WO2006120529A1

WO2006120529A1 - Aligning of optical devices

Info

Publication number: WO2006120529A1
Application number: PCT/IB2006/001163
Authority: WO
Inventors: Klaus Müller; Trevor James Kirsten
Original assignee: Csir
Priority date: 2005-05-06
Filing date: 2006-05-05
Publication date: 2006-11-16

Abstract

The invention is illustrated, as an example, by a sniper situation. A sniper's eye 16 observes a target 12 via an aligner 20, and a beam splitter 24 along a line of sight 14. The beam splitter 24 projects the image 12 onto a charge coupled video camera 18 which shows the image on a monitor to a controller of the sniper. A frame 22 ensures that the camera 18 and the beam splitter are directed along a line of sight in constant relation to the frame. If the eye 16 deviates from the line of sight of the camera, the image seen by the eye 16 is affected and the sniper can adjust. The aligner 20 has a plurality of narrow, straight, sight passages surrounded by walls. Misalignment of the eye 16 causes partial obscurement, which is progressive with the angle of misalignment, of the image.

Description

ALIGNING OF OPTICAL DEVICES

THIS INVENTION relates to aligning of optical devices. It relates more specifically to a method of aligning optical devices along a common sight line, to an optical aligning apparatus and to an optical aligner.

In accordance with a first aspect of this invention, there is provided a method of aligning optical devices along a common sight line, including connecting an optical aligner having an axis and a first optical device having a first sight line in fixed orientation such that said axis and said first sight line are optically aligned; arranging a second optical device, having a second sight line, in spatial relationship with the optical aligner and the first optical device and aligning the second sight line along the axis of the aligner, optical alignment of at least one of the first and second sight lines being by deflection or reflection.

The method may include affecting optical sight of the second optical device if aiming thereof (along the second sight line) deviates from the axis of the aligner. Advantageously, a degree in which the optical sight of the second optical device is affected, may be progressive with increased deviation from the axis of the aligner. Conveniently, the optical sight of the second optical device may be affected by decreasing translucence.

In a preferred method, the aligner may include a plurality of contiguous sight passages, each having an axis. Said axes of the plurality of sight passages may be radially aligned to a common focal point, said axes forming a composite axis of the aligner, the first and second optical devices being positioned optically at said focal point. Optical alignment of said one of the first and the second sight lines by deflection or reflection may be by means of a beam splitter operating between an object being observed and respectively the first and second optical devices.

One of the optical devices may be in the form of a camera. The camera may be a video camera. The camera may be a charge coupled camera.

The other of the first and the second optical device may be an eye, e.g. a human eye. Then, the aligner and the first optical device may be mounted on a head of a person of which the eye is the second optical device.

In accordance with a second aspect of the invention, there is provided an optical aligning apparatus including first and second optical devices having first and second sight lines and an optical aligner having an axis, in which the first optical device and the aligner are connected in fixed orientation such that said first sight line and said axis are aligned; in which the second optical device is arranged in spatial relationship with the optical aligner and the second optical device; in which at least one of the first and the second optical devices has an aiming facility for aiming it along said axis by means of deflection or reflection.

Advantageously, the aligner may be adapted to have maximum translucence along the axis, and reduced translucence along a line deviating from the axis. Translucence may progressively be reduced in accordance with a progressive degree of deviation. The translucence may be reduced by means of progressive reduction of a cross-sectional area of a passage through the aligner normal to the direction of said deviating passage of light.

The apparatus may include a beam splitter between a point of observation along the axis of the aligner and respectively the first and second optical devices for splitting beams of light transmitted in use along said axis to the first and second optical devices.

One of the first and second optical devices may be a camera. The camera may be a video camera having an output connectable to a monitor. The video camera may be a charged coupled video camera.

The other of the first and the second optical devices may be an eye. Said eye may be a human eye. Then, the aligner and the first optical device may be mountable on or connectable to a head of a person of which the eye is the second optical device.

In accordance with a third aspect of the invention, there is provided an optical aligner having an axis and being maximally translucent along said axis, and being of reduced translucence along lines deviating from said axis, the aligner including a plurality of contiguous passages having walls, cross-sectional areas of the passages being at a maximum when optically observed on axis, and being reduced when optically observed at an angle deviating from the axis.

The third aspect can alternatively be defined as providing an optical aligner having an optical axis and including a plurality of contiguous, straight through passages, each having an axis and being defined by surrounding walls, at least one of the through passages being co-axial with the optical axis of the optical aligner, projections of the walls being at a minimum when observed along said optical axis of the aligner, and increasing when observed at an angle deviating from said optical axis.

Said axis may be a composite axis, the passages being radially aligned in a common focal point. Said radial alignment may be three-dimensional. The passages may be divergent in accordance with respective radii through the focal point.

The passages may be arranged correspondingly obliquely in a substrate, which may be in the form of a rectangular plate.

The invention is now described by way of example with reference to the accompanying diagrammatic drawings. In the drawings Figure 1 shows, schematically, aligning of two optical devices along a common sight line to a target;

Figure 2 shows, in front view, an optical aligner in accordance with the invention;

Figure 3 shows a section taken at Ill-Ill in Figure 2; Figure 4 shows a section taken at IV-IV in Figure 2;

Figures 5, 6 and 7 show a view to the target of Figure 1 respectively on axis, and along sight lines deviating from an axis of the aligner; and

Figure 8 corresponds to Figure 3, but shows a different embodiment.

With reference to Figure 1 of the drawings, reference numeral 10 generally indicates application of the method of the invention in a sniper situation. A target is indicated by reference numeral 12 which is on a sight line generally indicated by reference numeral 14 to an optical device generally indicated by reference numeral 16 and which is in the form of a human eye, more specifically the eye of a sniper.

In accordance with the invention, a second optical device, more specifically in the form of a camera 18, and the eye 16 are to be aligned along a common sight line, for example the sight line 14 when both the eye 1 6 and the camera 18 are aimed at the target 12. Aligning the eye 16 and the camera 18 along a common sight line is effected by means of an optical aligner generally indicated by reference numeral 20 and having an axis, coinciding with the common sight line, and which, in an aligned configuration, coincides with the sight line 14. The optical devices, namely the eye 16, the camera 18 and also the optical aligner 20 are all mounted on a common base 22. In this embodiment, the base 22 may, for example, be a device mounted on a head of the sniper, more specifically it may be in the form of a frame similar to a spectacle frame.

Alignment of the camera 18 along the common sight line is by deflection by means of a beam splitter 24 arranged on the common sightline.

It is to be appreciated that the arrangement is such that the eye 16 and the camera 18 are aligned along a common sight line, which is along an axis of the optical aligner 20. By means of the optical aligner 20, in use, it is ensured that such common sight line coincides with the sight line 14 to the target 12, as will be described hereinafter.

With reference to Figures 2, 3 and 4, the optical aligner 20 is shown and described in more detail. As shown in Figures 2 and 3, a central axis of the aligner 20 is indicated by reference numeral 20.1 . The concept of "central axis" will be described in more detail below.

The aligner 20 has a peripheral rim 20.2 having a pair of attachment formations in the form of stubs 20.3 by means of which it can easily be mounted. Conveniently, the general orientation of the optical aligner 20 is at an angle to the central axis 20.1 , in this embodiment at an axis of 45°, to coincide with the orientation of the beam splitter 24 which is arranged to deflect a portion of light beams transmitted along the common sight line, to the camera 18, and to pass the remaining portion to the eye 16.

The peripheral rim 20.2 surrounds a grid generally indicated by reference numeral 20.4 and which is composed of a plurality of sight passages 20.5 defined by walls or divisions 20.6, and being arranged in a matrix. The sight passages 20.5 are all respectively on radii intersecting at a focal point 21 shown in Figure 4, and which will correspond with the position of the eye 16 and, by deflection, also with the position of the camera 18. The single optically centered sight passage at the position 20.1 is on axis in respect of the common sight line between the eye 16 and the camera 18.

Each of the sight passages 20.5 is divergent in accordance with its radial position relative to the focal point 21 . As can be seen in Figure 4, in this embodiment, the horizontal and vertical cross-dimensions of the sight passages 20.5 subtend angles of about 1 ° whereas the angle subtended by a pitch is about 1 ,45°. The grid 20.4 subtends an angle of preferably more than 15°, in the region of about 20°, but this will depend on the specific application for which the aligner is intended.

With reference to Figures 1 and 5, when the common sight line of the eye 16 and the camera 18 coincides with the sight line 14 to the target 12, a clear view, shown in Figure 5, is seen by both the eye 16 and the camera 18. The observable cross-sectional areas of the sight passages 20.5 are at a maximum. The walls or divisions 20.6 intermediate the respective sight passages 20.5 are seen in the form of thin lines, i.e. the observable projections of the walls or divisions are at a minimum.

With reference to Figure 6, when the eye 16, bearing in mind that the sniper controls the direction of the common line of sight of the eye 16 and the camera 18, deviates from the sight line 14 to the target 12, the view of the target seen by the eye 16 is progressively obscured in accordance with the degree of deviation by the grid divisions 20.6 becoming wider and more intrusive and the cross sectional areas of the sight passages 20.5 being reduced. Furthermore, with reference to Figure 7, when the deviation is in a horizontal plane, obscuring of a target is by means of vertical lines whereas the horizontal lines remain narrow and non-intrusive. Similarly, if the deviation is along a vertical plane, the vertical lines will remain narrow and non-intrusive, whereas the horizontal lines will increasingly become wider, obscuring the target progressively. If the deviation is both horizontal and vertical, both the horizontal and vertical lines will become wider and more intrusive to obscure the target as shown in Figure 6.

It is to be appreciated that the view from the camera 18 remains unobscured, but the centre of the image will shift.

In this fashion, the sniper, via his eye 16, can ensure that the common sight line between the eye 1 6 and the camera 1 8 coincides with the sight line 14 to a target to ensure that the eye 16 and someone monitoring an image derived from the camera 1 8, observe the same target.

The aligner may be manufactured in a material and in accordance with a process appropriate for a particular application, predominantly bearing in mind the number of aligners to be produced.

The Applicant believes that moulding in a synthetic polymeric material will generally be the most suitable general method of manufacture.

If a small number of aligners is to be produced, a process of stereolithography can be used. It would be possible to use injection moulding for mass production.

The invention was described by way of example with reference to a sniper controlled by a controller or commander via an image on a monitor obtained via a video camera. It will be apparent that the invention can have other applications as well. One such other application is where a surgeon operating on a patient is assisted or controlled by another surgeon from a remote location (even a vastly remote location) via a video camera image on a monitor. A similar application may be in disposal or deactivation of exploding devices, and the like.

It is to be appreciated that different applications will have different requirements, e.g. in respect of outer dimensions and shape of the peripheral rim and mounting formations, the size, shape and arrangement of the sight passages, the angular shift between adjacent sight passages, the field of view or angle which is subtended by the aligner, the percentage amount of light required to be passed by the aligner, and the like. Thus, detail features of the aligner may differ, even differ vastly, from one application to another, while still remaining within the scope of the invention.

Thus, for example, and with reference to Figure 8, a variant embodiment of an optical aligner in accordance with the invention is shown in a view corresponding to Figure 3. The optical aligner of Figure 8, indicated by reference numeral 120, is in virtually all respects similar to the optical aligner 20 of Figure 3 and it is not described in detail. Similar reference numerals denote similar components or features. Emphasis is merely placed on one particular aspect, namely that the walls or divisions 1 20.6 forming the sight passages 120.5 are not parallel as in the embodiment of Figure 3, but that faces of the walls are on radial lines radiating from the central point on which the sight passages 120.5 are oriented on axis. Thus, the walls 120.6 are slightly taper in a direction toward the central point. This has the advantage that the upstream projections of the walls as seen by a user are slightly narrower. This may be of importance in applications where the central point is close to the aligner, or if maximizing the amount of light passed by the aligner is crucial, and the like.

It has a secondary advantage in that, when the aligner is produced in the form of a moulding, for example an injection moulding, the taper in the walls facilitates demoulding. It is to be appreciated that the aligner 120 differs in shape and possibly also size from the aligner 20 of Figure 3. It is emphasized that such difference or differences will be dictated by the particular application and are not relevant in respect of the inventive aspects.

With reference to Figure 1 , it is to be noted that the general oblique nature of the aligner 20 is due to the desire to have the aligner 20 generally parallel to the beam splitter 24 to prevent any light from entering the beam splitter from the side and which promotes neatness and compactness and simplifies construction or assembly of the optical device.

It is further to be appreciated that, generally, the average length of the sight passages in an aligner will be in some relation to the width of the sight passages. It is to be appreciated that, for a specific ratio of length of sight passage to width of sight passage, a predetermined angular deviation from an on- axis orientation corresponds to the difference between fully open and fully closed conditions. This characteristic can also be expressed by saying that generally, for short sight passages, the cross dimension would be correspondingly small, and vice versa.

Claims

CLAIMS:

1 . A method of aligning optical devices along a common sight line, including connecting an optical aligner having an axis and a first optical device having a first sight line in fixed orientation such that said axis and said first sight line are optically aligned; arranging a second optical device, having a second sight line, in spatial relationship with the optical aligner and the first optical device and aligning the second sight line along the axis of the aligner, optical alignment of at least one of the first and second sight lines being by deflection or reflection.

2. A method as claimed in Claim 1 which includes affecting optical sight of the second optical device if aiming thereof along the second sight line deviates from the axis of the aligner.

3. A method as claimed in Claim 2 in which a degree in which the optical sight of the second optical device is affected, is progressive with increased deviation from the axis of the aligner.

4. A method as claimed in Claim 2 or Claim 3 in which the optical sight of the second optical device is affected by decreasing translucence.

5. A method as claimed in any one of the preceding Claims in which the aligner includes a plurality of contiguous sight passages, each having an axis.

6. A method as claimed in Claim 5 in which said axes of the plurality of sight passages are radially aligned to a common focal point, said axes forming a composite axis of the aligner, the first and second optical devices being positioned optically at said focal point.

7. A method as claimed in Claim 6 in which optical alignment of said one of the first and the second sight lines by deflection or reflection is by means of a beam splitter operating between an object being observed and respectively the first and second optical devices.

8. A method as claimed in any one of the preceding Claims in which one of the optical devices is in the form of a camera.

9. A method as claimed in Claim 8 in which the camera is a video camera.

10. A method as claimed in Claim 8 or Claim 9 in which the camera is a charge coupled camera.

1 1 . A method as claimed in any one of the preceding Claims in which the other of the first and the second optical device is an eye.

12. A method as claimed in Claim 1 1 in which said eye is a human eye.

13. A method as claimed in Claim 1 2 in which the aligner and the first optical device are mounted on a head of a person of which the eye is the second optical device.

14. An optical aligning apparatus including first and second optical devices having first and second sight lines and an optical aligner having an axis, in which the first optical device and the aligner are connected in fixed orientation such that said first sight line and said axis are aligned; in which the second optical device is arranged in spatial relationship with the optical aligner and the second optical device; in which at least one of the first and the second optical devices has an aiming facility for aiming it along said axis by means of deflection or reflection.

1 5. An apparatus as claimed in Claim 14 in which the aligner is adapted to have maximum translucence along the axis, and reduced translucence along a line deviating from the axis.

16. An apparatus as claimed in Claim 1 5 in which translucence is progressively reduced in accordance with a progressive degree of deviation.

17. An apparatus as claimed in Claim 16 in which the translucence is reduced by means of progressive reduction of a cross-sectional area of a passage through the aligner normal to the direction of said deviating passage of light.

1 8. An apparatus as claimed in any one of Claim 14 to Claim 17 inclusive which includes a beam splitter between a point of observation along the axis of the aligner and respectively the first and second optical devices for splitting beams of light transmitted in use along said axis to the first and second optical devices.

19. An apparatus as claimed in any one of Claim 14 to Claim 18 inclusive in which one of the first and second optical devices is a camera.

20. An apparatus as claimed in Claim 19 in which the camera is a video camera having an output connectable to a monitor.

21 . An apparatus as claimed in Claim 20 in which the video camera is a charged coupled video camera.

22. An apparatus as claimed in any one of Claim 14 to Claim 21 inclusive in which the other of the first and the second optical devices is an eye.

23. An apparatus as claimed in Claim 22 in which said eye is a human eye.

24. An apparatus as claimed in Claim 23 in which the aligner and the first optical device are mountable on a head of a person of which the eye is the second optical device.

25. An optical aligner having an axis and being maximally translucent along an axis thereof, and being of reduced translucence along lines deviating from said axis, the aligner including a plurality of contiguous, straight through passages having walls, cross-sectional areas of the passages being at a maximum when optically observed on axis, and being reduced when optically observed at an angle deviating from the axis.

26. An optical aligner having an optical axis and including a plurality of contiguous, straight through passages, each having an axis and being defined by surrounding walls, at least one of the through passages being co-axial with the optical axis of the optical aligner, projections of the walls being at a minimum when observed along said optical axis of the aligner, and increasing when observed at an angle deviating from said optical axis.

27. An optical aligner as claimed in Claim 25 or Claim 26 in which said axis is a composite axis, the passages being radially aligned in a common focal point.

28. An optical aligner as claimed in Claim 27 in which radial alignment is three-dimensional.

29. An optical aligner as claimed in Claim 28 in which the passages are divergent in accordance with respective radii through the focal point.

30. An optical aligner as claimed in Claim 27, Claim 28 or Claim 28 in which the passages are arranged correspondingly obliquely in a substrate, which is in the form of a generally rectangular plate.