Patent ID: 11914161
Assignee: LUMUS LTD.
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 13:
14. An apparatus, comprising:
a light-transmitting substrate having at least two parallel major surfaces for guiding light by internal reflection, a first of the major surfaces being deployed in facing relation to an eye;
an image projector that produces light, polarized in a first polarization direction, corresponding to a collimated image;
a first optical coupling configuration that introduces the light corresponding to the collimated image into the light-transmitting substrate such that the light corresponding to the collimated image propagates within the light-transmitting substrate by internal reflection at the parallel major surfaces;
a second optical coupling configuration that deflects a proportion of the light corresponding to the collimated image propagating within the light-transmitting substrate;
an optical element associated with the first of the major surfaces, the optical element configured to selectively apply optical power to incident light in accordance with at least one property of the incident light that includes a polarization direction of the incident light, such that the optical element applies optical power to incident light returned from the eye that is polarized in a second polarization direction orthogonal to the first polarization direction so as to collimate the incident light returned from the eye that is polarized in the second polarization direction, and such that the optical element applies substantially no optical power to the light corresponding to the collimated image coupled out of the light-transmitting substrate, wherein the second optical coupling configuration deflects the collimated light that is polarized in the second polarization direction into the light-transmitting substrate so as to propagate within the light-transmitting substrate by internal reflection;
optics associated with the light-transmitting substrate and configured for converting the collimated light that is polarized in the second polarization direction, propagating within the light-transmitting substrate by internal reflection, into converging beams of captured light, wherein the first optical coupling configuration deflects a proportion of the collimated light that is polarized in the second polarization direction, propagating within the light-transmitting substrate, toward the optics;
an optical sensor deployed for sensing the captured light; and
at least one processor electrically associated with the optical sensor and configured to process signals from the optical sensor to derive a current gaze direction of the eye.