Comb-drive MEMS resonant scanner with full circumferential range and large out-of-plane translational displacement

Abstract

A scanning assembly for an optical instrument includes a reflector and a folded beam spring assembly coupled to the reflector to deflect the reflector for beam scanning. A lever suspension assembly is coupled to the folded beam spring assembly and provides torsional movement of the reflector for beam scanning in a two-dimensional area, thereby achieving a large total scanning angle and a large vertical displacement.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 820,032, filed on March 18, 2019, which is incorporated herein by reference in its entirety.

[0003] Government Interest Statement

[0004] This invention was made with government support under EB020644 awarded by the National Institutes of Health. The government has certain rights in this invention. Technical Field

[0005] The present disclosure relates generally to techniques for imaging tissue using optical instruments, and more particularly to techniques that allow real-time scanning using optical instruments. Background Art

[0006] The brief description of the related art provided herein is for the purpose of generally presenting the context of the present disclosure. To the extent described in this brief description of the related art section, the work of the presently named inventors and aspects of the description that may not otherwise qualify as prior art at the time of filing are neither explicitly nor implicitly admitted as prior art to the present disclosure.

[0007] Resonant devices fabricated using microelectromechanical systems (MEMS) technology have been used to perform fast scans with large amplitudes and low power consumption. MEMS technology is characterized by high mechanical reliability and has been used in applications including projection displays, light detection and ranging (LiDAR), three-dimensional (3D) depth sensing, and Fourier transform infrared (FTIR) spectroscopy. Using conventional MEMS design and fabrication methods, resonant devices have been developed that can achieve optical scan angles up to 90°. While this level of performance is sufficient for many applications, for emerging areas such as panoramic imaging and surround monitoring, even larger displacement and deflection angles are required.

[0008] In response to the need for larger displacement and deflection angles, multiple MEMS scanners with wide-angle optics have been attempted. However, current designs result in increased complexity and size. Other MEMS scanners have been proposed to utilize actuation techniques that employ large forces or moments, motion conversion mechanisms, high-fracture materials as flexible pivots, or vacuum packaging to reduce damping. Among other proposed electrostatic, electromagnetic, and thin-film piezoelectric technologies, the prospect of low-cost batch manufacturing capabilities is shown, and therefore, it is an increasingly common MEMS-based approach to increase scanning range. There is still a need for more efficient MEMS scanners, especially scanners that can achieve translational and torsional motion, because they allow true three-dimensional (3D) scanning to be performed.

[0009] To date, designs of MEMS resonant scanners that have demonstrated large travel have focused only on translational or torsional motion. Only a few approaches involving thin-film piezoelectric and thermoelectric actuation mechanisms can provide large amplitude motion in both modes. The deformable membrane structures in piezoelectric and thermoelectric MEMS scanners are usually designed with sufficient length to provide large deformations, but at the expense of limited scanning speed. Electrostatic actuation has the advantages of fast response time, low power consumption, and ease of integration, despite the limited operating range due to the pull-in effect and high actuation voltage requirements.

[0010] There is a need for improved MEMS resonant scanners that can be used for both 3D and 2D imaging. Summary of the invention

[0011] To address the above problems, the present application describes a MEMS resonant scanner assembly and an apparatus for deploying the same. The MEMS resonant scanner may be a comb-drive MEMS resonant scanner with an optical scan angle greater than 360° at ambient pressure. In addition to this extremely large scan range and rotational movement, various examples herein enable large out-of-plane translations for axial scanning and volumetric imaging. In various examples, out-of-plane translations greater than 100 μm, greater than 200 μm, greater than 300 μm, greater than 400 μm, and greater than 500 μm may be achieved. Total scan angles greater than 100°, greater than 200°, greater than 300°, greater than 400°, greater than 500°, etc. may be achieved in X-axis and Y-axis motion.

[0012] According to an example, a scanning assembly for use in an optical instrument includes: a frame that provides support; a reflector that is suspended in an interior area of ​​the frame; a folded beam spring assembly that is connected to the reflector and is configured to provide deflection of the reflector for light beam scanning in an out-of-plane direction; a lever suspension assembly that is connected to the frame of the scanning assembly and to the folded beam spring assembly positioned between the lever suspension assembly and the reflector, the lever suspension assembly being configured to provide torsional movement of the reflector for light beam scanning in a two-dimensional area, the lever suspension assembly having a lever arm; and a comb drive assembly that is connected to the lever suspension assembly for controlling torsional and / or translational movement of the reflector.

[0013] In some examples, the lever suspension assembly includes a first lever suspension and a second lever suspension, each of the first lever suspension and the second lever suspension having a lever arm mechanically coupled to a frame of the scanning assembly and to a folded beam spring assembly, each lever arm being flexible to provide deflection of the reflector.

[0014] In some examples, each of the first lever suspension and the second lever suspension includes an H-shaped torsion spring.

[0015] In some examples, the folded beam spring assembly includes a first folded beam spring assembly and a second folded beam spring assembly, each coupled to opposite sides of the reflector and each configured to provide deflection of the reflector in an out-of-plane direction.

[0016] In some examples, each of the first and second folded beam spring assemblies includes four multi-turn central clamped folded beam springs connected to the reflector by connecting arms. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] For a more complete understanding of the present disclosure, reference should be made to the following detailed description and accompanying drawings, in which like reference numerals represent like elements throughout the figures, and in which:

[0018] Figure 1 Depicted is an optical probe having a proximal end and a distal end having a tip accommodating a 2D scanner according to an example.

[0019] Figure 2 A top view of a 2D scanner according to an example.

[0020] Figure 3 To show the twisting rotation according to the example Figure 2 Side cross-sectional view of the 2D scanner.

[0021] Figure 4 To demonstrate the out-of-plane translation displacement according to the example Figure 2 Side cross-sectional view of the 2D scanner.

[0022] Figure 5 According to the example, the chip frame is attached as a pivot for moving Figure 2 Top view of the H-shaped torsion spring with an example of a 2D scanner.

[0023] Figure 6 For example, for mobile Figure 2 2D scanner example. Top view of a multi-turn centrally clamped folded beam spring.

[0024] Fig. 7A A rigid body model for translational (yaw) movement of a 3D scanner according to an example is shown. Figure 7B A rigid body model for torsional movement of a 2D scanner according to an example is shown.

[0025] Fig. 8A and Figure 8B A finite element model (FEM) modal analysis for a 2D scanner according to an example is shown. Fig. 8A The first mode is shown to be torsional (reflected) and occurs at a resonant frequency of 792.34 Hz. Figure 8B The second mode is shown as translation (deflection) and occurs at a resonant frequency of 1000.05 Hz.

[0026] Figure 9A-9D Different steps in a manufacturing process for forming a 2D scanner according to an example are shown. Fig.9A Deposition of a plasma enhanced chemical vapor deposition (PECVD) SiO2 hard mask layer is shown. Fig. 9B Double-sided patterning is shown. Fig. 9C Deep reactive ion etching (DRIE) etching is shown. Fig.9D Buffered hydrofluoric acid (BHF) SiO2 etch and release, rinse and dry, and Al deposition are shown.

[0027] Figure 10A-10C Scanning electron microscope (SEM) images of an example 2D scanner, an H-shaped spring of a lever arm, and a multi-turn center-clamped folded beam spring are shown, respectively.

[0028] Fig.11A and Fig. 11B Schematic diagrams depicting movement of a reflector of a 2D scanner mounted on a substrate and a picture of the reflector of the 2D scanner according to an example are respectively shown.

[0029] Fig. 12A and Fig. 12BPictures of 2D scanner motion according to an example are shown, respectively, showing (a) torsional mode with ~±90° mechanical scan angle and (b) out-of-plane translational mode with displacement of >466 μm (thickness of the device chip).

[0030] Fig.13 Example rotational scanning angles that may be achieved by a 2D scanner are shown according to an example.

[0031] Figures 14A-14D is a graph of the frequency response according to an example, showing the first and second superharmonic resonances ( Fig.14A ), Example of achieving a maximum optical scan angle of 494° at 1.707kHz using 100V ( Fig. 14B ), using 80V can achieve a large scanning angle of up to 205° near 10ωt0 ( Fig. 14C ) and the unstable region disappears when the up-sweep (low to high frequency) and down-sweep (high to low frequency) of the frequency response curve coincide near 62ωt0 at 80V ( Fig.14D ).

[0032] Fig.15A and Fig. 15B FIG. 10 shows scanner parameters according to an example, and in particular shows the relationship between drive voltage and frequency ( Fig.15A ) and the relationship between the maximum vertical displacement and the driving voltage ( Fig. 15B ).

[0033] Figure 16A-16B A graph showing the frequency response of a 2D scanner for translational motion under different driving frequency conditions according to an example.

[0034] Fig.17A and Fig. 17B The relationship among the driving frequency, driving voltage and maximum optical scanning angle for the translation mode according to the example is shown, showing the relationship between the driving voltage and the frequency ( Fig.17A ), and the relationship between the maximum vertical displacement and the driving voltage ( Fig. 17B ).

[0035] Fig.18 Depicted is an example block diagram showing various components used in an example embodiment implementing a 2D scanner, according to an example.

[0036] The skilled person will appreciate that the elements in the figures are illustrated only for simplicity and clarity, and are not necessarily drawn to scale. For example, the size and / or relative positioning of some of the elements in the figures may be magnified relative to other elements to help improve the understanding of the various embodiments of the present invention. In addition, common but well-understood elements that are useful or necessary in commercially feasible embodiments are generally not depicted so as to less obstruct the views of these various embodiments. It should also be understood that certain actions and / or steps may be described or depicted in a specific order of occurrence, and those skilled in the art will understand that such specificity regarding the sequence is not actually required. It should also be understood that, except for different specific meanings to be otherwise set forth herein, the terms and expressions used herein have the common technical meanings given to such terms and expressions by those skilled in the art as described above. DETAILED DESCRIPTION

[0037] Generally speaking, according to these various embodiments, techniques are provided for the design, fabrication, and performance of compact, integrated two-dimensional (2D) MEMS scanners. The size of these 2D MEMS scanners allows them to be incorporated into endoscopic devices and other small form factor applications.

[0038] The 3D MEMS scanning technology described herein is capable of producing both large angular deflections and out-of-plane displacements. For example, total scan angles of greater than about 100°, greater than about 200°, greater than about 300°, greater than about 400°, greater than about 500°, etc., can be achieved in X-axis and Y-axis motion. The 2D MEMS scanner technology described herein can achieve such operating conditions in vertical displacement, with a depth of scan along the Z axis of greater than about 200 μm, greater than about 300 μm, greater than about 400 μm, greater than about 500 μm, greater than about 600 μm, etc.

[0039] Figure 2 A 2D optical scanner 200 according to an example is depicted. The 2D optical scanner has three degrees of freedom along the x-axis, y-axis, and z-axis, respectively. The 2D optical scanner 200 includes a specular reflector 202 centered at a central region of the scanner 200. The reflector 202 may be coated with a reflective surface that is reflective in the visible and / or infrared regions. In some examples including an endoscopic environment, the reflector 202 has a diameter of 1.5 mm.

[0040] The reflector 202 is supported by two symmetrical lever-based suspensions 204 and 206, each having lever arms 204A, 204B and 206A, 206B, respectively. These lever arms 204A, 204B, 206A, and 206B extend from a frame 210 of the scanner 200 and are flexible to provide compliance for moving the reflector 202 in a torsional (e.g., rotational) path (e.g., for scanning the XY plane) and a yaw (e.g., linear out-of-plane displacement) path (e.g., for scanning along the Z axis). Figure 3 An example of torsional path deflection of the reflector 202 using a lever arm is shown. Figure 4 An example of a deflection path traversed by reflector 202 is shown. That is, scanner 200 includes a method for implementing Figure 3 and Figure 4 The suspension shown has the function of translating motion of out-of-plane displacement (deflection) and rotation (torsional movement) into a compliant mechanism.

[0041] Each of the lever arms 204A, 204B, 206A, and 206B is designed to have a trapezoidal geometry with a pair of H-shaped torsion springs 220 attached to the frame 210 . Figure 5 A top view of one of the H-shaped torsion springs 220 attached to the frame 210 and acting as a pivot for both torsion and deflection path movement of the reflector 202 is shown. The H-shaped torsion spring 220 is formed of partially overlapping grooves to facilitate movement and is characterized by two different design geometries, a spacing width W between adjacent grooves, and a spacing width W between adjacent grooves. H and overlap length L H This example design of an H-shaped torsion spring allows for large angles of rotation while providing high resistance to lateral bending.

[0042] In the example shown, suspensions 204 and 206 are identical but are disposed on opposite sides of reflector 202 and are patterned as reflected images of each other. Suspension 204 includes comb drive 212. Suspension 206 includes comb drive 214. In the example shown, comb drives 212 and 214 are multi-row comb drives.

[0043] In addition to the comb drives 212 and 214, the reflector 202 is also moved by a pair of four multi-turn center clamped folded beam springs 222 and 224 for converting motion and connecting the reflector 202 to the lever arms 204A, 204B, 206A and 206B. One half of the spring 222 is shown in FIG. Figure 6, two folding beam sides 222A and 222B, a connecting arm 226 mechanically coupled to the reflector 202, and a lever connecting end 228 for mechanically coupling to the level 204A are shown. The design of these springs 222 and 224 enables large deflection in the folding direction while providing high resistance to lateral bending.

[0044] In operation, two comb drives 212 and 214 are formed as in-plane structures in the silicon layer of a silicon-on-insulator (SOI) wafer. The two drives 212 and 214 are used to excite the 3D scanner 200 under resonance. The double-row comb arrangement of the drives 212 and 214 provides a large electrostatic torque. A high ratio of reflector translation or rotation to lever rotation is achieved by directly attaching the multi-turn central clamping folded beam springs 222 and 224 along the central axis of the reflector 202. The vertical displacement along the Z axis and the rotation (scanning) angle of the reflector depend not only on the rotation of the lever arms 204 and 206, but also on the deformation of the multi-turn folded beam springs 222 and 224.

[0045] An example rigid body model of a 2D scanner similar to the example rigid body model of scanner 200 is shown in Fig. 7A and Figure 7B In the model, the motion of the reflector and the lever is described. The multi-turn folded beam spring is treated as a tension and torsion spring connected in series. The equation of motion can be expressed as follows:

[0046]

[0047]

[0048] where z L is the vertical displacement provided by the lever arm at its free end, z m is the vertical displacement provided by the multi-turn folded beam spring, L is the total length of the lever arm, θ is the rotation angle of the lever arm, and θ m is the total bending angle produced by the multi-turn folded beam spring at the center axis of the mirror. Finally, z i and θ i are the vertical displacement and torsion angle produced by individual beams of the multi-turn folded beam spring, respectively.

[0049] Large vertical displacements and scan angles can be achieved using designs with long levers and soft springs but at lower resonant frequencies. However, the ability to modify the geometric parameters of multiple components in the lever-based compliance mechanism allows us greater design flexibility to meet various amplitude and speed requirements. For example, applying equations (1) and (2), we can achieve large vertical displacements and scan angles with a small rotation of the lever. The comb drive between the lever arm and the scanner frame can be arranged to generate and apply a large electrostatic torque over a significant portion of the entire oscillation period. In addition, using the proposed design, we have found that due to z i and θ i It is only a fraction of the vertical displacement and torsion angle of the mirror, so the risk of fracture caused by large deformation and pressure is significantly reduced.

[0050] The equations of motion for the 2D scanner 200 are derived using the Euler-Lagrange method. The equations of torsional motion are as follows in equations (3) and (4):

[0051]

[0052] Among them J M and b Mr are the damping coefficients in the inertial and torsional modes of the reflector, respectively, and k mt is the equivalent torsion spring constant. The torsional motion of the lever arm is expressed as:

[0053]

[0054] Among them J L and b L is the inertia and damping coefficient of the lever arm, k L is the torsion spring constant of the H-spring, T es is the electrostatic torque, k me is the equivalent extension spring constant of a single multi-turn center-clamped beam folding spring, and L O is the distance from the pivot of the lever arm to the center axis of the reflector. An H-shaped spring may be located at one end of the lever arm and used as a pivot connected to the anchor. The pivot is connected to the chip frame.

[0055] The equation for out-of-plane translational motion is given by:

[0056]

[0057] Where M is the mass of the reflector, b Mt is the damping coefficient of the reflector in translation mode, and k me is the equivalent tension spring constant of a single multi-turn center-clamped folded beam spring.

[0058] The finite element model (FEM) was used to optimize the 2D scanner structure to achieve stable motion in torsion and translation modes and avoid crosstalk introduced by mechanical and electrical connections. The geometric parameters of the H-shaped torsion spring, multi-turn folded beam spring and lever arm are shown in Table 1.

[0059] Table 1. Geometric parameters of scanner components.

[0060] length width thickness Number of turns H-shaped torsion spring <![CDATA[L H =200μm]]> <![CDATA[W H =10μm]]> 50μm 1 Multi-turn center-clamp folded beam spring <![CDATA[L M =400μm]]> <![CDATA[W M =7μm]]> 50μm 17 Lever arm <![CDATA[L A =1475μm]]> ─ 50μm ─

[0061] In this example, the results of the FEM modal analysis are shown in Fig. 8A and Figure 8B In. First ( Fig. 8A ) and the second ( Figure 8B ) modes are torsional and translational, respectively, and occur at resonant frequencies of ~792 and ~1 Hz, respectively, as shown. In a parametric resonant system, large amplitude motion is achieved using a drive frequency that is twice the natural frequency. These results show that the frequencies of different modes in the scanner can be identified and optimized to avoid crosstalk.

[0062] Example Fabrication and Devices

[0063] Figure 9A-9D An example manufacturing process for forming a 3D scanner similar to scanner 200 is shown. In the example shown, a two mask process is used. An SOI wafer having a 50 μm silicon device layer, a 0.5 μm silicon dioxide (SiO2) buried layer, and a 415 μm silicon handle layer is used. Fig.9A As shown in FIG, a 0.6 μm SiO2 layer and a 2.5 μm SiO2 layer are formed on the front and back sides of the SOI wafer using plasma enhanced chemical vapor deposition (PECVD), respectively. These layers form a hard mask used to pattern the structure and protect the surface from scratches and contamination. See FIG. Fig. 9B , the top and bottom surfaces of the SOI wafer are patterned by photolithography using a top structure and a back mask, respectively. Fig. 9C After the PECVD SiO2 layer is removed by plasma etching, deep reactive ion etching (DRIE) is used to etch away the exposed silicon and the handle layer. Fig.9D After a buffered hydrofluoric acid (BHF) etching process is performed to remove the SiO2 layer, an isopropyl alcohol (IPA) rinse and drying process is performed to release the movable structure. Finally, an ~60nm aluminum (Al) layer is coated on the exposed surface of the silicon device layer using an electron beam evaporation process.

[0064] Figure 10A-10CScanning electron microscope (SEM) images of an example 3D scanner are provided, showing the overall view of the 2D scanner 300, the H-shaped spring 302, and the multi-turn center clamped folded beam spring 304. The dynamic performance of the 3D scanner 300 is characterized by sweeping the drive frequency to electrostatically excite the resonant mode. Laser scanning is used to measure the optical scan angle This parameter is measured as the internal angle of the arc scan α projected in a plane perpendicular to the torsion axis of the specular reflector, as Fig.11A The fabrication device is mounted on the substrate along only one edge, as shown in Fig. 11B This arrangement prevents the mounted substrate from blocking the deflected light in the torsional mode of oscillation and reduces squeeze damping in the out-of-plane translational mode of oscillation. A displacement sensor is used to measure the travel of the specular reflector in the translational mode.

[0065] In the example, the resonant torsional mode is scanned at a ±90° mechanical scan angle ( Fig. 12A ), and the motion of the 2D scanner 300 is shown in the resonant out-of-plane translation mode with a displacement of >466 μm (12B). In this example, the 2D scanner produces a wide rotational scan angle, such as by Fig.13 The full circumference pattern of the reflected laser beam is shown.

[0066] Figures 14A-14D The torsional motion performance of the example 2D scanner 300 is shown. As we have shown, the 2D scanner, as a parametric resonant scanner, can exhibit extremely nonlinear behavior in the torsional mode. The response to a square wave drive signal at a frequency close to twice the natural frequency (ωt0) exhibits a stiffness hardening-softening hybrid behavior, and Fig. 14B The maximum optical scan angle of 494° was achieved at 1.707kHz and 100V. In addition to this second superharmonic and first resonance, other higher superharmonic resonances were observed, see Fig.14A When the frequency of the sine wave drive signal is close to 10ωt0 at 80V and a large scanning angle of up to 205° is achieved (see Fig. 14C ), a softening of the stiffness is observed. However, when the up- and down-sweeps of the frequency response curve are overlapped using a sine wave drive signal at 80V at a frequency close to 62ωt0, the unstable region disappears, see Fig.14D While this performance data is provided by way of example, it demonstrates the range of robustness and wide optical scan angle range and adjustability that can be achieved using the inventive design.

[0067] The relationship between the drive frequency, voltage and the maximum optical scan angle using a square wave signal and a 50% duty cycle close to twice the natural frequency of the torsional mode is Fig.15A The optical scan angle of ∼200° at 40 V is shown in Fig. 15B middle.

[0068] Out-of-plane translational motion performance: In some instances, 2D scanners exhibit stiffness hardening-softening-mixed behavior in translational (deflection or out-of-plane) mode. Figures 16A-16D High-order superharmonic resonances are shown in , which show the vertical displacement measured from the neutral reflector position under different driving frequency conditions. Fig.17A and Fig. 17B An example of the relationship between drive frequency, voltage, and maximum displacement for a square wave signal and a 50% duty cycle sweep frequency close to twice the natural frequency of the translation mode is shown. A maximum vertical displacement of 561 μm was obtained by down-sweeping a square wave drive frequency of 50% duty cycle close to 1912 Hz at 80 V. A displacement of ~310 μm was obtained at a low drive voltage of 40 V.

[0069] The performance values ​​provided are provided as examples. We examined other device configurations of the scanner technology in this article with similar results in 3D and 2D scanning. In an example, a 2D scanner is formed with a 0.7mm diameter mirror that performs an out-of-plane translation displacement of ~320μm at 4.405kHz, and a torsion scan with a mechanical scan angle of ~±90° at 8.425kHz is developed. In another example, a 2D scanner with a 3mm diameter mirror is developed, which performs an out-of-plane translation scan with a displacement of ~780μm at 652Hz, and a torsion scan with a mechanical scan angle of ~±90° at 188Hz is developed. In another example, a 3D scanner that performs switchable horizontal / vertical 2D scanning is developed, which is capable of producing dense Lissajous scan patterns in a horizontal 2D scanning mode.

[0070] The present technology provides a comb-driven MEMS resonant 2D scanner based on a lever-based compliant mechanism for torsional or (out-of-plane) translational scanning. The design herein enables an extremely large scanning range in ambient pressure with little risk of mechanical breakage. Furthermore, the design of the lever-based compliant mechanism is very flexible.

[0071] The design and fabrication of high-speed MEMS scanners for optical applications is extremely challenging. Over the past 40 years, most MEMS scanners have made little progress in the amplitude of deflection angles and translational displacements. Optical instruments typically require large mirror sizes to capture maximum light. Therefore, large forces and moments are required to quickly achieve high scan amplitudes. In addition, air damping increases significantly with larger mirror sizes and faster scan speeds, thus requiring compact chip sizes.

[0072] But relatively high voltage is required to obtain a large scanning range. The present technology using comb drive devices demonstrates high performance, including fast scanning speed with extremely large amplitude without using vacuum packaging, low power consumption, compact size and easy manufacturing. This performance level can be deployed in miniature optical systems, including endoscopic devices, to perform panoramic imaging and surround monitoring. In addition, because the actuator is placed between the chip frame and the lever arm and its movement is only a part of the reflected movement, it is reasonable to expect that the proposed lever-based compliance can be integrated into MEMS resonant scanners using other actuation technologies such as thin film piezoelectric and electromagnetic actuation to achieve ultra-large scanning ranges at low drive voltages.

[0073] Fig.18 A system 400 is shown, which shows various components for implementing an example embodiment of a 2D MEMS scanner discussed herein. Device 402 may have a controller 404, which is operably connected to a database 414 via a link 422 connected to an input / output (I / O) circuit 412. It should be noted that, although not shown, additional databases may be linked to the controller 404 in a known manner. Controller 404 includes a program memory 406, a processor 408 (which may be referred to as a microcontroller or microprocessor), a random access memory (RAM) 410, and an input / output (I / O) circuit 412, all interconnected via an address / data bus 420. It should be understood that, although only one microprocessor 408 is shown, controller 404 may include multiple microprocessors 408. Similarly, the memory of controller 404 may include multiple RAMs 410 and multiple program memories 406. Although I / O circuit 412 is shown as a single block, it should be understood that I / O circuit 412 may include multiple different types of I / O circuits. For example, one or more of RAM 410 and program memory 406 may be implemented as semiconductor memory, magnetically readable memory, and / or optically readable memory.

[0074] The program memory 406 and / or RAM 410 may store various application programs (i.e., machine-readable instructions) for execution by the microprocessor 408. For example, the operating system 430 may generally control the operation of the device 402 (including the 3D scanner 110) and provide a user interface to the test equipment to implement the processes described herein. The program memory 406 and / or RAM 410 may also store various subroutines 432 for accessing specific functions of the device 402. The program memory 406 and / or RAM 410 may further store data related to the configuration and / or operation of the device 402 and / or related to the operation of one or more subroutines. For example, the data may be data collected by the 3D scanner 110, data determined and / or calculated by the processor 408, etc. In addition to the controller 404, the device 402 may also include other hardware resources. The device 202 may also be connected to various types of input / output hardware, such as a visual display 426 and one or more input devices 428 (e.g., keypads, keyboards, etc.) to fine-tune the actuation of the torsional and translational scans. In an embodiment, display 426 is touch sensitive and may cooperate with a software keyboard routine as one of software routines 432 to receive user input. In some examples, device 202 may communicate with connected devices through a wired or wireless network interface 434 connected to a communication network 436.

[0075] Throughout the entire specification, multiple instances can implement components, operations or structures described as single instances. Although the individual operations of one or more methods are shown and described as individual operations, one or more of the individual operations can be performed simultaneously, and do not need to perform the operations in the order shown. The structure and function presented as independent components in the example configuration can be implemented as a combined structure or component. Similarly, the structure and function presented as a single component can be implemented as an independent component. These and other changes, modifications, additions and improvements all fall within the scope of this paper theme.

[0076] In addition, certain embodiments are described herein as comprising logic or a number of routines, subroutines, applications, or instructions. These may constitute software (e.g., code embodied on a non-transitory machine-readable medium) or hardware. In hardware, routines, etc. are tangible units that are capable of performing certain operations and may be configured or arranged in a certain manner. In example embodiments, one or more computer systems (e.g., independent client or server computer systems) or one or more hardware modules of a computer system (e.g., a processor or a group of processors) may be configured by software (e.g., an application or an application portion) to be a hardware module that operates to perform certain operations as described herein.

[0077] In various embodiments, hardware modules may be implemented mechanically or electronically. For example, a hardware module may include dedicated circuits or logic that are permanently configured to perform certain operations (e.g., a dedicated processor such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC)). A hardware module may also include programmable logic or circuits that are temporarily configured to perform certain operations by software (e.g., as contained in a dedicated processor or other programmable processor). It should be understood that the decision to implement a hardware module mechanically in a dedicated and permanently configured circuit or in a temporarily configured circuit (e.g., configured by software) may be driven by cost and time considerations.

[0078] Thus, the term "hardware module" should be understood to encompass tangible entities, referring to entities that are physically constructed, permanently configured (e.g., hardwired), or temporarily configured (e.g., programmed) to operate in a certain manner or to perform certain operations described herein. In view of embodiments in which hardware modules are temporarily configured (e.g., programmed), it is not necessary to configure or instantiate each hardware module at any one time. For example, where the hardware modules include a general-purpose processor configured using software, the general-purpose processor can be configured into corresponding different hardware modules at different times. Thus, software can configure a processor, for example, to constitute a particular module at one time and to constitute a different module at a different time.

[0079] A hardware module may provide information to other hardware modules, or receive information from other hardware modules. Therefore, the hardware modules may be considered to be communicatively connected. In the case where multiple such hardware modules exist simultaneously, communication may be achieved by signal transmission (e.g., through appropriate circuits and buses) connecting the hardware modules. In embodiments where multiple hardware modules are configured or instantiated at different times, communication between such hardware modules may be achieved, for example, by storing and retrieving information in a memory structure accessible to multiple hardware modules. For example, a hardware module may perform an operation and store the output of such operation in a memory device to which it is communicatively connected. Then, another hardware module may access this memory device at a later time to retrieve and process the stored output. A hardware module may also initiate communication with an input or output device, and may operate on a resource (e.g., a collection of information).

[0080] The various operations of the example methods described herein may be performed at least in part by one or more processors that are temporarily configured (e.g., by software) or permanently configured to perform the relevant operations. Such processors, whether temporarily or permanently configured, may constitute processor-implemented modules that operate to perform one or more operations or functions. In some example embodiments, the modules referred to herein may include processor-implemented modules.

[0081] Similarly, the methods or routines described herein may be implemented at least in part by a processor. For example, at least some operations of a method may be performed by one or more processors or a hardware module implemented by the processor. Some of the executions in the operation may be distributed between one or more processors that not only reside in a single machine but also across multiple machine deployments. In some example embodiments, one or more processors may be located at a single location (e.g., in a home environment, in an office environment, or as a server farm), but in other embodiments, the processor may be distributed across multiple locations.

[0082] The execution of some of the operations may be distributed between one or more processors that reside not only in a single machine but also deployed across multiple machines. In some exemplary embodiments, one or more processors or processor-implemented modules may be located in a single geographic location (e.g., in a home environment, an office environment, or a server farm). In other exemplary embodiments, one or more processors or processor-implemented modules may be distributed in multiple geographic locations.

[0083] Unless otherwise expressly stated, discussions herein using terms such as "processing," "computing," "calculating," "determining," "presenting," "displaying," and the like may refer to the action or process of a machine (e.g., a computer) to manipulate or transform data represented as physical (e.g., electrical, magnetic, or optical) quantities in one or more memories (e.g., volatile memory, non-volatile memory, or a combination thereof), registers, or other machine components that receive, store, transmit, or display information.

[0084] As used herein, any reference to "one embodiment" or "an embodiment" means that a particular element, feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The phrase "in one embodiment" appearing in various places in the specification does not necessarily all refer to the same embodiment.

[0085] For example, some embodiments may be described using the term "connection" to indicate that two or more elements are in direct physical contact or electrical contact. For example, some embodiments may be described using the term "connection" to indicate that two or more elements are in direct physical contact or electrical contact. However, the term "connection" may also refer to two or more elements that are not in direct contact with each other, but still cooperate or interact with each other. The embodiments are not limited to this context.

[0086] Those skilled in the art will appreciate that various modifications, changes and combinations may be made to the embodiments described above without departing from the scope of the present invention, and such modifications, changes and combinations are considered to be within the scope of the inventive concept.

[0087] Although the present invention has been described with reference to specific examples, the specific examples are intended to be illustrative rather than limiting, and it will be apparent to those skilled in the art that changes, additions and / or deletions may be made to the disclosed embodiments without departing from the spirit and scope of the present invention.

[0088] The foregoing description has been given for the purpose of clearness of understanding only, and no unnecessary limitations are to be understood therefrom, since modifications within the scope of the invention may be apparent to one skilled in the art.

Claims

1. A scanning assembly for use in an optical instrument, the scanning assembly comprising: a frame, which provides support; a reflector suspended in an interior region of the frame for scanning with a beam of the optical instrument; a folded beam-spring assembly coupled to the reflector and configured to provide deflection of the reflector for beam scanning in an out-of-plane direction; a lever suspension assembly coupled to the frame of the scanning assembly and to the folded beam spring assembly positioned between the lever suspension assembly and the reflector, the lever suspension assembly configured to provide torsional movement of the reflector for beam scanning in a two-dimensional area, the lever suspension assembly having a lever arm; as well as A comb drive assembly is connected to the lever suspension assembly for controlling torsional and / or translational movement of the reflector.

2. A scanning assembly according to claim 1, wherein the lever suspension assembly includes a first lever suspension and a second lever suspension, each of the first lever suspension and the second lever suspension having a lever arm, the lever arm being mechanically connected to the frame of the scanning assembly and connected to the folding beam spring assembly, each lever arm being flexible to provide deflection of the reflector. 3 . The scanning assembly of claim 2 , wherein each of the first lever suspension and the second lever suspension comprises an H-shaped torsion spring.

4. The scanning assembly of claim 1 , wherein the folded beam spring assembly comprises a first folded beam spring assembly and a second folded beam spring assembly, wherein the first folded beam spring assembly and the second folded beam spring assembly are each connected to opposite sides of the reflector and are each configured to provide a deflection of the reflector in an out-of-plane direction.

5. The scanning assembly of claim 4, wherein each of the first and second folded beam spring assemblies comprises four multi-turn central clamping folded beam springs connected to the reflector by connecting arms.

6. The scanning assembly of claim 1, wherein the folded beam spring assembly and the lever suspension assembly are configured to perform beam scanning at a scanning angle greater than 100°.

7. The scanning assembly of claim 1, wherein the folded beam spring assembly and the lever suspension assembly are configured to perform beam scanning at a scanning angle greater than 200°.

8. The scanning assembly of claim 1, wherein the folded beam spring assembly and the lever suspension assembly are configured to perform beam scanning at a scanning angle greater than 300°.

9. The scanning assembly of claim 1, wherein the folded beam spring assembly and the lever suspension assembly are configured to perform beam scanning at a scanning angle greater than 400°.

10. The scanning assembly of claim 1, wherein the folded beam spring assembly and the lever suspension assembly are configured to perform beam scanning at a scanning angle greater than 500°.

11. The scanning assembly of claim 1, wherein the folded beam spring assembly and the lever suspension assembly are configured to perform beam scanning in the out-of-plane direction over a range greater than 200 μm.

12. The scanning assembly of claim 1, wherein the folded beam spring assembly and the lever suspension assembly are configured to perform beam scanning in the out-of-plane direction over a range greater than 300 μm.

13. The scanning assembly of claim 1, wherein the folded beam spring assembly and the lever suspension assembly are configured for beam scanning in the out-of-plane direction over a range greater than 400 μm.

14. The scanning assembly of claim 1, wherein the folded beam spring assembly and the lever suspension assembly are configured for beam scanning in the out-of-plane direction over a range greater than 500 μm.

15. The scanning assembly of claim 1, wherein the folded beam spring assembly and the lever suspension assembly are configured for beam scanning in the out-of-plane direction over a range greater than 600 μm.

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