JP2002334980A - Radiation image recording apparatus and recorded radiation image reading apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve high speed responsiveness of reading and efficiency of reading latent image charges, by storing latent image charges in a charge storing section of a solid-state radiation detector, in which an electrode layer irradiated with electromagnetic waves for reading are formed, by alternately arranging first stripe electrodes for transmitting the electromagnetic waves for reading and second stripe electrodes for shielding the electromagnetic waves for reading, so that the charges localize without adding a control voltage source, etc. SOLUTION: The apparatus has a voltage applying means 30 for applying a DC voltage between a first electrode layer 21 and second stripe electrodes 27, and a first resistor R1 and a second resistor R2 which are connected in series. One end of the resistor R1 is connected to the electrode 21, the other end of the resistor R1 is connected to electrodes 26, and one end of the resistor R2 is connected to the electrodes 27. Thus, a control voltage for controlling the electric field distribution, formed between the electrodes 26 and 27 by the DC voltage, is applied to the electrodes 26.

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 as a latent image charge in accordance with the dose of irradiated radiation to convert a radiation image into an electrostatic latent image The present invention relates to a radiographic image recording apparatus for recording, and a radiographic image recording and reading apparatus for recording a radiographic image as an electrostatic latent image and reading the recorded electrostatic latent image in the same manner as described above.

[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 a radiation image is recorded as an electrostatic latent image, and the radiation image is read from the detector by scanning a detector on which the radiation image is recorded with a laser beam or a line light source (for example, US Pat. Japanese Patent No. 4535468).

The applicant of the present application has proposed in Japanese Patent Application Laid-Open No. 2000-284056 a solid-state radiation detector capable of achieving both high-speed readout response and efficient signal charge extraction. The radiation solid-state detector described in Japanese Patent Application Laid-Open No. 2000-284056 has a first electrode layer having transparency for recording radiation or light emitted by excitation of radiation, recording radiation or irradiation of the light. A photoconductive layer for recording, which exhibits conductivity when exposed to light, a power storage unit, which accumulates an amount of charge corresponding to the dose of irradiated radiation as a latent image charge, and exhibits conductivity when irradiated with electromagnetic waves for reading. A reading photoconductive layer, a second electrode layer irradiated with a reading electromagnetic wave, in this order, the second electrode layer,
The first is composed of a large number of linear electrodes that transmit electromagnetic waves for reading.
It has a stripe electrode and a second stripe electrode for shielding electromagnetic waves for reading, and the first stripe electrode and the second stripe electrode are alternately arranged substantially in parallel.

In the above solid-state radiation detector, the radiation transmitted through the subject while the voltage is applied so that the first electrode layer has a negative potential and the second electrode layer has a positive potential is the radiation solid-state detector. When the first electrode layer of the detector is irradiated, the radiation transmitted through the first electrode layer generates a charge pair in the recording photoconductive layer in accordance with the dose of the radiation, and the negative charge is stored in the power storage unit. And a radiation image is recorded as an electrostatic latent image. At this time, if the first stripe electrode and the second stripe electrode are connected to each other to perform the recording with the same potential, the latent image charge is accumulated in the power storage unit at a position corresponding to both electrodes.

When the electromagnetic wave for reading is applied to the second electrode layer of the solid-state radiation detector, the electromagnetic wave passes through the first stripe electrode and is applied to the photoconductive layer for reading. A charge pair is generated in the conductive layer, and a positive charge of the charge pair is combined with a negative charge stored in the power storage unit, and the negative charge is a positive charge charged on the first stripe electrode and the second stripe electrode. The reading of the electrostatic latent image is performed by combining with the above. In the reading, for example, a current detection amplifier is connected to the first stripe electrode or the second stripe electrode, and the connected stripe electrode of the current detection amplifier is grounded via an imminent short circuit of the current detection amplifier, and the other is connected to the other. By performing grounding on the stripe electrodes, both stripe electrodes are set to the same potential. At this time, the reading is performed by combining the negative charge generated by the irradiation of the reading electromagnetic wave with the positive charge charged on the first stripe electrode and the second stripe electrode, but the reading is actually performed. Most of the electric signal detected by the current detection amplifier by the coupling is such that the positive charge charged on the second stripe electrode moves to the first stripe electrode via the current detection amplifier, and is irradiated by the electromagnetic wave for reading. It is caused by combining with the generated negative charge. Therefore, the ideal reading efficiency when reading as described above is determined by the ratio of the width of the first stripe electrode to the width of the second stripe electrode, that is, the ratio of the capacitance of both electrodes.

Here, in the recording in the radiation solid state detector, the inventor applied a DC voltage between the first electrode layer and the second stripe electrode, and changed the electric field distribution formed by the voltage application. The control is performed by applying a predetermined control voltage to the first stripe electrode to localize the latent image charges stored in the power storage unit to the power storage unit at a position corresponding to the second stripe electrode connected to the current detection amplifier. Thus, a method for improving reading efficiency has been proposed. Also,
Instead of applying a predetermined control voltage to the first stripe electrode as described above, by leaving the first stripe electrode open, the potential of the first stripe electrode is set to a potential closer to the first electrode layer than to the second stripe electrode. By doing so, a method has been proposed in which latent image charges are localized and stored in the power storage unit at a position corresponding to the second stripe electrode. Further, in the above method, the same applies when the voltage applied to the first stripe electrode and the second stripe electrode is reversed, that is, the DC voltage is applied between the first electrode layer and the first stripe electrode. By applying a voltage and applying a predetermined control voltage to the second stripe electrode by applying a predetermined control voltage to the second stripe electrode, or by opening the second stripe electrode, the position corresponding to the first stripe electrode is changed. The latent image charges can be localized and stored in the power storage unit.

[0007]

However, when recording a radiation image using the solid-state radiation detector as described above, an electric field distribution is formed between the first electrode layer and the second electrode layer. Voltage source for controlling the distribution of the electric field and a control voltage source for controlling the electric field distribution need to be provided separately, which increases the cost. Further, when recording is performed in an open state without applying a control voltage to the first stripe electrode or the second stripe electrode, the control voltage source is unnecessary, but the first stripe electrode or the second stripe electrode is not required.
A relatively expensive relay dedicated to high voltage for switching the stripe electrode to an open state is required, which also causes a problem of cost increase. Further, when the first stripe electrode or the second stripe electrode is kept open, there is a disadvantage that accurate potential control is impossible and reproducibility is poor as compared with the case where the control voltage is applied.

[0008] The present invention has been made in view of the above problems,
It is possible to localize the latent image charge in the power storage unit by applying the control voltage without increasing the cost due to the addition of a control voltage source or a high-voltage dedicated relay, and the high-speed response of reading the latent image charge It is an object of the present invention to provide a radiation image recording apparatus capable of improving read efficiency and a radiation image recording / reading apparatus capable of performing the above-described reading using the radiation image recording apparatus. is there.

[0009]

According to the first aspect of the present invention, there is provided a first radiation image recording apparatus comprising: a first electrode layer having transparency for recording radiation or light emitted by excitation of the radiation; A recording photoconductive layer that exhibits conductivity by being irradiated with the radiation or the light, a power storage unit that accumulates an amount of charge corresponding to a dose of the irradiated radiation as a latent image charge, and is irradiated with a reading electromagnetic wave. A first stripe electrode comprising a plurality of linear electrodes for generating photocharge pairs in response to the irradiation of the electromagnetic wave for reading and the electromagnetic wave for reading; A second stripe electrode composed of a large number of linear electrodes for generating no photocharge with respect to the electromagnetic wave, and the first stripe electrode and the second stripe electrode are alternately arranged substantially in parallel. Electrode layer The radiation image is stored in the power storage unit by irradiating the solid-state radiation detector with the radiation for recording and storing an amount of charge corresponding to the dose of the irradiated radiation as a latent image charge in the power storage unit. In a radiation image recording apparatus for recording as an electrostatic latent image, a first electrode layer and a second
A voltage applying means for applying a DC voltage between the first electrode and the stripe electrode; a first resistor and a second resistor connected in series; one end of the first resistor is connected to the first electrode layer; ,
The other end of the first resistor is connected to the first stripe electrode, and one end of the second resistor that is not connected to the first resistor is the second resistor.
By being connected to the stripe electrode, a control voltage for controlling an electric field distribution formed between the first electrode layer and the second stripe electrode is applied to the first stripe electrode by a DC voltage. There is a feature.

A second radiation image recording apparatus according to the present invention comprises a first electrode layer having transparency to recording radiation or light emitted by excitation of the radiation, recording radiation or irradiation of the light. A photoconductive layer for recording, which exhibits conductivity when exposed to light, a power storage unit, which accumulates an amount of charge corresponding to the dose of irradiated radiation as a latent image charge, and exhibits conductivity when irradiated with electromagnetic waves for reading. A photoconductive layer for reading, a first stripe electrode composed of a number of linear electrodes for generating photocharge pairs when irradiated with electromagnetic waves for reading, and a photocharge for electromagnetic waves for reading; A second electrode layer having a second stripe electrode composed of a large number of linear electrodes for non-generation is provided, in which the first stripe electrodes and the second stripe electrodes are alternately arranged substantially in parallel. Release The radiation image is recorded as an electrostatic latent image on the power storage unit by irradiating the solid-state radiation detector with radiation for recording and accumulating an amount of charge corresponding to the dose of the irradiated radiation as a latent image charge on the power storage unit. A radiation image recording apparatus comprising: a voltage application unit for applying a DC voltage between the first electrode layer and the first stripe electrode; a first resistor and a second resistor connected in series; One end of one resistor is connected to the first electrode layer, the other end of the first resistor is connected to the second stripe electrode, and one end of the second resistor is connected to the first electrode layer.
By being connected to the stripe electrode, a control voltage for controlling an electric field distribution formed between the first electrode layer and the first stripe electrode is applied to the second stripe electrode by a DC voltage. It is characterized by the following.

[0011] The radiation image recording and reading apparatus according to the present invention comprises:
The first and second radiographic image recording devices and the radioactive solid state detector in which the radiographic image is recorded as an electrostatic latent image.
Reading light irradiating means for irradiating the reading electrode with electromagnetic waves for reading, and an electric signal having a level corresponding to the amount of latent image charges accumulated in the power storage unit generated in response to irradiation of the reading electromagnetic waves by the reading light irradiating means And a relay means for short-circuiting both ends of the second resistor based on a predetermined control signal, and the image signal obtaining means is connected to the first stripe electrode or The first stripe electrode and the second stripe electrode are connected to the second stripe electrode, and both ends of the second resistor are short-circuited by the relay means, so that the first stripe electrode and the second stripe electrode have substantially the same potential, and a predetermined electromagnetic wave is irradiated by the reading light irradiation means. The electrostatic latent image is read by detecting the electric signal by the image signal acquiring means.

Here, the "first stripe electrode comprising a large number of linear electrodes for generating photocharge pairs" is an electrode which transmits electromagnetic waves for reading and generates a pair of charges in the photoconductive layer for reading. The “second stripe electrode composed of a large number of linear electrodes for non-generation of photocharge pairs” is an electrode that blocks electromagnetic waves for reading and does not generate charge pairs in the photoconductive layer for reading, but is completely blocked. The present invention is not limited to an electrode that does not generate a charge pair at all, but also includes an electrode that has some transparency to the electromagnetic wave but does not cause a substantial problem with the charge pair generated thereby. Therefore, all the charge pairs generated in the reading photoconductive layer are not always caused by the electromagnetic waves transmitted through the first stripe electrode, and the charge pairs in the reading photoconductive layer are also generated by the electromagnetic waves slightly transmitted through the second stripe electrode. Can occur.

The term “irradiating the solid-state radiation detector with recording radiation” means directly or indirectly irradiating recording radiation carrying a radiation image of a subject. It is not limited to directly irradiating radiation to the solid-state radiation detector, but also includes irradiating the radiation solid-state detector with light generated in the scintillator, for example, by irradiating radiation to a scintillator (phosphor). .

The "control voltage" applied to the first stripe electrode in the first radiation image recording apparatus is as follows:
A magnitude for controlling an electric field distribution formed between the first electrode layer and the second stripe electrode so that the latent image charge is locally accumulated in the power storage unit at a position corresponding to the second stripe electrode. It is desirable that For example, a control voltage may be applied so that the potential of the first stripe electrode is closer to the potential of the first electrode layer than the potential of the second stripe electrode. The same applies to the "control voltage" applied to the second stripe electrode in the second radiographic image recording apparatus, and the electric field distribution formed between the first electrode layer and the first stripe electrode is expressed by the latent voltage. It is desirable that the size of the image charge is controlled so as to be localized and stored in the power storage unit at a position corresponding to the first stripe electrode.

The "image signal acquisition means" in the above-mentioned radiation image recording / reading apparatus means, for example, a current detection amplifier, but is not limited to this. Can be.

The "reading light irradiating means" may irradiate the solid-state radiation detector by scanning the beam light over the entire surface or irradiate the solid-state radiation detector by sub-scanning with a line light source. It may be something. Further, the reading electromagnetic wave may be continuous light emitted continuously or pulsed light emitted in a pulse shape.

The "predetermined control signal" is a control signal for starting reading of the solid-state radiation detector on which the radiation image is recorded.

[0018]

According to the first radiation image recording apparatus of the present invention, the radiation solid state detector is irradiated with radiation for recording, and an electric charge of an amount corresponding to the dose of the irradiated radiation is stored in the power storage unit. A voltage applying means for applying a DC voltage between a first electrode layer and a second stripe electrode in a radiation image recording apparatus for recording a radiation image as an electrostatic latent image on a power storage unit by accumulating the radiation image as a latent image charge. And a first resistor and a second resistor connected in series, one end of the first resistor is connected to the first electrode layer, and the other end of the first resistor is connected to the first stripe electrode. Since one end of the second resistor that is connected and not connected to the first resistor is connected to the second stripe electrode, the second resistor is formed between the first electrode layer and the second stripe electrode by a DC voltage. For controlling the applied electric field distribution Since the voltage is applied to the first stripe electrode, the control voltage can be applied to the first stripe electrode without providing a control voltage source to control the electric field distribution separately from the DC voltage source. The localization of the latent image charge in the power storage unit can be performed by applying the control voltage without increasing the cost, and the high-speed response and the read efficiency of the latent image charge can be improved. Further, in this case, the DC voltage applied between the first electrode layer and the second stripe electrode and the timing of applying the control voltage can be synchronized without requiring a control signal or the like. .

According to the second radiation image recording apparatus of the present invention, the solid radiation detector is irradiated with radiation for recording, and an electric charge of an amount corresponding to the dose of the irradiated radiation is stored in the power storage unit. In a radiation image recording apparatus that records a radiation image as an electrostatic latent image in a power storage unit by accumulating the charge as an electric charge, a voltage application unit that applies a DC voltage between the first electrode layer and the first stripe electrode; A first resistor and a second resistor are connected in series, one end of the first resistor is connected to the first electrode layer, and the other end of the first resistor is connected to the second stripe electrode. Since one end of the second resistor not connected to the first resistor is connected to the first stripe electrode, the second resistor is formed between the first electrode layer and the first stripe electrode by a DC voltage. The control voltage for controlling the electric field distribution Since There were to be applied to the second stripe electrode, it is possible to obtain the same effect as in the first radiation image recording apparatus.

When the radiation image is recorded on the solid-state radiation detector using the first and second radiation image recording devices and the above-mentioned reading is performed, the first and second radiation image recording devices are used. Unless the second resistor in the device is made sufficiently small compared to the first resistor (for example, when the first resistor is 5 MΩ, the second resistor should be about 100 kΩ). However, according to the radiation image recording and reading apparatus of the present invention,
Relay means for short-circuiting both ends of the second resistor based on a predetermined control signal; connecting the image signal obtaining means to the first stripe electrode or the second stripe electrode; The first stripe electrode and the second stripe electrode are set to substantially the same potential by short-circuiting, and a predetermined electromagnetic wave is irradiated by a reading light irradiation unit, and an electric signal is detected by an image signal obtaining unit to detect an electrostatic latent image. , The selection of the first resistor and the second resistor is not restricted as described above, and the response of signal detection can be prevented from lowering.

[0021]

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 image recording and reading apparatus according to the present invention, and FIG.
FIG. 1 is a diagram showing a schematic configuration of a radiation solid state detector for recording a radiation image by a radiation image recording and reading apparatus according to the present invention. 2 (A) is a perspective view, FIG. 2 (B) is an XZ sectional view of a Q arrow finger part, and FIG. 2 (C) is an XY sectional view of a P arrow finger part.

First, the radiation solid state detector shown in FIG. 2 in which a radiation image is recorded by the radiation image recording and reading apparatus according to the present invention will be described. The radiation solid-state detector 20 illustrated in FIG. 2 has a first electrode layer 21 that is transparent to recording radiation (for example, X-rays and the like; hereinafter, referred to as recording light) L1, and has transmitted through the electrode layer 21. The recording photoconductive layer 22, which exhibits conductivity when irradiated with the recording light L1, acts substantially as an insulator against latent image charges and negative charges, for example, and has a polarity opposite to that of the latent image charges. For the transport charge (positive charge in the above-described example), the charge transport layer 23 which functions as a substantially conductor, and a reading electromagnetic wave (hereinafter referred to as reading light) L2
, A first stripe electrode 26 composed of a number of elements 26a for generating photocharge pairs and a non-photocharge pair for non-generation of photocharges in response to the irradiation of the reading light L2. A second electrode layer 25 having a second stripe electrode 27 composed of a large number of elements 27a, in which each element 26a and each element 27a are alternately arranged substantially in parallel, are laminated in this order. is there.

The space between each element 26a and each element 27a of the second electrode layer 25 is filled with, for example, a polymer material such as polyethylene in which a small amount of pigment such as carbon black is dispersed. On the other hand, it has a light shielding property. The first stripe electrode 26 and the second stripe electrode 27 are electrically insulated.
The second stripe electrode 27 is 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 substantially at the interface between the recording photoconductive layer 22 and the charge transport layer 23. It is a conductive member.

The second stripe electrodes 27 are AL,
The element 27a is coated with a metal such as Cr and has a light shielding property against the reading light L2.
In the reading photoconductive layer 24 corresponding to (1), a charge pair for extracting a signal is not generated. The second stripe electrode 27 only needs to have conductivity,
It can be made of a single metal such as gold, silver, chromium, platinum or an alloy such as indium oxide.

The recording photoconductive layer 22 may be 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 is, 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 total thickness of the charge transport layer 23 and the reading photoconductive layer 24 is preferably not more than の of the thickness of the recording photoconductive layer 22. Therefore, for example, it is preferably set to 1/10 or less, further preferably 1/20 or less.

As the first stripe electrodes of the electrode layers 21 and 25, for example, a Nesa film formed by applying a conductive substance on a transparent glass plate is suitable. Further, an ITO film (Indium Tin Oxide) and an IDIXO (Idemitsu Indium X-metal Oxide; an amorphous light-transmitting oxide film);
Idemitsu Kosan Co., Ltd. can be used with a thickness of 50 to 200 nm.

Next, a first embodiment of the radiation image recording and reading apparatus according to the present invention, which records and reads a radiation image using the radiation image solid state detector 20, will be described.

The radiation image recording and reading apparatus according to the present embodiment includes the radiation solid state detector 20, recording light irradiation means 70 for irradiating the radiation solid state detector with recording light, and recording light irradiation by the recording light irradiation means 70. Voltage applying means 30 for applying a DC voltage between the first electrode layer 21 and the second electrode layer 25 when recording a radiation image by irradiation, one end connected to the first electrode layer 21 and the other end Is a second resistor R to be described later.
2 and a second resistor R2 having one end connected to the first resistor and the other end connected to the second stripe electrode (that is, the first resistor R1 and the second The reading light irradiating means 80 for irradiating a reading light for reading a radiation image recorded on the solid-state radiation detector 20 is connected to the two resistors R2 in series. Photoconductive layer 24 for reading by irradiation of reading light
Image signal acquisition means 5 for detecting an electric signal corresponding to the latent image charge stored in power storage unit 29 by generation of a charge pair within
0 (shown in FIG. 3) and a relay means 40 for making the first stripe electrode 26 and the second stripe electrode 27 the same potential by short-circuiting the second resistor at the time of reading.

A subject 10 is provided above the first electrode layer 21. The subject 10 has a blocking portion 10a for blocking recording light L1 emitted from the recording light irradiating means 70, and a recording light transmitting portion. There is a transmission part 10b. The recording light irradiating means 70 irradiates the recording L1 to the subject 10 uniformly.

The voltage applying means 30 is a DC voltage source capable of applying a DC voltage of a predetermined magnitude between the first electrode layer 21 and the second electrode layer 25 at the time of recording a radiation image.

The first resistor R1 and the second resistor R2 are connected in parallel with the voltage applying means 30 as shown in FIG.
Each resistor is connected in series, and one end of the second resistor R2 is grounded. The first resistor R1 and the second resistor R2 divide the DC voltage applied by the voltage applying means 30 and apply a control voltage to the first stripe electrode 26. In the present embodiment, a voltage closer to the voltage applied to the first electrode layer 21 than the voltage applied to the second stripe electrode 27 is applied to the first stripe electrode 26 as a control voltage. , The electric field distribution formed by the first electrode layer 21 and the second stripe electrode 27 is controlled. In the present embodiment, R1 = 5MΩ, R2 =
It is 1 MΩ.

The reading light irradiating means 80 reads the reading light linearly.
The scanning exposure is performed in the longitudinal direction of both electrodes (Y direction in FIG. 2) while making L1 substantially orthogonal to the first and second stripe electrodes 26 and 27. In this scanning exposure, continuous light may be applied, or pulsed light may be applied.

The image signal obtaining means 50 is connected to the second stripe electrode 27 as shown in FIG. 3 and obtains an electric signal corresponding to the amount of the latent image charge stored in the power storage unit 29. It comprises a number of current detection amplifiers connected to each element 27a of the stripe electrode 27.

The relay means 40 is for short-circuiting the second resistor R2 based on a predetermined control signal.

Next, the operation of the radiation image recording / reading apparatus according to the present invention having the above-described configuration in which a radiation image is recorded as an electrostatic latent image on the radiation image detector 20 and further the recorded electrostatic latent image is read will be described. . The negative and positive charges generated in the recording photoconductive layer 22 by the recording light L1 are represented by circles of-or + in the drawing.

First, when an electrostatic latent image is recorded on the solid-state radiation detector 20, a DC voltage of a predetermined magnitude is applied between the first electrode layer 21 and the second stripe electrode 27 by the voltage applying means 30. To charge the first electrode layer 21 negatively,
The second stripe electrode 27 is positively charged. At this time,
The control voltage is applied to the first stripe electrode 26 by the action of the voltage division of the first resistor R1 and the second resistor R2 connected as described above. By applying the voltage, a U-shaped electric field as shown in FIG. 1 is formed between the first electrode layer 21 and each element 27a of the second stripe electrode 27.
Since the potential of the first stripe electrode 26 is set to a potential closer to the potential of the first electrode layer 21 than the potential of the second stripe electrode 27, the potential of the second stripe electrode 27 is reduced.
A valley of potential is formed thereon.

Next, radiation is applied to the subject 10. The radiation transmitted through the transmitting portion 10b of the subject 10
The solid-state radiation detector 20 is irradiated as recording light L1 carrying a radiation image of zero. Then, the radiation solid state detector 20
A pair of positive and negative charges is generated in the recording photoconductive layer 22, and the negative charges move to the power storage unit 29 along the electric field distribution and are stored as latent image charges. At this time, since the valley of the potential is formed on the second stripe electrode 27 as described above, a large amount of latent image charges can be locally stored in the corresponding power storage unit 29.

On the other hand, the positive charges generated in the recording photoconductive layer 22 move at high speed toward the first electrode layer 21, and at the interface between the first electrode layer 21 and the recording photoconductive layer 22. The positive electrode charged by the application of the DC voltage to the first electrode layer 21 is coupled with and disappears. Further, since the recording light L1 does not pass through the light-shielding portion 10a of the subject 10, the portion of the solid-state radiation detector 20 corresponding to the stock of the subject 10a does not change at all.

By irradiating the subject 10 with radiation in this manner, charges corresponding to the subject image are stored in the power storage unit 2 existing at the interface between the recording photoconductive layer 22 and the charge transport layer 23.
9 can be stored. The amount of the accumulated latent image charge is transmitted through the subject 10 and is
This latent image charge carries an electrostatic latent image since it is substantially proportional to the dose of radiation incident on zero, and the electrostatic latent image is recorded on the solid-state radiation detector 20.

Next, the process of reading the electrostatic latent image recorded on the solid-state radiation detector 20 as described above will be described with reference to FIGS. Note that, similarly to the recording process, the negative and positive charges generated in the reading photoconductive layer 24 by the reading light L2 are represented by circles of-or +.

When reading the electrostatic latent image from the solid-state radiation detector 20, first, the voltage supply by the voltage applying means 30 at the time of the recording is stopped, and the first electrode layer 21 is grounded. . The relay means 40 is connected to the second resistor R
2 by short-circuiting the first stripe electrode 26 and the second stripe electrode 26.
The stripe electrodes 27 are set to the same potential (ground potential).

Next, when the reading light irradiating means 80 irradiates the reading photoconductive layer 24 with the reading light L2, the portion corresponding to the two elements 27a of the second stripe electrode 27, that is, the space above both elements 27a. The latent image charges of the portions are sequentially read out by combining with the positive charges charged on the two elements 27a. That is, as shown in FIG. 3, a discharge is generated from the element 26a of the first stripe electrode located at the center of the pixel toward the latent image charge (in the sky) corresponding to the element 26a on both sides thereof, thereby reading out. Progresses. 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. Note that the relay means 40 is not shown in FIG.

According to the first embodiment of the radiation image recording apparatus according to the present invention, the voltage application means 30 for applying a DC voltage between the first electrode layer 21 and the second stripe electrode 27 is connected in series with the voltage application means 30. It has a first resistor R1 and a second resistor R2 connected, one end of the first resistor R1 is connected to the first electrode layer 21, and the other end of the first resistor R1 is a first stripe. One end of the second resistor R2, which is not connected to the first resistor R1 but is connected to the second stripe electrode 27, is connected to the electrode 26.
The control voltage for controlling the electric field distribution formed between the first electrode layer 21 and the second stripe electrode 27 is applied to the first stripe electrode 26, so that the electric field distribution is independent of the DC voltage source. It is possible to apply a control voltage to the first stripe electrode 26 without providing a control voltage source for controlling the voltage, thereby localizing the latent image charges in the power storage unit by applying the control voltage, It is possible to improve the high-speed response and read efficiency of reading the latent image charges. In this case, the DC voltage applied between the first electrode layer 21 and the second stripe electrode 27 and the application timing of the control voltage should be synchronized without requiring a control signal or the like. Can be.

Next, a second embodiment of the radiation image recording and reading apparatus according to the present invention will be described. FIG. 4 is a diagram showing a schematic configuration of a radiation image recording and reading apparatus according to a second embodiment of the present invention. The solid-state radiation detector for recording and reading a radiation image by the radiation image recording and reading apparatus according to the present embodiment is the same as that used in the first embodiment. Elements that are the same as those described above are given the same numbers, and descriptions thereof are omitted unless otherwise required.

In the radiation image recording / reading apparatus according to the present embodiment, one end of the first resistor R1 is connected to the first electrode layer 21 and the other end is connected to the first stripe electrode 26 in the first embodiment. On the other hand, one end of the first resistor R1 is connected to the first electrode layer 21 and the other end is connected to the second stripe electrode 27, and the second resistor R2 is connected to the first resistor R1. The connection is made to the first stripe electrode 26. That is, the electric field distribution formed between the first electrode layer 21 and the first stripe electrode 26 is controlled by the control voltage applied to the second stripe electrode 27.

In the radiation image recording and reading apparatus according to the present embodiment, when an electrostatic latent image is recorded on the radiation solid state detector 20, a voltage is applied between the first electrode layer 21 and the first stripe electrode 26. A DC voltage of a predetermined magnitude is applied by the means 30 to charge the first electrode layer 21 negatively, charge the first stripe electrode 27 positively, and apply a predetermined control voltage to the second stripe electrode 27. I do. At this time, the second
For example, by applying a control voltage to the stripe electrode 27 so as to approach the potential of the first electrode layer 21 in the same manner as in the first embodiment, more potential is stored in the power storage unit 29 corresponding to the first stripe electrode. The image charges can be locally accumulated.

When the electrostatic latent image recorded on the solid-state radiation detector 20 is read, the first stripe electrode 26 and the second stripe electrode 27 are relayed by the relay means 40 as in the first embodiment. Is short-circuited and a reading is performed. When the reading light irradiating means 80 irradiates the reading photoconductive layer 24 with the reading light L2, the portion corresponding to the element 26a of the first stripe electrode 26, that is, the element 26a
Are sequentially read out by combining the latent image charges in the sky portion with the positive charges charged in the element 26a. Other operations are the same as those in the first embodiment. Also, in the present embodiment, the same effect as in the first embodiment can be obtained.

In the first and second embodiments, the first resistor R1 = 5MΩ and the second resistor R2 = 5MΩ.
Although the resistance is set to 1 MΩ, the relay means 40 does not need to be provided when the second resistor R2 is set to about 100 kΩ, which is sufficiently smaller than the first resistor R1. Therefore, for example, the thickness of the recording photoconductive layer 22 of the solid-state radiation detector 20 is approximately 500 μm, and the total thickness of the reading photoconductive layer 24, the charge transport layer 23, and the power storage unit 29 is approximately 10 to 11 μm.
m, the potential of the first stripe electrode 26 or the second stripe electrode 27 to which the control voltage is applied is stored in the power storage unit 2.
When setting each resistance value to be substantially the same as the potential of the first resistor R1 = 500 MΩ and the second resistor R2 =
The potential may be set to 100 kΩ (the potential inside the solid-state radiation detector 20 is proportional to the distance from the first electrode layer 21). In this case, the relay means 40 becomes unnecessary as described above.

The solid-state radiation detector 20 used in the first and second embodiments may have a form as shown in FIG. 5 (A) is a perspective view, FIG. 5 (B) is an XZ sectional view of the Q arrow finger part, and FIG. 5 (C) is an XY sectional view of the P arrow finger part. Elements that are the same as the elements of the solid-state radiation detector 20 shown in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted unless particularly necessary. The solid-state radiation detector 20b has a configuration in which both elements 26a of the first stripe electrode 26 and elements 27a of the second stripe electrode 27 are alternately provided in one pixel line of the solid-state radiation detector 20. is there. In the illustrated solid-state radiation detector 20b, three elements 26a and 27a are provided in one pixel. When recording and reading are performed using the solid-state radiation detector 20b, the elements 26a and 27a may be handled collectively in units of one pixel. Radiation solid state detector 20, 20
If the size of one pixel line b the same, the solid-state radiation detector each element 26a of 20b, the width _{W b} of 27a ', _{W c'} is the width _W b of the radiation solid-state detector 20, than _{W c} Set narrow. In today's advanced semiconductor formation technology, it is easy to form both elements 26a and 27a sufficiently narrow, and the solid-state radiation detector 20b can be easily manufactured.

In this manner, the radiation solid state detector 20
Distance D1 between power storage unit 29 and electrode layer 25
And the ratio D1 of the distance D2 between the two elements 26a and 27a.
/ D2 can be easily increased. As a result, the element 2a on both sides of the element 26a
Discharge toward the latent image charge corresponding to 7a is facilitated,
The reading time can be shorter than that of the solid-state radiation detector 20.

In the detectors 20 and 20b, 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. Although it 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.

[Brief description of the drawings]

FIG. 1 is a diagram showing a radiation image recording and reading apparatus according to a first embodiment and a recording process of the radiation image;

FIG. 2 is a perspective view (A) of the solid-state radiation detector used in the first and second embodiments of the present invention, and is an XZ of an arrow Q finger part.
Cross-sectional view (B), XY cross-sectional view of P arrow finger part (C)

FIG. 3 is a view showing a process of reading an electrostatic latent image in the radiation image recording and reading apparatus according to the first embodiment;

FIG. 4 is a diagram showing a radiation image recording and reading apparatus according to a second embodiment and a recording process of the radiation image;

5 is a perspective view of a radiation solid state detector having a form different from that of the solid state radiation detector shown in FIG. 2, (A), an XZ sectional view of a Q arrow finger part (B), and an XY sectional view of a P arrow finger part (C).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Subject 10a Blocking part 10b Transmission part 20, 20b 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 First stripe electrode 27 First 2 stripe electrode 26a element (first stripe electrode) 27a element (second stripe electrode) 29 power storage unit 30 voltage application unit 40 relay unit 50 image signal acquisition unit 70 recording light irradiation unit 80 read light irradiation unit L1 recording radiation ( Recording light) L2 Electromagnetic wave for reading (reading light)

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) H04N 1/028 H04N 5/321 5C072 1/04 G01T 1/20 E 5F088 5/30 H01L 27/14 K 5/321 31 / 00 A // G01T 1/20 H04N 1/04 EF term (reference) 2G083 AA04 BB03 BB04 CC10 DD11 DD17 EE10 2G088 EE01 FF02 GG19 GG21 JJ05 JJ09 JJ32 JJ33 KK32 KK40 LL12 LL15 LL30 4M118 AB01A01CB01A01CB01A01CB DD02 GA10 5C024 AX12 AX16 AX17 CY14 GX09 5C051 AA01 DA06 DB01 DB04 DB06 DB08 DB18 DC02 DC03 DC07 EA00 5C072 AA01 BA03 CA02 EA04 FA01 FB27 SA03 VA01 5F088 AA11 BA01 BA02 BB03 BB07 DA05 FA09 JA17

Claims (3)

[Claims] 1. A first electrode layer having transparency to recording radiation or light emitted by excitation of the radiation, and recording exhibiting conductivity by being irradiated with the recording radiation or the light. A photoconductive layer for use, a power storage unit for accumulating an amount of charge corresponding to the dose of the irradiated radiation as a latent image charge, a photoconductive layer for reading which exhibits conductivity by being irradiated with electromagnetic waves for reading, and the reading A first stripe electrode composed of a large number of linear electrodes for generating photocharge pairs with respect to the irradiation of the reading electromagnetic wave, and a photocharge pair for non-generation with respect to the reading electromagnetic wave. A second stripe electrode composed of a large number of linear electrodes;
The radiation for recording is applied to a radiation solid state detector having a second electrode layer in which stripe electrodes and the second stripe electrodes are alternately arranged substantially in parallel, in this order, and the irradiation is performed. A radiation image recording apparatus that records a radiation image as an electrostatic latent image on the power storage unit by accumulating charge in an amount corresponding to the dose of radiation in the power storage unit as the latent image charge, wherein the first electrode layer Voltage applying means for applying a DC voltage between the first and second stripe electrodes, and a first resistor and a second resistor connected in series, one end of the first resistor being connected to the first resistor. An electrode layer, the other end of the first resistor is connected to a first stripe electrode,
Since one end of the second resistor that is not connected to the first resistor is connected to the second stripe electrode, the first electrode layer and the second electrode are connected by the DC voltage.
A radiation image recording apparatus, wherein a control voltage for controlling an electric field distribution formed between the stripe electrodes is applied to the first stripe electrodes. 2. A first electrode layer having transparency to recording radiation or light emitted by excitation of the radiation, a recording exhibiting conductivity by being irradiated with the recording radiation or the light. A photoconductive layer for use, a power storage unit for accumulating an amount of charge corresponding to the dose of the irradiated radiation as a latent image charge, a photoconductive layer for reading which exhibits conductivity by being irradiated with electromagnetic waves for reading, and the reading A first stripe electrode composed of a large number of linear electrodes for generating photocharge pairs with respect to the irradiation of the reading electromagnetic wave, and a photocharge pair for non-generation with respect to the reading electromagnetic wave. A second stripe electrode composed of a large number of linear electrodes;
The radiation for recording is applied to a radiation solid state detector having a second electrode layer in which stripe electrodes and the second stripe electrodes are alternately arranged substantially in parallel, in this order, and the irradiation is performed. A radiation image recording apparatus that records a radiation image as an electrostatic latent image on the power storage unit by accumulating charge in an amount corresponding to the dose of radiation in the power storage unit as the latent image charge, wherein the first electrode layer Voltage applying means for applying a DC voltage between the first resistor and the first stripe electrode; and a first resistor and a second resistor connected in series, one end of the first resistor being connected to the first resistor. Connected to an electrode layer, the other end of the first resistor is connected to a second stripe electrode,
Since the one end of the second resistor that is not connected to the first resistor is connected to the first stripe electrode, the first electrode layer and the first electrode are connected by the DC voltage.
A radiation image recording apparatus, wherein a control voltage for controlling an electric field distribution formed between the stripe electrodes is applied to the second stripe electrodes. 3. The radiation image recording apparatus according to claim 1, wherein the reading electromagnetic wave is applied to the second electrode layer of the radiation solid state detector on which the radiation image is recorded as the electrostatic latent image. Reading light irradiating means for irradiating, and image signal acquisition for detecting an electric signal of a level corresponding to the amount of latent image charges accumulated in the power storage unit generated in response to irradiation of the reading electromagnetic wave by the reading light irradiating means And a relay means for short-circuiting both ends of the second resistor based on a predetermined control signal, wherein the image signal obtaining means is connected to a first stripe electrode or a second stripe electrode.
The first stripe electrode and the second stripe electrode are connected to a stripe electrode, and both ends of the second resistor are short-circuited by the relay means so that the first stripe electrode and the second stripe electrode have substantially the same potential. A radiation image recording / reading apparatus which reads the electrostatic latent image by irradiating the electromagnetic wave with the image signal and detecting the electric signal by the image signal acquiring means.