Helmet mounted display

Claim 2

A display assembly suitable for mounting on a helmet, comprising: spatial light modulator means for forming a display; a source of laser light; optical path means for providing an optical path between the source of laser light and the spatial light modulator means so that the laser light illuminates the spatial light modulator means, the optical path means including a single optical fiber along which the laser light for illuminating the spatial light modulator means is conveyed; optical system means for forming an image of the display superposed on the field of view of the wearer of the helmet, the optical system means including an objective system to produce an intermediate image of the display, the intermediate image lying in a plane, means, including a holographic collimating and combining element, for producing said image of the display from the intermediate image, and a diffuser located in the plane of the intermediate image; and a polarising beam splitter interposed between the spatial light modulator means and the optical system means.

Claim 3

A display assembly as claimed in claim 1, wherein the optical path means further comprises another diffuser which is interposed between the source of laser light and the spatial light modulator means.

Claim 4

A display assembly as claimed in claim 1, wherein the diffuser comprises a holographic diffuser.

Claim 5

A display assembly as claimed in claim 1, wherein the diffuser comprises a Dammann grating.

Claim 6

A display assembly suitable for mounting on a helmet, comprising: spatial light modulator means for forming a display, the spatial light modulator means reflecting light; a source of laser light; optical path means for providing an optical path between the source of laser light and the spatial light modulator means so that the laser light illuminates the spatial light modulator means, the optical path means including a single optical fiber along which the laser light for illuminating the spatial light modulator means is conveyed; and optical system means for forming an image of the display superposed on the field of view of the wearer of the helmet, the optical system means including an objective system to produce an intermediate image of the display, the intermediate image lying in a plane, means, including a holographic collimating and combining element, for producing said image of the display from the intermediate image, a diffuser located in the plane of the intermediate image, and an objective lens which is disposed adjacent the spatial light modulator means, the objective lens being traversed by both the optical path and by modulated light reflected by the spatial light modulator means.

Claim 7

A display assembly suitable for mounting on a helmet, comprising: spatial light modulator means for forming a display, the spatial light modulator means reflecting light; a source of laser light; optical path means for providing an optical path between the source of laser light and the spatial light modulator means so that the laser light illuminates the spatial light modulator means, the optical path means including a single optical fiber along which the laser light for illuminating the spatial light modulator means is conveyed; and optical system means for forming an image of the display superposed on the field of view of the wearer of the helmet, the optical system means including an objective system to produce an intermediate image of the display, the intermediate image lying in a plane, means, including a holographic collimating and combining element, for producing said image of the display from the intermediate image, a diffuser located in the plane of the intermediate image, and an objective lens which is disposed adjacent the spatial light modulator means, the objective lens being traversed by both the optical path and by modulated light reflected by the spatial light modulator means.

Claim 8

A display assembly as claimed in claim 5, further comprising a first polariser which is traversed by the reflected light, and wherein the optical path means further comprises a second polariser.

Claim 9

A display assembly suitable for mounting on a helmet, comprising: spatial light modulator means for forming a display; a source of laser light; optical path means for providing an optical path between the source of laser light and the spatial light modulator means so that the laser light illuminates the spatial light modulator means, the optical path means including a single optical fiber along which the laser light for illuminating the spatial light modulator means is conveyed and a mode scrambler connected to the single optical fiber; and optical system means for forming an image of the display superposed on the field of view of the wearer of the helmet, the optical system means including an objective system to produce an intermediate image of the display, the intermediate image lying in a plane, means, including a holographic collimating and combining element, for producing said image of the display from the intermediate image, and a diffuser located in the plane of the intermediate image.

Claim 10

A display assembly suitable for mounting on a helmet, comprising: spatial light modulator means for forming a display; a source of laser light; optical path means for providing an optical path between the source of laser light and the spatial light modulator means so that the laser light illuminates the spatial light modulator means, the optical path means including a single optical fiber along which the laser light for illuminating the spatial light modulator means is conveyed and a mode scrambler connected to the single optical fiber; and optical system means for forming an image of the display superposed on the field of view of the wearer of the helmet, the optical system means including an objective system to produce an intermediate image of the display, the intermediate image lying in a plane, means, including a holographic collimating and combining element, for producing said image of the display from the intermediate image, and a diffuser located in the plane of the intermediate image.

Claim 11

A display assembly suitable for mounting on a helmet, comprising: spatial light modulator means for forming a display; a source of laser light; optical path means for providing an optical path between the source of laser light and the spatial light modulator means so that the laser light illuminates the spatial light modulator means, the optical path means including a single optical fiber along which the laser light for illuminating the spatial light modulator means is conveyed; and optical system means for forming an image of the display superposed on the field of view of the wearer of the helmet, the optical system means including an objective system to produce an intermediate image of the display, the intermediate image lying in a plane, means, including a holographic collimating and combining element, for producing said image of the display from the intermediate image, and a diffuser located in the plane of the intermediate image, the diffuser comprising a Dammann grating.

Claim 12

A display assembly suitable for mounting on a helmet, comprising: spatial light modulator means for forming a display; a source of laser light; optical path means for providing an optical path between the source of laser light and the spatial light modulator means so that the laser light illuminates the spatial light modulator means, the optical path means including a single optical fiber along which the laser light for illuminating the spatial light modulator means is conveyed; and optical system means for forming an image of the display superposed on the field of view of the wearer of the helmet, the optical system means including an objective system to produce an intermediate image of the display, the intermediate image lying in a plane, means, including a holographic collimating and combining element, for producing said image of the display from the intermediate image, and a diffuser located in the plane of the intermediate image, the diffuser comprising a Dammann grating.

Claim 13

A display assembly as claimed in claim 8, wherein the helmet has a visor, and wherein the holographic collimating and combining element is disposed on the visor.

Claim 14

A display assembly as claimed in claim 8, wherein the holographic collimating and combining element is a reflection hologram.

Claim 15

A display assembly as claimed in claim 8, wherein the spatial light modulator means comprises an electrically addressable spatial light modulator.

Claim 16

A display assembly as claimed in claim 8, wherein the source of laser light comprises a helium neon laser.

Claim 17

A display assembly as claimed in claim 8, wherein the spatial light modulator means comprises a reflective light modulator in which the angle of polarisation of light reflected therefrom is selectively adjustable.

Claim 18

A display assembly as claimed in claim 8, wherein the spatial light modulator means comprises a transmissive light modulator.

Claim 19

A display assembly, comprising: a source of laser light; spatial light modulator means for forming a display, the spatial light modulator means being illuminated by the laser light; an objective system to produce an intermediate image of the display, the intermediate image lying in a plane; means, including a holographic collimating combiner, for producing, from the intermediate image, another image that is visible to a viewer; and a diffuser located in the plane of the intermediate image, wherein the objective system comprises a plurality of transmission holograms which are disposed between the diffuser and the spatial light modulator means.

Claim 20

A display assembly, comprising: a source of laser light; spatial light modulator means for forming a display, the spatial light modulator means being illuminated by the laser light; an objective system to produce an intermediate image of the display, the intermediate image lying in a plane; means, including a holographic collimating combiner, for producing, from the intermediate image, another image that is visible to a viewer; and a diffuser located in the plane of the intermediate image, wherein the objective system comprises a plurality of transmission holograms which are disposed between the diffuser and the spatial light modulator means.

Claim 21

A display assembly as claimed in claim 15, further comprising a transparent body having a surface, the holographic collimating combiner being disposed on the surface of the transparent body.

Claim 22

A display assembly as claimed in claim 15, further comprising a single optical fiber which carries all of the laser light that illuminates the spatial light modulator means.

Claim 23

A display assembly as claimed in claim 15, wherein the spatial light modulator means is reflective, and further comprising a positive lens through which the laser light passes both before and after reflection by the spatial light modulator means.

Claim 24

A display assembly as claimed in claim 15, wherein the diffuser comprises a Dammann grating.