JP2002190584A - Radiation image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of data transmission paths, and excluding external effects and the effect of failures, using a portable recording medium. SOLUTION: A recording means 7 incorporates a detachable portable recording medium 8, and photographed digital image data is recorded on the recording medium 8. When transmitting digital image data, only the recording medium 8 is ejected from the recording means 7 and then inserted into a storage server or the like, which comprises a read device for the recording medium 8, for transmission of the digital image data. Inserting of the recording medium 8 into the recording means 7 is detected, and a power source of an imaging device is turned on, when the medium is inserted, while it is turned off when ejected. The remaining capacity of the recording medium 8 is detected, when it is inserted; and if the remaining capacity is estimated to be less than digital image data size, an imaging-disabled condition is kept.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation imaging apparatus using a flat panel sensor in which imaging devices are arranged in a matrix in a radiation imaging unit.

[0002]

2. Description of the Related Art Conventionally, a method of irradiating a subject with radiation, detecting the intensity distribution of the radiation transmitted through the subject, and obtaining a radiation image of the subject has been widely used in the field of industrial nondestructive inspection and medical diagnosis. ing. As a specific example of a general method for obtaining a radiation image of a subject, a so-called fluorescent plate (or intensifying screen) that emits fluorescence with respect to radiation and a silver halide film are combined, and radiation transmitted by irradiating the subject with radiation is used. Is converted into visible light with a fluorescent plate to form a latent image on the silver halide film, and then the silver halide film is chemically treated to obtain a visible image. The radiographic image obtained by this method is an analog photograph and can be used for diagnosis, inspection, and the like.

Further, a CR (Computed Radiography) device using an IP (Imaging Plate) having an inducible phosphor layer has begun to be widely used. When the secondary excitation is performed by visible light such as a red laser beam, induced phosphorescence is generated. The CR device acquires a radiation image by detecting this light emission with an optical sensor such as a photomultiplier tube,
The apparatus outputs a visible light image to a photographic material, a CRT, or the like based on the image data. Although the CR device is a digital device, it is an indirect digital radiation imaging device because it requires an image forming process of reading by secondary excitation. The reason for writing the indirect type here is that the captured image cannot be displayed immediately as in the case of the analog technology.

On the other hand, recently, a technique of acquiring a digital image by using a photoelectric conversion device in which pixels including minute photoelectric conversion elements, switching elements, and the like are arranged in a lattice as an image receiving means has been developed. This imaging device can immediately display the acquired image data, and is called a direct digital imaging device.

[0005] Advantages of the digital photographing apparatus over the analog photographic technique include filmless operation, enlargement of acquired information by image processing, and creation of a database. An advantage of the direct digital photographing device over the indirect digital photographing device is immediacy. While the indirect type requires an image forming process called secondary excitation, the direct type converts a radiation image into digital data immediately after imaging. Furthermore, the direct digital imaging device does not require a reading device, while the indirect digital imaging device requires a separate reading device for secondary excitation.

[0006]

Digital image data from a direct type digital photographing apparatus is transferred to a host computer or a storage server by wire or wireless data transmission. In a stationary digital photographing apparatus, various restrictions are imposed on data transmission by wire.

Usually, a host computer, a storage server, and the like are often installed in a room separate from a photographing room.
In addition, when wiring is performed along a ceiling, a wall, under the floor, or the like so as not to hinder shooting, the distance between the shooting device and the host computer is several to several tens of meters. These are not desirable because they not only impose a load on the work at the time of installation, but are more susceptible to the effects of voltage drop, disturbance noise, and the like on the transmission path as the transmission distance becomes longer. Also, in the case of wireless data transmission, besides the transmission distance, the effects of obstacles, etc., there is also a movement to restrict the use of radio waves itself, as seen in measures such as the ban on the use of mobile phones in hospitals. , Making it difficult to implement.

In the case where the photographing device is portable,
After photographing, a troublesome operation of transporting the photographing device to a place where wired or wireless data transmission is possible and performing data transmission occurs. In particular, in the case where the photoelectric conversion unit, a control unit for driving the photoelectric conversion unit, a power supply for driving the imaging device, a storage unit for temporarily storing image data, and the like are included in one unit. In addition, the overall weight is heavier than that of a conventional film cassette, and carrying the same causes a physical load on the user.

An object of the present invention is to solve the above-mentioned problems,
It is an object of the present invention to provide a radiographic apparatus incorporating a portable recording medium.

[0010]

According to the present invention, there is provided a radiation imaging apparatus comprising: a radiation imaging unit in which imaging elements for generating electric charges having a correlation with the intensity of incident radiation are arranged in a grid; A conversion unit connected to the radiation imaging unit for converting the electric charge into a digital pixel value; and a recording unit connected to the conversion unit for receiving and recording the digital pixel value using a detachable and portable recording medium from the apparatus main body. Means, and a power supply connected to the radiation imaging means, the conversion means, and the recording means for operating these means.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail based on the illustrated embodiment. FIG. 1 is a schematic view of an imaging apparatus. A conversion unit 2, a driving unit 3, and a data bus 4 are arranged around a flat panel sensor 1 having a photoelectric conversion element for detecting a radiation image. A power supply 5 is connected to each of the conversion means 2, the conversion means 2, and the drive means 3, and the power supply 5 is further connected to a recording means 7 having a detection mechanism 6. The data bus 4 is connected to the conversion means 2 and the recording means 7. The recording means 7 includes a solid-state recording medium using a semiconductor storage element or the like, a magnetic recording medium represented by a hard disk, a magneto-optical recording medium represented by an MO, a CD-R / RW, a DVD-ROM, and the like.
A detachable portable recording medium 8 such as an optical recording medium represented by a ROM / RAM or the like can be mounted.

When actually photographing using the photographing apparatus, the recording medium 8 is first inserted into the recording means 7. Further, when it is detected that the recording medium 8 has been inserted through the contact type or non-contact type detection mechanism 6 provided in the insertion opening of the recording medium 8, the power supply 5 is turned on. The initialization operation of the flat panel sensor 1 and the like may be performed. When the detection mechanism 6 detects that the recording medium 8 has been ejected, the power supply 5 is turned off.

When the recording medium 8 is inserted or before the initialization operation of the flat panel sensor 1 is started, the inserted recording medium 8
Is detected, and if the remaining capacity is less than the set of digital pixel values output from the conversion means 2, that is, the capacity of the image output in one photographing, the flat panel sensor 1 is initialized. The state in which photographing is not possible may be maintained without shifting to the operation. As a result, it is possible to prevent a problem that an image cannot be stored in spite of taking an image by irradiating radiation.

When the object is irradiated with the radiation, it is converted by a photoelectric conversion element (not shown) on the flat panel sensor 1 into a charge corresponding to the intensity of the radiation incident on each pixel. After the irradiation, an A / D conversion process for converting the electric charge of each pixel into a digital pixel value by the conversion means 2 is executed.

The converted digital pixel values are transmitted to the recording means 7 via the data bus 4 in accordance with the order of the pixels forming the image. The recording means 7 records the sent digital pixel value on the portable recording medium 8 inserted before photographing.

After the digital pixel values are recorded on the recording medium 8, the flat panel sensor 1 is initialized to prepare for the next irradiation. When the same photographing device is used for continuous photographing, the above operation is repeated. At that time, the digital pixel value of each photographing is treated as one digital image, and the recording medium 8 The data is recorded in another area on the same recording medium as far as the remaining capacity allows.

Further, when photographing is performed by the second photographing device due to a change in the region to be photographed, the recording medium 8 inserted in the first photographing device is discharged, and the second photographing is performed. The recording medium 8 is inserted into the device. The operation of the second photographing device is the same as that of the first photographing device.

When reading the image data recorded on the recording medium 8, the recording medium 8 is taken out from the photographing apparatus main body, and
The recording medium 8 is transported and inserted into a host computer or a storage server for reading. As a matter of course, it is necessary that a computer capable of reading the recording medium 8 be provided on the computer that performs the reading. However, today, the recording medium 8 is common, and both the medium and the recording / reading device are easily available.

FIG. 2 shows a configuration diagram of an equivalent circuit corresponding to one pixel of the photoelectric conversion element provided on the flat panel sensor 1. In this example, an amorphous silicon sensor is used as a detection element. The function and configuration of the A / D converter are the same even when other solid-state imaging devices such as charge-coupled devices are used. One element of the photodetector comprises a photodetector 11 and a switching TFT 12 for controlling charge accumulation and reading, and is generally made of amorphous silicon formed on a glass substrate.

The capacitor 13 in the light detecting section 11 is
It may be simply a photodiode 14 having a parasitic capacitance, or it may be a photodetector that includes in parallel the photodiode 14 and an additional capacitor 13 that improves the dynamic range of the detector. The anode A of the photodiode is connected to a bias line Lb, which is a common electrode, and the cathode K is connected to a controllable switching TFT 12 for reading out the charge stored in the capacitor 13.
The switching TFT 12 is a thin film transistor connected between the cathode K of the photodiode 14 and the charge readout amplifier 15, and between the switching TFT 12 and the amplifier 15, a resetting switching element 17 and a DC A series circuit with the power supply 18 is connected in parallel.

After the reset switching element 17 is operated by the switching TFT 12 and the signal charge, and the capacitor 13 is discharged, a charge corresponding to the radiation dose is generated in the photodiode 14 by the radiation of radiation, Stored.

Thereafter, the reset switching element 17 is operated again by the switching TFT 12 and the signal charge, whereby the charge is transferred to the capacitance element 16, and the amount accumulated by the photodiode 14 is converted into a potential signal by the amplifier 1.
5 and A / D converted to detect the incident radiation dose.

[0023]

As described above, the radiation imaging apparatus according to the present invention has a built-in portable recording medium which is detachable from the imaging apparatus main body, and records the photographed digital image data on the recording medium. At the time of transmission, only the recording medium is ejected from the photographing apparatus main body, transported, connected to a storage server, etc., and digital image data is transmitted, so that there is no need to connect the photographing apparatus main body to the storage server. It is possible to avoid problems such as a distance, an influence of an obstacle, and restrictions on radio wave use. Also, by transporting only the recording medium, the load associated with transport is reduced as compared to a portable imaging device.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a radiation imaging apparatus according to an embodiment.

FIG. 2 is a configuration diagram of an equivalent circuit corresponding to one pixel of a photoelectric conversion element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flat panel sensor 2 Conversion means 3 Driving means 4 Data bus 5 Power supply 6 Detecting means 7 Recording means 8 Recording medium 11 Light detection unit 12 Switching TFT 13 Capacitor 14 Photodiode 15 Amplifier 16 Capacitance element 17 Reset switching element 18 DC power supply

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 5/225 H04N 5/32 5/32 7/18 L 7/18 H01L 27/14 K F term (reference ) 2G088 EE01 EE27 EE30 FF02 GG19 JJ05 KK20 KK39 4M118 AA10 AB01 AB10 BA05 CA02 CB06 CB11 FB03 FB09 FB13 FB16 5C022 AA08 AB40 AB67 AC69 CA00 5C024 AX12 CY14 HX46 HX58 5C05 CA03 GA03 EA03

Claims (3)

[Claims] 1. A radiation imaging unit in which imaging elements that generate charges having a correlation with incident radiation intensity are arranged in a grid, a conversion unit connected to the radiation imaging unit and converting the charges into digital pixel values, A recording unit for receiving and recording the digital pixel value by using a portable recording medium which is detachable from the apparatus main body and connected to the conversion unit; and a radiation imaging unit, the conversion unit, and a recording unit connected to the recording unit. A radiation imaging apparatus having a power supply for operating the means. 2. A detecting means for detecting an insertion state of the recording medium, wherein when the insertion of the recording medium is detected, the power supply is turned on and an initialization operation of the radiation imaging means is performed to perform the recording. 2. The radiation imaging apparatus according to claim 1, wherein the power supply is turned off when the ejection of the medium is detected. 3. An initialization operation of the radiation imaging means when a remaining capacity of the recording medium is detected and the remaining capacity is less than a capacity capable of recording a set of digital pixel values output from the conversion means. 3. The radiation imaging apparatus according to claim 2, wherein a state in which imaging is not possible is maintained without performing the operation.