Lightweight holographic sight

• US 6,490,060 B1
• Filed: 10/13/2000
• Issued: 12/03/2002
• Est. Priority Date: 10/14/1999
• Status: Expired due to Term

• Current Assignee: Eotech, LLC
• Original Assignee: EOTech, Inc.
• Inventors: Tai, Anthony M., Sieczka, Eric J.
• Primary Examiner(s): Spyrou, Cassandra
• Assistant Examiner(s): BOUTSIKARIS, LEONIDAS
• Application Number:
  US09/687,624
• Time in Patent Office: 781 Days
• Field of Search: 359/15, 359/19, 359/1, 359/16, 356/247
• US Class Current: 359/15
• CPC Class Codes: F41G 1/30 Reflecting-sights specially adapted for smallarms or ordnance reflecting-sights in general G02B
• CPC Class Codes: G02B 23/14 Viewfinders for photographic apparatus G03B13/02
• CPC Class Codes: G02B 5/32 Holograms used as optical elements

Abstract

A lightweight contact holographic sight includes a housing and a base which form a compartment containing a laser diode, an associated power source, and optical elements including a mirror, an off axis collimator, a reflection grating, and an image hologram of a reticle pattern, wherein the optical elements are arranged within the compartment to direct and fold the laser beam in a substantially generally vertical path. In one aspect of the invention, an elevation and windage adjustment mechanism is provided to rotate the reflection grating about two orthogonal axes to thereby adjust the projected reticle pattern for windage and elevation. In another aspect of the invention a removable battery compartment including a cam surface which is releasably contacted by a cam lever arm pivotally mounted on the sight housing or the base to allow for quick tool-less removal of the compartment for battery replacement.

Claims

1. A holographic sight comprising:

a base including a mounting mechanism;

a housing, which together with the base, define a compartment containing,

a laser diode emitting a light beam of visible wavelength, optical elements mounted within the compartment to direct the beam in a folded path within the compartment, wherein the path of the beam within the optical compartment is primarily substantially perpendicular to the path of the beam directed from the hologram to the target, the optical elements including,

a hologram of a reticle pattern mounted in the path of the beam to project a reticle pattern to the target plane,

a folding mirror mounted in the path of the beam to direct the beam from the laser diode on a path substantially perpendicular to the path to the target,

a reflective off-axis collimator mounted in the path of the beam to collimate the beam and direct the beam from the folding mirror on a path also substantially perpendicular to the path to the target but in the opposite direction of the path of the beam between the folding mirror and the collimator, and

a reflective diffraction grating mounted in the path of the collimated beam to diffract the beam and direct the beam from the collimator to the hologram on a path also substantially perpendicular to the path to the target but in the opposite direction of the path of the beam between the collimator and the diffraction grating; and

a power source operably connected to the laser diode;

wherein the reflective diffraction grating provides an adjustment mechanism for adjusting the path of the beam within the compartment to change the windage and elevation of the path of the beam directed from the hologram to the target.

2. The holographic sight of claim 1 wherein the adjustment mechanism comprises a frame upon which the diffraction grating is mounted for pivotal rotation about a first axis, and which frame is, in turn, mounted in the housing for pivotal rotation about a second axis orthogonal to the first axis.

3. The holographic sight of claim 2 wherein the collimator comprises a refractive material including a first spherical surface having a first radius of curvature and a second, reflective spherical surface having a second radius of curvature, and wherein the collimator is mounted in the path of the beam such that the beam first contacts the first spherical surface, is transmitted through the collimator onto the second spherical surface, and is reflected off of the second spherical surface and again through the collimator material.

4. The holographic sight of claim 3 wherein the refractive material is glass.

5. The holographic sight of claim 1 wherein the power source is at least one battery, and further including a removable battery compartment comprising battery compartment housing including a receptacle for each of the at least one batteries, a mating surface and at least one alignment surface, and wherein the sight includes a wall on the housing having, for each of the at least one batteries, a terminal suitable for electrical connection, and at least one alignment tab, and further including a lever arm having a cam surface, the lever arm being pivotally mounted on the base for movement between a closed position in which the cam surface of the lever arm contacts the mating surface on the battery compartment, urging the battery compartment into a tight fit against the housing and the base of the sight with the at least one alignment surface in contact with its corresponding alignment tab, and an open position in which the cam surface of the lever arm is moved out of contact with the battery compartment, thereby allowing the battery compartment to be slidably positioned out of contact with the tabs and off the sight to facilitate removal and replacement of the batteries within the battery compartment.

6. The holographic sight of claim 1 further including a mounting mechanism on the base of the sight, the mounting mechanism including first and second radiused registration surfaces suitable for alignment and contact with the upper and lower surfaces of one dovetail rail located on the device to which the sight is to be mounted, a third fixed radiused surface suitable to contact one of the upper or lower surfaces on the opposite side of the dovetail rail, and a slidably positionable clamp including a fourth radiused surface suitable to contact the other of the upper or lower surface of the other side of the dovetail rail, and a threaded fastener connecting the clamp to the base such that the clamp may be moved from an open position in which the fourth radiused surface of the clamp is not in contact with the dovetail rail, to a clamped position in which the fourth radiused surface contacts one side of the dovetail rail and urges the first, second and third radiused surfaces into friction fit with the dovetail rail.

7. A holographic sight comprising:

a base including a mounting mechanism;

a housing, which together with the base, define a compartment containing,

a laser diode emitting a light beam of visible wavelength, optical elements including,

a hologram of a reticle pattern mounted in the path of the beam to project a reticle pattern to a target plane,

a collimator mounted in the path of the beam to collimate the beam and direct the beam from the laser diode, and

a reflective diffraction grating mounted in the path of the collimated beam to diffract the beam and direct the diffracted beam to the hologram; and

an adjustment mechanism for adjusting the path of the beam within the compartment to change the windage and elevation of the path of the beam directed from the hologram to the target, the adjustment mechanism comprising a frame within which the diffraction grating is mounted, a first adjuster for rotating the frame about a first axis, and a second adjuster for rotating the frame about a second axis orthogonal to the first axis, whereby the reticle pattern can be adjusted for windage and elevation; and

a power source operably connected to the laser diode.

8. The holographic sight of claim 7 wherein the adjustment mechanism first adjuster for rotating the frame about the first axis includes a pivoting shaft upon which the frame is pivotally mounted at one end of the frame, and wherein the frame includes an inclined plane located on the end of the frame opposite the end upon which the frame is pivotally mounted, a threaded first adjustment shaft mounted parallel to the pivoting shaft and including a nut threadably mounted thereon, the nut including a cam surface which contacts the inclined plane on the frame and, as the nut is moved along the length of the first adjustment shaft upon rotation of the shaft, the cam surface moves along the inclined surface to rotate the frame, and wherein the frame further includes a flexure arm upon which the diffraction grating is mounted, which flexure arm is mounted at one end of the arm to one side of the frame such that the flexure arm may be flexed to pivot about an axis that is orthogonal to the axis of rotation of the pivoting shaft, and wherein the flexure arm includes a second inclined plane located on the end of the flexure arm opposite the end of the arm which is pivotally mounted to the frame, a second threaded adjustment shaft mounted parallel to the pivoting shaft and including a nut threadably mounted thereon, the nut including a cam surface which contacts the inclined plane on the flexure arm and, as the nut is moved along the length of the second adjustment shaft upon rotation of the shaft, the cam surface moves along the inclined surface to rotate the flexure arm, whereby the diffraction grating may be adjustably rotated about two orthogonal axes.

9. A holographic sight comprising:

base including a mounting mechanism;

a housing, which together with the base, define a compartment containing,

a laser diode emitting a light beam of visible wavelength, and optical elements including,

a hologram of a reticle pattern mounted in the path of the beam to project a reticle pattern to a target plane,

a folding mirror mounted in the path of the beam to direct the beam from the laser diode,

a reflective off-axis collimator mounted in the path of the beam to collimate the beam and direct the beam from the folding mirror, the collimator comprising a refractive material including a first spherical surface having a first radius of curvature and a second, reflective spherical surface having a second radius of curvature, and wherein the collimator is mounted in the path of the beam such that the beam first contacts the first spherical surface, is transmitted through the collimator onto the second spherical surface, and is reflected off of the second spherical surface and again through the collimator material, and

a reflective diffraction grating mounted in the path of the collimated beam to diffract the beam and direct the beam from the collimator to the hologram; and

a power source operably connected to the laser diode.

10. A holographic sight comprising:

a base including a mounting mechanism;

a housing, which together with the base, define a compartment containing,

a laser diode emitting a light beam of visible wavelength, and optical elements including,

a hologram of a reticle pattern mounted in the path of the beam to project a reticle pattern to a target plane,

a collimator mounted in the path of the beam to collimate the beam and direct the beam from the laser diode, and

a reflective diffraction grating mounted in the path of the collimated beam to diffract the beam and direct the beam to the hologram; and

a power source operably connected to the laser diode, wherein the power source is mounted within a removable power source compartment removable battery compartment comprising a power source compartment housing including a receptacle for each of the at least one power sources, a mating surface and at least one alignment surface, and wherein the sight includes a wall on the housing having, for each of the at least one power sources, a terminal suitable for electrical connection of the power sources to the laser diode, and at least one alignment tab, and further including a lever arm having a cam surface, the lever arm being pivotally mounted on the base for movement between a closed position in which the cam surface of the lever arm contacts the mating surface on the power source compartment, urging the power source compartment into a tight fit against the housing and the base of the sight with the at least one alignment surface in contact with its corresponding alignment tab, and an open position in which the cam surface of the lever arm is moved out of contact with the power source compartment, thereby allowing the power source compartment to be slidably positioned out of contact with the tabs and off the sight to facilitate removal and replacement of the power sources within the compartment.

11. A holographic sight comprising:

a base including a mounting mechanism,the mounting mechanism including first and second radiused registration surfaces suitable for alignment and contact with the upper and lower surfaces of one dovetail rail located on the device to which the sight is to be mounted, a third fixed radiused surface suitable to contact one of the upper or lower surfaces on the opposite side of the dovetail rail, and a slidably positionable clamp including a fourth radiused surface suitable to contact the other of the upper or lower surface of the other side of the dovetail rail, and a threaded fastener connecting the clamp to the base such that the clamp may be moved from an open position in which the fourth radiused surface of the clamp is not in contact with the dovetail rail, to a clamped position in which the fourth radiused surface contacts one side of the dovetail rail and urges the first, second and third radiused surfaces into friction fit with the dovetail rail;

a housing, which together with the base, define a compartment containing,

a laser diode emitting a light beam of visible wavelength, and optical elements including,

a hologram of a reticle pattern mounted in the path of the beam to project a reticle pattern to a target plane,

a collimator mounted in the path of the beam to collimate the beam and direct the beam from the laser diode, and

a reflective diffraction grating mounted in the path of the collimated beam to diffract the beam and direct the diffracted to hologram; and

a power source operably connected to the laser diode.