JP2003086781A - Solid-state radiation detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently read accumulated electric charges in a solid-state radiation detector provided with a substripe electrode. SOLUTION: A 1st conductive layer 21, a photoconductive layer 22 for recording, a charge transfer layer 23, a photoconductive layer 24 for reading, a 2nd conductive layer 25 having a stripe electrode 26 composed of many linear elements 26a and a substripe electrode 27 composed of many linear elements 27a, an insulating layer 30, and a base 18 are arranged in this order. A shading film 31 is provided at parts corresponding to the respective elements 27a on the base 18 and parts between the elements 26a and 27a to constitute a solid- state radiation detector 20a. In this case, the ratio of the width of the elements 27a to the width of the elements 26a is made 0.5 to 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation solid-state detector having a power storage unit for accumulating as a latent image charge an amount of charge corresponding to a dose of irradiated radiation or an amount of light emitted by excitation of the radiation. It is a thing.

[0002]

2. Description of the Related Art Today, in radiography for the purpose of medical diagnosis and the like, charges obtained by detecting radiation are temporarily accumulated in a power storage unit as latent image charges, and the accumulated latent image charges represent radiation image information. Various types of radiation image information recording / reading apparatuses have been proposed that use a radiation solid-state detector (hereinafter also simply referred to as a detector) that converts and outputs an electric signal. Various types of solid-state radiation detectors to be used in this device have been proposed. However, from the viewpoint of the charge reading process for reading out the accumulated charges to the outside, the reading light (reading electromagnetic wave) is detected. ) Is used to read the light.

The applicant of the present invention has disclosed a solid-state radiation detector of the optical reading system, which can achieve both high-speed read response and efficient extraction of signal charges, as disclosed in Japanese Patent Laid-Open No. 2000-105.
297, JP 2000-284056 A, JP 200
0-284057, recording radiation or light emitted by excitation of the radiation (hereinafter referred to as recording light)
A first conductive layer having transparency to the recording layer, a recording photoconductive layer which exhibits conductivity by receiving recording light, and a substantially insulator for charges having the same polarity as the charges charged in the first conductive layer. A charge-transporting layer that acts on the charges of the same polarity and the charges of the opposite polarity to act as a substantially conductive material, and a reading light that exhibits conductivity by being irradiated with reading light (electromagnetic waves for reading). A conductive layer and a second conductive layer that is transparent to reading light are laminated in this order, and image information is carried in a power storage unit formed at the interface between the recording photoconductive layer and the charge transport layer. A detector that accumulates signal charge (latent image charge) is proposed.

Then, the above-mentioned Japanese Patent Laid-Open No. 2000-284056.
And Japanese Patent Application Laid-Open No. 2000-284057, in particular, a stripe formed by a photoconductive pair generating linear electrode having a second conductive layer electrode transparent to reading light and having a large number of reading light transmitting. In addition to the electrodes, a large number of photocharge pair non-generating linear electrodes for outputting an electric signal of a level corresponding to the amount of latent image charges accumulated in the electricity storage unit are alternately arranged with the photocharge pair generating linear electrodes. A detector provided in the second conductive layer so as to be parallel to each other is proposed.

As described above, by providing the sub-stripe electrode composed of a large number of photocharge 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. It is possible to charge the sub-stripe electrodes with the charge rearrangement at the time of reading, which is the transport charge having the opposite polarity to the latent image charge accumulated in the power storage unit by the recording light. 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 the sub-stripe electrode is not provided. As a result, it is possible to increase the amount of signal charges that can be taken out from the detector to improve the reading efficiency, and to achieve both high-speed read response and efficient extraction of signal charges. It has become.

[0006]

By the way, in the detector having the sub-stripe electrodes as described above, the ratio of the width of the photocharge pair generating linear electrode to the width of the photocharge pair non-generating linear electrode is set. , Greatly affects the reading efficiency of accumulated charges.

For example, when the width of the photocharge pair non-generating linear electrode is made wider than the width of the photocharge pair generating linear electrode, the first conductive layer and the second conductive layer are formed after the irradiation of the recording radiation. When a short circuit occurs, the amount of charge that is induced in the photocharge pair-non-generated linear electrodes increases, but the signal detection efficiency improves. The amount of effective light decreases, and the line resistance of the photocharge pair generating linear electrode increases, making it difficult to detect a signal.

Further, when the width of the photocharge pair non-generating linear electrode is narrowed with respect to the width of the photocharge pair generating linear electrode, the width of the photocharge pair generating linear electrode is large, so that the light reading pair can be read at the time of reading light. The effective light amount is large, and the line resistance of the photocharge pair generating linear electrode is small, which facilitates signal detection. On the other hand, when the first conductive layer and the second conductive layer are short-circuited after the irradiation of the recording radiation, the amount of charges induced in the photocharge pair non-generating linear electrode is reduced, so that the signal detection efficiency is reduced.

As described above, various problems occur unless the ratio of the width of the photocharge pair generating linear electrode to the width of the photocharge pair non-generating linear electrode is optimized.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a solid-state radiation detector provided with a sub-striped electrode, which can efficiently read out accumulated charges. To do.

[0011]

Means for Solving the Problems The inventor of the present invention has disclosed the above-mentioned Japanese Unexamined Patent Application Publication No.
In a detector provided with a sub-striped electrode described in Japanese Patent Application Laid-Open No. 000-284056, a relationship between a ratio of a width of a photocharge pair to a non-generated linear electrode to a width of a photocharge pair to a generated linear electrode and a reading efficiency is investigated. However, as a result of this investigation, they found that there is a relationship as shown in FIG.
FIG. 7 is a graph showing the relationship between the two, where the vertical axis represents the reading efficiency and the horizontal axis represents the ratio of the width of the photocharge pair generating linear electrode to the width of the photocharge pair non-generating linear electrode.

Conventionally, it has been considered that the reading efficiency is improved by making the width of the photocharge pair non-generating linear electrode relatively wider than the width of the photocharge pair generating linear electrode. As shown in FIG. 7, it was found that the reading efficiency was highest when the ratio was 1, that is, when the width of the photocharge pair generating linear electrode and the width of the photocharge pair non-generating linear electrode were the same.

The present invention was made based on the above new findings. That is, the solid-state radiation detector according to the present invention includes a first conductive layer that is transparent to recording light, a recording photoconductive layer that exhibits photoconductivity when irradiated with recording light, and a recording light conductive layer. A power storage unit that accumulates an amount of charge corresponding to the amount of light as a latent image charge, a reading photoconductive layer that exhibits photoconductivity by being irradiated with the reading light, and a large number of light transmissive to the reading light. A second conductive layer including a charge pair generating linear electrode and a large number of photocharge pair non-generating linear electrodes, in which the photocharge pair generating linear electrodes and the photocharge pair non-generating linear electrodes are alternately arranged. In the solid-state radiation detector formed by stacking and in this order, the ratio of the width of the photocharge to the non-generated linear electrode to the width of the photocharge to the generated linear electrode is in the range of 0.5 to 10. It is what

The "radiation solid state detector" has a first conductive layer, a recording photoconductive layer, a reading photoconductive layer and a second conductive layer in this order, and also has a recording photoconductive layer and a reading photoconductive layer. A power storage unit is formed between the photoconductive layer and another layer, and a microconductive member (microplate)
It does not matter even if it is formed by stacking etc. Further, 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.

As a method of forming the above-mentioned power storage unit, a method of providing a charge transport layer and forming the power storage unit at the interface between this charge transport layer and the recording photoconductive layer (Japanese Patent Laid-Open No. 2000- 105297, JP 2000-28
No. 4056), a method of forming a storage layer in the trap layer or at the interface between the trap layer and the recording photoconductive layer (for example, US Pat. No. 4,535,546).
No. 8), or a method of providing a minute conductive member or the like for concentrating and storing latent image charges (Japanese Patent Laid-Open No. 2000-2000)
(See Japanese Patent Publication No. 284057) and the like may be used.

The "photoelectric charge pair generating linear electrode having transparency to the reading light" is an electrode which transmits the reading light and generates a charge pair in the reading photoconductive layer. The “photoelectric charge pair non-generating linear electrode” is an electrode for outputting an electric signal of a level corresponding to the amount of latent image charge accumulated in the electricity storage unit, and has a light shielding property against reading light. It is desirable that the photocharge pair non-generating linear electrode has a light shielding property 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. There is no.
Here, the “light-shielding property” is not limited to the one that completely blocks the reading light and does not generate the charge pair at all, and the charge pair generated by the reading light even if it has some transparency to the reading light. Including items that do not pose a problem. Therefore, all the charge pairs generated in the reading photoconductive layer are not limited to only the reading light transmitted through the photocharge pair generating linear electrode, and are not caused by the reading light slightly passing through the photocharge pair non-generating linear electrode. Also, charge pairs can be generated in the reading photoconductive layer.

Further, the "reading light" may be any light as long as it can move the charge in the electrostatic recording medium and electrically read the electrostatic latent image. Specifically, the reading light is light or radiation. Etc.

In the solid-state radiation detector according to the present invention,
The ratio of the width of the photocharge-to-non-generated linear electrodes to the width of the photocharge-to-generated linear electrodes is more preferably 0.8 to 1.5.
It is desirable to set the range to.

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. The recording method and the reading method using and the device can be used as they are without changing.

[0020]

According to the solid-state radiation detector of the present invention, the ratio of the width of the photocharge to the non-generated linear electrode to the width of the photocharge to the generated linear electrode is optimized to be 0.5 to 10.
The amount of accumulated charge that can be taken out can be increased, and reading efficiency and image S / N can be improved.

That is, as shown in FIG. 7 described above, by setting the ratio of the width of the photocharge pair to the non-generation linear electrode to the width of the photocharge pair generating linear electrode to 0.5 to 10, the highest reading can be achieved. The reading efficiency close to the efficiency can be realized, and the S / N of the image can be improved. In addition, this ratio is 0.8 to 1.5
If so, it is possible to realize a further excellent reading efficiency.

[0022]

BEST MODE FOR CARRYING OUT 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 solid-state radiation detector of the present invention,
1A is a perspective view of the solid-state radiation detector 20a, FIG.
1B is an XZ sectional view of the Q arrow finger portion of the radiation solid-state detector 20a, and FIG. 1C is an XY sectional view of the P arrow finger portion of the radiation solid detector 20a. Further, FIG. 2 is a sectional view similar to FIG. 1B for explaining the cycle when the pair of the charge-pair generating linear electrode and the charge-pair non-generating linear electrode is one cycle.
Note that, in FIG. 2, the support 18, the insulating layer 30, and the light shielding film 31 are omitted.

The solid-state radiation detector 20a is a first conductive layer 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. 21, this first conductive layer 2
1. A recording photoconductive layer 22 that exhibits a conductivity by generating a charge pair upon receiving the irradiation of the recording light that has passed through 1, and is a substantially insulator with respect to the latent image polar charge (for example, negative charge) of the charge pair. Charge transport layer 23 that acts as an electric conductor and acts substantially as a conductor with respect to the transport polar charge (the positive charge in the above example) having the opposite polarity to the latent image polar charge, and the charge by receiving the reading light. The photoconductive layer for reading 24 which generates a pair and exhibits conductivity, the second conductive layer 25 including the stripe electrode 26 and the sub-stripe electrode 27, the insulating layer 30 which is transparent to the reading light, and the reading light. The support 18 having transparency is arranged 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 the latent image polar charge carrying the image information generated in the recording photoconductive layer 22 is formed. It

As the support 18, a glass substrate or the like which is transparent to the reading light can be used. Further, in addition to being transparent to the reading light, it is more desirable to use a substance whose thermal expansion coefficient 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 coefficient of thermal expansion of Se is 3.68 × 10 ⁻⁵ / K @ 40.
Considering that the temperature is 1.0 ° C., the coefficient of thermal expansion is 1.0 to 10.
0 × 10 ⁻⁵ / K @ 40 ° C., more preferably 4.0.
Use a substance that is 8.0 × 10 ⁻⁵ / K @ 40 ° C.
As a substance having a coefficient of thermal expansion within this range, an organic polymer material such as polycarbonate or polymethylmethacrylate (PMMA) can be used. As a result, the thermal expansion of the support 18 as a substrate and the photoconductive layer for reading 24 (Se film) can be matched, and a large temperature cycle can be performed in a special environment, for example, during ship transportation under cold weather conditions. Even if received, thermal stress occurs at the interface between the support 18 and the reading photoconductive layer 24, and the two physically separate.
There is no problem of destruction due to the difference in thermal expansion, such as the reading photoconductive layer 24 breaking or the support 18 cracking. Furthermore, organic polymer materials have the advantage of being more resistant to impacts than glass substrates.

The material of the recording photoconductive layer 22 is a-
Se (amorphous selenium), PbO, PbI_Two  Etc.
Lead (II) oxide, lead (II) iodide, Bi₁₂(Ge, S
i) O ₂₀, Bi_TwoI_Three/ Organic polymer nanocomposite
Photoconductive material containing at least one of
Is appropriate.

As the material of the charge transport layer 23, it is better that 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 large (for example, 1
0 ² or more, preferably 10 ³ or higher) poly N- vinylcarbazole (PVK), N, N'-diphenyl -N, N'-bis (3-methylphenyl) - [1,1'-biphenyl] -4, Four'
An organic compound such as diamine (TPD) or discotic liquid crystal, or a polymer dispersion of TPD (polycarbonate, polystyrene, PUK), Cl of 10 to 20
A semiconductor material such as 0 ppm doped a-Se is suitable. In particular, organic compounds (PVK, TPD, discotic liquid crystal, etc.) are preferable because they have light insensitivity. Further, since the permittivity is generally small, the charge transport layer 23 and the reading photoconductive layer 24 have small capacities, and at the time of reading. The signal extraction efficiency of can be increased. It should be noted that "having light insensitivity" means that it exhibits almost no conductivity even when irradiated with recording light or reading light.

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 (phaseII of Vanadyl phthal
Cyanine), CuPc (Cupper phtalocyanine), and the like, and a photoconductive substance containing at least one as a main component is suitable.

The thickness of the recording photoconductive layer 22 is 50 μm or more and 1000 in order to sufficiently absorb the recording light.
It is preferably not more than μm.

The charge transport layer 23 and the reading photoconductive layer 24 are also provided.
It is desirable that the sum of the thicknesses of and is less than or equal to 1/2 of the thickness of the recording photoconductive layer 22, and the thinner the thickness, the better the response at the time of reading. Is preferably 1/100 or less.

The materials of the above layers are the same as those of the first conductive layer 21.
Is charged with a negative charge, and the second conductive layer 25 is charged with a positive charge, and a negative charge as a latent image polar charge is accumulated in the electricity storage unit 29 formed at the interface between the recording photoconductive layer 22 and the charge transport layer 23. At the same time, the charge transport layer 23 functions as a so-called hole transport layer in which the mobility of the positive charge as the transport polarity charge having the opposite polarity is larger than the mobility of the negative charge as the latent image polarity charge. However, they may have opposite polarities, and when reversing the polarities as described above, the charge transporting layer that functions as a hole transporting layer may be used as an electron transporting layer. Only minor changes, such as changing to a charge transport layer that functions as a layer, are required.

For example, as the recording photoconductive layer 22, a photoconductive substance such as the above-mentioned amorphous selenium a-Se, lead (II) oxide, and lead (II) iodide can be used in the same manner, and the charge transport layer 23 can be made of N. -Trinitrofluorenylidene-aniline (TNFA) dielectrics, trinitrofluorenone (TNF) / polyester dispersions, asymmetric diphenoquinone derivatives are suitable, and the above-mentioned metal-free phthalocyanine and metal phthalocyanine are the same as the reading photoconductive layer 24. Can be used for

In the detector 20a, the power storage unit 29
Was formed at the interface between the recording photoconductive layer 22 and the charge transport layer 23, but the invention is not limited to this. For example, US Pat. No. 4,535,468.
As described in No. 5, the electricity storage unit may be formed by a trap layer that accumulates latent image polar charges as traps.

Any material may be used as the first conductive layer 21 as long as it is transparent to recording light. For example, when it is made to be transparent to visible light, it is known as a light-transmissive metal thin film. Film (SnO ₂ ), ITO (Indium Tin O
xide) or IDIXO (Idemitsu IndiumX-m) which is an amorphous light-transmissive metal oxide that is easy to etch
etal Oxide; Idemitsu Kosan Co., Ltd., etc.
It can be used with a thickness of about 200 nm, preferably 100 nm or more. In addition, aluminum Al, gold Au,
A pure metal such as molybdenum Mo or chromium Cr is used, for example, 20
By setting the thickness to be less than or equal to nm (preferably about 10 nm), it is possible to impart the transparency to visible light. Note that X-rays are used as the recording light, and the first conductive layer 21
When recording the image by irradiating the X-ray from the side,
Since the conductive layer 21 does not need to transmit visible light, the first conductive layer 21 is made of, for example, Al having a thickness of 100 nm.
A pure metal such as Au or Au can also be used.

The second conductive layer 25 includes a stripe electrode 26 formed by arranging a large number of reading light transmitting elements (photoelectric charge pair generating linear electrodes) 26a in a stripe pattern and a large number of reading light shielding elements (light Charge pair non-generated linear electrode) 27a
Sub-stripe electrode 27 in which the electrodes are arranged in a stripe pattern
It has and. The elements 26a and 27a are arranged such that the elements 26a and the elements 27a are arranged alternately and in parallel with each other. A part of the reading photoconductive layer 24 is interposed between both elements, and the stripe electrode 26 and the sub-stripe electrode 27 are electrically insulated. The sub-stripe electrode 27 is a conductive element for outputting an electric signal of a level corresponding to the amount of latent image charge accumulated in the electricity storage unit 29 formed at the substantially interface between the recording photoconductive layer 22 and the charge transport layer 23. It is a member.

Here, the material of the electrode material forming each element 26a of the stripe electrode 26 is ITO (In
dium Tin Oxide), IDIXO (Idemitsu Indium X-me
talOxide; Idemitsu Kosan Co., Ltd., aluminum or molybdenum can be used. Further, as the material of the electrode material forming each element 27a of the sub-stripe electrode 27, aluminum, molybdenum, chromium or the like can be used.

In the present embodiment, the thickness of the photoconductive layer for reading 24 is 30 μm, the width of the elements 26a and 27a is 30 μm, and the width between adjacent elements is 20 μm, that is, the period is 100 μm. . Further, the pixel pitch is 100 μm, and one pixel element is composed of one pair of elements.
Further, in the present embodiment, the ratio of the width of the element 27a (photocharge pair non-generating linear electrode) to the element 26a (photocharge pair generating linear electrode) is 1.0.

As shown in FIG. 2, here, the period is from the middle of the element 26a of the pair A and the element 27a of the pair B adjacent to the pair A to the element 27a of the pair A.
And the length between the pair 26 and the element 26a of the pair C adjacent to the pair A.

Further, each element 27a on the support 18
Also, a light-shielding film made of a member having poor light transmittance 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 in a portion corresponding to between the element 26a and the element 27a. 31 is provided.

The member of the light-shielding film 31 does not necessarily have an insulating property, and the light-shielding film 31 has a specific resistance of 2 × 10 ⁻⁶ or more (more preferably 1 × 10 6).
¹⁵ Ω · cm or less) can be used. For example, metal materials such as Al, Mo, and Cr can be used, and organic materials include MOS ₂ , WSi ₂ , and TiN.
Etc. can be used. It is more preferable to use a light-shielding film 31 having a specific resistance of 1 Ω · cm or more.

Further, at least when a conductive member such as a metal material is used as the member of the light shielding film 31, the light shielding film 3
In order to avoid direct contact between the element 1 and the element 27a, an insulator is arranged between them. The detector 20a of the present embodiment is provided with an insulating layer 30 made of SiO ₂ or the like between the second conductive layer 25 and the support 18 as this insulator. The insulating layer 30 has a thickness of about 0.01 to 10 μm, more preferably about 0.1 μ to 1 μm, and most preferably 0.5 μm.
The degree is good.

In this detector 20a, a capacitor C * a is formed between the first conductive layer 21 and the electricity storage section 29 with the recording photoconductive layer 22 interposed therebetween, and the charge transport layer 23 and the reading photoconductive layer are formed. A capacitor C * b is formed between the electricity storage unit 29 and the stripe electrode 26 (element 26a) with the electricity storage unit 29 and the sub-stripe electrode 27 (via the reading photoconductive layer 24 and the charge transport layer 23 interposed therebetween). A capacitor C * c is formed between it and the element 27a). At the time of charge rearrangement during reading, each capacitor C * a,
Amount Q + a, Q + of positive charges distributed to C * b, C * c
In b and Q + c, the total Q + is the same as the amount Q- of latent image polar charge, and is an amount proportional to the capacitances Ca, Cb, and Cc of each capacitor. This can be expressed by the following formula.

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 / (Get Ca + Cb + Cc) Then, take out the detector and detect it. The signal charge amount is the positive charge amount Q + distributed to the capacitors C * a and C * c.
It becomes the same as the sum of a and Q + c (Q + a + Q + c), and the positive charge distributed to the capacitor C * b cannot be taken out as a signal charge (for details, see Japanese Patent Laid-Open No. 2000-284056).

Considering the capacities of the capacitors C * b and C * c formed by the stripe electrode 26 and the sub-stripe electrode 27, the capacity ratio Cb: Cc is determined by the width ratio Wb: Wc of each element 26a, 27a. Becomes On the other hand, the capacitance Ca of the capacitor C * a and the capacitance Cb of the capacitor C * b have substantially no significant effect even if the sub-stripe electrode 27 is provided.

As a result, during charge rearrangement during reading, the amount of positive charges Q + b distributed to the capacitor C * b can be made relatively smaller than when the sub-stripe electrode 27 is not provided. The amount of signal charge that can be taken out from the detector 20a via the sub-stripe electrode 27 can be made relatively larger than that in the case where the sub-stripe electrode 27 is not provided.

Further, since the ratio of the width of the element 27a to the width of the element 26a is set to 1.0 and set within the preferable range of 0.5 to 10, the amount of accumulated charge that can be taken out can be increased, It is possible to improve reading efficiency and image S / N.

Next, a second embodiment of the solid-state radiation detector according to the present invention will be described with reference to FIG. Figure 3
FIG. 4 is a sectional view of a solid-state radiation detector 20b according to the present embodiment. In addition, in the figure, the support 18, the insulating layer 30, and the light shielding film 31 are omitted. Further, in FIG. 3, the detector 20 according to the first embodiment shown in FIG.
Elements that are the same as the elements of a are given the same numbers, and descriptions thereof are omitted unless necessary.

The radiation solid-state detector 20b has a second conductive layer including a first conductive layer 21, a recording photoconductive layer 22, a charge transport layer 23, a reading photoconductive layer 24, a stripe electrode 26 and a sub-stripe electrode 27. The layer 25, the insulating layer 30, and the support 18 are arranged in this order. Further, a light shielding film 31 is provided on each element 27a on the support 18 and on a portion corresponding to between the element 26a and the element 27a. The same layer as the detector 20a according to the first embodiment is used for each layer.

In this embodiment, the thickness of the photoconductive layer for reading 24 is 30 μm, the width of the element 26a is 25 μm, the width of the element 27a is 35 μm, and the width between adjacent elements is 20 μm, that is, the period. 10
It is set to 0 μm. The pixel pitch is 100 μm,
An electrode for one pixel is composed of a pair of elements. Further, in the present embodiment, the ratio of the width of the element 27a to the width of the element 26a is 1.4.

Also in this embodiment, the element 26
Since the ratio of the width of the element 27a to the width of a is 1.4 and set within the preferable range of 0.5 to 10, it is possible to obtain the same effect as that of the first embodiment.

Next, a third embodiment of the solid-state radiation detector according to the present invention will be described with reference to FIG. Figure 4
FIG. 4 is a sectional view of a solid-state radiation detector 20c according to the present embodiment. In addition, in the figure, the support 18, the insulating layer 30, and the light shielding film 31 are omitted. Further, in FIG. 4, the detector 20 according to the first embodiment shown in FIG.
Elements that are the same as the elements of a are given the same numbers, and descriptions thereof are omitted unless necessary.

This radiation solid-state detector 20c has a second conductive layer having a first conductive layer 21, a recording photoconductive layer 22, a charge transport layer 23, a reading photoconductive layer 24, a stripe electrode 26 and a sub-stripe electrode 27. The layer 25, the insulating layer 30, and the support 18 are arranged in this order. Further, a light shielding film 31 is provided on each element 27a on the support 18 and on a portion corresponding to between the element 26a and the element 27a. The same layer as the detector 20a according to the first embodiment is used for each layer.

In this embodiment, the reading photoconductive layer 24 has a thickness of 10 μm, the elements 26a and 27a have a width of 15 μm, and the width between adjacent elements is 10 μm, that is, the period is 50 μm. . The pixel pitch is 100 μm, and the electrodes for one pixel are composed of two pairs of elements. Further, in the present embodiment, the ratio of the width of the element 27a to the width of the element 26a is 1.0.

Also in this embodiment, the element 26
Since the ratio of the width of the element 27a to the width of a is 1.0 and set within the preferable range of 0.5 to 10, it is possible to obtain the same effect as that of the first embodiment.

Next, a fourth embodiment of the solid-state radiation detector according to the present invention will be described with reference to FIG. Figure 5
FIG. 4 is a sectional view of a solid-state radiation detector 20d according to the present embodiment. In addition, in the figure, the support 18, the insulating layer 30, and the light shielding film 31 are omitted. Further, in FIG. 5, the detector 20 according to the first embodiment shown in FIG.
Elements that are the same as the elements of a are given the same numbers, and descriptions thereof are omitted unless necessary.

This radiation solid-state detector 20d has a second conductive layer including a first conductive layer 21, a recording photoconductive layer 22, a charge transport layer 23, a reading photoconductive layer 24, a stripe electrode 26 and a sub-stripe electrode 27. The layer 25, the insulating layer 30, and the support 18 are arranged in this order. Further, a light shielding film 31 is provided on each element 27a on the support 18 and on a portion corresponding to between the element 26a and the element 27a. The same layer as the detector 20a according to the first embodiment is used for each layer.

In the present embodiment, the thickness of the reading photoconductive layer 24 is 10 μm, the width of the element 26a is 20 μm, the width of the element 27a is 10 μm, and the width between adjacent elements is 10 μm, that is, the period. 50
μm. The pixel pitch is 100 μm and 1
The pixel electrodes are composed of two pairs of elements. In the present embodiment, the ratio of the width of the element 27a to the width of the element 26a is 0.5.

Also in this embodiment, the element 26
Since the ratio of the width of the element 27a to the width of a is set to 0.5 and set within the preferable range of 0.5 to 10, it is possible to obtain the same effect as that of the first embodiment.

Next, a fifth embodiment of the solid-state radiation detector according to the present invention will be described with reference to FIG. Figure 6
FIG. 4 is a sectional view of a solid-state radiation detector 20e according to the present embodiment. In addition, in the figure, the support 18, the insulating layer 30, and the light shielding film 31 are omitted. Further, in FIG. 6, the detector 20 according to the first embodiment shown in FIG.
Elements that are the same as the elements of a are given the same numbers, and descriptions thereof are omitted unless necessary.

This radiation solid-state detector 20e has a second conductive layer including a first conductive layer 21, a recording photoconductive layer 22, a charge transport layer 23, a reading photoconductive layer 24, a stripe electrode 26 and a sub-stripe electrode 27. The layer 25, the insulating layer 30, and the support 18 are arranged in this order. Further, a light shielding film 31 is provided on each element 27a on the support 18 and on a portion corresponding to between the element 26a and the element 27a. The same layer as the detector 20a according to the first embodiment is used for each layer.

In the present embodiment, the thickness of the reading photoconductive layer 24 is 10 μm, the width of the element 26a is 10 μm, the width of the element 27a is 20 μm, and the width between adjacent elements is 10 μm, that is, the period. 50
μm. The pixel pitch is 100 μm and 1
The pixel electrodes are composed of two pairs of elements. In the present embodiment, the ratio of the width of the element 27a to the width of the element 26a is 2.0.

Also in this embodiment, the element 26
The ratio of the width of the element 27a to the width of a is 2.0 and is set within the preferable range of 0.5 to 10. Therefore, the same effect as that of the first embodiment can be obtained.

Although the preferred embodiments of the solid-state radiation detector according to the present invention have been described above, the present invention is not limited to the above-mentioned embodiments, and various modifications can be made without changing the gist of the invention. Is possible.

For example, the detector according to the above embodiment is
In either case, the recording photoconductive layer exhibits conductivity by irradiation with recording radiation, but the recording photoconductive layer of the detector according to the present invention is not necessarily limited to this. The photoconductive layer may be made conductive by irradiation with light emitted by excitation of recording radiation (see JP-A-2000-105297). In this case, the so-called X that converts the wavelength of the recording radiation on the surface of the first conductive layer into light in another wavelength range, such as blue light, is used.
It is preferable that a wavelength conversion layer called a line scintillator is laminated. As the wavelength conversion layer, it is preferable to use, for example, cesium iodide (CsI) or the like. Also, the first
The conductive layer is transparent to the light emitted from the wavelength conversion layer when excited by the recording radiation.

Further, the detector 20a according to the above-mentioned embodiment.
(E) to (e) are those in which a charge transport layer is provided between the recording photoconductive layer and the reading photoconductive layer, and a power storage unit is formed at the interface between the recording photoconductive layer and the charge transport layer. The charge transport layer may be replaced with a trap layer. When the trap layer is used, the latent image charge is captured by 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. Further, a microplate may be provided at the interface between the trap layer and the recording photoconductive layer for each pixel.

[Brief description of 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 portion (B), and P.
XY sectional view of the arrow finger portion (C)

FIG. 2 is a sectional view of the solid-state radiation detector according to the first embodiment of the present invention.

FIG. 3 is a sectional view of a solid-state radiation 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 solid-state radiation detector according to a fifth embodiment of the present invention.

FIG. 7 is a graph showing the relationship between the ratio of the width of the photocharge pair generating linear electrode to the width of the photocharge pair non-generating linear electrode and the reading efficiency.

[Explanation of symbols]

20a-20e Solid state radiation detector 21 First conductive layer 22 Photoconductive layer for recording 23 Charge transport layer 24 Photoconductive layer for reading 25 Second conductive layer 26 stripe electrodes 26a element (photoelectric charge pair generation linear electrode) 27 Sub-stripe electrode 27a element (photoelectric charge pair non-generated linear electrode) 28 microplates 29 power storage unit

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2G088 EE01 GG21 JJ31                 4M118 AA01 AB01 BA19 BA30 CB05                       CB11 GA05 GA10 GB11 HA25                       HA26                 5C024 AX16 AX17 GX07                 5F088 AA11 AB05 BA02 BA03 BA16                       BB07 FA09 HA10

Claims (2)

[Claims] 1. A first conductive layer having transmissivity for recording light, a recording photoconductive layer exhibiting photoconductivity by being irradiated with the recording light, and a recording conductive layer according to a light amount of the recording light. A storage unit for accumulating a certain amount of electric charges as latent image charges, a reading photoconductive layer exhibiting photoconductivity by being irradiated with reading light, and generation of a large number of photocharge pairs having transparency to the reading light. A linear electrode and a large number of photocharge pair non-generated linear electrodes,
In the radiation solid state detector, the second conductive layer in which the photocharge pair generating linear electrodes and the photocharge pair non-generating linear electrodes are alternately arranged is laminated in this order, wherein the photocharge pair generating is The radiation solid-state detector, wherein the ratio of the width of the photocharge to the width of the non-generated linear electrode with respect to the width of the linear electrode is in the range of 0.5 to 10. 2. The ratio of the width of the photocharge-to-non-generated linear electrode to the width of the photocharge-to-generated linear electrode is 0.8 to 1.
The solid state radiation detector according to claim 1, wherein the solid state detector has a range of 5.