Holographic pattern generation for head-mounted display (HMD) eye tracking using an array of parabolic mirrors
A system for making a holographic medium for use in generating light patterns for eye tracking includes a light source configured to provide light and a beam splitter configured to separate the light into a first portion of the light and a second portion of the light that is spatially separated from the first portion of the light. The system also includes a first set of optical elements configured to transmit the first portion of the light for providing a first wide-field beam onto an optically recordable medium, a second set of optical elements configured to transmit the second portion of the light for providing a second wide-field beam, and a plurality of parabolic reflectors optically coupled with the second set of optical elements and configured to receive the second wide-field beam and project a plurality of separate light patterns onto the optically recordable medium for forming the holographic medium.
1. A system for making a holographic medium for use in generating light patterns for eye tracking, the system including:
a light source configured to provide light;
a beam splitter configured to separate the light into a first portion of the light and a second portion of the light that is spatially separated from the first portion of the light;
a first set of optical elements configured to transmit the first portion of the light for providing a first wide-field beam onto an optically recordable medium;
a second set of optical elements configured to transmit the second portion of the light for providing a second wide-field beam; and
a plurality of parabolic reflectors optically coupled with the second set of optical elements and configured to receive the second wide-field beam and project a plurality of separate light patterns onto the optically recordable medium for forming the holographic medium, wherein:
the plurality of parabolic reflectors includes a first parabolic reflector having a first size with a first curvature, and a second parabolic reflector having a second size with a second curvature, and
the first size is different from the second size or the first curvature is different from the second curvature.
2. The system of claim 1 , wherein the plurality of parabolic reflectors is arranged in a circular configuration.
3. The system of claim 1 , wherein the plurality of parabolic reflectors is arranged in a rectangular configuration.
4. The system of claim 1 , wherein each parabolic reflector of the plurality of parabolic reflectors is configured to focus a respective portion of the second wide-field beam on a reference focal plane.
5. The system of claim 1 , wherein the first parabolic reflector is configured to project a first light pattern of the plurality of separate light patterns onto the optically recordable medium at a first angle, and the second parabolic reflector is configured to project a second light pattern of the plurality of separate light patterns onto the optically recordable medium at a second angle that is distinct from the first angle.
6. The system of claim 1 , including a plurality of attenuators optically coupled with the plurality of parabolic reflectors and configured to attenuate intensity of light provided by respective parabolic reflectors of the plurality of parabolic reflectors.
7. The system of claim 1 , including one or more lenses coupled with the plurality of parabolic reflectors.
8. A method for making a holographic medium for use in generating light patterns for eye tracking, the method including:
providing light from the light source of the system of claim 1 ;
separating, with the beam splitter of the system, the light into a first portion of the light and a second portion of the light that is spatially separated from the first portion of the light;
transmitting the first portion of the light through the first set of optical elements of the system to provide a first wide-field beam;
transmitting the second portion of the light through the second set of optical elements of the system to provide a second wide-field beam that is spatially separated from the first wide-field beam onto an optically recordable medium;
reflecting the second wide-field beam with the plurality of parabolic reflectors of the system to provide a plurality of separate light patterns; and
concurrently projecting the first wide-field beam and reflecting the plurality of separate light patterns onto the optically recordable medium to form the holographic medium.
9. The method of claim 8 , wherein the plurality of parabolic reflectors is arranged in a circular configuration.
10. The method of claim 9 , including projecting the plurality of separate light patterns arranged in a circular configuration.
11. The method of claim 8 , wherein the plurality of parabolic reflectors is arranged in a rectangular configuration.
12. The method of claim 11 , including projecting the plurality of separate light patterns arranged in a rectangular configuration.
13. The method of claim 8 , including focusing the second wide-field beam onto a focal plane that is adjacent to the optically recordable medium.
14. The method of claim 8 , including projecting, with the first parabolic reflector of the plurality of parabolic reflectors, a first light pattern of the plurality of separate light patterns onto the optically recordable medium at a first angle, and projecting, with the second parabolic reflector of the plurality of parabolic reflectors, a second light pattern of the plurality of separate light patterns onto the optically recordable medium at a second angle that is distinct from the first angle.
15. The method of claim 8 , including attenuating, with a first attenuator optically coupled with the first parabolic reflector of the plurality of parabolic reflectors, intensity of light provided to the first parabolic reflector by a first attenuation factor and attenuating, with a second attenuator optically coupled with the second parabolic reflector, that is distinct from the first parabolic reflector, of the plurality of parabolic reflectors, intensity of light provided to the second parabolic reflector by a second attenuation factor that is distinct from the first attenuation factor.
16. A system for making a holographic medium for use in generating light patterns for eye tracking, the system including:
a light source configured to provide light;
a beam splitter configured to separate the light into a first portion of the light and a second portion of the light that is spatially separated from the first portion of the light;
a first set of optical elements configured to transmit the first portion of the light for providing a first wide-field beam onto an optically recordable medium;
a second set of optical elements configured to transmit the second portion of the light for providing a second wide-field beam;
a plurality of parabolic reflectors optically coupled with the second set of optical elements and configured to receive the second wide-field beam and project a plurality of separate light patterns onto the optically recordable medium for forming the holographic medium; and
a plurality of attenuators optically coupled with the plurality of parabolic reflectors and configured to attenuate intensity of light provided by respective parabolic reflectors of the plurality of parabolic reflectors,
wherein the plurality of attenuators includes a first attenuator optically coupled with a first parabolic reflector of the plurality of parabolic reflectors and configured to attenuate intensity of light provided by the first parabolic reflector by a first attenuation factor and a second attenuator optically coupled with a second parabolic reflector, that is distinct from the first parabolic reflector, of the plurality of parabolic reflectors and configured to attenuate intensity of light provided by the second parabolic reflector by a second attenuation factor that is distinct from the first attenuation factor.