Methods and Apparatus for Active Transparency Modulation

• US 20170323615A1
• Filed: 05/04/2017
• Published: 11/09/2017
• 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.
• Granted Patent: US 10,522,106 B2
• Time in Patent Office: 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 see-through optical lens or waveguide element comprising:

an active transparency modulation film comprising an electrochromic pixel layer applied to one side of the see-through optical lens or waveguide element, each pixel of the electrochromic pixel layer being electrically controllable by a processor to be transparent in a first state and opaque in a second state, whereby patterns of opaque areas may be electrically controlled for projection of images onto the back side of the patterns without the images being ghosted by light coming from the backside of the images.

2. The see-through optical lens or waveguide element of claim 1 wherein the active transparency modulation film is a composite of one or more of transparent polymer substrates, transparent conductive oxide electrodes, thin film transistor arrays, or electrochromic pixel arrays.

3. The see-through optical lens or waveguide element of claim 1 wherein the active transparency modulation film is a tungsten trioxide thin film or polymer dispersed liquid crystal based film laminated on a surface of the see-through optical lens or waveguide element.

4. The see-through optical lens or waveguide element of claim 1 wherein the see-through optical lens or waveguide element is comprised of glass.

5. The see-through optical lens or waveguide element of claim 1 further comprising a graphics processing unit and memory storing a rendered outline and depth buffer information and coupled to a video coprocessor for activating on the electrochromic film only the pixels that are contained inside the outline to create a region of reduced transparency.

6. The see-through optical lens or waveguide element of claim 5 further comprising an imaging unit including a light engine coupled to the graphics processing unit to project an image to the region of reduced transparency to enhance the solidness of the image using the active transparency modulation film.

7. The see-through optical lens or waveguide element of claim 1 wherein each pixel of the electrochromic pixel layer is modulated by proportional voltage modulation between transparency and opaqueness.

8. The see-through optical lens or waveguide element of claim 1 wherein each pixel of the electrochromatic pixel layer is pulse-width modulated for control between transparency and opaqueness.

9. The see-through optical lens or waveguide element of claim 1 as the lenses in a pair of glasses, the active transparency modulation film being oriented to controllably block light from passing through the lenses toward eyes of a wearer of the glasses.

10. The see-through optical lens or waveguide element of claim 9 further comprising one or more environment monitoring cameras.

11. The see-through optical lens or waveguide element of claim 9 further comprising at least one head tracking sensor and at least two eye tracking sensors.

12. 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.

13. The method of claim 12 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.

14. The method of claim 12 wherein the image is generated under program control.

15. The method of claim 12 wherein a degree of transparency of the area of lesser transparency is based on an ambient illumination of the viewer'"'"'s environment.

16. The method of claim 12 wherein defining the area of lesser transparency comprises determining a boundary of the image using an image segmentation process.

17. The method of claim 16 wherein the image segmentation process is a convex hull algorithm.

18. The method of claim 12 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.

19. The method of claim 12 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.

20. 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.