GB2291720A

GB2291720A - Optical apparatus having self-adjusting eyepiece reticles that maintain a predetermined orientation at any interpupillary distance

Info

Publication number: GB2291720A
Application number: GB9515177A
Authority: GB
Inventors: Guenter Brueck
Original assignee: Hughes Aircraft Co
Current assignee: Raytheon Co
Priority date: 1994-07-25
Filing date: 1995-07-24
Publication date: 1996-01-31
Also published as: GB9515177D0; CA2154492A1

Abstract

Optical apparatus, e.g. binoculars 10, comprises first and second bodies 14, 15 that house optical elements that are rotatable relative to each other around a predetermined axis. A rotatable reticle mount 12 is disposed in the first body that is rotatable around its axis, and an eyepiece reticle 16 is disposed in the rotatable reticle mount 12. A gear system 20 is employed to rotate the reticle so that it has a fixed viewing orientation at any interpupillary distance. The gear system comprises a first bevel gear 21 centered on the predetermined axis 25, a second bevel gear 23 disposed on the rotatable reticle mount, and a drive shaft 13 with ends having bevel gears connecting the first and second bevel gears. The drive shaft may be flexible. The first and second gears 21, 22 may have a gear ratio of 1:1. The optical apparatus may further comprise a second rotatable reticle mount disposed in the second body that is rotatable around its axis and a second gear system. The second gear system may comprise a third bevel gear disposed on the second rotatable reticle mount 12a, and a second drive shaft with ends having bevel gears connecting the first and third bevel gears. An embodiment of the optical apparatus employs bevel gears disposed on stationary objective lens mounts, gears on rotatable reticle mounts, and gear systems coupled between these mounts. <IMAGE>

Description

OPTICAL APPARATUS HAVING SELF-ADJUSTING EYEPIECE RETICLES THAT MAINTAIN A PREDETERMINED ORIENTATION AT ANY INTERPUPILLARY DISTANCE BACKGROUND The present invention relates to binoculars, and more particularly, to a selfadjusting eyepiece reticle for use in such binoculars that maintains a horizontal or vertical reticle position at any interpupillary distance adjustment.

Conventional binoculars are generally adjustable in that the respective eyepiece reticles for each eye may be rotated relative to a central axis of the binoculars in order to increase or decrease the interpupillary distance. However, in binoculars that have an engraved reticle, the nornal rotational movement required to change the interpupillarv distance angularly rotates the reticles relative to one another. Consequently, it is necessary to provide an adjustment mechanism for such conventional binoculars in order to maintains a horizontal reticle position when the interpupillary distance is adjusted.

It is therefore an objective of the present invention to provide for a selfadjusting eyepiece reticle for use in a set of binoculars that maintains a horizontal or vertical reticle position at any interpupillary distance adjustment.

SUMMARY OF THE INVENTION In order to meet the above and other objectives, the present invention provides for optical apparatus, and in particular, binoculars, having one or more self-adjusting eyepiece reticles that maintain a horizontal or vertical reticle position, or predetermined orientation, at any interpupillary distance adjustment. In general, the optical apparatus comprises first and second bodies that house optical elements for viewing therethrough, and that are rotatable relative to each other around a predetermined axis. A rotatable reticle mount having an axis is disposed in the first body that is rotatable around this axis. An eyepiece reticle is disposed in the rotatable reticle mount. A gear system is employed to rotate the reticle so that its position or orientation is generally horizontal or vertical at any interpupillary distance.The gear system comprises a first bevel gear centered on the predetermined axis, a second bevel gear disposed on the rotatable reticle mount, and a drive shaft having ends comprising bevel gears connecting the first and second bevel gears. The drive shaft may be flexible, depending upon the design of the optical apparatus. The first and second gears have a 1:1 gear ratio. The optical apparatus may further comprise a second rotatable reticle mount disposed in the second body that is rotatable around its axis and a second gear system. The second gear system comprises a third bevel gear disposed on the second rotatable reticle mount, and a second drive shaft having bevel gear ends connecting the first and third bevel gears.

A second embodiment of the optical apparatus comprises first, second and third bodies that house optical elements for viewing therethrough, and that are rotatable relative to each other. A pair of gears are integrated into stationary objective lens mounts disposed in the first body. First and second rotatable reticle mounts are disposed in the second and third bodies that are rotatable relative to their respective axes. An eyepiece reticle is disposed in each rotatable reticle mount. A first gear system is coupled between the first and second bodies that comprises a first bevel gear disposed in the first body, a second bevel gear disposed on the rotatable reticle mount of the second body and a drive shaft having bevel gears connecting the first and second bevel gears.A second gear system is coupled between the first and third bodies that comprises a third bevel gear disposed in the first body, a fourth bevel gear disposed on the rotatable reticle mount of the third body, and a drive shaft having bevel gears connecting the third and fourth bevel gears.

The present invention prevents errors due to tilted reticles, for example, when used for distance determination. The present invention is also more precise because the reticles do not tilt relative to a user's eyes, and hence the reticle is easier to read. The present invention may be used in any type of binocular or microscope body design.

BRIEF DESCRIPTION OF THE DRAWINGS The various feat tires and advantages of the present invention may be more readily understood with reference to the following detailed description taken in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which: Fig. 1 illustrates a first embodiment of optical apparatus having self-adjusting eyepiece reticles in accordance with the principles of the present invention; and Figs. 2 and 3 illustrate side and top views, respectively, detailing the gearing employed in the optical apparatus of Fig. 1; Fig. 4 illustrates a second embodiment of optical apparatus having self-adjusting eyepiece reticles in accordance with the principles of the present invention; and Figs. 5 and 6 illustrate side and top views, respectively, detailing the gearing employed in the optical apparatus of Fig. 4.

DETAILED DESCRIPTION Referring to the drawing figures, Fig. 1 illustrates a first embodiment of optical apparatus 10 comprising a pair of binoculars 10 having at least one self-adjusting eyepiece reticle 16 in accordance with the principles of the present invention. The reticle 16 ideally remains in a horizontal or vertical position or predetermined orientation at any interpupillary distance setting. The binoculars 10 have two binocular bodies 14, 15 that house optical elements and the eyepiece reticle 16. The reticle 16 is disposed in a tumtable reticle mount 12 which is rotatable around its axis or center.

The present invention uses a simple gear system 20, having integrated bevel gears 21, 22, respectively, facing each other. One bevel gear 21 is located on a shaft 11 centered about a hinge axis 25 or optical axis 25 of the binoculars 10 and a second bevel gear 22 is located on the turntable reticle mount 12 of a selected one of the bodies 14, 15. The two bevel gears 21, 22 are connected by a drive shaft 13 having bevel gears 23, 24, or ends 23, 24. The drive shaft 13 may be flexible, if desired, depending upon the optical design.

The required gear ratio for gears 21, 22 disposed between the hinge axis 25 and reticle 16 is 1:1. In order to set the interpupillary distance, the binocular bodies 14, 15 are rotated around their hinge axis by an amount equal an angle A. The reticle reacts with an angular step B = A/2 in the opposite direction, turning on an ocular axis, which generally corresponds to the hinge axis 25. Tn practice, a user tilts both binocular bodies 14, 15 simultaneously by an angular amount A/2 at each body 14, 15, providing the required total angle A. At the same time, the reticle mount 12 with the reticle 16 turns with the same speed in the opposite direction, for an equivalent of B = A/2, remaining in a horizontal or vertical position.

Using reticles 16 in both eyepieces requires a second drive shaft 13a and second rotatable reticle mount I 2a disposed in a generally symmetrical manner to the left of the hinge axis 25, or optical axis 25, in a manner generally shown in Fig. 1. More particularly, the second self-adjusting eyepiece reticle 16 is housed in the second rotatable reticle mount 12a in the second body 15. The second rotatable reticle mount 12a and second self-adjusting eyepiece reticle 16 are rotatable around an axis of the second mount 1 2a. A second gear system 20a is provided that comprises a third bevel gear 22a disposed on the second rotatable reticle mount 12a, and the second drive shaft 1 3a which has bevel gears 23a, 24a on its ends that connect the first and third bevel gears 21, 22a.

Referring to Figs. 2 and 3, they illustrates side and top views, respectively, of gearing employed in the optical apparatus 10 of Fig. 1 for moving the self-adjusting eyepiece reticles 16. The drive shaft 13 incorporates bevel gears 23, 24 having a number of teeth corresponding to (c) and (d), respectively. The number of teeth on the shaft 11 corresponds to (a), while the number of teeth on the turntable reticle mount 12 corresponds to (b) in the equations below.

The required gear ratio is achieved through various combinations of teeth on the gears 21, 22, and gears 23, 24. The equations below may be used to define the number of teeth to achieve a gear ratio of 1:1. As mentioned above, the reticle 16 revolves with angle B = A/2 at both bodies 14, 15, to achieve a total angle A, while the gear ratio remains 1:1. For any three gears or gears, the number of teeth are selected.

For the remaining gear, the number of teeth must be calculated. The number of teeth for the fourth gear or gear is given by the equation: ac/db = 1. Therefore, a = db/c; b = ac/d; c = db/a; and d = ac/b.

Referring to Fig. 4, some binoculars 10a are designed to tilt or rotate around an axis 26 of an objective lens (an objective axis 26) to achieve interpupillary space adjustment. Fig. 4 illustrates a second embodiment of optical apparatus 10a, or binoculars 10a, having self-adjusting eyepiece reticles 16 in accordance with the principles of the present invention. Figs. 5 and 6 illustrate side and top views, respectively, detailing gearing 20a employed in the optical apparatus 1 0a of Fig. 4.

In this embodiment a pair of gears 21, 21a are integrated into stationary objective lens mounts 27, 27a disposed in a central body 15, while gears 22, 22a on the reticle mounts 12, l2a, and gears 23, 24, 23a, 24a on first and second gear shafts 13, 1 3a have gear ratios of 1:1, and are principally unchanged from the first embodiment described above with regard to Figs. 1-3. This second embodiment of the optical apparatus lOa includes the central body 15 and two symmetrically disposed lateral bodies 14, 14a that house the reticles 16. Each reticle mount 12, 12a rotates relative to its axis 17 when the lateral bodies 14, 14a are rotated relative to each other and to the central body 15 to adjust the interpupillary distance. The bodies rotate relative to a respective objective axis 26.

The present invention prevents errors caused by tilted reticles 16, when used for distance determination, for example. The present invention provides for optical apparatus 10 that is also more precise because the reticles 16 do not tilt relative to a user's eyes, and hence the reticles 16 are easier to read. The present invention may be used in any type of binocular or microscope body design.

Thus there has been described a new and improved optical apparatus or binoculars comprising self-adjusting eyepiece reticles that maintains a horizontal or vertical reticle position, or predetermined orientation, at any interpupillary distance adjustment. It is to be understood that the above-described embodiments are merely illustrative of some of the many specific embodiments that represent applications of the principles of the present invention. Clearly, numerous and other arrangements can be readily devised by those skilled in the art without departing from the scope of the invention.

Claims

What is claimed is:

1. Optical apparatus comprising: first and second bodies that house optical elements for viewing therethrough, and that are rotatable relative to each other; a rotatable reticle mount disposed in the first body that is rotatable relative to its axis; an eyepiece reticle disposed in the rotatable reticle mount; and a gear system comprising: a first bevel gear that is fixed relative to the optical apparatus; a second bevel gear disposed on the rotatable reticle mount; and a drive shaft having bevel gears connecting the first and second bevel gears, for maintaining the reticle in a predetermined orientation regardless of the relative rotation between the first and second bodies.

2. The apparatus of Claim 1 wherein the drive shaft is flexible.

3. The apparatus of Claim 1 wherein the first and second gears each have a gear ratio of 1:1.

4. The apparatus of Claim 1 wherein the optical apparatus comprises a pair of binoculars and wherein the gear system causes the reticle to rotate so as to remain in the predetermined orientation at any interpupillary distance setting.

5. The apparatus of Claim 1 wherein the first and second bodies are rotatable around a hinge axis of the optical apparatus.

6. The apparatus of Claim 1 wherein the first body is rotatable around an objective axis of the optical apparatus.

7. The apparatus of Claim 1 further comprising: a second rotatable reticle mount disposed in the second body that is rotatable relative to its axis; and a second gear system comprising: a third bevel gear disposed on the second rotatable reticle mount; and a second drive shaft having bevel gears connecting the first and third bevel gears.

8. Binoculars comprising: first and second binocular bodies that house optical elements for viewing therethrough, and that are rotatable relative to each other around a predetermined axis; a rotatable reticle mount disposed in a selected one of the binocular bodies that is rotatable relative to its axis; an eyepiece reticle disposed in the rotatable reticle mount; and a gear system comprising: a first bevel gear centered relative to the predetermined axis; a second bevel gear disposed on the rotatable reticle mount; and a drive shaft having bevel gears connecting the first and second bevel gears.

9. The binoculars of Claim 8 wherein the drive shaft is flexible.

10. The binoculars of Claim 8 wherein the first and second gears each have a gear ratio of 1:1.

11. The binoculars of Claim 8 further comprising: a second rotatable reticle mount disposed in the second body that is rotatable relative to its axis; and a second gear system comprising: a third bevel gear disposed on the second rotatable reticle mount; and a second drive shaft having bevel gears connecting the first and third bevel gears.

12. Optical apparatus comprising: first, second and third bodies that house optical elements for viewing therethrough, and that are rotatable relative to each other; first and second rotatable reticle mounts disposed in the second and third bodies that are rotatable relative to their respective axes; an eyepiece reticle disposed in each rotatable reticle mount; a first gear system comprising: a first bevel gear disposed in the first body; a second bevel gear disposed on the rotatable reticle mount of the second body; and a drive shaft having bevel gears connecting the first and second bevel gears; and a second gear system comprising: a third bevel gear disposed in the first body; a fourth bevel gear disposed on the rotatable reticle mount of the third body; and a drive shaft having bevel gears connecting the third and fourth bevel gears.

13. The optical apparatus of Claim 12 wherein the drive shaft is flexible.

14. The optical apparatus of Claim 12 wherein the first and second gears and the third and fourth gears respectively have gear ratios of 1:1.

15. An optical apparatus substantially as hereinbefore described with reference to and as shaft in the zccompenying drawings.