Optical alignment method and system for transparent displays to overcome parallax
A method is performed using a transparent display alignment system in a vehicle. The transparent display alignment system includes a transparent display through which a user's eyes behind the transparent display view an external scene in front of the transparent display. The method comprises: receiving an eye position of the eyes, a vehicle position for the vehicle, and an external object position of an external object in the external scene; computing a parallax-free position on the transparent display that intersects with a line-of-sight from the eye position to the external object position through the transparent display, at least based on the eye position, the vehicle position, and the external object position; and positioning a graphic object on the transparent display at the parallax-free position to align the eye position, the graphic object, and the external object to avoid parallax when the eyes view the external object through the transparent display.
1 . A transparent display alignment system, comprising:
a transparent display through which eyes of a user view an external scene in front of the transparent display, which is fixed in position and physically detached from the user;
a reference display spaced-apart from the transparent display;
aim sights, including a first visible marker on the transparent display and a second visible marker on the reference display and spaced-apart from the first visible marker along an aim site-line extending from a fixed eye position behind the transparent display, through the aim sights, and to the external scene, such that the aim sights serve as an eye-alignment guide for moving the eyes to the fixed eye position for parallax-free viewing of the external scene; and
a controller coupled to the transparent display to perform:
computing a parallax-free position on the transparent display that intersects with a sight-line from the fixed eye position, through the transparent display, and to an external object in the external scene; and
positioning a graphic object on the transparent display at the parallax-free position to avoid parallax when the external object is viewed through the transparent display from the fixed eye position.
2 . The transparent display alignment system of claim 1 , wherein the transparent display is detached from the user to allow relative movement between the user and the transparent display.
3 . The transparent display alignment system of claim 1 , wherein the controller is configured to perform positioning by:
positioning the graphic object on the transparent display at the parallax-free position to align the fixed eye position, the graphic object, and the external object to avoid the parallax when the eyes view the external object through the transparent display from the fixed eye position.
4 . The transparent display alignment system of claim 1 , wherein:
the second visible marker includes a reticle presented on the reference display.
5 . The transparent display alignment system of claim 4 , wherein:
the reticle includes a virtual reticle.
6 . The transparent display alignment system of claim 1 , wherein:
the first visible marker is a physical marker that is affixed to the transparent display.
7 . The transparent display alignment system of claim 1 , wherein:
the first visible marker is a virtual marker displayed on the transparent display.
8 . The transparent display alignment system of claim 1 , wherein:
the transparent display alignment system is deployed in an aircraft or a ground vehicle.