RFID READING DEVICE FOR ITEMS SUSPENDED IN AIRWAYS

Abstract

RFID tag identification device for a group of hanging elements (P) transported on an overhead track (y), the device comprising at least one RFID antenna (5) and a metal reading drawer, characterized in that: the metal reading drawer comprises a passive part (1A) and an active part (1B) mounted on at least one linear drive guide (4A, 4B) such that the passive part (1A) and the active part (1B) are horizontally movable symmetrically between an open position, in which the passive part (1A) and the active part (1B) are separated leaving a free passage for the overhead track (V) and the group of hanging elements (P), and a closed position, in which the passive part (1A) and the active part (1B) are joined by their closing edges forming a closed metal enclosure around the group of hanging elements (P); and wherein the device comprises: - a perimeter seal (2) of elastic material with a metallic coating arranged along the closing perimeter of one of the two parts of the metal reading drawer (1A, 1B), said perimeter seal (2) having a discontinuity in the area corresponding to the airway (V); and - a microwave absorber (3) arranged in said discontinuity area of the perimeter seal (2), fixed to both parts of the metal reading drawer (1A, 1B).

Description

RFID READING DEVICE FOR ITEMS SUSPENDED IN OVERHEADS OBJECT OF THE INVENTION The invention belongs to the logistics sector in the field of traceability, control and identification equipment and systems using RFID technology applied to warehouses and distribution centers that operate with garments hung in blocks on overhead transport systems. More particularly, the present invention relates to an RFID tag identification device for a group of hanging elements transported over an overhead track, forming a closed metallic enclosure around the group of hanging elements for reading their RFID tags with minimal leakage of electromagnetic waves. BACKGROUND OF THE INVENTION RFID (radio-frequency identification) technology allows for the remote identification, storage, and transmission of data using tags that respond to radio frequency signals emitted by reader antennas. This technology is widely implemented in the textile and fashion industry for inventory management in warehouses and garment control in stores, enabling the simultaneous identification of a large number of items without the need for individual inspection. In high-volume textile distribution warehouses, garments are typically transported on hangers via overhead conveyor systems, moving in blocks along their route through the warehouse. For RFID identification of these blocks of hanging garments, reading stations are known in the prior art. These stations consist of tunnels through which the block of garments passes, containing a series of reading antennas. However, these stations usually operate in an open configuration, meaning without any enclosure to seal the garments during reading. This configuration causes significant leakage of radio frequency waves to the outside, resulting in cross-reading of garments located outside the measurement zone. To minimize this effect, these stations operate at low transmission power, which reduces reading capacity and speed, especially for garments with complex fabrics. Solutions incorporating partial closure elements, such as curtains at the tunnel's entrance and exit, are also known. While these curtains partially reduce wave leakage, they do not provide a sufficient seal to allow for increased transmission power, leaving gaps of tens of centimeters distributed along the entire vertical length of the enclosure. Additionally, a minimum separation of approximately two meters between consecutive blocks of garments is required to prevent cross-reading, which limits the system's productivity. Other known solutions employ closing systems using sliding, hinged, or guillotine-type doors. However, these systems present significant drawbacks, as they substantially increase the technical complexity and cost of the equipment, and also generate wave leaks in the sliding surfaces, without the increased complexity resulting in a substantial improvement in airtightness. On the other hand, RFID reading devices based on a single, vertically moving drawer are known in the prior art. As this drawer descends onto a lower tray, it forms a Faraday cage around the product to be identified, as described in documents ES2989032T3 and EP4524812A1. These devices offer significantly superior electromagnetic sealing compared to open solutions, allowing for higher power and faster reading speeds. However, their single-drawer, vertically moving design makes them incompatible with overhead garment conveyor systems, as the overhead track prevents the drawer from closing vertically. Furthermore, the sealing gasket used in these devices is designed for closure on a rigid lower tray, but it is unsuitable for large horizontal systems where straightness tolerances are more difficult to control. Therefore, there is a need in the state of the art to provide an RFID identification device for garments hung on the airway that combines the advantages of the airtight closure of known drawer devices with air transport systems, mainly solving the sealing problems in the airway area. DESCRIPTION OF THE INVENTION The present invention solves the aforementioned problems by providing an RFID tag identification device for suspended items transported on an overhead line. In a first aspect, the present invention relates to an RFID tag identification device for a group of suspended items transported on an overhead line, comprising at least one RFID antenna and a metallic reading drawer.The reading drawer comprises a passive and an active part mounted on at least one linear drive guide, such that the passive and active parts are horizontally movable symmetrically between an open position, in which both parts are separated, leaving a clear passage for the overhead track and the hanging items, and a closed position, in which the passive and active parts are joined at their closing edges, forming a closed metal enclosure around the hanging items. Advantageously, this double-drawer architecture with symmetrical horizontal movement allows the device to be integrated into overhead garment conveyor lines, overcoming the structural incompatibility of known single-drawer devices with vertical movement. The device comprises a perimeter seal made of elastic material with a metallic coating, arranged along the perimeter of one of the two parts of the reading drawer. This perimeter seal has a discontinuity in the area corresponding to the airway. The perimeter seal is fixed to only one of the two parts of the reading drawer, whichever is less important. In the area of ​​discontinuity of the perimeter seal, the device includes a microwave absorber fixed to both parts of the reading drawer. Advantageously, this combination of perimeter seal and microwave absorber constitutes a hybrid sealing system that achieves high electromagnetic airtightness, with millimeter-scale wave leakage focused exclusively on the airway area.This result contrasts favorably with known solutions such as sliding doors or curtains, in which leaks have dimensions on the order of tens of centimeters and are distributed along the entire vertical length of the closure. In a preferred embodiment of the invention, the closing edges of the passive and active parts of the reading drawer have a 90° fold forming a flat face on each of said parts. The perimeter seal has an L-shaped cross-section, comprising an anchoring flange fixed to the flat face of one of the two parts of the reading drawer and a free flange projecting perpendicularly from said flat face, such that in the closed position the flat face of the other part of the reading drawer presses on said free flange, elastically deforming it until it adopts a C-shaped cross-section, with the perimeter seal simultaneously in contact with the flat faces of both parts of the reading drawer.Advantageously, the 90° fold at the closing edges provides high rigidity to the drawers and better control of their geometry, while the elastic deformation of the L-shaped to C-shaped joint creates double contact between the joint and both flat surfaces, absorbing significant irregularities and misalignments between the drawers. This solution is particularly advantageous in large drawers, on the order of two meters in height, where controlling the straightness tolerance of the closing edges is especially critical. Preferably, the perimeter seal is made of metallic foam, a material that combines the elastic properties necessary for deformation from L-section to C-section with the metallic coating properties necessary to ensure the electromagnetic continuity of the enclosed metal enclosure in the closing area between both parts of the reading drawer. In a preferred embodiment, the passive and active parts of the reading drawer are made of perforated aluminum. Preferably, the perforations have a diameter of 5 mm and a center-to-center spacing of 12 mm. This specific dimension is based on electromagnetic considerations: the 5 mm perforations represent only a minimal percentage of the wavelength of UHF RFID signals—extremely small proportions that are unlikely to affect the wave. Therefore, the electromagnetic field cannot escape through the perforations, maintaining confinement and preventing cross-reading. Additionally, the perforated aluminum reduces the weight of the drawers compared to a continuous sheet, which is advantageous in terms of overall weight and the sizing of the drive mechanisms. Regarding the microwave absorber, in a preferred embodiment it is made of polyurethane foam with carbon-impregnated layers and is attached to both parts of the reading drawer using adhesive, although fixing it with screws or by simple insertion into a recess provided for this purpose in the airway area is also considered. Preferably, the microwave absorber has a cross-sectional geometry complementary to the cross-section of the airway, so that it fits the shape of the airway in the discontinuity area of ​​the perimeter seal. This geometry is obtained by cutting the microwave absorber with the negative profile of the cross-section of the specific airway for each installation, which allows the device to be adapted to different types of airways for transporting hanging garments.In a preferred embodiment, the microwave absorber comprises six layers of carbon-impregnated foam, a configuration that provides effective absorption of RFID waves in the airway area while minimizing electromagnetic leakage in that area. In a preferred embodiment of the invention, the device comprises a first linear guide arranged at the top of the device and a second linear guide arranged at the bottom of the device. Each of these linear guides comprises a first carriage attached to the passive part and a second carriage attached to the active part, the first and second carriages of each linear guide being symmetrically movable. The first and second linear guides are driven by independent servomotors. The use of two independent linear guides, one upper and one lower, each with its own servomotor, allows for independent adjustment of the closing mechanism of the upper and lower parts of the reading drawer, thus compensating for any misalignment between the upper and lower parts of large drawers. For the identification of RFID tags on the group of hanging elements, in a preferred embodiment the active part comprises four RFID antennas, one arranged at each corner of the active part. Each RFID antenna is oriented at a different angle with respect to the others, with an angular difference between any pair of RFID antennas of between 5° and 10°. The arrangement of the antennas at the corners of the active part maximizes the coverage of the interior volume of the enclosed metal enclosure, while the individual angular variation between antennas minimizes the formation of standing waves due to the reflection of electromagnetic waves in an enclosure of symmetrical geometry, thus improving the probability of reading all the RFID tags present on the group of hanging elements. In one embodiment of the invention, the device comprises a structural chassis formed by vertical columns arranged at the ends of the chassis, upper and lower horizontal rails connecting the ends of said columns, and a central rigid structure for mounting the first and second linear guides. The passive and active parts of the reading drawer are mounted on the structural chassis by means of these linear guides. This structural configuration provides the necessary rigidity to ensure the alignment of the drawers during repeated opening and closing cycles. In one embodiment of the invention, the device comprises at least one photoelectric curtain arranged inside each of the two parts of the reading drawer, at the device's entry and exit points, such that the photoelectric curtains face each other. The integration of the photoelectric curtains within the drawers themselves allows them to move in unison with the drawers during opening and closing cycles, ensuring the detection of any items that might become trapped between the two parts of the reading drawer. In one embodiment of the invention, the device comprises an area security scanner disposed at the base of the device, oriented towards the operator access areas, and configured to detect the presence of people within a predefined security perimeter around the device. Another aspect of the present invention relates to a method for reading RFID tags for a group of suspended items transported on an overhead track by the device described above. This method comprises the following steps: detecting the arrival of the group of suspended items at the reading zone of the device, using suitable detection means; then, emitting a stop signal to the control system of the conveyor line, so that the group of suspended items is stopped inside the device with the passive and active parts of the reading drawer in the open position; subsequently, actuating the first and second linear guides to horizontally and symmetrically move the passive and active parts of the reading drawer from the open position to the closed position, forming the enclosed metal enclosure around the group of suspended items;Next, the RFID antennas are activated to read the RFID tags of the group of items hanging inside the enclosed metal enclosure; once the reading is complete, the first and second linear guides are actuated to move the passive and active parts of the reading drawer from the closed position to the open position; and finally, a run signal is sent to the transport line control system to resume the movement of the group of hanging items. The actuation stage for the first and second linear guides to move to the closed position involves independent adjustment of the closing speed and force of the first linear guide, located at the top of the device, and the second linear guide, located at the bottom of the device, using their respective independent servomotors. This independent adjustment compensates for any misalignment between the top and bottom of the drawers, ensuring a uniform closure along the entire height of the reading drawer. Prior to the first installation of the device, the procedure for use includes a stage of adapting the microwave absorber to the specific airway of the installation, which consists of cutting the microwave absorber with the negative profile of the cross-section of said airway, so that the microwave absorber is adjusted to the shape of the airway in the discontinuity zone of the perimeter joint, and fixing the microwave absorber thus cut to both parts of the reading drawer by means of the fixing means provided. In one embodiment of the invention, the stage of detecting the arrival of the group of hanging items comprises verifying, by means of photoelectric curtains arranged inside each of the two parts of the reading drawer, that no items are trapped between the passive and active parts of the reading drawer before initiating the movement to the closed position. Likewise, during the movement to the closed position, the photoelectric curtains continuously monitor for the presence of items between the two parts of the reading drawer, stopping the movement if any are detected. In accordance with all the above characteristics, the device of the present invention provides significant technical advantages over the prior art, enabling RFID identification of groups of items suspended overhead with electromagnetic tightness far superior to known solutions, with millimeter-sized wave leakage focused on the airway area compared to leakage of tens of centimeters distributed along the entire vertical axis of the seal in previous solutions. This improved tightness allows operation at higher emission power, increasing reading speed and reliability, especially for items with complex fabrics, and reducing the minimum separation required between consecutive groups of items on the conveyor line. BRIEF DESCRIPTION OF THE FIGURES To complete the description of the invention and to aid in a better understanding of its characteristics, according to a preferred embodiment thereof, a set of drawings is included in which, for illustrative and non-limiting purposes, the following figures have been represented: - Figure 1 shows an overall perspective view of the RFID tag identification device for hanging items, with the reading drawer in the open position, the airway (which is not part of the invention) and the hanging item group (which is not part of the invention). - Figure 2 shows a detail of the perimeter seal arranged along the closing perimeter of one of the parts of the reading drawer, highlighting the deformation of the free wing of the seal until it adopts a C-shaped geometry in the closed position. - Figure 3 shows a detail of the airway area with the microwave absorber positioned in the discontinuity area of ​​the perimeter joint, with the reading drawer in the open position. - Figure 4 shows a detail of the assembly with the reading drawer in the closed position around the airway, where the relationship between the perimeter seal, the microwave absorber and the airway can be seen. - Figure 5 shows a front perspective view of the device in the open and closed positions, where the upper and lower linear drive guides, the displacement carriages, and the group of elements suspended above the airway can be seen. - Figure 6 shows an interior view of the active part of the reading drawer, where the arrangement in the corners of four RFID antennas and their individual angles can be seen, according to an embodiment of the invention. - Figure 7 shows a view of the structural chassis of an embodiment of the device of the present invention. - Figure 8 shows a view of the photoelectric curtain arranged inside each of the two parts of the reading drawer. - Figure 9 shows an area security scanner arranged at the base of the device, according to one embodiment of the invention, oriented towards the intended operator access areas. List of alphanumeric references used 1A Passive part of the reading drawer 1B Active part of the reading drawer 2 Perimeter joint 3 Microwave absorber 4A First linear guide (upper) 4B Second linear guide (lower) 5 RFID Antennas 6 Structural chassis 7A First guide car (4A) , attached to (1A) 7B Second guide car (4A) , attached to (1B) 7C First guide car (4B) , attached to (1A) 7D Second guide car (4B) , attached to (1B) 8 Area Security Scanner 9 Photoelectric curtain 10 Predefined security perimeter 11. Compartment for absorber P Group of hanging elements V Air transport S Hangers / pushers DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION The present invention describes an RFID tag identification device for a group of suspended items transported on an overhead line. A preferred embodiment of the invention is then described with reference to Figures 1 to 6, using numerical references to link the illustrated parts to the description. The device comprises a metal reading drawer consisting of two parts: a passive part (1A) and an active part (1B). Both parts are mounted on linear drive guides so that they can be moved horizontally and symmetrically between an open and a closed position. In the open position, the passive part (1A) and the active part (1B) are separated, leaving a clear passage for the airway (V) and the hanging element group (P). In the closed position, the passive part (1A) and the active part (1B) are joined at their closing edges, forming a closed metal enclosure around the hanging element group (P). The airway (V) and the hanging element group (P), as well as the hangers or pushers (S) that support them, are not part of the invention and are shown in the figures only to illustrate the device's context of use. Figure 1 shows a general perspective view of the RFID tag identification device for hanging items, with the reading drawer in the open position. This figure shows the assembly formed by the passive part (1A) and the active part (1B) of the reading drawer, separated to allow a clear passage for the airway (V) and the group of hanging items (P) supported by the hangers or pushers (S). As shown in Figure 1, the device comprises a perimeter seal (2) made of elastic material with a metallic coating, arranged along the closing perimeter of one of the two parts of the reading drawer (1A, 1B). The perimeter seal (2) runs along the entire closing perimeter except for the area corresponding to the airway (V), where it has a discontinuity. At this discontinuity, the device comprises a microwave absorber (3) arranged on both parts of the reading drawer (1A, 1B). The combination of the perimeter seal (2) and the microwave absorber (3) results in a seal that covers the entire closing perimeter of the reading drawer, including the airway (V) area, whose irregular geometry prevents the use of the perimeter seal (2) in that area. Figure 2 shows a detail of the closing area between the passive part (1A) and the active part (1B) of the reading drawer, illustrating the deformation of the perimeter seal (2) along the closing perimeter at two different points in a closing sequence. In the embodiment shown, the closing edges of the passive part (1A) and the active part (1B) have a 90° fold that forms a flat surface on each part. This fold provides high rigidity to the drawers and improved control of their geometry, which is particularly relevant in large drawers, on the order of two meters in height, where controlling the straightness tolerance of the closing edges is especially critical. As shown in Figure 2, the perimeter seal (2) has an L-shaped cross-section, comprising an anchoring flange fixed to the flat face of one of the two parts of the reading drawer (1A, 1B) and a free flange that protrudes perpendicularly from this flat face. Thus, in the closed position, the flat face of the other part of the reading drawer presses against this free flange, elastically deforming it into a C-shaped cross-section. The perimeter seal (2) then comes into simultaneous contact with the flat faces of both parts of the reading drawer (1A, 1B). This elastic deformation of the seal from an L-shaped to a C-shaped cross-section creates double contact between the perimeter seal (2) and both flat faces, absorbing irregularities and misalignments between the drawers that would otherwise compromise the continuity of the closure. In the preferred embodiment, the perimeter seal (2) is made of metallic foam, a material that combines the elastic properties necessary for the described deformation with the metallic coating properties necessary to ensure the electromagnetic continuity of the enclosed metallic enclosure in the closing area between both parts of the reading drawer (1A, 1B). Figure 3 shows a detail of the airway area (V) with the microwave absorber (3) positioned in the discontinuity area of ​​the perimeter seal (2), with the reading drawer in the open position. As can be seen in this figure, the perimeter seal (2) has a discontinuity in the area corresponding to the airway (V), whose irregular cross-section prevents the use of the perimeter seal (2) in that area. To cover this discontinuity zone, a microwave absorber (3) is attached to both parts of the reading drawer (1A, 1B). In the embodiment shown, the microwave absorber (3) is made of polyurethane foam with carbon-impregnated layers, a material that has the necessary flexibility to adapt to the irregular geometry of the airway (V) and the electromagnetic wave absorption properties required to minimize leakage in this area. Preferably, the microwave absorber (3) comprises six carbon-impregnated foam layers, a configuration that provides effective absorption of RFID waves in the airway (V) area. As shown in Figure 3, the microwave absorber (3) has a cross-sectional geometry complementary to the cross-section of the airway (V), so that it fits the shape of the airway (V) in the discontinuity area of ​​the perimeter seal (2). This geometry is obtained by cutting the microwave absorber (3) with the negative profile of the airway cross-section (V) specific to each installation, allowing the device to be adapted to different types of airways for transporting hanging garments. The microwave absorber (3) is fixed to both parts of the reading drawer (1A, 1B) using adhesive, although it can also be fixed with screws or by simply inserting it into a recess (11) provided for this purpose in the airway area. Figure 4 shows a detail of the assembly with the reading drawer in the closed position around the airway (V), where the relationship between the perimeter seal (2), the microwave absorber (3), and the airway (V) can be seen. As can be observed in this figure, in the closed position, the passive part (1A) and the active part (1B) are joined by their closing edges, forming a closed metal enclosure around the group of suspended elements (P). In the preferred embodiment, the passive (1A) and active (1B) parts of the reading drawer are made of perforated aluminum. Preferably, the perforations have a diameter of 5 mm and a center-to-center spacing of 12 mm. This dimensioning is based on electromagnetic considerations: the 5 mm perforations represent only 1.4% of the wavelength of UHF RFID signals, an extremely small proportion for the wave to be affected, so the electromagnetic field cannot escape through the perforations, remaining confined within the closed metal enclosure. Additionally, the perforated aluminum reduces the weight of the drawers compared to a continuous sheet, which is advantageous for the sizing of the drive mechanisms. As shown in Figure 4, in the closed position, the hybrid sealing system formed by the perimeter seal (2) and the microwave absorber (3) covers the entire perimeter of the reading drawer. The perimeter seal (2), elastically deformed into a C-section by the pressure of the flat faces of both parts of the reading drawer (1A, 1B), ensures a continuous seal along the entire perimeter, while the microwave absorber (3), shaped to the airway (V), covers the discontinuity area of ​​the perimeter seal (2). This combination achieves an electromagnetic airtightness of approximately 95%, with millimeter-sized wave leaks focused exclusively on the airway (V) area, in contrast to known sliding door or curtain solutions, where leaks are on the order of tens of centimeters and are distributed along the entire vertical length of the seal. Figure 5 shows a front perspective view of the device in the open and closed positions, illustrating the drive system that enables the symmetrical horizontal movement of the passive (1A) and active (1B) parts of the reading drawer. As shown in the figure, the device comprises a first linear guide (4A) located at the top of the device and a second linear guide (4B) located at the bottom. Each of these linear guides (4A, 4B) comprises a first carriage (7A, 7C) attached to the passive part (1A) and a second carriage (7B, 7D) attached to the active part (1B). The first and second carriages of each linear guide (4A, 4B) are symmetrically movable, such that when the linear guides (4A, 4B) are actuated, both parts of the reading drawer move simultaneously and symmetrically around the central axis of the device. The first linear guide (4A) and the second linear guide (4B) are driven by independent servomotors. The use of two independent linear guides, one upper and one lower, each with its own servomotor, allows for independent adjustment of the closing mechanism of the upper and lower sections of the reading drawer, compensating for any misalignment between the two ends. This feature is particularly relevant in large drawers, on the order of two meters in height, where straightness and alignment tolerances are difficult to control along the entire height of the drawer. Figure 6 shows an interior view of the active part (1B) of the reading drawer, illustrating the arrangement of the four RFID antennas (5) and their individual angles. As shown in the figure, the active part (1B) comprises four RFID antennas (5), one positioned at each corner. This corner arrangement maximizes coverage of the enclosed metal housing, ensuring that the waves emitted by the antennas (5) reach the entire group of suspended elements (P) housed inside the reading drawer. Each RFID antenna (5) is oriented at a different angle relative to the others, with the four antennas (5) having individual angles (θ, β, θ, θ) and an angular difference between any pair of antennas (5) of between 5° and 10°.This individual angular variation between antennas minimizes the formation of standing waves due to the reflections of electromagnetic waves in the closed metallic enclosure of symmetrical geometry, thus improving the probability of reading all RFID tags present in the group of hanging elements (P). Figure 7 shows a view of the structural chassis (6) of the device. The structural chassis (6) comprises vertical columns arranged at the corners of the device, upper and lower horizontal rails connecting the ends of these columns, and a central rigid structure for mounting the first linear guide (4A) and the second linear guide (4B), such that the passive part (1A) and the active part (1B) of the reading drawer are mounted to the structural chassis (6) by means of these linear guides (4A, 4B). This structural configuration provides the necessary rigidity to ensure the alignment of the drawers during repeated opening and closing cycles. Figure 8 shows a view of the photoelectric curtain (9) of the device. In the embodiment shown, the device comprises a photoelectric curtain (9) arranged inside each of the two parts of the reading drawer (1A, 1B), in the device's entry and exit areas, such that the photoelectric curtains (9) face each other. The integration of the photoelectric curtains (9) inside the drawers themselves allows them to move together with the drawers during opening and closing cycles, ensuring at all times the detection of any items that might become trapped between the two parts of the reading drawer (1A, 1B). Figure 9 shows a view of the device's area security scanner (8). In the embodiment shown, the device comprises an area security scanner (8) disposed at the base of the device, oriented towards the intended operator access areas. The area security scanner (8) is configured to detect the presence of people within a predefined security perimeter (10) around the device. The present invention is not limited to the embodiment described herein. Other configurations may be implemented by those skilled in the art, taking into account this description. The scope of the invention is defined by the following claims.

Claims

1. An RFID tag identification device for a group of hanging elements (P) transported on an overhead track (y), the device comprising at least one RFID antenna (5) and a metal reading drawer, characterized in that: the metal reading drawer comprises a passive part (1A) and an active part (1B) mounted on at least one linear drive guide (4A, 4B) such that the passive part (1A) and the active part (1B) are horizontally movable symmetrically between an open position, in which the passive part (1A) and the active part (1B) are separated leaving a free passage for the overhead track (V) and the group of hanging elements (P), and a closed position,wherein the passive part (1A) and the active part (1B) are joined by their closing edges forming a closed metallic enclosure around the group of suspended elements (P); and wherein the device comprises: - a perimeter seal (2) of elastic material with a metallic coating arranged along the closing perimeter of one of the two parts of the metal reading drawer (1A, 1B), said perimeter seal (2) having a discontinuity in the area corresponding to the airway (V); and - a microwave absorber (3) arranged in said discontinuity area of ​​the perimeter seal (2), fixed to both parts of the metal reading drawer (1A, 1B).

2. Device according to claim 1, wherein the closing edges of the passive part (1A) and the active part (1B) of the metal reading drawer have a 90° fold forming a flat face on each of said parts; and wherein the perimeter seal (2) has an L-shaped cross-section,comprising an anchoring wing fixed to the flat face of one of the two parts of the metal reading drawer (1A, 1B) and a free wing projecting perpendicularly from said flat face, such that in the closed position the flat face of the other part of the metal reading drawer presses against said free wing, elastically deforming it until it adopts a C-shaped cross-section, the perimeter seal (2) being in simultaneous contact with the flat faces of both parts of the metal reading drawer (1A, 1B).

3. Device according to any of the preceding claims, wherein the perimeter seal (2) is made of metal foam.

4. Device according to any of the preceding claims, wherein the passive part (1A) and the active part (1B) of the metal reading drawer are made of perforated aluminum.

5. Device according to claim 4,wherein the perforations have a diameter of 5 mm and a center-to-center spacing of 12 mm.

6. Device according to any of the preceding claims, wherein the microwave absorber (3) is made of polyurethane foam with carbon-impregnated layers and is fixed to both parts of the metal reading drawer (1A, 1B).

7. Device according to claim 6, wherein the microwave absorber (3) has a cross-sectional geometry complementary to the cross-section of the airway (V), such that the microwave absorber (3) conforms to the shape of the airway (V) in the discontinuity zone of the perimeter seal (2).

8. Device according to claim 6 or 7, wherein the microwave absorber (3) is fixed to the passive part (1A) and the active part (1B) of the metal reading drawer by means of a fastening method selectable from: adhesive means,screws or a recess (11) provided in the track area for insertion of the absorber.

9. Device according to claim 6, 7 or 8, wherein the microwave absorber (3) comprises six layers of carbon-impregnated foam.

10. Device according to any of the preceding claims, wherein the device comprises a first linear guide (4A) disposed in the upper part of the device and a second linear guide (4B) disposed in the lower part of the device, each of said drive linear guides (4A, 4B) comprising a first carriage (7A, 7C) fixed to the passive part (1A) and a second carriage (7B, 7D) fixed to the active part (1B), the first carriage and the second carriage of each linear guide (4A, 4B) being symmetrically movable; and wherein the first linear guide (4A) and the second linear guide (4B) are driven by independent servomotors.

11. Device according to any of the preceding claims,wherein the active part (1B) comprises four RFID antennas (5), one arranged at each corner of the active part (1B), each RFID antenna (5) being oriented at a different angle with respect to the others, with an angular difference between any pair of RFID antennas (5) of between 5° and 10°.

12. Device according to any of the preceding claims, wherein the device comprises: a structural chassis (6) formed by vertical columns arranged at the corners of the chassis, upper and lower horizontal rails joining the ends of said columns, and a central rigid structure for mounting the linear drive guides (4A, 4B), such that the passive part (1A) and the active part (1B) of the metal reading drawer are mounted on the structural chassis (6) by means of said linear drive guides.

13. Device according to any of the preceding claims,wherein the device comprises: a photoelectric curtain (9) disposed inside each of the two parts of the metal reading drawer (1A, 1B), in the entry and exit areas of the device, such that said photoelectric curtains (9) face each other.

14. Device according to any of the preceding claims, wherein the device comprises: an area security scanner (8) disposed in the base of the device, oriented towards the operator access areas, and configured to detect the presence of persons within a predefined security perimeter (10) around the device.