Patent Description:
Optical sights are typically used in conjunction with a firearm to aid a shooter in properly aligning a barrel of the firearm with a desired target. Properly aligning the barrel of the firearm relative to a target results in a projectile fired from the firearm impacting the target at a desired location. Conventional optical sights are typically mounted at a top surface of the firearm and include an aiming point for use by the shooter in aligning the optical sight and, thus, the barrel of the firearm relative to the target. Such aiming points may be illuminated to further aid a shooter in quickly and accurately aligning the optical sight and firearm relative to a target.

Optical sights may be used in conjunction with a variety of firearms and, as such, may provide different features depending on the particular firearm and/or application. For example, optical sights designed for use in close-target situations are compact and designed to allow a shooter to quickly train the optical sight and firearm on a target. One such optical sight is a so-called reflex sight that is useful in close-target situations by providing the shooter with fast-target acquisition and aiming of a firearm. Such reflex sights are typically more compact than an optical sight used on a rifle, for example, to allow mounting of other systems on the firearm (i.e., laser pointers, ranging devices, etc.) and to reduce the overall size and weight of the combined firearm and optical sight. Further, such reflex sights provide a field-of-view that allows the shooter to quickly position the optical sight and firearm relative to a target without reducing the situational awareness of the shooter.

A reticle may indicate an aiming point on the field-of-view. Reflex sights typically require an illumination device to illuminate the reticle. The illumination device may be powered by a power source. Some reflex sights use photo sensors to sense ambient light conditions and determine a brightness of the illumination device based on the ambient light condition. The photo sensors sample current ambient light conditions and provide information to a microcontroller in the optic to adjust the reticle brightness. <CIT> discloses an optical sight according to the preamble of claim <NUM>.

Reflex sights typically require an illumination device to illuminate a reticle. The illumination device may be powered by a power source. Some reflex sights use photoelectric sensors to sense ambient light conditions and determine a brightness of the illumination device based on the ambient light condition. The photoelectric sensors sample current ambient light conditions and provide information to a microcontroller in the optic to adjust the reticle brightness. The receiver detects the change in light and converts the change to an electrical output.

The photoelectric sensor may be positioned in a location to optimize the sensing of the ambient light conditions and provide an accurate interpretation of the target scene. Positioning the photoelectric sensor to be front-facing and towards a top of the optic provides a better vantage point to detect ambient light at the target scene. The optic having the more accurate detection of ambient light may then provide an appropriate reticle brightness for the target scene.

The photoelectric sensor location of the present disclosure is advantageous over photoelectric sensor locations currently used in the industry. Photoelectric sensors placed near the light source within the housing of the optic may be buried deep and light from the target scene may be partially obscured by the lens and/or housing. Light sources, natural or otherwise, may be reflected from the rear of the optic and therefor tarnish the interpretation of the target scene by the photoelectric sensor if the photoelectric sensor is disposed nearby. Photoelectric sensors located on a top of the housing, above the lens, and pointing upwards may be well-exposed but located improperly, such that light conditions are sampled above the optic but not at the target scene. Photoelectric sensors placed beneath the lens may be well exposed to light but may be obscured by the pistol slide or backup iron sights when the optic is installed on the firearm, thus diminishing the accuracy of the detection of light at the target scene.

Thus, current locations of photoelectric sensors in the industry may be inaccurate in many situations, including, for example, when there is a bright light at the weapon and low light at the target and when there is low light at the weapon and bright light at the target. Each of these situations would result in the aiming point being either too bright or too dim. The photoelectric sensor of the present disclosure solves these issues by accurately detecting light at the target scene, without being obscured by portions of the optics housing, the firearm, or backup sights. With an accurate detection of light at the target scene, the controller may accurately control illumination of the reticle such that the brightness is appropriate for the ambient light conditions.

Now referring to <FIG>, an example optical sight <NUM> according to the present disclosure is illustrated. The optical sight <NUM> may be a reflex sight. The optical sight <NUM> includes a housing <NUM>, an adjustment assembly <NUM>, an illumination assembly <NUM>, and an optical element <NUM>. Each of the adjustment assembly <NUM>, the illumination assembly <NUM>, and the optical element <NUM> is supported by, and attached to, the housing <NUM>, such that the housing <NUM> supports the adjustment assembly <NUM>, illumination assembly <NUM>, and the optical element <NUM> relative to a firearm <NUM>. When the housing <NUM> is mounted to the firearm <NUM>, the illumination assembly <NUM> cooperates with the optical element <NUM> to display a reticle <NUM> on the optical element <NUM> to facilitate alignment of a trajectory of the firearm <NUM> with a target object (not shown). The adjustment assembly <NUM> interacts with the illumination assembly <NUM> to move the illumination assembly <NUM> relative to the housing <NUM> to adjust a position of the reticle <NUM> relative to the optical element <NUM>. While the optical sight <NUM> may be used with various firearms, the optical sight <NUM> will be described hereinafter and shown in the drawings as being associated with a barrel <NUM> of the firearm <NUM>.

Referring to <FIG>, the housing <NUM> may include a main body <NUM> and an upwardly extending optical element housing <NUM> extending generally from the main body <NUM>. The main body <NUM> may include a first aperture <NUM> formed through a top surface <NUM> and a second aperture <NUM> formed through a side surface <NUM>. The top surface <NUM> may include a series of graduations <NUM> generally surrounding a perimeter of the first aperture <NUM>, while the side surface <NUM> may likewise include a series of graduations <NUM> that generally surround an outer perimeter of the second aperture <NUM>. The graduations <NUM>, <NUM> may cooperate with the adjustment assembly <NUM> to position the illumination assembly <NUM> relative to the optical element <NUM>, as will be described further below.

The main body <NUM> may also include a recess <NUM>. The recess <NUM> allows the illumination assembly <NUM> to direct light generally from the main body <NUM> of the housing <NUM> toward the optical element <NUM>. The recess <NUM> may be formed generally between a pair of attachment apertures <NUM> that are disposed generally within the recess <NUM> and between the main body <NUM> and the upwardly extending optical element housing <NUM>. The attachment apertures <NUM> selectively receive a pair of fasteners <NUM> that removably attach the housing <NUM> to the firearm <NUM>.

In one configuration, the fasteners <NUM> include a threaded shank <NUM>, a head portion <NUM>, and a taper <NUM> extending generally between the threaded shank <NUM> and the head portion <NUM>. The head portion <NUM> may include a hexagonal recess <NUM> as well as a longitudinal slot <NUM> that cooperate with an external tool (not shown) to rotate the fasteners <NUM> relative to the main body <NUM> of the housing <NUM> and selectively attach the housing <NUM> to the firearm <NUM>. The hexagonal recess <NUM> may be used with a tool having a mating male portion while the longitudinal slot <NUM> may be used with a tool having a substantially flat male end. While the head portion <NUM> is described as including the hexagonal recess <NUM> and the longitudinal slot <NUM> that receive tools having a respective mating configuration, the longitudinal slot <NUM> may be sized such that any flat surface can be used to rotate the fasteners <NUM> relative to the housing <NUM>. For example, the longitudinal slots <NUM> may include a sufficient width and thickness to allow a spent shell casing to be used to rotate the fasteners relative to the housing <NUM>.

With particular reference to <FIG>, the upwardly extending optical element housing <NUM> is shown and may include a pair of posts <NUM>, an opening <NUM>, and a cross member <NUM> extending generally over the opening <NUM> and between the posts <NUM>. The posts <NUM> may extend generally perpendicular to the main body <NUM>. A rear wall <NUM> of each post <NUM> may be formed at an angle from about <NUM> degrees (<NUM>°) to about <NUM>°, and from about <NUM>° to about <NUM>° relative to the main body <NUM> and may extend a predetermined distance above the opening <NUM>. The opening <NUM> may include a generally D-shape to accommodate the optical element <NUM> therein. The cross member <NUM> provides the opening <NUM> with the D-shape and may include a bottom surface <NUM> opposing the opening <NUM> having a convex shape corresponding to the optical element <NUM> and a top surface <NUM> having a concave shape. The concave shape of the top surface <NUM> allows the top surface <NUM> to extend from the main body <NUM> a shorter distance than each of the posts <NUM>. In other words, the posts <NUM> extend from the main body <NUM> a greater distance than does the top surface <NUM> of the cross member <NUM>. As such, should the housing <NUM> be dropped such that the upwardly extending optical element housing <NUM> contacts a hard surface, the force associated with the upwardly extending optical element housing <NUM> contacting the hard surface is received by a distal end of each post <NUM> and is transmitted to the main body <NUM> rather than being received at the generally convex bottom surface <NUM> of the cross member <NUM>. Transmitting forces generally away from the opening <NUM> and through the posts <NUM> toward the main body <NUM> protects the optical element <NUM> disposed within the opening <NUM> and prevents the optical element <NUM> from being fractured should the housing <NUM> be dropped or suffer an impact event.

The main body <NUM> and upwardly extending optical element housing <NUM> may be integrally, and monolithically, formed and may be formed of a one-piece metal construction. Forming the main body <NUM> and the upwardly extending optical element housing <NUM> as a one-piece metal body strengthens the housing <NUM> and allows the housing <NUM> to withstand forces applied to either the main body <NUM> or the upwardly extending optical element housing <NUM>. In particular, forces applied to the posts <NUM> of the upwardly extending optical element housing <NUM> are directly transferred from the upwardly extending optical element housing <NUM> to the main body <NUM>. Such forces are therefore diverted away from the optical element <NUM>, thereby protecting the optical element <NUM>, as described above. Forming the main body of a one-piece metal construction enhances the ability of the posts <NUM> in transmitting forces from a distal end of each post <NUM> to the main body <NUM>.

The adjustment assembly <NUM> is supported by the housing <NUM> and adjusts a position of the illumination assembly <NUM> relative to the housing <NUM> to adjust a position of the reticle <NUM> relative to the optical element <NUM>. The adjustment assembly <NUM> includes a height-adjustment mechanism, or elevation-adjustment mechanism, <NUM> that adjusts an UP/DOWN position of the reticle <NUM> and a windage-adjustment mechanism, or lateral adjustment mechanism, <NUM> that adjusts a left-right position of the reticle <NUM> relative to the optical element <NUM>.

Referring to <FIG>, the height-adjustment mechanism <NUM> includes an adjustment screw <NUM> and an adjuster block <NUM>. The adjustment screw <NUM> is rotatably received within the first aperture <NUM> of the main body <NUM> and may be rotated relative to the graduations <NUM>. The adjustment screw <NUM> includes a threaded body <NUM>, a head <NUM>, and a taper <NUM> extending generally between the threaded body <NUM> and the head <NUM>. The head <NUM> may include a slot <NUM> to allow a tool (not shown) to be inserted into the head <NUM> to rotate the head <NUM> relative to the housing <NUM>. A seal <NUM> may be disposed between the taper <NUM> of the adjustment screw <NUM> and an inner surface of the first aperture <NUM> to prevent debris from entering the main body <NUM>. In one configuration, the seal <NUM> is an O-ring seal that is received generally around the taper <NUM> of the adjustment screw <NUM>.

A clip <NUM> may be disposed generally at a junction of the threaded body <NUM> and the taper <NUM> to permit rotational movement of the adjustment screw <NUM> relative to the main body <NUM> while concurrently preventing withdrawal of the adjustment screw <NUM> from the main body <NUM>. The clip <NUM> may be received generally around the adjustment screw <NUM> once the adjustment screw <NUM> is inserted into the main body <NUM>.

A seal <NUM> may be positioned generally between the head <NUM> of the adjustment screw <NUM> and the threaded body <NUM> to prevent debris from entering the housing <NUM>. The seal may engage the taper <NUM> of the adjustment screw <NUM> and may similarly engage a surface proximate to the first aperture <NUM> of the main body <NUM>. In one configuration, the seal <NUM> is an O-ring and generally surrounds the taper <NUM> of the adjustment screw <NUM>.

The taper <NUM> includes a series of detents <NUM> in communication with a detent pin <NUM>. The detent pin <NUM> is slidably supported within a bore <NUM> of the housing <NUM>, whereby the bore <NUM> is in communication with the first aperture <NUM> of the main body <NUM>. A biasing member <NUM> such as, for example, a coil spring, is disposed within the bore <NUM> (<FIG>) and imparts a biasing force on the detent pin <NUM> to urge the detent pin <NUM> into the first aperture <NUM>. When the adjustment screw <NUM> is inserted into the first aperture <NUM>, a distal end of the detent pin <NUM> may engage the detents <NUM> formed in the taper <NUM> of the screw <NUM>. When the screw <NUM> is rotated relative to the housing <NUM>, the detent pin <NUM> is moved into an out of engagement with adjacent detents <NUM> and makes an audible noise to allow the user to know exactly how much the screw <NUM> has been rotated relative to the housing <NUM>.

The detent pin <NUM> may include a tapered portion <NUM> terminating at a point <NUM> at a distal end of the detent pin <NUM>. Likewise, each detent <NUM> may include a tapered surface <NUM>, whereby the tapered portion <NUM> of the detent pin <NUM> engages the tapered surface <NUM> of a respective detent <NUM> to allow the screw <NUM> to be rotated in two directions relative to the housing <NUM> and to facilitate movement of the point <NUM> of the detent pin <NUM> into and out of each detent <NUM> when the screw <NUM> is rotated relative to the housing <NUM>. The angle of the tapered portion <NUM> of the detent pin <NUM> and/or that of the tapered surface <NUM> of the detents <NUM> can be adjusted to either increase or decrease the force required to rotate the screw <NUM> relative to the housing <NUM> and/or to adjust the audible noise created when the screw <NUM> is rotated relative to the housing <NUM>. Furthermore, the spring constant of the biasing member <NUM> may also be adjusted to both adjust the force required to rotate the screw <NUM> relative to the housing <NUM> as well as to adjust the audible noise created when the detent pin <NUM> moves from one detent <NUM> to an adjacent detent <NUM> caused by rotation of the screw relative to the housing <NUM>.

The head <NUM> of the adjustment screw <NUM> may also include a marker <NUM> formed therein. The marker <NUM> may be an indicator formed in the surface of the head <NUM> to indicate an adjustment position of the adjustment screw <NUM>. The marker <NUM> may be painted on and/or laser etched into the surface of the head <NUM>. For example, the marker <NUM> may be an arrow-shaped marker, a V-shaped marker, a continuous-line marker, a broken-line marker, etc. When the adjustment screw <NUM> is rotated relative to the housing <NUM> the marker <NUM> moves from a first position to a second position indicating adjustment of the height-adjustment mechanism <NUM>.

The adjuster block <NUM> may interact with the illumination assembly <NUM> to move the illumination assembly <NUM> up/down relative to the housing <NUM>. The adjuster block <NUM> may include a threaded bore <NUM> and a projection <NUM> engaged with the illumination assembly <NUM>. The adjustment screw <NUM> may be threadably received within the threaded bore <NUM> of the adjuster block <NUM> such that when the adjustment screw <NUM> is rotated relative to the housing <NUM>, the adjuster block <NUM> is moved along an axis substantially perpendicular to the top surface <NUM> of the main body <NUM>.

The projection <NUM> may be slideably received within a slot <NUM> in the illumination assembly <NUM>. The projection <NUM> may be permitted to slide along a longitudinal axis of the windage adjustment mechanism <NUM> without moving the illumination assembly <NUM> to allow for left/right adjustment of the illumination assembly <NUM>. The projection <NUM> may contact the sidewalls of the slot <NUM> during adjustment of the adjustment screw <NUM> to adjust the up/down position of the illumination assembly <NUM>. Because the projection <NUM> is in engagement with the illumination assembly <NUM> and is fixed for movement with the adjuster block <NUM>, up/down movement of the projection <NUM> similarly causes the illumination assembly <NUM> to move up/down relative to the housing <NUM>.

A biasing member <NUM> is disposed between the adjuster block <NUM> and the illumination assembly <NUM> and biases the adjuster block <NUM> generally along the longitudinal axis of the housing <NUM> to account for any tolerances in the housing <NUM>, illumination assembly <NUM>, screw <NUM>, and/or adjuster block <NUM>. In one configuration, the biasing member <NUM> is an O-ring and applies a force on the adjuster block <NUM> to maintain the adjustment assembly <NUM> in a desired position in a direction substantially parallel to the longitudinal axis of the housing <NUM> (i.e., substantially parallel to a line of sight). Allowing the O-ring to impart a force on the adjuster block <NUM> maintains tight engagement between the adjustment screw <NUM> and the adjuster block <NUM> and therefore allows for precise manipulation and movement of the adjuster block <NUM> relative to the housing <NUM> while concurrently maintaining a desired position of the adjustment assembly <NUM> in the direction substantially parallel to the line of sight.

The position of the illumination assembly <NUM> relative to the housing <NUM> may be determined based on the position of the adjustment screw <NUM> relative to the housing <NUM>. For example, the graduations <NUM> formed on the top surface <NUM> of the main body <NUM> may help in determining the relative position of the adjustment screw <NUM> relative to the main body <NUM> and, thus, the position of the illumination assembly <NUM> relative to the main body <NUM>.

The graduations <NUM> may be permanently attached to the top surface <NUM> of the housing <NUM> either via paint and/or laser etching. As such, the graduations <NUM> maintain the same fixed position relative to the top surface <NUM> and allow a user to know precisely how much the adjustment screw <NUM> has moved relative to the housing <NUM>. Furthermore, each graduation <NUM> may be positioned relative to each detent <NUM> such that each audible noise or "click" corresponds to movement of the screw <NUM> one graduation <NUM>.

Once adjustment of the adjustment screw <NUM> is completed, the biasing member <NUM>, in conjunction with the adjuster block <NUM>, prevents unintended rotation of the adjustment screw <NUM> due to vibration and the like relative to the housing <NUM> and, as such, maintains the adjusted position of the adjustment screw <NUM>.

A biasing member <NUM> (or a pair of biasing members <NUM>) is used on conjunction with biasing member <NUM> to further maintain a position of the screw <NUM> relative to the housing <NUM>. The biasing member <NUM> applies a force on the adjuster block <NUM> and is positioned between the adjuster block <NUM> and the housing <NUM> to exert a force on the adjuster block <NUM>. In another configuration, the biasing member <NUM> may be positioned between a portion of the illumination assembly <NUM> and the housing <NUM> to indirectly impart a force on the adjuster block <NUM>. In either configuration, the biasing member <NUM> may be a coil spring and may be received within a bore <NUM> of either the adjuster block <NUM> or the illumination assembly <NUM>. Alternatively, the biasing member <NUM> may be positioned and held relative to the adjuster block <NUM> by a post (not shown) received within the bore <NUM> of the adjuster block <NUM> of the illumination assembly <NUM>. Imparting a force on the adjuster block <NUM> likewise applies a force on the screw <NUM> and therefore resists relative movement between the screw <NUM> and the adjuster block <NUM>.

With continuing reference to <FIG>, the windage-adjustment mechanism <NUM> includes an adjustment screw <NUM>, a first adjuster block <NUM>, a second adjuster block <NUM>, and a biasing member <NUM>. The adjustment screw <NUM> is of a similar construction to that of the adjustment screw <NUM> and includes a threaded body <NUM>, a head <NUM>, a taper <NUM> extending generally between the threaded body <NUM> and the head <NUM>, and a slot <NUM> formed in the head <NUM>. Additionally, the adjustment screw <NUM> may include an adjustment indicator, or adjustment marking, <NUM> (<FIG>) formed in the head <NUM> to indicate an adjustment position of the adjustment screw <NUM>. The adjustment indicator <NUM> may be painted on and/or laser etched into the surface of the head <NUM>. For example, the adjustment indicator <NUM> may be an arrow, a V-shaped mark, a continuous-line mark, a broken-line mark, etc..

As with the adjustment screw <NUM>, the adjustment screw <NUM> may be rotated relative to the housing <NUM> but is not permitted to move along a longitudinal axis extending substantially perpendicular to the side surface <NUM> of the main body <NUM>. A clip <NUM> may be disposed generally at a junction of the threaded body <NUM> and the taper <NUM> to permit rotational movement of the adjustment screw <NUM> relative to the main body <NUM> while concurrently preventing withdrawal of the adjustment screw <NUM> from the main body <NUM>. The clip <NUM> may be received generally around the adjustment screw <NUM> once the adjustment screw <NUM> is inserted into the main body <NUM>.

A seal <NUM> may be positioned generally between the head <NUM> of the adjustment screw <NUM> and the housing <NUM> to prevent debris from entering the housing <NUM>. The seal may engage the taper <NUM> of the adjustment screw <NUM> and may similarly engage a surface proximate to the second aperture <NUM> of the main body <NUM>. In one configuration, the seal <NUM> is an O-ring and generally surrounds the taper <NUM> of the adjustment screw <NUM>.

The taper <NUM> includes a series of detents <NUM> in communication with a detent pin <NUM>. The detent pin <NUM> is slidably supported within a bore <NUM> (<FIG>) of the housing <NUM>, whereby the bore <NUM> is in communication with the second aperture <NUM> of the main body <NUM>. A biasing member <NUM> such as, for example, a coil spring, is disposed within the bore <NUM> and imparts a biasing force on the detent pin <NUM> to urge the detent pin <NUM> into the second aperture <NUM>. When the screw <NUM> is inserted into the second aperture <NUM>, a distal end of the detent pin <NUM> may engage the detents <NUM> formed in the taper <NUM> of the screw <NUM>. When the screw <NUM> is rotated relative to the housing <NUM>, the detent pin <NUM> is moved into an out of engagement with adjacent detents <NUM> and makes an audible noise to allow the user to know exactly how much the screw <NUM> has been rotated relative to the housing <NUM>.

The detent pin <NUM> may include a tapered portion <NUM> terminating at a point <NUM> at a distal end of the detent pin <NUM>. Likewise, each detent <NUM> may include a tapered surface <NUM>, whereby the tapered portion <NUM> of the detent pin <NUM> engages the tapered surface <NUM> of a respective detent <NUM> to allow the screw <NUM> to be rotated in two directions relative to the housing <NUM> and to facilitate movement of the point <NUM> of the detent pin <NUM> into and out of each detent <NUM> when the screw <NUM> is rotated relative to the housing <NUM>. The angle of the tapered portion <NUM> of the detent pin <NUM> and/or that of the tapered surface <NUM> of the detents <NUM> can be adjusted to either increase or decrease the force required to rotate the screw <NUM> relative to the housing <NUM> and/or to adjust the audible noise created when the screw <NUM> is rotated relative to the housing <NUM>. Furthermore, the spring constant of the biasing member <NUM> may also be adjusted to both adjust the force required to rotate the screw <NUM> relative to the housing <NUM> as well as to adjust the audible noise created when the detent pin <NUM> moves from one detent <NUM> to an adjacent detent <NUM> caused by rotation of the screw <NUM> relative to the housing <NUM>.

The first adjuster block <NUM> includes a threaded bore <NUM>. As with the adjuster block <NUM>, the threaded body <NUM> of the adjustment screw <NUM> is threadably received therein such that rotation of the adjustment screw <NUM> relative to the main body <NUM> causes the first adjuster block <NUM> to translate relative to the housing <NUM> along the longitudinal axis extending substantially perpendicular to the side surface <NUM>. The first adjuster block <NUM> engages the illumination assembly <NUM> on a surface opposite the adjustment screw <NUM>. Thus, translation of the first adjuster block <NUM> correlates to translation of the illumination assembly <NUM>. Translating the illumination assembly <NUM> relative to the housing <NUM> similarly causes the reticle <NUM> to be translated relative to the optical element <NUM> to adjust the position of the reticle <NUM> relative to the optical element <NUM>. Adjusting the left/right position of the reticle <NUM> relative to the optical element <NUM> adjusts the "windage" of the optical sight <NUM>.

The second adjuster block <NUM> is similar to the first adjuster block <NUM> with the exception that the second adjuster block <NUM> does not include a threaded bore. Rather, the second adjuster block <NUM> engages a portion of the illumination assembly <NUM> such that at least a portion of the illumination assembly <NUM> is disposed between the first and second adjuster blocks <NUM>, <NUM>, as shown in <FIG>.

The second adjuster block <NUM> includes a bore <NUM> partially formed therethrough. The bore <NUM> receives at least a portion of the biasing member <NUM> therein such that the biasing member <NUM> imparts a force on an end surface generally within the bore <NUM>. Providing the second adjuster block <NUM> with an internal bore <NUM> reduces the weight of the second adjuster block <NUM> and, as such, reduces the overall weight of the optical sight <NUM>. As with the height-adjustment mechanism <NUM>, imparting a bias on the adjuster blocks <NUM>, <NUM> and, thus, the adjustment screw <NUM>, prevents inadvertent rotation of the adjustment screw <NUM> relative to the housing <NUM>. Preventing inadvertent rotation of the adjustment screw <NUM> relative to the housing <NUM> prevents unwanted movement of the reticle <NUM> relative to the optical element <NUM> and ensures that the set position of the adjustment screw <NUM> relative to the housing <NUM> is maintained. While the biasing member <NUM> is shown as being a coil spring, any biasing member that imparts a force on the adjuster blocks <NUM>, <NUM> to urge the adjuster blocks generally toward the side surface <NUM> such as, for example, a linear spring, may be employed.

The graduations <NUM> (<FIG>) that are permanently affixed to or formed in the side surface <NUM> of the housing <NUM> help facilitate adjustment of the adjustment screw <NUM> relative to the housing <NUM> and allow a user to visually observe the position of the adjustment screw <NUM> relative to the housing <NUM>. As with the graduations <NUM>, the graduations <NUM> may be painted on and/or laser etched into the housing <NUM> such that the graduations <NUM> are permanently fixed relative to the housing <NUM>. Furthermore, each graduation <NUM> may be positioned relative to each detent <NUM> such that each audible noise or "click" corresponds to movement of the screw <NUM> one graduation <NUM>.

With particular reference to <FIG>, the illumination assembly <NUM> is shown and includes a circuit board <NUM>, a light source <NUM>, and a power source <NUM>. The circuit board <NUM> is supported by a substrate, or block, <NUM> generally within the housing <NUM>, which includes the slot <NUM> that slidably receives the projection <NUM> of the adjuster block <NUM>. As described above, the adjuster block <NUM> is moved up/down when the adjustment screw <NUM> is rotated relative to the housing <NUM>. Because the projection <NUM> is received within the slot <NUM> of the substrate <NUM>, up or down movement of the adjuster block <NUM> relative to the housing <NUM> causes concurrent up or down movement of the substrate <NUM> relative to the housing <NUM>.

The projection <NUM> is slidably received within the slot <NUM> to permit the substrate <NUM> to translate along the longitudinal axis of the windage adjustment mechanism <NUM> relative to the projection <NUM> when the first and second adjuster blocks <NUM>, <NUM> are moved in the left/right directions relative to the housing <NUM>.

The substrate <NUM> is a U-shaped block having a baseplate <NUM> extending between a pair of sidewalls <NUM> defining a cavity or recess <NUM> therein. The circuit board <NUM>, the light source <NUM>, and the power source <NUM> are supported within the recess <NUM>.

A front face <NUM> of each of the sidewalls <NUM> may make surface contact with the housing <NUM>. An outside face <NUM> of each of the sidewalls <NUM> may engage the first and second adjuster blocks <NUM>, <NUM>, respectively. The outside face <NUM> of each of the sidewalls <NUM> may be a flat face, extending along a single plane such that the entire outside face <NUM> of each sidewall <NUM> contacts the first or second adjuster block <NUM>, <NUM>, respectively. Because the outside face <NUM> is a flat face that contacts the first or second adjuster block <NUM>, <NUM>, the substrate <NUM> is decoupled from potential rotation with the first adjuster block <NUM>. Further, a quantity of components and dimensions are minimalized to reduce a tolerance stack-up dictating an amount of compression on the biasing member <NUM> between the substrate <NUM> and the adjustment block <NUM>.

The circuit board <NUM> may be fixedly attached to the baseplate <NUM> of the substrate <NUM> through a contact strip <NUM> (described below). As such, the circuit board <NUM> may be fixed for movement with the substrate <NUM> such that when the substrate <NUM> is moved by either the adjuster block <NUM> or the first and second adjuster blocks <NUM>, <NUM>, the circuit board <NUM> is moved therewith.

The circuit board <NUM> may support the light source <NUM> such that movement of the circuit board <NUM> relative to the housing <NUM> causes concurrent movement of the light source <NUM> relative to the housing <NUM>. In one configuration, the light source <NUM> is encapsulated on the circuit board <NUM> using a transparent epoxy or other coating. In another configuration, the light source <NUM> may be disposed proximate to the circuit board <NUM> and may be attached thereto.

The light source <NUM> may include a laser, a light-emitting diode (LED), a fiber optic, a tritium lamp, another suitable device configured to emit light, or a combination of these. The light source <NUM> may include multiple light sources fixed on a light source base plate supported by the circuit board <NUM> or substrate <NUM>. The light source <NUM> may be selectively controlled by the circuit board <NUM> (for example, by a processor or microprocessor on the circuit board <NUM>) in response to ambient light conditions. Illumination of the light source <NUM> causes the light source <NUM> to direct light generally toward the optical element <NUM> to display the reticle <NUM> on the optical element <NUM>.

The light source <NUM> may be controlled by the circuit board <NUM> through a discrete system, a pulse width modulation (PWM) system, or a combination of these. For example, in the discrete system, a consistent supply of power is provided to the light source <NUM> to illuminate the light source <NUM>. One or more resistors may be incorporated to change a voltage supplied to the light source <NUM> and control a brightness of the light source <NUM>. For example, one resistor for each brightness level is provided to control the brightness of the light source <NUM>. Thus, the circuit board <NUM> is able to control the light source <NUM> to a variety of brightness levels.

For example, in the pulse width modulation (PWM) system, the circuit board <NUM> may supply power to the light source <NUM> in an ON-OFF pattern for a particular duty cycle. A voltage regulator may be incorporated to control the voltage pulses provided to the light source <NUM>. The circuit board <NUM> may control the perceived brightness of the light source <NUM> by cycling the light source <NUM> ON and OFF at a frequency high enough that a user's eye does not detect that the light source is being turned ON/OFF. The perceived brightness is a function of the frequency at which the light source is being turned ON/OFF and the duty cycle which represents how long the light source <NUM> is ON versus how long the light source <NUM> is OFF.

The frequency may be a rate at which the light source <NUM> is turned ON/OFF, and the duty cycle may be the length of time that the light source <NUM> is turned ON/OFF. The light source <NUM> may receive voltage pulses, for example, at a longer duty cycle to produce a brighter light, and the light source <NUM> may receive voltage pulses at a shorter duty cycle to produce a dimmer light. For example, at a <NUM>% duty cycle, the light source <NUM> may be illuminated <NUM>% of the time and off <NUM>% of the time. At a <NUM>% duty cycle, the light source <NUM> may be illuminated <NUM>% of the time and off <NUM>% of the time. At an <NUM>% duty cycle, the light source <NUM> may be illuminated <NUM>% of the time and off <NUM>% of the time. At a <NUM>% duty cycle, the light source <NUM> may be illuminated <NUM>% of the time. The frequency for each of the duty cycles, or the time period from start of cycle to start of cycle, may not change. Thus, an increased duty cycle increases the perceived brightness of the light source <NUM>.

Frequencies in the hundreds of Hz are often fast enough that the human eye cannot perceive that the light source is being switched ON/OFF and perceives a constant light source. In most scenarios these low frequency implementations are sufficient, especially in scenarios in which the light source is stationary. However, when the light source is moving, and the eye is following this movement, the eye can begin to see the cycling on/off of the light source. In some circumstances, such as when an optical sight is moved quickly, poorly executed PWM may be illuminated as a series of dots, known as "PWM visibility. " A reflex sight mounted to a weapon presents several scenarios in which the eye is following the light source and the light source is moving. Examples include panning the weapon to track/follow a target and "resetting" the aiming point on a target during recoil. In these scenarios, if the frequency of PWM is not above a certain threshold the user will see the cycling ON/OFF of the reticle. This can become distracting to the shooter. In the case of recoil the user may see what appears to be "multiple" reticles as they try and steady the firearm back on the target.

The minimum frequency threshold for visibility may be impacted by duty cycle. For example, at high duty cycles ><NUM>%, the minimum visibility frequency may be lower, for example only, <NUM>. However, if the duty cycle is lowered to <<NUM>%, PWM may start to become visible to some users at <NUM>. PWM visibility may also be user dependent. Some users may detect PWM at lower frequencies than others. For example, some people may not detect PWM at <NUM> and a low duty cycle. Others may detect PWM at <NUM> regardless of duty cycle. Obtained through a series of testing, the optical sight <NUM> of the present disclosure runs a PWM system that operates at <NUM> or greater to eliminate "PWM visibility.

The PWM system requires fewer resistors (only one resistor, as compared to three resistors for three brightness settings in a discrete system) and fewer inputs/outputs on a processor of the circuit board <NUM> (only one input/output, as compared to three inputs/outputs in a discrete system). With fewer inputs and outputs on the processor, the processor size is reduced and/or eliminates a need for an additional expander chip on the processor.

PWM may allow for easier "tuning" of the brightness settings during development since changing the perceived brightness can be accomplished through software changes; whereas a discrete system requires a changing of the physical resistor to change the perceived brightness. Additionally, in some cases, the PWM strategy may increase battery life of the optical sight <NUM>. Use of PWM along with the discrete system allows for optimal reticle illumination considering battery life, reticle brightness, and user preference.

The reticle <NUM> may be a dot reticle (<FIG>), a ring reticle, a crosshair reticle, a combination of these (<FIG> - combination dot reticle and ring reticle), or any other suitable reticle. The reticle <NUM> may incorporate a first reticle 34A, such as a dot reticle, for example, for use in a first set of conditions and a second reticle 34B, such as a ring reticle, for example, for use in a second set of conditions. The reticles 34A and 34B may be used in different brightness settings, such as night vision, very low light, low light, and bright light conditions. The first reticle 34A and the second reticle 34B may be controlled by the discrete system, by pulse width modulation (PWM), or by a combination of these. For example, the first reticle 34A or the second reticle 34B may be controlled by PWM for some brightness settings and by the discrete system for other brightness settings. Controlling the reticle <NUM> with PWM and the discrete system allows the perceived brightness to be controlled and changed.

For example, the first reticle 34A or the second reticle 34B may be controlled by PWM during all brightness levels. For example, if there are eleven brightness settings, the first reticle 34A or the second reticle 34B may be illuminated by PWM for all eleven brightness settings.

For example, the first reticle 34A or the second reticle 34B may be controlled by the discrete system during a portion of brightness levels. For example, if there are eleven brightness settings, the first reticle 34A or the second reticle 34B may be illuminated by PWM and the discrete system for four of the eleven brightness settings.

The circuit board <NUM>, light source <NUM>, and substrate <NUM> are protected from environmental conditions by a window <NUM> that may be disposed generally between the light source <NUM> and the optical element <NUM>. The window <NUM> may be sealed against the housing <NUM> by an epoxy or other suitable adhesive. Positioning epoxy between the window <NUM> and the housing <NUM> prevents debris from entering the housing <NUM> and contacting components of the illumination assembly <NUM> and adjustment assembly <NUM>.

The housing <NUM> may project or extend generally over an edge of the window <NUM> to restrict water and other debris from contacting an outer surface of the window <NUM>. Preventing water and other debris from contacting an outer surface of the window <NUM> ensures that light from the light source <NUM> is not diverted, reflected, or blocked and therefore reaches the optical element <NUM>. Because the optical sight <NUM> may be used on a firearm <NUM> by law enforcement and/or military personnel, the optical sight <NUM> may be subjected to extreme weather conditions such as, for example, rain, wind, and ice. Providing the housing <NUM> that extends over the window <NUM> helps prevent such weather conditions from reaching the window <NUM> and therefore improves the ability of the light source <NUM> to consistently provide light to the optical element <NUM> and display the reticle <NUM> thereon.

The power source <NUM> may be in electrical communication with at least one of the circuit board <NUM> and light source <NUM> via the contact strip <NUM> (<FIG> and <FIG>). In one configuration, the power source <NUM> may be a battery having a generally circular shape. The battery may be received within a recess <NUM> (<FIG>) of the housing <NUM> and may be held within the recess <NUM> by a lid <NUM> threadably received within the recess <NUM>, which allows for removal and replacement of the battery when the battery requires replacement.

The power source <NUM> may be housed within the recess <NUM> in an assembly including the lid <NUM>, the power source <NUM>, a retainer <NUM>, and the contact strip <NUM>, in that order (<FIG> and <FIG>). The lid <NUM> may include a seal <NUM> disposed between the power source <NUM> and the lid <NUM> and a seal <NUM> disposed on an outside of the lid <NUM> for engagement with the housing <NUM>. The seals <NUM> and <NUM> may be O-rings or other appropriate seals for protecting the recess <NUM> and power source <NUM> from debris and moisture. For example, the seals <NUM> and <NUM> may be formed of an elastomer or another appropriate sealing material.

The retainer <NUM> may define a battery cavity <NUM> for receiving the power source <NUM> therein. The retainer <NUM> may be a tubular wall having external threads that engage with threads in the recess <NUM> of the housing <NUM>. The retainer <NUM> may be positioned on top of the contact strip <NUM> and may provide access to contacts <NUM> fixed to the contact strip <NUM>. The power source <NUM> may be positioned within the battery cavity <NUM> and directly engaged with the contacts <NUM>. The seal <NUM> may bias the power source <NUM> into a position within the retainer <NUM> and against the contacts <NUM>. Power may then be transmitted from the power source <NUM>, through the contacts <NUM>, and to the contact strip <NUM> to be distributed throughout the optical sight <NUM>.

Referring to <FIG>, <FIG>, <FIG>, and <FIG>, a photoelectric detector <NUM> may be disposed proximate the optical element <NUM> that allows light to be collected at the target object and be transmitted to the circuit board <NUM> via the contact strip <NUM>. More particularly, the contact strip <NUM> extends from the power source <NUM> to the circuit board <NUM> and from the power source <NUM> to the photoelectric detector <NUM> such that the circuit board <NUM>, power source <NUM> and photoelectric detector <NUM> are all in electrical communication (<FIG>). The circuit board <NUM> selectively causes the light source <NUM> to illuminate in response to ambient light conditions detected at the target object by the photoelectric detector <NUM>.

As shown, more particularly, in <FIG>, <FIG>, and <FIG>, the photoelectric detector <NUM> may be disposed in an upper corner <NUM> of a forward, or front, face of the housing <NUM>, pointing downrange of the user. For example, the photoelectric detector <NUM> may be disposed in the upwardly extending optical element housing <NUM> in a position between the optical element <NUM> and an intersection of the cross member <NUM> and the post <NUM>. Because of the concave top surface <NUM> and the convex bottom surface <NUM> of the cross member <NUM>, the intersection of the cross member <NUM> and the post <NUM> forms a shoulder, or ear, <NUM> in the upwardly extending optical element housing <NUM>. The shoulder <NUM> may be a triangular section defined by the cross member <NUM>, post <NUM>, and opening <NUM>. The photoelectric detector <NUM> may be disposed within an aperture <NUM> approximately centered in the shoulder <NUM>.

Positioning the photoelectric detector <NUM> in the shoulder <NUM> of the upwardly extending optical element housing <NUM> and pointing the photoelectric detector <NUM> downrange of the user provides a line-of-sight from the photoelectric detector <NUM> to the target object without obstruction. Having a clear line-of-sight allows the light intensity at the target object to be accurately detected by the photoelectric detector <NUM>.

The position of the photoelectric detector <NUM> in the shoulder <NUM> is advantageous over other configurations in the art. For example, as compared to placement of a sensor on the top surface <NUM> of the upwardly extending optical element housing <NUM>, the photoelectric detector <NUM> in the shoulder <NUM> is directed downrange at the target object and can provide an accurate reading of ambient light at the target object. As compared to placement of a sensor below the optical element <NUM>, the photoelectric detector <NUM> in the shoulder <NUM> is not obstructed by back up sights, iron sights, mounting hardware, portions of the barrel <NUM> or any other parts projecting upwardly from the firearm <NUM>, which gives the photoelectric detector <NUM> in the shoulder <NUM> a clear line-of-sight to the target object. As compared to placement of a sensor on or near the circuit board <NUM>, the photoelectric detector <NUM> in the shoulder <NUM> is not obstructed by any portion of the optical sight <NUM> and can provide an accurate reading of ambient light at the target object.

Providing an accurate measurement of ambient light at the target object is advantageous over sensors detecting ambient light at the optical sight. Knowing the light conditions at the target object allows the optical sight <NUM> to adjust a brightness of the light source <NUM> based on the light conditions at the target object, which provides an advantage in situations where the light conditions are different at the target object than at the optical sight. For example, when entering a dark space from a well-lit space, being positioned in a dark room and focusing on a target outside or in a well-lit room, standing in or shooting into a shadow, etc., are all situations which benefit from controlling the brightness of the reticle <NUM> based on the sensed light at the target object.

The photoelectric detector <NUM> may include a lens <NUM> and a sensor chip <NUM> connected to an arm <NUM> of the contact strip <NUM>. The arm <NUM> of the contact strip <NUM> may be a flexible circuit that bends and twists in the post <NUM> of the upwardly extending optical element housing <NUM> to route the arm <NUM> from the photoelectric detector <NUM> to the power source <NUM>. For example, the arm <NUM> may extend from the power source <NUM>, along a wall of the post <NUM>, and twist over to align with the power source <NUM>. A distal end <NUM> of the arm <NUM> may fit between, or be sandwiched between, the sensor chip <NUM> and the lens <NUM>.

The sensor chip <NUM> may be disposed on the distal end <NUM> of the arm <NUM>. A center <NUM> of the sensor chip <NUM> may be aligned with an aperture <NUM> in the distal end <NUM> of the arm <NUM>. The aperture <NUM> may allow the sensor chip <NUM> to sense light on a side of the arm <NUM> opposite the sensor chip <NUM>.

The lens <NUM> may be a rod-shaped lens that projects through the aperture <NUM> in the upwardly extending optical element housing <NUM>. Alternatively, the lens <NUM> may be a spherical lens, a curved-plate lens, or any appropriately-shaped lens. The lens <NUM> may be a transparent lens. For example, the lens <NUM> may be formed of glass, plastic, or another suitable, transparent material.

A proximal end <NUM> of the lens <NUM> may abut the distal end <NUM> of the arm <NUM> and be axially aligned with the aperture <NUM>. A distal end <NUM> of the lens <NUM> may be axially aligned with the target image when the optical sight <NUM> is aligned with the target image, such that the distal end <NUM> of the lens <NUM> communicates ambient light from the target image through the lens <NUM>, through the aperture <NUM>, and to the sensor chip <NUM>.

The sensor chip <NUM> may be configured to detect light through the aperture <NUM>. For example, the sensor chip <NUM> may include a photodiode or other suitable type of device configured to detect light. For example, the photodiode may be a photoconductive detector, a photovoltaic detector, or another suitable detector. For example, the photo diode may be a p-i-n detector, an avalanche photodiode, a schottky barrier photodiode, a metal-semiconductor-metal photodiode, a type II superlattice photodetector, a photoelectromagnetic detector, a quantum well intersubband photodetector, and a quantum dot infrared photodetector.

The illumination assembly <NUM> may include a first actuation member <NUM> and a second actuation member <NUM>. Each actuation member <NUM>, <NUM> may be used to control illumination of the light source <NUM> and each may be associated with a cover <NUM>, <NUM>. The actuation members <NUM>, <NUM> may be electrically connected to the contact strip <NUM>, such that the actuation members <NUM>, <NUM> are in electrical communication with the circuit board <NUM>. For example, each of the actuation members <NUM>, <NUM> may be fixed on an arm <NUM>, <NUM> of the contact strip <NUM>.

In one configuration, the first and second actuation members <NUM>, <NUM> may be button switches in contact with respective covers <NUM>, <NUM>. The covers <NUM>, <NUM> may be formed from a flexible material such as rubber or plastic such that when a force is applied to either cover <NUM>, <NUM>, the respective cover <NUM>, <NUM> deflects and transmits the applied force to the associated actuation member <NUM>, <NUM>. When either cover <NUM>, <NUM> is depressed, the actuation member <NUM>, <NUM> associated with the particular cover <NUM>, <NUM> is actuated to control operation of the light source <NUM>. Such control may be facilitated by providing descriptive markings on at least one of the covers <NUM>, <NUM>. For example, providing one actuation member <NUM> with a positive sign (+) and providing the other actuation member <NUM> with a negative sign (-) provides the user with a quick reference as to which cover <NUM>, <NUM> and associated actuation member <NUM>, <NUM> increases (+) or decreases (-) illumination.

With particular reference to <FIG>, the optical element <NUM> is shown to include a doublet lens having a first lens <NUM>, a second lens <NUM>, and a dichroic coating <NUM> formed on at least one of the first and second lenses <NUM>, <NUM> to allow light from the light source <NUM> to be reflected thereon. Coating one of the lenses <NUM>, <NUM> with the dichroic coating <NUM> allows the light source <NUM> to generate the reticle <NUM> in an area generally between the lenses <NUM>, <NUM> and therefore allows the reticle <NUM> to be displayed on the optical element <NUM>. The lenses <NUM>, <NUM> may include a substantially D-shape and may include an upper surface <NUM> having a generally convex shape. Once the optical element <NUM> is installed in the housing <NUM>, the upper surface <NUM> of the optical element <NUM> may be positioned generally adjacent to the bottom surface <NUM> of the cross member <NUM>.

The lenses <NUM>, <NUM> may be spherical lenses, whereby at least one of the lenses <NUM>, <NUM> includes a diameter substantially within a range of about <NUM> millimeters to about <NUM> millimeters, or within a range of about <NUM> millimeters to about <NUM> millimeters, or about <NUM> millimeters, having a tolerance of plus or minus <NUM> millimeters. Once the spherical lenses <NUM>, <NUM> are formed, an overall height of the lenses <NUM>, <NUM> may be substantially within a range of about <NUM> millimeters to about <NUM> millimeters, or within a range of about <NUM> millimeters to about <NUM> millimeters, or about <NUM> millimeters, having a tolerance of plus or minus <NUM> millimeters. Regardless of the exact size of the lenses <NUM>, <NUM>, the optical element <NUM> may include an effective focal length within a range of about <NUM> millimeters to about <NUM> millimeters, or within a range of about <NUM> millimeters to about <NUM> millimeters, or about <NUM> millimeters, having a tolerance of plus or minus <NUM> millimeters. The optical element <NUM> may be formed from SCHOTT S-<NUM> Grade A fine annealed material.

With continued reference to <FIG>, operation of the optical sight <NUM> will be described in detail. Once the optical sight <NUM> is mounted to the firearm <NUM>, the optical sight <NUM> may be adjusted to properly align the position of the reticle <NUM> relative to the barrel <NUM> of the firearm <NUM>. A flathead screwdriver, a generally flat member (such as a coin or spent ammunition shell), or another appropriate member may be inserted into the slot <NUM> of the adjustment screw <NUM> to rotate the adjustment screw <NUM> relative to the housing <NUM>. Rotation of the adjustment screw <NUM> relative to the housing <NUM> causes concurrent up/down movement of the adjuster block <NUM> relative to the housing <NUM>. Because the projection <NUM> of the adjuster block <NUM> is slidably received within a slot <NUM> of the substrate <NUM>, the substrate <NUM> is caused to move concurrently in the up or down direction with the adjuster block <NUM>.

Movement of the substrate <NUM> in either the up or down direction causes concurrent movement of the circuit board <NUM> in the up or down direction. Because the light source <NUM> is mounted on the circuit board <NUM> or otherwise fixed to the substrate <NUM>, the light source <NUM> is similarly caused to move in either the up or down direction. The light source <NUM> outputs light through the window <NUM> and toward the optical element <NUM> to generate the reticle <NUM> on the optical element <NUM>. Therefore, up or down movement of the substrate <NUM> and light source <NUM> causes concurrent up or down movement of the reticle <NUM> on the optical element <NUM>.

Once the position of the reticle <NUM> is adjusted in the up/down direction, the flathead screwdriver or other member may be removed from engagement with the adjustment screw <NUM>. As with the height-adjustment mechanism <NUM> of the optical sight <NUM>, the up/down position of the reticle <NUM> relative to the optical element <NUM> is maintained due to the force imparted on the adjuster block <NUM> by biasing members <NUM>, <NUM>. Specifically, biasing members <NUM> apply a force on the adjuster block <NUM> between the housing <NUM> and the adjuster block <NUM> while biasing member <NUM> applies a force directly on the adjustment screw <NUM> to hold the adjuster screw in place. Additionally, the biasing member <NUM> applies a force on the adjuster block <NUM> between the substrate <NUM> and the adjuster block <NUM>.

The left/right (i.e., windage) of the reticle <NUM> may be adjusted by inserting a flathead screwdriver, a flat member (such as a coin or spent ammunition shell), or another appropriate member into the slot <NUM> of the adjustment screw <NUM>. Once the flathead screwdriver or other flat member is inserted into the slot <NUM> of the adjustment screw <NUM>, rotation of the adjustment screw <NUM> relative to the housing <NUM> causes concurrent movement of the first and second adjuster blocks <NUM>, <NUM>. Movement of the adjuster blocks <NUM>, <NUM> causes concurrent movement of the substrate <NUM> relative to the housing <NUM> in a direction toward and away from the side surface <NUM> of the main body <NUM>. Because the substrate <NUM> supports the light source <NUM>, movement of the substrate <NUM> in either the left or right direction relative to the housing <NUM> similarly causes movement of the light source <NUM> relative to the housing <NUM>. As described above, movement of the light source <NUM> relative to the housing <NUM> causes concurrent movement of the reticle <NUM> relative to the optical element <NUM>. Once the position of the reticle <NUM> relative to the optical element <NUM> is adjusted, the flathead screwdriver or flat tool may be removed from engagement with the adjustment screw <NUM>. As with the windage-adjustment mechanism <NUM> of the optical sight <NUM>, the set position of the windage is maintained due to the force imparted on the first and second adjuster blocks <NUM>, <NUM> by the biasing member <NUM>.

Once the up/down position and windage position of the reticle <NUM> is properly adjusted relative to the optical element <NUM>, the optical sight <NUM> may be used to align the barrel <NUM> of the firearm <NUM> relative to a target (not shown).

The reticle <NUM> may be illuminated by the light source <NUM>. For example, in low ambient light conditions at the target object, sufficient light may be projected by the light source <NUM> when the light source is controlled solely by PWM and only one of the first reticle 34A and the second reticle 34B may be necessary. Thus the other of the first reticle 34A and the second reticle 34B, controlled by resistors, is not illuminated. Under brighter or daytime conditions, the light source <NUM> may illuminate both the first reticle 34A and the second reticle 34B using both resistors and PWM. Under bright conditions at the target object, the first reticle 34A may be illuminated in conjunction with the second reticle 34A to provide a sufficient aiming point at the target object. Alternatively, under brighter or daytime conditions, the light source <NUM> may illuminate both of the first reticle 34A and the second reticle 34B using only resistors or only PWM.

The brightness of the reticle <NUM> may be automatically controlled at the circuit board <NUM>. For example, with reference to <FIG>, the circuit board <NUM> may include a processor, or microprocessor, <NUM> and a memory <NUM>. The microprocessor <NUM> may receive the signal from the photoelectric detector <NUM> and determine whether to illuminate the first reticle 34A, the second reticle 34B, or the first reticle 34A and the second reticle 34B. Alternatively, the microprocessor <NUM> may receive a signal from a user input and determine whether to illuminate the first reticle 34A, the second reticle 34B, or the first reticle 34A and the second reticle 34B based on the user input. Referring to <FIG>, the automatic brightness may be controlled according to a brightness curve. More particularly, in a normal mode, the circuit board <NUM> may control the brightness of the light source <NUM> according to a first curve <NUM>. The first curve <NUM> may have a lower brightness setting at low light and may increase to a higher brightness setting as brightness increases. The user may have the option to increase or decrease the first curve <NUM> based on user preference (for example, using first and second actuation members <NUM>, <NUM>). For example, if the user prefers a brighter reticle <NUM>, the user may increase the auto brightness setting to a high setting, following a second curve <NUM>. If the user prefers a dimmer reticle <NUM>, the user may decrease the auto brightness setting to a low setting, following a third curve <NUM>. The curves <NUM> and <NUM> may follow the same slope as the curve <NUM>, but may be shifted one level up or one level down to adjust the overall brightness accordingly.

Referring to <FIG>, the automatic brightness may be controlled according to an alternative brightness curve. More particularly, in a normal mode, the circuit board <NUM> may control the brightness of the light source <NUM> according to a first curve <NUM>. The first curve <NUM> may be similar to the first curve <NUM> and have a lower brightness setting at low light and may increase to a higher brightness setting as brightness increases. The user may have the option to increase or decrease the first curve <NUM> based on user preference. For example, if the user prefers a brighter reticle <NUM>, the user may increase the auto brightness setting to a high setting, following a second curve <NUM>. As compared to the first curve <NUM>, the second curve <NUM> may be shifted up and may have a sharper, or greater, slope for increasing light intensity as the sensed light brightens. If the user prefers a dimmer reticle <NUM>, the user may decrease the auto brightness setting to a low setting, following a third curve <NUM>. As compared to the first curve <NUM>, the third curve <NUM> may be shifted down and may have a softer, or smaller, slope for increasing light intensity as the sensed light brightens.

Once the processor <NUM> determines a brightness level from the appropriate curve, the processor <NUM> connects power to one or more resistors <NUM> to illuminate the light source <NUM>. For example, in a configuration where the light source <NUM> includes <NUM> brightness settings for each of the reticles 34A and 34B, the circuit board <NUM> may house <NUM> resistors. The voltage for <NUM> brightness settings for the reticle 34A (for example, the dot reticle) may be controlled by <NUM> resistors, with <NUM> resistors controlling the voltage for <NUM> PWM settings and <NUM> resistors controlling the voltage for <NUM> discrete settings. Meanwhile, the voltage for the <NUM> PWM brightness settings for the reticle 34B (for example, the ring reticle) may be controlled by <NUM> resistors. The implementation of PWM in this example, saves the optic <NUM> resistors and <NUM> inputs/outputs from the processor <NUM>.

Because the optical element <NUM> includes the dichroic coating <NUM> disposed on at least one of the first lens <NUM> and the second lens <NUM>, the wave length of the light from the light source <NUM> is reflected and causes the reticle <NUM> to appear in the optical element <NUM> along the line-of-sight. The reticle <NUM> may be used by the user to align the barrel <NUM> of the firearm <NUM> with the target object.

Referring to <FIG>, the user may be able to select whether to illuminate the first reticle 34A, the second reticle 34B, or the first reticle 34A and the second reticle 34B. The user may further adjust the brightness of the second reticle 34B relative to the first reticle 34A. The user may further adjust the brightness of the first reticle 34A relative to the second reticle 34B.

The ability to adjust relative brightness may provide the user with the ability to tune the reticle 34A, 34B to their own preference, or to a particular shooting scenario. For example where the brightness of the second reticle 34B may be adjusted relative to the first reticle 34A, if a user is expecting to primarily be in a close-quarters scenario, the user may want a bright second reticle 34B (for example, the segmented circle) as a primary gross aiming point, but still have the first reticle 34A (for example, the dot) available should the user need to take a more precise shot. Since the first reticle 34A is dimmer than the second reticle 34B in this scenario, the first reticle 34A will not provide any distraction or large obscuration. In the opposite scenario, the user may want the first reticle 34A (for example, the dot) brightly lit for precise shooting, but still have a dim second reticle 34B (for example, the segmented circle) should the user need to take shots at close-quarters. The latter scenario allows the user to easily focus on the first reticle 34A, and prevents the second reticle 34B from obscuring the target, or overpowering (washing-out) the first reticle 34A. Allowing the first and second reticle 34A, 34B to have different brightness levels can aid a user in easily focusing on the "brighter" of the two reticles 34A, 34B, without having to completely turn off the other reticle 34A, 34B. The dimmer reticle 34A, 34B will still be available to the user should they need it, but will be far less distracting when the user doesn't need the dimmer reticle 34A, 34B as the primary aiming point.

For example, <FIG> illustrates the above example where the brightness of the second reticle 34B may be adjusted relative to the first reticle 34A. A default setting of the optic <NUM> may be that the first reticle 34A and the second reticle 34B are at "equivalent brightness" (shown by the solid line and the dotted line in <FIG>). For example a dot and a ring together would appear to be equally as bright. Through a series of button presses or other user inputs, the user may access a mode in which they can adjust the brightness of the second reticle 34B relative to the first reticle 34A. They can choose between the default setting (equal brightness), a high setting in which the second reticle 34B is brighter than the first reticle 34A (for example, the dashed line), and a low setting in which the second reticle 34B is dimmer than the first reticle 34A (for example, the dash-dot line).

During the default setting, the first reticle 34A may operate along the solid line and the second reticle 34B may operate along the dotted line. If the user chooses the high setting, the first reticle 34A may continue operation along the solid line and the operation of the second reticle 34B may transition from the dotted line to the dashed line. If the user chooses the low setting, the first reticle 34A may continue operation along the solid line and the operation of the second reticle 34B may transition from the dotted line to the dash-dot line. If the second reticle 34B is operating in the high setting and the user chooses the default setting, or decreases the brightness setting, operation of the second reticle 34B may transition from the dashed line to the dotted line. If the second reticle 34B is operating in the low setting and the user chooses the default setting, or increases the brightness setting, operation of the second reticle 34B may transition from the dash-dot line to the dotted line. Operation would be similar for the example where brightness of the first reticle 34A may be changed relative to the second reticle 34B. In this case, the first reticle 34A may move between the dotted line, dashed line, and dash-dot line along with user input, while the second reticle 34B would remain on the solid line.

Now referring to <FIG>, a flowchart for a method <NUM> of controlling brightness of the reticle is illustrated. The method <NUM> may be executed by the circuit board <NUM>, the microprocessor or processor <NUM> on the circuit board <NUM>, or a controller on the microprocessor or processor <NUM>.

The method <NUM> starts at <NUM>. At <NUM>, brightness of the reticle is controlled according to a default curve. For example, the circuit board <NUM> may receive the output from the photoelectric detector <NUM> and may control the light source <NUM> to illuminate the reticle <NUM> according to a default curve. For example, the default curve may be a nominal factory setting as illustrated in <FIG> and <FIG>. For example, the default curve may be a nominal factory setting as illustrated in the solid line and dotted line in <FIG>. Alternatively, the default curve may be any curve stored in the memory <NUM> of the circuit board <NUM>.

At <NUM>, a check for input received from a user is performed. For example, the user may input commands for brightness of the reticle using the first actuation member <NUM> and the second actuation member <NUM>. Each actuation member <NUM>, <NUM> may be associated with a cover <NUM>, <NUM>. For example, the first actuation member <NUM> associated with the cover <NUM> may be pressed to decrease, or dim, the illumination. For example, the second actuation member <NUM> associated with the cover <NUM> may be pressed to increase, or brighten, the illumination. The cover <NUM> may include a minus sign and the cover <NUM> may include a plus sign to indicate the function of the actuation member <NUM>, <NUM>. Alternatively, the user input may be received from a series of buttons or other actuation members.

If false at <NUM>, method <NUM> returns to <NUM> and illumination is controlled according to the default curve. If true at <NUM>, the default curve is changed to a new curve according to the user input at <NUM>. For example, if the default curve is the nominal factory setting (thin solid line) in <FIG> or <FIG> and the user input is activation of the first actuation member <NUM> through the cover <NUM>, the default curve is changed to the decreased auto brightness curve (the dashed line) in <FIG> or <FIG>. For example, if the default curve is the nominal factory setting (thin solid line) in <FIG> or <FIG> and the user input is activation of the second actuation member <NUM> through the cover <NUM>, the default curve is changed to the increased auto brightness curve (the bold solid line) in <FIG> or <FIG>.

Alternatively, if the default curve is the increased auto brightness curve (the bold solid line) in <FIG> or <FIG> and the user input is activation of the first actuation member <NUM> through the cover <NUM>, the default curve is changed to the nominal factory setting (thin solid line) in <FIG> or <FIG>. For example, if the default curve is the decreased auto brightness curve (the dashed line) in <FIG> or <FIG> and the user input is activation of the second actuation member <NUM> through the cover <NUM>, the default curve is changed to the nominal factory setting (thin solid line) in <FIG> or <FIG>.

Similarly, the brightness of the second reticle 34B may be adjusted relative to the first reticle 34A or the brightness of the first reticle 34A may be adjusted relative to the second reticle 34B. More particularly, the default brightness of the first reticle 34A may be the solid line in <FIG> and the default brightness of the second reticle 34B may be the dotted line in <FIG>. The solid line may be similar to the dotted line and have a lower power output at lower brightness settings and may increase the power output as the brightness setting increases. If the user input increases the auto brightness setting to a high setting, the dotted line may transition to the dashed line in <FIG>. As compared to the dotted line, the dashed line may be shifted up, having a higher reticle power output for each brightness setting. If the user input decreases the auto brightness setting to a low setting, the dotted line may transition to the dash-dot line in <FIG>. As compared to the dotted line, the dash-dot line may be shifted down, having less reticle power output for each brightness setting. The same scenarios would be true for adjusting the first reticle 34A relative to the second reticle 34B.

At <NUM>, brightness of the reticle is controlled according to the new curve. For example, the circuit board <NUM> may receive the output from the photoelectric detector <NUM> and may control the light source <NUM> to illuminate the reticle <NUM> according to the new curve. As illustrated in <FIG> and <FIG>, as the brightness output from the photoelectric detector <NUM> increases, the brightness setting for the light source <NUM> and illumination of the reticle <NUM> increases. Likewise in <FIG>, as the brightness setting increases, the reticle power output for the reticle increases.

At <NUM>, a check for input received from a power input is performed. For example, the user may select a power button to power up or power down the optic <NUM>. Alternatively, for example, the light source <NUM> may be on a timer and may shut off after illumination for a threshold amount of time.

If false at <NUM>, method <NUM> may return to <NUM>. If true at <NUM>, method <NUM> may power down, or shut off, the light source <NUM> at <NUM>. Method <NUM> ends at <NUM>.

Claim 1:
An optical sight (<NUM>) comprising:
a housing (<NUM>);
an optical element (<NUM>) supported by the housing (<NUM>);
a light source (<NUM>) configured to provide a reticle (<NUM>) on the optical element (<NUM>), the light source (<NUM>) being mounted on an adjustment plate (<NUM>); and
a light source adjuster (<NUM>, <NUM>) configured to change a position of the reticle (<NUM>) relative to the optical element (<NUM>),
wherein the light source adjuster (<NUM>, <NUM>) includes
an adjustment screw (<NUM>; <NUM>),
an adjuster block (<NUM>; <NUM>) configured to threadably receive the adjustment screw (<NUM>; <NUM>), the adjuster block (<NUM>; <NUM>) being directly engaged with the adjustment plate (<NUM>), and
a biasing mechanism (<NUM>, <NUM>, <NUM>; <NUM>; <NUM>) configured to apply a force to retain the adjuster block (<NUM>; <NUM>) in an adjustment position,
wherein rotation of the adjustment screw (<NUM>; <NUM>) moves the adjuster block (<NUM>; <NUM>), and movement of the adjuster block (<NUM>; <NUM>) moves the adjustment plate (<NUM>), and
wherein the light source adjuster (<NUM>, <NUM>) includes the light source (<NUM>),
characterized in that
the adjustment plate (<NUM>) is a U-shaped plate (<NUM>) defining a recess (<NUM>), and
the light source (<NUM>) is supported by the adjustment plate (<NUM>) within the recess (<NUM>).