SURFACE AND SUBSURFACE DETECTION DEVICE

• US 3,713,156 A
• Filed: 10/12/1970
• Issued: 01/23/1973
• Est. Priority Date: 10/12/1970
• Status: Expired due to Term

• Current Assignee: Robert G. Pothier
• Original Assignee: Robert G. Pothier
• Inventors: Pothier, Robert G.
• Primary Examiner(s): Tubbesing, T. H.
• Application Number:
  US05/080,066
• Time in Patent Office: 834 Days
• Field of Search: 343/17
• US Class Current: 342/22
• CPC Class Codes: G01S 13/887 for detection of concealed objects, e.g. contraband or weapons
• CPC Class Codes: G01S 7/04 Display arrangements
• CPC Class Codes: G01V 8/005 operating with millimetre waves, e.g. measuring the black losey radiation

Abstract

Detector apparatus in which the target area is illuminated by microwave energy in the millimeter range. A microwave lens element focuses the reflected millimeter waves to a focal plane. A microwave to thermal converter is disposed in the focal plane to convert the reflected microwave images to thermal images. A liquid crystal display or an IR area detector, such as a line scan unit is employed to convert the thermal images to a visible display of images in the target area.

Claims

1. Apparatus for detecting surface and subsurface objects comprising:

means for illuminating said objects with microwave energy whereby said objects reflect a microwave energy pattern;

an energy focussing element for focussing said reflected energy pattern on a focal plane;

an energy converter element including a sheet of resistive material disposed within said plane to convert said reflected microwave energy pattern to a thermal energy pattern; and

display means including a layer of liquid crystal material affixed to said resistive sheet so as to respond to the thermal energy pattern produced by said resistive sheet in response to said reflected microwave energy pattern to display a visual image pattern of said objects.

2. Apparatus as set forth in claim 1 wherein illuminating means includes a. an antenna element positioned to radiate energy toward said objects, and b. an oscillator arranged to feed millimeter wave energy to said antenna element.

3. Apparatus as set forth in claim 2 and further including a modulator coupled to said oscillator for providing pulsed operation thereof whereby said objects are illuminated by flashes of millimeter wave energy.

4. Apparatus as set forth in claim 3 and further including a television monitor, storage means for recording said visual image pattern and for playing back said stored pattern for display on said monitor.

5. Apparatus as set forth in claim 3 and further including a rotatable plate upon which the objects are positioned;

means for rotating said plate; and

means for operating said modulator in synchronism with the rotating means.

6. Apparatus as set forth in claim 2 and further including a rotatable plate upon which the objects are positioned;

means for rotating said plate; and

means for operating said oscillator to provide said millimeter wave energy as a continuous wave.

7. Apparatus for detecting surface and subsurface objects comprising:

means for illuminating said objects with microwave energy whereby said objects reflect a microwave energy pattern;

an energy focussing element for focussing said reflected energy pattern on a focal plane;

an energy converter element including a sheet of resistive material disposed within said plane to convert said reflected microwave energy pattern to a thermal energy pattern; and

display means including a. an IR detector for scanning said thermal energy pattern to produce a video signal, and b. a television monitor responsive to said video signal to display a visual image pattern of said objects.

8. Apparatus as set forth in claim 7 wherein illuminating means includes a. an antenna element positioned to radiate energy toward said objects, and b. an oscillator arranged to feed millimeter wave energy to said antenna element.

9. Apparatus as set forth in claim 8 and further including a modulator coupled to said oscillator for providing pulsed opEration thereof whereby said objects are illuminated by flashes of millimeter wave energy.