JP3970668B2 - Radiation solid state detector - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a radiation solid-state detector having a power storage unit that accumulates as a latent image charge an amount of charge corresponding to the dose of irradiated radiation or the amount of light emitted by excitation of the radiation.
[0002]
[Prior art]
Today, in radiography for medical diagnosis and the like, charges obtained by detecting radiation are temporarily stored as latent image charges in a power storage unit, and the stored latent image charges are converted into electrical signals representing radiation image information. Various radiation image information recording / reading apparatuses using a radiation solid state detector (hereinafter also simply referred to as a detector) have been proposed. Various types of solid-state radiation detectors used in this apparatus have been proposed. From the viewpoint of a charge reading process for reading out the accumulated charges to the outside, reading light (electromagnetic waves for reading) is applied to the detector. There is an optical readout type that reads out by irradiating.
[0003]
The present applicant has disclosed, as optical radiation type radiation solid state detectors capable of achieving both high-speed readout response and efficient signal charge extraction, JP-A-2000-105297, JP-A-2000-284056, No. 2000-284057, a first conductive layer that is transparent to recording radiation or light emitted by excitation of the radiation (hereinafter referred to as recording light), and recording that exhibits conductivity by receiving recording light Acts as a substantially insulator for charges of the same polarity as those charged in the photoconductive layer and first conductive layer, and acts as a conductor for charges of the same polarity and opposite polarity. A charge transporting layer, a reading photoconductive layer that exhibits conductivity when irradiated with reading light (reading electromagnetic waves), and a second conductive layer that is transparent to the reading light are laminated in this order. The power storage unit and the recording photoconductive layer is formed at the interface between the charge transport layer, it proposes a detector for accumulating signal charges carrying the image information (latent image charges).
[0004]
In JP-A-2000-284056 and JP-A-2000-284057, in particular, the charge of the second conductive layer having transparency to the reading light is applied to the photocharge having transparency to a large number of reading lights. A stripe electrode composed of pair-generating linear electrodes and a plurality of photoelectric charge-non-generating linear electrodes for outputting an electric signal at a level corresponding to the amount of latent image charges accumulated in the power storage unit A detector provided in the second conductive layer so as to be alternately and parallel to the charge pair generating linear electrodes is proposed.
[0005]
As described above, by providing the sub-stripe electrode composed of a large number of photoelectric charge pair non-generating linear electrodes in the second conductive layer, a new capacitor is formed between the power storage unit and the sub-stripe electrode. Transport charges having a polarity opposite to that of the latent image charge accumulated in the power storage unit can be charged to the sub-stripe electrode by charge rearrangement at the time of reading. As a result, the amount of the transport charge distributed to the capacitor formed between the stripe electrode and the power storage unit via the reading photoconductive layer is made relatively smaller than in the case where this sub-stripe electrode is not provided. As a result, it is possible to increase the amount of signal charge that can be taken out from the detector to improve the reading efficiency, and to achieve both high-speed reading response and efficient signal charge extraction. It has become.
[0006]
[Problems to be solved by the invention]
By the way, in the detector including the sub-striped electrode as described above, the width of the photocharge pair generating linear electrode, the width of the photocharge versus non-generating linear electrode, and the width between the linear electrodes are determined by the accumulated charge reading. Greatly affects efficiency.
[0007]
For example, if the width of the photocharge pair generating linear electrode and the width of the photocharge pair non-generating linear electrode are narrowed, the electrical resistance increases, which may cause a delay in the read signal. There is a risk of disconnection due to defective etching or the like.
[0008]
In addition, when the width between each linear electrode is narrowed, there is a risk that a discharge will occur when a high voltage is applied to each linear electrode, and that there will be a short circuit between the linear electrodes, or that dust or the like may be mixed during electrode manufacturing. This may cause a short circuit between the linear electrodes.
[0009]
In addition, when the width of the photocharge pair generating linear electrode, the width of the photocharge pair non-generating linear electrode, and the width between the linear electrodes are widened, the latent image charge accumulated in the power storage unit is converted into the photogenerated charge. Since the jump distance to be erased becomes long, the reading efficiency of the detector is lowered.
[0010]
As described above, various problems occur unless the width of the photocharge pair generating linear electrodes, the width of the photocharge pair non-generating linear electrodes, and the width between the linear electrodes are optimized.
[0011]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a radiation solid-state detector that can efficiently read stored charges in a radiation solid-state detector provided with a sub-striped electrode. is there.
[0012]
[Means for Solving the Problems]
The radiation solid state detector according to the present invention includes a first conductive layer that is transmissive to recording light, a recording photoconductive layer that exhibits photoconductivity when irradiated with recording light, and the amount of recording light. A power storage unit that accumulates a corresponding amount of charge as a latent image charge, a reading photoconductive layer that exhibits photoconductivity when irradiated with reading light, and a number of photocharge pairs that are transparent to the reading light. A second conductive layer comprising a generation linear electrode and a number of photoelectric charge pair non-generation linear electrodes, wherein the photo charge pair generation linear electrodes and the photo charge pair non-generation linear electrodes are alternately arranged; In the radiation solid state detector laminated in this order, when the pair of the photocharge pair generating linear electrode and the photocharge pair non-generating linear electrode is one period, the period is in the range of 10 μm to 150 μm. It is characterized by.
[0013]
Here, “a pair of a photocharge pair generating linear electrode and a photocharge pair non-generating linear electrode is defined as one cycle” means that the pair of photocharge generating linear electrodes of the pair A, as shown in FIG. A pair of photocharge pair non-generated linear electrode of pair A and a pair of photocharge pair generated linear electrode of pair C adjacent to pair A from the middle of the pair of photocharge pair non-generated linear electrode of pair B adjacent to pair A This means that one cycle is up to the middle. Therefore, the width of the “period” is such that the photocharge pair non-generating line of the pair A from the middle between the photocharge pair generating linear electrode of the pair A and the photocharge pair non-generating linear electrode of the pair B adjacent to the pair A. And the length between the pair of photocharge pair generating linear electrodes adjacent to the pair A. Further, the pixel pitch does not have to be the same as the above period, and for example, one pixel may be composed of linear electrodes for four periods. Further, the above pairs are not necessarily arranged continuously. For example, as shown in FIG. 6, it is possible to adopt a mode in which each pair is arranged (thinned out) at intervals of one pair every three pairs. is there.
[0014]
The “radiation solid state detector” includes a first conductive layer, a recording photoconductive layer, a reading photoconductive layer, and a second conductive layer in this order, and the recording photoconductive layer and the reading photoconductive layer. The power storage unit may be formed between the two layers, and another layer, a micro conductive member (micro plate), or the like may be stacked. In addition, this radiation solid-state detector is capable of recording image information as an electrostatic latent image by irradiating light carrying radiation image information (radiation or light generated by excitation of radiation). It can be anything.
[0015]
As a method for forming the power storage unit, a method of forming a power storage unit at the interface between the charge transport layer and the recording photoconductive layer by providing a charge transport layer (Japanese Patent Laid-Open No. 2000-105297 by the present applicant). , JP 2000-284056 A), a method in which a trap layer is provided and a power storage portion is formed in the trap layer or at the interface between the trap layer and the recording photoconductive layer (for example, see US Pat. No. 4,535,468), or It is preferable to use a method of providing a minute conductive member or the like for concentrating latent image charges and storing electricity (see Japanese Patent Application Laid-Open No. 2000-284057 by the present applicant).
[0016]
Further, the “photocharge pair generating linear electrode having transparency to reading light” is an electrode that transmits the reading light and generates charge pairs in the reading photoconductive layer. Further, the “photocharge pair non-generating linear electrode” is an electrode for outputting an electric signal at a level corresponding to the amount of latent image charge accumulated in the power storage unit, and has a light shielding property against the reading light. However, when a light-shielding film having a light shielding property is provided between the photocharge pair non-generating linear electrode and the reading light irradiation means, the light charge non-generating linear electrode is not necessarily required to have a light shielding property. There is no. Here, the “light-shielding property” is not limited to the one in which the reading light is completely blocked and no charge pair is generated. Including those that do not cause any substantial problems. Therefore, the charge pairs generated in the photoconductive layer for reading are not necessarily all due to the reading light transmitted through the photocharge pair generating linear electrodes, but by the reading light slightly transmitted through the photocharge pair non-generating linear electrodes. Also, it is assumed that charge pairs can be generated in the reading photoconductive layer.
[0017]
Further, the “reading light” is not limited as long as it can move the electric charge in the electrostatic recording body and can electrically read the electrostatic latent image. Specifically, it is light, radiation, or the like. .
[0018]
When recording or reading a radiation image using the detector according to the present invention, for example, a conventional detector to which the present invention is not applied as described in Japanese Patent Application Laid-Open No. 2000-284056 is used. The recording method, the reading method, and the apparatus can be used without change.
[0019]
【The invention's effect】
According to the radiation solid state detector according to the present invention, when the pair of the photocharge pair generating linear electrode and the photocharge pair non-generating linear electrode is set to one period, this period is optimized from 10 μm to 150 μm, and therefore can be taken out. The amount of accumulated charge can be increased, and reading efficiency and image S / N can be improved.
[0020]
That is, when the width is smaller than 10 μm, the electric resistance of each linear electrode becomes high, so that there is a possibility that the read signal is delayed, and that there is a possibility that disconnection due to an etching defect or the like occurs during electrode manufacture. Also, since the width between the linear electrodes becomes narrow, there is a risk that a discharge will occur when a high voltage is applied to each linear electrode, and there is a risk of short-circuiting between the linear electrodes. There is a risk of short circuit between the linear electrodes.
[0021]
When the width is larger than 150 μm, the distance from the center of the photocharge pair generating linear electrode to the center of the photocharge pair generating linear electrode adjacent to the photocharge pair generating linear electrode becomes long. Since the jump distance over which the photogenerated charges go out of the latent image charge accumulated in the power storage unit becomes longer, the reading efficiency of the detector is lowered.
[0022]
Therefore, these problems can be avoided by setting the above period to a range of 10 μm to 150 μm, and a highly reliable radiation solid state detector can be provided.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
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 first embodiment of a radiation solid detector of the present invention, FIG. 1 (A) is a perspective view of a radiation solid detector 20a, and FIG. 1 (B) is a radiation solid detection. FIG. 1C is an XY cross-sectional view of the P-arrow portion of the radiation solid detector 20a. FIG. 2 is a cross-sectional view similar to FIG. 1B for explaining a cycle when a pair of the charge pair generating linear electrode and the charge pair non-generating linear electrode is defined as one cycle. In FIG. 2, the support 18, the insulating layer 30, and the light shielding film 31 are omitted.
[0024]
The radiation solid detector 20a includes a first conductive layer 21 having transparency to recording light (radiation or light generated by excitation of radiation) carrying image information of radiation such as X-rays transmitted through a subject, A recording photoconductive layer 22 that generates conductivity by receiving irradiation of recording light transmitted through the first conductive layer 21 and exhibits conductivity, and a latent image polar charge (for example, negative charge) in the charge pair. Is a charge transport layer 23 that acts as a substantially conductive material for a transport polarity charge (positive charge in the above example) having a polarity opposite to that of the latent image polar charge. A photoconductive layer for reading 24 that generates electric charge pairs by receiving the light, a second conductive layer 25 including a stripe electrode 26 and a sub-striped electrode 27, an insulating layer 30 that is transparent to read light, For reading light The support 18 that is transparent and is made by arranging in this order. At the interface between the recording photoconductive layer 22 and the charge transport layer 23, a two-dimensionally distributed power storage unit 29 for accumulating latent image polar charges carrying image information generated in the recording photoconductive layer 22 is formed. The
[0025]
As the support 18, a glass substrate that is transparent to the reading light can be used. In addition to being transparent to the reading light, it is more desirable to use a material whose coefficient of thermal expansion is relatively close to that of the reading photoconductive layer 24. For example, when a-Se (amorphous selenium) is used as the reading photoconductive layer 24, the thermal expansion coefficient of Se is 3.68 × 10. ^-5 Considering that it is / K @ 40 ° C., the coefficient of thermal expansion is 1.0 to 10.0 × 10 ^-5 / K @ 40 ° C., more preferably 4.0 to 8.0 × 10 ^-5 Use material that is / K @ 40 ° C. An organic polymer material such as polycarbonate or polymethyl methacrylate (PMMA) can be used as the substance having a thermal expansion coefficient in this range. As a result, the thermal expansion of the support 18 as a substrate and the photoconductive layer 24 for reading (Se film) can be matched, and a large temperature cycle can be achieved in a special environment, for example, during shipping in a cold climate. Even if it is received, thermal stress is generated at the interface between the support 18 and the reading photoconductive layer 24, and the two are physically separated, the reading photoconductive layer 24 is broken, or the support 18 is cracked. The problem of destruction due to the difference does not occur. Furthermore, the organic polymer material has a merit that it is more resistant to impact than the glass substrate.
[0026]
Examples of the material for the recording photoconductive layer 22 include a-Se (amorphous selenium), PbO, and PbI. ₂ Lead oxide (II), lead iodide (II), Bi ₁₂ (Ge, Si) O ₂₀ , Bi ₂ I ₃ / A photoconductive substance containing at least one of organic polymer nanocomposites as a main component is suitable.
[0027]
As the substance of the charge transport layer 23, for example, the difference between the mobility of the negative charge charged in the first conductive layer 21 and the mobility of the positive charge having the opposite polarity is better (for example, 10 ² Or more, preferably 10 ³ Above) Poly N-vinylcarbazole (PVK), N, N′-diphenyl-N, N′-bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine (TPD), An organic compound such as a discotic liquid crystal, a TPD polymer (polycarbonate, polystyrene, PUK) dispersion, or a semiconductor material such as a-Se doped with 10 to 200 ppm of Cl is suitable. In particular, organic compounds (PVK, TPD, discotic liquid crystal, etc.) are preferable because they have light insensitivity, and since the dielectric constant is generally small, the capacitance of the charge transport layer 23 and the reading photoconductive layer 24 is reduced, so that reading is possible. The signal extraction efficiency can be increased. Note that “having light insensitivity” means that the material hardly exhibits conductivity even when irradiated with recording light or reading light.
[0028]
Examples of the material of the reading photoconductive layer 24 include a-Se, Se-Te, Se-As-Te, metal-free phthalocyanine, metal phthalocyanine, MgPc (Magnesium phtalocyanine), VoPc (phase II of Vanadyl phthalocyanine), and CuPc (Cupper phtalocyanine). ) And the like, and a photoconductive substance mainly containing at least one of them is preferred.
[0029]
The thickness of the recording photoconductive layer 22 is preferably 50 μm or more and 1000 μm or less so that the recording light can be sufficiently absorbed.
[0030]
Further, the total thickness of the charge transport layer 23 and the reading photoconductive layer 24 is preferably less than or equal to ½ of the thickness of the recording photoconductive layer 22. Therefore, for example, it is preferably 1/10 or less, more preferably 1/100 or less.
[0031]
The material of each of the above layers is a power storage formed at the interface between the recording photoconductive layer 22 and the charge transport layer 23 by charging the first conductive layer 21 with a negative charge and the second conductive layer 25 with a positive charge. The negative charge as the latent image polar charge is accumulated in the portion 29, and the charge transport layer 23 moves the positive charge as the transport polar charge having the opposite polarity to the mobility of the negative charge as the latent image polar charge. Although the degree is larger, it is an example of a suitable one that functions as a so-called hole transport layer, each of these may be a charge of opposite polarity, and when reversing the polarity in this way, It is only necessary to make a slight change such as changing the charge transport layer functioning as a hole transport layer to a charge transport layer functioning as an electron transport layer.
[0032]
For example, a photoconductive material such as the above-described amorphous selenium a-Se, lead (II) oxide, lead (II) iodide or the like can be used as the recording photoconductive layer 22, and N-trinitro as the charge transport layer 23. Fluorenylidene / aniline (TNFA) dielectric, trinitrofluorenone (TNF) / polyester dispersion, and asymmetric diphenoquinone derivatives are suitable, and the above-described metal-free phthalocyanine and metal phthalocyanine can be used as the photoconductive layer 24 for reading. .
[0033]
In the detector 20a, the power storage unit 29 is formed at the interface between the recording photoconductive layer 22 and the charge transport layer 23. However, the present invention is not limited to this, for example, as described in US Pat. No. 4,535,468, The power storage unit may be formed of a trap layer that accumulates latent image polar charges as traps.
[0034]
The first conductive layer 21 may be any layer as long as it is transmissive to recording light. For example, when it is transmissive to visible light, a well-known Nesa film (SnO film) is used as a light-transmissive metal thin film. ₂ ), ITO (Indium Tin Oxide), or IDIXO (Idemitsu Indium X-metal Oxide; Idemitsu Kosan Co., Ltd.), which is an amorphous transparent metal oxide that is easy to etch, is preferably about 50 to 200 nm thick. Can be used with a thickness of 100 nm or more. Further, by making a pure metal such as aluminum Al, gold Au, molybdenum Mo, and chromium Cr to have a thickness of, for example, 20 nm or less (preferably about 10 nm), transparency to visible light can be given. In the case where X-rays are used as recording light and an image is recorded by irradiating the X-rays from the first conductive layer 21 side, the first conductive layer 21 does not need to be transparent to visible light. The first conductive layer 21 may be made of a pure metal such as Al or Au having a thickness of 100 nm, for example.
[0035]
The second conductive layer 25 includes a stripe electrode 26 formed by arranging a large number of read light transmitting elements (photo charge pair generating linear electrodes) 26a in a stripe shape and a large number of read light blocking elements (photo charge pair non-conductive). Generation linear electrode) 27a and sub-striped electrodes 27 arranged in a stripe shape. The elements 26a and 27a are arranged so that the elements 26a and 27a are alternately arranged in parallel with each other. A part of the read photoconductive layer 24 is interposed between the two elements, and the stripe electrode 26 and the sub stripe electrode 27 are electrically insulated. The sub-striped electrode 27 is a conductive material for outputting an electric signal of a level corresponding to the amount of latent image charge accumulated 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 a member.
[0036]
Here, as a material of an electrode material forming each element 26a of the stripe electrode 26, ITO (Indium Tin Oxide), IDIXO (Idemitsu Indium X-metal Oxide; Idemitsu Kosan Co., Ltd.), aluminum, molybdenum, or the like is used. Can do. Further, as a material of an electrode material for forming each element 27a of the sub stripe electrode 27, aluminum, molybdenum, chromium, or the like can be used.
[0037]
In the present embodiment, the thickness of the reading photoconductive layer 24 is 10 μm, the width of the element 26a and the element 27a is 15 μm, the width between adjacent elements is 10 μm, that is, the period is 50 μm. The pixel pitch is 50 μm, and the electrode for one pixel is composed of one pair of elements.
[0038]
Further, light is applied to the element 27a on the support 18 and the portion corresponding to the space between the element 26a and the element 27a so that the irradiation intensity of the reading light to the element 27a is smaller than the irradiation intensity of the reading light to the element 26a. A light shielding film 31 made of a member with poor transparency is provided.
[0039]
The member of the light shielding film 31 is not necessarily insulative, and the specific resistance of the light shielding film 31 is 2 × 10. ^-6 Or more (more preferably 1 × 10 ¹⁵ Ω · cm or less) can be used. For example, Al, Mo, Cr, etc. can be used for metal materials, and MOS for organic materials. ₂ , WSi ₂ TiN or the like can be used. It is more preferable to use a light shielding film 31 having a specific resistance of 1 Ω · cm or more.
[0040]
Further, when a conductive member such as a metal material is used as at least the member of the light shielding film 31, an insulator is disposed between the light shielding film 31 and the element 27a in order to avoid direct contact. The detector 20a of the present embodiment has an SiO 2 between the second conductive layer 25 and the support 18 as the insulator. ₂ An insulating layer 30 made of or the like is provided. The insulating layer 30 has a thickness of about 0.01 to 10 μm, more preferably about 0.1 to 1 μm, and most preferably about 0.5 μm.
[0041]
In this detector 20a, a capacitor C * a is formed between the first conductive layer 21 and the power storage unit 29 with the recording photoconductive layer 22 interposed therebetween, and the charge transport layer 23 and the reading photoconductive layer 24 are sandwiched therebetween. Thus, a capacitor C * b is formed between the power storage unit 29 and the stripe electrode 26 (element 26a), and the power storage unit 29 and the sub-striped electrode 27 (element 27a) are interposed via the read photoconductive layer 24 and the charge transport layer 23. Is formed with a capacitor C * c. The amount of positive charge Q + a, Q + b, Q + c distributed to each capacitor C * a, C * b, C * c during charge rearrangement at the time of reading is the sum of Q + and the amount Q− of latent image polar charge. In the same manner, the amounts are proportional to the capacitances Ca, Cb, and Cc of each capacitor. This can be expressed by the following formula.
[0042]
Q- = Q + = Q + a + Q + b + Q + c
Q + a = Q + × Ca / (Ca + Cb + Cc)
Q + b = Q + × Cb / (Ca + Cb + Cc)
Q + c = Q + × Cc / (Ca + Cb + Cc)
The amount of signal charge that can be extracted from the detector 20a is the same as the sum of the positive charge amounts Q + a and Q + c (Q + a + Q + c) distributed to the capacitors C * a and C * c, and the positive charge distributed to the capacitor C * b. Cannot be taken out as a signal charge (refer to Japanese Patent Laid-Open No. 2000-284056 for details).
[0043]
Here, considering the capacitances of the capacitors C * b and C * c by the stripe electrode 26 and the sub stripe electrode 27, the capacitance ratio Cb: Cc is the ratio Wb: Wc of the widths of the elements 26a and 27a. On the other hand, the capacitance Ca of the capacitor C * a and the capacitance Cb of the capacitor C * b are not substantially affected even if the sub-striped electrode 27 is provided.
[0044]
As a result, the amount of positive charge Q + b distributed to the capacitor C * b during charge rearrangement at the time of reading can be made relatively smaller than when the sub-striped electrode 27 is not provided. The amount of signal charge that can be extracted from the detector 20a via the sub-striped electrode 27 can be made relatively larger than when the sub-striped electrode 27 is not provided.
[0045]
In the radiation solid state detector according to the present embodiment, when the pair of the element 26a and the element 27a is one cycle, this cycle is set to 50 μm, and is set within a preferable range of 10 μm to 150 μm, and thus can be taken out. The amount of charge can be increased, and reading efficiency and image S / N can be improved.
[0046]
Next, a second embodiment of the radiation solid state detector according to the present invention will be described with reference to FIG. FIG. 3 is a cross-sectional view of the radiation solid state detector 20b according to the present embodiment. In addition, in this figure, the support body 18, the insulating layer 30, and the light shielding film 31 are abbreviate | omitted. In FIG. 3, elements that are the same as those of the detector 20 a according to the first embodiment shown in FIG. 1 are given the same reference numerals, and descriptions thereof are omitted unless particularly necessary.
[0047]
The radiation solid detector 20b includes a first conductive layer 21, a recording photoconductive layer 22, a charge transport layer 23, a reading photoconductive layer 24, a second conductive layer 25 including a stripe electrode 26 and a sub-stripe electrode 27, The insulating layer 30 and the support 18 are arranged in this order. In addition, a light shielding film 31 is provided on a portion corresponding to each element 27a on the support 18 and between the element 26a and the element 27a. For each layer, the same one as the detector 20a according to the first embodiment is used.
[0048]
In the present embodiment, the thickness of the reading photoconductive layer 24 is 30 μm, the width of the element 26a and the element 27a is 30 μm, the width between adjacent elements is 20 μm, that is, the period is 100 μm. The pixel pitch is 100 μm, and the electrode for one pixel is composed of one pair of elements.
[0049]
Also in this embodiment, since the cycle is set to 100 μm and set within a preferable range of 10 μm to 150 μm, it is possible to obtain the same effect as that of the first embodiment.
[0050]
Next, a third embodiment of the radiation solid detector according to the present invention will be described with reference to FIG. FIG. 4 is a cross-sectional view of the radiation solid state detector 20c according to the present embodiment. In addition, in this figure, the support body 18, the insulating layer 30, and the light shielding film 31 are abbreviate | omitted. In FIG. 4, elements that are the same as those of the detector 20 a according to the first embodiment shown in FIG. 1 are given the same reference numerals, and descriptions thereof are omitted unless particularly necessary.
[0051]
The radiation solid detector 20c includes a first conductive layer 21, a recording photoconductive layer 22, a charge transport layer 23, a reading photoconductive layer 24, a second conductive layer 25 including a stripe electrode 26 and a sub-stripe electrode 27, The insulating layer 30 and the support 18 are arranged in this order. In addition, a light shielding film 31 is provided on a portion corresponding to each element 27a on the support 18 and between the element 26a and the element 27a. For each layer, the same one as the detector 20a according to the first embodiment is used.
[0052]
In the present embodiment, the thickness of the reading photoconductive layer 24 is 10 μm, the width of the element 26a and the element 27a is 15 μm, the width between adjacent elements is 10 μm, that is, the period is 50 μm. The pixel pitch is 100 μm, and the electrode for one pixel is composed of two pairs of elements.
[0053]
Also in the present embodiment, since the period is set to 50 μm and set within a preferable range of 10 μm to 150 μm, the same effect as that of the first embodiment can be obtained.
[0054]
Next, a fourth embodiment of the radiation solid state detector according to the present invention will be described with reference to FIG. FIG. 5 is a cross-sectional view of the radiation solid detector 20d according to the present embodiment. In addition, in this figure, the support body 18, the insulating layer 30, and the light shielding film 31 are abbreviate | omitted. In FIG. 5, elements that are the same as those of the detector 20 a according to the first embodiment shown in FIG. 1 are given the same reference numerals, and descriptions thereof are omitted unless particularly necessary.
[0055]
The radiation solid detector 20d includes a first conductive layer 21, a recording photoconductive layer 22, a charge transport layer 23, a reading photoconductive layer 24, a second conductive layer 25 including a stripe electrode 26 and a sub-stripe electrode 27, The insulating layer 30 and the support 18 are arranged in this order. In addition, a light shielding film 31 is provided on a portion corresponding to each element 27a on the support 18 and between the element 26a and the element 27a. For each layer, the same one as the detector 20a according to the first embodiment is used.
[0056]
In the present embodiment, the thickness of the reading photoconductive layer 24 is 5 μm, the width of the element 26a and the element 27a is 7.5 μm, the width between adjacent elements is 5 μm, that is, the period is 25 μm. The pixel pitch is 100 μm, and the electrode for one pixel is composed of four pairs of elements.
[0057]
Also in the present embodiment, since the cycle is set to 25 μm and set within a preferable range of 10 μm to 150 μm, the same effect as that of the first embodiment can be obtained.
[0058]
Next, a fifth embodiment of the radiation solid detector according to the present invention will be described with reference to FIG. FIG. 6 is a cross-sectional view of the radiation solid state detector 20e according to the present embodiment. In addition, in this figure, the support body 18, the insulating layer 30, and the light shielding film 31 are abbreviate | omitted. In FIG. 6, the same reference numerals are given to the same elements as those of the detector 20a according to the first embodiment shown in FIG. 1, and the description thereof will be omitted unless particularly required.
[0059]
The radiation solid detector 20e includes a first conductive layer 21, a recording photoconductive layer 22, a charge transport layer 23, a reading photoconductive layer 24, a second conductive layer 25 including a stripe electrode 26 and a sub-stripe electrode 27, The insulating layer 30 and the support 18 are arranged in this order. In addition, a light shielding film 31 is provided on a portion corresponding to each element 27a on the support 18 and between the element 26a and the element 27a. For each layer, the same one as the detector 20a according to the first embodiment is used.
[0060]
In the present embodiment, the thickness of the reading photoconductive layer 24 is 5 μm, the width of the element 26a and the element 27a is 7.5 μm, the width between adjacent elements is 5 μm, that is, the period is 25 μm. In addition, the pixel pitch is 100 μm, and every three pairs are spaced apart by one pair, and the electrode for one pixel is constituted by three pairs of elements.
[0061]
Also in the present embodiment, since the cycle is set to 25 μm and set within a preferable range of 10 μm to 150 μm, the same effect as that of the first embodiment can be obtained.
[0062]
Next, a sixth embodiment of the radiation solid detector according to the present invention will be described with reference to FIG. FIG. 7 is a cross-sectional view of the radiation solid state detector 20f according to the present embodiment. In addition, in this figure, the support body 18, the insulating layer 30, and the light shielding film 31 are abbreviate | omitted. In FIG. 7, elements that are the same as those of the detector 20 a according to the first embodiment shown in FIG. 1 are given the same reference numerals, and descriptions thereof are omitted unless particularly necessary.
[0063]
The radiation solid detector 20f includes a first conductive layer 21, a recording photoconductive layer 22, a charge transport layer 23, a reading photoconductive layer 24, a second conductive layer 25 including a stripe electrode 26 and a sub-stripe electrode 27, The insulating layer 30 and the support 18 are arranged in this order. In addition, a light shielding film 31 is provided on a portion corresponding to each element 27a on the support 18 and between the element 26a and the element 27a. For each layer, the same one as the detector 20a according to the first embodiment is used.
[0064]
In the present embodiment, the thickness of the reading photoconductive layer 24 is 10 μm, the width of the element 26a and the element 27a is 15 μm, the width between adjacent elements is 10 μm, that is, the period is 50 μm. The pixel pitch is 150 μm, and the electrode for one pixel is composed of three pairs of elements.
[0065]
Also in the present embodiment, since the period is set to 50 μm and set within a preferable range of 10 μm to 150 μm, the same effect as that of the first embodiment can be obtained.
[0066]
Next, a seventh embodiment of the radiation solid detector according to the present invention will be described with reference to FIG. FIG. 8 is a sectional view of a radiation solid state detector 20g according to this embodiment. In addition, in this figure, the support body 18, the insulating layer 30, and the light shielding film 31 are abbreviate | omitted. In FIG. 8, the same reference numerals are given to the same elements as those of the detector 20a according to the first embodiment shown in FIG. 1, and the description thereof is omitted unless particularly required.
[0067]
The radiation solid state detector 20g includes a first conductive layer 21, a recording photoconductive layer 22, a charge transport layer 23, a reading photoconductive layer 24, a second conductive layer 25 including a stripe electrode 26 and a sub-stripe electrode 27, The insulating layer 30 and the support 18 are arranged in this order. In addition, a light shielding film 31 is provided on a portion corresponding to each element 27a on the support 18 and between the element 26a and the element 27a. For each layer, the same one as the detector 20a according to the first embodiment is used.
[0068]
In the present embodiment, the thickness of the reading photoconductive layer 24 is 10 μm, the width of the element 26a and the element 27a is 45 μm, the width between adjacent elements is 30 μm, that is, the period is 150 μm. The pixel pitch is 150 μm, and the electrode for one pixel is composed of one pair of elements.
[0069]
Further, in this detector 20g, a large number of discrete rectangular microplates (microconductive members) 28 are adjacent to the power storage unit 29 that is the interface between the recording photoconductive layer 22 and the charge transport layer 23. 28 is disposed directly above the pair of element 26a and element 27a with an interval between them. The length of each side of the microplate 28 is substantially the same as the above period (set to be slightly smaller in order to provide an interval with respect to the adjacent microplate), that is, the same dimension as the minimum resolvable pixel pitch. Is set to The position where the microplate 28 is disposed is the pixel position on the detector.
[0070]
Also in the present embodiment, since the cycle is set to 150 μm and set within the preferable range of 10 μm to 150 μm, the same effect as that of the first embodiment can be obtained.
[0071]
Next, an eighth embodiment of the radiation solid state detector according to the present invention will be described with reference to FIG. FIG. 9 is a sectional view of a radiation solid state detector 20h according to this embodiment. In addition, in this figure, the support body 18, the insulating layer 30, and the light shielding film 31 are abbreviate | omitted. In FIG. 9, elements that are the same as the elements of the detector 20 a according to the first embodiment shown in FIG. 1 are given the same reference numerals, and descriptions thereof are omitted unless particularly necessary.
[0072]
The radiation solid detector 20h includes a first conductive layer 21, a recording photoconductive layer 22, a charge transport layer 23, a reading photoconductive layer 24, a second conductive layer 25 including a stripe electrode 26 and a sub-strip electrode 27, The insulating layer 30 and the support 18 are arranged in this order. In addition, a light shielding film 31 is provided on a portion corresponding to each element 27a on the support 18 and between the element 26a and the element 27a. For each layer, the same one as the detector 20a according to the first embodiment is used.
[0073]
In the present embodiment, the thickness of the reading photoconductive layer 24 is 30 μm, the width of the element 26a and the element 27a is 30 μm, the width between adjacent elements is 20 μm, that is, the period is 100 μm. The pixel pitch is 200 μm, and the electrode for one pixel is composed of two pairs of elements.
[0074]
Also in this embodiment, since the cycle is set to 100 μm and set within a preferable range of 10 μm to 150 μm, it is possible to obtain the same effect as that of the first embodiment.
[0075]
The preferred embodiments of the radiation solid state detector according to the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without changing the gist of the invention. is there.
[0076]
For example, in any of the detectors according to the above-described embodiments, the recording photoconductive layer exhibits conductivity when irradiated with recording radiation. However, the recording photoconductive layer of the detector according to the present invention is not necessarily provided. However, the present invention is not limited to this, and the recording photoconductive layer may exhibit conductivity when irradiated with light emitted by excitation of recording radiation (see JP-A-2000-105297). In this case, a wavelength conversion layer called a so-called X-ray scintillator that converts the wavelength of recording radiation into light of another wavelength region such as blue light may be laminated on the surface of the first conductive layer. As this wavelength conversion layer, for example, cesium iodide (CsI) is preferably used. The first conductive layer is transmissive to light emitted from the wavelength conversion layer by excitation of recording radiation.
[0077]
In the detectors 20a to 20g according to the above-described embodiments, a charge transport layer is provided between the recording photoconductive layer and the reading photoconductive layer, and a power storage unit is provided at the interface between the recording photoconductive layer and the charge transport layer. However, the charge transport layer may be replaced with a trap layer. In the case of the trap layer, the latent image charge is trapped in the trap layer, and the latent image charge is accumulated in the trap layer or at the interface between the trap layer and the recording photoconductive layer. In addition, a microplate may be provided for each pixel at the interface between the trap layer and the recording photoconductive layer.
[Brief description of the drawings]
FIG. 1 is a perspective view (A) of a radiation solid detector according to a first embodiment of the present invention, an XZ sectional view (B) of a Q arrow portion, and an XY sectional view (C) of a P arrow portion.
FIG. 2 is a sectional view of the radiation solid state detector according to the first embodiment of the invention.
FIG. 3 is a cross-sectional view of a radiation solid state detector according to a second embodiment of the present invention.
FIG. 4 is a sectional view of a radiation solid state detector according to a third embodiment of the present invention.
FIG. 5 is a sectional view of a radiation solid state detector according to a fourth embodiment of the present invention.
FIG. 6 is a sectional view of a radiation solid state detector according to a fifth embodiment of the invention.
FIG. 7 is a sectional view of a radiation solid state detector according to a sixth embodiment of the present invention;
FIG. 8 is a sectional view of a radiation solid state detector according to a seventh embodiment of the present invention.
FIG. 9 is a sectional view of a radiation solid state detector according to an eighth embodiment of the present invention.
[Explanation of symbols]
20a-20h radiation solid state detector
21 First conductive layer
22 Photoconductive layer for recording
23 Charge transport layer
24 Photoconductive layer for reading
25 Second conductive layer
26 Striped electrode
26a element (photo charge pair generating linear electrode)
27 Sub-striped electrode
27a element (photo charge vs. non-generating linear electrode)
28 Microplate
29 Power storage unit

Claims (1)

A first conductive layer that is transparent to the recording light;
A photoconductive layer for recording that exhibits photoconductivity by being irradiated with the recording light;
A power storage unit that accumulates an amount of charge corresponding to the amount of the recording light as a latent image charge;
A photoconductive layer for reading that exhibits photoconductivity by receiving irradiation of reading light;
The second conductive layer is laminated in this order,
The second conductive layer includes a plurality of photoelectric charge pair generating linear electrodes that are transparent to the reading light, and a large number of photoelectric charge pair generating non-generating linear electrodes, In the radiation solid state detector in which the electrodes and the photocharge pair non-generating linear electrodes are arranged alternately and parallel to each other ,
A radiation solid state detector, wherein a period of the pair of the photocharge pair generating linear electrode and the photocharge pair non-generating linear electrode is one period, and the period is in a range of 10 μm to 150 μm.

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