Bar code reading engine, code reading device and bar code reading method

Abstract

The embodiment of the invention provides a bar code reading engine, code reading equipment and a bar code reading method. The bar code reading engine comprises a first imaging unit, a second imaging unit, an aiming unit and a control unit, wherein the first imaging unit comprises a variable-focus short-focus lens assembly, the back focal length of the first imaging unit can be changed, clear imaging of bar codes at different distances is achieved, and the depth of field of the bar code recognition engine is enlarged. Meanwhile, the second imaging unit comprises a telephoto lens assembly with a fixed focal length, and the second imaging unit is configured to be capable of clearly imaging at a preset distance, so that when the user positions the target bar code at the preset distance based on the aiming unit, the bar code can be read based on the image acquired by the second imaging unit; therefore, accurate reading of the minimum code is ensured.

Description

Technical Field

[0001] This application relates to the field of machine vision technology, and in particular to a barcode reading engine, barcode reading device and barcode reading method. Background Technology

[0002] A barcode reading engine is the core module of a barcode or QR code reader. It primarily uses imaging optical elements to capture images of barcodes or QR codes, processes and decodes these images, and then reads the corresponding data information. Due to its small size, fast decoding speed, and high reliability, it is widely used in logistics, warehousing, and industrial identification.

[0003] To expand the scanning range of the barcode reading engine, the imaging optical element needs to have a large reading depth of field; and to improve the scanning accuracy, a high barcode reading precision is required.

[0004] In related technologies, there are two solutions to improve depth of field: one is a dual-camera scanning engine solution using two fixed-focal-length imaging modules. One is a short-focal-length imaging module for reading barcodes in close-range areas; the other is a long-focal-length imaging module for reading barcodes in distant areas. The working distance of the two imaging modules is stitched together to achieve a large reading depth of field. The other solution uses an adjustable-focal-length imaging module with a T-lens (focusing lens) or a liquid lens in the barcode reading engine. While both solutions can improve depth of field, their minimum unit size for QR code reading is above 0.1mm. However, in some application scenarios, the minimum unit size of the QR code is less than 0.1mm. Such barcode reading engines cannot correctly recognize these small-sized QR codes.

[0005] In related technologies, to improve barcode reading accuracy, a telephoto, small-field-of-view imaging module is typically used in the barcode reading engine for close-range reading. However, while this method improves barcode reading accuracy, the depth of field is relatively low, generally only a few centimeters in the working range, making it difficult to adapt to application scenarios with a large working range.

[0006] Therefore, how to make the barcode reading engine have both a large reading depth and higher barcode reading accuracy is an urgent problem to be solved. Summary of the Invention

[0007] The purpose of this application is to provide a barcode reading engine, a barcode reading device, and a barcode reading method, so that the barcode reading engine has both a large reading depth and higher barcode reading accuracy. The specific technical solution is as follows:

[0008] This application provides a barcode reading engine, including:

[0009] The first imaging unit includes: a zoomable short-focus lens assembly and a first image sensor; used to preferentially acquire a first barcode image within a first preset distance range;

[0010] The second imaging unit includes: a telephoto lens assembly with a fixed focal length and a second image sensor; the focal length of the telephoto lens assembly is greater than the maximum focal length of the short-focal-length lens assembly; it is used to preferentially acquire a second barcode image within a second preset distance range; the second imaging unit is configured to be able to clearly image at a preset distance; the preset distance is located within the second preset distance range;

[0011] The aiming unit is used to send an aiming pattern to the target barcode to aim at the target barcode; so that the user can confirm whether the target barcode is located at the center of the field of view of the first imaging unit or the second imaging unit, and whether the target barcode is located at a preset distance based on the aiming pattern.

[0012] The control unit is used to control the aiming unit to turn on and off, and when the aiming pattern hits the target barcode, it determines whether the first imaging unit or the second imaging unit should acquire the image first, based on the current distance between the barcode reading engine and the target barcode, the first preset distance range and the second preset distance range; and performs barcode reading based on the acquired image to read the data information corresponding to the target barcode.

[0013] In some embodiments, the barcode reading engine further includes a ranging unit; the ranging unit is used to detect the current distance between the barcode reading engine and the target barcode and send it to the control unit, so that the control unit determines that the first imaging unit should prioritize acquiring the image when the current distance is within a first preset distance range, or determines that the second imaging unit should prioritize acquiring the image when the current distance is within a second preset distance range.

[0014] In some embodiments, the control unit is further configured to perform image processing on the image acquired by the first imaging unit, determine the position of the aiming pattern in the acquired image, and determine the current distance between the barcode reading engine and the target barcode based on the position of the aiming pattern in the acquired image.

[0015] In some embodiments, the first imaging unit and the second imaging unit are misaligned, and the first imaging optical axis of the first imaging unit is parallel to the second imaging optical axis of the second imaging unit; the aiming unit includes: a first aiming subunit and a second aiming subunit; the first aiming subunit is used to send a first aiming beam to the target barcode to form a first aiming pattern on the target barcode; the second aiming subunit is used to send a second aiming beam to the target barcode to form a second aiming pattern on the target barcode;

[0016] The first aiming subunit and the second aiming subunit are offset; wherein, the first aiming optical axis of the first aiming subunit is parallel to the first imaging optical axis and the second imaging optical axis; the second aiming optical axis of the second aiming subunit has an inclined angle relative to the first imaging optical axis and the second imaging optical axis; so that the second aiming beam and the first aiming beam have an inclined angle, forming a beam intersection point;

[0017] The second imaging optical axis of the second imaging unit passes through the beam intersection point, and the beam intersection point is located at a preset distance where the second imaging unit can clearly image the target barcode. Based on the beam intersection point, it is ensured that the second aiming pattern and the first aiming pattern have an overlapping area. The user can confirm whether the target barcode is in the center of the field of view of the second imaging unit and whether it is located at a preset distance where the second imaging unit can clearly image the target barcode, based on whether the target barcode is in the overlapping area of ​​the first aiming pattern and the second aiming pattern.

[0018] In some embodiments, the first aiming pattern is a cross laser spot used to indicate the image center of the first imaging unit; the second aiming pattern is a circular spot used to indicate the image center of the second imaging unit; if the circular spot and the cross laser spot have overlapping areas, it indicates that the target barcode is located at a preset distance where the second imaging unit can clearly image it.

[0019] In some embodiments, the variable focal length short-focus lens assembly of the first imaging unit includes: a short-focus lens base, a short-focus lens, a bracket, and a variable focal length optical element arranged sequentially along the direction of the first imaging optical axis of the first imaging unit; the positions of the short-focus lens and the variable focal length optical element correspond to the first image sensor; the fixed focal length telephoto lens assembly of the second imaging unit includes: a telephoto lens base and a telephoto lens arranged sequentially along the direction of the second imaging optical axis of the second imaging unit; the position of the telephoto lens corresponds to the second image sensor.

[0020] In some embodiments, the focal length of the variable focal length short-focus lens assembly is between 3-7mm; the focal length of the fixed focal length telephoto lens assembly is between 12-20mm; and the preset distance is preset based on user operating habits.

[0021] In some embodiments, the barcode reading engine further includes: a supplementary lighting unit; the supplementary lighting unit is used to illuminate the field of view of the first imaging unit and the second imaging unit.

[0022] In some embodiments, the first imaging unit, the second imaging unit, the aiming unit, and the control unit are disposed in the housing; one end face of the housing is a scanning end face, and the scanning end face is provided with a first imaging through hole, a second imaging through hole, and an aiming through hole arranged at intervals; the first imaging unit and the second imaging unit respectively acquire images through the first imaging through hole and the second imaging through hole; the aiming unit sends an aiming pattern to the target barcode through the aiming through hole.

[0023] In some embodiments, the barcode reading engine further includes: a ranging unit; a ranging through hole is also provided on the scanning end face of the housing; the ranging unit detects the current distance between the barcode reading engine and the target barcode through the ranging through hole.

[0024] In some embodiments, the aiming unit includes: a first aiming subunit and a second aiming subunit; the aiming through hole includes: a first aiming through hole and a second aiming through hole; the first aiming subunit sends a first aiming pattern to the target barcode through the first aiming through hole; the second aiming subunit sends a second aiming pattern to the target barcode through the second aiming through hole.

[0025] In some embodiments, the barcode reading engine further includes: a supplementary light unit; a supplementary light through hole is also provided on the scanning end face of the housing; the supplementary light unit illuminates the field of view of the first imaging unit and the second imaging unit through the supplementary light through hole.

[0026] This application embodiment also provides a barcode reading device, including any of the aforementioned barcode reading engines and a device housing; the barcode reading engine is disposed in the device housing.

[0027] This application also provides a barcode reading method, applied to the control unit of the aforementioned barcode reading engine, the method comprising:

[0028] The aiming unit is activated, sending an aiming pattern to the target barcode;

[0029] Obtain the current distance between the barcode reading engine and the target barcode; wherein, the current distance is adjusted by the user by adjusting the position of the barcode reading engine according to whether the target barcode is a regular barcode or a very small barcode, and the state of the aiming pattern on the target barcode;

[0030] If the current distance is within the first preset distance range, it is determined that the first imaging unit will prioritize acquiring the image; if the current distance is within the second preset distance range or the target barcode is within the preset distance where the second imaging unit can clearly image it, it is determined that the second imaging unit will prioritize acquiring the image.

[0031] The image acquired by the first imaging unit or the image acquired by the second imaging unit is subjected to barcode reading in order to read the data information corresponding to the target barcode.

[0032] In some embodiments, the step of obtaining the current distance between the barcode reading engine and the target barcode includes:

[0033] Receive current distance information sent by the ranging unit set in the barcode reading engine; or,

[0034] Image processing is performed on the image acquired by the first imaging unit to determine the position of the aiming pattern in the acquired image, and based on the position of the aiming pattern in the acquired image, the current distance between the barcode reading engine and the target barcode is determined.

[0035] In some embodiments, the aiming unit of the barcode reading engine includes: a first aiming subunit and a second aiming subunit; the control of the aiming unit to activate and send an aiming pattern to the target barcode includes:

[0036] The system controls the first aiming subunit to send a first aiming beam to the target barcode to form a first aiming pattern on the target barcode; and controls the second aiming subunit to send a second aiming beam to the target barcode to form a second aiming pattern on the target barcode; so that when the target barcode is a very small code, the user can adjust the position of the barcode reading engine so that the target barcode is located in the overlapping area of ​​the first aiming pattern and the second aiming pattern, at which time the target barcode is located at the center of the field of view of the second imaging unit and at a preset distance where the second imaging unit can clearly image it; when the target barcode is a normal code, the user can aim the center of the first aiming pattern onto the target barcode.

[0037] In some embodiments, if the current distance is within a first preset distance range, and barcode reading is performed on the image acquired by the first imaging unit but no data information corresponding to the barcode is read, then the second imaging unit is controlled to acquire an image, and barcode reading is performed on the image acquired by the second imaging unit.

[0038] If, when the current distance is within the second preset distance range, barcode scanning is performed on the image acquired by the second imaging unit and no data information corresponding to the barcode is read, then the first imaging unit is controlled to acquire an image, and barcode scanning is performed on the image acquired by the first imaging unit.

[0039] Beneficial effects of the embodiments in this application:

[0040] The barcode reading engine, reading device, and barcode reading method provided in this application embodiment include a first imaging unit and a second imaging unit. The first imaging unit includes a variable-focus short-focal-length lens assembly, which can change the back focal length of the first imaging unit to achieve clear imaging of barcodes at different distances, thus expanding the depth of field of the barcode reading engine. Simultaneously, the second imaging unit includes a fixed-focal-length telephoto lens assembly, which can focus at close range and can be used to read extremely small barcodes, improving barcode reading accuracy. In particular, since the second imaging unit can clearly image at a preset distance, when a user positions the target barcode at the preset distance based on the aiming unit, barcode reading can be performed based on the image captured by the second imaging unit, thereby ensuring accurate reading of extremely small barcodes. Through repeated testing by the inventors, the barcode reading engine provided in this application embodiment can support reading QR codes with a minimum unit size of 0.04mm.

[0041] In addition, the barcode reading engine provided in this application embodiment can prioritize selecting the first imaging unit or the second imaging unit to acquire images and perform barcode reading based on the current distance between the barcode reading engine and the target barcode. Compared with the method of two imaging units polling to acquire images and performing barcode reading in turn, it can quickly read the data information corresponding to the target barcode, speed up the scanning speed, and improve the scanning efficiency.

[0042] Of course, implementing any product or method of this application does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other embodiments can be obtained based on these drawings.

[0044] Figure 1a A first-angle structural schematic diagram of an embodiment of the barcode reading engine provided in this application;

[0045] Figure 1b for Figure 1a The diagram shows another structural view of the barcode reading engine.

[0046] Figure 2 for Figure 1a The diagram shows a structural breakdown of the barcode reading engine.

[0047] Figure 3 for Figure 2 The diagram shows the optical path principle of the first and second imaging units of the barcode reading engine.

[0048] Figure 4 for Figure 2 The diagram shows a structural breakdown of the first imaging unit of the barcode reading engine.

[0049] Figure 5 for Figure 2 The diagram shows an exploded view of the second imaging unit of the barcode reading engine.

[0050] Figure 6a for Figure 2 The diagram shows the optical path principle of the aiming unit in the barcode reading engine.

[0051] Figure 6b for Figure 6a The diagram shows the aiming effect of the aiming unit in the barcode reading engine.

[0052] Figure 7 A flowchart of the barcode reading method provided in the embodiments of this application.

[0053] Figure label:

[0054] First imaging unit 100, short focal length lens assembly 110, short focal length lens base 111, short focal length lens 112, bracket 113, variable focal length optical element 114, first image sensor 120;

[0055] Second imaging unit 200, telephoto lens assembly 210, telephoto lens base 211, telephoto lens 212, second image sensor 220;

[0056] Aiming unit 300, first aiming subunit 310, first aiming beam 311, laser module 312, diffractive optical element 313, cross-shaped laser spot 314, second aiming subunit 320, second aiming beam 321, aiming lamp bead 322, aiming lens 323, circular spot 324;

[0057] Control unit 400, ranging unit 500, supplementary lighting unit 600, first supplementary lighting sub-unit 610, first supplementary lighting lamp 611, first collimating lens 612, first supplementary lighting lens 613, second supplementary lighting sub-unit 620, second supplementary lighting lamp 621, second collimating lens 622, second supplementary lighting lens 623;

[0058] Housing 700; scanning end face 710, first imaging through hole 720, second imaging through hole 730, aiming through hole 740, first aiming through hole 741, second aiming through hole 742; ranging through hole 750, supplementary light through hole 760, first supplementary light through hole 761, second supplementary light through hole 762;

[0059] First control circuit board 800, second control circuit board 900, first FPC (flexible printed circuit board) connecting line 810, second FPC connecting line 910, first interface connector 920, and second interface connector 930. Detailed Implementation

[0060] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art based on this application are within the scope of protection of this application.

[0061] To enable the barcode reading engine to have both a large reading depth and higher barcode reading accuracy, this application provides a barcode reading engine, a barcode reading device, and a barcode reading method.

[0062] First, the barcode reading engine provided in the embodiments of this application will be described in detail.

[0063] See Figure 1a , Figure 1b and Figure 2 ,in, Figure 1a A first-angle structural schematic diagram of an embodiment of the barcode reading engine provided in this application; Figure 1b for Figure 1a The diagram shows another structural view of the barcode reading engine. Figure 2 for Figure 1a The diagram shows a breakdown of the structure of a barcode reading engine.

[0064] like Figure 1a , Figure 1b and Figure 2 As shown, the barcode reading engine provided in this embodiment includes: a first imaging unit 100, a second imaging unit 200, an aiming unit 300, and a control unit 400, wherein:

[0065] The first imaging unit 100 includes a variable focal length short-focus lens assembly 110 and a first image sensor 120; it is used to preferentially acquire a first barcode image within a first preset distance range. The second imaging unit 200 includes a fixed focal length telephoto lens assembly 210 and a second image sensor 220; the focal length of the telephoto lens assembly is greater than the maximum focal length of the short-focus lens assembly; it is used to preferentially acquire a second barcode image within a second preset distance range. The second imaging unit 200 is configured to be able to clearly image at a preset distance; the preset distance is located within the second preset distance range.

[0066] The aiming unit 300 is used to send an aiming pattern to the target barcode to aim at the target barcode; so that the user can confirm whether the target barcode is located at the center of the field of view of the first imaging unit 100 or the second imaging unit 200, and whether the target barcode is located at a preset distance, based on the aiming pattern.

[0067] The control unit 400 is used to control the aiming unit to turn on or off, and when the aiming pattern hits the target barcode, it determines whether the first imaging unit or the second imaging unit should acquire the image first, based on the current distance between the barcode reading engine and the target barcode, the first preset distance range and the second preset distance range; and performs barcode reading based on the acquired image to read the data information corresponding to the target barcode.

[0068] In the barcode reading engine provided in this application embodiment, the first imaging unit 100 includes a variable-focus short-focal-length lens assembly 110, which can change the back focal length of the first imaging unit 100 under the control of the control unit 400, thereby achieving clear imaging of barcodes at different distances and expanding the depth of field of the barcode reading engine. Specifically, the control unit 400 can control the voltage applied to the variable-focus short-focal-length lens assembly 110 according to the current distance, thereby changing the focal length of the variable-focus short-focal-length lens assembly 110 and thus changing the back focal length of the first imaging unit 100.

[0069] Meanwhile, the fixed-focal-length telephoto lens assembly 210 included in the second imaging unit 200 can focus at close range and can be used to read extremely small codes, improving barcode reading accuracy. In particular, since the second imaging unit 200 can clearly image at a preset distance, when a user positions the target barcode at the preset distance based on the aiming unit 300, barcode reading can be performed based on the image captured by the second imaging unit 200, ensuring accurate reading of extremely small codes. Through repeated testing by the inventors, the barcode reading engine provided in this application embodiment can support reading QR codes with a minimum unit size of 0.04mm.

[0070] In this embodiment, the field of view of the first imaging unit 100 covers the field of view of the second imaging unit 200, and the depth of field of the first imaging unit 100 covers the depth of field of the second imaging unit 200. For example, in the case of a preset distance of 100mm, see... Figure 3 , Figure 3 for Figure 2 The diagram shows the optical path of the first and second imaging units of the barcode reading engine; as shown. Figure 3 As shown, the depth of field of the first imaging unit 100 covers the depth of field of the second imaging unit 200. The depth of field of the first imaging unit 100 can range from 30mm to 1000mm, while the depth of field of the second imaging unit 200 is smaller, allowing it to operate at a preset distance (i.e.,...). Figure 3A clear image can be obtained at a distance of 100mm from the center of the image; simply move the target barcode to this position. Figure 3 At a distance of 100mm, accurate barcode reading is possible even for extremely small codes with a minimum unit size of 0.04mm. In this embodiment, the first imaging module 100 uses a variable-focus short-focal-length lens assembly 110, resulting in a large depth of field, enabling the stitching effect of the depth of field from two imaging modules as described in related technologies. Meanwhile, the second imaging module 200 uses a fixed-focal-length telephoto imaging module 210 for close-range barcode reading, capable of recognizing even extremely small codes.

[0071] In addition, the barcode reading engine provided in this application embodiment can prioritize the first imaging unit 100 or the second imaging unit 200 to acquire images and perform barcode reading based on the current distance between the barcode reading engine and the target barcode. Compared with the method of two imaging units polling to acquire images and performing barcode reading in turn, it can quickly read the data information corresponding to the target barcode, speed up the scanning speed and improve the scanning efficiency.

[0072] In the barcode reading engine provided in this application embodiment, the current distance between the barcode reading engine and the target barcode can be obtained through at least the following two implementation methods:

[0073] The first method, such as Figure 2 As shown, a ranging unit 500 is set in the barcode reading engine. This ranging unit 500 can detect the current distance between the barcode reading engine and the target barcode and send it to the control unit 400. Specifically, the ranging unit 500 can be a TOF (Time of Flight) ranging unit, which calculates the distance by calculating the time difference between the transmission and reception of the light signal.

[0074] The second approach, instead of including a ranging unit in the barcode reading engine, employs an aiming unit ranging scheme. This utilizes the principle that the aiming pattern's position within the image differs at different distances to determine the current distance to the target barcode. Specifically, the control unit 400 performs image processing on the image acquired by the first imaging unit 100 to determine the position of the aiming pattern within the acquired image, and based on this position, determines the current distance between the barcode reading engine and the target barcode.

[0075] In this embodiment, the aiming unit may include a laser module for aiming by emitting a laser aiming pattern. In this case, the laser module can be used for ranging. Specifically, the coordinates (x1, y1) of the laser center in the image can be calibrated at a fixed distance at the factory, and these coordinates are written into the control unit. Then, during use, the laser aiming pattern is projected onto the target barcode to obtain an image with the laser aiming pattern, and the aiming coordinates (x2, y2) at the current distance are obtained. By analyzing the difference between the coordinates (x1, y1) and (x2, y2), the current distance can be determined.

[0076] Regardless of which method is used, after obtaining the current distance, the control unit 400 can select which imaging unit to acquire the image based on the current distance. For example, if the current distance is within the first preset distance range, it is determined that the first imaging unit 100 will acquire the image first; if the current distance is within the second preset distance range, it is determined that the second imaging unit 200 will acquire the image first.

[0077] In practical applications, the priority of image acquisition by the imaging unit depends on the preset distance for clear imaging by the second imaging unit. This preset distance can be pre-set based on user operating habits, such as 50mm, 60mm, 80mm, 100mm, 110mm, 120mm, etc., and is not limited here. Taking a preset distance of 100mm for clear imaging by the second imaging unit as an example, the first preset distance range can be 0-80mm and 120mm-∞. If the current distance is within this range, the control unit 400 prioritizes controlling the first imaging unit 100 to acquire images based on the variable focal length short-focus lens assembly 110. The second preset distance range can be 80mm-120mm. If the current distance is within this range, the control unit 400 prioritizes controlling the second imaging unit 200 to acquire images based on the fixed focal length telephoto lens assembly 210.

[0078] It should be noted that the control unit 400 prioritizes which imaging unit to acquire images. If the image acquired by the first imaging unit cannot be read to recognize the data information corresponding to the barcode, it can switch to another imaging unit for image acquisition and barcode reading. For example, if the image acquired by the first imaging unit 100 cannot be read to recognize the data information corresponding to the barcode at a distance of approximately 80mm or 120mm, it can switch to the second imaging unit 200 for image acquisition. This further ensures that the barcode reading engine can recognize the data information corresponding to the barcode.

[0079] With the preset distance of the second imaging unit 200 being 100mm, when the user positions the target barcode at 100mm based on the aiming unit 300, the second imaging unit 200 can achieve clear imaging, thus enabling accurate reading of extremely small codes. Through repeated testing by the inventors, the barcode reading engine provided in this application embodiment can support reading QR codes with a minimum unit size of 0.04mm.

[0080] like Figure 1a , Figure 1b and Figure 2 As shown in the embodiments of this application, the barcode reading engine may further include: a supplementary lighting unit 600; the supplementary lighting unit 600 is used to illuminate the fields of view of the first imaging unit 100 and the second imaging unit 200. In this embodiment, by setting the supplementary lighting unit 600, when the ambient light is low, supplementary lighting is provided to the fields of view of the first imaging unit 100 and the second imaging unit 200, which can improve the clarity of the images acquired by the first imaging unit 100 and the second imaging unit 200 in low ambient light conditions.

[0081] like Figure 1a , Figure 1b and Figure 2 As shown, the barcode reading engine in this embodiment also includes a housing 700, in which the aforementioned first imaging unit 100, second imaging unit 200, aiming unit 300, control unit 400, ranging unit 500, and supplementary lighting unit 600 are all housed. The control unit 400 is located inside the housing 700. The first imaging unit 100, second imaging unit 200, aiming unit 300, ranging unit 500, and supplementary lighting unit 600 can all receive or emit light through corresponding through-holes on the scanning end face 710 of the housing 700. In this embodiment, the housing 700 ensures the stable installation of each unit.

[0082] The following is about Figure 2 The first imaging unit 100, the second imaging unit 200, the aiming unit 300, the control unit 400, the ranging unit 500, and the supplementary lighting unit 600 in the illustrated embodiment are described in detail.

[0083] like Figure 2 As shown, in this embodiment, the first imaging unit 100 and the second imaging unit 200 are misaligned, and the first imaging optical axis of the first imaging unit 100 is parallel to the second imaging optical axis of the second imaging unit 200. The field of view of the first imaging unit 100 covers the field of view of the second imaging unit 200, and the depth of field of the first imaging unit 100 covers the depth of field of the second imaging unit 200.

[0084] See Figure 2 and Figure 4 ,in, Figure 4 for Figure 2 The diagram shows a structural breakdown of the first imaging unit of the barcode reading engine. Figure 2 and Figure 4 As shown, the first imaging unit 100 includes: a zoomable short-focus lens assembly 110 and a first image sensor 120. Wherein, as... Figure 4 As shown, the short focal length lens assembly 110 includes: a short focal length lens base 111, a short focal length lens 112, a bracket 113, and a variable focal length optical element 114 arranged sequentially along the direction of the first imaging optical axis of the first imaging unit 100; the positions of the short focal length lens 112 and the variable focal length optical element 114 correspond to the first image sensor 120.

[0085] Specifically, such as Figure 2 and Figure 4 As shown, in this embodiment, the variable-focus optical element 114 of the first imaging unit 100 rests on the bracket 113 and can be fixed by adhesive. The bracket 113 can also be fixed to the short-focus lens base 111 by adhesive, and the short-focus lens 112 is attached and fixed to the short-focus lens base 111. In this embodiment, the focal length of the short-focus lens 112 is 3mm to 7mm, for example, it can be 3mm, 5mm, 6mm or 7mm, etc. In other embodiments, the focal length of the short-focus lens 112 can be designed according to actual needs, and there is no limitation here. Figure 2 and Figure 4 As shown, the first imaging unit 100 is disposed on the first control circuit board 800, wherein the first image sensor 120 is soldered on the first control circuit board 800, and the short focal length lens base 111 is installed at the corresponding position of the first image sensor 120.

[0086] In this embodiment, the zoom optical element 114 is a T-lens lens, which is mounted on the outside of the short-focus lens 112 via a bracket 113. In other embodiments, the position of the zoom optical element 114 is not limited; it can be located inside the short-focus lens 112 or between the first image sensor 120 and the short-focus lens 112, as long as it enables zoom functionality. In other embodiments, the zoom optical element 114 can also be a voice coil motor or a liquid lens, or other optical elements capable of zoom functionality; no limitation is imposed here.

[0087] In this embodiment, both the first image sensor 120 and the variable focus optical element 114 can be connected via an FPC cable ( Figure 2(Not shown) is electrically connected to the control unit 400 located on the second control circuit board 900. The first image sensor 120 can acquire images under the control of the control unit 400; the variable focus optical element 114 can change the back focal length of the first imaging unit 100 under the control of the control unit 400, so as to achieve clear imaging of barcodes at different distances and expand the depth of field of the barcode reading engine.

[0088] See Figure 2 and Figure 5 ,in, Figure 5 for Figure 2 The diagram shows a structural breakdown of the second imaging unit of the barcode reading engine. Figure 2 and Figure 5 As shown, the second imaging unit 200 includes: a telephoto lens assembly 210 with a fixed focal length and a second image sensor 220, wherein, as Figure 5 As shown, the telephoto lens assembly 210 includes a telephoto lens base 211 and a telephoto lens 212 arranged sequentially along the direction of the second imaging optical axis of the second imaging unit 200; the position of the telephoto lens 212 corresponds to the second image sensor 220.

[0089] Specifically, in this embodiment, the telephoto lens 212 has a focal length of 12mm to 18mm, for example, it can be 12mm, 13mm, 15mm or 18mm, etc., with a small depth of field, and is used to read extremely small codes. The focal length of the telephoto lens 212 in this embodiment is designed according to actual needs, as long as it can read extremely small codes, there is no limitation here.

[0090] In this embodiment, the second imaging unit 200 is capable of producing a clear image at a preset distance (e.g., 100mm) based on the telephoto lens 212. The telephoto lens base 211 is used to attach and fix the telephoto lens 212. The second image sensor 220 is soldered onto the second control circuit board 900 and electrically connected to the control unit 400. The second image sensor 220 is capable of acquiring images under the control of the control unit 400.

[0091] By applying this embodiment, when it is necessary to read the microcode, the user can position the target barcode at a preset distance (e.g., 100mm) based on the aiming unit 300, acquire the image through the second imaging unit 200, and read the barcode based on the image acquired by the second imaging unit 200, thus ensuring accurate reading of the microcode.

[0092] like Figure 1a , Figure 1b and Figure 2As shown, the first control circuit board 800 is disposed inside the housing 700, and the second control circuit board 900 is disposed on the side of the housing 700 opposite to the scanning end face 710. The second control circuit board 900 and the housing 700 cooperate to form a receiving space, in which each unit can be installed. The control unit 400 can be disposed on the second control circuit board 900. The first control circuit board 800 and the second control circuit board 900 can be electrically connected through the first FPC connection 810, and both the first control circuit board 800 and the second control circuit board 900 can be attached to the housing 700 by screws.

[0093] like Figure 1a As shown, in this embodiment, the first imaging unit 100 and the second imaging unit 200 acquire images through a first imaging through-hole 720 and a second imaging through-hole 730 that are staggered and spaced apart on the scanning end face 710 of the housing 700. The first imaging through-hole 720 and the second imaging through-hole 730 are not on the same horizontal line or the same vertical line.

[0094] like Figure 2 As shown, the aiming unit 300 in this embodiment may include: a first aiming subunit 310 and a second aiming subunit 320; the first aiming subunit 310 is used to send a first aiming beam 311 to the target barcode to form a first aiming pattern on the target barcode; the second aiming subunit 320 is used to send a second aiming beam 321 to the target barcode to form a second aiming pattern on the target barcode. In this embodiment, the first aiming pattern may be a cross-shaped laser spot 314, and the second aiming pattern may be a circular spot 324.

[0095] In this embodiment, the first aiming subunit 310 and the second aiming subunit 320 are staggered; wherein, the first aiming optical axis of the first aiming subunit 310 is parallel to the first imaging optical axis and the second imaging optical axis; the second aiming optical axis of the second aiming subunit 320 has an inclined angle relative to the first imaging optical axis and the second imaging optical axis; so that the second aiming beam 321 and the first aiming beam 311 have an inclined angle, forming a beam intersection point.

[0096] The second imaging optical axis of the second imaging unit 200 passes through the beam intersection point, and the beam intersection point is located at a preset distance where the second imaging unit 200 can clearly image the target barcode. Based on the beam intersection point, it is ensured that the second aiming pattern and the first aiming pattern have an overlapping area. The user can confirm whether the target barcode is in the center of the field of view of the second imaging unit and whether it is located at the preset distance where the second imaging unit can clearly image the target barcode based on whether the target barcode is in the overlapping area of ​​the first and second aiming patterns. For example, when scanning ordinary barcodes or QR codes with a minimum unit size of 0.1mm or more, the user can adjust the distance between the barcode reading engine and the target barcode, and can read the data information corresponding to the target barcode by observing that the first aiming pattern hits the target barcode. Among them, the barcode reading effect is best when the center of the first aiming pattern, that is, the center of the cross-shaped laser spot 314, hits the target barcode. If the target barcode is extremely small, the user can adjust the distance between the barcode reading engine and the target barcode. When the second aiming pattern and the first aiming pattern overlap, for example, when the circular spot 324 is located on the horizontal line of the cross-shaped laser spot 314 and the circular spot 324 hits the target barcode, the target barcode is located at the center of the field of view of the second imaging unit and at a preset distance where the second imaging unit can clearly image it, and the data information corresponding to the target barcode can be read.

[0097] For details, see Figure 1a , Figure 2 , Figure 6a and Figure 6b ,in, Figure 6a for Figure 2 The diagram shows the optical path principle of the aiming unit in the barcode reading engine. Figure 6b for Figure 6a The diagram shows the aiming effect of the aiming unit in the barcode reading engine.

[0098] like Figure 1aAs shown, in this embodiment, the first aiming subunit 310 and the second aiming subunit 320 emit a first aiming pattern and a second aiming pattern through two aiming through holes 740: the first aiming through hole 741 and the second aiming through hole 742, which are staggered and spaced apart on the scanning end face 710 of the housing 700. The first aiming through hole 741 and the second aiming through hole 742 are not on the same horizontal line or the same vertical line. Specifically, the first aiming through hole 741 and the second imaging through hole 730 have only a horizontal deviation and no vertical deviation, that is, the first aiming through hole 741 and the second imaging through hole 730 can be on the same horizontal line. The first aiming through hole 741 and the first imaging through hole 720 have only a vertical deviation and no horizontal deviation, that is, the first aiming through hole 741 and the first imaging through hole 720 can be on the same vertical line. The second aiming through hole 742 and the second imaging through hole 730 can be on the same vertical line, and the second aiming through hole 742 can be on the same horizontal line as the first imaging through hole 720. Figure 1a As shown, the first aiming through-hole 741, the first imaging through-hole 720, the second aiming through-hole 742, and the second imaging through-hole 730 can be understood as being located at the four corners of a rectangle. This staggered arrangement not only results in a compact structure but also simplifies the optical path design.

[0099] like Figure 2 , Figure 6a and Figure 6b As shown, in this embodiment, the first aiming subunit 310 includes a laser module 312 and a diffractive optical element 313; the second aiming subunit 320 includes an aiming lamp bead 322 and an aiming lens 323.

[0100] In this embodiment, the laser module 312 of the first aiming subunit 310 can be mounted on the second control circuit board 900, and the diffractive optical element 313 can be mounted at the position of the first aiming through hole 741 on the scanning end face 710 of the housing 700. In this way, the laser emitted by the laser module 312 is diffracted by the diffractive optical element 313 to produce a first aiming beam 311, so as to form a first aiming pattern, such as a cross-shaped laser spot 314, on the target barcode.

[0101] In this embodiment, the aiming lamp 322 of the second aiming subunit 320 can be mounted on the first control circuit board 800, and the aiming lens 323 can be mounted at the position of the second aiming through hole 742 on the scanning end face 710 of the housing 700. In this way, the light emitted by the aiming lamp 322 passes through the aiming lens 323 and is projected at a certain tilt angle to form a second aiming pattern, such as a circular light spot 324, on the target barcode.

[0102] In this embodiment, the first aiming pattern can be a crosshair laser spot 314, used to indicate the image center of the first imaging unit 100, and in conjunction with the second aiming pattern, to indicate the optimal working distance of the second imaging unit 200. The second aiming pattern can be an LED circular spot 324, used to prompt the user of the optimal working distance of the second imaging unit 200; and when it coincides with the first aiming pattern, it indicates the image center of the second imaging unit 200. Here, the optimal working distance can be a preset distance at which the second imaging unit can clearly image.

[0103] like Figure 6a As shown, the second aiming beam 321 emitted by the second aiming subunit 320 is fired at a certain tilt angle and will coincide with the first aiming beam 311 emitted by the first aiming subunit 310 at a certain distance, forming a beam intersection point. In this embodiment, the second imaging unit 200 is a telephoto lens used to read very small codes. It has a small depth of field and is focused at a preset distance, for example, 100mm.

[0104] In practical applications, during the production process of the barcode reading engine, by adjusting the position of the aiming lens 323, the tilt angle of the second aiming beam 321 emitted by the second aiming subunit 320 can be changed, so that the overlap position of the first aiming pattern and the second aiming pattern is consistent with the preset position for clear imaging by the second imaging unit. That is, the center of the LED circular light spot 324 emitted by the second aiming subunit 320 can overlap with the cross laser light spot 314 emitted by the first aiming subunit 310 at the preset distance for clear imaging by the second imaging unit.

[0105] Meanwhile, in this embodiment, the second imaging optical axis of the second imaging unit 200 also passes through the beam intersection point, i.e., at 100mm, which is also the image center point of the second imaging unit 200. Although the cross center of the cross laser spot 324 has a slight deviation from the image center of the first imaging unit 100, the field of view of the first imaging unit 100 is large, and the deviation can be ignored. Therefore, the cross center of the cross laser spot 314 can be used to indicate the image center of the first imaging unit 100.

[0106] By applying the barcode reading engine of this embodiment, users can determine the approximate distance between the barcode reading engine and the target barcode by observing the relative positions of the LED circular light spot 324 and the cross laser light spot 314. Figure 6bAs shown, if the LED circular spot 324 is above the horizontal line of the cross laser spot 314, it indicates that the current distance between the barcode reading engine and the target barcode is within 100mm; if the LED circular spot 324 is below the horizontal line of the cross laser spot 314, it indicates that the current distance between the barcode reading engine and the target barcode is more than 100mm; if the LED circular spot 324 coincides with the horizontal line of the cross laser spot 314, it indicates that the current distance is 100mm. If the target barcode is located at the center of the LED circular spot 324, it indicates that the target barcode is at the center of the field of view of the second imaging unit 200. When reading very small barcodes using the second imaging unit 200, the user can read the data information corresponding to the target barcode by adjusting the current distance between the barcode reading engine and the target barcode to 100mm and making the target barcode located at the center of the LED circular spot 324.

[0107] In this embodiment, by setting two aiming units to emit aiming patterns of different shapes, the user can determine the current distance between the barcode reading engine and the target barcode by observing whether the two aiming patterns of different shapes overlap. Then, the current distance between the barcode reading engine and the target barcode is adjusted to a preset distance at which the second imaging unit 200 can clearly image the barcode, ensuring that the second imaging unit 200 can read very small codes and improving the barcode reading accuracy.

[0108] like Figure 1b and Figure 2 As shown, in this embodiment, the control unit 400 can be disposed on the side of the second control circuit board 900 facing the scanning end face 710. It can be electrically connected to the second imaging unit 200, the laser module 312 of the first aiming subunit 310, and the first interface connector 920 disposed on the second circuit board 900; electrically connected to the first imaging unit 100, the aiming lamp 322 of the second aiming subunit 320, and the supplementary lighting unit 600 on the first control circuit board 800 via the first FPC connection cable 810; and electrically connected to the ranging unit 500 via the second FPC connection cable 910, to control the opening and closing of these units. The processor in the control unit 400 can perform image processing and decoding on the images acquired by the first imaging unit 100 and the second imaging unit 200 to identify the data information corresponding to the target barcode. The first interface connector 920 is used for transmitting information with external devices.

[0109] like Figure 1a and Figure 2 As shown, in this embodiment, a ranging through-hole 750 can be provided on the scanning end face 710 of the housing 700, which is spaced apart from other through-holes, and the ranging unit 500 is mounted on the ranging through-hole 750. Figure 1b and Figure 2As shown, the ranging unit 500 is connected to the back of the second control circuit board 900 via the second FPC connection cable 910, and is electrically connected to the control unit 400 via the second interface connector 930 located on the back of the second control circuit board 900. Under the control of the control unit 400, it is turned on or off, and sends the ranging result to the control unit 400.

[0110] like Figure 1a and Figure 2 As shown, in this embodiment, the supplementary lighting unit 600 may include a first supplementary lighting subunit 610 and a second supplementary lighting subunit 620. A first supplementary lighting through-hole 761 and a second supplementary lighting through-hole 762 may be provided on the scanning end face 710 of the housing 700. The first supplementary lighting through-hole 761 and the second supplementary lighting through-hole 762 may be disposed above the ranging through-hole 750, spaced vertically. The first supplementary lighting subunit 610 and the second supplementary lighting subunit 620 illuminate the field of view of the first imaging unit 100 and the second imaging unit 200 through the first supplementary lighting through-hole 761 and the second supplementary lighting through-hole 762.

[0111] Specifically, such as Figure 2 As shown, the first supplementary lighting subunit 610 may include: a first supplementary lighting lamp 611, a first collimating lens 612, and a first supplementary lighting lens 613; the second supplementary lighting subunit 620 may include: a second supplementary lighting lamp 621, a second collimating lens 622, and a second supplementary lighting lens 623. The first supplementary lighting lamp 611 and the second supplementary lighting lamp 621 may be disposed on the first control circuit board 800; the first collimating lens 612 and the second collimating lens 622 are respectively disposed on the side of the first supplementary lighting lamp 611 and the second supplementary lighting lamp 621 facing the scanning end face 710; the first supplementary lighting lens 613 and the second supplementary lighting lens 623 are respectively disposed on the two supplementary lighting through holes 760 of the scanning end face 710: the first supplementary lighting through hole 761 and the second supplementary lighting through hole 762.

[0112] The light emitted from the first supplementary light bulb 611 is collimated by the first collimating lens 612 and then emitted through the first supplementary light lens 613; it is used to provide supplementary lighting for the fields of view of the first imaging unit 100 and the second imaging unit 200. The light emitted from the second supplementary light bulb 621 is collimated by the second collimating lens 622 and then emitted through the second supplementary light lens 623; it is used to provide supplementary lighting for the fields of view of the first imaging unit 100 and the second imaging unit 200.

[0113] It should be noted that in other embodiments, the first supplementary light unit 610 and the second supplementary light unit 620 can emit light at different supplementary light angles; for example, the first supplementary light unit 610 is adapted to the imaging angle of the first imaging unit 100 for supplementary light, providing supplementary light for a large-angle field of view; the second supplementary light unit 620 is adapted to the imaging angle of the second imaging unit 200 for supplementary light for a small-angle field of view. In this embodiment, the first supplementary light unit 610 and the second supplementary light unit 620 have the same angle and are adapted to the imaging angle of the first imaging unit 100 for supplementary light.

[0114] In other embodiments, the first supplementary light bulb 611 and the second supplementary light bulb 621 can emit light of different colors; for example, the first supplementary light bulb 611 can emit red light and the second supplementary light bulb 621 can emit white light; in this embodiment, both the first supplementary light bulb 611 and the second supplementary light bulb 621 emit white light.

[0115] In some embodiments, depending on the actual conditions at the installation site, only the first supplementary lighting subunit 610 may be retained, while the second supplementary lighting subunit 620 may be omitted. No restrictions are imposed here. Since the field of view of the second imaging unit 200 is located within the field of view of the first imaging unit 100, retaining only the first supplementary lighting subunit 610 can accommodate the supplementary lighting requirements of the second imaging unit 200.

[0116] In this embodiment, by setting up a first supplementary light sub-unit 610 and a second supplementary light sub-unit 620, supplementary light is provided to the field of view of the first imaging unit 100 and the second imaging unit 200 when the ambient light is low, which can improve the clarity of the images captured by the first imaging unit 100 and the second imaging unit 200 when the ambient light is low.

[0117] Secondly, this application embodiment also provides a barcode reading device, which includes any of the aforementioned barcode reading engines and a device housing; the barcode reading engine is disposed in the device housing.

[0118] Specifically, the barcode reading device can be a fixed barcode reader, a handheld barcode reader with a handle, or a PDA (personal assistant) type barcode scanning terminal, etc.

[0119] Finally, the barcode reading method provided in the embodiments of this application will be described in detail.

[0120] See Figure 7 , Figure 7 A flowchart of the barcode reading method provided in the embodiments of this application; as follows: Figure 7 As shown, this method is applied to the control unit of the aforementioned barcode reading engine and includes the following steps:

[0121] Step S101: Control the aiming unit to turn on and send the aiming pattern to the target barcode;

[0122] In this step, the barcode reading engine's aiming unit is activated and emits an aiming pattern, which the user can align with the target barcode.

[0123] Step S102: Obtain the current distance between the barcode reading engine and the target barcode;

[0124] The current distance is adjusted by the user based on whether the target barcode is a regular barcode or a very small barcode, and the state of the aiming pattern on the target barcode, by adjusting the position of the barcode reading engine.

[0125] Furthermore, the barcode reading engine provided in this application embodiment can obtain the current distance between the barcode reading engine and the target barcode through at least the following two implementation methods:

[0126] The first method, such as Figure 2 As shown, a ranging unit 500 is set in the barcode reading engine. This ranging unit 500 can detect the current distance between the barcode reading engine and the target barcode and send it to the control unit 400. Specifically, the ranging unit 500 can be a TOF ranging unit, which calculates the distance by calculating the time difference between the transmission and reception of the light signal.

[0127] The second approach, instead of including a ranging unit in the barcode reading engine, employs an aiming unit ranging scheme. This utilizes the principle that the position of the aiming pattern within the image differs at different distances to determine the current distance to the barcode being measured. Specifically, the control unit 400 performs image processing on the image acquired by the first imaging unit 100 to determine the position of the aiming pattern within the acquired image. Based on the position of the aiming pattern in the acquired image, it determines the current distance between the barcode reading engine and the target barcode.

[0128] Step S103: If the current distance is within the first preset distance range, determine that the first imaging unit will prioritize acquiring the image; if the current distance is within the second preset distance range or the target barcode is within the preset distance where the second imaging unit can clearly image the image, determine that the second imaging unit will prioritize acquiring the image.

[0129] In this embodiment, before scanning, the user can determine whether the target barcode is a very small code or a regular code. If the target barcode is very small, the user can adjust the position of the barcode reading engine, adjusting the current distance to within a second preset distance range. This ensures the target barcode is located at the center of the second imaging unit's field of view and at a preset distance where the second imaging unit can clearly image it, allowing the controller to prioritize image acquisition by the second imaging unit. If the target barcode is a regular code, the user can aim the center of the aiming pattern onto the target barcode, allowing the controller to control either the first or second imaging unit to acquire the image based on the current distance.

[0130] In this step, if a separate ranging unit is used for ranging, after aiming but before the first or second imaging unit acquires an image, the aiming unit should be turned off to ensure that the acquired image does not contain the aiming pattern, thus preventing interference with barcode reading. If an aiming unit ranging scheme is used, the aiming unit can be turned off after the first imaging unit acquires several frames for ranging, and the images acquired after turning off the aiming unit can be used for barcode reading, preventing interference from the aiming pattern.

[0131] Step S104: Barcode reading is performed on the image acquired by the first imaging unit or the image acquired by the second imaging unit to read the data information corresponding to the target barcode.

[0132] The barcode reading engine in this embodiment, through the variable-focus short-focal-length lens assembly included in the first imaging unit, can change the back focal length of the first imaging unit, achieving clear imaging of barcodes at different distances and expanding the depth of field of the barcode reading engine. Simultaneously, the fixed-focal-length telephoto lens assembly included in the second imaging unit can focus at close range and can be used to read extremely small codes, improving barcode reading accuracy.

[0133] Since the second imaging unit can clearly image at a preset distance, when a user positions the target barcode at the preset distance based on the aiming unit, the barcode can be read based on the image captured by the second imaging unit, thus ensuring accurate reading of extremely small codes. Through repeated testing by the inventors, the barcode reading engine provided in this application embodiment can support reading QR codes with a minimum unit size of 0.04mm.

[0134] As described above, the barcode reading engine's aiming unit provided in this application embodiment includes: a first aiming subunit and a second aiming subunit. In this case, the above step S101, controlling the aiming unit to open and sending an aiming pattern to the target barcode, may include:

[0135] The first aiming subunit is controlled to send a first aiming beam to the target barcode to form a first aiming pattern, such as a cross laser spot 314, on the target barcode; and the second aiming subunit is controlled to send a second aiming beam to the target barcode to form a second aiming pattern, such as an LED circular spot 324, on the target barcode.

[0136] In this way, when the target barcode is a standard barcode, the user adjusts the position of the barcode reading engine to align the first aiming pattern, such as the center of the crosshair of the crosshair laser spot 314, onto the target barcode. When the target barcode is a very small barcode, the user adjusts the position of the barcode reading engine so that the target barcode is located in the overlapping area of ​​the first and second aiming patterns. At this point, the target barcode is located at the center of the field of view of the second imaging unit and at a preset distance from which the second imaging unit can clearly image it. Figure 6b As shown, when the horizontal lines of the LED circular spot 324 and the cross laser spot 314 coincide, and the target barcode is located on the LED circular spot 324, it indicates that the target barcode is located at the center of the field of view of the second imaging unit and at a preset distance where the second imaging unit can clearly image it.

[0137] This simplifies the user experience. Specifically, users can scan the target barcode using the following steps:

[0138] The first step is for the user to determine whether the target barcode to be read is a very small barcode or a regular barcode;

[0139] The second step involves the user adjusting the position of the barcode reading engine when the target barcode is very small, so that the horizontal line of the LED circular spot 324 and the cross laser spot 314 coincides, and the target barcode is located on the LED circular spot 324.

[0140] In this case, the control unit of the barcode reading engine selects the second imaging unit 200, including the telephoto lens assembly 210, to acquire images based on the ranging results, and performs barcode reading based on the images acquired by the second imaging unit 200.

[0141] The third step, if the target barcode is a regular barcode, is for the user to align the center of the crosshair of the cross laser spot 314 with the target barcode.

[0142] In this scenario, the control unit of the barcode reading engine, based on the ranging results, selects the first imaging unit 100 to prioritize image acquisition when the current distance is within a first preset distance range; and performs barcode reading based on the image acquired by the first imaging unit 100 to identify the data information corresponding to the target barcode. When the current distance is within a second preset distance range, the second imaging unit 200 is selected to prioritize image acquisition; and performs barcode reading based on the image acquired by the second imaging unit 200 to identify the data information corresponding to the target barcode.

[0143] In addition, the barcode reading engine provided in this application embodiment can prioritize selecting the first imaging unit or the second imaging unit to acquire images and perform barcode reading based on the current distance between the barcode reading engine and the target barcode. Compared with the method of two imaging units polling to acquire images and performing barcode reading in sequence, it can quickly read the data information corresponding to the target barcode, speed up the scanning speed, and improve the scanning efficiency.

[0144] It should be noted that the control unit prioritizes which imaging unit to acquire images based on the current distance. If the image acquired by the current imaging unit cannot be read to obtain the data information corresponding to the barcode, it can switch to another imaging unit to acquire images and then perform barcode reading.

[0145] Specifically, if the current distance is within the first preset distance range, and barcode reading is performed on the image acquired by the first imaging unit but no corresponding data information is read, then the second imaging unit is controlled to acquire an image, and barcode reading is performed on the image acquired by the second imaging unit.

[0146] If, when the current distance is within the second preset distance range, barcode scanning is performed on the image acquired by the second imaging unit and no data information corresponding to the barcode is read, then the first imaging unit is controlled to acquire an image, and barcode scanning is performed on the image acquired by the first imaging unit.

[0147] For example, if the image acquired by the first imaging unit 100 cannot read the data information corresponding to the barcode in the vicinity of 80mm or 120mm, the image can be acquired by the second imaging unit 200.

[0148] This further ensures that the barcode reading engine can read the data information corresponding to the barcode.

[0149] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0150] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application are included within the scope of protection of this application.

Claims

1. A bar code reading engine, comprising: The bar code reading engine comprises: a first imaging unit (100) comprising a variable-focus short-focus lens assembly (110) and a first image sensor (120); the first imaging unit (100) is configured to preferentially acquire a first bar code image within a first preset distance range; a second imaging unit (200) comprising a fixed-focus long-focus lens assembly (210) and a second image sensor (220); the long-focus lens assembly (210) has a focal length greater than a maximum focal length of the short-focus lens assembly (110); the second imaging unit (200) is configured to preferentially acquire a second bar code image within a second preset distance range; the second imaging unit (200) is configured to clearly image at a preset distance; the preset distance is within the second preset distance range; an aiming unit (300) configured to send an aiming pattern to a target bar code to aim at the target bar code; the aiming unit (300) is configured to enable a user to confirm, based on the aiming pattern, whether the target bar code is located at a center of a field of view of the first imaging unit (100) or the second imaging unit (200) and whether the target bar code is located at the preset distance; a control unit (400) configured to control the aiming unit (300) to turn on and turn off, and in a case where the aiming pattern hits the target bar code, determine, based on a current distance between the bar code reading engine and the target bar code, the first preset distance range, and the second preset distance range, whether the first imaging unit (100) or the second imaging unit (200) preferentially acquires an image; and perform bar code reading based on the acquired image to read out data information corresponding to the target bar code.

2. The bar code symbol reading engine of claim 1, wherein, The bar code reading engine further comprises a ranging unit (500) configured to detect the current distance between the bar code reading engine and the target bar code and send the current distance to the control unit (400) to enable the control unit (400) to determine, in a case where the current distance is within the first preset distance range, that the first imaging unit (100) preferentially acquires the image, or in a case where the current distance is within the second preset distance range, that the second imaging unit (200) preferentially acquires the image.

3. The bar code reading engine according to claim 1, wherein the control unit (400) is further configured to perform image processing on the image acquired by the first imaging unit (100), determine a position of the aiming pattern in the acquired image, and determine the current distance between the bar code reading engine and the target bar code based on the position of the aiming pattern in the acquired image.

4. The bar code reading engine according to claim 1, wherein the first imaging unit (100) and the second imaging unit (200) are arranged in a staggered manner, and a first imaging optical axis of the first imaging unit (100) is parallel to a second imaging optical axis of the second imaging unit (200). ​ ​ ​ The aiming unit (300) comprises a first aiming subunit (310) and a second aiming subunit (320); the first aiming subunit (310) is configured to send a first aiming light beam (311) to a target barcode to form a first aiming pattern on the target barcode; the second aiming subunit (320) is configured to send a second aiming light beam (321) to the target barcode to form a second aiming pattern on the target barcode; The first aiming subunit (310) and the second aiming subunit (320) are arranged in a staggered manner; wherein a first aiming optical axis of the first aiming subunit (310) is parallel to the first imaging optical axis and the second imaging optical axis; The second aiming subunit (320) has a second aiming optical axis with an inclination angle relative to the first imaging optical axis and the second imaging optical axis; so that the second aiming light beam (321) and the first aiming light beam (311) have an inclination angle, forming a light beam intersection point; The second imaging optical axis of the second imaging unit (200) passes through the light beam intersection point, and the light beam intersection point is located at a preset distance within a clear imaging range of the second imaging unit; based on the light beam intersection point, the second aiming pattern and the first aiming pattern have an overlapping area; a user can confirm whether the target barcode is in the center of the field of view of the second imaging unit and whether the target barcode is located within the preset distance of the clear imaging range of the second imaging unit based on whether the target barcode is in the overlapping area of the first aiming pattern and the second aiming pattern.

5. The barcode reading engine according to claim 4, wherein The first aiming pattern is a cross laser spot (314) for indicating the image center of the first imaging unit (200); The second aiming pattern is a circular spot (324) for indicating the image center of the second imaging unit (200); When the circular spot (324) and the cross laser spot (314) have an overlapping area, it indicates that the target barcode is located within the preset distance of the clear imaging range of the second imaging unit.

6. The barcode reading engine according to claim 4, wherein The variable-focus short-focus lens assembly (110) of the first imaging unit (100) comprises, in sequence along the direction of the first imaging optical axis of the first imaging unit (100), a short-focus lens base (111), a short-focus lens (112), a bracket (113), and a variable-focus optical element (114); the positions of the short-focus lens (112) and the variable-focus optical element (114) correspond to the first image sensor (120); The fixed-focus long-focus lens assembly (210) of the second imaging unit (200) comprises, in sequence along the direction of the second imaging optical axis of the second imaging unit (200), a long-focus lens base (211) and a long-focus lens (212); the position of the long-focus lens (212) corresponds to the second image sensor (220).

7. The barcode reading engine according to claim 1, wherein The focal length of the variable-focus short-focus lens assembly (110) is between 3-7 mm. The fixed focal length of the long-focus lens assembly (210) is between 12-20mm; The preset distance is set based on user operation habits.

8. The bar code symbol reading engine of claim 1, wherein, The bar code reading engine further comprises a light supplement unit (600). The light supplement unit (600) is configured to irradiate the first imaging unit (100) and the second imaging unit (200) with light supplement in their fields of view.

9. The bar code reading engine of claim 1, wherein, The first imaging unit (100), the second imaging unit (200), the aiming unit (300) and the control unit (400) are arranged in a housing (700). One end surface of the housing (700) is a scanning end surface (710), and the scanning end surface (710) is provided with a first imaging through hole (720), a second imaging through hole (730) and an aiming through hole (740) arranged at intervals. The first imaging unit (100) and the second imaging unit (200) respectively collect images through the first imaging through hole (720) and the second imaging through hole (730); and the aiming unit (300) sends an aiming pattern to the target bar code through the aiming through hole (740).

10. The bar code symbol reading engine of claim 9, wherein, The bar code reading engine further comprises a ranging unit (500), and the scanning end surface (710) of the housing (700) is further provided with a ranging through hole (750). The ranging unit (500) detects the current distance between the bar code reading engine and the target bar code through the ranging through hole (750).

11. The bar code reading engine of claim 9, wherein, The aiming unit (300) comprises a first aiming subunit (310) and a second aiming subunit (320), and the aiming through hole (740) comprises a first aiming through hole (741) and a second aiming through hole (742). The first aiming subunit (310) sends a first aiming pattern to the target bar code through the first aiming through hole (741); and the second aiming subunit (320) sends a second aiming pattern to the target bar code through the second aiming through hole (742).

12. The bar code symbol reading engine of Claim 9, wherein, The bar code reading engine further comprises a light supplement unit (600), and the scanning end surface (710) of the housing (700) is further provided with a light supplement through hole (760). The light supplement unit (600) irradiates the first imaging unit (100) and the second imaging unit (200) with light supplement in their fields of view through the light supplement through hole (760).

13. A code reading device characterized by: The bar code reading engine and the device housing of any one of claims 1-12; The bar code reading engine is arranged in the device housing.

14. A method of bar code reading, characterized by, The control unit applied to the bar code reading engine of any one of claims 1-12, the method comprising: controlling the aiming unit to be turned on to send an aiming pattern to the target bar code; obtaining the current distance between the bar code reading engine and the target bar code; wherein the current distance is adjusted by adjusting the position of the bar code reading engine according to whether the target bar code is a normal code or a very small code and the state of the aiming pattern on the target bar code. In a case that the current distance is within the first preset distance range, it is determined that the first imaging unit is used to preferentially acquire the image; in a case that the current distance is within the second preset distance range or the target barcode is located at the preset distance at which the second imaging unit can clearly image, it is determined that the second imaging unit is used to preferentially acquire the image; The image acquired by the first imaging unit or the image acquired by the second imaging unit is subjected to barcode reading, so as to read out the data information corresponding to the target barcode.

15. The barcode reading method according to claim 14, wherein the step of obtaining the current distance between the barcode reading engine and the target barcode comprises: receiving the current distance information sent by a distance measuring unit arranged in the barcode reading engine; or performing image processing on the image acquired by the first imaging unit, determining the position of the aiming pattern in the acquired image, and determining the current distance between the barcode reading engine and the target barcode based on the position of the aiming pattern in the acquired image.

16. The barcode reading method according to claim 14, wherein the aiming unit of the barcode reading engine comprises a first aiming subunit and a second aiming subunit; and the step of controlling the aiming unit to send the aiming pattern to the target barcode comprises: controlling the first aiming subunit to send a first aiming light beam to the target barcode to form a first aiming pattern on the target barcode; and controlling the second aiming subunit to send a second aiming light beam to the target barcode to form a second aiming pattern on the target barcode; so that, in a case that the target barcode is an extremely small code, a user adjusts the position of the barcode reading engine so that the target barcode is located at the overlapping area of the first aiming pattern and the second aiming pattern, at this time, the target barcode is located at the center of the field of view of the second imaging unit and at the preset distance at which the second imaging unit can clearly image; and in a case that the target barcode is a normal code, the user hits the center of the first aiming pattern to the target barcode.

17. The barcode reading method according to claim 14, wherein in a case that the current distance is within the first preset distance range, if the barcode corresponding data information is not read out by performing barcode reading on the image acquired by the first imaging unit, the second imaging unit is controlled to acquire the image, and the barcode reading is performed on the image acquired by the second imaging unit; in a case that the current distance is within the second preset distance range, if the barcode corresponding data information is not read out by performing barcode reading on the image acquired by the second imaging unit, the first imaging unit is controlled to acquire the image, and the barcode reading is performed on the image acquired by the first imaging unit. ​ ​ ​ ​

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