WO2022211761A1

WO2022211761A1 - Holographic sight with reflective concave diffraction grating

Info

Publication number: WO2022211761A1
Application number: PCT/TR2022/050263
Authority: WO
Inventors: Murat Şahi̇n; Ulaş ÇIRPICI; Aydan YALLI; Cihan GÜLPINAR; İslam Çağri ÖZDEMİR; Mine ERTOK
Original assignee: Aselsan Hassas Opti̇k Sanayi̇ Ve Ti̇caret Anoni̇m Şi̇rketi̇
Priority date: 2021-03-27
Filing date: 2022-03-24
Publication date: 2022-10-06
Also published as: TR202105554A2

Abstract

The present invention relates to a holographic sight that has a reticle which is readily visible at high and low ambient light conditions, and utilizes different, larger reticle patterns than a single dot, to allow for better visibility of the reticle pattern, and, thereby, increased accuracy when aiming at moving targets.

Description

HOLOGRAPHIC SIGHT WITH REFLECTIVE CONCAVE DIFFRACTION GRATING

Field of the Invention

The invention relates to a holographic gun sight that facilitates aiming and enables the user to shoot the target with pinpoint accuracy.

In particular, the invention relates to a holographic sight that has a reticle which is readily visible at high and low ambient light conditions, and utilizes different, larger reticle patterns than a single dot, to allow for better visibility of the reticle pattern, and, thereby, increased accuracy when aiming at moving targets.

State of the Art

There are several types of sights of utilized with firearms, especially hand-held weapons such as rifles and pistols. With the advancements in weapons, sights also greatly improved; the simplest type of gun sights that consist of a small notch on the rear end of the weapon and a bar on the far end of weapon have been replaced by telescopic, reflex type and laser designator sights. Each of these sight systems come with their own benefits and drawbacks, and they are preferred according to their particular area of use. Following the recent developments in the hologram technology, a new solution has been developed for sights and now the hologram technology can be employed on sights. Accordingly, the patent application no. US5483362 owned by the Environment Res Inst relates to a compact, inexpensive holographic gun sight which may be effectively used with small arms. In line with said patent application no. US5483362, by simply illuminating a reticle image hologram with a laser diode, the angular position of the reconstructed image will not be stable. The reticle position will shift with a change in the case temperature of the laser diode, hence the position of the image will not be stable. To produce a stable reticle image over a wide temperature range, the illuminating beam is diffracted first by grating. The wavelength dependency can be removed by matching the dispersions of the grating and the reticle hologram. The patent application no. US5483362 also discloses that a transmission grating bonded onto a prism is used to produce a dispersion equal to, but with the opposite sign of, the dispersion of the image hologram. In a preferred embodiment of the present invention, a reflection grating is used to compensate for the wavelength dependency of the diffraction by the image hologram. Another invention on holographic sights is the patent application no. US6490060B1 , which comprises a laser diode, and optical elements including a mirror, a collimator, a diffraction grating and an image hologram. The mirror directs the beam from the laser diode onto the collimator. The collimated beam is directed to the hologram by the diffraction grating. The drawbacks of the prior art described above with two patent applications necessitated a new invention by the inventor. Unlike the prior art, the present invention comprises a biconcave lens to direct beam onto the whole surface of the diffraction grating with a view to fixing the reticle image position of a change in the temperature of the laser diode. The biconcave lens enables to direct light on the whole surface of the diffraction grating, thereby producing a more stable hologram image compared to the prior art.

It is a technical problem to direct light beam onto the hologram from the diffraction grating, which is used for reducing shifts in the position of the reticle pattern due to variations in the wavelength caused by temperature. To overcome this problem, light beams are directed onto the hologram by way of reflection through the surface of the diffraction grating. A more compact device is provided by removing the optical elements such as prism and mirror, and making the diffraction grating reflective.

Another technical issue experienced in the field is that a high degree of interference beams can be visible outside the field of vision. For this issue, an upper body ceiling model was designed to prevent the delivery of interference pattern at high order.

Based on the current requirements described above and the existing applications in prior art, the present invention provides a compact holographic sight that uses less optical elements than prior art by way of making the diffraction grating reflective with a view to eliminating said drawbacks of the prior art and minimizing the number of optical elements and manufacturing costs.

Summary of the Invention The aim of the invention is to provide a holographic sight that has a reticle which is readily visible at high and low ambient light conditions, and utilizes different, larger reticle patterns than a single dot, to allow for better visibility of the reticle pattern, and, thereby, increased accuracy when aiming at moving targets.

Another aim of the invention is to minimize the number of optical elements and manufacturing costs. Accordingly, a compact sight that uses less optical elements than prior art is provided by way of making the diffraction grating reflective.

Another aim of the invention is to better minimize variations in the wavelength at high and low temperature values compared to the prior art.

Another aim of the invention is to provide a holographic sight that employs biconcave lens to deliver a more stable and uninterrupted image when viewed from different angles of the sight aperture.

Another aim of the invention is to provide sighting having the properties described above with a size and weight suitable for use in hand-held firearms.

Another aim of the invention is to provide a gun sight that has a reticle which is readily visible at high and low ambient light conditions.

Yet another aim of the invention is to provide a compact sight having tools to adjust the horizontal and vertical height of the reticle pattern. Accordingly, the invention comprises horizontal and vertical height adjustment mechanisms to move holographic image to zero the sight.

In order to achieve the objectives described above, the invention relates to a holographic gun sight that facilitates aiming and enables the user to shoot the target with pinpoint accuracy, comprising at least one laser diode as a light source, at least a power source functionally connected to said laser diode, and at least one hologram at the upper body, further comprising at least one biconcave lens which receives light beams coming from said laser diode light source and reflects the beams to fully cover the surface of the reflective concave diffraction grating with a wider angle, and at least one reflective diffraction grating which reflects the beams onto said hologram by way of reflection for reducing shifts in the position of the reticle pattern due to variations in the wavelength caused by temperature. To realize all objectives described above and further referred to in the below detailed description, the present invention brings many benefits thanks to the described properties.

The below drawings and the detailed description set out with reference to the accompanying drawings provide for a clearer understanding of the structural and characteristic properties and all benefits of the present invention; therefore, the evaluation needs to take these drawings and the detailed description into account.

Brief Description of the Drawings

Figure 1 is a cross-sectional side view of the holographic sight according to the invention.

Figure 2 is a side view of the holographic sight according to the invention.

Figure 3 is a rear view of the holographic sight according to the invention.

Figure 4 is a cross-sectional rear view of the holographic sight according to the invention.

List of Reference Numerals

1. Laser diode

2. Biconcave lens

3. Reflective concave diffraction grating

4. Flologram

5. Protective window

6. Power source

7. Upper body ceiling

8. Florizontal adjustment mechanism

9. Vertical (height) adjustment mechanism

10. NV button

11. Brightness adjustment button

12. Brightness adjustment button

13. Mounting apparatus

14. Restricting screw Detailed Description of the Invention

In order to facilitate a better understanding of the present invention, this detailed description demonstrates the preferred embodiments of the holographic sight having reflective concave diffraction grating in a non-limiting manner. Holographic sight comprises two parts as lower body and upper body. As shown in Figure 1 , the lower body contains a module containing a laser diode (1), a biconcave lens (2) and a reflective concave diffraction grating (3). Light beam reflected from said reflective concave diffraction grating (3) is directed to at least one hologram (4) positioned on the upper body and the upper body additional comprises a protective window (5). The holographic sight comprises a power source (6) that is functionally connected to said laser diode (1 ).

Said biconcave lens (2) receives light beams coming out of the laser diode (1) light source and reflects the beams to fully cover the surface of the reflective concave diffraction grating (3) with a wider angle. The hologram (4) is positioned on the upper body to form an angle of 3° to the vertical axis. B earns reflected on the reflective concave diffracting grating (3) are reflected to form an angle of 42°10 ^' with the hologram (4). Upper body ceiling (7) is designed to block visibility of interference beams outside the field of vision at high degrees due to diffraction grating.

The holographic sight according to the invention comprises at least one horizontal adjustment mechanism (8) and at least one vertical (height) adjustment mechanism (9) to move holographic image to zero the sight. The module which comprises the laser diode (1), the biconcave lens (2) and the reflective concave diffraction grating (3) is moved on the horizontal axis by way of the horizontal adjustment mechanism (8) and the vertical axis by way of the vertical (height) adjustment mechanism (9) to zero the sight.

In addition to day mode, the holographic sight also works in night mode. There is a NV button (10) to activate the night vision mode and also brightness adjustment buttons (11 , 12) are present to increase or decrease the brightness level. The brightness level adjustment is provided by pulse width modulation of the laser light source. The holographic sight also comprises a mounting apparatus (13) to mount it on a gun. After mounting on the gun using the mounting apparatus (13), the holographic sight is fixed in placed by way of the locking mechanism.

The holographic sight is provided with at least one restricting screw (14) as detailed in Figure 4 to restrict the horizontal adjustment mechanism (8) and vertical (height) mechanism (9) movement in positive and negative directions. The stopping function of this detail helps prevent backlash.

Claims

1. A holographic gun sight that facilitates aiming and enables the user to shoot the target with pinpoint accuracy, comprising at least one laser diode (1) as a light source, at least a power source (6) functionally connected to said laser diode (1), and at least one hologram (4) at the upper body, characterized by comprising; at least one biconcave lens (2) which receives light beams coming from said laser diode (1) light source and reflects the beams to fully cover the surface of a reflective concave diffraction grating (3) with a wider angle, and at least one reflective concave diffraction grating (3) which reflects the beams onto said hologram (4) by way of reflection for reducing shifts in the position of the reticle pattern due to variations in the wavelength caused by temperature.

2. A holographic sight according to Claim 1 , characterized in that; said hologram (4) is positioned on the upper body to form an angle of 3°to the vertical axis.

3. A holographic sight according to Claim 1 , characterized in that; beams reflected on said reflective concave diffraction grating (3) are reflected to form an angle of 42°10 with the hologram (4).

4. A holographic sight according to Claim 1 , characterized by comprising; an upper body ceiling (7) that is designed to block visibility of interference beams outside the field of vision at high order due to diffraction grating.

5. A holographic sight according to Claim 1 , characterized by comprising; at least one horizontal adjustment mechanism (8) and at least one vertical (height) adjustment mechanism (9) to move holographic image to zero the sight.

6. A holographic sight according to Claim 1 , characterized by comprising; at least one NV button (10) activate the night vision mode.

7. A holographic sight according to Claim 1 , characterized by comprising; brightness adjustment buttons (11 , 12) to are present to increase or decrease the brightness level.

8. A holographic sight according to Claim 1, characterized by comprising; a mounting apparatus (13) to mount it on a gun.

9. A holographic sight according to Claim 1 , characterized by comprising; at least one restricting screw (14) to restrict the horizontal adjustment mechanism (8) and vertical (height) mechanism (9) movement in positive and negative directions.

10. A holographic sight according to Claim 1 , characterized in that; the reflective concave diffraction grating (3) to serve the same function as optical elements including a prism or a mirror, without using such elements.