Gesture input system based on self-mixing interferometry with wearable or handheld device

Abstract

The invention relates to a gesture input system with a wearable or handheld device based on self-mixing interferometry. A wearable device includes a device housing configured to be worn on a first surface of a user, a set of one or more SMI sensors, and a processor. The set of one or more SMI sensors is mounted within the device housing and configured to emit a set of one or more beams of electromagnetic radiation, wherein each beam is emitted in a different direction extending away from the first surface. The set of one or more SMI sensors is also configured to generate a set of one or more SMI signals containing information about a relationship between the device housing and the second surface. The processor is configured to extract the relationship between the device housing and the second surface from digitized samples of the set of one or more SMI signals.

Description

[0001] This application is a divisional application of Chinese patent application 202010885729.7, whose application date is August 28, 2020 and whose invention name is “Gesture input system based on self-mixing interferometry measurement with wearable or handheld device”. Technical Field

[0002] This patent application is non-provisional and claims the benefit of U.S. Provisional Patent Application No. 62 / 896,801, filed on September 6, 2019, pursuant to 35 U.S.C. §1.19(e), the contents of which are incorporated herein by reference as if fully disclosed herein. Technical Field

[0004] The embodiments generally relate to devices including self-mixing interferometry (SMI) sensors, and more particularly, to SMI-based gesture input systems including at least one of a wearable device or a handheld device. Background Art

[0005] Sensor systems are included in many electronic devices today, including electronic devices such as smart phones, computers (e.g., tablets or laptops), wearable electronic devices (e.g., electronic watches or health monitors), game controllers, navigation systems (e.g., vehicle navigation systems or robot navigation systems), etc. The sensor systems can variously sense the presence of an object, the distance to an object or the proximity of an object, the movement of an object (e.g., whether an object is moving, or the speed, acceleration, or direction of the object's movement), etc.

[0006] Given the wide range of applications for sensor systems, any new development in the configuration or operation of sensor systems may be useful. New developments that may be particularly useful are those that reduce the cost, size, complexity, number of parts, or manufacturing time of sensor systems, or that improve the sensitivity or speed of sensor system operation. Summary of the invention

[0007] Embodiments of the systems, devices, methods, and apparatus described in the present disclosure relate to the configuration and operation of an SMI-based gesture input system including one or more SMI sensors. The SMI sensors may be used to determine a relationship between a wearable or handheld device and a surface, or a relationship between a wearable device and a handheld device, or a relationship between different wearable devices or different handheld devices. The relationship may include a characterization of one or more of the position, orientation, or motion of the wearable or handheld device relative to one or more surfaces. In some cases, the relationship may be used to identify one or more gestures made by a user of the SMI-based gesture input system.

[0008] An SMI sensor is defined herein as a sensor configured to: generate electromagnetic radiation (e.g., light); emit electromagnetic radiation from a resonant cavity (e.g., a resonant optical cavity); receive reflection or backscatter of electromagnetic radiation (e.g., electromagnetic radiation reflected or backscattered from a surface or an object having a surface (collectively referred to herein as a surface) back into the resonant cavity); coherently or partially coherently self-mix the generated and reflected / backscattered electromagnetic radiation within the resonant cavity; and produce an output indicative of the self-mixing (i.e., an SMI signal). The generated, emitted, and received electromagnetic radiation may be coherent or partially coherent. In some examples, the electromagnetic radiation emitted by the SMI sensor may be generated by an electromagnetic radiation source such as a vertical cavity surface emitting laser (VCSEL), a vertical external cavity surface emitting laser (VECSEL), a quantum dot laser (QDL), a quantum cascade laser (QCL), or a light emitting diode (LED) (e.g., an organic LED (OLED), a resonant cavity LED (RC-LED), a micro-LED (mLED), a super luminescent LED (SLED), or an edge emitting LED), etc. The generated, emitted, and received electromagnetic radiation may include, for example, visible or invisible light (e.g., green light, infrared (IR) light, ultraviolet (UV) light, etc.). The output of the SMI sensor (i.e., the SMI signal) may include a photocurrent generated by a photodetector (e.g., a photodiode) that is integrated with the electromagnetic radiation source of the sensor or positioned below, above, or next to the electromagnetic radiation source of the sensor. Alternatively or in addition, the output of the SMI sensor may include a measurement of a current or junction voltage of the electromagnetic radiation source of the SMI sensor.

[0009] In a first aspect, the present disclosure describes a wearable device comprising a device housing configured to be worn on a first surface of a user, a set of one or more SMI sensors, and a processor. The set of one or more SMI sensors may be mounted within the device housing and configured to emit a set of one or more electromagnetic radiation beams, wherein each beam is emitted in a different direction extending away from the first surface. The set of one or more SMI sensors may also be configured to generate a set of one or more SMI signals containing information about a relationship between the device housing and a second surface. The processor may be configured to extract the relationship between the device housing and the second surface from digitized samples of the set of one or more SMI signals.

[0010] In another aspect of the present disclosure, the present disclosure describes a gesture input system. The gesture input system includes a wearable device configured to be worn by a user and an object configured to be held by the user. The gesture input system also includes a set of one or more SMI sensors and a processing system. Each SMI sensor may be mounted in the wearable device or the object, and may be configured to emit an electromagnetic radiation beam and generate an SMI signal. The processing system may be housed in at least one of the wearable device or the object, and may be configured to receive a set of one or more SMI signals from the set of one or more SMI sensors. The processing system may also be configured to extract information about at least one of the following from the set of one or more SMI signals: a time-varying relationship between the wearable device and the object, or a time-varying relationship between the wearable device and a surface other than the surface of the object.

[0011] In another aspect, the present disclosure describes a method for identifying a gesture type. The method may include emitting an electromagnetic radiation beam from each SMI sensor in a set of one or more SMI sensors disposed in a wearable device; sampling an SMI signal generated by each SMI sensor to generate a time-varying sample stream for each SMI sensor; using a processor of the wearable device and the time-varying sample stream of at least one SMI sensor in the set of one or more SMI sensors to determine movement of the wearable device relative to a surface; and transmitting information indicating the movement of the wearable device from the wearable device to a remote device.

[0012] In addition to the illustrative aspects and embodiments described, further aspects and embodiments will become apparent by reference to the drawings and by study of the following descriptions. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present disclosure will be readily understood through the following detailed description in conjunction with the accompanying drawings, in which like reference numerals refer to like structural elements, and in which:

[0014] Figure 1 An exemplary SMI-based gesture input system including a wearable device is shown;

[0015] Figure 2 and Figure 3 Additional examples of SMI-based gesture input systems including wearable devices are shown;

[0016] Figure 4 A wearable device having a set of SMI sensors is shown, and a processor of the device can select a subset of SMI sensors from the set of SMI sensors to determine a relationship between the wearable device and a surface;

[0017] Figure 5 Another exemplary SMI-based gesture input system is shown, the system comprising more than one device;

[0018] Figure 6 Shown is a reference Figure 5 An example of the system described, wherein the wearable device is a finger ring, and the object is shaped as one or more of a stylus, a pen, a pencil, a marker, or a paintbrush;

[0019] Figure 7 Shown is a reference Figure 5 An alternative embodiment of the system, wherein the object is also a wearable device;

[0020] FIG. 8A to FIG. 8D The reference Figures 1 to 7 an exemplary SMI sensor for use in one or more of the SMI-based gesture input systems described above;

[0021] 9A to 9D shows that it can be compared with the reference Figures 1 to 8D Different beam shaping or beam steering optics for use with any of the SMI sensors described;

[0022] Fig.10 A triangulation bias process for determining the velocity and absolute distance of a surface (or object) using self-mixing interferometry is shown;

[0023] Fig.11 shows the reference for use Fig.10 The process is a block diagram of a system for implementing a spectrum analysis process;

[0024] Fig.12 A sinusoidal bias process for determining the displacement of a surface (or object) using quadrature demodulation using self-mixing interferometry is shown;

[0025] Fig.13 An exemplary method of identifying gesture types is shown; and

[0026] Fig.14 An exemplary electrical block diagram of an electronic device is shown.

[0027] The use of cross-hatching or shading in the drawings is generally provided to clarify boundaries between adjacent elements and also to facilitate legibility of the drawings. Thus, the presence or absence of cross-hatching or shading does not express or indicate any preference or requirement for particular materials, material properties, element proportions, element sizes, commonality of similar illustrated elements, or any other characteristic, property, or attribute of any element shown in the drawings.

[0028] Furthermore, it should be understood that the proportions and sizes (relative or absolute) of the various features and elements (and collections and groupings thereof) and the boundaries, spacings, and positional relationships presented therebetween are provided in the accompanying drawings solely to facilitate understanding of the various embodiments described herein, and therefore may not necessarily be presented or illustrated to scale and are not intended to indicate any preference or requirement for the embodiments illustrated to exclude the embodiments described in conjunction therewith. DETAILED DESCRIPTION

[0029] Reference will now be made specifically to the representative embodiments shown in the accompanying drawings. It should be understood that the following description is not intended to limit the embodiments to a preferred embodiment. On the contrary, it is intended to cover alternatives, modifications and equivalent forms that may be included in the spirit and scope of the embodiments defined by the appended claims.

[0030] The following description relates to the configuration and operation of an SMI-based gesture input system (i.e., a system that can use signals received from one or more SMI sensors to recognize gestures made by a user). The SMI sensor can be used to optically measure the relative motion (displacement) between the SMI sensor and a target (e.g., a surface or object) with sub-wavelength resolution. When the displacement measurement result is associated with the measurement time, the velocity of the target can also be measured. In addition, by modulating the SMI sensor with a known wavelength modulation (e.g., triangular modulation), the absolute distance from the SMI sensor to the target can be measured.

[0031] Tracking a user's finger movements and / or recognizing a user's gestures (e.g., gestures made with one or more fingers, hands, arms, etc.) may be useful in augmented reality (AR), virtual reality (VR), and mixed reality (MR) applications, among other applications. In some applications, it is useful for a user to be able to provide input to a system by interacting with a surface (e.g., gesturing on any random surface such as a tabletop, wall, or paper) or by gesturing in free space. In such applications, an SMI-based gesture input system may be used to track a user's finger movements with reference to any surface (including, in some cases, the surface of another finger, the user's palm, etc.).

[0032] This document describes SMI-based gesture input systems and devices that can be worn or held by a user. Some of the systems include a single wearable device or handheld device. Other systems may include two or more wearable devices and / or handheld devices. The system may be provided with more or fewer SMI sensors, which typically enable finer or lower resolution tracking, or more complex or less complex gesture detection / recognition. For example, with one SMI sensor, rolling along a single axis can be detected. With two SMI sensors, user motion in a plane can be tracked. With three or more SMI sensors, movement in the x, y, and z directions can be tracked. Motion tracking with six degrees of freedom can also be tracked with three or more SMI sensors, and in some cases, by modulating the SMI sensors in specific or different ways.

[0033] Compared to conventional optical tracking methods such as optical flow and spot tracking, the SMI-based tracking method can block ambient light (e.g., sunlight or other ambient light) and track motion with six degrees of freedom without the need for supplementary sensors for determining the distance to the target surface. The SMI-based gesture input system can also be used in a dark room (e.g., a room without ambient light).

[0034] refer to Figures 1 to 14 However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these drawings is for illustrative purposes only and should not be construed as limiting.

[0035] Directional terms, such as "top", "bottom", "upper", "lower", "front", "rear", "above", "below", "below", "left", "right", etc., are used with reference to the orientation of some components in some of the figures described below. Because components in various embodiments can be positioned in a plurality of different orientations, the directional terms are used for illustrative purposes only and are not limiting in any way. Directional terms are intended to be interpreted broadly and, therefore, should not be interpreted to exclude components oriented in different ways. The use of alternative terms, such as "or", is intended to represent different combinations of alternative elements. For example, A or B is intended to include A or B, or A and B.

[0036] Figure 1 An exemplary SMI-based gesture input system 100 is shown. System 100 includes a device housing 102, a set of one or more SMI sensors 104 mounted within device housing 102, a processing system 106 mounted within device housing 102, and / or a communication interface 108 mounted within device housing 102.

[0037] The device housing 102 may take various forms, and in some cases may be configured to be worn or held by the user 110. When the device housing 102 is configured to be worn by the user 110, the device housing 102 may define a wearable device, such as a ring, a whole or part of a glove, a sleeve, etc. When the device housing 102 is configured to be held by the user 110, the device housing 102 may define a stylus, another writing instrument (e.g., a pen or pencil), an arbitrary object, etc. In any case, the device housing 102 may be made of various materials (such as plastic, metal, or ceramic materials). In some cases, the device housing 102 may include multiple components, such as a first and second ring that snap together or otherwise fasten (e.g., by an adhesive or solder), a first and second semicircular tube that snap together or otherwise fasten (e.g., by an adhesive or solder), or one or more parts that define an open partial circle having one or more open ends plugged by a cover.

[0038] Each of the SMI sensors 104 may include an electromagnetic radiation source. The electromagnetic radiation source may include a resonant cavity from which an electromagnetic radiation beam 112 is emitted. The electromagnetic radiation beam 112 may include a coherent (or partially coherent) mixture of 1) electromagnetic radiation generated by the electromagnetic radiation source, and 2) electromagnetic radiation received into the resonant cavity of the electromagnetic radiation source after being reflected or backscattered from the surface 114. Each of the SMI sensors 104 may include a photodetector that generates an SMI signal 116 containing information about a relationship between the SMI sensor 104 and the surface 114. The SMI signal 116 generated by the SMI sensor 104 contains information corresponding to information contained in the electromagnetic radiation waveform received by the SMI sensor 104. Alternatively, the SMI sensor 104 may output a measurement of a current or junction voltage of its electromagnetic radiation source as the SMI signal 116.

[0039] The one or more SMI sensors 104 may emit a set of one or more electromagnetic radiation beams 112. Different beams 112 may be emitted in different directions. In some cases, some or all of the beams 112 may be emitted in a direction extending away from a first surface of the user 110 (e.g., away from a surface on which the device housing 102 is worn by the user 110). Some (or all) of the beams 112 may be emitted toward a second surface (e.g., surface 114). The SMI signal 116 generated by the set of one or more SMI sensors 104 may include not only information about the relationship between the individual SMI sensors 104 and the surface 114, but also information about the relationship between the device housing 102 and the surface 114, and therefore information about the position, orientation, or movement of the user 110 who is wearing or holding the device housing 102.

[0040] The processing system 106 may include, for example, one or more digital-to-analog converters 118 (ADCs) for digitizing the SMI signals 116 output by the SMI sensors 104 (e.g., one ADC 118 for each SMI sensor 104), a processor 120, and / or other components. In some cases, the processing system 106 may include filters, amplifiers, or other discrete circuits for processing the SMI signals 116. The processor 120 may take various forms, such as a microprocessor, a microcontroller, an application specific integrated circuit (ASIC), and the like.

[0041] The processor 120 may be configured to extract the relationship between the device housing 102 and the surface 114 from the digitized samples of the one or more SMI signals 116. When the system 100 includes only one SMI sensor 104, or when the processor 120 uses only one SMI signal 116, the processor 120 may determine, for example, the movement of the device housing 102 along the axis of the SMI sensor's transmitted beam 112 (e.g., in the x, y, or z direction of a Cartesian coordinate system) (and thus determine the movement of the user 110). When the system 100 includes only two SMI sensors 104, or when the processor 120 uses only two SMI signals 116, the processor 120 may determine, for example, the movement of the device housing 102 in a plane (e.g., in the xy, xz, or yz plane of a Cartesian coordinate system, assuming that the beam 112 is tilted (i.e., not perpendicular or parallel to) the plane) (and thus determine the movement of the user 110). When the system 100 includes only at least three SMI sensors 104, or when the processor 120 uses at least three SMI signals 116, the processor 120 can determine, for example, the movement of the device housing 102 in free space (e.g., in the xyz space of a Cartesian coordinate system) (and therefore the movement of the user 110).

[0042] When the system 100 includes two or three SMI sensors 104, the beams 112 emitted by the SMI sensors 104 preferably have orthogonal axes that decouple the SMI signals 116 to improve sensitivity and minimize errors, and this simplifies the processing burden (i.e., computational burden) placed on the processor 120. However, if the angle between the beam 112 and the direction of the measured displacement is known, the beam 112 need not have orthogonal axes. When the system 100 generates more SMI signals 116 than the processor 120 requires, or when the system 100 includes more than three SMI sensors 104, the processor 120 may analyze digitized samples of the plurality of SMI signals 116 and (based at least in part on the analysis) identify at least one SMI signal from the plurality of SMI signals 116 from which the relationship between the device housing 102 and the surface 114 is extracted. In the latter case, it is recognized that in some cases the device housing 102 may be positioned in various ways such that its SMI sensor 104 may emit the electromagnetic radiation beam 112 in useless directions, or in directions that cause different beams 112 to impinge on different surfaces. Accordingly, the processor 120 may analyze digitized samples of multiple SMI signals 116 to determine which SMI signals 116 appear to contain useful information about the same surface (e.g., the processor 120 may be programmed to assume that SMI signals 116 indicating surfaces within a threshold distance are generated by SMI sensors 104 facing toward the user's palm or other nearby body part, and then ignore those SMI signals 116. Alternatively, a user 110 of the system may position the device housing 102 such that its SMI sensor 104 emits the electromagnetic radiation beam 112 in a useful direction.

[0043] In some embodiments, the processor 120 may be configured to transmit information indicating the relationship between the device housing 102 and the surface 114 using the communication interface 108. The information may be transmitted to a remote device. In some cases, the transmitted information may include a sequence of time-dependent measurement results, or a sequence of time-dependent positions, orientations, or movements. In other cases, the processor 120 may be configured to recognize one or more gestures made by the user 110 and transmit indications of the one or more gestures (these indications are in the form of information indicating the relationship between the device housing 102 and the surface 114). The processor 120 can identify the gesture of the user 110 by comparing the sequence of changes in one or more SMI signals 116 obtained from one or more SMI sensors 104 with one or more stored sequences that have been associated with one or more gestures. For example, the processor 120 may compare the sequence of changes in the SMI signal 116 with a stored sequence corresponding to a press or poke, and when a match is determined (or the sequence is determined to be similar enough to indicate a match), the processor 120 may indicate that the user 110 has made a press or poke gesture. Similarly, upon comparing a set of sequences of changes in SMI signals 116 to a set of stored sequences corresponding to user 110 writing the letter “A” or a set of stored sequences corresponding to user 110 making a circular motion, and determining a match with one of these gestures, processor 120 may indicate that user 110 has drawn the letter “A” or has made a circular gesture. In addition to or in lieu of comparing the sequence of changes in one or more SMI signals 116 to the stored sequence of changes, processor 120 may determine a set of time-dependent positions, orientations, motion vectors, or other pieces of information in one, two, or three dimensions based on the sequence of changes in one or more SMI signals 116, and may compare this alternative information to stored information that has been associated with one or more predetermined gestures.

[0044] When determining the motion of the device housing 102 relative to the surface 114, there is an ambiguity between displacement and rotation when only a sequence of three time-dependent measurements is used. This is because the characterization of motion in a Cartesian coordinate system requires the characterization of six degrees of freedom (6DoF). The characterization of 6DoF requires the characterization of six unknowns, which therefore requires a sequence of six time-dependent measurements—for example, not only measurements of displacement along three axes (x-axis, y-axis, and z-axis), but also rotations about each of the three axes (e.g., yaw, pitch, and roll). In other words, the processor 120 cannot solve for the six unknowns using a sequence of only three time-dependent measurements. In order to provide three additional sequences of time-dependent measurements, the processor 120 may use SMI signals 116 obtained by six different SMI sensors 104, which emit beams 112 pointing in six different directions toward the surface 114. Alternatively, the processor 120 may obtain a sequence of two or more time-dependent measurements from each SMI sensor 104 in a smaller number of SMI sensors 104. For example, the processor 120 may alternatively modulate the input of each SMI sensor 104 in a group of three SMI sensors 104 using a sine waveform and a triangular waveform, and obtain a sequence of time-dependent measurements for each modulation type from each SMI sensor in the three SMI sensors 104 (e.g., the processor 120 may modulate the input of each SMI sensor 104 using a sine waveform during a first set of time periods, and modulate the input of each SMI sensor 104 using a triangular waveform during a second set of time periods). Modulating the input using a triangular waveform may provide absolute distance measurements, which may not be obtained using sine waveform modulation.

[0045] The communication interface 108 may include a wired and / or wireless communication interface (eg, a wireless communication interface) that can be used to communicate with a remote device (eg, a mobile phone, a digital watch, a tablet computer, or a laptop computer). Low Energy (BLE), Wi-Fi, or Universal Serial Bus (USB) interface).

[0046] Figure 2 and Figure 3 shows examples of SMI-based gesture input systems that can be referenced Figure 1 Embodiments of the system described. Figure 2An exemplary SMI-based gesture input system in the form of a closed loop 200 is shown. The closed loop 200 can be configured to receive a user's finger 202 (i.e., the closed loop 200 can be a finger ring). A set of SMI sensors 204 housed within the closed loop 200 can transmit an electromagnetic radiation beam 206 through an aperture and / or window element that is transparent to the wavelength of the transmitted beam 206. By way of example, the closed loop 200 includes three SMI sensors 204 that transmit orthogonal electromagnetic radiation beams 206. In alternative embodiments, the closed loop 200 may include more or fewer SMI sensors 204 that transmit orthogonal or non-orthogonal electromagnetic radiation beams 206.

[0047] Figure 3 An exemplary SMI-based gesture input system in the form of an open loop 300 is shown. The open loop 300 may be configured to receive a user's finger 302 (e.g., the open loop 300 may be a finger ring). The open loop 300 may include SMI sensors 304 that are configured to emit electromagnetic radiation beams 306 along a ring body 308 of the open loop and / or from one or both ends 310, 312 of the ring body 308 of the open loop (e.g., from covers at the ends 310, 312 of the ring body 308 of the open loop). By way of example, the open loop 300 includes three SMI sensors 304 that emit orthogonal electromagnetic radiation beams 306. In alternative embodiments, the open loop 300 may include more or fewer SMI sensors 304 that emit orthogonal or non-orthogonal electromagnetic radiation beams 306. Although the SMI sensors 304 are Figure 3 300 , but alternatively, all of the SMI sensors 304 (or more or fewer SMI sensors 304 ) may be disposed proximate to one end of the open loop 300 .

[0048] like Figure 3 As shown, an open loop may be useful because it may not obstruct the inner surface of a user's hand, which in some cases may improve the user's ability to grasp an object, feel texture on a surface, or receive tactile output provided via the surface.

[0049] In some embodiments, reference Figures 1 to 3 The wearable device described in any of the figures can determine the absolute distance, direction and speed of the surface relative to the SMI sensor by triangulating the input to the SMI sensor, as shown in reference Fig.10 and Fig.11 The displacement of the surface can then be obtained by integrating the velocity. In some embodiments, the wearable device can use I / Q demodulation to determine the displacement and direction of the surface relative to the SMI sensor (in the time domain), as described in reference Fig.12 Triangular modulation can then be used to obtain the absolute distance.

[0050] In some cases, a wearable device such as a finger ring may include a deformable or compressible insert that enables the finger ring to be worn farther away from or closer to a user's fingertips.

[0051] In some cases, the ring may be rotated by the user so that it may alternately sense the surface beneath the user's hand, the surface of an object held by the user, adjacent fingers, and the like.

[0052] In some cases, the wearable device may include sensors other than the SMI sensor, such as an inertial measurement unit (IMU). In some cases, additional sensors may also be used to characterize motion. The wearable device may also include a haptic engine to provide tactile feedback to the user, battery, or other components.

[0053] Figure 4 A wearable device 400 is shown having a set of SMI sensors 402 from which a processor of the device 400 may select a subset 404 to determine a relationship between the wearable device 400 and a surface 406. Alternatively, the processor of the device 400 may use SMI signals generated by different subsets 404, 408 of the SMI sensors 402 to determine a relationship between the wearable device 400 and different surfaces 406, 410 (e.g., a tabletop 406 and a user's finger 410 adjacent to the finger on which the device 400 is worn). By way of example, the wearable device 400 is shown as a closed finger ring (e.g., having a finger 410 with a reference finger). Figure 2 The closed loop form factor is similar to the form factor of wearable devices of the type described herein. In alternative embodiments, the device 400 may take other forms.

[0054] exist Figure 4 , the SMI sensors 402 are grouped into subsets of three SMI sensors 402, and the subsets are located at different locations around the circumference of the device 400. In other embodiments, the subsets of SMI sensors 402 may have different numbers of SMI sensors 402 (in some cases, only one SMI sensor 402). In some embodiments, the SMI sensors 402 may not be arranged in discrete subsets, and the processor of the device 400 may analyze SMI signals received from the SMI sensors 402 and dynamically identify one or more subsets of the SMI sensors 402 in response to analyzing the SMI signals. The processor may also determine that one or more of the SMI sensors do not generate useful SMI signals, and exclude those SMI sensors from being included in any subset (and in some cases, those SMI sensors may not be used until a change in the SMI signals of those SMI sensors is identified).

[0055] In some embodiments of device 400 (or in embodiments of other devices described herein), device 400 may include one or more sensors for determining the orientation of device 400 relative to its user (e.g., relative to the finger on which device 400 is worn, one or more adjacent fingers, the user's palm, etc.) or a surface (e.g., a tabletop, a sheet of paper, a wall, the surface of the user's body, etc.). The sensors may include, for example, one or more of a proximity sensor, a contact sensor, a pressure sensor, an accelerometer, an IMU, etc.

[0056] Figure 5 Another exemplary SMI-based gesture input system 500 is shown. Figure 1 Compared to the systems described above, system 500 may include more than one device. For example, system 500 may include a wearable device 502 configured to be worn by a user, and an object 504 configured to be held by the user.

[0057] In some embodiments, the wearable device 502 may be similar to the reference Figure 1 The wearable device described herein may include a device housing 506, a set of one or more SMI sensors 508 mounted in the device housing 506, a processing system 510 mounted in the device housing 506, and / or a communication interface 512 mounted in the device housing 102. The device housing 506, the SMI sensor 508, the processing system 510, and / or the communication interface 512 may be similar to the wearable device described herein. Figure 1 In some embodiments, the wearable device 502 may be a finger ring, such as the one shown in FIG. Figure 2 or Figure 3 described.

[0058] In some embodiments, object 504 may be shaped as one or more of a stylus, a pen, a pencil, a marker, or a paintbrush. Object 504 may also take other forms.

[0059] In some cases, one or more of the SMI sensors 508 in the wearable device 502 may emit a beam of electromagnetic radiation 514 that shines on the object 504. When the object 504 is moved by the user, such as for writing or drawing, the relationship between the wearable device 502 and the object 504 may be changed. The processing system 510 may extract information about the time-varying relationship between the wearable device 502 and the object 504 (and / or about the time-varying relationship between the wearable device 502 and the surface other than the surface of the object 504) from the SMI signal of the SMI sensor 508, and in some cases may recognize one or more gestures made by the user. In some cases, the gesture may include an alphanumeric string (one or more characters) written by the user. In these cases, the processing system 510 may be configured to recognize the alphanumeric string from the information about the time-varying relationship between the wearable device 502 and the object 504. The SMI sensor 508 may also or alternatively be used to determine whether the user is holding the object 504, and to track or predict the movement of the object 504. For example, if the object 504 is a writing instrument (e.g., a pen), the SMI signal generated by the SMI sensor 508 may be analyzed to determine whether the user is holding the object 504, and in some cases, whether the user is loosely or tightly holding the object 504. The processing system 510 may determine whether the user is about to write, make a gesture, etc. based on the presence of the object 504 and / or the user's grasping and / or the movement of the object 504. The processing system 510 may then fully wake up the wearable device 502 in response to the presence, grasping and / or movement of the object 504; or begin recording the movement of the object 504 and / or recognize the letters written, gestures made, etc. by the user using the object 504. In some embodiments, when the object 504 is not detected, the processing system 510 may switch the wearable device 502 to a first mode, in which the SMI sensor 508 is used to track movement relative to the table or the user; and when the object 504 is detected, the wearable device 502 is switched to a second mode, in which the SMI sensor 508 is used to track the movement of the object 504. In some embodiments, the SMI sensor 508 can track the movement of the object 504 by tracking the movement of the wearable device 502 relative to a tabletop or other surface (i.e., a surface other than the surface of the object 504). This is because the user's grip on the object 504 can affect the way the user holds their hand or moves their fingers, and the position or movement of the hand / fingers relative to the non-object surface can indicate how the user moves the object 504 (e.g., indicating the letters the user is writing or gestures made with the object 504). In some cases, the wearable device 502 can effectively turn any object (including dumb objects or non-electronic objects) into a smart pen or the like.

[0060] In some cases, the wearable device 502 may have relatively more SMI sensors 508, such as Figure 4 As described. In some cases, in addition to the wearable device 502 having one or more SMI sensors 508 therein, the object 504 may also have one or more SMI sensors 516 therein. When provided, the SMI sensor 516 may be used similarly to the SMI sensor 508 included in the wearable device 502, and the relationship of the object 504 to the wearable device, the user's skin (i.e., the user's surface), or a remote surface (e.g., surface 518) may be determined. The SMI sensor 516 may be positioned along the body of the object 504 (e.g., close to where the user may hold the object 504) or near the tip of the object 504 (e.g., close to the pointing, writing, or drawing tip of the object 504). In some embodiments, the object 504 may include a processing system and / or a communication interface for transmitting an SMI signal generated by the SMI sensor 516 or information related to or derived therefrom to the wearable device 502. Alternatively or in addition, the processing system and / or the communication interface may receive an SMI signal or information related to or derived therefrom from the wearable device 502. Wearable device 502 and object 504 may communicate wirelessly or may be connected via wires, cables, and / or conductors. In some embodiments, the processing system 510 of wearable device 502 may bear most of the processing burden (e.g., recognizing gestures). In other embodiments, the processing system of object 504 may bear most of the processing burden, or the processing burden may be shared. In other embodiments, object 504 may include SMI sensors and processing systems for all systems.

[0061] Figure 6 Shown is a reference Figure 5 An example of the system is described wherein the wearable device 502 is a finger ring and the object 504 is shaped as one or more of a stylus, a pen, a pencil, a marker, or a paintbrush.

[0062] In some cases, a SMI-based gesture input system may include more than one wearable device and / or more than one handheld device. For example, Figure 7 Shown is a reference Figure 5 An alternative embodiment of the system described, wherein the object 504 is also a wearable device. By way of example, both the wearable device 502 and the object 504 are shown as finger rings. For example, the finger ring worn on the user's thumb and index finger can be used to recognize gestures, such as pinching, zooming, rotating, etc.

[0063] SMI-based gesture input systems, such as reference Figures 1 to 7One of the systems described may be used in some cases to provide input to an AR, VR, or MR application. The SMI-based gesture input system may also be used as an anchor for another system. For example, in a camera-based gesture input system, it may be difficult to determine whether the camera or the user's hand (or finger) is moving. The SMI-based gesture input system may replace a camera-based gesture input system, or may provide anchor information to a camera-based gesture input system.

[0064] Fig. 8A The reference Figures 1 to 7 A first exemplary SMI sensor 800 for use in one or more of the described SMI-based gesture input systems. In this example, the SMI sensor 800 may include a VCSEL 802 with an integrated resonant cavity (or intracavity) photodetector (RCPD) 804.

[0065] Figure 8B The reference Figures 1 to 7 A second exemplary SMI sensor 810 for use in one or more of the described SMI-based gesture input systems. In this example, the SMI sensor 810 may include a VCSEL 812 with an external on-chip RCPD 814. For example, the RCPD 814 may form a disk surrounding the VCSEL 812.

[0066] Figure 8C The reference Figures 1 to 7 A third exemplary SMI sensor 820 for use in one or more of the described SMI-based gesture input systems. In this example, the SMI sensor 820 may include a VCSEL 822 with an external off-chip photodetector 824.

[0067] Fig.8D The reference Figures 1 to 7 A fourth exemplary SMI sensor 830 for use in one or more of the described SMI-based gesture input systems. In this example, the SMI sensor 830 may include a dual-emission VCSEL 832 with an external off-chip photodetector 834. For example, the top emission may be emitted toward an optical device and / or another target, and the bottom emission may be provided to the external off-chip photodetector 834.

[0068] 9A to 9D shows that it can be compared with the reference Figures 1 to 8D Any of the SMI sensors described herein may be used in conjunction with different beam shaping or beam steering optics. Fig.9AShown is a beam shaping optic 900 (eg, a lens or collimator) that collimates a beam of electromagnetic radiation 902 emitted by an SMI sensor 904. A collimated beam may be useful when the range supported by the device is relatively large (eg, when the device has a range of approximately ten centimeters). Fig. 9B A beam shaping optic 910 (eg, a lens) is shown focusing an electromagnetic radiation beam 912 emitted by an SMI sensor 914. Focusing the electromagnetic radiation beam may be useful when the range supported by the device is limited (eg, limited to a few centimeters). Fig. 9C A beam steering optic 920 (e.g., a lens or a set of lenses) is shown directing electromagnetic radiation beams 922 emitted by a set of SMI sensors 924 so that the beams 922 converge. Alternatively, the SMI sensors 924 may be configured or oriented so that their beams converge without the optic 920. In some embodiments, the beam steering optic 920 may include a beam shaping optic (such as, for example, a lens or a set of lenses). Fig.9A or Fig. 9B The beam shaping optical devices described herein) or are associated with these beam shaping optical devices. Fig.9D A beam steering optic 930 (e.g., a lens or a set of lenses) is shown directing a beam of electromagnetic radiation 932 emitted by a set of SMI sensors 934 such that the beam 932 is dispersed. Alternatively, the SMI sensors 934 may be configured or oriented such that their beams are dispersed without the optic 930. In some embodiments, the beam steering optic 930 may include a beam shaping optic (such as, for example, a lens or a set of lenses). Fig.9A or Fig. 9B The beam shaping optical devices described herein) or are associated with these beam shaping optical devices.

[0069] Fig.10 A triangulation bias process 1000 is shown for determining the velocity and absolute distance of a surface (or object) using self-mixing interferometry. The process 1000 may be referred to as Figures 1 to 7 One or more of the systems or devices described herein are used to modulate an SMI sensor using a triangular waveform, for example, as described in reference Figure 1 described.

[0070] At the initial stage 1002, an initial signal is generated, such as by a digital or analog signal generator. At stage 1006-1, the generated initial signal is processed as needed to generate a triangular waveform modulated current 1102 (see Fig.11 If desired, stage 1006-1 may be an operation of a DAC (eg, when the initial signal is the output of a digital step generator), low pass filtering (such as to remove quantization noise from the DAC), and voltage-to-current conversion.

[0071] Applying the modulated current 1102 to the VCSEL induces an SMI output 1118 (ie, a change in the interferometric properties of the VCSEL). To simplify the discussion, it will be assumed that the SMI output 1118 is from a photodetector, but in other embodiments, the SMI output may be from another component.

[0072] exist Fig.10 At initial stage 1004 of the present invention, SMI output 1118 is received. At stage 1006-2, initial processing of SMI output 1118 is performed as desired. Stage 1006-2 may include high pass filtering or digital subtraction.

[0073] At stage 1008, if necessary, the processor may equalize the received signals to match the peak-to-peak value, average value, RMS value, or any other characteristic value of the signals. For example, the SMI output 1118 may be a primarily triangular waveform component that matches the modulation current 1102, with the signal having smaller and higher frequency components due to changes in the interferometric measurement characteristics. High pass filtering may be applied to the SMI output 1118 to obtain a component signal related to the interferometric measurement characteristics. This stage may also include separating and / or subtracting portions of the SMI output 1118 and the modulation current 1102 that correspond to the rise and fall time intervals of the modulation current 1102. This stage may include sampling the separated information.

[0074] At stages 1010 and 1012, separate Fast Fourier Transforms (FFTs) are first performed on the portions of the processed SMI output 1118 corresponding to the rise and fall time intervals. The two FFT spectra may be analyzed at stage 1014.

[0075] At stage 1016, the FFT spectrum may be further processed, for example to remove artifacts and reduce noise. Such further processing may include peak detection and Gaussian fitting around the detected peaks to improve frequency accuracy. Based on the processed FFT spectrum data, information about the absolute distance may be obtained at stage 1018.

[0076] Fig.11 It shows that the above can be achieved with respect to Fig.10 The system for spectrum analysis described in the method (e.g., reference Figures 1 to 71100). In the exemplary system shown, the system includes generating an initial digital signal and processing it as needed to generate a modulated current 1102 as an input to the VCSEL 1110. In the illustrative example, the initial step signal can be generated by a digital generator to approximate a trigonometric function. The digital output value of the digital generator is used in a digital-to-analog converter (DAC) 1104. The resulting voltage signal can then be filtered by a low-pass filter 1106 to remove quantization noise. Alternatively, an integrator-based analog signal generator can be used to directly generate an equivalent voltage signal. The filtered voltage signal is then input to a voltage-to-current converter 1108 to generate some form of the desired modulated current 1102 for input to the VCSEL 1110.

[0077] As described above, movement of the target may cause changes in interferometric parameters, such as parameters of the VCSEL 1110 or parameters of the photodetector operating in the system. These changes may be measured to produce an SMI output 1118. In the illustrated embodiment, it will be assumed that the SMI output 1118 is measured by a photodetector. For a modulation current 1102 having a triangular waveform, the SMI output 1118 may be a triangular wave of similar period combined with smaller and higher frequency signals associated with interferometric characteristics. In some cases, the SMI output 1118 may not be completely linear even if the modulation current 1102 is linear. This may be due to the non-linear relationship of the bias current to the light output curve of the VCSEL 1110 (e.g., due to non-ideal factors such as self-heating effects).

[0078] The SMI output 1118 is first passed to a high pass filter 1120, which can effectively convert the main rising and falling ramp components of the SMI output 1118 into a DC offset. Since the SMI output 1118 can generally be a current, a transimpedance amplifier 1122 can generate a corresponding voltage output (amplified or unamplified) for further processing.

[0079] The voltage output may then be sampled and quantized by the ADC block 1124. It may be helpful to apply equalization immediately before applying the digital FFT to the output of the ADC block 1124. The initial digital signal value from the digital generator used to generate the modulation current 1102 is used as an input to the digital high pass filter 1112 to generate a digital signal associated with the output of the ADC block 1124. The digital variable gain block 1114 may apply an adjustable gain to the output of the digital high pass filter 1112.

[0080] The output of the digital variable gain block 1114 is used as one input to the digital equalizer and subtractor block 1116. The other input to the digital equalizer and subtractor block 1116 is the output of the ADC block 1124. These two signals are differential and are used as part of the feedback to adjust the gain provided by the digital variable gain block 1114.

[0081] Equalization and subtraction can be used to clean any remaining artifacts that may be present in the SMI output 1118 from the triangles. For example, if there are slope errors or nonlinearities in the SMI output 1118, the digital high pass filter 1112 may not completely eliminate the triangles and artifacts may still exist. In this case, these artifacts may appear as low frequency components after the FFT, making peak detection difficult for nearby objects. Applying equalization and subtraction can partially or completely remove these artifacts.

[0082] Once the best correlation is obtained through feedback, an FFT indicated by block 1128 may be applied to the components of the output of the ADC block 1124 corresponding to the rising and falling sides of the triangle wave. From the resulting FFT spectrum, the peak frequencies detected on the rising and falling sides may be used to infer absolute distance and / or directional velocity, as described above and indicated by block 1126.

[0083] The method just described and its variations involve applying spectral analysis to the SMI output. However, it should be understood that this is an example. In other specific implementations, alternative methods for determining absolute distance can be obtained directly from the time domain SMI output without applying spectral analysis. Various configurations are possible and contemplated without departing from the scope of the present disclosure.

[0084] Fig.12 A sinusoidal bias process 1200 is shown for determining the displacement of a surface (or object) using quadrature demodulation using self-mixing interferometry. The process 1200 may be referred to as Figures 1 to 7 One or more of the systems or devices described herein are used to modulate a SMI sensor using a sinusoidal waveform, for example, as described in reference Figure 1 described.

[0085] As explained in more detail below, Fig.12 Components for generating a sinusoidally modulated bias current and applying it to a VCSEL are shown. The sinusoidal bias current can generate an output current in the photodetector 1216 that depends on the frequency of the sinusoidal bias and the displacement of the structural components of the device. Fig.12In the circuit of , the output current of the photodetector 1216 is digitally sampled and then multiplied with a first sine wave at the original sinusoidal modulation frequency of the bias current and a second sine wave at a frequency twice the original frequency. The two separate multiplied outputs are then each low pass filtered and the phase of the interferometric measurement parameter can be calculated. Thereafter, at least the phase is used to determine the displacement.

[0086] The DC voltage generator 1202 is used to generate a constant bias voltage. The sine wave generator 1204 can generate a sinusoidal signal of approximately a single frequency to be combined with the constant voltage. Fig.12 As shown, the sine wave generator 1204 is a digital generator, but in other specific implementations, the sine wave generator can generate an analog sine wave. Low pass filter 1206-1 provides filtering of the output of DC voltage generator 1202 to reduce undesired changes in the constant bias voltage. Band pass filter 1206-2 can be used to reduce distortion and noise in the output of sine wave generator 1204 to reduce noise, quantization or other distortion, or its signal away from its intended modulation frequency ω. m frequency components.

[0087] Circuit adder 1208 combines the low pass filtered constant bias voltage and the band pass filtered sine wave to produce a combined voltage signal on link 1209. Fig.12 In the embodiment of the present invention, the combined voltage signal has the following form: V0+V m sin(ω m t). This voltage signal is used as an input to the voltage-to-current converter 1210 to generate a current to drive the lasing of the VCSEL 1214. The current on line 1213 from the voltage-to-current converter 1210 may have the following form: I0+I m sin(ω m t).

[0088] VCSEL 1214 is thus driven to emit laser light modulated as described above. Reflections of the modulated laser light may then be received back into the laser cavity of VCSEL 1214 and cause self-mixing interference. The resulting emitted optical power of VCSEL 1214 may be modified due to self-mixing interference, and the modification may be detected by photodetector 1216. As described above, in this case, the photocurrent output of photodetector 1216 on link 1215 may have the following form: Since the I / Q components to be used in subsequent stages are based only on the third term, the first two terms may be removed or reduced by a differential transimpedance amplifier and anti-aliasing (DTIA / AA) filter 1218. To perform this removal / reduction, a proportional or scaled value of the first two terms is generated by a voltage divider 1212. The voltage divider 1212 may use as input the combined voltage signal generated by the circuit adder 1208 on link 1209. The output of the voltage divider 1212 on link 1211 may then have the following form: α(V0+V m sin(ω m t)). The photodetector current and this output of the voltage divider 1212 may be an input to a DTIA / AA filter 1218. The output of the DTIA / AA filter 1218 may then be at least largely proportional to the third term of the photodetector current.

[0089] The output of the DTIA / AA filter 1218 may then be quantized for subsequent calculations by the ADC block 1220. In addition, the output of the ADC block 1220 may have a residual signal component that is proportional to the sine wave originally generated by the sine wave generator 1204. To filter this residual signal component, the initially generated sine wave may be scaled at the multiplier block 1224-3 (such as by multiplying by a factor indicative of β) and then subtracted from the output of the ADC block 1220 at the subtraction block 1222. The Fourier expansion of the term, the filtered output on link 1221 may have the following form: A+Bsin(ω m t)+C cos(2ω m t)+Dsin(3ω m t)+… The filtered output can then be used to extract the I / Q components by mixing.

[0090] Multiplier block 1224-1 mixes (multiplies) the digital sine wave initially generated by sine wave generator 1204 on link 1207 with the filtered output on link 1221. This product is then low pass filtered at block 1228-1 to obtain the Q component described above, possibly after scaling by a number related to the amount of frequency modulation of the laser and the distance to the target.

[0091] Additionally, the initially generated digital sine wave is used as an input into the squaring / filtering block 1226 to produce a digital cosine wave having a frequency that is twice the frequency of the initially generated digital sine wave. The digital cosine wave is then mixed (multiplied) with the filtered output of the ADC block 1220 on link 1221 at the multiplier block 1224-2. The product is then low pass filtered at block 1228-2 to obtain the I component described above, possibly after scaling by a number related to the amount of frequency modulation of the laser and the distance to the target.

[0092] The phase calculation component 1230 then uses the Q component and the I component to obtain a phase from which the displacement of the target can be calculated as described above.

[0093] Those skilled in the art will appreciate that although Fig.12 The illustrated embodiment utilizes a digital form of the initially generated sine wave produced by sine wave generator 1204 on link 1207, but in other embodiments, the initially generated sine wave may be an analog signal and mixed with the analog output of DTIA / AA filter 1218. In other embodiments, voltage divider 1212 may be a variable voltage divider. In other embodiments, voltage divider 1212 may be omitted, and DTIA / AA filter 1218 may be a single-ended DTIA / AA filter. In such embodiments, subtraction may be performed digitally only at subtraction block 1222. In other embodiments, subtraction block 1222 may be omitted, and subtraction of the modulation current may not be performed.

[0094] Fig.12 The circuit can be applied to realize the above using Q′∝Lowpass{I PD ×sin(3ω m t)}. Some applications of such circuits may include directly generating a mixed signal sin(2ω m t) and sin(3ω m t), and multiplying each mixed signal by the output of ADC block 1220, and then applying corresponding low pass filtering, such as by blocks 1228-1, 1228-2. The DTIA / AA filter 1218 may then be replaced by a filter to remove or substantially reduce the initial modulation frequency ω m I PD The entire component of . Those skilled in the art will recognize that other circuits for implementing the modified I / Q method are applicable. For example, the chain 1207 can be multiplied by the output of the square / filter block 1226, and then bandpass filtering can be performed to suppress the division of sin(3ω m t) to generate the signal sin(3ω m t).

[0095] In additional and / or alternative embodiments, the I / Q time domain based method just described may be used with the spectrum based method of the first series of embodiments. The spectrum method of the first series may be used to determine the absolute distance to the target at a particular time and provide a value of L0. Thereafter, during subsequent time intervals, any of the various I / Q methods just described may be used to determine ΔL.

[0096] In additional and / or alternative embodiments, a spectral method based on a triangular wave modulation of the bias current of the VCSEL can be used as a guide to the I / Q time domain method. The I / Q method operates optimally in the case where J1(b)=J2(b) so that the I and Q components have the same amplitude. However, b depends on the distance L. One embodiment can apply a triangular wave modulation to the bias current of the VCSEL to determine the distance to the point of interest. This distance is then used to find the optimal peak-to-peak sinusoidal modulation of the bias current for use in the I / Q method. Such a dual method can provide improved signal-to-noise ratio and displacement accuracy obtained according to the I / Q method.

[0097] Fig.13 An exemplary method 1300 of identifying a gesture type is shown. The method 1300 may be performed, for example, by any of the processing systems or processors described herein.

[0098] At block 1302, method 1300 may include emitting an electromagnetic radiation beam from each SMI sensor in a set of one or more SMI sensors disposed in a wearable device. Alternatively, an electromagnetic radiation beam may be emitted from each SMI sensor in a set of one or more SMI sensors disposed in a handheld device.

[0099] At block 1304 , method 1300 may include sampling the SMI signal generated by each SMI sensor to produce a time-varying sample stream for each SMI sensor.

[0100] At block 1306, method 1300 may include using a processor of the wearable device and a time-varying sample stream of at least one SMI sensor in the set of one or more SMI sensors to determine movement of the wearable device (or handheld device) relative to the surface. The operation at block 1306 may also or alternatively include determining a position and / or orientation of the wearable device (or handheld device) relative to the surface.

[0101] At block 1308, method 1300 may include transmitting information indicative of the movement of the wearable device (or handheld device) from the wearable device (or handheld device) to a remote device.

[0102] In some embodiments, method 1300 may include modulating an input to the SMI sensor (or to each SMI sensor) using a triangular waveform or a sinusoidal waveform. In some embodiments, method 1300 may include: 1) modulating an input to the SMI sensor (or to each SMI sensor) using a first type of modulation when generating a first subset of samples in a time-varying sample stream for the SMI sensor; and 2) modulating an input to the SMI sensor (or to each SMI sensor) using a second type of modulation when generating a second subset of samples in a time-varying sample stream for the SMI sensor, wherein the first type of modulation is different from the second type of modulation (e.g., triangular modulation versus sinusoidal modulation).

[0103] In some embodiments of method 1300, the at least one SMI sensor may include three SMI sensors, and determining the movement of the wearable device (or handheld device) relative to the surface may include determining the movement of the wearable device in 6DoF.

[0104] In some embodiments of method 1300, the group of one or more SMI sensors includes multiple SMI sensors, and method 1300 may include analyzing a time-varying sample stream generated for the multiple SMI sensors, and identifying at least one SMI sensor for determining movement of the wearable device (or handheld device) relative to the surface based at least in part on the analysis.

[0105] In some embodiments of method 1300, the at least one SMI sensor may be a first subset of one or more SMI sensors, and the surface may be a first surface. In these embodiments, method 1300 may include using a processor of the wearable device (or handheld device) and a time-varying sample stream of a second subset of one or more SMI sensors in the set of one or more SMI sensors to determine movement of the wearable device (or handheld device) relative to a second surface.

[0106] Fig.14 An exemplary electrical block diagram of an electronic device 1400 is shown, which in some cases may be implemented as a reference Figures 1 to 7 and Fig.13Any of the devices described. The electronic device 1400 may include an electronic display 1402 (e.g., a light emitting display), a processor 1404, a power supply 1406, a memory 1408 or storage device, a sensor system 1410, or an input / output (I / O) mechanism 1412 (e.g., an input / output device, an input / output port, or a tactile input / output interface). The processor 1404 may control some or all operations of the electronic device 1400. The processor 1404 may communicate directly or indirectly with some or all other components of the electronic device 1400. For example, a system bus or other communication mechanism 1414 may provide communication between the electronic display 1402, the processor 1404, the power supply 1406, the memory 1408, the sensor system 1410, and the I / O mechanism 1412.

[0107] Processor 1404 may be implemented as any electronic device capable of processing, receiving, or sending data or instructions, whether in the form of software or firmware or encoded in other ways. For example, processor 1404 may include a microprocessor, a central processing unit (CPU), an application specific integrated circuit (ASIC), a digital signal processor (DSP), a controller, or a combination of such devices. As used herein, the term "processor" is intended to cover a single processor or processing unit, multiple processors, multiple processing units, or one or more other appropriately configured computing elements. In some cases, processor 1404 may provide reference Figures 1 to 7 and Figures 10 to 13 Part or all of the processing system or processor.

[0108] It should be noted that components of electronic device 1400 may be controlled by multiple processors. For example, selected components of electronic device 1400 (e.g., sensor system 1410) may be controlled by a first processor and other components of electronic device 1400 (e.g., electronic display 1402) may be controlled by a second processor, where the first processor and the second processor may or may not be in communication with each other.

[0109] The power supply 1406 may be implemented using any device capable of providing energy to the electronic device 1400. For example, the power supply 1406 may include one or more batteries or rechargeable batteries. Additionally or alternatively, the power supply 1406 may include a power connector or a power cord that connects the electronic device 1400 to another power source such as a wall outlet.

[0110] Memory 1408 can store electronic data that can be used by electronic device 1400. For example, memory 1408 can store electronic data or content, such as, for example, audio and video files, documents and applications, device settings and user preferences, timing signals, control signals, and data structures or databases. Memory 1408 can include any type of memory. By way of example only, memory 1408 can include random access memory, read-only memory, flash memory, removable memory, other types of storage elements, or combinations of these memory types.

[0111] The electronic device 1400 may also include one or more sensor systems 1410 positioned at substantially any location on the electronic device 1400. In some cases, the sensor system 1410 may include one or more SMI sensors, such as those described in reference to FIG. Figures 1 to 13 . The sensor system 1410 may be configured to sense one or more types of parameters, such as, but not limited to, vibration; light; touch; force; heat; movement; relative motion; biometric data of a user (e.g., biometrics); air quality; proximity; location; connectivity; and the like. By way of example, the sensor system 1410 may include an SMI sensor, a thermal sensor, a position sensor, an optical or optical sensor, an accelerometer, a pressure transducer, a gyroscope, a magnetometer, a health monitoring sensor, and an air quality sensor, among others. In addition, the one or more sensor systems 1410 may utilize any suitable sensing technology, including, but not limited to, interferometry, magnetism, capacitance, ultrasonic, resistance, optical, acoustic, ultrasonic, piezoelectric, or technology.

[0112] The I / O mechanism 1412 may transmit or receive data from a user or another electronic device. The I / O mechanism 1412 may include an electronic display 1402, a touch sensing input surface, a crown, one or more buttons (e.g., a graphical user interface "home" button), one or more cameras (including an under-display camera), one or more microphones or speakers, one or more ports such as a microphone port, and / or a keyboard. Additionally or alternatively, the I / O mechanism 1412 may send electronic signals via a communication interface such as a wireless, wired, and / or optical communication interface. Examples of wireless and wired communication interfaces include, but are not limited to, cellular and Wi-Fi communication interfaces.

[0113] The above description uses specific nomenclature to provide a thorough understanding of the embodiments for explanation. However, it will be apparent to those skilled in the art that, after reading this specification, the embodiments can be practiced without specific details. Therefore, for the purpose of illustration and description, the foregoing description of the specific embodiments described herein is presented. These descriptions are not intended to be exhaustive or to limit the embodiments to the precise form disclosed. It will be apparent to those of ordinary skill in the art that, after reading this specification, many modifications and variations are possible in view of the above teachings.

Claims

1. A wearable device, comprising: a device housing configured to be worn by a user; a set of self-mixing interferometry (SMI) sensors mounted within the device housing and configured to: emitting a set of electromagnetic radiation beams; as well as generating a set of SMI signals containing information about the user relative to a surface; and a processor configured to: generating a set of digitized samples of an SMI signal in the set of SMI signals; analyzing the digitized sample set; Based at least in part on the analyzing, identifying at least one SMI signal from the set of SMI signals, extracting the information about the user relative to the surface from the at least one SMI signal; as well as Information about the user relative to the surface is extracted from the digitized samples of the at least one SMI signal.

2. The wearable device according to claim 1, wherein the SMI sensor comprises at least three SMI sensors.

3. The wearable device of claim 1 , wherein the processor is configured to modulate the input of each SMI sensor in the set of SMI sensors using a triangular waveform.

4. The wearable device according to claim 1, wherein the processor is configured to: during a first group of time periods, modulate the input of each SMI sensor in the group of SMI sensors using a sinusoidal waveform; and during a second group of time periods, modulate the input of each SMI sensor in the group of SMI sensors using a triangular waveform.

5. The wearable device of claim 2, wherein the at least three SMI sensors are configured to emit orthogonal beams of electromagnetic radiation.

6. The wearable device of claim 2, wherein the at least three SMI sensors are configured to emit a converging beam of electromagnetic radiation.

7. The wearable device of claim 1, wherein the device housing defines a closed loop configured to receive a finger.

8. The wearable device of claim 1, wherein the device housing defines an open ring configured to receive a finger.

9. A wearable device according to claim 1, wherein the processor is configured to: analyze the digitized sample group to determine whether different electromagnetic radiation beams in the group of electromagnetic radiation beams may impinge on the surface or on different surfaces; and identify the at least one SMI signal based at least in part on determining that each SMI signal in the at least one SMI signal corresponds to an electromagnetic radiation beam impinging on the surface, and extract information about the user relative to the surface from the at least one SMI signal.

10. The wearable device according to claim 1, further comprising: A wireless communication interface mounted within the device housing; wherein: the processor is configured to use the wireless communication interface to send information about the user relative to the surface.

11. A method for identifying a gesture type, comprising: emitting a beam of electromagnetic radiation from each of a set of self-mixing interferometry (SMI) sensors disposed in the wearable device; sampling the SMI signal generated by each SMI sensor to produce a set of time-varying sample streams for the set of SMI sensors; generating a corresponding set of digitized samples for each time-varying sample stream in the set of time-varying sample streams; analyzing, using a processor of the wearable device, the corresponding set of digitized samples of each time-varying sample stream; identifying, using the processor and based at least in part on the analyzing, at least one SMI signal in the set of SMI signals, extracting information about movement of the user from the at least one SMI signal; as well as The movement of the user is determined using the processor and based at least in part on the at least one SMI signal.

12. The method according to claim 11, further comprising: An input to an SMI sensor included in the set of SMI sensors is modulated using a triangular waveform.

13. The method according to claim 11, further comprising: modulating an input to an SMI sensor included in the set of SMI sensors using a first type of modulation when generating a first subset of samples in a time-varying sample stream for the SMI sensor; And when generating a second subset of samples in the time-varying sample stream for the SMI sensor, modulating an input to an SMI sensor included in the set of SMI sensors using a second type of modulation; wherein the first type of modulation is different from the second type of modulation.

14. The method according to claim 11, wherein: The set of SMI sensors includes three SMI sensors; and determining the movement of the user includes determining the movement of the wearable device in six degrees of freedom.

15. The method of claim 11, wherein: Analyzing the set of digitized samples includes determining whether different electromagnetic radiation beams in the set of electromagnetic radiation beams are likely to impinge on the same surface or different surfaces; and identifying the at least one SMI signal based at least in part on determining that each SMI signal in the at least one SMI signal corresponds to an electromagnetic radiation beam impinging on the same surface, and extracting information about the user from the at least one SMI signal.

16. A wearable device comprising: a device housing configured to be worn by a user; a set of one or more self-mixing interferometry (SMI) sensors mounted within the device housing and configured to: emitting a set of one or more beams of electromagnetic radiation; as well as generating a set of SMI signals containing information about the user relative to the surface; and a processor configured to modulate an input of each SMI sensor in the set of SMI sensors using different waveforms during different time periods; generating a set of digitized samples of the set of SMI signals; as well as Information about the user relative to the surface is extracted from the set of digitized samples.

17. The wearable device of claim 16, wherein the information about the user relative to the surface includes a gesture made by the user.

18. The wearable device of claim 17, wherein the information about the user relative to the surface comprises an alphanumeric string formed by the user on or adjacent to the surface.

19. The wearable device of claim 16, wherein the wearable device comprises a finger ring.

20. The wearable device of claim 16, wherein the input of each SMI sensor in the set of SMI sensors is modulated differently in two or more different time periods.

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