JP2001349947A - Solid radial ray detector, and method and device for recording and reading radial ray image using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve both high speed responsiveness of reading and reading efficiency in a radial ray image information recording and reading device using a solid radial ray detector. SOLUTION: In the detector 20 comprising, by laminating, a first electrode layer 21, a photoconductive layer 22 for recording which provides conductivity by receiving radiation of recording light, a charge transport layer 23 which acts roughly as insulation to latent image charges, and which acts roughly as conductor to transport charges of the opposite polarity to the latent image charges, a photoconductive layer 24 for reading which provides conductivity by receiving radiation of reading light, and an electrode layer 25 having a stripe electrode 26, a subsidiary electrode 27 comprising a number of elements 27a is provided in the electrode layer 25, and each element 27a of the subsidiary electrode 27 is disposed alternately with an element 26a in the stripe electrode 26 to be roughly parallel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-state radiation detector having a power storage unit for accumulating an amount of electric charge corresponding to the dose of irradiated radiation as a latent image charge, and to use the detector to generate radiation image information. The present invention relates to a method and an apparatus for recording an image as an electrostatic latent image and reading the recorded electrostatic latent image.

[0002]

2. Description of the Related Art Conventionally, in medical radiography and the like, radiation having a photoconductor such as a selenium plate or the like sensitive to radiation such as X-rays has been used in order to reduce the exposure dose received by a subject and improve diagnostic performance. By using a solid state detector (electrostatic recording medium) as a photoreceptor, irradiating the detector with X-rays, and accumulating an amount of charge corresponding to the dose of the irradiated radiation in a power storage unit in the detector, A method is known in which radiation image information is recorded as an electrostatic latent image, and the radiation image information is read from the detector by scanning a detector on which the radiation image information is recorded with a laser beam or a line light source ( For example, U.S. Pat. No. 4,535,468).

The method according to US Pat. No. 4,535,468 is:
A detector having a three-layer structure including an X-ray photoconductive layer, a charge storage layer (also referred to as an intermediate layer or a trap layer) for storing charges generated in the X-ray photoconductive layer, and a reading photoconductive layer in this order is used. During recording, a high voltage is applied between the electrodes provided on both sides of the three layers during recording to irradiate X-rays to accumulate latent image charges in the charge accumulation layer, and then short-circuit the electrodes to form a latent image. The charge is read. In this method, the reading speed is increased and the responsiveness is improved by making the reading photoconductive layer of the detector thinner than the X-ray photoconductive layer.

[0004]

However, in the method according to the above-mentioned U.S. Pat. No. 4,535,468, since the photoconductive layer for reading is made thinner than the X-ray photoconductive layer, the amount of signal charges detected outside is small. There is a problem. Further, the charge storage layer cannot be made thick because both the electron and the hole have low charge mobilities. This is because if the film thickness is increased, the response becomes slow or an afterimage occurs. On the other hand, when the film thickness is small, the amount of charge that can be stored decreases. That is, it is difficult to achieve both high-speed readout response and efficient signal charge extraction.

On the other hand, the applicant of the present invention has disclosed in Japanese Patent Application Nos. 10-232824 and 10-271374 a solid-state radiation detector capable of achieving both high-speed readout response and efficient signal charge extraction. And a recording apparatus for recording radiation image information on the detector and a reading method and apparatus for reading radiation image information from the detector on which the radiation image information is recorded as an electrostatic latent image.

The method described in Japanese Patent Application No. 10-232824 discloses a recording photoconductive layer which exhibits conductivity when irradiated with recording radiation or light emitted by the excitation of this radiation, a latent image charge. A charge transporting layer that acts as a substantially insulator and acts substantially as a conductor with respect to transport charges having a polarity opposite to that of the latent image charges, and exhibits electrical conductivity when irradiated with electromagnetic waves for reading. Using a solid-state radiation detector having a reading photoconductive layer in this order, irradiating the recording photoconductive layer side of the detector with recording radiation, and an amount of charge corresponding to the irradiated radiation dose. Is stored in a power storage unit formed substantially at the interface between the recording photoconductive layer and the charge transport layer, thereby recording radiation image information as an electrostatic latent image, reading out the recorded electrostatic latent image, and reading the radiation image. Get information.

The present invention relates to the above-mentioned Japanese Patent Application No.
As with the detector and the recording device and the reading device proposed in Japanese Patent Application No. 232824 and the like, the object is to achieve both high-speed readout response and efficient extraction of signal charges. No. 10-232824, a solid-state radiation detector capable of further enhancing its performance, a method and apparatus for recording radiation image information on this detector, and radiation from the detector on which the radiation image information is recorded It is an object to provide a method and an apparatus for reading image information.

[0008]

A first solid-state radiation detector according to the present invention is disclosed in Japanese Patent Application Nos. 10-232824 and 10-2713.
What further improves the detector etc. described in No. 74,
That is, in a solid-state radiation detector that records radiation image information as an electrostatic latent image by irradiating radiation, a first electrode layer that is permeable to recording radiation or light emitted by the excitation of the radiation. A recording photoconductive layer that exhibits conductivity by receiving the radiation or the light, a power storage unit that accumulates an amount of charge corresponding to the dose of the irradiated radiation as a latent image charge, and irradiation with an electromagnetic wave for reading. A reading photoconductive layer exhibiting conductivity by receiving, and a second electrode layer to be irradiated with a reading electromagnetic wave, in this order, the second electrode layer is irradiated with the reading electromagnetic wave. A first stripe electrode composed of a large number of linear electrodes for generating photocharge pairs, and a second stripe electrode composed of a large number of linear electrodes for non-generation of photocharges against electromagnetic waves for reading, 1st stripe It is characterized in that the poles and the second stripe electrode is formed by substantially parallel arranged alternately.

A second solid-state radiation detector according to the present invention is a solid-state radiation detector for recording radiation image information as an electrostatic latent image by irradiating radiation, the radiation for recording or the light emitted by excitation of radiation. A first electrode layer that is permeable to light, a recording radiation or a recording photoconductive layer that exhibits electrical conductivity when irradiated with the light, and a latent charge having an amount corresponding to the dose of the irradiated radiation. A power storage unit that accumulates as image charge, a reading photoconductive layer that exhibits conductivity by being irradiated with the reading electromagnetic wave, and a second electrode layer that is irradiated with the reading electromagnetic wave, in this order, The second electrode layer includes a first stripe electrode composed of a large number of linear electrodes having transparency with respect to irradiation of reading electromagnetic waves, and a second stripe electrode having light shielding properties with respect to reading electromagnetic waves. Yes And it is characterized in that the first stripe electrode and the second stripe electrode is formed by substantially parallel arranged alternately.

Here, the above-mentioned "linear electrode" means an electrode having an elongated shape as a whole, as long as it has an elongated shape, any electrode such as a cylindrical electrode or a prismatic electrode can be used. However, a plate electrode is particularly preferable.

In the solid-state radiation detector, the second stripe electrode may be coated with a metal of Al or Cr.

Also, one pixel line of the solid-state radiation detector can be composed of one first stripe electrode and a second stripe electrode adjacent to the one first stripe electrode.

Further, one pixel line of the solid-state radiation detector may be composed of a plurality of first stripe electrodes and a second stripe electrode adjacent to each of the plurality of first stripe electrodes.

The power storage unit has a conductive member extending on the first stripe electrode and the second stripe electrode and provided separately for each pixel of the solid-state radiation detector, and is stored by the conductive member. Latent image charge can be maintained at the same potential.

Here, the above "provided for each pixel"
Means that each pixel is preferably provided with one conductive member so that the latent image charges are made to have the same potential and the charges in the peripheral portion of the pixel can be moved to the central portion of the pixel during reading. This does not include a configuration in which a large number of conductive members are randomly arranged for one pixel, and charges in the peripheral portion of the pixel cannot be moved to the central portion of the pixel during reading.

[0016] Further, the expression "separately" means that each conductive member is disposed in a discrete state, that is, in a floating state in which it is not connected to other pixels. Note that when a plurality of conductive members are provided for one pixel, it is preferable to electrically connect members for one pixel.

It is preferable that the size of the conductive member is set to be substantially the same as the pixel pitch. Alternatively, the latent image charges may be concentrated at the pixel central portion by setting the pixel pitch to be smaller than the pixel pitch, for example, 以下 or less, and by disposing the latent image charge at the pixel central portion. The size of the conductive member is, for example, the diameter in the case of a circular conductive member, and the length of each side in the case of a rectangular conductive member.
In addition, the shape of the conductive member may be any shape such as a circle and a square.

The charge transport layer, which acts substantially as an insulator with respect to the latent image charge, and acts substantially as a conductor with respect to the charge of the opposite polarity to the latent image charge, is formed as a recording photoconductive layer. It can be provided between the reading photoconductive layer and the power storage unit at the interface between the charge transport layer and the reading photoconductive layer.

Further, a trap layer for capturing the latent image charge is
It may be provided between the recording photoconductive layer and the reading photoconductive layer, and the power storage unit may be formed in the trap layer or at the interface between the trap layer and the recording photoconductive layer. Out.

Further, the width of the second stripe electrode can be wider than the width of the first stripe electrode.

Further, in the first radiation image recording method according to the present invention, the radiation solid state detector is irradiated with radiation, and an electric charge corresponding to the dose of the irradiated radiation is stored in a power storage unit of the radiation solid state detector. By accumulating as image charge,
In a radiation image recording method for recording radiation image information as an electrostatic latent image in a power storage unit, the first stripe electrode and the second stripe electrode are set to substantially the same potential, and the first electrode layer and the second electrode layer are The recording is performed by applying a DC voltage during the recording.

Further, in the second radiation image recording method according to the present invention, the radiation solid state detector is irradiated with radiation, and a charge of an amount corresponding to the dose of the irradiated radiation is stored in a power storage unit of the radiation solid state detector. By accumulating as image charge,
In a radiographic image recording method of recording radiographic image information as an electrostatic latent image in a power storage unit, a second stripe electrode is opened, and a DC voltage is applied between the first stripe electrode and the first electrode layer. It is characterized by recording.

Further, in the third radiation image recording method according to the present invention, the radiation solid state detector is irradiated with radiation, and an electric charge of an amount corresponding to the dose of the irradiated radiation is stored in a power storage unit of the radiation solid state detector. By accumulating as image charge,
In a radiation image recording method for recording radiation image information as an electrostatic latent image on a power storage unit, a direct current voltage is applied between a first stripe electrode and a first electrode layer, and the first stripe electrode is applied by applying the direct current voltage. The recording is performed by applying a control voltage for adjusting an electric field distribution formed between the first and second electrode layers to the second stripe electrode.

Here, in the first to third radiographic image recording methods, the above-mentioned “irradiating the radioactive solid state detector with radiation” means that recording radiation that carries radiographic image information of a subject is applied to the detector. Direct or indirect irradiation, not limited to direct irradiation of recording radiation to the detector, for example, scintillator (fluorescent material)
Irradiating the detector with light emitted by the excitation of the recording radiation, such as fluorescence emitted in the scintillator.

In the third radiation image recording method, the "control voltage" is a voltage having a magnitude that the second stripe electrode has a predetermined influence on a latent image charge accumulation process during recording. For example, the size can be made to be substantially the same as the electric field distribution to be formed when the second stripe electrode is not provided.

Also, by positively approaching, moving away from, or keeping the potential of the second electrode layer the same, it is possible to change the region where the latent image charge is formed.
This makes it possible to improve the signal extraction efficiency and the signal read response speed.

This control voltage may be a DC voltage,
It may be an AC voltage. The AC voltage is not limited to the sine wave voltage, and may have any waveform as long as it can improve the signal extraction efficiency and the signal read response speed as described above.

Further, according to the radiation image reading method of the present invention, in the radiation image reading method of reading radiation image information from the radiation solid state detector, the first stripe electrode and the second stripe electrode are made to have substantially the same potential, and By irradiating the second electrode layer with an electromagnetic wave, an electric signal having a level corresponding to the amount of the latent image charge stored in the power storage unit is obtained.

Here, the “electromagnetic wave for reading” may be a continuous wave emitted continuously or a pulse wave emitted in a pulse shape, but the pulse wave is more preferable. Since a large current can be detected and even a pixel having a small amount of latent image charge can be detected as a sufficiently large current, the S / N of an image can be dramatically improved. It is advantageous.

When a detector provided with the above-mentioned "conductive member" is used, the latent image charge is concentrated on the conductive member and the latent image charge is accumulated. It is preferable to irradiate a reading electromagnetic wave to the reading photoconductive layer corresponding to. In this reading, the conductive member may be left open.

Further, the radiation image recording apparatus according to the present invention is an apparatus for realizing the first or third radiation image recording method, wherein a direct current voltage is applied between the first electrode layer and the first stripe electrode. A voltage applying means for applying voltage, and a control voltage applying means for applying a control voltage for adjusting an electric field distribution formed between both electrode layers to a second stripe electrode by a DC voltage applied by the voltage applying means. It is characterized by being.

The radiation image recording apparatus according to the present invention is an apparatus for realizing the second radiation image recording method, wherein a voltage for applying a DC voltage between the first electrode layer and the first stripe electrode is provided. And a switching means for opening the second stripe electrode for adjusting an electric field distribution formed between the two electrode layers by a DC voltage applied by the voltage applying means. It is.

The radiation image reading apparatus according to the present invention is an apparatus for realizing the above radiation image reading method,
By causing the first stripe electrode and the second stripe electrode to have substantially the same potential, and irradiating the second electrode layer with an electromagnetic wave for reading, the level of electricity corresponding to the amount of latent image charges stored in the power storage unit is obtained. An image signal obtaining means for obtaining a signal is provided.

Further, in the above radiation image reading apparatus, the image signal obtaining means may be connected to the first stripe electrode.

[0035]

According to the solid-state radiation detector of the present invention, the second electrode layer is formed of a first stripe electrode composed of a large number of linear electrodes for generating photocharge pairs in response to irradiation of electromagnetic waves for reading. A second stripe electrode composed of a large number of linear electrodes for generating no photocharge with respect to the electromagnetic wave for reading, and the first stripe electrodes and the second stripe electrodes are alternately arranged substantially in parallel. Therefore, a new capacitor can be formed between the power storage unit formed between the recording photoconductive layer and the read photoconductive layer and the second stripe electrode. The transport charges having the opposite polarity to the accumulated latent image charges can also be charged to the second stripe electrode by charge rearrangement at the time of reading, and the second stripe electrode can be charged via the reading photoconductive layer. Between the first stripe electrode and the power storage unit The amount of the transport charge distributed to the capacitor formed by the above can be relatively reduced as compared with the case where the second stripe electrode is not provided, and the amount of the signal charge which can be taken out from the detector to the outside is increased. As a result, the reading efficiency can be improved.

According to the radiation image reading method and apparatus according to the present invention, the signal charge representing the radiation image information is read out from the detector according to the present invention on which the radiation image information is recorded via the second stripe electrode, and is stored in the power storage unit. An electric signal of a level corresponding to the amount of the accumulated latent image charge is obtained. Therefore, more charges can be read from the detector, so that the reading efficiency is increased, a larger signal can be obtained, and the S / N of an image can be improved.

Further, even if the second stripe electrode is provided, the thickness of the recording photoconductive layer or the read photoconductive layer is not substantially largely affected, so that the read response is adversely affected. Without, for example, as described in Japanese Patent Application Nos. 10-232824 and 10-271374, the total thickness of the charge transport layer and the reading photoconductive layer is determined by the thickness of the recording photoconductive layer. By making it thinner, the responsiveness at the time of reading can be improved. That is, according to the present invention, the reading efficiency can be further improved as compared with the case where the conventional detector is used, while maintaining the high-speed response at the time of reading.

Further, according to the radiation image recording method and apparatus of the present invention, the control voltage for adjusting the electric field distribution formed between the first electrode layer and the second electrode layer is adjusted to the second voltage.
Since the voltage is applied to the stripe electrode, it is possible to improve the signal extraction efficiency and the signal read response speed.

If the conductive member for making the latent image charges have the same potential is a detector specially provided in the power storage unit for each pixel of the image represented by the electric signal, the conductive member is stored on the conductive member. In addition, all the latent image charges of each pixel can be set to the same potential, and the readout efficiency can be improved as compared with the case where there is no conductive member. This is because the potential of the latent image charge is kept constant within the range of the conductive member, so that the latent image charge in the peripheral portion of the pixel, which is generally difficult to read, is transferred to the center of the conductive member as far as the readout proceeds within the conductive member. This is because the latent image can be moved to the central portion, that is, the central portion of the pixel, and the latent image charge can be more sufficiently discharged.

Further, the pixel can be formed at a fixed position where the conductive member is provided, and it becomes easy to correct the structure noise.

Further, by setting the size of the conductive member to be smaller than the pixel pitch and arranging the conductive member in the center of the pixel, the electric field distribution formed at the time of recording can be made a distribution shape attracted to the conductive member. The latent image charges can be concentrated and accumulated in the central portion of the pixel, and the sharpness of the image can be improved.

When a conductive member is provided on a detector provided with a charge transport layer and a trap layer, the charge storage effect of each of these layers can be used. That is, when the size of the conductive member is set smaller than the pixel pitch, when these layers are not provided, the charge not captured by the conductive member cannot be accumulated as a latent image charge, which is effective in improving sharpness. Can cause a problem that the amount of accumulated charge is reduced, but by accumulating the charge as a latent image charge in each layer, it is possible to improve the sharpness without reducing the amount of accumulated charge.

[0043]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a schematic configuration of a solid-state radiation detector according to a first embodiment of the present invention, and FIG.
1B is a perspective view, FIG. 1B is an XZ sectional view of the Q arrow finger portion,
(C) is XY sectional drawing of the arrow part of P. This detector 20
Is a first electrode layer 21 that is permeable to recording radiation (for example, X-rays or the like; hereinafter, referred to as recording light) L1, and is irradiated with recording light L1 that has passed through this electrode layer 21. The recording photoconductive layer 22, which exhibits conductivity, acts substantially as an insulator with respect to the latent image charge (for example, negative charge) and has a transport charge having a polarity opposite to that of the latent image charge (positive in the above-described example). Charge), the charge transport layer 23 acting substantially as a conductor, and the reading photoconductive layer 2 exhibiting conductivity when irradiated with a reading electromagnetic wave (hereinafter referred to as reading light) L2.
4. Second electrode layer 25 having transparency to reading light L2
Are laminated in this order, and the sub-electrode 27 is provided in the electrode layer 25.

The electrodes of the electrode layer 25 are composed of a number of elements 26.
a are arranged in a stripe shape, and a microplate 28 having substantially the same size as the pixel pitch is provided on a power storage unit 29 which is an interface between the recording photoconductive layer 22 and the charge transport layer 23. Is provided.

Sub-electrode 27 provided in electrode layer 25
Is a large number of elements 27a arranged in a stripe pattern. Each element 27a is
7a and the elements 26a of the stripe electrode 26 are arranged alternately. The space 25a between the two elements is filled with a polymer material such as polyethylene in which a slight amount of pigment such as carbon black is dispersed, and has a light shielding property against the reading light L2. The stripe electrode 26 and the sub-electrode 27 are electrically insulated. The sub-electrode 27 is a conductive member for outputting an electric signal of a level corresponding to the amount of the latent image charge stored in the power storage unit 29 formed at a substantially interface between the recording photoconductive layer 22 and the charge transport layer 23. It is.

The sub-electrode 27 is coated with a metal such as AL or Cr, and is formed so as to have a light-shielding property with respect to the reading light L2, and is provided in the reading photoconductive layer 24 corresponding to the element 27a. , So that charge pairs for signal extraction are not generated. The sub-electrode 27 only needs to have conductivity, and can be made of a single metal such as gold, silver, chromium, and platinum, or an alloy such as indium oxide.

When the voltage of the sub electrode 27 is
If the potential is controlled to be the same as 6, the electric field distribution formed between the electrode layer 21 and the electrode layer 25 can be made uniform. In addition, if the sub-electrode is opened or the potential of the stripe electrode 26 is controlled to be closer to the potential of the electrode layer 21, the latent image charges can be more concentratedly accumulated on the stripe electrode 26. Become.

The microplate 28 is provided with the element 26
It extends not only directly above a but also directly above the element 27a. Thereby, the latent image charges accumulated on the microplate 28 are always kept at the same potential, and can freely move on the microplate 28,
Discharge during reading is facilitated. The microplate 28 may be arranged so that the center thereof is located directly above the element 27a, so that the charges around the pixels can be more easily collected.

The microplate 28 is deposited on the dielectric layer using, for example, vacuum evaporation or chemical
It is made of a single metal such as silver, aluminum, copper, chromium, titanium, or platinum, or an alloy such as indium oxide, and can be formed from an extremely thin film. The microplate 18 can be deposited as a continuous layer, which is then etched to form a plurality of individual discrete microplates having dimensions in the same range as the smallest resolvable pixel. .
This discrete microplate can also be made using optical microfabrication techniques such as laser ablation or photoetching ("Imaging Procesing &Materials" Ch)
apter 18 “Imaging for Microfabrication” (JMSh
aw, IBM Watson Research Center).

The recording photoconductive layer 22 is made of a material such as amorphous selenium (a-Se), lead (II) such as PbO or PbI ₂ , lead (II) iodide, or Bi ₁₂ (Ge, Si).
_{O 2 0, Bi 2 I 3} / photoconductive material containing as a main component at least one organic polymer nanocomposite and the like are suitable.

As the substance of the charge transport layer 23, for example, the larger the difference between the mobility of the negative charge charged on the electrode layer 21 and the mobility of the positive charge having the opposite polarity, the better (for example, 10 ²
Or more, preferably 10 ³ or higher) poly N- vinylcarbazole (PVK), N, N'-diphenyl -N, N'-bis (3-
Organic compounds such as methylphenyl)-[1,1'-biphenyl] -4,4'-diamine (TPD) and discotic liquid crystal, or TPD polymer (polycarbonate, polystyrene, PUK) dispersion, Cl 200 ppm
Semiconductor materials such as doped a-Se are suitable. In particular, organic compounds (PVK, TPD, discotic liquid crystal, etc.) are preferable because they have light insensitivity, and the dielectric constant is generally small, so that the capacities of the charge transport layer 23 and the reading photoconductive layer 24 become small, so Can be increased in signal extraction efficiency. Here, “having light insensitivity” means that the material hardly exhibits conductivity even when irradiated with the recording light L1 or the reading light L2.

The material of the reading photoconductive layer 24 is a-
Se, Se-Te, Se-As-Te, metal-free phthalocyanine, metal phthalocyanine, MgPc (Magnesium ph
talocyanine), VoPc (phase II of Vanadyl phthal)
Preferred is a photoconductive material containing at least one of ocyanine), CuPc (Cupper phtalocyanine) and the like as a main component.

The thickness of the recording photoconductive layer 12 should be 50 μm or more and 100 μm or more in order to sufficiently absorb the recording light L1.
0 μm or less, and in this example, about 55 μm.
It is set to 00 μm. The charge transport layer 23 and the photoconductive layer 2
4 is 厚 of the thickness of the recording photoconductive layer 22.
It is desirable that the value be equal to or less than 1. Also, the thinner the thickness, the better the responsiveness at the time of reading.

As the electrode layer 21, for example, a Nesa film formed by applying a conductive substance on a transparent glass plate is suitable.

In the detector 20, a capacitor C _{* c} is formed between the power storage unit 29 and the sub-electrode 27 via the reading photoconductive layer 24 and the charge transport layer 23. Even when the sub-electrode 27 is provided, the capacitance C _a of the capacitor C _{* c} formed between the electrode layer 21 and the power storage unit 29 via the recording photoconductive layer 22, and the reading photoconductive layer 24 and the capacitance C _{c of the} capacitor C _{* b} formed between the power storage unit 29 and the stripe electrode 26 through the charge transport layer 23 does not appear substantially greater impact.

[0057] In this case, the capacitor _C * b, and consider the capacity of _{C * c,} the capacitance ratio _{C *} b: the _{C * c,} each element 26a, the width of the 27a ratio _W b: the _{W c.} Thus, during charge rearrangement, the amount of positive charge Q _{+ b} distributed to the capacitor C _{* b} can be made relatively smaller than when the sub-electrode 27 is not provided, and flows out of the detector 20 to the outside. The current can be made relatively larger than when the sub-electrode 27 is not provided.

In the detector 20, since at least the capacitance of the capacitors C _{* b} and C _{* c} is determined by the width ratio of the elements 26a and 27a forming the electrodes, the structure of the detector is simple. Easy to manufacture.

FIG. 2 is a diagram showing a schematic configuration of a solid-state radiation detector according to a second embodiment of the present invention.
(A) is a perspective view, FIG. 2 (B) is an XZ sectional view of a Q arrow finger part,
FIG. 2C is an XY cross-sectional view of the P arrow finger portion. Note that FIG.
In FIG. 7, the same elements as those of the detector 20 according to the second embodiment shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted unless otherwise required. The detector 20a according to the second embodiment removes the microplate 28 of the detector 20, connects the stripe electrode 26 and the sub-electrode 27 during recording, and
7 is positively used for forming an electric field distribution.

FIG. 3A is a charge model showing an electrostatic latent image recording process when recording is performed by connecting the stripe electrode 26 and the sub-electrode 27, and FIG. 9 is an electric charge model showing a process of reading an electrostatic latent image with respect to a transmission unit 9a. Stripe electrode 26 and sub-electrode 27
Is connected, the latent image charge is transferred to the element 2
It is accumulated not only at the position corresponding to 6a, but also at the position corresponding to the element 27a. At the time of reading, when the reading light L2 is irradiated on the photoconductive layer 24, the latent image charges of the portions corresponding to the two elements 27a, that is, the sky portions of both elements 27a are sequentially read out via the two elements 27a. It is. That is, as shown in FIG. 3B, a discharge is generated from the element 26a located at the center of the pixel toward the latent image charge (in the sky) corresponding to the element 27a on both sides thereof, whereby reading is performed. proceed. In order to extract more signal charges, it is preferable to make the width of the element 27a wider than the width of the element 26a.

FIG. 4 is a diagram showing a schematic configuration of a solid-state radiation detector according to a third embodiment of the present invention.
(A) is a perspective view, FIG. 4 (B) is an XZ sectional view of the Q arrow finger part,
FIG. 4C is an XY cross-sectional view of the arrow P part. FIG.
In FIG. 1, the same elements as those of the detector 20 according to the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted unless otherwise necessary. The detector 20b according to the third embodiment removes the microplate 28 of the detector 20 and, within one pixel,
Element 26a of stripe electrode 26 and sub-electrode 27
Of the elements 27a are alternately provided. In the illustrated detector 20a, within one pixel,
Three elements 26a and 27a are provided respectively. When recording and reading are performed using this detector 20b, each element 26a, 27
It is good to handle a in one pixel unit. If the size of one pixel of the detectors 20 and 20b is the same, the widths W _b ′ and W of the respective elements 26a and 27a of the detector 20b
_c ′ is set to be narrower than the widths W _b and W _{c of the} detector 20. In today's advanced semiconductor formation technology, it is easy to form both elements 26a, 27a sufficiently narrow, and the detector 20b can be easily manufactured.

With this configuration, compared to the detector 20 a according to the second embodiment, the power storage unit 29 and the electrode layer 25
The ratio D1 / D2 of the distance D1 between the two elements 26a and 27a to the distance D2 between the two elements 26a and 27a can be easily increased. This facilitates discharge from the element 26a toward the latent image charge corresponding to the element 27a on both sides thereof, and the reading time can be made shorter than that of the detector 20a. This is particularly effective when the microplate 28 is not provided.

FIG. 5 is a diagram showing a schematic configuration of a solid-state radiation detector according to a fourth embodiment of the present invention.
(A) is a perspective view, FIG. 5 (B) is an XZ sectional view of the Q arrow finger part,
FIG. 5C is an XY cross-sectional view of the P arrow finger part. FIG.
The detector 2 according to the first embodiment shown in FIG.
Elements that are the same as elements of 0 are given the same numbers, and descriptions thereof are omitted unless otherwise required. The detector 20c according to the fourth embodiment has a configuration in which the charge transport layer 23 is removed from the detector 20a.

The detailed description of the operation in the recording and reading steps when the detector 20c is used is omitted, but in the recording step, the negative charges generated in the recording photoconductive layer 23 are removed by the microplate 28. In the reading process, the latent image charge can be more sufficiently discharged, and unread portions are reduced.

Further, in each of the detectors according to the above embodiments, the recording photoconductive layer exhibits conductivity when irradiated with recording radiation. The conductive layer is not necessarily limited to this, and the recording photoconductive layer may have conductivity when irradiated with light emitted by exciting recording radiation (see Japanese Patent Application No. 10-232824). ). In this case, a wavelength conversion layer called a so-called X-ray scintillator for converting the radiation for recording into light of another wavelength region, such as blue light, is laminated on the surface of the first electrode layer.
As this wavelength conversion layer, for example, cesium iodide (Cs
It is preferable to use I) and the like. The first electrode layer is permeable to light emitted from the wavelength conversion layer by exciting recording radiation.

In each of the detectors 20, 20a and 20b, a charge transport layer is provided between the recording photoconductive layer and the read photoconductive layer, and a charge is stored at an interface between the recording photoconductive layer and the charge transport layer. Although a portion is formed, in the present invention, the charge transport layer may be replaced with a trap layer. When a trap layer is used, the latent image charges are captured by the trap layer, and the latent image charges are accumulated in the trap layer or at the interface between the trap layer and the recording photoconductive layer. In addition, at the interface between the trap layer and the recording photoconductive layer,
Particularly, a microplate may be provided.

In the detector according to the above-described embodiment, one rectangular microplate is provided for each pixel. However, the pixel is formed at a fixed position, and the latent image charge is reduced. As long as the potential can be made the same and the latent image charge in the peripheral portion of the pixel can be sufficiently discharged in the reading process, or the latent image charge can be concentrated in the central portion of the pixel in the recording process, the number thereof is slightly increased. May be more. For example, four triangular conductive members are arranged as a whole for each pixel so as to form a square, and in a recording process or a reading process, the vertices of the triangular member in the center of the square are opposed to each other. For example, a latent image charge is collected, or a fan-shaped conductive member is disposed in a circular shape as a whole.

[Brief description of the drawings]

FIG. 1 is a perspective view of a solid-state radiation detector according to a first embodiment of the present invention (A), an XZ sectional view of a Q arrow finger part (B), and P
XY sectional view of arrow finger part (C)

FIG. 2 is a perspective view of a solid-state radiation detector according to a second embodiment of the present invention (A), an XZ cross-sectional view of an arrow Q part (B), P
XY sectional view of arrow finger part (C)

FIG. 3 shows a charge model (A) showing a process of recording an electrostatic latent image and a charge model (B) showing a process of reading an electrostatic latent image when the solid-state radiation detector according to the second embodiment is used.

FIG. 4 is a perspective view of a solid-state radiation detector according to a third embodiment of the present invention (A), an XZ sectional view of an arrow Q part (B), P
XY sectional view of arrow finger part (C)

5A is a perspective view of a solid-state radiation detector according to a fourth embodiment of the present invention, FIG.
XY sectional view of arrow finger part (C)

[Explanation of symbols]

Reference Signs List 20 radiation solid state detector 21 first electrode layer 22 photoconductive layer for recording 23 charge transport layer 24 photoconductive layer for reading 25 second electrode layer 26 stripe electrode 27 sub-electrode (first conductive member) 28 microplate (first) 2 conductive member) 29 power storage unit 71 image signal acquisition unit 72 power supply (functions as voltage application unit and control voltage application unit) L1 radiation for recording (recording light) L2 electromagnetic wave for reading (reading light)

Claims (17)

[Claims] 1. A solid-state radiation detector for recording radiation image information as an electrostatic latent image by irradiating radiation, wherein a first electrode having transparency to recording radiation or light emitted by excitation of the radiation. A layer, a recording photoconductive layer that exhibits conductivity when irradiated with the recording radiation or the light, a power storage unit that accumulates an amount of charge corresponding to the dose of the irradiated radiation as a latent image charge, and reading. A reading photoconductive layer which exhibits conductivity by being irradiated with electromagnetic waves for reading, a second electrode layer irradiated with the reading electromagnetic waves, in this order, the second electrode layer comprises: A first stripe electrode composed of a large number of linear electrodes for generating photocharge pairs with respect to the irradiation of the electromagnetic waves for reading, and a large number of linear electrodes for non-generation of photocharges with respect to the electromagnetic waves for reading; 2nd Stra A radiation solid-state detector, comprising: a first stripe electrode and a second stripe electrode that are alternately arranged substantially in parallel with each other. 2. A solid-state radiation detector for recording radiation image information as an electrostatic latent image by irradiating radiation, wherein a first electrode having transparency to radiation for recording or light emitted by excitation of the radiation. A layer, a recording photoconductive layer that exhibits conductivity when irradiated with the recording radiation or the light, a power storage unit that accumulates an amount of charge corresponding to the dose of the irradiated radiation as a latent image charge, and reading. A reading photoconductive layer which exhibits conductivity by being irradiated with electromagnetic waves for reading, a second electrode layer irradiated with the reading electromagnetic waves, in this order, the second electrode layer comprises: A first stripe electrode composed of a large number of linear electrodes having transparency with respect to irradiation of the reading electromagnetic wave, and a second stripe electrode having a light shielding property with respect to the reading electromagnetic wave; 1s A radiation solid-state detector in which a tripe electrode and the second stripe electrode are alternately arranged substantially in parallel. 3. The radiation solid-state detector according to claim 1, wherein the second stripe electrode is coated with a metal of Al or Cr. 4. A method according to claim 1, wherein one pixel line of said solid-state radiation detector includes one said first stripe electrode and said second stripe electrode adjacent to said one first stripe electrode. The solid-state radiation detector according to any one of claims 1 to 3. 5. A method according to claim 1, wherein one pixel line of said solid-state radiation detector includes a plurality of said first stripe electrodes and said second stripe electrodes adjacent to each of said plurality of first stripe electrodes. The solid-state radiation detector according to any one of claims 1 to 3. 6. The power storage unit has a conductive member that extends on the first stripe electrode and the second stripe electrode and is provided separately for each pixel of the solid-state radiation detector. The radiation solid-state detector according to any one of claims 1 to 5, wherein the stored latent image charges are held at the same potential by the following. 7. A charge transport layer, which acts substantially as an insulator with respect to the latent image charges and acts substantially as a conductor with respect to charges having a polarity opposite to that of the latent image charges, comprises: The power storage unit is provided between a conductive layer and the reading photoconductive layer, and the power storage unit is formed at an interface between the charge transport layer and the reading photoconductive layer. The solid-state radiation detector according to claim 1. 8. A trap layer for capturing the latent image charge,
The power storage unit is provided between the recording photoconductive layer and the reading photoconductive layer, and the power storage unit is formed in the trap layer or at an interface between the trap layer and the recording photoconductive layer. The radiation solid-state detector according to any one of claims 1 to 6. 9. The radiation solid-state detector according to claim 1, wherein a width of the second stripe electrode is wider than a width of the first stripe electrode. 10. A radiation solid-state detector according to claim 1, wherein the radiation solid-state detector is irradiated with radiation, and a charge of an amount corresponding to the dose of the irradiated radiation is stored in a power storage unit of the radiation solid-state detector. In the radiation image recording method of recording radiation image information as an electrostatic latent image on the power storage unit by accumulating the image charge as an image charge, the first stripe electrode and the second stripe electrode have substantially the same potential, A radiation image recording method, wherein the recording is performed by applying a DC voltage between a first electrode layer and a second electrode layer. 11. A radiation solid-state detector according to claim 1, wherein the radiation solid-state detector is irradiated with radiation, and a charge corresponding to an amount of the irradiated radiation is stored in a power storage unit of the radiation solid-state detector. In a radiation image recording method of recording radiation image information as an electrostatic latent image in the power storage unit by accumulating as image charge, the second stripe electrode is opened, and the first stripe electrode and the first stripe electrode are opened. A radiation image recording method, wherein the recording is performed by applying a direct current voltage to an electrode layer. 12. A radiation solid-state detector according to claim 1, wherein the radiation solid-state detector is irradiated with radiation, and a charge of an amount corresponding to the dose of the irradiated radiation is stored in a power storage unit of the radiation solid-state detector. In a radiographic image recording method of recording radiographic image information as an electrostatic latent image in the power storage unit by accumulating it as image charges, a direct current voltage is applied between the first stripe electrode and the first electrode layer. And performing the recording by applying a control voltage for adjusting an electric field distribution formed between the first stripe electrode and the first electrode layer to the second stripe electrode by applying the DC voltage. A radiographic image recording method, characterized in that: 13. The radiation image reading method for reading the radiation image information from the radiation solid state detector according to claim 1, wherein the radiation image information is recorded as an electrostatic latent image. And causing the second stripe electrode to have substantially the same potential, and irradiating the readout electromagnetic wave to the second electrode layer to generate an electric signal having a level corresponding to the amount of latent image charges stored in the power storage unit. A method for reading a radiation image, comprising: 14. A radiation solid-state detector according to claim 1, wherein the radiation solid-state detector is irradiated with radiation, and a charge of an amount corresponding to a dose of the irradiated radiation is stored in a power storage unit of the radiation solid-state detector. In a radiation image recording apparatus that records radiation image information as an electrostatic latent image in the power storage unit by accumulating the radiation image information as an image charge, a DC voltage is applied between the first electrode layer and the first stripe electrode. Voltage applying means; and control voltage applying means for applying, to the second stripe electrode, a control voltage for adjusting an electric field distribution formed between both electrode layers by a DC voltage applied by the voltage applying means. A radiation image recording apparatus, comprising: 15. A radiation solid-state detector according to any one of claims 1 to 9, wherein the radiation solid-state detector is irradiated with radiation, and a charge of an amount corresponding to a dose of the irradiated radiation is stored in a power storage unit of the radiation solid-state detector. In a radiation image recording apparatus that records radiation image information as an electrostatic latent image in the power storage unit by accumulating the radiation image information as an image charge, a DC voltage is applied between the first electrode layer and the first stripe electrode. Radiation comprising: voltage applying means; and switching means for opening the second stripe electrode to adjust an electric field distribution formed between both electrode layers by a DC voltage applied by the voltage applying means. Image recording device. 16. The radiation image reading apparatus according to claim 1, wherein the radiation image information is recorded as an electrostatic latent image, and wherein the radiation image information is read from the radiation solid state detector. And the second stripe electrode are made to have substantially the same potential, and the reading electromagnetic wave is applied to the second electrode layer, whereby an electric charge of a level corresponding to the amount of the latent image charges stored in the power storage unit is obtained. A radiation image reading apparatus, comprising: an image signal obtaining unit for obtaining a signal. 17. The image display device according to claim 16, wherein said image signal acquiring means is connected to a first stripe electrode.
A radiation image reading apparatus according to claim 1.