Illumination control for imaging system with multiple image sensors

Abstract

The invention relates to illumination control for an imaging system with multiple image sensors. An imaging system is disclosed, comprising: a first image sensor associated with a first illumination source, where the first image sensor is configured to capture a first image of a target symbol; a second image sensor; and a controller including processing circuitry, the controller communicatively coupled with the first illumination source, the first image sensor, and the second image sensor, where the controller is configured to: process the first image to estimate a distance between the first image sensor and the target symbol; determining a first exposure period of the second image sensor based on a distance estimate; and modifying one or more characteristics of the first exposure period of the second image sensor based on at least one illumination pulse of the first illumination source.

Description

[0001] This application is a divisional application of the invention patent application with the national application number 202210090187.3. The application date of the invention patent application is January 25, 2022, and the invention title is "Illumination Control for an Imaging System with Multiple Image Sensors". Technical Field

[0002] Embodiments of the present disclosure generally relate to imaging systems having multiple image sensors and, more particularly, to illumination control for image sensors of an imaging system. Background Art

[0003] Imaging devices and systems have been applied in fields more complex and advanced than mere photography. There has been a continuing need to improve the imaging capabilities of these devices and systems to accommodate new capabilities. In terms of currently available imaging systems, factors such as a miniaturized form factor have led to an increase in interference between components of the imaging system. In such systems, it remains challenging to operate these components in a synchronized manner to prevent any adverse effects on each other's capabilities. Summary of the Invention

[0004] Generally speaking, embodiments of the present disclosure provided herein are configured for illumination control and synchronization in a multi-imager environment. By examining the following drawings and detailed description, additional specific implementations of alternative illuminator components and / or one or more of alternative illumination imaging systems and devices will be or will become apparent to those skilled in the art. All such additional specific implementations included within this specification are intended to be within the scope of the present disclosure and are protected by the following claims.

[0005] According to some exemplary embodiments, an imaging system is provided herein. In an exemplary embodiment, the imaging system includes a first illumination source associated with a first image sensor, the first illumination source being configured to operate based on a first illumination pulse train. The imaging system further includes a second image sensor and a controller communicatively coupled to each of the first illumination source, the first image sensor, and the second image sensor. In some exemplary embodiments, the controller is configured to determine a first exposure period of the second image sensor and modify one or more characteristics of the first illumination pulse train to accommodate the first exposure period of the second image sensor.

[0006] Additionally or alternatively, in some embodiments of the imaging system, to modify the one or more characteristics of the first illumination pulse train, the controller is further configured to insert at least one additional illumination pulse into the first illumination pulse train such that either a start time period or an end time period of an illumination period of the at least one additional illumination pulse is aligned with a corresponding one of a start time period or an end time period of the first exposure period of the second image sensor.

[0007] Additionally or alternatively, in some embodiments of the imaging system, to modify one or more characteristics of the first illumination pulse train, the controller is further configured to insert at least one additional illumination pulse into the first illumination pulse train such that illumination of the first image sensor corresponding to the at least one additional illumination pulse overlaps in time with the autofocus period of the second image sensor.

[0008] Additionally or alternatively, in some embodiments of the imaging system, to modify one or more characteristics of the first illumination pulse train, the controller is further configured to increase the timing delay between a pair of temporally successive illumination pulses of the first illumination pulse train such that one of the start time period or the end time period of the first exposure period is aligned with the corresponding one of the start time period or the end time period of the increased timing delay.

[0009] Additionally or alternatively, in some embodiments of the imaging system, the first image sensor is exposed during at least a second exposure period. In some exemplary embodiments, the exposure of the first image sensor during the second exposure period starts simultaneously with the start time period of the first illumination pulse of the first illumination pulse train, and the end time period of the second exposure period extends beyond the end time period of the first illumination pulse of the first illumination pulse train.

[0010] Additionally or alternatively, in some embodiments of the imaging system, the controller is further configured to obtain an image frame captured by exposure of the second image sensor during a first exposure period. In some exemplary embodiments, the controller is further configured to determine the luminance of the image frame and activate a second illumination source associated with the second image sensor based on the determined luminance of the image frame, wherein the second illumination source is configured to operate based on a second illumination pulse train.

[0011] Additionally or alternatively, in some embodiments of the imaging system, the exposure of the first image sensor starts simultaneously with the activation of the first illumination source.

[0012] Additionally or alternatively, in some embodiments of the imaging system, the second image sensor remains deactivated during the first illumination period of the first illumination pulse of the first illumination pulse train. Additionally or alternatively, in some embodiments, the second image sensor is exposed during a portion of the second illumination period of the second illumination pulse of the first illumination pulse train.

[0013] In some exemplary embodiments, an imaging method is provided. The method can be implemented using any of numerous specific implementations, such as via hardware, software, and / or firmware of a multi-sensor imaging engine and / or multi-sensor imaging device as described herein. In some exemplary implementations of the method, the exemplary method includes operating a first illumination source associated with a first image sensor based on a first train of illumination pulses. The exemplary method further includes determining a first exposure period of a second image sensor and modifying one or more characteristics of the first train of illumination pulses to accommodate the first exposure period of the second image sensor.

[0014] Additionally or alternatively, in some embodiments of the method, modifying the one or more characteristics of the first train of illumination pulses includes inserting at least one additional illumination pulse into the first train of illumination pulses such that one of a start time period or an end time period of an illumination period of the at least one additional illumination pulse is aligned with a corresponding one of a start time period or an end time period of the first exposure period of the second image sensor.

[0015] Additionally or alternatively, in some embodiments of the method, modifying the one or more characteristics of the first train of illumination pulses includes inserting at least one additional illumination pulse into the first train of illumination pulses such that illumination of the first image sensor corresponding to the at least one additional illumination pulse overlaps in time with an autofocus period of the second image sensor.

[0016] Additionally or alternatively, in some embodiments of the method, modifying the one or more characteristics of the first train of illumination pulses includes increasing a timing delay between a pair of temporally successive illumination pulses of the first train of illumination pulses such that one of a start time period or an end time period of the first exposure period is aligned with a corresponding one of a start time period or an end time period of the increased timing delay.

[0017] Additionally or alternatively, in some embodiments of the method, the method further includes causing an exposure of the first image sensor during at least a second exposure period. In some exemplary embodiments, the exposure of the first image sensor during the second exposure period starts simultaneously with a start time period of a first illumination pulse of the first train of illumination pulses. In some exemplary embodiments, an end time period of the second exposure period extends beyond an end time period of the first illumination pulse of the first train of illumination pulses.

[0018] Additionally or alternatively, in some embodiments of the method, the method further includes obtaining an image frame captured by exposure during a first exposure period by a second image sensor. The exemplary method further includes determining the luminance of the image frame and activating a second illumination source associated with the second image sensor based on the determined luminance of the image frame, the second illumination source being configured to operate based on a second illumination pulse train.

[0019] In some exemplary embodiments, a device is provided. In an exemplary embodiment, the device includes a memory configured to store executable instructions; and one or more processors. In some exemplary embodiments, the one or more processors are configured to execute the executable instructions to control the operation of a first illumination source associated with a first image sensor based on a first illumination pulse train. In some exemplary embodiments, the one or more processors are further configured to determine a first exposure period of a second image sensor and modify one or more characteristics of the first illumination pulse train to accommodate the first exposure period of the second image sensor.

[0020] Additionally or alternatively, in some embodiments of the device, to modify the one or more characteristics of the first illumination pulse train, the one or more processors are further configured to insert at least one additional illumination pulse into the first illumination pulse train such that one of a start time period or an end time period of an illumination period of the at least one additional illumination pulse is aligned with a corresponding one of a start time period or an end time period of the first exposure period of the second image sensor.

[0021] Additionally or alternatively, in some embodiments of the device, to modify the one or more characteristics of the first illumination pulse train, the one or more processors are further configured to insert at least one additional illumination pulse into the first illumination pulse train such that illumination of the first image sensor corresponding to the at least one additional illumination pulse overlaps in time with an autofocus period of the second image sensor.

[0022] Additionally or alternatively, in some embodiments of the device, to modify the one or more characteristics of the first illumination pulse train, the one or more processors are further configured to increase a timing delay between a pair of temporally successive illumination pulses of the first illumination pulse train such that one of a start time period or an end time period of the first exposure period is aligned with a corresponding one of a start time period or an end time period of the increased timing delay.

[0023] Additionally or alternatively, in some embodiments of the device, the one or more processors are further configured to obtain an image frame captured by exposure of a second image sensor during a first exposure period. In some exemplary embodiments of the device, the one or more processors are further configured to determine the luminance of the image frame and activate a second illumination source associated with the second image sensor based on the determined luminance of the image frame, wherein the second illumination source is configured to operate based on a second illumination pulse train. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Accordingly, having generally described embodiments of the present disclosure, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and in which:

[0025] Figure 1A FIG. 1 shows a block diagram of an exemplary multi-sensor imaging system in accordance with an exemplary embodiment of the present disclosure;

[0026] Figure 1B FIG. 2 shows a block diagram of an exemplary multi-sensor imaging engine in accordance with an exemplary embodiment of the present disclosure;

[0027] Figure 2 FIG. 3 shows a block diagram of an exemplary multi-sensor imaging device in accordance with an exemplary embodiment of the present disclosure;

[0028] Figure 3 FIG. 4 shows a visualization of a field of view associated with an exemplary multi-sensor imaging device in accordance with an exemplary embodiment of the present disclosure;

[0029] Figure 4 FIG. 5 shows a visualization of a first illumination generated by an exemplary multi-sensor imaging system in accordance with an exemplary embodiment of the present disclosure;

[0030] Figure 5 FIG. 6 shows a visualization of a second illumination generated by an exemplary multi-sensor imaging system in accordance with an exemplary embodiment of the present disclosure;

[0031] Figure 6 FIG. 7 shows a timing diagram associated with the operational functions of an exemplary multi-sensor imaging system in accordance with an exemplary embodiment of the present disclosure;

[0032] Figure 7 FIG. 8 shows a flow chart depicting exemplary operations of a process for illumination control in a multi-imager environment in accordance with an exemplary embodiment of the present disclosure;

[0033] Figure 8A flowchart according to an exemplary embodiment of the present disclosure is shown, which depicts exemplary operations of a process for modifying one or more characteristics of a first illumination pulse train to accommodate a first exposure period of a second image sensor of an exemplary multi-sensor imaging system;

[0034] Figure 9 A flowchart according to an exemplary embodiment of the present disclosure is shown, which depicts exemplary operations of another process for modifying one or more characteristics of a first illumination pulse train to accommodate a first exposure period of a second image sensor of an exemplary multi-sensor imaging system;

[0035] Figure 10 A flowchart according to an exemplary embodiment of the present disclosure is shown, which depicts exemplary operations of another process for modifying one or more characteristics of a first illumination pulse train to accommodate a first exposure period of a second image sensor of an exemplary multi-sensor imaging system;

[0036] Figure 11 A timing diagram according to an exemplary embodiment of the present disclosure associated with the operating functions of an exemplary multi-sensor imaging system for reducing flicker is shown;

[0037] Figure 12A 、 Figure 12B and Figure 12C A flowchart of an exemplary workflow of a symbol decoding process according to an exemplary embodiment of the present disclosure is shown;

[0038] Figure 13 A flowchart of an exemplary workflow of a flicker reduction process according to an exemplary embodiment of the present disclosure is shown; and

[0039] Figure 14 A flowchart of an exemplary workflow of a flicker reduction process for extended far-field exposure of an imaging device according to an exemplary embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0040] Embodiments of the present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all, embodiments of the disclosure are shown. In fact, the embodiments of the present disclosure can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Throughout the specification, like reference numerals refer to like elements.

[0041] Imaging devices such as label readers are used in various scenarios, each of which requires meeting a specific set of imaging requirements in order to continuously perform operations associated with the label reader, such as symbol decoding. Additionally, certain safety requirements related to, for example, the operator of the label reader must be met to ensure compliance with statutory rules. Label readers typically need to scan symbols attached to a surface from a close range to successfully decode them. However, in some environments such as warehouses, it is not possible to scan and successfully decode symbols attached to packages and consignments by reaching each consignment from a close range. Therefore, an extended range label reader is provided that does not require the operator to individually reach each consignment from a close range. Due to the far-field scanning capabilities of the extended range reader, such an extended range label reader is capable of scanning multiple symbols from a single operator position. Such label readers include multiple image sensors and associated optics to provide these capabilities.

[0042] The lighting requirements of these sensors can vary significantly. For example, one or more image sensors of a label reader may require lighting even during data readout, while other sensors may not have such a requirement. Thus, keeping the light source of one image sensor activated for a longer period can result in interfering with the exposure period of another sensor that does not desire the lighting. Such interference can produce images that are defective in terms of one or more imaging characteristics, thus adversely affecting the resulting image processing tasks. This problem is particularly prevalent in miniaturized imaging devices where sensors, light sources, and other optical components and parts are closely arranged. Additionally, in the context of a multi-imager environment (e.g., including multiple imagers and / or multiple light sources), the original embodiments such as capturing images by alternating between imagers and / or light sources exacerbate the flicker effect and thus exacerbate the associated negative effects.

[0043] Typically in scenarios where the image sensors are of different types, it is difficult to synchronize the lighting of the sensors for successful operation. For example, when a label reader includes a rolling shutter sensor for imaging in the far field and a global shutter sensor for imaging in the near field, due to the extended lighting time of the rolling shutter during data readout, it is difficult to ensure optimal lighting conditions for the global shutter sensor. This results in producing undesirable effects such as the snappiness of the images captured by the global shutter sensor. Additionally, the extended lighting time can also cause heating, thus affecting the thermal management system in a barcode scanner. Moreover, in an outdoor environment, since there is sufficient ambient light available, far-field imaging may not always require lighting. Therefore, the aiming device of the imaging system may not be distinguishable from the background, thus requiring rapid focusing to adjust the focusing position of the image sensor.

[0044] Additionally, controlling the illumination of such devices can be used to provide a more desirable visual appearance to the operator. For example, if the illumination pulses are within a certain frequency range (e.g., below a certain threshold frequency), the operator may experience headaches and / or seizures due to visual exposure to the illumination. In a multi-imager context with multiple illumination sources, each illumination source should be configured accordingly to prevent such negative health effects and undesirable visual appearances. In any case, if cycling through these illumination sources and / or otherwise frequently switching between these illumination sources, the operator may experience a "flickering" effect that may be undesirable or also harmful.

[0045] Some embodiments described herein relate to a dual-illumination framework for a multi-sensor imaging system that includes a plurality of illumination sources and a plurality of image sensors. Some embodiments described herein utilize a first illumination source and a first image sensor to capture an image during one or more illumination pulses of a train of illumination pulses associated with the first illumination source. The embodiments also utilize a second image sensor to capture an image, where the exposure period of the second image sensor is considered to modify the first train of illumination pulses such that the illumination of the first illumination source does not introduce any undesirable effects in the image captured by the second image sensor. Additionally, the illumination of the second image sensor is timed in a manner that does not affect the image captured by the first image sensor.

[0046] In some embodiments, one or more events can be triggered indicating a situation where activation of a second illumination source is needed. In this regard, the second illumination source can produce a second illumination for illuminating a second field of view associated with the second image sensor. In one such exemplary context, activation of the second illumination source is triggered after determining that no object has been detected within the captured image in a first field of view using the first illumination source and / or in a second field of view using ambient light illumination and thus the object may be at a greater distance from the imaging device. Activation of the second illumination source can be triggered in response to detecting one or more events and / or situations, such as in response to processing one or more previously captured images to determine that a threshold number of images have been captured and no object has been detected within the captured image under very low illumination conditions (e.g., below a certain whiteness value threshold).

[0047] In such cases, changing to another illumination source enables triggering of the second image sensor during the illumination pulses of the newly activated second illumination source to improve the effective read range of the device. In embodiments having more than two illumination sources, the same considerations can continue to apply for cycling through more than two illumination sources, thereby for example narrowing the field of view illuminated by each illumination source and extending the effective range of each cycle. Alternatively, one or more illumination sources can be skipped, for example immediately cycling from the widest illumination source to the narrowest illumination source in such a case without using one or more intermediate illumination sources.

[0048] Such embodiments provide effective synchronization of illumination sources and reduction and / or elimination of flicker, while being able to capture images effectively and efficiently for processing. The operation of such embodiments captures images in a manner that may enable successful completion of image processing tasks such as marking or symbol scanning, while increasing the likelihood of capturing images within a desired operating time frame that includes data sufficient for successful processing. By implementing the various exemplary embodiments described herein, the operating efficiency of the imaging device is maintained or improved while addressing the challenges caused by using multiple sensors and illumination sources.

[0049] In some embodiments, some of the above operations may be modified or further amplified. Additionally, in some embodiments, additional optional operations may also be included. The modifications, amplifications, or additions to the above operations may be performed in any order and in any combination.

[0050] Those skilled in the art to which the present disclosure pertains will, after benefiting from the foregoing description and the teachings presented in the related drawings, conceive of many modifications and other embodiments of the disclosure set forth herein. Accordingly, it is to be understood that the embodiments are not limited to the specific embodiments disclosed, and that the modifications and other embodiments are intended to be included within the scope of the appended claims. Additionally, although the above description and the related drawings describe example embodiments in the context of certain example combinations of elements and / or functions, it should be understood that different combinations of elements and / or functions may be provided by alternative embodiments without departing from the scope of the appended claims. In this regard, for example, different combinations of elements and / or functions than those explicitly described above are also contemplated, as may be shown in some of the appended claims. Although specific terms are employed herein, they are used in a general and descriptive sense only and not for purposes of limitation.

[0051] Definition

[0052] The term "illumination" refers to one or more light rays generated by an illumination source within a defined field of view. In at least one exemplary context, illumination includes one or more illumination pulses generated by a corresponding illumination source. In some embodiments, illumination is generated based on a "defined pulse frequency", which refers to the rate of illumination pulses generated by the illumination source. Additionally or alternatively, in some embodiments, illumination is generated based on a "defined pulse phase", which refers to the activation period during which the illumination source generates the corresponding illumination.

[0053] ​​Thus, a plurality of illumination pulses having a defined pulse frequency can together constitute an "illumination pulse train". Each illumination pulse can have a duration in the time domain called an "illumination period". Thus, the illumination period can refer to the duration during which the amplitude of the illumination pulse remains non-zero. That is, the illumination period of an illumination pulse refers to the period during which the illumination source corresponding to the illumination pulse remains active.

[0054] In at least one exemplary context, an illumination pulse is associated with an "illumination pulse start time", which is electronic management data indicating the time at which the corresponding illumination source will start generating the illumination pulse. Additionally or alternatively, in at least one such context, the illumination pulse is associated with an "illumination pulse end time", which is electronic management data indicating the time at which the corresponding illumination source will stop generating the illumination pulse.

[0055] The term "start time period of the illumination period" refers to a time period of a threshold duration starting from the illumination pulse start time, where the threshold duration can have a configurable value. In at least one exemplary context, the threshold duration can be zero, and thus, the terms start time period of the illumination period and illumination pulse start time can refer to the same time instance. Each illumination pulse can have a separate start time period.

[0056] The term "end time period of the illumination period" refers to a time period of a threshold duration ending at the illumination pulse end time, where the threshold duration can have a configurable value. In at least one exemplary context, the threshold duration can be zero, and thus, the terms end time period of the illumination period and illumination pulse end time can refer to the same time instance. Each illumination pulse can have a separate end time period.

[0057] The term "illumination source" (also referred to as "illuminator source" or "illuminator") refers to one or more light-generating hardware, devices, and / or components configured to generate illumination in a desired field of view. Non-limiting examples of illumination sources include one or more light-emitting diodes (LEDs), lasers, etc.

[0058] The term "near-field illumination source" refers to an illumination source configured to generate illumination to illuminate a near field associated with a near-field image sensor. In at least one exemplary context, the near-field illumination source is configured to generate illumination in a wider field of view compared to a far-field illumination source.

[0059] The term "far-field illumination source" refers to an illumination source configured to generate illumination to illuminate a far field associated with a far-field imager. In at least one exemplary context, the far-field illumination source is configured to generate illumination in a narrower field of view compared to a near-field illumination source.

[0060] The term "near-field illumination" refers to a specific illumination generated by a near-field illumination source. In some embodiments, the near-field illumination is associated with the illumination of the near field captured by a near-field image sensor. The term "near-field illumination pulse" refers to an illumination pulse of the near-field illumination associated with a near-field sensor.

[0061] The term "far-field illumination" refers to a specific illumination generated by a far-field illumination source. In some embodiments, the far-field illumination is associated with the illumination of the far field captured by a far-field image sensor. The term "far-field illumination pulse" refers to an illumination pulse of the far-field illumination.

[0062] The term "imager" refers to one or more components configured to capture an image representing a specific field of view. In at least one exemplary context, the imager includes at least one optical component (e.g., a lens and / or an associated housing) that defines a specific field of view. Additionally or alternatively, in at least one exemplary context, the imager includes an image sensor that is configured to output an image based on light, such as light that is coupled to the image sensor via an optical component.

[0063] The term "image sensor" refers to one or more components configured to generate an image represented by a data object based on light incident on the image sensor. In some such exemplary contexts, the image sensor converts light waves interacting with the image sensor into a signal representing the image output by the sensor.

[0064] The term "near-field image sensor" refers to an image sensor configured to capture an image of a near field. In at least one context, the near-field image sensor includes at least one near-field optical component that defines the near field, and an electronic sensor. In at least one exemplary context, the near-field image sensor may include a global shutter. In some exemplary contexts, the near-field image sensor may include a rolling shutter. The term "near-field image" refers to the electronic data generated by the near-field image sensor that embodies the captured representation of the near field.

[0065] The term "far-field image sensor" refers to an image sensor configured to capture an image of a far field. In at least one context, the far-field image sensor includes at least one far-field optical component that defines the far field, and an electronic sensor. In at least one exemplary context, the far-field image sensor may include a rolling shutter. In some exemplary contexts, the far-field image sensor may include a global shutter. The term "far-field image" refers to the electronic data generated by the far-field image sensor that embodies the captured representation of the far field.

[0066] The term "exposure period" refers to electronic data representing the length of time for which an image sensor is configured to be exposed to oncoming light. In at least one exemplary embodiment, the image sensor of the imager is configured to utilize a variable exposure time, which can be set to a specific exposure time value.

[0067] The term "start time period of the exposure period" refers to a time period of a threshold duration starting from the start point of the exposure period. The threshold duration can have a configurable value. In one example, the threshold duration can be zero, and thus, the terms start time period of the exposure period and start point of the exposure period can refer to the same time instance.

[0068] The term "end time period of the exposure period" refers to a time period of a threshold duration ending at the end point of the exposure period, where the threshold duration can have a configurable value. In one example, the threshold duration can be zero, and thus, the terms end time period of the exposure period and end point of the exposure period can refer to the same time instance.

[0069] Figure 1A A block diagram of an exemplary multi-sensor imaging system 10 (hereinafter, also referred to as imaging system 10) in accordance with an exemplary embodiment of the present disclosure is shown. The multi-sensor imaging system 10 includes an imaging engine 100, a communication interface 40, an activation component 60, and one or more peripheral components 80 communicatively coupled to a controller 20. In some exemplary embodiments, the imaging system 10 may include fewer or more components than Figure 1A shown. The imaging system 10 is configured to capture one or more images of a target in one or more fields of view using one or more illumination sources. The imaging system 10 processes the one or more images to perform one or more image processing tasks, such as label reading. Thus, in some exemplary embodiments of the present disclosure, the imaging system 10 may be embodied in part or in whole as a label or symbol reader or a handheld device capable of reading labels and similar symbols. Figure 2 An exemplary embodiment of the imaging system 10 is shown in, the details of which will be described in subsequent portions of the present disclosure.

[0070] The controller 20 may be configured to perform one or more control operations associated with the imaging system 10. For example, the controller 20 may control the imaging engine 100 to cause image capture of a target in the field of view of the imaging engine 100. Additionally, the controller 20 may process the captured images to perform one or more image processing tasks. The controller 20 may be embodied as a central processing unit (CPU) including one or more processors and a memory. In some exemplary embodiments, the controller 20 may be implemented using one or more microcontroller units (MCUs) as one or more of various hardware processing devices, such as a coprocessor, a microprocessor, a digital signal processor (DSP), a processing element with or without an accompanying DSP, or various other processing circuits, including integrated circuits such as, for example, an ASIC (application specific integrated circuit), an FPGA (field programmable gate array), a hardware accelerator, a dedicated computer chip, etc. In some embodiments, the processor of the controller 20 may include one or more processing cores that are configured to operate independently. A multi-core processor may implement multiple processing within a single physical package. Additionally or alternatively, the processor may include one or more processors configured in a bus string configuration to enable independent execution of instructions, pipelining, and / or multithreading.

[0071] The memory may be non-transitory and may include, for example, one or more volatile memories and / or non-volatile memories. For example, the memory may be an electronic storage device (e.g., a computer-readable storage medium) that includes gates configured to store data (e.g., bits) retrievable by a machine (e.g., a computing device such as a processor). The memory may be configured to store information, data, content, applications, instructions, etc. for enabling the device to perform various functions in accordance with the exemplary embodiments of the present invention. For example, the memory may be configured to buffer data for processing by the processor. Additionally or alternatively, the memory may be configured to store instructions for execution by the processor.

[0072] A processor (and / or a coprocessor or any other processing circuitry that aids or otherwise relates to the processor) may communicate with a memory via a bus for transferring information among the components of the imaging system 10. The processor may be configured to execute instructions stored in the memory or otherwise accessible to the processor. Additionally or alternatively, the processor may be configured to execute hard-coded functions. Thus, whether configured by a hardware approach, a software approach, or a combination thereof, the processor may represent an entity (e.g., physically embodied in the form of circuitry) capable of performing operations in accordance with embodiments of the present invention while being correspondingly configured. Thus, for example, when the processor is embodied as an ASIC, an FPGA, etc., the processor may be specifically configured hardware for performing the operations described herein. Alternatively, for another example, when the processor is embodied as an executor of software instructions, the instructions may specifically configure the processor to execute the algorithms and / or operations described herein when the instructions are executed. Among other things, the processor may further include a clock, an arithmetic logic unit (ALU), and logic gates configured to support the operation of the controller 20.

[0073] The communication interface 40 may include an input interface and an output interface for supporting communication to and from the imaging system 10. The communication interface 40 may be any device, such as a device or circuitry embodied in hardware or a combination of hardware and software, configured to receive and / or transmit data to / from a communication device that communicates with the imaging system 10. In this regard, the communication interface 40 may include, for example, an antenna (or antennas) and support hardware and / or software for enabling communication with a wireless communication network. Additionally or alternatively, the communication interface 40 may include circuitry for interacting with the antenna to cause transmission of a signal via the antenna or for processing reception of a signal received via the antenna. In some environments, the communication interface 40 may alternatively or additionally support wired communication. Thus, for example, the communication interface 40 may include a communication modem and / or other hardware and / or software for supporting communication via a cable, a digital subscriber line (DSL), a universal serial bus (USB), or other mechanisms.

[0074] The activation component 60 may include hardware, software, firmware, and / or combinations thereof configured to indicate to a user to initiate (and / or terminate) a desired function. For example, the activation component 60 may transmit an activation signal to cause the controller 20 to start the operation of the imaging engine 100, such as starting illumination by one or more illumination sources and / or capturing one or more images by an image sensor. Additionally or alternatively, the activation component 60 may transmit a deactivation signal to the controller 20 to terminate the corresponding function, such as stopping scanning via the image sensor. In some embodiments, the activation component 60 is embodied as one or more buttons, triggers, and / or other physical components disposed in or on the body of the base. For example, in at least one exemplary context, the activation component 60 is embodied as one or more "trigger" components that, when engaged by an operator (e.g., when the operator squeezes the trigger), transmit a signal to the controller 20 to initiate the corresponding function. In some such embodiments, when the operator disengages the component (e.g., when the operator releases the trigger), the activation component may transmit a deactivation signal to the controller 20 to stop such function. Alternatively or additionally, in at least some embodiments, the activation component 60 is embodied as not having any components directly engaged by the operator. For example, when the imaging system 10 is embodied as an imaging device, the activation component 60 may be embodied as hardware and / or software or combinations thereof for detecting that the imaging device has been raised and / or positioned at a predefined "scanning" position and / or lowered from that position to trigger deactivation. Alternatively or additionally, the activation component 60 may be embodied as a user interface element of the imaging system 10. In such embodiments, the activation component 60 embodied as a user interface element may be configured to receive input from a user on the user interface and, in turn, transmit a corresponding command to the controller 20.

[0075] One or more peripheral components 80 include other structural and functional elements of the imaging system 10, such as, for example, a display device, a user interface, a housing, a base, a power supply, and the like. One or more of the peripheral components 80 may be controlled by the controller and may operate in accordance with instructions or controls provided by the controller 20.

[0076] Figure 1BAn exemplary multi-sensor imaging engine (hereinafter also referred to as "imaging engine") according to an exemplary embodiment of the present disclosure is shown. Specifically, as shown, the exemplary multi-sensor imaging engine is embodied as a multi-sensor imaging engine 100. The multi-sensor imaging engine 100 includes a plurality of image sensors, particularly a near-field image sensor and / or a far-field image sensor, which are configured to capture image data objects in a near field associated with the near-field image sensor and a far field associated with the far-field image sensor, respectively. In at least one exemplary context, the multi-sensor imaging engine 100 is configured to capture images for the purpose of label reading in different ranges, such as a short-range using the near-field image sensor and a long-range using the far-field image sensor.

[0077] As shown, the multi-sensor imaging engine 100 includes near-field image capture optics 104A. The near-field capture optics 104A may be embodied as one or more lenses and / or other optical components that are configured to allow light to pass laterally through the corresponding image sensor (specifically, the near-field image sensor 102A) and interact with it. In this regard, the near-field image capture optics 104A may define a specific field of view that can be captured by the near-field image sensor 102A. In some embodiments, the near-field image capture optics 104A defines a near field associated with a first focusing range such that objects located at the first focusing range and / or within a determinable offset are clearly visible in the image captured by the near-field image sensor 102A.

[0078] In addition, as shown, the multi-sensor imaging engine 100 includes far-field image capture optics 104B. The far-field image capture optics 104B may be embodied as one or more lenses and / or other optical components that are configured to allow light to pass laterally through the corresponding image sensor (specifically, the far-field image sensor 102B) and interact with it. In this regard, the far-field image capture optics 104B may define a second field of view that can be captured by the far-field image sensor 102B. In some embodiments, the far-field image capture optics 104B defines a far field associated with a second focusing range such that objects located at the second focusing range and / or within a determinable offset are clearly visible in the image captured by the far-field image sensor 102B. In some such embodiments, the near field is wider than the far field, such that the captured data represents more of the environment within the field of view of the multi-sensor imaging engine 100. The far field may be narrower than the near field and focused on a farther range to enable clearer capture of objects located at a greater range than objects that can be clearly captured in the near field. The illumination source and the physical layout of the image sensors may be varied in different applications.

[0079] In some exemplary embodiments, the near-field imaging sensor 102A may include a global shutter to provide enhanced motion tolerance. The near-field imaging sensor 102A may use a large field of view (FOV), which enables applications such as but not limited to optical character recognition (OCR), image reconstruction, machine learning, etc. In some embodiments, the far-field sensor 102B may include a rolling shutter. The far-field image sensor 102B uses a small FOV to improve sampling in the far field. Additionally, each of the near-field image sensor 102A and the far-field image sensor 102B may have an associated focusing mechanism. The focusing mechanism may include a focusing scheme that controls the movement of one or more focusing lenses along the optical axis direction of the image sensor (102A or 102B). To this end, in some embodiments, the focusing scheme may include one or more motors, such as stepper motors. The focusing scheme may provide multiple discrete focusing positions in each field of view, and the motor may move the focusing optics of a particular image sensor to each of the discrete focusing positions to exhibit the focusing mechanism. For example, in some exemplary embodiments, to change the focus of the far-field imaging sensor 102B, the corresponding motor may move the associated focusing optics of the far-field image sensor 102B to three discrete focusing positions in the far field. The operation of each focusing mechanism may be controlled by a processing component (such as Figure 1A the controller 20 or the processor 202).

[0080] In some embodiments, such as shown, each image sensor (or a subset thereof) is associated with one or more components for generating illumination that is configured to illuminate the field of view defined by the image sensor. For example, as shown, the multi-sensor imaging engine 100 further includes a near-field illumination source 106A and a corresponding near-field projection optics 108A. The near-field illumination source 106A can generate illumination pulses that constitute a near-field illumination pulse train. That is, the near-field illumination source 106A is activated for a certain time period and then remains deactivated for a set time period before the next activation. The near-field illumination source 106A is configured to generate light in the direction of the optical axis of the near-field projection optics 108A. The light is refracted through the near-field projection optics 108A to generate near-field illumination, which can be generated as a desired pattern based on the configuration and design of the near-field projection optics 108A. In this regard, the illumination generated by the light exiting the near-field projection optics 108A can illuminate a specific field of view, such as a near-field that can be captured by the near-field image sensor 102A. It should be understood that in some embodiments, the near-field illuminator 106A and / or the near-field projection optics 108A can be designed such that the near-field illumination specifically illuminates the near-field and can affect the function of the far-field image sensor 102B without adversely affecting the function of the near-field image sensor 102A. For example, at least in part due to the close proximity of the components, the reflected light can interact with the far-field image sensor 102B and adversely affect the image created via the far-field image sensor 102B. In some exemplary embodiments, the near-field illumination source 106A can generate near-field illumination based on one or more illumination pulses that constitute a near-field illumination pulse train.

[0081] Similarly, the multi-sensor imaging engine 100 further includes a far-field illumination source 106B and a corresponding far-field projection optics 108B. The far-field illumination source 106B generates far-field illumination pulses that constitute a far-field illumination pulse train. The far-field illumination source 106B is configured to generate light in the direction of the far-field projection optics 108B. The light is refracted through the far-field projection optics 108B to generate far-field illumination, which can be generated as a desired pattern based on the configuration and design of the far-field projection optics 108B. In this regard, the far-field illumination can illuminate a specific field of view, such as a far-field that can be captured by the far-field image sensor 102B. It should be understood that the far-field illumination source 106B and / or the far-field projection optics 108B can be designed such that the far-field illumination specifically illuminates the far-field without generating reflections that are sufficient to adversely affect the operation of the near-field image sensor 102A and / or the far-field image sensor 102B.

[0082] Additionally or alternatively, optionally in some embodiments, the multi-sensor imaging engine 100 further includes a sight illuminator source 110. The sight illuminator source 110 is configured to generate light in the direction of the sight projection optics 112. For example, the sight illuminator source includes one or more laser diodes and / or high-intensity LEDs, which are configured to generate light that is sufficiently intense and / or focused. The light is refracted through the sight projection optics 112 to generate sight illumination, which can be generated as a desired pattern based on the configuration and design of the sight projection optics 112. In one exemplary context, for purposes such as barcode scanning, the sight pattern can be generated as a laser line pattern.

[0083] The multi-sensor imaging engine 100 further includes a protective window 114. The protective window 114 includes one or more optical components that are configured to allow the generated light to exit the engine 100 and to allow incident light to be received through the image capture optics 104A and 104B for interaction with the corresponding image sensors 102A and 102B. In some contexts, the protective window 114 reflects at least a portion of the illumination projected by the far-field projection optics 108B and / or the near-field projection optics 108A, and it can interact with the image sensors 102A and / or 102B through light leakage or through the corresponding image capture optics 104A and / or 104B. For example, at least a portion of the near-field illumination can be reflected toward the far-field image sensor 102B, and if the far-field image sensor 102B is triggered during an illumination pulse, at least a portion of the near-field illumination can adversely affect the operation of the far-field image sensor. In at least one exemplary context, the far-field illuminator source 106B generates focused light and / or otherwise well-designed light such that the far-field illumination generated by the far-field projection optics 108B is not reflected sufficiently to adversely affect the near-field image sensor 102A.

[0084] It should be understood that in other embodiments, the multi-sensor imaging engine can include any number of image capture optics, image sensors, illumination sources, and / or any combination thereof. In this regard, the imaging engine 100 can be extended to capture any number of fields of view, each of which can be associated with a corresponding illuminator that is designed to specifically illuminate the corresponding field of view. One or more of the illumination sources can adversely affect the operation of another illuminator. In such cases, when one such illumination source is activated, the adversely affected image sensor can be activated between the illumination pulses of the illumination source, as described herein. Such operations can be implemented for any combination of illumination sources and image sensors.

[0085] In some embodiments, the multi-sensor imaging engine 100 includes one or more processing components (e.g., a processor and / or other processing circuitry) for controlling the activation of one or more components of the multi-sensor imaging engine 100. For example, in at least one exemplary embodiment, the multi-sensor imaging engine 100 includes a processor configured to time illumination pulses of the near-field illumination source 106A and / or the far-field illumination source 106B, and / or control the exposure of the near-field image sensor 102A and / or the far-field image sensor 102B. In some such contexts, the processor is embodied as any one of numerous specific implementations of processing circuitry, such as an FPGA, an ASIC, a microprocessor, a CPU, etc. In at least some embodiments, the processor may communicate with one or more memory devices having computer-coded instructions that, when executed by the processor, implement such functions. In some embodiments, it should be understood that the processor may include one or more sub-processors, remote processors (e.g., a "cloud" processor), etc., and / or may communicate with one or more additional processors for performing such functions. For example, in at least one embodiment, the processor may communicate with and / or operate in conjunction with another processor within the imaging device (e.g., relative to Figure 2 the processor 202 shown and described).

[0086] Figure 2 An exemplary multi-sensor imaging device in accordance with an exemplary embodiment of the present disclosure is shown. Specifically, Figure 2 an exemplary multi-sensor imaging device 200 is shown. As shown, the multi-sensor imaging device 200 includes a device base 210 for housing various components of the device. In this regard, it should be understood that the device base may be embodied as any one of numerous base designs, using any one of numerous materials, etc., to be adapted to position the various components of the multi-sensor imaging device 200 for operation. In at least one exemplary context, the device base 210 may be embodied as a handheld device base, a wearable base, etc.

[0087] The multi-sensor imaging device 200 includes the multi-sensor imaging engine 100 as described above with respect to Figure 1B the description. The multi-sensor imaging device 200 further includes a processor 202. The processor 202 (and / or any other co-processor and / or auxiliary processor 202 and / or processing circuitry otherwise associated with the processor 202) may provide processing functionality to the multi-sensor imaging device 200. In this regard, the processor 202 may be embodied in any one of numerous ways as discussed with respect to Figure 1A the controller 20.

[0088] In some exemplary embodiments, the processor 202 is configured to provide functionality for operating one or more components of the multi-sensor imaging device 200. For example, the processor 202 may be configured to activate the far-field illumination source 106B, the near-field illumination source 106A, and / or the sight illumination source 110. Additionally or alternatively, in some embodiments, the processor 202 is configured to activate the near-field image sensor 102A and / or the far-field image sensor 102B to expose the corresponding image sensors, and / or to read out the captured data to generate an image based on the captured data during the exposure. Additionally or alternatively, in some embodiments, the processor 202 is configured to process the captured image, for example, based on one or more image processing tasks. In one such exemplary context, the processor 202 is configured to perform an attempt to detect and decode visual markers (such as 1D and / or 2D barcodes) from the captured image. In this regard, the processor 202 may be configured to utilize a visual marker parsing algorithm and / or a visual marker decoding algorithm to provide such functionality.

[0089] Additionally or alternatively, optionally in some embodiments, the multi-sensor imaging device 200 further includes an activation component 206. The activation component 206 may be embodied in numerous ways as discussed regarding the activation component 60 of Figure 1A the activation component 60.

[0090] Additionally or alternatively, optionally in some embodiments, the imaging device 200 further includes a display 208. The display 208 may be embodied as an LCD, an LED, and / or other screen devices configured for data provided by one or more components of the device 200. For example, in some embodiments, the display 208 is configured to render a user interface that includes text, images, control elements, and / or other data provided by the processor 202 for rendering. In some embodiments, for example, the display 208 is embodied as an LCD and / or LED monitor integrated with the surface of the device base 210 and visible to the operator, for example, to provide information decoded from a barcode and / or information associated with such information decoded from a barcode. In one or more embodiments, the display 208 may be configured to receive user engagement, and / or may transmit one or more corresponding signals to the processor 202 based on user engagement to trigger a function. In some such embodiments, the display 208 provides user interface functionality embodying the activation component 206, for example, to enable an operator to initiate and / or terminate a scanning function via interaction with the user interface.

[0091] Additionally or alternatively, optionally in some embodiments, the dual imaging device 200 further includes a memory 204. The memory 204 can provide storage functionality, such as to store data processed by the multi-sensor imaging device 200 and / or instructions for providing the functionality described herein. In some embodiments, the processor 202 can communicate with the memory 204 via a bus to transfer information between components of the device and / or retrieve instructions for execution. The memory 204 can be embodied in numerous ways discussed with reference to Figure 1A the controller 20 of. The memory 204 can be configured to store information, data, content, applications, instructions, etc. for enabling the imaging device 200 to perform various functions according to some exemplary embodiments. In some embodiments, the memory 204 includes computer-coded instructions for execution by the processor 202, such as to perform the functions described herein and / or in combination with hard-coded functions executed via the processor 202. For example, when the processor 202 is embodied as an executor of software instructions, these instructions can specifically configure the processor 202 to perform the algorithms and / or operations described herein when executing these instructions. Non-limiting exemplary embodiments of the multi-sensor imaging engine 100 and the multi-sensor imaging device 200 are described in U.S. Patent Application 16 / 684,124, titled "INTEGRATED ILLUMINATION-AIMER IMAGING APPARATUSES," filed on November 14, 2019, the entire content of which is incorporated herein by reference. It should be understood that one or more of such components can be configured to provide illumination synchronization as described herein.

[0092] In some exemplary embodiments of the present disclosure, the processor 202 and the memory 204 can be embodied together as an imaging control device or an illumination control device, and thus can be fixedly or removably coupled to the imaging device 200, or can be partially or fully located outside the imaging device 200. In some embodiments, the imaging control device can be embodied as an integrated circuit operatively coupled to the imaging device 200.

[0093] Figure 3 Visualization of the field of view that can be captured by an exemplary multi-sensor image device is shown. For example, as Figure 3 shown, a near field of view 302 and a far field of view 304 that can be captured by the multi-sensor imaging device 200 are shown. As shown, the near field of view 302 is wider than the far field of view, such that more of the environment can be captured within the near field of view 302 than within the far field of view 304.

[0094] In addition, as shown, the far field of view 304 extends further than the near field of view 302. In this regard, the narrow nature of the far field of view 304, compared to the near field of view 302, may enable a more detailed representation of a particular portion of the environment to be captured. In some embodiments, the corresponding near-field image sensor and the corresponding far-field image sensor of the multi-sensor imaging device 200 may capture the near field of view 302 and the far field of view 304. The near field of view 302 may be associated with a near focal range at a particular distance from the corresponding image sensor in the multi-sensor imaging device 200. Additionally or alternatively, the far field of view 304 may be associated with a far focal range at another distance from the corresponding image sensor in the multi-sensor imaging device 200. In this regard, the near-field focus range may be closer to the far-field focus range such that objects that are further away from the multi-sensor imaging device 200 have better focus when captured via the far-field image sensor compared to the near-field image sensor, thereby allowing for an extended range.

[0095] The multi-sensor imaging device 200 may be configured to provide illumination specifically for illuminating each of the fields of view 302 and 304. In this regard, the illumination source may be specifically designed to match the field of view of the corresponding image sensor such that the illumination properly illuminates the corresponding field of view without overspill or underillumination. Using another illumination source to generate illumination during illumination and performing capture during a non-corresponding image sensor may result in overspill (e.g., when using the far-field image sensor for capture during a near-field illumination pulse) and / or underillumination (e.g., when using the near-field image sensor for capture during a far-field illumination pulse), which may affect the quality of the data in the captured image due to, for example, overillumination and / or underillumination, as described. For example, Figure 4 Visualization of near-field illumination produced by a multi-sensor imaging device (e.g., multi-sensor imaging device 200) according to an exemplary embodiment of the present disclosure is shown. In this regard, near-field illumination 402 may be generated to substantially or fully illuminate the near field of view 302. The near-field illumination 402 may be generated according to an illumination pattern that sufficiently illuminates the entire near field of view 302 for capture.

[0096] Figure 5A visualization of far-field illumination generated by an exemplary multi-sensor imaging device (e.g., multi-sensor imaging device 200) according to an exemplary embodiment of the present disclosure is shown. In this regard, far-field illumination 404 may be generated so as to substantially or completely illuminate the far field of view 304. Far-field illumination 504 may be generated according to an illumination pattern that sufficiently illuminates the entire far field of view 304 for capture by a corresponding far-field image sensor. Far-field illumination 504 may illuminate only a certain percentage of the near field of view 302, such as a central percentage of the near field of view 302 (e.g., 25%, 50%, etc.). In this regard, activating far-field illumination may be problematic for capturing sufficient images of certain visual markers, such as those extending beyond the boundaries of the far field of view 304 at a particular distance. Therefore, it is desirable to utilize an appropriate illuminator for each image sensor while minimizing flicker and minimizing operating time to increase the likelihood and efficiency of successful visual marker detection and decoding.

[0097] Figure 6 A timing diagram 600 associated with the operational functionality of an exemplary multi-sensor imaging system is shown in accordance with an exemplary embodiment. The timing diagram 600 illustrates the activation and deactivation timing of various components of the multi-sensor imaging device 200 (e.g., but not limited to, near-field illumination source, near-field image sensor, far-field illumination source, far-field image sensor, focus mechanism). Figure 6 The pulses in the timing diagram 600 of the imaging system 10 / imaging device 200 are used to illustrate several separate processes associated with the imaging system 10 / imaging device 200. The vertical extension of the pulses in the timing diagram does not necessarily specify the amplitude of the pulse. According to some exemplary embodiments, each pulse in the timing diagram 600 may be defined by the length of the active time of the associated component / process, followed by the length of the inactive time of the associated component / process. Each pulse may have a corresponding period, which may be defined as the duration during which the amplitude of the pulse remains non-zero. The period of the pulse may start at the start time instance (pulse start time) and end at the end time instance (pulse end time). As used herein, the start time period of the period of the term pulse may refer to a time period of a threshold duration starting from the pulse start time, wherein the threshold duration may have a configurable value. In one example, the threshold duration may be zero, and therefore, the start time period of the period and the pulse start time may refer to the same time instance. Similarly, the end time period of the period of the term pulse may refer to a time period of a threshold duration ending at the pulse end time, wherein the threshold duration may have a configurable value. In at least one exemplary context, the threshold duration may be zero, and thus, the end time of the cycle and the pulse end time may refer to the same time instance. In some exemplary embodiments, the corresponding threshold duration may be configured according to one or more performance parameters of the controller 20 and / or the imaging engine 100.

[0098] As shown in timing diagram 600, some pulses associated with a particular operation of a particular component of imaging system 10 / imaging device 200 may be temporally aligned with, partially or fully overlap, or may not overlap with one or more other pulses associated with one or more operations of another component of imaging system 10 / imaging device 200. For example, the start point of near-field illumination pulse 602A is temporally aligned with the start point of pulse 604 (also referred to as near-field exposure pulse 604) associated with the exposure of the near-field image sensor. As another example, near-field illumination pulse 602A may not overlap with pulse 606 (also referred to as near-field readout pulse 606) associated with the readout of the near-field image sensor. As yet another example, pulse 614A (also referred to as far-field exposure pulse 614A) associated with the exposure of the far-field image sensor overlaps with near-field readout pulse 606.

[0099] The imaging system / imaging device may utilize executable instructions corresponding to the operations shown in timing diagram 600 to perform a smooth execution of one or more imaging or image processing tasks. For example, each image sensor activation may include two steps to capture a corresponding image: exposing the image sensor and reading out from the image sensor. In this regard, it should be understood that processor 202 may be configured, for example, to enable the activation of various components based on the timing diagram. According to some exemplary embodiments, the image sensors (102A, 102B) may be operated in such a way that the exposure period of the far-field image sensor 102B is adjusted or adapted to the illumination pulse train of the near-field illumination source 106A. Such modification of the illumination pulse train of the near-field illumination source 106A to accommodate the exposure period of the far-field image sensor 102B may be accomplished in various ways, some examples of which will be discussed with reference to Figures 8 to 10 be discussed.

[0100] As shown, timing diagram 600 includes a near-field illumination pulse train 602 used by near-field illumination source 106A to generate near-field illumination. Near-field illumination pulse train 602 includes a plurality of illumination pulses, such as illumination pulses 602A, 602B, 602C, 602D, and 602E. It should be noted that in an unmodified form, the near-field illumination pulses may include only illumination pulses similar to illumination pulse 602A generated at a certain fixed frequency. Controller 20 or processor 202 may add illumination pulses similar to additional illumination pulses 602B through 602E to adapt exposure pulses 614 of far-field image sensor 102B to near-field illumination pulse train 602, thereby alleviating illumination issues associated with multi-sensor imaging device 200 / system 10. In this regard, each near-field illumination pulse may be defined by a length of active time (e.g., near-field illumination source 106A on-time), followed by a length of non-active time (e.g., near-field illumination source 106A off-time). In an exemplary context, multi-sensor imaging device 200 may be configured to periodically generate near-field illumination pulse 602A with a 1.5 millisecond ("ms") on-time, followed by a 14.5 ms off-time. In this regard, each illumination pulse 602A may begin, last for 1.5 ms, then end, and then another illumination pulse 602A may begin after 14.5 ms has elapsed. For the sake of avoiding occlusion, only one illumination pulse 602A is shown in near-field illumination pulse train 602. However, it is anticipated that in an unmodified form, near-field illumination pulse train 602, in accordance with the exemplary embodiments described herein, includes a plurality of such illumination pulses 602A. Near-field illumination source 106A may generate additional illumination pulses 602B through 602E in a similar manner as described above with the same or different on-times and off-times. Each of illumination pulses 602A through 602E may extend a duration called an illumination period in the time domain. In the above exemplary embodiment, for example, each illumination pulse 602A may have an illumination period equal to 1.5 milliseconds. The illumination period of an illumination pulse may begin at a first time instance and end at a second time instance. Thus, the first time instance may correspond to the illumination pulse start time of the illumination pulse, and the second time instance may correspond to the illumination pulse end time of the illumination pulse.

[0101] In some exemplary embodiments, when generating near-field illumination, both the near-field image sensor 102A and the far-field image sensor 102B can be activated. As shown, the exposure pulse 604 of the near-field image sensor can be fully or substantially aligned with the near-field illumination pulse 602A of the near-field illumination pulse train 602. That is, the exposure of the near-field image sensor during the exposure pulse 604 can start simultaneously with the start time period of the near-field illumination pulse 602A of the near-field illumination pulse train 602. In some exemplary embodiments, the end time period of the near-field exposure pulse 604 can extend beyond the end time period of the near-field illumination pulse 602A of the near-field illumination pulse train 602. For example, as shown, the near-field image sensor exposure starts at the rising edge of the exposure pulse 604, which is aligned with the rising edge of the first near-field illumination pulse 602A. The exposure of the near-field image sensor 102A ends at a time instance beyond the falling edge of the first near-field illumination pulse 602A. In this regard, the near-field image sensor 102A is exposed during the entire (or nearly the entire) first near-field illumination pulse 602A, thereby maximizing the likelihood of capturing sufficient data to successfully complete an image processing task such as barcode scanning.

[0102] It should be understood that in some embodiments, when it is desired to expose an image sensor during an illumination pulse, the illumination pulse can occur at any point during the exposure of the image sensor. For example, in the case where the near-field image sensor 102A is to be exposed during a near-field illumination pulse, the exposure can start before the illumination pulse, or the illumination pulse can occur at a later time during the exposure. As one such example, in the context where the near-field image sensor 102A is associated with an exposure time value of 4.5 ms and each near-field illumination pulse lasts 1.5 ms, the exposure of the near-field image sensor 102A can start at any time between the start of the illumination pulse and 3 ms before the start time of the illumination pulse, such that the entire illumination pulse occurs during the exposure. It should be understood that for any combination of differently configured image sensors and / or illumination sources, the specific timing can be different.

[0103] As shown, the near-field image sensor 102A is subsequently read out in pulse 606 to generate and / or process a corresponding image (e.g., the first near-field image) in pulse 608. In parallel with the start point of the readout from the near-field image sensor 102A in pulse 606, the exposure of the far-field sensor 102B can start in pulse 614. Then, as the exposure of the far-field sensor 102B ends in the far-field exposure pulse 614, the readout from the far-field sensor can start in pulse 616 to generate and / or process a corresponding image (e.g., the first far-field image) in pulse 618.

[0104] It should be noted that, in some exemplary embodiments, the start time period of the exposure cycle of the far - field exposure pulse 614 may be exactly or substantially aligned with the start time period of the readout cycle of the pulse 606. Additionally, the end time period of the exposure cycle of the far - field exposure pulse 614 may be exactly or substantially aligned with the start time period of the readout cycle of the pulse 616.

[0105] The timing of the illumination pulse, corresponding exposure, readout, and / or processing can be determined in any of numerous ways. For example, in at least one exemplary embodiment, the timing for activating the illumination pulse and / or the image sensor exposure can be pre - determined and / or hard - coded for execution by one or more associated processors. Additionally or alternatively, in some embodiments, the timing offset until the next illumination pulse can be determined based on the pulse frequency of the generated illumination and / or the start time of the illumination pulse (e.g., the time when the first illumination pulse is generated). The exposure of one or more image sensors can be appropriately timed based on the known and / or determinable current time, illumination pulse frequency, determined offset, and / or the exposure time value of the image sensor to be exposed. For example, based on such data, the exposure of the image sensor can be triggered such that the image sensor remains exposed for the entire illumination pulse in some cases and / or remains exposed for all or part of the time between illumination pulses in other cases.

[0106] Each illumination source is used to illuminate a desired field of view for capture by a corresponding image sensor, thereby increasing the likelihood of successfully completing an image - processing task such as barcode scanning.

[0107] Figure 7 A flowchart according to an exemplary embodiment of the present disclosure is shown, which depicts exemplary operations of a process 700 for illumination control in a multi - imager environment. It will be described in conjunction with Figure 6 the timing diagram 600 shown Figure 7 . The process 700 can be implemented by the imaging system 10 or the imaging device 200 described with reference to Figure 1A and Figure 2 . The process 700 includes, at 702, operating a first illumination source by a controller 20 / processor 202 based on a first illumination pulse train. The first illumination source can correspond to a light source associated with a near - field sensor. For example, the first illumination source can be the near - field illumination source 106A described with reference to Figures 1B to 2 . The first illumination source can illuminate the near - field of the near - field image sensor according to the first illumination pulse train. The first illumination pulse train can correspond to Figure 6The near-field illumination pulse train 602 as shown in the timing diagram. In some exemplary embodiments, the first illumination pulse train may have a constant pulse frequency of about 60 to 90 Hz to generate short, bright illumination pulses. In some sensitive applications, the pulse frequency may be set to a constant value exceeding 90 Hz.

[0108] Process 700 further includes, at 704, determining, by controller 20 / processor 202, a first exposure period of the second image sensor. In some exemplary embodiments, the second image sensor may be the far-field image sensor 102B, and thus, the first exposure period may correspond to the exposure period of the far-field sensor 102B. Illumination and exposure of the second image sensor may be controlled or caused by a control or processing medium such as controller 20 or processor 202. Thus, the first exposure period of the second image sensor may be pre-determined and / or hard-coded for execution by one or more associated processors. In some exemplary embodiments, the exposure period may be dynamically calculated based on one or more imaging parameters associated with the second image sensor.

[0109] Process 700 further includes, at 706, modifying, by controller 20 / processor 202, one or more characteristics of the first illumination pulse train to accommodate the first exposure period of the second image sensor. By modifying the one or more characteristics such as the pulse frequency of the first illumination pulse train, process 700 provides an effective measure for suppressing "illumination spillover" from the far-field image sensor into the near-field image sensor (and vice versa). Modifying the one or more characteristics of the first illumination pulse train may be performed with the aim of reducing illumination interference between the image sensors of the imaging system. Thus, the one or more characteristics of the first illumination pulse train may be modified in numerous ways. In some exemplary embodiments, one or more additional illumination pulses may be added or inserted into the first illumination pulse train to avoid illumination interference with the exposure of the second image sensor, the details of which are described respectively with reference to Figure 8 and Figure 9 Processes 706A and 706B provided. Additionally or alternatively, in some exemplary embodiments, the timing delay between a pair of temporally successive illumination pulses of the first illumination pulse train may be increased to avoid illumination interference with the exposure of the second image sensor, the details of which are described with reference to Figure 10 Process 706C provided.

[0110] Process 700 at 708 includes operating a first illumination source associated with a first image sensor by the controller 20 / processor 202 based on a modified first illumination pulse train. Accordingly, the controller 20 / processor 202 controls subsequent activations of the near-field illumination source based on the modified near-field illumination pulse train. The exposure of the near-field image sensor is correspondingly aligned with the illumination pulses of the modified near-field illumination pulse train for image capture by the near-field image sensor. Since the modified near-field illumination pulse train is generated taking into account the exposure period of the far-field image sensor, the possibility of illumination spillover between the two sensors is reduced or in some cases eliminated. Accordingly, process 700 provides an effective measure for operating a multi-sensor imaging system / device. Thus, a device that performs or utilizes process 700 results in improvements in imaging and / or subsequent image processing tasks.

[0111] Figure 8 A flowchart is shown in accordance with at least one exemplary embodiment of the present disclosure, which depicts exemplary operations of process 706A for modifying one or more characteristics of a first illumination pulse train to accommodate a first exposure period of a second image sensor of an exemplary multi-sensor imaging system. In some exemplary embodiments, process 706A may be triggered in scenarios where illumination synchronization and flicker control or elimination are desired.

[0112] Process 706A includes, at 802, determining, by the controller 20 / processor 202, a start time period and an end time period of a first exposure period of a second image sensor. As previously described, the second image sensor may be the far-field image sensor 102B. Accordingly, the controller 20 / processor 202 may determine the bounds of the exposure period of the far-field image sensor. Additionally, as discussed in step 704 with reference to Figure 7 the first exposure period of the second image sensor may be pre-determined and / or hard-coded for execution by one or more associated processors. In some exemplary embodiments, the exposure period may be dynamically calculated based on one or more imaging parameters associated with the second image sensor. The controller 20 / processor 202 may obtain data related to the exposure period of the far-field image sensor from any of the sources mentioned above and determine the start time period and the end time period of the exposure period.

[0113] At step 804, process 706A includes generating, by controller 20 / processor 202, at least one additional illumination pulse of a first illumination pulse train of a first image sensor. The at least one additional illumination pulse can be generated to be inserted into the first illumination pulse train. Accordingly, process 706A also includes, at 806, inserting, by controller 20 / processor 202, the at least one additional illumination pulse into the first illumination pulse train such that a start time period and / or an end time period of an illumination period of the at least one additional illumination pulse is aligned with a start time period and / or an end time period of a first exposure period of a second image sensor. That is, the at least one additional illumination pulse can be added or inserted into one or more “discretionary regions” of pulses corresponding to the exposure period of the second image sensor. A “discretionary region” can correspond to such portions of an exposure period in which an object or a portion thereof is not captured. As discussed, the second image sensor can be a far-field image sensor, and in a typical scenario, an initial window and a terminal window associated with a pulse corresponding to the exposure period of the far-field image sensor may not be associated with the capture of an object because an object is typically captured within a center window of the exposure period of the far-field image sensor. Thus, in the example shown herein, the initial window and the terminal window of the exposure period can correspond to discretionary regions. However, it is contemplated that additionally or alternatively, any other portion of the exposure period can also be defined as a discretionary region within the scope of the present disclosure.

[0114] As Figure 6 shown, one or more additional illumination pulses 602B and 602E (shown in dashed lines) are generated and inserted into the near-field illumination pulse train 602 such that a start time period of an illumination period of illumination pulse 602B is aligned with a start time period of an exposure pulse 614A of the far-field image sensor, and a start time period of an illumination period of illumination pulse 602E is aligned with a start time period of an exposure pulse 614B of the far-field image sensor.

[0115] Figure 9 FIG. 706B is a flow chart showing another process for modifying one or more characteristics of a first illumination pulse train to accommodate a first exposure period of a second image sensor of an exemplary multi-sensor imaging system, in accordance with at least one exemplary embodiment of the present disclosure. In some exemplary embodiments, process 706B can be triggered in scenarios where illumination synchronization and flicker elimination are desired.

[0116] Process 706B includes, at 902, determining, by controller 20 / processor 202, an autofocus cycle of the second image sensor. During operation of the second image sensor for imaging in the far field, the image sensor is required to move to one of a number of focus positions. A shift from an initial position of the image sensor (and / or associated optics) to one of the focus positions occurs during the autofocus cycle. The autofocus cycle may be predefined and stored in the memory of the imaging engine, or may be dynamically calculated based on one or more imaging parameters. In either case, controller 20 / processor 202 may obtain or otherwise calculate the autofocus cycle.

[0117] At step 904, process 706B includes generating, by controller 20 / processor 202, at least one additional illumination pulse of a first illumination pulse train of the first image sensor. The at least one additional illumination pulse may be generated to be inserted into the first illumination pulse train. Accordingly, process 706B also includes, at 906, inserting, by controller 20 / processor 202, the at least one additional illumination pulse into the first illumination pulse train such that illumination of the first image sensor corresponding to the at least one additional illumination pulse overlaps in time with the autofocus cycle of the second image sensor. That is, the at least one additional illumination pulse may be added or inserted into a position in the first illumination pulse train that is aligned with the period of motor movement of the second image sensor.

[0118] As Figure 6 shown, the one or more additional illumination pulses 602D (shown in thick dashed lines) are generated and inserted into the near-field illumination pulse train 602 such that the illumination period of illumination pulse 602D overlaps with the autofocus motor movement pulse 610.

[0119] Figure 10 A flowchart is shown in accordance with at least one exemplary embodiment of the present disclosure that depicts exemplary operations of another process 706C for modifying one or more characteristics of a first illumination pulse train to accommodate a first exposure period of a second image sensor of an exemplary multi-sensor imaging system. Process 706C includes, at 1002, determining, by controller 20 / processor 202, a start time period and an end time period of a first exposure period of the second image sensor. As previously described, the second image sensor may be the far-field image sensor 102B. Accordingly, controller 20 / processor 202 may determine the bounds (start time period and end time period) of the exposure period of the far-field image sensor. Additionally, as referenced Figure 7As discussed in step 704, the first exposure period of the second image sensor can be predetermined and / or hard-coded for execution by one or more associated processors. In some exemplary embodiments, the exposure period can be dynamically calculated based on one or more imaging parameters associated with the second image sensor. The controller 20 / processor 202 can obtain data related to the exposure period of the far-field image sensor from any of the sources mentioned above and determine the start time period and end time period of the exposure period.

[0120] Process 706C further includes, at 1004, determining, by the controller 20 / processor 202, a pair of temporally subsequent illumination pulses of the first illumination pulse train near the time closest to the first exposure period of the second image sensor. The controller 20 / processor 202 can determine the start time instance and end time instance of the exposure period of the far-field image sensor. The controller 20 / processor 202 can map the determined start time instance and end time instance of the exposure period to the near-field illumination pulse train to determine a pair of temporally subsequent illumination pulses in the near-field illumination pulse train that are closest to the determined start time instance and end time instance of the exposure period on the time axis, respectively.

[0121] Process 706C further includes, at 1006, increasing, by the controller 20 / processor 202, the timing delay between a pair of eligible temporally subsequent illumination pulses of the first illumination pulse train such that one of the start time period or end time period of the first exposure period is aligned with the corresponding one of the start time period or end time period of the increased timing delay. As Figure 11 shown in the exemplary timing diagram 1100 of, illumination pulse pairs 1104, 1106 and illumination pulse pairs 1108, 1110 of the near-field illumination pulse train can be selected as a pair of eligible temporally subsequent illumination pulses that are closest to the start time instance and end time instance of the exposure period 1112. Thus, the controller 20 / processor 202 can increase the timing delay between the illumination pulses (1102 to 1110) such that the start time period and / or end time period of the exposure period 1112 is aligned with the corresponding one of the falling edge of illumination pulse 1104 and the rising edge of illumination pulse 1106, respectively. The deviation of the falling edge of illumination pulse 1104 from the start time period of the exposure period 1112 can be within a threshold delay, and the deviation of the rising edge of illumination pulse 1106 from the end time period of the exposure period 1112 can be within another threshold delay. Similar modifications can be made to other pulses of the exposure period to align with a corresponding pair of illumination pulses. The duration between the rising edge of illumination pulse 1104 and the falling edge of illumination pulse 1106 defines the increased timing delay. Thus, as Figure 11As shown by the modified near-field illumination pulse train, the start time period and the end time period of the exposure period 1112 of the far-field image sensor are aligned with the corresponding one of the start time period or the end time period of the increased timing delay.

[0122] Figure 12A and Figure 12B illustrates an exemplary workflow of a symbol decoding process performed by an exemplary multi-sensor imaging system according to at least one exemplary embodiment of the present disclosure. In some exemplary embodiments, the imaging system 10 and / or the imaging device 200 may include an exemplary symbol reading device (such as a mark reader) or be part of such an exemplary symbol reading device. As Figure 12A 、 Figure 12B and Figure 12C shown, the processes 1200A, 1200B, and 1200C provide a symbol decoding method that includes various aspects of the method 700. When implementing the processes 1200A, 1200B, and 1200C, a symbol reader having multiple image sensors can mitigate problems caused by illumination spillover and flicker, and thus can provide error-free or error-reduced symbol image capture. This results in faster and more efficient decoding of symbols. Through the following disclosure of the workflow, additional advantages of the workflow will become apparent.

[0123] Some or all of the steps of the processes 1200A, 1200B, and 1200C may be performed by appropriate data processing means and control means. For example, in some exemplary embodiments, the processes 1200A, 1200B, and 1200C may be executed by a controller or one or more processors of the symbol reader. In some exemplary embodiments, the controller of the symbol reader may be embodied in a manner similar to that described for the controller 20 of the reference imaging system 10.

[0124] Process 1200A is triggered upon receipt of an input from a user to the activation component 206 of the imaging device 200. In response, process 1200A begins at 1202 by turning on the sight as an indicator. As described with reference to Figure 2 , the sight illumination source 110 and the sight projection optics 112 may together produce a sight as a desired pattern. Next, at 1204, process 1200A includes turning on the near-field illumination. The near-field illumination can be generated in a variety of ways, such as as previously discussed in this disclosure. In some exemplary embodiments, the near-field illumination is generated according to a near-field illumination pulse train having a fixed pulse frequency. Individual near-field illumination pulses may have a short duration, such as 1.5 ms.

[0125] The exposure of the near-field image sensor begins substantially simultaneously with the activation of the near-field illumination source at 1206. In some exemplary embodiments, the near-field image sensor may include a global shutter and may have a large field of view. In some exemplary embodiments, the near-field image sensor may include a rolling shutter. Subsequently, at 1208, process 1200A may include transmitting data from the near-field image sensor to capture a first near-field image. That is, charge may be read out to construct the image frame captured by the near-field image sensor.

[0126] In parallel with step 1208, at 1210, process 1200A includes beginning the exposure of a far-field image sensor in the far field. In some exemplary embodiments, the far-field image sensor may include a rolling shutter and may have a field of view that is narrower compared to the near-field image sensor. After the exposure period of the far-field image sensor has elapsed, data transmission from the far-field image sensor may be started at 1212 to capture a first far-field image.

[0127] At 1214, when capturing the first near-field image, process 1200A includes processing the first near-field image and beginning a first decoding run. The first near-field image is processed to obtain a distance estimate of the target symbol in the image. For this purpose, any suitable image processing-based distance estimation technique may be utilized (such as but not limited to using a disparity-based technique or the difference in sharpness of images from the near-field image sensor and the far-field image sensor). For example, as a binary test, it may be determined based on the decoding result of the first decoding run whether the target symbol has been successfully captured in the first near-field image. The result of the distance estimation may be used to decide whether the first far-field image will be used instead of the first near-field image to decode the symbol. In an exemplary scenario where the target symbol is outside the maximum imaging range of the near-field image sensor, the captured first near-field image frame may not indicate the target symbol with an acceptable clarity, brightness, contrast level, etc. Thus, near-field imaging may not be an appropriate way to decode the symbol. In such cases, the far-field image sensor may be relied upon to attempt a successful decoding.

[0128] Process 1200A at 1216 includes determining whether the symbol has been successfully decoded in a first decoding run. If the symbol is successfully decoded from the first near-field image, processing of the first far-field image may not be required and control of the steps transfers to step 1246 of FIG. 1200C, where the decoded symbol may be output by the symbol decoder. However, if the symbol decoder does not successfully decode the symbol at 1214, process 1200A includes, at 1218, moving the imaging engine and thus the far-field image sensor to a corresponding focus position. The movement to the corresponding focus position includes determining a specific focus position from a set of foci based on the distance estimated in step 1214. The focus position of the image sensor may be discretely defined as discrete steps to be traversed by the focus motor of the imaging engine. After the movement of the imaging engine at 1218, control of the steps transfers to Figure 12B the two parallel processes shown in process 1200B of

[0129] Process 1200B includes a first process and a second process. The first process includes steps 1220 to 1232 intended to process and image using the far-field image sensor, and the second process includes steps 1234 to 1242 intended to image using the near-field image sensor. In some exemplary embodiments, the second process including steps 1234 to 1242 may be skipped in one or more iterations of processes 1200A, 1200B, and 1200C.

[0130] Process 1200B includes, at 1220, processing a far field image (in this case, a first far field image) and starting a second decoding run. The first far field image may be processed to decode the target symbol and other parameters of the image may be obtained by the processing. The other parameters may be, for example, the brightness of the first far field image. Using these parameters, one or more sensor parameters of the far field image sensor to be adjusted may be determined. Subsequently, at 1222, it is determined whether the symbol is successfully decoded in the second decoding run. If the result of the check at 1222 is positive (yes), then control of the step is transferred to step 1246 of Figure 1200C, where the decoded symbol may be output by the symbol decoder. However, if the symbol decoder does not successfully decode the symbol at 1222, then control of the step is transferred to 1224, where it is determined whether illumination in the far field is required. Such a determination may be made, for example, on the first far field image by any suitable image processing technique. If it is determined that far field illumination is required, then the far field illumination source may be turned on at 1226 and control may be transferred to step 1228. However, if far field illumination is not required, control may pass directly to step 1228. At 1228, exposure of the far field sensor begins with or without illumination in the far field, as the case may be. Subsequently, data transmission from the far field image sensor may be completed at 1230 to obtain a second far field image. The second far field image may be processed at 1232 and a third decoding run attempted. Next, control passes to Figure 12C Step 1244 of process 1200C is shown.

[0131] In a parallel second flow of process 1200B, when it is determined that the symbol decoder cannot successfully decode the symbol, the near-field illumination pulse is modified at 1234 to accommodate one or more exposure cycles of the far-field image sensor. Figures 8 to 10 The modification of the near-field illumination pulses may be accomplished by modifying the near-field illumination pulse train in the numerous ways discussed. Subsequently, at 1236, near-field illumination may be initiated in accordance with the modified near-field illumination pulses, and at 1238, the near-field image sensor may be exposed in the near field. The illumination and exposure of the near-field image sensor after the illumination pulse modification may be accomplished in a manner similar to that described at steps 1204 and 1206, respectively. At 1240, process 1200B includes initiating data transmission of the near-field image sensor to capture a second near-field image. At 1242, the second near-field image may be processed, and the symbol decoder may attempt a fourth decoding run. Next, control passes to Figure 12C Step 1244 of process 1200C is shown.

[0132] At 1244, it is determined whether the symbol is decoded in any one of the third decoding run 1232 or the fourth decoding run 1242. If the symbol decoder can successfully decode the target symbol from any one of the second far-field image or the second near-field image, the control of the step goes to 1246, where the decoded symbol is output by the symbol decoder. However, if it is determined at 1244 that the symbol decoder has not successfully decoded the symbol, the control goes to 1248, where it is determined whether there are any focused positions that have not yet been accessed. That is, process 1200C includes determining whether, among the focused positions of the far-field image sensor, there are any focused positions from which imaging in the far field has not been performed in any iteration. If there are still no such focused positions from which imaging in the far field has not been performed (i.e., all focused positions have been accessed), it is inferred that the target symbol is outside the imaging range of the symbol decoder or there is no target symbol in the imaged field of view. Therefore, at 1250, an error message indicating that the target symbol cannot be decoded by the symbol decoder can be output. However, if it is determined at 1248 that there is still one or more focused positions that have not been accessed, the control goes to 1252, where the imaging engine moves to the corresponding unaccessed position in the far field. The movement of the imaging engine can be performed in a manner similar to that described in step 1218 of reference Figure 12B . The movement to the focused position can be scheduled in ascending order (i.e., among the discrete focused positions of the far-field image sensor, moving from a closer focused position to a farther focused position). Subsequently, the control returns to the two parallel processes at steps 1220 and 1234 in process 1200B.

[0133] In this way, Figures 12A to 12C the exemplary workflow shown can be used to perform symbol decoding by a symbol decoder, whereby due to the improved illumination control provided by the modification of the near-field illumination pulses (pulse trains), the likelihood of successfully decoding the target symbol from the near-field image and the far-field image is significantly increased. Such improvements in the decoding process result in an improvement in the overall functionality of the symbol decoder device itself.

[0134] Although described in the context of a terminal application as symbol decoding Figures 12A to 12CThe exemplary workflow shown, but it is expected that within the scope of the present disclosure, other terminal application tasks utilizing dual or multiple image sensors (and thus multiple illumination sources) can also be modified to benefit from the improved illumination control and synchronization framework provided herein. That is, the scope of the present disclosure should never be limited to a single symbol decoder, and suitable modifications can be made to extend the illumination control framework to similar terminal use cases, such as mobile phones based on multiple cameras. In some exemplary contexts, a multi-image sensor device can be embodied as a smartphone with at least two cameras. The camera can have the same or separate illumination sources associated with each of them. At least one camera in a smartphone can be considered a main camera, which is associated with image capture in bright, well-lit and poorly lit situations. The image quality of such a camera can be directly associated with megapixel (MP) intensity, and so in some exemplary embodiments, the main camera can have 12, 24, 48 or 64MP. One or more other cameras in a smartphone can be considered as auxiliary cameras associated with one or more image enhancement functions. For example, a smartphone can have a telephoto lens that supports a super zoom option. In some exemplary embodiments, the telephoto lens can support a zoom factor between 2x and 10x. In some more advanced embodiments, the smartphone may have an ultra-wide angle lens for enhancing the field of view of the smartphone. Additionally or optionally, in some exemplary embodiments, the smartphone may include a depth sensor to measure the depth of background objects compared to the main object in the field of view. One or more cameras of the smartphone may have different lighting requirements to support the general imaging capabilities of the smartphone. For example, while the main camera may require an illumination flash for imaging in a low-light scene, the monochrome lens of the smartphone may experience a spike in brightness during imaging in the same pulse. Therefore, the resulting image may be affected in terms of one or more imaging parameters.

[0135] The exemplary embodiments described herein help alleviate the aforementioned problems by providing an effective solution for synchronizing the illumination of multiple cameras in a smartphone. Figures 6 to 12C As shown, the exposure of one or more cameras can be designed or adjusted to overlap with or be outside the exposure of one or more other cameras as required. Since the exemplary embodiment also provides an adaptive process for illumination synchronization, the proposed solution is applicable to various imaging scenarios and situations.

[0136] In some exemplary embodiments, in a multi-imager environment such as a multi-image sensor device, cycling between illumination sources (e.g., near-field illumination sources and far-field illumination sources) during symbol reading / decoding may cause a flickering effect to an operator of the multi-image sensor device. Therefore, the lighting control framework may also include one or more frameworks for reducing flickering.Figure 13 Shows an exemplary workflow of a general flash reduction process 1300 performed by an exemplary multi-sensor imaging system according to at least one exemplary embodiment of the present disclosure.

[0137] At 1302, process 1300 includes operating a first illumination source associated with a near-field sensor based on a first illumination pulse train. The first illumination source may be the near-field illumination source 106A discussed in reference Figure 2 . Thus, the first source illumination source may be operated according to a near-field illumination pulse train such as Figure 6 the near-field illumination pulse train 602 or Figure 11 the near-field illumination pulse train. The first near-field illumination source may be configured to produce pulsed illumination in the near field of the imaging engine. Each individual pulse may have a short duration such as 1.5 ms and may be periodic or non-periodic with respect to other illumination pulses of the pulse train.

[0138] At 1304, process 1300 includes causing an exposure of the near-field sensor during a first exposure period. The start time period of the first exposure period may be substantially or completely aligned with the start time period of the illumination period of the first illumination source. That is, the exposure of the near-field image sensor may start substantially simultaneously with the activation of the first illumination source, as shown in the timing diagram 1100 of Figure 11 . The exposure of the near-field image sensor may continue for a period that ends after the end of the illumination period of the first illumination source (i.e., after the activation period of the first illumination source).

[0139] At 1306, process 1300 includes causing an exposure of the far-field sensor during a second exposure period that does not overlap with any illumination period of the first illumination source. For example, the far-field image sensor of the imaging device 200 / imaging system 10 may be exposed during the second exposure period. The start time period and the end time period of the second exposure period of the far-field image sensor may be scheduled in such a way that they do not overlap with the illumination period of any illumination pulse of the near-field illumination pulse train. That is, the exposure of the far-field image sensor may occur during a time period when the first illumination source is deactivated.

[0140] In this way, modifying the near-field illumination pulse train to accommodate the far-field exposure period ensures that illumination spillover from the far-field illumination does not occur into the exposure of the near-field image sensor and vice versa. Since the far-field image sensor is only exposed during the deactivation period of the near-field illumination source, there is no interference from the near-field illumination source in the exposure of the far-field image sensor. Additionally, this arrangement ensures that these illuminations (near-field illumination and far-field illumination) are generated substantially sequentially (i.e., there is no or very little time gap between the activation of the near-field illumination and the activation of the far-field illumination for consecutive pulses). Thus, the operator is not able to perceive a significant flicker caused by the dimming and brightening of the illumination sources.

[0141] In some exemplary embodiments, the target to be captured may be located at a relatively large distance from the imaging engine. Accordingly, a far-field image sensor may be used to capture the target. Additionally, when the far-field image sensor includes, for example, a rolling shutter, such a scenario may be equivalent to imaging from the farthest focus (shortest focal length) of the far-field image sensor, which requires the longest exposure of the far-field image sensor. In such scenarios, maintaining the far-field illumination source activated for a long duration may pose several problems for the operation of the imaging engine, such as overheating due to the extended activation of the far-field illumination source. Thus, for such scenarios, a framework for reducing the activation time of the far-field illumination source while ensuring that far-field imaging is not affected may be desirable. Figure 14 An exemplary workflow of a flicker reduction process 1400 (specifically, an extended far-field exposure) performed by an exemplary multi-sensor imaging system in accordance with at least one exemplary embodiment of the present disclosure is shown.

[0142] Process 1400 includes, at 1402, operating a first illumination source associated with a near-field sensor based on a first illumination pulse train. Step 1402 may be performed in a manner similar to step 1302.

[0143] Process 1400 includes, at 1402, causing an exposure of the near-field sensor during a first exposure period, the start time period of the first exposure period being aligned with the start time period of the illumination period of the first illumination source. Step 1402 may be performed in a manner similar to step 1304.

[0144] Process 1400 further includes, at 1406, causing an exposure of the far-field sensor during a second exposure period, the second exposure period overlapping at least one illumination period of the first illumination source. For example, the far-field image sensor of the imaging device 200 / imaging system 10 may be exposed during the second exposure period. In some exemplary embodiments, the start time period or the end time period of the second exposure period of the far-field image sensor may be scheduled such that the start time period or the end time period of the second exposure period of the far-field image sensor is exactly or substantially aligned with the start time period or the end time period of the illumination period of the illumination pulse of the near-field illumination pulse train. For example, as Figure 6 shown, the start time period of the far-field exposure pulse 614A is aligned with the illumination pulse 602B of the near-field illumination pulse train 602.

[0145] In an exemplary context where the target to be captured falls within the central region of the field of view of a far-field image sensor, to extend the exposure time of the far-field image sensor, the exposure may be modified so that at most only a small number of top and bottom rows of the far-field image sensor based on a rolling shutter are exposed when the near-field illumination source is activated. This minimizes reflections and light leakage / illumination spillover to the outer top and bottom regions of the far-field image, thereby ensuring that the smallest-sized region falling within the central region of the field of view of the far-field sensor in such a context does not receive illumination from the near-field illumination source, as it would interfere with the automatic gain control operation and general decoding. Thus, the resulting captured image is free from any adverse effects that may be caused by illumination spillover from the near-field illumination source.

[0146] It is expected that within the scope of the present disclosure, if the target to be captured falls within a region other than the central region of the field of view of the far-field image sensor, the smallest-sized region may be configured by the operator / administrator of the imaging engine. That is, the smallest-sized region may be defined based on the position of the target to be captured within the field of view of the far-field image sensor.

[0147] In this way, Figure 14 an exemplary embodiment of the flicker reduction process provides an effective reduction in operator-perceivable flicker by ensuring an overlap between the exposure period of the far-field image sensor and the illumination period of the near-field illumination source.

[0148] It should be understood that the above in Figure 7 , Figure 8 , Figure 9 , Figure 10 , Figure 12A , Figure 12B , Figure 12C , Figure 13 and Figure 14Each block in the flowchart illustration and combinations of blocks in the flowchart illustration can be implemented by various means, such as hardware, firmware, processors, circuitry, and / or other communication devices associated with the execution of software including one or more computer program instructions. For example, one or more of the above processes can be embodied by computer program instructions. In this regard, the computer program instructions embodying the above processes can be stored by a memory device of a device employing an embodiment of the present invention and executed by a processor of an imaging device / system. It should be understood that any such computer program instructions can be loaded onto a computer or other programmable apparatus (e.g., hardware) to produce a machine, such that the resulting computer or other programmable apparatus implements the functions specified in the flowchart block. These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable apparatus to operate in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture, the execution of which implements the functions specified in the flowchart block. The computer program instructions can also be loaded onto a computer or other programmable apparatus to cause a series of operations to be performed on the computer or other programmable apparatus, thereby producing a computer-implemented process, such that the instructions executed on the computer or other programmable apparatus provide operations for implementing the functions specified in the flowchart block.

[0149] Accordingly, the blocks in the flowchart support combinations of means for performing the specified functions and combinations of operations for performing the specified functions / operations. It will also be understood that one or more blocks in the flowchart and combinations of blocks in the flowchart can be implemented by a special purpose computer system based on hardware that performs the specified functions or by a combination of special purpose hardware and computer instructions.

[0150] Although an exemplary processing system has been described above, specific implementations of the subject matter and functional operations described herein can be implemented in other types of digital electronic circuitry or in computer software, firmware, or hardware (including the structures disclosed in this specification and structural equivalents thereof) or in combinations of one or more of them.

[0151] Embodiments of the subject matter and the operations described in this specification can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structures disclosed in this specification and their structural equivalents, or in combinations of one or more of them. Embodiments of the subject matter described in this specification can be implemented as one or more computer programs (i.e., one or more modules of computer program instructions) encoded on a computer storage medium for execution by, or to control the operation of, an information / data processing apparatus. Alternatively or additionally, the program instructions can be encoded on an artificially generated propagated signal (e.g., a machine-generated electrical, optical, or electromagnetic signal) that is generated to encode information / data for transmission to a suitable receiver apparatus for execution by the information / data processing apparatus. A computer storage medium can be a computer-readable storage device, a computer-readable storage substrate, a random or serial access memory array or device, or a combination of one or more of them, or can include within a computer-readable storage device, a computer-readable storage substrate, a random or serial access memory array or device, or a combination of one or more of them. Further, although a computer storage medium is not a propagated signal, a computer storage medium can be a source or destination of computer program instructions encoded in an artificially generated propagated signal. A computer storage medium can also be one or more separate physical components or media (e.g., multiple CDs, disks, or other storage devices), or can include within one or more separate physical components or media.

[0152] The operations described in this specification can be implemented as operations performed by an information / data processing apparatus on information / data stored on one or more computer-readable storage devices or received from other sources.

[0153] The term “data processing apparatus” encompasses all kinds of apparatus, devices, and machines for processing data, including, for example, a programmable processor, a computer, a system-on-a-chip, or multiple of the foregoing devices or a combination of them. The apparatus can include dedicated logic circuitry (e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit)). In addition to hardware, the apparatus can also include code that creates an execution environment for the computer program being considered (e.g., code that constitutes processor firmware, a protocol stack, a repository management system, an operating system, a cross-platform runtime environment, a virtual machine, or a combination of one or more of them). The apparatus and the execution environment can implement various computing model infrastructures, such as web services, distributed computing infrastructures, and grid computing infrastructures.

[0154] A computer program (also known as a program, software, software application, script, or code) can be written in any form of programming language (including compiled or interpreted languages, declarative languages, or procedural languages), and the computer program can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, object, or other unit suitable for a computing environment. A computer program can, but need not, correspond to a file in a file system. The program can be stored as part of a file that holds other programs or information / data (e.g., one or more scripts stored in a markup language document), stored in a single file dedicated to the program being considered, or stored in multiple coordinated files (e.g., files that store one or more modules, subroutines, or portions of code).

[0155] The processes and logical flows described herein can be performed by one or more programmable processors executing one or more computer programs to perform actions by operating on input information / data and generating output. By way of example, processors suitable for executing a computer program include both general and special purpose microprocessors, as well as any one or more processors of any kind of digital computer. In general, a processor will receive instructions and information / data from a read only memory or a random access memory or both. The essential elements of a computer are a processor for performing actions in accordance with instructions and one or more memories for storing the instructions and data. In general, a computer will also include one or more mass storage devices for storing data (e.g., magnetic disks, magneto-optical disks, or optical disks), or operatively coupled to the one or more mass storage devices to receive information / data from or transfer information / data to the one or more mass storage devices, or both. However, a computer need not have such devices. Devices suitable for storing computer program instructions and information / data include all forms of non-volatile memory, media, and memory devices, including by way of example semiconductor memory devices such as EPROM, EEPROM, and flash memory devices; magnetic disks such as internal hard disks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.

[0156] To provide for interaction with a user, implementations of the subject matter described herein may be implemented on a computer having a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information / data to the user and a keyboard and a pointing device (e.g., a mouse or a trackball by which the user can provide input to the computer). Other types of devices may also be used to provide for interaction with the user; for example, feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form, including acoustic, speech, or tactile input. Additionally, the computer may interact with the user by sending documents to and receiving documents from the device used by the user; for example, by sending a web page to a web browser in response to a request received from the web browser on a client device of the user.

[0157] Although this specification contains many specific implementation details, these should not be construed as limitations on the scope of any disclosure or of what may be claimed, but rather as descriptions of features specific to particular implementations of a particular disclosure. Certain features that are described in the context of separate implementations may also be implemented in combination within a single implementation. Conversely, various features that are described in the context of a single implementation may also be implemented separately in multiple implementations or in any suitable sub-combination. Additionally, although features may be described above as acting in certain combinations and even initially claimed as such, in some cases, one or more features from a claimed combination may be excluded from the combination, and the claimed combination may be directed to a sub-combination or a variation of a sub-combination.

[0158] Similarly, although operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all of the illustrated operations be performed to achieve a desired result. In some cases, multitasking and parallel processing may be advantageous. Additionally, the separation of various system components in the above-described implementations should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems may generally be integrated together in a single software product or grouped into multiple software products.

[0159] Thus, particular implementations of the subject matter have been described. Other implementations are within the scope of the following claims. In some cases, the acts recited in the claims may be performed in a different order and still achieve the desired result. Additionally, the processes depicted in the drawings do not necessarily require the particular order or sequential order shown to achieve the desired result. In certain implementations, multitasking and parallel processing may be advantageous.

Claims

1. An imaging system, comprising: a first image sensor associated with a first illumination source, wherein the first image sensor is configured to capture a first image of a target symbol; a second image sensor; and a controller including a processing circuit, the controller being communicatively coupled to the first illumination source, the first image sensor, and the second image sensor, wherein the controller is configured to: process the first image to estimate a distance between the first image sensor and the target symbol; determine a first exposure period of the second image sensor based on the distance estimate; and modify one or more characteristics of the first exposure period of the second image sensor based on at least one illumination pulse of the first illumination source.

2. The imaging system according to claim 1, wherein one or more characteristics of the first exposure period of the second image sensor comprise: a minimum size region defined based on a position where the target symbol is captured in a field of view of the second image sensor.

3. The imaging system according to claim 1, wherein the controller is further configured to: determine whether decoding of the target symbol is successful based on image processing of the first image; and change a focusing position of the second image sensor when decoding is not successful.

4. The imaging system according to claim 3, wherein the controller is further configured to change the focusing position based on the distance estimate.

5. The imaging system according to claim 1, wherein, to modify one or more characteristics of the first exposure period of the second image sensor, the controller is further configured to: completely or substantially align a start period or an end period of the first exposure period of the second image sensor with a start period or an end period of an illumination period of at least one illumination pulse of the first illumination source.

6. The imaging system according to claim 1, wherein, to modify one or more characteristics of the first exposure period of the second image sensor, the controller is further configured to: avoid an overlap between the first exposure period of the second image sensor and at least one illumination pulse of the first illumination source.

7. The imaging system according to claim 6, wherein, to avoid an overlap between the first exposure period of the second image sensor and at least one illumination pulse of the first illumination source, the controller is further configured to: schedule a start period and an end period of the first exposure period of the second image sensor such that they do not overlap with at least one illumination pulse of the first illumination source.

8. An imaging method, comprising: operating a first image sensor associated with a first illumination source, wherein the first image sensor is configured to capture a first image of a target symbol; processing the first image to estimate a distance between the first image sensor and the target symbol; determining a first exposure period of a second image sensor based on the distance estimate; and modifying one or more characteristics of the first exposure period of the second image sensor based on at least one illumination pulse of the first illumination source.

9. The imaging method according to claim 8, further Comprising: Determining whether decoding of the target symbol is successful based on image processing of the first image; And Changing a focus position of the second image sensor when decoding is not successful, wherein the change in the focus position is based on the distance estimate.

10. The imaging method according to claim 8, wherein modifying one or more characteristics of the first exposure period of the second image sensor Comprising: Fully or substantially aligning a start period or an end period of the first exposure period of the second image sensor with a start period or an end period of an illumination period of at least one illumination pulse of the first illumination source.

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