Wide-field of view (FOV) imaging devices with active foveation capability

• US 9,851,563 B2
• Filed: 04/04/2013
• Issued: 12/26/2017
• Est. Priority Date: 04/05/2012
• Status: Active Grant

• Current Assignee: Magic Leap, Inc.
• Original Assignee: Magic Leap, Inc.
• Inventors: Gao, Chunyu, Hua, Hong
• Primary Examiner(s): Rahaman, Mohammed
• Assistant Examiner(s): Boylan, James
• Application Number:
  US13/856,847
• Publication Number:
  US 20140218468A1
• Time in Patent Office: 1,727 Days
• Field of Search: 348 36, 348 39
• 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 foveated imaging system capable of capturing a wide field of view image and a foveated image, where the foveated image is a controllable region of interest of the wide field of view image.

Claims

1. A foveated imaging system, capable of capturing a wide field of view image and a foveated image, where the foveated image is a controllable region of interest of the wide field of view image, the system comprising:

a. an objective lens, facing an external scene, configured to receive incoming light from an external scene and to focus the light upon a beamsplitter;

b. a beamsplitter, configured to split the incoming light from the external scene into a wide field of view imaging path and a foveated imaging path;

c. the wide field of view imaging path comprising;

i. a first stop, separate from the objective lens, which limits the amount of light received in the wide field of view path from the beamsplitter;

ii. a wide field of view imaging lens, different from the objective lens and configured to receive light from the first stop and form a wide field view image on a wide field of view imaging sensor;

iii. a wide field of view imaging sensor, configured to receive light from the wide field of view imaging lens;

d. the foveated imaging path consisting of;

i. a second stop, which limits the amount of light received in the foveated imaging path from the beamsplitter;

ii. a scanning mirror, the scanning mirror being a multi-axis movable mirror configured to reflect the light from the beamsplitter;

iii. a reflective surface, disposed upon the beamsplitter, configured to direct light reflected by the scanning mirror;

iv. a foveated imaging lens, configured to receive a portion of the light, associated with a region of interest of the external scene, from the scanning mirror, and form a foveated image on a foveated imaging sensor; and

v. a foveated imaging sensor, configured to receive light from the foveated imaging lens,

wherein the incoming light from the external scene passes through the objective lens-to the beamsplitter,

wherein the beamsplitter divides the light into the two optical paths, the wide field of view imaging path and the foveated imaging path,

wherein the light passes through the first stop to the wide field of view imaging lens-along the wide field of view imaging path,

wherein the wide field of view imaging lens focuses the wide field of view image upon the wide field of view imaging sensor,

wherein the light passes through the second stop to the scanning mirror along the foveated imaging path,

wherein the scanning mirror reflects a region of interest toward the foveated imaging lens through the reflective surface on the beam splitter,

wherein the foveated imaging lens focuses the foveated image upon the foveated imaging sensor, and

wherein the two images are recorded by the wide field of view and foveated sensors, a wide field of view image and a higher resolution image of the region of interest within it.

2. The foveated imaging system according to claim 1, wherein the objective lens is disposed on the front of the system,

wherein the beamsplitter is disposed adjacent to objective lens, and receives light from the objective lens,

wherein the first stop is in optical communication with the beamsplitter along the wide field of view imaging path,

wherein the second stop is in optical communication with the beamsplitter along the foveated imaging path,

wherein the scanning mirror is disposed immediately behind the second stop in the foveated imaging path, and receives light from the beamsplitter along the foveated imaging path and reflects the light back to the beamsplitter,

wherein the wide-field of view imaging lens is disposed to face the first stop along the wide field of view imaging path, and receives light from the beamsplitter through the first stop-along the wide field of view path,

wherein the foveated imaging lens is disposed to face the beamsplitter, and receives light from the beamsplitter reflected from the scanning mirror along the foveated imaging path,

wherein the wide-field of view imaging sensor is disposed to face the wide field of view imaging lens, and

wherein the foveated imaging sensor is disposed to face the foveated imaging lens.

3. The foveated imaging system according to any one of the preceding claims, where the objective lens is a group of rotationally symmetric lenses to capture a substantially hemispherical shaped field of view.

4. The foveated imaging system according to any one of claims 1-2, where the objective lens utilizes a curved mirror along with necessary rotationally symmetric refractive optical elements to capture a substantially ring shaped field of view.

5. The foveated imaging system according to any one of claims 1-2, where the foveated imaging lens contains aspherical reflective or refractive surfaces.

6. The foveated imaging system according to any one of claims 1-2, where the wide field of view imaging lens is a group of rotationally symmetric lenses that magnify the wide field of view image.

7. The foveated imaging system according to any one of claims 1-2, where the wide field of view imaging lens contains aspherical reflective or refractive surfaces.