Directional tobacco product

Abstract

Disclosed is a device for orienting a tobacco product (20) containing a strip-shaped component (4). The device includes means (12) for generating an image of the tobacco product, means (18) for determining an apparent width of the strip-shaped component from the image, means (18) for determining an amount of rotation of the tobacco product (20) based on the apparent width, and means (16) for rotating the tobacco product by the determined amount of rotation relative to the imaging means (12). This can allow the product (20) to be rotated such that the strip-shaped component has a known orientation relative to the imaging means.

Description

[0001] The present invention relates to techniques for orienting tobacco products containing internal strip components. The present invention applies particularly but not exclusively to heated tobacco products containing a susceptor.

[0002] Various types of heated tobacco products have started to appear on the market. These products are characterized by the ability to heat a tobacco column without burning or smoldering to release an aerosol containing nicotine and flavor. A particular type of heated tobacco product involves the use of a metal plate or susceptor contained within the tobacco column, which is inductively heated by surrounding electronics. This product avoids the need for an insertable blade that may break and the need to clean a heating element. Examples of such products are disclosed in WO2017 / 085242, the subject matter of which is incorporated herein by reference.

[0003] During the production process of tobacco products, it is necessary to ensure that the quality of the products is maintained. In the case of articles with internal susceptors, the positioning and forming accuracy of the susceptors are key quality measures in the production process. Therefore, measurement is taken as part of the quality assurance and quality control processes. For example, WO 2020 / 012162 (the subject matter of which is incorporated herein by reference) discloses an apparatus for analyzing rod-shaped tobacco products that produces an x-ray image of the product under test. This can allow detection of defects in internal components.

[0004] One challenge faced by quality assurance / quality control professionals is that the required measurements may be orientation-dependent. For example, it may be necessary to take measurements with an internal strip component, such as a susceptor, at right angles to or in a straight line with a detector. An example of such a requirement is transmission imaging of the product to measure the position of the susceptor relative to the circumferential wrapper and the circular ends of the tobacco segment. Measuring a large number of articles with precise orientation relative to a sensor can be a time-consuming, labor-intensive, and error-prone task.

[0005] Co-pending UK patent application No. 1917430.9 (the subject matter of which is incorporated herein by reference) discloses a technique for orienting a heated tobacco product containing a susceptor such that the product is in a known orientation for subsequent testing. The technique involves using a magnetic system to rotate the product. It has been found that this technique can effectively pre-align the product before testing. However, a disadvantage of this solution is that the magnetic system requires space to operate and increases the cost and complexity of the construction of the testing apparatus. In addition, it is only applicable to ferromagnetic susceptors and is not applicable to alternative materials that may be employed.

[0006] Accordingly, there is a desire to provide a technique for orienting a tobacco product such that an internal strip component is at a known angle, which minimizes space, cost, and complexity and will be applicable to a variety of different materials.

[0007] According to one aspect of the present invention, there is provided an apparatus for orienting a tobacco product comprising a strip component, the apparatus comprising:

[0008] means for generating an image of the tobacco product;

[0009] means for determining an apparent width of the strip component from the image;

[0010] means for determining a rotation amount based on the apparent width; and

[0011] means for rotating the product by the determined rotation amount relative to the imaging means.

[0012] The present invention can provide the advantage that by determining the rotation amount based on the apparent width of the strip component in an image of the tobacco product, it is possible to rotate the product such that the strip component has a known orientation relative to the imaging means. This can be achieved using an imaging means that can also be used for testing the product, thereby minimizing any additional space, cost, and complexity. For example, the orientation process can avoid the need for a magnetic rotation system and can be used with non-ferromagnetic strip components.

[0013] "Strip component" preferably refers to a component having a width greater than its thickness, preferably significantly greater than its thickness. For example, the width can be at least 5, 10, 15, or 20 times greater than the thickness.

[0014] Preferably, the strip component is an internal component. For example, the strip component can be a susceptor. The susceptor can be located within the tobacco column and can be arranged to heat the tobacco by inductive heating. The tobacco product can be used with an inductive heating device for inductively heating the strip component.

[0015] Preferably, the rotation amount is the rotation amount expected to bring the strip component to a known orientation relative to the field of view of the imaging means. For example, the rotation amount can be the rotation amount expected to align the strip component with the field of view of the imaging means or to make it perpendicular to the field of view of the imaging means, or to make it at any other angle. This can allow, for example, side imaging and / or front imaging of the strip component, which can help detect defects in the strip component.

[0016] Preferably, the amount of rotation is calculated from the apparent width and the nominal width of the strip-shaped component. The nominal width of the strip-shaped component can be a predetermined value stored in the memory. The nominal width can be based on known or expected properties of the strip-shaped component, e.g., the known width of the strips of the material from which the strip-shaped component is made. Thus, the inherent dimensions and shape of the strip-shaped component can be used to calculate the amount of rotation.

[0017] In one embodiment, the amount of rotation is calculated from the apparent width and the nominal width using inverse trigonometric functions. For example, if it is desired to rotate the sample such that the strip-shaped component is aligned with the field of view of the imaging device, the amount of rotation can be calculated from the equation where θ is the amount of rotation, W1 is the apparent width of the strip-shaped component, and W is the nominal width of the strip-shaped component. On the other hand, if it is desired to rotate the sample such that the strip-shaped component is perpendicular to the field of view of the imaging device, the amount of rotation can be calculated from the equation Alternatively, inverse trigonometric functions can be used to estimate the current angle of the strip-shaped component relative to the field of view, and the amount of rotation required to bring the strip-shaped component to another desired angle can be calculated by adding or subtracting the estimated current value.

[0018] As an alternative to inverse trigonometric functions, a look-up table that maps the apparent width to the amount of rotation can be used to determine the amount of rotation. Such a look-up table can contain predetermined values that can be obtained, for example, by empirical measurements and / or trigonometric calculations.

[0019] In some embodiments, the strip-shaped component can have rotational symmetry. In this case, the same apparent width can be produced if the strip-shaped component is oriented the same angle clockwise or counterclockwise. Thus, the alignment process may need to take into account the fact that the rotation should be clockwise or counterclockwise.

[0020] In a preferred embodiment, the imaging device is arranged to produce a second image of the article after the article has been rotated. In this case, the means for determining the apparent width can be arranged to determine a second apparent width of the strip-shaped component from the second image. The device can then be arranged to compare the second apparent width with the first apparent width and, depending on the result of the comparison, rotate the sample in a direction opposite to the direction in which the sample was initially rotated. For example, if the result of the comparison indicates that the apparent width has been changed in a manner opposite to the way it would be expected if the original rotation was in the correct direction, the device can be arranged to rotate the sample in the opposite direction in order to bring the strip-shaped component to the desired orientation relative to the field of view of the imaging device. This can allow the device to compensate for the fact that the original rotation may have been in the incorrect direction.

[0021] For example, if it is desired to rotate the sample such that the strip component is aligned with the field of view of the imaging device, the apparatus can be arranged to determine whether a second apparent width is greater than a first apparent width, and if the second apparent width is greater than the first apparent width, rotate the sample in a direction opposite to the direction in which the sample was initially rotated. On the other hand, if it is desired to rotate the sample such that the strip component is perpendicular to the field of view of the imaging device, the apparatus can be arranged to determine whether the second apparent width is less than the first apparent width, and if the second apparent width is less than the first apparent width, rotate the sample in a direction opposite to the direction in which the sample was initially rotated.

[0022] In one embodiment, the sample is rotated in a direction opposite to its initial rotation direction by an amount that is twice the initial rotation amount. In another embodiment, a second rotation amount is determined based on the second apparent width, and the sample is rotated in the opposite direction by the second rotation amount. The second rotation amount is preferably the amount of rotation that is expected to bring the strip component to the desired orientation relative to the field of view of the imaging device after the initial rotation. Alternatively, some combination of these two arrangements can be used. For example, a (possibly weighted) average of the first rotation amount and the second rotation amount can be used.

[0023] As an alternative, if the strip component contains asymmetric and visible features in the image, such as markers, indentations or bends, or if the strip component itself is asymmetric, the apparatus can be arranged to identify these features in the image and determine the rotation direction based on their position in the image.

[0024] In a preferred embodiment, a check can be made to determine whether the article is already in the desired orientation before determining the rotation amount and / or rotating the article. Thus, the apparatus can include means for comparing the apparent width of the strip component with a nominal size (possibly allowing some error tolerance), and the apparatus can be arranged to perform the rotation depending on the result of the comparison. For example, if the apparent width has a predetermined relationship with the nominal size, then the article can be considered to be in the correct orientation. Thus, if the apparent width has a predetermined relationship with the nominal size, the orientation process can be terminated.

[0025] The nominal size can be equivalent to the size that the apparent width would be expected to have if it were in the correct orientation. For example, the nominal size can be one of a nominal thickness and a nominal width. The nominal size can be a predetermined value and / or can be stored in a memory. The predetermined relationship can be one of: less than or equal to; and greater than or equal to (possibly allowing some error tolerance).

[0026] For example, if it is desired to rotate the sample such that the strip component is aligned with the field of view of the imaging device, the apparent width of the strip component can be compared to the nominal thickness. In this case, if the apparent width is less than or equal to the nominal thickness, the strip component can be considered to be aligned with the field of view, and in this case, the orientation process can be terminated. On the other hand, if it is desired to rotate the sample such that the strip component is perpendicular to the field of view, the apparent width of the strip component can be compared to the nominal width. In this case, if the apparent width is greater than or equal to the nominal width (within the required error tolerance), the orientation process can be terminated.

[0027] The above steps can also be performed after rotation has been carried out and a second (or subsequent) image has been taken.

[0028] If desired, after rotating the sample using any of the above techniques, the amount of rotation can be further fine-tuned. For example, successive small incremental rotations can be performed and the apparent width compared to the nominal width after each rotation until the apparent width has a predetermined relationship with the nominal dimensions within the required error tolerance. The direction of rotation can be determined based on previous results.

[0029] In one embodiment, the apparatus is arranged such that after rotating the sample, the sample is subsequently rotated 90° and another image is taken. In this case, the apparent width of the strip component in the another image can be determined and the width so determined can be used for subsequent calculation of the amount of rotation. For example, in the case where the original rotation aligns the strip component with the field of view of the imaging device, the apparent width of the strip component in the another image can be used to provide an updated value of the nominal width. In the case where the original rotation makes the strip component perpendicular to the field of view of the imaging device, the apparent width of the strip component in the another image can be used to provide an updated value of the nominal thickness.

[0030] Alternatively, the imaging device can be arranged to take two (or more) images of the sample, which two images correspond to, for example, a front view and a side view of the sample.

[0031] In any of the above arrangements, rotating the article relative to the imaging device can be achieved by rotating the article or rotating the imaging device or both. However, in a preferred embodiment, the rotation is of the tobacco article. For example, the tobacco article can be rod-shaped and the tobacco article can be rotated about its longitudinal axis.

[0032] The apparatus for rotating the article can include means for holding the article while it is being rotated. The holding means is preferably configured to hold the article releasably. For example, the holding means can include a mechanical chuck, a vacuum chuck, a clamp, a flexible medium such as an expandable sleeve or rubber, an expanding iris or any other suitable holding mechanism.

[0033] A device for rotating an article may include an actuator for physically rotating the article, such as an electric motor. The actuator is preferably configured such that a holding device for holding the article rotates.

[0034] The device for rotating an article may include a position encoder. The device may use the output of the position encoder to ensure that the article has been rotated by the correct amount.

[0035] Preferably, the imaging device is arranged for transmission imaging of the article. This may allow the imaging device to produce an image of the article that includes internal components, such as sensors.

[0036] For example, the imaging device may be arranged to produce an x-ray image of a sample. Thus, the device may include an x-ray imaging system that is arranged to produce an x-ray image of a tobacco article.

[0037] In any of the above arrangements, the device may include processing means (such as a processor running appropriate software) for determining the apparent width and / or for determining the amount of rotation. Any of the other functions described above may also be performed by or under the control of the processing means.

[0038] In a preferred embodiment, the device is arranged to test a tobacco article after it has been oriented. Thus, the device may be a test device for testing tobacco articles. This may allow the orientation of the tobacco article to be performed by the same device that is also used to test the article. This may avoid the need to provide a separate piece of equipment, such as a magnetic system, to perform the orientation, which may in turn help to minimize the size, cost, and complexity of the device.

[0039] The test device may be arranged to detect defects in the tobacco article, such as defects in the strip component. For example, the test may be used as part of a quality screening process test against pass and fail criteria.

[0040] For example, the device may be arranged to produce an image of a sample of the strip component with the field of view of the imaging device side-on (parallel), and analyze the image to detect defects. The defect may be, for example, one or more of the following: a deformed component; a misplaced component; a component of improper size; a missing component; a bent component; a folded component; an off-center component; and a distorted component; or any other defect.

[0041] According to another aspect of the present invention, there is provided a device arranged to orient a tobacco article comprising a strip component, the device including:

[0042] An x-ray imaging system arranged to produce an x-ray image of the tobacco article;

[0043] A processor arranged to determine an apparent width of a strip component from an image and to determine a rotation amount based on the apparent width; and

[0044] A rotation mechanism arranged to rotate an article relative to an imaging system by the determined rotation amount.

[0045] A corresponding method may also be provided. Thus, according to another aspect of the present invention, there is provided a method of orienting a tobacco article comprising a strip component, the method comprising:

[0046] Generating an image of the tobacco article;

[0047] Determining an apparent width of the strip component from the image;

[0048] Determining a rotation amount based on the apparent width; and

[0049] Rotating the article relative to the imaging device by the determined rotation amount.

[0050] Any of the above features may be provided together in any suitable combination. Features of one aspect of the invention may be provided with any other aspect. Device features may be provided with the method aspect and vice versa.

[0051] Preferred features of the present invention will now be described, purely by way of example, with reference to the respective drawings in which:

[0052] Figure 1 Shows the components of a heated tobacco article with a susceptor;

[0053] Figure 2 (A) to 2(C) show different types of deformation in the susceptor;

[0054] Figure 3 Shows the change in the apparent width of the susceptor caused by changing the angle between the source / detector and the sample;

[0055] Figure 4 Shows a plot of angle versus apparent width;

[0056] Figure 5 Shows the components of a system for orienting a heated tobacco article in one embodiment of the present invention;

[0057] Figure 6 Shows how the rotation angle is calculated;

[0058] Figure 7 Shows the steps taken by the orientation system in one embodiment;

[0059] Figure 8 Shows an example of an x-ray image of a sample with its susceptor aligned with the imaging system;

[0060] Figure 9 shows the components of a system for analyzing a heated tobacco product in another embodiment;

[0061] Figure 10 (A) through 10(D) show the process of imaging and rotating a sample in one embodiment; and Figure 11 shows the steps taken by an orientation system in another embodiment.

[0062] The tobacco industry has recently seen several innovations in the field of heated tobacco products. One particular innovation involves the use of metal plates or sensors within the tobacco column.

[0063] Figure 1 shows the components of an exemplary heated tobacco product with a sensor. Referring to Figure 1 , the heated tobacco product 2 includes a tobacco column 3 with a metal sensor blade 4. The sensor blade 4 is made of a magnetically and electrically conductive metal material. The heated tobacco product 2 includes a cooling / condensing element 5 and a particulate filter 6. The cooling / condensing element 5 is in the form of a hollow cellulose acetate tube. The heated tobacco product 2 can be wrapped in paper in a manner similar to a traditional cigarette to form a rod-shaped product. Various other components may be present in the product in addition to, or instead of, those shown.

[0064] Figure 1 The heated tobacco product is designed to be inserted into a heating device with an inductive heating source. The inductive heating source generates an alternating magnetic field that induces an alternating magnetic field in the sensor 4. This induced alternating magnetic field generates heat in the sensor. At least a portion of the heat generated in the sensor 4 is transferred to the tobacco column 3 to release an aerosol containing nicotine and flavor. The aerosol passes through the cooling element 5 and the filter 6 and is inhaled by the user.

[0065] For example, a process for manufacturing a heated tobacco product such as Figure 1 shown is described in WO 2017 / 005705, the subject matter of which is incorporated herein by reference.

[0066] During the manufacturing process of a tobacco product, it is important to monitor and control the process to ensure that no defects occur in the final product. Therefore, inspection methods are used for quality control of the production process.

[0067] The key to the quality of a tobacco product with a metal sensor is to ensure that the metal strip has the correct thickness and is correctly placed within the tobacco column without any deformation or distortion.

[0068] Figure 2(A) through 2(C) show some different types of deformations that may be caused by the cutting of the susceptor and the process of placing the susceptor in the tobacco rod. Assume that a correctly formed susceptor is made from a flat strip of material having a length L, a width W, and a thickness T. A correctly formed susceptor is as shown in Figure 2 (A). In this case, a side view of the susceptor will show a susceptor having a thickness T, and a front view of the susceptor will show a susceptor having a width W. A distorted susceptor is as shown in Figure 2 (B). In this case, a side view of the susceptor will show a susceptor having an apparent thickness T’, and a front view of the susceptor will show a susceptor having an apparent width W’. Figure 2 (C) shows a dish-shaped recessed susceptor. In this case, a side view of the susceptor will show a susceptor having an apparent thickness T”, and a front view of the susceptor will show a susceptor having an apparent width W”.

[0069] Thus, it can be seen that when the susceptor is deformed, the apparent width and thickness of the susceptor will change. It can also be seen that when viewing the susceptor from the side, it is not easy to distinguish a dish-shaped recessed or distorted defective susceptor from a susceptor having an incorrect thickness. In principle, a plan view of the susceptor can provide some indication of the type of deformation. However, in practice, there is a possibility of misdiagnosis when viewing from the end to determine the deformed thickness of the susceptor, because the distortion in the susceptor may not extend throughout the entire length of the rod and may therefore be masked. In addition, in the final product, the end of the susceptor may be covered by another element such as filter material or located below the end of the tobacco rod and is therefore not visible.

[0070] As disclosed in WO 2020 / 012162, one way to determine whether a susceptor is deformed or whether the thickness specification is correct is to use a penetration system, such as an x-ray system, to view the susceptor from the edge. This form of x-ray analysis is essentially achieved by the high-density metal susceptor projecting a darker “shadow” than the surroundings on the detector.

[0071] One challenge in such a system is to ensure that the susceptor hidden inside the cigarette rod is correctly aligned with the x-ray source and the detector so as to form an image of the side or front of the susceptor and that this image is not angled with respect to the source / detector combination. If the detector / source is at an angle to the plane of the susceptor, then the apparent width of the susceptor will change. If this measurement is used to determine whether the susceptor is dish-shaped recessed or distorted, then an incorrect high projected width result will be reported, which may incorrectly fail the acceptance criteria and / or incorrectly warn of a processing problem.

[0072] Figure 3Shows the change in the apparent width of the receptor caused by changing the angle between the source / detector and the sample. The apparent width of an ideal receptor is measured as it rotates to obtain a plot of angle versus apparent width.

[0073] Figure 4 Shows an example plot of angle versus apparent width. This principle can be used as a tool for calibrating a sample in a transmissive optical system, such as an x-ray system, in order to give a true measurement of the receptor's size and thickness, shape integrity (no distortion, bending, dish-shaped depressions, etc.), and so on, and thereby allow the evaluation of a set of pass / fail criteria for construction.

[0074] If an x-ray detection system is equipped with a rotation system, a set of images can be created at different rotation angles, and the minimum "width" of the receptor can be determined. It has been found that the accuracy of the rotation angle relative to the light source may be required to be 3° or less to produce images that can be used to determine the receptor width. However, a disadvantage of this scheme is that it is very time-consuming because each image must be taken, collected, and analyzed. In practice, the formation and processing of each image may take 10 seconds, and the sample must be rotated between each image. The further the receptor alignment is from "true", the more time the process takes. If this is a measure of manufacturing control (where defective products can be manufactured at a rate of 10,000 or more per minute), then this time-consuming process can be a significant problem.

[0075] Another approach is to use a magnet system to "pre-align" the rod. Such a system is disclosed in co-pending UK patent application number GB1917430.9. However, a disadvantage of this scheme is that the magnetic system requires space to operate and increases the cost and complexity of the x-ray system construction. In addition, it is only applicable to ferromagnetic receptors and not to alternative materials that may be used. Finally, the angular accuracy of this rotation technique may not be sufficient to detect and analyze some potential receptor defects.

[0076] In an embodiment of the present invention, knowledge of the expected size and shape of the receptor is used as part of the alignment process to bring the article into a known orientation. This can then allow, for example, side imaging of the receptor with an x-ray system.

[0077] Figure 5 Shows the components of a system for orienting a heated tobacco product in an embodiment of the present invention. Refer to Figure 5, the system includes an x-ray source 10, an x-ray detector 12, a vacuum chuck 14, a motor 16, and a control unit 18. In operation, the vacuum chuck 14 is used to hold the sample 20 using vacuum. The x-ray source 10 is used to irradiate the sample 20 with x-rays. The x-rays are detected by the detector 12, which forms an x-ray image of the sample. The motor 16 is used to rotate the vacuum chuck 14 so that the sample 20 rotates about its longitudinal axis. The control unit 18 controls the operation of the motor 16, the x-ray source 10, and the detector 12. The control unit can also send and / or receive data and / or commands from other devices.

[0078] In operation, the detector 12 is used to take an x-ray image of the sample 20. The resulting image data is fed from the detector 12 to the control unit 18. The control unit 18 analyzes the image data using an image processing algorithm to determine the apparent width of the receptor in the image of the sample. The control unit then uses the apparent width, along with knowledge of the nominal width of the receptor, to calculate the rotation angle that would be expected to align the receptor with the field of view of the imaging system, which will be explained below. Once the rotation angle is calculated, the control unit 18 controls the motor 16 to rotate the sample 20 about its longitudinal axis by the calculated angle.

[0079] After rotation, the detector 12 takes a new image of the sample and feeds it to the control unit 18. The control unit then determines the apparent width of the receptor in the new image. This can be used to check if the rotation was successful. If necessary, the sample can be rotated one or more further times to align it with the imaging system.

[0080] Once the sample has been aligned, further imaging processing algorithms can be used to determine the size and shape of the receptor and thus determine if the receptor is within specification. Suitable image processing algorithms for determining the size of an object in an image are known in the art and are not described further herein.

[0081] Figure 6 Shows how the rotation angle of the sample is calculated.

[0082] In Figure 6 , a plan view of the receptor is shown as a solid line. The receptor has a nominal width W. The nominal width W is the expected width of the receptor, based on the width of the raw material from which the receptor is formed. The apparent width of the receptor as seen by the detector is W1. The angle θ is the angle by which the receptor needs to be rotated to align it with the field of view of the detector. When aligned with the detector, the position of the receptor is shown as a dashed line. It is assumed that the thickness T of the receptor is much smaller than its width.

[0083] From Figure 6 it can be seen that, first approximation:

[0084]

[0085] Therefore, the value of θ can be calculated by the following formula:

[0086]

[0087] Therefore, the apparent width of the receptor, along with knowledge of its expected or nominal width, can be used to calculate the magnitude of the rotation angle that would be expected to align the receptor with the field of view of the x-ray system using Equation (2) above.

[0088] However, as can be seen from Figure 6 the receptor has rotational symmetry. Thus, if the receptor is oriented the same amount clockwise or counterclockwise, the same apparent width will result. Therefore, the alignment process needs to account for the fact that the rotation may need to be clockwise or counterclockwise. This can be done by first rotating the sample by an angle θ in one direction, then taking a new image of the sample and checking that the apparent width has actually decreased. If the rotation did not decrease the apparent width (indicating the original rotation direction was incorrect), then the sample is rotated in the opposite direction by an angle of 2θ.

[0089] Figure 7 Shows the steps taken by the orientation system to align the receptor with the x-ray imaging system in one embodiment. Referring to Figure 7 , in step 100, an image of the sample is taken. In step 102, the apparent width W1 of the receptor in the image of the sample is measured. In step 104, the apparent width W1 is compared to the expected thickness T. In step 106, it is determined whether the apparent width W1 is less than or equal to the expected or nominal thickness T (within the desired error tolerance). If this is the case, the receptor is considered to be aligned with the imaging system and the alignment process stops. On the other hand, if the apparent width W1 is greater than the expected thickness T, then in step 108, the rotation angle θ is calculated using Equation (2) above, where W is the expected or nominal width of the receptor. In step 110, the sample is rotated by the angle θ in one direction (in this case, clockwise).

[0090] In step 112, an image of the sample at the new position is taken. In step 114, the apparent width W2 of the receptor in the new image is measured. In step 116, it is determined whether the value of W2 is greater than the value of W1. If the value of W2 (the apparent width of the receptor in the second image) is greater than the value of W1 (the apparent width in the first image), it is considered that the sample has rotated in the wrong direction. In this case, in step 120, the sample is rotated by an angle of twice θ in the opposite direction (here, counterclockwise). This is done to correct the original (incorrect) rotation and rotate the sample to the position where the receptor is considered to be aligned with the field of view. Then the image is resampled (step 112), and the new apparent width is measured (step 114). Since the new apparent width should be less than the previous apparent width (step 116), the process proceeds normally to step 118. However, if desired, the number of sample rotations can be limited.

[0091] On the other hand, if the value of W2 is not greater than the value of W1, the original rotation direction is considered correct. In this case, in step 118, it is determined whether the apparent width W2 is less than or equal to the expected or nominal thickness T (within the required error tolerance). If W2 is less than or equal to T, it is considered that the receptor is aligned, and the alignment process stops.

[0092] On the other hand, if the apparent width W2 is greater than the expected thickness T, the receptor may be distorted, bent, or otherwise out of specification. In this case, in step 122, it is indicated that the receptor is defective. For example, this can be achieved by generating an alarm signal or sending a fault signal to another piece of equipment. In step 124, the sample is rejected, and then the process stops.

[0093] In the above arrangement, the calculation of the rotation angle assumes that the value of W is larger than the value of T. In the case of a foil receptor, this is a reasonable assumption. Generally speaking, the above calculation can be used for cases where the value of W is large enough compared to the value of T to give the required level of accuracy, for example, the maximum error is 3° or less.

[0094] However, when calculating the rotation angle θ, alternative receptor geometries may require considering the value of T. This can be done by using appropriate trigonometric calculations.

[0095] In addition, additional steps can be added to provide more precise receptor width measurements and more details about the structure / defects in the receptor. The confirmation of the width of the receptor can be obtained by 90° rotation and calculation, and if necessary, this calculation can be used again to "fine-tune" the receptor edge alignment.

[0096] If desired, different rotation angle values can be calculated to rotate the sample such that the sensor is at a different angle to the field of view, such as perpendicular or 45°. For example, the rotation angle expected to make the sensor perpendicular to the field of view can be calculated by the following formula:

[0097]

[0098] In this case, the above alignment process will be adjusted appropriately to rotate the sample such that the sensor is perpendicular to the field of view.

[0099] As an alternative to calculating the rotation angle, a look-up table can be used that maps the apparent width W1 to the rotation angle θ using predetermined values.

[0100] Once the alignment process has been performed, an image of the sample can be taken of the sensor in the case of a side view. Once the side image has been obtained, the thickness or deformation of the sensor can be obtained using known image analysis techniques and tools.

[0101] For example, in one embodiment, a "best fit" box can be drawn around the sensor to produce the smallest side dimensions. This numerical analysis can be compared with pass / fail criteria within the equipment and give an indication of the quality of sensor formation and the ultimate acceptability of the heated tobacco product.

[0102] Figure 8 An example of an x-ray image of a sample with the sensor aligned to the imaging system is shown. In Figure 8 the sensor can be seen in the center of the image, within the tobacco column. A "best fit" box has been drawn around the sensor using image processing software. From this, various dimensions can be obtained, such as the thickness of the sensor and the distance from the edge of the tobacco column in each direction. These measurements can be used as part of a quality control process. Similar techniques can also be used to determine the apparent width of the sensor.

[0103] In the above arrangement, the system basically consists of five elements, namely an x-ray illumination source, a device for detecting x-rays in the form of an image, a device for holding the sample to be tested, a device for rotating the sample to be tested, and a device for controlling the process and performing the necessary calculations.

[0104] In a preferred embodiment, the x-ray source is selected and configured such that it irradiates an area of interest of a sample to be tested that is immediately in front of the detector system. The energy of the x-rays used is selected such that they have sufficient penetration power for testing and are suitable for the detection device. It is generally desirable to use lower energy x-rays because these rays have lower penetrating power, thus greatly reducing the shielding requirements for operator safety. However, these so-called "soft" x-rays cannot have too low an energy because they may not be able to penetrate the sample or may not be detectable in the detector area. A compromise needs to be reached based on practical considerations.

[0105] The type of source - collimated or wide beam - is selected again depending on the detector system chosen.

[0106] As an alternative, it is also possible to use oblique illumination or backscattering or other forms of electromagnetic radiation instead of x-rays, although this may be less effective in practice.

[0107] The detector can be a device such as a large area detection plate. Such a device can image an area of the sample to be tested in a single exposure. This has some disadvantages in terms of the type and energy of the source and the high cost of the detector, which is proportional to the size of the illuminated area to be analyzed.

[0108] An alternative detector can be a region image sensor based on CMOS / CCD technology, as described in WO2020 / 012162. In such a system, small strip or panel detectors are in line with a low power collimated x-ray source. The sample to be tested is fixed and moved through the x-ray beam, and a high-quality image of one (or several) rows of pixels over the entire length of the sample is generated at one time. Due to its relatively low cost and simplicity, this arrangement may be preferred.

[0109] The third element is a device for holding the sample to be tested. This device must also meet many different requirements. First, the holding mechanism must hold the sample firmly because any slippage during the initial imaging or rotation will invalidate the measurement and compensation of the presentation angle of the receptor. On the other hand, the holding mechanism should not obscure the area of interest. In some embodiments, only a part of the sample can be imaged at any one time. In this case, a part of the test sample can be held. Care must also be taken not to damage or distort the sample.

[0110] The holding mechanism can take the form of a clamp, an expandable sleeve or a rubber or other flexible medium or an expanding iris. However, in a preferred embodiment, the holding mechanism takes the form of a foot on which the sample lies and a vacuum that holds the sample on a surface that is substantially transparent to x-rays. The advantage of this solution is that the entire sample can be imaged without any loss and held firmly enough to meet the requirements of the system.

[0111] Once held, the rod under test needs to be rotated. The rotation mechanism should have no recoil, or a compensating mechanism is required to eliminate any recoil in the system. This can take the form of a mechanical device or software that "loads" a movement to eliminate recoil, a process to eliminate the effect of recoil, where the recoil, for example, always approaches from a single direction of rotation.

[0112] The rotation system can employ a rack and pinion type movement, a simple driven gear, a belt drive, a timing belt, etc. In most cases, the basis is a motor and a gear drive system.

[0113] The rotation needs to be absolute because the rotation angle is calculated from the initial image and thus must be rotated for compensation. The amount of rotation can be determined by using a stepper motor configuration and counting the number of steps traveled, where the degree of travel is a function of the number of steps per rotation of the motor and any gearbox configuration. Alternatively, the rotation mechanism or shaft can be fitted with an encoder that reads back the angular position of the sample. In this way, the correct amount of rotation is applied, and this is particularly effective in a system where mechanical recoil has been eliminated.

[0114] It is important that there is no lateral movement during rotation. For practical purposes, it may be necessary to release the device that holds the sample steady in front of the source and detector. If the relationship between the source and the sample is maintained and understood, it is also feasible to remove the sample from the field of view of the source / detector, rotate it, and return it.

[0115] Figure 9 Components of a system for analyzing a heated tobacco product in another embodiment are shown. The system includes an x-ray source 30, an x-ray panel detector 32, a vacuum chuck 34, a platform 36, a drive motor 38, a lead screw 40, a position encoder 42, a control unit 44, and a rotary chuck 46. The x-ray source 30, the x-ray panel detector 32, the vacuum chuck 34, the drive motor 38, and the control unit 44 can be the same as or similar to the x-ray source 10, the x-ray panel detector 12, the vacuum chuck 14, the drive motor 16, and the control unit 18 described above with reference to Figure 5 described. Referring to Figure 9 , the vacuum chuck 34 is used to hold the sample 20 using vacuum. The vacuum chuck 34 is attached to the platform 36, and the platform 36 is translated by the drive motor 38 and the lead screw 40. The lead screw 40 is aligned with the axis of the sample 20 such that rotation of the motor 38 causes the sample to move axially relative to the source 30 and the detector 32. The control unit 44 is used to control the operation of the motor 38 to move the sample 20 to a suitable position for imaging. The precise position reference of the vacuum chuck is measured by the position encoder 42 and sent to the control unit 44.

[0116] In operation, the sample 20 is first moved to a position within the field of view of the detector 32 in the region of interest. An image of the sample is then taken by the panel detector 32 and transmitted to the control unit 44. The sample is then moved axially to another position. At this position, additional images are taken and transmitted to the control unit 44. This process can be repeated for a number of different positions of the sample. Preferably, the sample is moved such that images are taken along its entire length, each image adjacent or overlapping the next. If desired, certain portions of the sample can be imaged and / or have a reduced exposure time compared to other portions as the sample is moved. The control unit 44 includes suitable imaging algorithms for generating a composite image based on the individual images of different regions of the sample acquired by the panel detector 32. The resulting image data can be analyzed to determine the size of the receptors in the sample in the manner described above.

[0117] In this embodiment, the source 30 is a collimated low-energy x-ray source. The detector 32 is a flat panel detector, for example of the CMOS (complementary metal oxide semiconductor) or CCD (charge coupled device) type. Alternatively, a line detector can be used instead of the panel detector. The x-ray system can be, for example, as described in International Patent Application No. WO 2020 / 012162, although other types of x-ray imaging systems can also be used.

[0118] In Figure 9 the arrangement, the sample is rotated out of the analysis area by the rotary chuck 46. The rotary chuck 46 includes a clamping mechanism 48 and a rotation mechanism 50. The clamping mechanism 48 includes an expandable rubber sleeve that is arranged to clamp the sample firmly enough to hold it in place without damaging it. The rotation mechanism 50 includes a motor that allows the clamping mechanism to rotate in a controlled manner. The rotary chuck 46 operates under the control of the control unit 44.

[0119] In operation, the sample 20 is first held by the clamping mechanism 48 in the rotary chuck 46. The clamping mechanism then releases the sample so that it falls onto the platform 36. Once on the platform, the sample is held in place by the vacuum chuck 34. The sample 20 is then lowered through the x-ray beam and a first image is established by the detector 32 and the control unit 44.

[0120] Once the first image of the sample 20 is generated, the sample is raised so that it is outside the analysis area. Then, the top of the sample is gripped by the gripping mechanism 48 without rotating or translating it. The sample is released by the vacuum chuck 34 and then rotated by the rotary chuck 46 by an angle calculated in any of the above ways. Then, the sample is again held on the platform 36 by vacuum, and the rotary chuck releases the sample. Then, the sample passes through the source and detector again to generate a second image. This can be repeated several times. Once the sample is correctly aligned, measurements can be made as part of the quality control process. Once the measurements are complete, the platform 36 is removed and the vacuum is released to drop the sample that is no longer needed into the collection bin.

[0121] Figure 10 (A) through 10(D) illustrate the process of imaging and rotating a sample in one embodiment. Referring to Figure 10 (A), the sample 20 first lands on the platform 36 and is held by the vacuum chuck 34 in a position outside the field of view of the detector 32 and the source 30. The platform is lowered and a first image of the entire sample is captured. Referring to Figure 10 (B), the sample is outside the field of view of the source / detector. The direction of travel is reversed and the sample is raised until it enters the rotary chuck 46. Referring to Figure 10 (C), the sample is gripped by the gripping mechanism 48, which includes a set of rubber fingers or sleeves that grip the sample firmly yet gently. The holding vacuum is released and the platform 36 is moved away from the sample. Then, the rotary chuck 46 rotates by the correct angle to compensate for the angle of the sensor towards the detector plane. Then the platform 36 is raised, the holding vacuum is applied again, and then the rotary chuck 46 is released. Referring to Figure 10 (D), the sample held firmly on the platform 36 is lowered and the source / detector takes a second image as described above.

[0122] Figure 11 Illustrates the steps taken by the orientation system in another embodiment. In Figure 11 , steps 100 to 116 are the same as or similar to the corresponding steps described above with reference to Figure 7 and are therefore not described further. [[ID=Twenty - one]] [[ID=Twenty - two]]

[0123] [[ID=Twenty - three]]In [[ID=Twenty - four]] Figure 11 [[ID=Twenty - five]]'s arrangement, if it is determined in step 116 that the value of W2 is greater than the value of W1, the process proceeds to step 130. In step 130, a new rotation angle θ2 is calculated according to the following formula [[ID=Twenty - six]] [[ID=Twenty - seven]]

[0124] [[ID=Twenty - eight]] [[ID=Twenty - nine]] [[ID=Thirty]]

[0125] Where W2 is the apparent width of the receptor in the second image, and W is the expected or nominal width of the receptor. Then, in step 132, the sample is rotated counterclockwise by an angle θ2. This corrects the original (incorrect) rotation and rotates the sample to the position where the receptor is considered to be aligned with the field of view. Then, in step 134, the image is resampled, and in step 136, the apparent width W2 of the new version is measured. In step 118, it is determined whether the apparent width W2 is less than or equal to the expected or nominal thickness T (within the required error tolerance). If W2 is less than or equal to T, the receptor is considered to be aligned, and the alignment process stops.

[0126] On the other hand, if the apparent width W2 is greater than the expected thickness T, the receptor may be distorted, bent, or otherwise out of specification. In this case, in step 122, it is indicated that the receptor is defective, and in step 124, the sample is rejected.

[0127] Figure 11 One advantage of the arrangement shown is that it is possible to measure a larger value of the apparent width with higher precision compared to a smaller value of the apparent width. Therefore, it is possible to align the receptor with higher precision by recalculating the rotation angle in step 130.

[0128] In an alternative arrangement, the average value of the values 2θ1 and θ2 can be calculated, and the sample is rotated counterclockwise by this average value.

[0129] In Figure 7 and 11 In any of the embodiments shown, before indicating the defective receptor in step 122 and rejecting the sample in step 124, further attempts can be made to align the sample. For example, multiple incremental rotations can be performed, and after each rotation, a new image is taken, and the apparent width is compared with the nominal thickness T. The analysis of the apparent width in previous attempts can indicate the direction in which the rotation should occur. This process can continue until the apparent width is less than or equal to the nominal thickness T (within the required error tolerance), or until the apparent width starts to increase, or until a predetermined number of attempts have been made. This may help to compensate for any inaccuracies in the previous steps.

[0130] In any of the above embodiments, the means (e.g., control units 18, 44) for controlling the process and performing the necessary calculations can be implemented as a processor and associated memory running appropriate software to perform the functions described above.

[0131] Accordingly, it should be understood that embodiments of the present invention relate to a method for aligning a sensor or a metal element within a rod-shaped article relative to an imaging system (e.g., an x-ray system). An initial image of the rod passing through, which may be misaligned with respect to the source / detector, together with the nominal dimensions of the sensor or metal element, can be used to calculate the angle of the sensor or metal element relative to the source and detector of the imaging system. The imaging system is equipped with a rotation device that can be applied to the sample under test. The rotation system rotates the sample under test up to the calculated angle of the sensor or metal element with respect to the source detector of the imaging system, so that a second image can be obtained, at which time the sensor is orthogonal (at its edge) to the source / detector. After rotation, if the apparent width of the sensor increases, the sample under test is rotated in the opposite direction to the first rotation by twice the calculated rotation angle. The rotation mechanism can be equipped with an absolute angle encoder to determine the rotation angle. The recoil in the rotation system can be compensated by mechanically or arithmetically adjusting the angle of sample rotation. Alternatively, the source and detector can be rotated relative to the sample under test. The sample can be rotated 90° and imaged to determine the true width of the sensor. This determination can be used to provide a fine compensation for rotation towards the image edge. The upper edge on the image of the sensor can be used to determine the thickness of the sensor. The upper edge on the image of the sensor can be used to determine whether any distortion, dish-shaped depression, or other deformation has occurred in the formation of the sensor. The imaging source can be an x-ray source. The imaging source and the rotation device can be controlled by an electronic device and a microprocessor. Sensor analysis can be used as part of a quality screening process for passing and failing control criteria.

[0132] It should be understood that the embodiments of the present invention have been described above only by way of example, and changes in details are possible. For example, the features of one embodiment can be used in any other embodiment. Although the present invention is described as being used with a heated tobacco product having an internal sensor, other types of tobacco products can also be used as an alternative. The exact structure of the product may vary, and the above description is for illustrative purposes only. The present invention can also be used for other types of smoking articles containing strip components other than sensors. Other changes in details will be obvious to those skilled in the art.

Claims

1. An apparatus for orienting a tobacco product containing a strip-shaped component, the apparatus comprising: an imaging device for generating an image of the tobacco product; a device for determining an apparent width of the strip-shaped component by measuring a width of the strip-shaped component in the image; a device for determining a rotation amount based on the apparent width; and a device for rotating the product by the determined rotation amount relative to the imaging device.

2. The device according to claim 1, characterized in that, The strip-shaped component is a sensor.

3. The device according to claim 1 or 2, characterized in that, The rotation amount is an amount expected to bring the strip-shaped component to a known orientation relative to a field of view of the imaging device.

4. The device according to claim 1 or 2, characterized in that, The rotation amount is an amount expected to align the strip-shaped component with the field of view of the imaging device or to make it perpendicular to the field of view.

5. The device according to claim 1 or 2, characterized in that, The rotation amount is calculated from the apparent width and a nominal width of the strip-shaped component, wherein the nominal width is a known or expected width of the strip-shaped component.

6. The device according to claim 5, characterized in that The nominal width is a predetermined value.

7. The device according to claim 5, characterized in that, The rotation amount is calculated from the apparent width and the nominal width using an inverse trigonometric function.

8. The device according to claim 5, characterized in that, The amount of rotation is calculated according to the equation where θ is the amount of rotation, W1 is the apparent width, and W is the nominal width.

9. The device according to claim 1 or 2, characterized in that, The imaging device is arranged to generate a second image of the product after the product has been rotated, and the device for determining the apparent width is arranged to determine a second apparent width of the strip-shaped component by measuring a width of the strip-shaped component in the second image.

10. The device according to claim 9, characterized in that, The apparatus is arranged to compare the second apparent width with the apparent width and, depending on the result of the comparison, to rotate the product in a direction opposite to the direction in which the product was initially rotated.

11. The device according to claim 10, characterized in that, If the comparison result indicates that the apparent width changes in a manner opposite to the way it would be expected if the original rotation had been in the correct direction, the apparatus is arranged to rotate the product in the opposite direction.

12. The device according to claim 9, characterized in that, The apparatus is arranged to determine whether the second apparent width is greater than the apparent width, and if the second apparent width is greater than the apparent width, to rotate the product in a direction opposite to the direction in which the product was initially rotated.

13. The device according to claim 1 or 2, characterized in that, The apparatus includes a device for comparing the apparent width of the strip-shaped component with a nominal dimension, and the apparatus is arranged to perform a rotation depending on the result of the comparison, wherein the nominal dimension is one of a nominal thickness and a nominal width, the nominal thickness is a known or expected thickness of the strip-shaped component, and the nominal width is a known or expected width of the strip-shaped component.

14. The device according to claim 13, characterized in that, If the apparent width has a predetermined relationship with the nominal dimension, the orientation process terminates.

15. The device according to claim 1 or 2, characterized in that, The device for determining the apparent width of the strip-shaped component is arranged to analyze the image of the tobacco product using an image processing algorithm to determine the apparent width of the strip-shaped component in the image of the tobacco product.

16. The device according to claim 1 or 2, characterized in that, The apparatus is arranged such that after the product has been rotated, the product is then rotated 90° and another image is taken.

17. The device according to claim 16, characterized in that, The apparent width of the strip-shaped component in the other image is determined by measuring the width of the strip-shaped component in the other image, and the thus determined apparent width is used in a subsequent calculation of the rotation amount.

18. The device according to claim 1 or 2, characterized in that, The tobacco product is rod-shaped and the tobacco product is rotated about its longitudinal axis.

19. The device according to claim 1 or 2, characterized in that, The imaging device is arranged for transmission imaging of the article.

20. The device according to claim 1 or 2, characterized in that, The imaging device is arranged to produce an x-ray image of the article.

21. The device according to claim 1 or 2, characterized in that, The apparatus includes processing means for determining the apparent width and / or for determining the amount of rotation.

22. The device according to claim 1 or 2, characterized in that, The apparatus is a test apparatus for testing the tobacco article.

23. The device according to claim 22, wherein, The apparatus is arranged to produce an image of the article using the strip assembly parallel to the field of view of the imaging device and to analyze the image to detect a defect in the strip assembly.

24. An apparatus arranged to orient a tobacco article comprising a strip assembly, the apparatus comprising: An x-ray imaging system arranged to produce an x-ray image of the tobacco article; A processor arranged to determine the apparent width of the strip assembly by measuring the width of the strip assembly in the image and to determine the amount of rotation based on the apparent width; And A rotation mechanism arranged to rotate the article relative to the imaging system by the determined amount of rotation.

25. A method of orienting a tobacco article comprising a strip assembly, the method comprising: Producing an image of the tobacco article; Determining the apparent width of the strip assembly by measuring the width of the strip assembly in the image; Determining the amount of rotation based on the apparent width; And Rotating the article relative to the imaging device by the determined amount of rotation.

Images