Second imaging device adaptable for use with first imaging device and method for using same
A second imaging device such as a thermal imager adapted for use with a first imaging device such as an image intensifier night vision goggle system whereby the output image of the second imaging device is collimated and projected upon the objective lens of the first imaging device to provide an optically fused image to the viewer.
1. A device for optically fusing thermal and intensified images of a scene, comprising:
a first imaging device configured to view ambient light reflected from the scene, the first imaging device having a first objective lens with a first field of view and a center, an image intensifier tube arranged to receive and intensify ambient light from the first objective lens imaged thereon, and at least one eyepiece for viewing the intensified ambient light as the intensified image of the scene; and
a second imaging device removably and adjustably mounted to the first imaging device, the second imaging device configured to view infrared light emitted from the scene, the second imaging device having a second objective lens with a second field of view that is substantially the same as the first field of view, a focal plane array arranged to receive an infrared image of the scene from the second objective lens, an electronic display operably connected to the focal plane array and configured to output a visible representation of the thermal image, and projection optics for receiving the visible representation of the thermal image and projecting it into the first objective lens offset of the center thereof and proximal thereto so that the visible representation of the thermal image is in at least approximate alignment with the intensified image of the scene when viewed through the at least one eyepiece of the first imaging device.
2. The device according to claim 1 , wherein the electronic display comprises an organic light-emitting diode (OLED) display operably arranged relative to collimating optics so that the visible representation of the thermal image displayed on the OLED is collimated when entering the first objective lens.
3. The device according to claim 1 , wherein the infrared light has a wavelength in the range from about 1 microns to about 30 microns.
4. The device according to claim 1 , further including a clamp configured to allow the second imaging device to be said removably and adjustably mounted to the first imaging device in a clip-on fashion.
5. The device according to claim 1 , further comprising adjusting means for adjusting a position of the electronic display output with respect to the first objective lens.
6. The device according to claim 5 , wherein said adjusting means is comprised of electronic circuitry.
7. The device according to claim 5 , wherein said adjusting means is mechanical.
8. A method of presenting a scene to a viewer, comprising:
collecting reflected visible ambient light from the scene with a first objective lens having a center, and forming a first image from the collected visible ambient light;
intensifying the first image to form an intensified first image and then presenting the intensified first image through at least one eyepiece;
collecting infrared light emitted from the scene with a second objective lens and forming a thermal image;
converting the thermal image to a visible representation of the thermal image; and
projecting the visible representation of the thermal image into the first objective lens at a location offset from the center of the first objective lens so as to not completely obscure said first objective lens and so as to present, through the at least one eyepiece, the visible representation of the thermal image in alignment with the intensified first image in a fused image.
9. The method according to claim 8 , wherein the first objective lens is part of a first imaging device and the second objective lens is part of a second imaging device, the method further comprising removably coupling the second imaging device to the first imaging device.
10. The method according to claim 8 , further comprising collimating the visible representation of the thermal image.
11. The method of claim 8 , wherein the location is a user-defined position with respect to the first objective lens.
12. A device for viewing a scene at visible and infrared wavelengths, comprising:
a night-vision device configured to receive visible ambient light from a scene with a first objective lens having a center and form an intensified image of the scene using an image intensifier, the intensified image being viewable through at least one eyepiece; and
a thermal imager that is removably mounted to the night-vision device with a mounting device, the thermal imager having a second objective lens and being configured to form a thermal image of the scene at the infrared wavelength and convert the thermal image to a visible representation of the thermal image of the scene using imaging electronics, the thermal imager further including a projector configured to project the visible representation of the thermal image into the first objective lens so that the visible representation of the thermal image and the intensified image can be simultaneously viewed through the at least one eyepiece.
13. The device according to claim 12 , wherein the night-vision device comprises night-vision goggles having two eyepieces.
14. The device according to claim 12 , wherein the night-vision device has a single eyepiece.
15. The device according to claim 12 , wherein the mounting device includes a clip-on feature that allows the thermal imager to be clipped onto the night-vision device.
16. The device according to claim 12 , wherein the imaging electronics includes a focal plane array (FPA), FPA processing electronics, and a display that displays the visible representation of the thermal image.
17. The device according to claim 16 , wherein the display comprises an organic light-emitting diode display.
18. The device according to claim 12 , wherein the infrared wavelength is in the range from about 8 microns to about 14 microns.
19. The device according to claim 12 , wherein the infrared wavelength is in the range from about 1 micron to about 30 microns.
20. The device according to claim 12 , wherein the projector is configured so that said projecting the visible representation of the thermal image into the first objective lens is performed using collimated light.
21. The device according to claim 12 , wherein the projector is positioned relative to the night vision device such that the projector is offset of the center of the first objective lens.