GB2619960A - X-ray imaging apparatus - Google Patents

Abstract

An X-ray imaging apparatus 200 for imaging an object 210 that has curved portions on its outer surface, comprises an X-ray emitter 220, a digital detector 230, and a support 270 for holding the object to be imaged. In use, the emitter is on one side the object and the detector is on the other side, opposite the emitter. The apparatus further comprises means to rotate the object around a longitudinal axis to present portions of its outer surface which have curved profiles in an orientation such that the tangent to the surface of the portion being imaged is substantially perpendicular to a direction of X-rays emitted by the X-ray emitter. There may be a support at each end of the object and the support may include the rotational movement means, which may be powered. The apparatus may include means to move the object and/or the emitter parallel or perpendicular to the longitudinal axis to image in discrete sections. The apparatus may include an enclosure 280 including x-ray shielding. The enclosure may have entrance and exit doors through which the object may pass.

Description

X-ray imaging apparatus The present invention relates generally to an X-ray imaging apparatus and a method of producing X-ray images of a relatively linear shaped object comprising portions of its outer surface having curved profiles, and finds particular, although not exclusive, utility in imaging helicopter blades, turbine blades, rotor blades and other bladelike structures which include a twisted body, and/or an aerofoil profile.

Helicopter blades are highly sophisticated products, consisting of a matrix of various materials and composites. Each rotor blade is often manufactured as a composite, with foam or honeycomb materials forming the core of the blade. The blades are often covered with one or more layers of fibre-reinforced plastics on the outside. For further reinforcement, carbon, Keylar or glass fibres are often included in highly stressed areas, such as the trailing edge, and other complex parts such as the "rear-wall corner joints" of the composite frame. These layers follow the contours of the body and are often not planar.

The continued exposure to severe load spectrums may induce damage in the rotor blade, and continuous periodic inspections are therefore required to ensure continued availability of the rotorcraft and its safe operation. However, the inspection of these structures is not a trivial matter, with the complexity of design and myriad of materials used, particularly for inner structures, where geometry and different material properties and anisotropy make inspection difficult.

This is also exacerbated by the external shapes (and internal non-planar layers) which are often complex, leading to difficulties in imaging them using traditional X-ray imaging equipment. Producing clear internal images of the blades is also difficult due to their composite nature as discussed above. Furthermore, analysis of any produced X-ray images is difficult due to the external shape and internal configurations.

There is accordingly a need for both helicopter rotor blades and turbofan fan blades, along with other large aerospace blades (together 'blades') to be tested nondestructively during manufacture and also throughout the products lifetime 1.-use 30 (maintenance).

In a first aspect, the present invention provides an X-ray imaging apparatus for imaging a relatively linear shaped object comprising portions of its outer surface having curved profiles, the apparatus comprising an X-ray array of at least two X-ray emitters, a digital detector, and at least one support For holding the object to be imaged, wherein the emitters arc arranged on one side of the object, in use, and the detector is arranged opposite the emitters, on the other side of the object, in use, wherein the apparatus further comprises rotational movement means for rotating the object around its longitudinal axis and arranged to present portions of the outer surface, which have curved profiles, in an orientation such that the tangent to the surface of the relevant portion is substantially perpendicular to a direction of X-rays emitted by at least one of the X-ray emitters. in this way, X-ray images may be formed of variously located "slices" through the object. the object may comprise various layers of material, which also have curved profiles, in a similar manner to the outer surface of the object. Accordingly, by arranging the outer surface in an orientation such that the tangent to the surface of the relevant portion is always substantially perpendicular to a direction of the emitted X-rays, the resultant image of each "slice" may show the various layers in a similar orientation to each other image/slice. This may allow for the various layers to be relatively easily followed by a human eye when viewing the various images one after another in a "video" style format, from one end of the object to the other. In this respect, the images may be combined to create 3-dimensional tomosynthesis images. This may allow for the state of the structural integrity of the object, such as to look for &lamination, to be assessed by on-site personnel, less-qualified than presently required. Also, the processing of the images by the computer processor may be faster than images taken of a similar object without the orientation of the object being arranged such that the tangent to the surface of the relevant portion is substantially perpendicular to a direction of X-rays emitted. This may allow for real-time structural integrity reviews to be undertaken rather than having to wait for more time-consuming image processing to be undertaken, possibly off-site with the images being sent back later.

The at least one support may comprise the rotational movement means. For instance, the support may comprise a clamp for grasping and retaining the object and a motor for rotation of the clamp. The X-ray imaging apparatus may comprise two supports, each arrangeable at either end of the linear shaped object, in use. Either or both supports may comprise rotational movement means so as to rotate die object, in use.

The X-ray imaging apparatus may further comprise linear tnovetnent means for moving the object, in use, relative to the X-ray emitter array. For instance, the apparatus may comprise a track and cooperating track-engaging members (such as wheels or sliders) and a motor, such that the object may move along the track.

The linear movement means may be arranged to move the object, in use, parallel and/or perpendicular to the longitudinal axis of the object, Sc) that the object is imageable in discrete sections, so as to create an image of each "slice".

The linear movement means may be arranged to raise and lower the object, in use, relative to the X-ray emitter array. This may be effected by the use of any one or more of a motor, scissor lifts, rams, etc. The X-ray imaging apparatus may further comprise X-ray emitter movement means for moving the X-ray emitter array relative to the object, in use. For instance, the apparatus may comprise a track and cooperating track-engaging members (such as wheels or sliders) and a motor, such that the X-ray emitter array may move along the track. The X-ray emitter movement means may be arranged to move the X-ray emitter parallel and/or perpendicular to the longitudinal axis of the object, in use, so that the object is imageable in discrete sections, so as to create an image of each "slice".

The X-ray imaging apparatus may further comprise rotational movement locator means arranged to move the rotational movement means relative to the X-ray emitter array, parallel and/or perpendicular to the longitudinal axis of the object, in use. In this way, if the X-ray emitter array and detector remains stationary relative to the local environment, the object may be moved relative to, and between, them, and still be rotated relative to them, in use.

The X-ray emitter array may be arranged to direct X-rays, in use, downwardly towards the object, and the detector may be arranged underneath the object, in use. In this way the likelihood of X-rays escaping any enclosure may be reduced.

The X-ray emitter array may comprise a linear 1-dimensional array of emitters.

For wstance, the emitters may be arranged in a straight line adjacent one another.

The X-ray emitter array may comprise one or more flat panel 2-dimensional arrays of emitters. For instance, the emitters may be arranged in a 2-dimensional grid. Individual emitters within the array may be energised as required.

The at least one support may comprise material which is substantially transparent to X-rays. This may reduce the need to avoid the support being arranged between the emitters and detector.

The at least one support may comprise a conveyor belt upon which the object may be arranged for imaging. The belt may be used to move the object linearly relative to the emitters and detector.

The X-ray imaging apparatus may further comprise an enclosure including X-ray shielding to substantially prevent X-rays from travelling beyond the enclosure.

The enclosure may include an entrance and an exit, and an entrance door and an exit door, arranged to allow the passage of the object, in use, into and out of the enclosure. The doors may comprise flexible flaps.

The X-ray imaging apparatus may further comprise labyrinthine means to substantially prevent X-rays from travelling through the entrance and exits from within the enclosure.

In a second aspect, the invention provides a method of producing X-ray images of a relatively linear shaped object comprising portions of its outer surface having curved profiles, comprising the steps of providing an X-ray imaging apparatus according to the first aspect; providing an object to be imaged; using the at least one support to hold the object; using the rotational movement means to rotate the object around its longitudinal axis so as to present a first portion of the outer surface, which has a curved profile, in an orientation such that the tangent to the surface of the first portion is substantially perpendicular to a direction of X-rays emitted by at least one of the X-ray emitters; emitting X-rays through the object: detecting the emitted X-rays after they have passed through the object; processing said detected X-rays to produce a first X-ray image of the object.

The method may further comprise the step of moving the object relative to the X-ray emitter array, and/or moving the X-ray emitter array relative to the object; rotating the object to present a second portion of the outer surface, in an orientation such that the tangent to the surface of the relevant portion is substantially perpendicular to a direction of X-rays emitted by at least one of the X-ray emitters; emitting X-rays through the object; detecting the emitted X-rays after they have passed through the object; processing said detected X-rays to produce a second X-ray image of the object The method may further comprise the step of repeating the movement of the object and/or X-ray emitter array to produce further X-ray images of further portions of the object.

The method may further comprise the step of creating a 3-dimensional image from the first, second and further images.

The object may be any one of a rotor blade, a helicopter blade, and a turbine blade The above and other characteristics, features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. This description is given for the sake of example only, without limiting the scope of the invention. The reference figures quoted below refer to the attached drawings.

Figure 1 is a schematic view of a part of an X-ray imaging device; Figure 2 is a series of four schematic views of part of another X-ray imaging device; and Figures 3 to 5 are schematic views of different X-ray imaging devices The present invention will be described with respect to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. Each drawing may not include all of the features of the invention and therefore should not necessarily be considered to bc an CtilbOdirIltilt of the invention. Tn the drawings, the sfze of some of the elements may be exaggerated and not drawn to scale for illustrative purposes. The dimensions and the relative dimensions do not correspond to actual reductions to practice of the invention.

Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequence, either temporally, spatially, in ranking or in any other manner. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that operation is capable in other sequences than described or illustrated herein. Likewise, method steps described or claimed in a particular sequence may be understood to operate in a different sequence.

Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that operation is capable in other orientations than described or illustrated herein.

Tt is to be noticed that the term "comprising", used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. it is thus to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof Thus, the scope of the expression "a device comprising means A and B" should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B. Similarly, it is to be noticed that the term "connected", used in the description, should not be interpreted as being restricted to direct connections only. Thus, the scope of the expression "a device A connected to a device B" should not be limited to devices or systems wherein an output of device A is directly connected to an input of device 13. It means that there exists a path between an output of A and an input of B which may be a path including other devices or means. "Connected" may mean that two or more elements are either in direct physical or electrical contact, or that two or more elements are not in direct contact with each other but yet still co-operate or interact with each other. For instance, wireless connectivity is contemplated.

Reference throughout this specification to "an embodiment" or "an aspect" means that a particular feature, structure or characteristic described in connection with the embodiment or aspect is included in at least one embodiment or aspect of the present invention. thus, appearances of the phrases "in one embodiment", "in an embodiment", or "in an aspect" in various places throughout this specification are not necessarily all referring to the same embodiment or aspect, but may refer to different embodiments or aspects. Furthermore, the particular features, structures or characteristics of any one embodiment or aspect of the invention may be combined in any suitable manner with any other particular feature, structure or characteristic of another embodiment or aspect of the invention, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments or aspects.

Similarly, it should be appreciated that in the description various features of the invention arc sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Moreover, the description of any individual drawing or aspect should not necessarily be considered to be an embodiment of the invention. Rather, as the following claims reflect, inventive aspects lie in fewer than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention. Furthermore, while some embodiments described herein include some features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form yet further embodiments, as will be understood by those skilled in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practised without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this

description.

In the discussion of the invention, unless stated to the contrary, the disclosure of alternative values for the upper or lower limit of the permitted range of a parameter, coupled with an indication that one of said values is more highly preferred than the other, is to be construed as an implied statement that each intermediate value of said parameter, lying between the more preferred and the less preferred of said alternatives, is itself preferred to said less preferred value and also to each value lying between said less preferred value and said intermediate value.

The use of the term "at least one" may mean only one in certain circumstances.

The use of the term "any" may mean "all" and/or "each" in certain circumstances.

The principles of the invention will now be described by a detailed description of at least one drawing relating to exemplary features. It is clear that other arrangements can be configured according to the knowledge of persons skilled in the art without departing from the underlying concept or technical teaching, the invention being limited only by the terms of the appended claims.

Figure 1 depicts how part of an object 10 may be imaged using an X-ray imaging device comprising an X-ray emitter 20 arranged above the object 10, and an X-ray detector arranged below the object 10. A representation of the X-rays is shown by the triangle 40.

Only a portion of the object 10 is shown. Tt includes a curved outer surface. If the object includes laminar layers lying substantially parallel to the curved upper and outer surface then it will be understood that the resulting X-ray imagewill 1 show the layers at an angle to the horizontal. This means that after the object has been X-rayed in discrete sections along its entire length, the layers shown in each image will not align relatively easily with those of adjacent images. this leads to difficulties in interpretation of the images by a semi-skilled operator, for instance when checking for delamination.

Alternatively, substantial processing may be required to create a single image from the various individual images such the single image may be viewed and interpreted by the semi-skilled operator.

Tn Figure 2, a similarly shaped object 10 is shown in four different positions relative to the same X-ray emitter 120 and X-ray detector 130. In each of the four shows positions, the object 10 has been rotated about an axis which is oriented into the page, and perpendicular to the direction of X-rays 140 emitted from the X-ray emitter 120 towards the X-ray detector 130.

Accordingly, the object has been rotated so as to present to the X-ray emitter a portion of the curved outer surface in an orientation such that the tangent to the surface of this portion is substantially perpendicular to a direction of X-rays 140 emitted by the X-ray emitter 120.

In this way, the laminar layers which lie substantially parallel to the curved upper and outer surface will be shown in the resulting X-ray images as layers lying approximately parallel to the horizontal. This means that after the object has been X-rayed in discrete sections along its entire length, the layers shown in each image will align relatively easily with those of adjacent images. This means that interpretation of the images by a semiskilled operator, for instance when checking for dclamination, will be readily straightforward as they will be able to follow the layers along the image and any unexpected increases in gaps between layers, or movements of layers relative to the outer surface of the object, or portions of uneven layers, or changes in thickness of layers, will be easily visible without need of substantial processing.

Tt will be understood that apparatus may be provided to rotate the object around other axes, as required. Example apparatus 200 is shown in side view in Figure 3, where the object 210 is a blade including a twisted, and curved, outer surface.

The object 210 is supported at each end by supports 270. These supports 270 may include a rotatable portion, powered by an electric motor, for example, so as to rotate the object 210 about its longitudinal axis. It will be understood that only one support 270 may include a rotatable portion, with the other support 270 freely rotatable.

The object 210 is imageable by means of an X-ray emitter 220 located above the object 210 and a digital detector 230 located below the object 210. The X-ray emitter 220 is attached, by an attachment member 222, to a bracket 225 which, in turn, is attached to a conveyor (continuous) belt 251 which is arranged around two wheels 250 or rollers. In use, the belt 251 may be driven such that the X-ray emitter 220 is movable relative to the object 210. Furthermore, the attachment member 222 may raise or lower the X-ray emitter 220 relative to the object 210 so that it is always maintained in close relationship thereto. This close relationship allows for lower powered X-ray emissions to be used and also reduces the likelihood of stray X-rays escaping from the apparatus 200.

In a similar manner, the digital detector 230 is attached, by an attachment member 232, to a bracket 235 which, in turn, is attached to a conveyor (continuous) belt 261 which is arranged around two wheels 260 or rollers. In use, the belt 261 may be driven such that the digital detector 230 is movable relative to the object 210. Furthermore, the attachment member 232 may raise or lower the digital detector 230 relative to the object 210 so that it is always maintained in close relationship thereto. This close relationship also allows for lower powered X-ray emissions to be used and also reduces the likelihood of stray X-rays escaping from the apparatus 200.

The apparatus 200 is arranged within an enclosure 280 which is relatively opaque to X-rays Sc) as to prevent X-ray leaving the apparatus for health and safety reasons. The enclosure 280 is large enough to accommodate all of the object 210. The enclosure 280 may have a length of 10.5 metres, but other sizes are contemplated. Doors may be provided (not shown) for access.

The supports 270 may be attached via supporting poles 272 to drives 275 which allow for the supports 270 to travel up and down the poles 272 so as to lower and raise the object 210 relative to the enclosure 280, as required. Also, the drives 273 may be arranged to move the poles 272 and supports 270 laterally (into and out of the page and perpendicularly to the longitudinal length of the object 210) within the enclosure 280 so that relatively wide objects may be imaged in portions. Alternatively, or additionally, the X-ray emitter 220 and X-ray detector 230 may be moved laterally across the belts 251, 161. Alternatively, or additionally, the belts 251, 161 may be moved laterally across the enclosure 280. All of these possible movements may be provided manually and/or by means of motors or pneumatic/hydraulic rams. Other means are contemplated.

The support 270 may also be able to rotate the object 210 about its longitudinal axis so as to present portions of the outer surface of the object in particular, selected orientations as explained herein.

Another example of apparatus 300 is shown in side view in Figure 4. In this case, the X-ray emitter 320 and digital detector 330 are enclosed within an enclosure 380 which is relatively smaller than the object 310 to be imaged. Emitted X-rays 340 are indicated. The supports 370 are arranged outside the enclosure 380 but may operate in the same way as those described with respect to Figure 3. For instance, they may include drives 375 and poles 372 for raising and lowering the object 310 relative to the enclosure.

They may also be able to rotate the object 310 about its longitudinal axis so as to present portions of the outer surface of the object in particular, selected orientations as explained herein.

They may also be arranged to move the supports 370 laterally relative to the X-ray emitter and digittl detector so that relatively wide objects may be fully imaged in discrete portions.

In this example, the enclosure 380 is arranged on a conveyor (continuous) belt 260, arranged underneath the object 310, so that it may be moved along the length of the object 310. In this way, portions of the object 310 may be imaged progressively along its 25 length.

Although not shown, the enclosure may include means for raising and lowering the X-ray emitter 320 and digital detector 330 relative to the object 310 so as to keep the 'distance to object' to a minimum. Also, the enclosure may include means for moving the X-ray emitter 320 and digital detector 330 laterally relative to the object 310 so that relatively wide objects may be fully imaged in discrete portions.

It will be noted that the enclosure 380 is not long enough to accommodate all of a relatively long object 310 as is shown in Figure 3. Therefore, doors or openings are provided on either side of the enclosure 380 through which the object may pass as it is being imaged along its length in discrete portions.

To reduce or prevent X-rays from escaping the enclosure 380, flexible flaps 390 are provided around the openings. Such flaps 390 may comprise substantially X-ray opaque material and be rigid, yet flexible, enough to allow movement of the object 310 through the enclosure 380 and its rotation within.

Another example apparatus is shown in Figure 5. This time the view is a plan view. 't he object 410 is another twisted blade-like object held at either end by supports 470. The supports 470 may rottte by means of rods 472 which attach them to drives 464 which, in turn, are arranged on tracks 476 allowing movement of the drives 474, rods 472, supports 470 and thus the object 410 laterally between legs 478, and rotationally about its longitudinal axis.

The X-ray emitter 420 is arranged within an enclosure 480 in a similar manner to that described with reference to Figure 4. The emitter 420 may travel laterally within the enclosure 480 along a track 426 between supports 428.

The enclosure 480 will also comprise a digital detector (not shown) underneath the object 410, and openings (not shown) to allow the object 410 to pass through and rotate within. Flaps may be provided to reduce or prevent X-rays escaping the enclosure 480 in a similar manner to those described with reference to Figure 4.

A continuous conveyor belt 460 is arranged underneath the enclosure for moving it along the length of the object 410, although other means for moving the enclosure are contemplated.

Alternatively, the belt 460 may be arranged under the object 410 but above the detector (not shown). In this case, the belt 460 may be transparent to X-rays.

Tt will be understood that the various means and methods for moving the objects 210, 310, 410 relative to the X-ray emitters 220, 320, 420 and detectors 230, 330 described with reference to Figures 3, 4 and 5 may be employed in different combinations as those described.

Alternatively, or additionally, to the flaps 390 described with reference to Figures 4 and 5, labyrinths of X-ray absorbing material may be arranged about the openings of the enclosures to prevent X-rays escaping therefrom. The labyrinths may be arranged to move with the enclosure and with the lateral, longitudinal and rotational of the object relative to, and through, the enclosure.

Although the descriptions of the Figures refer to an "X-ray emitter" it is to be understood that there may be one or more emitter unit, each unit COTT1priSing one or more sources of X-rays. The emitters may be angled in towards each other to reduce X-ray scatter.

The resultant X-ray digital images may be processed for the determination of damage, delamination, wear, and other defects and thus identify when an object may need repair or replacement. Such determination may include the use of artificial intelligence, and/or by reference to predetermined rules.

The apparatus described herein may allow personnel to be within 5 to 10 metres thereof without risk to their health through the absorption of stray X-rays.

The processors may be arranged to stitch together adjacent discrete X-ray images so as to create a digital 3-dimensional tomosynthesis image of the entire object.

Fiducial markers, which may be arranged on a tape and may be removably -adhered to the object, may be used to provide references for the stitching together of the images.

The fiducial markers are arranged to be visible to human-eye and therefore to image identification/recognition software running on the computer processors.

Alternatively, or additionally, the image identification/recognition software may bc arranged to identify and reference the internal fibre patterns of the objects to aid stitching together of adjacent images to create the overall image.

The X-ray absorbing material used in the enclosures, flaps and labyrinths may include lead. The term "flaps" may include "curtains".

The processor may be arranged to compare X-ray images produced at different times to aid the identification of defects in the object.

Claims (1)

1. CLAIMS1. An X-ray imaging apparatus for imaging a relatively linear shaped object comprising portions of its outer surface having curved profiles, the apparatus comprising an X-ray array of at least two X-ray emitters, a digital detector, and at least one support for holding the object to be imaged, wherein the emitters are arranged on one side of the object, in use, and the detector is arranged opposite the emitters, on the other side of the object, in use, wherein the apparatus further comprises rotational movement means for rotating the object around its longitudinal axis so as to present portions of the outer surface which have curved profiles in an orientation such that the tangent to the surface of the relevant portion is substantially perpendicular to a direction of X-rays emitted by at least one of the X-ray emitters. 2. 3. 4. 6. 7.The X-ray imaging apparatus of claim I, wherein the at least one support comprises the rotational movement means.The X-ray imaging apparatus of either one of claims 1 and 2, comprising two supports, each arrangeable at either end of the linear shaped object, in use.The X-ray imaging apparatus of any preceding claim, further comprising linear movement means for moving the object, in use, relative to the X-ray emitter array.The X-ray imaging apparatus of claim 4, wherein the linear movement means is arranged to move the object, in use, parallel and/or perpendicular to the longitudinal axis of the object, so that the object is imageable in discrete sections.the X-ray imaging apparatus of claim 5, wherein the linear movement means are arranged to raise and lower the object, in use, relative to the X-ray emitter array.The X-ray imaging apparatus of any preceding claim, Further comprising X-ray emitter movement means for moving the X-ray emitter array relative to the object, in use.8 The X-ray imaging apparatus of claim 7, wherein the X-ray emitter movement means is arranged to move the X-ray emitter parallel and/or perpendicular to the longitudinal axis of the object, in use, so that the object is imageable in discrete sections.9. The X-ray imaging apparatus of any preceding claim, further comprising rotational movement locator means arranged to move the rotational movement means relative to the X-ray emitter array, parallel and/or perpendicular to the longitudinal axis of the object, in use.10. the X-ray imaging apparatus of any preceding claim, wherein the X-ray emitter array is arranged to direct X-rays, in use, downwardly towards the object, and wherein the detector is arranged underneath the object, in use.11. The X-ray imaging apparatus of any preceding claim, wherein the X-ray emitter array comprises a linear, 1-dimensional, array of emitters.12. The X-ray imaging apparatus of any preceding claim, wherein the X-ray emitter array comprises one or more flat panel, 2-dimensional, arrays of emitters.13. The X-ray imaging apparatus of any preceding claim, wherein the at least one support comprises material which is substantially transparent to X-rays.14. The X-ray imaging apparatus of any preceding claim, wherein the at least one support comprises a conveyor belt 13. the X-ray imaging apparatus of any preceding claim, further comprising an enclosure including X-ray shielding to substantially prevent X-rays from travelling beyond the enclosure.16. The X-ray imaging apparatus of claim 15, wherein the enclosure includes an entrance and an exit and an entrance door and an exit door, arranged to allow the passage of the object, in use, into and out of the enclosure.17. the X-ray imaging apparatus of claim 16, further comprising labyrinthine means to substantially prevent X-rays from travelling through the entrance and exits.18. A method of producing X-ray images of a relatively linear shaped object comprising portions of its outer surface having curved profiles, comprising the steps of providing an X-ray imaging apparatus according to any preceding claim; providing an object to be imaged; using the at least one support to hold the object; using the rotational movement means to rotate the object around its longitudinal axis so as to present a first portion of the outer surface, which has a curved profile, in an orientation such that the tangent to the surface of the first portion is substantially perpendicular to a direction of X-rays emitted by at least one of the X-ray emitters; emitting X-rays through the object; detecting the emitted X-rays after they have passed through the object; processing said detected X-rays to produce a first X-ray image of the object.19. The method of claim 18, when dependent on claim 7, farther comprising the step of moving the object relative to the X-ray emitter array, and/or moving the X-ray emitter array relative to the object; rotating the object to present a second portion of the outer surface, in an orientation such that the tangent to the surface of the relevant portion is substantially perpendicular to a direction of X-rays emitted by at least one of the X-ray emitters; emitting X-rays through the object; detecting the emitted X-rays after they have passed through the object; processing said detected X-rays to produce a second X-ray image of the object.20. The method of claim 19, farther comprising the step of repeating the movement of the object and/or X-ray emitter array to produce further X-ray images of further portions of the object.21. The method of claim; 20, further comprising the step of creating a 3-dimensional image from the first, second and further images.22. The method of any one of claims 18 to 21, wherein the object is any one of a rotor blade, a helicopter blade, and a turbine blade.