collimating mirror530, one of the support arms110and120or the spherical mirror) should be approximately one-half the radius of the support arms110and120.

As discussed above, the NTE display100may include a camera160to track a position of a user's eye540. In the embodiment illustrated inFIG. 5, the camera160is aimed towards the beam splitter520. The beam splitter520is positioned to reflect an image of the user's eye540, which can then be received by the camera160.

FIG. 6illustrates a side view of another exemplary NTE display100. The ocular assembly130illustrated inFIG. 6includes an image source610and a prism assembly620. The image source610produces an image which is directed towards the prism assembly620. The prism assembly620acts as a collimator and reflects the image towards the user's eye540while at the same time providing a good see-through performance. The prism assembly includes a curved internal combiner surface622from which the rays reflect toward the eye. The extra section to the right of the internal combiner surface622provides undeflected see-through.

In other embodiments, the ocular assembly may utilize a refractive collimator, a waveguide-based combiner system, a catadioptric system or other systems as known in the art.

Other mechanisms to move the ocular assembly130across a user's field of view may be used. For example, multi-bar linkages, multiple solenoid or other linear actuators or galvanometers.FIG. 7, for example, illustrates a side view of yet another exemplary NTE display700NTE display700includes a single support arm110and an ocular assembly130. The ocular assembly130includes an image source710, a beam splitter720and a first collimating mirror730. The image source710, beam splitter720and first collimating mirror730are rotatable about an axis. The controller140connected to the ocular assembly130rotates the image source710, beam splitter720and first collimating mirror730such that an image is projected towards a second collimating mirror740. The second collimating mirror740is movable along the support arm110. The ocular assembly130may be automatically controlled via motors150and a camera160in a similar manner as discussed above, manually controllable, or a combination thereof. In another embodiment, for example, multiple collimating mirrors740may be fixed along the support arm110. In this embodiment, the image source710, beam splitter720and first collimating mirror730can be rotated to project an image towards any of the multiple collimating mirrors740to project the image towards a desired location. In other exemplary embodiments, mirror740can be made as a flat mirror or combiner, as this has the benefit that the collimation optics do not have to dynamically adjust for aberrations associated with an off-axis curved combiner. In yet other embodiments, the orientation of mirror740can be controlled by rocking or translating mirror740tangentially along an ellipsoidal path associated with support arm110, to ensure the correct angle for directing the displayed light toward the pupil of the eye.

Returning toFIG. 1, the NTE display100may further include at least one clamping mechanism170. In one embodiment, for example, the support arms110and120and the ocular assembly130may each have a clamping mechanism170coupled thereto. In other embodiments, for example, only the support arms110and120may include a clamping mechanism170. The clamping mechanism170fixes the position of the respective support arms110and120and ocular assembly130to minimize vibrations and other unintended motion of the respective components. The clamping mechanism may utilize any type of motion dampening technology, for example, electromechanical, electromagnetic or electrostatic. One benefit of the embodiment, for example, is that by clamping the support arms110and120and the ocular assembly130in place, the NTE display100does not have to waste any power utilizing the motors150to hold the components in place.

Further, in one embodiment, for example, support arms110and120each include a counter weight180. The counter weights180can be placed to manage and partially counteract inertial effects associated with the movement of the support arms110and120due to the motors150or from manual movement.

The NTE display100may also include an enclosure190. The enclosure can enclose some of, or all of, the support arms110and120, the ocular assembly130, the clamping mechanisms170and the counterweights180. In one embodiment, for example, the enclosure190includes two curved transparent surfaces where some or all of the components of the NTE display100are enclosed therein. The curve may substantially match the curve of the support arms110and120. In another embodiment, for example, the enclosure could be a flat surface.

In yet another embodiment, for example, the ocular assembly130may be coupled to the enclosure. In this embodiment, the ocular assembly could be mounted to the enclosure via a magnetic retaining piece, for example on the opposing side of the enclosure surface. The ocular assembly could then be manually moved along the surface of the enclosure190. Bearings, or other low friction sliders, could be coupled to the ocular assembly130to ease the movement along the surface of the enclosure.

As discussed above, the ocular assembly130may include a sliding mechanism to substantially maintain a position of the ocular assembly at a position along one or more of the support arms110and120.FIG. 8illustrates an exemplary sliding mechanism800. The sliding mechanism800includes brackets810and820for coupling to the support arms110and120. The sliding mechanism800further includes a pin mechanism830to enable relative rotation about the pin mechanism830between the two brackets810and820. In one embodiment, for example, the ocular assembly130could attach to (or be an extension of) one of these two brackets810and820. In the embodiment illustrated inFIG. 8, the channel of each bracket810and820are curved to match the curvatures of the two support arms110and120. However, in other embodiments, the channels could be straight.

The term “exemplary” is used herein to represent one example, instance or illustration that may have any number of alternates. Any implementation described herein as “exemplary” should not necessarily be construed as preferred or advantageous over other implementations.

Although several exemplary embodiments have been presented in the foregoing description, it should be appreciated that a vast number of alternate but equivalent variations exist, and the examples presented herein are not intended to limit the scope, applicability, or configuration of the invention in any way. To the contrary, various changes may be made in the function and arrangement of the various features described herein without departing from the scope of the claims and their legal equivalents.