WO1999027408A1

WO1999027408A1 - A set of reticles which enable the user to correct parallax

Info

Publication number: WO1999027408A1
Application number: PCT/IL1998/000570
Authority: WO
Inventors: Gil Thieberger; Mor Inbar-Marcus
Original assignee: Gil Thieberger; Inbar Marcus Mor
Priority date: 1997-11-24
Filing date: 1998-11-22
Publication date: 1999-06-03
Also published as: AU1257399A

Abstract

This invention relates to a novel set of reticles that enable the user to avoid the parallax error of a scope without requiring mechanical adjustments. A main reticle (28) is placed at one of the focal planes of the scope. A secondary reticle (32) or reticles are placed in front of or behind the main reticle, but not at the focal plane. When the user's eye is on the optical axis (Z) of the scope, there is no parallax error and the image of the secondary reticles coincide with the image of the main reticle, or the images complement themselves. When the user's eye is not on the optical axis of the scope, there is a parallax error and the image of the secondary reticles will not coincide with the image of the main reticle, or the images will not complement themselves, and the user will see the primary reticle and the secondary reticle/s, or parts of them, or a broken reticles image. The reticles may have any desired pattern, may be illuminated by any well known in the art method, such as optical fiber, self illuminating substances, light source, or any other equivalent methods.

Description

A SET OF RETICLES WHICH ENABLE

THE USER TO CORRECT PARALLAX

Background of the invention

1. Field of the invention

The present invention relates to telescopes, specifically to a novel set of cross-hairs or reticle scales which enable the user to avoid the parallax error of optical systems such as, for example, optical weapons sight scopes, archery sight scopes, viewfinders and the like.

2. Terms definition

The term "scope" as used herein is defined as any optical magnifying or not magnifying imaging system, including at least one focal plane, that may incorporate reticle or reticles, such as aiming systems, weapon sight scopes, firearms and airguns telescopes, archery sight scopes, viewfinders, observation systems, measurement systems, and the like.

The term "reticle" as used herein is defined as any aiming aids or observation aids or measurement aids such as cross-hairs, reticle scale, cross-scale, single point, dots, arrows, flat points, three dimensional objects, any marks added to the image made by the scope, or any other two or three dimensional combination of the aforementioned, or any fraction of the aforementioned, incorporated with the scope.

The term "three-dimensional reticle" as used herein is defined as a system incorporating at least 2 two-dimensional reticles or at least one three-dimensional reticle and/or any combination of the aforementioned.

The term "optical axis" as used herein is defined as the predefined axis made by the three-dimensional reticle. Whenever the scope has to be zeroed and/or has to be synchronized with another product, the term "optical axis" as used herein is defined as the predefined axis made by the three-dimensional reticle after zeroing.

Description of Prior Art

In general, sight scope includes a sleeve-like scope body. This scope body has an objective lens system at the front-end portion thereof and an eyepiece lens system at the rear end portion thereof. Usually an erecting sleeve is received in the scope body. An erecting lens system is fixed within the erecting sleeve so that the user can see the target as an erect image. A plane reticle is placed at one of the focal planes of the scope (that are sometimes refer to as object plane and/or image plane).

When the scope is out of focus, the image of the target is formed either in front of, or behind the plane reticle. This problem is called "Parallax". The Parallax error is visible as an apparent movement of the reticle in relation to the target when the user moves his head.

There is no parallax, at any distance, as long as the eye is lined up exactly with the optical axis of the scope. An exit pupil small enough to do this is impractical because the user would lose his target often. A rubber flexible eyepiece to do this is not comfortable and not accurate enough.

There is no parallax, at one distance, in which the scope is in focus. Scopes with adjustable objectives enable the user to adjust the scope's focus according to the distance of the target. The main problem of those scopes is that the exact range of the target always has to be anticipated, otherwise, the focus has to be adjusted while the user views the target. In addition, those scopes have many expensive mechanical adjustments. As the scope has less mechanical adjustments, it is more reliable, waterproof, fogproof and shockproof.

All the prior art scopes have a plane reticle at one of the focal planes, i.e. at the image plane, or at the object plane, or at both of them as can be seen for example in U.S. Pat. No. 4,403,421 issued to Shepherd, which disclose a scope having two reticles, one at the object plane and one at the image plane.

The prior art scopes are not providing the user with means for finding the optical axis without significant reduction of the scope's field of view and the image quality.

The wish has been expressed to have a scope which enables the user to find the optical axis, without significant reduction of the scope's field of view and the image quality, and by that avoiding the parallax error at any distance and any magnification.

Objects of the invention

In view of the aforementioned needs and problems in the prior art, it is a primary object of the present invention to provide a system, relying on principals of optical geometry, that can provide the user with information about the location of the eye in relation to the optical axis of a scope and, optionally, information about the distance between the eye and the scope. That information is provided without requiring mechanical adjustments. That information enables the user to avoid the parallax error for any target distance.

It is another object of the present invention to provide novel sets of complementary reticles which enable the user to aim more precisely and to take easier and quicker shot.

It is another object of the present invention to provide a parallax avoiding means that are very light, and require minimum changes in the current available scopes' line of production.

It is another object of the present invention to provide a parallax avoiding means that enable the user to avoid the parallax error without losing eye contact with the target, or without using hands in order to correct and adjust the adjustable lens in the scope.

It is another object of the present invention to provide a way to convert regular scopes to parallax-free scopes according to the present invention. The adjustable objective solution forces the user to know the exact range to the target in order to make the right correction. Doing so is possible in many ways; some of them making the user reveal himself by using Opto-Electric systems. Therefor, it is another object of the present invention to provide a parallax avoiding mechanism that do not requires the user to know the exact range to the target in order to make the right correction.

It is another object of the present invention to provide a parallax avoiding aid that is simple to use even by the most inexperienced user.

It is another object of the present invention to provide a parallax avoiding aid that can help the most inexperienced user to find the right location of his eye.

Summary of the invention

The scope according to the present invention contains at least two reticles. The reticle that will be called herein the main reticle, is the "regular" reticle that appears in all of the known in the art scopes. It is located at one of the scopes focal planes (i.e. at the object plane or at the image plane, as appears in all of the known in the art scopes). The main reticle may have any known in the art pattern.

All the additional reticle or reticles, which will be called herein the secondary reticle/s, are located in front of or behind the main reticle (and not at one of the scopes focal planes). The secondary reticle/s are designed and located in such a way that whenever the user's eye is on the optical axis of the scope, at least two images, of any of the reticles, will coincident. Hereinafter coincident and overlap are meant the same. When the user's eye is not on the optical axis of the scope, those images will not coincident.

For example, the secondary reticle may be designed to coincident with the main reticle. In that case, whenever the user sees only the main reticle, his eye is placed on the optical axis of the scope, so there is no parallax error. When the user sees the secondary reticle (or parts of it), his eye is not placed on the optical axis of the scope, therefore he should move his head until his eye will be placed on the optical axis.

The main and secondary reticle/s may be designed and located in such a way that whenever the user's eye is on the optical axis of the scope, the images of the main and secondary reticle/s will complement themselves into a predefined pattern. Whenever the user's eye is not on the optical axis of the scope, the images of the main and secondary reticle/s will not form the above-predefined shape, i.e. the user will notice a non-continuous pattern. Whenever the user sees a continuous reticle, his eye is placed on the optical axis of the scope, so there is no parallax error. The avoidance of the parallax error, according to the present invention, is achieved without requiring mechanical adjustments, and does not depend on the distance of the scope from the target.

The reticles may have any desired pattern, may be illuminated by any well known in the art method, such as optical fiber, self illuminating substances, light source such as for example LED (light emitting diode), or any other equivalent methods

Brief description of the drawings

FIG.1 is a schematic representation of a previous art reticle.

FIG. 2 is a schematic representation of a previous art reticle placed in a reticle housing. FIG. 3 is a schematic representation of a previous art four flat points reticle.

FIG. 4 is a schematic representation of a set of reticles according to the present invention.

FIG. 5 shows how the set of reticles that appear in FIG. 4 are looked like to the user when his eye is placed on the optical axis of the scope. FIG. 6 shows how the user sees the set of reticles that appear in FIG. 4 when his eye is not placed on the optical axis of the scope.

FIG. 7 is a schematic representation of a three-dimensional main reticle according to the present invention.

FIG. 8 is a schematic representation of a three-dimensional secondary reticle according to the present invention.

FIGS. 9 and 10 are a profile view of variable distance set of reticles according to the present invention.

FIG. 11 shows a main reticle and two complementary secondary reticles according to the present invention. FIG. 12 shows a complementary main reticle and two complementary secondary reticles according to the present invention.

FIG. 13 shows how the user sees the set of complementary reticles that appear in Fig. 12 when his eye is not placed on the optical axis of the scope.

Detailed description of preferred embodiments

It is well known in the art that there is no parallax, at any distance, as long as the eye is lined up exactly with the optical axis of the scope. By using simple principals of optical geometry, it is found that the amount of parallax error depends on the distance between the image of the target to the reticle. Whenever the image of the target is formed on the reticle, there is no parallax error. As the distance between the image of the target to the reticle increases, the parallax error increases. FIG. 1 is an example of a previous art reticle 28, which is plane and made of four flat points 25 and a cross hair 27. The reticle is placed in a reticle house 30, as seen in FIG. 2.

FIG. 3 is a reticle 32 that contains only the four thick points 25 of the reticle shown in FIG. 1. FIG. 4 is an example of a set of reticles according to the present invention. The reticles are placed in a reticle house 30. The main reticle 28 is identical to the reticle shown in FIG. l and is placed exactly at the place that the reticle shown in FIG. 1 would have been placed (i.e. at the focal plane).

The secondary reticle 32 is placed in front of or behind the main reticle 28 in such a way that when the user's eye is lined up exactly with the optical axis of the scope Z, the image of the secondary reticle 32 will coincident with the image of the main reticle 28, as shown in FIG. 5. For example, each point on the four points 25 of the main reticle (x,y,z) has its corresponding point (x,y,z ± L) on the secondary reticle/s when the distance between the main reticle 28 to the secondary reticle 32 is L. The distance between the image of the target to the main reticle 28 is smaller than the distance between the image of the target to the secondary reticle 32. As a result, the amount of parallax error of the main reticle 28 is smaller than the amount of parallax error of the secondary reticle 32. Whenever the user's eye is not lined up exactly with the optical axis of the scope, the difference in the amount of parallax error and the different locations of the reticles, becomes expressed in the appearance of the secondary reticle 32, as shown for instance in FIG. 6, i.e. the image of the secondary reticle 32 will not coincident with the image of the main reticle 28. Whenever the scope has two or more focal planes, the main reticle may be located in one of those focal planes, and the secondary reticle may be located near another focal plane. When all the reticles are not located around the same focal plane, and at least one reticle is located in front of the erecting sleeve and at least one reticle is behind the erecting sleeve, a compensating solution is required, in order to keep all the reticles aligned at the optical axis of the scope. For example, the main reticle is located at the focal plane (closest to the eyepiece) and the secondary reticle is located near another focal plane (in front of the erecting sleeve) and is moving in the same direction as the erecting sleeve, in the proper ratio needed to keep the reticles aligned. In that example, when the erecting sleeve is moved for lateral and/or elevation adjustment, the position of the image of the secondary reticle relative to the image of the main reticle remains the same.

The target acquisition is done by using the main reticle, which is very clear (because it is located at the focal plane). The primary purpose of the secondary reticle/s is to help the user to line up his eye with the optical axis of the scope (and by that eliminate parallax). As the secondary reticle/s are located further from the focal plane, their image is less clear and their parallax error become more visible and the relative movement between the main reticle to the secondary reticle/s increase. Therefore, the secondary reticle/s should be located as far as possible from the focal plane, as long as they are clear enough to enable the user to correct his eye location.

It is to be understood that the above described set of reticles is just an illustration of the principles of the present invention. There are however, innumerable modifications and changes which may be devised by those skill in the art which may embody the principles of the present invention and fall within the spirit and scope thereof. The principles of the present invention can be applied to any type of reticles, which may have any desired pattern, which may enables the user to estimate range and trajectory without requiring mechanical adjustments. The following preferred embodiments demonstrate additional possible modifications.

In another preferred embodiment of the present invention, as shown for example in FIG. 7, there is only one three-dimensional reticle 40. When the user's eye is lined up exactly with the optical axis of the scope Z, the reticle 40 looks clear and thin.

When the user's eye is not lined up exactly with the optical axis of the scope, the user sees the three dimensional structure of the reticle. o

In another preferred embodiment of the present invention, Whenever the three-dimensional reticle incorporates reticles which are not symmetric in relation to the focal plane or not made of overlapping reticle lines crossing the optical axis of the scope (Z), the three-dimensional reticle enables the user to locate his eye at a predefined eye-relief

In another preferred embodiment of the present invention, the secondary reticle/s

42 are three-dimensional, as seen for example in FIG. 8. When the user's eye is lined up exactly with the optical axis of the scope, the secondary reticle 42 looks clear and thin. When the user's eye is not lined up exactly with the optical axis of the scope, he sees circle and shadows instead of a clear thin circle.

The secondary reticle/s 42 may have a cone shape in accordance with the Ray- Tracing design of the scope.

42 may be made of an optical filter that transmits only a specific wavelength or wavelength. For example, referring to FIG. 8, the secondary reticle 42 may pass only wavelength in the range of 600 to 650 nanometer. Whenever the eye is not lined up exactly with the optical axis of the scope, a red shadow appears.

In another preferred embodiment of the present invention, the distance of the secondary reticle (45, 46) from the main reticle 28 is not constant, as shown for example in the cross sectional view of FIGS. 9 and 10. Some people find it easier to use this set of reticles because they can find their optimal point on the secondary reticle which is clear enough and has as much parallax error as possible.

In another preferred embodiment of the present invention, the secondary reticles complete each other to a predefined pattern whenever the user's eye is located on the optical axis of the scope. The complementary reticles enable the user to take notice of less than a line thickness diversions easily. The complementary reticles may have any desired pattern, such as circle/s, rectangle/s, diamond/s, grid, letter/s etc. The image of the complementary reticles may be located anywhere within the image made by the scope. FIG. 11 is an example of a main reticle 28 and secondary complementary reticles

(50 and 51) that complete each other to a full and smooth circle. Chrome deposition or etching into glass or any other well known in the art method or a combination of well known in the art methods may be used for making the reticles. The reticles are placed one after another in a reticle housing 30 such as shown for example on FIG. 4 or in any equivalent means for securing/supporting the reticles, or in any other well known in the art method for securing/supporting the reticles, herein after refer to as "reticle housing". When the user's eye is not lined up exactly with the optical axis of the scope, the image of those secondary reticles looks like a broken circle.

In another preferred embodiment of the present invention, as shown for example in FIG. 12, the secondary reticles (54 and 55) complete themselves and complete the main reticle 56. FIG. 13 is an example of the viewed image of the reticles when the eye is not lined up exactly with the optical axis of the scope. When the scope is being used under unfavorable condition such as during twilight, in a dark place, or in aiming at blackish or dark target, the reticle should be illuminated so it can be seen easily by the user. Each of the reticles of the present invention may be illuminated by any well known in the art method, such as optical fiber, self illuminating substances, light source, or any other equivalent methods. Each of the reticles of the present invention may be made of any well known in the art materials, including self illumining materials and reflecting materials.

When using the set of reticles of the present invention with a variable power (zoom) scope, the distances between the reticles may require adjustment due to magnification changes. In order to change those distances between the reticles, a moveable secondary reticle is required. Most zoom scopes has an external dial or ring that has to be rotated in order to change the magnification. That dial or ring can be used for change those distances between the reticles.

The preferred embodiment consists of several basic elements: the external zoom ring or dial has an inner part, in a ring shape, inside the scope's body, in which a thread is made in the inner part of the ring. Another element is a secondary reticle housing, tube like, featuring a matching screwing to the one in the inner zoom ring, and two bulges on the upper and lower external diameter, located at the front of the housing. According to the rotation direction of the external zoom ring, the internal second reticle housing screwing may be right or left as needed. Other elements are two slides in the inner diameter of the scope's body, in which the bulges of the secondary reticle housing can move only forward and backward, in order to prevent rotation of the reticles around the optical axis of the scope. That preferred embodiment works in the following manner: the secondary reticle housing is partly screwed into the inner zoom ring screwing, which does not move forward and/or backward but only rotates, and the two bulges are located inside the slides. When the external zoom ring or dial is moved, in order to change the magnification, the internal zoom ring moves as well, causing the secondary reticle housing (and the secondary reticle himself) to move as well. The bulges in the slides permits only forward and/or backward movement, making the secondary reticle staying aligned to the main reticle, and changing the distance between the two reticles. Thus the rotation of the magnification ring or dial corrects simultaneously the magnification and the distances between the main and secondary reticles, in order to maintain the complimentary effect and needed sharpness. The reticle of the present invention may be formed in a variety of well known in the art methods of reticle construction or any aiming aides, observing aids, or measuring aids construction.

Although the invention has been shown in terms of preferred embodiments, it will be apparent to those of skill in the art that numerous modifications and variations and adaptations of the present invention to various usages and conditions may be made without departing from the true spirit and extent thereof, as set forth in the accompanying claims. Thus, For example, the secondary reticle of the present invention can be projected at infinity in the field of view. That can be done by well know in the art means of reticle projection system. In another example, the scope may comprise reticles which non of them is placed at a focal plane.

Numerous combinations of preferred embodiments and/or their modifications may be made without departing from the true spirit and scope. Any desired reticle pattern can be made according to the principles of the present invention. The terms, expression, and processes which have been employed in this application are used herein as terms of description and not of limitation, and thus there is no intention, in the use of such terms, expression, and processes, of excluding equivalents of the features shown and described, or portions thereof, it being recognized that the scope of the invention is defined and limited only by the following claims.

Claims

We Claim:

I. A scope, comprising: a) a main reticle placed approximately in a focal plane of said scope, b) at least one secondary reticle placed nearby said main reticle. 2. The scope of claim 1, wherein said reticles provide the user with means for avoiding parallax error.

3. The scope of claim 1, wherein said main reticle and said at least one secondary reticle are connected or manufactured as a single device.

4. The scope of claim 1, wherein said scope having means for illuminating at least one of said reticles .

5. At least one object, characterized by the fact that after incorporated within a scope, said object provides the scope's user with means for returning his eye repeatedly to approximately the same location, without significant reduction of said scope's field of view and without significant decreasing said scope's exit pupil.

6. The object of claim 5, wherein said same location is on the optical axis of said scope.

7. The object of claim 5, wherein said same location is a predefined eye-relief on the optical axis of said scope. 8. The object of claim 5, wherein said object is a three-dimensional reticle.

9. The three-dimensional reticle of claim 8, characterized by the fact that whenever the user's eye is not located at said location, the image of said reticle seems fragmented in relation to the predefined image of said reticle that seems whenever the user's eye is located at said location. 10. The three-dimensional reticle of claim 8, characterized by the fact that whenever the user's eye is located at said location, minimal field of view will be blocked by images made by said three-dimensional reticle.

I I . The three-dimensional reticle of claim 8, wherein one reticle of said three-dimensional reticle is placed at a focal plane. 12. A scope, comprising: a) at least two focal planes, b) a main reticle placed approximately in a first focal plane of said scope, c) at least two secondary reticles placed nearby a second focal plane of said scope, d) all said secondary reticles are not located at the same plane, whereby, at least two of said main and secondary reticles provide the scope's user 5 with means for returning his eye repeatedly to approximately the same location.

13. The scope of claim 12, characterized by the fact that whenever the user's eye is not located at a predetermined location, the image of said secondary reticles seems fragmented in relation to the predefined image of said secondary reticles that seems whenever the user's eye is located at said predetermined location. 10 14. The scope of claim 12, characterized by the fact that whenever the user's eye is located at a predetermined location, minimal field of view will be blocked by images made by said secondary reticles.

15. A method of forming a reticle image that enables a scope's user to return his eye repeatedly to approximately the same location in relation to a scope, without 15 significant reduction of said scope's field of view and without significant decreasing said scope's exit pupil, comprising a three-dimensional reticle.

16. The method of claim 15, wherein said same location is on the optical axis of said scope.

17. The method of claim 15, wherein said same location is a predefined eye-relief on 20 the optical axis of said scope.

18. The method of claim 15, wherein the forming of said reticle image utilizing the fact that the amount of parallax error depends on the distance between the reticle to the focal plane.

19. The method of claim 15, characterize by the fact that whenever the user's eye is 25 located at said same location, at least one predetermined zone of the image of said reticles complement itself to a predetermined shape.

20. The method of claim 15, characterize by the fact that whenever the user's eye is located at said same location, at least one predetermined part of at least two predetermined reticles overlap. 30 21. The method of claim 16, characterize by the fact that whenever the user's eye moves along said optical axis of said scope, at least one predetermined part of at least two predetermined reticles form a predetermined pattern whenever the user's eye is located at a predefined distance from the scope.

2. A scope, comprising: a) at least two focal planes, b) a main reticle placed approximately in a first focal plane of said scope, c) at least one secondary reticle placed nearby one of said focal planes of said scope, d) means for synchronizing said main reticle with said secondary reticle, whereby, at least two of all said reticles provide the scope's user with means for returning his eye repeatedly to approximately the same location.