Rapidly flashing thermal image beacon

• US 7,399,967 B1
• Filed: 09/28/2007
• Issued: 07/15/2008
• Est. Priority Date: 09/28/2007
• Status: Active Grant

• Current Assignee: Cejay Engineering, LLC
• Original Assignee: Derek Haynes, Michael John Thomas, Stuart M. Jenkins
• Inventors: Jenkins, Stuart M., Haynes, Derek, Thomas, Michael
• Primary Examiner(s): Porta; David P.
• Assistant Examiner(s): Gaworecki; Mark R
• Application Number:
  US11/904,830
• Time in Patent Office: 291 Days
• Field of Search: 250/338.1, 250/493.1, 250/495.1, 250/504.R
• US Class Current: 250/338.1
• CPC Class Codes: F41G 1/36 with infrared light source
• CPC Class Codes: F41H 11/12 Means for clearing land minefields; Systems specially adapted for detection of landmines
• CPC Class Codes: F41J 2/02 Active targets transmitting infrared radiation

Abstract

A system comprised of a one or more rapidly flashing thermal image beacons, a plurality of sensors, a control subsystem, input means, and a power source. Each beacon being comprised of a precision machined and polished parabolic or elliptical mirror. A resistive heating element is nominally positioned at the mirror focal point. The heating element is mounted on a carriage which can be moved backwards and forwards by a microprocessor-controlled mechanism. The resulting oscillatory action creates a rapidly changing coded flashing thermal image.

Claims

1. A thermal image identification marking system, comprising:

a plurality of thermal image beacons emitting in the infrared (IR) range, each thermal image beacon comprising;

a precision machined and polished parabolic mirror within a housing, said mirror having a concave reflective face with a mirror focal point;

a black heat source transmitting thermal energy, said heat source being nominally positioned at the mirror focal point;

a carriage with said heat source mounted thereon, said carriage being mounted on a raceway; and

a mechanism attached to said carriage and adapted to moving said carriage in a backwards and forward direction along said raceway, into and out of said mirror focal point;

a microprocessor system within said housing and attached to said mechanism and providing control commands to said mechanism; and

a power source within said housing.

2. A system as recited in claim 1, wherein:

the mechanism is comprised of a screw thread driven by a motor.

3. A system as recited in claim 2, further comprising:

a plurality of sensors functionally divided into three groups, namely a first group adapted to measure a thermal IR emission from each beacon, a second group adapted to measure thermal IR emission from background or thermal IR surface radiation from the mirror housings, and a third group adapted to measure ambient thermal IR emission from sources in close proximity to the IR beacons;

a control subsystem connected to said beacons and said sensors, said control subsystem adapted to read the thermal infrared emissions from each group of sensors; and

a power source adapted to provide electrical power to the control subsystem.

4. A system as recited in claim 3, further comprising:

input means to the control subsystem comprised a an IR emitter contrast control and an IR mode control, said contrast control enabling the setting of a thermal IR emission difference between each heating element and background or ambient thermal IR emission levels, said mode control enabling a setting of code for the speed of movement of the carriage holding the heating element, as well as setting the mode of display from a group selected from flashing, steady, or changing thermal IR emission intensity.

5. A system as recited in claim 4, further comprising:

an infrared sensitive diode detector positioned in the mirror housing and connected to the microprocessor system, said diode detector providing output to a negative feedback circuit within the microprocessor system, which continuously maintains the infrared output from the heating element to a level set below the absorption level of the housing.

6. A system as recited in claim 5, wherein:

the parabolic mirror has en elliptical shape.

7. A system as recited in claim 6, wherein:

the black heat source is a resistive heating element comprised of a resistive wire wound on a ceramic element.

8. A system as recited in claim 7, wherein:

all sensors provide their measurement data back to the control subsystem.