Helmet visor display employing reflective, refractive and diffractive optical elements
First Claim
1. A helmet visor display comprising:
- an image source generator operable to generate an imagea combiner; and
a relay module comprising refractive elements; and
at least one diffractive optical element, said image being relayed from said image generator to said combiner by said relay module;
wherein the relay module is comprised of a front-end collimating lens group disposed close to the combiner, a rear-end focusing lens group disposed close to the image source generator, and a pupil lens group disposed therebetween, and wherein the collimating lens group and the focusing lens group are disposed on opposite sides of the pupil lens group to form a symmetric relay lens group, to partially self-compensate for asymmetric aberrations.
4 Assignments
0 Petitions
Accused Products
Abstract
An improved helmet visor display comprising three elements, including a tilted combiner, a refractive/diffractive relay module, and an image generator. The tilted combiner is a reflective-type combiner having either a spherical surface shape or a generalized aspheric surface shape. The relay module comprises a front-end collimating lens group, a pupil lens group in the middle, and a rear-end focusing lens group. The collimating lens group is comprised of one refractive doublet and one refractive-diffractive optical element. The combination of the refractive doublet and the refractive-diffractive optical element corrects for primary and secondary axial chromatic aberration, and significantly reduces higher order aberration as a result of power reduction in most lens elements. The pupil lens group comprises a conic or aspheric lens which reduces spherical aberration and enlarges the eye pupil. The focusing lens group comprises a refractive doublet and a wedge that relays the light emerging from the pupil lens group onto the image generator. A crown-flint refractive doublet in conjunction with a diffractive optical element may be employed in the focusing lens group to reduce primary and secondary lateral chromatic aberration and chromatic distortion. The wedge is used to reduce axial coma introduced by the tilted combiner.
-
Citations
13 Claims
-
1. A helmet visor display comprising:
-
an image source generator operable to generate an image a combiner; and a relay module comprising refractive elements; and
at least one diffractive optical element, said image being relayed from said image generator to said combiner by said relay module;wherein the relay module is comprised of a front-end collimating lens group disposed close to the combiner, a rear-end focusing lens group disposed close to the image source generator, and a pupil lens group disposed therebetween, and wherein the collimating lens group and the focusing lens group are disposed on opposite sides of the pupil lens group to form a symmetric relay lens group, to partially self-compensate for asymmetric aberrations. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
Specification