Radiant energy – Radiation controlling means
Patent
1989-10-23
1991-05-07
Fields, Carolyn E.
Radiant energy
Radiation controlling means
33241, G02B 2300
Patent
active
050139258
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a collimating mark device provided with an infrared collimating mark intended to be observed through a sight.
It is known that the firing direction of a gun, that is to say the direction of the end of the firing barrel of the gun, and the viewing direction of a viewing sight are brought into coincidence with each other by reflecting an externally generated light image (collimating mark), for example a dot or a cross, via a mirror placed on the end of the firing barrel into the sight and bringing the image thus obtained in the site into coincidence with a fixed alignment mark.
Such a technique can be used in other situations in which the centre lines of two elements have to be adjusted to be parallel to or in line with each other. As an example, mention may be made of the alignment of the centres of a long lathe.
In order to bring the image of the collimating mark in the sight into coincidence with a fixed alignment mark, the position of the sight is adjustable.
In this manner, the alignment of the sight with respect to the firing direction can be checked at any desired instant and corrected if necessary, and compensation may be made for mechanical and thermal effects which may cause both the firing direction and the viewing direction of the sight to vary. This is of considerable importance because even a small deviation from the ideal position leads to a large difference between the actual point of impact and the desired point of impact of a projectile which has been fired.
By carrying out the check at various elevations of the firing barrel, it is also possible for the tracking of the viewing direction of the sight and the barrel to be adjusted.
The known systems are quite satisfactory provided visible light is employed. If infrared sights which comprise an infrared camera and a collimating mark formed with infrared light are used, problems arise, however, because it is not readily possible to form an image of an infrared collimating mark sharply in the sight. As a consequence of this, it is also not readily possible to being the blurred image of the collimating mark after conversion to visible form accurately into coincidence with the fixed alignment mark.
There are several reasons for the loss of definition of a collimating mark formed with infrared light, a visible image of which is formed in the sight. A first reason is the fact that infrared light has a relatively large wavelength, as a result of which defraction phenomena are more likely to play a role than in the case of visible light. These defraction phenomena play a greater role, the smaller the optical elements are which are used in the infrared light path. In the case of a field adjustment device, the mirror or collimator placed on the firing barrel should always have small dimensions, in the order of 2 to 3 cm diameter, in order to keep the mass inertia forces encountered on the mirror or collimator during the sometimes violent movements of the firing barrel as small as possible.
A further reason for the loss of definition of a collimating mark formed with infrared light after it has been converted into a visible collimating mark is that this conversion is usually carried out in the infra-red cameras normally used in I.R. aiming systems by scanning the infrared image presented with discrete detectors which scan the image presented in accordance with a predetermined pattern. The width of the image lines of the image which is built up in this manner is not negligible with respect to the lines of the collimating mark.
As a consequence of the two reasons mentioned above, a blurred visible collimating mark is produced which is difficult to bring accurately into coincidence with the fixed alignment mark. The result is that different people usually adjust the sight and the firing direction in different positions with respect to each other, although only one position is correct.
This problem is further intensified if the fixed alignment mark is itself obtained by generating a signal electronically in predetermined positions o
REFERENCES:
patent: 2553540 (1951-05-01), Beckerman
patent: 2700318 (1951-10-01), Snyder
patent: 3684383 (1972-08-01), Johansson
patent: 3974585 (1976-08-01), Dunham
patent: 4383474 (1983-05-01), Paurus et al.
patent: 4588253 (1986-05-01), Brunson
patent: 4832451 (1989-05-01), Trescott
patent: 4877324 (1989-10-01), Hauri et al.
B.V. Optische Industrie "De Oude Delft"
Dunn Drew A.
Fields Carolyn E.
Marn Louis E.
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