The present invention relates to a security scanning system comprising a cart and a scanning system as well as a method of scanning a cart, where the scanning system and cart are adapted so that items provided on the higher surface are scanned separately from those provided on the lower surface, by the same beam.

A security scanning system may be seen in US2007/003009, US2013/0276388 and US2018/0203155.

In a first aspect, the invention relates to a security assembly comprising a cart and a scanning system, wherein: the cart has a first surface configured to carry items and a second surface configured to carry items, where the second surface is elevated, relative to the first surface, and at least partly overlapping, when projected on to a horizontal plane, the first surface, and the scanning system has at least one emitter of electromagnetic radiation and one or more detectors, the emitter and detector(s) defining a beam plane having an angle, to a horizontal plane, of below 60 degrees.

In this context, the cart usually will be movable relative to the scanning system. In some situations, the cart may be transported vis-a-vis the scanning system such as when engaged by a translator and translated past or inside the scanning system. The cart may be transported on separate transporting means, such as a belt, or may be guided and allowed to roll on e.g. own wheels if provided.

Often, the same scanning system is used in relation to a plurality of carts. A scanning process preferably takes less than 5 minutes, such as less than 3 minutes, such as less than 1 minute.

In a simple embodiment, however, the scanning system may provide merely X-ray images or models, such as 2D or 3D models, of items carried on the surfaces, which images or models may then be evaluated by a human operator to determine whether the item(s) comprises illegal or undesired elements or substances, such as knives, lighters, explosives, drugs, flammable substances or the like. If an item is flagged as potentially relevant, a human operator may then open the item to him/herself determine whether the item is safe or not. As will be made clear below, the scanning system may comprise a processor or the like for analysing data derived by the scanning system to either automatically arrive at a decision as to whether an item needs further scrutiny or not. Alternatively, the processor may pre- process the data before a human operator makes the determination. Such pre-processing may be determining or identifying a particular substance from a radiation absorption or scattering of the substance, the highlighting of particular elements in an image or model, or the like.

Any further analysis of an item initially flagged as relevant may be made, as described, by a human operator and/or by another scanning or analysis system.

The analysis performed based on information derived by the present scanning system may be of the same type and performed using the same means as the analysis of the prior art systems. The advantage of the present system is that the analysis may be more simple or more precise, as the overlap described below is not seen.

The cart has a first surface configured to carry items and a second surface configured to carry items, where the second surface is elevated, relative to the first surface, and at least partly overlapping the first surface, when projected on to a horizontal plane.

In this context, the surface may be an uninterrupted surface, such as a sheet of a metal, or a more open surface, such as a surface with holes or openings, such as when defined by a number of elongate elements or a mesh/net. A surface may or may not define boundaries or sides, such as by defining a tray or shelf-like structure.

The first surface may have an angle to horizontal, such as between 1 and 10 degrees, such as 2-9 degrees, 2-8 degrees, 3-8 degrees, 3-5 degrees or the like. Often, this surface tilts in relation to the intended direction of movement of the cart, such as in a direction forward of the cart so that the forward portion is lower than the back portion (in the direction of movement), or so that the back portion is lower than the forward portion.

Typical carts have handlebars for a person or passage to push and control the cart. At the handle bars, an elevated tray or surface is often designed for the person's small items, such as a hand bag, purchased products (tax-free cosmetics, alcohol or the like), and a larger surface is provided closer to the floor for the person's carry-on luggage, such as a small suitcase or backpack.

That the two surfaces overlap when projected on to the horizontal plane will make the overall outline of the cart smaller while allowing the desired space or volume for the items. This overlap, however, creates problems when radiation is launched perpendicularly to horizontal and thus through the items on both surfaces. In that situation, the images or information generated by the penetrating rays will comprise information from items on both surfaces, which makes analysis based on such information more difficult.

It is noted that as real estate is expensive in airports, it is also not desired to have a larger scanning system than required. No such limitations are as critical in the height direction. Thus, it is normally desired to provide the emitter/detector elements above/below the cart, as this system will not take up much more space than the cart, which is highly desirable.

In order to be able to analyse all portions of the items, a single emitter, such as a more or less point-sized emitter, may be combined with a linear detector (straight, bent or curved) or a number of detectors which then output information based on the radiation's penetration of different portions of the item(s). Clearly, the opposite set-up could be possible where a number of sources emit radiation toward either a number of detectors or a single detector. What is desired is information stemming from radiation penetration of different portions of the items, as is usual in this area of technology.

According to the invention, the emitter(s) and detector(s) define a beam plane having an angle, to a horizontal plane, of below 60 degrees. In this context, the plane may be defined by radiation output in a fan or the like and/or a plane defined by the emitter(s) and detector(s) being provided in that plane. The plane may be flat or curved. The radiation may be output in a beam which is rather narrow, and/or the detectors may be single detectors in a direction out of the plane, so that the detection is performed by detecting multiple points in time while translating the cart in relation to the plane. Alternatively, the detector may be a 2D detector configured to generate at a single point in time information relating to radiation having penetrated at least substantially all portions of all items.

In one embodiment, the system comprises multiple sets of emitters and corresponding detectors at least substantially provided in the same plane, so that the cart is irradiated from multiple sides, where each irradiation comprises one or more of the emitters of a set emitting radiation and the detectors of that set receiving the radiation. Then, one or more emitters of another set emit radiation and the detectors of that set detect radiation. An emitter and/or a detector may form part of multiple sets. Alternatively, the same set may be rotated in the plane and around the cart. In this manner, the cart is irradiated from different sides, often 12 different sides or angles, so that a more detailed image of the cart and its contents may be derived. These sets, such as a - or the - emitter thereof may be positioned around the cart, such as around a predetermined position in the plane, alternatively, the detector(s) and emitter(s) of each set may be provided in individual planes, which then are at least substantially parallel. The positions may be evenly distributed, such as a predetermined numbers of degrees around the point, such as with the predetermined number of degrees between neighbouring detectors, such as 360°/12=30° between neighbouring emitters when 12 emitters are provided. The emitter(s) and/or detector(s) of each set may be controlled, if desired, to be operated when a same portion of the cart is positioned in the plane or the plane of that set.

The angle of the plane may be below 55 degrees, such as below 50 degrees, such as below 45 degrees, such as below 40 degrees, such as below 35 degrees to the horizontal plane.

The angle is sufficiently low for the radiation to penetrate only the items on the first surface or the items on the second surface.

It may be desired that the angle is no less than 10 degrees, such as no less than 15 degrees, such as no less than 20 degrees, such as no less than 25 degrees, such as no less than 30 degrees.

In one embodiment, the emitter(s) and detector(s) are provided on either side of the cart. In this manner, the emitter is desirably provided at a distance from the cart for the radiation therefrom to be able to fan out sufficiently for it to cover all portions of the cart. Thus, the real estate of the scanning system may be increased.

In another embodiment, one of the emitter(s) and the detector(s) is provided at a height above a height of the cart and the other of the emitter(s) and the detector(s) is provided at a height below a lowest portion of the cart, such as below a surface on which the cart moves during scanning. In this manner, the cart may move horizontally along a straight line while being scanned. When the emitters and detectors are provided below and above the cart, the real estate taken up by the scanning system is low. However, the length of the scanning system may be slightly extended due to the lower angle than usual for the beam plane.

It may be desired that the radiation emitter(s) is/are positioned below floor level, as this may assist in containing radiation emitted in directions other than toward the cart and detector(s). In that situation, the detector(s) may be provided not far above the cart, such as above a maximum outline or extent allowed by the cart, so that the main extent of the scanning system outside of the portion where the cart and radiation meet, i.e. the fanning-out portion of the radiation between the emitter and the cart, may be below the ground surface, where it may take up no real estate on the floor level.

In one embodiment: the cart has a longitudinal direction and an overall outline when projected on to the horizontal plane, the first and second surface overlap, when projected on to the horizontal plane, in a first area of the overall outline, a second area exists within the overall outline and not including the first area, the second and first areas being positioned along the longitudinal direction, and the cart is oriented, relative to the beam plane, so that the beam plane is at a lower height at the first area and at a larger height at the second area.

Often, the cart as engaging means, such as handle bars, scanners, monitors or the like, and often at the second surface, which then normally would be the back end of the cart, which the person will push or drive in front of the person. Then, most of the first surface would extend in front of the second surface, and at a lower position, often close to the floor.

Thus, the beam is launched in a direction where the second surface may be above the beam and the first surface and items thereon may be below the beam. In this context, it may be desirably to define a maximum height of items provided on the first surface. It may also be desired to define a preferred position or area for such items to ensure that the radiation does not penetrate items both on the first and second surfaces.

Thus, it may be desired that the first surface comprises a stopping element in a portion overlapping, in the horizontal plane, with the second surface. This stopping element may prevent the item(s) on the first surface to move more into the area of overlap, when projected on to the horizontal plane, than the stopping element. If the item(s) were allowed to move further toward that direction, they, depending also on their height, could enter the radiation when penetrating the items on the second surface.

It may be desired to define a maximum height for items on the first surface, as it is desired that the beam plane may extend between the second surface and any and all items on the first surface.

In one embodiment, the first and second surfaces are surfaces of elements which are transparent to the electromagnetic radiation. In this situation, the surfaces and elements will not themselves block the radiation, rendering the analysis less useful. Actually, it may be desired that the cart comprises a frame attached to the first and second surfaces, where the frame is transparent to the electromagnetic radiation. This will enable detection of the situation where a person has attempted to conceal illegal elements or substances in the actual frame of the cart.

Another aspect of the invention relates to a method of scanning a cart comprising a first surface configured to carry items and a second surface configured to carry items, where the second surface is elevated, relative to the first surface, and at least partly overlapping the first surface, when projected on to a horizontal plane, the method comprising the steps of: translating the cart relative to a scanning system comprising at least one emitter of electromagnetic radiation and one or more detectors to: first transport all items provided on one of the first and second surfaces through the beam plane and subsequently transport all items on the other of the first and second surfaces through the beam plane.

In this context, it is noted that all embodiments, situations, considerations and the like from the first aspect of the invention are equally valid in this context.

Thus, the cart may be as described above. The cart has the two surfaces capable of holding or supporting items, such as for use in an airport and/or in a security scanning context.

The method comprises the step of translating the cart relative to the scanning system or at least the beam or beam plane thereof. Clearly, the cart may be translated in relation to a scanning system having stationary parts, but a cart may be stationary within a system having a translating scanning portion, such as a unit holding the emitter(s) and detector(s).

By this translation, all items provided on one of the surfaces is/are firstly provided through the beam plane. Thus, information may be derived from the radiation or detector output relating only to these items.

Subsequently, the items on the other surface are provided through the beam plane, and information may be derived specifically to these items. When the items are provided through the beam plane separately in time, the transmitted, absorbed, scattered or detected radiation and thus the output of the detectors will depend only on items on one surface. No overlap is seen. This makes any analysis of such radiation or information faster and/or more reliable in that the items on the two surfaces will not interfere in the radiation or information.

Clearly, it is not relevant which surface and which items are provided through the beam plane first.

In one embodiment, the method further comprises the step of collecting radiation having penetrated the items provided on the first and second surfaces and deriving information relating to one or more elements or substances in the items. This information may relate to particular elements in the items or particular substances therein. The contents of containers may be analyzed and information may be derived as to what the contents are and whether such contents are allowed or not. Elements and substances may be prohibited or provided on a list of relevant elements and substances. If an element is identified in an item from the information, the item or cart may be flagged for further analysis. The same may be the situation if a particular substance is identified. The further analysis may be performed by a person or by the same or another scanning system.

As mentioned above, the system may comprise a number of sets of one or more emitters and detectors in order to provide the radiation through the cart sequentially - or simultaneously - from multiple sides or angles.

As mentioned, the items on the first and second surfaces are transported through the beam plane at different points in time, often with no overlap. Thus, the method may further comprise performing an analysis of one more first item(s) provided on the first surface and one or more second item(s) provided on the second surface, wherein the analysis of the first and second elements are performed separately. When no interference or overlap is seen between the items, the analysis may be simpler or more precise. For example, it may be indicated with a higher precision in which item a particular element or substance is identified.

In one embodiment, the translating step comprises directing a beam of electromagnetic radiation on to and through the items on the first and second surfaces. As mentioned above, this radiation may be X-ray radiation as is often used in security scanners. The emission and detection thereof and the analysis of the output of the detectors may be as is usual in the trade. In one situation, the directing step comprises directing the beam from one or more emitter(s) provided on one side of the cart toward one or more detector(s) provided on another side of the cart. Thus, between an emitter and a detector, a straight line may exist which is horizontal. In this situation, the real estate taken up by the scanning system is larger but the height may be limited.

In another situation, the directing step comprises directing the beam from one or more emitter(s) provided at a height above a height of the cart and on to one or more detector(s) provided below a lowest portion of the cart. Thus, between an emitter and a detector, a straight line may exist which is provided in a vertical plane. In this situation, the real estate taken up by the system may be smaller where the height may be larger.

It may, on the other hand, be desired that the directing step comprises directing the beam from one or more emitter(s) provided below a lowest portion of the cart and on to one or more detector(s) provided at a height above a height of the cart. Thus, between an emitter and a detector, a straight line may exist which is provided in a vertical plane. In this situation, the real estate taken up by the system may also be low, and as the fanning-out portion of the emitter may be provided below the floor surface, the height may also be kept low.

In the following, preferred embodiments will be described with reference to the drawing, wherein:

Figure 1 illustrates a security scanning set-up comprising a cart carrying items and Figure 2 illustrates multiple sets of emitter and detectors.

In figure 1, a security system 10 is illustrated comprising an emitter 12 of electromagnetic radiation, typically X-ray, and a detector 14 for that radiation.

A cart 30 is illustrated having a frame 38 and an upper compartment or surface 34 for holding items 22, such as luggage, and a lower compartment or surface 32 for holding items 20, such as luggage. The cart may be of the type seen in airports. The present cart may be made of a material which may be penetrated by the radiation so that no dangerous or forbidden elements or substances may be stored or hidden in the frame 38.

In order to reduce the footprint of the cart, the upper surface 34 may be provided completely or partly above the lower surface 32, as it would be seen when both surfaces are projected on to a horizontal plane. The system 10 may be for use in a security scanning in an airport.

A relative movement 16 is provided between the detector/emitter and the cart 30 so that the contents of the cart, and optionally also the cart itself, are scanned during this relative movement. This relative movement may be obtained by a drive engaging the cart 30 and translating it along a predetermined path, track or direction.

The radiation may form a fan or the like defining a plane which is translated, often perpendicular to the plane, in relation to the cart. The detector may be a line-shaped detector or comprise a number of detectors in order to detect the radiation having penetrated different portions of the cart and items in that plane. Naturally, a line-shaped emitter or a number of emitters may be provided if desired, such as in combination with one detector.

In this manner, a number of detections, each representing a "slice" through the cart and items, may be provided of the items 20/22, as is usual, in order to analyze these items and determine whether they can be considered safe or if they comprise elements or substances which need further analysis. Analysis may, as is usual, be provided across slices or between slices, when the relative movement between the detector/emitter and the cart is known.

In the present system, the emitter/detector and the upper and lower surfaces are provided relative to each other so that each detection or "slice" relates to only one of the items 22/20. This is obtained by providing a sufficiently low angle, a, between the plane of the emitter/detector and the horizontal plane. Providing a lower angle, a, will, for the same minimum height of the loaded cart 30, require a larger horizontal use of real-estate by the emitter/detector system. It has the advantage, however, that the radiation received or detected has not penetrated items of both the upper surface 34 and the lower surface 32. In this manner, the analysis of the item(s) 22 on the upper surface 34 may be wholly separate from the analysis of the item(s) 20 on the lower surface 32. This not only makes it easier to determine in which item 20/22 a problematic element or substance is detected but it also prevents objects in one item from shadowing objects in the other.

A back stop 33 may be provided in order to ensure that the items 20 on the lower surface 32 do not move further to the back than this stop, to ensure that the item 20, such as when having a height, above the surface 32, of no more than a threshold height, does not move to a position where it overlaps, in the plane,

A means of tilting the cart may be provided, by e.g. lifting the front part 32 of the cart so that further separation between items 20/22 may be achieved when the cart is translated through the plane or line from an emitter 12 and a detector 14. In that manner, the cart design may be used, even if the scanner has an angle not optimized for the cart.

In figure 2, two sets of emitters and detectors (12-1 and 14-1 and 12-2 and 14-2, respectively) are provided. These may be in the same plane or each may be in a plane where the two planes are then parallel. It is seen that the radiation through the cart 30 is from different positions or angles (in this case, a 90° angle has been chosen), so that the contents of the cart is better analyzed. Multiple sets of detectors and emitter(s) may be provided. All sets may be in the same plane or multiple planes which may then be parallel. Naturally, one or more sets may be rotated in its plane and around the cart, so that in that manner, radiation may be launched through the cart from different angles.