Bidirectional off-axis fiber optic rotary connector with involute-type steering device

Abstract

The present invention discloses a bidirectional off-axis optical fiber rotary connector containing an involute-type steering device, and the rotary connector is mainly composed of an outer sleeve, an involute-type prism, a coupling lens group and a hollow annular base. At one end of the outer sleeve, a signal light beam enters the interior of the rotary connector at a certain angle, and is transmitted in a reflection manner inside the rotary connector. After a certain number of reflections, the signal light beam is emitted from the exit window on the hollow annular base. The exit light beam is deflected and converged by the involute-type prism, and then coupled to the optical fiber collimator through the coupling lens group to complete forward transmission. At the other end of the outer sleeve, the signal light beam is coupled into another optical fiber collimator after passing through another group of the same structure, completing reverse transmission and finally realizing bidirectional transmission. Compared with the prior art, the bidirectional off-axis optical fiber rotary connector disclosed by the present invention can realize off-axis and bidirectional transmission of optical signals, and effectively solves the problem of bidirectional transmission of rotating optical signals when the central channel is occupied.

Description

Technical Field

[0001] The invention relates to the field of optical fiber rotary connectors, in particular to a bidirectional off-axis optical fiber rotary connector. Background Art

[0002] Fiber optic rotary connector is an optical communication device that uses optical fiber as a medium and optical signal as a carrier to transmit optical signals between two relatively rotating parts. Fiber optic rotary connectors are widely used, such as periscopes on military armored vehicles, medical CT scanners, industrial robots, photoelectric theodolites, deep-water acoustic towing systems, deep-sea optical fiber exploration systems, etc.

[0003] Fiber optic rotary connectors are divided into coaxial and off-axis types. The optical axis and rotation axis of coaxial fiber optic rotary connectors coincide. The optical path structure of this device is simple and easy to manufacture, so it is widely used. However, when the central axis position of the rotary connector is occupied by other media or devices, the coaxial fiber optic rotary connector is no longer applicable. In this application, the optical axis and rotation axis of the rotary connector need to be separated, that is, the light beam is transmitted in an off-axis manner. The device that transmits optical signals in this way is called an off-axis fiber optic rotary connector.

[0004] At present, off-axis optical fiber rotary connectors of different structures are disclosed in domestic and foreign patent documents, each of which has advantages and disadvantages.

[0005] Patent No. US4934783, published on June 19, 1990, discloses an inner wall reflective hollow off-axis optical fiber rotary connector. The optical signal outside the rotating axis is incident on the inner wall reflector at a certain angle and is reflected multiple times. It is finally collected by the lens on the stator and received by the optical detector. In this structure, after the light beam passes through the inner wall multiple times at a certain angle, the divergence angle of the light beam becomes larger, which is not conducive to the convergence of the transmission light beam, resulting in increased insertion loss, and the failure to achieve bidirectional signal transmission, which affects the scope of use of the device.

[0006] Patent number US5297225, published on March 22, 1994, discloses a waveguide-coupled hollow off-axis optical fiber rotary connector, which uses a ring waveguide with a V-groove as a transmission channel to complete the bidirectional rotation transmission of optical signals. The incident optical signal is constrained to propagate in the ring waveguide with a V-groove, and is reflected into the output end when encountering a reflector set in the waveguide. Since a reflector is installed in the waveguide device, the requirements for integration technology and signal coupling technology are high. At the same time, the signal light is spatially coupled into the waveguide, and its coupling loss is also large, thereby affecting the performance of the entire device. In addition, the V-groove requires a high degree of precision, the assembly is difficult, and the device yield is low.

[0007] The patent document with the patent publication number CN114740573A and the publication date of July 12, 2022 discloses a collimator-coupled hollow off-axis optical fiber rotary connector. The invention realizes bidirectional transmission of optical signals by symmetrically arranged optical input end collimators and optical output end collimators rotating relative to each other on the same hollow rotating axis. Since the rotary connector needs to be coupled multiple times during operation, the optical signal loss is large. At the same time, as the rotor rotates, the coupling efficiency changes greatly, the signal is unstable, and continuous signal transmission cannot be achieved.

[0008] The patent document with the patent publication number CN103033886A and the publication date of April 10, 2013 discloses a hollow off-axis optical fiber rotary connector based on photonic crystal, including an incident end, a photonic crystal with a composite defect and a receiving end. The incident end includes a paraxial rotating incident light, and the incident end constitutes the mover of the optical fiber rotary connector; by introducing defects in the periodic medium structure of the photonic crystal to control the transmission direction of the optical signal, the optical transmission between the off-axis rotating light incident end and the stationary light receiving end is realized. However, this processing and manufacturing method of introducing annular and linear defects in a three-dimensional photonic crystal is difficult to realize, and it also fails to realize bidirectional signal transmission, making it difficult to put it into further use.

[0009] The patent document with patent publication number CN108710177A and publication date October 26, 2018 discloses a conical reflective hollow off-axis optical fiber rotary connector. The optical signal enters the connector at a certain angle and is emitted after multiple reflections between the conical surface and the plane. The emitted light beam is coupled into the optical fiber after passing through the annular grating and the lens group. Since it uses an annular grating, it is difficult to process. At the same time, the connector fails to realize bidirectional transmission of optical signals, limiting its scope of application.

[0010] The patent document with patent publication number CN108680997A and publication date October 19, 2018 discloses a multi-channel hollow fiber optic rotary connector. The off-axis optical signal enters the interior of the mechanism for multiple reflection transmission. The connector also cannot achieve bidirectional transmission of signals, and the use of the device is limited.

[0011] Although the hollow off-axis fiber optic rotary connectors proposed in the above patent documents can realize the rotational transmission of optical signals, they all have their own disadvantages, such as low transmission efficiency, complex structure, unstable signal, and inability to transmit bidirectionally. The existence of these problems limits their application and promotion. Summary of the invention

[0012] In view of the above-mentioned prior art, the present invention provides a bidirectional off-axis optical fiber rotary connector with an involute-type steering device to overcome the problems of the prior art, which can realize off-axis and bidirectional transmission of signal light beams.

[0013] In order to solve the above technical problems, the present invention proposes a bidirectional off-axis optical fiber rotary connector containing an involute-type steering device, comprising an outer sleeve and a light-shielding cylinder, wherein a circle of radial grooves is provided on the inner side surface of the outer sleeve at the middle position of the axial direction, and a gasket aligned with the axial position of the radial groove is mounted on the light-shielding cylinder; between the outer sleeve and the light-shielding cylinder, a first rotary connector for forward transmission of optical signals and a second rotary connector for reverse transmission of optical signals are respectively provided on both sides of the gasket;

[0014] The first rotary connector includes an inner sleeve and a receiving end plate which are arranged between the outer sleeve and the light-shielding cylinder, and are arranged in sequence along the axial direction from the input end of the optical signal to the side of the gasket, and the inner sleeve and the receiving end plate are tightly connected to the outer sleeve; an input end plate and a hollow annular cone are arranged in sequence inside the inner sleeve and along the axial direction from the input end of the optical signal to the receiving end plate; the input end plate includes an input outer plate and an input inner plate connected by a slot; the input outer plate and the input inner plate are rotatably connected to the inner sleeve by rolling bearings respectively; the input outer plate is provided with n first input channels which are arranged on different circumferences respectively, n≥1, and the input inner plate is provided with n first input channels which correspond to the n first input channels on the input outer plate one by one A second input channel is connected through the inner sleeve; a fiber collimator A is arranged in each of the second input channels, and the incident direction of the fiber collimator A forms a certain angle with the direction of the first input channel; a reflective film is arranged on the inner surface of the hollow annular cone, and m exit windows are arranged on the cone plate of the hollow annular cone, and m receiving channels corresponding to the positions of the m exit windows are arranged on the receiving end plate, and a fiber collimator B is arranged in each receiving channel; a steering device and a coupling lens group of an involute surface type tightly connected to the inner sleeve are arranged in sequence between the exit end of each exit window and the fiber collimator B in the corresponding receiving channel; an output channel is arranged on the outer sleeve along the axial direction from the output end of the signal to the step end face of the radial groove;

[0015] The structure of the second rotary connector is the same as that of the first rotary connector.

[0016] Furthermore, the bidirectional off-axis optical fiber rotary connector with an involute-type steering device of the present invention, wherein:

[0017] The involute-type steering device is a prism or a reflector whose working surface is an involute surface.

[0018] The prism or reflector with the involute surface as the working surface has the effect of steering and converging the light beam. The involute surface is formed by taking a straight line as the baseline and an involute as the path, and the baseline is continuously scanned on the path to generate a curved surface; the equation of the involute is:

[0019] x=r b ×cosθ k +θ k × b ×sinθ k

[0020] y=r b ×sinθ k -θ k × b ×cosθ k

[0021] Among them, r b is the base circle radius, θ k is the angle of point K on the involute, in radians.

[0022] The number of the input channels is the same as the number of the exit windows on the cone panel of the hollow annular cone, and the distribution positions of the second input channels, exit windows, coupling lens groups and receiving channels of the same number correspond one to one.

[0023] The number of the input channels is twice the number of the exit windows on the cone panel of the hollow annular cone, and two exit windows are distributed on the distribution circumference of each second input channel, and the distribution positions of the same number of exit windows, coupling lens groups and receiving channels correspond one to one.

[0024] The fiber optic collimator A and the fiber optic collimator B have the same structure, both consisting of an optical fiber and a collimating lens. The collimating lens is a C-lens lens, a self-focusing lens, or a ball lens system.

[0025] The optical fiber of the optical fiber collimator A is led out through the first input channel and the second input channel that are connected, and the optical fiber of the optical fiber collimator B is led out through the output channel.

[0026] The optical fiber led out to the outside of the rotary connector is armored to protect the optical fiber from being easily broken.

[0027] The coupling lens group is composed of at least lens A, lens B and a lens sleeve.

[0028] The involute-type steering device and the coupling lens group are tightly connected to the inner sleeve via a fixed end plate.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] In the present invention, the central channel can be used to transmit important resources such as oil and gas, and can also be used as a connection channel for solid rods. The involute prism has a steering and convergence effect on the light beam. The light beam passing through the involute prism can be efficiently coupled into the optical fiber, thereby improving the transmission efficiency of the entire system. The bidirectional off-axis optical fiber rotary connector containing the involute prism of the present invention effectively solves the problem of bidirectional transmission of off-axis optical signals when the central axis is occupied. The entire system has high transmission efficiency, simple structure, and stable signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of Example 1 of a bidirectional off-axis optical fiber rotary connector containing an involute prism;

[0032] Figure 2(a) shows Figure 1 An end view of the input inner plate A shown in FIG.

[0033] Figure 2(b) shows Figure 1 An end view of the input inner plate B shown in FIG.

[0034] Figure 3(a) shows Figure 1 An end view of the hollow annular cone A shown in FIG.

[0035] Figure 3(b) shows Figure 1 An end view of the hollow annular cone B shown in FIG.

[0036] Figure 4 for Figure 1 A side view of the coupling lens assembly shown in;

[0037] Figure 5(a) shows Figure 1 The receiving end plate A end view is shown in FIG.

[0038] Figure 5(b) shows Figure 1 The receiving end plate B end view is shown in FIG.

[0039] Figure 6 It is a schematic diagram of the steering and convergence effect of the involute surface on the incident light beam;

[0040] Figure 7 yes Figure 1 The three views of the involute prism shown in , (a) is a side view, (b) is a front view, and (c) is a bottom view;

[0041] Figure 8 It is a structural schematic diagram of Example 2 of a bidirectional off-axis optical fiber rotary connector containing an involute reflector;

[0042] Fig. 9 yes Figure 8 The three views of the involute reflector shown in , (a) is a side view, (b) is a front view, and (c) is a bottom view.

[0043] In the figure:

[0044] 1-Input outer plate A 2-Input inner plate A 3-Bearing washer A

[0045] 4-Rolling bearing A 5-Inner sleeve A 6-Sleeve cover

[0046] 7-Outer sleeve 8-Hollow annular cone A 9-Reflective film A

[0047] 10-Exit window A 11-Involute prism A 12-Coupling lens group A

[0048] 13-receiving end board A 14-receiving channel A 15-output optical fiber A

[0049] 16- receiving end plate B 17- inner sleeve B 18- forward output channel

[0050] 19-Input channel D 20-Transmission fiber A 21-Input channel E

[0051] 22-Input channel F 23-Light shielding tube 24-Bolt

[0052] 25-Input outer plate B 26-Input inner plate B 27-Bearing washer B

[0053] 28-Rolling bearing B 29-Reflective film B 30-Hollow annular cone B

[0054] 31-Exit window D 32-Involute prism B 33-Fixed end plate B

[0055] 34-coupling lens group B 35-receiving channel D 36-output optical fiber B

[0056] 37-washer 38-fixing end plate A 39-fixing screw

[0057] 40-reverse output channel 41-input channel A 42-transmission fiber B

[0058] 43-Input channel B 44-Input channel C 45-Center through hole

[0059] 46-Exit window B 47-Exit window C 48-Lens A

[0060] 49- Lens B 50- Lens tube 51- Receiving channel B

[0061] 52-receiving channel C 53-exit window E 54-exit window F

[0062] 55-Receiving channel E 56-Receiving channel F 57-Involute reflector A

[0063] 58-fixed frame A 59-involute reflector B 60-fixed frame B

[0064] 61-incident circle 62-incident beam 63-outgoing beam

[0065] 64-involute surface 65-baseline 66-involute DETAILED DESCRIPTION

[0066] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but the following embodiments are by no means intended to limit the present invention in any way.

[0067] The present invention provides a bidirectional off-axis optical fiber rotary connector containing an involute prism, such as Figure 1 As shown, its structure is: it includes an outer sleeve 7, one end of the outer sleeve 7 is provided with an inner sleeve A5, and the outer sleeve 7 and the inner sleeve A5 are tightly connected.

[0068] An input end plate (including an input outer plate A1 and an input inner plate A2) is provided at one end of the inner sleeve A5, and the input outer plate A1 is connected to the input inner plate A2 by a card groove, and a rolling bearing A4 is provided between the input outer plate A1 and the input inner plate A2 and the inner sleeve A5 for connection, and the two rolling bearings A4 are separated by a bearing gasket A3, and a receiving end plate A13 is provided at the other end of the inner sleeve A5, and the receiving end plate A13 is tightly connected to the outer sleeve 7; the input outer plate A1, the input inner plate A2, the inner sleeve A5, the outer sleeve 7 and the receiving end plate A13 are all coaxially arranged, and the input outer plate A1, the input inner plate A2, the inner sleeve A5, the outer sleeve 7 and the receiving end plate A13 are coaxially arranged. 13 is provided with a through central through hole 45, in which a light shielding tube 23 is embedded. One end of the light shielding tube 23 is provided with a thread 24 and is fixedly connected with a bolt 24.

[0069] An input channel is respectively arranged on the n different circumferences of the input inner plate A2, where n≥1. A fiber collimator A is arranged in each input channel of the input inner plate A2. In order to allow light to enter the connector and be transmitted along the designed path, in the present invention, the incident direction of the fiber collimator A forms a certain angle with the direction of the input channel. The calculation of the angle can be obtained by analyzing the plane-cone reflection path equation. FIG2(a) shows the layout of the input channels (i.e., input channel A 41, input channel B 43, and input channel C 44) on the three circumferences of the input inner plate A2. An input channel is respectively arranged on the n different circumferences of the input outer plate A1, which corresponds one-to-one to the input channel of the input inner plate A2.

[0070] like Figure 1 As shown, a hollow annular cone A8 coaxial with the light-shielding tube 23 is fixed inside the inner sleeve A5, and a reflective film A9 is provided on the inner end face of the input inner plate A2 and the inner surface of the hollow annular cone A8; m exit windows are provided on the conical surface of the hollow annular cone 8, and FIG3(a) shows a situation in which each of the three circumferences of the hollow annular cone A8 has an exit window (i.e., exit window A10, exit window B46, and exit window C47).

[0071] like Figure 1 As shown, an involute prism A11 is provided at the exit port of the hollow annular cone 8, and one ends of the m involute prisms A11 correspond one-to-one to the positions of the m exit windows of the hollow annular cone 9, and a card slot is provided between the involute prism A11 and the hollow annular cone A8 for mating connection; a coupling lens group A12 is provided at the other end of the involute prism A11, and the m coupling lens groups A12 correspond one-to-one to the positions of the m involute prisms A11; the involute prism A11 and the coupling lens group A12 are tightly connected to the inner sleeve A5 by a fixed end plate A38. Figure 4 It is shown that the coupling lens group A12, 34 is composed of lens A48, lens B49, and lens tube 50.

[0072] like Figure 1 As shown, the receiving end plate 13 is provided with m receiving channels, and the m receiving channels correspond to the center positions of the m coupling lens groups A12 one by one, and a fiber collimator is provided in each receiving channel. FIG5(a) shows the receiving channels (i.e., receiving channel A14, receiving channel B51, and receiving channel C52) corresponding to the center positions of the coupling lens groups A12 one by one.

[0073] An inner sleeve B17 is disposed at the other end of the outer sleeve 7, and the outer sleeve 7 and the inner sleeve B17 are tightly connected. An input end plate (including an input outer plate B25 and an input inner plate B26) is also provided at one end of the inner sleeve B17. The input outer plate B25 and the input inner plate B26 are connected by a slot. A rolling bearing B28 is provided between the input outer plate B25 and the input inner plate B26 and the inner sleeve B17 for connection. The two rolling bearings B28 are separated by a bearing gasket B27. A receiving end plate B16 is provided at the other end of the inner sleeve B17. The receiving end plate B16 is tightly connected to the outer sleeve 7. The input outer plate B25, the input inner plate B26, the inner sleeve B17, the outer sleeve 7 and the receiving end plate B16 are coaxially arranged. The input outer plate B25, the input inner plate B26, the inner sleeve B17, the outer sleeve 7 and the receiving end plate B16 are also provided with a through central through hole 45.

[0074] An input channel is respectively provided on n different circumferences of the input inner plate B26, and a fiber collimator B is provided in each input channel of the input inner plate B26. Similarly, in order to allow light to enter the connector and be transmitted along a designed path, in the present invention, the incident direction of the fiber collimator B forms a certain angle with the direction of the input channel, and the calculation of the angle is as described above.

[0075] Figure 2(b) shows the layout of the input channels (i.e., input channel A19, input channel E21, and input channel C22) on the three circumferences of the input inner plate B26. An input channel is respectively provided on the n different circumferences of the input outer plate B25, which corresponds one-to-one to the input channel of the input inner plate B26.

[0076] like Figure 1 As shown, a hollow annular cone B30 coaxial with the light-shielding tube 23 is fixed inside the inner sleeve B17, and the inner end face of the input inner plate B26 and the inner surface of the hollow annular cone B30 are both provided with a reflective film B29; m exit windows are provided on the cone surface of the hollow annular cone B30, and FIG3(b) shows a situation in which there is an exit window on each of the three circumferences of the hollow annular cone B30 (i.e., exit window D31, exit window E53, and exit window F54).

[0077] like Figure 1 As shown, an involute prism B32 is provided at the exit port of the hollow annular cone B30, and one end of the m involute prisms B32 respectively corresponds to the positions of the m exit windows of the hollow annular cone B30, and a card slot is provided between the involute prism B32 and the hollow annular cone B30 for mating connection; a coupling lens group B34 is provided at the other end of the involute prism B32, and the m coupling lens groups B34 respectively correspond to the positions of the m involute prisms B32; the involute prism B32 and the coupling lens group B34 are tightly connected to the inner sleeve B17 by a fixed end plate B33.

[0078] like Figure 1 As shown, the receiving end plate B16 is provided with m receiving channels, and the m receiving channels correspond one-to-one to the center positions of the m coupling lens groups respectively. A fiber collimator is provided in each receiving channel. FIG5(b) shows the receiving channels (i.e., receiving channel D35, receiving channel E55, and receiving channel F56) corresponding one-to-one to the center positions of the coupling lens group B34.

[0079] The receiving end plate A13 is separated from the receiving end plate B16 by a gasket 37. The two ends of the outer sleeve 7 are respectively provided with an output channel, including a forward output channel 18 and a reverse output channel 40. One end of the outer sleeve 7 is provided with a sleeve cover 6, and the sleeve cover 6 is provided with an output channel corresponding to the output channel at one end of the outer sleeve 7. The outer sleeve 7 and the sleeve cover 6 are connected by fixing screws 39.

[0080] Example 1

[0081] A bidirectional off-axis optical fiber rotary connector containing an involute prism, wherein m=n=3 in this embodiment.

[0082] Figure 1 - FIG. 5 shows the basic structure of the bidirectional off-axis optical fiber rotary connector containing an involute prism according to the present invention. The working process of this embodiment is as follows:

[0083] At one end of the rotary connector, three groups of optical signals to be transmitted are transmitted from input channel A41, input channel B43, and input channel C44 to three groups of optical fiber collimators through transmission optical fiber B42. After the three groups of optical fiber collimators convert the three groups of optical signals into parallel light beams, they enter the interior of the rotary connector at a certain angle for transmission. Since the inner surface of the input inner plate A2 and the inner conical surface of the hollow annular cone 8 are respectively coated with a reflective film A9, the input signal light beam is reflected when it is transmitted to the inner conical surface of the hollow annular cone 8. The three groups of signal light beams are returned to the interior of the rotary connector and transmitted to the inner surface of the input inner plate A2. When the three groups of signal light beams are transmitted to the inner surface of the rotor, they are reflected again. The three groups of signal light beams are reflected back to the interior of the rotary connector for continued transmission. After a certain number of reflections, the three groups of signal light beams are respectively emitted from the exit window A10, exit window B46, and exit window C47 located on the conical surface of the hollow annular cone 8. The three groups of signal light beams emitted respectively pass through the involute prism A11 corresponding to the exit window. After being turned and converged by the involute prism A11, the three groups of signal light beams propagate parallel to the main axis. After passing through the coupling lens group A12, the spot size of the three groups of signal light beams parallel to the main axis will be reduced and smaller than the core diameter of the optical fiber at the focus. They are respectively coupled to the three groups of optical fiber collimators located in the receiving channel A14, the receiving channel B51, and the receiving channel C52. The three groups of signals are output by the three groups of output optical fibers A15 through the forward output channel 18 of the outer sleeve 7, completing the forward transmission of the signal.

[0084] At the other end of the rotary connector, three groups of optical signals to be transmitted are transmitted from input channel D19, input channel E21, and input channel F22 to three groups of optical fiber collimators through transmission optical fiber A20. After the three groups of optical fiber collimators convert the three groups of optical signals into parallel light beams, they enter the interior of the rotary connector at a certain angle for transmission. Since the inner surface of the input inner plate B26 and the inner conical surface of the hollow annular cone B30 are respectively coated with a reflective film B29, the input signal light beam is reflected when it is transmitted to the inner conical surface of the hollow annular cone B30, and the three groups of signal light beams are returned to the interior of the rotary connector and transmitted to the inner surface of the input inner plate B26. When the three groups of signal light beams are transmitted to the inner surface of the rotor, they are reflected again. The three groups of signal light beams are reflected back to the interior of the rotary connector for continued transmission. After a certain number of reflections, the three groups of signal light beams are respectively emitted from the exit window D31, the exit window E53, and the exit window F54 located on the conical surface of the hollow annular cone B30. The three groups of signal light beams emitted respectively pass through the involute prism B32 corresponding to the exit window. After the steering and focusing action of the involute prism B32, the three groups of signal light beams propagate parallel to the main axis. After the three groups of signal light beams parallel to the main axis pass through the coupling lens group B34, the spot size will be reduced and smaller than the core diameter of the optical fiber at the focus. They are respectively coupled to the three groups of optical fiber collimators located in the receiving channel D35, the receiving channel E55, and the receiving channel F56. The three groups of signals are output by the three groups of output optical fibers B36 through the reverse output channel 40 of the outer sleeve 7, completing the reverse transmission of the signal, and finally realizing the bidirectional transmission of the optical signal by the rotary connector.

[0085] During signal transmission, since the input end plate is connected to the inner sleeve A5 and the inner sleeve B17 through the rolling bearing A4, the input end plate can rotate freely around the center axis relative to the inner sleeve A5, the inner sleeve B17 and the outer sleeve 7, thereby realizing dynamic input of the signal.

[0086] The involute prism A11 and the involute prism B32 described in the present invention have the function of steering and converging the light beam. The light beam passing through the involute prism can be efficiently coupled into the optical fiber, thereby improving the transmission efficiency of the entire system. The involute prism refers to a prism whose working surface is an involute surface. Figure 6 and Figure 7 (a) Figure 7 (b) and Figure 7 As shown in (c), the involute surface 64 is a curved surface generated by continuously scanning the baseline 65 on the path with a straight line as the baseline 65 and an involute line 66 as the path.

[0087] The involute equation is:

[0088] x=r b ×cosθ k +θ k × b ×sinθk

[0089] y=r b ×sinθ k -θ k × b ×cosθ k

[0090] Among them, r b is the base circle radius, θ k is the angle of point K on the involute, in radians.

[0091] Figure 6 Schematic diagram of the deflection and convergence effect of the involute surface on the incident light beam. The incident light beam 62 is emitted from the incident circle 61 and is perpendicular to the radial direction of the incident circle 61. The involute surface 64 is coated with a reflective film as a reflective surface. When the incident light beam 62 is transmitted to point B of the involute surface 64 at a certain angle, the incident light beam 62 is decomposed into a component BU perpendicular to MN and a component BV parallel to MN. When the incident light beam component BU is transmitted to the involute surface, it is transmitted in the opposite direction along the original path, and changes from BU to BU′. The component BU′ and the component BV are synthesized into the outgoing light beam 63, thereby completing the deflection and convergence of the incident light beam 62. Figure 7 (a), (b) and (c) are Figure 1 The side view, front view and bottom view of the involute prism shown in FIG.

[0092] Example 2

[0093] like Figure 8 As shown, the involute-type steering device in the present invention can also be an involute-type reflector. The involute-type reflector A57 is tightly connected to the inner sleeve A5 by a fixing frame A58 and a fixed end plate A38. Fig. 9 (a), (b) and (c) are the side view, front view and bottom view of the involute reflector respectively. The involute reflector B59 is tightly connected to the inner sleeve B17 by a fixing frame B60 and a fixing end plate B33, and the rest of the structure is basically the same as that described in Example 1.

[0094] The light shielding tube 23 described in the present invention can reduce the influence of the external environment on the signal transmission of the rotary connector. At the same time, a channel for transmitting resources such as oil and gas can be added at the position of the light shielding tube 23, and it can also be used as a connection channel for the solid rod. The bidirectional off-axis optical fiber rotary connector containing an involute prism of the present invention effectively solves the problem of bidirectional transmission of off-axis optical signals when the central axis of the rotary connector is occupied.

[0095] The optical fiber collimator described in the present invention is composed of an optical fiber and a collimating lens, and the collimating lens can be a C-lens lens, a self-focusing lens or a ball lens system.

[0096] The coupling system described in the present invention is composed of at least lens A48, lens B49 and lens sleeve 50.

[0097] The off-axis optical fiber rotary connector of the present invention performs armor packaging on the optical fiber exposed outside the rotary connector to protect the optical fiber from being easily broken.

[0098] The core of the bidirectional off-axis optical fiber rotary connector with involute prism invented by the present invention lies in the precise processing of the hollow annular cone, the optical coating of the inner surface of the hollow annular cone, the inner end surface of the input end plate and the surface of the involute optical device, the processing of the involute optical device and the precise assembly of the overall optical device. The hollow annular cone can be processed and manufactured with aluminum alloy, stainless steel or brass. The optical reflective film plated on the surface of the involute optical device, the inner surface of the hollow annular cone and the inner end surface of the input end plate can be plated with gold, silver or aluminum. The involute optical device and lens can be processed and manufactured with optical glass or optical plastic.

[0099] Although the present invention has been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can make many modifications without departing from the purpose of the present invention, all of which are within the protection of the present invention.

Claims

1. A bidirectional off-axis optical fiber rotary connector with an involute-type steering device, comprising an outer sleeve (7) and a light-shielding cylinder (23), characterized in that: A circle of radial grooves is provided on the inner side surface of the outer sleeve (7) at the middle position in the axial direction, and a gasket (37) is mounted on the light-shielding cylinder (23) and is aligned with the axial position of the radial grooves; a first rotary connector for forward transmission of optical signals and a second rotary connector for reverse transmission of optical signals are provided on both sides of the gasket (37) between the outer sleeve (7) and the light-shielding cylinder (23); The first rotary connector comprises an inner sleeve and a receiving end plate which are arranged between the outer sleeve (7) and the light shielding cylinder (23) and are arranged in sequence along the axial direction from the input end of the optical signal to the side surface of the gasket (37), and the inner sleeve and the receiving end plate are tightly connected to the outer sleeve (7); An input end plate and a hollow annular cone are sequentially arranged in the inner sleeve and axially from the input end of the optical signal to the receiving end plate; the input end plate comprises an input outer plate and an input inner plate connected by a slot; the input outer plate and the input inner plate are rotatably connected to the inner sleeve via rolling bearings respectively; the input outer plate is provided with n first input channels arranged on different circumferences, n≥1, and the input inner plate is provided with n second input channels corresponding to and connected with the n first input channels on the input outer plate; each of the second input channels is provided with an optical fiber collimator A, and the incident direction of the optical fiber collimator A forms a certain angle with the direction of the first input channel; The inner surface of the hollow annular cone is provided with a reflective film, the cone plate of the hollow annular cone is provided with m exit windows, the receiving end plate is provided with m receiving channels corresponding to the positions of the m exit windows, and each receiving channel is provided with a fiber collimator B; between the exit end of each exit window and the fiber collimator B in the corresponding receiving channel, an involute-type steering device and a coupling lens group tightly connected to the inner sleeve are provided in sequence; on the outer sleeve (7), an output channel is provided along the axial direction from the output end of the signal to the step end face of the radial groove; The structure of the second rotary connector is the same as that of the first rotary connector.

2. The bidirectional off-axis optical fiber rotary connector with an involute-type steering device according to claim 1, characterized in that: The involute-type steering device is a prism or a reflector whose working surface is an involute surface.

3. The bidirectional off-axis optical fiber rotary connector with an involute-type steering device according to claim 2, characterized in that: The prism or reflector with the working surface being an involute surface has a deflecting and converging effect on the light beam. The involute surface (64) is formed by: taking a straight line as a baseline and an involute as a path, the baseline is continuously scanned on the path to generate a curved surface; the equation of the involute is: x=r b ×cosθ k +θ k ×r b ×sinθ k y=r b ×sinθ k -θ k ×r b ×cosθ k Among them, r b is the base circle radius, θ k is the angle of point K on the involute, in radians.

4. The bidirectional off-axis optical fiber rotary connector with an involute-type steering device according to claim 1, characterized in that: m=n, and the distribution positions of the second input channels, exit windows, coupling lens groups and receiving channels of the same number correspond to each other.

5. The bidirectional off-axis optical fiber rotary connector with an involute-type steering device according to claim 1, characterized in that: m=2n, two exit windows are distributed on the distribution circumference of each second input channel, and the distribution positions of the m exit windows, the m coupling lens groups and the m receiving channels correspond one to one.

6. The bidirectional off-axis optical fiber rotary connector with an involute-type steering device according to claim 1, characterized in that: The fiber optic collimator A and the fiber optic collimator B have the same structure, both consisting of an optical fiber and a collimating lens. The collimating lens is a C-lens lens, a self-focusing lens, or a ball lens system.

7. The bidirectional off-axis optical fiber rotary connector with an involute-type steering device according to claim 6, characterized in that: The optical fiber of the optical fiber collimator A is led out through the first input channel and the second input channel that are connected, and the optical fiber of the optical fiber collimator B is led out through the output channel.

8. The bidirectional off-axis optical fiber rotary connector with an involute-type steering device according to claim 7, characterized in that: The optical fiber led out to the outside of the rotary connector is armored to protect the optical fiber from being easily broken.

9. The bidirectional off-axis optical fiber rotary connector with an involute-type steering device according to claim 1, characterized in that: The coupling lens group is composed of at least lens A, lens B and a lens sleeve.

10. The bidirectional off-axis optical fiber rotary connector with an involute-type steering device according to claim 1, characterized in that: The involute-type steering device and the coupling lens group are tightly connected to the inner sleeve via a fixed end plate.

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