Optical assembly with adjustable focus after active alignment systems and methods

Abstract

Various devices and methods are provided for optically aligning imaging devices. In one example, an imaging device includes an optical assembly comprising: a barrel comprising a first threaded interface, a holder comprising a second threaded interface engaged with the first threaded interface of the barrel, and an optical element disposed at least partially within the barrel. The imaging device also includes a sensor assembly fixed relative to the holder and configured to capture images of a scene received through the optical element. In response to rotation of the barrel, the threaded interfaces are configured to adjust the barrel between: a first position wherein the barrel is fully seated in the holder to maintain the optical element at a minimum displacement, and a second position wherein the barrel is moved within the holder to maintain the optical element at a maximum displacement. Additional devices and methods are also provided.

Description

OPTICAL ASSEMBLY WITH ADJUSTABLE FOCUS AFTER ACTIVE ALIGNMENT SYSTEMS AND METHODS Nile Fairfield, Bruce Covington, and Jeff Scott CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No.63 / 551,004 filed February 7, 2024 and entitled “OPTICAL ASSEMBLY WITH ADJUSTABLE FOCUS AFTER ACTIVE ALIGNMENT SYSTEMS AND METHODS,” which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present disclosure relates generally to imaging and, more particularly, to optical alignment of imaging devices. BACKGROUND

[0003] Imaging systems are used in a variety of applications to capture images of scenes. Some conventional imaging systems may permanently secure an optical element relative to a sensor assembly during manufacture to achieve an infinity focus across the field of view of the sensor assembly. Unfortunately, such implementations restrict a user’s ability to adjust the focus of the imaging system while in the field, thus, preventing the user from setting the focus to short distances.

[0004] Other conventional imaging systems may permit the user to adjust the position of the optical element relative to the sensor assembly. However, such implementations are often difficult to adjust and can prevent a user from easily achieving a reliable infinity focus when desired. Thus, it will be appreciated that conventional manufacturing processes for imaging systems result in various complications in their design and operation. SUMMARY

[0005] In one embodiment, an imaging device includes an optical assembly comprising: a barrel comprising a first threaded interface, a holder comprising a second threaded interface engaged with the first threaded interface of the barrel, and an optical element disposed at least partially within the barrel; a sensor assembly fixed relative to the holderand configured to capture images of a scene received through the optical element; and wherein, in response to rotation of the barrel, the threaded interfaces are configured to adjust the barrel between: a first position wherein the barrel is fully seated in the holder to maintain the optical element at a minimum displacement from the sensor assembly, and a second position wherein the barrel is moved within the holder to maintain the optical element at a maximum displacement from the sensor assembly.

[0006] In another embodiment, a method includes engaging a first threaded interface of a barrel of an optical assembly with a second threaded interface of a holder of the optical assembly, wherein an optical element is disposed at least partially within the barrel; fixing a sensor assembly relative to the holder, wherein the sensor assembly is configured to capture images of a scene received through the optical element; and adjusting, in response to rotation of the barrel, the threaded interfaces between: a first position wherein the barrel is fully seated in the holder to maintain the optical element at a minimum displacement from the sensor assembly, and a second position wherein the barrel is moved within the holder to maintain the optical element at a maximum displacement from the sensor assembly.

[0007] The scope of the present disclosure is defined by the claims, which are incorporated into this section by reference. A more complete understanding of embodiments of the present disclosure will be afforded to those skilled in the art, as well as a realization of additional advantages thereof, by a consideration of the following detailed description of one or more embodiments. Reference will be made to the appended sheets of drawings that will first be described briefly. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG.1 illustrates a block diagram of an imaging device in accordance with an embodiment of the present disclosure.

[0009] FIG.2 illustrates a perspective view of an imaging device in accordance with an embodiment of the present disclosure.

[0010] FIG.3A illustrates an exploded perspective view of the imaging device of FIG.2 in accordance with an embodiment of the present disclosure.

[0011] FIG.3B illustrates an exploded cross-sectional view of the imaging device of FIG. 2, as seen along the lines of the section 3B-3B taken therein, in accordance with an embodiment of the present disclosure.

[0012] FIG.4 illustrates a perspective view of a barrel of an imaging device in accordance with an embodiment of the present disclosure.

[0013] FIG.5 illustrates a perspective view of a holder of an imaging device in accordance with an embodiment of the present disclosure.

[0014] FIG.6 illustrates a perspective view of various components of an imaging device in accordance with an embodiment of the present disclosure.

[0015] FIG.7 illustrates a perspective view of a sensor assembly of an imaging device in accordance with an embodiment of the present disclosure.

[0016] FIG.8 illustrates a perspective view of a holder and a sensor assembly of the imaging device of FIG.2, as seen along the lines of the section 3B-3B taken therein, in accordance with an embodiment of the present disclosure.

[0017] FIG.9A illustrates a side view of the imaging device of FIG.2 in a first position, as seen along the lines of the section 3B-3B taken therein, in accordance with an embodiment of the present disclosure.

[0018] FIG.9B illustrates a side view of the imaging device of FIG.2 in a second position, as seen along the lines of the section 3B-3B taken therein, in accordance with an embodiment of the present disclosure.

[0019] FIG.10A illustrates a cutaway of the imaging device of FIG.9A in accordance with an embodiment of the present disclosure.

[0020] FIG.10B illustrates a cutaway of the imaging device of FIG.9B in accordance with an embodiment of the present disclosure.

[0021] FIG.11 illustrates a flow diagram of an exemplary process for manufacturing the imaging device in accordance with an embodiment of the present disclosure.

[0022] Embodiments of the present disclosure and their advantages are best understood by referring to the detailed description that follows. It is noted that sizes of various components and distances between these components are not drawn to scale in thefigures. It should be appreciated that like reference numerals are used to identify like elements illustrated in one or more of the figures. DETAILED DESCRIPTION

[0023] The detailed description set forth below is intended as a description of various configurations of the subject technology and is not intended to represent the only configurations in which the subject technology can be practiced. The appended drawings are incorporated herein and constitute a part of the detailed description. The detailed description includes specific details for the purpose of providing a thorough understanding of the subject technology. However, it will be clear and apparent to those skilled in the art that the subject technology is not limited to the specific details set forth herein and may be practiced using one or more embodiments. In one or more instances, structures and components are shown in block diagram form in order to avoid obscuring the concepts of the subject technology.

[0024] In one or more embodiments, various devices, systems, and methods are provided. In some aspects, such devices, systems, and methods may be used for infrared imaging (e.g., thermal imaging and / or other wavelengths), visible light imaging, and / or any desired wavelengths.

[0025] An adjustable focus of an imaging device is desirable, however, mechanical tolerances often result in variable focus across the field of view of the imaging device. Additionally, manual focus in a factory is often insufficient to achieve a maximum focus for a given lens with corrected tip, tilt, yaw, pitch, or roll. Furthermore, active alignment with a glue interface can overcome issues with mechanical tolerances and may achieve the best focus for a given lens. However, the focus of the lens is then fixed and cannot be adjusted after active alignment because of adherence of the lens to the sensor assembly.

[0026] Various embodiments of the present disclosure provide an imaging device that may be operated with an adjustable focus even after an active alignment process has been performed during manufacture. For example, during manufacture of the imaging device, an optical assembly (e.g., including a barrel, one or more associated optical elements, and a holder threadably engaged with the barrel) may be provided with the barrel fully seated (e.g., bottomed out) in the holder (e.g., wherein threaded interfaces of the barrel and the holder are fully engaged with each other at a stop position) to position the optical element to provide an infinity focus for the sensor assembly. While so positioned, an activealignment process may be performed during which the optical assembly and the sensor assembly are aligned relative to each other (e.g., through the use of an active alignment apparatus) and secured relative to each other (e.g., by securing the sensor assembly to the holder). Thus, the imaging device may achieve a reliable and accurately aligned infinity focus while the barrel is fully seated in the holder.

[0027] Following the active alignment process, the position of the barrel (and consequently the associated optical elements) may be selectively moved away from the sensor assembly (e.g., through adjustment of the threaded interfaces of the barrel and the holder) in order to shorten the focus distance as may be desired by a user. If an infinity focus is subsequently desired, then the barrel may be easily repositioned into the fully seated position to again achieve a reliable infinity focus.

[0028] Referring now to the drawings, wherein the showings are for purposes of illustrating embodiments of the present disclosure and not for purposes of limiting the same, FIG.1 illustrates a block diagram of an imaging device 100 (e.g., an imaging system) in accordance with an embodiment of the present disclosure. Imaging device 100 may be configured to capture an image of a scene 101 that is within a field of view (FoV) 103 of imaging device 100. In one or more embodiments, imaging device 100 may be configured to capture and process visible and / or non-visible light images. For instance, and without limitation, imaging device 100 may be used to capture and process thermal images (e.g., thermal image frames). For example, imaging device 100 may be implemented as a thermal camera.

[0029] Still referring to FIG.1, imaging device 100 may include an optical assembly 102 and a sensor assembly 110. Optical assembly 102 may include a barrel 104, a holder 106, and an optical element 108 (e.g., a lens, see FIG.2), as discussed further in this disclosure. Sensor assembly 110 may include a sensor 112, which may be at least partially disposed within a housing 114 of sensor assembly 110.

[0030] In some embodiments, imaging device 100 may also include housing 114 with various electronic components disposed therein, including a logic device 116, machine- readable medium 120, memory component 118, display component 122, control component 124, other sensing components 126, and other components 128 (e.g., additional components such as one or more circuit boards, heatsinks, communication component, and / or other components as appropriate). In one or more embodiments,housing 114 may include a monolithic structure or may be constructed from various components. Housing 114 may be composed of one or more various materials, such as metal, thermoplastic, polymer, glass, fiberglass, and the like. Housing 114 may fully enclose or partially enclose one or more components of imaging device 100.

[0031] In various embodiments, imaging device 100 may be implemented, for example, as a camera system such as a portable handheld camera system, a small form factor camera system implemented as part of another device, a fixed camera system, and / or other appropriate implementations. In various embodiments, imaging device 100 may be handheld or mounted to a vehicle, such as a car, truck, aerial vehicle, watercraft, and the like.

[0032] In some embodiments, logic device 116 may include, for example, a microprocessor, a single-core processor, a multi-core processor, a control circuit, a microcontroller, a programmable logic device configured to perform processing operations, a digital signal processing (DSP) device, one or more memories for storing executable instructions (e.g., software, firmware, or other instructions), and / or any other appropriate combinations of processing device and / or memory to execute instructions to perform appropriate operations. Logic device 116 may be configured to interface and communicate with the various components illustrated in FIG.1. In various embodiments, it should be appreciated that processing operations and / or instructions may be integrated in software and / or hardware as part of logic device 116, or code (e.g., software or configuration data) which may be stored in memory component 118. Embodiments of processing operations and / or instructions disclosed in this disclosure may be stored by machine-readable medium 120 in a non-transitory manner (e.g., a memory, a hard drive, a compact disk, a digital video disk, or a flash memory) to be executed by a computer (e.g., logic or processor-based system) to perform various operations.

[0033] In various embodiments, machine-readable medium 120 may be included as part of imaging device 100 and / or separate from imaging device 100, with stored instructions provided to imaging device 100 by connecting machine-readable medium 120 to imaging device 100 and / or by imaging device 100 downloading (e.g., via a wired or wireless link) the instructions from the machine-readable medium (e.g., containing the non-transitory information). In various embodiments, as described herein, instructions provide for real time applications of processing various images of scene 101. In an aspect, a scene may be referred to as an object, a target scene, or a target object.

[0034] In some embodiments, memory component 118 may include one or more memory devices (e.g., one or more memories) to store data and information. The one or more memory devices may include various types of memory including volatile and non-volatile memory devices, such as RAM (Random Access Memory), ROM (Read-Only Memory), EEPROM (Electrically-Erasable Read-Only Memory), flash memory, or other types of memory. In some embodiments, logic device 116 is configured to execute software stored in memory component 118 and / or machine-readable medium 120 to perform various methods, processes, and operations in a manner as described herein.

[0035] In some embodiments, sensor 112 may include an array of sensors (e.g., any type of visible light, infrared, ultraviolet, or other type of detector) for capturing images of scene 101. In various embodiments, sensors 112 may be configured to convert captured images of scene 101 as digital data (e.g., via an analog-to-digital converter included as part of the sensor or separate from the sensor as part of imaging device 100). An imager interface of sensor assembly 110 may provide the captured images to logic device 116 which may be used to process the images (e.g., image frames), store the original and / or processed images in memory component 118, and / or retrieve stored images from memory component 118.

[0036] In some embodiments, logic device 116 may be configured to receive images from sensor assembly 110, process the images, store the original and / or processed images in memory component 118, and / or retrieve stored images from memory component 118. In various aspects, logic device 116 may be configured to receive images from the imager via wired or wireless communication. Logic device 116 may be configured to process images stored in memory component 118 to provide images (e.g., raw and / or processed images) to display component 122 for viewing by a user.

[0037] In some embodiments, display component 122 may include an image display device (e.g., a liquid crystal display (LCD)) or various other types of generally known video displays or monitors. Logic device 116 may be configured to display image data and information on display component 122. Logic device 116 may be configured to retrieve image data and information from memory component 118 and display any retrieved image data and information on display component 122. Display component 122 may include display electronics, which may be utilized by logic device 116 to display image data and information. Display component 122 may receive image data and informationdirectly from sensor 112 via logic device 116, or the image data and information may be transferred from memory component 118 via logic device 116.

[0038] In some embodiments, control component 124 may include a user input and / or interface device having one or more user actuated components, such as one or more push buttons, slide bars, rotatable knobs or a keyboard, that are configured to generate one or more user actuated input control signals. Control component 124 may be configured to be integrated as part of display component 122 to operate as both a user input device and a display device, such as, for example, a touch screen device configured to receive input signals from a user touching different parts of a screen of display component 122. Logic device 116 may be configured to sense control input signals from control component 124 and respond to any sensed control input signals received therefrom.

[0039] In some embodiments, control component 124 may include a control panel unit (e.g., a wired or wireless handheld control unit) having one or more user-activated mechanisms (e.g., buttons, knobs, sliders, or others) configured to interface with a user and receive user input control signals. In various embodiments, it should be appreciated that the control panel unit may be configured to include one or more other user-activated mechanisms to provide various other control operations of imaging device 100, such as auto-focus, menu enable and selection, field of view, brightness, contrast, gain, offset, spatial, temporal, and / or various other features and / or parameters.

[0040] In some embodiments, control component 124 may include a graphical user interface (GUI), which may be integrated as part of display component 122 (e.g., a user actuated touch screen), having one or more images of the user-activated mechanisms (e.g., buttons, knobs, sliders, or others), which are configured to interface with a user and receive user input control signals via display component 122. As an example, for one or more embodiments as discussed further herein, display component 122 and control component 124 may represent appropriate portions of a tablet, a laptop computer, a desktop computer, or other type of device.

[0041] In some embodiments, imaging device 100 may include one or more other types of sensing components 126, including environmental and / or operational sensors, depending on the sensed application or implementation, which provide information to logic device 116 (e.g., by receiving sensor information from each sensing component 160). In various embodiments, other sensing components 126 may be configured to provide data andinformation related to environmental conditions, such as internal and / or external temperature conditions, lighting conditions (e.g., day, night, dusk, and / or dawn), humidity levels, specific weather conditions (e.g., sun, rain, and / or snow), distance (e.g., laser rangefinder), rotation (e.g., a gyroscope), and / or whether a tunnel, a covered parking garage, or that some type of enclosure has been entered or exited. Accordingly, other sensing components 126 may include one or more conventional sensors as would be known by those skilled in the art for monitoring various conditions (e.g., environmental conditions) that may have an effect (e.g., on the image appearance) on the data provided by sensor 112.

[0042] In some embodiments, other sensing components 126 may include devices that relay information to logic device 116 via wireless communication. For example, each of the other sensing components 126 may be configured to receive information from a satellite, through a local broadcast (e.g., radio frequency) transmission, through a mobile or cellular network and / or through information beacons in an infrastructure (e.g., a transportation or highway information beacon infrastructure) or various other wired or wireless techniques.

[0043] In some embodiments, the communication component of imaging device 100 may be implemented as a connector (e.g., to interface one or more electronic components to an external device), a network interface component (NIC) configured for communication with a network including other devices in the network, and / or other implementations. In various embodiments, the communication component may include one or more wired or wireless communication components, such as an Ethernet connection, a wireless local area network (WLAN) component based on the IEEE 802.11 standards, a wireless broadband component, mobile cellular component, a wireless satellite component, or various other types of wireless communication components including radio frequency (RF), microwave frequency (MWF), and / or infrared frequency (IRF) components configured for communication with a network. As such, communication component may include an antenna coupled thereto for wireless communication purposes. In other embodiments, the communication component may be configured to interface with a DSL (e.g., Digital Subscriber Line) modem, a PSTN (Public Switched Telephone Network) modem, an Ethernet device, and / or various other types of wired and / or wireless network communication devices configured for communication with a network.

[0044] In some embodiments, a network may be implemented as a single network or a combination of multiple networks. For example, in various embodiments, the network may include the Internet and / or one or more intranets, landline networks, wireless networks, and / or other appropriate types of communication networks. In another example, the network may include a wireless telecommunications network (e.g., cellular phone network) configured to communicate with other communication networks, such as the Internet. As such, in various embodiments, imaging device 100 and / or its individual associated components may be associated with a particular network link such as for example a URL (Uniform Resource Locator), an IP (Internet Protocol) address, and / or a mobile phone number.

[0045] Now referring to FIG.2, a perspective view of imaging device 100 is shown in accordance with an embodiment of the present disclosure. In one or more embodiments, optical element 108 may be disposed within barrel 104. For example, barrel 104 may include a lumen configured to receive optical element 108. In some embodiments, optical element 108 may include one or more windows, lenses, mirrors, beamsplitters, beam couplers, and / or other components. In an embodiment, optical element 108 may include one or more chalcogenide lenses, such as lenses made of As40Se60, that allow for imaging in a wide infrared spectrum. Other materials, such as silicon, germanium, and germanium arsenide selenium (GeAsSe), may be utilized depending on desired transmission characteristics, such as desired transmission wavelengths and / or ray transfer matrix characteristics. Optical element 108 may receive electromagnetic (EM) radiation through an aperture of barrel 104 and pass the EM radiation to sensor 112 (e.g., an image capture component or imager). For example, optical element 108 may direct and / or focus EM radiation on a surface of sensor 112 (e.g., sensor plane).

[0046] Optical element 108 of imaging device 100 may be transmissive of electromagnetic radiation within a waveband dependent on a desired application. In various embodiments, imaging device 100 may include an infrared imaging device for facilitating capture of a waveband encompassing at least a portion of the thermal infrared spectrum, such as a mid-wave infrared spectrum and / or a long-wave infrared spectrum. Lens material used to manufacture lenses is generally based on a desired application (e.g., a desired transmission waveband of the lens elements). In some applications, optical element 108 may include a single lens element that may be or may include a refractive element that refracts EM radiation onto sensor 112 (e.g., detector array). In otherapplications, imaging device 100 may include a plurality or series of lenses, where each lens may receive and direct EM radiation to a subsequent lens of the series, with a last lens receiving and directing EM radiation to sensor 112.

[0047] Still referring to FIG.2, sensor assembly 110 may include an image capture component or imager. For instance, sensor assembly 110 may include one or more sensors 112 (e.g., visible-light sensor, infrared sensor, ultraviolet sensor, any combination thereof, and the like) for capturing image signals representative of an image of scene 101. In one or more non-limiting embodiments, sensor 112 may capture (e.g., detect or sense) infrared radiation with wavelengths in the range from around 700 nm to around 1 mm, or portion thereof. For example, in some embodiments, sensor 112 may include one or more sensors sensitive to (e.g., better detect) thermal infrared wavelengths, including mid-wave infrared (MWIR) radiation (e.g., EM radiation with wavelength of 2-7 μm) and / or long- wave infrared (LWIR) radiation (e.g., electromagnetic radiation with wavelength of 7-15 μm). In one embodiment, sensor 112 may represent (e.g., convert) or facilitate representation of a captured thermal image signal of scene 101 as digital data (e.g., via an analog-to-digital converter), as discussed previously in FIG.1. For instance, logic device 116 may receive image data (e.g., one or more images) captured at sensor 112 and may communicate the captured image data to other components or devices, such as via wired and / or wireless communication. In various embodiments, imaging device 100 may capture an image (e.g., image frame), for example, of scene 101. An image may include one or more images or one or more videos of the scene.

[0048] Still referring to FIG.2, imaging device 100 includes barrel 104 to hold (e.g., receive, secure, align) optical element 108 (e.g., one or more lenses). Barrel 104 may define a lumen, such as an elongated opening through the length of barrel 104 that optical element 108 may be at least partially disposed within. For example, barrel 104 may define an opening 202 that optical element 108 may at least be partially disposed within. In one or more embodiments, the opening 202 may be defined by the protective enclosure of barrel 104 that allows EM radiation to reach optical element 108. In various embodiments, barrel 104 may have a substantially cylindrical shape.

[0049] As shown in FIG.2, holder 106 may be configured to receive barrel 104 such that barrel 104 may be at least partially disposed within holder 106. Barrel 104 may be selectively connected to holder 106 using an engagement component (e.g., threaded interfaces of barrel and holder), as discussed further in this disclosure below. In non-limiting exemplary embodiments, barrel 104 may include an engagement component that connects to a complementary engagement component of holder 106 such that holder 106 may receive at least a portion of barrel 104. In various embodiments, engagement component may facilitate rotation, translation, and / or other movement of barrel relative to holder 106 and / or sensor assembly 110. In some cases, engagement component may be utilized to facilitate alignment of a lens element during molding, machining, and / or assembling.

[0050] Still referring to FIG.2, sensor assembly 110 includes housing 114, which may be attached or fixed to holder 106, as discussed further in this disclosure. In various embodiments, housing 114 may enclose sensor 112. In some cases, housing 114 may contain a processor or logic device to process image data from sensor, memory to store raw image data and / or processed image data, a power source (e.g., battery), and / or other components to facilitate operation of imaging device 100, as previously discussed in FIG. 1. Housing 114 may be implemented as a protective enclosure of one or more components of imaging device 100, as shown in FIG.1. Housing 114 may be composed of various materials, such as, but not limited, to carbon fiber, polymer, fiberglass, metal, glass, and the like.

[0051] Now referring to FIGS.3A and 3B, an exploded perspective view and cross- sectional view, respectively, are shown of imaging device 100 in accordance with embodiments of the present disclosure. In one or more embodiments, imaging device 100 may include barrel 104 having a first threaded interface 304, optical element 108, an primary O-ring 302, a spring 308 (also referred to in this disclosure as a “compression spring”), a washer 310, a secondary O-ring 312, fasteners 314 (e.g., nails, screws, pins, and the like) of holder 106, holder 106 having a second threaded interface 306 configured to engage with first threaded interface 304 of barrel 104, a shutter assembly 316 of holder 106, a backplate 318 of holder 106, a fixing component 320 (e.g., adhesive, fastener, or the like), a spring contact 322 of sensor assembly 110, a lid 324 of sensor assembly 110, sensor 112 of sensor assembly 110, a heat spreader 326 of sensor assembly 110, a printed circuit board (PCB) 328 of sensor assembly 110, a front portion 330 of housing 114 of sensor assembly 110, a rear portion 332 of housing 114 of sensor assembly 110, a DRAM 334 (e.g., memory component 118) of sensor assembly 110, a connector 336 of sensor assembly 110, a primary printed circuit board (PCB) 338 (e.g., logic device 116) ofsensor assembly 110, an FPGA 340, a power source 342 of sensor assembly 110, and a contact 344 of sensor assembly 110.

[0052] FIG.3B provides a cross-sectional exploded view of imaging device 100 taken along the lines of the section 3B-3B of FIG.2 in accordance with an embodiment of the present disclosure. As shown in FIG.3B, imaging device 100 may include a central axis A. Central axis A may be coaxially aligned to an optical axis B of barrel 104 (shown in FIG.4).

[0053] Now referring to FIG.4, a perspective view of barrel 104 of imaging device 100 is shown in accordance with an embodiment of the present disclosure. Barrel 104 may include a first portion 402 and a second portion 404. First portion 402 may include a front portion of barrel 104, where the front portion is directed at (e.g., faces) scene 101. Second portion 404 may include a rear portion of barrel 104, where the rear portion is directed at (e.g., faces) sensor assembly 110, such as sensor 112 of sensor assembly 110. In some cases, first portion 402 may have a different diameter from second portion 404. For instance, in some non-limiting embodiments, first portion 402 may include a great diameter than the diameter of second portion 404 such that an external surface of first portion 402 is substantially flush with an external surface of holder 106 when barrel 104 and holder 106 are engaged (e.g., barrel 104 is at least partially disposed within holder 106).

[0054] In one or more embodiments, barrel 104 includes a first threaded interface 304. First threaded interface 304 may include a spiraling ramp that traverses along a surface of barrel 104, such as along an outer surface of second portion 404, to create steps within the surface and is configured to engage a complementary threaded interface to selectively attach (e.g., join or connect) two or more components (e.g., barrel 104 and holder 106). First threaded interface 304 may be disposed on an external surface of second portion 404 (e.g., shaft) of barrel 104. For instance, first threaded interface 304 may extend about a perimeter (e.g., along the circumference) of the external surface of second portion 404. In some cases, first threaded interface 304 may protrude from (e.g., be raised relative to) the external surface of second portion 404 of barrel 104. In other cases, first threaded interface 304 may be substantially flush with the external surface of second portion 404. In other cases, first threaded interface 304 may be substantially receded relative to the external surface of second portion 404. First threaded interface 304 may include variousthread pitches, thread counts, thread angles, helix angles, minor diameters, major diameters, pitch diameters, and the like.

[0055] Still referring to FIG.4, imaging device 100 may include one or more O-rings, where each O-ring may be disposed about at least a portion of second portion 404 of barrel 104. In one or more embodiments, primary O-ring may be disposed about second portion 404 and abutting first threaded interface 304. Primary O-ring 302 may assist in facilitating movement of barrel 104 within holder 106, as discussed further in this disclosure below. Primary O-ring 302 may also prevent undesirable movement of barrel 104 within holder 106 so that barrel remains in a seated position. In one or more embodiments, secondary O-ring 312 may be disposed about second portion of barrel 104 such that secondary O-ring abuts an opposing side of first threaded interface 304 from primary O-ring. In some cases, washer 310 may be disposed between secondary O-ring 312 and first threaded interface 304. Secondary O-ring may prevent debris of threaded interfaces from reaching sensor assembly 110 (e.g., sensor 112). In some embodiments, second portion 404 may include a smooth surface such that the O-rings and washer may be easily slid along external surface of second portion when barrel 104 is moved relative to holder 106.

[0056] In one or more embodiments, imaging device 100 includes spring 308. In various embodiments, spring 308 may include a compression spring. For example, spring 308 may include a wave spring. Spring 308 may include a helical construction or any other construction configured to provide a force along the axis of wind of spring 308 (e.g., central axis A). In one or more embodiments, spring 308 may be disposed about second portion 404 of barrel 104 and configured to bias first threaded interface 304 and washer 310 or secondary O-ring 312. Spring 308 may be implemented to prevent undesirable movement of barrel 104 relative to holder 106 when seated in a particular position (e.g., a first position or second position), as discussed further below in this disclosure.

[0057] Still referring to FIG.4, in some embodiments, optical element 108 may include a front lens, which is directed at scene 101 (shown in FIG.1), and a rear lens, which is directed at sensor 112. In other embodiments, optical element 108 may include one lens having a front surface, facing scene 101, and a rear surface, facing sensor 112. In one or more embodiments, optical element 108 may have an optical axis B. As previously mentioned in this disclosure, in some embodiments, optical axis B may be the same as or coaxially aligned with central axis A. For instance, and without limitation, during activealignment of imaging device 100, optical axis B and central axis A may be coaxially aligned.

[0058] In one or more embodiments, optical element 108 may be configured to transmit a wide spectrum of infrared light. Optical element 108 may have specific optical characteristics. For example, and without limitation, optical element 108 may include a specific effective focal length (EFL) and modulation transfer function (MTF). In various embodiments, optical element 108 may include one or more components (e.g., lenses) that are coordinated to direct and focus light onto sensor 112 (e.g., an image capture portion of sensor assembly 110). In one or more embodiments, optical element 108 may be fixed relative to barrel 104.

[0059] Now referring to FIG.5, a perspective view of holder 106 is shown in accordance with an embodiment of the present disclosure. Holder 106 may include second threaded interface 306 configured to engage with first threaded interface 304 of barrel 104. Second threaded interface 306 may include a complementary threaded interface that is configured to engage first threaded interface 304. In various embodiments, first threaded interface 304 and second threaded interface 306 may be implemented as an engagement component configured to selectively connect barrel 104 and holder 106.

[0060] In some embodiments, holder 106 may include a receptacle portion 502 extending from a base 504. In various embodiments, receptacle portion 502 may include a cylindrical interface. In some embodiments, base 504 may include shutter assembly 316 and backplate 318. Receptacle portion 502 may include a complementary threaded interface (e.g., second threaded interface 306). For instance, second threaded interface 306 may be disposed on an inner surface 508 of receptacle portion 502 such that when barrel 104 is disposed at least partially within receptacle portion 502, first threaded interface 304 and second threaded interface 306 are engaged. For instance, second threaded interface 306 may extend about an internal perimeter (e.g., along the internal circumference) of the internal surface of receptacle portion 502. In some cases, second threaded interface 306 may protrude from (e.g., be raised relative to) internal surface 508 of receptacle portion 502 of holder 106. In other cases, second threaded interface 306 may be substantially flush with internal surface 508 of receptacle portion 502. In other cases, second threaded interface 306 may be substantially receded relative to the internal surface of receptacle portion 502. Second threaded interface 306 may include a spiraling ramp that traverses along inner surface 508 of holder 106 to create steps within the innersurface and is configured to engage complementary threaded interface of barrel 104 (e.g., first threaded interface 304) to selectively attach (e.g., join or connect) two or more components (e.g., barrel 104 and holder 106). Second threaded interface 306 may include various thread pitches, thread counts, thread angle, helix angle, minor diameter, major diameter, pitch diameter, and the like.

[0061] Still referring to FIG.5, holder 106 may include shutter assembly 316 and backplate 318. In various embodiments, shutter assembly 316 may be disposed between holder 106 and backplate 318. Backplate 318 may be attached to a rear surface of shutter assembly 316 to secure holder 106, shutter assembly 316, and backplate 318 together. For instance, fasteners 314 may be disposed within aligned apertures of holder 106, shutter assembly 316, and backplate 318 to secure them together.

[0062] Now referring to FIG.6, a perspective view of various components of imaging device 100 in accordance with an embodiment of the present disclosure is shown. For instance, shutter assembly 316 and backplate 318 are shown proximate to sensor assembly 110. Shutter assembly 316 may include a window 602 that allows light from optical element 108 to pass through holder 106 to sensor assembly 110 (e.g., sensor 112), as previously discussed in this disclosure. In one or more embodiments, shutter assembly 316 may include a beveled surface, where the beveled surface is substantially angled relative to a front-facing surface of shutter assembly 316. Sensor 112 of sensor assembly 110 may be substantially aligned with window 602 so that sensor 112 is centered relative to window 602 (e.g., a sensor plane of sensor 112 and window 602 share a central axis). Sensor 112 may be positioned adjacent to backplate 318 and at least a portion of housing 114 of sensor assembly 110 may abut backplate 318. In some embodiments, window 602 may include spatial dimensions comparable to a front optical surface of sensor 112. For example, window 602 and a front optical surface of sensor 11 (e.g., sensor plane of sensor 112) may have similar or the same dimensions (e.g., area).

[0063] Now referring to FIG.7, a perspective view of sensor assembly 110 is shown in accordance with an embodiment of the present disclosure. Sensor assembly 110 may be selectively fixed relative to holder 106, using, for example, fixing component 320, and configured to capture images of scene 101 (shown in FIG.1) received through optical element 108. Sensor assembly 110 may include lid 324, which at least partially covers sensor 112. In some cases, lid 324 may provide a protective layer over sensor 112 and / ora vacuum seal. In various embodiments, lid 324 may be composed of a transparent or semi-transparent material.

[0064] In one or more embodiments, sensor 112 may be mounted to heat spreader 326. Heat spreader 326 may include a heat sink or any other component configured to transfer energy as heat. Heat spreader 326 may include a passive or active heat spreader.

[0065] Still referring to FIG.7, sensor 112 of sensor assembly 110 may include an image capture component (e.g., imager) configured to capture images viewed through barrel 104, as previously discussed in FIG.1. In various embodiments, sensor 112 may be at least partially disposed within housing 114, which may include a front portion 330 and a rear portion 332, as discussed. Sensor 112 may include an array of sensors, such as for example, an array of microbolometers configured to detect EM radiation. As one example, the arrays of microbolometers may be configured to detect long-wave infrared light of wavelengths between 7.5 μm and 13.5 μm. In various embodiments, imaging device 100 may include an infrared imaging device, as previously mentioned herein. As previously mentioned in this disclosure, sensor 112 may include various types of sensors. For instance, sensor 112 may include an infrared (IR) focal plane array (FPA) sensor to detect infrared radiation passing through a lid (e.g., vacuum-package window) of sensor assembly and provide thermal image data in response thereto. In various embodiments, the FPA may include a detector array and a readout circuit (e.g., PCB 328). The detector array may be implemented using various types of infrared detectors (e.g., quantum wells, microbolometers, or other types), and the like. In a non-limiting exemplary embodiment, optical element 108 may receive EM radiation from scene 101 and pass (e.g., direct and / or focus) the electromagnetic radiation to the FPA.

[0066] Image data generated by sensor 112 may include infrared data values (e.g., thermal infrared data values). As an example, the FPA may include or may be coupled to an analog-to-digital converter (ADC) circuit that generates infrared data values based on infrared radiation. The infrared data values may provide temperatures for different portions of scene 101, such as provide temperatures of objects, persons, and / or other aspects in the scene 101. In some cases, the infrared image data may be represented in an image according to a palette, such that a visual representation value (e.g., color value or grayscale value) of each pixel of the image is indicative of a temperature associated with that pixel. The infrared image data may be displayed (e.g., to a user), stored, and / or processed using components described in FIG.1.

[0067] Now referring to FIG.8, a perspective view of holder 106 and sensor assembly 110 of imaging device 100, as seen along the lines of the section 3B-3B of FIG.2, is shown in accordance with an embodiment of the present disclosure. As shown in FIG.8, primary O-ring 302, secondary O-ring 312, washer 310, and spring 308 may abut inner surface 508 of holder 106 when barrel 104 is disposed at least partially within holder 106. In some cases, second threaded interface 306 of holder 106 may be positioned between primary O-ring 302 and spring 308. In some embodiments, inner surface 508 of holder 106 may include a stepped surface that one or more components of imaging device 100 may abut and / or bias during operation of imaging device 100, as discussed further in this disclosure below.

[0068] Now referring to FIGS.9A and 9B, side cross-sectional views of imaging device 100 along line 3B-3B of FIG.2 are shown in accordance with embodiments of the present disclosure. In various embodiments, imaging device 100 may be operated with an adjustable focus even after an active alignment process has been performed during manufacture. For example, during manufacture of imaging device 100, optical assembly (e.g., including barrel 104, one or more associated optical elements 108, and holder 106 threadably engaged with barrel 104) may be provided with barrel 104 fully seated in holder 106, where threaded interfaces of the barrel and the holder are fully engaged with each other at a stop position, to position optical element 108 to provide an infinity focus for sensor assembly 110. While fully seated, an active alignment process may be performed during which optical assembly 102 and sensor assembly 110 may be aligned relative to each other (e.g., through the use of an active alignment apparatus). For instance, sensor assembly 110 may be moved relative to optical assembly 102 until an ideal infinity focus is achieved. Once aligned, optical assembly 102 and sensor assembly 110 may be secured relative to each other (e.g., by securing sensor assembly 110 to holder 106). For instance, optical assembly 102 and sensor assembly 110 may be secured to each other using an adhesive (e.g., epoxy, ultraviolet (UV) curing adhesive, rubber cement, and the like). As a result, imaging device 100 may achieve a reliable and accurately aligned infinity focus while barrel 104 is fully seated in holder 106.

[0069] Following the active alignment process, the position of barrel 104 (and consequently the associated optical elements) may be selectively moved away from sensor assembly 110, using, for example, adjustment of the threaded interfaces of barrel 104 and holder 106, in order to shorten the focus distance as may be desired by a user. Ifan infinity focus is subsequently desired after adjustment, then barrel 104 may be easily repositioned into the fully seated position to again achieve a reliable infinity focus. Thus, the user may reliably achieve an infinity focus at any time after the active alignment process by the fully seated position providing the infinity focus of imaging device 100.

[0070] FIG.9A illustrates a side view of imaging device 100 in a first position, as seen along the lines of the section 3B-3B taken therein, in accordance with an embodiment of the present disclosure. As shown in FIG.9A, barrel 104 may be positioned in a first position x relative to holder 106. For instance, barrel 104 may be fully seated (e.g., bottomed out) in holder 106 such that threaded interfaces 304 and 306 of barrel 104 and holder 306, respectively, are fully engaged with each other at a stop position (e.g., position x) to position optical element 108 to provide an infinity focus for sensor assembly 110. In response to rotation of barrel 104, threaded interfaces 304 and 306 are configured to adjust barrel 104 between first position x, where barrel 104 is fully seated in holder 106 to maintain optical element 108 at a minimum displacement d from sensor assembly 110, and a second position x’, where barrel 104 is positioned at a maximum displacement d’ from sensor assembly 110, as shown in FIG.9B, which illustrates a side view of imaging device 100 in a second position, as seen along the lines of the section 3B-3B taken therein, in accordance with an embodiment of the present disclosure. In various embodiments, second position x’ may be a distance x from first position x. Similarly, maximum displacement d' may vary by a difference d from minimum displacement d, as shown in FIG.9B.

[0071] In various embodiments, when barrel 104 is fully seated in position x, a focal distance (i.e. a distance between the lens and the sensor) may be at a minimum amount. For example, focal distance may include a minimum displacement d when barrel 104 is in position x. A focus of optical element 108 is set at infinity when barrel 104 is in first position x. In various embodiments, when barrel 104 is seated in position x’, a focal distance may be at a maximum amount. For instance, and without limitation, when barrel 104 is in position x’, the focal distance may include a maximum displacement d’. In one or more embodiments, in response to rotation of barrel 104, threaded interfaces 304 and 306 are configured to adjust a position of barrel 104 to an intermediate position between first position x and second position x’ such that barrel 104 is at an intermediary displacement, and thus the focal distance is an intermediary amount. Focus of imaging device 100 may then be set to an intermediary distance when barrel 104 is at anintermediate position. In one or more embodiments, barrel 104 may be moved to one or more intermediary positions based on a desired distance of focus of imaging device 100.

[0072] Referring now to FIGS.10A and 10B, cutaways of imaging device 100 in FIGS.9A and 9B, respectively, are shown in accordance with one or more embodiments of the present disclosure. Referring to FIG.10A, sensor assembly 110 may be fixed relative to holder 106 following the active alignment process performed to align optical assembly 102 with sensor assembly 110 while barrel 104 is in first position x (e.g., fully seated). Active alignment, for the purposes of this disclosure, includes a technique for mechanically positioning components and / or elements of an imaging device to improve accuracy of the imaging device and achieve an image with the best possible focus over the entire captured image. Active alignment may include positioning one or more optical elements in real time while sensor 112 is powered up to align various degrees of freedom (e.g., five or six degrees of freedom). For instance, active alignment may include aligning optical element 108 relative to sensor 112 (e.g., an image or sensor plane of sensor 112) to achieve an ideal point-to-point lateral resolution in an object plane perpendicular to the optical axis. The active alignment process may include measuring optical characteristics (e.g., degrees of freedom) of optical element 108 and sensor 112 in real time and, in response, adjusting one or more optical characteristics to achieve desirable tolerances for each degree of freedom. In other instances, adjustments during active alignment may include aligning optical axis B of optical element 108 with a center of a sensor plane of sensor 112 (e.g., an active area of sensor 112), positioning optical axis B orthogonally to the sensor plane of sensor 112, positioning the sensor plane in the center of the depth of focus, and the like.

[0073] Still referring to FIG.10A, during the active alignment process, an adhesive (e.g., fixing component 320) may be applied to a surface of housing 114 of sensor assembly 110 and / or holder 106 (e.g., backplate 318 of holder 106). Adhesive may include a glue, rubber cement, epoxy, or other binding materials. Holder 106 and sensor assembly may then be positioned proximate to each other such that holder 106 and sensor assembly 110 are contacting. Adhesive may remain mailable (e.g., uncured) during the active alignment process so that holder 106 and sensor assembly 110 may be moved relative to each other during the alignment of the degrees of freedom. Once optical element 108 and sensor 112 are desirably positioned relative to each other, the adhesive may be cured to fix optical element 108 relative to sensor 112. In various embodiments, fixing component320 may be cured using, for example, light fixation (e.g., ultraviolet (UV) light curing) and / or heat curing.

[0074] In one or more embodiments, the active alignment process may include performing active alignment of six degrees of freedom of barrel 104 in relation to sensor assembly 110 (e.g., a surface of sensor 112). Six-axis active alignment may include adjusting six degrees of freedom, such as, for example, focus, tilt, shift, and rotation. More specifically, alignment of the degrees of freedom may include adjusting the following: bore site, such that optical axis B is approximately in the middle of sensor 112; focus, where the image plane or optical element is approximately on the sensor plane; tilt, where the image plane of optical element 108 is substantially parallel to the sensor plane; rotation, where the mechanical reference and sensor are substantially parallel.

[0075] Still referring to FIG.10A, when barrel 104 is in position x, barrel 104 may be fully seated within holder 106. When fully seated, second portion 404 of barrel 104 may be completely disposed within holder and / or an edge of holder 106 may abut first portion 402 of barrel 104. In one or more embodiments, when barrel 104 is disposed within holder 106 and threaded interfaces 304 and 306 are engaged, primary O-ring may be disposed within a recess 1008 of barrel 104 defined at least in part by a front side 1002 of first threaded interface 304. In one or more embodiments, spring 308 may bias a rear side 1004 of first threaded interface 304 and an abutment surface 1006 of holder 106. In some embodiments, imaging device 100 may include washer 310 such that spring 308 may bias rear side 1004 of first threaded interface 304 and washer 310, which then biases abutment surface 1006 of holder 106. Spring 308 may be compressed a maximum amount when barrel 104 is fully seated within holder 106. Spring 308 may be configured to prevent undesirable movement of barrel 104 relative to holder 106, as previously discussed in this disclosure above. In various embodiments, secondary O-ring 312 may be disposed within a notch of holder 106. Secondary O-ring may prevent debris from threaded interfaces 304 and 306 from reaching sensor assembly 110.

[0076] Performing active alignment when barrel is fully seated allows for infinity focus to be readily and easily achieved after adjustment of focus by a user during operation of imaging device 100. For instance, a user may adjust a distance of focus of imaging device 100 to focus on a close object by moving barrel 104 to an intermediary position. In order to easily achieve a focus at infinity again, the user may fully seat barrel 104within holder 106 at position x. This allows for consistent, convenient, and accurate usage of imaging device 100 in the field.

[0077] As shown in FIG.10B, in response to rotation of barrel 104, threaded interfaces 304 and 306 are configured to adjust barrel 104 between first position x, where barrel 104 is fully seated in holder 106 to maintain optical element 108 at a minimum displacement d from the sensor assembly 110 (e.g., plane of sensor 112), and second position x’, where barrel 104 is moved within holder 106 to maintain optical element 108 at a maximum displacement d’ from sensor assembly. When barrel 104 is in position x’, barrel 104 is partially seated (e.g., minimally seated) within holder 106. When partially seated, second portion 404 of barrel 104 is partially disposed within holder 106. In some embodiments, spring 308 may be at a maximum length when barrel 104 is in position x’, biasing rear side 1004 and abutment surface 1006.

[0078] FIG.11 illustrates a flow diagram of a process 1100 for manufacturing imaging device 100 in accordance with an embodiment of the disclosure. For explanatory purposes, process 1100 is primarily described within this disclosure with reference to imaging device 100 and its associated arrangement of components as described in FIGS. 1-10B. However, process 1100 is not limited to such implementations. Any step, sub- step, sub-process, or block of process 1100 may be performed in an order or arrangement different from the embodiments illustrated in FIG.11; some may be omitted, others may be added, and some may be performed simultaneously as appropriate.

[0079] As shown at block 1105, process 1100 may include placing barrel 104 within holder 106. In one or more embodiment, placing barrel 104 within holder may include disposing at least a portion (e.g., second portion 404) of barrel 104 within holder 106 and engaging first threaded interface 304 of barrel 104 and second threaded interface 306 of holder 106.

[0080] As shown at block 1110, process 1100 may include bottoming out barrel 104 within holder 106 into first seated position (e.g., first position x). For instance, bottoming out barrel 104 may include rotating barrel 104 such that barrel 104 rotates about axis A and moves to first seated position x. Sensor assembly 110 may have an infinite focus distance (e.g., infinity focus) while barrel 104 is in first position x. Sensor assembly 110 may have a minimum focus distance (e.g., minimum focus position of the lens) while barrel 104 is in second position x’.

[0081] As shown at block 1115, process 1100 may include positioning optical assembly 102 next to sensor assembly 110. For instance, optical assembly 102 may be positioned proximate to sensor assembly 110.

[0082] As shown at block 1120, process 1100 may include performing active alignment process (e.g., operation) to align barrel 104 with sensor 112. In various embodiments, process 1100 may include actively aligning optical assembly 102 relative to sensor assembly 110. In one or more embodiments, the active alignment process includes performing active alignment of six degrees of freedom of barrel 104 in relation to sensor assembly 110.

[0083] As shown at block 1125, process 1100 may include connecting holder 106 to sensor assembly 110. For instance, process 1100 may include fixing holder 106 relative to sensor assembly 110 after the aligning. In one or more embodiments, process 1100 may include performing, prior to the fixing, an active alignment process to align optical assembly 102 with sensor assembly 110 while barrel 104 is in first position x. Holder 106 may include backplate 318 and sensor assembly 110 may be fixed to backplate 318. For example, sensor assembly 110 may be fixed to backplate 318 of holder using a fastener of fixing component (e.g., adhesive).

[0084] As shown at block 1130, process 1100 may include altering, in response to rotation of barrel 104, a focus distance of imaging device 100. For instance, process 1100 may include adjusting, by threaded interfaces and in response to rotation of barrel 104, barrel 104 to an intermediate position between first position x and the second position x’ such that sensor assembly 110 has an intermediate focus distance (e.g., intermediate focus position). In one or more embodiments, process 1100 may include biasing, using spring 308 rear side of first threaded interface 304 and abutment surface of holder 106 to prevent unintentional movement of barrel 104 relative to holder 106. In one or more embodiments, process 1100 may include abutting, by O-ring, first threaded interface 304 to prevent unintentional movement of barrel 104 relative to holder in conjunction with spring 308.

[0085] Where applicable, various embodiments provided by the present disclosure can be implemented using hardware, software, or combinations of hardware and software. Also, where applicable, the various hardware components and / or software components set forth herein can be combined into composite components comprising software, hardware,and / or both without departing from the spirit of the present disclosure. Where applicable, the various hardware components and / or software components set forth herein can be separated into sub-components comprising software, hardware, or both without departing from the spirit of the present disclosure. In addition, where applicable, it is contemplated that software components can be implemented as hardware components, and vice versa.

[0086] Software in accordance with the present disclosure, such as non-transitory instructions, program code, and / or data, can be stored on one or more non-transitory machine-readable mediums. It is also contemplated that software identified herein can be implemented using one or more general purpose or specific purpose computers and / or computer systems, networked and / or otherwise. Where applicable, the ordering of various steps described herein can be changed, combined into composite steps, and / or separated into sub-steps to provide features described herein.

[0087] The foregoing description is not intended to limit the present disclosure to the precise forms or particular fields of use disclosed. Embodiments described above illustrate but do not limit the invention. It is contemplated that various alternate embodiments and / or modifications to the present invention, whether explicitly described or implied herein, are possible in light of the disclosure. Accordingly, the scope of the invention is defined only by the following claims.

Claims

CLAIMS What is claimed is:

1. An imaging device comprising: an optical assembly comprising: a barrel comprising a first threaded interface, a holder comprising a second threaded interface engaged with the first threaded interface of the barrel, and an optical element disposed at least partially within the barrel; a sensor assembly fixed relative to the holder and configured to capture images of a scene received through the optical element; and wherein, in response to rotation of the barrel, the threaded interfaces are configured to adjust the barrel between: a first position wherein the barrel is fully seated in the holder to maintain the optical element at a minimum displacement from the sensor assembly, and a second position wherein the barrel is moved within the holder to maintain the optical element at a maximum displacement from the sensor assembly.

2. The imaging device of claim 1, wherein the sensor assembly is fixed relative to the holder following an active alignment process performed to align the optical assembly with the sensor assembly while the barrel is in the first position.

3. The imaging device of claim 2, wherein active alignment process performs active alignment of six degrees of freedom of the barrel in relation to the sensor assembly.

4. The imaging device of claim 1, wherein: the sensor assembly has an infinite focus distance while the barrel is in the first position; and the sensor assembly has a minimum focus distance while the barrel is in the second position.

5. The imaging device of claim 1, wherein, in response to rotation of the barrel, the threaded interfaces are configured to adjust the barrel to an intermediate position between the first position and the second position such that the sensor assembly has an intermediate focus position.

6. The imaging device of claim 1, wherein: the holder further comprises a backplate; and the sensor assembly is fixed to the backplate.

7. The imaging device of claim 1, further comprising a compression spring configured to bias a rear side of the first threaded interface and an abutment surface of the holder to prevent unintentional movement of the barrel relative to the holder.

8. The imaging device of claim 7, wherein the compression spring is a wave spring.

9. The imaging device of claim 7, further comprising: an O-ring disposed about a portion of the barrel and abutting the first threaded interface to prevent unintentional movement of the barrel relative to the holder in conjunction with the compression spring.

10. A method of manufacturing the imaging device of claim 1, the method comprising: engaging the first threaded interface of the barrel and the second threaded interface of the holder; rotating the barrel to move the barrel to the first position; actively aligning the optical assembly relative to the sensor assembly; and fixing the holder relative to the sensor assembly after the aligning.

11. A method comprising: engaging a first threaded interface of a barrel of an optical assembly with a second threaded interface of a holder of the optical assembly, wherein an optical element is disposed at least partially within the barrel; fixing a sensor assembly relative to the holder, wherein the sensor assembly is configured to capture images of a scene received through the optical element; andadjusting, in response to rotation of the barrel, the threaded interfaces between: a first position wherein the barrel is fully seated in the holder to maintain the optical element at a minimum displacement from the sensor assembly, and a second position wherein the barrel is moved within the holder to maintain the optical element at a maximum displacement from the sensor assembly.

12. The method of claim 11, further comprising: performing, prior to the fixing, an active alignment process to align the optical assembly with the sensor assembly while the barrel is in the first position.

13. The method of claim 12, wherein the active alignment process performs active alignment of six degrees of freedom of the barrel in relation to the sensor assembly.

14. The method of claim 12, wherein: the sensor assembly has an infinite focus distance while the barrel is in the first position; and the sensor assembly has a minimum focus distance while the barrel is in the second position.

15. The method of claim 12, further comprising adjusting, by the threaded interfaces and in response to rotation of the barrel, the barrel to an intermediate position between the first position and the second position such that the sensor assembly has an intermediate focus position.

16. The method of claim 12, wherein: the holder further comprises a backplate; and the sensor assembly is fixed to the backplate.

17. The method of claim 12, further comprising biasing, using a compression spring, a rear side of the first threaded interface and an abutment surface of the holder to prevent unintentional movement of the barrel relative to the holder.

18. The method of claim 17, wherein the compression spring is a wave spring.

19. The method of claim 17, further comprising abutting, by an O-ring disposed about a portion of the barrel, the first threaded interface to prevent unintentional movement of the barrel relative to the holder in conjunction with the compression spring.

20. The imaging device of claim 1, wherein the sensor assembly comprises an array of infrared sensors.

Images