Synthetic aperture based real time holographic imaging

• US 5,379,133 A
• Filed: 09/09/1993
• Issued: 01/03/1995
• Est. Priority Date: 06/19/1992
• Status: Expired due to Fees

• Current Assignee: ATL Corporation
• Original Assignee: ATL Corporation
• Inventors: Kirk, Ronald L.
• Primary Examiner(s): Ben, Loha
• Assistant Examiner(s): Juba, Jr., John
• Application Number:
  US08/118,577
• Time in Patent Office: 481 Days
• Field of Search: 359/9, 359/22, 359/23, 359/24, 359/25, 359/15, 359/462
• US Class Current: 359/15
• CPC Class Codes: G02B 27/58 Optics for apodization or superresolution; Optical synthetic aperture systems
• CPC Class Codes: G02B 5/32 Holograms used as optical elements
• CPC Class Codes: H04N 13/243 using three or more 2D image sensors
• CPC Class Codes: H04N 13/32 using arrays of controllable light sources; using moving apertures or moving light sources
• CPC Class Codes: H04N 13/346 using prisms or semi-transparent mirrors

Abstract

Apparatus, system, and method is described wherein a synthetic aperture based sequence of image samples are generated with respect to a subject to be stereoscopically imaged. These sample images are presented to the spaced inputs of a holographic integrated combiner screen to be presented at an output aperture in laterally spaced mutual positioning. That spacing is selected, in one aspect, as one-half of the interpupillary distance of human eyes and thus binocular stereoscopic viewing at the aperture is achieved. The combiner screen may be utilized in conjunction with a holographic optical image combiner architecture which additionally employs a lens assembly such as a projecting lens to generate multi-zone outputs, each zone of which may be presented for stereoscopic viewing at a discrete viewing station. Correction for chromatic aberration of the holographic optical components is described.

Claims

1. A planar holographic film combiner component having a centrally disposed axis extending outwardly therefrom, and having at least two mutually superimposed holographic optical lens components thereon, said holographic optical lens components having back focal lengths extending to spaced apart image receiving positions offset from said axis an amount effective to avoid a view of objects thereat along a sighting path adjacent said axis, and having forward focal lengths extending generally oppositely with respect to said back focal lengths to mutually adjacent focal points spaced apart by an amount corresponding with one-half of the interpupillary distance between the eyes of a human to define an output aperture for generating a binocular parallax view of synthetic aperture derived images provided at said image receiving positions, each of said images being provided by an image generating display.

2. The combiner component of claim 1 in which said adjacent focal points are spaced apart about 3.5 cm.

3. The combiner component of claim 1 in which:

said image receiving positions are mutually spaced apart a distance effective to receive said synthetic aperture derived images from cathode ray tubes.

4. The combiner component of claim 1 in which said holographic optical lens components are constructed with correction for chromatic aberration.

5. An imaging system for stereoscopically imaging an array of at least two discrete synthetic aperture derived images of an object, comprising:

a first planar holographic film component having a centrally disposed axis extending outwardly normally thereto, and having at least two fringe pattern derived first optical components thereon with back focal lengths extending to spaced apart first image receiving positions located at predetermined positions offset from said axis for receiving said synthetic aperture derived images, and having forward focal lengths extending generally oppositely from said first optical components to first focal points spaced apart a first predetermined distance to define a first output aperture;

a second holographic film component having fringe pattern derived second optical components thereon corresponding in number with said first optical components, said second optical components having back focal lengths extending to second image receiving positions located to receive images transmitted by said first optical components at said first output aperture and having forward focal lengths extending from said second optical components to second focal points within a viewing aperture zone, said second optical components having a magnification factor with respect to said first predetermined distance to provide said second focal points at a lateral spacing corresponding with one-half of the interpupillar distance between the eyes of a human.

6. The imaging system of claim 5 in which said second holographic film component is configured to generate at least two said viewing aperture zones at spaced apart observing station locations.

7. The imaging system of claim 5 in which said fringe pattern derived second optical components of the second holographic film component are reflective and are configured to generate at least two said viewing aperture zones at spaced apart viewing station locations.

8. The imaging system of claim 5 including a field lens assembly having a focusing element and positioned intermediate said first and second holographic film components at a location for optically transmitting images at said first output aperture of said first holographic film component to said second image receiving positions of said second holographic film component.

9. The imaging system of claim 8 in which:

said first and second holographic film components are transmissive; and

said second holographic film component is configured to generate at least two said viewing aperture zones at spaced apart viewing locations.

10. The imaging system of claim 5 in which:

said fringe pattern derived second optical components of the second holographic film component are reflective and are configured to derive at least two said viewing aperture zones at spaced apart viewing station locations; and

including a projection lens assembly having a focusing element and positioned intermediate said first and second holographic components at a location for projecting images at said first output aperture of said first holographic component to said second image receiving positions of said second holographic film component.

11. The imaging system of claim 5 in which said lateral spacing of said second focal points is about 3.5 cm.

12. The imaging system of claim 5 in which said first predetermined distance between said first focal points is a value in centimeters equal to about 3.5 divided by said magnification factor.

13. The imaging system of claim 5 in which said first image receiving positions are offset from said axis an amount effective to avoid a view of objects thereat along a sighting path adjacent said axis from said first output aperture.

14. A method for generating a stereoscopic image of a subject, comprising the steps of:

generating a spatial sequence of a predetermined number of images of said subject from a corresponding spatial sequence of laterally spaced, select imaging positions, said spatial sequence of images defining a synthetic aperture;

providing a holographic film combiner component having a centrally disposed axis extending outwardly normally therefrom, and having a number of mutually superimposed holographic optical lens components corresponding with said predetermined number of images, said holographic optical lens components having back focal lengths extending to spaced apart image receiving positions offset from said axis, and having forward focal lengths extending generally oppositely with respect to said back focal lengths to mutually adjacent focal points at an output aperture spaced apart by an amount corresponding with one-half the interpupillary distance between the eyes of a human;

locating a viewing station at said output aperture; and

projecting said images from an image generating display simultaneously in said generated spatial sequence at a corresponding spatial sequence of said spaced apart image receiving positions to effect their corresponding projection at said output aperture.

15. The method of claim 14 in which:

said step for providing said holographic film combiner component includes the construction of said optical components with correction for chromatic aberration.

16. A method for generating a stereoscopic image of a subject, comprising the steps of:

generating a spatial sequence of a predetermined number of images of said subject from a corresponding spatial sequence of laterally spaced, select imaging positions, said spatial sequence of images defining a synthetic aperture;

forming a first holographic film component having a centrally disposed axis extending outwardly normally thereto, and having a number of first optical components corresponding with said predetermined number of images, said first optical components having back focal lengths extending to spaced apart image receiving positions offset from said axis and having forward focal lengths extending to focal points laterally spaced part in mutual adjacency by a first predetermined distance at a first output aperture;

forming a second holographic film component having a number of second optical components corresponding with said number of first optical components, said second optical components having back focal lengths extending to second image receiving positions and having forward focal lengths extending from said second optical components to second focal points within a viewing aperture zone, said second optical components having a magnification factor with respect to said first predetermined distance to provide said second focal points at a lateral spacing corresponding with one-half of the interpupillary distance between the eyes of a human;

positioning said second holographic film component to locate said second receiving positions for receiving images transmitted from said first optical components at said fast output aperture;

locating a viewing station at said viewing aperture zone; and

projecting said images simultaneously in said generated spatial sequence at a corresponding spatial sequence of said spaced apart first holographic film component image receiving positions to effect their corresponding presence at said viewing aperture zone.

17. The method of claim 16 in which:

said second holographic film component is formed having a configuration generating at least two said viewing aperture zones; and

said viewing station is located at each said zone.

18. The method of claim 17 in which said first and second holographic film components are formed as transmissive optical devices.

19. The method of claim 16 including the steps of providing a variable focus lens intermediate said first and second holographic film components;

and transmitting therewith images at said first output aperture into said second image receiving positions.

20. The method of claim 16 in which:

said second optical components are formed as reflective optical component, and are configured to provide at least two said viewing aperture zones;

a further step is included, said step being the step of providing a projection lens assembly positioned intermediate said first and second holographic components at a location for projecting images at said first output aperture to said second image receiving positions; and

a viewing station is located at each said viewing aperture zones.