JPH0396898A - X-ray image detector - Google Patents

Abstract

PURPOSE:To irradiate an image converting element with X rays without being disturbed by an obstacle and to obtain an image of high resolution by placing an X-ray irradiation source on the side on which a reflection conductive layer of the image converting element is provided, and writing an X-ray image in the image converting element by this X-ray irradiation. CONSTITUTION:An object 34 to be inspected is irradiated with X rays from an X-ray radiation source 32 placed on the side on which a metallic thin film electrode 23 of an X-ray image converting element 30 is provided, and the surface of the metallic thin film electrode 23 is irradiated therewith. In such a way, an object X-ray image is written in a single crystal plate 22 of the image converting element 30. A read-out system is placed on the side on which a transparent electrode 26 of the X-ray image converting element 30 is provided. That is, a light source 36, a polarizer 38, a convex lens 42, a beam splitter 40, and a CCD image pickup element 48 of a CCD camera 46 are placed. Therefore, a write part and a read-out part are separated completely, and a structural interference of an X-ray image write system and a read-out optical system is avoided effectively.

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to an X-ray image detector used in the X-ray fluoroscopic inspection of industrial products, the medical field, etc., and in particular, as an X-ray image conversion element. The present invention relates to an X-ray image detector using a single crystal plate that also has a conduction effect.

(Background technology) Conventionally, bismuth silicon oxide (BS○: Bi
+2Sj○2o), bismuth germanium oxide (
Single-crystal plates such as BG○:B\i 12G e○zo), which have both electro-optic and photoconductive effects, can be used as image conversion elements, so-called FROM (Bockels Readout Optical Modulator) elements. A variety of studies have been conducted on the use of this technology in two-dimensional image processing devices, information processing devices, and the like. The basic structure of this FROM element is, as shown in FIG. It has a structure in which electrodes 6, 6 are provided.

Incidentally, a write operation using such a PROM element is normally performed as follows. First, a predetermined voltage is applied from the external power supply 8 between the electrodes 6 and 6 provided on both sides of the BS○ crystal 2, and a uniform electric field is created inside the crystal perpendicular to the crystal plane. An image using blue light (approximately 450 nm) is formed on the surface. B
Since the S○ crystal 2 has a photoconductive effect showing high sensitivity in the blue region, carriers are excited in the crystal according to the amount of writing light. Then, these carriers move within the crystal due to the electric field generated by the applied voltage and reach the insulating layer 4,
Forms a charge distribution corresponding to the writing light amount and distribution. In the area where these carriers exist, the electric field created by the carriers reduces the electric field inside the crystal, creating an electric field distribution corresponding to the writing light amount distribution, which is recorded in the BS○ crystal 2. .

On the other hand, the readout operation of images recorded in this way is performed by the BS
This is done by utilizing the electro-optic effect of the O crystal 2. That is, the BSO crystal 2 has birefringence proportional to the electric field strength inside the crystal due to the electro-optic effect. Further, the directions of the two principal axes of the refractive index ellipsoid are perpendicular to the direction of the electric field. Therefore, as shown in FIG. 2, a red color (6
When linearly polarized light with a diameter of about 0.0 nm) is made incident on the PROM element 12 having the structure as shown in FIG. 1 as read light,
Depending on the local electric field within the BSO crystal 2 of the PROM element 12, the read light becomes elliptically polarized light.

Note that since the photoconductive effect of the BSO crystal 2 has no sensitivity in the red region, the recorded information is not destroyed by the readout light irradiation. By placing a polarizing plate (analyzer) 14 orthogonal to the input side polarizing plate 10 on the output side, it is possible to obtain a readout light intensity corresponding to the ellipticity of the elliptically polarized light, thereby reducing the FR
The input image recorded on the OM element 12 can be read out.

Note that the image recorded on the BSO crystal 2 of the PROM element 12 is erased by irradiating the entire surface of the BS○ crystal 2 with strong blue light. Further, the FROM element 12 may be constructed using a BGO crystal or the like in addition to the BS○ crystal, and has the same function as described above.

On the other hand, a method is known in which X-rays are used as writing light for input images of such FROM elements (M. Graser.
Jr. et. al. “Appl. Phys.
．． Lett. J. 34(8). 15. Aprj
(1979)) - Similar to the blue light mentioned above, single crystals such as BS○ have a highly sensitive photoconductive effect for X-rays, so even if it is an X-ray image, This is because the writing can be done. This technique employs the same element structure as in FIG. 1, except that X-rays are used as the writing light, and the method of reading out the image after recording the image information is also the same.

However, the previously proposed X-ray image detection method using FROM elements has many practical problems and has not yet been put into practical use.One of the major reasons for this is that the optical system Resolution may be limited due to structure.

In other words, such conventional X-ray image detection systems employ an optical system structure in which the readout light passes through the FROM element. It has to be placed on the same side as one of the detectors, and therefore these optical devices block the X-rays, making it impossible to irradiate the χ-rays from the front of the FROM element. In addition, the object to be inspected is
If placed in contact with the R○M element, the readout light will be blocked, so the distance between the FROM element and the object to be inspected must be set to such an extent that the readout light is not blocked. Moreover, unlike visible light, it is impossible to form an X-ray image using an optical system. For these reasons, with the conventional X-ray image detection method, it is difficult to write a clear X-ray image to the FROM element, and the FR
The "blur" of the X-ray image was greater than the resolution performance of the OM element, and the performance of the FROM element was not fully utilized.

(Problem to be solved) The present invention has been made against this background, and the problem to be solved is to irradiate the FROM element with X-rays without being blocked by obstacles. The object of the present invention is to provide an X-ray image detector that can obtain high-resolution images by making it possible to read out images.

(Solution Means) In order to solve the above-mentioned problems, the present invention has the following features:
A single crystal plate having an electro-optic effect and a photoconductive effect, a reflective conductive layer provided on one side of the single crystal plate that reflects light but can transmit X-rays, and the other side of the single crystal plate. an insulating layer that can transmit light and is provided on the surface of the insulating layer, and a transparent layer that is provided on the insulating layer and applies a predetermined electric field to the insulating layer and the single crystal plate in cooperation with the reflective conductive layer. X having a conductive layer
In an X-ray image detector using a radiation image conversion element, an X-ray irradiation source is disposed on the side of the image conversion element on which the reflective conductive layer is provided, and X-ray irradiation from the X-ray irradiation source While allowing an X-ray image to be written on the image conversion element, on the side of the image conversion element on which the transparent conductive layer is provided,
A light source that irradiates the image conversion element with a predetermined readout light and an optical system that forms an image of the readout light reflected from the image conversion element are arranged, The gist of the present invention is an X-ray image detector characterized in that the X-ray image is read out using the light source and the optical system.

In addition, in such an X-ray image detector, advantageously, a reflecting mirror is disposed in the optical path of the optical system, so that the direction of X-ray irradiation from the X-ray irradiation source and the optical axis of the imaging system are perpendicular to each other. Alternatively, a medium may be arranged in the optical path of the optical system to block X-rays while allowing readout light to pass through.

Further, in one embodiment of the X-ray image detector according to the present invention, a plurality of the image conversion elements are used, and
The writing position of the X-ray image by the radiation source, the reading position of the XwA image by the light source and the optical system, and the erasing position of the X-ray image are made different, and by moving these image conversion elements, the writing position, the A structure is adopted in which the reading position and the erasing position are sequentially arranged.

q 10 Furthermore, in the present invention, a surface emitting light source may be used as the light source, or a structure may be adopted in which the optical system is provided with a lens means for changing the viewing range of the read image.

Furthermore, in the present invention, controlling the amount of X-ray irradiation,
In order to obtain an X-ray image detector capable of setting an optimal irradiation dose and obtaining a clear image, it is advantageous to use (a) X-ray measurement to measure the X-ray illumination dose from the X-ray irradiation source; means, and X,%I measured by the X-ray measuring means;! A configuration further includes an X-ray irradiation control device that controls the χ-ray irradiation time by the X-ray irradiation source based on the irradiation dose; (b) a light measurement means that measures the intensity of the readout light from the light source; A configuration is adopted in which the apparatus further includes an X-ray irradiation control device that controls the X-ray irradiation time by the X-ray irradiation source based on the readout light intensity measured by the optical measurement means.

(Specific Structure/Examples) Hereinafter, the configuration of the present invention will be explained in more detail based on the examples shown in the drawings.

First, FIG. 3 shows an X-ray image detector according to the present invention. This shows an example of the X-ray image conversion element used, in which 22 is a single crystal plate having an electro-optic effect and a photoconductive effect, for example, bismuth silicon oxide (B i +zS i 020). It is made of a known single-crystal material such as bismuth germanium oxide (Bi, GeOzo) or the like.

Note that this single crystal plate 22 generally has a thickness of about 10 μm to 5 μm, and both surfaces thereof are polished according to a known appropriate method.

Then, for one surface of such a single crystal plate 22,
The metal thin film electrode 23 as a reflective conductive layer according to the present invention is
It is defined by a predetermined thickness, in other words, a thickness that reflects light but allows X-rays to pass through. As the material for the metal thin film electrode 23, conductive materials with excellent X-ray transmittance, such as gold, silver, platinum, aluminum, and metallic beryllium, are preferably used. Further, the film thickness of the metal thin film electrode 23 is made sufficiently thin so that it can transmit X-rays, and is generally 1 μm thick.
This makes it possible to write an X-ray image from the side of the metal thin film electrode 23, but the reading light is reflected on the surface of the metal thin film electrode 23. Therefore, a reflective readout optical system can be used, and the readout light source and the imaging part can be positioned on the same side with the X-ray image conversion element in the center, thereby completely separating the writing part and the reading part. It is possible to separate it into two parts.

Note that on the other surface of the single crystal plate 22, which is the side on which this readout optical system is provided, an insulating layer 24 that can transmit light is provided, as in the conventional FROM element, and furthermore, indium oxide is formed on the insulating layer 24 that can transmit light. A transparent electrode (conductive layer) 26 made of a known transparent conductive material such as the like is used. By applying a voltage (for example, about 0 to 30 KV) from an external power source 28 between the transparent electrode 26 and the metal thin film electrode 23, a predetermined electric field is applied to the single crystal plate 22 and the insulating layer 24. can be added.

By the way, the insulating layer 2 provided on the single crystal plate 22
4 can be formed of a known organic insulator such as polyparaxylene or polystyrene, or an inorganic insulator such as glass or mineral.

In addition, regarding the shape of the transparent electrode 26 that applies a predetermined electric field to the single crystal plate 22 and the insulating layer 24, a method similar to the conventional method is adopted. A method of directly forming a transparent electrode, or a method of forming a transparent electrode plate in which a transparent electrode layer is provided on a predetermined plate such as glass, etc.
A method of pasting it onto the insulating layer 24 using a suitable optical adhesive may be adopted as appropriate.

The present invention uses an X-ray image conversion element having such a configuration to construct a device (X-ray image detector) that writes and reads images. An X-ray source (X-ray irradiation source) is placed on one side of the X-ray image conversion element, and a readout system is placed on the other side of the X-ray image conversion element.

That is, as shown in FIG. 4, the X-ray source 32 is placed on the side where the metal thin film electrode 23 of the X-ray image conversion element 30 is provided.
is arranged, and the object to be inspected 34 is irradiated with X-rays from this X-ray source 32 or 13 14, thereby producing X-rays having image information to be recorded; The light is irradiated onto the surface of the metal thin film electrode 23 of the image conversion element 30 on the shape-sensitive side.

As a result, the desired X-ray image is written on the single crystal plate 22 of the image conversion element 30.

On the other hand, the readout optical system is arranged on the other side of the X-ray image conversion element 30, in other words, on the side where the transparent electrode 26 is provided, and there, a predetermined readout light, that is, has a photoconductive effect. Therefore, a light source 36 for irradiating the X-ray image conversion element 30 with light that does not destroy written information, such as red light, a polarizer 38, and a polarizer 38,
A convex lens 42 for irradiating the light perpendicular to 0 and forming an image of the reflected readout light, a beam sprick 40 for separating the irradiation light and the reflected light, and a light intensity corresponding to the ellipticity of the elliptically polarized light of the readout light. an analyzer 44 for obtaining the reading light, and a light receiving means for receiving the read light transmitted through the analyzer 44.
A CCD image sensor 48 of a CCD camera 46 is arranged. Here, the beam splinter 40 can be replaced by a half beam splitter, and the polarizer 38, beam splinter 40, and analyzer 44 can also be replaced by a PBS (bolarized beam splitter).

Therefore, in an X-ray image detector with such a structure,
The X-ray image is written on one side of the X-ray image conversion element 30, while the X-ray image written on the X-ray image conversion element 30 is written on the other side of the X-ray image conversion element 30. Therefore, the writing section and the reading section are completely separated, so that structural interference between the X-ray image writing system and the reading optical system can be effectively avoided, and thereby, Object to be inspected (3
4) Advantageously obtain a clear X-ray image by irradiating the X-ray from the front with the X-ray as close as possible to the X-ray image conversion element 30 and writing the X-ray image. This made it possible to obtain an X-ray image detector with a high resolution of 15 16 that can sufficiently identify even a fine metal wire of, for example, about 25 μm.

Further, a fifth example showing another example of the X-ray image detector according to the present invention is also provided.
In the figure, a reflecting mirror 50 is disposed in the optical path of the reading optical system, and the reading light reflected by the metal thin film electrode 23 of the X-ray image conversion element 30 is reflected by the reflecting mirror 50 from the X-ray source 32. Line irradiation direction (vertical direction in the figure)
This makes the direction of X-ray irradiation and the optical axis of the imaging system perpendicular, and the X-rays are reflected in the direction perpendicular to the imaging device part (46, 48). There is no noise caused by X-rays.
This makes it possible to advantageously extract good images.

However, when an electronic component is irradiated with X-rays, the high-energy X-ray photons will excite charges inside the semiconductor, adversely affecting the component, and in the worst case, leading to destruction. Even in the case of the target X-ray image detector, when a CCD camera, image pickup tube, etc. is used to detect the readout image, the same is true; when the camera, etc. is irradiated with X-rays, the image signal is This is because noise will be added to the image and the image on the monitor will become distorted.

Furthermore, in order to better prevent noise from entering the readout image due to such X-ray irradiation, a shielding plate 52 such as a lead plate is placed between the X-ray source 32 and the readout optical system, as shown in the figure. It is desirable that the X-rays from the X-rays a32 not reach the CCD camera 46, its imaging device 48, etc.

In the X-ray image detector shown in FIG. 5, readout light is incident on the beam sprick 40 from a light source (36) arranged perpendicular to the plane of the drawing through a polarizer (38). Further, from this beam splinter 40, the light is made to enter the side of the X-ray image conversion element 30 on which the transparent electrode 26 is provided via a convex lens 42 and a reflecting mirror 50. Further, as described above, the readout light reflected from the X-ray image conversion element 30 is reflected by the reflecting mirror 50, and then passes through the convex lens 42, the beam splitter 40, and the analyzer 44, and is then detected by the CCD camera 46. The light is received by the CCD image sensor 48.

Furthermore, in order to eliminate noise from being mixed into the readout image due to such X-ray illumination, there is a method in which the optical axis of the imaging system does not coincide with the X-ray irradiation direction by providing a reflecting mirror 50 as in the above example. In addition, a medium that blocks X-rays but allows readout light to pass through, such as lead glass, is placed closer to the X-ray image conversion element 30 than the imaging device part (46, 48), for example, in FIG. If it is placed between the CCD image sensor 48 and the χ-ray irradiation direction and the optical axis of the imaging system, it is possible to obtain a good image without noise due to χ-rays even if the χ-ray irradiation direction and the optical axis of the imaging system coincide. It is.

By the way, the X-ray image conversion element cannot output images in real time because images are written and read out alternately. To approach quasi-real-time operation, it is possible to shorten the writing, reading, and erasing cycles, but the voltage applied to the image conversion element is usually as high as several kilovolts, and the speed cannot be increased easily.

Furthermore, since the writing speed and erasing speed are determined by the physical properties of the crystal plate (BSO, etc.) of the image conversion element, it is impossible to increase the speed beyond a certain limit.

Therefore, in the X-ray image detector according to the present invention, a plurality of X-ray image conversion elements 30 are used as shown in FIG. 6 in order to shorten the image readout cycle compared to the conventional one.
By placing them on the rotary table 54 and rotating them, a shift arrangement is adopted in which writing, reading, and erasing operations are performed on each element 30 in parallel. In short, while using a plurality of X-ray image conversion elements 30, the writing position of the X-ray image by the X-ray m (32), the light source (36) and the optical system (3B40, 42.4)
4, 46, and 48), and the X-ray image conversion elements 30 are sequentially moved so that they are sequentially arranged at the writing position and the reading position. Further, after the X-ray image conversion element 30 has been read out, the recorded image is sequentially irradiated with blue light to erase the recorded image 19 20 .

In addition, in the case of an X-ray image detector, when a readout image is detected by the camera (46) and displayed on the monitor screen, the resolution of the final image is limited by the number of pixels of the monitor screen, so it is very effective. Even if an image conversion element with a high area and high resolution is manufactured, it is not possible to observe all the pixels on a monitor screen at once, but as shown in Figs. By providing a lens means that changes the field of view, it becomes possible to read out the entire image or a partially enlarged image depending on the purpose. In addition, in the example shown in FIG. 7,
A field lens 5 is provided between the analyzer 44 and the CCD image sensor 48.
6 is arranged, and a readout image is captured by an imaging system made up of two lenses consisting of the field lens 56 and the convex lens 42. By changing the focal length and position of the field lens 56, The image readout range and magnification ratio can be easily changed. This field lens 56
For example, as shown in FIG.
This can be done by attaching the lens holder 58 and rotating the lens holder 58.

Further, in the X-ray box image detector according to the present invention shown in FIG. 9, a surface emitting light source 60 is used as a light source of the readout optical system.
This makes the optical system compact and simple, thereby making it possible to downsize the entire X-ray image detector. In the reflective image conversion element 30, the readout light is collimated, and therefore, the state in which the read light is perpendicularly incident on the image conversion element 30 is most efficient in terms of light intensity, and a bright image can be formed. .

On the other hand, when attempting to irradiate a large area using a single light source in order to eliminate unevenness in image brightness, the distance between the light source and the image conversion element increases, and the X-ray image detector This becomes a factor that hinders miniaturization. Note that as the surface-emitting light source 60, a surface-emitting LED, a surface-emitting fluorescent lamp, an electroluminescent element (EL) light emitter, or the like is used.

21 22 In addition, the X-ray image detector that shapes the X-ray image based on the difference in the amount of transmitted X-ray light from the object to be inspected (34) has good gradation expression and a wide dynamic range. However, the dynamic range of current image conversion elements is relatively narrow at about 15 dB, so depending on the X-ray irradiation conditions, it is easy to become unexposed or overexposed.
However, by providing a control system for controlling the chi-ray irradiation amount, as shown in FIG. 10, a clear image can be advantageously obtained.

That is, in FIG. 10, the light separated by a half mirror 62 arranged in the optical path of the imaging system of the readout light is focused by a convex lens 64, and the light intensity is measured by an optical measuring device such as a photomultiplier or a photodiode. 66 , and based on the readout light intensity measured by the optical measuring device 66 , the X-ray illumination control device 68 estimates the writing amount, determines the optimal X-ray irradiation conditions, and This allows the X-ray irradiation time to be controlled.

Further, instead of measuring the readout light intensity, it is also possible to measure the X-ray irradiation dose from the chi-ray source 32 and control the X-ray irradiation time based on the measurement. That is, the X-ray irradiation dose from the X-ray source 32 is measured by an X-ray dosimeter 70 such as an ion chamber dosimeter, a scintillation detector, or a semiconductor detector arranged on the side of the X-ray image conversion element 30. Based on the measured value, the X-ray irradiation time by the X-ray source 32 is controlled in the X-ray irradiation control device 68.

Although the specific configuration of the present invention has been described in detail based on some preferred embodiments according to the present invention, the present invention is not limited in any way by such embodiments or specific explanations based on them. The present invention may be implemented in forms with various changes, modifications, improvements, etc. based on the knowledge of those skilled in the art, without departing from the spirit of the present invention.
It should be understood that such embodiments are also included.

(Effects of the Invention) As is clear from the above description, in the X-ray image detector according to the present invention, the X-ray source and the readout optical system are arranged on opposite sides of the X-ray image conversion element. Because the writing part and the reading part can be completely separated from each other, the object to be inspected can be brought as close as possible to the recording surface of the image conversion element and X-rays can be irradiated from the front. It is possible to obtain high resolution images with 25μ
This makes it possible to create an X-ray image detector that can sufficiently identify metal wires as small as 100 m.

Further, in the present invention, the optical path of the readout optical system of the X-ray image detector may be configured so that the X-ray illumination direction and the optical axis of the imaging system are perpendicular to each other through a reflecting mirror. By arranging a medium that shields χ rays and shielding the imaging device portion from X-rays, it is also possible to obtain good images with less noise caused by X-rays.

Furthermore, in the X-ray image detector according to the present invention, a plurality of image conversion elements are used, and the image conversion elements are sequentially moved to perform operations such as writing and reading on each element in parallel. This has the advantage of shortening the writing/reading time for one screen, making it possible to obtain continuous images as close to real-time operation as possible, and adding lens means for changing the field of view of the readout image to the readout optical system. By providing a It has also become possible to use it as a line image detector.

Furthermore, if the light source of the readout optical system is a surface emitting light source,
The optical system of the readout light is simplified, and the size of the X-ray image detector can be advantageously reduced.Furthermore, by providing a control system to control the amount of chi-ray irradiation, By setting the optimum amount of X-ray irradiation, clear images can be easily obtained.

[Brief explanation of drawings]

25 26 FIG. 1 is a schematic explanatory diagram of a conventional X-ray image conversion element, and FIG. 2 is a schematic explanatory diagram of a conventional X-ray image detector using such an image conversion element. FIG. 3 is a schematic explanatory diagram showing an example of an X-ray image conversion element used in the present invention, and FIG. 4 is an X-ray image detector according to the present invention using such an X-ray image conversion element. It is an explanatory diagram of an arrangement form showing an example. Further, FIG. 5, FIG. 7, FIG. 9, and FIG. 10 are explanatory diagrams of arrangement forms showing other different examples of the X-ray image detector according to the present invention, and further, FIG. FIG. 8 is an explanatory diagram showing writing, reading, and erasing operations for a plurality of X-ray image conversion elements provided on a table;
The figure is an explanatory diagram showing a lens holder to which a plurality of field lenses are attached. 22: Single crystal plate 23: Metal thin film electrode 24: Insulating layer 26: Transparent electrode 28: Power source 30: X-ray image conversion element 27: X-ray source; Light source: Beam spur: Convex lens, 2 CCD cameras, 2 reflecting mirrors, 2 rotating tables : Lens holder: Half mirror: Light measuring device = X-ray dosimeter 34: Inspected object 38; Polarizer vine 44: 48: 52: 56; 60: 64: 68: Analyzer CCD image pickup element shielding plate field of view lens surface emission Light source convex lens X-ray irradiation control device

Claims (8)

[Claims] (1) A single crystal plate having an electro-optic effect and a photoconductive effect,
provided on one side of the single crystal plate, which reflects light;
a reflective conductive layer through which X-rays can pass; an insulating layer through which light can pass, provided on the other surface of the single crystal plate; An X-ray image detector using an X-ray image conversion element having a transparent conductive layer that applies a predetermined electric field in cooperation with the reflective conductive layer, wherein the reflective conductive layer of the image conversion element is provided. X on the side
A radiation source is disposed so that an X-ray image is written on the image conversion element by X-ray radiation from the X-ray radiation source, while a side of the image conversion element on which the transparent conductive layer is provided is provided with an X-ray image. , a light source that irradiates the image conversion element with predetermined readout light, and an optical system that forms an image of the readout light reflected from the image conversion element. An X-ray image detector, characterized in that said X-ray image is read out by said light source and optical system. (2) A reflecting mirror is disposed in the optical path of the optical system so that the direction of X-ray irradiation from the X-ray irradiation source and the optical axis of the imaging system are perpendicular to each other. 1) The X-ray image detector described above. (3) The X-ray image detector according to claim (1), characterized in that a medium is disposed in the optical path of the optical system to block X-rays while allowing readout light to pass therethrough. (4) While using a plurality of the image conversion elements,
differentiating the writing position of the X-ray image by the radiation source, the reading position of the X-ray image by the light source and the optical system, and the erasing position of the X-ray image, and moving these image conversion elements;
Claims (1) to (3) characterized in that the writing position, the reading position, and the erasing position are sequentially arranged.
The X-ray image detector according to any one of the above. (5) The X-ray image detector according to any one of claims (1) to (4), characterized in that the optical system is provided with a lens means for changing the field of view of the readout image. (6) Claims (1) to (1) wherein the light source is a surface emitting light source.
The X-ray image detector according to any one of 5). (7) X for measuring the X-ray irradiation dose from the X-ray irradiation source
It is characterized by further comprising a radiation measuring means and an X-ray irradiation control device that controls the X-ray irradiation time by the X-ray irradiation source based on the X-ray irradiation dose measured by the X-ray measuring means. The X-ray image detector according to any one of claims (1) to (6). (8) A light measuring means for measuring the intensity of the readout light from the light source, and an X for controlling the X-ray irradiation time by the X-ray irradiation source based on the readout light intensity measured by the light measuring means.
The X-ray image detector according to claim 1, further comprising a radiation irradiation control device.