Field

The specification discloses apparatus for inspecting a rod shaped article, and more particularly apparatus for inspecting a cigarette.

Background

Various methods exist for determining information on the cross-sectional profile of cigarettes for manufacturing quality control.

Summary In one embodiment there is provided an apparatus for inspecting a rod shaped article, comprising a projector arrangement configured to project two or more beams of electromagnetic radiation in a direction parallel to the longitudinal axis of the rod shaped article, wherein the two or more beams of electromagnetic radiation do not substantially overlap; a receiver arrangement configured to receive electromagnetic radiation of the two or more beams which is not interrupted by the article; and a processor arrangement configured to receive information on the electromagnetic radiation received and to determine, from the information on the electromagnetic radiation received, information on the cross-sectional profile of the rod shaped article. The information on the electromagnetic radiation received may comprise information on the amount of electromagnetic radiation received. Moreover, information on the cross-sectional profile of the rod shaped article may comprise information on the cross- sectional extent of the article.

The processor arrangement may determine, from the information on the

electromagnetic radiation received, information on the cross-sectional profile of the rod shaped article by determining information on what parts of the cross-section of the two or more beams are not interrupted or information on which of the two or more beams are not interrupted. Moreover, the information on cross-sectional profile of the rod shaped article may comprise information on the cross-sectional shape of the article. Furthermore, the determining of information on the cross-sectional shape of the rod shaped article may comprise using information on the location relative to the rod shaped article of the uninterrupted parts of the cross-section of the two or more beams or using information on the location relative to the rod shaped article of the

uninterrupted beams.

The apparatus for inspecting a rod shaped article may comprise a locating arrangement configured to receive the rod shaped article and to locate the received rod shaped article relative to the projector arrangement, such that the two or more beams of

electromagnetic radiation are projected in the direction parallel to the longitudinal axis of the rod shaped article. For example, the locating arrangement may comprise a conveyer drum comprising one or more longitudinal grooves around its circumference; and wherein receiving the rod shaped article comprises receiving the rod shaped article in one of the one or more longitudinal grooves.

In another embodiment a machine is provided comprising the apparatus for inspecting a rod shaped article according to embodiments described herein. For example, the machine maybe a machine for manufacturing rod shaped articles.

Brief Description of the Drawings Embodiments of the invention will now be described, by way of example only, with reference to accompanying drawings, in which:

FIG. l is an illustration of an apparatus for inspecting rod shaped articles, wherein a first cigarette is being inspected by the apparatus for inspecting rod shaped articles; FIG. 2 illustrates sectional view A-A of FIG. l;

FIG. 3 illustrates sectional view A-A of FIG. l, wherein the first cigarette is replaced by a second cigarette;

FIG. 4 illustrates sectional view A-A of FIG. l, wherein the first cigarette is replaced by a third cigarette; FIG. 5 is an illustration of a portion of a cigarette making machine comprising the apparatus for inspecting rod shaped articles of FIG. l;

FIG. 6 is an illustration of the apparatus for inspecting rod shaped articles of FIG. 5, wherein the first cigarette is being inspected;

FIG. 7 illustrates sectional view A' -A' of FIG. 6; FIG. 8 illustrates an extent of the cross-sectional profile of the first cigarette which may be determined by the inspection apparatus of FIG. 6;

FIG. 9 illustrates sectional view A' -A' of FIG. 6, wherein the first cigarette is replaced by the second cigarette; FIG. io illustrates an extent of the cross-sectional profile of the second cigarette which may be determined by the inspection apparatus of FIG. 6;

FIG. 11 illustrates sectional view A' -A' of FIG. 6, wherein the first cigarette is replaced by the third cigarette;

FIG. 12 illustrates a further example of the apparatus for inspecting rod shaped articles of FIG. 5, wherein the first cigarette is being inspected;

FIG. 13 illustrates sectional view B-B of FIG. 12;

FIG. 14 illustrates an extent of the cross-sectional profile of the first cigarette which may be determined by the inspection apparatus of FIG. 12;

FIG. 15 illustrates sectional view B-B of FIG. 12, wherein the first cigarette is replaced by a fourth cigarette;

FIG. 16 illustrates an extent of the cross-sectional profile of the fourth cigarette which may be determined by the inspection apparatus of FIG. 12;

FIG. 17 illustrates sectional view B-B of FIG. 12, wherein the first cigarette is replaced by the third cigarette; and FIG. 18 illustrates an extent of the cross-sectional profile of the third cigarette which may be determined by the inspection apparatus of FIG. 12.

Detailed Description of the Invention

As used herein, the term "smoking article" includes smokeable products such as cigarettes, cigars and cigarillos, whether based on tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco or tobacco substitutes, and also heat-not- burn products (i.e. products in which flavour is generated from a smoking material by the application of heat without causing combustion of the material). Any reference to a cigarette can be replaced by a reference to a smoking article. With reference to FIG. 1, an apparatus for inspecting rod shaped articles 1 is shown, comprising a projector arrangement 2, a receiver arrangement 3 and a processor 4. The apparatus for inspecting rod shaped articles 1 is, in places, herein referred to as the inspection apparatus 1.

The inspection apparatus 1 is configured to inspect rod shaped cigarettes located at an inspection location 5. In FIG. 1, a first cigarette 6 is shown located at the inspection location 5.

The projector arrangement 2 is configured to project a plurality of beams 7 of electromagnetic radiation (EM radiation) in a direction parallel to a longitudinal axis X of the first cigarette 6, wherein the plurality of beams 7 of EM radiation do not substantially overlap.

The receiver arrangement 3 is configured to receive EM radiation of the plurality of beams 7 which is not interrupted by the first cigarette 6. Moreover, the receiver arrangement 3 is configured to provide the processor 4 with information on the EM radiation received.

The processor 4 is configured to determine, from the information on the EM radiation received, information on the cross-sectional profile of the first cigarette 6 to detect manufacturing defects in the first cigarette. The information on the cross-sectional profile comprises information on the extent of the cross-section of the first cigarette 6 relative to two or more of the beams 7.

In more detail, the projector arrangement 2 comprises a laser configured to project a plurality of thin annular beams 7 of coherent light in a direction towards a first end 8 of the first cigarette 6, such that the annular beams 7 are concentric. For example, the laser may comprise a Z-Laser™ ZM12DM5.

Moreover, the projector arrangement 2 is configured such that the projected annular beams 7 are concentric with the longitudinal axis X of the first cigarette 6. The projector arrangement 2 is further configured such that the projected annular beams 7 are of different cross-sectional diameters and therefore do not overlap each other. Working from the innermost annular beam outwards, the plurality of annular beams 7 comprises a first beam 9, a second beam 10, a third beam 11, a fourth beam 12 and a fifth beam 13. Although five beams 9, 10, 11, 12, 13 are described, it should be understood that different pluralities of beams may be used.

The EM radiation from the beams, or portions of the beams 9 - 13, capable of being interrupted by a cigarette positioned at the inspection location 5 is herein referred to collectively as the inspection radiation 14. The inspection radiation 14 which passes a cigarette located at the inspection location 5 is herein referred to as the uninterrupted radiation 15.

The receiver arrangement 3 comprises an optics arrangement 16 and a first sensor arrangement 17. The optics arrangement 16 comprises a lens 18 configured to focus the uninterrupted radiation 15 to a focal area 19 at the first sensor arrangement 17.

The first sensor arrangement 17 comprises an infrared optical sensor configured to receive the uninterrupted radiation 15 at the focal area 19 and to output to the processor 4 a voltage as a function of the amount of EM radiation received. The information on the EM radiation received therefore comprises the voltage output by the first sensor arrangement 17. For example, the optical sensor 17 may comprise a Texas Advanced Optoelectronic Solutions (TAOS™) Infrared Light -to- Voltage Optical Sensor such as the TSL260R, TSL261R or TSL262R. Each beam, if uninterrupted, comprises EM radiation energy sufficient to cause the receiver arrangement 3 to generate a voltage according to Table 1.

Table 1:

Beams of the inspection radiation 14 Voltage (V) generated by the receiver arrangement 3 due to each beam

First beam 9 A

Second beam 10 B

Third beam 11 C

Fourth beam 12 D

Fifth beam 13 E The processor 4 is configured to compare a received voltage with predetermined, stored voltage values in order to determine information on the extent of the cross- section of an inspected cigarette. The processor 4 may be configured to do this by accessing stored profile information corresponding to the predetermined voltages.

The predetermined voltages each comprise the voltage produced by different sequences of one or more of the beams reaching the receiver arrangement 3 uninterrupted, wherein the beam sequences each begin with the fifth beam 13 and work successively inwards towards the longitudinal axis X. Each predetermined voltage is therefore associated with a sequence of received beams of the inspection radiation. Table 2 provides a list of the predetermined voltages and the

corresponding sequences of received beams. Table 2:

If the processor 4 determines that a received voltage matches a predetermined voltage, then the processor 4 accesses profile information corresponding to the predetermined voltage. The accessed profile information indicates that the cigarette profile extends to between the last beam in the beam sequence corresponding to the predetermined voltage and the next beam inwards of the last beam. For example, the beam sequence corresponding to the first predetermined voltage Vi comprises only the fifth beam 13. The next beam inwards of the fifth beam 13 towards the longitudinal axis X is the fourth beam 12. The profile information corresponding to the first predetermined voltage Vi therefore indicates that the cigarette profile extends to between the fifth beam 13 and the fourth beam 12.

Information indicating that the extent of the profile of a cigarette being inspected lies between two of the beams may for example comprise information indicating the likely cross-sectional diameter or cross-sectional area of the cigarette based on information on the cross-sectional geometry of the beams 7.

As the beams 7 are thin, i.e. they have a small radial extent as compared with the radial dimension of the cigarette 6, if a voltage received by the processor 4 lies between two successive predetermined voltages, comprising a lower and a higher predetermined voltage, then the profile information accessed by the processor 4 may for example indicate that the profile of the cigarette being inspected predominantly extends to between the last beam in the beam sequence

corresponding to the higher predetermined voltage and the next beam inwards of the last beam. Moreover, the profile information may also indicate that a portion of the profile of the cigarette extends beyond the last beam in the beam sequence corresponding to the higher predetermined voltage.

For example, if the processor 4 receives a voltage lying between the first predetermined voltage Vi and the second predetermined voltage V2, the processor 4 may access profile information indicating that the cigarette profile

predominantly extends to between the fourth beam 12 and the third beam 11. Moreover, the accessed profile information may also indicate that a portion of the profile of the cigarette extends beyond the fourth beam 12. Comparing a received voltage with predetermined voltage values in order to determine information on the extent of the cross-section of a cigarette is described in more detail with reference to FIG. 2, FIG. 3 and FIG. 4.

FIG. 2 shows sectional view A-A of FIG. 1. The A-A plane is orthogonal to the annular beams 7 and lies between the second end 21 of the cigarette and the receiver arrangement 3. Sectional view A-A is a view from the A-A plane looking toward the second end 21 of the first cigarette 6.

Due to the extent of the first cigarette 6, the uninterrupted radiation 15 comprises only the third beam 11, the fourth beam 12 and the fifth beam 13. This

uninterrupted radiation 15 therefore causes the receiver arrangement 3 to generate a first voltage equal to the sum of E, D and C.

In this case, comparing the received voltage with predetermined voltage values in order to determine information on the extent of the cross-section of the first cigarette 6, comprises the processor 4 determining that the first voltage matches the third predetermined voltage V3. Moreover, the processor 4 accesses first profile information corresponding to the third predetermined voltage V3. The first profile information indicates that the cross-sectional profile of the first cigarette 6 extends into the region between the third beam 11 and the second beam 10.

FIG. 3 shows sectional view A-A of FIG. 1, wherein the first cigarette 6 is replaced by a second cigarette 22. The second cigarette 22 is larger in diameter than the first cigarette 6, such that it also blocks the third beam 11. The receiving arrangement 3 generates a second voltage of the sum of E and D, and the processor 4 therefore determines that the extent of the profile of the second cigarette 22 lies between the fourth beam 12 and the third beam 11. FIG. 4 shows sectional view A-A of FIG. 1, wherein the first cigarette 6 is replaced by a third cigarette 23. The third cigarette 23 is of the same diameter as the first cigarette 6 however, it comprises a manufacturing error 24 wherein material protrudes from the surface of the cigarette. For example, the manufacturing error 24 may comprise flagging. The protruding material 24 interrupts an area of the cross-section of the third beam 11. The receiving arrangement 3 therefore generates a third voltage between the sum of E, D and C and the sum of E and D.

The processor 4 determines that the third voltage lies between the second predetermined voltage V2 and the third predetermined voltage V3. The processor 4 may therefore access second profile information indicating that the extent of the profile of the third cigarette 23 lies predominantly between the third beam 11 and the second beam 10. Moreover, the third profile information may also indicate that a part of the profile of the cigarette 23 extends beyond the third beam 11.

It will be appreciated from the foregoing that the inspection apparatus can be used to check that the cigarette under inspection has a diameter or cross sectional area within preset manufacturing tolerances defined by the radii of the beams 9-13. It will also be understood that the described process may also be used to provide an indication that the cigarette suffers from flagging and also an indication that it may be non-circular in cross section, indicating a manufacturing error, when the voltage produced by the receiver arrangement 3 deviates from one of the predetermined voltages V by more than a given amount.

Although the optics arrangement 16 is described as comprising a focal lens 18, the optics arrangement 16 may comprise different arrangements of optical apparatus configured so as to deliver the uninterrupted radiation 15 to the sensor

arrangement 17.

The inspection apparatus 1 of FIG. 1 can be used in a machine for making cigarettes. For example, the inspection apparatus 1 may be used at a station for inspecting cigarettes in a cigarette making machine. An example of this is described with reference to FIG. 5.

Referring to FIG. 5, a portion of a cigarette making machine 24 is illustrated comprising the inspection apparatus 1.

The cigarettes 26 are inspected by the inspection apparatus 1 after undergoing a series of fabrication steps (not shown) performed at fabrication stations (not shown) along a production line of the machine 24. The fabrication steps include attaching rods of tobacco to opposite ends of a filter rod, cutting the filter rod to produce two cigarettes 26 back-to-back and re-aligning the cigarettes 26. The portion of the machine 24 illustrated in Figure 1 can be considered as a modified portion of a machine such as the Hauni Max manufactured by Hauni

Maschinenbau AG of Hamburg Germany. The portion of the machine 24 comprises a feeder drum 27, an inspection drum 28, an outlet drum 29 and a rej ect drum 30. The feeder drum 27, inspection drum 28, outlet drum 29 and reject drum 30 each comprise a conveyer drum with axially extending cylindrical grooves 31 around its circumference configured to receive cigarettes 26. The grooves 31 are configured such that the longitudinal axis of a cigarette 26 received at a groove 31 is parallel with the axis of the drum.

Moreover, the grooves 31 are configured such that only a first portion of the circumference of a cigarette 26 received in a groove 31 is in contact with the conveyer drum. The remaining second portion 26' of the circumference of the cigarette 26 protrudes from the surface of the conveyer drum. Cigarettes 26 can be held in the grooves 31 of the drums described herein by negative air pressure.

Aligned cigarettes 26 are fed in the direction of arrow R to be received in the grooves 31 of the feeder drum 27. The aligned cigarettes 26 are then transferred to an inspection drum 28. The inspection drum 28 is driven in synchronisation with the feeder drum 27 and the aligned cigarettes 26 are transferred from the feeder drum 27 to corresponding grooves 31 of the inspection drum 28.

Through the rotation of the inspection drum 28, the aligned cigarettes 26 are fed successively through the inspection apparatus 1. The inspection apparatus 1 is configured to inspect each cigarette 26 when, during the rotation of the inspection drum 28, the cigarette 26 reaches the inspection location 5.

A diverter gate G is controlled based on the profile information determined by the inspection apparatus 1. If the profile information indicates that a cigarette 26 satisfies quality control criteria, then that cigarette is fed in an accept path onto outlet drum 29 driven in synchronism with drum 28 and then passed in the direction of arrow Y onto an output conveyor (not shown) for packaging. If the profile information indicates that a cigarette does not satisfy quality control criteria, then it is diverted by the diverter gate G so that it continues on a reject path. The reject path comprises the cigarette continuing around the inspection drum 28, then transferring onto a reject drum 30 before being passed in the direction of arrow Z for disposal or recovery of materials. The diverting action of the gate G may be implemented or assisted by controlling or releasing negative pressure that can retain the cigarettes 26 in the grooves 31 of the inspection drum 28. FIG. 6 is an illustration of the inspection apparatus of the machine of FIG. 5. Also shown is the inspection drum 28, and the first cigarette 26, 6 received in a groove 31 of the inspection drum 28, such that the first cigarette 26, 6 is located at the aforementioned inspection location 5.

The configuration of the inspection drum 28 is such that the inspection drum 28 blocks portions of some of the plurality of projected annular beams 7. The inspection radiation 14' of this embodiment is therefore different to the inspection radiation 14 described with reference to FIG. 1. The inspection radiation 14' of this embodiment is described in more detail with reference to FIG. 7, FIG. 9 and FIG. 11.

As previously described, the processor 4 is configured to compare a received voltage from sensor 17 with predetermined, stored voltage values in order to determine information on the extent of the cross-section of an inspected cigarette, which will now be described with regard to this embodiment in more detail with reference to FIG. 7, FIG. 8, FIG. 9, FIG. 10 and FIG. 11.

FIG. 7 shows sectional view A' -A' of FIG. 6. The A' -A' plane is orthogonal to the annular beams 7 and lies between the second end 21 of the cigarette and the receiver arrangement 3. Sectional view A' -A' is a view from the A' -A' plane looking toward the second end 21 of the first cigarette 6. FIG. 9 and FIG. 11 each show sectional view A' -A' of FIG. 6, wherein the first cigarette is replaced by a different cigarette in each figure.

As is illustrated by FIG. 7, FIG. 9 and FIG. 11, the configuration of the inspection drum 28 is such that the inspection drum 28 blocks a first arc of the third beam 32, a first arc of the fourth beam 33 and a first arc of the fifth beam 34.

Consequently, in this embodiment, the beams of the inspection radiation 14' comprise the first beam 9, the second beam 10, the remaining second arc of the third beam 35, the remaining second arc of the fourth beam 36 and the remaining second arc of the fifth beam 37.

Each beam of the inspection radiation 14', if uninterrupted by a cigarette at the inspection location, comprises EM radiation energy sufficient to cause the receiver arrangement 3 to generate a voltage according to Table 3. Table 3:

Moreover, the predetermined voltages each comprise the voltage produced by different sequences of one or more of the beams of the inspection radiation 14' reaching the receiver arrangement 3 uninterrupted. In this embodiment, the beam sequences each begin with the second arc of the fifth beam 37 and work successively inwards towards the longitudinal axis X. Each predetermined voltag is therefore associated with a sequence of received beams of the inspection radiation. Table 4 provides a list of the predetermined voltages for this embodiment and the corresponding sequences of received beams.

Table 4:

As previously described, if a voltage received by the processor 4 is found to match a predetermined voltage, then the processor 4 accesses profile information corresponding to the predetermined voltage. The accessed profile information indicates that the cigarette profile extends to between the last beam in the beam sequence corresponding to the predetermined voltage and the next beam inwards of the last beam. Furthermore, as the beams 7 are thin as previously described, if a voltage received by the processor 4 lies between two successive predetermined voltages, comprising a lower and a higher predetermined voltage, then the profile information accessed by the processor 4 may for example indicate that the profile of the cigarette being inspected predominantly extends to between the last beam in the beam sequence corresponding to the higher predetermined voltage and the next beam inwards of the last beam. Moreover, the profile information may also indicate that a portion of the profile of the cigarette extends beyond the last beam in the beam sequence corresponding to the higher predetermined voltage. Information indicating the extent of the profile of a cigarette being inspected may be based on information on the geometry of the inspection drum 28. Regarding FIG. 7, due to the extent of the first cigarette 6, the uninterrupted radiation 15 comprises only the second arc of the third beam 35, the second arc of the fourth beam 36 and the second arc of the fifth beam 37. This uninterrupted radiation 15 therefore causes the receiver arrangement 3 to generate a fourth voltage equal to the sum of H, G and F.

In this case, comparing the received voltage with predetermined voltage values in order to determine information on the extent of the cross-section of the first cigarette 6, comprises the processor 4 determining that the fourth voltage matches the seventh predetermined voltage V7. Moreover, the processor 4 accesses third profile information corresponding to the seventh predetermined voltage V7. The third profile information indicates that the cross-sectional profile of the second portion 26' of the first cigarette 6 extends into the region between the second beam 10 and the second arc of the third beam 35.

FIG. 8 illustrates an extent 38 of the cross-sectional profile of the first cigarette 6 which may be determined by the inspection apparatus 1 of FIG. 6. FIG. 9 shows sectional view A' -A' of FIG. 6, wherein the first cigarette 6 is replaced by the second cigarette 22. The second cigarette 22 is larger in diameter than the first cigarette 6, such that it also blocks the second arc of the third beam 35. The receiving arrangement 3 generates a fifth voltage of the sum of H and G, and the processor 4 therefore determines that the extent of the profile of the second portion 26' of the second cigarette 22 lies between the second arc of the third beam 35 and the second arc of the fourth beam 36.

FIG. 10 illustrates an extent 39 of the cross-sectional profile of the second cigarette 22 which may be determined by the inspection apparatus 1 of FIG. 6.

FIG. 11 shows sectional view A' -A' of FIG. 6, wherein the first cigarette 6 is replaced by the third cigarette 23. The third cigarette 23 is of the same diameter as the first cigarette 6 however, it comprises a manufacturing error 24 wherein material protrudes from the surface of the cigarette. The protruding material 24 interrupts an area of cross-section of the second arc of the third beam 35. The receiving arrangement 3 therefore generates a sixth voltage between the sum of H, G and F and the sum of H and G.

The processor 4 determines that the sixth voltage lies between the sixth

predetermined voltage V6 and the seventh predetermined voltage V7. The processor 4 may therefore access fourth profile information indicating that the extent of the profile of the second portion 26' of the third cigarette 23 lies predominantly between the second beam 10 and the second arc of the third beam 35. Moreover, as the beams are thin, the fourth profile information may also indicate that a part of the profile of the second portion 26' of the cigarette 23 extends beyond the second arc of the third beam 35.

Although the machine of FIG. 5 is described as comprising the inspection apparatus 1 of FIG. 1, other types of inspection apparatus may be used. For example, FIG. 12 illustrates a second embodiment la of the inspection apparatus, wherein the reception arrangement 3 comprises a second sensor arrangement 40 in place of the optics arrangement 16 and the first sensor arrangement 17. Also shown in FIG. 12 is the inspection drum 28, and the first cigarette 26, 6 received in a groove 31 of the inspection drum 28, such that the first cigarette 26, 6 is located at the aforementioned inspection location 5.

The second sensor arrangement is described in more detail with reference to FIG. 13, FIG. 15 and FIG. 17. The processor 4 is configured to determine, from the information on the EM radiation received provided by the receiver arrangement 3, information on the cross- sectional profile of the rod shaped article. The second sensor arrangement 40 provides different information on the EM radiation received to that provided by the first sensor arrangement 17. The processor 4 of the inspection apparatus la of FIG. 12 is therefore configured differently to that of the inspection apparatus 1 of FIG. 1 and FIG. 6. Determination by the processor 4, of the second inspection apparatus embodiment la, of information on the cross-sectional profile of a cigarette is described in more detail with reference to FIG. 13, FIG. 14, FIG. 15, FIG. 16, FIG. 17 and FIG. 18. The configuration of the inspection drum 28 and the projector arrangement is as described with reference to FIG. 6, FIG. 7, FIG. 9 and FIG. 11. The inspection radiation 14' of this embodiment is therefore as described with reference to FIG. 6, FIG. 7, FIG. 9 and FIG. 11.

FIG. 13 shows sectional view B-B of FIG. 12. The B-B plane is orthogonal to the annular beams 7 and intersects the annular beams 7 before they reach the first end 8 of the first cigarette 6. Sectional view B-B is a view from the B-B plane looking toward the first end 8 of the first cigarette 6. FIG. 15 and FIG. 17 each show sectional view B-B of FIG. 12, wherein the first cigarette is replaced by a different cigarette in each figure.

The second sensor arrangement 40 comprises an arrangement of five infrared optical sensors, each configured to receive uninterrupted radiation 15 and to output a voltage proportional to the amount of EM radiation received. For example, the receiver arrangement 3 may comprise five Texas Advanced

Optoelectronic Solutions (TAOS™) Infrared Light-to-Voltage Optical Sensors, such as the TSL260R, TSL261R or TSL262R. The five infrared optical sensors comprise a first sensor 41, a second sensor 42, a third sensor 43, a fourth sensor 44 and a fifth sensor 45. The information on the EM radiation received therefore comprises the voltage output by each of the five sensors.

Each sensor is configured to detect light arriving over a finite sensing area. The five sensors are arranged at different locations relative to the first cigarette 6, such that their respective sensing areas are aligned with different non-overlapping portions of the cross-section of the inspection radiation 14'.

The first, third and fifth sensors are located at a first radial distance from a longitudinal axis L of the cylindrical groove 31, such that they each sense EM radiation over a radial span from the longitudinal axis L which encompasses sections of only the second arcs of the third, fourth and fifth beams.

The second and fourth sensors are located at a second radial distance from the longitudinal axis L of the cylindrical groove 31, such that they each sense EM radiation over a radial span from the longitudinal axis L which encompasses sections of only the first beam 9, the second beam 10 and the second arc of the third beam 35.

The sensing area of each sensor is therefore aligned with portions of only three beams of the inspection radiation 14'. This alignment is such that the EM radiation received at each sensor from each of the three beams, if not interrupted by the cigarette, is approximately equal. The EM radiation received at each sensor from a single one of the three beams with which the sensor is aligned causes the sensor to generate N volts. For example, if all three of the beams with which a sensor is aligned are not interrupted, then the sensor will generate 3N volts.

Relative to the inspection location 5, the first sensor 41 is located at a first sensor location, the second sensor 42 is located at a second sensor location, the third sensor 43 is located at a third sensor location, the fourth sensor 44 is located at a fourth sensor location and the fifth sensor 45 is located at a fifth sensor location.

Determination by the processor 4 of information on the profile of a cigarette comprises, for each sensor, comparing the voltage received from that sensor to predetermined voltage values and utilising information on the location of the sensor relative to the inspection location 5 and information on the cross-sectional geometry of the beams

7-

For each sensor, the predetermined voltages each comprise the voltage produced at the sensor by different sequences of one or more of the beams aligned with the sensor reaching the sensor. The beam sequences each begin with the outer beam and work inwards, towards the longitudinal axis L of the groove 31. Each predetermined voltage is therefore associated with a sequence of received beams.

For each sensor, the predetermined voltages therefore comprise N, 2N and 3N.

For example, a predetermined voltage for the third sensor 43 of value 2N corresponds to a beam sequence comprising the fifth beam 13 and the fourth beam

12.

For each sensor, if the voltage received by the processor 4 matches one of the predetermined voltages, then the processor 4 determines that the extent of the profile of the cigarette aligned with that sensor's sensing area lies between the last beam in the beam sequence corresponding to the predetermined voltage and the next beam inwards of the last beam.

For example, if a voltage of 2N is received from the second sensor 42, the processor 4 determines that the profile of the cigarette aligned with the sensing area of the second sensor 42 extends into the region between the first beam 9 and the second beam 10.

As the beams are thin as previously described with reference to FIG. i, FIG.2, FIG.3 and FIG.4, if the voltage generated by one of the sensors lies between two successive predetermined voltages comprising a lower predetermined voltage and a higher predetermined voltage, then the processor 4 may determine that the extent of the cigarette profile aligned with the sensor's sensing area predominantly lies between the last beam in the beam sequence corresponding to the higher predetermined voltage and the next beam inwards of the last beam. Moreover, the processor 4 may also determine that a portion of the profile of the cigarette aligned with the sensor's sensing area extends beyond the last beam in the sequence corresponding to the higher predetermined voltage. For example, if the third sensor 43 generates a voltage lying between the N and 2N, the processor 4 may determine that the extent of the cigarette profile aligned with the sensing area of the third sensor 43 lies predominantly between the third beam 11 and the fourth beam 12. Moreover, the processor 4 may determine that a portion of the cigarette profile aligned with the sensing area of the third sensor 42 also extends beyond the fourth beam 12.

In this way, the processor 4 is configured to determine information on the cross- sectional profile of the cigarette 26 comprising its extent in the radial plane of each of the sensors from the longitudinal axis L of the groove 31, and thereby to determine information on the overall extent of the profile of the cigarette and on the shape of the profile of the cigarette 26.

With regard to FIG. 13, the uninterrupted radiation 15 comprises only the second arc of the third beam 35, the second arc of the fourth beam 36 and the second arc of the fifth beam 37. The first, third and fifth sensors therefore generate 3N volts each. Furthermore, the second and fourth sensors each generate N volts.

The processor 4 determines that the areas of the cross-sectional profile of the first cigarette 6 aligned with the first, third and fifth sensor locations extend to within the third beam 11. Moreover, the processor 4 also determines that the areas of the cross-sectional profile of the first cigarette 6 aligned with the second and fourth sensor locations extend to between the second beam 10 and the third beam 11. The processor 4 may therefore determine that the first cigarette 6 is circular in cross-section and may determine information on the first cigarette's diameter and cross-sectional area.

For example, the quality control criteria may require that cigarettes 26 be of a circular cross-section and of a diameter such that the profile of the cigarette extends to the region between the second beam 10 and the third beam 11. In this case, the profile information determined by the inspection apparatus la for the first cigarette 6 results in the first cigarette 6 satisfying the quality control criteria and being fed onto the accept path. FIG. 14 illustrates an extent 46 of the cross-sectional profile of the first cigarette 6 which may be determined by the inspection apparatus la of FIG. 12.

FIG. 15 shows sectional view B-B of the apparatus of FIG. 12 wherein the first cigarette 6 is replaced by a fourth cigarette 47. The fourth cigarette 47 is larger in cross-sectional area than the first cigarette 6 and has an oval cross-sectional shape, such that it blocks the second arc of the third beam 35 at the second, third and fourth sensors only.

The first and fifth sensors therefore generate 3N volts each. Furthermore, the second and fourth sensors generate no voltage and the third sensor 43 generates 2N volts.

The processor 4 therefore determines that the areas of the cross-sectional profile of the fourth cigarette 47 aligned with the first and fifth sensor locations extend to within the third beam 11. Moreover, the processor 4 determines that the areas of the cross-sectional profile of the fourth cigarette 47 aligned with the second and fourth sensor locations extend beyond the third beam 11. Furthermore, the processor 4 determines that the area of the cross-sectional profile of the fourth cigarette 47 aligned with the third sensor location extends to between the third beam 11 and the fourth beam 12. The processor 4 may therefore determine that the fourth cigarette 47 is oval in cross-section.

For example, the profile information determined by the inspection apparatus la for the fourth cigarette 47 results in the fourth cigarette not satisfying the quality control criteria and being fed onto the rej ect path.

FIG. 16 illustrates an extent 48 of the cross-sectional profile of the fourth cigarette 47 which may be determined by the inspection apparatus la in the case of FIG. 15.

FIG. 17 shows sectional view B-B of the apparatus of FIG. 12, wherein the first cigarette 6 is replaced by the third cigarette 23. The third cigarette 23 is of the same diameter as the first cigarette 6. However, the third cigarette 23 comprises a manufacturing error 24 wherein material protrudes from the surface of the cigarette. The protruding material 24 blocks the region of the third beam 11 aligned with the fourth sensor 44 only. The first, third and fifth sensors therefore generate 3N volts each. Furthermore, the second sensor 42 generates N volts and the fourth sensor 44 generates no voltage. The processor 4 determines that the areas of the cross-sectional profile of the third cigarette 23 aligned with the first, third and fifth sensor locations extend to within the third beam 11. Moreover, the processor 4 also determines that the area of the cross-sectional profile of the third cigarette 23 aligned with the second sensor 42 location extends to between the second beam 10 and the third beam 11. Furthermore, the processor 4 determines that the area of the cross-sectional profile of the third cigarette 23 aligned with the fourth sensor location extends beyond the third beam 11. The processor 4 may therefore determine that the profile of the third cigarette 23 comprises a manufacturing error in the area of the cigarette profile aligned with the fourth sensor location. For example, the profile information determined by the inspection apparatus la for the third cigarette 23 may result in the third cigarette 23 not satisfying the quality control criteria and being fed onto the reject path. FIG. 18 illustrates an extent 49 of the cross-sectional profile of the third cigarette 23 which may be determined by the inspection apparatus la in the case of FIG. 17.

Although the inspection apparatus 1 and the second inspection apparatus embodiment la are described as being configured to inspect cigarettes 26 received on an inspection drum 28 of the machine 24, one or more inspection apparatus 1, la may additionally or alternatively be used at other areas of the machine 24 to inspect rod shaped smoking articles at other steps in the manufacturing process.

With regard to the embodiments described herein, the following alternatives and variations will now be described.

Although the projector arrangement 2 is described as being configured to project concentric annular beams 7 of EM radiation, other configurations of the plurality of projected beams 7 are possible. For example, any beam configuration comprising two or more beams of EM radiation projected in a direction parallel to the longitudinal axis of a cigarette, wherein the two or more beams of EM radiation do not substantially overlap may be used.

For example, the cross-section of one or more of the plurality of projected beams 7 may comprise an arc centred on the longitudinal axis of the cigarette to be inspected or that of a pencil beam. Moreover, the plurality of beams 7 may not be projected at different distances from the longitudinal axis of the cigarette to be inspected. The EM radiation emitted by the projector arrangement may for example comprise infrared (IR) light or visible light. Moreover, although the projector arrangement 2 is described as being configured to project EM radiation comprising coherent light, other types of EM radiation may be used. As described, the receiver arrangement 3 is configured appropriately so as to receive uninterrupted radiation 15 of what ever type is used, and to provide the processor 4 with information on the EM radiation received. The beams 7 of EM radiation projected by the projector arrangement 2 are described as not overlapping. However, it should be understood that some degree of overlapping may occur. For example, each of the beams 7 may comprise a Gaussian profile, making a small degree of overlapping very difficult to avoid. The plurality of beams 7 may therefore be described as not substantially overlapping.

The processor 4 may comprise one or more processors or microcontrollers (MCU). The inspection apparatus 1, la may further comprise a controller configured to control the projector arrangement 2, the receiver arrangement 3 and/or the processor 4. Moreover, the controller may comprise the processor 4. For example, the controller 2 may comprise a central processing unit (CPU) or one or more processors or microcontrollers (MCU). The inspection apparatus 1, la may further comprise a memory configured to store data and instructions for use by the inspection apparatus 1, la. For example, the memory 3 may comprise a non-volatile memory such as read only memory (ROM), RAM, a hard disk drive (HDD) or flash memory such as a solid state drive (SSD).

Although the projector arrangement 2 is described as being configured to project inspection radiation 14, 14' in a direction parallel to the longitudinal axis of a cigarette at the inspection location 5, this may comprise projecting beams 7 in a direction substantially parallel to the longitudinal axis of a cigarette.

The projector arrangement 2 may be configured to vary the distribution and geometry of the plurality of beams 7 projected to suit different types of cigarette.

The plurality of beams 7 projected by the projector arrangement 2 may or may not be equally spaced apart. Inspection drum 28 described with reference to FIG. 5 is configured to

successively locate cigarettes received on the inspection drum 28 at the inspection location 5. The inspection drum 28 can therefore be referred to as a location arrangement configured to locate a cigarette to be inspected at the inspection location 5. Moreover, the location arrangement may be considered to be part of the inspection apparatus 1, la. In this case, it should be understood that other types of location arrangements are possible. For example, the location

arrangement may instead comprise a conveyer belt on which cigarettes are received and are successively conveyed to the inspection location 5 of the inspection apparatus 1, la.

Although the inspection apparatus 1, la is predominantly described as being configured to inspect cigarettes, it should be understood that the inspection apparatus may be configured to inspect any rod shaped article. For example, the machine 24 of FIG. 5 may be a machine 24 for manufacturing rod shaped food articles.

The inspection apparatus 1, la may be configured to be fitted to a machine.

Moreover, the inspection apparatus 1, la may be configured to be retrofitted to a machine. In this case, retrofitting the inspection apparatus 1, la may comprise removing an inspection system already installed on the machine and then installing the apparatus for inspecting a rod shaped articles 1, la on the machine.

The processor 4 is described as being configured to perform various functions and/or operations. It should be understood that various computational methods different to those described can be used by the processor 4. For example, accessing profile information corresponding to a predetermined voltage may instead comprise applying the predetermined voltage to an algorithm for determining profile information.

Unless specifically stated otherwise as apparent from the description above, it is appreciated that throughout the description, discussions utilising terms such as "processing" or "computing" or "determining" or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system memories or registers or other such information storage, transmission or display devices.

The various embodiments described above facilitate a number of improvements. The inspection apparatus 1, la facilitates increased sensitivity in detecting the extent of the cross-sectional profile of a cigarette as compared with using only a single beam of light of a large cross-sectional area to determine information on the extent of the profile of an article based on how it interrupts only the cross-section of the single beam.

In more detail, if one is interested in detecting whether the cross-sectional profile of a cigarette extends into a first region between a first point and a second point, proj ecting a first beam of EM radiation through the first point and a second beam of EM radiation through the second point facilitates increased detection sensitivity over the use of a single beam of a cross-section large enough to span the two points. If the profile of the cigarette extends into the first region, a greater proportional change can occur in the EM radiation passing the first region uninterrupted if the separate first and second beams are used as opposed to the single beam.

The inspection apparatus l, la facilitates improved detection of information on the profile of rod shaped articles due to the use of separate beams comprising cross- sectional profiles similar in shape to the exterior of rod shaped articles.

In order to address various issues and advance the art, the entirety of this disclosure shows by way of illustration various embodiments in which the claimed invention(s) may be practiced and provide for superior inspection of rod shaped articles. The advantages and features of the disclosure are of a representative sample of

embodiments only, and are not exhaustive and/ or exclusive. They are presented only to assist in understanding and teach the claimed features. It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects of the disclosure are not to be considered limitations on the disclosure as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilised and modifications may be made without departing from the scope and/ or spirit of the disclosure. Various embodiments may suitably comprise, consist of, or consist essentially of, various combinations of the disclosed elements, components, features, parts, steps, means, etc. In addition, the disclosure includes other inventions not presently claimed, but which may be claimed in future. Any feature of any embodiment can be used independently of, or in combination with, any other feature.