Directionally illuminated waveguide arrangement

• US 10,048,500 B2
• Filed: 01/30/2017
• Issued: 08/14/2018
• Est. Priority Date: 05/18/2012
• Status: Active Grant

• Current Assignee: Reald Spark, LLC
• Original Assignee: Reald Spark, LLC
• Inventors: Woodgate, Graham J., Robinson, Michael G., Harrold, Jonathan, Schuck, Miller H.
• Primary Examiner(s): Wilkes, Zachary
• Assistant Examiner(s): King, George G
• Application Number:
  US15/419,473
• Publication Number:
  US 20170139110A1
• Time in Patent Office: 561 Days
• Field of Search: 359 13, 359466
• CPC Class Codes: G02B 2027/0134 of stereoscopic type
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 27/02 Viewing or reading apparatus stereoscopic systems G02B30/00
• CPC Class Codes: G02B 30/33 involving directional light or back-light sources
• CPC Class Codes: G02B 6/0013 Means for improving the coupling-in of light from the light source into the light guide coupling light into light guides in general G02B6/42
• CPC Class Codes: G02B 6/0023 provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source
• CPC Class Codes: G02B 6/0048 with stepwise taper
• CPC Class Codes: G02B 6/0055 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0061 to provide homogeneous light output intensity
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02B 6/262 Optical details of coupling light into, or out of, or between fibre ends, e.g. special fibre end shapes or associated optical elements
• CPC Class Codes: G02B 6/32 having lens focusing means positioned between opposed fibre ends with lens being an integral part of the single fibre end G02B6/262
• CPC Class Codes: G02C 7/02 Lenses; Lens systems ; Methods of designing lenses
• CPC Class Codes: G02F 1/011 in optical waveguides, not otherwise provided for in this subclass
• CPC Class Codes: H04N 13/00 Stereoscopic video systems; Multi-view video systems; Details thereof
• CPC Class Codes: H04N 13/32 using arrays of controllable light sources; using moving apertures or moving light sources
• CPC Class Codes: H04N 13/324 Colour aspects
• CPC Class Codes: H04N 13/337 using polarisation multiplexing
• CPC Class Codes: H04N 13/344 with head-mounted left-right displays
• CPC Class Codes: H04N 13/354 : for displaying sequentially
• CPC Class Codes: H04N 13/356 : having separate monoscopic and stereoscopic modes
• CPC Class Codes: H04N 13/363 : using image projection screens volumetric display H04N13/388
• CPC Class Codes: H04N 13/368 : for two or more viewers
• CPC Class Codes: H04N 13/371 : for tracking viewers with different interocular distances; for tracking rotational head movements around the vertical axis
• CPC Class Codes: H04N 13/376 : for tracking left-right translational head movements, i.e. lateral movements
• CPC Class Codes: H04N 13/378 : for tracking rotational head movements around an axis perpendicular to the screen
• CPC Class Codes: H04N 13/38 : for tracking vertical translational head movements
• CPC Class Codes: H04N 13/383 : for tracking with gaze detection, i.e. detecting the lines of sight of the viewer's eyes
• CPC Class Codes: H04N 2013/403 : the images being monoscopic
• CPC Class Codes: H04N 2013/405 : the images being stereoscopic or three dimensional

Abstract

Disclosed is a light guiding valve apparatus comprising an optical valve, a two dimensional light source array and a focusing optic for providing large area collimated illumination from localized light sources. A stepped waveguide may be a stepped structure, in which the steps may be extraction features optically hidden to guided light, propagating in a first forward direction. Returning light propagating in a second backward direction may be refracted, diffracted, or reflected by the features to provide discrete illumination beams exiting from the top surface of the waveguide. A two dimensional array of viewing windows may be produced. Such controlled illumination may provide for efficient, multi-user autostereoscopic displays with wide viewing freedom and low cross talk and near-eye displays that are substantially transparent.

Claims

1. A head-mounted apparatus, comprising:

a waveguide comprising an input end, and first and second, opposed guide surfaces for guiding light along the waveguide, the first guide surface being arranged to guide light by total internal reflection and the second guide surface having a stepped shape comprising a plurality of facets extending in a lateral direction across the waveguide and oriented to reflect input light from the input end through the first guide surface as output light, and intermediate regions between the facets that are arranged to direct light through the waveguide without extracting it, the waveguide attached to a head worn mount arranged to extend across at least one eye of a user when worn on the head of the user; and

an illumination system selectively operable to provide the input light directed from different lateral positions distributed in the lateral direction and further directed in different input directions distributed perpendicular to the lateral direction, the output light in output directions that are distributed, with respect to a normal to the first guide surface, in the lateral direction in dependence on the lateral position of the input light and are further distributed, with respect to a normal to the first guide surface, perpendicular to the lateral direction in dependence on the input direction of the input light; and

further comprising a control system arranged to operate the illumination system to provide the input light directed from the different lateral positions and further directed in the different input directions in accordance with image data representing an image.

2. A head-mounted apparatus according to claim 1, wherein the pitch of the facets is irregular.

3. A head-mounted apparatus according to claim 1, further comprising a compensating optical element extending across the second guide surface of the waveguide and having a surface facing the second guide surface that has a matching shape.

4. A head-mounted apparatus according to claim 1, being a pair of spectacles comprising lenses arranged to extend across both eyes of the user when the pair of spectacles is worn.

5. A pair of spectacles according to claim 4, wherein the lenses are corrective lenses having optical power for correcting eyesight.

6. A pair of spectacles according to claim 5, wherein the corrective lenses are separate elements from the waveguide.

7. A pair of spectacles according to claim 5, wherein the corrective lenses are formed by a guide surface of the waveguide.

8. A near-eye display apparatus arranged to display a collimated image represented by image data, the display apparatus comprising:

a waveguide comprising an input end, and first and second, opposed guide surfaces for guiding light along the waveguide, the first guide surface being arranged to guide light by total internal reflection and the second guide surface having a stepped shape comprising a plurality of facets extending in a lateral direction across the waveguide and oriented to reflect input light from the input end through the first guide surface as output light, and intermediate regions between the facets that are arranged to direct light through the waveguide without extracting it;

an illumination system selectively operable to provide the input light directed from different lateral positions distributed in the lateral direction and further directed in different input directions distributed perpendicular to the lateral direction, the output light in output directions that are distributed, with respect to a normal to the first guide surface, in the lateral direction in dependence on the lateral position of the input light and are further distributed, with respect to a normal to the first guide surface, perpendicular to the lateral direction in dependence on the input direction of the input light; and

a control system arranged to operate the illumination system to provide the input light directed from the different lateral positions and further directed in the different input directions in accordance with the image data.

9. A near-eye display apparatus according to claim 8, wherein the illumination system comprises a one-dimensional array of light sources distributed across the input end of the waveguide in the lateral direction to provide the input light from different lateral positions distributed in the lateral direction and a deflector element arranged between the array of light sources and the waveguide that is selectively operable to deflect the light output by the array of light sources by different amounts perpendicular to the lateral direction to provide the input light in different input directions distributed perpendicular to the lateral direction, the control system being arranged to operate the operate the array of light sources to display successive lines of image data and to operate the deflector element in synchronization therewith.

10. A method of displaying a collimated image, the method comprising:

using a waveguide arrangement comprising a waveguide comprising an input end, and first and second, opposed guide surfaces for guiding light along the waveguide, the first guide surface being arranged to guide light by total internal reflection and the second guide surface having a stepped shape comprising a plurality of facets extending in a lateral direction across the waveguide and oriented to reflect input light from the input end through the first guide surface as output light, and intermediate regions between the facets that are arranged to direct light through the waveguide without extracting it, the waveguide further comprising an illumination system selectively operable to provide the input light directed from different lateral positions distributed in the lateral direction and further directed in different input directions distributed perpendicular to the lateral direction, the output light in output directions that are distributed, with respect to a normal to the first guide surface, in the lateral direction in dependence on the lateral position of the input light and are further distributed, with respect to a normal to the first guide surface, perpendicular to the lateral direction in dependence on the input direction of the input light;

operating the illumination system to provide the input light directed from the different lateral positions and further directed in the different input directions in accordance with image to be displayed so that the output light represents said image as a collimated image; and

displaying the collimated image for viewing by a user.