JP4179100B2 - X-ray tomographic imaging apparatus and method - Google Patents

Description

  The present invention relates to an X-ray tomographic imaging apparatus and method for inspecting a cross-sectional shape of a long object, a distribution state of foreign matter, a mixture, and the like.

  Conventionally, in the medical field, for example, a cross-sectional image obtained by longitudinally cutting an observation target of a long object such as a blood vessel or an intestine with a curved surface along the observation target, or an image opened so that the inside of the observation target can be observed is displayed. There has been proposed an image display device that can be used (see, for example, Patent Document 1).

  As another example, FIG. 11 shows an example of a method for acquiring long projection data in an X-ray tomographic imaging apparatus (X-ray CT apparatus). A cylinder with a slit 101a at the center in the vicinity of the rotating shaft 101b of the inspection object is used as the inspection object gripping jig 101, and a long material (hereinafter referred to as a material) cut into a sheet shape as the inspection object in the central slit 101a. Also referred to as an object gripping jig 101 on which the material 100 is placed in the vicinity of the X-ray focal point 103 of the conical (cone beam) X-ray irradiated from the microfocus X-ray tube 102. This is a technique for performing reconstruction calculation after acquiring projection data by capturing an enlarged projection image of the material 100 that is rotated in small increments and cut by the two-dimensional detector 104.

Further, FIG. 12 shows an example in which a projection image of a long material is acquired for reconstruction calculation without continuously cutting the material. In the figure, parts corresponding to those in FIG. A cylindrical member 114 having a very good cylindricity is fixed in front of the X-ray focal point 103 of the X-rays irradiated from the X-ray tube 102, and the long material 111 is wound using the cylindrical member 114 as a guide to supply (supply side) A certain amount of material is drawn from the reel 112 in small increments per unit time so that only the long material 111 draws an arc in small increments in front of the X-ray focal point 103 in the course of winding on the take-up (winding side) reel 113. This is a method for obtaining a projection image on the two-dimensional detector 104 by moving it.
Japanese Patent Laid-Open No. 11-318884

  However, although the thing of patent document 1 can display the cross-sectional image of the blood vessel or the intestine based on the acquired data, and the image cut open, the observation range is limited to a part of long thing, and it is a short cut. However, the object to be observed is limited to a human body and cannot be applied to observation of a long material such as a sheet-like long material or a cable.

  In addition, the size of the two-dimensional detector used in the X-ray tomographic imaging apparatus is usually about A4 paper size. On the other hand, a long material reel is generally about 400 mm in diameter, which is more than twice as large as the above-described two-dimensional detector. If the material reel is used as it is, the substance is too large, and it is extremely difficult to project the entire image of the material reel on an enlarged projection image and to perform a three-dimensional microscopic exploration of the inside of the material by performing reconstruction calculation. As shown in FIG. 11, even if a long material is cut and a magnified projection data inside a very small amount of material is imaged and reconstructed and calculated, the volume of the long material that can be reconstructed at once is extremely large. It is difficult to say that the entire image of the long material is grasped with a small amount, and it takes time and effort to cut the long material, and the cutting history itself is not preferable for the long material.

  In addition, the method shown in FIG. 12 restricts traveling to both sides of the cylindrical member 114 for guiding the fixed object to be inspected, as in the case of FIG. In order to obtain highly accurate reconstruction calculation, the material 111 needs to be finely moved into a 360-degree circular shape while the cylindrical member 114 is guided. However, as can be understood from the figure, there is a problem that not only the rotation of 360 degrees can be performed but also projection data corresponding to the rotation of about 270 degrees at most in front of the X-ray focal point 103 can be acquired. It was. Another problem is that the projection data is acquired in small increments while sliding the material 111 along the fixed cylindrical member 114. However, depending on the rigidity of the material 111, the material 111 does not run in close contact with the cylindrical member 114. There was a concern that caused.

  In view of such a point, the present invention proposes an X-ray tomographic imaging apparatus and method that can efficiently acquire a reconstructed image without cutting a long object.

In order to solve the above problems and achieve the object, an X-ray tomographic imaging apparatus of the present invention includes:
An X-ray source;
A two-dimensional detector that detects X-rays emitted from the X-ray source and transmitted through the object to be examined, and picks up a projected image of the object ;
Two reels (for example, a supply reel and a take-up reel) for winding a long material as the object to be inspected;
A substantially cylindrical for have a elongated material insertion portion comprising a gap in which the elongated material sent from one reel to the other reel is inserted, the rotation axis of the central axis the inspection of the substantially cylindrical And a winding member that is substantially parallel to and perpendicular to the perpendicular drawn from the X-ray focal point of the X-ray source to the two-dimensional detector ;
While sandwiching the arbitrary part of the long material of the course to be wound on the other reel from one reel to the elongated component inserting portion, to rotate the take-up member integrally as a rotation about the central axis , it assumes a predetermined amount winding the elongated material of one reel and the other reel to said take-up member, and returns a predetermined amount of the wound the elongated material to the winding member in one reel and the other reel It has a rotating means,
In the process of winding the long material fed from one reel with the other reel, the rotating means winds the winding in a state where an arbitrary part of the long material is sandwiched between the long material insertion portions of the winding member. A predetermined amount of the long material is wound around the winding member, the winding member is rotated by a predetermined angle in a direction to increase or decrease the number of windings of the long material wound around the winding member, and the winding is performed. A projected image for each angle of the long material of the portion wound around the member is captured .

  According to the present invention, the rotating means rotates integrally with the winding member in a state where the long material is sandwiched between the winding members having the long material insertion portion, so that the long material is not cut. Projection data can be acquired by capturing a transmission X-ray projection image of an arbitrary part of a long material.

In addition, the winding material is wound around the winding material by a certain amount, and the winding member is rotated by a predetermined angle in a direction to increase or decrease the number of windings of the wound long material. It is possible to take a projected image for each angle of the long material.

In addition, the present invention, after taking a projection image for each angle, rotates the winding member on which the long material is wound by the rotating means in the direction opposite to the winding direction, and returns the length more than the length returned to one reel. The winding member is supplied to the other reel in a stationary state.

  According to the present invention, the projection member is obtained once by supplying the take-up reel to the take-up reel in a state where the take-up member is stationary by rotating the take-up member reversely by the rotating means and returning to the supply reel. For the completed part, the projection data of the same part is not acquired multiple times.

In the present invention, one reel and the other reel are arranged so as to straddle a perpendicular line dropped from the X-ray focal point to the two-dimensional detector at a substantially right angle, both reel rotation axes are substantially coaxial, and the winding is performed. It arrange | positions perpendicularly | vertically to the rotating shaft of a member, It is characterized by the above-mentioned.

  According to the present invention, the supply reel, the take-up reel, the take-up member, the X-ray source, the two-dimensional detector and the like are arranged in a compact manner by the above-described configuration.

The present invention includes a tension measuring means for measuring the tension applied to both ends of one of the reel side and the other reel side of the elongated material which is inserted into the elongated material insertion portion of the winding member, the one reel and the other A tension generating means for controlling the rotation of the reel, and a tension control calculating means for calculating control information to be given to each tension generating means of one reel and the other reel based on the measurement information of the tension measuring means. Based on the control information of the tension control calculating means, each tension generating means is controlled so that the tension applied to both ends of the long material on one reel side and the other reel side becomes equal and constant.

  According to the present invention, the long material tension at both ends of the winding core is always controlled to be equal and constant, so that the long material does not expand or contract in the length direction during the acquisition of projection data.

An X-ray tomographic imaging method of the present invention includes an X-ray source,
A two-dimensional detector that detects X-rays emitted from the X-ray source and transmitted through the object to be examined, and picks up a projected image of the object;
Two reels for winding the long material as the object to be inspected;
It is a substantially cylinder having a long material insertion portion comprising a gap into which the long material fed from one reel to the other reel is inserted, and the central axis of the substantially cylinder is the rotation axis of the object to be inspected A winding member that is substantially parallel and perpendicular to the perpendicular drawn from the X-ray focal point of the X-ray source to the two-dimensional detector;
In a state where an arbitrary portion of the long material being wound from one reel to the other reel is sandwiched in the long material insertion portion, the long material is rotated integrally with the winding member around the central axis. , Causing the take-up member to take up a predetermined amount of the long material of one reel and the other reel, and returning the long material taken up by the take-up member to the one reel and the other reel by a predetermined amount With rotating means
An X-ray tomographic imaging method using an X-ray tomographic imaging apparatus comprising :
In the process of winding the long material fed from one reel with the other reel, the rotation means inserts the long material with the outer diameter being approximately cylindrical and the central axis being parallel to the axis of rotation of the object to be inspected. A long material is wound on the winding member in a state where an arbitrary portion of the long material is sandwiched between the long material insertion portion of the winding member having a long material insertion portion made of
Rotate the winding member by a predetermined angle in a direction to increase or decrease the number of windings of the long material wound on the winding member,
And acquires the projection data by imaging a projection image for each angle of the long material of the part being wound on the take-up member.

  According to the present invention, in a state where the long material is sandwiched between the winding member having the long material insertion portion, the rotating means rotates integrally with the winding member, and the long material is fixed to the winding member. A projected image of each length of the long material wound around the winding member by rotating the winding member by a predetermined angle in the direction of increasing or decreasing the number of windings of the long material wound up. The projection data can be acquired for an arbitrary part of the long material without cutting the long material.

  According to the present invention, in a state where the long material is sandwiched between the winding member having the long material insertion portion, the rotating means rotates integrally with the winding member, and the long material is fixed to the winding member. The winding member is rotated by a predetermined angle in the direction of increasing or decreasing the number of windings of the wound long material, and the projection of the long material wound around the winding member at each angle. Since the image is captured and projection data is acquired for any part of the long material without cutting the long material, a reconstructed image can be obtained efficiently without damaging the material. There is an effect that it is possible to realize the detection and the distribution state of the fine particles constituting the material over the entire length of the long material.

  Further, the rotation axis of the supply reel and the take-up reel arranged so as to straddle the perpendicular line dropped from the X-ray focal point to the two-dimensional detector can be rotated substantially on the same axis, and the rotation of the rotation mechanism of the inspection object When arranged perpendicular to the axis, the supply reel, the take-up reel and the take-up member, the X-ray source, the two-dimensional detector, and the like can be compactly assembled, and the installation area of the entire apparatus can be reduced.

  In addition, the material tension applied to both ends of the supply reel side and the take-up reel side of the long material inserted into the long material insertion portion of the winding member is always controlled to be equal and constant, so that the material can be obtained during the acquisition of projection data. There is an effect that a highly reliable reconstructed image can be obtained without extending or shrinking in the length direction. In addition, by always knowing the outermost diameter of the supply reel by calculation, it is possible to know the absolute coordinates in the entire long material of the part for which projection data acquisition has been completed once, so duplicate projection data for the same part Is obtained from multiple inefficient work.

  Hereinafter, with reference to FIGS. 1-9, about one embodiment of the X-ray tomography apparatus of this invention, as a long thing to-be-inspected object, for example, long sheet materials, such as a battery negative electrode and a positive electrode sheet material (henceforth, This will be described as an example.

  FIG. 1 shows a concept of a method for inspecting a long sheet material of this example without cutting. A long sheet is wound between a supply (supply side) reel 2 on which a film-like long sheet material is wound and a take-up (winding side) reel 3 for winding the long sheet material 1 supplied from the supply reel 2. The material 1 is wound into a double spiral shape as shown in FIG. 2 by a winding core (hereinafter, also simply referred to as a core) 4 which is a winding member and is a winding member without being cut. In this example, the outer diameter of the core 4 is assumed to be less than one-tenth of the material reel diameter in consideration of the size of the enlarged projection image to be picked up, but the present invention is not limited to this.

  Three types of the supply reel 2, the take-up reel 3 and the sheet material take-up core 4 that rotate integrally with the inspection object turning mechanism 11 shown in FIG. The height at which the material is wound is equal to the height of these two types of reels, the two types of reels and the rotation center axis are parallel to each other, and a perpendicular line (under the plane of the drawing) drawn from an X-ray focal point (not shown) to the two-dimensional detector. Direction from top to bottom) and substantially perpendicular to each other. Further, between the double spiral core 4 and the two types of reels, there are one or more fixed guides each capable of regulating the running height (material width direction) of the sheet material having upper and lower flanges (not shown), and The angle at which the sheet material 1 enters the double helix part to be described later is always kept constant to stabilize the traveling of the sheet material.

  FIG. 2 shows an enlarged view of a state in which a sheet material is wound around the winding core 4 which is a main part of FIG. A slit (long material insertion portion) 5 having a width equal to or greater than the thickness of the material is placed in a substantially cylindrical shape, placed perpendicularly to the vertical direction of the winding member in parallel with the rotation axis, and the resulting two substantially half-cylinders. Assuming the winding cores 4 that are shifted from each other by the thickness of the sheet material and face each other, calculation of the winding length and the like becomes easy. When the winding core 4 is rotated with the sheet material 1 sandwiched between the slits 5 of the winding core 4, the sheet materials from the supply reel 2 and the take-up reel 3 are alternately overlapped to form a double spiral. Winded up. In the following description, the portion 1a wound in a double spiral shape on the winding core 4 of the sheet material is referred to as a double spiral portion. Then, while rotating the winding core 4, the double spiral portion of the sheet material wound around the winding core 4 is irradiated with X-rays to obtain projection data of the sheet material.

  From the state in which the core 4 that winds the long sheet material 1 in a double spiral shape is bare, the material length that the core 4 winds at a constant angular velocity according to the thickness of the sheet material is continuously obtained by calculation, In accordance with this, the rotational speeds of the supply reel 2 and the take-up reel 3 are adjusted. Note that the number of windings by the core 4 may be one rotation or a plurality of rotations. When a plurality of rotations are wound, a wide range of the long sheet material can be observed at a time, which is efficient.

  Further, in the example of FIG. 2, roundness (curved surface) 4 a is provided at each of the portions where the semi-cylindrical portion and the sheet material come into contact with each other and the tension is generated when the sheet material of the winding core 4 is wound (left rotation). I try to prevent damage. In FIG. 1 and FIG. 2, the description of a fixed guide, a reel direct connection motor, and the like is omitted.

  FIG. 3 is an overall view showing a schematic shape and positional relationship of each part constituting the X-ray tomographic imaging apparatus. The inspection object rotating mechanism 11 functions as a rotating means for mounting the winding core 4 and rotating integrally with the winding core 4. The rotating mechanism itself is configured by a conventionally known technique. Reference numeral 12 denotes a microfocus X-ray source, an X-ray tube that emits X-rays, and reference numeral 14 denotes a two-dimensional detector that captures a projection image of a sheet material by X-rays. A projection image having an enlargement ratio corresponding to the distance relationship with the search portion of the material 1 is obtained. Reference numeral 15 denotes an anti-vibration table on which each device and member is placed and removes vibrations so that the projection data is not shaken. Reference numeral 16 denotes an ionizing radiation shielding structure that covers the entire device so that X-rays do not leak outside. It is. Although the reel drive motors of the supply reel 2 and the take-up reel 3 are not shown, they may be directly connected motors on the same axis of the reel.

  4 shows a core 4 in which the X-ray focal point 13 and the sheet material 1 shown in FIG. 3 are wound in a double spiral shape, and a sheet material path system (running system) from the supply reel 2 to the take-up reel 3.

  The supply reel 2 and the take-up reel 3 around which the sheet material 1 is wound are rotatable about the same axis, and are substantially orthogonal to the perpendicular line dropped from the X-ray focal point 13 to the two-dimensional detector 14, and the supply reel 2 and the take-up reel 3 is a shape straddling the above-mentioned perpendicular line, and is arranged symmetrically. At this time, the sheet material 1 is wound up in a double spiral cylindrical shape (double spiral portion) in which the central axis close to the X-ray focal point 13 is near the rotation axis of the inspection object and parallel to the rotation axis. Or at least one inclined guide 7S in the middle of the path of the sheet material from the double spiral to the angle of the sheet material 1 entering the double spiral by correcting the traveling direction of the sheet material approximately 90 degrees. Alternatively, one or more fixed guides 6S that determine the angle of entry into the inclined guide 7S are provided so that the sheet material travel regulation is performed correctly and without causing unnecessary stresses such as twisting on the material. The sheet material path system from the double spiral portion to the take-up reel side is assumed to be symmetric with the above-described supply reel side path system.

  The structure of the fixed guide or the rotating guide is generally the same as that found in a tape running system such as a VTR (Videotape Recorder).

  In this example, the sheet materials 1 respectively disposed so as to straddle a perpendicular line dropped from the X-ray focal point 13 to the two-dimensional detector 14 between the X-ray focal point 13 and the two-dimensional detector 14 are supplied. The X-ray tube 1 is brought close to the sheet material 1 passing through the supply reel 2 and the take-up reel 3 for winding the sheet material, and the winding core 4 is rotated by a predetermined angle integrally with the inspection object rotating mechanism 11. However, the double spiral portion is irradiated with conical (cone beam) X-rays, and the transmitted X-rays are projected onto the two-dimensional detector 14 to obtain enlarged projection data having an enlargement ratio of, for example, 10 times or more. .

  Then, after acquiring a predetermined number of projection data, the reconstructed image of the reconstructed sheet material search site is viewed to inspect the cross-sectional shape, the distribution state of the foreign matter or the mixture, and the like. In this example, in the process of rotating the winding core 4, the outermost circumference of the double helix part increases or decreases due to the rotation of the winding core 4, so that the number of turns increases or decreases. May not be used during the reconstruction process.

  FIG. 5 shows an external view of an example of the winding core and the inspected object rotating mechanism of this example. A represents a schematic top view of the winding core placed on the inspected object rotating mechanism, and B represents The schematic side view of the to-be-inspected object rotation mechanism and the winding core which rotates integrally is represented.

  The cross-sectional shape of the sheet material winding core at the center of the double helix part whose outer shape is substantially broken at the center of the cylinder is “right double” or “depending on the rotation direction of winding without damaging the sheet material” It is conceivable to have a cross-sectional shape such as a “left two-eyed” family crest, and in this example, the cross-sectional shape is the left two-sided and the winding direction is indicated by arrows. When the sheet material is passed through the gap 25 extending in the vertical direction of the two reeds and the take-up core 24 is rotated to take up the sheet material, the supply reel side and the take-up reel side By selecting the rotation direction in which the tension is generated, the sheet material can be prevented from being damaged by the tension applied to the sheet material when the sheet material is wound around the gap 25 and wound.

  Reference numerals 24U and 24L denote an upper flange and a lower flange provided in the winding core 24 for regulating the sheet material width direction, respectively. If the upper and lower flanges for regulating the width of the sheet material are provided in the double spiral winding portion in the same manner as the fixed guide having the upper and lower flanges as described in FIG. 1, the traveling of the sheet material 1 becomes more stable.

  FIG. 6 shows a schematic diagram of an example of a sheet material path system (travel system) and a material tension measuring device. The example of FIG. 6 can be applied to the case where the reel rotation axis direction is either FIG. 1 or FIG. With respect to the perpendicular line from the X-ray focal point 13 of the X-ray irradiated from the X-ray tube 12 on the right side to the winding core 4 on the inspection object rotating mechanism 11 to the two-dimensional detector (not shown) on the left side of the drawing, The sheet material traveling between the supply reel and the supply sheet arranged so as to sandwich the core 4 is traveling substantially at right angles (vertical direction in the figure), and between the core 4 and the supply reel and take-up reel. Are respectively provided with fixed guides 26S and 26T and rotation guides 28S and 28T, and tension detectors 27S and 27T are provided between the respective fixed guides and the rotation guides.

  When the tension generated on the supply reel side material at both ends of the core 4 and the tension generated on the take-up reel side material are wound in a double spiral shape before acquisition of projection data, the tension is an individual tension measuring means. Information which is measured by the detectors 27S and 27T and applied to the required torque of the drive motor of each reel, which is the tension generating means, is calculated and controlled so that the tension generated in these two types of reels is always a constant value and equal to each other. During the acquisition of projection data, both ends of the core 4, that is, supply reel side and take-up reel side tensions are individually measured and controlled to the same tension as that used when winding.

  As an example of the tension measuring mechanism of the tension detector, for example, a take-up side tension detector 27T is bonded to a plate member 30T that receives a bending moment 29T by tension, and a strain gauge 31T is attached to the front and back to form a bridge. It may be a measurement principle that converts the bending stress into tension while measuring the bending stress. A take-up reel direct drive motor (drive motor) which is an example of a tension control mechanism is omitted. The supply side is also provided with a tension measurement mechanism and a tension control mechanism equivalent to those on the take-up side.

  Further, as another tension control mechanism, it is possible to control a pressing pressure of a pad that contacts a part of a reel rotation mechanism (not shown), or a magnetic disk (yoke) that is fastened to a part of the reel rotation mechanism and rotates. The rotation speed of a magnetized disk that maintains a small distance (gap) in a non-contact manner or a mechanism such as an electromagnetic clutch that controls the gap may be used. With the latter mechanism, the material tension is kept constant by changing the direction of rotation of the magnetized disk, regardless of whether the winding core takes up or unwinds the material during projection data acquisition. It is possible to control.

  FIG. 7 shows a block diagram of the material tension control circuit of the example of FIG. Information on the tension detected by the supply-side tension detector 27S and the take-up-side tension detector 27T is supplied to the voltage detection circuits 31S and 31T, respectively, and is input to the tension control calculation circuit 32 as a voltage value. Information to be supplied to the tension control means of the side reel is calculated, and the calculated information is supplied to the voltage control circuits 33S and 33T, respectively, to control the rotation of the supply side motor 34S and the take-up side motor 34T. The X-ray tomographic imaging apparatus of this example includes an arithmetic processing unit such as a CPU (Central Processing Unit) (not shown), a ROM (Read Only Memory) for storing a program to be executed by the CPU, and a RAM (RAM) used as a work area of the CPU. Random Access Memory), and the CPU performs calculation and control processing in the tension control calculation circuit described above.

  The outermost diameter of the material wound on the supply reel and take-up reel changes gradually as it is wound on the core 4 and the reel rotation speed per unit time also changes gradually. Supply reels at both ends of the core 4 by continuously measuring the reel rotation speed and continuously calculating the “material outermost diameter” on the reel that gradually changes from the rotation speed per unit time and the winding length of the core 4 Both the supply reel and the take-up reel are controlled so that the tension applied to the side material and the tension applied to the take-up reel side material are always controlled to be equal and constant while being wound around the core 4 in a double spiral shape before acquiring projection data. The required torque of the two directly connected drive means (motors) 34S and 34T connected to the reel is calculated, and the reel is rotated while being wound around the core 4. Providing separately that the electromotive force to rotate in a direction opposite to the direction (the rotational force) is gradually changing shape according to each individual arithmetic result.

  Furthermore, during the acquisition of projection data, the core 4 gradually takes up or gradually unwinds the material at both ends of the core 4, that is, the supply side and take-up side material tensions, to the same tension as the above-described material tension when winding in advance on the same principle. Accordingly, the reel direct coupling motors 34S and 34T are equally controlled while changing the direction of the rotational force. When the material take-up core 4 takes up a new part during the acquisition of projection data, information is sent to the tension generating mechanism to apply a load to the reel rotating mechanism so that the material tension at both ends of the core 4 is always controlled to be equal and constant.

  Referring to FIG. 8, a method for calculating the torque and the like to be generated in each reel direct-coupled motor in order to uniformly control the total length of the material taken up by winding core 4 and the tension generated on each reel, supply side, and take-up side. Will be described. In FIG. 8, only the supply side is shown, and the winding core 4 composed of two substantially semi-cylinders that are opposed to each other up and down by the thickness of the material rotating at a constant speed as described above takes up an extremely thin length. From the approximate expression for determining the overall length of the length material and the material traveling speed determined from the stepwise approximate expression corresponding to the rotation speed (1, 2, 3,. The material outermost diameter R on the supply reel 2 is obtained, and the result shows a route for calculating the torque that should be generated for the reel direct connection motor, which is an example of a tension control mechanism, to control the winding tension T to be constant.

Symbols in FIG. 8 and the following calculation formula are defined as follows.
L: Supply reel winding length r _n: winding radius r _0: winding core radius n: winding core rotational speed t: sheet material thickness T: tension T ₀ of the supply reel side: winding core just prior to the tension X: supply reel motor Shoyo torque R: supply reel material OD k _1: load by rotating the guide shaft k _2: load by fixed guide shaft omega: supply reel angular velocity omega _0: the winding core angular velocity

From FIG. 8, the winding radius r _n when winding core 4 is around n times,

If the angular velocity ω _{0 at} which the winding core 4 rotates is constant, the material radius R on the supply reel 2 is

The tension T on the supply reel 2 side to be applied to the sheet material 1 is

The torque X to be generated in the supply reel direct-coupled motor in order to obtain the tension T on the supply reel 2 side is:

The supply side material total length L taken up by the winding core 4 is:

  The take-up reel take-up hub starts up in a bare state and measures the number of revolutions per supply reel unit time at the beginning of winding to take up the long material. The outermost thickness of the original supply reel 2 is measured from the thickness of the long material. The diameter and the total length of the long material are calculated.

  In addition, which part of the entire length of the material wound around the supply reel is wound in a double spiral manner on the core 4, the supply reel rotational speed measurement result at that moment and the gradually changing winding of the core 4. By calculating the cutting length, the outermost diameter of the material wound around the supply reel is recognized, and the absolute position of the material that has undergone the projection calculation and reconstruction calculation is acquired continuously. The projection data of the same part is not repeatedly acquired.

In the concept in which the core 4 is wound between two reels in the middle of two reels in a double spiral shape, a tension control mechanism equivalent to that on the supply side is required on the take-up side.

  The X-ray tomographic imaging method of the present invention will be described with reference to the flowchart of FIG. 9 and FIGS. 3 and 4. A program for executing this flowchart is stored in the ROM.

  First, the supply-side sheet material leader seed of the X-ray tomographic imaging apparatus shown in FIGS. 3 and 4 is wound around the take-up side through a gap (slot 5) in the middle crack portion of the stationary winding core 4 (step S1). ).

  The take-up reel 3 is rotated to a position where the center point is sandwiched between the gaps in the middle crack portion of the take-up core 4, and the sheet material 1 is wound on the take-up side while maintaining the tension generated in the sheet material 1 at a predetermined value. (Step S2).

  The center point serves as a reference for the position of the sheet material when acquiring the enlarged projection data. When the sheet material 1 is wound around the take-up reel, the naked take-up reel is activated and the trapezoidal driving low speed region of the motor is activated. Rotate less than 180 ° in the state reached. At the moment when the take-up reel enters the low speed range from the acceleration range, the number of rotations of the supply reel that rotates with the take-up reel is measured, and the outermost diameter of the supply reel is calculated. The total length of the long sheet material is determined from the determined outer diameter of the supply reel. It is determined which part of the obtained total length is the center point for acquiring the first enlarged projection data. It is desirable that the center point is substantially in the middle of the middle crack portion (long material insertion portion) of the winding core.

  After step S2, the take-up reel and the supply reel are stopped (step S3), the take-up core 4 is turned by the inspected object rotation mechanism 11 to take up the required amount of sheet material (step S4), and the X-ray tube 1 is moved. Turn on (step S5).

  The core 4 turns in small increments by a predetermined angle only in either the direction in which the number of turns of the core wound up in a double helix increases or decreases (step S6), and X-rays are emitted from the X-ray tube 1. Is projected onto the sheet material double spiral portion of the winding core 4 to acquire projection data (step S7).

  It is determined whether or not a predetermined number of pieces of projection data has been acquired (step S8). If the predetermined number of sheets has not been reached, the process returns to step S6, and the core 4 having the sheet material 1 wound in a double spiral shape is further returned. A predetermined angular displacement is rotated, new projection data is acquired, and it is determined again in step 8 whether the acquisition of the predetermined number of projection data has been completed.

  If the acquisition of the predetermined number of projection data is completed in step 8, the X-ray tube 1 is turned off (step S9).

  The sheet material 1 wound around the core 4 is turned in the direction opposite to the direction in which the core is wound, the sheet material 1 is returned to the supply reel 2 and the take-up reel 3, and the core is split (long material passage portion). It will be in the naked state only passed (step S10).

  Then, the sheet material 1 is taken up by the take-up reel 2 and moved to the next sheet material search site (step S11). And when inspecting a new exploration site | part of the sheet | seat raw material 1, a series of processes from step S3 are repeated.

  According to the present example configured as described above, in the case of a sheet material without cutting a long material between the large supply reel 2 and the take-up reel 3 as in this example in the X-ray tomographic imaging apparatus, A certain amount of a double helix is wound around a small-diameter core that provides an enlarged projection image commensurate with the size of the detector. If a predetermined number of pieces of enlarged projection data are acquired while rotating the core in small increments while irradiating the X-ray source with the microfocus X-ray source to the part wound up in a long distance without damaging the material at any part of the long material It is possible to efficiently obtain a reconstructed image, to detect foreign matters inside the material, and to grasp the distribution state of fine particles constituting the material over the entire length of the material.

  If the structure as shown in FIGS. 3 and 4 is adopted, that is, the supply reel 2 and the take-up reel 3 arranged so as to straddle a perpendicular line dropped from the X-ray focal point 13 to the two-dimensional detector 14 at a substantially right angle. If the rotating shaft can be rotated substantially on the same axis and is arranged perpendicular to the rotating shaft of the inspected object rotating mechanism 11, the apparatus is compact and the installation area is reduced.

  In addition, by controlling the material tension applied to both ends of the supply reel side and the take-up reel side of the long material inserted into the long material insertion portion of the take-up core by a reel drive direct connection motor (not shown) at all times, During the acquisition of projection data, the material does not expand and contract in the length direction, and a highly reliable reconstructed image is obtained.

  In addition, by always knowing the outermost diameter of the supply reel by calculation, it is possible to know the absolute coordinates of the entire long material of the part once the projection data acquisition has been completed, so the projection of the same part overlaps. It is freed from inefficient work such as acquiring data multiple times.

  Next, referring to FIG. 10, in another embodiment of the X-ray tomographic imaging apparatus of the present invention, a long material such as an optical fiber cable having a substantially circular cross section is used as a long object to be inspected. Will be described. This example shows a winding core 44 that is wound in a single coil in the middle of a traveling path from a supply reel to a take-up reel without cutting a long material having a substantially circular cross section such as an optical fiber cable. FIG. 7A is a top view of the winding core with a flange as viewed from the top flange, and FIG. 7B is a side view of the lower half of the winding core in a cross-sectional view taken along the line II of FIG. 7A. About another structure, it is the same as that of the case where the to-be-inspected object of FIGS. 3-5 is a elongate sheet material.

  When handling a long material such as an optical fiber cable having a substantially circular cross section, for example, a winding core 44 having a right double cross section is used, and a single or a plurality of spirals are spirally formed so that the space between the upper and lower flanges 24U and 24L is close. Turn it back up and wind it up multiple times. The process is the same as in the case of the sheet material until the material having a circular cross section is sandwiched between the winding core 44 whose center is cracked, and the winding cores on the supply reel side and the take-up reel side according to the rotation of the core 44 during winding. The material guides in the vicinity are gradually separated from each other up and down, and the material having a circular cross section is wound up spirally so as to form an electromagnetic coil winding in which the upper and lower flanges 24U and 24L of the winding core 44 are in close contact with each other. In other words, one half is supplied from the supply reel from the intermediate point 43 in the width direction above and below the winding core 44, and the other half takes the core winding means supplied from the take-up reel. The above-mentioned “turning back” means that each material wound along with the rotation of the core 44 fed out from the supply reel side and the take-up reel side with the intermediate point 43 as a boundary is formed between the upper and lower flanges 24U and 24L and the intermediate point 43. It means to reciprocate between each.

  The upper half from the center of the core is supplied from the supply reel side and the lower half is supplied from the take-up reel side in a single coil shape, but the reverse is not a problem. The coiled winding method may be multiple and not single, but the vertical division with respect to the core 44 must be constant even during multiple winding. In order to wind up the material in a close coil shape as shown in FIG. 8, there may be guides for guiding the material while swinging the head up and down at both ends 44 of the winding core.

  In the example of the long material having a substantially circular cross section, the material thickness in the case of the long sheet material is replaced with the material diameter, so that the length of FIGS. 6 to 8 is the same as that of the long sheet material. The path system of the scale, the tension control circuit block, and the calculation formula can be applied.

  According to this example, the long material 41 having a substantially circular cross section is cut between the supply reel and the take-up reel as in the case where the object to be inspected in the examples of FIGS. 1 to 9 is a long sheet material. Without wrapping the long material into a coiled shape, a fixed amount is wound around a small-diameter core 44 where an enlarged projection image corresponding to the size of the two-dimensional detector is obtained. If a predetermined number of enlarged projection data are acquired while rotating the core 44 in small increments while irradiating the focused X-ray source with X-rays, an arbitrary part of the long material 41 is efficiently reconstructed without damaging the material. An image is obtained, and it is possible to detect a foreign substance or the like inside the material and to grasp the distribution state of the fine particles constituting the material over the entire long material.

  Moreover, by winding the material 41 having a substantially circular cross section around the core 44 in a coil shape, the space required for winding can be made smaller than when wound in a double spiral shape.

  In the present invention, the tension applied to the material on the supply reel side at both ends of the core and the tension applied to the material on the take-up reel side are always equalized and constant while being wound around the core in a double spiral shape or a coil shape before acquiring projection data. For the purpose of control, the information given to the tension generating active element that controls the material tension by the mechanical load against the reel rotation individually connected to both the reel rotation mechanism of the supply reel and the take-up reel is calculated and wound on the core. However, information to the tension generating mechanism that generates tension that acts to rotate in the direction opposite to the direction in which each reel is rotated may be individually given in a form that gradually changes in accordance with individual calculation results.

  Further, the present invention is not limited to the above-described embodiments, and various other configurations can be taken without departing from the gist of the present invention.

It is explanatory drawing which shows the concept of the example of one embodiment of this invention. It is an enlarged view of the principal part of FIG. 1 is an overall apparatus diagram of an example of an embodiment; It is explanatory drawing of the path | pass system of the elongate sheet material of the example of one Embodiment. It is an external view of the winding core and the to-be-inspected object rotation mechanism of the example of one embodiment. It is explanatory drawing of the sheet material path | pass system and tension | tensile_strength measurement of the example of one Embodiment. It is a block diagram which shows the structure of the tension control circuit of the example of one Embodiment. It is explanatory drawing of the tension measurement by the side of a supply reel of the example of one Embodiment. It is a flowchart explaining the X-ray tomographic imaging method of this invention. It is explanatory drawing of the example of other embodiment of this invention. It is explanatory drawing of a prior art example. It is explanatory drawing of another prior art example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Long sheet material, 2 ... Supply (supply) reel, 3 ... Take-up (winding) reel, 4, 24, 44 ... Winding core (winding member), 5 ... Slotting (long material insertion part) ), 6S, 6T: Fixed guide, 7S, 7T: Inclined guide, 11: Inspected object rotating mechanism, 12: X-ray tube, 13: X-ray focal point, 14: Two-dimensional detector, 24U, 24L ... Flange, 25 ... Gap (long material insertion part), 26S, 26T ... Fixed guide, 27S, 27T ... Tension detector, 28S, 28T ... Rotation guide, 41 ... Substantially circular long material, 42S, 42T ... Guide guide

Claims (7)

An X-ray source;
A two-dimensional detector for capturing the projected image of emitted detects X-rays transmitted through the object to be tested the test subject from the X-ray source,
Two reels for winding the long material as the object to be inspected;
A substantially cylindrical for have a elongated material insertion portion comprising a gap in which the elongated material sent from one reel to the other reel is inserted, the rotation axis of the central axis the inspection of the substantially cylindrical And a winding member that is substantially parallel to and perpendicular to the perpendicular drawn from the X-ray focal point of the X-ray source to the two-dimensional detector ;
While sandwiching the arbitrary part of the long material of the course to be wound on the other reel from one reel to the elongated component inserting portion, to rotate the take-up member integrally as a rotation about the central axis , it assumes a predetermined amount winding the elongated material of one reel and the other reel to said take-up member, and returns a predetermined amount of the wound the elongated material to the winding member in one reel and the other reel It has a rotating means,
In the process of winding the long material fed from one reel with the other reel, the rotating means winds the winding in a state where an arbitrary part of the long material is sandwiched between the long material insertion portions of the winding member. A predetermined amount of the long material is wound around the winding member, the winding member is rotated by a predetermined angle in a direction to increase or decrease the number of windings of the long material wound around the winding member, and the winding is performed. An X-ray tomographic imaging apparatus that captures a projected image of each portion of the long material wound around a member at each angle . The X-ray tomographic imaging apparatus according to claim 1,
After capturing the projected image for each angle, the winding member around which the long material is wound is rotated by the rotating means in the direction opposite to the winding direction, and the length more than the length returned to one of the reels is wound. An X-ray tomographic imaging apparatus that supplies the other reel with the take-up member stationary. The X-ray tomographic imaging apparatus according to claim 1,
Said elongate material X-ray tomographic imaging apparatus wherein the take-up member is that the winding of the elongated material in a double helix shape in the case of the sheet material. The X-ray tomographic imaging apparatus according to claim 1,
When the long material has a substantially circular cross section, the winding member winds the long material into a coil shape.
X-ray tomographic imaging apparatus. The X-ray tomographic imaging apparatus according to claim 1,
One reel and the other reel are arranged so as to straddle a perpendicular line dropped from the X-ray focal point of the X-ray source to the two-dimensional detector, and both reel rotation axes are substantially coaxial, and the winding An X-ray tomographic imaging apparatus arranged perpendicular to the rotation axis of the take-up member. The X-ray tomographic imaging apparatus according to claim 1,
And tension measurement means for measuring the tension applied to both ends of one of the reel side and the other reel side of the elongated material which is inserted into the elongated material insertion portion of the winding member,
A tension generating means for controlling the rotation of the one reel and the other reel,
And a tension control operation means for calculating the control information to be given to each tension generating means of the one reel and the other reel on the basis of the measurement information of the tension measuring means,
Based on the control information of the tension control operation unit, X-rays tomography tension applied to both ends of one of the reel side and the other reel side of the elongated material to control the respective tension generating means so that the same constant apparatus. An X-ray source;
A two-dimensional detector that detects X-rays emitted from the X-ray source and transmitted through the object to be examined, and picks up a projected image of the object;
Two reels for winding the long material as the object to be inspected;
It is a substantially cylinder having a long material insertion portion comprising a gap into which the long material fed from one reel to the other reel is inserted, and the central axis of the substantially cylinder is the rotation axis of the object to be inspected A winding member that is substantially parallel and perpendicular to the perpendicular drawn from the X-ray focal point of the X-ray source to the two-dimensional detector;
In a state where an arbitrary portion of the long material being wound from one reel to the other reel is sandwiched in the long material insertion portion, the long material is rotated integrally with the winding member around the central axis. , Causing the take-up member to take up a predetermined amount of the long material of one reel and the other reel, and returning the long material taken up by the take-up member to the one reel and the other reel by a predetermined amount With rotating means
An X-ray tomographic imaging method using an X-ray tomographic imaging apparatus comprising :
Said elongated material is fed from one reel in the process of winding the other reel, said by rotating means, said winding in a state of sandwiching the arbitrary part of the elongated material to the elongated material insertion portion of the take-up member the elongated material to take member takes a certain amount winding,
It said winding member in the direction of increasing or decreasing the number of windings of the elongated material is wound on the take-up member is rotated by a predetermined angle,
An X-ray tomographic imaging method of acquiring projection data by capturing a projection image of each angle of the long material of a portion wound around the winding member .

Images