Visor with point sun blocking

• US 4,848,890 A
• Filed: 08/27/1987
• Issued: 07/18/1989
• Est. Priority Date: 08/27/1987
• Status: Expired due to Term

• Current Assignee: The Research Foundation for The State University of New York (State University of New York)
• Original Assignee: Grumman Aerospace Corporation (Northrop Grumman Corporation)
• Inventors: Horn, Michael
• Primary Examiner(s): Bovernick, Rodney B.
• Assistant Examiner(s): Dziezynski, P. M.
• Application Number:
  US07/090,055
• Time in Patent Office: 691 Days
• Field of Search: 351/158, 351/41, 351/44, 351/45, 350/331 R
• US Class Current: 351/44
• CPC Class Codes: A61F 9/023 with variable transmission, e.g. photochromic for welding A61F9/067
• CPC Class Codes: G02C 7/101 having an electro-optical light valve electro-optical elements per se G02F

Abstract

Eye gear is provided to protect a wearer from irritating direct sunlight. Liquid crystal matrices are positioned over the wearer'"'"'s eyes and a sun-tracking photosensor and related electronics determines the area of direct sunlight within the viewer'"'"'s field of view. Segments of the matrix corresponding to the sunlit area are switched to a light-blocking state so that the remaining unaffected field of the view may be maintained.

Claims

1. Protective eye gear for minimizing the effects of irritating sunlight in a field of view, the eye gear comprising:

a light-transmissive lens to be positioned over a wearer'"'"'s eyes;

a matrix of electrically controlled and normally transparent segments mounted over the lens, individual segments being selectively switched to block direct sunlight from a wearer'"'"'s field of view;

photosensor means located in proximity to the lens for tracking the area of direct sunlight relative to a wearer'"'"'s entire field of view; and

control means connected between the photosensor means and the matrix segments for selectively switching segments in the matrix to a light-blocking state, the switched segments corresponding to the area of the wearer'"'"'s field of view where direct sunlight exists;

wherein segment light blocking is accompanied by a remaining clear field of the view for the wearer;

the photosensor means including a plurality of individual segments located adjacent one another; and

a lens mounted over the segments for focussing direct sunlight onto a portion of the segments, corresponding to the location of the direct sunlight within the otherwise clear field of view;

the control means including

(a) comparator means having inputs connected to respective photosensor segments for detecting which photosensor segments are receiving direct sunlight;

(b) memory means connected to the output of the comparator means and containing a look-up table for establishing a unique memory output dependent upon the condition of the photosensor segments at a moment in time and selecting which of the matrix segments are to be switched to a sun-blocking state corresponding to the photosensor segments receiving direct sunlight; and

(c) driver means connected between the output of the memory means and the matrix segments for switching selected segments between light-blocking and light-transmitting states; and

(d) means connected between the driver and a second matrix mounted over a second lens for offsetting blocking segments thereof corresponding to blocked segments of the first matrix but corrected for parallax.

2. The structure set forth in claim 1 wherein the matrices are fabricated from liquid crystal segments.

3. The structure set forth in claim 2 wherein the photosensor segments are fabricated from photodiodes.

4. The structure set forth in claim 2 wherein the photosensor segments are fabricated from charge-coupled devices.

5. A method for protecting a person'"'"'s vision from strong light within a field of view, the method comprising the steps:

tracking the strong light on a multi-segment photosensor area corresponding to a field of view;

comparing the states of the photosensor segments with a look-up table for establishing a unique memory output dependent upon the condition of the photosensor segments at a moment in time;

interposing matrix means between the light and a person'"'"'s eye;

selectively switching individual segments of the matrix means to a light-blocking state in response to the memory output corresponding to shifts of incident strong light on the photosensor area while maintaining unaffected matrix segments in a light-transmitting state thereby only blocking the wearer'"'"'s field of view in the area of strong light exposure.

6. The method set forth in claim 5 together with the step of providing two matrices, one over each of the wearer'"'"'s eyes;

and

offsetting the blocked segments in one matrix relative to the other for achieving parallax correction.