Product inspection device

Abstract

The present invention provides an item inspection device that can perform good inspections while increasing the transport speed and reducing the output of the X-ray generator, while effectively suppressing the effects of the decrease in the detection signal level of the line sensor. [Solution] The system includes a detection data output unit 31 that takes a detection signal from an X-ray detector 22 and outputs detection data, an image generation unit 34 that generates an inspection image based on the detection data, and an inspection processing unit 35 that performs an inspection process to inspect the quality state of the item W based on the inspection image data. When it is detected that specific inspection conditions that degrade the image quality of the inspection image are met, the system further includes a level conversion processing unit 32 that adjusts the detection data to improve the image quality of the inspection image. When the specific inspection conditions are met, the image generation unit 34 generates an inspection image with an expanded range of density values ​​based on the adjusted detection data, and the inspection processing unit 35 performs an inspection process based on the data of the inspection image with an expanded range of density values.

Description

Technical Field

[0001] The present invention relates to an article inspection apparatus, and more particularly to an article inspection apparatus that acquires image data corresponding to the dose distribution transmitted through a conveyed article x-ray by the periodic detection operation of a line sensor type X-ray detector, and determines the quality state of the inspected article based on the image data.

Background Art

[0002] In article inspection apparatuses for inspecting the quality state of articles such as food, for example, the presence or absence of mixed foreign matter, missing items, internal shapes, etc., radiation that can penetrate the article, such as X-rays, is applied to the article being conveyed, and the radiation that has passed through the conveyed article x-ray is detected by the periodic detection operation (main scanning) of a line sensor to acquire image data, and it is known to determine the quality state of the inspected article based on a predetermined image processing result for the image data.

[0003] Further, in the X-ray inspection type article inspection apparatus, logarithmic conversion processing to gradation density data corresponding to the sensitivity of the human eye, image filter processing to reduce noise for determining the quality state of the inspected article, image filter processing to emphasize the likelihood of foreign matter and prevent erroneous determination, etc. are applied as necessary to the transmitted X-ray image data including the physical property information of the inspected object, and further threshold processing is applied to perform inspection processing such as determining the presence or absence of mixed foreign matter.

[0004] As a conventional article inspection apparatus of this type, for example, there is an apparatus in which an X-ray image at the time of setting associated with the product type information of the article to be inspected is stored in a memory in the form of a compressed image or the like, so that the article of the product type to be selected at the time of product type selection inspection can be easily grasped visually, and the collation and determination of the set product type including inspection conditions can be facilitated (for example, see Patent Document 1).

[0005] In this device, when the operating conditions for the X-ray detection means and the X-ray image generation unit are set for each type of item to be inspected, the X-ray image generated by the X-ray image generation unit is stored as X-ray image information at the time of setting, associated with setting information for each type, such as type number, item name, number of contents, weight, shape, tube current, tube voltage, transport speed, judgment threshold, mask processing conditions, etc. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2007-232586 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, with regard to the aforementioned product inspection equipment, as the demands for not only improved inspection performance but also energy saving and extended lifespan become more sophisticated, the following challenges have become apparent.

[0008] In other words, if the material handling speed is increased to meet the demand for increased productivity, and the output power of the X-ray generator is reduced to meet the demands for energy saving and longer lifespan, the output level of the detection signal from the licensor will decrease.

[0009] For example, in a scintillator-type licensor, if the scanning period is shortened to ensure the required image resolution for faster item transport speeds, the amount of transmitted X-rays received by the scintillator at each detection target area decreases compared to when transporting items at low speeds. This reduces the amount of scintillator light received by the photodiode, which in turn reduces the detection signal level (output range (dynamic range)) of each detection element in the licensor, resulting in a deterioration of the density resolution of the X-ray image.

[0010] Furthermore, due to the afterglow characteristics of the scintillator, at scanning cycles corresponding to high transport speeds in line sensors, the afterglow of the scintillator can overlap with the detection signal of the next cycle, causing the image to blur and resulting in a deterioration of the spatial resolution of the X-ray image.

[0011] Therefore, with conventional material inspection equipment, there are concerns that in the high-speed transport range, the density distribution of the X-ray image may not be suitable for proper processing, making it impossible to perform accurate and reliable inspections.

[0012] This invention was made to solve the above-mentioned conventional problems, and aims to increase the speed of article transport. Transform While aiming, of The objective is to provide an article inspection device that can effectively suppress the effects of a decrease in the detection signal level of the licensor in high transport speed ranges and other inspection conditions, thereby enabling good inspection. [Means for solving the problem]

[0013] The article inspection device according to the present invention, in order to achieve the above objective, (1) An article inspection apparatus comprising: an X-ray generator that irradiates an article to be inspected with X-rays as it is transported by a conveyor belt in an article transport section and passes through an inspection area; an X-ray detector that sequentially detects the X-rays that have passed through the article to be inspected and outputs a detection signal for each; and a control unit that acquires the detection signals at a predetermined period, generates an inspection image based on the output detection data, processes the inspection image, compares it with a judgment threshold, performs inspection processing for each article to be inspected, and outputs the judgment result to a display operation unit, wherein the transport speed of the article to be inspected by the conveyor belt is set, and the processing conditions for image processing that converts adjacent pixel groups in the inspection image into one pixel are set in stages for multiple speed ranges of the transport speed, and the control unit performs the image processing according to any of the processing conditions and outputs the judgment result. .

[0014] With this configuration, The control unit detects that the signal level of the detection signal acquired from the X-ray detector decreases due to the high transport speed of the inspected item and insufficient X-ray irradiation time. Degrading the image quality of the examination images The inspection conditions (hereinafter, identification of Test conditions (Also known as) The following is true. At that time, the detection signal corresponds Detection data can check Adjustments were made to improve the image quality of the inspection images. re Based on the data from the examination images 、 The inspection process will be carried out. Therefore, the item transport speed will be high. Transform If planned (Further reductions in the X-ray generator's power output may be considered.) However, at each predetermined scanning cycle, the X-ray detector... Take This allows for effective suppression of the effects of reduced signal levels in the incoming detection signals, enabling smooth and efficient product inspection.

[0015] this case 、Each detection signal output from the plurality of X-ray detection elements of the X-ray detector has a signal level that varies according to the dose of X-rays incident on the respective detection elements And the detection signal corresponds The detection data reflects the signal level. Further, adjusting to improve the image quality of the inspection image typically means executing processing to improve the signal-to-noise ratio (S / N) value of the detection data to enable expansion of the density value range (dynamic range) of the inspection image, but it may also be processing to reduce noise components. Specifically, the detection data is X-ray image data having density values ​​based on the respective detection signals for multiple pixels of the X-ray image, and the inspection image can be configured to have the required image quality by performing image processing (e.g., binning or kernel processing) in the X-ray image to convert adjacent groups of a predetermined number of pixels into a single pixel.

[0016] specific When the inspection condition is satisfied In reality is executed Image processing Functionally, this corresponds to processing for adjusting image brightness according to the exposure amount ( x-ray irradiation time and irradiation intensity), similar to gain adjustment of a digital camera, and may be, for example, binning processing or kernel processing (filter processing). x-ray The detector is not limited to one row x-ray in which the detection element rows are aligned in the main scanning direction, and may be a plurality of rows that are adjacent to each other in the sub-scanning direction and aligned in the main scanning direction.

[0017] (2) In a preferred embodiment of the present invention, The control unit can further detect the degradation state of the X-ray generator and the X-ray detector, and set image processing conditions for converting adjacent pixel groups in the inspection image into single pixels according to the degradation state.

[0018] (3) Furthermore, the processing conditions can be configured to be the bin size for binning, which involves dividing the inspection image into small regions and adding or averaging the pixel values. In this case, the detection data of the item under inspection can be adjusted by binning, which is performed using the image data of each small region as the unit when the X-ray image of the item under inspection is divided into multiple small regions. Therefore, image reduction can be achieved while suppressing the loss of information due to pixel decimation, and even when the item transport speed is increased, the effect of the decrease in the signal level of the detection signal taken in from the X-ray detector to the detection data output unit can be effectively suppressed, enabling good item inspection processing.

[0019] (4) The processing conditions can also be configured to be the kernel size of a kernel process that divides the inspection image into small regions and filters them.

[0020] (5) In a preferred embodiment of the present invention teeth , a sensitivity reduction detecting means for detecting a significant reduction state in the detection sensitivity of the aforementioned X-ray detector is provided, and the specific of inspection condition may include a condition that the significant reduction state in the detection sensitivity is detected by the sensitivity reduction detecting means ru, to . moreover In this case, by the sensitivity reduction detecting means x-rayWhen a significant decrease in the detector's detection sensitivity is detected, the detection data output unit outputs the detection data However, The image quality of the inspection images is adjusted to improve it. Therefore, the required image quality of the inspection images is ensured, enabling the execution of a good product inspection process.

[0021] (6) Preferred embodiment of the present invention The control unit, The aforementioned of The inspection conditions are met when either of the following conditions is met: a first specific transport condition in which the transport speed of the item to be inspected passing through a predetermined section on the transport path is equal to or greater than a first transport speed equal to a predetermined speed, and less than a second transport speed that is higher than the first transport speed; or a second specific transport condition in which the transport speed is in the high transport speed range of the second transport speed or higher. And, before The amount of adjustment of the detection data for the inspected item is greater when the second specific transport condition is set than when the first specific transport condition is set, as detected by the inspection condition detection means. can check The system can be configured to adjust the detection data of the inspected item so that it increases when it is released. In this way, when either of the first or second specific transport conditions is met, that is, when any of the multiple specific transport conditions set in stages are met, the amount of adjustment of the detection data of the inspected item changes according to the stage of the condition, and the decrease in the signal level of the detection signal in the high-speed transport area is suppressed more effectively.

[0022] (7) In a preferred embodiment of the present invention, The aforementioned specific inspection conditions may further include the condition that the transmittance of the item under inspection in the X-ray transmission direction falls within the low transmittance range among a plurality of preset transmittance ranges. In this case, when the transmittance of the item under inspection falls within the low transmittance range, the detection data output from the detection data output unit is adjusted to improve the image quality of the inspection image. Therefore, the required image quality of the inspection image can be ensured, and a good inspection process for item inspection can be performed.

[0023] (8) Furthermore, in this case, Detection data of the item to be inspected Take When obtaining the data, the transmittance of the inspected item is calculated based on the ratio of image density inside and outside the image area of ​​the inspected item in the detection data, and according to the calculated value of the transmittance, X-ray generator of x-ray The system can be configured to have an automatic setting function that allows for variable setting of irradiation conditions. In this case, according to the calculated transmittance value X-ray generator from x-rayThe irradiation output conditions, such as the tube voltage of the X-ray tube, can be set automatically. x-ray Even with inspected items that exhibit low transmittance, the decrease in the signal level of the detection signal will be more effectively suppressed.

[0024] (9) In a preferred embodiment of the present invention, the above X-ray generator It has an X-ray tube death, The X-ray tube voltage can be controlled to a different voltage value from other transport speed ranges in a specific transport speed range before or after switching between the first specific transport conditions and the second specific transport conditions. In this case, by controlling the X-ray tube voltage in a specific transport speed range before or after switching between the first specific transport conditions and the second specific transport conditions, x-ray This allows for adjustment of the transmission amount, effectively mitigating the effects of the decrease in the signal level of the detection signal before and after switching the transport conditions.

[0025] (10) In a preferred embodiment of the present invention, the The X-ray generator was previously The system can be further configured to include an X-ray line sensor camera with an image processing circuit capable of image binning. This configuration reduces the pre-processing load on the image processing circuit. [Effects of the Invention]

[0026] According to the present invention, the article conveying speed is high Transform While trying to plan, Degrading the image quality of the examination images. identification of This invention provides an article inspection device that can effectively suppress the effects of a decrease in the detection signal level of the licensor in high transport speed ranges and other inspection conditions, thereby enabling successful inspection. [Brief explanation of the drawing]

[0027] [Figure 1] This is a schematic diagram showing an article inspection device according to the first embodiment of the present invention. [Figure 2] This is an explanatory diagram of the sensor configuration of the X-ray detector and the circuit configuration of the transmission image data generation unit in the article inspection apparatus according to the first embodiment of the present invention. [Figure 3] This is an explanatory diagram of the binning process of X-ray image data, which is output as a detection signal from an X-ray detector and acquired by a detection data output unit in an article inspection apparatus according to the first embodiment of the present invention. [Figure 4] This setting table, provided in the first embodiment of the present invention, illustrates a guideline for setting the tube voltage of the X-ray source according to the X-ray transmittance, in conjunction with the binning processing conditions of the X-ray image data set according to the transport speed of the item to be inspected, and can be used when the tube voltage is automatically set. [Figure 5] This flowchart shows the procedure for setting binning processing conditions and tube voltage according to the transport speed and other product type setting information of the article to be inspected in the article inspection apparatus according to the first embodiment of the present invention. [Figure 6] This flowchart shows the procedure for binning X-ray image data acquired by the detection data output unit in the article inspection apparatus according to the first embodiment of the present invention. [Figure 7] This is a schematic diagram showing an article inspection device according to a second embodiment of the present invention. [Modes for carrying out the invention]

[0028] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

[0029] [First Embodiment] Figures 1 to 6 show an article inspection apparatus according to the first embodiment of the present invention.

[0030] First, let me explain the structure.

[0031] As shown in Figure 1, the article inspection apparatus 1 according to the first embodiment of the present invention has an article transport unit 10, an X-ray inspection unit 20, a control unit 30, and a display operation unit 40, and constitutes part of an article inspection system that includes a sorting device (not shown) located downstream of the article transport unit 10.

[0032] This item inspection device 1 is a device that inspects an item W to be inspected using radiation that can penetrate the item, such as X-rays, and has a foreign object detection function that can determine whether or not foreign objects are mixed in the item W to be inspected using X-rays. However, it may also have functions other than foreign object detection, such as missing item inspection, mass inspection, inspection of the shape of the item to be inspected, such as thickness and length, and detection of packaging defects such as contents being caught in the seal. Furthermore, the radiation is not limited to X-rays.

[0033] The article transport unit 10 of the article inspection device 1 has a belt 11 that is looped over a pair of parallel rollers 12 and 13, and the article to be inspected W is transported in a predetermined transport direction Db by the transport path 11a, which is the upper part of the belt 11. The article transport unit 10 also includes a transport drive motor (not shown) that rotates one of the rollers 12 or 13 at a variable set speed to advance the belt 11 at a predetermined transport speed, and an encoder for detecting the rotation speed. Furthermore, the predetermined transport speed at which the article transport unit 10 transports the article to be inspected W is set in advance as part of the product setting information according to the product type (for example, according to the X-ray transmittance described later) when the product type of the article to be inspected W is registered. It goes without saying that although a belt conveyor is used here, the article to be inspected W may also be moved in the predetermined transport direction Db by another type of conveyor.

[0034] The X-ray inspection unit 20 of the item inspection device 1 is an X-ray generator 2 that irradiates the item W to be inspected with X-rays as it passes through a predetermined inspection area Zx, which is a predetermined section on the transport path 11a. 1 and A line sensor type X-ray detector 2 detects the amount of X-rays transmitted through the object W being inspected (hereinafter referred to as the X-ray transmission amount). 2 and It has.

[0035] The X-ray generator 21 emits X-rays at the item W to be inspected as it moves at a predetermined transport speed within the inspection area Zx on the transport path 11a of the item transport unit 10. X This is the X-ray irradiation section that emits rays.

[0036] This X-ray generator 21 has, for example, an X-ray tube 23 inside a metal box 24, and the X-ray tube 23 is immersed in insulating oil (not shown) for cooling inside the box 24. The X-ray tube 23, although a detailed description of its structure is omitted, is configured such that electrons emitted from a cathode-side filament within the enclosure and focused by a focusing electrode collide with a target on the anode side opposite the filament, thereby generating X-rays from the target. The X-ray generator 21 may also have a collimator that limits the X-ray irradiation field to a predetermined shape.

[0037] The X-ray tube 23 is also positioned so that its longitudinal direction is approximately parallel to the predetermined transport direction Db, and the X-rays generated by the X-ray tube 23 in the X-ray generator 21 are irradiated downwards and perpendicular to the transport direction from the X-ray window 24a on the bottom side of the box 24. The anode of the X-ray tube 23 may be of a fixed type or a rotating type.

[0038] The X-ray generator 21, which has an X-ray tube 23, irradiates an X-ray beam Br with a predetermined beam shape, for example, a fan beam shape as shown by the dotted line in Figures 1 and 2, at a predetermined position in the transport direction of the transport section 10, in a direction perpendicular to the predetermined transport direction Db, thereby irradiating the item to be inspected W passing through the detection region Zx with X-rays at an irradiation intensity within a predetermined range, and directing the X-rays that have passed through the item to be inspected W into the line sensor type X-ray detector 22.

[0039] Furthermore, the X-ray generator 21 has drive power supply circuits 25 and 26 that drive the X-ray tube 23 to a state where it can generate X-rays. One of the drive power supply circuits 25 applies a potential corresponding to a predetermined operating voltage to the focusing electrode on the cathode side of the X-ray tube 23, and also applies a predetermined ignition voltage that provides thermionic emission energy to the filament on the cathode side. The other drive power supply circuit 26 applies a positive potential corresponding to a high operating anode voltage to the anode 23a of the X-ray tube 23.

[0040] The X-ray detector 22 of the X-ray inspection unit 20 has a plurality of X-ray detection elements 221 to 22N (detection elements) that each receive X-rays and convert them into electrical signals. The detector performs a detection operation, i.e., a main scan, in which each of the plurality of X-ray detection elements 221 to 22N detects the X-rays that have passed through the item W to be inspected from the X-ray generator 21 at a predetermined period.

[0041] As shown in Figure 2, the X-ray detector 22 is composed of a single X-ray line sensor in which multiple X-ray detection elements 221 to 22N are integrally connected, and is positioned on the lower side of the transport path 11a which is inside the loop-shaped belt 11 of the item transport unit 10, detecting the multiple X-ray detection elements 221 to 22N. X-ray generator It is positioned opposite to 21. Here, for example, if the width of each sensor in the Da direction of the multiple X-ray detection elements 221 to 22N is 1 mm, and the gap between sensors is small enough to be negligible relative to the sensor width, and the width in the width direction (Da direction in the figure) of the transport path 11a that transports the item to be inspected W is 200 mm, then a line sensor with approximately 200 sensors would suffice.

[0042] Furthermore, the multiple X-ray detection elements 221 to 22N of the X-ray detector 22 output a detection signal with a signal level (pulse peak value) corresponding to the amount of X-rays transmitted through the object W under inspection. Therefore, the detection data generated and output by the detection data output unit 31 is transmitted image data, and represents the density of the transmitted image corresponding to the pulse peak value of the detection signal output per unit time by each X-ray detection element 221 to 22N. Note that the multiple X-ray detection elements 221 to 22N may be scintillator-type detection elements or photon-type detection elements.

[0043] Although the detailed configuration of the control unit 30 is not shown, it is realized by a combination of hardware such as a CPU (Central Processing Unit) and RAM (Random Access Memory), and software such as programs that perform various functions on that hardware. The hardware referred to here may include FPGAs (Field Programmable Gate Arrays) and DSPs (Digital Signal Processors). The various functions referred to here are the functions of the following multiple functional units that perform tasks such as acquiring and outputting detection data capable of generating an X-ray image of the item W under inspection, generating inspection image data, and controlling predetermined inspection processing and display output.

[0044] As shown in Figure 1, the control unit 30 is configured as a plurality of functional units that perform the aforementioned functions, including a detection data output unit 31, a level conversion processing unit 32 (image data adjustment means), a variety control unit 33 (inspection condition detection means), an image generation unit 34, an inspection processing unit 35 (inspection image processing means), a determination unit 36, and a deterioration detection unit 37 (inspection condition detection means). Based on variety information and various detection information pre-set in the variety control unit 33, it performs predetermined item inspections and control of display output for the item to be inspected W.

[0045] Specifically, the detection data output unit 31 acquires detection signals output from the X-ray detector 22 of the X-ray inspection unit 20, that is, each detection signal from a plurality of X-ray detection elements 221 to 22N, at predetermined intervals, and outputs detection data capable of generating two-dimensional X-ray image data of the item W to be inspected.

[0046] In other words, the detection data output unit 31 acquires detection signals from multiple X-ray detection elements 221 to 22N of the X-ray detector 22 at predetermined intervals during the period when the item W to be inspected passes between the X-ray generator 21 and the X-ray detector 22 (at a predetermined position in the transport direction), performs A / D conversion and other predetermined signal processing as described later, and outputs detection data from each of the multiple X-ray detection elements 221 to 22N at predetermined intervals from the transmission image data output unit 55.

[0047] Since the signal level (peak value) of each detection signal output from the multiple X-ray detection elements 221 to 22N changes according to the dose of X-rays incident on each element, the detection data output from the detection data output unit 31 reflects that signal level.

[0048] As shown in Figure 2, the detection data output unit 31 includes A / D conversion units 511 to 51N that receive X-ray detection signals in the Da direction from multiple X-ray detection elements 221 to 22N of the X-ray detector 22, and a transmission image data output unit 55 that generates and outputs transmission image data of a line image corresponding to the scan time, based on the output signals from the A / D conversion units 511 to 51N that are output at a predetermined calculation cycle, and the positions of the detection width regions in the Da direction from the multiple X-ray detection elements 221 to 22N and the elapsed time during the scan time.

[0049] The outputs of the A / D conversion units 511-51N are directly connected to the transmission image data output unit 55 in the case of a scintillator-type detection element, and in the case of a photon detection type, as shown enclosed by a dashed line in Figure 2, they are connected to the transmission image data output unit 55 via a pulse height detection unit 521-52N that detects the pulse height value of the X-ray detection signal, a region determination unit 531-53N that determines the X-ray energy region detected based on the pulse height value detected by the pulse height detection unit 521-52N, and a region-specific accumulation unit 541-54N that acquires signal values ​​for each energy region of the X-ray detection signal according to the determination results of the region determination unit 531-53N at a predetermined calculation period and performs a process to accumulate these signal values ​​during the same scan time (main scan period).

[0050] The detection data output unit 31 sequentially acquires detection data, which includes two-dimensional position information determined by the Db direction, which is the transport direction of the item W under inspection, and the Da direction, where the X-ray detection elements 221 to 22N are aligned, and data equivalent to the image density value corresponding to the signal charge of the detection signal for each position, at a predetermined scanning cycle and stores it in a first-in, first-out image memory or the like. This enables the output of detection data capable of generating an X-ray transmission image of the item W under inspection to the control block 32 at a predetermined transfer rate.

[0051] In this case, the irradiation intensity of X-rays from the X-ray generator 21 and the period of the main scan by the multiple X-ray detection elements 221-22N of the X-ray detector 22 are set to values ​​specific to this device, and the transport speed of the item transport 10 and other inspection conditions are set in advance according to the type information of the items to be inspected.

[0052] The variety control unit 33 stores variety setting information, which is pre-set and registered for each variety of item W to be inspected, in memory. Based on this variety setting information (for example, variety number, item name, number of contents, weight, shape, tube current, tube voltage, transport speed, judgment threshold, mask processing conditions, etc.), it variably sets various parameters related to the inspection conditions and has the function of controlling the item transport unit 10, X-ray inspection unit 20, control unit 30, and display operation unit 40 to the operating conditions required according to the variety.

[0053] Furthermore, when a variety is selected by a selection operation from the display operation unit 40, the variety control unit 33 identifies inspection conditions based on the setting information of that variety and other detection information, and does not reduce the image quality of the inspection image generated by the image generation unit 34. Specific testing conditions (hereinafter, Specific testing conditions (That is) For example, the transport speed of the item to be inspected W passing through the inspection area Zx on the transport path 11a reaches a predetermined speed or higher, moreover The system has a function of detecting in advance whether the X-ray transmittance of the object W to be inspected in the direction of X-ray transmission falls within the low transmittance range among a plurality of preset transmittance ranges.

[0054] The specific inspection conditions referred to here also include conditions such as insufficient X-ray irradiation intensity from the X-ray generator 21 to the item W under inspection, or insufficient X-ray irradiation time, when the specific inspection conditions are met. Level conversion processing unit 32 The adjustment performed by this means functionally adjusting the exposure amount of the image, similar to the gain adjustment in a digital camera. x-rayThis corresponds to a process that adjusts according to the irradiation time and irradiation intensity, and can be, for example, binning or kernel processing (filtering). X-ray detector 22 teeth, x-ray The array of detection elements is not limited to a single array aligned in the main scanning direction, but may also consist of multiple arrays that are adjacent in the sub-scanning direction and aligned in the main scanning direction (for example, an X-ray TDI camera system).

[0055] The image generation unit 34 generates an inspection image consisting of multiple pixels, each having a corresponding density value, based on the detection data output from the detection data output unit 31 in response to the detection signals from multiple X-ray detection elements 221 to 22N for each main scan of the X-ray detector 22 for the item W under inspection.

[0056] The inspection processing unit 35 is configured to perform a predetermined inspection process for inspecting a predetermined quality state of the item W being inspected, based on the inspection image data of the item W being inspected. The predetermined inspection process for the item W being inspected here has the function of performing image processing suitable for judgment processing and visual confirmation work (more specifically, image processing that sets the grayscale level based on the result of logarithmically transforming the detection signal level according to the sensitivity of the human eye, processing that emphasizes and sharpens abrupt changes in image density values ​​near the contour of foreign objects, and processing that detects edges and lines corresponding to the contours of foreign objects and fixed-shape contents, etc.) in order to automatically and / or visually determine whether or not there are foreign objects or missing items in the item W being inspected using X-rays. Of course, depending on the required item inspection content, the inspection processing unit 35 may also have the function of performing image processing suitable for mass inspection, inspection of the shape of the item being inspected such as thickness and length, and detection of packaging defects such as contents being caught in the seal, instead of inspection image processing for foreign object detection or missing item inspection.

[0057] The determination unit 36 ​​uses image data of the item W to be inspected, which has been processed by the inspection processing unit 35, to execute a known predetermined determination processing program that uses key parameters that specify the determination conditions for item inspection for each type, such as foreign object detection limit, foreign object area ratio, and density limit, to determine whether the quality status of the item W to be inspected is acceptable or unacceptable. For example, after applying image processing suitable for the determination processing to the inspection image, the determination unit 36 ​​compares it with a predetermined threshold to determine whether or not there are foreign objects such as metal foreign objects with high X-ray absorption rates, and sequentially outputs the determination result on the touch panel screen of the display operation unit 40.

[0058] The deterioration detection unit 37 has a deterioration detection function that detects a predetermined deterioration state of the X-ray generator 21 and the X-ray detector 22, and supplies the deterioration detection information as detection information to the variety control unit 33, which is an inspection condition detection means. In other words, the deterioration detection unit 37 works in cooperation with the variety control unit 33 to identify inspection conditions based on the variety setting information and inspection conditions based on other detection information when a variety is selected, and also has the function of an inspection condition detection means that detects in advance when a variety is selected whether specific inspection conditions that degrade the image quality of the inspection image generated by the image generation unit 34 are met.

[0059] Although not shown in detail, the X-ray generator 21 is switchable to a vacuum level measurement mode by the control unit 30 and has first and second measurement power supply circuits 27 and 28 that allow the X-ray tube 23 to be operated as a vacuum level measuring instrument when this vacuum level measurement mode is selected. The first measurement power supply circuit 27 applies a positive potential corresponding to a predetermined measurement voltage to the focusing electrode of the X-ray tube 23 and also applies an illumination voltage that provides thermionic emission energy to the cathode filament. The second measurement power supply circuit 28 applies a positive potential corresponding to a predetermined measurement voltage to the anode.

[0060] Furthermore, the degradation detection unit 37 of the control unit 30 operates when the aforementioned vacuum level measurement mode is selected, and can estimate and calculate the vacuum level of the X-ray tube 23 that deteriorates over time. Based on the calculated vacuum level, it has the function of estimating the remaining lifespan and degree of deterioration of the X-ray tube 23. Such vacuum level measurement and the function of estimating the remaining lifespan of the X-ray tube 23 based on the vacuum level measurement results are similar to those disclosed in International Publication No. 2019 / 117172, for example, as an X-ray generator utilizing the principle of an ionization vacuum gauge. From its remaining lifespan, it is possible to determine whether the X-ray irradiation intensity has decreased to below a predetermined intensity due to the deterioration of the X-ray tube 23 over time, and whether it has reached a level that can induce deterioration of the image quality of the inspection image.

[0061] Furthermore, the X-ray detector 22 is provided with, in addition to the multiple X-ray detection elements 221 to 22N, an X-ray detection element (not shown) located near but outside the range of the main scanning range of the X-ray detector 22, its signal detection circuit (A / D conversion unit, pulse height detection unit, region determination unit, and region-specific accumulation unit), and a removable X-ray shielding cover that covers the X-ray detection element for degradation detection (each not shown). By comparing the signal levels of the detection signals of the multiple X-ray detection elements 221 to 22N and the detection signals of the X-ray detection element for degradation detection at predetermined intervals, the degradation of the detection sensitivity can be detected. In other words, the degradation detection unit 37 has the function of a sensitivity degradation detection means that detects a significant decrease in the detection sensitivity of the X-ray detector 22, and such a sensitivity degradation detection means function can be obtained with a sensor configuration similar to that disclosed in, for example, Japanese Patent Application Publication No. 2002-168806.

[0062] Therefore, the deterioration detection unit 37 can detect when the irradiation intensity of X-rays irradiated from the X-ray generator 21 onto the item W under inspection falls below a predetermined intensity, thereby confirming that a specific inspection condition has been met due to this deterioration state. It can also detect when a significant decrease in the detection sensitivity of the X-ray detector 22 is detected, thereby confirming that a specific inspection condition has been met due to this deterioration state.

[0063] In other words, the specific inspection condition referred to here is that the transport speed of the item to be inspected passing through the inspection area Zx on the transport path 11a reaches a predetermined speed or higher. This includes the following conditions: or moreover When the irradiation intensity of the X-rays irradiated from the X-ray generator 21 onto the item W under inspection falls below a predetermined intensity, Then The condition or, If the transmittance of the object W being inspected in the X-ray transmission direction is within the low transmittance range among a set of multiple transmittance ranges, or if a significant decrease in the detection sensitivity of the X-ray detector 22 is detected, Then This includes the following conditions It's okay to be there .

[0064] The level conversion processing unit 32 is an image data adjustment means that adjusts the detection data output from the detection data output unit 31 to improve the image quality of the inspection image generated by the image generation unit 34 when the variety control unit 33 and the deterioration detection unit 37 detect that specific inspection conditions have been met. Adjusting to improve the image quality of the inspection image typically involves performing a process to improve the signal-to-noise ratio (S / N) of the detection data, thereby expanding the range of density values ​​(dynamic range) of the inspection image, but it may also involve a process to reduce noise components.

[0065] Here The aforementioned specific inspection conditions are set in stages such that a specific inspection condition is met when either of the following conditions is met: a first specific transport condition in which the transport speed of the item to be inspected W passing through the inspection area Zx on the transport path 11a of the item transport unit 10 is equal to or greater than a first transport speed (for example, 40 m / min shown in Figure 4), which is a predetermined speed that is relatively faster than the normal transport speed for the same type of item, and less than a second specific transport condition in which the transport speed is higher than the first transport speed (for example, 90 m / min shown in Figure 4); or a second specific transport condition in which the transport speed is in the high transport speed range of the second transport speed or higher.

[0066] The level conversion processing unit 32 has a processing function that adjusts the detection data of the item under inspection W such that the amount of adjustment of the detection data of the item under inspection W increases when the item under inspection W is detected to have a second specific transport condition set, compared to when the item under inspection W is detected to have a first specific transport condition set, by the item under inspection control unit 33 or / and the deterioration detection unit 37.

[0067] Specifically, as shown in Figure 3, the detection data output from the detection data output unit 31 allows for the generation of an X-ray image of part or all of the item W under inspection. When a segment image Sim1 corresponding to a predetermined number of adjacent pixel groups is obtained from this X-ray image, the level conversion processing unit 32 performs a predetermined binning process according to the detection information from the variety control unit 33 and / or the deterioration detection unit 37, which are inspection condition detection means.

[0068] In other words, the level conversion processing unit 32 divides the segment image Sim1 into multiple sub-segment regions S1a, S1b, S1c, and S1d (small regions) in a binning manner. The 32 then performs a binning process, integrating multiple pixel values ​​corresponding to the density values ​​(charges of the detected signals) within each small region (in Figure 3, for example, the pixel values ​​in the upper left sub-segment region S1a of the segment image Sim1 before binning are shown as "1", "2", "5", and "6" indicating their respective pixel positions) as processing units, and integrating them into a single pixel value corresponding to one density value (in Figure 3, for example, the upper left pixel value in the segment image Sim2 after binning is shown as "1" indicating its pixel position). As a result, the level conversion processing unit 32 adjusts the pixel value data corresponding to the density values ​​of the X-ray image data of the item W under inspection to improve the image quality of the inspection image while reducing the size of the inspection image, thereby improving the signal-to-noise ratio (S / N) and increasing the image processing speed.

[0069] The binning process here may be either a process of integrating multiple pixel values ​​corresponding to multiple density values ​​within each binned sub-region into a single pixel value, or a process of integrating multiple pixel values ​​into a single pixel value obtained by averaging them. In the former case, there is an effect similar to improving the signal-to-noise ratio by increasing the signal level of the detection signal from the X-ray detector 22, while in the latter case, there is an effect similar to improving the signal-to-noise ratio by reducing the noise component.

[0070] Here, we will describe the processing for adjusting the detected data as binning, which is a suitable example. However, kernel processing (filtering with a predetermined kernel size) for density conversion, such as expanding the dynamic range of density values ​​in the inspection image, which can contribute to improving the signal-to-noise ratio (S / N), can also be performed.

[0071] Furthermore, as shown in Figure 4, when the variety control unit 33 detects that a first specific transport condition has been set based on the transport speed setting value included in the variety information of the inspected item W by the item transport unit 10, the level conversion processing unit 32 sets the bin division size to 2x2, and when the variety control unit 33 detects that a second specific transport condition has been set, it sets the bin division size to 4x4, and executes binning processes with different adjustment amounts for each.

[0072] Therefore, the level conversion processing unit 32 performs binning processing for each specific transport condition, using the image data of the inspected item W obtained from the detection data output unit 31, such that the amount of adjustment made when the product type control unit 33 detects that a second specific transport condition has been set is greater than the amount of adjustment made when the product type control unit 33 detects that a first specific transport condition has been set.

[0073] Furthermore, as shown in Figure 4, when the transport speed of the item to be inspected W passing through the inspection area Zx on the transport path 11a of the item transport unit 10 is less than the normal transport speed range for the same type of product, for example, less than 40 m / min as shown in Figure 4, and the product control unit 33 does not detect that the specific inspection conditions have been met, the level conversion processing unit 32 sets the bin division size to 1 × 1 and does not perform the binning process.

[0074] Furthermore, in addition to the data adjustments performed by the level conversion processing unit 32 as described above, as shown in Figure 4, the product type control unit 33 controls the tube voltage of the X-ray tube 23, which is the X-ray irradiation condition of the X-ray generator 21, to different voltage values ​​depending on whether the transport speed of the item to be inspected W passing through the inspection area Zx on the transport path 11a of the item transport unit 10 is on the lower end of the normal transport speed range for the same product type (10 to 19 (m / min) in the figure) or on the higher end of the normal transport speed range (20 to 39 (m / min) in the figure).

[0075] Furthermore, even when the product type control unit 33 determines that specific inspection conditions are met, it controls the tube voltage of the X-ray tube 23, which is the X-ray irradiation condition of the X-ray generator 21, to different voltage values ​​in the same figure depending on whether the transport speed of the item to be inspected W passing through the inspection area Zx on the transport path 11a of the item transport unit 10 is set to a first transport speed (e.g., 40 m / min) or higher and less than the second transport speed (e.g., 90 m / min), or to a second transport speed (e.g., 20 m / min or higher).

[0076] In other words, the variety control unit 33 controls the tube voltage of the X-ray tube 23 to a different voltage value from other transport speed ranges in a specific transport speed range before or after switching between the first specific transport conditions and the second specific transport conditions.

[0077] Furthermore, in this embodiment, the level conversion processing unit 32 and the variety control unit 33, when setting the variety, pass a sample of the item to be inspected W through the inspection area Zx on the transport path 11a to acquire image data of the item to be inspected W with the detection data output unit 31, and calculate the transmittance of the item to be inspected W based on the image density ratio inside and outside the image area of ​​the item to be inspected W in the image data.

[0078] For example, when the product control unit 33 estimates, based on the product information of the item W to be inspected, that the transmittance of the item W to be inspected is within a specific transmittance range, for example, within the low transmittance range of a set of multiple transmittance ranges, it automatically adjusts the tube voltage of the X-ray tube 23 of the X-ray generator 21 according to that transmittance.

[0079] In this case, when the tube voltage is high, the X-ray generator 21 can irradiate X-rays with a relatively short wavelength and relatively strong penetrating power, and when the tube voltage is low, the X-ray generator 21 can irradiate X-rays with a relatively long wavelength and relatively weak penetrating power.

[0080] Therefore, the level conversion processing unit 32 and the product control unit 33 have the function of improving the signal-to-noise ratio (S / N) by variably setting the tube voltage of the X-ray tube 23, which is the X-ray irradiation condition of the X-ray generator 21. This not only reduces the size of the inspection image while adjusting the pixel value data corresponding to the density value of the X-ray image data of the item to be inspected W to the side that improves the image quality of the inspection image through binning processing in the level conversion processing unit 32, but also by variably setting the tube voltage of the X-ray tube 23.

[0081] The display operation unit 40 is a flat panel display that can input requested information to the control unit 30 in response to operation inputs, and can display the variety list and variety setting information stored in the variety control unit 33 on the screen.

[0082] Next, I will explain the mechanism of action.

[0083] Figure 5 is a flowchart showing the procedures for various setting processes performed in the article inspection apparatus 1 of this embodiment configured as described above, and Figure 6 is a flowchart showing the procedure for applying adjustments to the detection data of the X-ray transmission image according to the inspection conditions during article inspection to suppress the deterioration of image quality.

[0084] In the article inspection device 1 of this embodiment, configured as described above, when registering a new type of article to be inspected W, first, production conditions and the selection of the type are set, and then information about the article to be inspected W of that type, such as the type number, name, number of contents, weight, shape, etc., is set and input (steps S11 and S12 in Figure 5).

[0085] Furthermore, the driving conditions of the X-ray tube 23 of the X-ray detection unit 20, namely the tube voltage that determines the irradiation intensity and the tube current that determines the irradiation X-ray dose, are set to appropriate initial setting levels. The detection sensitivity of the X-ray detector 22 is adjusted so that the amount of X-ray transmission in each transmission area on the belt surface alone is equal across the entire width direction of the transport path 11a when no items are being transported. Subsequently, detection conditions are set so that the belt surface of the transport path 11a of the article transport unit 10 when no items are being transported is used as a reference surface without items to be inspected. Finally, noise cut thresholds and the like for the X-ray image data to be taken into the detection data output unit 31 are set.

[0086] Furthermore, using a sample of the item W to be inspected, detailed settings are made for parameters such as the transport speed of the transport path 11a of the item transport unit 10, the threshold value for judgment in the judgment unit 36, and other parameters. The initial setting data entered with these settings is then written to the variety control unit 33, for example, as a variety parameter file, and is kept in a readable state when input specifying a variety is made.

[0087] Once the necessary setup process is complete, a series of inspection control programs are then executed. For example, a variety selection screen is displayed on the touch panel of the display operation unit 40. When input is made to specify the variety of the item W to be inspected, the previously set setting information is read from the variety parameter file in the variety control unit 33. Then, when an operation input such as pressing the start button to instruct the start of measurement is made, the transport of the item W to be inspected by the transport path 11a of the item transport unit 10 begins.

[0088] Therefore, the operating conditions of the product inspection device 1 at this time are those that perform an inspection of the predetermined quality state using the detection conditions and judgment conditions set in advance for the selected product type.

[0089] Next, when the item to be inspected W is placed upstream of the transport path 11a of the item transport unit 10, it is detected by an item detection sensor (not shown) before or during its loading onto the transport path 11a.

[0090] Next, based on the transport direction length of the item to be inspected W detected by the item detection sensor or a preset item detection cycle, the X-ray detector 22 repeatedly performs line scanning while the item to be inspected W passes through a predetermined inspection area Zx, and each detection signal from multiple X-ray detection elements 221 to 22N is taken up by the detection data output unit 31 with each line scan. Furthermore, the transmission amount data for the number of detection elements N of the X-ray detector 22 is sequentially stored in the image memory of the detection data output unit 31, and when the above-mentioned A / D conversion and other processing are performed, X-ray image data corresponding to the X-ray transmission amount distribution for each item to be inspected W is generated and output as detection data from the detection data output unit 31 to the image generation unit 34 that generates the inspection image.

[0091] Then, the image generation unit 34 generates an inspection image based on the detection data output unit 31, and this inspection image is sent to the inspection processing unit 35, where the inspection processing unit 35 performs inspection processing related to a predetermined item inspection based on the data of the inspection image.

[0092] In this embodiment, prior to such article inspection, if the variety control unit 33 and / or the deterioration detection unit 37 has previously detected that specific inspection conditions, i.e., inspection conditions that degrade the image quality of the inspection image generated by the image generation unit 34, are met, the detection data output from the detection data output unit 31 is processed by the level conversion processing unit 32, located between the detection data output unit 31 and the image generation unit 34, to improve the image quality of the inspection image through the aforementioned binning and kernel processing. ru Data adjustments will be performed.

[0093] Specifically, first, the variety control unit 33 determines whether or not the first special inspection condition is met (step S13). If the first special inspection condition is met (YES in step S13), then the first binning processing condition of a bin division size of 2x2 is set (step S14).

[0094] On the other hand, if the first special inspection condition is not met (if the answer is NO in step S13), then it is determined whether or not the second special inspection condition is met (step S15). If the second special inspection condition is met (if the answer is YES in step S5), then a second binning processing condition with a bin division size of 4x4 is set (step S16).

[0095] If neither the first nor the second special inspection condition is met in the above-mentioned determination process, the bin division size will be 1x1, and binning will not be set.

[0096] Next, under normal inspection conditions, which are within the normal transport speed range, or under either the first special inspection conditions or the second special inspection conditions, the tube voltage [kV] for each transmittance is set to the respective set values ​​shown in Figure 4, depending on whether the speed range in which the bins are divided is on the low-speed or high-speed side (step S17).

[0097] Next, when performing an item inspection, the data adjustment conditions set as described above are first read into the level conversion processing unit 32 of the control unit 30 (step S21), then it is checked whether or not the inspection is in operation (step S22). If the inspection is in operation (if YES in step S22), then it is determined whether or not the line sensor detection signal has been captured by the detection data output unit 31 by the main scan of the X-ray detection unit 22, and after waiting for the acquisition of the detection data, binning processing according to the inspection conditions is performed on the acquired data (step S24).

[0098] On the other hand, if the inspection is not in operation (if NO in step S22), it is then determined whether a predetermined termination condition (for example, the planned production quantity has been reached or another termination request has occurred) is met (step S25). If the predetermined termination condition is met (if YES in step S25), the current process is terminated.

[0099] On the other hand, if the predetermined termination condition is not met (NO in step S25), the process returns to the step of determining whether or not the inspection is in operation (S22).

[0100] In this way, the adjusted detection data, which has been adjusted by the level conversion processing unit 32 according to the detection conditions, is taken into the image generation unit 34. The image generation unit 34 then generates an inspection image that can improve the signal-to-noise ratio, for example, an inspection image with an expanded range of density values ​​(dynamic range) of multiple pixels, based on the adjusted detection data adjusted by the level conversion processing unit 32. Therefore, the inspection processing unit 35 can perform inspection processing related to a predetermined item inspection based on the data of the inspection image with the expanded range of density values.

[0101] As a result, even when the item transport speed in the item transport unit 10 is increased and the output of the X-ray generator 21 is reduced in the item inspection device 1, it becomes possible to perform good item inspection processing while effectively suppressing the effect of the decrease in the signal level of the detection signal taken up by the detection data output unit 31 from the licensor-type X-ray detector 22 at each predetermined main scanning cycle.

[0102] Furthermore, in this embodiment, the detection data from the detection data output unit 31 is X-ray image data having density values ​​based on the detection signals of multiple pixels in the X-ray image, and the level conversion processing unit 32, which is an image data adjustment means, performs image processing, such as binning or kernel processing, to convert adjacent groups of a predetermined number of pixels into one pixel each in the X-ray image, thereby enabling the inspection image to have the required image quality. Therefore, the required image quality of the inspection image can be ensured, and inspection processing for good product inspection can be performed.

[0103] Furthermore, in this embodiment, the specific inspection conditions include the condition that the transport speed of the item to be inspected W passing through a predetermined section on the transport path 11a reaches a predetermined speed or higher, or that the irradiation intensity of the X-rays irradiated onto the item to be inspected W from the X-ray generator 21 has decreased to below a predetermined intensity. Therefore, when the transport speed enters a specific high-speed range or the X-ray irradiation intensity decreases to below a predetermined intensity, and the signal level of the detection signal taken up by the detection data output unit 31 from the X-ray detector 22 decreases at each predetermined scanning cycle, the detection data output from the detection data output unit 31 is adjusted by the level conversion processing unit 32 to improve the image quality of the inspection image.

[0104] Furthermore, since the specific inspection conditions include the condition that the transmittance of the item W to be inspected in the X-ray transmission direction falls within the low transmittance range among a plurality of preset transmittance ranges, when the transmittance of the item W to be inspected falls within the low transmittance range, the detection data output from the detection data output unit 31 is adjusted by the level conversion processing unit 32 to improve the image quality of the inspection image.

[0105] Furthermore, in this embodiment, the variety control unit 33 X-ray detector 22The system also includes a sensitivity reduction detection means that detects a significant decrease in the detection sensitivity of the X-ray detector 22. The specific inspection conditions include the condition that a significant decrease in the detection sensitivity of the X-ray detector 22 has been detected by the sensitivity reduction detection means. When a significant decrease in the detection sensitivity of the X-ray detector 22 is detected, the detection data output from the detection data output unit 31 is adjusted by the level conversion processing unit 32 to improve the image quality of the inspection image.

[0106] Therefore, in this embodiment, the required image quality of the inspection images can be ensured, and a good inspection process for product inspection can be performed.

[0107] Furthermore, in this embodiment, the specific inspection conditions are met when either a first specific transport condition, in which the transport speed of the item to be inspected W is equal to a predetermined speed (a first transport speed) or higher and less than a second transport speed, or a second specific transport condition, in which the transport speed is in the high transport speed range (above the second transport speed), is met. The level conversion processing unit 32 adjusts the detection data of the item to be inspected W such that the amount of adjustment of the detection data of the item to be inspected W increases more when the second specific transport condition is detected to be set than when the first specific transport condition is detected to be set by the product control unit 33 (or / and deterioration detection unit 37). Therefore, when either the first or second specific transport condition, that is, any of the multiple specific transport conditions set in stages, is met, the amount of adjustment of the detection data of the item to be inspected W changes according to the stage of the condition, and the decrease in the signal level of the detection signal in the high-speed transport region is more effectively suppressed.

[0108] Furthermore, in this embodiment, the level conversion processing unit 32 adjusts the detection data of the item under inspection by binning, which is performed on the image data of each small region when the X-ray image of the item under inspection W is divided into multiple small regions, as described above. Therefore, since image reduction can be performed while suppressing the loss of information due to pixel downsampling, even when the item transport speed is increased or the output of the X-ray generator is reduced, the effect of the decrease in the signal level of the detection signal taken in by the detection data output unit from the X-ray detector can be effectively suppressed, and a good item inspection process can be performed.

[0109] Furthermore, in this embodiment, when the level conversion processing unit 32 passes a sample of the item to be inspected through a predetermined section on the transport path 11a and the detection data output unit 31 acquires detection data of the item to be inspected W, it has an automatic setting function that accurately calculates the transmittance of the item to be inspected W based on the image density ratio inside and outside the image area of ​​the item to be inspected W in the detection data, and variably sets the tube voltage of the X-ray tube 23, which affects the X-ray irradiation conditions, such as the penetrating power (X-ray energy), according to the calculated transmittance value.Therefore, even if the item to be inspected W has low X-ray transmittance, the decrease in the signal level of the detection signal will be suppressed more effectively.

[0110] In this embodiment, as shown in Figure 4, the tube voltage of the X-ray tube 23 is controlled to a different voltage value from other transport speed ranges in a specific transport speed range before or after switching between the first specific transport condition and the second specific transport condition. Therefore, by controlling the tube voltage of the X-ray tube 23 in a specific transport speed range before or after switching between the first specific transport condition and the second specific transport condition, the penetrating power and amount of X-rays can be adjusted, and the effect of the decrease in the signal level of the detection signal before and after switching the transport condition can be effectively suppressed.

[0111] Thus, in this embodiment, while increasing the speed of article transport in the article transport unit 10 and reducing the output of the X-ray generator 21, it is possible to effectively suppress the effect of the decrease in the detection signal level of the X-ray generator 21 in the high transport speed region and other areas that are specific inspection conditions, thereby providing an article inspection device 1 that can perform good inspections.

[0112] In this embodiment, the level conversion processing unit 32, which is an image data adjustment means, was placed separately from the X-ray detector 22 and provided within the control unit 30. However, it goes without saying that the level conversion processing unit 32, which is an image data adjustment means, may also be incorporated into the X-ray detector 22.

[0113] [Second Embodiment] Figure 7 shows an article inspection apparatus according to a second embodiment of the present invention.

[0114] This embodiment differs from the first embodiment in that, instead of providing the data processing function unit corresponding to the detection data output unit 31 and level conversion processing unit 32 in the first embodiment within the control unit 30, it is integrated into the X-ray detector. However, other configurations are the same as those of the first embodiment. Therefore, the differences from the first embodiment will be explained below.

[0115] In the article inspection apparatus 1 of this embodiment, the X-ray inspection unit 20 includes an X-ray generator 21 and an X-ray detector 62. The X-ray detector 62 is an X-ray line sensor camera in which a detector body portion 62a, which corresponds to the X-ray detector 22 in the first embodiment, and a data processing function unit 70, which corresponds to the detection data output unit 31 and the level conversion processing unit 32 in the first embodiment, are integrally incorporated.

[0116] In this embodiment, the functions of the detection data output unit 31 and the level conversion processing unit 32 in the first embodiment can be performed by the data processing function unit 70 incorporated into the X-ray detector 62. Therefore, a simpler control unit 30A can be adopted, which has a configuration in which the detection data output unit 31 and the level conversion processing unit 32, which are data acquisition and preprocessing functions, are removed from the control unit 30 of the first embodiment, and noise immunity during the transmission image data acquisition stage can be improved. Accordingly, the effect of the decrease in the detection signal level of the X-ray generator 21 in high transport speed regions and other specific inspection conditions can be suppressed more effectively, and good inspections can be performed.

[0117] In this embodiment as well, while increasing the speed of item transport in the item transport unit 10 and reducing the output of the X-ray generator 21, the X-rays in the high transport speed range and other areas that are specific inspection conditions are maintained. detection vessel 62 This provides an article inspection device that can effectively suppress the effects of a decrease in the detection signal level and perform good inspections.

[0118] Na Oh, XThe means for detecting the deterioration of the X-ray generator 21 and the X-ray detector 22 are not limited to those exemplified as the deterioration detection unit 37, but can of course also be applied to conventional vacuum degree deterioration detection techniques for other X-ray tubes or techniques for detecting a decrease in the detection sensitivity of the X-ray generator 21.

[0119] As described above, the article inspection apparatus of the present invention achieves high article transport speed and low output of the X-ray generator while effectively suppressing the effect of the decrease in the detection signal level of the line sensor type X-ray detector in high transport speed ranges and other specific inspection conditions, thereby enabling good inspection. The present invention has the ability to transmit through the transported article. x-ray This is useful for all types of product inspection equipment that acquire image data corresponding to the dose distribution through the periodic detection operation of a line sensor type X-ray detector, and then determine the quality status of the inspected product based on that image data. [Explanation of Symbols]

[0120] 1. Item inspection device 10. Goods transport section 11. Belt (conveyor belt) 11a Conveyor path 12, 13 Laura 20 X-ray Examination Department 21 X-ray generator (X radiation source, irradiation part) 22 X-ray detectors (X (Line detection unit) 221~22N Multiple X-ray detection elements (detection elements) 23 X-ray tube 24a X-ray window 23a Anode 24 Box body 25 One of the drive power supply circuits 26 Other drive power supply circuit 27. First Measurement Power Supply Circuit 28. Second Measurement Power Supply Circuit 30, 30A Control Unit 31 Detection data output unit 32 Level conversion processing unit (image data adjustment means) 33 Variety control unit (inspection condition detection means, sensitivity reduction detection means) 34 Image generation unit 35. Inspection Processing Unit (Inspection Image Processing Means) 36 Judgment section 37. Deterioration detection unit (inspection condition detection means) 40 Display operation section 511~51N A / D Conversion Unit 521~52N Wave height detection unit 531~53N Area determination section 541~54N Area-specific cumulative part 55 Transparent Image Data Output Unit 62 X-ray detectors 62a Detector body 70 Image processing function unit (detection data output unit, image data adjustment means) Da Main scanning direction (carrier path width direction) Db predetermined transport direction W: Items under inspection Zx Inspection area (predetermined interval)

Claims

1. An X-ray generator (21) that irradiates an article to be inspected (W) with X-rays as it is transported by a conveyor belt (11) of an article transport unit (10) and passes through an inspection area (Zx), An X-ray detector (22) sequentially detects X-rays that have passed through the item to be inspected and outputs a detection signal for each, A control unit (30) generates an inspection image based on the detection data output by acquiring the detection signal at a predetermined period, processes the inspection image and compares it with a judgment threshold to perform inspection processing for each item to be inspected and outputs the judgment result to a display operation unit (40), In an article inspection device (1) equipped with, The control unit, The conveying speed of the items to be inspected by the conveyor belt is set. The image processing conditions for converting adjacent pixel groups in the inspection image into a single pixel are set in steps for multiple speed ranges of the transport speed. The image processing is performed according to any of the processing conditions, and the determination result is output. Product inspection device.

2. The control unit further comprises: The deterioration state of the X-ray generator and the X-ray detector is detected, Depending on the state of deterioration, image processing conditions are set to convert adjacent groups of pixels in the inspection image into a single pixel. The article inspection apparatus according to claim 1.

3. The article inspection apparatus according to claim 1 or 2, wherein the processing condition is the bin size for binning, which divides the inspection image into small regions and adds or averages the pixel values.

4. The article inspection apparatus according to claim 1 or 2, wherein the processing condition is the kernel size of a kernel process that divides the inspection image into small regions and filters them.

Images