JP2007155433A - Cassette for radiation detection - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To establish the vibration countermeasure of the flexible substrate and also to secure optical precision of the reading light in the radiation detection cassette in which the solid radiation detector and the light source for reading light source are stored. <P>SOLUTION: In the cassette 2 for detecting radiation, the solid radiation detector 30 and a linear light source 31 are housed in a cabinet 20; a base 25 for holding the solid radiation detector 30 is constituted with an annular part on which the solid radiation detector 30 is held and the linear light source 31 is housed in the annular part, and on the outside of an annular part the flexible substrate 50 is connected with the solid radiation detector 30, and the light source driving means is fixed and held to the base 25. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention particularly relates to a vibration countermeasure in a radiation detection cassette in which a radiation solid state detector, a reading light source and the like are accommodated in a housing.

  2. Description of the Related Art Various types of radiation solid state detectors that detect radiation transmitted through a subject and output an image signal representing a radiation image related to the subject have been proposed and put into practical use in radiography for medical diagnosis and the like. The present applicant has disclosed, as Patent Document 1, Patent Document 2, etc., a recording radiation or a radiation solid-state detector of an optical readout system that can achieve both high-speed readout response and efficient signal charge extraction. A first conductive layer that is transparent to light emitted by excitation of the radiation (hereinafter referred to as recording light), a recording photoconductive layer that exhibits conductivity by receiving recording light, and the first conductive layer are charged. A charge transport layer that acts as a substantially insulator for charges of the same polarity as the charge, and acts as a conductor for charges of the opposite polarity to the charge of the same polarity, and is irradiated with reading light. Is formed by laminating a reading photoconductive layer exhibiting conductivity and a second conductive layer transparent to reading light in this order, and is formed at the interface between the recording photoconductive layer and the charge transport layer. Latent image carrying image information It proposes a solid state radiation detector for storing a load (electrostatic latent image).

In addition, the radiation solid state detector as described above, a linear light source (scanning light source) for scanning and exposing reading light to the radiation solid state detector, and a signal for processing an image signal output from the radiation solid state detector Various types of radiation detection cassettes in which a processing substrate or the like is housed in a housing have been proposed and put into practical use (Patent Document 3 and the like). Such a radiation detection cassette is relatively thin and of a size that can be transported. For example, for a patient who cannot move, radiation detection is performed under the part that the patient wants to shoot while lying on the bed. It is possible to perform imaging with a very high degree of freedom, for example, by placing an imaging cassette and moving the radiation source included in the radiation image information recording apparatus to a position facing the radiation detection cassette across the patient.
JP 2000-105297 A JP 2000-284056 A Japanese Unexamined Patent Publication No. 07-140255

  By the way, in the radiation detection cassette as described above, the radiation solid detector is usually held by a plate-shaped base, and the signal processing substrate and the radiation solid detector arranged on the back side of the base are TCP (Tape). It is connected by a flexible board such as Carrier Package).

  This flexible substrate is sensitive to vibration, and if vibration is transmitted to the flexible substrate, it may cause noise. However, in the conventional structure, it is difficult to directly hold the flexible substrate on the base. No effective measures have been taken with respect to vibrations.

  Moreover, since it is preferable that the base itself holding the radiation solid state detector is not affected by external vibrations, it may be possible to fix the base to the housing via a soft vibration-proof member. In this case, there is a possibility that the relative positional relationship between the radiation solid state detector and the linear light source may be slightly changed, which makes it difficult to ensure the optical accuracy of the reading light.

  The present invention has been made in view of the above problems, and in a radiation detection cassette in which a radiation solid detector, a reading light source, and the like are housed in a housing, a countermeasure against vibration of a flexible substrate connected to the radiation solid detector is provided. An object of the present invention is to provide a radiation detection cassette that enables the optical accuracy of the reading light.

  A radiation detection cassette according to the present invention is a radiation solid state detector that records image information upon receiving irradiation of radiation carrying image information, and outputs an image signal representing the recorded image information by scanning with reading light. A reading light source for irradiating the radiation solid detector with reading light, a signal processing board for processing an image signal output from the radiation solid detector, a flexible board for connecting the radiation solid detector and the signal processing board, A base having an annular portion, holding the radiation solid detector on the upper surface of the annular portion, housing the reading light source inside the annular portion, and holding a flexible substrate on the outer surface of the annular portion; The driving means that is held and that scans and moves the reading light source is housed in a housing.

  In the above, the “radiation solid state detector” is a detector that detects radiation carrying image information of a subject and outputs an image signal representing a radiation image related to the subject, and directly or once converts incident radiation into light. Then, the charge is converted into electric charge, and the electric charge is temporarily stored in the power storage unit, and then the electric charge is output to the outside, whereby an image signal representing a radiographic image related to the subject can be obtained.

  The “driving means” is a device that scans and moves the reading light source so that the entire surface of the radiation solid state detector is scanned by the reading light. For example, when the reading light source is a point light source, The point light source is moved in a two-dimensional manner in the main scanning direction and the sub-scanning direction. When the reading light source is a linear light source, the linear light source is scanned one-dimensionally in the sub-scanning direction. It is to be moved.

  In the radiation detection cassette according to the present invention, it is preferable that the base and / or the member held by the base is connected to the inside of the housing by a heat conductive member.

  Moreover, it is preferable that the base is fixed in the housing via a vibration isolating member.

  The radiation detection cassette according to the present invention is a radiation detection cassette containing a radiation solid detector, a reading light source and the like inside a housing, and has a base structure for holding the radiation solid detector, and has an annular portion. The radiation solid detector is held on the upper surface of the annular portion, the reading light source is accommodated inside the annular portion, and the flexible substrate connected to the radiation solid detector is held on the outer surface of the annular portion. Since the driving means is held on the flexible substrate, it is possible to take measures against vibration of the flexible substrate and to secure the optical accuracy of the reading light.

  A radiation detection cassette according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration diagram of a breast X-ray imaging apparatus using the radiation detection cassette.

  As shown in FIG. 1, the breast X-ray imaging apparatus includes an imaging apparatus body 1 and a radiation detection cassette 2 loaded in the imaging apparatus body 1.

  The imaging apparatus main body 1 includes an imaging table 10, an arm unit 12 installed on the imaging table 10, and a cassette loading unit 14 installed on the arm unit 12.

  The arm portion 12 rotates in the direction of arrow A about the joint portion 14a with the imaging table 10 as an axis. The arm unit 12 rotates by itself and also rotates the cassette loading unit 14 in the arrow A direction. A radiation source is built in the radiation emitting unit 12a which is a part of the arm unit 12. The radiation emitted from the radiation emitting unit 12 a is applied to the cassette loading unit 14, and is applied to the radiation solid detector 30 in the cassette 2 loaded in the cassette loading unit 14. Note that X-ray imaging by the breast X-ray imaging apparatus is performed in a state where the subject is positioned between the radiation emitting unit 12 a of the arm unit 12 and the cassette loading unit 14. The X-ray imaging is performed in a state where the arm unit 12 rotates according to the X-ray imaging purpose and the arm unit 12 is inclined at various angles.

  FIG. 2 is a schematic configuration diagram of the cassette 2 loaded in the cassette loading unit 14 of the imaging apparatus main body 1, FIG. 3 is a diagram in which the radiation solid state detector 30 is not shown in the schematic configuration diagram shown in FIG. 2, and FIG. A sectional view taken along line IV-IV in FIG. 2, and FIG. 5 shows a schematic configuration diagram of the radiation solid state detector 30. As shown in FIG.

  The cassette 2 includes a radiation solid detector 30, a base 25 for holding the radiation solid detector 30, and a linear light source that emits line-shaped reading light toward the radiation solid detector 30 in a rectangular parallelepiped housing 20. 31, light source driving means for linearly moving the linear light source 31, a flexible substrate 50 on which a charge amplifier IC 51 for detecting an image signal output from the radiation solid detector 30 is mounted, and an image signal output from the radiation solid detector 30 A signal processing board 52 that performs the above processing, and an image transfer board 54 that is connected to the signal processing board 52 and the flexible board 53 and transmits an image signal received from the signal processing board 52 to an external device. It will be.

  The housing 20 is mainly made of a material such as aluminum or magnesium that blocks light, but a carbon plate 21 is disposed at the radiation incident portion, and does not prevent radiation from entering the radiation solid detector 30. It is configured as follows.

  As shown in FIG. 5, the radiation solid detector 30 is charged with the first electrode layer 33 that transmits the radiation L <b> 1 carrying the radiation image and the irradiation of the radiation L <b> 1 that transmits the first electrode layer 33. The recording photoconductive layer 34 that is generated, the charge transport layer that acts as an insulator for the charges generated in the recording photoconductive layer 34 and acts as a conductor for transport charges having the opposite polarity to the charges 35, a photoconductive layer for reading 36 that generates an electric charge when irradiated with the reading light L2, and a second electrode layer 37 in which linear electrodes 37a extending linearly that transmit the reading light L2 are arranged in parallel. They are laminated in this order. Each linear electrode 37 a of the second electrode layer 37 is connected to the flexible substrate 50.

  In the radiation solid detector 30, the radiation L1 is irradiated from the first electrode layer 33 side, and an amount of latent image charges corresponding to the dose of the irradiated radiation L1 is generated by the recording photoconductive layer 34 and the charge transport layer 35. A radiographic image is recorded by being accumulated in the power storage unit 38 formed at the interface with. Then, the reading light L2 irradiated from the second electrode layer 37 side passes through the linear electrode 37a and is irradiated to the reading photoconductive layer 36, and is generated in the reading photoconductive layer 36 by the irradiation of the reading light L2. The charge of one polarity is combined with the latent image charge in the power storage unit 38, and the charge of the other polarity is detected by the flexible substrate 50 (charge amplifier IC51) connected to the linear electrode 37a. Read out as an electrical signal.

  The radiation solid detector 30 and the linear light source 31 are installed so that the length direction of the linear light source 31 and the length direction of the linear electrode 37a of the radiation solid detector 30 are substantially orthogonal.

  The light source driving means includes a motor 40 fixed to the base 25, a drive pulley 41 connected to the rotation shaft of the motor 40, a pulley 42 supported on the rotation shaft fixed to the base 25, and a drive pulley. The belt 43 is suspended between the pulley 41 and the pulley 42 and holds the linear light source 31. The scan shaft 44 is fixed to the base 25 and restricts the movement of the linear light source 31.

  The base 25 has a rectangular annular part, and has a shape having a flat bottom plate part with the inside of the annular part closed at the bottom, and is made of a highly rigid material such as aluminum die cast.

  The base 25 holds the radiation solid detector 30 by the holding member 26 on the upper surface of the annular portion.

  Further, the base 25 holds the flexible substrate 50 by the heat sink 62 on the outer surface of the annular portion, and holds the signal processing substrate 52 connected to the flexible substrate 50 on the lower surface of the base 25. An anti-vibration gel 60 is disposed between the outer surface of the base 25 and the flexible substrate 50, and an anti-vibration gel 61 is disposed between the charge amplifier IC 51 mounted on the flexible substrate 50 and the heat sink 62. And configured to suppress vibration of the flexible substrate 50.

  Further, the base 25 is configured to hold the light source driving means and accommodate the linear light source 31 inside the annular portion.

  With the above-described configuration, the flexible substrate 50 can be appropriately held, so that vibration of the flexible substrate 50 can be suppressed. Further, the radiation solid detector 30 and the light source driving means (linear light source 31) ) Is held by the same base 25, it is possible to ensure the optical accuracy of the reading light.

  The base 25 is attached to a column 28 fixed to the housing 20 via a vibration-proof gel 27. Thereby, it is possible to suppress the vibration from the outside of the housing 20 from directly propagating to the base 25.

  Furthermore, the heat sink 62 and the housing 20 are connected by a heat conducting ribbon 64 in a state in which no tension is applied. By adopting such a configuration, vibration from the outside of the housing 20 is directly applied to the base 25. The heat generated in the charge amplifier IC 51 can be released to the housing without being propagated.

1 is a schematic configuration diagram of an X-ray imaging apparatus for breasts using a linear motion mobile unit driving apparatus according to a first embodiment of the present invention. Schematic configuration diagram of a cassette loaded in a cassette loading unit of the above-mentioned mammogram Schematic configuration diagram in which the radiation image detector is not displayed in the schematic configuration diagram of the cassette shown in FIG. Sectional view of the above cassette (IV-IV sectional view in FIG. 2) Schematic configuration diagram of a radiation solid state detector installed in the cassette

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image pick-up device main body 2 Cassette 10 Imaging stand 12 Arm part 12a Radiation emission part 14 Cassette loading part 20 Case 21 Carbon plate 25 Base 26 Holding member 30 Radiation solid state detector 31 Linear light source 40 Motor 41 Drive pulley 42 Pulley 43 Belt 44 Scan shaft 50 Flexible substrate 51 Charge amplifier IC
52 Signal Processing Board 53 Flexible Board 54 Image Transfer Board 60 Antivibration Gel 61 Antivibration Gel 62 Heat Sink 63 Screw 64 Thermal Conductive Ribbon

Claims (3)

A radiation solid detector that receives the irradiation of radiation carrying image information, records the image information, and outputs an image signal representing the recorded image information by scanning with reading light;
A reading light source for irradiating the radiation solid detector with reading light;
A signal processing board for processing an image signal output from the radiation solid state detector;
A flexible substrate connecting the radiation solid state detector and the signal processing substrate;
A base having an annular portion, holding the radiation solid detector on an upper surface of the annular portion, housing the reading light source inside the annular portion, and holding the flexible substrate on an outer surface of the annular portion; When,
A radiation detection cassette, wherein a driving means held on the base and for scanning and moving the reading light source is housed in a housing.   The radiation detection cassette according to claim 1, wherein the base and / or a member held on the base is connected to the inside of the housing by a heat conductive member.   The radiation detection cassette according to claim 1, wherein the base is fixed in the housing via a vibration isolation member.

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