JP2006329822A - Electromagnetic wave detector and inspection device therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic wave detector for detecting X rays (electromagnetic waves) with high sensitivity and forming an image of high resolving power to perform inspection of high precision even in the case of inspection by irradiation with low-energy X rays (electromagnetic waves). <P>SOLUTION: An X-ray inspection device 10 has a substrate 31, a photodiode 32 and a phosphor 33 so that the photodiode 32 and the phosphor 33 are arranged in this order on the side of an X-ray irradiator 13. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is mounted on an electromagnetic wave detector or the like that irradiates an article to be inspected with an electromagnetic wave such as an X-ray and inspects the article based on an image formed based on a detection signal of the transmitted electromagnetic wave. The present invention relates to an electromagnetic wave detector such as an X-ray detector.

  Conventionally, in the production line of products such as food, in order to prevent the defective product from being shipped when foreign matter is mixed into the product or the product is cracked or broken, the product has failed using an X-ray inspection device. Inspection is being conducted. In this X-ray inspection apparatus, X-rays are irradiated to an article that is continuously conveyed by a conveyor, and the X-ray transmission state is detected by an X-ray detection unit so that no foreign matter is mixed in the article. Is determined.

In such an X-ray inspection apparatus, a detector that detects transmitted light of X-rays irradiated on a product to be inspected is provided with a scintillator that converts X-rays into visible light immediately above the photodiode chip. The visible light converted from X-rays is detected by a photodiode (see Patent Document 1).
Japanese Patent Laid-Open No. 2003-066149 (published on March 5, 2003)

However, the conventional radiation detector has the following problems.
That is, in the radiation detector disclosed in the above publication, as shown in FIG. 9A, since the scintillator and the photodiode chip are arranged in this order as viewed from the X-ray source, the wavelength region is 0.06 nm to 0. When X-rays having a low energy of about .01 nm are irradiated, X-rays absorbed on the surface of the scintillator emit light as shown in FIG. 9B. However, in such a configuration, since the emitted light is attenuated and scattered while passing through the scintillator, it becomes easy to enter the adjacent pixels in the photodiode chip, so that the resolution of the image is lowered. As a result, when low-energy X-rays are irradiated, it is difficult to create a high-resolution X-ray image, and it may be difficult to perform a highly efficient and highly accurate inspection.

  The subject of the present invention is to detect X-rays (electromagnetic waves) with high sensitivity even when irradiating with low-energy X-rays (electromagnetic waves), and create a high-resolution image for high-precision inspection. An object of the present invention is to provide an electromagnetic wave detector capable of performing the above.

  An electromagnetic wave detector according to a first invention is an electromagnetic wave detector for detecting an electromagnetic wave transmitted through an article among electromagnetic waves irradiated to the article, the irradiator, a wavelength conversion unit, a detection unit, It has. The irradiator irradiates the article with the first electromagnetic wave. The wavelength conversion unit converts the first electromagnetic wave transmitted through the article into a second electromagnetic wave having a longer wavelength than the first electromagnetic wave. The detection unit transmits the first electromagnetic wave and detects the second electromagnetic wave converted by the wavelength conversion unit. The detection unit is provided between the irradiator and the wavelength conversion unit.

Here, in the electromagnetic wave detector that detects the electromagnetic wave (second electromagnetic wave) after wavelength conversion by converting the wavelength of the electromagnetic wave (first electromagnetic wave) such as X-rays emitted from the irradiator, the detection unit as viewed from the irradiator. Is arranged in front of the wavelength conversion unit, that is, the irradiator, the detection unit, and the wavelength conversion unit in this order.
Here, the electromagnetic waves include electron beams, visible light, and the like in addition to radiation such as X-rays. The wavelength conversion unit includes, for example, a scintillator that absorbs X-rays (wavelength of about 0.03 nm) and emits visible light (wavelength of about 420 to 900 nm). The detection unit includes, for example, a photodiode that detects visible light converted by the wavelength conversion unit. The detection unit is formed of, for example, a Si thin film or the like and has a property or a structure that transmits the first electromagnetic wave. The first electromagnetic wave irradiated to the article to be inspected from the irradiator passes through the article and then first passes through the detection unit. And the 1st electromagnetic wave which passed the detection part reaches | attains a wavelength conversion part, and wavelength conversion is performed here. The wavelength-converted second electromagnetic wave is, for example, converted from X-rays to visible light and detected by the detection unit that has just passed.

  Usually, when inspecting an article having a low density, an electromagnetic wave with low energy may be used to improve the contrast of a two-dimensional image created based on the detection result in the detection unit. However, when the energy of the electromagnetic wave emitted from the irradiator is low, wavelength conversion is performed near the surface of the wavelength conversion unit. For this reason, in the configuration in which the wavelength conversion unit is provided on the irradiator side of the detection unit as in the conventional X-ray detector, the second electromagnetic wave converted in wavelength on the surface on the irradiator side of the wavelength conversion unit is In some cases, the detection unit attenuates and scatters while passing through the wavelength conversion unit until it reaches the detection unit, and cannot be accurately detected by the detection unit. As a result, for example, the resolution of an image created based on the detection result of the second electromagnetic wave in the detection unit may be reduced, and it may be difficult to perform a highly accurate inspection.

Therefore, in the electromagnetic wave detector of the present invention, the detector is disposed close to the surface on the irradiator side of the wavelength converter that performs wavelength conversion of the electromagnetic wave.
Thereby, for example, even when a low-energy electromagnetic wave is irradiated with a low-density article as an inspection target, the second electromagnetic wave that has been wavelength-converted on the surface on the irradiator side in the wavelength conversion unit is irradiated in the wavelength conversion unit. In the detection part arrange | positioned in the vicinity of the side surface, it can detect efficiently and correctly. As a result, for example, even when an inspection such as foreign object detection is performed using an image created based on the detection result of the second electromagnetic wave, a high-resolution image can be created and a high-precision inspection can be performed. .

The electromagnetic wave detector which concerns on 2nd invention is an electromagnetic wave detector which concerns on 1st invention, Comprising: The board | substrate for fixing a detection part is further provided.
Here, for example, a detection unit such as a photodiode formed of Si or the like is fixed to a substrate formed of ceramic or the like.
Thereby, since a detection part can be stably fixedly arranged, the detection in a detection part can be performed stably.

The electromagnetic wave detector which concerns on 3rd invention is an electromagnetic wave detector which concerns on 1st or 2nd invention, Comprising: Electromagnetic waves are X-rays.
Here, X-rays are used as electromagnetic waves irradiated to the article to be inspected, and the amount of electromagnetic waves obtained by converting the wavelength of transmitted light of X-rays irradiated to the articles in the detection unit is calculated. To detect.

As a result, general X-rays can be used as the electromagnetic waves used in the inspection apparatus. For example, in order to create an X-ray image with improved contrast even when inspection is performed on a low-density article. Even when energy X-rays are irradiated, a high-resolution X-ray image can be created.
The electromagnetic wave detector which concerns on 4th invention is an electromagnetic wave detector which concerns on 3rd invention, Comprising: A wavelength conversion part absorbs X-ray | X_line and discharge | releases visible light.

Here, in an X-ray detector that irradiates an object to be inspected with X-rays and detects the transmitted light, a scintillator that absorbs X-rays and converts it into visible light is used as a wavelength conversion unit. Yes.
Here, the wavelength of X-rays is about 0.03 nm, and the wavelength of visible light is 420 nm to 900 nm.

Thereby, in the scintillator which functions as a wavelength conversion part, the wavelength of the X-ray irradiated from the irradiator can be converted into visible light by converting from 0.03 nm to 420 to 900 nm.
The electromagnetic wave detector which concerns on 5th invention is the electromagnetic wave detector which concerns on 4th invention, Comprising: A detection part is a photodiode which detects visible light.

Here, a photodiode is used as a detection unit for detecting the second electromagnetic wave (visible light).
Thereby, visible light obtained by converting the wavelength of X-rays in a wavelength converter such as a scintillator can be reliably detected in the photodiode.
An inspection apparatus according to a sixth aspect includes the electromagnetic wave detector according to any one of the first to fifth aspects, an image creation unit, and an inspection unit. The image creation unit creates a two-dimensional image based on the detection result in the electromagnetic wave detector. The inspection unit inspects the article based on the two-dimensional image created by the image creation unit.

Here, the above-described electromagnetic wave detector is mounted in an inspection apparatus that inspects foreign matters mixed in an article using a two-dimensional image created based on the detection result of the electromagnetic wave detector.
Thereby, the second electromagnetic wave can be detected with high efficiency and high accuracy, and a two-dimensional image with high resolution can be created. As a result, highly accurate inspection can be performed by performing various inspections based on a two-dimensional image with high resolution.

  According to the electromagnetic wave detector of the present invention, for example, even when low-energy electromagnetic waves are irradiated with a low-density article as an inspection target, the second electromagnetic wave that has been wavelength-converted on the surface on the irradiator side in the wavelength conversion unit, In the wavelength conversion unit, detection can be performed efficiently and accurately in the detection unit arranged close to the surface on the irradiator side.

An X-ray detector (electromagnetic wave detector) according to an embodiment of the present invention and an X-ray inspection apparatus (inspection apparatus) equipped with the same will be described below with reference to FIGS.
[Configuration of X-ray inspection apparatus 10 as a whole]
As shown in FIG. 1, the X-ray inspection apparatus 10 of the present embodiment is one of apparatuses that perform quality inspection in a production line for products such as food. The X-ray inspection apparatus 10 irradiates X-rays on products that are continuously conveyed, detects X-rays transmitted through the products, and foreign matters are mixed into the products based on X-ray images that are created. Check if there is any.

  A product (article) G to be inspected by the X-ray inspection apparatus 10 is carried to the X-ray inspection apparatus 10 by a front conveyor 60 as shown in FIG. The product G is determined by the X-ray inspection apparatus 10 for the presence or absence of contamination. The determination result in the X-ray inspection apparatus 10 is transmitted to a distribution mechanism 70 disposed on the downstream side of the X-ray inspection apparatus 10. The distribution mechanism 70 sends the product G to the regular line conveyor 80 as it is when the product G is determined to be a non-defective product in the X-ray inspection apparatus 10. On the other hand, when the product G is determined to be a defective product containing foreign matter in the X-ray inspection apparatus 10, the arm 70a having the downstream end as a rotation shaft rotates so as to block the conveyance path. As a result, the product G determined to be defective can be collected by the defective product collection box 90 arranged at a position off the conveyance path.

  As shown in FIG. 1, the X-ray inspection apparatus 10 mainly includes a shield box 11, a conveyor 12, a shield noren 16, and a monitor 26 with a touch panel function. As shown in FIG. 3, an X-ray irradiator (irradiator) 13, an X-ray line sensor (X-ray detector, electromagnetic wave detector) 14, and a control computer (image creation unit, inspection) Part) 20 (see FIG. 5).

[Shield box 11]
The shield box 11 has an opening 11a for carrying in and out the product on both the entrance side and the exit side of the product G. In this shield box 11, a conveyor 12, an X-ray irradiator 13, an X-ray line sensor 14, a control computer 20 and the like are accommodated.
Further, as shown in FIG. 1, the opening 11 a is closed by a shield noren 16 in order to prevent leakage of X-rays to the outside of the shield box 11. This shielding nolen 16 has a rubber nolene portion containing lead and is pushed away by the product when the product is carried in and out.

In addition to the monitor 26, a key insertion slot, a power switch, and the like are disposed on the upper front portion of the shield box 11.
[Conveyor 12]
The conveyor 12 conveys commodities in the shield box 11, and is driven by a conveyor motor 12f included in the control block of FIG. The conveyance speed by the conveyor 12 is finely controlled by the inverter control of the conveyor motor 12f by the control computer 20 so as to be the set speed input by the operator.

As shown in FIG. 3, the conveyor 12 includes a conveyor belt 12 a and a conveyor frame 12 b and is attached to the shield box 11 in a removable state. Thereby, in order to keep the inside of the shield box 11 clean when inspecting food or the like, the conveyor can be removed and frequently washed.
The conveyor belt 12a is an endless belt, and is supported by the conveyor frame 12b from the inside of the belt. And the object mounted on the belt is conveyed in a predetermined direction by receiving the driving force of the conveyor motor 12f and rotating.

  The conveyor frame 12b supports the conveyor belt 12a from the inside of the endless belt, and is long in a direction perpendicular to the conveying direction at a position facing the inner surface of the conveyor belt 12a as shown in FIG. It has the opening part 12c opened. The opening 12c is formed on a line connecting the X-ray irradiator 13 and the X-ray line sensor 14 in the conveyor frame 12b. In other words, the opening 12c is formed in the X-ray irradiation region from the X-ray irradiator 13 in the conveyor frame 12b so that X-rays that have passed through the product G are not blocked by the conveyor frame 12b.

[X-ray irradiator 13]
As shown in FIG. 3, the X-ray irradiator 13 is disposed above the conveyor 12, and an X-ray line sensor disposed below the conveyor 12 through an opening 12 c formed in the conveyor frame 12 b. X-rays are irradiated in a fan shape toward 14 (see the hatched portion in FIG. 3).
[X-ray line sensor 14]
The X-ray line sensor 14 is disposed below the conveyor 12 (opening 12c), and detects X-rays (first electromagnetic waves) transmitted through the product G and the conveyor belt 12a. As shown in FIGS. 3 and 4, the X-ray line sensor 14 includes a plurality of pixels 14 a that are horizontally arranged in a straight line in a direction orthogonal to the conveying direction by the conveyor 12.

4 shows an X-ray irradiation state in the X-ray inspection apparatus 10 and a graph showing the X-ray dose detected in each pixel 14a constituting the line sensor 14 at that time.
In addition, as shown in FIGS. 6A and 6B, the X-ray line sensor 14 of the present embodiment includes a substrate 31, a photodiode (detection unit) 32, and a phosphor (wavelength conversion unit) 33. And have.

The substrate 31 is a ceramic substrate having a thickness of about 1.6 to 2.4 mm, in order to stably detect the visible light (second electromagnetic wave) in the photodiode 32 by firmly fixing the photodiode 32. Is provided. An opening 31a is formed in the substrate 31, and the photodiode 32 is exposed from the opening 31a.
The photodiode 32 is disposed at a position sandwiched between the substrate 31 and the phosphor 33, and detects visible light (second electromagnetic wave) emitted from the phosphor 33 attached to the back surface side. The photodiode 32 is formed of a Si thin film having a thickness of about 0.1 mm and has a property of transmitting X-rays. The plurality of pixels 32a included in the photodiode 32 correspond to the above-described pixel 14a.

  The phosphor 33 is disposed close to the photodiode 32 so as to be attached below the photodiode 32 when viewed from the X-ray irradiator 13. The phosphor 33 absorbs the X-rays that have passed through the photodiode 31 exposed from the opening 31a after passing through the product G, and then emitted, and emits visible light. At this time, the phosphor 33 converts the absorbed X-ray wavelength (about 0.03 nm) to about 420 to 900 nm. Thereby, the phosphor 33 functions as a wavelength conversion unit that converts X-rays (first electromagnetic waves) having a wavelength of about 0.03 nm into visible light (second electromagnetic waves) having a wavelength of about 420 to 900 nm. In the phosphor 33, when the energy of the X-rays to be absorbed is high, the phosphor 33 reaches a relatively deep layer and emits light. On the other hand, when the energy of the X-rays is low (for example, the wavelength region of the X-ray is 0. In the case of 06 nm to 0.01 nm), light is emitted near the surface without reaching the deep layer.

  And in this embodiment, each structure mentioned above is arrange | positioned in order of the board | substrate 31, the photodiode 32, and the fluorescent substance 33 from the X-ray irradiator 13 side. For this reason, the X-rays irradiated from the X-ray irradiator 13 pass through the product G being conveyed, and are then irradiated from the opening 31a portion of the substrate 31 to the photodiode 32 portion. Then, as shown in FIG. 7, the X-rays pass through the photodiode 32 formed by the Si thin film and reach the phosphor 33. At this time, the phosphor 33 emits visible light at a depth position where X-rays varying according to the energy of the X-rays are absorbed. Specifically, when the energy of the irradiated X-ray is low (for example, when the wavelength region of the X-ray is 0.06 nm to 0.01 nm), the X-ray emits light near the surface layer of the phosphor 33. When the energy of is high, light is emitted near the deep portion of the phosphor 33. The photodiode 32 detects X-rays by detecting the visible light emitted and emitted from the phosphor 33 at each pixel 32a included in the photodiode 32 arranged so as to be close to it.

[Monitor 26]
The monitor 26 is a full dot display liquid crystal display. Further, the monitor 26 has a touch panel function, and displays a screen for prompting parameter input relating to initial setting, foreign object detection determination, and the like.
The monitor 26 displays an X-ray image that has been created based on the detection result of the X-ray line sensor 14 and has undergone image processing. As a result, the presence / absence, location, size, etc. of foreign matter contained in the product G can be visually recognized by the user.

[Control Computer 20]
In the CPU 21, the control computer 20 executes an image processing routine, an inspection determination processing routine, and the like included in the control program. The control computer 20 also stores and accumulates X-ray images corresponding to defective products, inspection results, X-ray image correction data, and the like in a storage unit such as a CF (Compact Flash: registered trademark) 25.

As a specific configuration, as shown in FIG. 5, the control computer 20 is equipped with a CPU 21, and a ROM 22, a RAM 23, and a CF 25 as a main storage unit controlled by the CPU 21.
The CF 25 stores information on various programs and information on X-ray images to be inspected for contamination, information on the position of detected foreign matter, and the like.

Further, the control computer 20 includes a display control circuit for controlling data display on the monitor 26, a key input circuit for fetching key input data from the touch panel of the monitor 26, and an I / O for controlling data printing in a printer (not shown). USB 24 as an external connection terminal is provided.
The CPU 21, ROM 22, RAM 23, CF 25, and the like are connected to each other via a bus line such as an address bus or a data bus.

Furthermore, the control computer 20 is connected to a conveyor motor 12f, a rotary encoder 12g, an X-ray irradiator 13, an X-ray line sensor 14, a photoelectric sensor 15, and the like.
The control computer 20 receives the conveyance speed of the conveyor 12 detected by the rotary encoder 12g attached to the conveyor motor 12f.
Further, the control computer 20 receives a signal from the photoelectric sensor 15 as a synchronous sensor composed of a pair of light projectors and light receivers arranged with a conveyor interposed therebetween, and the product G as an inspection object is an X-ray line. The timing to come to the position of the sensor 14 is detected.

<Determination of contamination by the control computer 20>
[Create X-ray image]
When the control computer 20 receives a signal from the photoelectric sensor 15 and the product G passes through the fan-shaped X-ray irradiation portion (see the hatched portion shown in FIG. 3) irradiated from the X-ray irradiator 13, X-ray fluoroscopic image signals from the line sensor 14 are acquired at fine time intervals. Then, the control computer 20 creates a two-dimensional X-ray image including the product G and the background portion for each line of the X-ray line sensor 14 based on these X-ray fluoroscopic image signals. That is, data at each time is obtained from each pixel 14a (pixel 32a) of the X-ray line sensor 14 with a fine time interval, and an X-ray image is created from each data. Then, by combining the plurality of X-ray images in the order of time, an entire two-dimensional image including the entire product G and the background portion is formed.

[Mask area setting]
In the X-ray inspection apparatus 10 of the present embodiment, a mask area is set for designating an area to be excluded from the inspection area for the two-dimensional image formed by the control computer 20.
Specifically, a background portion extracted using a histogram created based on the brightness in each pixel is set as a mask area.

[Foreign matter detection]
The control computer 20 inspects whether or not a foreign substance is contained in an area corresponding to the product G set with the mask area described above.
As a specific detection method, there is a detection method based on a binarization process in which pixels included in an X-ray image are binarized using a predetermined density as a threshold to detect a pixel darker than the predetermined density as a foreign object. It is possible to use a detection method or the like based on a differential process that detects a foreign object by extracting an isolated dark region by taking a difference from the average value of the density of surrounding pixels.

Thereby, the foreign material which exists in the area | region corresponded to articles | goods can be detected.
[Features of the X-ray inspection apparatus 10]
(1)
In the X-ray inspection apparatus 10 of this embodiment, as shown in FIGS. 6A, 6B, and 7, the photodiode 32 and the phosphor 33 are arranged in this order as viewed from the X-ray irradiator 13 side. ing.

  In the conventional X-ray inspection apparatus, in consideration of the necessity of firmly fixing the photodiode to the substrate, as shown in FIG. 9A, the phosphor, A configuration in which photodiodes are arranged in order is common, and a detection result obtained by detecting visible light emitted from a phosphor with a photodiode is transmitted as an electric signal to a control unit or the like. In such a configuration, when a relatively high energy X-ray is irradiated, as shown in FIG. 9B, light is emitted in the deep part of the phosphor to emit visible light. It can be detected in the photodiode relatively efficiently. On the other hand, for example, when a product G having a low density is inspected, low energy X-rays having a wavelength region of about 0.06 nm to 0.01 nm may be irradiated to create an X-ray image with high contrast. is there. In this case, as shown in FIG. 9B, the light emission position in the phosphor is a portion close to the surface layer, so that visible light passes through the phosphor from the light emission position until reaching the photodiode. May be attenuated and scattered, and may not be efficiently detected by the photodiode.

Therefore, in the X-ray inspection apparatus 10 of the present embodiment, the arrangement order of the phosphor 33 and the photodiode 32 is reversed compared to the conventional configuration shown in FIG. That is, as shown in FIG. 6A, FIG. 7 and the like, the X-ray line sensor 14 is configured by arranging the photodiode 32 and the phosphor 33 in this order when viewed from the X-ray irradiator 13 side.
As a result, even when inspection is performed by irradiating low-energy X-rays (first electromagnetic waves), visible light (second electromagnetic waves) emitted in the vicinity of the surface of the phosphor 33 does not pass through the phosphor 33. Since it is detected by the diode 32, attenuation and scattering of visible light before passing through the phosphor 33 can be prevented. Since the visible light emission position on the phosphor 33 and the visible light detection position on the photodiode 32 are close to each other, the transmitted X-rays are incident on a pixel adjacent to the pixel of the photodiode 32 that is supposed to be incident. The occurrence of so-called crosstalk can be prevented. As a result, since X-rays that have passed through the product G can be detected efficiently, the S / N ratio can be improved, and a high-resolution inspection can be performed by creating a high-resolution X-ray image. .

(2)
As shown in FIGS. 6A and 6B, the X-ray inspection apparatus 10 of the present embodiment includes a substrate 31 for fixing a photodiode 32 chip formed of a Si thin film.
Thereby, even when the photodiode 32 is formed of a Si thin film having a thickness of about 0.1 mm, the visible light can be detected in a stable state by being fixed to the substrate 31 so as to be attached. be able to.

Further, in the X-ray inspection apparatus 10 of the present embodiment, the arrangement order of the photodiode and the phosphor is changed as compared with the conventional X-ray detector, but as shown in FIG. By adopting a configuration such as forming the opening 31 a in the substrate 31, the photodiode 32 can be firmly fixed to the substrate 31.
(3)
In the X-ray inspection apparatus 10 of the present embodiment, X-rays are used as electromagnetic waves to be applied to the product G to be inspected.

Thus, by using X-rays generally used for non-destructive inspection, it is easy to use at the time of inspection, and a detector capable of performing high-efficiency detection even when irradiated with low-energy X-rays. Can be provided.
(4)
In the X-ray inspection apparatus 10 of the present embodiment, a phosphor 33 that absorbs X-rays and emits visible light is used as a wavelength conversion unit that converts X-rays as first electromagnetic waves into visible light as second electromagnetic waves. ing.

Thereby, in the phosphor 33, the wavelength of the X-ray (about 0.03 nm) is converted into the wavelength range of visible light (about 420 to 900 nm), and the visible light is detected by the photodiode 32, thereby indirectly. X-ray detection can be performed.
(5)
In the X-ray inspection apparatus 10 of the present embodiment, a photodiode 32 is used as a detection unit that detects visible light as the second electromagnetic wave.

Thereby, the visible light converted from the X-rays in the phosphor 33 as the wavelength conversion unit can be detected in the photodiode 32 arranged so as to be close to the phosphor 33.
(6)
In the X-ray inspection apparatus 10 of the present embodiment, the control computer 20 creates an X-ray image based on the X-ray detection result in the X-ray line sensor 14 and also checks for contamination by foreign matter based on the X-ray image. Do.

As a result, even when the product G is inspected by irradiating low-energy X-rays, high-precision X-ray detection can be performed without reducing the detection efficiency of the photodiode 32. As a result, the S / N ratio is improved, and it becomes possible to create a high-resolution X-ray image and perform a highly accurate inspection.
[Other Embodiments]
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the summary of invention.

(A)
In the embodiment described above, an example using the X-ray line sensor 14 having a configuration in which the photodiode 32 and the phosphor 32 are attached to the lower side of the substrate 31 has been described. However, the present invention is not limited to this.
For example, as shown in FIGS. 8A and 8B, a notch is formed near the center of the substrate 31, and the phosphor 32 is embedded in the notch. You may use the X-ray line sensor (X-ray detector, electromagnetic wave detector) 44 of the structure which affixed the photodiode 32 on it.

Even in this case, the photodiode 32 can be reliably fixed to the substrate 31 while maintaining the positional relationship between the photodiode 32 and the phosphor 33.
(B)
In the said embodiment, while using X-ray as electromagnetic waves, the example which used the X-ray line sensor 14 as an electromagnetic wave detector was given and demonstrated. However, the present invention is not limited to this.

For example, radiation other than X-rays (for example, γ-rays), electron beams, and the like may be used, and an electromagnetic wave detector that detects them may be used. Even in this case, when an inspection is performed by irradiating a low-energy electromagnetic wave, an effect similar to the above can be obtained in which a high-resolution two-dimensional image can be created by efficiently detecting the electromagnetic wave transmitted through the article. be able to.
(C)
In the said embodiment, the scintillator which absorbs an X-ray and emits visible light was given and demonstrated as the wavelength conversion part. However, the present invention is not limited to this.

For example, a wavelength conversion unit that absorbs X-rays to emit infrared rays, or a wavelength conversion unit that converts electromagnetic waves other than X-rays into visible light, infrared rays, or the like may be used. Even in this case, similarly to the above, when an inspection is performed by irradiating a low-energy electromagnetic wave, it is possible to efficiently detect the electromagnetic wave transmitted through the article and create a high-resolution two-dimensional image.
(D)
In the above-described embodiment, the X-ray inspection apparatus 10 has been described by taking an example of inspecting contamination. However, the present invention is not limited to this.

For example, the present invention can also be applied to an inspection apparatus that performs an inspection for confirming the number of articles included in the product G and an inspection of whether or not an article such as an oxygen scavenger exists.
(E)
In the embodiment described above, an example has been described in which a two-dimensional X-ray image is created based on the detection result of the X-ray line sensor 14 and a foreign matter contamination inspection is performed with reference to the X-ray image. However, the present invention is not limited to this.

  For example, various inspections may be performed based on the detection result in the X-ray line sensor 14 without creating an X-ray image.

  The electromagnetic wave detector of the present invention has an effect of efficiently detecting an electromagnetic wave transmitted through an article to be inspected even when an inspection is performed by irradiating a low energy electromagnetic wave. The present invention can be widely applied to various inspection apparatuses that perform inspection.

1 is an external perspective view of an X-ray inspection apparatus according to an embodiment of the present invention. The figure which shows the structure before and behind the X-ray inspection apparatus of FIG. FIG. 2 is a simplified configuration diagram inside a shield box of the X-ray inspection apparatus of FIG. 1. The schematic diagram which shows the principle of the foreign material mixing inspection by the X-ray inspection apparatus of FIG. The control block diagram which shows the structure of the control computer with which the X-ray inspection apparatus of FIG. 1 is provided. (A) And (b) is the perspective view and side sectional view which show the detailed structure of the X-ray line sensor with which the X-ray inspection apparatus of FIG. 1 is mounted. The schematic diagram which shows a state when the X-ray of the low energy in the X-ray line sensor shown in FIG. 6 is detected. (A) And (b) is the perspective view and side sectional view which show the structure of the X-ray detector with which the X-ray inspection apparatus which concerns on other embodiment of this invention is mounted. (A) And (b) is a figure which shows the detection principle of the X-ray in the conventional X-ray detector.

Explanation of symbols

10 X-ray inspection equipment (inspection equipment)
11 Shield Box 11a Opening 12 Conveyor 12a Conveyor Belt 12b Conveyor Frame 12c Opening 12f Conveyor Motor 12g Rotary Encoder 13 X-ray Irradiator (Irradiator)
14 X-ray line sensor (X-ray detector, electromagnetic wave detector)
14a Pixel 15 Photoelectric sensor 16 Shielding nolen 20 Control computer (image creation unit, inspection unit)
21 CPU
22 ROM
23 RAM
24 USB (external connection terminal)
25 CF (Compact Flash: registered trademark)
26 Monitor 31 Substrate 31a Opening 32 Photodiode (detection unit)
32a pixel 33 phosphor (wavelength converter)
44 X-ray line sensor (X-ray detector, electromagnetic wave detector)
60 Pre-stage conveyor 70 Sorting mechanism 70a Arm 80 Line conveyor G Product (article)

Claims (6)

An electromagnetic wave detector for detecting an electromagnetic wave transmitted through the article among the electromagnetic waves irradiated to the article,
An irradiator that irradiates the article with a first electromagnetic wave;
A wavelength converter that converts the first electromagnetic wave transmitted through the article into a second electromagnetic wave having a longer wavelength than the first electromagnetic wave;
Detecting the second electromagnetic wave transmitted through the first electromagnetic wave and converted in the wavelength conversion unit, and a detection unit provided between the irradiator and the wavelength conversion unit;
With
Electromagnetic wave detector. A substrate for fixing the detection unit;
The electromagnetic wave detector according to claim 1. The electromagnetic wave is X-ray.
The electromagnetic wave detector according to claim 1 or 2. The wavelength conversion unit absorbs the X-ray and emits visible light.
The electromagnetic wave detector according to claim 3. The detection unit is a photodiode that detects the visible light.
The electromagnetic wave detector according to claim 4. The electromagnetic wave detector according to any one of claims 1 to 5,
An image creation unit for creating a two-dimensional image based on a detection result in the electromagnetic wave detector;
An inspection unit that inspects the article based on the two-dimensional image created in the image creation unit,
Inspection device.

Images