CCD Head and eye position indicator

• US 4,568,159 A
• Filed: 11/26/1982
• Issued: 02/04/1986
• Est. Priority Date: 11/26/1982
• Status: Expired due to Fees

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Baldwin, Dorothy M.
• Primary Examiner(s): Bovernick, Rodney B.
• Assistant Examiner(s): Dzierzynski, Paul M.
• Application Number:
  US06/444,639
• Time in Patent Office: 1,166 Days
• Field of Search: 351/209, 351/210, 350/322
• US Class Current: 351/210
• CPC Class Codes: A61B 3/113 for determining or recording eye movement
• CPC Class Codes: G01S 5/163 Determination of attitude using inertial means G01C9/00; control of attitude G05D1/49

Abstract

A head and eye tracking apparatus utilizes a plurality of coded IR emitte mounted in a reflective surface, as a reference base. A reference lens aligned with the user'"'"'s head references a limited number of the emitters within its field of view and transmits the image to a fiber optic bundle. Simultaneously, an IR reflection from the user'"'"'s eye is superimposed on the image and transferred via the fiber optic bundle. A CCD array detects the IR transmission and provides a high speed read-out to a computer which can determine head and eye positions from the geometry of the emitters referenced by the lens.

Claims

1. An apparatus for head and eye tracking a live subject and generating positional outputs corresponding thereto, comprising in combination:

a plurality of coded light emitters affixed to a projection area whereupon a visual presentation may be projected, each said emitter oriented to direct invisible light toward said subject and being distinctively coded one from the other so that each is separately identifiable by its output;

optical means removably attached to the head of said subject for referencing a portion of said projection area encompassing less than all but more than two of said coded light emitters wherein said portion is fixed in size and correlated to the head orientation of said subject, and can vary in placement throughout said projection area;

a light source of invisible light directed toward the eye of said subject such that said invisible light is reflected by said eye and said reflection indicates the position of the eye;

charge coupled devices arranged in an array for detecting said individual light emitters and said source, said devices having a very high readout rate and outputs corresponding to detected said emitters and said source;

a fiber optic bundle optically coupled to said referencing means and said light source for transferring said reflected light and said light from said referencing means to said detecting means;

means for imaging said transferred light on said detecting means; and

means for computing the spatial orientation of the head and eye outputting said computed data to control said visual presentation, operably connected to receive positional data from said detecting means.

2. An apparatus according to claim 1, wherein said plurality of coded light emitters is an array of IR emitters, each emitter having a distinctive code and a discrete location within said projection area.

3. An apparatus according to claim 1, wherein said referencing means comprises:

an imaging lens for focusing light from said portion of said projection area into said fiber optic bundle for transferring said light; and

means for mounting said lens on said subject along his facial centerline above his eyes.

4. The apparatus of claim 1, wherein said light source is an infrared source.

5. The apparatus of claim 1, wherein said array of charge coupled devices comprises:

a plurality of sub-arrays of charge coupled devices; and

means for simultaneous readout of data generated by said sub-arrays, operably connected between said sub-arrays and said computing means.

6. The apparatus of claim 1, further comprising a beam splitter supported by said apparatus at a position forward the eyes of said subject such that the reflection from said light source is coupled into said fiber optic bundle.

7. An apparatus for the rapid measurement of head and eye movements, for use in a training simulation which utilizes a helmet mounted projector to reflect computer generated images from a spherically domed screen surrounding the user, comprising in combination:

a plurality of infrared emitters embedded within said screen such that IR light therefrom is incident upon the helmet of said user, each of said emitters being distinctly coded in accordance with its fixed position within said screen;

an imaging lens mounted to said helmet referencing a portion of said screen which encompasses more than two but less than all of said IR emitters, wherein the position of said portion of said screen is correlated to the orientation of said helmet and can vary throughout said screen;

means for directing an IR light source toward the eye of the user for reflecting therefrom such that said reflection is indicative of the position of the eye, cooperatively mounted on said helmet;

a CCD array for detecting said IR radiation from said emitters and source, each CCD corresponding to a respective area on said screen, and said array having a very high readout rate, outputting an electronic signal in accordance with the emitters and source detected;

fiber optic means for transferring light from said imaging lens to said CCD array;

means for optically mating said fiber optic means to said CCD;

means for optically superimposing said reflected IR light from said user at said fiber optic means onto said light from said emitters; and

means coupled to said CCD array output for computing head and eye orientation.