Lens unit of imaging assembly

Abstract

An imaging assembly includes a housing, a lens unit mounted within the housing. The lens unit includes at least one lens positioned along an optical axis and one or more ball bearings attached to the lens unit to enable the lens unit to be slidably displaced within the housing along the optical axis. A calibration mechanism positioned at one end of the housing is used to calibrate the at least one lens by positioning the lens unit at an optimal focus position, wherein the calibration mechanism is rotated to enable the lens unit to be slidably displaced and position the lens unit at the optimal focus position, and wherein the optimal focus position is one of a near-field focus position or a far-field focus position.

Description

Technical Field

[0001] Exemplary embodiments of the present invention generally relate to a lens unit of an imaging assembly, and more particularly, to a mechanism for calibrating the focal position of a lens within a lens unit. Background Art

[0002] Imaging components / modules are used with many electronic devices such as mobile phones, personal data assistants (PDAs), computers, bar code readers, etc. Recently, there have been many developments in the field of imaging technology that have made imaging modules small, reliable, easy to use, and robust. However, typically, the implementation of imaging modules in electronic devices is subject to various constraints, such as size, cost, and complexity, which has driven the need for imaging module designs that allow low manufacturing costs to be achieved with less complex hardware while maintaining image quality at a high standard. Further, one or more lenses used in the imaging module may require calibration. Through hard work, intelligence, and innovation, many of these identified problems have been solved by the development solutions included in the embodiments of the present disclosure, and many examples of these solutions are described in detail herein. Summary of the invention

[0003] The following is a brief summary of the invention to provide a basic understanding of some aspects of the disclosed material handling system. This summary is not an exhaustive review and is neither intended to identify key or important elements nor to describe the scope of such elements. Its purpose is to serve as a prelude to the detailed embodiments provided later, giving some concepts of the described features in a simplified form.

[0004] Various exemplary embodiments described herein relate to an optical device comprising an image sensor and an imaging assembly for focusing optical radiation from a target onto the image sensor. The imaging assembly comprises a housing and a lens unit configured to be actuated to one of a far-field focal position and a near-field focal position by applying a magnetic force. The lens unit comprises one or more ball bearings attached to the lens unit to enable the lens unit to be slidably displaced along an optical axis within the housing in response to the magnetic force. The imaging assembly further comprises a first nut and a second nut rotatably attached to the housing. The far-field focal position and the near-field focal position of the lens unit are calibrated based on the positions of the first nut and the second nut.

[0005] Various exemplary embodiments described herein relate to an optical device wherein the housing includes one or more rails to guide one or more ball bearings.

[0006] Various exemplary embodiments described herein relate to an optical device wherein the imaging assembly further includes a drive mechanism comprising one or more coils attached to the housing and one or more magnets attached to the lens unit, wherein the coils and magnets are energized at a selected voltage level to generate a magnetic force.

[0007] Various exemplary embodiments described herein relate to an optical device in which one or more ball bearings are rotatably attached to one or more recesses integrally formed on an outer portion of a lens unit.

[0008] Various exemplary embodiments described herein relate to an optical device, wherein the lens unit further includes an optical filter positioned along the optical axis together with the at least one lens to pass optical radiation of a predefined wavelength.

[0009] Various exemplary embodiments described herein relate to an imaging assembly including a housing, a lens unit mounted within the housing. The lens unit includes at least one lens positioned along an optical axis and one or more ball bearings attached to the lens unit to enable the lens unit to be slidably displaced within the housing along the optical axis. A calibration mechanism positioned at one end of the housing is used to calibrate the at least one lens by positioning the lens unit at an optimal focus position, wherein the calibration mechanism is rotated to enable the lens unit to be slidably displaced and position the lens unit at the optimal focus position, and wherein the optimal focus position is one of a near-field focus position or a far-field focus position.

[0010] Various exemplary embodiments described herein are directed to an imaging assembly that includes a drive mechanism including one or more coils attached to a housing and one or more magnets attached to a lens unit.

[0011] Various exemplary embodiments described herein relate to an imaging assembly in which one or more ball bearings are used to linearly displace a lens unit along an optical axis in response to one of a magnetic force or a gravitational force, wherein the magnetic force is induced by selectively energizing a coil and a magnet.

[0012] Various exemplary embodiments described herein relate to a method for pre-calibrating and positioning a lens unit of an imaging assembly at an optimal focus position. The method includes displacing the imaging assembly at a first position so that the lens unit slides toward a calibration mechanism along an optical axis under gravity; and rotating the calibration mechanism when abutting the lens unit to calibrate the optimal focus position of the lens unit. The optimal focus position is one of a near-field focus position or a far-field focus position. The method further includes displacing the imaging assembly at a second position in response to the position of a target being captured by the imaging assembly and applying a magnetic force to the lens unit to slide the lens unit from a default focus position to the calibrated optimal focus position.

[0013] Various exemplary embodiments described herein relate to a method for pre-aligning and positioning a lens unit of an imaging assembly at an optimal focus position, wherein applying a magnetic force further comprises selectively energizing a coil and a magnet positioned within a housing of the imaging assembly.

[0014] The above-mentioned summary of the invention is provided only for the purpose of summarizing some exemplary embodiments, so as to provide a basic understanding of some aspects of the present disclosure. Therefore, it should be understood that the above-mentioned embodiments are only examples and should not be construed as narrowing the scope or essence of the present disclosure in any way. It should be understood that in addition to those summarized here, the scope of the present disclosure also covers many possible embodiments, some of which will be further described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The description of the exemplary embodiments may be read in conjunction with the accompanying drawings. It should be understood that for simplicity and clarity of illustration, the elements shown in the figures are not necessarily drawn to scale. For example, the dimensions of some of the elements are exaggerated relative to other elements. Embodiments incorporating the teachings of the present disclosure are shown and described with respect to the drawings presented herein, in which:

[0016] Figure 1 A block diagram of an exemplary imaging system according to an embodiment of the present subject matter is shown.

[0017] Figure 2 A fragmentary, partially cut-away side view of an exemplary optical device having an imaging assembly according to an embodiment of the present subject matter is shown.

[0018] Figure 3 A block diagram schematic diagram of an exemplary imaging device according to an embodiment of the present subject matter is shown.

[0019] Figure 4 An exploded view of an imaging assembly according to an embodiment of the inventive subject matter is shown.

[0020] Figure 5A and Figure 5B A perspective view of a housing of an imaging assembly according to an embodiment of the present inventive subject matter is shown.

[0021] Figure 6 A perspective view of a calibration mechanism attached to a housing of an imaging assembly is shown in accordance with an embodiment of the present subject matter.

[0022] Figure 7 The combination of embodiments according to the subject matter of the present invention is shown Figure 4 , Figure 5 and Figure 6 A perspective view of an imaging assembly with the discussed components in assembled form.

[0023] Figure 8 The present invention is shown in an assembled form according to an embodiment of the subject matter of the present invention. Figure 7 A fragmentary, partial cross-sectional view of an imaging assembly illustrating one or more optical components positioned within an interior portion of a lens unit.

[0024] 9A to 9E A combination of embodiments depicting the subject matter of the present invention is shown. Figure 7 and Figure 8 A block diagram of an exemplary calibration method for the discussed imaging assembly is shown.

[0025] Fig.10 The use of an embodiment according to the subject matter of the present invention is shown Figure 4 A perspective view of an exemplary optical arrangement of imaging components of a dual-mode imaging system.

[0026] Fig.11 A flow chart is shown of an exemplary method for pre-calibrating and positioning a lens unit of an imaging assembly at an optimal focus position in accordance with an embodiment of the present subject matter. DETAILED DESCRIPTION

[0027] Some embodiments of the invention will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all, embodiments of the invention are shown. In fact, the present disclosure can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; on the contrary, these embodiments are provided so that the present disclosure meets applicable legal requirements. Unless otherwise indicated, the terms "or" and "optionally" are used herein in both alternative and combined senses. The terms "exemplary" and "exemplary" are used for examples without indication of quality level. Throughout the content, similar reference numerals refer to similar elements.

[0028] The components shown in the figures represent components that may or may not be present in the various embodiments of the invention described herein, such that an embodiment may include fewer or more components than shown in the figures without departing from the scope of the invention.

[0029] Turning now to the drawings, the detailed description shown below in conjunction with the drawings is intended to describe various configurations and is not intended to represent the only configuration in which the concepts described herein may be practiced. The detailed description includes specific details to provide a comprehensive understanding of the various concepts, wherein like reference numerals represent similar components throughout the several views. However, it is apparent to those skilled in the art that these concepts may be practiced without these specific details.

[0030] The term "comprising" means including but not limited to, and should be interpreted in the manner commonly used in the patent context. It should be understood that the use of broad terms such as "comprising," "including," and "having" provides support for narrower terms such as "consisting of," "consisting essentially of," and "consisting essentially of." Furthermore, to the extent that the terms "includes" and "including" and variations thereof are used in the detailed description or claims, these terms are intended to be inclusive in a manner similar to the term "comprising."

[0031] References in this specification to "one embodiment," "embodiment," "multiple embodiments," or "one or more embodiments" are intended to indicate that a particular feature, structure, or characteristic described in conjunction with the embodiment is included in at least one embodiment of the present disclosure. The appearance of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. In addition, various features are described that may be present in some embodiments but not in other embodiments. Similarly, various requirements are described that may be requirements of some embodiments but not in other embodiments.

[0032] Additionally, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation, aspect, or design described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations, aspects, or designs. Rather, the use of the word exemplary is intended to present concepts in a concrete manner.

[0033] It should be understood that the use of specific parts, equipment and / or parameter names and / or their corresponding acronyms such as those of the utility, logic and / or firmware of the execution described herein is only exemplary and does not mean to imply any limitation to the embodiment. Therefore, the embodiment can be described with different naming and / or terms, which are used to describe the parts, equipment, parameters, methods and / or functions herein, but are not limited thereto. The reference to any specific protocol or proprietary name when describing one or more elements, features or concepts of the embodiment is provided only as an example of a specific implementation, and this reference does not limit the claimed embodiment to be extended to the embodiment using different elements, features, protocols or concept names. Therefore, each term utilized herein will be interpreted in its broadest sense in the context of utilizing the term.

[0034] Specifically and with respect to the various functions performed by the above-described components, devices, circuits, systems, etc., unless otherwise specified, the terms used to describe such components (including references to "means") are intended to correspond to any components that, while not structurally equivalent to the disclosed structures (which perform the functions in the exemplary aspects of the embodiments shown herein), still perform the specific functions of the components (e.g., functionally equivalent). In this regard, it will also be recognized that the embodiments include systems and computer-readable media having computer-executable instructions for performing the actions and / or events of the various methods.

[0035] Reference will now be made to exemplary embodiments, which are illustrated in the accompanying drawings. Other embodiments may be in various forms, and the exemplary embodiments should not be construed as being limited to the embodiments set forth herein. On the contrary, these representative embodiments are described in detail so that this disclosure will be thorough and complete, and will fully convey the scope, structure, operation, functionality, and potential applicability to those skilled in the art. Where possible, the same reference numerals will be used throughout the accompanying drawings to refer to the same or similar parts. The term "scan" or "scanning" used herein refers to imaging or extracting data from information-bearing optics (symbols). The term imaging used herein refers to shooting, capturing, or creating an electronic image.

[0036] One or more lenses used in an imaging module may require calibration to maintain the lens in an optimal focus position (e.g., near-field calibration, far-field calibration, etc.). A typical calibration involves positioning the lens at a specific location on the imaging module at a certain distance from the image sensor to establish the optimal focus position. Conventionally, such calibration is performed via a manual process, where the lens is secured via a fixture, translation features, or pinning features and manually adjusted. Such manual calibration is a time-consuming and labor-intensive task, where the optical components within the imaging module may be subjected to external forces, resulting in lens distortion, which in turn results in poor or unstable focus positions. Further, manual calibration using additional hardware such as a fixture, translation features, or pinning features increases the cost and complexity of the imaging module.

[0037] In some examples and as disclosed herein, an imaging assembly employs a design with fewer components for calibration, the components including a housing, a lens unit mounted within the housing, one or more ball bearings, and a calibration mechanism. The lens unit includes at least one lens positioned along an optical axis and one or more ball bearings attached to the lens unit to enable the lens unit to be slidably displaced within the housing along the optical axis. The calibration mechanism positioned at one end of the housing is used to calibrate the at least one lens by positioning the lens unit at an optimal focus position, wherein the calibration mechanism is rotated when the lens unit is adjacent to the lens unit to enable the lens unit to be slidably displaced using the one or more ball bearings until the lens unit is in the optimal focus position, and wherein the optimal focus position is one of a near-field focus position or a far-field focus position. The position of the calibration mechanism is maintained for future use during operation.

[0038] In some examples, the far-field focus position and the near-field focus position of the lens unit in the housing are preset or calibrated by a calibration mechanism that includes a first nut and a second nut that are rotatably attached to the housing. Thus, when the lens unit is pushed to the front or rear of the housing during calibration, rotation of the first nut and the second nut moves the lens unit to a position where the focus of the optical radiation is aligned with the image sensor. The position of the front nut and / or the rear nut is maintained so as to allow the lens unit to move to the front nut (near-field focus position) or the rear nut (far-field focus position) during operation.

[0039] In some examples, the imaging assembly further includes a drive mechanism comprising one or more coils attached to the housing and one or more magnets attached to the lens unit, wherein the coils and magnets are energized at a selected voltage level to generate a magnetic force to actuate the lens unit to one of a rear nut or rear stop (far-field focus position) and a front nut or front stop (near-field focus position).

[0040] According to the examples herein, an imaging assembly with optimal focus position adjustment using less complex hardware for calibration has been achieved.

[0041] In the following detailed description of the exemplary embodiments of the present disclosure, specific representative embodiments that can practice the present disclosure are described in sufficient detail to enable those skilled in the art to practice the disclosed embodiments. For example, specific details such as specific method sequences, structures, elements, and connectors have been presented herein. However, it should be understood that it is not necessary to implement the embodiments of the present disclosure using the specific details proposed. It should also be understood that other embodiments can be utilized, and logical, architectural, programmatic, mechanical, electrical, and other changes can be made without departing from the general scope of the present disclosure. Therefore, the following detailed description is not restrictive, and the scope of the present disclosure is limited by the appended claims and their equivalents.

[0042] Throughout this specification, the terms 'optical imager' or 'optical device' may be used interchangeably, and these terms should be considered as examples of any device that may be configured to capture one or more images of a subject.

[0043] As used herein, the term "imaging assembly" may collectively refer to one or more components that help focus optical radiation or light from a target to an image sensor. Thus, the use of any such terms should not be construed to limit the spirit and scope of the embodiments of the present disclosure.

[0044] As used herein, the term "imaging system" may collectively refer to a system in which one or more optical devices are available, each of which has an "imaging component" described in conjunction with one or more embodiments. Therefore, the use of any such terms should not be construed as limiting the spirit and scope of the embodiments of the present disclosure.

[0045] With specific reference now to the drawings and the illustrative embodiments depicted therein, Figure 1A block diagram of an exemplary imaging system 100 according to an embodiment of the present subject matter is shown. The imaging system 100 includes a plurality of optical devices or imagers 112 that can be operated and utilized in the presence of information bearing optics (IBI). The optical device or imager 112 can be a stationary or handheld device that utilizes an image capture device to extract data from a target. An operator can aim the handheld optical imager 112 at a target and actuate a button or trigger 115 on the optical imager 112 to control all or part of the operation of the imager 112. The imager 112 can be utilized in a presentation mode, where the imager 112 takes continuous images without the need for trigger activation. The exemplary optical imager 112 can be a mobile device, such as a handheld scanner, a portable data terminal (PDT), a personal digital assistant (PDA), a mobile phone, etc. A portable data terminal or PDT is typically an electronic device for inputting or retrieving data via wireless transmission (WLAN or WWAN), and can also be used as an optical imager used in a repository, warehouse, hospital, or in the field for accessing a database from a remote location. A personal digital assistant (PDA) is a handheld device that is typically used as a personal organizer and may have many uses, such as computing, acting as a clock and calendar, playing computer games, accessing the Internet, sending and receiving emails, acting as a radio or stereo, video recording, recording notes, acting as an address book, etc. An exemplary optical imager 112 may have a display 116. An exemplary optical imager 112 may have a plurality of subsystems disposed within a housing 117 configured to be handheld. For example, the imager may have a handle portion 111. An exemplary optical imager 112 may communicate directly (wired or wirelessly) with a local transaction processing system 140, such as a cash register, customer station, or employee station, or a local host / server 125, or through a charging station or cradle 138. An exemplary local server 125 or optical imager 112 may communicate with a network 120 and / or a remote / web server 134.

[0046] Figure 2 An enlarged partial cross-sectional view of an exemplary optical device or optical imager 112 is shown, which may include an imaging assembly 110 enclosed in an imager frame 117 .

[0047] refer to Figure 3, an exemplary imaging system may include an imaging component 110, which may include an image sensor 132. The exemplary image sensor 132 converts light or other electromagnetic energy reflected from a target and provides an output signal representing the light or other electromagnetic energy. The image sensor 132 may be a pixel array suitable for operating in a global shutter or full-frame shutter mode or alternately in a rolling shutter mode. The image sensor may be a color or monochrome 2D solid-state image sensor implemented in any of CCD, CMOS, NMOS, PMOS, CID, CMD, back-illuminated technology. The imager 112 may be a progressive or interlaced imager. The image sensor 132 may include an array of photosensitive photodiodes (or pixels) that convert incident light energy into electrical charge. Many solid-state image sensors also allow addressing of a full-frame area of ​​image data. The exemplary image sensor 132 may use a monochrome image sensor, which may include a filter element that defines color-sensitive pixel elements dispersed throughout the monochrome pixel array. The operation of the monochrome image sensor is to subsample the color image (monochrome or full color) using the associated optimal sensor settings for image capture or reading scanning. An exemplary monochrome image sensor is described in U.S. Patent Publication No. 20060274171, entitled "DIGITAL PICTURE TAKING OPTICAL IMAGER HAVING HYBRID MONOCHROME AND COLORIMAGE SENSOR ARRAY", which is hereby incorporated by reference in its entirety. An exemplary image sensor 132 may include an image sensor processor, an analog-to-digital converter (ADC), and other circuitry.

[0048] The imaging assembly 110 may include a programmable control circuit or imaging device processor 152 that controls the amount of illumination provided by the LED 16 by controlling the output power provided by the LED power supply 123. The processor 152 may also control other functions and devices, such as an aimer power supply for powering the aimer LED 18. The processor 152 may include a predetermined amount of memory for storing data and configurable blocks of analog and digital logic, and a programmable interconnect. An illumination optic (not shown), an aimer optical component 25 (such as a lens, diffuser, wedge, reflector, etc.) may be used to direct light in the direction of the target object T. A laser or light emitting diode (LED), such as a white LED or a red infrared LED, may be used. If the ambient light level is high enough to allow a high quality image of the object T to be taken, then the illumination may be eliminated or disabled. The illumination may also be located away from the imaging device to eliminate or reduce specular reflections.

[0049] In an exemplary embodiment, the imaging assembly includes an imaging optics 40 for focusing light from a target onto the image sensor device 132. The imaging assembly 110 has an imaging optics or lens 40 having an optical axis (OA) for receiving light reflected from the target T and directing or projecting the reflected light from the target T to the image sensor 132. The optical axis is a line of symmetry passing through the imaging optics. The imaging optics 40 has a focus where parallel light rays from a point at infinity converge at the focus. If the focus coincides with the image sensor 132, then the target (at the point at infinity) is "in focus". If the light from the target point converges around the image sensor 132 and is desirable at the image sensor, then the target T is considered to be in focus. Conversely, if the light cannot be well converged, then the target is out of focus. "Focusing" is the process of adjusting the distance between the receiving optics and the image sensor 132 to bring the target T into approximate focus.

[0050] Figure 4 An exploded view of an imaging assembly 401 is shown in accordance with an embodiment of the present subject matter. Figure 4 A portion of the imaging assembly 110 is shown with optical and non-optical components that enable precise focus calibration. Throughout the specification, this portion of the imaging assembly 110 will be referred to as imaging assembly 401 hereinafter.

[0051] According to an embodiment, the imaging assembly 401 may be positioned within the optical device 112, as previously described in connection with Figures 1 to 3 According to an embodiment, the imaging assembly 401 includes a housing 402 , a lens unit 404 , one or more ball bearings 408 a , a drive mechanism 406 , and a calibration mechanism 408 .

[0052] According to an embodiment, the lens unit 404 is positioned in the housing 402. According to an embodiment, the housing 402 may be formed as a single molded structure in which the back cover 417 and the coil plate 419 form a part of the structure to form a housing. According to an embodiment, the lens unit 404 includes at least one lens positioned along the optical axis 411 to focus the optical radiation from the target onto the image sensor. According to another embodiment, the lens unit 404 includes a pair of lenses 40 to focus the optical radiation. In some examples, the lens unit 404 may further include an optical filter (not shown), which may be positioned along the optical axis 411 of at least one lens to allow optical radiation of a predetermined wavelength to pass.

[0053] According to an embodiment, the drive mechanism includes one or more magnets 406b and one or more coils 406a wound on an iron core 406c. In some examples, the one or more magnets 406b may form a part of the lens unit 404, and the one or more coils 406a may form a part of the housing 402. The drive mechanism 406 may be capable of driving the lens unit 404 by applying a magnetic force. In some examples, a magnetic force is generated by energizing the coil 406a wound on the iron core 406c, which in turn drives the magnet 406b under a repulsive magnetic force. In addition, although Figure 4 The exemplary embodiment depicted in shows a pair of magnets 406b that are one-to-one correlation with a pair of coils 406a, but other embodiments are possible using other configurations. For example, rather than a pair of magnets 406b, a single magnet 406b corresponds to two or more coils 406a. In some examples, coil 406a may include multiple turns of conductive wire. Electrical signals may be received from one or more circuits attached to coil plate 419, or any circuit at one end of coil wire and the other end of coil wire may be grounded.

[0054] According to an embodiment, one or more ball bearings 408a form part of the lens unit 404. The ball bearings 408a enable the lens unit 404 to be slidably displaced within the housing 402 under the influence of magnetic force or under the influence of gravity. According to an embodiment, the ball bearings are provided so that the lens unit can move freely inside the housing without any friction during movement. In some examples, the ball bearings 408a may include a ball bearing separation ring or a bearing block to support the balls. In addition, although Figure 4 The exemplary embodiment depicted in shows four ball bearings 408a, but other embodiments are possible using other configurations that may employ more than four ball bearings. In some examples, the lens unit may include one or more recesses 415 integrally disposed along the circumference of the outer portion 413 of the lens unit 404 to accommodate one or more ball bearings.

[0055] According to an embodiment, the calibration mechanism 408 is configured to calibrate one or more lens positions of at least one lens by positioning the lens unit at an optimal focus position (e.g., at a near-field focus position or a far-field focus position). The calibration mechanism 408 may include at least one nut forming a portion of the housing 404. The at least one nut may be rotated to linearly displace the lens unit 404 using one or more ball bearings 408a until the lens unit 404 is at the optimal focus position. According to an embodiment, the calibration mechanism 408 includes a first nut 409 and a second nut 410. The optimal focus position of the lens unit 404 is preset by rotating the first nut 409 and the second nut 410.

[0056] According to an embodiment, the position of the first nut is a front stop and the position of the second nut is a rear stop. Thus, when the lens unit is magnetically driven away from the home or default position, the front stop and / or the rear stop effectively stops the lens unit at the near field focus position or the far field focus position.

[0057] like Figure 5A and Figure 5B As shown, the housing 402 includes a front end 503, a rear end 505, one or more guide rails 502a, one or more first threaded portions 501, and one or more mating protrusions 502. According to an embodiment, one or more guide rails 502a are integrally formed on an inner portion of the housing 402, which is mated with the lens unit 404. In some examples, the one or more guide rails 502a may be U-shaped or C-shaped grooves. In some examples, the inner portion of the housing 402 may be flat without any shape of groove. The guide rails 502a may guide the ball bearings 408a. In this regard, the ball bearings 408a may allow the lens unit 404 to be slidably displaced within the housing along the optical axis 411.

[0058] According to an embodiment, the front end of the housing 402 may accommodate the first nut, and the rear end of the housing 402 may accommodate the second nut. According to an embodiment, one or more first threaded portions 501 are integrally formed on the front end 503 of the first housing 402 .

[0059] According to an embodiment, the rear cover 417 may be coupled to the rear end 505 of the housing 402. The rear end of the housing may include one or more first threaded portions 501. In some examples, the rear end 505 may be provided with one or more mating protrusions 502 to couple with the rear cover 417. In some examples, the rear cover 417 and the second nut 410 may be a single integrated structure that may be coupled to the rear end 505 of the housing 402. According to another embodiment, the rear end 505 of the housing 402 may include one or more first threaded portions 501. According to an embodiment, one or more first threaded portions 501 are provided to enable the first nut 409 and the second nut 410 to be rotatably coupled to the housing 402.

[0060] Figure 6A perspective view of one of the first nut 409 or the second nut 410 rotatably coupled to the housing 402 is shown. In one example, the first nut 409 and the second nut 410 may be identical in structure. According to an embodiment, the first nut 409 and the second nut 410 include one or more second threaded portions 420. The second threaded portion 420 may be integrally formed on the first nut 409 and the second nut 410. According to an embodiment, one or more first threaded portions 501 are mechanically coupled to one or more second threaded portions 420 of one of the first nut 409 or the second nut 410. In some examples, the first threaded portion 501 may be a concave threaded portion, and the second threaded portion 420 may be a convex threaded portion, or vice versa. In this regard, the second threaded portion 420 may be screwed or rotated into the first threaded portion 501 to mechanically couple the first nut 409 and the second nut 410 to the front and rear ends of the housing 402, respectively.

[0061] According to an embodiment, the first nut 409 and the second nut 410 may include a keyway 602. The keyway 602 is provided to facilitate the screwing or rotational movement of the first nut 409 and the second nut 410. For example, the keyway 602 may cooperate with a suitable key element that can rotate or screw the first nut 409 and the second nut 410 relative to the housing 402 in a clockwise or counterclockwise direction.

[0062] Figure 7 Shows the combination Figure 4 , Figure 5 and Figure 6 A perspective view of the imaging assembly 401 with the components discussed in assembled form. It can be seen that the first nut 409 and the second nut 410 are coupled to the front end 503 and the rear end 505 of the housing 404 when assembled. Figure 7 One or more ball bearings 408a are shown coupled to an outer portion 413 of the lens unit 404 .

[0063] like Figure 7 As shown, one or more ball bearings 408a cooperate with the inner portion of the housing 402 when assembled. In this regard, when the lens unit 404 is positioned within the housing 402, the ball bearings 408a can move on corresponding rails 502a on the first housing 402. According to an embodiment, the lens unit 404 slides linearly within the housing 402 using the one or more ball bearings 408a without any friction between the lens unit 404 and the housing 402 during movement.

[0064] In some examples and during calibration, the lens unit 404 may be displaced from one position to another within the housing 402 under gravity or magnetic force. According to an embodiment, the lens unit 404 may be displaced by gravity using one or more ball bearings 408a to calibrate the lens unit to an optimal focus position. For example, the far-field focus position and the near-field focus position of the lens unit are pre-calibrated by the first nut 409 and the second nut 410 by displacing the lens unit 404 toward the first nut 409 and the second nut 410 under gravity. This calibration method is described in conjunction with FIG. 9.

[0065] According to another embodiment, the lens unit 404 can be displaced by magnetic force using one or more ball bearings 408a to position the lens unit 404. For example, when the imaging assembly 401 is deployed to capture an image of a target, the lens unit 404 can be displaced by the drive mechanism 406 to a pre-calibrated far-field focus position or a near-field focus position. Figure 8 Such displacement of the lens unit 404 by applying a magnetic force is described.

[0066] Figure 8 Shown in assembled form Figure 7 4 is a fragmentary, partial cross-sectional view of an imaging assembly 401 of FIG. 4 showing one or more optical components positioned within an interior portion of a lens unit 404. As previously discussed, the lens unit 404 can be actuated to a default or primary focus position, a front stop (near field focus position), and / or a rear stop (far field focus position). The near field focus position and / or the far field focus position can be pre-calibrated.

[0067] According to an embodiment, the lens unit 404 can be shifted from a default focus position to a far-field focus position or a near-field focus position by applying a magnetic force. The magnetic force is provided by the drive mechanism 406.

[0068] like Figure 8 As shown, a drive mechanism 406 including a pair of magnets 406b is attached to an outer portion 413 of the lens unit 404. The pair of coils 406a having cores 406c are attached to the housing 402. According to an embodiment, the magnets 406b may be positioned in a spaced-apart, facing relationship with the coils 406a. According to an embodiment, the lens unit 404 may be pre-calibrated using a first nut 409 and a second nut 410, which are attached to the housing 404 at a front end 503 or front stop and a rear end 505 or rear stop, respectively, before applying magnetic forces. This calibration positions the far field focus position or the near field focus position of the lens unit 404.

[0069] When the imaging assembly 401 is in operation, a lens unit 404 including a pair of lenses 40a, 40b and an optical filter 801 is attached to an inner portion of the lens unit 404, and the lens unit can be actuated to move to a far-field focus position or a near-field focus position based on the position of a target to be captured by the imaging assembly 401. For example, the lens unit 404 can be set to a default focus position while initiating image capture of a target. Figure 8 As shown, the lens unit is held at a default focus position by the magnetic attraction between the magnet 406b and the core 406c. In this regard, when the lens unit 404 is displaced to a far-field focus position or a near-field focus position based on the position of the target, the coil 406a is energized to move the lens unit 404 from the default focus position.

[0070] For example, a current is applied to the coil 406a and an electromagnetic field is set by the current flowing through the coil 406a, thereby causing a magnetic repulsion force to displace the lens unit 404 and the magnet 406b relative to the coil 406a. This magnetic force can displace the lens unit 404 so that it slides linearly toward the first nut 409 or the second nut 410 in the housing 402. In this regard, the displacement of the lens unit 404 toward the first nut 409 or the front stopper indicates that the lens unit is located at a far-field focal position, and the displacement of the lens unit 404 toward the second nut 410 or the rear stopper indicates that the lens unit 404 is located at a near-field focal position. Therefore, the lens unit 404 is displaced in the optical axis direction by means of the interaction between the magnetic field generated by the power flowing through the coil 406a and the magnetic field of the magnet 406b. According to an embodiment, when the current stops flowing through the coil 406a, the lens unit 404 can return to the default focal position.

[0071] 9A to 9E A combination of embodiments depicting the subject matter of the present invention is shown. Figure 7 and Figure 8 A block diagram of an exemplary calibration method for the discussed imaging assembly is shown. 9A to 9E 4 is a symbolic representation of an imaging assembly 401 having a lens unit 404, a first nut 409, and a second nut 410. Such symbolic representation is shown for the purpose of ease of explanation of calibration techniques of the lens unit 404 and should not be considered to limit the scope of the present disclosure. 9A to 9E , it is shown that the imaging assembly 401 can be tilted vertically to allow the lens unit 404 to shift toward the first nut 409 or the second nut 410 under gravity. In some examples, one or more ball bearings 408a slide the lens unit 404 so that the lens unit 404 can move toward the front end 503 or the rear end 505 of the housing 402 without any friction when mating with the first nut 409 and the second nut 410.

[0072] exist 9A to 9DIn the exemplary embodiment shown, the lens unit 404 is calibrated using a first nut 409 and a second nut 410. The first nut 409 and the second nut 410 are rotated to calibrate the far-field focal position and the near-field focal position of the lens unit 404. In some examples, the lens unit 404 may be rotated up to 180 degrees, allowing the lens unit 404 to move toward the second nut 410 under gravity before calibrating the near-field focal position of the lens unit 404. The 180 degree rotation may also occur before calibrating the far-field focal position of the lens unit 404.

[0073] In some examples, calibration may involve the step of monitoring the focus of the optical radiation on the image sensor 132. The optical radiation is symbolically represented using two lines (i.e., reflected light rays from a target). The two lines converge at a point represented by a circle, which may be a focus. The focus is incident on the image sensor 132. In other words, when the focus is aligned with the image sensor 132, the focal length between the image sensor 132 and at least one lens 40 of the lens unit 404 is constant and precise.

[0074] Thus, during calibration, the first nut 409 and the second nut 410 may be rotated until the focus of the optical radiation is aligned with the image sensor 132 to register the far field focus position and the near field focus position, respectively. In this regard, the rotation of the first nut 409 and the second nut 410 linearly pushes the lens unit 404, which is displaced by gravity, to register the far field focus position and the near field focus position of the lens unit 404. Thus, the positions of the first nut 409 and the second nut 410 represent the far field focus position and the near field focus position of the lens unit 404, and thus may be used to stop the lens unit at those positions during operation.

[0075] Fig. 9B and Fig.9D A symbolic representation of rotating the first nut 409 and the second nut 410 to calibrate the far-field focus position and the near-field focus position of the lens unit 404 is shown. In this regard, in some examples, the first nut 409 and the second nut 410 are provided as part of the housing 402 to freely calibrate and register the optimal focus position of the lens unit 404 without the need for complex hardware, thereby eliminating the requirement for the laborious task of calibration.

[0076] Further, a ball bearing 408 a is provided to the lens unit 404 so that the lens unit 404 can move freely within the housing 402 , which enables the lens unit 404 to smoothly transition to different focus positions. Fig.9E 4 shows a symbolic representation of the lens unit 404 in a default position after pre-calibration is completed. The lens unit 404 is held in the default position by the interaction between the magnet 406b and the iron core 406c. Figure 8As discussed, the lens unit 404 may be shifted between a default focus position and a near field / far field focus position under the influence of magnetic forces. In this regard, the imaging assembly 401 disclosed in examples herein may be self-sufficient to provide both calibration and automatic adjustment arrangements for focus.

[0077] Fig.10 The use of an embodiment according to the subject matter of the present invention is shown Figure 4 1. A perspective view of a dual-mode imaging system of an exemplary optical device 112 of an imaging assembly 401. The optical device 112 can use a dual-mode imaging system to allow multiple focusable fields of view. In an exemplary embodiment, the dual-mode imaging system has a near-field image sensor 132a and a far-field image sensor 132b. The dual-mode imaging system can be configured to read, for example, a barcode, an optical character, or an RFID tag. Fig.10 As shown, the imaging system includes a near-field imaging component 401a and a far-field imaging component 401b. According to an embodiment, the near-field imaging component 401a and the far-field imaging component 401b may include at least one lens 40 positioned along an optical axis 411 to focus the optical radiation at a focal point on the near-field image sensor 132a and the far-field image sensor 132b, respectively. In some examples, the near-field image sensor 132a and the far-field image sensor 132b may include a plurality of photodetectors arranged in a matrix that captures photons from the optical radiation and outputs an electronic signal.

[0078] The near-field image sensor 132a and the far-field image sensor 132b may be mounted to a corresponding PCB (printed circuit board) 903. The image sensors 132a, 132b are electrically and mechanically connected to the corresponding printed circuit board 1003, wherein the printed circuit board 1003 may include one or more active and passive electronic circuits for processing electrical signals from the image sensors 132a, 132b. The combined output from the electronic circuits may be processed by a signal processing circuit system to obtain an image output. In some examples, the image sensors 132a, 132b may be a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS).

[0079] like Fig.10 As shown, the dual-mode imaging system further includes an illuminator lens 1005 mounted in the same plane as the image sensors 132a, 132b between the imaging assemblies 401a, 401b. In some examples, the illuminator lens 1005 may include a lens array positioned in front of an illumination source (e.g., a light emitting diode (LED)) to evenly distribute optical radiation or light within the target area. In addition, the near-field imaging assembly 401a and the far-field imaging assembly 401b may include a compressible rubber gasket 1002 positioned in contact with or sealed with at least one lens 40 of the imaging assembly 401.

[0080] like Fig.10 As shown in the exemplary embodiment of the present invention, one of the imaging components 401a, 401b or both of the imaging components 401a, 401b may include a lens unit 404 and may be calibrated as previously discussed in conjunction with the aforementioned figures to provide an imaging component 401a, 401b configuration to perform both far-field focus and near-field focus with ease of calibration.

[0081] Fig.11 A flow chart of an exemplary method for calibrating a lens unit of an imaging assembly at an optimal focus position according to an embodiment of the inventive subject matter is shown. As previously discussed, a calibration mechanism including a first nut and a second nut can be used to calibrate the lens unit of the imaging assembly. The first nut and the second nut pre-register the optimal focus position of the lens unit. The imaging assembly includes a drive mechanism to actuate the lens unit to the optimal focus position.

[0082] In step 1102, a lens unit of the imaging assembly is displaced under gravity when the imaging assembly is tilted to a first position. The first position may be a vertically oriented position. The lens unit may slide along the optical axis toward a calibration mechanism under gravity when tilted to the first position. In some examples, the lens unit may use one or more ball bearings attached to the lens unit to freely fall without any friction toward the calibration mechanism. The calibration mechanism includes one of a first nut or a second nut.

[0083] In step 1104, the calibration mechanism may be rotated while abutting the lens unit to calibrate the best focus position of the lens unit. The best focus position is one of a near-field focus position or a far-field focus position. For example, the near-field focus position of the lens unit is aligned using the second nut, and the far-field focus position of the lens unit is aligned using the first nut. In this regard, the step of pre-calibrating the lens unit is freely performed with the first nut, the second nut, and the ball bearing.

[0084] In step 1106, the imaging assembly may be shifted to a second position and held in that position by magnetic forces. The second position may be a default focus position.

[0085] The lens unit can be positioned at a default focus position, and a magnetic force is applied to the lens unit to slide the lens unit from the default focus position to a calibrated optimal focus position in response to the position of the target being captured by the imaging assembly. For example, based on the position of the target, the drive mechanism can provide a magnetic force to move the lens unit toward the first nut or toward the second nut to position the lens unit at a calibrated near-field focus position or far-field focus position. The magnetic force can be applied by selectively energizing a coil and a magnet positioned within the housing of the imaging assembly. In this regard, the imaging assembly is provided with the ability to move the lens unit up to a near-field focus position or a far-field focus position freely pre-calibrated by the first nut and the second nut.

[0086] The various illustrative logic blocks, modules, circuits and algorithmic steps described in conjunction with the embodiments disclosed herein can be implemented as electronic hardware, computer software or a combination of the two. In order to clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits and steps have been described above generally according to their functions. Whether such functions are implemented as hardware or software depends on the specific application and the design constraints imposed on the whole system. The technician can implement the described functions in different ways for each specific application, but such specific implementation decisions should not be interpreted as causing deviations from the scope of the present invention.

[0087] The foregoing description of the embodiments has been presented for the purpose of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. According to the above teachings, obvious modifications or changes can be made. The embodiments are selected and described in order to best illustrate the principles of the present invention and its practical application, so that those of ordinary skill in the art can best utilize the present invention in various embodiments and with various modifications suitable for the intended specific use. Although only a limited number of embodiments of the present invention are explained in detail, it should be understood that the scope of the present invention is not limited to the details of the construction and arrangement of the components set forth in the preceding description or shown in the accompanying drawings. The present invention can have other embodiments and can be practiced or implemented in various ways. In addition, when describing the embodiments, for the sake of clarity, specific terms are used. It should be understood that each specific term includes all technical equivalents that operate in a similar manner to achieve similar purposes.

Claims

1. An optical device, comprising: Image sensor; and An imaging assembly for focusing optical radiation from a target onto the image sensor, wherein the imaging assembly comprises: case; A lens unit configured to be actuated to one of a far-field focal position and a near-field focal position by applying a magnetic force, wherein the lens unit comprises: one or more ball bearings attached to the lens unit to enable the lens unit to be slidably displaced within the housing along the optical axis in response to the magnetic force; and a first nut and a second nut rotatably attached to the housing, wherein the far-field focus position and the near-field focus position of the lens unit are calibrated based on positions of the first nut and the second nut, wherein the imaging assembly is configured to tilt so that the lens unit is displaced along the optical axis toward the first nut under gravity; wherein the first nut is configured to rotate relative to the housing in a clockwise or counterclockwise direction to calibrate a far-field focal position of the lens unit; wherein the lens unit is configured to rotate to 180 degrees, thereby allowing the lens unit to move toward the second nut under gravity; and The second nut is configured to rotate relative to the housing in a clockwise or counterclockwise direction to calibrate the near-field focal position of the lens unit. 2 . The optical device according to claim 1 , wherein the housing comprises one or more guide rails to guide the one or more ball bearings to allow the lens unit to be displaced along the optical axis toward the first nut or toward the second nut under gravity.

3. An optical device according to claim 1, wherein the imaging component further includes a drive mechanism, the drive mechanism comprising one or more coils attached to the housing and one or more magnets attached to the lens unit, wherein the coils and the magnets are energized at a selected voltage level to generate the magnetic force. 4 . The optical device according to claim 1 , wherein the one or more ball bearings are rotatably attached to one or more recesses integrally formed on an outer portion of the lens unit.

5. The optical device of claim 1, wherein the lens unit further comprises an optical filter positioned along the optical axis together with at least one lens to pass the optical radiation of a predefined wavelength. 6 . The optical device of claim 1 , further comprising a drive mechanism including one or more coils attached to the housing and one or more magnets attached to the lens unit.

7. The optical device of claim 6, wherein the one or more ball bearings linearly displace the lens unit along the optical axis in response to one of a magnetic force or a gravitational force, wherein the magnetic force is induced by selectively energizing the coil and the magnet. 8 . The optical device according to claim 1 , wherein the first nut and the second nut are configured to rotate to displace the lens unit.

9. The optical device of claim 1, wherein the housing comprises a rear end and a front end, wherein the second nut is configured to interact with the rear end of the housing, and wherein the first nut is configured to interact with the front end of the housing.

10. The optical device of claim 1, wherein the lens unit abuts the first nut during calibration of a near-field focus position.

11. The optical device of claim 1, wherein the lens unit abuts the second nut during calibration of a far-field focus position.

12. An imaging assembly, comprising: case; A lens unit, wherein the lens unit is mounted in the housing, wherein the lens unit comprises: at least one lens, the at least one lens positioned along an optical axis; one or more ball bearings attached to the lens unit to enable the lens unit to be slidably displaced within the housing along the optical axis; and A calibration mechanism positioned at one end of the housing to calibrate the at least one lens by positioning the lens unit at an optimal focus position, wherein the imaging assembly is configured to tilt so that the lens unit shifts along the optical axis toward the calibration mechanism under gravity, wherein the calibration mechanism is rotated in a clockwise or counterclockwise direction relative to the housing to calibrate the optimal focus position of the lens unit, and wherein the optimal focus position is one of a near-field focus position or a far-field focus position.

13. The imaging assembly of claim 12, further comprising a drive mechanism comprising one or more coils attached to the housing and one or more magnets attached to the lens unit.

14. The imaging assembly of claim 13, wherein the one or more ball bearings are used to linearly displace the lens unit along the optical axis in response to one of a magnetic force or a gravitational force, wherein the magnetic force is induced by selectively energizing the coil and the magnet. 15 . The imaging assembly of claim 14 , wherein the calibration mechanism further comprises a first nut and a second nut, the first nut and the second nut being configured to rotate to displace the lens unit.

16. The imaging assembly of claim 15, wherein the housing comprises a rear end and a front end, wherein the second nut is configured to interact with the rear end of the housing, and wherein the first nut is configured to interact with the front end of the housing.

17. The imaging assembly of claim 16, wherein the lens unit abuts the first nut during calibration of the near-field focus position.

18. The imaging assembly of claim 16, wherein the lens unit abuts the second nut during calibration of a far-field focus position.

19. A method for pre-calibrating and positioning a lens unit of an imaging assembly at an optimal focus position, the method comprising: displacing the imaging assembly at a first position to slide the lens unit along the optical axis toward a calibration mechanism under gravity; rotating the calibration mechanism in a clockwise or counterclockwise direction to calibrate the optimal focus position when abutting the lens unit, and rotating the lens unit to 180 degrees to shift the lens unit toward the calibration mechanism to calibrate the optimal focus position of the lens unit, wherein the optimal focus position is one of a near-field focus position or a far-field focus position; as well as The imaging assembly is displaced at a second position in response to the position of the target being captured by the imaging assembly and a magnetic force is applied to the lens unit to slide the lens unit from a default focus position to a calibrated optimal focus position.

20. The method of claim 19, wherein applying the magnetic force further comprises: A coil and a magnet positioned within a housing of the imaging assembly are selectively energized.

Images