Method of extending the field of view in a head-up display
First Claim
1. A method for providing an extending instantanous field of view in elevation to a head-up display, said display including a combiner through which a scene may be viewed by an observer, and a display unit having a display surface from which light of a predetermined wavelength is directed by a collimating lens onto the combiner for reflection towards the observer combined with said scene, said method comprising providing a combiner in the form of a thick phase holographic optical element and disposing the thick phase holographic optical element so that the element extends between the limits of the chosen instantaneous field of view in the elevation direction and is oriented so as to provide an extended instantaneous field of view in said direction perpendicular to the nominal sight-line, said element having a holographic fringe pattern formed therein in the form of parallel fringe planes, and said element being disposed such that each fringe plane extends perpendicular to the plane bisecting the angle of intersection between the said nominal sight-line and the optical axis extending between the combiner and the collimating lens, and such that the individual fringe planes are inclined to the plane of the combiner.
3 Assignments
0 Petitions
Accused Products
Abstract
A method is provided for extending the field of view of a head-up display includes a combiner (31) through which a scene may be viewed by an observer (10), and a display unit (14) having a display surface 13 from which light is directed by a collimating lens (17) on to the combiner. The method involves using combiner which comprises a thick phase holographic optical element extending between the limits of the total field of view in the elevation direction and having a fringe pattern formed therein. The pattern is in the form of parallel fringes 32 and the combiner is disposed so that the fringes extend perpendicular to the elevation direction and are aligned perpendicular to the plane bisecting the angle of intersection of the light-line (11) and the optical axis (16) of the collimating lens (17).
11 Citations
5 Claims
- 1. A method for providing an extending instantanous field of view in elevation to a head-up display, said display including a combiner through which a scene may be viewed by an observer, and a display unit having a display surface from which light of a predetermined wavelength is directed by a collimating lens onto the combiner for reflection towards the observer combined with said scene, said method comprising providing a combiner in the form of a thick phase holographic optical element and disposing the thick phase holographic optical element so that the element extends between the limits of the chosen instantaneous field of view in the elevation direction and is oriented so as to provide an extended instantaneous field of view in said direction perpendicular to the nominal sight-line, said element having a holographic fringe pattern formed therein in the form of parallel fringe planes, and said element being disposed such that each fringe plane extends perpendicular to the plane bisecting the angle of intersection between the said nominal sight-line and the optical axis extending between the combiner and the collimating lens, and such that the individual fringe planes are inclined to the plane of the combiner.
Specification