US-12619086-B2 - Near-eye display systems utilizing an array of projectors

US12619086B2US 12619086 B2US12619086 B2US 12619086B2US-12619086-B2

Abstract

The present disclosure describes near-eye display systems including an array of projectors and a one-dimensional exit pupil expander. The array of projectors can be arranged along a first dimension and can output image light towards an input coupler within a waveguide that provides one-dimensional exit pupil expansion. In some implementations, arrays of monochromatic projectors are implemented and arranged in offset columns. The input coupler in-couples the image light from the array of projectors into a TIR path within the waveguide. Different optical elements, including diffractive and reflective optics, may be implemented as the input coupler. The image light travels within the waveguide until it interacts with an output coupler. Upon interaction with the output coupler, the image light is expanded in a second dimension transverse to the first dimension and is coupled out of the waveguide.

Inventors

Joel Steven Kollin
Andreas Georgiou
Ishan CHATTERJEE
Bernard Charles Kress
Maria Esther Pace
Mario Possiwan

Assignees

MICROSOFT TECHNOLOGY LICENSING, LLC

Dates

Publication Date: 20260505
Application Date: 20220914

Claims (20)

1 . A near-eye display system comprising: an array of projector displays arranged in a first dimension, wherein each projector display of the array of projector displays is configured to output image light such that the array of projector displays output image light having an exit pupil expanded in the first dimension; and a waveguide comprising an input coupler to in-couple the image light from the array of projector displays into the waveguide, and an output coupler to expand an exit pupil of the near-eye display system along a second dimension transverse to the first dimension, and out-couple the image light out of the waveguide.
2 . The near-eye display system of claim 1 , wherein the waveguide comprises plastic or glass.
3 . The near-eye display system of claim 1 , wherein projector display of the array of projector displays comprises a light-emitting display or an illuminated light-modulating device.
4 . The near-eye display system of claim 1 , wherein the input coupler comprises one or more of a holographic diffraction grating, a surface relief grating, a prism, or a mirror.
5 . The near-eye display system of claim 1 , wherein the array of projector displays comprises a first plurality of projector displays for outputting light within a wavelength range of 600 nm-770 nm, a second plurality of projector displays for outputting light within a wavelength range of 495 nm-600 nm, and a third plurality of projector displays for outputting light within a wavelength range of 430 nm-495 nm.
6 . The near-eye display system of claim 5 , wherein the input coupler comprises a dichroic filter.
7 . The near-eye display system of claim 1 , wherein the output coupler comprises one or more of a holographic diffraction grating, a surface relief grating, or a partially reflective mirror.
8 . The near-eye display system of claim 1 , wherein the waveguide is curved, and the array of projector displays is arranged in a curved configuration.
9 . The near-eye display system of claim 1 , wherein the array of projector displays comprises a first column of projector displays and a second column of projector displays offset from the first column.
10 . The near-eye display system of claim 1 , wherein the input coupler comprises: a first optical element for in-coupling image light from a first projector display in the array of projector displays having a first portion of a field of view; and a second optical element for in-coupling image light from a second projector display in the array of projector displays having a second portion of the field of view different from the first portion of the field of view.
11 . A near-eye display system comprising: an array of light-emitting displays arranged in a first dimension, wherein each light-emitting display of the array of light-emitting displays is configured to output image light such that the array of light-emitting displays output image light having an exit pupil expanded in the first dimension; and a waveguide comprising: an extended input coupler to in-couple the image light from the array of light-emitting displays having the exit pupil expanded in the first dimension into the waveguide; and an output coupler to expand the in-coupled image light in a second dimension transverse to the first dimension and to out-couple the image light out of the waveguide.
12 . The near-eye display system of claim 11 , wherein the waveguide is made of plastic.
13 . The near-eye display system of claim 11 , wherein the waveguide is made of glass.
14 . The near-eye display system of claim 11 , wherein the extended input coupler comprises one or more of a holographic diffraction grating, a surface relief grating, a prism, a mirror, or a dichroic filter.
15 . The near-eye display system of claim 11 , wherein the output coupler comprises one or more of a holographic diffraction grating, a surface relief grating, or a partially reflective mirror.
16 . The near-eye display system of claim 11 , wherein the waveguide is curved.
17 . A method for providing two-dimensional exit pupil expansion, the method comprising: projecting image light using an array of projector displays arranged in a first dimension, wherein each projector display of the array of projector displays is configured to output image light such that the array of projector displays output image light having an exit pupil expanded in the first dimension; using an input coupler, redirecting the projected image light towards an output coupler within a waveguide in a total internal reflection path; using the output coupler, expanding the redirected image light in a second dimension transverse to the first dimension; and using the output coupler, out-couple the expanded image light out of the waveguide.
18 . The method of claim 17 , wherein the array of projector displays comprises a first plurality of projector displays for outputting light within a wavelength range of 600 nm-770 nm, a second plurality of projector displays for outputting light within a wavelength range of 495 nm-600 nm, and a third plurality of projector displays for outputting light within a wavelength range of 430 nm-495 nm.
19 . The method of claim 17 , wherein the array of projector displays comprises a first column of projector displays and a second column of projector displays offset from the first column.
20 . The method of claim 17 , wherein: the input coupler comprises one or more of a diffraction grating, a prism, a mirror, or a dichroic filter; and the output coupler comprises one or more of a one or more of a holographic diffraction grating, a surface relief grating, or a partially reflective mirror.

Description

BACKGROUND Near-eye display (NED) technology may be used to create a virtual image in the field of view (FoV) of one or both eyes of a user. Such technology may be incorporated into wearable displays such as head-mounted displays (HMDs), which can be implemented in the form of different devices. Common implementations include helmet-mounted displays, eyeglasses, visors, and other eyewear. Rather than creating a real image on a surface, a near-eye display presents the virtual images to the eye such that they appear at a distance, making such technology well-suited for applications in augmented reality (AR), virtual reality (VR), and mixed reality (MR). Near-eye displays generally include a projector and various imaging optics components depending on the specific application. The projector may comprise a light-emitting display (e.g., displays utilizing light-emitting diodes (LEDs), microLEDs (μLEDs), or organic light-emitting diodes (OLEDs)), or an illuminated light-modulating device (e.g., liquid-crystal displays (LCDs), liquid-crystal on silicon (LCOS) displays, or digital micromirror devices (DMDs)). The attainable image resolution, contrast, and color accuracy is a function of a type of projector implemented along with the imaging optics utilized. One class of imaging optics commonly used for NEDs includes waveguide optics. These systems implement a waveguide that collects light at the input and relays it to the eye, allowing for the projector and other components to be located out of the FoV of a user. Additionally, waveguide optics allow for the integration of multiple optical functions into a thin, transparent, lightweight substrate. For example, the waveguide outcouples light at a multiplicity of points, allowing the exit pupil to be replicated and thus expanding the effective eyebox of the NED. SUMMARY Examples are disclosed that relate to near-eye display systems including an array of projectors and a one-dimensional exit pupil expander. The array of projectors can be arranged along a first dimension and can output image light towards an input coupler within a waveguide that provides one-dimensional exit pupil expansion. In some implementations, arrays of monochromatic projectors are implemented and arranged in offset columns. The input coupler couples the image light from the array of projectors into a TIR path within the waveguide. Various optical elements, including diffractive and reflective optics, can be implemented as the input coupler. The image light travels within the waveguide until it interacts with an output coupler. Upon interaction with the output coupler, the image light is expanded in a second dimension transverse to the first dimension and is coupled out of the waveguide. Different optical elements, including diffractive and reflective optics, may be implemented as the output coupler. This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to implementations that solve any or all disadvantages noted in any part of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an example near-eye display system in accordance with an implementation of the present disclosure. FIG. 2 shows an example near-eye display system comprising an eyebox on a side of the waveguide opposite an array of projectors in accordance with an implementation of the present disclosure. FIGS. 3A-3C show example waveguides implementing different types of optical elements as input and output couplers in accordance with various implementations of the present disclosure. FIG. 4 shows an example waveguide for receiving light expanded in one dimension in accordance with an implementation of the present disclosure. FIG. 5 shows an example near-eye display system utilizing bird bath optics and a polarization-selective reflector in accordance with an implementation of the present disclosure. FIG. 6 shows an example near-eye display system implementing full color using monochromatic projectors in accordance with an implementation of the present disclosure. FIG. 7 shows an example near-eye display system implementing full color using diffraction gratings as an input coupler in accordance with an implementation of the present disclosure. FIG. 8 shows an example near-eye display system implementing full color using two sets of monochromatic projectors positioned at opposite ends of a waveguide in accordance with an implementation of the present disclosure. FIG. 9 conceptually illustrates an example of the use of multiple sets of monochromatic projectors in accordance with an implementation of the present disclosure. FIGS. 10A-10D show different example packing arrangements for an array of proje