Displaying information to aircraft pilots

Claim 2

A virtual image display for an aircraft having a windscreen characterized by a symmetrically oriented center line, the display comprising: a light transmissive optical combining element laterally positioned across the windscreen and attached thereto; first image generating means located within the cockpit of the aircraft for projecting a virtual image of preselected symbols on the right side of the combining element, with respect to the centerline; second image generating means located within the cockpit of the aircraft for projecting a virtual image of separate preselected symbols on the left side of the combining element, with respect to the centerline, the right and left virtual images being contiguous; a pilot's head being locatable in a space where the field of view of each eye through the combining element includes the superposition of an observed object appearing outside the windscreen and the virtual image appearing on the same side of the centerline as that eye thereby avoiding either of the pilot's eyes from seeing the virtual image appearing on an opposite side of the centerline.

Claim 3

The system set forth in claim 1 wherein the combining element is a straight plate including diffraction means serving as a reflecting lens for collimating rays of light impinging thereon from the first and second image generating means.

Claim 4

The system set forth in claim 1 wherein the combining element has a preselected curvature and serves as a reflecting lens for collimating rays of light impinging thereon from the first and second generating means.

Claim 5

The system set forth in claim 1 together with means connected to the first and second mage generating means for providing a correction factor to the position of each projected symbol as a function of azimuth and elevation symbol position on the combining means, thereby compensating for parallax error of the superimposed object and ensuring alignment between the superimposed object and the symbols.

Claim 6

The system set forth in claim 1 wherein eye boxes are defined when the pilot's head is correctly positioned to perceive the field of view, and further wherein the overlap in the horizontal dimension of each eye box, if used, is less than the least interocular dimension of the population of pilots to be served by the system.

Claim 7

The system set forth in claim 4 wherein eye boxes are defined when the pilot's head is correctly positioned to perceive the field of view, and further wherein the horizontal dimension of each eye box, if overlap is used, is less than the least interocular dimension of the population of pilots to be served by the system.

Claim 8

The system set forth in claim 6 wherein the symbols include instrument panel displays projected on a lower portion of the combining element so that the virtual image thereof appears in an area of a cockpit normally occupied by an instrument panel thereby enabling removal of conventional instrument panel displays.

Claim 11

9 . A part of an aircraft or a simulation of part of an aircraft, the aircraft part or simulation having a windscreen (10) and, further back than the front of the windscreen but forwardly of a position normally to be occupied by a pilot's head, a light-transmissive optical combining element (48), there being image-generating means (52) for projecting virtual images on the combining element representing relevant data so that the pilot can view said images and simultaneously see, through the combining element, objects forwardly of the windscreen, characterised in that said image-generating means (52) is a first of two image-generating means (52 and 50) and it projects virtual images of first preselected symbols on the right side of an area of the combining element (48) so that such images can be seen by the pilot's right eye but not his left eye when his head is in the'normal position, whereas the second image-generating means (50) projects virtual images of second preselected symbols, different from the first preselected symbols, on the left side of said area of the combining element (48) where such images can be seen by the pilot's left eye but not his right eye when his head is in the normal position.

Claim 12

9 . A part of an aircraft or a simulation of part of an aircraft, the aircraft part or simulation having a windscreen (10) and, further back than the front of the windscreen but forwardly of a position normally to be occupied by a pilot's head, a light-transmissive optical combining element (48), there being image-generating means (52) for projecting virtual images on the combining element representing relevant data so that the pilot can view said images and simultaneously see, through the combining element, objects forwardly of the windscreen, characterised in that said image-generating means (52) is a first of two image-generating means (52 and 50) and it projects virtual images of first preselected symbols on the right side of an area of the combining element (48) so that such images can be seen by the pilot's right eye but not his left eye when his head is in the'normal position, whereas the second image-generating means (50) projects virtual images of second preselected symbols, different from the first preselected symbols, on the left side of said area of the combining element (48) where such images can be seen by the pilot's left eye but not his right eye when his head is in the normal position.

Claim 13

An aircraft part or simulation according to claim 9, wherein opposite sides of the combining element (48) are very close to or touching opposite sides of the windscreen (10) and/or the top of the combining element (48) is very close to or touching the windscreen (10).