Mechanical connectors used in fiber optic imaging systems

Abstract

An apparatus includes: an optical fiber; an actuator; and a connector that mechanically couples the actuator to the optical fiber. The optical fiber passes through a hole extending along an axis through a neck. The optical fiber is attached to the connector at a surface of the neck facing the axis. The connector also includes a bushing that extends along the axis. The actuator is mechanically attached to the connector at an inner surface of the bushing that faces the axis. The connector also includes a flexible element that extends radially from the neck to the bushing. During operation, the connector couples a force from the actuator to the optical fiber to change the orientation of a portion of the optical fiber extending from the neck relative to the axis.

Description

[0001] This application is a divisional application of a patent application with an application date of May 29, 2018, application number 201880048898.6, and name “Mechanical connector used in a fiber optic imaging system”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of priority to U.S. Provisional Application Serial No. 62 / 513,082, filed on May 31, 2017. The entire contents of U.S. Application Serial No. 62 / 513,082 are incorporated herein by reference. Technical Field

[0004] The present disclosure relates to mechanical connectors used in fiber optic imaging systems such as fiber scanning displays. Background Art

[0005] An imaging system may be used to present visual information to a user. For example, an imaging system may include optical components that project an image onto an imaging surface so that one or more users can view the image. In some cases, an imaging system may be incorporated into a head-mounted display device to present visual information in a more immersive manner. For example, a head-mounted display may be used to present visual information for a virtual reality (VR) or augmented reality (AR) system. Summary of the invention

[0006] Embodiments of mechanical connections for physically coupling an actuator to a waveguide are described herein. One or more of the described embodiments may be used in conjunction with a fiber optic imaging system such as a fiber scanning display device.

[0007] Embodiments of mechanical connectors may provide various advantages. For example, one or more of the mechanical connectors described herein may enable a fiber optic imaging system to operate with high precision, thereby improving image quality. Furthermore, one or more of the mechanical connectors described herein may be precisely and consistently constructed, and thus may be suitable for use in variation-specific applications (e.g., for use in imaging systems such as fiber scanning displays that are highly sensitive to the characteristics of the mechanical connector). Furthermore, the mechanical connector may be easily manufactured in large quantities. Furthermore, the design of the mechanical connector may be easily modified and implemented, and thus may be easily used in a variety of different applications.

[0008] In general, in one aspect, a device includes: an optical fiber; an actuator; and a connector that mechanically couples the actuator to the optical fiber. The connector includes a neck extending along an axis. The optical fiber passes through a hole extending through the neck along the axis. The optical fiber is attached to the connector at a surface of the neck facing the axis. The connector also includes a bushing extending along the axis. The actuator is mechanically attached to the connector at an inner surface of the bushing facing the axis. The connector also includes a flexible element extending radially from the neck to the bushing. During operation, the connector couples a force from the actuator to the optical fiber to change the orientation of a portion of the optical fiber extending from the neck relative to the axis.

[0009] Implementations of this aspect may include one or more of the following features.

[0010] In some embodiments, the flexible element may include an annular portion extending between the neck and the bushing.

[0011] In some embodiments, the flexible element may include one or more beams extending between the neck and the bushing.

[0012] In some embodiments, the bushing may extend along the shaft in a direction away from the neck.

[0013] In some embodiments, the bushing may extend along the shaft around a periphery of the neck.

[0014] In some embodiments, the connector may be rotationally symmetric about the axis. The connector may have at least four-fold rotational symmetry about the axis.

[0015] In some embodiments, the connector may have a first stiffness relative to the axis, a second stiffness relative to a first radial direction, and a third stiffness relative to a second radial direction orthogonal to the first radial direction. The first stiffness may be greater than the second stiffness and the third stiffness. The second stiffness and the third stiffness may be substantially equal.

[0016] In some embodiments, the connector may include crystalline silicon. The crystalline silicon may have a (111) crystal structure.

[0017] In some embodiments, the connector may include amorphous silicon.

[0018] In some embodiments, the connector may include one or more layers of silicon and one or more layers of electrically insulating material. The electrically insulating material may include silicon dioxide.

[0019] In some embodiments, the outer portion may have a substantially circular cross-section.The neck may have an inner diameter of less than 200 μm.The neck may have an outer diameter of less than 300 μm.

[0020] In some embodiments, the neck may define one or more slots along a periphery of the neck.

[0021] In some embodiments, the bushing may have a substantially circular cross-section.The bushing may have an inner diameter of less than 1500 μm.The bushing may have an outer diameter of less than 2000 μm.

[0022] In some embodiments, the bushing may define one or more slots along a periphery of the bushing.

[0023] In some embodiments, the device may further include an illumination source in optical communication with the optical fiber. The illumination source may be configured to direct light into the optical fiber during operation. The actuator may be configured to change the orientation of a portion of the optical fiber during operation so that the first end of the optical fiber traverses a predetermined pattern. The light guide may be configured to receive light from the illumination source during operation, direct the received light to one end of the optical fiber, and emit the received light from the first end of the optical fiber.

[0024] In some embodiments, the flexible member may define one or more slots extending through the flexible member.

[0025] In some embodiments, the one or more slots may be arranged helically about the shaft.

[0026] In some embodiments, the flexible element may include a gimbal structure.The gimbal structure may include a ring, a plurality of inner beams mechanically coupling the neck to the ring, and a plurality of outer beams mechanically coupling the ring to the bushing.

[0027] The details of one or more embodiments are set forth in the accompanying drawings and the detailed description that follows. Other features and advantages will be apparent from the detailed description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1A is a schematic diagram of an example fiber scanning display device.

[0029] Figure 1B An example deflection of the waveguide tip is shown.

[0030] Figure 1C A graph showing an example modulation pattern is shown.

[0031] Figure 1D An example scan pattern is shown.

[0032] Figure 2A Perspective views of an example actuator, an example waveguide, and an example mechanical connection are shown.

[0033] Figure 2B Shows Figure 2A A cross-sectional view of the components shown.

[0034] Figure 3A Shows Figure 2A and Figure 2B A front perspective view of an example mechanical connector is shown.

[0035] Figure 3B Shows Figure 2A and Figure 2B A rear perspective view of an example mechanical connector is shown.

[0036] Figure 3C Shows Figure 2A and Figure 2B A cross-sectional view of an example mechanical connector is shown.

[0037] Figure 3D Shows Figure 2A and Figure 2B A top view of an example mechanical connector is shown.

[0038] Figure 4A Shows Figure 2A and Figure 2B A rear perspective view of an example mechanical connector is shown.

[0039] Figure 4B Shows Figure 2A and Figure 2B A top view of an example mechanical connector is shown.

[0040] Figure 4C Show Figure 2A A perspective view of an example actuator, example waveguide, and example mechanical connections are shown.

[0041] Figure 5A A perspective view of another example mechanical connector is shown.

[0042] Figure 5B Shows Figure 5A A top view of the mechanical connection is shown.

[0043] Figure 5C Shows Figure 5A A cross-sectional view of the mechanical connection shown.

[0044] Fig. 6A A perspective view of another example mechanical connector is shown.

[0045] Figure 6B Shows Fig. 6A A top view of the mechanical connection is shown.

[0046] Figure 6C Shows Fig. 6A A cross-sectional view of the mechanical connection shown.

[0047] Fig. 7A A perspective view of another example mechanical connector is shown.

[0048] Figure 7B Shows Fig. 7A A top view of the mechanical connection is shown.

[0049] Figure 7C Shows Fig. 7A A cross-sectional view of the mechanical connection shown.

[0050] FIG. 8A to FIG. 8C An example micromachining process for creating a mechanical connection is shown. DETAILED DESCRIPTION

[0051] Typically, a fiber scanning display (FSD) device projects an image onto an imaging surface by directing a temporally modulated light pattern through an optical fiber while vibrating the tip of the optical fiber. For example, an FSD device may use an actuator to vibrate an optical fiber so that the tip of the optical fiber travels or "sweeps" a predictable predetermined pattern or path (e.g., a spiral). As the tip of the optical fiber scans the pattern, modulated light is transmitted through the optical fiber so that light is emitted from the tip of the optical fiber in a spatially correlated manner. Thus, by continuously vibrating the optical fiber while transmitting a series of light pulses into the optical fiber, an image may be spatially "scanned" onto an imaging surface.

[0052] Figure 1A An example FSD device 100 is schematically shown. The FSD device 100 includes a plurality of radiation sources 102a-c (e.g., a red laser, a green laser, and a blue laser, respectively) configured to emit light. The radiation sources 102a-c are optically coupled to a first waveguide 104 (e.g., a red-green-blue (RGB) combiner) so that the light emitted by each of the radiation sources is combined. The combined light from the first waveguide 104 is relayed by a second waveguide 106 (e.g., a single-mode optical fiber) optically coupled to the first waveguide 104. Then, the light from the second waveguide 106 is emitted from its tip 108 (e.g., a cantilevered optical fiber tip).

[0053] The emitted light passes through the lens assembly 110, which focuses the emitted light onto the image plane 112. When emitting light, the waveguide tip 108 is scanned along one or more axes by the actuator 114 (e.g., a piezoelectric tube actuator) so that the emitted light is projected according to a scanning pattern (e.g., a spiral shape) along the image plane 112. Therefore, a scanned image (e.g., a spiral scanned image) is formed on the image plane 112.

[0054] like Figure 1B As shown, the waveguide tip 108 can be scanned by imparting a force to the waveguide 106 using the actuator 114. The waveguide 106 is flexible so that the waveguide tip 108 is deflected by an angle α relative to a longitudinal axis 150 of the actuator 114. The operation of the actuator 114 can be selectively adjusted to deflect the waveguide tip 108 along one or more axes orthogonal to the axis 150 so that the waveguide tip 108 scans a specific predetermined pattern.

[0055] The intensity of light emitted by the radiation sources 102a-c is modulated so that the light is coupled into the waveguide 106 as a sequence of pulses. The FSD device 100 coordinates the sequence of pulses by actuation of the waveguide tip 108 so that light is selectively emitted from the waveguide tip 108 in a spatially correlated manner to form an image. For example, when the actuator 114 continuously scans the waveguide tip 108 according to a predictable predetermined pattern, the radiation sources 102a-c can selectively emit light and / or adjust the intensity of the light emission according to the pattern and in sufficiently short time intervals so that the light pattern sequentially formed on the image plane 112 is presented to the user as an image. For example, this can be used to depict objects, shapes, and / or patterns on the image plane 112. In addition, the radiation sources can also emit light according to dynamic patterns, such as projecting a sequence of different images onto the image source over time (e.g., in order to impart a sense of motion on the image plane 112, such as in a video sequence).

[0056] like Figure 1A As shown, the FSD device 100 includes a drive module 116 that coordinates the operation of the actuator 114 and the operation of the radiation sources 102a-c. For example, the drive module 116 can generate a drive signal to the actuator 114 to control the actuation of the actuator 114 (e.g., so that the actuator 114 causes the waveguide tip 108 to scan a predictable predetermined pattern). The drive module 116 can also generate a pixel modulation signal based on the actuation of the actuator 114 to adjust the output of the radiation sources 102a-c. The drive signal and the pixel modulation signal can be transmitted to the actuator 114 simultaneously so that pixels are formed at specific spatial locations along the image plane 112.

[0057] As an example, you can Figure 1CThe exemplary pattern shown in the graph 160 of FIG. 1 modulates the drive signal so that the signal constitutes a sinusoidal drive signal that is amplitude modulated over time. The drive signal can include a sinusoidal signal portion that drives one scan axis of the actuator 114, and a second sinusoidal signal portion that drives a second scan axis. The second sinusoidal drive signal is phase-shifted relative to the first drive signal portion so that the waveguide tip 108 sweeps a circular scan pattern. The sinusoidal drive signal can be amplitude modulated over time to enlarge and reduce the circular scan pattern to form a spiral scan pattern that fills the area. Figure 1D A simplified scanning pattern 170 is shown. Similarly, a pixel modulation signal may be generated according to the scanning pattern 170 such that pixels are formed at specific spatial locations along the scanning pattern 170.

[0058] In some cases, multiple FSD devices may be used in combination (e.g., in a two-dimensional array) to improve the quality of the projected image. As an example, multiple FSD devices may be implemented in an array to increase the resolution of the projected image, increase the pixel density of the projected image, and / or increase the frame rate of the projected image.

[0059] Embodiments of the FSD device 100 may be used for various imaging applications. For example, in some cases, the FSD device 100 is implemented in a head mounted display device. One or more FSD devices 100 may be used to project an image onto an eyepiece positioned above the user's eyes so that the image is within the user's field of view. In some cases, the FSD device 100 may be implemented as part of a "virtual reality" system or an "augmented reality" system to present images in a visually immersive manner.

[0060] As about Figure 1A As described, the actuator 114 imparts a force on the waveguide 106 such that the waveguide tip 108 is scanned along one or more axes according to a predictable, predetermined pattern. This can be accomplished by mechanically coupling the actuator 114 to the waveguide 106 using a mechanical connection 200.

[0061] Figure 2A and Figure 2B A perspective view of an example actuator 114, an example waveguide 106, and an example mechanical connection 200 is shown. Figure 2A ) and cross-sectional view ( Figure 2B ). For ease of illustration, a portion of the actuator 114 has been omitted. FIG. 3A to FIG. 3D Shown according to the front perspective view ( Figure 3A )、Back perspective( Figure 3B )、Sectional view( Figure 3C ) and top view ( Figure 3D )'s mechanical connector 200.

[0062] The actuator 114 extends along the longitudinal axis 150. The actuator 114 has a tubular configuration and includes an outer wall 204 surrounding a hollow interior passage 206. The actuator 114 has a circular or substantially circular cross-section. In some cases, the actuator 114 is a piezoelectric tube actuator.

[0063] The waveguide 106 passes through the interior passage 206 of the actuator 114 and extends along the longitudinal axis 150. The waveguide 106 is mechanically coupled to the actuator 114 via the mechanical connection 200 so that forces caused by the actuator 114 (e.g., caused by vibrations generated by the actuator 114 along its outer wall 204) are coupled to the waveguide 106. The waveguide 106 may be an optical fiber (e.g., a single-mode optical fiber).

[0064] The mechanical connector 200 includes a neck portion 208, a bushing portion 210, and a flexible element portion 212. In some cases, the mechanical connector 200 can be implemented as a unitary component. In some cases, the mechanical connector 200 can be constructed from two or more separate components.

[0065] The neck portion 208 is configured to be attached to the waveguide 106 so that the mechanical connector and the waveguide 106 are mechanically coupled. In some cases, the neck portion 208 can be mechanically and / or chemically attached to the waveguide 106. For example, the neck portion 208 can be attached to the waveguide 106 by metallization or diffusion. As another example, the neck portion 208 can be attached to the waveguide 106 by using urethane, epoxy, or nanoparticles.

[0066] The neck portion 208 extends along the longitudinal axis 150. The neck portion 208 has a tubular configuration and includes an outer wall 214 surrounding a hollow interior passage 216.

[0067] The internal passage 216 is sized to accommodate the waveguide 106. In some cases, the cross-sectional shape of the internal passage 216 can be the same or substantially the same as the waveguide 106. For example, if the cross-sectional shape of the waveguide 106 is circular or substantially circular, the internal passage 216 can also have a circular or substantially circular cross-section. In some cases, the diameter of the internal passage 216 can be substantially the same as the diameter of the waveguide 106 so that the waveguide 106 securely contacts the inner surface 218 of the outer wall 214 that faces the longitudinal axis 150 (e.g., via a friction fit).

[0068] In some cases, the neck portion 208 may include one or more slots along the outer wall 214. For example, FIG. 3A to FIG. 3C As shown, the neck portion 208 may include a plurality of slots 220 extending through the outer wall 214. Each slot 220 may extend partially or entirely along the neck portion 208. The slots 220 may be useful, for example, to facilitate bending of the mechanical connector 200. FIG. 3A to FIG. 3C As shown, the slots 220 may be evenly spaced azimuthally about the longitudinal axis 150. Although Figure 2A and FIG. 3A to FIG. 3C Four slots 220 are shown, but in practice, the neck portion 208 may include any number of slots (eg, one, two, three, or more slots), or no slots at all.

[0069] The bushing portion 210 is configured to be mechanically coupled to the actuator 114. The bushing portion 210 extends along the longitudinal axis 150. The bushing portion 210 has a tubular configuration and includes an outer wall 222 surrounding a hollow interior passage 224.

[0070] The internal passage 224 is sized to accommodate the actuator 114. In some cases, the cross-sectional shape of the internal passage 224 can be the same or substantially the same as the cross-sectional shape of the actuator 114. For example, if the cross-sectional shape of the actuator 114 is circular or substantially circular, the internal passage 224 can also have a circular or substantially circular cross-section. In some cases, the diameter of the internal passage 224 can be substantially the same as the diameter of the actuator 114 so that the actuator 114 firmly contacts the inner surface 226 of the outer wall 222 facing the longitudinal axis 150 (e.g., through a friction fit). In some cases, the diameter of the internal passage 224 can be greater than the diameter of the actuator 114 so that a gap area 228 is defined between the inner surface 226 of the outer wall 222 and the actuator 114.

[0071] In some cases, the sleeve portion 210 may include one or more slots along the outer wall 222. For example, Figure 2A and FIG. 3A to FIG. 3C As shown, the sleeve portion 210 may include a plurality of slots 230 extending through the outer wall 222. Each slot 230 may extend partially or completely along the sleeve portion 210. The slots 230 may be useful, for example, to facilitate bending of the mechanical connector 200. Figure 2A and FIG. 3A to FIG. 3C Four slots 230 are shown, but in practice, the bushing portion 210 may include any number of slots (eg, one, two, three, or more slots), or no slots at all.

[0072] Flexible member portion 212 is configured to mechanically couple neck portion 208 to bushing portion 210 such that forces imparted to bushing portion 210 (e.g., forces caused by vibrations generated by actuator 114) are coupled to neck portion 208. In some cases, a portion of flexible member portion 212 or the entirety of flexible member portion 212 may bend relative to neck portion 208 and / or bushing portion 210 such that neck portion 208 and bushing portion 210 are not rigidly coupled together.

[0073] The flexible member portion 212 may include various structures extending between the neck portion 208 and the sleeve portion 210. For example, FIG. 2A to FIG. 2B and FIG. 3A to FIG. 3D As shown, the flexible member portion 212 may include an annular portion 232 (eg, a flange or rim), and a beam 234 extending between and interconnecting the neck portion 208 and the bushing portion 210. Figure 2A , Figure 3A and Figure 3D Four beams 234 are shown, but in practice, the flexible member portion 212 has any number of beams 234 (e.g., one, two, three, or more slits). In some cases, the flexible member portion 212 may not have any beams at all, and the annular portion 232 may extend from the neck portion 208 to the bushing portion 210 alone. Also, in some cases, the flexible member portion 212 may not include any annular portion 232 at all (e.g., each of the beams 234 may extend directly from the neck portion 208 to the bushing portion 210). Other configurations may also be used to vary the stiffness of the flexible member portion 212.

[0074] In some cases, the mechanical connector 200 can be rotationally symmetric about the longitudinal axis 150. In some cases, the mechanical connector 200 can have at least four-fold rotational symmetry about the longitudinal axis 150.

[0075] In some cases, the mechanical connector 200 may have a direction-dependent stiffness. Figure 3D , the mechanical connector 200 may have a first translational stiffness k relative to the longitudinal axis 150 (ie, the z-axis) z , the second translation stiffness k relative to the x-axis x and the third translation stiffness k relative to the y-axis y (where x, y and z axes refer to the axes of the Cartesian coordinate system). The first translation stiffness k z can be different from the second translation stiffness k x and the third translational stiffness k y For example, the first translation stiffness k z Can be greater than the second translation stiffness k x and the third translation stiffness k y In addition, in some cases, the second translation stiffness k x and the third translational stiffness k y Can be basically the same.

[0076] In addition, the mechanical connection 200 may have a first rotational stiffness k about the x-axis. θx , the second rotational stiffness k around the y axis θyThe first rotational stiffness k θx and the second rotational stiffness k θy can be substantially the same, and each rotational stiffness can be less than the first translational stiffness k z .

[0077] This combination of stiffnesses can be useful, for example, because it enables the mechanical link 200 to couple forces from the actuator 114 uniformly relative to the xy plane so that during operation of the actuator 114, the waveguide 106 is less likely to exhibit direction-dependent bias relative to the xy plane. As a result, the waveguide 106 is more likely to follow a predictable, predetermined scanning pattern, thereby improving projected image quality. In addition, due to the first translational stiffness k z is relatively large, so the waveguide 106 translates less along the z-axis while still allowing it to vibrate relative to the x- and y-axes.

[0078] Furthermore, in some cases, the stiffness can be modified to change the behavior of the waveguide 106 (e.g., to increase or decrease the deflection angle of the waveguide tip 108 during operation of the actuator 114 and / or to change the natural frequency or resonant frequency of the waveguide tip 108 during operation). Thus, the performance of the FSD device 100 can be adjusted by modifying the stiffness of the mechanical connection 200. In some cases, the mechanical connection 200 enables the waveguide tip 108 to scan a pattern at a frequency of approximately 10 kHz to 150 kHz and to achieve radial deflections of between 600 μm and 1800 μm (e.g., the tip 108 traverses a circular or substantially circular path with a diameter of between 600 μm and 1800 μm). Other performance characteristics are also possible, depending on the implementation.

[0079] For example, in some cases, the typical radial translation stiffness can be between 0.375N / mm and 6.0N / mm, while the buckling mode stiffness can be between 1.7N / mm and 28N / mm. In some cases, the typical axial translation stiffness can be between 1.2N / mm and 20.0N / mm, while the buckling mode stiffness can be between 20.0N / mm and 360.0N / mm. In some cases, the typical rotational stiffness can be between 0.1N*mm / Rad and 1.6N*mm / Rad, while the buckling mode stiffness can be between 0.15N*mm / Rad and 2.5N*mm / Rad.

[0080] In some cases, each slot 220 may be radially aligned with a corresponding slot 230 and a corresponding beam 234. For example, Figure 4A and Figure 4BAs shown, the first slot 220a, the first slot 230a, and the first beam 234a are respectively arranged in a first radial direction 402a relative to the longitudinal axis 150. In addition, the second slot 220b, the second slot 230b, and the second beam 234b are respectively arranged in a second radial direction 402b relative to the longitudinal axis 150. In addition, the third slot 220c, the third slot 230c, and the third beam 234c are respectively arranged in a third radial direction 402c relative to the longitudinal axis 150. In addition, the fourth slot 220d, the fourth slot 230d, and the fourth beam 234d are respectively arranged in a fourth radial direction 402d relative to the longitudinal axis 150.

[0081] Furthermore, the directions may be evenly spaced azimuthally about the longitudinal axis 150. For example, Figure 4A and Figure 4B As shown, radial directions 236 a - d are azimuthally spaced apart in 90° increments relative to longitudinal axis 150 .

[0082] In some cases, radial directions 236a-d may be aligned with respective piezoelectric elements of actuator 114. For example, in Figure 4C In the example shown, the actuator 114 includes: four rows of piezoelectric elements (e.g., piezoelectric ceramic elements) that are uniformly spaced azimuthally about the longitudinal axis 150; and electrode plates that are disposed between adjacent piezoelectric elements (due to the Figure 4C 4, showing only two piezoelectric elements 404a and 404b and three electrode plates 406a-c). Figure 4C As shown, the first radial direction 402a may be radially aligned with the first piezoelectric element 404a, and the second radial direction 402b may be radially aligned with the second piezoelectric element 404b. Similarly, the third radial direction 402c and the fourth radial direction 402d may be radially aligned with the third piezoelectric element and the fourth piezoelectric element, respectively.

[0083] For example, this configuration may be used to define an axis of motion of the FSD device 100 during operation of the actuator 114 and / or to reduce direction-dependent bias relative to the xy plane.

[0084] although Figure 2A , Figure 2B , FIG. 3A to FIG. 3D and FIG. 4A to FIG. 4C An example configuration of the mechanical connector 200 is shown, but this is merely an illustrative example. In practice, the configuration of the mechanical connector may be different depending on the application (e.g., to accommodate actuators and / or waveguides of different sizes, to provide different stiffness characteristics, to provide different waveguide deflection characteristics, etc.).

[0085] As an example, FIG. 5A to FIG. 5C Another mechanical connection 500 is shown. Figure 5Ashows a perspective view of a mechanical connector 500, Figure 5B shows a top view of a mechanical connector 500, Figure 5C A cross-sectional view of the mechanical connector 500 along plane A is shown.

[0086] Mechanical connector 500 is similar to mechanical connector 200 in some respects. For example, mechanical connector 500 includes neck portion 502, bushing portion 504, and flexible element portion 506. Neck portion 502 is configured to be mechanically coupled to a waveguide (e.g., waveguide 106) via a mechanical and / or chemical attachment therebetween. In addition, bushing portion 504 is configured to be mechanically coupled to an actuator (e.g., actuator 114). In addition, flexible element portion 506 is configured to mechanically couple neck portion 502 to bushing portion 504 so that a force imparted to bushing portion 504 (e.g., a force caused by vibration generated by the actuator) is coupled to neck portion 502.

[0087] The flexible member portion 506 also includes an annular portion 508 (eg, a flange or rim) extending between and interconnecting the neck portion 502 and the bushing portion 504. A plurality of slots may be defined on the annular portion 508. For example, FIG. 5A to FIG. 5C As shown, three slots 510 may be defined on the annular portion 508, each slot extending spirally outward from the neck portion 502. The slots 510 may be defined rotationally symmetrically about a longitudinal axis 512 of the mechanical connector 500 (e.g., each slot 510 may be rotationally offset by 120° from an adjacent slot 510). FIG. 5A to FIG. 5C Three slots 510 are shown, but this is merely an illustrative example. In practice, the mechanical connector may include any number of slots 510 (eg, one, two, three, four, or more).

[0088] In addition, if Figure 5B As shown, the slot 510 is confined within an imaginary circle B. In practice, the size of circle B may be different such that the slot 510 occupies a larger or smaller area within the annular portion 508 .

[0089] In addition, if Figure 5A and Figure 5C As shown, the mechanical connector 500 also includes a central stepped structure 514. The central stepped structure 514 extends outwardly from the flexible element portion 506 and surrounds the neck portion 502, thereby forming a step or notch 516. The central stepped structure 514 can be used to provide additional rigidity to the mechanical connector 500, for example.

[0090] FIG. 6A to FIG. 6C Another example mechanical connector 600 is shown. Fig. 6A shows a perspective view of a mechanical connector 600, Figure 6B shows a top view of a mechanical connector 600, Figure 6C A cross-sectional view of the mechanical connector 600 along plane A is shown.

[0091] Mechanical connector 600 is similar to mechanical connector 200 in some respects. For example, mechanical connector 600 includes neck portion 602, sleeve portion 604, and flexible element portion 606. Neck portion 602 is configured to be mechanically coupled to a waveguide (e.g., waveguide 106) via a mechanical and / or chemical attachment therebetween. Furthermore, sleeve portion 604 is configured to be mechanically coupled to an actuator (e.g., actuator 114). Furthermore, flexible element portion 606 is configured to mechanically couple neck portion 602 to sleeve portion 604 so that a force imparted to sleeve portion 604 (e.g., a force caused by vibrations generated by the actuator) is coupled to neck portion 602.

[0092] The mechanical connector 600 also includes a central stepped structure 610. The central stepped structure 610 includes a plurality of finger structures 612, each of which extends outwardly from the flexible element portion 606. For example, Fig. 6A and Figure 6B As shown, the mechanical connector 600 may include eight finger structures 612 that protrude from the flexible element portion 606 and surround the neck portion 602. The finger structures 612 may be arranged rotationally symmetrically about the longitudinal axis 608 of the mechanical connector 600 (e.g., each finger structure 612 may be rotationally offset by 45° from an adjacent finger structure 612). FIG. 6A to FIG. 6C Eight finger structures 612 are shown, but this is merely an illustrative example. In practice, the mechanical connector may include any number of finger structures 612 (eg, one, two, three, four, or more).

[0093] In addition, the finger structure 612 forms a step or notch 614. FIG. 5A to FIG. 5C In a similar manner to that described above, the central stepped structure 610 may be used, for example, to provide additional rigidity to the mechanical connector 600 .

[0094] FIG. 7A to FIG. 7C Another example mechanical connector 700 is shown. Fig. 7A shows a perspective view of a mechanical connector 700, Figure 7B shows a top view of a mechanical connector 700, Figure 7C A cross-sectional view of the mechanical connector 700 along plane D is shown.

[0095] The mechanical connector 700 includes a neck portion 702, a bushing portion 704, and a universal joint structure 706. The neck portion 702 is configured to be mechanically coupled to a waveguide (e.g., waveguide 106) via a mechanical and / or chemical attachment therebetween. In addition, the bushing portion 704 is configured to be mechanically coupled to an actuator (e.g., actuator 114).

[0096] In addition, the gimbal structure 706 is configured to mechanically couple the neck portion 702 to the bushing portion 704 so that forces imparted to the bushing portion 704 (e.g., forces caused by vibrations generated by the actuator) are coupled to the neck portion 702. The gimbal structure 706 includes a ring 708, an inner beam 710 that mechanically couples the ring 708 to the neck portion 702, and an outer beam 712 that mechanically couples the ring 708 to the bushing portion 704.

[0097] like Figure 7B As shown, the ring 708 is oval in shape and centered about the longitudinal axis 714 of the mechanical connector 700. The inner beam 710 extends inwardly from the inner periphery of the ring 708 along the major axis 716 of the ring 708. The outer beam 712 extends outwardly from the outer periphery of the ring 708 along the minor axis 718 of the ring 708. In addition, the major axis 716 is orthogonal to the minor axis 718. Therefore, the inner beam 710 and the outer beam 712 are rotated 90 degrees relative to each other.

[0098] The gimbal structure 706 enables the neck portion 702 to rotate relative to the bushing portion 704 substantially about two discrete axes of rotation (e.g., about a major axis 716 and about a minor axis 718). For example, when the ring 708 is mechanically coupled to the bushing portion 704 via the outer beam 712, the ring 708 can rotate relative to the bushing portion 704 about the minor axis 718. This rotation, in turn, similarly causes the neck portion 702 to rotate relative to the bushing portion 704 about the minor axis 718. Furthermore, because the ring 708 is mechanically coupled to the neck portion 702 via the inner beam 710, the neck portion 702 can rotate relative to the ring 708 about the major axis 716.

[0099] This arrangement limits movement of the neck portion 702 relative to the bushing portion 704 along a discrete number of rotational axes. This can be used, for example, to improve the operating characteristics of the mechanical connection (eg, by eliminating or otherwise reducing erroneous movement along other rotational axes).

[0100] Although example mechanical connectors are depicted herein, it should be understood that they are not necessarily drawn to scale. In practice, the size of each structure of the mechanical connector may vary depending on the application. As an example, various sizes of the mechanical connector are described below. However, it should be understood that in practice, other sizes are also possible.

[0101] In some cases, the inner diameter of the bushing portion can be between 500 μm and 1500 μm (e.g., 502 μm, 612 μm, 804 μm, 940 μm, or 1242 μm). In some cases, the outer diameter of the bushing portion can be between 800 μm and 2000 μm (e.g., 802 μm, 912 μm, 802 μm, 912 μm, 1104 μm, 1214 μm, 1240 μm, and 1542 μm).

[0102] In some cases, the inner diameter of the neck portion can be between 20 μm and 200 μm (e.g., 26 μm, 72 μm, 82 μm, 84 μm, 102 μm, 127 μm, 129 μm, 140 μm, 185 μm, 204 μm, 260 μm, and 556 μm). In some cases, the outer diameter of the neck portion can be 300 μm or less (e.g., 300 μm, 150 μm, 100 μm, and 50 μm).

[0103] In some cases, the inner diameter of the central stepped structure can be between 50 μm and 1000 μm (e.g., 84 μm, 127 μm, 129 μm, 130 μm, 160 μm, 185 μm, 190 μm, 204 μm, 260 μm, and 556 μm). In some cases, the radial thickness of the central stepped structure can be between 10 μm and 60 μm (e.g., 20 μm and 50 μm).

[0104] In some cases, the thickness of the flexible member portion may be between 20 μm and 60 μm (eg, 30 μm and 50 μm).

[0105] In some cases, the thickness of the inner beam of the gimbal structure (e.g., in a direction orthogonal to the longitudinal axis of the mechanical connection) can be between 5 μm and 50 μm (e.g., 10 μm and 15 μm). In some cases, the thickness of the outer beam of the gimbal structure (e.g., in a direction orthogonal to the longitudinal axis of the mechanical connection) can be between 5 μm and 50 μm (e.g., 11 μm and 17 μm). In some cases, the length of the outer beam of the gimbal structure (e.g., in another direction orthogonal to the longitudinal axis of the mechanical connection) can be between 50 μm and 150 μm (e.g., 100 μm and 125 μm).

[0106] In some cases, the thickness of the spirally extending slot defined along the flexible element portion can be between 10 μm and 100 μm (e.g., 18 μm, 21 μm, 22 μm, 26 μm, 28 μm, 32 μm, 35 μm, 72 μm, 78 μm, 81 μm). In some cases, the spirally extending slot can be parameterized by the following formula: x(t)=(A 1 +B 1*T*π / 180)*(cos(T*π / 180) / 1000 and y(t)=(A 1 +B 1 *T*π / 180)*(sin(T*π / 180) / 1000, where 0≤T≤θ f . A 1 It can be between 100 μm and 200 μm (for example, 102 μm, 108 μm, 111 μm, 124 μm, 125 μm, 129 μm, 135 μm, 175 μm, 181 μm). 1 It can be between 10 μm and 100 μm (e.g., 23 μm, 24 μm, 25 μm, 28 μm, 30 μm, 31 μm, 32 μm, 52 μm, and 53 μm). f It can be between 200° and 350° (e.g., 220°, 262°, 272°, 277°, 278°, 279°, 296°, 299°, 301°, 304°, 315°).

[0107] Furthermore, while various configurations are described herein, it should be understood that various features may be combined into a single mechanical connector and / or excluded from a mechanical connector. As an example, the mechanical connector may include one or more of the following: a helically extending slot defined on a portion of the flexible element (e.g., FIG. 5A to FIG. 5C as shown), a central stepped structure (e.g. FIG. 5A to FIG. 5C and FIG. 6A to FIG. 6C ), a central stepped structure with finger-like structures (e.g., FIG. 6A to FIG. 6C As shown), universal joint structure (for example, as FIG. 7A to FIG. 7C ), a slot defined on the bushing portion (e.g., as Figure 3B ), a slot defined on the neck portion (e.g., as Figure 3B as shown) or any combination thereof.

[0108] A variety of materials may be used to construct the mechanical connector. For example, in some cases, the mechanical connector may be constructed in part or in whole from silicon. In some cases, the mechanical connector may be constructed using crystalline silicon (e.g., silicon having a (111) crystal structure) and / or amorphous silicon. In some cases, the mechanical connector may be constructed using one or more layers of silicon and / or one or more layers of an electrically insulating material (e.g., silicon dioxide).

[0109] In some cases, mechanical connections can be constructed using semiconductor micromachining techniques. FIG. 8A to FIG. 8C A simplified example is shown.

[0110] As an example, Fig. 8AA cross-sectional view of a wafer 800 is shown. The wafer 800 includes a device layer 810 (e.g., a silicon layer), a buried oxide layer 820 (e.g., a silicon dioxide layer), and a handle layer 830 (e.g., a silicon layer). These layers may be formed, for example, by successively depositing each of the layers on a substrate (e.g., using oxidation, physical vapor deposition, chemical vapor deposition, electroplating, spin coating, or other layer deposition techniques).

[0111] One or more features may be defined by selectively adding material to and / or removing material from the wafer 800. For example, Figure 8B As shown, material may be etched away from wafer 800 to define channel 840 .

[0112] Material may be added to and / or removed from wafer 800 in such a way that the remaining material forms a mechanical connection. Figure 8C As shown, material may be selectively removed along the perimeter of the wafer 800 so that a substantially cylindrical portion of the wafer 800 remains, forming the periphery of the outer wall 222 of the bushing portion 210 of the mechanical connector 200. Additionally, material may be selectively removed along the interior of the wafer 800 to define the interior channels 216 and 224. In a similar manner, additional material may be removed from the wafer 800 to define each of the other structures of the mechanical connector 200. As an example, the wafer 800 may be etched using a photolithography technique (e.g., wet etching or dry etching, such as reactive ion etching and deep reactive ion etching).

[0113] The use of micromachining techniques to produce mechanical connectors can provide various advantages. For example, in some cases, mechanical connectors can be precisely and consistently constructed and thus be suitable for use in specific varying applications (e.g., for use in imaging systems such as FSD devices that are highly sensitive to the characteristics of the mechanical connectors). In addition, mechanical connectors are easy to mass produce. Furthermore, the design of mechanical connectors can be easily modified and implemented and thus can be easily used in a variety of different applications.

[0114] although FIG. 8A to FIG. 8C An example micromachining process is shown, but this is only a simplified example. In practice, other micromachining techniques may be used to produce mechanical connectors and / or to produce mechanical connectors with different structural features than those shown herein. For example, similar techniques may also be used to form any other mechanical connectors described herein (e.g., mechanical connectors 500, 600, and 700).

[0115] A number of embodiments have been described. However, it will be appreciated that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.

Claims

1. A fiber optical system comprising: optical fiber; an actuator configured to generate a force to change the orientation of the first end of the optical fiber; as well as a connector that mechanically couples the actuator to the optical fiber, wherein the connector is configured to couple the force generated by the actuator to the optical fiber, wherein the connector comprises: a neck extending along the axis, the optical fiber passing through a hole through the neck extending along the axis, wherein the optical fiber is attached to the connector at a surface of the neck facing the axis, a bushing extending along the shaft, wherein the actuator is mechanically attached to the connection member at an inner surface of the bushing facing the shaft, and a flexible element extending radially from the neck to the bushing, wherein the connecting member has a first stiffness relative to the axis, a second stiffness relative to a first radial direction, and a third stiffness relative to a second radial direction orthogonal to the first radial direction, and Wherein, the first stiffness is greater than the second stiffness and the third stiffness.

2. The fiber optical system according to claim 1, wherein: The connector includes crystalline silicon.

3. The fiber optical system according to claim 2, wherein: The crystalline silicon has a (111) crystal structure.

4. The fiber optical system according to claim 1, wherein: The connecting member includes amorphous silicon.

5. The fiber optical system according to claim 1, wherein: The connector includes one or more layers of silicon and one or more layers of electrically insulating material.

6. A fiber optical system comprising: optical fiber; an actuator configured to generate a force to change the orientation of the first end of the optical fiber; as well as a connector that mechanically couples the actuator to the optical fiber, wherein the connector is configured to couple the force generated by the actuator to the optical fiber, wherein the connector comprises: a neck extending along the shaft, the optical fiber passing through a hole through the neck extending along the shaft, wherein the optical fiber is attached to the connector at a surface of the neck facing the shaft, and wherein the neck defines one or more slots along a periphery of the neck, a bushing extending along the shaft, wherein the actuator is mechanically attached to the connection member at an inner surface of the bushing facing the shaft, and A flexible member extends radially from the neck to the bushing.

7. The fiber optic system of claim 6, wherein the one or more slots are arranged helically about the axis.

8. A fiber optic system comprising: optical fiber; an actuator configured to generate a force to change the orientation of the first end of the optical fiber; as well as a connector that mechanically couples the actuator to the optical fiber, wherein the connector is configured to couple the force generated by the actuator to the optical fiber, wherein the connector comprises: a neck extending along the axis, the optical fiber passing through a hole through the neck extending along the axis, wherein the optical fiber is attached to the connector at a surface of the neck facing the axis, a bushing extending along the shaft, wherein the actuator is mechanically attached to the connection member at an inner surface of the bushing facing the shaft, and A flexible element extends radially from the neck to the bushing, wherein the flexible element includes a universal joint structure.

9. A fiber optic system comprising: optical fiber; an actuator configured to generate a force to change the orientation of the first end of the optical fiber; as well as a connector that mechanically couples the actuator to the optical fiber, wherein the connector is configured to couple the force generated by the actuator to the optical fiber, wherein the connector comprises: a neck extending along the axis, the optical fiber passing through a hole through the neck extending along the axis, wherein the optical fiber is attached to the connector at a surface of the neck facing the axis, a bushing extending along the shaft, wherein the actuator is mechanically attached to the connection member at an inner surface of the bushing facing the shaft, and A flexible element extends radially from the neck to the bushing, wherein the flexible element includes one or more beams extending from the neck to the bushing.

10. The fiber optic system of claim 1, further comprising an illumination source in optical communication with the optical fiber, wherein: The illumination source is configured to direct light into the optical fiber during operation.

11. The fiber optical system according to claim 10, wherein: The actuator is configured to change the orientation of a portion of the optical fiber during operation such that the first end of the optical fiber traverses a predetermined pattern.

12. The fiber optic system of claim 11, further comprising a light guide, wherein: The light guide is configured to receive light from the illumination source during operation, direct the received light to an end of the optical fiber, and emit the received light from the first end of the optical fiber.

13. A method for operating a fiber optic system, the fiber optic system comprising an optical fiber, an actuator configured to generate a force to change the orientation of a first end of the optical fiber, and a mechanical connection coupling the actuator to the optical fiber, wherein the mechanical connection is configured to couple the force generated by the actuator to the optical fiber, the method comprising: directing light from a light source into the optical fiber, the optical fiber passing through a hole through a neck of a connector, the mechanical connector being mechanically attached to the actuator along an inner surface of a bushing of the mechanical connector, the neck and bushing being mechanically coupled by a flexible member extending from the neck to the bushing; The actuator is operated to change the orientation of the first end of the optical fiber extending from the mechanical connector according to a helical pattern.

14. The method according to claim 13, further comprising: The light is emitted from the first end of the optical fiber toward a subject.

15. The method according to claim 14, wherein: The object is the user's eyes.

16. The method according to claim 13, further comprising: generating pixel modulation signals and driving signals; using the light source to generate the light according to the pixel modulation signal; as well as The actuator is operated according to the drive signal.

17. The method according to claim 16, wherein: The pixel modulation signal adjusts the output of the light source according to the spiral pattern.

18. The method according to claim 17, wherein: The drive signal regulates operation of the actuator to change the orientation of the first end of the optical fiber according to the helical pattern.

19. The method of claim 17, further comprising emitting light from the first end of the optical fiber to form an image on an image plane.

20. The method of claim 13, wherein operating the actuator comprises using the mechanical connection to couple a mechanical force generated by the actuator to the optical fiber.

21. The method according to claim 20, wherein: The flexible element of the mechanical connector includes one or more beams extending between the neck and the bushing, and wherein the mechanical force generated by the actuator is coupled to the optical fiber at least in part through the one or more beams.

22. The method according to claim 20, wherein: The flexible element of the mechanical connector includes a gimbal structure, and wherein the mechanical force generated by the actuator is coupled to the optical fiber at least partially through the gimbal structure.

23. A fiber optic system comprising: optical fiber; an actuator configured to generate a force to change the orientation of the first end of the optical fiber according to a helical pattern; as well as a connector that mechanically couples the actuator to the optical fiber, wherein the connector is configured to couple the force generated by the actuator to the optical fiber, wherein the connector comprises: a neck extending along the axis, the optical fiber passing through a hole through the neck extending along the axis, wherein the optical fiber is attached to the connector at a surface of the neck facing the axis, a bushing extending along the shaft, wherein the actuator is mechanically attached to the connection member at an inner surface of the bushing facing the shaft, and A flexible member extends radially from the neck to the bushing.

24. The fiber optic system of claim 23, wherein: The optical fiber is configured to emit the light from the first end of the optical fiber toward a subject.

25. The fiber optic system of claim 24, wherein: The object is the user's eyes.

26. The fiber optic system of claim 23, further comprising: A driving module configured to generate a pixel modulation signal; and A light source is configured to generate light according to the pixel modulation signal and provide the light to a second end of the optical fiber opposite the first end, wherein the pixel modulation signal adjusts the output of the light source according to the spiral pattern.

27. The fiber optic system of claim 26, wherein: The drive module is configured to generate a drive signal, wherein the drive signal regulates operation of the actuator to change the orientation of the first end of the optical fiber according to the helical pattern.

28. The fiber optic system of claim 27, wherein: The fiber optic system includes a head mounted display device.

29. The fiber optic system of claim 23, wherein: The actuator includes a plurality of piezoelectric elements azimuthally spaced about the axis.

30. The fiber optic system of claim 29, wherein: The plurality of piezoelectric elements are evenly spaced apart in azimuth.

31. The fiber optic system of claim 29, wherein: The plurality of piezoelectric elements are azimuthally spaced apart by 90°.

32. The fiber optic system of claim 23, wherein: The flexible element includes one or more beams extending between the neck and the bushing.

33. The fiber optic system of claim 23, wherein: The connecting member has a first stiffness relative to the axis, a second stiffness relative to a first radial direction, and a third stiffness relative to a second radial direction orthogonal to the first radial direction, wherein the first stiffness is greater than the second stiffness and the third stiffness.

34. The fiber optic system of claim 23, wherein: The connector includes crystalline silicon.

35. The fiber optic system of claim 23, wherein: The connecting member includes amorphous silicon.

36. The fiber optic system of claim 23, wherein: The connector includes one or more layers of silicon and one or more layers of electrically insulating material.

37. The fiber optic system of claim 23, wherein: The neck defines one or more slots along a periphery of the neck.

38. The fiber optic system of claim 23, wherein: The flexible element defines one or more slots extending therethrough, the one or more slots being helically arranged about the shaft.

39. The fiber optic system of claim 23, wherein: The flexible element includes a universal joint structure.

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