Combined day and night weapon sight

Abstract

A combination day / night sight includes an image intensifying sensor / display combination and a daytime optical path length compensator that may be selectively placed within the optical path. Use of the optical path length compensator when the image intensifying sensor / display is not being used eliminates the need for moving optical elements. The night sight therefore requires no change in focus or bore sight adjustment after switching between day and night operations.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to night vision devices. More specifically, the present invention provides a combined day and night sight capable of providing an intensified and potentially magnified sight picture at night or under poor viewing conditions, and a potentially magnified sight picture in more favorable light and viewing conditions. [0003] 2. Description of the Related Art [0004] The use of a light source to illuminate the target—whether visible light or infrared—has the disadvantage of indicating the location of the shooter. Laser aiming devices carry the same disadvantage. Thermal infrared imaging, which does not require a light source, has the disadvantage of producing an unnatural image. Light gathering and intensifying night vision devices produce natural images, but are only useful to the extent that there is available light to gather and intensify. The use of tritium illuminated sights, while making...

AI Technical Summary

Benefits of technology

[0012] The present invention provides a combination day and night observation device that is particularly suited for use as a sight for a firearm, but which may also be used for observation. The invention includes an image intensifying sensor / display combination and a daytime optical path length compensator having substantially the same optical path length as the image intensifying sensor / display combination. For the purpose of this description, two day / night sight components have substantially the same optical path if the substitution of one component for the other does not require a change in either the focus or the bore sight of the weapon upon which the sight is mounted for shooting at typical shooting distances. Either the image intensifying sensor / display or the daytime optical path length compensator may be placed within the optical path defined within the sight, depending on whether the sight is used in good or poor viewing or lighting conditions. The use of the optical path length compensator eliminates the need for moving optical elements to compensate for the change in the optical pathway when the image intensifying sensor / display is moved outside of the optical path for daytime use.

[0017] It is another object of the invention to provide a combination day / night sight that is more compact, lighter weight, and exhibits better performance than existing combination day / night sights.

[0019] It is another object of the invention to provide a combination day / night sight that presents a magnified image to the user.

[0021] It is another object of the invention to provide a combination day / night sight requiring no change in focus or bore sight adjustment after switching between day and night operation.

Problems solved by technology

The use of a light source to illuminate the target—whether visible light or infrared—has the disadvantage of indicating the location of the shooter.

Laser aiming devices carry the same disadvantage.

Thermal infrared imaging, which does not require a light source, has the disadvantage of producing an unnatural image.

Light gathering and intensifying night vision devices produce natural images, but are only useful to the extent that there is available light to gather and intensify.

The use of tritium illuminated sights, while making the sights more visible, fails to illuminate the target even if the tritium—illuminated aiming reticle is within a telescopic sight providing light gathering and magnification.

Additionally, both night vision equipment and daytime telescopic sight add weight and bulk to the weapons with which they are used.

In addition to making the sight unnecessarily heavy, the use of two optical paths creates a likelihood of differences between point of aim and point of impact from one optical path to the other.

However, image intensifier tubes are delicate instruments, subject to damage when removed.

Furthermore, a temperature difference between the image intensifier and the scope upon insertion of the image intensifier may cause fogging of the sight.

Such movement of both the daytime optics and the image intensifier tube raises the issue of the repeatability of these movements.

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