1981-01-23
1984-05-08
Lieberman, Eli
350 9618, C02B 726
Patent
active
044471149
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention relates to a rotary optical coupler between a first array of optical conductors and a second identical array of optical conductors, which optical coupler comprises an optical body for a mirror-symmetric transfer of radiation between the two arrays of optical conductors, said optical body being further capable of rotating about the rotation axis of the optical coupler at the same angular velocity but in opposite direction with respect to the two arrays of optical conductors. An optical conductor is here understood to be in particular an optical fibre guide.
The rotary optical coupler is utilised for the transfer of digital data between mutually rotatable units, and is known from the U.S. Pat. No. 4,027,945. In this patent the optical body consists of a prism, preferably a Dove prism or a Pechan prism. The application of a Dove prism has however the disadvantage that, due to the reflection of the light at each of the two end faces, the path of the individual light rays is frequency-dependent. Consequently, in view of the fixed arrays of the optical conductors, the light intensity of the radiation transferred is frequency-dependent. The application of a Pechan prism on the other hand has the disadvantage that, due to a five-fold reflection of the incident light and the associated long path length, the intensity of the light transferred is reduced. Also, because of the large ratio between the optical path length within the prism and the width of the prism, the optical conductors have to be aligned very accurately, or the permitted number of optical conductors will be limited. Further, in both cases it is desirable to dispose the end members of the individual optical conductors at some distance from each other to avoid crosstalk between the various conductors. Other types of prisms have similar disadvantages.
SUMMARY OF THE INVENTION
It is an object of the invention to obviate the above disadvantages.
According to the invention, the optical body of a rotary optical coupler of the type set forth in the opening paragraph provides for a refractionless passage of the supplied radiation by means of a single collective image transformation. In this way the disadvantages due to the frequency-dependent refraction and multiple reflections is obviated.
BRIEF DESCRIPTION OF THE DRAWING
The present invention will now be described with reference to five embodiments of a rotary optical coupler schematically illustrated in the accompanying figures, in which:
FIG. 1 is a first embodiment of a rotary optical coupler;
FIG. 2 is a second embodiment of a rotary optical coupler;
FIG. 3 is a third embodiment of a rotary optical coupler;
FIG. 4 is a fourth embodiment of a rotary optical coupler;
FIGS. 5A and 5B are a part of the fourth embodiment of a rotary optical coupler;
FIGS. 6A and 6B are a fifth embodiment of a rotary optical coupler;
FIG. 7 is a part of the fifth embodiment of a rotary optical coupler;
FIG. 8 is a cross section of a bundle of optical conductors; and
FIG. 9 is an explanatory view.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the embodiments described below an optical fibre guide is used as conductor. Moreover, the more appropriate term "optical slip rings" will be used as much as possible, instead of "rotary optical coupler". Instead of fibre optical conductors, opto-electric conductors, known from the cited U.S. patent, can be applied.
FIG. 1 is a first embodiment of optical slip rings for two arrays of optical conductors 1A-1N and 2A-2N, where the optical conductors of one array are rotatable as one whole about an axis 3 with respect to the other array of optical conductors. The optical slip rings also comprise an optical body 4 for transmitting light from an optical conductor 1i of the first array, where i=A, . . . , N, to a correspondingly indexed optical conductor 2i of the second array. In this embodiment the optical body 4 is a spherical transparent body consisting of two hemispheres, separated by a thin circular reflector 5 having two light-reflecting
REFERENCES:
patent: 4258976 (1981-03-01), Scott et al.
Hollandse Signaalapparaten B.V.
Kraus Robert J.
Lieberman Eli
LandOfFree
Optical slip rings does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Optical slip rings, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical slip rings will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1599259