Optical configuration for a compact integrated day/night viewing and laser range finding system

Patent metadata

Field	Value
Publication number	US-9593945-B2
Application number	US-201313901682-A
Country	US
Kind code	B2
Filing date	May 24, 2013
Priority date	May 24, 2013
Publication date	Mar 14, 2017
Grant date	Mar 14, 2017

Abstract

A compact integrated optical system including an eyepiece, a reflective telescope, and a multi-spectral combiner optically coupled between the reflective telescope and the eyepiece, and configured to direct visible light received via the reflective telescope assembly along a direct view optical path to the eyepiece assembly. In one example, the multi-spectral combiner includes a display that displays a visual representation of the imagery of the viewed scene, and laser range-finder transceiver that transmits and receives a laser beam via the reflective telescope. A pair of beamsplitters is used to separate the imaging optical path from the direct view and laser range-finding optical paths. A blocking device is used to enable laser range-finding capability during daytime viewing of the imaging optical path imagery on the display. The reflective telescope provides a common aperture for the direct view optical path, an imaging optical path, and the laser range-finder transceiver.

First claim

What is claimed is:

1. An optical system comprising:
an eyepiece assembly;
a reflective telescope assembly; and
a multi-spectral combiner assembly optically coupled between the reflective telescope assembly and the eyepiece assembly and configured to direct visible light received via the reflective telescope assembly along a direct view optical path to the eyepiece assembly, and including:
an imaging sub-system configured to receive electromagnetic radiation from the reflective telescope assembly along an imaging optical path and to provide a first signal representative of imagery of a viewed scene;
a display coupled to the eyepiece assembly and to the imaging sub-system and configured to receive the first signal and to display a visual representation of the imagery of the viewed scene;
a laser range-finder transceiver configured to transmit and receive a laser beam via the reflective telescope assembly;
a first beamsplitter configured to transmit the electromagnetic radiation from the reflective telescope assembly to the imaging sub-system and to reflect the visible light and a majority of the laser beam;
a second beamsplitter optically coupled to the first beamsplitter and configured to reflect the laser beam, to transmit the visible light to direct the visible light along the direct view optical path to the eyepiece assembly, and to reflect display light from the display along a display optical path to the eyepiece assembly; and
a blocking device positioned between the first beamsplitter and the second beamsplitter and configured to block the visible light reflected by the first beamsplitter from reaching the second beamsplitter;

wherein the reflective telescope assembly provides a common aperture for the direct view optical path, the imaging optical path, and the laser range-finder transceiver.

2. The optical system of claim 1 , wherein the imaging sub-system is a thermal imaging sub-system, and the electromagnetic radiation is infrared radiation.

3. The optical system of claim 1 , wherein the blocking device is movable into and out of the direct view optical path between the first and second beamsplitters such that the blocking device is positioned in the direct view optical path and operable to block the visible light during a night viewing mode of the optical system, and is positioned out of the direct view optical path to allow the visible light to reach the second beamsplitter during a day viewing mode of the optical system.

4. The optical system of claim 3 , wherein the blocking device is optically transmissive to the laser beam.

5. The optical system of claim 1 , further comprising:
a laser position sensing assembly; and
wherein the first beamsplitter is configured to transmit a portion of the laser beam to the laser position sensing assembly.

6. The optical system of claim 5 , wherein the display is further configured to display a reticle representing a position of the laser beam within a field of view of the optical system.

7. The optical system of claim 1 , wherein the reflective telescope assembly includes four mirrors and is configured to produce an intermediate image.

8. The optical system of claim 7 , wherein each of the four mirrors is aspheric, and wherein at least one of the four mirrors has a freeform surface profile.

9. The optical system of claim 1 , wherein the electromagnetic radiation is at least one of longwave infrared (LWIR) radiation in a wavelength range of approximately 8-12 μm, midwave infrared (MWIR) radiation in a wavelength range of approximately 3-5 μm, shortwave infrared (SWIR) radiation is a wavelength range of approximately 0.9-1.7 μm, near infrared (NIR) radiation in a wavelength range of approximately 0.7-0.9 μm, and a color television spectral band having a wavelength range of approximately 0.4-0.7 μm.

10. The optical system of claim 1 , wherein the laser beam has a wavelength of approximately 1.54 micrometers.

11. The optical system of claim 1 , wherein the multi-spectral combiner assembly further comprises at least one lens positioned in collimated space in the display optical path and configured to adjust a magnification of the display as viewed through the eyepiece assembly independently of a magnification along the direct view optical path.

12. The optical system of claim 1 , wherein the multi-spectral combiner assembly further includes a direct view objective optic positioned in the direct view optical path and configured to direct the visible light to the eyepiece assembly.

13. A method of operating an optical system to provide integrated laser range-finding and day and night viewing capability, the method comprising:
directing visible light along a direct view optical path from a common aperture to an eyepiece assembly in a day viewing mode of the optical system;
receiving infrared radiation along an infrared optical path via the common aperture;
displaying infrared imagery produced from the received infrared radiation on a display in a night viewing mode of the optical system;
transmitting and receiving a laser beam along a laser path via the common aperture to provide the laser range-finding;
separating the infrared optical path from the direct view optical path and laser path using a first beamsplitter;
separating the direct view optical path from the laser path using a second beamsplitter;
blocking the visible light from reaching the eyepiece assembly during the night viewing mode of the optical system; and
reflecting display light from the display to the eyepiece assembly with the second beamsplitter in the night viewing mode of the optical system.

14. The method of claim 13 , further comprising displaying a reticle on the display, the reticle being representative of a position of the laser beam in a field of view of the optical system.

15. The method of claim 13 , further comprising magnifying the display as viewed through the eyepiece independently of magnification along the direct view optical path.

16. The method of claim 13 , wherein receiving the infrared radiation includes receiving at least one of longwave infrared (LWIR) radiation in a wavelength range of approximately 8-12 micrometers, midwave infrared (MWIR) radiation in a wavelength range of approximately 3-5 μm, shortwave infrared (SWIR) radiation in a wavelength range of approximately 0.9-1.7 μm, and near infrared (NIR) radiation in a wavelength range of approximately 0.7-0.9 μm.

17. The method of claim 13 , wherein transmitting and receiving the laser beam includes transmitting and receiving a laser beam having a wavelength of approximately 1.54 micrometers.

18. The method of claim 13 , wherein separating the infrared optical path from the direct view optical path and laser path includes transmitting the infrared radiation through the first beamsplitter, and reflecting the visible light and a majority of the laser beam to the second beamsplitter.

19. An optical system comprising:
an eyepiece assembly;
a reflective telescope assembly;
a multi-spectral combiner assembly optically coupled between the reflective telescope assembly and the eyepiece assembly and configured to direct visible light received via the reflective telescope assembly along a direct view optical path to the eyepiece assembly, and including:
an imaging sub-system configured to receive electromagnetic radiation from the reflective telescope assembly along an imaging optical path and to provide a first signal representative of imagery of a viewed scene;
a display coupled to the eyepiece assembly and to the imaging sub-system and

Assignees

• Raytheon Co

Inventors

• Sisney Brent L
• Chipper Robert B
• Jackson John

Classifications

• G02B27/141

  using dichroic mirrors · CPC title

• G01S17/86

  Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders · CPC title

• G02B23/10

  reflecting into the field of view additional indications, e.g. from collimator · CPC title

• G02B13/146 Primary

  with corrections for use in multiple wavelength bands, such as infrared and visible light, e.g. FLIR systems · CPC title

• F41G1/32

  Night sights, e.g. luminescent {(optical aspects of sighting devices G02B23/00, G02B27/00)} · CPC title