Thermal reflex sight
A reflex sight comprises two apertures. One aperture is a direct view optical path of the target scene. The other aperture is a digital (e.g., thermal) camera or image intensifier. A beam combiner with two reflective surfaces (for example, a Bauernfeind, Penta, or other prism bonded to a wedge prism) and afocal eyepiece optics overlay the digital image or intensified image onto the direct view scene with matched magnification.
1. An aiming sight comprising:
a beam combiner comprising a first planar outer surface oriented perpendicularly to a first axis, a second planar outer surface oriented parallel to and oppositely positioned from the first planar outer surface, an internal coated planar surface oriented at an acute angle with respect to the first and second outer planar surfaces, and a third planar outer surface;
either an image intensifier or a display for a digital camera;
an afocal eyepiece; and
a first housing comprising the beam combiner, the image intensifier or display for a digital camera, and the afocal eyepiece;
wherein the housing is adapted to be attached to a firearm;
wherein a first optical path is coaxial with the first axis and provides a direct view in the visible spectrum straight through the first and second outer planar surfaces of the beam combiner of a target scene at which the aiming sight is aimed;
wherein along a second optical path the afocal eyepiece collects light from the image intensifier or the digital camera display to produce afocal light rays that are incident on and transmitted through the third planar outer surface of the beam combiner, then incident on the first planar outer surface of the beam combiner from inside the beam combiner at an angle resulting in total internal reflection of the rays by the first planar outer surface toward the internal coated planar surface, then reflected by the internal coated planar surface along the first axis as an afocal image of the target scene overlaying and magnification matched with the direct view of the target scene.
2. The aiming sight of claim 1 comprising a digital camera display, wherein the first housing comprises a digital camera connected to provide a signal to the digital camera display.
3. The aiming sight of claim 1 comprising a digital camera display, wherein:
a digital camera configured to provide a signal to the digital camera display is housed in a separate housing adapted for mounting to the firearm; and
the first housing is adapted to be attached to a firearm telescopic magnifying scope with the direct view optical path passing through the magnifying scope.
4. The aiming sight of claim 1 comprising an image intensifier.
5. The aiming sight of claim 1 , wherein a coating on the internal coated surface reflects visible light having a wavelength greater than a cutoff wavelength and transmits light having a wavelength shorter than a cutoff wavelength, and the light from the image intensifier or digital camera display has a wavelength greater than the cutoff wavelength.
6. The aiming sight of claim 1 , wherein a coating on the internal coated surface is a narrow spectral band reflective coating and the light emitted by the digital camera display or image intensifier is substantially monochromatic with a center wavelength closely coinciding with the center wavelength of the narrow band reflective coating.
7. The aiming sight of claim 1 comprising a digital camera display connected to receive a signal from a digital camera, wherein the display is controllable to provide a full image of the target scene, an outline image of bright portions of the target scene, or a mixed full and outline image of the target scene.
8. The aiming sight of claim 1 comprising a digital camera display connected to receive a signal from a digital camera, wherein the display is controllable to overlay a dot, reticle, crosshair, or combination thereof with the afocal image and direct view to provide a reference for where the firearm is aimed.
9. The aiming sight of claim 1 comprising a digital camera display connected to receive a signal from a digital camera sensitive to light in the ultraviolet spectral range of about 200 nm to about 400 nm.
10. The aiming sight of claim 1 comprising a digital camera display connected to receive a signal from a digital camera sensitive to light in the visible spectral range of about 400 nm to about 700 nm.
11. The aiming sight of claim 1 comprising a digital camera display connected to receive a signal from a digital camera sensitive to light in the near infrared spectral range of about 700 nm to about 1100 nm.
12. The aiming sight of claim 1 comprising a digital camera display connected to receive a signal from a digital camera sensitive to light in the short wave infrared spectral range of about 1100 nm to about 3000 nm.
13. The aiming sight of claim 1 comprising a digital camera display connected to receive a signal from a digital camera sensitive to light in the mid wave infrared (MWIR) spectral range of about 3000 nm to about 5000 nm.
14. The aiming sight of claim 1 comprising a digital camera display connected to receive a signal from a digital camera sensitive to light in long wave infrared (LWIR) spectral range of about 7000 nm to about 12000 nm.
15. The aiming sight of claim 1 comprising a digital camera display, wherein:
the first housing comprises a digital camera connected to provide a signal to the digital camera display; and
the display is controllable to provide a full image of the target scene, an outline image of bright portions of the target scene, or a mixed full and outline image of the target scene.
16. The aiming sight of claim 15 , wherein a coating on the internal coated surface reflects visible light having a wavelength greater than a cutoff wavelength and transmits light having a wavelength shorter than a cutoff wavelength, and the light from the digital camera display has a wavelength greater than the cutoff wavelength.
17. The aiming sight of claim 15 , wherein a coating on the internal coated surface is a narrow spectral band reflective coating and the light emitted by the digital camera display is substantially monochromatic with a center wavelength closely coinciding with the center wavelength of the narrow band reflective coating.
18. The aiming sight of claim 15 wherein the digital camera is sensitive to light in the ultraviolet spectral range of about 200 nm to about 400 nm.
19. The aiming sight of claim 15 wherein the digital camera is sensitive to light in the visible spectral range of about 400 nm to about 700 nm.
20. The aiming sight of claim 15 wherein the digital camera is sensitive to light in the near infrared spectral range of about 700 nm to about 1100 nm.
21. The aiming sight of claim 15 wherein the digital camera is sensitive to light in the short wave infrared spectral range of about 1100 nm to about 3000 nm.
22. The aiming sight of claim 15 wherein the digital camera is sensitive to light in long wave infrared (LWIR) spectral range of about 7000 nm to about 12000 nm.
23. The aiming sight of claim 15 wherein the digital camera is sensitive to light in the mid wave infrared (MWIR) spectral range of about 3000 nm to about 5000 nm.
24. The aiming sight of claim 1 comprising a digital camera display, wherein:
a digital camera configured to provide a signal to the digital camera display is housed in a separate housing adapted for mounting to the firearm;
the first housing is adapted to be attached to a firearm telescopic magnifying scope with the direct view optical path passing through the magnifying scope; and
the display is controllable to provide a full image of the target scene, an outline image of bright portions of the target scene, or a mixed full and outline image of the target scene.
25. The aiming sight of claim 24 , wherein a coating on the internal coated surface reflects visible light having a wavelength greater than a cutoff wavelength and transmits light having a wavelength shorter than a cutoff wavelength, and the light from the digital camera display has a wavelength greater than the cutoff wavelength.
26. The aiming sight of claim 24 , wherein a coating on the internal coated surface is a narrow spectral band reflective coating and the light emitted by the digital camera display is substantially monochromatic with a center wavelength closely coinciding with the center wavelength of the narrow band reflective coating.
27. The aiming sight of claim 24 wherein the digital camera is sensitive to light in the ultraviolet spectral range of about 200 nm to about 400 nm.
28. The aiming sight of claim 24 wherein the digital camera is sensitive to light in the visible spectral range of about 400 nm to about 700 nm.
29. The aiming sight of claim 24 wherein the digital camera is sensitive to light in the near infrared spectral range of about 700 nm to about 1100 nm.
30. The aiming sight of claim 24 wherein the digital camera is sensitive to light in the short wave infrared spectral range of about 1100 nm to about 3000 nm.
31. The aiming sight of claim 24 wherein the digital camera is sensitive to light in long wave infrared (LWIR) spectral range of about 7000 nm to about 12000 nm.
32. The aiming sight of claim 24 wherein the digital camera is sensitive to light in the mid wave infrared (MWIR) spectral range of about 3000 nm to about 5000 nm.