Patent Description:
Holographic sporting/combat optic is a non-magnifying weapon sight that allows the user looking through an optical viewing window to see a reticle superimposed at a specific distance in the field of view. The reticle is a three-dimensional holographic image recorded on a holographic recording medium. The reticle is formed when a light beam is projected through the holographic recording medium.

Conventional holographic sporting/combat optics spread the optical path over numerous components within a cavity. To account for windage and elevation adjustments, the optical components in the optical path are adjusted. By modifying the optical path, error is introduced into the reticle output. Error may be caused by an intended output (i.e. adjust by turning knob) or an unintended output (i.e. it is cold and the substrate material flexed causing the optical path to shift).

Alternatively, the holographic sporting/combat optics may rely upon components fixed in a cavity. The cavity in turn rests upon a mechanism that will account for windage and elevation by moving the entire cavity as a whole which keeps the optical path intact. Although less prone to error, this approach requires costly housing materials (i.e., rigid materials that will not flex under temperature/high stress). In either approach, the manufacturing process requires tight controls because one is assembling the optical path into the cavity of the holographic sporting/combat optic.

Therefore it is desirable to provide a holographic porting/combat optic that simplifies manufacturing process while reducing the physical size and improving accuracy.

<CIT> discloses a method for design and manufacturing of optics for holographic sight.

According to the invention, a holographic sporting/combat optic is presented for use with a weapon. A housing defines an optical viewing window along a line of sight axis and is configured to mount to a weapon. A laser diode is arranged in the housing and operates to emit a beam of light. A beam changing lens is arranged in the housing. The beam changing lens (cylinder or the like) receives the beam of light from the laser diode and operates to focus the beam of light into a line. A carrier is also disposed in the optical viewing window, such that two opposing planar surfaces of the carrier align with the optical viewing window. An incoming holographic optical element is disposed adjacent to one of the opposing planar surfaces of the carrier and operates to collimate light incident thereon. An outgoing holographic optical element is disposed adjacent to the other opposing planar surface of the carrier and, in response to light incident thereon, the outgoing holographic optical element operates to project a reticle image in the optical viewing window. One or more light guides may be arranged in the housing, such that the light guides are configured receive light from the beam changing lens and guide the light towards the incoming holographic optical element.

In one embodiment, the incoming holographic optical element and/or the outgoing holographic optical element are further defined as an emulsion. The emulsion preferably maintains consistency after exposure. In one example, the emulsion has a grain size less than eight nanometers and includes silver halide.

Referring to <FIG> and <FIG>, a holographic sporting/combat optic <NUM> is shown mounted to a weapon <NUM>. The holographic sporting/combat optic <NUM> allows a user to look through an optical viewing window <NUM> and projects a reticle image into the field of view as seen through the optical viewing window. A housing <NUM> of the holographic sporting/combat optic <NUM> defines an interior chamber for housing optical components therein. A mounting base <NUM> is provided on the bottom of the housing <NUM> and functions to attach the holographic sporting/combat optic <NUM> to the weapon <NUM>. Various types of attachment methods may be employed depending upon the type of weapon. While the weapon is shown as a handgun, it is readily understood that the holographic sporting/combat optic <NUM> may be suitable for use with other types of weapons, including a rifle, a bow, etc..

Within the housing <NUM>, the holographic sporting/combat optic <NUM> includes a light source (e.g., a laser diode <NUM>), a beam changing lens <NUM> and a carrier <NUM>. The light source <NUM> is powered by a power source <NUM>, such as a battery, and operates to emit a beam of light. The beam changing lens <NUM> receives the beam of light from the laser diode <NUM> and transforms the beam of light into a line. A carrier <NUM> is disposed in the optical viewing window and configured to receive the line of light from the beam changing lens <NUM>. In one embodiment, the carrier <NUM> is comprised of a unitary transparent material (e.g., glass). The carrier <NUM> further defines two opposing planar surfaces through which the light passes. An incoming holographic optical element <NUM> is disposed adjacent to one of the opposing planar surfaces of the carrier and operates to collimate light incident thereon. An outgoing holographic optical element <NUM> is disposed adjacent to the other opposing planar surface of the carrier <NUM>. In response to light incident thereon, the outgoing holographic optical element <NUM> operates to project a reticle image in the optical viewing window. In this embodiment, the incident light was collimated by the incoming holographic optical element <NUM> and passed through the carrier <NUM> before reaching the outgoing holographic optical element <NUM>. In some embodiments, one or more light guides are arranged in the housing. The one or more light guides are configured to receive light from the beam changing lens <NUM> and guide the light towards the incoming holographic optical element as further described below. In some embodiments, more than one holographic optical element can be used.

An adjustment mechanism <NUM> is interfaced between the housing <NUM> and the mounting base <NUM>. The adjustment mechanism <NUM> enables the user to move the housing <NUM> relative to the mounting base <NUM>. More specifically, the adjustment mechanism <NUM> includes a subassembly for adjusting elevational angle of the housing and another subassembly for adjusting azimuth angle of the housing. Different types of mechanical or electro-mechanical mechanisms are known in the art and may be implemented with the holographic sight <NUM>.

<FIG> further illustrates an example embodiment of a holographic sporting/combat optic <NUM> defining a line a sight axis <NUM> for viewing a reticle. To generate the reticle, a laser diode <NUM> emits a beam of light in a first direction along an axis that is parallel to the line of sight axis and towards a beam changing lens <NUM>. The beam changing lens <NUM> (e.g., cylinder lens) receives the beam of light and transforms the beam of light into a line.

One or more light guides are used to direct the line of light onto the holographic optical elements. In this embodiment, a first light guide <NUM> receives the line of light from the beam changing lens <NUM> and guides the light along the same axis. The first light guide <NUM> includes an angled surface <NUM> at an end distal from the beam changing lens <NUM> which redirects the light in a second direction upwards at substantially ninety degrees. The angled surface <NUM> of the first light guide may be coated with a reflective coating, such as silver. A second light guide <NUM> receives the reflected light from the angled surface of the first light guide <NUM>. The second light guide in turn directs the light in a third direction which is opposite to the first direction and towards the holographic optical elements. It is noted that this third direction is parallel with the line of sight axis <NUM>. The first and second light guides <NUM>, <NUM> may be comprised of glass or another transparent material. Although different arrangements for directing the light from the diode to the holographic optical elements are envisioned, this particular arrangement results in a compact package.

A carrier <NUM> is disposed in the optical viewing window along the line of sight axis. In this embodiment, the carrier <NUM> is a cuboid that defines two opposing planar surfaces which align with the optical viewing window. The carrier <NUM> is preferably comprised of a unitary transparent material, such as glass. By using a unitary carrier <NUM>, the optical path is exposed and controlled on a lab table. This produces an optical path that is sealed and whose accuracy will not be jeopardized by the environment.

An incoming holographic optical element <NUM> is disposed adjacent to and/or on the planar surface facing the second light guide <NUM>. The incoming holographic optical element <NUM> receives the light from the second light guide and collimates the light incident thereon. Similarly, an outgoing holographic optical element <NUM> is disposed adjacent to and/or on the other opposing planar surface of the carrier. In response to light incident thereon, the outgoing holographic optical element <NUM> operates to project a reticle image in the optical viewing window.

In the example embodiment, the incoming holographic optical element and/or the outgoing holographic optical element are implemented using an emulsion. The emulsion preferably has a grain size less than eight nanometers and maintains consistency after exposure. The incoming holographic optical element (HOE) is recorded such to allow for light (the beam) to be collimated at an angle to allow the outgoing HOE to be displayed properly to the user. The outgoing HOE contains the image reticle(s). The grain size is required to have appropriate exposable material to allow for multiple images without fading or degradation on the outgoing HOE. On the incoming HOE, it is required to set the beam angle appropriately. The consistency is required because if the emulsion were to shrink after being exposed it would cause the angle to change and thus not display the image correctly. In some instances, the emulsion may be comprised of silver halide although it is readily understood that other types of materials may be used for the emulsion.

Emulsion forming the holographic optical element are typically sealed against the surfaces of the carrier <NUM>. For example, the incoming holographic optical element <NUM> is encased between the carrier <NUM> and an opposing surface of the second light guide <NUM>; whereas, the outgoing holographic optical element <NUM> is encased by a glass cover <NUM>. A clear adhesive <NUM> may be used and interposed between the glass cover <NUM> and the outgoing holographic optical element <NUM>, for example adhesives commercially available from Norland Products. It is to be understood that only the relevant optical components are discussed in relation to <FIG>, but that other components may be incorporated in the holographic sporting/combat optic <NUM>.

With reference to <FIG>, a composite reticle image <NUM> may be projected by the outgoing holographic optical element <NUM> of the holographic sporting/combat optic <NUM> in either a transmission or reflective hologram manner. In an example embodiment, the composite reticle image is comprised of two or more reticle elements. For example, the composite reticle image <NUM> includes a first reticle element <NUM>, a second reticle element <NUM>, a third reticle element <NUM> and fourth reticle element <NUM>. Each reticle element preferably includes multiple markings. For example, the first reticle element <NUM> may be a center dot surrounded by a circle; whereas, the second reticle element <NUM>, the third reticle element <NUM> and fourth reticle element <NUM> may be two dashes (or dots, chevrons, arrows or other geometric shape) positioned at different spacing above or below the center dot. More importantly, each of these four reticle elements is captured at a different distance from the weapon during different exposures of the holographic recording element. The reticle elements can be recorded by the outgoing holographic optical element <NUM> using holographic image multiplexing. In some embodiments, one or more reticle elements may be positioned above the center dot while other reticle elements are positioned below the center dot. In other embodiments, reticle elements above the center dot are reference points for one type of weapon; whereas, reticle elements below the center dot are reference points for another type of weapon. It is understood that a composite reticle image <NUM> can include more or less than four reticle elements.

More specifically, each reticle element (i.e., layer) is captured at whatever distance is required to align that layer with a ballistic reference point. For example, if the center reference dot's effective distance is <NUM> meters, the dot's layer would be captured at that distance. If the second reference dashes are accurate at <NUM> meters, those dashes are captured at that distance (and so on). As seen in <FIG>, the first reticle element <NUM>, the second reticle element <NUM>, the third reticle element <NUM> and the fourth reticle element <NUM> are captured at <NUM> meters, <NUM> meters, <NUM> meters and <NUM> meters, respectively. These distances are merely illustrative and may vary in different embodiments.

When the user observes the composite reticle image directly through the optic's line of sight, the user sees one reticle image <NUM>, with various ballistic reference points that exist at their individually captured distances, thereby minimizing or eliminating parallax when aimed at targets at those distances. In other words, different parts of a single composite reticle image <NUM> are captured in the emulsion at different times, and each time records its particular set of ballistic data at its own specific distance (relative to the selected ballistic characteristics of a chosen weapon platform and type of ammunition). Each reference point captured in space would exhibit parallax as a real object would at that distance. Subsequently, when the user aligns the ballistic reference point with a target at the same or a similar distance, the reference point's location at the target plane would significantly reduce or eliminate the overall impact of parallax on the user's accuracy and ability to hit the target.

In another aspect of this disclosure, the holographic sporting/combat optic <NUM> may be configured to generate different reticle images using the same holographic optical element as seen in <FIG>. This technique relies upon two or more light sources <NUM>, <NUM> operating at different wavelengths. For example, a first light source <NUM> emits a beam of light at a first wavelength; whereas, a second light source <NUM> emits a beam of light at a second wavelength. The two light beams are then combined and directed towards the holographic optical element <NUM>.

One or more optical waveguides are arranged in the housing. The optical waveguides are configured to receive light from the first light source <NUM> and the second light source <NUM> and direct the light from the first light source <NUM> and the second light source <NUM> onto the holographic optical element <NUM>. In one example, a first dicroic mirror <NUM> is arranged to receive the light from the first light source <NUM> and direct the light from the first light source <NUM> through a second dicroic mirror <NUM> towards the holographic optical element <NUM>; whereas, the second dicroic mirror <NUM> is arranged to receive light from the first dicroic mirror <NUM> and the second light source <NUM> and direct the light towards the holographic optical element <NUM>. Other types of optical waveguides and arrangements for the optical waveguides are contemplated and fall within the broader aspects of this disclosure.

A holographic optical element is disposed in the housing of the holographic sporting/combat optic <NUM> and operates to project a composite reticle image in the optical viewing window. In the example embodiment, a single carrier with holographic optical elements mounted on opposing sides as described above is used in this embodiment. This technique for generating different reticle images, however, is not limited to this type of holographic optical element.

In a simplified example, the composite reticle image recorded on the holographic optical element <NUM> is comprised of at least a first reticle element and a second reticle element. The first reticle element projects into the optical viewing window in response to light having the first wavelength and the second reticle element projects into the optical viewing window in response to light having the second wavelength. In this way, different reticle elements can be selectively included or omitted from the composite reticle image by turning on or off light sources emitting light at different wavelengths.

Reticles are preferably designed to correspond to known ballistic reference points for a particular weapon. In the example embodiment, each reticle element in the composite reticle image corresponds to ballistic reference points for the same weapon platform. For a given weapon platform and ammunition type, a ballistic reference point may be defined as a distance from the weapon (along the line of sight axis) and an expected deviation (e.g., drop distance) by a projectile fired by the weapon from the line of sight axis at the corresponding distance. It is readily understood that the placement of the reticle elements compensate for the corresponding drop distance.

Using the technique above, a single holographic sporting/combat optic <NUM> can be designed to project reticles for more than one weapon. For example, a reticle for a weapon of a first type may be recorded onto the holographic optical element as well as a reticle for a weapon of a second type. The reticle for the weapon of a first type is projected into the optical viewing window in response to light having the first wavelength and the reticle for the weapon of the second type is projected into the optical viewing window in response to light having a different wavelength. By turning on and off the respective light sources, the reticle of interest can be selected. This example is merely illustrative. It is envisioned that this technique may be used to selectively introduce reticle elements that represent other types of data.

In some embodiments, the light from the two light sources have wavelengths that are different but close in length such that the color of the two reticles appear to be the same (e.g., reddish). In other embodiments, the light from the two light sources have wavelengths that are further apart from each other such that the color of the two reticles have different colors (e.g., one is red and the other is blue).

With continued reference to <FIG>, the holographic sporting/combat optic <NUM> may be interfaced with a controller <NUM>. The controller <NUM> selectively turns on and off the light sources to control the reticle elements projected into the composite reticle image. In an exemplary embodiment, the controller <NUM> is implemented as a microcontroller. It should be understood that the logic for the controller <NUM> can be implemented in hardware logic, software logic, or a combination of hardware and software logic. In this regard, controller <NUM> can be or can include any of a digital signal processor (DSP), microprocessor, microcontroller, or other programmable device which are programmed with software implementing the above described methods. It should be understood that alternatively the controller is or includes other logic devices, such as a Field Programmable Gate Array (FPGA), a complex programmable logic device (CPLD), or application specific integrated circuit (ASIC). When it is stated that controller <NUM> performs a function or is configured to perform a function, it should be understood that controller <NUM> is configured to do so with appropriate logic (such as in software, logic devices, or a combination thereof).

In an example embodiment, a user input <NUM> provides the input command to the controller <NUM>. For example, the user input <NUM> may be a user actuated switch. Depending on the switch position, controller <NUM> selectively operates the light devices. In one position, the first light source is turned on and the second light source is turned off. In a second position, the first light source is off but the second light source is turned on. In a third position, both light sources are off. In this way, the light source are selectively operable in accordance with an input from the user. It is understood that the switch can be used to support more than two light devices and different on/off combinations thereof. Moreover, it is envisioned that other types of user inputs, such as a touchscreen, may be used in place of the switch.

Claim 1:
A holographic sporting/combat optic (<NUM>) suitable for use with a weapon, comprising:
a housing (<NUM>) defining an optical viewing window (<NUM>) (<NUM>) along a line of sight axis and configured to mount to a weapon (<NUM>);
a laser diode (<NUM>, <NUM>) arranged in the housing (<NUM>) and operable to emit a beam of light;
a beam changing lens (<NUM>) arranged in the housing (<NUM>), wherein the beam changing lens (<NUM>) receives the beam of light from the laser diode (<NUM>, <NUM>) and operates to transform the beam of light into a line;
a carrier (<NUM>) disposed in the optical viewing window and comprised of a unitary transparent material, the carrier (<NUM>) defining first and second opposing planar surfaces which align with the optical viewing window;
an incoming holographic optical element (<NUM>) disposed adjacent to the first opposing planar surface of the carrier (<NUM>), the incoming holographic optical element (<NUM>) being operable to collimate light incident thereon in a direction perpendicular to the second opposing planar surface;
an outgoing holographic optical element (<NUM>) disposed adjacent to the second opposing planar surface of the carrier (<NUM>), such that the outgoing holographic optical element (<NUM>) is opposite of and facing the incoming holographic optical element (<NUM>) within the optical viewing window, wherein the outgoing holographic optical element (<NUM>) operates to project a reticle (<NUM>) image in the optical viewing window in response to collimated light incident thereon; and
one or more light guides (<NUM>, <NUM>) arranged in the housing (<NUM>), the one or more light guides (<NUM>, <NUM>) configured to receive light from the beam changing lens (<NUM>) and guide the light towards the incoming holographic optical element (<NUM>), wherein the incoming holographic optical element (<NUM>) is encased between the carrier (<NUM>) and the one or more light guides (<NUM>, <NUM>), and wherein the outgoing holographic optical element (<NUM>) is encased between the carrier (<NUM>) and a cover element (<NUM>) opposite of the carrier (<NUM>).