JP2002048871A - Image pickup device, radiation detection device, and image processing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation image pickup device for X rays, etc., which both has performance of high resolution and moving pictures that an X-ray digital photographing device for medical diagnosis needs to have and is wide in sensor effective area, small-sized, and low-priced and then applicable to high-precision medical treatment, an image pickup device which is suitably used for the radiation image pickup device, and an image processing system which uses them. SOLUTION: Photoelectric converting devices each having a substrate where photoelectric converting elements as pixels are arranged and a photoconductor which guides incident light to the photoelectric converting elements are arranged so that photoelectric converting devices whose photoconductors are different in thickness are adjacent to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus, a radiation detection apparatus, and an image processing system, and more particularly to reduction of radiation damage such as X-rays, reduction in size and weight, and reduction in photoelectric conversion without loss of resolution. The present invention relates to a radiation detection (imaging) device capable of expanding an input range by connecting devices, and an image processing system using the same.

[0002]

2. Description of the Related Art Conventionally, a film screen system combining an intensifying screen and an X-ray photographic film has been often used for X-ray photography for the purpose of medical diagnosis. According to this method, the X-ray transmitted through the subject contains information inside the subject, which is converted into visible light proportional to the intensity of the X-ray by the intensifying screen, and is exposed on the X-ray film.

In recent years, X-rays have been converted to X-rays by phosphors.
An X-ray digital imaging apparatus that converts visible light proportional to the intensity of a line, converts it into an electric signal using a photoelectric conversion element, and converts it into a digital signal with an AD converter has begun to be used.

As an example of this, on a substrate made of glass,
An X-ray digital radiographing device that consists of a stack of phosphors that convert X-rays into visible light, or a bundle of optical fibers by heat, etc. Using a softened and elongated tapered optical fiber, a photoelectric conversion element such as a CCD is arranged on the side where the taper is narrowed, and a module in which a phosphor is laminated on the opposite side to the photoelectric conversion element is a two-dimensional module. An X-ray digital radiographing apparatus and the like which are connected to each other have been proposed.

[0005]

The above-mentioned X-ray digital imaging apparatus is mainly used for medical diagnosis and the like. In order to perform early detection and accurate diagnosis of an abnormal location,
It is necessary to ensure high resolution, low noise, moving image, wide shooting area, and the like.

[0006] However, the conventional X-ray digital imaging apparatus has the following problems. That is, in an apparatus in which a photoelectric conversion element which becomes a pixel using a semiconductor made of amorphous silicon or the like on a glass substrate, the effective size of the sensor array can be increased, but the size of each pixel is reduced. This is difficult in terms of process and device characteristics.

On the other hand, when a photoelectric conversion element such as a CCD, which is formed on a silicon substrate, is used, the size of each pixel can be reduced, and high sensitivity and high speed driving are possible. Although it is easy to capture an image, it is not possible to increase the effective area of the sensor array due to process constraints and the like.

Therefore, as shown in FIG. 6, by using an optical fiber processed in a tapered shape so that the non-sensor regions of the photoelectric conversion elements do not overlap with each other, the number of photoelectric conversion elements serving as pixels is increased, and An expanded effective area was also proposed. That is, in FIG. 6, 1 is a substrate on which a photoelectric conversion element is formed, 2 is a scintillator that converts X-rays into light such as visible light having a wavelength detectable by the photoelectric conversion element, and 8 is a tapered shape. Optical fiber, 10 is protective glass,
Numeral 11 denotes wire bonding, and numeral 12 denotes a ceramic package.

However, this tapered optical fiber 8
Although it is expensive and thick and heavy, it is possible to join several pieces, but it is an impractical measure to obtain a sensor effective area necessary for chest imaging.

[0010] Due to such a problem, X for medical diagnosis is used.
It was still difficult to achieve both high resolution and moving image plane performance required for a line digital photographing apparatus and a wide sensor effective area, miniaturization and low cost of the apparatus.

An object of the present invention is to achieve both high resolution and moving image plane performance required for a medical diagnostic X-ray digital imaging apparatus, a wide effective sensor area, miniaturization of the apparatus, and cost reduction. An object of the present invention is to provide a radiation imaging apparatus for X-rays or the like that can withstand highly accurate medical treatment, a suitable imaging apparatus used for the radiation imaging apparatus, and an image processing system using the same.

[0012]

Therefore, an image pickup apparatus according to the present invention has a photoelectric conversion device having a substrate on which a plurality of photoelectric conversion elements serving as pixels are provided, and a light guide for guiding incident light to the photoelectric conversion elements. A plurality of converters are arranged so that photoelectric converters having different thicknesses of the light guide are adjacent to each other.

Further, a radiation detection (imaging) apparatus according to the present invention provides a scintillator for converting radiation into light, a substrate on which a plurality of photoelectric conversion elements serving as pixels are provided, and light from the scintillator being converted to photoelectric conversion elements. A plurality of photoelectric conversion devices having a light guide for guiding light are arranged such that photoelectric conversion devices having different thicknesses of the light guide are adjacent to each other.

In this case, as an embodiment of the present invention, a photoelectric conversion element, a photoelectric conversion element driving circuit, a signal processing circuit, and an external input / output terminal are provided on the substrate on which a plurality of photoelectric conversion elements are provided. The photoelectric conversion element drive circuit, the signal processing circuit, and the external input / output terminal excluding the photoelectric conversion element are arranged on one side of the substrate, and the light guide is provided with a plurality of photoelectric conversion elements. It is effective that the optical fiber plate has the same size as the light receiving area of the substrate, and that the optical fiber plate is made of a material containing lead.

Further, an image processing system according to the present invention comprises the above-described image pickup device or radiation detection device, image processing means for performing image processing of a signal from the image pickup device or radiation detection device, and a signal from the image processing means. It has a recording unit for recording, a display unit for displaying a signal from the image processing unit, and a transmission unit for transmitting a signal from the image processing unit.

Here, the radiation is α including X-rays.
Rays, β rays, γ rays, etc. Further, as the light guide, it is desirable to use an optical fiber plate as described above in order to guide the light to the photoelectric conversion element without dispersing the light. When the number is small, a light-transmitting substrate such as a glass substrate can be used.

As described above, according to the present invention, the light guide such as an optical fiber plate has a plate shape, and the size and the price are reduced as compared with the tapered light guide used in the conventional imaging apparatus. it can. In addition, the light guide is the same as the size of the light receiving portion of the photoelectric conversion element substrate, and the area of the photoelectric conversion element driving circuit, the processing circuit, the external electrode, and the like of the photoelectric conversion element substrate protrudes from the light guide, By arranging the light guides having different thicknesses adjacent to each other, the projecting areas of the photoelectric conversion element driving circuit, the processing circuit, and the external electrodes of the photoelectric conversion element substrate do not interfere with each other in design, Only the light receiving area can be arranged adjacently. That is, the light receiving range can be expanded.

Further, a light guide such as an optical fiber is made of a material containing lead, and X-rays that cannot be converted into light by the scintillator are shielded by lead, so that the X-rays are photoelectrically converted. The influence on the element can be reduced, and an image with less noise can be obtained.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to FIGS. The imaging apparatus of the present invention can be suitably used for an X-ray digital imaging apparatus described below.
The invention is not limited to the line imaging device.

FIG. 1 is a sectional view of an X-ray imaging apparatus according to the present invention, and FIG. 2 is a perspective view thereof. Here, 1 is a photoelectric conversion element substrate, 100 is a light receiving area in which the photoelectric conversion elements are two-dimensionally arranged, 101 to 104 are drive processing circuits for driving the photoelectric conversion elements, and signals obtained from the photoelectric conversion elements. Areas 2a and 2b for processing a signal processing circuit and external input / output terminals are optical fiber plates as light guides having different thicknesses.

The optical fiber plates 2a and 2b used this time are obtained by bundling a plurality of optical fibers each having a diameter of about 5 to 6 μm, heating and pressing them, and then cutting them into a plate shape. For each fiber diameter, a fiber having a resolution sufficiently smaller than that of the photoelectric conversion element was selected.

Reference numeral 4 denotes a scintillator for converting X-rays into visible light, and reference numeral 5a denotes a translucent adhesive for adhering the photoelectric conversion element substrate and the optical fiber plate. 5b is a translucent adhesive for bonding the modules. Reference numeral 6 denotes a flexible printed wiring board (FPC) for electrically connecting external input / output terminals of the photoelectric conversion element and the image processing system.

FIG. 3 shows a photoelectric conversion element substrate 1 according to this embodiment. 100 is an imaging area and 100 μ
m-square image sensors are two-dimensionally arranged and arranged to the end of the photoelectric conversion element substrate. 101 is a vertical drive circuit (V-S
R) and 102 are column scanning circuits (H-SR), 103 is a memory circuit and an amplifier circuit, and 104 is an electrode terminal, which is arranged on one side of the photoelectric conversion element 1.

In this embodiment, a thin optical fiber plate 2a having the same size as the imaging region 100 of the photoelectric conversion element 1 and having a small thickness is bonded using a light-transmitting adhesive 5a. The optical fiber plate needs to be cut in advance with a dicer or the like accurately so that it has the same area as the imaging region 100 of the photoelectric conversion element, and is bonded with an aligner capable of positioning on the order of microns. I have.

Further, when using the adhesive, it is necessary to take care that foreign matter and air bubbles do not enter between the optical fiber plate and the photoelectric conversion element. Further, the electrode terminal 104 of the photoelectric conversion element is formed by using an anisotropic conductive adhesive.
By electrically connecting a flexible printed wiring board (FPC) to the module, a module with a thin optical fiber plate was completed.

Similarly, the optical fiber plate 2b, which is thicker than the optical fiber plate 2a described above,
The module is completed with a thick optical fiber plate by bonding to the photoelectric conversion element substrate with the translucent adhesive 5a.
Finally, the light incidence side (the opposite side of the photoelectric conversion element substrate bonding surface) of the optical fiber plate of the thin module and the thick module is flush with each other, and the gap between the modules is set so that no gap is generated between the modules. Glue with a translucent adhesive.

By continuing this work and further bonding a module using a thick optical fiber, it is theoretically possible to manufacture an imaging device having an infinitely large imaging area (actually, a plurality of imaging devices can be manufactured). Stay in pieces).

Further, in the above-described image pickup apparatus, a phosphor 4 for converting X-rays into visible light is provided on the light incident side of the optical fiber plate (opposite to the photoelectric conversion element substrate bonding surface), as shown in FIG. An X-ray detection (imaging) device can be provided.

As the material of the phosphor, cesium iodide (CsI) or gadolinium sulfide (Gd ₂ O ₂ S ₂ ) is used, and is laminated by vacuum deposition. The laminated structure may be broken by touching or dissolved by humidity, so it is necessary to protect it with a moisture-permeable resin or the like. Also, a binder is mixed with gadolinium sulfide powder,
It may be bonded to a fiber plate by using an adhesive, which is processed into a film.

Thus, the X-ray detection (imaging) device of the present invention is constituted.

FIG. 5 illustrates a state in which the X-ray detection (imaging) device is incorporated in a medical image processing system. Here, the subject 6062 is irradiated with radiation 6060 from an X-ray source (X-ray tube) 6050, and the radiation transmitted to the rear side is converted into visible light by the above-described X-ray detection device (image sensor) 6040. Is stored in the memory of the image processor 6070 as a digital image signal. Then, the image signal is sent to the display 6080 to display the image, and at the same time, the film processor 610 in the doctor room is displayed.
0, and on the diagnostic display 6081 there,
Display images. An image is fixed on the film 6110 by a laser printer.

[0032]

As described above, according to the present invention,
A substrate on which a plurality of photoelectric conversion elements as pixels are provided,
By arranging a plurality of photoelectric conversion devices each having a light guide that guides incident light to the photoelectric conversion element in such a form that photoelectric conversion devices having different thicknesses of the light guides are adjacent to each other, furthermore, the radiation is further reduced. By combining a scintillator that converts light into a plurality of photoelectric conversion devices, the following effects can be obtained.

With high definition, high sensitivity, and thinness,
An image input device having a wide sensor effective area can be provided.

The photoelectric conversion element substrate is provided with a photoelectric conversion element, a driving circuit for driving the element, and a signal processing circuit on the photoelectric conversion element substrate, so that a gate line signal line of an adjacent photoelectric conversion element is connected. Since the necessity is eliminated, the structure is simplified to realize further lower cost.

The material of the optical fiber is made of a material containing lead, and the X-rays that have not been converted into visible light by the phosphor layer are shielded by the lead, so that the X-rays affect the photoelectric conversion element. , And an image without noise can be obtained.

In general, it achieves both high resolution and moving image performance required for an X-ray digital radiographing device for medical diagnosis, a wide sensor effective area, miniaturization and low cost of the device, and withstands high-precision medical treatment. The obtained X-ray imaging apparatus can be provided.

[Brief description of the drawings]

FIG. 1 is a structural sectional view of an imaging device according to an embodiment of the present invention.

FIG. 2 is also a perspective view.

FIG. 3 is also an internal layout diagram of the electric conversion element substrate.

FIG. 4 is a perspective view in which the imaging apparatus of the present invention is applied to an X-ray imaging apparatus.

FIG. 5 is a configuration diagram of an image processing system using an imaging device according to the present invention.

FIG. 6 is a structural sectional view of a conventional X-ray imaging apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photoelectric conversion element substrate 100 photoelectric conversion element 101 vertical drive circuit 102 column scanning circuit 103 memory circuit and amplifier circuit 104 electrode terminal 2 light guide member 2a thin optical fiber plate 2b thick optical fiber plate 4 phosphor 5 translucent adhesive 5a photoelectric conversion Adhesive for element substrate / light guide member 5b Adhesive between light guide member FPC 6 Flexible printed wiring board (FPC) 8 Tapered fiber 10 Protective glass 11 Wire bonding 12 Ceramic package

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 31/09 H04N 1/028 Z 31/0232 H01L 31/00 A H04N 1/028 31/02 C 1 / 04 H04N 1/04 EF term (reference) 2G088 EE01 EE27 FF02 FF14 GG14 GG19 GG20 JJ05 JJ09 JJ29 JJ30 JJ33 JJ37 LL11 5B047 AA17 BA02 BB04 BC01 BC08 BC14 5C051 AA01 BA02 BA06 DC01 VA01 BA01 DB01 DB01 EA04 EA11 JA01 JA14 JA17 KA01 KA08 LA07

Claims (11)

[Claims] 1. A photoelectric conversion apparatus comprising: a substrate on which a plurality of photoelectric conversion elements serving as pixels are provided; and a light guide for guiding incident light to the photoelectric conversion element. An imaging device, wherein a plurality of devices are arranged adjacent to each other. 2. The imaging device according to claim 1, wherein the substrate on which a plurality of photoelectric conversion elements are provided includes a photoelectric conversion element, a photoelectric conversion element driving circuit, a signal processing circuit, and an external input / output terminal. An imaging device, wherein a photoelectric conversion element driving circuit, a signal processing circuit, and an external input / output terminal excluding a photoelectric conversion element are arranged on one side of the substrate. 3. The imaging device according to claim 1, wherein the light guide has the same size as a light receiving area of the substrate on which a plurality of photoelectric conversion elements are arranged. 4. The imaging device according to claim 1, wherein the light guide is an optical fiber plate. 5. A scintillator for converting radiation into light,
A photoelectric conversion device having a substrate on which a plurality of photoelectric conversion elements serving as pixels are provided and a light guide for guiding light from the scintillator to the photoelectric conversion element is adjacent to a photoelectric conversion device having a different thickness of the light guide. A radiation detection device, wherein a plurality of radiation detection devices are arranged in such a manner that 6. The radiation detection apparatus according to claim 5, wherein the substrate on which a plurality of photoelectric conversion elements are provided is provided with a photoelectric conversion element, a photoelectric conversion element driving circuit, a signal processing circuit, and an external input / output terminal. The photoelectric conversion element drive circuit, the signal processing circuit, and the external input / output terminals excluding the photoelectric conversion element
A radiation detecting device, which is arranged on one side of the substrate. 7. The radiation detecting apparatus according to claim 5, wherein the light guide has the same size as a light receiving area of the substrate on which a plurality of photoelectric conversion elements are provided. 8. The radiation detecting apparatus according to claim 5, wherein the light guide is an optical fiber plate. 9. The radiation detection apparatus according to claim 8, wherein the optical fiber plate is manufactured from a material containing lead. 10. An image pickup apparatus according to claim 1, image processing means for processing a signal from the image pickup apparatus, and recording for recording a signal from the image processing means. An image processing system comprising: means; display means for displaying a signal from the image processing means; and transmission means for transmitting a signal from the image processing means. 11. A radiation detection apparatus according to claim 5, image processing means for performing image processing on a signal from the radiation detection apparatus, and recording the signal from the image processing means. An image processing system comprising: a recording unit; a display unit for displaying a signal from the image processing unit; and a transmission unit for transmitting a signal from the image processing unit.