Barcode recognition system

Abstract

The invention discloses a barcode recognition system. The barcode recognition system comprises a first image acquisition device, a second image acquisition device and a barcode recognition device, wherein the first image acquisition device is arranged above an article conveying belt; the second image acquisition device is arranged on the left side of the article conveying belt; the third image acquisition device is arranged on the right side of the article conveying belt; a target area covered by the first image acquisition device, the second image acquisition device and the third image acquisition device on the article conveying belt is divided into a bar code recognizable area and a bar code unrecognizable area, and the bar code recognizable area is located in front of the bar code unrecognizable area in the conveying direction of the article conveying belt. By means of the mode, the problem that at the moment, two or more objects possibly appear in the view of the camera at the same time, and at the moment, bar codes and objects are bound mistakenly is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bar code recognition, and particularly relates to a bar code recognition system. BACKGROUND

[0002] In express business, the flow speed of packages (articles) in express sites and sorting centers and the like greatly depends on the sorting efficiency of express packages, and package sorting mainly adopts bar code recognition technology to identify packages, compares the read bar code information with express information in a database, and then determines the destination and sorting path of the packages. Generally, a high-automation intelligent sorting scheme is adopted, that is, after unloading at the station, the packages are directly put on an article conveying belt before loading and unloading, and after single separation, the packages are sequentially sent to a code reading device, and in the process, the packages pass through at an arbitrary natural angle, and multiple cameras are required to realize six-face code reading of the packages. To further improve the package sorting efficiency, the methods of increasing the speed of the article conveying belt or reducing the package spacing are generally adopted, and the former has an upper limit, and the latter, when reducing from a large spacing such as 700 mm or more to a smaller spacing such as 500 mm to 300 mm, as shown in the following formulas, the angle of view of the camera (image acquisition device) is designed to cover a large package, and two or more packages may appear in the field of view of the camera responsible for the bar code recognition of the front and rear surfaces of the package at the same time, which may cause the problem of easy error in binding of the bar code and the package. Figure 1 and Figure 2 SUMMARY

[0003] The present application provides a bar code recognition system, which can solve the problem of easy error in binding of the bar code and the article when two or more articles appear in the field of view of the camera at the same time.

[0004] To solve the above technical problems, one technical scheme adopted by the present application is to provide a bar code recognition system, which comprises: a first image acquisition device, the first image acquisition device being arranged above an article conveying belt; a second image acquisition device, the second image acquisition device being arranged on the left side of the article conveying belt; and a third image acquisition device, the third image acquisition device being arranged on the right side of the article conveying belt; a target area covered by the first image acquisition device, the second image acquisition device and the third image acquisition device on the article conveying belt is divided into a bar code recognizable area and a bar code unrecognizable area, and in the conveying direction of the article conveying belt, the bar code recognizable area is located before the bar code unrecognizable area.

[0005] In the present application, the angle between the plane where the first image sensor in the first image acquisition device is located and the lens optical axis of the first image acquisition device satisfies the following condition: ; wherein, represents the angle between the plane where the first image sensor is located and the lens optical axis of the first image acquisition device, ​denotes the angle between the optical axis of the lens of the first image acquisition device and the horizontal plane of the article conveyor belt, denotes the focal length of the lens of the first image acquisition device, denotes the installation height of the first image acquisition relative to the article conveyor belt, denotes the maximum article height on the article conveyor belt, denotes the field of view angle of the first image acquisition device in the vertical plane, denotes the preset spacing between adjacent articles.

[0006] wherein, ranges between 88° and 89.5°.

[0007] wherein the first image acquisition device further satisfies the following conditions: condition 1: ; condition 2: ; condition 3: ; condition 4: ; wherein, denotes the pixel size, denotes the number of pixels occupied by the thinnest bar of the barcode in the image, denotes the barcode accuracy, denotes the vertical resolution of the first image acquisition device.

[0008] wherein the angle between the plane in which the second image sensor of the second image acquisition device is located and the optical axis of the lens of the second image acquisition device satisfies the following condition: ; wherein, denotes the angle between the plane in which the second image sensor is located and the optical axis of the lens of the second image acquisition device, denotes the angle between the optical axis of the lens of the second image acquisition device and the transport direction of the article conveyor belt, denotes the focal length of the lens of the second image acquisition device, denotes the preset spacing between adjacent articles, denotes the distance of the second image acquisition device to the article conveyor belt, denotes the field of view angle of the second image acquisition device in the horizontal plane.

[0009] wherein, ranges between 88° and 89°.

[0010] wherein the second image acquisition device further satisfies the following conditions: Condition 5: ; Condition 6: ; Condition 7: ; Condition 8: ; wherein, represents a pixel size, represents a number of pixels occupied by the thinnest bar of the barcode in the image, represents a barcode accuracy, represents a width of a conveying line of the conveying belt, represents a width of a horizontal field of view overlap area of the second image acquisition device and the third image acquisition device on the preset plane, represents a displacement amount of the article on the conveying belt, represents a pixel size, represents a horizontal resolution of the second image acquisition device.

[0011] wherein, an angle between a plane where the third image sensor in the third image acquisition device is located and a lens optical axis of the third image acquisition device satisfies the following condition: ; wherein, represents an angle between the plane where the third image sensor is located and a lens optical axis of the second image acquisition device, represents an angle between the lens optical axis of the third image acquisition device and a conveying direction of the conveying belt, represents a lens focal length of the third image acquisition device, represents a preset interval between adjacent articles, represents a distance from the third image acquisition device to the conveying belt, represents a field of view angle of the third image acquisition device in the horizontal plane.

[0012] wherein, ranges between 88°-89°.

[0013] The first image acquisition device, the second image acquisition device and the third image acquisition device are 2D image acquisition devices.

[0014] The bar code recognition system provided in the application sets the first image acquisition device above the article conveying belt, sets the second image acquisition device on the left side of the article conveying belt, and sets the third image acquisition device on the right side of the article conveying belt, thereby improving the problem of blind area in the field of view, and dividing the target area covered on the article conveying belt into a bar code identifiable area and a bar code non-identifiable area by using the first image acquisition device, the second image acquisition device and the third image acquisition device, wherein the bar code identifiable area is located before the bar code non-identifiable area in the conveying direction of the article conveying belt, so that the bar code of the article present in the bar code identifiable area can be clearly acquired and identified, and the bar code of the article present in the bar code non-identifiable area cannot be identified even if it is acquired, and can be clearly acquired and identified only when it enters the bar code identifiable area from the bar code non-identifiable area, thereby solving the problem that two or more articles may appear in the field of view of the camera at the same time, and the bar code is easily mistaken with the article. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without any creative effort. Among them: Figure 1 is a schematic diagram of continuous large package distribution of camera field of view range and near distance; Figure 2 is a schematic diagram of continuous small package distribution of camera field of view range, identifiable range and near distance; Figure 3 is a structural schematic diagram of an embodiment of the bar code recognition system provided in the application; Figure 4 is a schematic diagram of the scene corresponding to the first image acquisition device provided in the application; Figure 5 is a schematic diagram of the scene corresponding to the second image acquisition device and the third image acquisition device provided in the application; Figure 6 is a schematic diagram of the identifiable area scene corresponding to the first image acquisition device provided in the application; Figure 7 is a schematic diagram of the identifiable area scene corresponding to the second image acquisition device provided in the application; Figure 8 is a schematic diagram of the image acquired by the first image acquisition device provided in the application; Figure 9 is Figure 8 a schematic diagram of the bar code in the identifiable area in the above; Figure 10 isFigure 8 A diagram of a barcode located in an unidentifiable area. Detailed Implementation

[0016] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It is understood that the specific embodiments described herein are only for explaining this application and not for limiting it. Furthermore, it should be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings, not all structures. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0017] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0018] In the express delivery industry, the speed at which parcels (items) circulate in express stations and sorting centers largely depends on the sorting efficiency. Parcel sorting primarily uses barcode recognition technology to identify parcels. The barcode information is compared with express information in a database to determine the parcel's destination and sorting path. A highly automated intelligent sorting solution is generally adopted, where parcels are directly placed on a conveyor line (item conveyor belt) after unloading at the station and before loading and leaving. After individual parcels are separated, they are sequentially fed into the barcode reading device. During this process, parcels pass through at any natural angle, requiring multiple cameras to read the barcodes on all six sides. To further improve parcel sorting efficiency, methods such as increasing the conveyor speed or reducing the parcel spacing are generally adopted. The former has an adjustment limit, while the latter, when reducing from a large spacing (e.g., over 700mm) to a smaller spacing (e.g., 500mm-300mm), works as follows: Figure 1 and Figure 2 As shown, when the field of view of the camera (image acquisition device) is designed to cover a large package, more than two packages may appear simultaneously in the field of view of the camera responsible for barcode recognition on the front and back of the package. This can lead to errors in the binding of barcodes to packages.

[0019] Based on this, this application proposes to position a first image acquisition device above the conveyor belt; a second image acquisition device on the left side of the conveyor belt; and a third image acquisition device on the right side of the conveyor belt. This improves the problem of blind spots in the field of view. Furthermore, the first, second, and third image acquisition devices are used to divide the target area covered by the conveyor belt into a barcode-readable area and a barcode-unreadable area. In the conveying direction of the conveyor belt, the barcode-readable area precedes the barcode-unreadable area. This ensures that the barcodes of items appearing in the barcode-readable area can be clearly captured and identified, while the barcodes of items appearing in the barcode-unreadable area, even if captured, cannot be identified. Only when an item moves from the barcode-unreadable area into the barcode-readable area can it be clearly captured and identified. This solves the problem of errors in barcode-item binding that can occur when more than two items appear simultaneously in the camera's field of view. See any of the following embodiments for details.

[0020] See Figure 3 , Figure 3 This is a schematic diagram of the structure of an embodiment of the barcode recognition system provided in this application. Figure 3 This is a top view of the barcode recognition system. The barcode recognition system includes: a first image acquisition device 101, a second image acquisition device 102, and a third image acquisition device 103.

[0021] The first image acquisition device 101 is disposed above the conveyor belt. The first image acquisition device 101 is disposed above the conveyor belt and faces the conveyor belt, and is used to acquire images of the conveyor belt during its movement. Figure 3 In this context, 201, 202, and 203 represent the corresponding items on the conveyor belt. That is, items 201, 202, and 203 move toward the first image acquisition device 101 on the conveyor belt. In some embodiments, items 201, 202, and 203 may be packages or other items with barcodes.

[0022] The second image acquisition device 102 is located on the left side of the conveyor belt. The second image acquisition device 102 is located on the left side of the conveyor belt and faces the conveyor belt, and is used to acquire images of the conveyor belt during its movement from the left side.

[0023] The third image acquisition device 103 is located on the right side of the conveyor belt. The third image acquisition device 103 is located on the right side of the conveyor belt and faces the conveyor belt, and is used to acquire images of the conveyor belt during its movement from the right side of the conveyor belt.

[0024] In some embodiments, the first image acquisition device 101, the second image acquisition device 102, and the third image acquisition device 103 may be composed of cameras.

[0025] In some embodiments, the first image acquisition device 101 is disposed above the middle of the conveyor belt. The second image acquisition device 102 and the third image acquisition device 103 are installed on both sides of the conveyor belt and are symmetrically distributed about the central axis of the conveyor belt.

[0026] In one embodiment, the second image acquisition device 102 and the third image acquisition device 103 may not be symmetrically distributed, but their corresponding fields of view need to overlap.

[0027] The target area covered by the first image acquisition device 101, the second image acquisition device 102, and the third image acquisition device 103 on the conveyor belt is divided into a barcode identifiable area and a barcode non-identifiable area, wherein, in the conveying direction of the conveyor belt, the barcode identifiable area is located before the barcode non-identifiable area.

[0028] In some embodiments, the target area corresponds to a space; therefore, both the barcode identifiable area and the barcode non-identifiable area are a single space.

[0029] In some embodiments, the barcode recognition system may further include corresponding recognition devices connected to the first image acquisition device 101, the second image acquisition device 102, and the third image acquisition device 103, receiving images acquired by the first image acquisition device 101, the second image acquisition device 102, and the third image acquisition device 103, and performing barcode recognition from these images. The recognition device may be a terminal device, such as a computer.

[0030] In this embodiment, the first image acquisition device 101 is positioned above the conveyor belt; the second image acquisition device 102 is positioned on the left side of the conveyor belt; and the third image acquisition device 103 is positioned on the right side of the conveyor belt. This improves the problem of blind spots in the field of view. Furthermore, the first image acquisition device 101, the second image acquisition device 102, and the third image acquisition device 103 divide the target area covered by the conveyor belt into a barcode-readable area and a barcode-unreadable area. In the conveying direction of the conveyor belt, the barcode-readable area is located before the barcode-unreadable area. This ensures that the barcodes of items appearing in the barcode-readable area can be clearly acquired and identified, while the barcodes of items appearing in the barcode-unreadable area, even if acquired, cannot be identified. Only when an item moves from the barcode-unreadable area into the barcode-readable area can it be clearly acquired and identified. This solves the problem that when two or more items appear simultaneously in the camera's field of view, errors in barcode-item binding can easily occur.

[0031] In some embodiments, the imaging clarity of the barcode identifiable area should be as high as possible, and the identification of the barcode non-identifiable area should be minimized to prevent the barcode identifiable area from being bound to the package (item). The angle between the plane of the first image sensor in the first image acquisition device 101 and the optical axis of the lens of the first image acquisition device 101 satisfies the following condition: ;in, This represents the angle between the plane where the first image sensor is located and the optical axis of the lens of the first image acquisition device 101. This indicates the angle between the optical axis of the lens of the first image acquisition device 101 and the horizontal plane of the conveyor belt. This indicates the focal length of the lens of the first image acquisition device 101. This indicates the installation height of the first image acquisition relative to the conveyor belt. This indicates the maximum height of items on the conveyor belt. This indicates the field of view angle of the first image acquisition device 101 in the vertical plane. Indicates the preset interval between adjacent items.

[0032] See Figure 4 Taking a package as an example: the first image acquisition device 101 is a camera (including lens) responsible for photographing the left side of the package 202, and the angle between the lens optical axis and the horizontal plane is... The lens focal length is The field of view is The height of the lens from the surface of the conveyor belt is H2, the maximum height of the compatible items is H1, and the air gap between packages 201 and 202 is D; 401 is the image sensor inside the first image acquisition device 101, and the angle between its plane and the optical axis of the lens is... .normal =90°, Satisfy the following formula: .

[0033] Based on the aforementioned overall optical path design data and the above formula, the angle between the plane of the image sensor 401 of the first image acquisition device 101 and the optical axis of the lens can be obtained. The range is 88°~89.5°.

[0034] In some embodiments, further combined Figure 4 The first image acquisition device 101 also satisfies the following conditions: Condition 1: Condition 1 ensures that item 201 does not obstruct the view of item 202.

[0035] Condition 2: Condition 2 ensures that the camera's field of view covers the height of the object at 202.

[0036] Condition 3: Condition 3 can guarantee the pixel accuracy of the camera when recognizing barcodes on the bottom of item 202 at an angle of less than 45° to the horizontal plane.

[0037] Condition 4: Condition 4 can guarantee the required camera field of view as described above.

[0038] in, Indicates the pixel size. This indicates the number of pixels occupied by the thinnest line of the barcode in the image. Indicates barcode precision. This indicates the vertical resolution of the first image acquisition device 101.

[0039] Based on the above conditions, the design of the first image acquisition device 101 can be derived as follows: Camera specifications: When the maximum size of the object is less than 400mm, the vertical resolution N of the camera should be no less than 3000; when the maximum size of the object is between 400 and 700mm, the vertical resolution N of the camera should be between 3000 and 5500; the actual design of the solution uses a 5K*5K resolution camera or a 5472*3648 resolution camera, with a sensor pixel size of 2.4um or 2.5um; Lens specifications: Focal length The range is 20~25mm; Camera installation height: H2 = 1.1~1.5m; Camera axis tilt angle =45°~55°.

[0040] In some embodiments, the imaging clarity of the barcode identifiable area should be as high as possible, and the identification of the barcode non-identifiable area should be minimized to prevent the barcode identifiable area from becoming associated with the package (item). The angle between the plane of the second image sensor in the second image acquisition device 102 and the optical axis of the lens of the second image acquisition device 102 satisfies the following condition: ; in, This indicates the angle between the plane where the second image sensor is located and the optical axis of the lens of the second image acquisition device 102. This indicates the angle between the optical axis of the lens of the second image acquisition device 102 and the transmission direction of the conveyor belt. This indicates the focal length of the lens of the second image acquisition device 102. This indicates the preset interval between adjacent items. This indicates the distance from the second image acquisition device 102 to the conveyor belt. This indicates the field of view of the second image acquisition device 102 in the horizontal plane.

[0041] like Figure 5 As shown, the second image acquisition device 102 is a camera (including a lens) responsible for photographing the left side of the item, and the angle between the optical axis of the lens and the direction of movement of the item conveyor belt is... The lens focal length is The field of view is The distance from the lens to the edge of the conveyor belt is D2, and the air gap between adjacent items is D1; ​​402 is the image sensor inside the second image acquisition device 102, and the angle between its plane and the lens optical axis is... .normal =90°. Satisfy the following formula: .

[0042] Based on the aforementioned overall optical path design data and the above formula, the angle between the image sensor plane of the second image acquisition device 102 and the lens optical axis can be obtained. The range is 88°~89°.

[0043] In some embodiments, further combined Figure 5 The second image acquisition device 102 also satisfies at least one of the following conditions: Condition 5: Condition 5 ensures that an object adjacent to the object at position S1 does not obstruct the view of the object at position S2.

[0044] Condition 6: Condition 6 ensures that the camera's field of view covers the near-end height of the object.

[0045] Condition 7: Condition 7 can guarantee the pixel accuracy of the camera when the angle between the package to be inspected and the vertical plane at position S2 is within 45°.

[0046] Condition 8: Condition 8 can guarantee the required camera field of view as described above.

[0047] in, Indicates the pixel size. This indicates the number of pixels occupied by the thinnest line of the barcode in the image. Indicates barcode precision. This indicates the width of the conveyor belt for items. This indicates the width of the overlapping area of ​​the lateral field of view of the second image acquisition device 102 and the third image acquisition device 103 on the preset surface. This indicates the amount of displacement of items on the conveyor belt. Indicates the pixel size. This indicates the horizontal resolution of the second image acquisition device 102.

[0048] Based on the above conditions, the design of the second image acquisition device 102 can be derived as follows: Camera specifications: When the width of the conveyor belt is 0.8m~1.2m, the horizontal resolution M of the camera is 4500~6000; when the width of the conveyor belt is 0.6~0.8m, the horizontal resolution M of the camera is 3000~4500; the actual design uses a 5K*5K resolution camera or a 5472*3648 resolution camera, with a sensor pixel size of 2.4um or 2.5um; Lens specifications: Focal length The range is 20~25mm; Camera D2: D2 = 450~600mm; Angle between the camera axis and the direction of movement of the conveyor belt =35°~45°.

[0049] In some embodiments, the angle between the plane where the third image sensor is located in the third image acquisition device 103 and the optical axis of the lens of the third image acquisition device 103 satisfies the following condition: .

[0050] in, This indicates the angle between the plane where the third image sensor is located and the optical axis of the lens of the second image acquisition device 102. This indicates the angle between the optical axis of the lens of the third image acquisition device 103 and the transmission direction of the conveyor belt. This indicates the focal length of the lens of the third image acquisition device 103. This indicates the preset interval between adjacent items. This indicates the distance from the third image acquisition device 103 to the conveyor belt. This indicates the field of view of the third image acquisition device 103 in the horizontal plane.

[0051] in, It lies between 88° and 89°.

[0052] Similarly, since the third image acquisition device 103 and the second image acquisition device 102 are located on the left and right sides respectively, when the third image acquisition device 103 and the second image acquisition device 102 are centrally symmetrically distributed, the third image acquisition device 103 needs to meet the same conditions as the second image acquisition device 102.

[0053] By combining the first image acquisition device 101, the second image acquisition device 102, and the third image acquisition device 103, and designing an optical imaging system, it is possible to achieve blind-spot-free imaging of the front (back) of the target package in a close-range continuous package scenario, while ensuring the accuracy meets the decoding algorithm requirements.

[0054] After adjusting the angle between the image sensor and the lens optical axis in the first image acquisition device 101, the second image acquisition device 102, and the third image acquisition device 103, the areas of clear imaging in the first image acquisition device 101, the second image acquisition device 102, and the third image acquisition device 103 will change, such as... Figure 6 and Figure 7 As shown, the area with clear imaging (the identifiable area or the barcode-identifiable area) is limited to the vicinity of the package to be identified by the camera, while the imaging clarity of adjacent package areas will decrease significantly. Even if adjacent packages appear in the camera's field of view, the barcodes on them cannot be identified due to blurry imaging. The actual achievable effect is as follows: Figures 8-10 As shown. Figure 8 The barcode on the front of the package is like... Figure 9 The image is clearly identifiable. Figure 8 The barcode on the package located at the back is like... Figure 10 The image shown is too blurry to be recognized.

[0055] In some embodiments, the first image acquisition device 101, the second image acquisition device 102, and the third image acquisition device 103 are 2D image acquisition devices.

[0056] In summary, the barcode recognition system provided in this application places the first image acquisition device 101 above the conveyor belt, the second image acquisition device 102 on the left side of the conveyor belt, and the third image acquisition device 103 on the right side of the conveyor belt. This improves the problem of blind spots in the field of view. Furthermore, the first image acquisition device 101, the second image acquisition device 102, and the third image acquisition device 103 divide the target area covered by the conveyor belt into a barcode-recognizable area and a barcode-unrecognizable area. In the conveying direction of the conveyor belt, the barcode-recognizable area is located before the barcode-unrecognizable area. This ensures that the barcodes of items appearing in the barcode-recognizable area can be clearly captured and recognized, while the barcodes of items appearing in the barcode-unrecognizable area, even if captured, cannot be recognized. Only when an item moves from the barcode-unrecognizable area to the barcode-recognizable area can it be clearly captured and recognized. This solves the problem of errors in barcode-item binding that can occur when more than two items appear simultaneously in the camera's field of view. This proposal offers lower complexity and higher efficiency in barcode and package binding. Compared to existing technologies, this solution eliminates the need to collect multi-dimensional data and then perform complex data aggregation, logical reasoning, and judgment through software. Specifically, it involves designing an optical system, particularly the internal optical path of the barcode reader, to achieve regional differential control of image clarity. This directly limits the recognizability of barcodes in non-target areas, thereby preventing interference with barcode and package binding within the target area.

[0057] Furthermore, this application can solve the problems of blind spots and low barcode clarity in multi-faceted barcode recognition at close range. By designing the optical path to ensure the required field of view and accuracy for barcode reading, specifically by altering the clarity imaging area through internal optical path design, a larger relative aperture of the lens is achieved. This results in improved lens MTF and enhanced barcode contrast in the image. Furthermore, it allows for a reduction in camera exposure time or gain on existing light sources, thereby reducing motion blur or image noise.

[0058] Furthermore, the hardware system of this application is simpler, and the optical imaging system involved only includes a barcode reader camera and a lens. Compared with the prior art, there is no need to add a 3D camera, which has obvious advantages such as low complexity and high efficiency in terms of solution learning, installation, debugging and maintenance.

[0059] Furthermore, the required brightness of the light source for the camera associated with the front and rear readout codes is lower, which helps to reduce the power consumption of the light source and the number of LEDs. The method of implementation is to change the sharpness range through optical path design to reduce the required imaging depth of field, which can increase the light transmission capability of the lens aperture by 50% to 100%.

[0060] In the several embodiments provided in this application, it should be understood that the disclosed methods and devices can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of circuits or units is merely a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed.

[0061] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0062] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0063] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural changes made based on the description and drawings of this application, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A barcode recognition system, characterized in that, The barcode recognition system includes: A first image acquisition device is disposed above the conveyor belt; A second image acquisition device is located on the left side of the conveyor belt. A third image acquisition device is located on the right side of the conveyor belt. The target area covered by the first image acquisition device, the second image acquisition device, and the third image acquisition device on the item conveyor belt is divided into a barcode identifiable area and a barcode non-identifiable area, wherein, in the conveying direction of the item conveyor belt, the barcode identifiable area is located before the barcode non-identifiable area.

2. The barcode recognition system according to claim 1, characterized in that, The angle between the plane of the first image sensor in the first image acquisition device and the optical axis of the lens of the first image acquisition device satisfies the following condition: ； in, This represents the angle between the plane where the first image sensor is located and the optical axis of the lens of the first image acquisition device. This represents the angle between the optical axis of the lens of the first image acquisition device and the horizontal plane of the conveyor belt. This indicates the focal length of the lens of the first image acquisition device. This indicates the installation height of the first image acquisition relative to the conveyor belt of the items. This indicates the maximum height of items on the conveyor belt. This indicates the field of view angle of the first image acquisition device in the vertical plane. Indicates the preset interval between adjacent items.

3. The barcode recognition system according to claim 2, characterized in that, The range is between 88° and 89.5°.

4. The barcode recognition system according to claim 2, characterized in that, The first image acquisition device also meets the following conditions: Condition 1: ； Condition 2: ； Condition 3: ； Condition 4: ； in, Indicates the pixel size. This indicates the number of pixels occupied by the thinnest line of the barcode in the image. Indicates barcode precision. This indicates the vertical resolution of the first image acquisition device.

5. The barcode recognition system according to claim 1, characterized in that, in, The angle between the plane of the second image sensor in the second image acquisition device and the optical axis of the lens of the second image acquisition device satisfies the following condition: ； in, This indicates the angle between the plane where the second image sensor is located and the optical axis of the lens of the second image acquisition device. This indicates the angle between the optical axis of the lens of the second image acquisition device and the transmission direction of the conveyor belt. This indicates the focal length of the lens of the second image acquisition device. This indicates the preset interval between adjacent items. This indicates the distance from the second image acquisition device to the conveyor belt of the items. This indicates the field of view of the second image acquisition device in the horizontal plane.

6. The barcode recognition system according to claim 5, characterized in that, The range is between 88° and 89°.

7. The barcode recognition system according to claim 5, characterized in that, The second image acquisition device also meets the following conditions: Condition 5: ； Condition 6: ； Condition 7: ； Condition 8: ； in, Indicates the pixel size. This indicates the number of pixels occupied by the thinnest line of the barcode in the image. Indicates barcode precision. This indicates the width of the conveyor belt for the items. This indicates the width of the overlapping area of ​​the lateral field of view of the second image acquisition device and the third image acquisition device on the preset surface. This indicates the displacement of the items on the conveyor belt. Indicates the pixel size. This indicates the horizontal resolution of the second image acquisition device.

8. The barcode recognition system according to claim 1, characterized in that, in, The angle between the plane of the third image sensor in the third image acquisition device and the optical axis of the lens of the third image acquisition device satisfies the following condition: ； in, This indicates the angle between the plane where the third image sensor is located and the optical axis of the lens of the second image acquisition device. This indicates the angle between the optical axis of the lens of the third image acquisition device and the transmission direction of the conveyor belt. This indicates the focal length of the lens of the third image acquisition device. This indicates the preset interval between adjacent items. This indicates the distance from the third image acquisition device to the conveyor belt. This indicates the field of view angle of the third image acquisition device in the horizontal plane.

9. The barcode recognition system according to claim 8, characterized in that, The range is between 88° and 89°.

10. The barcode recognition system according to any one of claims 1-9, characterized in that, The first image acquisition device, the second image acquisition device, and the third image acquisition device are 2D image acquisition devices.

Images