Active Shielding Against Intense Illumination (ASAII) System for Direct Viewing

• US 20150092083A1
• Filed: 09/30/2013
• Published: 04/02/2015
• Est. Priority Date: 09/30/2013
• Status: Active Grant

• Current Assignee: Nghia Trong Lam
• Original Assignee: Nghia Trong Lam
• Inventors: Lam, Nghia Trong
• Granted Patent: US 9,323,053 B2
• Time in Patent Office: Days
• US Class Current: 348/234
• CPC Class Codes: G02B 2027/0118 comprising devices for improving the contrast of the display / brillance control visibility
• CPC Class Codes: G02B 2027/0138 comprising image capture systems, e.g. camera
• 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 27/0101 characterised by optical features G02B27/0172 takes precedence
• CPC Class Codes: G02B 27/017 Head mounted
• CPC Class Codes: H04N 23/71 Circuitry for evaluating the brightness variation

Abstract

A technique/system using imaging cameras to detect and actively track intense light sources, such as the Sun, then provide electronically-generated and localized shades, via the Liquid Crystal Display (LCD) shutter screen imbedded on viewing glasses or windshields, tracking the intense projections as they traverse across the viewing glasses during dynamic motion allowing the viewer to directly and comfortably observe the scene with intense light sources and any displays or objects in direct or nearby line-of-sight that are normally washed-out by eye saturation due to extremely intense illumination.

This intense illumination shielding technique/system can be used for providing improved vision in situations where the viewing location is confined relative to the primary viewing glasses where direct observation or see-through may occur with intense light sources in view from the near and far field and also with the entire system in a dynamic motion environment.

Claims

1. The Active Shielding Against Intense Illumination (ASAII) system comprises of the following components or any subset thereof:

a. Wide-angle imaging cameras with FOV large enough to track the intense illumination sources covering the entire field-of-view within which the viewers may observe them. Multiple cameras, placed with a separation in the direction where parallax is significant for near field sources, are required to resolve the parallax at specific eye position between cameras along that direction. The camera imaging direction/boresight must be co-linearly aligned with occupant viewing direction relative to the see-through glass.

b. A windshield/viewing glass imbedded with a Liquid Crystal Display (LCD) shutter screen that can modulate the intensity of the transmitted light at different addressable picture elements in azimuth and elevation angles relative to its calibration orientation and reference. This is referred as the LCD glass within this patent description.

c. The LCD Glass Calibration database performed at the Calibration Reference. This LCD Glass Calibration database allows for the determination of individually addressable pixels at specific angular location in Azimuth and Elevation relative to its reference on viewing axis. It also allows for accurate determination of the Shade displacement vector on LCD glass surface occurred during Shade Alignment process.

d. Control Switches or mechanism designed to allow for user inputs to precisely align the shade location on the active LCD glasses during viewing adjustment and/or system calibration process. There shall be input adjustments of shade location in viewing azimuth and elevation angles, shade oversize/roll-off gradient adjustments and variable background attenuation levels.

e. Shade Alignment algorithm will compute actual eye point, for the case where viewer is offset relative to system Design Eye Point, from data obtained when user successively and precisely replaces the electronically-generated shade over where the sun dynamically appears on the LCD glasses in different directions of his field of view.

f. The boresight alignment of the co-linearly aligned camera to the actual eye point for precise generation of active shades for effective shielding of the intense illumination.

g. Occupant viewing position determined from a retractable seat such as in a vehicle or aircraft cockpit (seat adjustment in the forward/aft, recline up/down angles for the corresponding size viewer) will be used in the initial shade location relative to system Design Eye Point prior to exercising the Shade Alignment algorithm for precise determination of the actual eye location. For eyeglasses, the system Design Eye Point is an arbitrarily designated location.

h. A processor to operate the cameras, to read user inputs from Control Switches, to perform LCD Glass Calibration, Shade Alignment algorithm, camera boresight alignment to eye position, and to control the operation of active LCD glasses.

2. The ASAII system, as referred in claim 1., can be used for casting localized active shades against lower background light attenuation shielding the viewer from intense illumination for enhanced visions in personal eyeglasses, helmet visors, goggles, vehicle windshields/glareshields, vehicle passenger/rear-view windows and glass-roofs. The active shades automatically track and neutralize intense light projections as they traverse across the LCD glasses allowing for direct viewing while preserving visual sensitivity and maximum see-through visibility range over the entire field of view in a dynamic motion environment.

4. The ASAII system, as referred in claim 1, employs multiple cameras for resolving parallax to provide active shielding in vehicle windshields/glareshields for operation in low light conditions during night times where headlights from approaching traffics in the near field or intense background light sources caused visual interferences.

6. The ASAII system, as referred in claim 1, shall be capable of casting localized active shades on fighter plane overhead cockpit glass canopy providing improved vision by permitting direct viewing of the intense illumination sources with maximum visibility range via lower background attenuation and offering potentially life and death advantages in close range aerial combats/dog fights.

8. The ASAII system, as referred in claim 1, shall provide active shielding against intense illumination in vehicle/aircraft HUD combiner for display contrast enhancement and maximum see-through visibility range in high ambient background conditions even when the sun is in direct line-of-sight and night operations with or without night vision goggles (NVG).

11. The ASAII system, as referred in claim 1, implemented in personal eyeglasses, visors and/or vehicle windshields/glareshields, will provide active shielding from intense light sources and direct laser illuminations, including lasers operating in the visible, Infra-red and Ultra Violet spectrum, while permitting for enhanced vision in the remaining field of view via user selectable/adjustable background attenuation proper for day and night conditions. The light/laser sources within viewer'"'"'s field of vision must be detected by the co-linearly aligned camera which will trigger the LCD shutter for maximum attenuation thus protecting his vision from permanent damage. Additional system prerequisites including the light detection/processing speed, LCD shutter switch-on time and its maximum attenuation level are utmost important factors that required design attention to guaranty eye damage protection.

15. A subset of the ASAII system, as referred in claim 1, shall provide localized and global background shades via LCD shutter screen in the imaging plane limiting light saturation allowing for enhanced contrast imaging capability in digital cameras and optical imaging systems.

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