GB2177517A - An optical slip ring - Google Patents

An optical slip ring Download PDF

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Publication number
GB2177517A
GB2177517A GB08516704A GB8516704A GB2177517A GB 2177517 A GB2177517 A GB 2177517A GB 08516704 A GB08516704 A GB 08516704A GB 8516704 A GB8516704 A GB 8516704A GB 2177517 A GB2177517 A GB 2177517A
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GB
United Kingdom
Prior art keywords
port
light
slip ring
optical slip
guide element
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB08516704A
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GB8516704D0 (en
GB2177517B (en
Inventor
Graham Michael Freakes
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
IDM ELECTRONICS Ltd
I D M ELECTRONICS Ltd
Original Assignee
IDM ELECTRONICS LTD
I D M ELECTRONICS Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Application filed by IDM ELECTRONICS LTD, I D M ELECTRONICS Ltd filed Critical IDM ELECTRONICS LTD
Priority to GB8516704A priority Critical patent/GB2177517B/en
Publication of GB8516704D0 publication Critical patent/GB8516704D0/en
Publication of GB2177517A publication Critical patent/GB2177517A/en
Application granted granted Critical
Publication of GB2177517B publication Critical patent/GB2177517B/en
Application status is Expired legal-status Critical

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Classifications

    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS, OR APPARATUS
    • G02B6/00Light guides
    • G02B6/24Coupling light guides
    • G02B6/42Coupling light guides with opto-electronic elements
    • G02B6/4201Packages, e.g. shape, construction, internal or external details
    • G02B6/4202Packages, e.g. shape, construction, internal or external details for coupling an active element with fibres without intermediate optical elements, e.g. fibres with plane ends, fibres with shaped ends, bundles
    • G02B6/4203Optical features
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS, OR APPARATUS
    • G02B6/00Light guides
    • G02B6/24Coupling light guides
    • G02B6/26Optical coupling means
    • G02B6/32Optical coupling means having lens focusing means positioned between opposed fibre ends
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS, OR APPARATUS
    • G02B6/00Light guides
    • G02B6/24Coupling light guides
    • G02B6/36Mechanical coupling means
    • G02B6/3604Rotary joints allowing relative rotational movement between opposing fibre or fibre bundle ends

Abstract

An optical slip ring comprises an inner member having an axis x and being located coaxially with an outer member and arranged for relative rotational movement about the coaxial axis. The inner member includes at least one light port c' directed outwardly from said axis and the outer member includes at least one light port A, B, C, D directed axially. At least one optical guide element 40 is interposed between the inner and outer members. Each element 40 has a light receiving surface R subtending an arc about the axis x greater than the arc subtended by a light emitting port. Light emitted from the port c' is refracted by the shape of the guide members 40 in a manner to converge towards the output end thereof aligned opposite a respective output port A, B, C, D. <IMAGE>

Description

SPECIFICATION An optical slip ring This invention relates to optical slip rings.

Figure 1 illustrates an optical slip ring known from the applicants U.K.patent 2098350B. The optical slip ring comprises a rotatable output member 1 and a second rotatable member 2 located intermediate of the member 1 and a stationary input member3. Both the input and output members have a corresponding numberof spaced light ports A', B' C' D' and A, B, C, D respectively and the intermediate member2 has a plurality of bundles of optical fibres fortransmitting light between the ports of the input and output member. As can be seen from the drawing, light from a light emitting port C' passes through three optical fibres to form a diverging output of light, some ofwhich enters a light receiving port C ofthe member 1.

Although this priorartslip ring is adequateformany purposes, itwill be apparentfrom Figure 1 thatthe coupling of lightfrom port C' to port C involves considerable losses. Referring to Figure 2, the diameterofthe cone of light emitted from port C' is equal to D min and each optical fibre has a core diameter d core and atotal diameter d clad. From this Figure it can be seen that the coupling between port C' and the three fibres shown in Figure 1 is given by the expression: Efficiency = 3 d2 core (2d clad + d core)2 Consequently if d core equals 100 micrometers and d clad equals 140 micrometers then the coupling efficiency is ofthe order of 20 percent.Those skilled in the art will appreciate thatthere are further coupling losses between the three fibres illustrated and the port C. As a result, the coupling efficiency between the port C' and the port C can be reduced to the order of less than 1 percent. Thus it can be seen that there is a problem with such optical slip rings regarding the coupling efficiency between the input and output ports.

Furthermore, in order to avoid signal level fluctuation fibres are threaded so that as members 2 and 3 rotate, the next fibres a I ig n i n g with port C' still provide a commu nication channel to port C. It can therefore be seen thatthe construction of member2 involves delicate interwearing of fibreswhich is difficult and timeconsum- ing particularly in small scale structures where the distance from port C' to C is approximately 2 cms. Those skilled in the art will also appreciate that such a structure is delicate and easily susceptible to damage.

Consequently, it is an object of the present invention to increase the efficiency of an optical slip ring by decreasing the losses in coupling and to simplify the construction oftheslip ring and enhance the ruggedness thereof.

According to the invention there is provided an optical slip ring comprising:- an inner membercoaxially located with an outer member and arranged for relative rotational movement about the coaxial axis, the inner member including at least one light port directed outwardly from said axis and the outer member including at least one light port directed axially, at least one light guide line element interposed between the inner and outer memberfor providing a light communication channel between a port of the inner member and a port ofthe outer member, and wherein the or each guide element has a light receiving end defining a light receiving surface substending as are about said axis greater than the are subtended by a light emitting port, a light emitting end stationary relative to the member receiving lighttherefrom, and means interposed Between said ends adapted to deflect light entering the elementthrough the receiving surface in a mannerto provide a substantially convergent emission output of light atthe emitting end of lightfor illiuminating a light receiving port.

By including a light guide element as described herein above a greater amount of lightfrom a light emitting port is converged to ultimately illuminate an output port, thus enhancing the efficiency ofthecoupling between input and output ports. In addition, the number of components is reduced compared with hitherto known slip rings so that construction thereof is simplified.

In one embodiment of the optical slip ring, the or each guide element comprises an annular segment having the light receiving surface subtending an are about said axis greaterthan the arc subtended buy a light emitting port, and the means interposed between said ends comprises a convex lens.

This form ofguide element is particularly simple and alignment problems are reduced compared with hitherto known optical slip rings. Furthermore, the annular segment provides mechanical ruggedness and reduces the number of components requiredforthe slip ring.

In an alternative embodiment ofthe optical slip ring the or each guide element, comprises a block of transparent refractive material having the light emitting end and an annular surface to define said light receiving surface, the block being formed to provide at least one reflecting surface arranged so that light entering through the receiving surface and impinging on the or each reflecting surface is deflected to the emitting end to provide the convergent emission output By employing reflecting surfaces the guide element is considerably simplified and alignment problems are reduced compared with hitherto known optical slip rings. In addition, by providing a block of transparent material the mechanical ruggedness of the optical slip ring.is increased.In addition, since the guide element now comprises a single component, assembly of the optical guide means is considerably simplified. Since the coupling efficiency have been improved, it is possible to relax optical alignmenttolerances.

Preferably at least one ofthe reflecting surfaces is externally mirrored to enhance reflection, although conveniently the block is angled so that deflection from the or each reflecting surface is by way of internal reflection so that a mirroring step is not required.

Aparticularly convenient form ofthe guide element has the blockformed in a generally arrowhead shape whereby the emission output is emitted from the point and the surface remote from the point forms said light receiving surface and the arrow head body is formed to provide the at least one reflecting surface.

In another embodiment of the invention, a transparent material cylinder is interposed between the light receiving surface and the light emitting port and a selffocusing lens is interposed between the point and the member receiving light. As a result light emitted from the light emitting port is allowed to expand naturally through a cylinder of transparent material before passing into the arrowhead shape block of transparent material which because of the self-focusing lens can be considerablythickerthan the diameter of the emitting port. The cylinder may have either uniform or graded refractive index. In this way, dirt problems associated with the optical slip ring have less effect. Awaveguide can also be inserted between the self focusing lens and the light receiving port to further enhance the coupling oflightto the receiving port.Conveniently the self focusing lens and waveguide can be replaced by a tapered clad rod oftransparent refractive material so that the number of components in the optical slip ring is reduced.

Furthermore, the inner member can include four light emitting ports spaced uniformly about the inner member, and the outer member can include one light receiving port and a single guide element.

In this way, good signal continuity and coupling efficiency can be achieved. As an alternative the outer member can include four light emitting ports and a guide element is provided for each outer element port, and a single port is provided on the inner member.

Examples ofthe present invention will now be described with reference to the accompanying drawings, in which Figure 1 illustrates a priorartform of an optical slip ring.

Figure2illustratesthecoupling between the input portandthe intermediate member of Figure 1.

Figure3aillustrates a plan view ofthe guide element in one embodimentofthe invention, Figure 3b illustrates a side view of the guide element shown in Figure 3a.

Figure 4a illustrates a plan view of the guide element in a further embodiment of the slip ring according to the invention.

Figure 4b illustrates a side view ofthe guide element shown in Figure 4a.

Figure 5a illustrates a plan view ofthe guide element of another embodiment of the invention.

Figure 5b illustrates a side view ofthe guide element shown in Figure 5a.

Figure 6illustrates an optical slip using embodying the invention.

Figures 7to 9illustrates further optical slip rings embodying the present invention.

Figure 10 illustrates a convenientform of arranging the light emitting port relative to the guide element.

Figures3to 5illustrate a single light emitting port C' and a single light receiving portCcorresponding to the ports shown in Figures 1. The remaining structure ofthe optical slip ring shown in Figure 1 has been omitted from Figures 3 to 5 forthe purposes of clarity. Common components in the Figures are identified by common numerals.

Referring to Figure 3a and Figure 3b, a guide element comprises the combination of a wave guide 30 adjacentto a lens 31. In Figure 3a, light is emitted from the port C',for example, an optical fibre, and transmitted via the guide element to a receiving port C, for example, a further optical fibre. The surface ofthe wave guide 30 facing the optical fibre C' has an arcuate surface corresponding to a portion of a radius aboutthe axis X ofthe optical slip ring. The wave guide comprises, for example a single piece of glass. It acts as an angular disperser and a vertical wave guide. The light emitted from the wave guide 30 is refracted by the lens 31 in a mannerto converge towards the optical fibre C as shown in the Figure.As a result, by suitable choice of wave guide and lens, a large proportion of light emitted from port C' can enter port C Furthermore, iffor example, the optical fibre C' rotates relative to the optical fibre C, the wave guide and lens combination maintain communication between the optical fibres C' and the fibre C over an angle of rotation of 90 degrees in the example shown. Accordingly, not only is coupling between thefibres C' and C increased but the coupling can extend overa large angleofrotationwithoutthe complexity compared with the priorartfibre opticguide element. It will be seen that signal level fluctuation is reduced since coupling between the two fibres C' and C occurs over an arc of rotation of 90 degrees.It will be noted that the inner su rface R of the wave guide 30 subtends an arcaboutthe axis of rotation which is largerthan the arc subtended by the output port ofthe optical fibre C'.

The coupling efficiency between the two fibres has been increased because the light is now emitted directly into a continuous aperture, the edge of the glass piece, rather than into a number of discrete apertures such as the optical fibres as shown in Figure 1.

At the same time the lens produces a converging emission cone suitable for direction into a light receiving port.

Figure 4 illustrates an improved embodiment of the invention wherein the wave guide and lens combination of Figure 3 has been reduced to a single arrowhead shaped piece of transparent material 40 as shown, for example glass. By having a single piece guide element it is unnecessary to maintain strict alignment tolerances as with the combination shown in Figure 3. In addition, the arrowhead shaped wave guide40 shown in Figure 4 is considerably more rugged than the combination shown in Figure 3. Accordingly, it is possible to reducethe optical tolerances and indeed, it is possibleto attach the outputfibre C by adhesiveto the element 40. Consequently increased efficiency, signal continuity and reduced fluctuation and a consider ablysimplerrugged mechanical design are achieved.

It would be desirable to relax optical alignmenttolerances still further, for example by reducing the required environmental cleanliness. Both Figures 3 and 4are suseptableto an optically opaque particle greaterthan 100 micrometers diameter, for example dust between fibre C' and the guide element.

Figure 5 offers a simple solution to this problem by using expanded beams. The light from the fibre C' is allowed to expand naturally through a cylinder 51 oftransparent material,forexample, plain glass, into the wave guide 40. Consequently whereas the guide element in Figure 4 only had a thickness approximately the port diameter this arrowhead shaped wave guide now has a 2mm thickness so that sensitivity to dust is reduced. In order to reduce the beam size at the point ofthe element 40 back to the 100 micrometer sizefor entry into the optical fibre C, a graded index rod lens 52 is used as shown in the Figure to reduce the beam size for illuminating the optical fibre C.

Figure 6 illustrates an optical slip ring embodying the present invention. The inputfibre C' is arranged to rotate aboutthe axis Xto define a radius S. Four ofthe arrowhead shaped optical guide elements 40 are arranged symetrically about the surface S, each element 40 having a surface R subtending an arc of slightly less than 90 degrees with respect to the axis X. Optical fibre outputs A, B, C and Dare arranged at the points of the four elements 40. It will be appreciated that as an alternative to the optical fibre C' rotating, itwould be possible to rotate the optical fibres A to D and their respective elements 40 whilst maintaining the optical fibre C' stationary. Accordingly, an output signal from optical fibre C' is communicated to outputfibresAto D overa range of rotation substantially equal to 360 degrees.Thus, ifthe outputs from optical fibres Ato Dare connected the signal level fluctuation ofthe optical slip ring in Figure 6 is very low.

Figure 7 illustrates a further arrow head shaped waveguide 40wherein the inner member3 rotates to bring optical fibres A' to D' into line with the output optical fibre C. As can be seen from the Figure, the light receiving surface subtends an angle of 180 degrees relative to the axis X ofthe member 3. In this particularcase,the guide member 40 is shaped such that light emitted on to the portion 70 of the light receiving surface is reflected ofthe surface 71 in a mannerto directthe lightthrough the element and into the optical fibre C. The surface 70 subtends an angle of 45 degrees relative to the axis X. The next surface 72 is preferably masked in a mannerto prevent the light directed thereon entering the optical fibre C. The surface 72 subtends an angle of 90 degrees relative the axis X.A further surface 73, which subtends an angle 45 degrees relative to the axis X, is arranged such that light entering the member40therethrough impinges on surface 74 in a mannerto reflecttherefrom and be directed into the optical fibre C. It can therefore be seen that as the member3 rotates one optical fibre is normally emitting light onto one ofthe surfaces 70 or 73. Consequently, signal continuity between the member 3andthe optical fibre C is maintained almostwithout break. Furthermore, because ofthe shape of guide member 40, that isto saythe angle ofthe surfaces 71 and 74, light emitted from the member3 is efficiently coupledtotheoutputfibre C.

The surfaces 71 and 74 can be silvered to produce a mirrorfinish to enhance coupling to the optical fibre C.

Alternatively, it is possible to anglethe surfaces 71 and74such that light emitted from the member3and entering the guide element is internally reflected towards the output fibre C. The surface 72 is preferably masked to avoid signal fluctuation in the outputfibre C since in certain circumstances light emitted from the member3 will comprise the light intensity from two optical fibres fluctuating down to light emitted from one optical fibre. It will be apparentthatthe choice of masking surface 72 is dependent upon the particular application ofthe optical slip ring.

Although the optical slip ring illustrated in Figure 7 is very useful, the guide member 40 can assume a disproportionate size since there can be a factor of the order of 12 between the length ofthe guide member 40 and the radius ofthe member 3. Consequently, in situations where the radius ofthe member3 is already quite large, the size ofthe guide member and length thereof can assume unrealistic proportions. Figure 8 illustrates a guide member40wherebythe effective length thereofcan be reduced.The guide member illustrated hasa light receiving surface 81 which subtends an angle of45 degrees relative to the axisX ofthe member3.Two surfaces 82 and 83 of the guide member40 comprise off axis parabolic surfaces so that light enteringthrough the surface 81 is firstly reflected from the surface 82 onto the surface 83 and therefrom directed towards the output optical fibre C. The advantage ofthis shape is that the output point of the guide member is effectively rotated relative to the light receiving surface thereby reducing the overall length ofthe guide member 40. Once again, the surfaces 82 and 83 can comprise a mirrored surfaces or be so angled that light entering surface 81 is internally reflected from the surfaces 82 and 83.Although the output end of the guide member 40 is shown as a point,forconvenience of manufacture, it may be preferableto have the guide member40 in theform of a block which extendstothe dotted line 84. It will be apparentthatwiththe guide member 40 shown in Figure 8, a further guide member40' would be required to maintain a full continuity between the light emitting fibres A' to D' and output fibre C.

Figure9 illustrates an alternative guide member40 wherein the light receiving surface 91 subtends an angle of 90 degrees relative to the axis X.

Consequently, the reflecting surfaces 92 and 93 have a different shape to those shown in Figure 8. Although both the embodiments in Figure 8 and 9 have two reflecting surfaces, it would be possible to construct a guide member having more than two reflecting surfaces.

Figure 10 illustrates a convenientway of arranging the light emitting fibres on the member 3 forapplications where the radius of the member 3 is particularly small. The optical fibres A' to D' are mounted parallel with the axis Xand a prism 101 is mounted in frontofthe guide element 40 so that light emitted from the optical fibreC' and focussed by a self focussing lens 102 is rotated 90 degrees by prism 101 to enterthe light receiving surface ofthe guide element 40. Figure 10 also shows a convenientway of reducing the beam width from the guide element40 and at the same time focusing the beam ontothe optical fibre C. This is achieved by placing a tapered clad rod of transparent material, for example glass in between the output end of the element 40 and the output fibre C.Such a construction is simpler than employing a selffocussing lens and a block ofglass.

It will be apparent to those skilled in the art that although the present description describes optical guide elementsforcommunicating lightfrom the inner member ports to the outer member ports, guide elements could be constructed for the reverse situation. In addition, although Figure 6 illustrates the use of four output fibres and only one inputfibre, other combinations could be employed, for example greaterthan fouroutput fibres could be employed.

The number of output fibres is determined by the effective angular field of view of the guide elements which in Figures 3 to 5 is shown as 90 degrees. If the number of input fibres is increased, it is necessary to incorporate an optical power splitter to the input which reduces the power available at the output.

Claims (21)

1. An optical slip ring comprising; an inner member coaxially located with an outer member and arranged for relative rotational movement aboutthe coaxial axis, the inner member including at least one light port directed outwardly from said axis and the outer member including at least one light port directed axially; at least one light guide element interposed between the inner and outer memberfor providing a light communication channel between a port ofthe inner member and a port ofthe outer member;; and wherein the or each guide element has a light receiving end defining a light receiving surface subtend- ing an arc about said axis greaterthan the arc subtended by a light emitting port, a light emitting end stationary relative to the member receiving lighttherefrom,and means interposed between said ends adapted to deflect light entering the element through the receiving surface in a mannerto provide a substantially convergent emission outputoflightatthe emitting end for illuminating a light receiving port.
2. An optical slip ring as claimed in claim 1 wherein the or each guide element comprises an annular segment having the light receiving surface subtending an arc about said axis greaterthan the arc subtended by a light emitting port, and the means interposed between said ends comprises a convex lens.
3. An optical slip ring as claimed in Claim 1 wherein the or each guide element comprises a blockof transparent refractive material having the light emitting end and an annular surface to define said light receiving surface, the block being formed to provide at least one reflecting surface arranged so that light entering through the receiving surface and inpinging on the or each reflecting surface is deflected to the emitting end to provide the convergent emission output.
4. An optical slip ring as claimed in claim 3 wherein at least one of the reflecting surfaces is externally mirrored.
5. An optical slip ring as claimed in claim 3 wherein the block is shaped so that deflection from the or each reflecting surface is by means of internal reflection.
6. An optical slip ring as claimed in any one of claims3 to 5 wherein the light receiving surface is masked two limit light entering the block to that light for impinging on the or each reflecting surface.
7. An optical slip ring as claimed in any one ofclaims3to 6wherein said block is formed in a generally arrowhead shape whereby the emission output is emitted from the point and the surface remote from the point forms said light receiving surface and the arrow head body is formed to provide the at least one reflecting surface.
8. An optical slip ring as claimed in anyoneofclaims3to 7wherein the light receiving surface is spaced from the light emitting port.
9. An optical slip ring as claimed in claim 8wherein the guide element includes atransparentmaterial cylinder interposed between the light receiving surface and the light emitting port.
10. An optical slip ring as claimed in claim 9 wherein the guide element includes a self focusing lens interposed between the emitting end and a light receiving port.
11. An optical slip ring as claimed in Claim l0whereinthe guide element including a lightwaveguide interposed between the self focusing lens and the light receiving port.
12. An optical slip ring as claimed in Claim 9 wherein the guide element includes a tapered clad rod of transparent refractive material interposed between the emitting end and a light receiving port.
13. An optical slip ring as claimed in any preceding claim wherein the outer member and the or each guide element rotate about a stationary inner member.
14. An optical slip ring as claimed in claim 7 whereinthe inner memberincludesfour light emitting ports spaced uniformaly aboutthe inner member, and the outer member includes one light receiving port and a single guide element.
15. An optical slip ring as claimed in any one of claims 1 to 12whereinthe inner member rotates andthe outer member and the or each guide element isstationary.
16. An optical slip ring as claimed in claim 15wherein the outer member includes four ports and a guide element is provided for each outer element port, and a single port is provided on the inner member.
17. An optical slip ring as claimed in any preceding claim wherein the arc subtended by the Iightreceiving surface is less than or equal to 90 degrees.
18. An optical slip as claimed in any preceding claim wherein the guide element includes a lens interposed between the light emitting port and the light receiving surface.
19. An optical waveguide as claimed in any preceding claim wherein a prism is provided immediately in front of the light emitting port whereby lighttherefrom is rotated substantially 90 degrees.
20. A guide element suitable for use in an optical slip ring according to any preceding claim.
21. An optical slip ring substantially as herein described with reference to Figures 3 to 10 of the accompanying drawings.
GB8516704A 1985-07-02 1985-07-02 An optical slip ring Expired GB2177517B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB8516704A GB2177517B (en) 1985-07-02 1985-07-02 An optical slip ring

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB8516704A GB2177517B (en) 1985-07-02 1985-07-02 An optical slip ring

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Publication Number Publication Date
GB8516704D0 GB8516704D0 (en) 1985-08-07
GB2177517A true GB2177517A (en) 1987-01-21
GB2177517B GB2177517B (en) 1989-07-19

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4749249A (en) * 1986-02-19 1988-06-07 United Technologies Corporation Fiber-optic rotary coupler with lossy microbends
EP1671168A2 (en) * 2003-09-26 2006-06-21 Moog Inc. Fiber optic rotary joint and associated reflector assembly
FR2970343A1 (en) * 2011-01-06 2012-07-13 Philippe Rhul Watch receiving device for obtaining endoscopic image of watch to e.g. show internal characteristics to customers in sales place, has mobile optical unit for contactless optical communication between watch and processing and control unit

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1275145A (en) * 1968-08-29 1972-05-24 Optische Ind De Oude Delft Nv Device for compensating cylindrical distortion in panoramic aerial recordings
GB1422891A (en) * 1973-05-31 1976-01-28 American Optical Corp Fibre otpic field flatteners
US4027945A (en) * 1976-03-04 1977-06-07 The United States Of America As Represented By The Secretary Of The Navy Optical sliprings
US4099833A (en) * 1974-03-08 1978-07-11 Galileo Electro-Optics Corp. Non-uniform fiber optic imaging system
EP0035054A1 (en) * 1980-02-28 1981-09-09 AEG - TELEFUNKEN Nachrichtentechnik GmbH Rotary joint for optical wave guide
GB2091899A (en) * 1980-12-16 1982-08-04 Kokusai Denshin Denwa Co Ltd Rotary joints for optical fibres

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1275145A (en) * 1968-08-29 1972-05-24 Optische Ind De Oude Delft Nv Device for compensating cylindrical distortion in panoramic aerial recordings
GB1422891A (en) * 1973-05-31 1976-01-28 American Optical Corp Fibre otpic field flatteners
US4099833A (en) * 1974-03-08 1978-07-11 Galileo Electro-Optics Corp. Non-uniform fiber optic imaging system
US4027945A (en) * 1976-03-04 1977-06-07 The United States Of America As Represented By The Secretary Of The Navy Optical sliprings
EP0035054A1 (en) * 1980-02-28 1981-09-09 AEG - TELEFUNKEN Nachrichtentechnik GmbH Rotary joint for optical wave guide
GB2091899A (en) * 1980-12-16 1982-08-04 Kokusai Denshin Denwa Co Ltd Rotary joints for optical fibres

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4749249A (en) * 1986-02-19 1988-06-07 United Technologies Corporation Fiber-optic rotary coupler with lossy microbends
EP1671168A2 (en) * 2003-09-26 2006-06-21 Moog Inc. Fiber optic rotary joint and associated reflector assembly
EP1671168A4 (en) * 2003-09-26 2007-07-04 Moog Inc Fiber optic rotary joint and associated reflector assembly
FR2970343A1 (en) * 2011-01-06 2012-07-13 Philippe Rhul Watch receiving device for obtaining endoscopic image of watch to e.g. show internal characteristics to customers in sales place, has mobile optical unit for contactless optical communication between watch and processing and control unit

Also Published As

Publication number Publication date
GB8516704D0 (en) 1985-08-07
GB2177517B (en) 1989-07-19

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