Fiberoptic rotary joint

Claim 2

A rotary joint for maintaining optical coupling between corresponding fibers in first and second sets of fiberoptic fibers, which sets are physically rotatable with respect to each other, characterised in that the rotary joint comprises first and second sets of collimating lenses (1, 3, 5; 1', 3', 5') for coupling the rotary joint to each of the fibers in said first and second sets, respectively, the collimating lenses being disposed to establish and receive individual parallel beams of light corresponding to optical data being transmitted through the fibers, in that the rotary joint further contains optical de-rotating means (51, 53) inserted in the light paths between the two sets of lenses for maintaining optical contact between the sets of lenses despite rotation of either set of lenses relative to the other set, the de-rotating means (51, 53) being rotatable about the same axis of rotation as the two sets of lenses and including optical means (51) for laterally displacing each light beam as a function of the relative rotation between the sets of lenses, and in that the rotary joint further contains means (59, 65) to rotate the de-rotating means through an angle which is a specified portion of the relative angular displacement between the two sets of lenses, the specified portion being selected to maintain optical contact between the displaced light beams and the respective lenses receiving the optical information being transmitted.

Claim 3

A rotary joint for use in a fiberoptic data transfer system wherein data is to be transferred between a first set of stationary fibers and a second set of fibers rotatable about a common axis, characterised in that the rotary joint comprises first and second sets of collimating lense (1, 3, 5; 1',3', 5') mounted in stationary (31) and rotatable (37) pattern plates, respectively, each of the lenses in the first and second sets being adapted to be coupled to different ones of the fibers in the first and second sets, respectively, the lenses in each pattern plate being disposed to transmit to, and receive from, the lenses in the other pattern plate parallel light beams positioned in a predetermined pattern about said common axis, in that the rotary joint further includes optical de-rotating means (51, 53) inserted in the paths of the light beams for maintaining optical contact between the sets of lenses despite rotation of the rotatable pattern plate (37), the de-rotating means (51, 53) being rotatable about said common axis and containing optical means (51) for laterally displacing each light beam as a function of the angular displacement of the de-rotating means, and in that the rotary joint further includes means (59, 65) to change the angular displacement of the de-rotating means (51, 53) in response to changes in the angular displacement of the rotatable pattern plate (37), the angular displacement changing means being adjusted to rotate the optical means (51) so as to maintain optical coupling between the two sets of lenses when the angular displacement of the rotatable pattern plate is changed.

Claim 4

A rotary joint for use in a fiberoptic data transfer system wherein data is to be transferred between a first set of stationary fibers and a second set of fibers rotatable about a common axis, characterised in that the rotary joint comprises first and second sets of collimating lense (1, 3, 5; 1',3', 5') mounted in stationary (31) and rotatable (37) pattern plates, respectively, each of the lenses in the first and second sets being adapted to be coupled to different ones of the fibers in the first and second sets, respectively, the lenses in each pattern plate being disposed to transmit to, and receive from, the lenses in the other pattern plate parallel light beams positioned in a predetermined pattern about said common axis, in that the rotary joint further includes optical de-rotating means (51, 53) inserted in the paths of the light beams for maintaining optical contact between the sets of lenses despite rotation of the rotatable pattern plate (37), the de-rotating means (51, 53) being rotatable about said common axis and containing optical means (51) for laterally displacing each light beam as a function of the angular displacement of the de-rotating means, and in that the rotary joint further includes means (59, 65) to change the angular displacement of the de-rotating means (51, 53) in response to changes in the angular displacement of the rotatable pattern plate (37), the angular displacement changing means being adjusted to rotate the optical means (51) so as to maintain optical coupling between the two sets of lenses when the angular displacement of the rotatable pattern plate is changed.

Claim 5

A rotary joint according to claim 1 or 2, characterised in that the means to change the angular displacement of the de-rotating means includes a gear train (47, 49, 63, 65) actuated in response to rotation of the rotatable pattern plate (37).

Claim 6

A rotary joint according to any of the preceding claims, characterised in that the optical means in the de-rotator is an optical prism (51).

Claim 7

A rotary joint according to claim 4, characterised in that the prism (51) is a Delta prism having a rectangular base (21), triangular end faces, and first and second sloping sides (25, 27) the prism being mounted so that it is rotatable about the common axis and so that this axis passes through the central portions of each sloping side (25, 27) and lies in a first plane parallel to the prism base (21) and in a second plane parallel to the end faces.

Claim 8

A rotary joint according to any of the preceding claims, characterised in that the rotary joint is mounted in a stationary housing supporting the stationary pattern plate (31), and in that the prism (51) is mounted on a rotatable plate (53) disposed in a plane normal to the collimated light beams and having an open central portion in which the prism is mounted so that the collimated light beams may pass unobstructed through the prism.

Claim 9

A rotary joint according to claim 6, characterised in that the rotatable pattern plate (37) is rotatably mounted in the housing in a plane normal to said common axis and on the opposite side of the prism from the stationary pattern plate (31).

Claim 10

A rotary joint according to claim 7, when appended to claim 3, characterised in that the gear train includes first and second ring gears (65, 47) integrally attached to the stationary pattern plate (31) and the rotatable pattern plates (37), respectively, each of the ring gears being disposed in planes parallel to the pattern plates and positioned concentrically around said common axis so that the collimated light beams may pass through the area of the gears without obstruction.

Claim 11

A rotary joint according to claim 8, characterised in that the gear train further includes first and second planetary gears (63, 49) integrally mounted on a common shaft (49) and positioned to engage the first and second ring gears (65, 47), respectively, the shaft (49) being rotatably mounted in a bearing (61) eccentrically positioned in the rotatable plate (53) supporting the prism (51), whereby rotation of the rotatable pattern plate (37) serves to rotate the prism (51) through an angle of one-half the magnitude of the angle of displacement of the rotatable pattern plate (37).

Claim 12

A rotary joint according to any of the preceding claims, characterised in that it further includes eccentric adjusting means for adjusting the lateral position of a set of collimating lenses (1, 3, 5; 1', 3', 5') so as to permit optimum coupling between the two sets of lenses.