Code scanning terminal

Abstract

The invention provides a code scanning terminal, and relates to the technical field of code scanning equipment. The code scanning terminal comprises a camera shooting unit which is used for collecting images in a view field; the aiming unit is used for projecting a first aiming pattern into the field of view of the camera unit; the diffraction unit is arranged on a projection light path of the aiming unit and divides the first aiming pattern into N second aiming patterns, and the axis of at least one second aiming pattern deflects towards the side close to the view field axis of the camera shooting unit compared with the axis of the first aiming pattern; the axis of at least one second aiming pattern deflects towards the side away from the view field axis of the camera shooting unit compared with the axis of the first aiming pattern. And the control unit is used for adjusting the focal length of the camera shooting unit according to the information of the second aiming pattern in the field of view of the camera shooting unit.

Description

Technical Field

[0001] The present invention relates to the technical field of code scanning equipment, and in particular to a code scanning terminal. Background Art

[0002] With the popularization of barcode applications and mobile payments, barcode recognition has gradually been applied to various industries in society. Barcode recognition usually adopts an image-based reading method. Due to the different distances between the barcode and the scanning device, the time used for lens focusing is prolonged. If the lens focusing time can be reduced, it will be of great help to the efficiency of image recognition. The general solution is to set a laser device on the scanning device, project laser for indication through the laser device, and perform auxiliary distance measurement according to the changes in the laser pattern on the barcode to obtain an estimated distance. According to the estimated distance, the focus can be quickly adjusted to reduce the lens focusing time, thereby reducing the power consumption of the entire scanning process. However, since the distance between the laser device and the image acquisition camera is fixed, the angle of the laser entering the camera's field of view is fixed, which leads to a certain blind spot in the near distance when using laser ranging, and the recognition accuracy is not high at a distance. Summary of the invention

[0003] The present invention provides a code scanning terminal and method, which are used to solve the problem in the prior art that the viewing angle of the laser entering the camera is fixed, resulting in a certain blind spot in the near distance and low recognition accuracy in the far distance when using laser ranging.

[0004] In a first aspect, the present invention provides a code scanning terminal, comprising: A camera unit, used to collect images within the field of view; A sighting unit, for projecting a first sighting pattern into the field of view of the camera unit; a diffraction unit, arranged on a projection light path of the aiming unit, and dividing the first aiming pattern into N second aiming patterns, wherein the axis of at least one of the second aiming patterns is deflected toward a side closer to the axis of the field of view of the camera unit than the axis of the first aiming pattern; and the axis of at least one of the second aiming patterns is deflected toward a side farther from the axis of the field of view of the camera unit than the axis of the first aiming pattern; The control unit is used to adjust the focal length of the camera unit according to the information of the second aiming pattern in the field of view of the camera unit.

[0005] A code scanning terminal provided according to the present invention also includes a storage unit, in which distance information corresponding to the second aiming pattern information is pre-stored. The control unit obtains the distance information based on the acquired second aiming pattern information and adjusts the focal length of the camera unit based on the distance information.

[0006] According to a code scanning terminal provided by the present invention, the field of view axis of the camera unit is located in a first direction.

[0007] According to a code scanning terminal provided by the present invention, the aiming unit and the camera unit are arranged side by side, the diffraction unit is arranged outside the field of view of the camera unit, and the aiming unit can project a first light beam parallel to the first direction to form a first aiming pattern.

[0008] According to a barcode scanning terminal provided by the present invention, the diffraction unit divides the first light beam into N second light beams, the N second light beams are located in the same horizontal plane, the angles between two adjacent second light beams are the same, each second light beam can form a second aiming pattern, and at least one of the second light beams is deflected toward a side closer to the field of view axis of the camera unit than the extension line of the first light beam.

[0009] According to a barcode scanning terminal provided by the present invention, at least one of the second light beams is deflected toward a side away from the field of view axis of the camera unit compared to an extension line of the first light beam.

[0010] According to a code scanning terminal provided by the present invention, one of the second light beams coincides with an extension line of the first light beam, and N is an odd number greater than or equal to 3.

[0011] According to a code scanning terminal provided by the present invention, the second aiming pattern has the same shape as the first aiming pattern.

[0012] According to a code scanning terminal provided by the present invention, the second aiming pattern is a light spot.

[0013] According to a code scanning terminal provided by the present invention, the information of the second aiming pattern includes the number of the second aiming patterns.

[0014] In a second aspect, the present invention further provides a code scanning method, comprising: Collecting images within the field of view; projecting a first aiming pattern into the field of view; Divide the first aiming pattern into N second aiming patterns, so that the axis of at least one second aiming pattern is deflected toward a side closer to the field of view axis than the axis of the first aiming pattern; and the axis of at least one second aiming pattern is deflected toward a side farther from the field of view axis than the axis of the first aiming pattern; Adjust the focus according to the information of the second aiming pattern in the field of view.

[0015] According to a code scanning method provided by the present invention, adjusting the focal length according to information of a second aiming pattern in the field of view includes: pre-storing distance information corresponding to the second aiming pattern information; Distance information is obtained according to the acquired information of the second aiming pattern, and the focal length is adjusted according to the distance information.

[0016] According to a code scanning method provided by the present invention, the field of view axis is located in a first direction.

[0017] According to a code scanning method provided by the present invention, a first aiming pattern is formed by projecting a first light beam parallel to the first direction.

[0018] According to a code scanning method provided by the present invention, the first light beam is divided into N second light beams, the N second light beams are located in the same horizontal plane, the angles between two adjacent second light beams are the same, and each second light beam can form a second aiming pattern, so that at least one of the second light beams is deflected toward a side closer to the axis of the field of view than the extension line of the first light beam; and at least one of the second light beams is deflected toward a side farther from the axis of the field of view than the extension line of the first light beam.

[0019] According to a code scanning method provided by the present invention, one of the second light beams coincides with an extension line of the first light beam, and N is an odd number greater than or equal to 3.

[0020] According to a code scanning method provided by the present invention, the second aiming pattern has the same shape as the first aiming pattern.

[0021] According to a code scanning method provided by the present invention, the second aiming pattern is a light spot.

[0022] According to a code scanning method provided by the present invention, the information of the second aiming pattern includes the number of the second aiming patterns.

[0023] The barcode scanning terminal and method provided by the present invention divide a single light beam into multiple light beams by arranging a diffraction element on the projection light path of the aiming unit, and expands the indication range of the light beam, so that at least one aiming light beam enters the field of view of the camera unit earlier, and at least one aiming light beam enters the field of view of the camera unit later, and the aiming light beam forms an aiming pattern on the target object, and the distance information can be quickly matched and acquired through the aiming pattern information on the target object, and then the focal length of the camera unit is adjusted according to the distance information, and the focus of the camera unit is focused on the surface of the target object, so that a clear image of the barcode on the surface of the target object is obtained more quickly, and the efficiency of the barcode scanning is improved, thereby reducing the power consumption of the barcode scanning process; at the same time, by arranging the diffraction element, the present invention solves the problem of reducing the blind area of ​​the distance measurement at the near field and improving the sensitivity of the distance measurement at the far field when using laser distance measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 is a schematic diagram of a code scanning terminal provided by the present invention; Figure 2 is a schematic diagram of beam distribution when N is an odd number; Figure 3 is a schematic diagram of beam distribution when N is an even number; Figure 4 is a flow chart of the code scanning method provided by the present invention; Figure 5 is another schematic diagram of the code scanning terminal provided by the present invention.

[0026] Reference numerals: 100, camera unit; 200, aiming unit; 300, diffraction unit; 400, control unit; 500, storage unit; 600, target object; 700, fill light unit. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] Combine the following Figure 1-Figure 4 The present invention describes a barcode scanning terminal and method. The barcode scanning terminal disclosed in the present invention can be a device capable of barcode scanning, such as a PDA, a mobile phone, a tablet computer, a scanner, etc.

[0029] In a first aspect, the present invention provides a code scanning terminal, comprising: a camera unit 100 , a sighting unit 200 , a diffraction unit 300 and a control unit 400 .

[0030] The camera unit 100 is used to capture images within the field of view; the camera unit 100 includes a lens, which is a zoom lens, which can be an adjustable lens or a liquid lens. By adjusting the focal length of the lens, a clear image of the barcode on the target object 600 in the field of view can be captured.

[0031] The aiming unit 200 is used to project a first aiming pattern into the field of view of the camera unit 100; specifically, the aiming unit 200 may be a laser emitter, which may emit visible laser light to generate an aiming pattern visible to the human eye on the target object 600. The laser emitter may also emit invisible light to form an aiming pattern invisible to the human eye, which may be collected by the camera unit 100 and displayed on a display screen for recognition by the human eye.

[0032] The diffraction unit 300 is disposed on the projection light path of the aiming unit 200, and divides the first aiming pattern into N second aiming patterns, wherein the axis of at least one second aiming pattern is deflected toward a side closer to the field of view axis of the camera unit 100 than the axis of the first aiming pattern; and the axis of at least one second aiming pattern is deflected toward a side farther from the field of view axis of the camera unit 100 than the axis of the first aiming pattern.

[0033] It is understandable that the above-mentioned diffraction unit 300 is a diffractive optical element (DOE for short), which usually uses a micro-nano etching process to form a two-dimensionally distributed diffraction sub-unit, each of which can have a specific morphology, refractive index, etc., to finely control the laser wavefront phase distribution. The laser diffracts after passing through each diffraction sub-unit, and generates interference at a certain distance (usually infinity or the focal plane of the lens), forming a specific light intensity distribution.

[0034] According to the function to be achieved by the DOE of the present invention, the DOE of the present invention is preferably a beam splitter element for splitting a single laser beam into multiple laser beams, each of which has the characteristics of the original beam (except for power and propagation angle). The device can directly manufacture a diffraction beam splitter pattern on a plano-convex lens. This will produce a multi-point pattern focused on a specific working plane, and the distance between the points can be customized. These points can be arranged in a straight line, a matrix or any other custom shape, such as a hexagon, a cross, a circle, a triangle, etc., and the number of points and their positions can be customized.

[0035] The control unit 400 is used to adjust the focus of the camera unit according to the information of the second aiming pattern in the field of view of the camera unit 100. The information of the second aiming pattern includes at least one of the number, size and brightness of the second aiming pattern.

[0036] In this embodiment, the barcode scanning terminal also includes a storage unit 500, in which the distance information corresponding to the second aiming pattern information is pre-stored. The control unit 400 obtains the distance information based on the acquired second aiming pattern information, and adjusts the focal length of the camera unit based on the distance information. The distance information here refers to the distance from the target object 600 to the lens. This distance can be divided into multiple intervals, such as 30-60cm, 60-90cm, 90-110cm, 110-120cm, etc. Each interval corresponds to a unique aiming pattern information. Of course, the setting of each interval is not limited to the above record, and can be set according to the actual application scenario. After obtaining the corresponding distance information according to the pattern information, the control unit 400 adjusts the focal length of the camera unit 100 to the corresponding distance interval, reducing the time for manual adjustment of the focal length.

[0037] For the convenience of description, it can be defined that the field of view axis of the camera unit 100 is located in the first direction.

[0038] The aiming unit 200 and the camera unit 100 are arranged side by side, and the side by side arrangement here can be side by side in the horizontal direction or side by side in the vertical direction. Because the aiming unit 200 and the camera unit 100 cannot overlap, the distance between the aiming unit 200 and the camera unit 100 is fixed. After the diffraction unit 300 of the present invention is removed, the field of view angle of the laser emitted by the aiming unit 200 entering the camera unit 100 is fixed, which results in a certain blind spot in the near distance and low recognition accuracy in the far distance when using laser ranging.

[0039] The diffraction unit 300 is disposed outside the field of view of the camera unit 100 . Preferably, the diffraction unit 300 is disposed near the projection end of the aiming unit 200 . The aiming unit 200 can project a first light beam parallel to a first direction to form a first aiming pattern.

[0040] The diffraction unit 300 divides the first light beam into N second light beams. In the present embodiment, the N second light beams can be set to be located on the same horizontal plane, and the angles between two adjacent second light beams are the same. Each second light beam can form a second aiming pattern after being projected onto the target object 600. At least one second light beam is deflected toward the side closer to the field of view axis of the camera unit 100 than the extension line of the first light beam, and at least one second light beam is deflected toward the side farther from the field of view axis of the camera unit 100 than the extension line of the first light beam.

[0041] In some embodiments, the N second light beams are located on the same vertical plane, or the N second light beams are distributed in a matrix manner; the arrangement of the second light beams can be set according to the actual application scenario. For example, for objects with a longer length, the N second light beams can be set to be located on the same horizontal plane; for objects with a higher height, the N second light beams can be set to be located on the same vertical plane; the N second light beams are distributed in a matrix manner and are suitable for objects of all sizes, but accordingly, the diffraction unit 300 is difficult to manufacture and has high cost.

[0042] In this embodiment, one of the second light beams coincides with the extension line of the first light beam, and N is an odd number greater than or equal to 3. The larger N is, the more second light beams there are, and the more second aiming patterns can be formed on the target object 600 at the same distance, so that the distance interval can be divided into finer areas, and the control unit can be closer to the optimal focal length when controlling the camera unit to focus.

[0043] In some embodiments, N may be an even number greater than or equal to 2.

[0044] The value of N is mainly to adapt to the arrangement of the second light beam. For example, if the second aiming pattern formed by the second light beam is arranged in a straight line, the value of N does not need to be so large; if the second aiming pattern formed by the second light beam is distributed in a matrix, the value of N is larger; in short, there is no clear regulation on the value of N, and it is determined based on the actual application scenario, combined with comprehensive factors such as the distance to the target object 600 and the size of the target object 600.

[0045] In this embodiment, the second aiming pattern has the same shape as the first aiming pattern, and the second aiming pattern is a light spot, that is, both the first aiming pattern and the second aiming pattern are light spots. The information of the second aiming pattern includes the number of the second aiming patterns.

[0046] In order to simplify the structure and calculation method of the present invention, the diffraction unit 300 of the present invention is a beam splitter element, which divides the first light beam into multiple second light beams, and then defines the first aiming pattern and the second aiming pattern to be light spots. That is to say, after the second light beam is projected onto the target object 600, the second aiming pattern formed is a point-shaped light spot. If there are multiple second aiming patterns on the target object 600, a row of point-shaped light spots is formed, and the point-shaped light spots are easy to be collected by the camera unit. Because they are point-shaped light spots, according to at least one of the number, size and brightness of the light spots, combined with the design parameters of the beam splitter element (including the number of N, the angle between two adjacent second light beams, the functional relationship between the projection distance of the second light beam and the size and brightness of the light spot, etc.), the distance between the aiming unit 200 and the diffraction unit 300 and the camera unit 100, the wavelength of the laser beam and other information, the approximate distance information from the target object 600 to the camera unit 100 can be calculated. For the convenience of calculation, the present invention only selects the number of light spots as the basis of the second aiming pattern information. Firstly, selecting only the number facilitates the design and manufacture of the beam splitter element, and secondly, there is no need to consider the error problem of the light spot brightness caused by the loss of laser during the transmission process.

[0047] It should be noted that only when the second light beam is projected onto the target object 600, the second aiming pattern will be displayed on the target object 600, and then the second aiming pattern will be collected by the camera unit 100. When matching the corresponding distance information according to the second aiming pattern information, the number of second aiming patterns on the target object 600 is also collected. For example, when there is one light spot on the target object 600, it means that the distance from the target object 600 to the camera unit 100 is 110-120 cm; when there are two light spots on the target object 600, it means that the distance from the target object 600 to the camera unit 100 is 90-110 cm; when there are three light spots on the target object 600, it means that the distance from the target object 600 to the camera unit 100 is 60-90 cm; when there are four light spots on the target object 600, it means that the distance from the target object 600 to the camera unit 100 is 30-60 cm; of course, the corresponding relationship between the distance range and the number of light spots is not limited to the above settings.

[0048] Furthermore, if Figure 5 As shown, the barcode scanning terminal of the present invention also includes a fill light unit 700, which is a fill light. The fill light unit 700 is arranged on one side of the lens, or, with the lens as the center, is distributed in an array on the outside of the lens. The fill light unit 700 is used to provide fill light when the control unit 400 adjusts the focal length of the camera unit 100 to capture the barcode image on the target object 600.

[0049] Specifically, when the barcode scanning terminal of the present invention is in use, the aiming unit 200 projects the aiming pattern into the field of view of the camera unit 100, and the camera unit 100 continuously collects images in the field of view. When the camera unit 100 collects the first frame of the image of the target object 600 with the second aiming pattern, this frame of image is defined as the first frame of image. That is, when the camera unit 100 collects the first frame of image, the control unit 400 obtains the distance information according to the information of the second aiming pattern in the first frame of image, and adjusts the focal length of the camera unit 100 so that the camera unit 1 00When capturing the next frame of the first frame, a clear barcode image on the target object 600 can be captured, and the next frame of the first frame is defined as the second frame. When the camera unit 100 captures the second frame, the aiming unit 200 pauses projecting the aiming pattern, i.e., the second aiming pattern is hidden. At the same time, the control unit 400 further controls the fill light unit 700 to light up for fill light, so as to further obtain a clear barcode image on the target object 600. The control unit 400 acquires and decodes the second frame, and the decoding success rate is further improved. It can be considered that when capturing the first frame, the aiming unit 200 works, and when capturing the second frame, the aiming unit 200 pauses working, and the fill light unit 700 works at the same time.

[0050] Furthermore, the luminous intensity level of the fill light unit 700 corresponds one-to-one to the distance interval range mentioned above. For example, when the distance is divided into 5 intervals, the luminous intensity of the fill light unit 700 is also divided into 5 levels. The greater the distance, the greater the luminous intensity level of the fill light unit 700.

[0051] It can be understood that the target object 600 targeted by the code scanning terminal of the present application is an object of uniform size, and the design parameters of the beam splitter element can be preset according to the size of the target object 600 to determine the corresponding relationship between the various values.

[0052] The code scanning method provided by the present invention is described below. The code scanning method described below and the code scanning terminal described above can be referenced to each other.

[0053] In a second aspect, the present invention provides a code scanning method, which is used in conjunction with the above-mentioned code scanning terminal, and the method includes: Collecting images within the field of view; projecting a first aiming pattern into the field of view; Divide the first aiming pattern into N second aiming patterns, so that the axis of at least one second aiming pattern is deflected toward a side closer to the field of view axis than the axis of the first aiming pattern; and the axis of at least one second aiming pattern is deflected toward a side farther from the field of view axis than the axis of the first aiming pattern; Adjust the focus according to the information of the second aiming pattern in the field of view. The specific steps include: pre-storing distance information corresponding to the second aiming pattern information; Distance information is obtained according to the acquired information of the second aiming pattern, and the focal length is adjusted according to the distance information.

[0054] In this embodiment, the field of view axis is located in a first direction, and a first aiming pattern is formed by projecting a first light beam parallel to the first direction.

[0055] In this embodiment, by dividing the first light beam into N second light beams, the N second light beams are located in the same horizontal plane, and the angles between two adjacent second light beams are the same, each second light beam can form a second aiming pattern, so that at least one second light beam is deflected toward a side closer to the axis of the field of view than the extension line of the first light beam; and at least one second light beam is deflected toward a side farther from the axis of the field of view than the extension line of the first light beam.

[0056] In this embodiment, one of the second light beams coincides with an extension line of the first light beam, and N is an odd number greater than or equal to 3.

[0057] In this embodiment, the second aiming pattern has the same shape as the first aiming pattern.

[0058] In this embodiment, the second aiming pattern is a light spot.

[0059] In this embodiment, the information of the second aiming pattern includes the number of the second aiming patterns.

[0060] It is worth mentioning that the code scanning method of the present invention is consistent with the code scanning terminal mentioned above in terms of workflow, and will not be elaborated on here.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A code scanning terminal, characterized in that: include: A camera unit, used to collect images within the field of view; A sighting unit, for projecting a first sighting pattern into the field of view of the camera unit; a diffraction unit, arranged on a projection light path of the aiming unit, and dividing the first aiming pattern into N second aiming patterns, wherein the axis of at least one of the second aiming patterns is deflected toward a side closer to the axis of the field of view of the camera unit than the axis of the first aiming pattern; and the axis of at least one of the second aiming patterns is deflected toward a side farther from the axis of the field of view of the camera unit than the axis of the first aiming pattern; The control unit is used to adjust the focal length of the camera unit according to the information of the second aiming pattern in the field of view of the camera unit.

2. The code scanning terminal according to claim 1, characterized in that: It also includes a storage unit, in which distance information corresponding to the second aiming pattern information is pre-stored. The control unit obtains the distance information according to the acquired second aiming pattern information and adjusts the focal length of the camera unit according to the distance information.

3. The code scanning terminal according to claim 1, characterized in that: The field of view axis of the camera unit is located in a first direction.

4. The code scanning terminal according to claim 3, characterized in that: The aiming unit is arranged side by side with the camera unit, the diffraction unit is arranged outside the field of view of the camera unit, and the aiming unit can project a first light beam parallel to the first direction to form a first aiming pattern.

5. The code scanning terminal according to claim 4, characterized in that: The diffraction unit divides the first light beam into N second light beams, the N second light beams are located in the same horizontal plane, the angles between two adjacent second light beams are the same, each second light beam can form a second aiming pattern, and at least one of the second light beams is deflected toward a side closer to the field of view axis of the camera unit than the extension line of the first light beam.

6. The code scanning terminal according to claim 5, characterized in that: At least one of the second light beams is deflected toward a side away from the field of view axis of the camera unit relative to an extension line of the first light beam.

7. The code scanning terminal according to claim 6, characterized in that: One of the second light beams coincides with an extension line of the first light beam, and N is an odd number greater than or equal to 3.

8. The code scanning terminal according to claim 1, characterized in that: The second aiming pattern has the same shape as the first aiming pattern.

9. The code scanning terminal according to claim 8, characterized in that: The second aiming pattern is a light spot.

10. The code scanning terminal according to claim 9, characterized in that: The information of the second aiming pattern includes the number of the second aiming patterns.

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