Image pickup device

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to an imaging device, and in particular, a one-dimensional or two-dimensional imaging capable of reading a radiation imaging device used for a video camera, a digital camera, a scanner, a medical measuring instrument, a non-destructive inspection device, or the like. Regarding the device. The imaging device of the present invention also includes a device that directly detects high-energy radiation rays (X-rays, γ-rays, α-rays, etc.).

【0002】

[Conventional technology]

An example of a conventional imaging device will be described by taking a medical radiation imaging device as an example.

【0003】

FIG. 6 is an example of the radiation imaging device under development in recent years. 30 is the radiation source, 31 is the subject, 32 is the cassette, and 33 is the radiation. The radiation 33 emitted from the radiation source 30 passes through the subject 31 and is incident on the cassette 32. The incident radiation 33 contains information on the subject 31.

【0004】

FIG. 7 is a schematic cross-sectional view of the cassette. The outer frame has a configuration in which the grit 35 is screwed to the housing 34, and the radiation solid-state imaging unit is located in the region 36 surrounded by the dotted line frame in the cassette.

【0005】

FIG. 8 is a top view of the radiation solid-state image sensor. 37 to 40 are sensor substrates whose upper surface is a light receiving portion, and 41 are pixel regions in which a photoelectric conversion element and a TFT element are formed on the sensor substrate. Reference numeral 42 is a base for holding the sensor substrate, and 43 is an adhesive 1 for fixing the sensor substrate and the base. The sensor substrates 37 to 40 are aligned so that the pixel pitches match in the two-dimensional direction, and are fixed to the base. This is because a plurality of small substrates having a good manufacturing yield are arranged to increase the area. Therefore, if one large-area substrate with good yield can be manufactured, a configuration without a base may be used.

【0006】

FIG. 9 is a cross-sectional view of the radiation solid-state imaging unit.

【0007】

44 is a fluorescent plate that converts radiation into visible light, CaWO₄And Gd₂O₂S: Tb³⁺A resin plate coated with a granular fluorescent material such as the above is used. 45 is an adhesive 2 for adhering the sensor substrate and the fluorescent plate.

【0008】

Reference numeral 46 denotes a metal film having a moisture-impermeable and radiation-permeable property (for example, an Al-deposited film), and the metal film is connected to the fluorescent plate via an adhesive 3 (47). When the photoelectric conversion element and the TFT element are required to be moisture-proof or electromagnetic wave shielded, the metal film is used for the purpose of sealing the fluorescent plate and the photoelectric conversion element and the TFT element. Further, in order to more reliably seal the fluorescent plate with the photoelectric conversion element and the TFT element, the space between the metal film and the sensor substrate is filled with the sealing material 2 (48).

【0009】

Reference numeral 49 denotes a lead-out electrode portion that exchanges an input signal for driving the photoelectric conversion element and the TFT element with an input system outside the sensor substrate. Similarly, 50 is a lead-out electrode section that exchanges the output signal obtained by reading the X-ray information with the output system outside the sensor board. The lead-out electrode portions for input and output are connected to the printed circuit board (53, 54) via the flexible circuit board (51, 52), respectively. ICs (55, 56) having input signal or output signal processing are mounted on the flexible circuit board. Further, a sealing material 1 (57) is provided at the joint portion between the lead-out electrode portion and the flexible circuit board in order to prevent electrolytic corrosion of the lead-out electrode portion, and a silicone resin, an acrylic resin, or an epoxy resin is generally used.

【0010】

The radiation solid-state imaging unit having the above configuration is supported by 58 supports in the cassette, and the support and the grid are fixed by 59 fixing materials having an adhesive or an adhesive on both sides. The printed circuit board is fixed to the housing by screwing with a mounting plate 60.

【0011】

The radiation solid-state image sensor having the above configuration converts the radiation transmitted from the radiation source through the subject and incident on the cassette into visible light in the fluorescent screen. Further, the converted visible light passes through the adhesive directly under the fluorescent plate and is incident on the photoelectric conversion element formed on the sensor substrate. This is photoelectrically converted and output as a two-dimensional image.

【0012】

Such a new radiation imaging device is expected to be applied as a simple diagnostic device that can be used in a medical examination room, an ambulance, etc., or as a replacement for a film cassette used in an existing recumbent type diagnostic device. For that purpose, it is necessary to make the device thinner and lighter.

【0013】

[Problems to be Solved by the Invention]

Such a new radiation imaging device is expected to be applied as a simple diagnostic device that can be used in a medical examination room, an ambulance, etc., or as a replacement for a film cassette used in an existing recumbent type diagnostic device. For that purpose, it is necessary to make the device thinner and lighter.

【0014】

However, when the thickness is reduced, the electrical interaction between the electronic components becomes remarkable. That is, electronic components such as sensor boards, printed circuit boards, and flexible circuit boards are arranged at very narrow intervals in the housing, and since they are used on an ambulance, the mounted components vibrate slightly. Therefore, when the distance between the parts is narrow and the parts vibrate with each other in this way, the capacitance between the wirings of the parts may change and noise may be generated. FIG. 10 is a partial cross-sectional view of a thin radiation imaging device for explaining a state in which vibration is applied to the thin radiation imaging device. As shown in FIG. 14, the distance a between the flexible circuit board provided with the IC for processing the output signal and the housing changes due to vibration.

【0015】

Further, if the member of the housing is made of an organic resin or the like as the weight is reduced, it may not be possible to secure a sufficient reference potential in the housing.

【0016】

Due to the above two causes, noise may be generated in the flexible circuit board, and the image quality of the radiation imaging apparatus may be significantly deteriorated.

【0017】

Therefore, an object of the present invention is to provide an imaging device that is not affected by vibration even if it is made thinner and can secure a sufficient reference potential in a housing even if it is made lighter.

【0018】

[Means for solving problems]

In the imaging apparatus of the present invention for solving the above problems, in the vicinity of a wiring group connecting a photoelectric conversion panel that outputs an electric charge in response to light or high-energy radiation and a processing circuit that processes the electric charge. A conductor is provided.

【0019】

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

【0020】

[Embodiment 1] FIG. 1 is a wiring diagram showing a relationship between a conductor and a circuit connected from a lead-out electrode portion of a sensor substrate to a printed circuit board through a flexible circuit board in an output signal processing unit. This conductor is arranged in the vicinity of a wiring group that connects a photoelectric conversion panel that outputs an electric charge in response to light or high-energy radiation and a processing circuit that processes the electric charge.

【0021】

56 is an IC, 1 is a charge integrator, 2 is a multiplier, 3 is a wiring part, 4 is a reference power supply, 5 is a conductor, and 50 is a pull-out electrode part. In this circuit diagram, the place where the distance from the external component changes during vibration and the wiring capacity is likely to change is the wiring part of 3, and in order to reduce this, a conductor 5 is placed in the vicinity of the wiring part 3 and This conductor 5 is connected to the same reference potential as the charge integrating amplifier existing in the IC. Further, the wiring portion 3 is a wiring portion of the flexible circuit board.

【0022】

FIG. 2 is a cross-sectional view of the image pickup apparatus of the present invention when the wiring of FIG. 1 is realized. 6 is a connection line, 7 is a terminal for connecting the reference potential provided on the printed circuit board, and 8 is a screw.

【0023】

FIG. 3 is an enlarged view of the flexible circuit board used in the image pickup apparatus of FIG. Reference numeral 9 denotes a hole provided in the flexible printed circuit board 52. The connection between the reference potential and the conductor 5 shown in FIG. 1 is reduced to the reference potential by connecting the terminal of 7 and an arbitrary part of the conductor 5 via the connection line of 6.

【0024】

The conductor 5 has a screw 8 made of an insulating material fixed to the support 42 through a hole 9 provided in the flexible circuit board 52. Since the conductor 5 is fixed with screws, it has a certain degree of rigidity, and a thick plate-like conductor is preferable. Specifically, copper, aluminum, or stainless steel is used.

【0025】

[Embodiment 2] FIG. 4 is a partial cross-sectional view of an image pickup apparatus that realizes the wiring diagram of FIG.

【0026】

FIG. 5 is an enlarged view of the flexible circuit board and the conductor used therein.

【0027】

For the same or equivalent as the above-described embodiment, the description thereof will be simplified or omitted.

【0028】

12 is an adhesive or an adhesive, 10 is a conductive agent, and 11 is a reference potential connection terminal provided on a flexible circuit board. The conductors are attached to the flexible circuit board 52 at regular intervals via 12 adhesives or adhesives. Since the conductor 61 is attached to a soft flexible circuit board, it is preferably in the form of a similarly soft film, and copper foil, aluminum foil, nickel foil, and stainless steel foil are used. Further, in this embodiment, the shape of the conductor is hollowed out only in the area of the IC in order to prevent the conductor from conducting the IC56 for the output signal. However, if an insulating layer is provided between the conductor and the output signal IC and there is no continuity, it is not necessary to cut through. Considering the electrolytic corrosion of the conductor and the connection terminal, it is preferable to use a silicone resin or an acrylic resin having a low concentration of sodium, potassium or chlorine as the adhesive or the pressure-sensitive adhesive.

【0029】

Further, the connection between the reference potential and the conductor shown in FIG. 1 is lowered to the reference potential by connecting 11 terminals and an arbitrary part of the conductor 61 via a conductor agent such as 10 silver paste.

【0030】

[Effect of the invention]

According to the present invention described above, noise is generated due to vibration by providing a conductor at a constant distance in the vicinity of a flexible circuit board provided with an IC for processing output signals and further setting the conductor and the IC to the same reference potential. Can be resolved.

[Simple explanation of drawings]

[Figure 1]

First Embodiment of the present invention, wiring diagram [Figure 2]

An electrical mounting structure embodying the wiring diagram of FIG. 1 according to the first embodiment of the present invention. [Fig. 3]

An enlarged view of the flexible circuit board shown in FIG. 2, the first embodiment of the present invention. [Fig. 4]

An electrical mounting structure embodying the wiring diagram of FIG. 1 according to the second embodiment of the present invention. [Fig. 5]

An enlarged view of the flexible circuit board and the conductor shown in FIG. 4 according to the second embodiment of the present invention. [Fig. 6]

An example of a medical radiation imaging system [Fig. 7]

Cross section of cassette [Fig. 8]

Cross-sectional view of the radiation solid-state image sensor [Fig. 9]

Top view of the radiation solid-state image sensor [Fig. 10]

The figure which showed the positional relationship between the group of electrical mounting parts connected to a sensor board, and a housing. [Explanation of symbols]

1 Charge integrator amplifier 2 Multiplexar 3 Wiring section 4 Reference power supply 5 conductor 6 Connection line 7 Reference potential connection terminal on the printed circuit board 8 screws 9 holes 10 Conductive agent 11 Connection terminal for reference potential of flexible circuit board 12 Adhesive or adhesive 30 Radioactive sources 31 Subject 32 cassette 33 Radiation 34 housing 35 grid 36 Radiation solid-state image sensor 37-40 sensor board 41 pixel area 42 base 43 Adhesive 1 44 Fluorescent plate 45 Adhesive 2 46 metal film 47 Adhesive 3 48 Encapsulant 2 49 Drawer electrode for input signal 50 Output signal lead-out electrode 51 Flexible circuit board for input signals 52 Flexible circuit board for output signal 53 Printed circuit board for input signal 54 Printed circuit board for output signal 55 IC for input signal 56 IC for output signal 57 Encapsulant 1 58 Support stand 59 Fixing material 60 mounting plate 61 Picture frame type conductor