IRIS CAP FOR BEACON

Abstract

An iris cap for a beacon is cylindrical in shape with defined wall length to create such an iris for the intended application. One application for example, an axicon will create defined output angle of emission dependent on the source emitter’s output angle and the axicon angle. Given the cost and difficulty of reproducing several MWIR/LWIR beacons for specific applications of maximum positive output angle, the Iris Cap introduces a simple solution. The Iris Cap can create specific maximum angles to reduce risk of over exposure of the beacon, simply by attaching the Iris Cap to the location of the emission with a countersunk screw.

Claims

1. A swappable iris cap that creates an iris for the MWIR/LWIR beacon emission.

2. The iris cap as claimed in claim 1, wherein the iris cap comprises an annular wall having an extent defining an effective iris for the beacon emission.

3. A MWIR/LWIR beacon comprising a quantum cascade laser; an axicon for reflecting light from the laser to create a beacon; and iris cap that creates an iris for the beacon.

4. The beacon as claimed in claim 3, wherein the iris cap is swappable.

5. The beacon as claimed in claim 3, wherein the iris cap comprises an annular wall having an extent defining an effective iris for the beacon emission.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In the accompanying drawings, reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale; emphasis has instead been placed upon illustrating the principles of the invention. Of the drawings:

[0016] FIG. 1A is a side perspective views showing a beacon powered off and FIG. 1B is a side perspective view showing the beacon powered on;

[0017] FIGS. 2A and 2B are a side plan view and a side cross sectional view of the beacon;

[0018] FIG. 3 is a side plan view of inventive Iris Cap;

[0019] FIG. 4 is a top-to-bottom isometric view of the Iris Cap;

[0020] FIG. 5 is a bottom-to-top isometric view of the iris cap;

[0021] FIG. 6A is a partial top view of a conventional beacon with the top cap;

[0022] FIG. 6B partial top view of a beacon 50 with the inventive iris cap; and

[0023] FIG. 7 is a pictorial representation of an aircraft relative to a MWIR/LWIR emitter beacon.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] The invention now will be described more fully hereinafter with reference to the accompanying drawings, in which illustrative embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0025] As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Further, the singular forms and the articles “a”, “an” and “the” are intended to include the plural forms as well, unless expressly stated otherwise. It will be further understood that the terms: includes, comprises, including and/or comprising, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Further, it will be understood that when an element, including component or subsystem, is referred to and/or shown as being connected or coupled to another element, it can be directly connected or coupled to the other element or intervening elements may be present.

[0026] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0027] FIG. 3 is a side plan view of the Iris Cap 100.

[0028] FIG. 4 is a top-to-bottom isometric view of the Iris Cap 100. This view shows the simple mounting of the cap via a countersunk hole 108 for a countersunk screw.

[0029] FIG. 5 is a bottom-to-top isometric view of the Iris Cap 100. This view captures the annular iris wall 110 on the outer diameter of the Iris Cap. The extent of this wall 110 in the axial direction defines the effective iris of the beacon.

[0030] This view shows how the outer wall protruding down. Thus, this wall 110 creates the iris effect of the accompanying MWIR/LWIR beacon. This wall 110 is increase or decrease in length to create a different iris effects on the MWIR/LWIRIR beacon and reduce the maximum output angle of the emission.

[0031] FIG. 6A is a partial top view of a conventional beacon with the top cap and FIG. 6B partial top view of a beacon 50 with the inventive iris cap 100. These figures show the axicon before and after adding the Iris Cap. Before attaching the cap, the positive angle of emission is at 25°, then after adding an Iris Cap 100 the positive angle is limited to only a positive angle of 20°. And this positive angle can be easily adapted to different missions by changing to a different iris cap provide a different emission angle.

[0032] Table 1 for a simple breakdown of the various heights the MWIR/LWIR beacon could be identified from assuming a point source of emission that spreads from 0° to the maximum angle declared in the table. Assume the emission can be detected up to 6 nautical miles.

TABLE-US-00001 Max angle 3 Nautical Miles 4 Nautical Miles 6 Nautical Miles 25° 8500 ft 11333 ft 17000 ft 15° 4884 ft 6512 ft 9769 ft 10° 3214 ft 4280 ft 6428 ft This data assumes a point source, and a detectable emission spanning from 0° to the maximum angle in the left most column. This also assumes the MWIR/LWIRIR emission source can emit over a distance up to 6 nautical miles. This table depicts how high up the MWIR/LWIRIR beacon can be seen from at these axicon defined positive angles of emission.

[0033] For example, if the user’s recipient camera or sensing system were on a boat, they may elect to only want an output of 15° to limit the maximum height over distance of their signal to reduce risk of alternative imaging or sensing systems on an aircraft from detecting their signal.

[0034] FIG. 7 is a pictorial representation, in support of table 1, of an aircraft relative to a MWIR/LWIR emitter being within the emission halo of the device based on high angle emission.

[0035] While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.