Inductive aiming trigger

Abstract

The present invention relates to an inductive aiming trigger. A handheld barcode reader may include a main structure, a handle extending from the main structure, and a trigger configured to be pulled by a user's finger that holds the handle. The barcode reader may further include a conductive element, an antenna, and electronics in electrical communication with the antenna, the antenna being configured to sense an inductance change caused by the trigger moving through the conductive element, and the electronics being configured to determine when the inductance change indicates that the user has selected to activate a pre-trigger aiming function.

Description

BACKGROUND OF THE INVENTION

[0001] Handheld barcode readers or scanners are typically in the form of a "gun" in which electro-optical devices are used to perform scanning or imaging of machine-readable markings (e.g., barcodes, QR codes, or other code formats). Other mobile barcode readers or portable data terminals are guns shaped by having a base in a handle, the handle having a trigger that enables the mobile barcode reader to perform barcode reading functions in the same or a similar manner as an integrated barcode reader. To assist the user of the scanner in imaging the machine-readable marking, the scanner can be configured to perform a pre-trigger aiming function, such as outputting an aiming pattern, such as illuminating in a box with a central feature or a shape defining the corners of a box with a central feature, so that the user of the scanner can more easily see where he or she is aiming the reader, thereby shortening the time taken to perform the barcode reading.

[0002] Conventional scanners use several different mechanisms to sense when the user attempts to activate the pre-trigger aiming function. One such mechanism involves using a photocell contained in a plastic seat with an electromechanical switch that rotates 90 degrees relative to the axis of the plunger of the scanner. One problem with such a configuration is that, given that the components used to position the photocell include (i) plastic components, (ii) rubber components, (iii) an electromechanical switch, and (iv) a printed circuit board (PCB) portion, it is difficult to achieve the accuracy of alignment with the photocell. In other words, the mechanical tolerances and assembly of the components often limit the reliability of the activation of the pre-trigger aiming function due to aging. Moreover, the electromechanical switch physically aligned with the trigger plunger and sensor has several drawbacks, including (i) an increase in the internal dimensions of the housing of the photocell, (ii) the need for additional PCB slots, and (iii) an increase in the complexity of the mold for producing the housing and the pre-trigger aiming sensing assembly to incorporate the pre-trigger aiming function. Thus, there is a need for a more reliable mechanism for initiating the pre-trigger aiming function with fewer components and improved reliability. SUMMARY OF THE INVENTION

[0003] To provide an improved pre-trigger aiming function, a contactless inductive pre-trigger configuration can be utilized. The inductive pre-aim trigger can be configured within an electromagnetic sensor and a conductive element that is sensed by the electromagnetic sensor when moved by the user moving the trigger of the handheld scanner. The sensor can sense an inductive change that causes the electronics to initiate the pre-trigger aiming function, such as generating a pre-trigger aiming pattern, to assist the user in imaging the machine-readable marking.

[0004] An embodiment of a handheld code reader may include a main structure and an electro-optical device positioned at the main structure. The electro-optical device may be configured to image or scan a machine-readable code. A handle may extend from the main structure and may be configured to enable a user to grasp the handle to operate the code reader. Electronics may be configured to cause the electro-optical device to perform (i) a pre-trigger aiming function and (ii) a code reading function. A trigger may be configured to be pulled by the user towards the handle. An antenna may be in electrical communication with the electronics and may be configured to sense an inductance change caused by the user pulling the trigger from a rest position to a pre-trigger aiming function position. A switch may be in electrical communication with the electronics and may be positioned to be activated by the trigger being pulled to a scan position.

[0005] A method of operating a code reader may include sensing an inductance change during operation of a trigger of the code reader and performing a pre-trigger aiming function in response to determining that the inductance change exceeds a pre-trigger inductance threshold level.

[0006] Another embodiment of a handheld code reader may include a main structure, a handle extending from the main structure, and a trigger configured to be pulled by a finger of a user grasping the handle. The code reader may further include a conductive element, an antenna, and electronics in electrical communication with the antenna, the antenna being configured to sense an inductance change caused by the trigger moving the conductive element, the electronics being configured to determine when the inductance change indicates that the user has selected to activate a pre-trigger aiming function. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Exemplary embodiments of the present invention are described in detail below with reference to the accompanying drawings, which are incorporated herein by reference, and in which:

[0008] Figure 1 is an illustrative illustration of an exemplary handheld code reader including a pre-trigger aiming function initiated by inductance sensing;

[0009] Figure 2 is an illustrative illustration of an exemplary pre-trigger aiming pattern to assist a user in imaging a machine-readable marker;

[0010] Figure 3A is an illustrative illustration of a Figure 2 pre-trigger aiming pattern displayed on a linear or one-dimensional code, such as a conventional bar code;

[0011] Figure 3B is an illustrative illustration of a Figure 2 pre-trigger aiming pattern displayed on a two-dimensional code, such as a QR code;

[0012] Figure 4A is an illustrative illustration of an exemplary trigger portion of the code reader;

[0013] Figure 4BAn illustrative description of a printed circuit board in which the upper switch is disposed adjacent to an antenna provided on the PCB;

[0014] Figure 4C An illustrative description of the trigger part in the reading position where the trigger activates the switch;

[0015] Figure 5 An illustrative description of an illustrative dome switch that can be used to activate an imaging function and optionally an pre-trigger aiming function according to the principles described herein;

[0016] Figure 6A and 6B An illustrative description of a switch including a metal dome, where the keycap can be in Figure 6A a first position in Figure 6B and a second position in

[0017] Figure 7 An illustrative description of a set of electronic devices and optoelectronic components for performing an inductive pre-trigger aiming function;

[0018] Figure 8 A flowchart of a process for performing a pre-trigger aiming function by inductive sensing using a reader;

[0019] Figure 9 A flowchart of a process for enabling a user of a reader to set a pre-trigger threshold level; and

[0020] Figure 10 A flowchart of a process for enabling a reader to perform a pre-trigger aiming function by inductive sensing using a reader. Detailed Description

[0021] Regarding Figure 1, an illustrative illustration of a handheld barcode reader 100 including a pre-trigger aiming function initiated by inductive sensing is shown. The barcode reader 100 includes a main structure 102 having a window 104, and an optical device (not shown) capable of scanning or imaging machine-readable marks (e.g., barcodes, QR codes, or other machine-readable codes) via the window 104. The main structure 102 is shown as a housing, but the main structure can alternatively be a support configured such that a mobile device (such as a mobile barcode scanner in the shape of a smartphone) can be fixed thereby. For example, the main structure 102 can alternatively include a flat surface on which the mobile device is placed and fixed to the flat surface by sides that extend upward from the flat surface and are shaped to secure the mobile device to the flat surface. A handle 106 can be connected to the main housing 102 and is configured to house electronics for performing barcode reading and pre-trigger aiming functionality as further described herein. A trigger 108 can be positioned near the top portion of the handle 106 and directly below the body 102 and is configured to enable a user to transition the trigger 105 between a rest position and a reading position, wherein, as further described herein, the reading position causes the barcode reader to capture an image of a machine-readable mark. Additionally, in accordance with the principles provided herein, as further described herein, the pre-trigger aiming function can be initiated in response to a change in inductance caused by the trigger.

[0022] Regarding Figure 2 , an illustrative illustration of an illustrative pre-trigger aiming illumination pattern 200 that assists a user in imaging a machine-readable mark is shown. The pre-trigger aiming illumination pattern 200 is shown as including first illumination features 202a - 202d (collectively 202), which together with second illumination features 206a - 206d (collectively 206) define a rectangular shape 204, and the second illumination features 206a - 206d define a square shape 208 located in the central region of the rectangular shape 204. It should be understood that alternative pre-trigger aiming illumination patterns can be utilized, such as a plus sign (+) disposed in the central region of the rectangular shape 204, lines defining the outer region of the rectangular shape 204, or any other shape defining a corner, edge, or interior portion of the region that the barcode reader will image during operation of the barcode reader. In an embodiment, the pre-trigger illumination pattern 200 can include only the rectangular shape 204 or other shapes inside the square shape 208, or only other shapes.

[0023] Regarding Figure 3A and 3B, an illustrative description of scenarios 300a and 300b is shown, in which a pre-trigger aiming pattern 302 is displayed on a linear or one-dimensional code 304a (such as a conventional bar code) and a two-dimensional code 304b (such as a QR code). The aiming light source(s) can be any illumination source, including LEDs or lasers. As further described herein, the pre-trigger aiming pattern 302 can include only a center feature (e.g., a simple dot, for example), or only perimeter-defining features, or both. As Figure 2 provided therein, the pre-trigger aiming pattern 302 can include perimeter-defining illumination features 306 and a center feature 308. The perimeter-defining illumination features 306 can be used to help the user image the code 304a being read, and the center illumination feature 308 can indicate that the reader is focused on aiming at the code 304a. Similarly, the two-dimensional code 304b is completely covered within a rectangle defined by the perimeter-defining illumination features 306, and the center illumination feature 308 is centered on the 2D code.

[0024] Regarding Figure 4A , an illustrative description of an illustrative trigger portion 400 of a reader is shown. The trigger 402 is shown in a resting position or state and can include a conductive element 404 attached to it. The conductive element 404 can be formed of any material that can be sensed by an inductive sensor by sensing magnetic field distortion. Although the conductive element 404 can be disposed on the trigger 402, alternative positions of the conductive element 404 can be utilized. Moreover, the conductive element 404 can be integrated into another component relative to the inductive sensor.

[0025] The switch 406 can be mounted to a printed circuit board (PCB) 408, which is configured to be pressed by the trigger 402. The switch 406 can be an electromechanical switch or other type of switch that is mechanically activated by the trigger 402. The PCB 408 can be positioned within a cavity defined by the handle of the reader and defines a rigid support for the switch 406 such that the switch 406 has minimal compliance or no compliance relative to the trigger 402 when the trigger 402 is operated by the user. By having minimal compliance or no compliance, the reader may be more robust over time because the amount of force required to cause the reader to perform a reading function remains constant over time, and warping or other elastic deformation of the support for the switch 406 is less likely to occur.

[0026] Regarding Figure 4B, an illustrative description of the PCB 408 is shown, on which the switch 406 is proximally coupled relative to the antenna 410 disposed on the PCB 408. The antenna 410 can be a circular antenna surrounding the switch 406. In an embodiment, as shown, the antenna 410 can include a plurality of concentric circular antennas. The antenna 410 can be printed on the PCB 408 and is in electrical communication with processing electronics capable of handling signals (see, for example, Figure 7 ), in which case a magnetic field distortion signal or an inductance change signal is sensed by the antenna 410. Although the antenna 410 can be formed by a circular antenna, it should be understood that alternative antenna shapes can be utilized. It should also be understood that instead of being positioned on the PCB 408, the antenna 410 can be positioned elsewhere and is capable of sensing an inductance change caused by the trigger 402 that moves a conductive element due to user movement. For example, the antenna can be positioned on or in the trigger 402, and the conductive element can be positioned at a relative position of the trigger 402. Alternatively, the antenna 410 can be positioned on or in the main housing of the reader. By applying the antenna 410 on the PCB 408, space and cost are saved as there is no additional PCB as in the case of previously using optical sensors for sensing the position of the trigger 402.

[0027] Regarding Figure 4C , an illustrative description of the trigger portion 400 of the trigger 402 in the reading position is shown, in which the trigger 402 activates the switch. As configured, the trigger plunger or conductive element 404 can press the switch 406 mounted to the PCB 408. In operation, when the trigger 402 is pulled from the resting state ( Figure 4A ) to the imaging state ( Figure 4C ), the conductive element 404 experiences a change in inductance, enabling the antenna 410 to sense the inductance change.

[0028] More specifically, a high-resolution, high-speed inductance-to-digital converter (see Figure 7 ) can be used to perform inductance sensing. Inductance sensing can be designed for several different functions and / or applications that the reader will perform based on inductive measurements. The position, rotation, or movement of an object such as the trigger 402 can be detected. The converter enables both inductance and impedance to be measured. Characterized by a wide inductor-capacitor (LC) sensor frequency range, the conductive element 404 with a wide range of conductive materials can be sensed. By using inductance sensing, inherently accurate and robust sensing can be utilized even in harsh industrial environments.

[0029] Regarding Figure 5, which shows an illustrative illustration of an illustrative leaf switch 500 according to the principles described herein. The leaf switch 500 can be used to initiate an imaging function and, optionally, initiate a pre-trigger aiming function. The leaf switch 500 can include a housing 502 and a leaf 504. The leaf 504 can be a flexible material, such as flexible metal, so as to be able to be repeatedly deformed without permanently damaging the shape of the leaf. In an embodiment, as Figure 6A and 6B further described in, the leaf 504 can be conductive and is used to be sensed by an inductive sensor.

[0030] Regarding Figure 6A and 6B , an illustrative illustration of a switch assembly 600a in an unpressed state and a switch assembly in a pressed state is shown. The switch assembly 600a can include a keycap 602, and the keycap 602 includes a leaf activator feature or a button 604. The leaf activator feature or the button 604 extends from the bottom surface of the keycap 602 so as to engage with the leaf switch 605 and press the leaf 606 of the leaf switch 605 mounted on the PCB 607. In an embodiment, in the unpressed state, the leaf activator feature 604 can contact or be slightly higher than the leaf 606, but does not deform the leaf 606. In the pressed state, the leaf activator feature 604 can deform the leaf and press the leaf to the contact 608b among the contacts 608a - 608c so as to activate the switch 605. In an embodiment, the switch assembly 600a can include the keycap 602 and the switch 605 in the same package. Alternatively, the keycap 602 can be located on the trigger of the reader and aligned with the leaf 606 of the switch 605 such that when the trigger is pulled to the image trigger position, the leaf activator feature 604 of the keycap 602 deforms the leaf 606, thereby initiating the pre-trigger aiming function as described below. When the leaf 606 is deformed to the image initiation state, the leaf 606 contacts the contact 608b to form a circuit loop and transmit an electrical signal to the processor to initiate image capture through the reader, for example.

[0031] As further shown, an inductance change sensor or antenna 610 can be printed, mounted, or positioned on the PCB 612 on which the switch 605 is mounted. The antenna 610 can be a circular antenna, such as Figure 4B the antenna 410. In this embodiment, instead of having such as Figure 4ARegarding the separate conductive element positioned on the trigger as shown, the metal leaf 606 of the leaf switch 605 can be used as the conductive element. That is, as the metal leaf 606 deforms, the inductance change can be sensed by the antenna 610. The shape, size, and spacing of the antenna 610 relative to the leaf switch 605 can vary according to the desired sensitivity, which can be a function of the antenna pattern generated by the antenna 610. As understood in the art, different antenna designs can generate different antenna patterns.

[0032] As previously described, by using the antenna 610 capable of performing high-resolution and high-precision measurements on the magnetic field distortion within the antenna pattern (i.e., the sensing area), the use of a conductive element (such as Figure 4A the conductive element 404) on the trigger can be avoided, and the deformation of the conductive metal leaf 606 inside the switch 605 mounted on the PCB 607 can be directly detected. That is, even the micrometer-scale deformation of the metal leaf 606 inside the switch 605 mounted on the PCB is sufficient to be detected by the sensor electronics with sufficient gain and signal-to-noise ratio.

[0033] Regarding Figure 7 , a block diagram of the electrical system 700 is shown. The electrical system 700 includes a set of electronic components, electro-optical components, and electromagnetic components for the reader to perform the inductive pre-trigger aiming function. The electrical system 700 can include electronics containing a processor 702, and the processor 702 can include a microprocessor, an application-specific integrated circuit (ASIC), and / or other electronics configured to sense inductance changes and perform the code reading function according to the principles described herein. The antenna 704 (which can be a circular antenna with one or more circular antenna elements) can be configured to sense the inductance change caused by the movement of the conductive element 706 by the trigger of the reader. The conductive element 706 can be formed of any conductive material that can be sensed by the antenna 704.

[0034] The antenna 704 can be in electrical communication with an inductance-to-digital (I / D) converter 708, and the ID converter 708 can be in electrical communication with the processor 702. The processor can further communicate with the switch 710, the aiming illuminator 712, the imaging illuminator 713, and the imager 714. The processor 702 can be configured to manage the functional operation of the reader, including the pre-trigger aiming function and the code imaging and decoding functions.

[0035] In operation, in response to the antenna 704 sensing an inductance level and / or an inductance change, an inductance sensing signal 716 can be generated. The inductance sensing signal 716 can be a dynamic analog signal representing the inductance change or relative position of the conductive element, a sine signal in response to sensing an inductance change, or any other analog signal. The inductance sensing signal 716 can be received and processed by the I / D converter 708. The I / D converter 708 can generate an inductance sensing digital signal 708 that digitally represents the inductance sensing signal 716.

[0036] The processor 702 can receive the inductance sensing digital signal 718 and determine the inductance level of the corresponding inductance sensing signal 716 to determine whether the inductance level is at a level to initiate a pre-trigger aiming function. When determining whether the inductance level indicates the initiation of the pre-trigger aiming function, the processor 702 can compare the instantaneous inductance level with the baseline inductance level when the trigger (i.e., the conductive element 706) is in a resting state or position. The inductance sensing can be passive or active. In response to the processor 702 determining that the instantaneous inductance level exceeds the pre-trigger aiming function threshold level, the processor 702 can generate a pre-trigger aiming signal 720 to cause the aiming illuminator 712 to generate a pre-trigger aiming pattern signal 722 within the projection area 724, thereby generating a pre-trigger aiming pattern 726. For example, the instantaneous inductance level can start at 0.0 henries (self-calibrated) in the resting state and end at 0.5 henries at the moment the switch is activated. If the pre-trigger aiming function threshold level is set at 0.25 henries (e.g., corresponding to a 2 mm trigger pull), then when the trigger is pulled 2 mm, the pre-trigger aiming function can be triggered and the inductance level can be 0.25 henries, which is 0.25 henries different from the resting state. The projection area 724 can be at an angle the same as or similar to the angle defining the field of view 726 of the imager 714, where the field of view 726 is used to capture an image or scan a scene where a machine-readable marker or code 730 is located. That is, the projection area 724 overlaps with the scene within the field of view 726 of the imager 714.

[0037] In response to the activation of switch 710 by pressing on the switch 710 in response to a trigger, switch 710 generates switch signal 732, and processor 702 may generate an image capture signal 708 to cause imager 714 to capture an image within the field of view 728. Similarly, in addition to processor 702 generating image capture signal 708, processor 720 may also generate an imaging illumination signal 736 to cause imaging illuminator 738 to generate an illumination signal (not shown) that illuminates code 730 being imaged. Similar to pre-trigger aiming pattern signal 722, the illumination signal may have the same or a similar field of view as imager 714 such that code 730 is illuminated. In an embodiment, imaging illuminator 738 may transition to an ON state prior to imager 714 capturing an image such that code 730 is illuminated prior to imager 714 capturing an image of code 730. As understood in the art, imager 714 may generate image data 734 for processor 702 to process and decode machine-readable indicia 730.

[0038] Reader 700 may further include a user interface 740 in electrical communication with processor 702. User interface 740 may include a touch-sensitive electronic display such that a graphical user interface may be displayed to the user for setting up and operating reader 700. In an alternative embodiment, user interface 740 may include electromechanical components such as knobs, switches, or other components that enable a user to set parameters such as a pre-trigger aiming threshold level. User interface 740 may be located on reader 700, but may also be located on an external device. Such an external placement of the user interface may be the case where reader 700 is wirelessly or by cable connected to a personal computer or other electronic device to be configured, where the configuration options may be pre-trigger settings options for setting the responsiveness and behavior of the pre-trigger aiming function. Since some readers do not have a user interface, enabling an external user interface to establish pre-trigger aiming or other settings may be more efficient and less expensive than alternative techniques for establishing pre-trigger aiming or other settings. In an embodiment, user interface 740 may enable a user to select factory settings for setting the pre-trigger aiming threshold level, and the factory settings may have multiple selection options (e.g., low, medium, high) or enable the user to select a range of levels.

[0039] As shown, a user may interact with user interface 740 to select a pre-trigger aiming inductance level 742, which may be transmitted from user interface 740 to processor 702. Reader 700 may have a factory setting for a pre-trigger aiming threshold level as a default and be capable of selecting or resetting the factory setting. The pre-trigger aiming threshold level may be stored in non-transitory memory and accessed during operation of reader 700. In an alternative embodiment, instead of performing a comparison of the resting state inductance level with the instantaneous inductance, the reader may be configured to have the ability for a user to set the inductance threshold level while pulling the trigger to a desired threshold position (e.g., pulling the trigger a desired amount and pressing a button). The processor may store the inductance value measured at the desired trigger position, and thereafter, the reader may use the stored inductance threshold level to determine the inductance change.

[0040] Regarding Figure 8 , a flowchart of a process 800 for self-calibrating a reader to perform a pre-trigger aiming function by using inductance sensing is shown. Process 800 may start at step 802, where it may be determined whether the trigger of the reader is in the resting position. If not, the process may repeat step 802. When in the resting position, the user may notify the reader (i.e., the processor of the reader) via a user interface (e.g., a touch screen, mechanical buttons, or otherwise) that the trigger of the reader is in the resting position (i.e., not being pulled towards the switch). At step 802, the inductance sensor may measure the resting position inductance value. At step 806, the resting position inductance value may be stored in non-transitory memory to be used as a reference value for inductance change during operation of the reader.

[0041] As previously described, the reader may be configured to self-calibrate at the resting position to set a base inductance value. In one embodiment, the manufacturer may set a pre-trigger inductance threshold level. The self-calibration process may be independent of establishing the pre-trigger threshold level and independent of the pre-trigger threshold level. In another embodiment, the user may set the pre-trigger inductance threshold level by allowing the user to pull the trigger to a desired position and press a button that causes the reader to store the pre-trigger inductance threshold level. Alternative techniques may be used to enable the user to configure the pre-trigger threshold. During operation, when the inductance change is greater than the resting inductance value by the pre-trigger inductance threshold level used as an offset or exceeds the pre-trigger inductance value set by the user moving the trigger to a desired position, the pre-trigger aiming function will be activated.

[0042] Regarding Figure 9, a flowchart of a process 900 for a user to set a pre-trigger threshold level of a reader is shown. In this process 900, the pre-trigger threshold can be configured by the user. The process 900 may start from step 902, in which the user moves the trigger to the desired pre-trigger threshold level position. In step 904, the inductive sensor can measure the pre-trigger inductive threshold level. To initiate step 904, the user can press a button or hold the trigger at a certain position for a certain period of time, such as 3 seconds. For example, if the reader is in the user calibration mode. In step 906, the pre-trigger inductive threshold level can be stored at the threshold level for determining when to initiate the pre-trigger aiming function during the normal operation of the reader.

[0043] Regarding Figure 10 , a flowchart of a process 1000 for a reader to perform a pre-trigger aiming function by using inductive sensing performed by the reader is shown. The process 1000 may start from step 1002 by sensing the instantaneous inductance value during the operation of the trigger of the reader. In step 1004, the inductance change relative to the rest position of the reader can be determined. This determination can be performed by previously executing the self-calibration operation provided in Figure 8 or the user setting operation provided in Figure 9 . In step 1006, it can be determined whether the inductance change exceeds the pre-trigger inductive threshold level. The pre-trigger inductive threshold level can be set to indicate the minimum level at which the user deliberately moves the trigger a certain distance (e.g., a 3 mm movement of the trigger). The pre-trigger inductive threshold level can be set to the corresponding inductance value corresponding to a certain movement distance, for example. It should be understood that the minimum level can be set based on the type of conductive element being sensed, the type of inductive sensor, the sensitivity of the inductive sensor, the signal-to-noise ratio of the inductive sensor, the resolution of the inductance-to-digital converter, or other aspects.

[0044] If in step 1006, it is determined that the inductance change does not exceed the pre-trigger inductive threshold level, the process returns to step 1002. Otherwise, if the inductance change does not exceed the pre-trigger inductive threshold level, the process can continue to step 1008, in which the pre-trigger aiming function can be performed. As previously described herein, such a pre-trigger aiming function can include generating a pre-trigger aiming signal to display a pre-trigger aiming pattern to help the user image a machine-readable mark with the reader.

[0045] An embodiment of the process of operating a reader may include sensing an inductance change during the operation of the trigger of the reader and, in response to determining that the inductance change exceeds the pre-trigger inductive threshold level, performing the pre-trigger aiming function.

[0046] The process may further include sensing an inductance change by sensing an inductance change in response to an inductor device passing through an electromagnetic field. Sensing the inductance change may further include sensing an inductance change in response to a metal tab of a leaf switch being deformed by a trigger of a reader.

[0047] The reader may be self-calibrated by sensing a resting state inductance value and storing the resting state inductance value. Sensing the inductance change may include: sensing an instantaneous inductance value, determining an inductance difference between the instantaneous inductance value and the resting state inductance value, and in response to the inductance difference exceeding a pre-trigger inductance threshold level, performing a pre-trigger aiming function. Sensing the inductance change may further include sensing the inductance change until a button is pressed to cause the reader to perform a scanning function.

[0048] The foregoing method descriptions and process flow diagrams are provided only as illustrative examples and are not intended to require or imply that the steps of the various embodiments must be performed in the order presented. As will be appreciated by those skilled in the art, the steps in the foregoing embodiments may be performed in any order. Words such as "then," "next," etc. are not intended to limit the order of the steps; these words are merely used to guide the reader through the overall description of the method. Although the process flow diagrams may depict the operations as a sequential process, many of the operations may be performed in parallel or concurrently. Additionally, the order of the operations may be rearranged. The process may correspond to a method, function, procedure, subroutine, subprogram, etc. When the process corresponds to a function, its termination may correspond to the function returning to the calling function or the main function.

[0049] The various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

[0050] Embodiments implemented using computer software can be implemented using software, firmware, middleware, microcode, a hardware description language, or any combination thereof. Code segments or machine-executable instructions can represent a process, a function, a subroutine, a program, a routine, a subroutine, a module, a software package, a class, or any combination of instructions, data structures, or program statements. A code segment can be coupled and / or communicate with another code segment or a hardware circuit by passing and / or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. can be passed, forwarded, or transmitted via any suitable means, including memory sharing, message passing, token passing, network transmission, etc.

[0051] The actual software code or specialized control hardware used to implement these systems and methods is not a limitation of the present invention. Therefore, the description of the operation and behavior of the systems and methods does not mention the specific software code that is understood to be designed to implement the systems and methods based on the description herein.

[0052] When implemented in software, the functions can be stored as one or more instructions or code on a non-transitory computer-readable or processor-readable storage medium. The steps of the methods or algorithms disclosed herein can be implemented with processor-executable software modules that can reside on a computer-readable or processor-readable storage medium. The non-transitory computer-readable or processor-readable medium includes both computer storage media and tangible storage media that facilitate the transfer of a computer program from one place to another. The non-transitory processor-readable storage medium can be any available medium accessible by a computer. By way of example and not limitation, such non-transitory processor-readable media can include RAM, ROM, EEPROM, CD-ROM, or other optical disk storage, magnetic disk storage, or other magnetic storage devices, or any other tangible storage medium that can be used to store the desired program code in the form of instructions or data structures and that is accessible by a computer or a processor. As used herein, disks and discs include compact discs (CDs), laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and Blu-ray discs, where disks typically reproduce data magnetically, while discs reproduce data optically using a laser. Combinations of the above should also be included within the scope of computer-readable media. Additionally, the operations of a method or algorithm can reside as code and / or instructions in one or any combination or set of code and / or instructions on a non-transitory processor-readable medium and / or a computer-readable medium that can be incorporated into a computer program product.

[0053] The foregoing description is for implementing the preferred embodiments of the present invention, and the scope of the present invention should not necessarily be limited by this description. Instead, the scope of the present invention is defined by the claims.

Claims

1. A handheld barcode reader, comprising: A main structure; An electro - optical device, positioned at the main structure and configured to image or scan machine - readable codes; A handle, extending from the main structure and configured to enable a user to grasp the handle to operate the barcode reader; An electronic device, configured to cause the electro - optical device to perform (i) a pre - trigger aiming function and (ii) a barcode reading function; A trigger, configured to be pulled by a user towards the handle; An antenna, in electrical communication with the electronic device and configured to sense an inductance change caused by the user pulling the trigger from a rest position to a pre - trigger aiming function position; And A switch, in electrical communication with the electronic device and positioned to be activated by the trigger being pulled to a scan position such that the trigger reaches the pre - trigger aiming function position before the scan position when starting from the rest position, to initiate the pre - trigger aiming function before the barcode reading function.

2. The barcode reader according to claim 1, wherein the switch comprises a metal shrapnel part.

3. The barcode reader according to claim 2, wherein the antenna is configured to sense an inductance change when the metal shrapnel is deformed by the trigger.

4. The barcode reader according to claim 1, wherein the electronic device is further configured to enable a user to set a pre - trigger aiming threshold level, and when the inductance change exceeds the pre - trigger aiming threshold level, the electronic device initiates the pre - trigger aiming function.

5. The barcode reader according to claim 1, further comprising a conductive element positioned on the trigger, and wherein the antenna is configured to sense a position change of the conductive element.

6. The barcode reader according to claim 1, wherein the electronic device is configured to determine a rest - state inductance value when the trigger is in the rest position and store the rest - state inductance value as a reference value.

7. The barcode reader according to claim 6, wherein the electronic device is further configured to: Sense an instantaneous inductance value; Determine an inductance difference between the instantaneous inductance value and the rest - state inductance value; and In response to determining that the inductance difference is higher than a pre - trigger threshold level, initiate the pre - trigger aiming function.

8. A method of operating a barcode reader, comprising: Sensing an inductance change during operation of a trigger of the barcode reader; And In response to determining that the inductance change exceeds a pre - trigger inductance threshold level, performing a pre - trigger aiming function before initiating a barcode reading function according to the position of the trigger during the operation of the trigger.

9. The method according to claim 8, wherein sensing the inductance change includes sensing an inductance change in response to an inductor device moving through an electromagnetic field.

10. The method according to claim 8, wherein sensing the inductance change includes sensing an inductance change in response to a metal shrapnel of a membrane switch being deformed by the trigger of the barcode reader.

11. The method according to claim 8, further comprising self - calibrating the barcode reader by: Sensing a rest - state inductance value; and Storing the rest - state inductance value.

12. The method according to claim 11, wherein sensing the inductance change includes: Sensing an instantaneous inductance value; Determine the inductance difference between the instantaneous inductance value and the resting state inductance value; and In response to the inductance difference exceeding the pre-trigger inductance threshold level, perform the pre-trigger aiming function.

13. The method according to claim 11, further comprising enabling a user to set the pre-trigger aiming threshold level.

14. A handheld barcode reader, comprising: A main structure; A handle extending from the main structure; A trigger configured to be pulled by a finger of a user holding the handle; A conductive element; An antenna configured to sense an inductance change caused by the trigger moving the conductive element; and An electronic device in electrical communication with the antenna and configured to determine when the inductance change indicates that the user has selected to activate the pre-trigger aiming function before activating the barcode reading function based on the position where the trigger is pulled.

15. The barcode reader according to claim 14, wherein the electronic device is configured to determine when the inductance change indicates that the user has selected to activate the pre-trigger aiming function includes sensing when the difference between the resting state inductance value and the instantaneous sensed value exceeds the pre-trigger inductance threshold level.

16. The barcode reader according to claim 14, wherein the antenna is a circular antenna positioned at the handle.

17. The barcode reader according to claim 14, wherein the electronic device is further configured to enable a user to set the pre-trigger aiming threshold level, and the pre-trigger aiming threshold level causes the electronic device to activate the pre-trigger aiming function when exceeded by the inductance change.

18. The barcode reader according to claim 14, wherein the conductive element is positioned on the trigger.

19. The barcode reader according to claim 14, further comprising a switch positioned to be pressed by the trigger, and wherein the conductive element is a metal shrapnel on the switch, and wherein the antenna surrounds the switch and is configured to sense the inductance change in response to the metal shrapnel being deformed by the trigger.

20. The barcode reader according to claim 14, wherein the electronic device causes a pre-trigger aiming illumination pattern to be projected from the barcode reader in response to determining when the inductance change exceeds the pre-trigger inductance threshold level.

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