Methods and apparatus for active transparency modulation

• US 10,522,106 B2
• Filed: 05/04/2017
• Issued: 12/31/2019
• Est. Priority Date: 05/05/2016
• Status: Active Grant

• Current Assignee: Ostendo Technologies Inc.
• Original Assignee: Ostendo Technologies Inc.
• Inventors: Hazra, Siddharth S., El-Ghoroury, Hussein S.
• Primary Examiner(s): Sajous, Wesner
• Application Number:
  US15/587,260
• Publication Number:
  US 20170323615A1
• Time in Patent Office: 971 Days
• CPC Class Codes: G02B 2027/0118 comprising devices for improving the contrast of the display / brillance control visibility
• CPC Class Codes: G02B 2027/014 comprising information/image processing systems
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G06F 3/147 using display panels
• CPC Class Codes: G06T 1/20 Processor architectures; Processor configuration, e.g. pipelining
• CPC Class Codes: G06T 11/60 Editing figures and text; Combining figures or text
• CPC Class Codes: G09G 2320/0257 Reduction of after-image effects
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2340/12 Overlay of images, i.e. displayed pixel being the result of switching between the corresponding input pixels
• CPC Class Codes: G09G 2360/08 Power processing, i.e. workload management for processors involved in display operations, such as CPUs or GPUs
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/002 to project the image of a two-dimensional display, such as an array of light emitting or modulating elements or a CRT
• CPC Class Codes: G09G 3/38 using electrochromic devices

Abstract

A viewing system is provided including an active transparency modulation film in the form of addressable arrays of electrochromic pixel structures. The viewing system may be used in, for instance, a head-mounted display (HMD) or head-up display (HUD). The film is located on one side of a viewing lens of the system and is selectively variable from opaque to transparent at certain regions on the lens to provide an opaque silhouetted image upon which a virtual image is projected. The viewing system including the film and pixel structure therefore provide improved viewing by minimizing the undesirable effects of image ghosting in a viewed scene.

Claims

1. A method of minimizing the undesirable effects of image ghosting in a viewed scene of a viewing system, the method comprising:

providing a see-through optical lens or waveguide element with an active transparency modulation film comprising an electrochromatic pixel layer applied to one side of the see-through optical lens or waveguide element, each pixel being electrically controllable by a processor to be transparent in a first state and to be opaque in a second state, and variable between the first state and the second state by proportional voltage or pulse width modulation;

defining, by control of selected pixels of the electrochromatic pixel layer, an area of lesser transparency to a viewer on the see-through optical lens or waveguide element; and

projecting an image onto the area of lesser transparency from the viewing side of the see-through optical lens or waveguide element;

whereby the image is superimposed onto the area of lesser transparency.

2. The method of claim 1 further comprising controlling which pixels are selected to determine the position of the area of lesser transparency of the see-through optical lens or waveguide element and controlling the position of the projected image on the see-through optical lens or waveguide element to keep the projected image superimposed on the area of lesser transparency as the projected image moves relative to the see-through optical lens or waveguide element.

3. The method of claim 1 wherein the image is generated under program control.

4. The method of claim 1 wherein a degree of transparency of the area of lesser transparency is based on an ambient illumination of the viewer'"'"'s environment.

5. The method of claim 1 wherein defining the area of lesser transparency comprises determining a boundary of the image using an image segmentation process.

6. The method of claim 5 wherein the image segmentation process is a convex hull algorithm.

7. The method of claim 1 further comprising scanning for a light source and determining a location of the light source, wherein defining the area of lesser transparency is based on the location of the light source.

8. The method of claim 1 further comprising obtaining information regarding the viewer'"'"'s eye gaze direction, interpupillary distance and head orientation to calculate a depth of the viewer'"'"'s focus.

9. A non-transitory machine-readable medium having instructions stored thereon, which when executed by a processor cause the processor to perform the following method of minimizing the undesirable effects of image ghosting in a viewed scene of a viewing system, the method comprising:

providing a see-through optical lens or waveguide element with an active transparency modulation film comprising an electrochromatic pixel layer applied to one side of the see-through optical lens or waveguide element, each pixel being electrically controllable by a processor to be transparent in a first state and to be opaque in a second state, and variable between the first state and the second state by proportional voltage or pulse width modulation;

defining, by control of selected pixels of the electrochromatic pixel layer, an area of lesser transparency to a viewer on the see-through optical lens or waveguide element; and

projecting an image onto the area of lesser transparency from the viewing side of the see-through optical lens or waveguide element;

whereby the image is superimposed onto the area of lesser transparency.