Active blindspot/lane departure detection mirror system

• US 8,282,225 B2
• Filed: 03/04/2009
• Issued: 10/09/2012
• Est. Priority Date: 03/04/2009
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Kohlstrand, Kelly Michael
• Primary Examiner(s): Chwasz, Jade R
• Application Number:
  US12/397,431
• Publication Number:
  US 20100226027A1
• Time in Patent Office: 1,315 Days
• Field of Search: 359/843, 359/844, 359/484.01, 359/485.07
• US Class Current: 359/843
• CPC Class Codes: B60R 1/082 using a single wide field mirror or an association of rigidly connected mirrors
• CPC Class Codes: G02B 2027/0123 comprising devices increasing the field of view
• CPC Class Codes: G02B 27/0101 characterised by optical features G02B27/0172 takes precedence
• CPC Class Codes: G02B 5/30 Polarising elements light-modulating devices with active elements G02F1/00

Abstract

A system and method to polarize a reflective layer on a vehicle mirror to reveal a convex mirror to view objects in a vehicle blindspot includes a primary mirror having first and second surfaces, an electrically polarizable reflective coating on at least a portion of the first surface reflective in a depolarized state and clear when polarized by an applied electric current, a blind zone viewing convex mirror adjacent to the second surface and proximal to the polarizable coating of the first surface; and a blind spot detection system electrically connected to the primary mirror and a power source to automatically apply current to the first surface when an object is detected in a blind spot and change the reflectivity polarizable coating on the first surface and expose the concave mirror and discontinuing current to the reflective coating once an object has passed out of the blind spot.

Claims

1. A vehicle mounted mirror system to automatically reflect light from a vehicle blind spot toward a driver, comprising:

a primary mirror having a first surface and a second surface, a convex mirror adjacent said second surface;

said convex mirror located to provide operator viewing of objects from said blind spot;

an electrically polarizable reflective coating on at least a portion of its-first surface overlaying said convex mirror;

said polarizable reflective coating being reflective in a depolarized state and substantially clear when polarized by an electric current applied thereto; and

a blind spot detection system electrically connected to the primary mirror and a power source adapted to automatically apply current to polarize said primary mirror first surface overlying said convex mirror when an object is detected in a blind spot and change the reflectivity of the reflective polarizable coating on at least a portion of the primary mirror first surface and expose the convex mirror to reflect light from the blind spot to the vehicle driver to permit the driver to see the object in the blind spot;

said blind spot detection system discontinuing current to the primary mirror thereby depolarizing the mirror surface over the convex mirror once an object has passed out of the blind spot.

2. The mirror system of claim 1, wherein said blind spot detection system utilizes radar, sonar or lidar to detect objects in the vehicle blind spot.

3. The mirror system of claim 1, wherein the convex mirror is smaller than said primary mirror and located off center from the primary mirror center.

4. The mirror system of claim 1, wherein said mirror is protected with an optically transparent hard layer.

5. The mirror of claim 4, wherein the transparent hard layer is plastic or glass.

6. The mirror of claim 1, wherein the polarizable layer is selected from a nematic, smectic and cholestric liquid crystal layer.

7. The mirror of claim 1, wherein said first layer is coated with an electrically conductive and optically transparent conductor to form electrodes.

8. The mirror of claim 1, wherein said first layer is coated with indium tin oxide (ITO), tin oxide, or other electrically conductive and optically transparent materials to form electrodes.

9. The mirror system of claim 1, wherein the primary mirror and the blind zone mirror are an integral structure.

10. A method to operate a mirror system to reflect light from a vehicle blind spot toward a driver, comprising:

detecting an object in a vehicle blind spot;

determining whether the detected object is keeping pace or gaining on said vehicle;

applying an electric current to a polarizable layer to polarize at least a portion of the layer to change reflectivity of the layer expose a convex mirror through which the operator may actually view objects in a vehicle blind spot and upon termination of application of electricity, the polarizable layer resumes reflectivity.