Variable spatial resolution focal plane

• US 5,235,656 A
• Filed: 01/24/1992
• Issued: 08/10/1993
• Est. Priority Date: 01/24/1992
• Status: Expired due to Term

• Current Assignee: Grumman Aerospace Corporation (Northrop Grumman Corporation)
• Original Assignee: Grumman Aerospace Corporation (Northrop Grumman Corporation)
• Inventors: Hilgeman, Theodore W.
• Primary Examiner(s): Mancuso, Joseph
• Application Number:
  US07/825,605
• Time in Patent Office: 564 Days
• Field of Search: 382/65, 382/62, 382/58, 382/66, 382/67, 382/68, 250/206.1, 250/206.2, 250/208.1, 250/216, 250/234
• US Class Current: 382/100
• CPC Class Codes: G02B 23/00 Telescopes, e.g. binoculars; Periscopes; Instruments for viewing the inside of hollow bodies; Viewfinders; Optical aiming or sighting devices
• CPC Class Codes: H04N 25/00 Circuitry of solid-state image sensors [SSIS]; Control thereof
• CPC Class Codes: H04N 25/41 Extracting pixel data from a plurality of image sensors simultaneously picking up an image, e.g. for increasing the field of view by combining the outputs of a plurality of sensors

Abstract

The light from a telescope impinges upon a tilted image plane. The plane primarily includes a mirror having a high spatial resolution focal plane imbedded therein. The mirror reflects image light rays to a lower spatial resolution focal plane. The detectors from the high spatial resolution focal plane and lower spatial resolution focal plane are connected to a computer which is capable of generating a display of the lower spatial resolution focal plane showing a general background scene as well as a superimposed display of the small high spatial resolution focal plane showing an enhanced image of a desired small area. The result is the minimization of the number of detectors that must be employed to obtain a satisfactory high spatial resolution area of interest with attendant minimization of computer processing time.

Claims

1. A variable spatial resolution focal plane assembly comprising:

an inclined plane mirror upon which an original image falls, the mirror reflecting a modified image;

a first focal plane having relatively densely positioned photodetectors physically mounted to a central portion of the mirror for generating a high spatial resolution signal corresponding to a first area within the original image;

an optical member for reimaging the reflected modified image to a second focal plane of less densely positioned photodetectors for generating a low spatial resolution signal corresponding to the remaining area of the original image;

means for moving the mirror and selectively aligning the first focal plane with different areas of the incident original image;

whereby greater image detail is obtained from the high spatial resolution signal while less image detail is simultaneously obtained from the low spatial resolution signal; and

means connected to the resolution signals for displaying the image detail of the high spatial resolution signal superimposed on the image detail of the low spatial resolution signal.

2. A method for displaying a high resolution image area superimposed upon a larger lower resolution image area comprising the steps:

directing an original image to fall incident upon an inclined image plane;

generating a high spatial resolution signal corresponding to a focal plane area within the original image plane;

selectively positioning the focal plane area relative to the incident original image;

reflecting, from the image plane, a modified image which includes the original image less an image portion on the focal plane area;

reimaging the reflected modified image;

generating a low spatial resolution signal corresponding to the reflected modified original image; and

connecting the high and low spatial resolution signals for displaying the image detail of the high spatial resolution signal superimposed on the image of the low resolution signal.