Apparatus for optical see-through head mounted display with mutual occlusion and opaqueness control capability

• US 9,726,893 B2
• Filed: 09/27/2016
• Issued: 08/08/2017
• Est. Priority Date: 04/05/2012
• Status: Active Grant

• Current Assignee: Magic Leap, Inc.
• Original Assignee: Magic Leap, Inc.
• Inventors: Lin, Yuxiang, Gao, Chunyu, Hua, Hong
• Primary Examiner(s): Won, Bumsuk
• Assistant Examiner(s): Washington, Tamara Y
• Application Number:
  US15/277,887
• Publication Number:
  US 20170031163A1
• Time in Patent Office: 315 Days
• Field of Search: 359618-638, 359402-406, 349 1, 349 5, 349 8, 349 11, 349 13
• CPC Class Codes: G02B 13/06 Panoramic objectives; So-called "sky lenses" including panoramic objectives having reflecting surfaces
• CPC Class Codes: G02B 2027/0118 comprising devices for improving the contrast of the display / brillance control visibility
• CPC Class Codes: G02B 2027/0145 creating an intermediate image
• CPC Class Codes: G02B 2027/015 involving arrangement aiming to get less bulky devices
• CPC Class Codes: G02B 25/001 Eyepieces
• CPC Class Codes: G02B 26/00 Optical devices or arrangements for the control of light using movable or deformable optical elements control of light by modification of the optical properties of the media of the elements involved therein G02F1/00
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 27/1066 for enhancing image performance, like resolution, pixel numbers, dual magnifications or dynamic range, by tiling, slicing or overlapping fields of view
• CPC Class Codes: G02B 27/144 using partially transparent surfaces without spectral selectivity G02B27/147 takes precedence
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• CPC Class Codes: G02B 5/04 Prisms
• CPC Class Codes: G03B 37/02 with scanning movement of lens or cameras
• CPC Class Codes: G06T 19/006 Mixed reality object pose determination, tracking or camera calibration for mixed reality G06T7/00
• CPC Class Codes: H04N 23/45 for generating image signals from two or more image sensors being of different type or operating in different modes, e.g. with a CMOS sensor for moving images in combination with a charge-coupled device [CCD] for still images
• CPC Class Codes: H04N 23/698 for achieving an enlarged field of view, e.g. panoramic image capture

Abstract

The present invention comprises a compact optical see-through head-mounted display capable of combining, a see-through image path with a virtual image path such that the opaqueness of the see-through image path can be modulated and the virtual image occludes parts of the see-through image and vice versa.

Claims

1. A compact optical see-through head-mounted display, capable of combining a see-through path with a virtual view path such that the opaqueness of the see-through path can be modulated and the virtual view occludes parts of the see-through view and vice versa, the display comprising:

a. a microdisplay for generating an image to be viewed by a user, the microdisplay having a virtual view path associated therewith;

b. a transmission-type spatial light modulator (640) for modifying the light from an external scene to block portions of the see-through view that are to be occluded the spatial light modulator having a see-through path (607) associated therewith;

c. an objective optics, facing an external scene, configured to receive the incoming light from the external scene and to focus the light upon the spatial light modulator, where the objective optics is a three-reflection freeform prism, comprising five optical freeform surfaces;

refractive surface S4, reflective surface S5, S4′ and

S6 and refractive surface S7, where the objective optics is configured to form an intermediate image inside the objective optics;

d. a beamsplitter configured to merge a digitally generated virtual image from a microdisplay and a modulated see-through image of an external scene passing from a spatial light modulator, producing a combined image;

e. an eyepiece configured to magnify the combined image, where the eyepiece is a two-reflection freeform prism, comprising four optical freeform surfaces;

refractive surface S1, reflective surface S2, reflective surface S1′ and

refractive surface S3;

f. an exit pupil configured to face the eyepiece, the exit pupil whereupon the user observes the combined view of the virtual and see-through views in which the virtual view occludes portions of the see-through view;

wherein the objective optics is disposed upon a front layer of the display, where the spatial light modulator is disposed on the back layer of the display at or near an intermediate image plane of the see-through path, facing a side of the beam splitter where the microdisplay is disposed on the back layer of the display, facing a different side of the beam splitter where the beam splitter is disposed such that the see-through path is merged with the virtual view path and the light from the merged path is directed to the eyepiece wherein the eyepiece is disposed upon the back layer of the display,

whereupon the incoming light from the external scene enters the objective optics through the refractive surface S4, is consecutively reflected by the reflective surfaces S5, S4′ and

S6, and exits the objective optics through the refractive surface S7 whereupon the incoming light forms an intermediate image at its focal plane on the spatial light modulator, whereupon the spatial light modulator modulates the light in the see-through path to occlude portions of the see-through view, whereupon the spatial light modulator transmits the modulated light into the beam splitter, whereupon the light from the microdisplay enters the beam splitter, whereupon the beamsplitter merges the modulated light in the see-through path with the light in the virtual view path and folds toward the eyepiece for viewing, whereupon the light from the beam splitter enters the eyepiece through the refractive surface S3, then is consecutively reflected by the reflective surfaces S1′ and

S2, and exits the eyepiece through the refractive surface S1 and reaches the exit pupil, where the viewer'"'"'s eye is aligned to see a combined view of a virtual view and a modulated see-through view.

2. The system of claim 1, where the refractive surface S1 and the reflective surface S1′

may the same physical surfaces and possess the same set of surface prescriptions.

3. The system of claim 1, where the refractive surface S4 and the reflective surface S4′

are the same physical surfaces and possess the same set of surface prescriptions.