Patent Description:
Known luggage scanning systems, such as explosives detection systems (EDS) that perform computed tomography (CT) scanning, are designed to scan a continuous stream of luggage and other objects to provide adequate throughput for travelers at an airport, for example. Baggage handling systems are designed to facilitate this stream of luggage, transporting luggage items throughout the airport. At least some baggage handling systems have been developed that use trays or totes to carry objects (e.g., luggage, bags, etc.). These systems facilitate more reliable bag tracking and enable faster transportation speeds within the system. Reliability and speed are important factors, particularly in medium and large sized airports, where bags often need to travel long distances and be transported between different locations within the airport.

However, in at least some known baggage handling systems, luggage is placed in trays that travel on top of a traditional conveyor belt. Such an arrangement significantly reduces a maximum size of luggage that can pass through a gantry of the EDS. Moreover, as a field of view (FOV) of the EDS is configured based upon the conveyor-belt surface, at least a portion of a large luggage item may therefore be outside of the FOV of the EDS when the large luggage item passes through the gantry in a tray on top of a conveyor belt. Accordingly, at least some luggage items may not be satisfactorily imaged. <CIT> describes a process for the sorting and storage of instruments, such as surgical instruments, which are to be used for a predetermined operation, such as a surgical operation, and an installation for implementation of this process. <CIT> describes systems and methods for cancelling the effect that transmittance variations of the conveyor chain have on the radiographic image produced by the scanner system. <CIT> describes an apparatus and method for scanning and inspecting baggage. <CIT> describes materials handling systems such as conveyor systems of the "flowing storage" type.

In one aspect, an imaging system according to claim <NUM> is provided.

In another aspect, not forming part of the presently claimed invention, a conveyor system is described. The conveyor system includes a conveyor duct including a first wall and an opposing second wall, a conveyor assembly coupled to the conveyor duct, and a tray. The conveyor assembly includes a first rail coupled to the first wall of the conveyor duct and a second rail coupled to the second wall of the conveyor duct, the first rail and the second rail defining a channel therebetween. The tray includes a base, wherein the conveyor assembly transports the tray, and wherein the base of the tray extends between and below the first rail and the second rail when the conveyor assembly is transporting the tray.

The imaging system described herein includes a gantry, an imaging assembly, and a conveyor assembly. The conveyor assembly is configured to transport objects (e.g., luggage items) through the gantry to be imaged by the imaging assembly. In the example embodiment, the conveyor assembly includes a conveyor configured to transport one or more trays on a pair of rails, such that the tray is positioned between and at least partially below the rails. This conveyor assembly facilitates transporting the objects through the field of view (FOV) of the imaging assembly. Accordingly, the imaging system described herein facilitates transportation of objects of increased size without sacrificing image quality thereof. The imaging system described herein may be implemented in, for example, a baggage handling system, a checkpoint system, a mail or package handling or sorting system, or any other such system.

Turning now to the figures, <FIG> and <FIG> illustrate one example embodiment of an imaging system <NUM> in accordance with the present disclosure. Imaging system <NUM> includes a gantry <NUM>, an imaging assembly <NUM>, and a conveyor assembly <NUM>. Conveyor assembly <NUM> is configured to convey an object <NUM> (as shown in <FIG>), such as a piece of luggage, through gantry <NUM> to be imaged by imaging assembly <NUM>. In the illustrated embodiment, imaging system <NUM> further includes a conveyor duct <NUM> on both an entrance side and an exit side of gantry <NUM>. Conveyor assembly <NUM> is coupled to conveyor duct <NUM>.

Imaging assembly <NUM> includes an x-ray source <NUM> on one side of gantry <NUM> that projects a fan beam of x-rays toward a detector array <NUM> on an opposite side of gantry <NUM>. Detector array <NUM> is formed by detector elements <NUM>, which are radiation detectors that each produce a signal having a magnitude that represents and is dependent on the intensity of the attenuated x-ray beam after it has passed through the object being imaged. During a helical scan that acquires x-ray projection data, gantry <NUM> along with the x-ray source <NUM> and detector array <NUM> rotate within an x-y plane and around the object about a center of rotation, while the object is moved through gantry <NUM> in a z-direction <NUM> perpendicular to the x-y plane of rotation. Gantry <NUM> and x-ray source <NUM> are controlled by a control system <NUM>, which includes a gantry controller <NUM>, an x-ray controller <NUM>, a data acquisition system (DAS) <NUM>, an image reconstructor <NUM>, a conveyor controller <NUM>, a computer <NUM>, a mass storage system <NUM>, an operator console <NUM>, and a display device <NUM>. Gantry controller <NUM> controls the rotational speed and position of gantry <NUM>, while x-ray controller <NUM> provides power and timing signals to x-ray source <NUM>, and DAS <NUM> acquires analog data from detector elements <NUM> and converts the data to digital form for subsequent processing. Image reconstructor <NUM> receives the digitized x-ray data from DAS <NUM> (or computer <NUM>) and performs preprocessing steps on the digitized x-ray data and an image reconstruction process.

<FIG> are diagrams illustrating an object <NUM> conveyed through a field of view (FOV) <NUM> of imaging assembly <NUM> (shown in <FIG>). FOV <NUM> defines the area through which object <NUM> can travel and be imaged by imaging assembly <NUM>. FOV <NUM> is predetermined based on the specific configuration of x-ray source <NUM> and detector array <NUM>. Moreover, FOV <NUM> is configured based on the geometry of gantry <NUM>, such that FOV <NUM> fits within the circumference of gantry <NUM>, as shown in <FIG>. If a much larger FOV is desired, typically a larger diameter gantry <NUM> must be used.

<FIG> illustrates a known conveyor assembly <NUM> including a conveyor belt <NUM>. Object <NUM> is placed on conveyor belt <NUM> and transported through FOV <NUM> of imaging assembly <NUM>. Object <NUM> lies fully within FOV <NUM> and therefore may be fully imaged. However, conveyor assemblies <NUM> including "bare" conveyor belts <NUM> (i.e., objects <NUM> are placed directly on belts <NUM>) have a disadvantage of low efficiency of tracking objects through a full baggage handling system (that includes conveyor assembly <NUM>).

<FIG> illustrates another known conveyor assembly <NUM> that attempts to overcome the disadvantage of conveyor assembly <NUM> by placing object <NUM> within a tray <NUM> carried on conveyor belt <NUM>. Trays <NUM> improve the efficiency of object tracking in conveyor assemblies <NUM>. However, as illustrated, placing objects <NUM> in trays <NUM> on top of conveyor belts <NUM> causes a new disadvantage to arise - large objects <NUM> do not fully fit within FOV <NUM>. In some cases, large objects <NUM> will not even fit within gantry <NUM>, reducing the maximum size of objects <NUM> that can be imaged using imaging system <NUM>.

<FIG> illustrates conveyor assembly <NUM> of imaging system <NUM>. With reference to <FIG> and <FIG>, conveyor assembly <NUM> does not include a belt <NUM> but instead includes a pair of rails <NUM> coupled to conveyor duct <NUM>. More specifically, conveyor assembly <NUM> includes a first rail <NUM> coupled to a first side wall <NUM> of conveyor duct <NUM> and a second rail <NUM> coupled to a second side wall <NUM> of conveyor duct <NUM>. As used herein, "rail" refers generally to structures suitable to convey (transport) a tray <NUM> as well as to support or retain trays <NUM> thereon. Accordingly, each "rail" <NUM>, <NUM> need not be one singular component but can include a plurality of separate components that cooperate to convey and support trays <NUM>. Rails <NUM>, <NUM> can include continuous rails (e.g., belts) and/or separate rail components (e.g., as illustrated in <FIG>). As illustrated in <FIG>, each rail <NUM>, <NUM> may include a plurality of pulley assemblies. In other embodiments, each rail <NUM>, <NUM> may include one or more chain belts and sprocket assemblies, or one or more "mini" conveyor belts. In still other embodiments, each rail <NUM>, <NUM> may include any other suitable conveying structure(s). Moreover, the space between rails <NUM>, <NUM> is open, with rails <NUM>, <NUM> defining an open or empty channel <NUM> such that rails <NUM>, <NUM> transport trays <NUM> between rails <NUM>, <NUM> (as opposed to transporting a tray <NUM> on top of a belt <NUM>, as shown in <FIG>).

Accordingly, as shown in <FIG>, conveyor assembly <NUM> enables a base <NUM> of tray <NUM> to sit between and below rails <NUM>, <NUM>, such that objects <NUM> sit lower and can be fully imaged within FOV <NUM>. In addition, base <NUM> of tray <NUM> is positioned within a bottom portion <NUM> of FOV <NUM>, such that object <NUM> is lowered with respect to a center <NUM> of FOV. In some embodiments, objects <NUM> may be substantially centered within FOV <NUM>. In this way, conveyor assembly <NUM> overcomes the disadvantages of conveyor assembly <NUM> (object tracking inefficiency) and conveyor assembly <NUM> (reduced maximum object size and/or incomplete imaging of large objects). Moreover, conveyor assembly <NUM> enables the imaging of larger objects <NUM> through a bore <NUM> defined by gantry <NUM> compared to conveyor assembly <NUM>, and conveyor assembly <NUM> ensures complete imaging of objects <NUM> that would have portions thereof "cut-off" from FOV <NUM> when using conveyor assembly <NUM>.

In the illustrated embodiment, imaging system <NUM> includes two conveyor ducts <NUM> and two conveyor assemblies <NUM> (collectively, "conveyor systems" <NUM>). One "front" conveyor assembly 106A transports trays <NUM> through a first "front" conveyor duct 108A and into gantry <NUM>, and another "rear" conveyor assembly 106B transports trays <NUM> out of gantry <NUM> and through a second "rear" conveyor duct 108B. In the example embodiment, conveyor controller <NUM> controls conveyor assemblies <NUM> to move at the same, constant speed for optimal imaging of object <NUM> by imaging assembly <NUM>. Moreover, in the example embodiment, conveyor ducts <NUM> are straight, such that conveyor assemblies <NUM> do not require additional guidance systems to move trays <NUM> therethrough. In other embodiments, imaging system <NUM> may include fewer or more conveyor ducts <NUM> and conveyor assemblies <NUM>. Additionally or alternatively, imaging system <NUM> may include otherwise configured conveyor systems <NUM> (e.g., conveyor systems <NUM> including much longer conveyor ducts than those illustrated in <FIG>).

Tray <NUM> includes base <NUM> configured to hold an object <NUM> thereon. Base <NUM> is illustrated as a concave base <NUM> having a curved, concave surface <NUM>. In other embodiments, base <NUM> may be a flat base <NUM> having a substantially planar surface. Base <NUM> includes first and second side edges <NUM>, <NUM> and first and second end edges <NUM>, <NUM>.

Tray <NUM> further includes two opposing side walls <NUM>, <NUM> and two opposing ends walls <NUM>, <NUM>. Each side wall <NUM>, <NUM> extends from a respective side edge <NUM>, <NUM> of base <NUM>. Likewise, each end wall <NUM>, <NUM> extends from a respective end edge <NUM>, <NUM> of base <NUM>. Each side wall <NUM>, <NUM> extends at an angle α from base <NUM>. Angle α may measure between about <NUM>° and about <NUM>°, in various embodiments. In the illustrated embodiment, angle α measures between about <NUM>° and about <NUM>°, or about <NUM>°. Each end wall <NUM>, <NUM> extends at an angle β from base <NUM>. Angle β may measure between about <NUM>° and about <NUM>°, in various embodiments. In the illustrated embodiment, angle β measures between about <NUM>° and about <NUM>°, or about <NUM>°.

A first side wall <NUM> of side walls <NUM>, <NUM> includes a first flange <NUM> extending from first side wall <NUM> along an edge <NUM> thereof opposite base <NUM>. Similarly, a second side wall <NUM> of side walls <NUM>, <NUM> includes a second flange <NUM> extending from second side wall <NUM> along an edge <NUM> thereof opposite base <NUM>. First and second flanges <NUM>, <NUM> are positioned atop respective rails <NUM>, <NUM> when tray <NUM> is placed in conveyor assembly <NUM>. Put another way, first rail <NUM> receives a bottom surface <NUM> of first flange <NUM>, and second rail <NUM> receives a bottom surface <NUM> of second flange <NUM>. Accordingly, as discussed above, when tray <NUM> is placed in conveyor assembly <NUM>, base <NUM> extends between and below rails <NUM>, <NUM> to position objects <NUM> lower, with respect to center <NUM> of FOV <NUM>.

Exemplary embodiments of methods and systems are described above in detail. The methods and systems are not limited to the specific embodiments described herein, but rather, components of systems and/or steps of the methods may be used independently and separately from other components and/or steps described herein. Accordingly, the exemplary embodiment can be implemented and used in connection with many other applications not specifically described herein. For example, the above-described tray conveyor systems gantry resting on support wheels may be implemented in any suitable conveyor and/or imaging system.

Although specific features of various embodiments of the invention may be shown in some drawings and not in others, this is for convenience only. In accordance with the principles of the invention, any feature of a drawing may be referenced and/or claimed in combination with any feature of any other drawing.

Claim 1:
An imaging system (<NUM>) comprising:
a conveyor duct (<NUM>) comprising a first wall and an opposing second wall;
a gantry (<NUM>) coupled to one end of said conveyor duct;
an imaging assembly (<NUM>) associated with said gantry, wherein said imaging assembly comprises:
an x-ray source (<NUM>); and
a plurality of detectors (<NUM>) defining a field of view, FOV, (<NUM>) of said imaging assembly;
a conveyor assembly (<NUM>) coupled to said conveyor duct, said conveyor assembly comprising a first rail coupled to said first wall of said conveyor duct and a second rail coupled to said second wall of said conveyor duct, said first rail and said second rail defining a channel therebetween; and
a tray (<NUM>) comprising a base, wherein said conveyor assembly is configured to transport said tray into said gantry, and wherein a base of said tray extends between and below said first rail and said second rail when said conveyor assembly is transporting said tray; and,
wherein said conveyor assembly (<NUM>) is configured to transport said tray (<NUM>) through the FOV (<NUM>) of said imaging assembly.