JP7508499B2 - Radiation image reader - Google Patents

Description

This disclosure relates to a radiation image reading device and program.

Patent document 1 discloses a medical imaging assembly including a first imaging plate and a second imaging plate for acquiring a first medical image and a second medical image. The image reading device in patent document 1 creates a composite image of a first digital image and a second digital image based on the first imaging plate and the second imaging plate.

JP 2011-212401 A

Here, there are imaging plates of multiple sizes. The imaging plate to be used is selected appropriately depending on the subject to be photographed. In dental X-ray photography using imaging plates, it is possible that small-sized imaging plates are generally used more frequently than large-sized imaging plates. There are many issues and high technical hurdles in scanning large-sized imaging plates using general detectors conventionally used in this field. On the other hand, if a detector capable of scanning large-sized imaging plates is installed, the cost of the device itself will be high. In addition, it will be over-specified in detecting (small-sized) imaging plates that are used frequently. Therefore, if a detector suitable for small-sized imaging plates can be used to read large-sized imaging plates, it will lead to a reduction in the cost of the device. The small-sized imaging plates and large-sized imaging plates described here are expedient expressions to show the difference between sizes that can be read by normal scanning using conventional general detectors and sizes that cannot be read. For example, the following is assumed. Small-sized imaging plates are imaging plates called "size 0" that are generally used for standard pediatric radiography in dental X-rays, imaging plates called "size 1" that are generally used for pediatric bitewing radiography, imaging plates called "size 2" that are generally used for standard adult radiography, and imaging plates called "size 3" that are generally used for adult bitewing radiography. Large-sized imaging plates are imaging plates with a size larger than "size 3" that are generally used for pediatric and adult occlusal radiography in dental X-rays.

According to Patent Document 1, a small-sized imaging plate can be used. However, a line originating from the boundary between the first imaging plate and the second imaging plate appears in the composite image.

The present disclosure therefore aims to make it possible to read imaging plates with a width greater than the detection width of the imaging plate's detector.

To solve the above problem, a radiation image reading device is a radiation image reading device that reads a radiation image from an imaging plate, and includes a holding section that holds the imaging plate, a reading section that includes an excitation light source that irradiates the imaging plate held in the holding section with excitation light, and a photodetector that detects luminescence light from the imaging plate due to the excitation light, and a scanning mechanism that moves the holding section relative to the reading section along a scanning direction that is horizontal to the imaging plate held in the holding section, and the reading section detects the luminescence light from the imaging plate in a reading area that extends in the scanning direction and in a direction perpendicular to the scanning direction by scanning with the scanning mechanism, and is capable of setting a plurality of reading areas that are shifted in a direction perpendicular to the scanning direction as the reading area.

The program for solving the above problem is a program for causing a computer that controls a radiation image reading device to execute the following processes: (a) a process in which the reading unit scans an imaging plate held in a holding unit along a scanning direction that is horizontal to the imaging plate so that reading can be performed on a plurality of reading areas including at least a first reading area and a second reading area that are shifted in a direction perpendicular to the scanning direction, and (b) a process in which image data is generated by combining first image data based on data read from the first reading area and second image data based on data read from the second reading area.

This radiation image reading device can read imaging plates with a width larger than the detection width of the imaging plate's detector.

In addition, this program can read imaging plates with a width larger than the detection width of the imaging plate's detector and generate image data.

1 is a schematic perspective view showing an example of the appearance of a reading device according to a first embodiment; FIG. 2 is a partial schematic diagram showing an example of a configuration inside a housing. 3 is a schematic cross-sectional view taken along line III-III in FIG. 2. 2 is a block diagram showing an example of the configuration of a control unit of the reading device; 11 is an explanatory diagram showing the relationship between a second imaging plate and a reading area. FIG. 11A and 11B are diagrams illustrating a process of generating whole image data by combining first image data and second image data. 10 is a flowchart showing an example of the operation of the reading device. FIG. 11 is a partial schematic view showing a shielding portion according to a first modified example. 13A and 13B are diagrams illustrating a process of generating whole image data by combining first image data and second image data in a first modified example. FIG. 11 is a partial schematic view showing a shielding portion according to a second modified example. FIG. 13 is a diagram showing a mark according to a third modified example. FIG. 13 is a partial schematic view showing an example of an arrangement of a first detection unit and a second detection unit according to a fourth modified example. 13 is a flowchart showing an example of the operation of a reading device according to a fifth modified example. FIG. 13 is a partial schematic view showing an example of a configuration inside a housing according to a sixth modified example. FIG. 11 is a partial schematic view showing an example of the internal configuration of a radiation image reading device according to a second embodiment. 2 is a partial schematic view showing an example of the internal configuration of the radiation image reading device of the above embodiment; FIG. FIG. 4 is a flowchart showing an example of the operation of the reading device according to the embodiment of the present invention.

{First embodiment}
The radiation image reading device and program according to the first embodiment will be described below. Fig. 1 is a schematic diagram showing an example of the appearance of a reading device 1. The reading device 1 is a device that reads a radiation image from an imaging plate 10 on which the radiation image is recorded. The reading device 1 can also be said to be a device that detects the radiation image recorded on the imaging plate 10.

The imaging plate 10 has a flat shape with a radiation image forming layer 11, and is a recording medium for recording a radiation image. The imaging plate 10 has, for example, a generally rectangular flat shape with rounded corners. The radiation image forming layer 11 is a layer that accumulates the energy of irradiated radiation and emits luminescent light corresponding to the accumulated energy when excited by excitation light. For example, the radiation image forming layer 11 is formed by applying a photostimulable phosphor to one main surface of a film formed of resin. X-rays, for example, are used as the radiation irradiated to the radiation image forming layer 11. When X-rays from an X-ray generator penetrate the object to be photographed and irradiate the imaging plate 10, energy corresponding to the intensity of the X-rays is accumulated in the radiation image forming layer 11. Since the intensity of the X-rays is based on the distribution of X-ray absorbing regions in the object to be photographed, the distribution of the energy accumulated in the radiation image forming layer 11 is a radiation image of the object to be photographed by X-rays. In this way, the imaging plate 10 records, for example, a radiation image by X-rays as a latent image. The reading device 1 reads the radiation image from the radiation image forming layer 11 and generates an image signal (also called image data) that represents the read radiation image (latent image).

In this example, for example, radiation is irradiated onto the imaging plate 10 while it is placed inside a person's mouth. Therefore, the imaging plate 10 is sized to fit inside a person's mouth. Then, for example, a radiation image of teeth is recorded on the radiation image forming layer 11 of the imaging plate 10. However, the use of the imaging plate 10 is not limited to this.

Hereinafter, the main surface of the imaging plate 10 facing the radiation image forming layer 11 may be referred to as the front surface. Also, the main surface of the imaging plate 10 opposite the front surface may be referred to as the back surface.

As shown in FIG. 1, the reading device 1 includes, for example, a housing 2. The housing 2 contains a configuration for reading a radiation image from an imaging plate 10. This configuration will be described later.

The housing 2 is provided with an insertion opening 2a and an ejection opening 2b. The insertion opening 2a is provided, for example, on the top surface of the housing 2. A user of the reading device 1 can insert an imaging plate 10 into the housing 2 through the insertion opening 2a. A radiation image is read from the imaging plate 10 inside the housing 2. The ejection opening 2b is provided, for example, on a lower part of one side surface of the housing 2. The imaging plate 10 after the radiation image has been read (also referred to as the read imaging plate 10) is ejected through the ejection opening 2b. A user of the reading device 1 can collect the read imaging plate 10 through the ejection opening 2b.

After reading out the radiation image from the imaging plate 10, the reading device 1 may erase the radiation image from the imaging plate 10. For example, the imaging plate 10 from which the radiation image has been erased may be discharged from the outlet 2b.

The housing 2 is provided with an operation unit 4 that accepts operations from a user, for example. The operation unit 4 includes, for example, a plurality of operation buttons 4a. Each operation button 4a is, for example, a hardware button. The plurality of operation buttons 4a include, for example, a power button and a start button for instructing the start of reading. The operation unit 4 is not limited to a push switch, and may include, for example, a touch sensor that detects a touch operation by the user. Note that there may be a single operation button, or three or more operation buttons may be provided depending on the functions of the reading device 1.

The housing 2 is provided with, for example, a display unit 3. The display unit 3 is configured with, for example, a liquid crystal display panel or an organic EL (electro-luminescence) display panel. The display unit 3 is capable of displaying various information such as characters, symbols, figures, and images. The display unit 3 may display a radiation image read from the imaging plate 10 (in other words, a detected radiation image). The display unit 3 may display information related to the progress of the reading, such as the time remaining until the end of reading after the start of reading the imaging plate 10. The display unit 3 may display warnings, cautions, or error information regarding erroneous operation of the reading device 1. Appropriate designs are possible.

When the operation unit 4 includes a touch sensor, the touch sensor and the display unit 3 may form a touch panel display having a display function and a touch detection function. In this case, at least one of the multiple operation buttons 4a may be replaced with a software button displayed on the touch panel display, and the operation unit 4 may not include multiple operation buttons 4a. In addition, the reading device 1 may not include a display unit 3.

The housing 2 is provided with plate storage cases 6 and 7 capable of storing, for example, an imaging plate 10. The plate storage cases 6 and 7 are provided, for example, on the top surface of the housing 2. The plate storage case 6 is a case with a partition, and the plate storage case 7 is a case with a lid. The reading device 1 does not need to be provided with at least one of the plate storage cases 6 and 7. Alternatively, the storage cases may be configured as separate entities.

A cable 5a of an AC adapter 5 extends from the housing 2 toward the outside. Power is supplied to each component of the reading device 1 from the AC adapter 5. The reading device 1 may be equipped with not only the AC adapter 5 but also a battery that supplies power to each component of the reading device 1. Alternatively, the reading device 1 may be equipped with a battery instead of the AC adapter 5.

<An example of the mechanism inside the housing>
Fig. 2 is a partial schematic diagram showing an example of the configuration inside the housing 2. Fig. 3 is a schematic cross-sectional view taken along line III-III in Fig. 2. Fig. 4 is a block diagram mainly showing an example of the configuration of a control unit 80 provided in the reading device 1. As will be described later, a holding unit 20 that holds the imaging plate 10 is capable of moving along a predetermined direction SC1 within the housing 2. The predetermined direction SC1 is the scanning direction SC1 by the scanning mechanism 50. Note that for the sake of convenience of explanation, only a portion of the reading device 1 is shown in Fig. 3 and the partial schematic diagrams below.

As shown in Figs. 2 to 4, the reading device 1 includes, for example, a holding unit 20, a reading unit 30 including an excitation light source 32 and a photodetector 40, a scanning mechanism 50 including a drive unit 52 and a pair of guide units 60, a control unit 80, and an interface unit 95. These components are provided inside the housing 2.

<About the control unit>
The control unit 80 can comprehensively manage the operation of the reading device 1 and can also be called a control circuit. The control unit 80 can control, for example, the display unit 3, the holding unit 20, the reading unit 30, the drive unit 52, and the interface unit 95. The control unit 80 can also perform processing according to a user operation received by the operation unit 4.

The control unit 80 is configured, for example, by a computer device including at least one processor 80a and a memory unit 80b. The at least one processor 80a included in the control unit 80 may include a CPU (Central Processing Unit) or a processor other than a CPU. In the control unit 80, the at least one processor 80a executes a program 80bp in the memory unit 80b (also called a memory circuit), thereby realizing various functions described below.

In the control unit 80, at least one processor 80a executes a program 80bp in the memory unit 80b to form functional blocks, such as an image processing unit 81, a display control unit 82, a drive control unit 83, a retention control unit 84, a detection control unit 85, and a light emission control unit 86.

The image processing unit 81 can perform image processing on, for example, an image signal (described below) output from the photodetector 40. The display control unit 82 can control the display of the display unit 3. The drive control unit 83 can control the drive unit 52. The retention control unit 84 can control the retention unit 20. The detection control unit 85 can control the photodetector 40. The light emission control unit 86 can control the excitation light source 32.

Note that some of the functions of the control unit 80 or all of the functions of the control unit 80 may be realized by a hardware circuit that does not require software (in other words, a program) to realize the function. For example, some of the functions of the image processing unit 81 or all of the functions of the image processing unit 81 may be realized by a hardware circuit that does not require software to realize the function. The image processing unit 81 may be an image processing circuit independent of other configurations. Also, some of the functions of the display control unit 82 or all of the functions of the display control unit 82 may be realized by a hardware circuit that does not require software to realize the function. The display control unit 82 may be a display control circuit independent of other configurations. Also, some of the functions of the drive control unit 83 or all of the functions of the drive control unit 83 may be realized by a hardware circuit that does not require software to realize the function. The drive control unit 83 may be a drive control circuit independent of other configurations. Also, some of the functions of the retention control unit 84 or all of the functions of the retention control unit 84 may be realized by a hardware circuit that does not require software to realize the function. The retention control unit 84 may be a display control circuit independent of other configurations.

In addition, some of the functions of the detection control unit 85 or all of the functions of the detection control unit 85 may be realized by a hardware circuit that does not require software to realize the function. The detection control unit 85 may be a detection control circuit independent of other configurations. In addition, some of the functions of the light emission control unit 86 or all of the functions of the light emission control unit 86 may be realized by a hardware circuit that does not require software to realize the function. The light emission control unit 86 may be a light emission control circuit independent of other configurations. For example, some or all of the functions of the detection control unit 85 and the light emission control unit 86 may be incorporated into the reading unit 30.

<Interface section>
The interface unit 95 can communicate with a device outside the housing 2 (hereinafter, also referred to as an external device), and can be called an interface circuit, a communication circuit, or a communication unit. The external device may include a personal computer, a mobile phone such as a smartphone, or other computer device. The external device may also include a data recording medium (e.g., a flash memory) that is detachable from the reading device 1. The interface unit 95 can receive a signal from the external device and input the received signal to the control unit 80. The interface unit 95 can also transmit a signal from the control unit 80 to the external device. For example, the interface unit 95 can transmit an image signal that has been image-processed in the image processing unit 81 of the control unit 80 to the external device. The interface unit 95 may perform wired communication with the external device, or may perform wireless communication. The communication between the interface unit 95 and the external device may be compliant with Ethernet, USB (Universal Serial Bus), Wi-Fi, or other standards.

<About the holding part>
The holding unit 20 holds the imaging plate 10 inserted through the insertion opening 2a of the housing 2. The holding unit 20 includes, for example, a support plate 21 that supports the imaging plate 10, and a fixing unit 22 that fixes the position of the imaging plate 10 supported by the support plate 21.

The support plate 21 has a main surface 21a (also called the support surface 21a) that supports the back surface of the imaging plate 10, and a main surface 21b (also called the opposite surface 21b) opposite the main surface 21a. The fixing portion 22 has, for example, a plurality of fixing portions 22a, 22b that face the peripheral portion of the imaging plate 10. The fixing portion 22 can also be called a fixing member. The plurality of fixing portions 22a, 22b face the peripheral portion of the imaging plate 10 so as to surround the peripheral portion. This fixes the position (i.e., relative position) and attitude (i.e., relative attitude) of the imaging plate 10 with respect to the support plate 21. In this example, for example, two fixing portions 22a or two fixing portions 22b face each of both long sides of the imaging plate 10. One fixing portion 22a or one fixing portion 22b faces each of both short sides of the imaging plate 10.

All or part of the fixed parts 22a, 22b may be movable toward and away from the imaging plate 10 supported by the support plate 21. In this example, the two fixed parts 22a facing one long side of the imaging plate 10 are fixed at a fixed position relative to the support plate 21, and the two fixed parts 22b facing the other long side are supported movably. The moving direction of the movable fixed part 22b is the direction of moving toward and away from the fixed part 22a supported at a fixed position on the support plate 21. In this example, the fixed part 22a facing one short side of the imaging plate 10 is fixed at a fixed position relative to the support plate 21, and the one fixed part 22b facing the other short side is supported movably. The moving direction of the movable fixed part 22b is the direction of moving toward and away from the fixed part 22a supported at a fixed position on the support plate 21.

The imaging plate 10 is inserted into the housing 2 through the insertion port 2a with each movable fixed portion 22b in the separated position, and is supported by the support plate 21. The movable fixed portion 22b then moves from the separated position to the close position, and the imaging plate 10 is pressed and held from its four edges by each fixed portion 22a, 22b. At this time, the imaging plate 10 is held in a fixed position and orientation by the holding portion 20, based on the fixed portion 22a, which is fixed in a fixed position on the support plate 21.

The holding unit 20 is configured to be capable of holding imaging plates 10 of different sizes. In this example, the different sized imaging plates 10 are assumed to be a first imaging plate 10A (shown by solid lines in Figs. 2 and 3) and a second imaging plate 10B (shown by two-dot chain lines in Figs. 2 and 3). Hereinafter, when distinguishing the imaging plates 10 by size, they will be distinguished as the first imaging plate 10A and the second imaging plate 10B. Note that the first imaging plate 10A and the second imaging plate 10B in this embodiment correspond to the small-sized imaging plate and the large-sized imaging plate, respectively (described in paragraph 0004).

The length of the second imaging plate 10B in the short side direction is greater than the length of the first imaging plate 10A in the short side direction. The first imaging plate 10A and the second imaging plate 10B are held in the holding portion 20 with their long sides aligned along the specified direction SC1. Therefore, in the direction perpendicular to the specified direction SC1, which is the scanning direction, the width of the second imaging plate 10B is greater than the width of the first imaging plate 10A.

In this example, the length of the long side of the second imaging plate 10B is greater than the length of the long side of the first imaging plate 10A. The length of the long side of the second imaging plate 10B may be the same as or longer than the length of the long side of the first imaging plate 10A.

The first imaging plate 10A can record, for example, a radiographic image of a few teeth or a portion of the dental arch. The second imaging plate 10B can record, for example, a radiographic image of a wide area of the dental arch or a radiographic image that includes, in part, a lesion such as a sialolith, a cyst, a tumor, or a fracture.

In this example, as described above, the two fixed parts 22b facing one long side and the fixed part 22b facing one short side move, so that both the first imaging plate 10A and the second imaging plate 10B can be held in a constant position and attitude based on the fixed part 22a.

The two movable fixed parts 22b and one fixed part 22b may be driven to move between a close position where they can approach the edge of the imaging plate 10 and a separated position away from the edge, for example, by control by the holding control unit 84. The movement of the fixed part 22b may be driven by a mechanism that combines, for example, a motor and a ball screw mechanism including a screw shaft and a net.

It is not essential that the fixed part 22b is moved and driven under the control of the holding control part 84. For example, the holding part 20 may be configured to be exposed from the housing 2 at the position where the imaging plate 10 is set, and the user may manually move the fixed part 22b to set the imaging plate 10 on the holding part 20. Alternatively, it is possible to set the imaging plate 10 on the holding part 20 by moving the fixed part 22b using the power of the drive part 52 driven under the control of the drive control part 83 by a mechanical mechanism. In such a case, it is not essential to have the holding control part 84. Also, it is not essential that the movable fixed part 22b exists. The imaging plate 10 inserted into the housing 2 from the insertion port 2a may be guided by gravity and a guide member utilizing the gravity so that it comes into contact with the fixed parts 22a in two directions in the holding part 20.

The holding unit 20 is not limited to the above example, and various holding configurations can be adopted. For example, the holding unit 20 may hold the imaging plate by suction using air pressure, etc.

<Scanning mechanism>
The scanning mechanism 50 moves the holding unit 20 relative to the reading unit 30 along a predetermined direction SC1, which is a scanning direction parallel to the imaging plate 10 held by the holding unit 20. In this embodiment, the scanning mechanism 50 includes a drive unit 52 and a pair of guide units 60.

The drive unit 52 is capable of driving the holding unit 20 to move along the specified direction SC1 under the control of the drive control unit 83. This allows the imaging plate 10 held by the holding unit 20 to also move along the specified direction SC1. It can also be said that the drive unit 52 is capable of moving the imaging plate 10 along the specified direction SC1 through the holding unit 20.

The pair of guide parts 60 extend along a specific direction SC1 on the opposite surface 21b of the support plate 21 of the holding part 20. The pair of guide parts 60 are formed in a long rod shape. Guide holes are formed on the opposite surface 21b of the support plate 21, through which the pair of guide parts 60 are inserted so as to be movable along their longitudinal direction. This allows the pair of guide parts 60 to guide the movement of the holding part 20 along the specific direction SC1. Note that the configuration of the guide parts 60 is not limited to this. For example, the guide parts may be rails that guide the edges of the support plate 21.

The drive unit 52 is composed of, for example, a ball screw mechanism having a motor 51a, a screw shaft portion 51b, and a nut portion 51c. The motor 51a is controlled by the drive control unit 83. The screw shaft portion 51b is a rod-shaped member having a screw groove formed around its periphery. The screw shaft portion 51b extends along a predetermined direction SC1 and is rotated by the motor 51a. The nut portion 51c is fixed to the holding unit 20. The nut portion 51c is fixed, for example, to the opposite surface 21b of the support plate 21 of the holding unit 20. The screw shaft portion 51b is screwed into the nut portion 51c. The screw shaft portion 51b rotates in the forward direction or reverse direction according to the rotation of the motor 51a in the forward direction or reverse direction. The holding unit 20 moves to one side along the predetermined direction SC1 according to the rotation of the screw shaft portion 51b in the forward direction under the guidance of a pair of guide portions 60. Additionally, the holding portion 20 moves to the other side along the specified direction SC1 in response to the rotation of the screw shaft portion 51b in the reverse direction.

The drive unit 52 can move the holding unit 20 holding the imaging plate 10 from the position where the imaging plate 10 is set to a reading start position where reading of the radiation image from the imaging plate 10 begins. In addition, when reading of the radiation image from the imaging plate 10 is completed, the drive unit 52 can move the holding unit 20 holding the imaging plate 10 to a position where the imaging plate 10 is ejected. Figures 2 and 3 show how the radiation image is read from the imaging plate 10.

The configuration of the scanning mechanism is not limited to the above example. For example, the scanning mechanism may be a linear motor that moves the holding unit 20. Also, when the holding unit 20 is supported at a fixed position within the housing, the scanning mechanism may be configured to move the reading unit 30 along the specified direction SC1 instead of the holding unit 20.

The control unit 80 can grasp the position of the reading unit 30 in the scanning direction SC1 by receiving a signal corresponding to the direction and amount of rotation of the motor 51a in the scanning mechanism 50. The signal corresponding to the direction and amount of rotation of the motor 51a may be, for example, an output from an encoder built into the motor 51a.

<About the reading unit>
The reading unit 30 includes an excitation light source 32 and a photodetector 40. In this example, the reading unit 30 includes a detection unit 31 in which one excitation light source 32 is integrated with one photodetector 40. For example, one excitation light source 32 and one photodetector 40 are housed in one case 31c and fixed at a fixed position and attitude in the case 31c, thereby forming a unit. The excitation light source 32 and the photodetector 40 may be fixed to the case 31c by screwing, adhesive fixing, or the like. It is not essential that the excitation light source 32 and the photodetector 40 are integrated. In addition, the positional relationship between the excitation light source 32 and the photodetector 40 is not limited to this form, and the positions of the excitation light source and the photodetector may be reversed. In addition, only one of the first detection unit 31A or the second detection unit 31B may have the above-mentioned reversed configuration.

The excitation light source 32 can irradiate the imaging plate 10 held by the holder 20 with excitation light L1 for exciting the radiation image forming layer 11. The excitation light source 32 emits the excitation light L1 toward the support surface 21a of the holder 20. The excitation light source 32 can scan the imaging plate 10 with the excitation light L1 in one direction (also called the line scanning direction SC2). The line scanning direction SC2 is a direction perpendicular to the predetermined direction SC1. That is, the line scanning direction SC2 is a direction perpendicular to the moving direction of the holder 20, for example, as in this embodiment. The line scanning direction SC2 may be oblique to the scanning direction SC1. The line scanning direction SC2 is the main scanning direction, and the predetermined direction SC1, which is the scanning direction by the scanning mechanism 50, may be considered to be the sub-scanning direction.

The excitation light L1 is, for example, a visible laser light. The excitation light L1 may be, for example, a red laser light or a laser light of another color. When the excitation light L1 is irradiated onto the radiation image forming layer 11, the radiation image forming layer 11 emits light in accordance with the distribution of energy stored in the radiation image forming layer 11, and emitted light L2 is emitted from the radiation image forming layer 11. The emitted light L2 is also called stimulated emission, and is, for example, blue visible light. The photodetector 40 detects the emitted light L2 from the imaging plate 10, and outputs an electrical signal according to the intensity of the detected emitted light L2.

The excitation light source 32 has, for example, a laser generating unit that generates and outputs the excitation light L1, and a scanning unit that scans the excitation light L1 on the imaging plate 10 in the line scanning direction SC2. The laser generating unit is, for example, a semiconductor laser, and is controlled by the light emission control unit 86. The laser generating unit may be a laser diode or another semiconductor laser. The scanning unit is, for example, a MEMS (Micro Electro Mechanical Systems) mirror that reflects the excitation light L1 from the laser generating unit toward the radiation image forming layer 11 of the imaging plate 10. The MEMS mirror changes the reflection angle of the excitation light L1 under the control of the light emission control unit 86 so that the irradiation point of the excitation light L1 on the radiation image forming layer 11 moves along the line scanning direction SC2. Note that, instead of the MEMS (Micro Electro Mechanical Systems) mirror, the mirror may be configured using a galvanometer mirror, a polygon mirror, or the like. Depending on the mirror configuration, a lens system configuration not included in the description so far may be required separately, but it can be used in the present invention by appropriate combination.

The light detector 40 includes an optical filter 42 on which the emitted light L2 (see FIG. 3) from the imaging plate 10 is incident, and a sensor 41 that detects the emitted light L2 emitted from the optical filter 42. The sensor 41 is controlled by the detection control unit 85. The optical filter 42 is disposed so as to face the detection surface of the emitted light L2 at the sensor 41. The transmittance (also called the emitted light transmittance) of the optical filter 42 for the emitted light L2 is high. Therefore, the optical filter 42 transmits the emitted light L2 from the imaging plate 10 sufficiently and emits it to the sensor 41. On the other hand, the transmittance (also called the excitation light transmittance) of the optical filter 42 for the excitation light L1 is lower than the emitted light transmittance. Therefore, the optical filter 42 attenuates the reflected light of the excitation light L1 at the imaging plate 10 toward the sensor 41. In this disclosure, the reflected light includes scattered light. Hereinafter, simply referring to reflected light means the reflected light of the excitation light L1. The optical filter 42 may be omitted.

The sensor 41 is capable of detecting the emitted light L2 transmitted through the optical filter 42 and outputting an electrical signal corresponding to the intensity of the detected emitted light L2. The sensor 41 may be composed of, for example, a plurality of photodiodes or a photomultiplier tube.

In the reading device 1, when a process (also called a reading process) is performed to read a radiation image from the imaging plate 10, the holding unit 20 holding the imaging plate 10 is transported to a reading start position by the scanning mechanism 50. Then, the reading unit 30 starts the reading process. In the reading process, the excitation light source 32 repeatedly executes a process (also called a line scanning direction scan) of scanning the imaging plate 10 with the excitation light L1 in a line scanning direction SC2 on the imaging plate 10 under the control of the light emission control unit 86. On the other hand, in the reading process, the scanning mechanism 50 moves the holding unit 20 holding the imaging plate 10 along a scanning direction SC1 along a predetermined direction SC1. The scanning direction SC1 is a direction perpendicular to the line scanning direction SC2. While the holding unit 20 is moving in the scanning direction SC1, the line scanning direction scan is repeatedly executed, so that the excitation light L1 is raster scanned on the radiation image forming layer 11 of the imaging plate 10. As a result, in the reading process, the entire area of the radiation image forming layer 11 is sequentially irradiated with the excitation light L1, and the entire area of the radiation image forming layer 11 is scanned with the excitation light L1. While the excitation light L1 is raster-scanning the radiation image forming layer 11, the sensor 41 of the reading unit 30 detects the luminescent light L2 sequentially emitted by the radiation image forming layer 11 in response to the raster scanning, thereby reading a radiation image from the radiation image forming layer 11. The sensor 41 outputs an image signal representing the read radiation image (latent image) (in other words, the detected radiation image) to the detection control unit 85 as a detection result of the luminescent light L2 during the raster scanning of the excitation light L1. This image signal includes the luminance values (in other words, pixel values) of a plurality of pixels representing the read radiation image (latent image). The sensor 41 outputs, for example, a grayscale image signal. Hereinafter, the radiation image read by the photodetector 40 may be referred to as a detected radiation image.

In this way, the reading unit 30 can detect emitted light from the imaging plate 10 in a reading area extending in the scanning direction SC1 and the line scanning direction SC2 perpendicular to the scanning direction SC1 by scanning with the scanning mechanism 50.

In this example, when the imaging plate 10 is properly held by the holding portion 20, as shown in FIG. 2, the short side direction of the imaging plate 10 is parallel to the line scanning direction SC2, and the long side direction of the imaging plate 10 is parallel to the scanning direction SC1.

In this example, the sensor 41 outputs a larger luminance value, for example, as the intensity of the detected light increases. In the radiation image forming layer 11 of the imaging plate 10, the intensity of the emitted light L2 from a portion where the radiation irradiation intensity is greater and the accumulated energy is greater is greater. Therefore, the luminance value output by the sensor 41 for an image based on the detection of the emitted light L2 from a portion of the radiation image forming layer 11 where the accumulated energy is greater increases.

For example, consider a case where a radiation image of teeth is recorded in the radiation image forming layer 11. In this case, the intensity of the emitted light L2 from the portion of the radiation image forming layer 11 where the radiation image of the teeth is recorded, i.e., the portion irradiated with radiation that has passed through the teeth, is relatively low. Therefore, the luminance value output from the sensor 41 for the portion of the detected radiation image where the teeth are shown is relatively low. On the other hand, the intensity of the emitted light L2 from the portion of the radiation image forming layer 11 that is directly irradiated with radiation (also referred to as the directly irradiated portion) is relatively high. Therefore, the luminance value output from the sensor 41 for the image of the detected radiation image that corresponds to the directly irradiated portion of the radiation image forming layer 11 is relatively high.

In this example, the optical filter 42 attenuates the excitation light L1, but may transmit the excitation light L1 to a certain extent. In this case, the sensor 41 detects not only the luminescent light L2 emitted by the imaging plate 10, but also the reflected light of the excitation light L1 from the imaging plate 10 to a certain extent. Therefore, the luminance value of the detected radiation image output from the sensor 41 includes a luminance value corresponding to the intensity of the detected luminescent light L2 (also called the luminance value corresponding to the emitted light) and a luminance value corresponding to the detected reflected light (also called the luminance value corresponding to the reflected light). The luminance value corresponding to the emitted light is, for example, 10 times or more the luminance value corresponding to the reflected light. Therefore, the detected radiation image based on the image signal output from the photodetector 40 is not significantly affected by the reflected light, and appropriately represents the radiation image recorded on the imaging plate 10.

<About the reading area>
Focusing on one detection unit 31 in the reading section 30, the overlapping range of the scanning range of the excitation light source 32 and the range in which the photodetector 40 can detect the emitted light L2 in the line scanning direction SC2 is the detection width of the photodetector 40 in the line scanning direction SC2. If this detection width is larger than the width of the imaging plate 10 in the line scanning direction SC2, one detection unit 31 can read the entire imaging plate 10 by one scan. However, if the detection width of the photodetector 40 is smaller than the width of the imaging plate 10 in the line scanning direction SC2, one detection unit 31 cannot read the entire imaging plate 10 by one scan. Hereinafter, a configuration for reading an imaging plate 10 that is larger than the detection width of the photodetector 40 in one detection unit 31 will be described.

For example, in the line scanning direction SC2, the detection width of the photodetector 40 in the detection unit 31 is the same as or larger than the width of the first imaging plate 10A. Also, for example, in the line scanning direction SC2, the detection width of the photodetector 40 in the detection unit 31 is smaller than the width of the second imaging plate 10B. Note that multiple sizes may be set for the first imaging plate 10A having a width smaller than the detection width of the photodetector 40 in the detection unit 31 in the line scanning direction SC2. Also, multiple sizes may be set for the second imaging plate 10B having a width larger than the detection width of the photodetector 40 in the detection unit 31 in the line scanning direction SC2.

Figure 5 is an explanatory diagram showing the relationship between the second imaging plate 10B and the various reading areas R, R1, and R2. For ease of explanation, a latent image I on the second imaging plate 10B is shown in Figure 5.

The entire reading area R suitable for reading the second imaging plate 10B is equal to or larger than the area including the second imaging plate 10B. Therefore, in the line scanning direction SC2, the width Wa of the entire reading area R is equal to or larger than the width Wip of the second imaging plate 10B.

On the other hand, as described above, the detection widths W1 and W2 of the photodetector 40 in one detection unit 31 are smaller than the width Wa. Therefore, the entire reading area R cannot be read by one detection unit 31 in one scan.

Therefore, in the reading unit 30, a plurality of reading regions including at least a first reading region R1 and a second reading region R2 shifted in a line scanning direction SC2 perpendicular to the scanning direction SC1 can be set as the reading region. In this example, each reading region R1, R2 is set so that each part of the entire reading region R belongs to either or both of the first reading region R1 and the second reading region R2. In this case, the first reading region R1 and the second reading region R2 may or may not overlap partially. Also, in the line scanning direction SC2, the width W1 of the first reading region R1 and the width W2 of the second reading region R2 may be the same or different. In this example, an example in which the reading regions R1, R2 partially overlap in the line scanning direction SC2 perpendicular to the scanning direction SC1 is described. When the first reading region R1 and the second reading region R2 partially overlap, a partial overlapping reading region RR is set in the middle of the width direction in the line scanning direction SC2 in the entire reading region R. This allows the detection unit 31 having detection widths W1 and W2 smaller than the width Wa of the entire reading region R to read the entire reading region R. The setting of the reading region in the present invention is not limited to the embodiment of two regions, the first reading region and the second reading region, but may be a configuration in which a plurality of reading regions (three or more regions) including the first reading region and the second reading region are set. For example, if a sensor smaller than a general sensor (photodetector) used for reading an imaging plate is installed and the small sensor is capable of reading an imaging plate with three or more reading regions set, it may be possible to further reduce the cost and weight of the device. In addition, in a configuration in which three or more reading areas are set, the operation and operation contents of each part and the area settings for the first reading area and the second reading area in the radiation image reading device are basically applied to the third reading area and subsequent reading areas in the same way.

Various configurations can be envisaged for enabling the reading unit 30 to set multiple reading areas including at least a first reading area R1 and a second reading area R2 shifted in the line scanning direction SC2. For example, the reading unit 30 may be configured to include multiple detection units 31 including a first detection unit 31A and a second detection unit 31B, with each detection unit reading a different reading area. In addition, for example, a single detection unit may be configured to read different reading areas sequentially by moving relatively in a direction intersecting the scanning direction SC1. In the following description, the multiple detection units 31 may be distinguished as a first detection unit 31A and a second detection unit 31B, as necessary.

An example of the former is described in this embodiment, and an example of the latter is described in the second embodiment.

<Regarding the multiple detection units provided in the reading unit>
2, 3, and 4, the reading section 30 includes a first detection unit 31A and a second detection unit 31B. As described above, the first detection unit 31A and the second detection unit 31B each include an excitation light source 32 and a photodetector 40. Hereinafter, as necessary, a distinction may be made between the photodetector 40A in the first detection unit 31A and the photodetector 40B in the second detection unit 31B.

The first detection unit 31A and the second detection unit 31B are positioned with a shift in the line scanning direction SC2 perpendicular to the scanning direction SC1, and therefore the first photodetector 40A and the second photodetector 40B are also positioned with a shift in the line scanning direction SC2. More specifically, the first photodetector 40A is positioned with a shift to one side of the line scanning direction SC2 with respect to the second imaging plate 10B held in the holding unit 20. The second photodetector 40B is positioned with a shift to the other side of the line scanning direction SC2 with respect to the second imaging plate 10B held in the holding unit 20. In the line scanning direction SC2, the first photodetector 40A and the second photodetector 40B partially overlap in the middle of the second imaging plate 10B. The first photodetector 40A can read the second imaging plate 10B in the first reading region R1, and the second photodetector 40B can read the second imaging plate 10B in the second reading region R2 (see FIG. 5 for reading regions R1 and R2).

In this embodiment, the first photodetector 40A and the second photodetector 40B are positioned offset in the scanning direction SC1. In this embodiment, the first detection unit 31A and the second detection unit 31B are positioned offset exclusively in the scanning direction SC1. As a result, when viewed along the scanning direction SC1, the part of the first photodetector 40A closer to the second photodetector 40B and the part of the second photodetector 40B closer to the first photodetector 40A can be arranged to overlap. As a result, as described above, the first reading area R1 and the second reading area R2 that partially overlap in the line scanning direction SC2 can be set. The first detection unit 31A and the second detection unit 31B are fixed by various fixing structures including various conventional structures such as a structure that screws into a frame 2F fixed at a fixed position in the housing 2 and a structure that fits and fixes to the frame of the detection unit.

<Image Processing Unit>
The image processing unit 81 of the control unit 80 receives image signals output from the sensor 41 of the first photodetector 40A and the sensor 41 of the second photodetector 40B through the detection control unit 85. The image processing unit 81 associates pixel position information with each of a plurality of luminance values included in the image signal from each sensor 41. The pixel position information associated with a certain luminance value is information indicating the position (also referred to as pixel position) of a pixel having the certain luminance value in the acquired image.

Figure 6 is a diagram explaining the process of combining first image data DR1 corresponding to the first reading area R1 and second image data DR2 corresponding to the second reading area R2 to generate overall image data DR corresponding to the overall reading area R (see Figure 5).

In the reading process, the scanning mechanism 50 moves the holding unit 20 along the scanning direction SC1 in accordance with the repetition of the line scanning direction scan. Specifically, during reading by the first detection unit 31A, the scanning mechanism 50 moves the holding unit 20 along the scanning direction SC1 so that the entire area of the first reading region R1 is irradiated with the excitation light L1 while the line scanning direction scan is performed a predetermined number of times. Then, the sensor 41 sequentially outputs a luminance value according to the irradiation position of the excitation light L1 in the first reading region R1 in accordance with the raster scan of the excitation light L1. Since the reading device 1 operates in this way in the reading process, if the first reading region R1 on the second imaging plate 10B, the detection range by the first photodetector 40A, the time required for one line scanning direction scan, the repetition period of the line scanning direction scan, and the number of times the line scanning direction scan is performed in the reading process are known, it is possible to know at what position in the entire image the luminance value output by the sensor 41 is the luminance value. Based on the information, the image processing unit 81 associates pixel position information with each of the multiple luminance values included in the image signal from the sensor 41. This results in the first image data DR1 based on the data read from the first reading region R1. The detection control unit 85 may also associate pixel position information with each of the multiple luminance values included in the image signal from the sensor 41.

Even during reading by the second detection unit 31B, pixel position information is associated with each of the multiple luminance values contained in the image signal from the sensor 41 in the same manner as described above. This results in second image data DR2 based on the data read from the second reading region R2.

The image processing unit 81 also generates overall image data DR by combining the first image data DR1 and the second image data DR2. The process of combining the first image data DR1 and the second image data DR2 can be performed by various processes including well-known image combining processes.

For example, the first image data DR1 and the second image data DR2 have a partial overlapping reading area RR. Therefore, the first image data DR1 and the second image data DR2 may be combined through a process of extracting feature points from each of the first image data DR1 and the second image data DR2, and a process of determining corresponding areas between the first image data DR1 and the second image data DR2 based on a comparison of each feature point.

In addition, the relative positional relationship between the first detection unit 31A and the second detection unit 31B in this device 1 can be known information. In addition, since the second imaging plate 10B held by the holding unit 20 moves along a fixed path, the positional relationship in which the first detection unit 31A and the second detection unit 31B read the second imaging plate 10B can also be considered to be always constant. Therefore, the relative positional relationship between the first image data DR1 detected by the first photodetector 40A of the first detection unit 31A and the second image data DR2 detected by the photodetector 40B of the second detection unit 31B can be considered to be constant. Therefore, the first image data DR1 and the second image data DR2 may be combined so that the default reference position in the first image data DR1 and the default reference position in the second image data DR2 coincide with each other. In other words, the first image data DR1 and the second image data DR2 may be combined using the pixel position information in the entire image data DR to be obtained.

When combining the first image data DR1 and the second image data DR2, the area outside the boundary between the first image data DR1 and the second image data DR2 may be deleted based on a boundary line (not shown) that passes through the overlapping reading area RR, and then the first image data DR1 and the second image data DR2 may be combined. The boundary line may be a line that passes through any part of the area estimated to be the overlapping reading area RR.

The boundary line may be set at the outer edge of the first reading region R1 in the overlapping reading region RR or in a region close to the outer edge (see B1 in FIG. 5). That is, when the imaging plate 10 is irradiated with excitation light, the energy stored in the stimulable phosphor is released. The overlapping reading region RR is irradiated with excitation light from the first detection unit 31A, and then with excitation light from the second detection unit 31B. For this reason, it is considered that the luminance value of the pixels in the overlapping reading region RR by the second photodetector 40B of the second detection unit 31B is smaller than the luminance value by the first photodetector 40A of the first detection unit 31A. Therefore, by setting the boundary line at the outer edge of the first reading region R1 or in a region close to the outer edge, the image in the overlapping reading region RR can be based on the first image data DR1 as much as possible, and it is easy to obtain a clear image in the overlapping reading region RR.

When combining the first image data DR1 and the second image data DR2, the overlapping reading region RR of the first image data DR1 and the overlapping reading region RR of the second image data DR2 may be weighted and overlapped in the overlapping reading region RR. In this case, as described above, since the data in the overlapping reading region RR of the first image data DR1 holds data more corresponding to the latent image, the weight of the overlapping reading region RR of the first image data DR1 may be set to be greater than the weight of the overlapping reading region RR of the second image data DR2.

The boundary line may be set inside the outer edge of the first reading region R1 and inside the outer edge of the second reading region R2 in the overlapping reading region RR (see range B2 in FIG. 5). That is, in the first detection unit 31A, the light from the excitation light source 32 is reflected by the MEMS mirror and enters the first reading region R1. The start or end point of the irradiation point of the excitation light L1 by the MEMS mirror is set to follow the outer edge of the first reading region R1, but there may be a certain limit to the positional accuracy of the start or end point of the irradiation point. For this reason, a state in which sufficient excitation light is not irradiated at the boundary of the first reading region R1 may occur, and the luminance value corresponding to the boundary in the first image data DR1 may not be a value corresponding to the latent image and may vary. A similar situation may occur with the second detection unit 31B. Therefore, by setting the boundary line inside the outer edge of the first reading area R1 and inside the outer edge of the second reading area R2 of the overlapping reading area RR, it is easy to obtain an image corresponding to the latent image even at the boundary of the overlapping reading area RR.

The generated overall image data DR is, for example, data in which pixel position information in the overall reading region R is associated with each of a plurality of luminance values. The image processing unit 81 outputs the generated overall image data DR to the display control unit 82. The display control unit 82, for example, causes the display unit 3 to display a detected radiation image of the overall reading region R including the first reading region R1 and the second reading region R2 based on image data corresponding to the overall reading region R. The display unit 3 may also display the first image data DR1 of the first reading region R1 and the second image data DR2 of the second reading region R2 before they are combined, or may display only the first image data DR1 or only the second image data DR2.

The image processing performed by the image processing unit 81 may include a luminance inversion process. The luminance inversion process is a process in which each luminance value of the image signal before the luminance inversion process is converted so that the luminance value becomes smaller as the luminance value becomes larger. Here, the maximum value of the range in which the luminance value can be taken is called the maximum luminance value. For example, a value obtained by subtracting a certain luminance value contained in the image signal before the luminance inversion process from the maximum luminance value becomes the certain luminance value after conversion. By performing the luminance inversion process on the image signal, the luminance value of the radiation image based on the detection of the emission light L2 from the part of the imaging plate 10 with small accumulated energy becomes large in the image signal after the image processing, unlike the image signal before the image processing, and the luminance value of the radiation image based on the detection of the emission light L2 from the part of the imaging plate 10 with large accumulated energy becomes small. Furthermore, in the image signal after the image processing, the luminance value of the unexposed region image and the luminance value of the imaging plate outer region image become larger than the luminance value of the detected radiation image. The luminance inversion process may be performed on the first image data DR1 and the second image data DR2, or may be performed on the entire image data DR.

The image processing performed by the image processing unit 81 may not include brightness inversion processing, or may include processing other than brightness inversion processing. The image processing may include, for example, at least one of offset correction and logarithmic conversion as processing other than brightness inversion processing.

When the first imaging plate 10A is the target, the reading process by the second detection unit 31B and the above-mentioned combining process may be omitted.

<Example of operation of the reading device>
FIG. 7 is a flowchart showing an example of the operation of the reading device 1. This operation is realized, for example, by the processor 80a executing a calculation according to the processing procedure described in the program 80bp. When the second imaging plate 10B inserted from the insertion port 2a of the housing 2 is held by the holding unit 20 and the start button included in the operation unit 4 is operated, step S1 in FIG. 7 is executed. The operation of the start button can also be said to be an operation to instruct the start of the series of processes shown in FIG. 7. Note that the execution of step S1 does not have to be configured as a manual start triggered by the operation of the start button, but may be configured as an automatic start triggered by, for example, detecting a state in which the second imaging plate 10B is held in a certain position and attitude by the holding unit 20 with a sensor or the like and using the detection signal.

In step S1, the scanning mechanism 50 moves the holding unit 20 to the reading start position under the control of the drive control unit 83.

Next, in step S2, the first reading process is executed. That is, the scanning mechanism 50 executes a first scan to move the holding portion 20 further from the reading start position along the scanning direction SC1. As a result, the first reading region R1 of the second imaging plate 10B passes below the first photodetector 40A in the first detection unit 31A along the scanning direction SC1 (see arrow SC1a in FIG. 2). During this first scan, the first photodetector 40A in the first detection unit 31A reads the second imaging plate 10B in the first reading region R1. As a result, the first image data DR1 is obtained.

In the next step S3, the second reading process is executed. Here, the scanning mechanism 50 moves the holding part 20 until the second imaging plate 10B passes the reading part 30, and then moves the holding part 20 in the opposite direction along the scanning direction SC1. That is, the scanning mechanism 50 executes a second scan in which the holding part 20 is moved in the opposite direction to the first scan. As a result, the second reading region R2 of the second imaging plate 10B passes under the second photodetector 40B in the second detection unit 31B along the scanning direction SC1 in the opposite direction to the first scan (see arrow SC1b in FIG. 2). During this second scan, the second photodetector 40B in the second detection unit 31B reads the imaging plate 10 in the second reading region R2. As a result, the second image data DR2 is obtained.

According to steps S2 and S3, the holding unit 20 is moved back and forth once. This enables a quick reading process. The second scan may be performed by moving the holding unit 20 in the return direction along the scanning direction SC1 after the first scan, and then moving the holding unit 20 in the same forward direction as the first scan. In this case, the direction of movement of the second imaging plate 10B relative to the first detection unit 31A and the second detection unit 31B is the same in the first reading process and the second reading process, so the reading conditions of the first image data DR1 and the second image data DR2 are common. This is expected to unify the image quality of the combined overall image data DR as a whole, improving the image quality.

In steps S2 and S3, the reading unit 30 scans the second imaging plate 10B held by the holding unit 20 over the entire reading area R along the scanning direction SC1 that is horizontal to the second imaging plate 10B so that reading can be performed on multiple reading areas including a first reading area R1 and a second reading area R2 that are shifted in a direction perpendicular to the scanning direction SC1.

In the next step S4, the scanning mechanism 50 moves the holding unit 20 to the ejection position. After this, in step S5, the fixed portion 22b is moved to release the holding of the second imaging plate 10B by the holding unit 20. This causes the second imaging plate 10B on the holding unit 20 to be ejected to the outlet 2b of the housing 2. Note that the processes of steps S4 and S5 relating to ejection may be performed after the combining process (S6 described below) or the display process (S7 described below).

In the next step S6, the control unit 80, under the control of the image processing unit 81, generates overall image data DR by combining the first image data DR1 based on the data read from the first reading area R1 and the second image data DR2 based on the data read from the second reading area R2.

Then, in step S7, the display unit 3 displays an overall image corresponding to the overall reading area R based on the overall image data DR under the control of the display control unit 82. Note that displaying the overall image data DR on the display unit 3 is optional. The overall image data DR may be stored in a memory unit. The memory unit may be a portable recording medium such as a flash memory or an optical recording medium. The overall image data DR may be transmitted to an external computer by wired or wireless communication. The overall image data DR may be displayed on an external display device such as a monitor provided on the external computer.

When the first imaging plate 10A is the target, steps S3 and S6 can be omitted, and the image based on the first image data DR1 acquired in step S2 can be treated as image data read from the first imaging plate 10A.

<Effects, etc.>
According to the reading device 1 configured as described above, a plurality of reading areas are set as reading areas, including at least a first reading area R1 and a second reading area R2 shifted in a direction perpendicular to the scanning direction SC1, so that it is possible to read a second imaging plate 10B having a width larger than the detection width of the photodetectors 40A, 40B.

In addition, to read the second imaging plate 10B with a large width, a first detection unit 31A and a second detection unit 31B having a detection width smaller than the width of the second imaging plate 10B can be used. The prices of the first detection unit 31A and the second detection unit 31B tend to be high depending on the detection width. Therefore, by combining the first detection unit 31A and the second detection unit 31B with a small detection width to read the second imaging plate 10B with a large width, it is possible to reduce the cost of the device compared to a configuration in which a single detection unit corresponding to the second imaging plate 10B with a large width is used to perform reading in one go.

In addition, when a small-sized imaging plate is used as in the prior art, lines resulting from the boundary between the first and second imaging plates appear in the composite image. In this embodiment, imaging can be performed using a single second imaging plate 10B, so lines resulting from the overlapping boundary of the imaging plates do not appear in the overall image. However, even with the conventional imaging method of using multiple small-sized imaging plates to capture an image equivalent to a large-sized imaging plate such as second imaging plate 10B, it is possible to perform reading processing using the reading device 1 of the present invention.

Furthermore, for the first imaging plate 10A, reading can be performed for one reading area by one detection unit 31. For the second imaging plate 10B, the entire reading area R of the second imaging plate 10B can be read by multiple reading processes for the multiple reading areas R1 and R2. This allows the reading size by the device 1 to be diversified.

In addition, in this embodiment, the first photodetector 40A of the first detection unit 31A and the second photodetector 40B of the second detection unit 31B are positioned offset in the line scanning direction SC2, so that the first reading region R1 and the second reading region R2 can be read without moving the detection units in the line scanning direction SC2. This allows the number of drive mechanisms and drive controls in the device 1 to be reduced.

In addition, the first reading region R1 is read during the first scan, and the second reading region R2 is read during the second scan, which is performed at a different time from the first scan. Therefore, the excitation light and the emitted light from the excitation light when reading the first reading region R1 are unlikely to affect the detection value when reading the second reading region R2. Conversely, the excitation light and the emitted light from the excitation light when reading the second reading region R2 are unlikely to affect the detection value when reading the first reading region R1. Therefore, the influences during reading are unlikely to affect each other, and the second imaging plate 10B can be read more accurately. For example, this is an effective configuration when the first detection unit 31A and the second detection unit 31B are close to each other and the excitation light or emitted light of one affects the detection of the other.

In addition, since the excitation light source 32 is integrated with one first photodetector 40A (or second photodetector 40B) to form a first detection unit 31A (or second detection unit 31B), the first photodetector 40A (or second photodetector 40B) and the excitation light source 32 can be easily handled as a single unit.

In addition, because the first reading region R1 and the second reading region R2 partially overlap in the scanning direction SC1, gaps are unlikely to occur between the image based on the reading of the first reading region R1 and the image based on the reading of the second reading region R2. Furthermore, when combining the first image data DR1 and the second image data DR2, the data of the overlapping reading region RR can be used as data for determining the corresponding positions. In this case, the first image data DR1 and the second image data DR2 can be combined with an accurate positional relationship.

In addition, since the first image data DR1 based on the data read from the first reading region R1 and the second image data DR2 based on the data read from the second reading region R2 are combined to generate overall image data DR, the image data read from the second imaging plate 10B can be provided as a single image for diagnosis, observation, etc.

Note that it is not essential that the first image data DR1 based on the data read from the first reading region R1 and the second image data DR2 based on the data read from the second reading region R2 are combined, and they may be provided as separate image data.

Below, we will explain various modifications based on the first embodiment.

<Modification>
Fig. 8 is a partial schematic diagram showing the shielding portions 110 and 112 according to the first modified example. In Fig. 8, the shielding portion 110 and the additional shielding portion 112 are added to the partial schematic diagram shown in Fig. 2. Fig. 9 is a diagram for explaining the process of combining the first image data DR1 and the second image data DR2 in this first modified example to generate the entire image data DR corresponding to the entire reading region R (see Fig. 5).

The shielding portion 110 covers at least a part of the second reading region R2 when reading the first reading region R1. For example, the shielding portion 110 is a light-shielding plate formed of an opaque resin plate, a metal plate, or the like. At least a part of the periphery of the shielding portion 110 is formed into a linear edge 110a extending along the scanning direction SC1. In this embodiment, the shielding portion 110 is formed into a square plate shape. The shielding portion 110 is fixed, for example, by screws, adhesive, or the like to the surface of the first detection unit 31A facing the holding portion 20. The shielding portion 110 is disposed, for example, at a position closer to the second imaging plate 10B than the emission position of the excitation light in the first detection unit 31A. The shielding portion 110 is maintained in a horizontal position with respect to the second imaging plate 10B held by the holding portion 20. In the line scanning direction SC2, the width of the shielding portion 110 is the same as or larger than the width of the second reading region R2. The shielding portion 110 may cover the area of the second reading region R2 where the excitation light from the first detection unit 31A is irradiated (including irradiation due to light leakage due to scattering, etc.). For example, in the scanning direction SC1, the shielding portion 110 covers at least the second reading region R2 at the position where the first photodetector 40A is provided. The linear edge 110a may be set so as to pass through the overlapping reading region RR. Also, for example, the linear edge 110a may be set inside the outer edge of the first reading region R1 and the outer edge of the second reading region R2 in the overlapping reading region RR. In other words, it is preferable but not essential that the width of the shielding portion 110 is the same as or larger than the width of the second reading region R2. In the irradiation region of the excitation light by the first detection unit 31A, it is sufficient that the irradiation region can be partially limited by dividing it with a linear line as a boundary.

When the holding part 20 passes a position facing the first detection unit 31A, it is preferable that the shielding part 110 is fixed in a position as close to the holding part 20 as possible, as long as the shielding part 110 does not interfere with the fixed parts 22a, 22b, etc. of the holding part 20.

By providing the shielding portion 110, the excitation light from the first detection unit 31A is less likely to be irradiated onto the second reading region R2 when reading the first reading region R1. This prevents the second reading region R2 from being exposed to light before reading, and allows the second reading region R2 to be read well. As a result, the accuracy of the generated image is improved.

In addition, by setting the straight edge 110a of the shielding portion 110 to pass through the overlapping reading region RR, as shown in FIG. 9, the boundary defined by the straight edge 110a appears as a clear line in the first image data DR1. This makes it possible to clearly define the boundary edge on the second reading region R2 side of the image read from the first reading region R1. By combining the first image data DR1 and the second image data DR2 using this line as a reference, a more precise and clear image can be obtained compared to when combining is performed using a boundary based on the detection width of the first detection unit 31A as a reference.

The additional shielding portion 112 covers at least a part of the first reading region R1 when reading the second reading region R2. For example, the additional shielding portion 112 is a light-shielding plate formed of an opaque resin plate, a metal plate, or the like. At least a part of the periphery of the additional shielding portion 112 is formed into a linear edge 112a extending along the scanning direction SC1. In this embodiment, the additional shielding portion 112 is formed into a square plate shape. The additional shielding portion 112 is fixed to the surface of the second detection unit 31B facing the holding portion 20 by screws, adhesive, or the like, in a similar configuration to the above-mentioned shielding portion 110. The additional shielding portion 112 is arranged, for example, at a position closer to the second imaging plate 10B than the emission position of the excitation light in the second detection unit 31B.

The additional shielding portion 112 is maintained in a horizontal position relative to the second imaging plate 10B held by the holding portion 20. In the line scanning direction SC2, the width of the additional shielding portion 112 is equal to or greater than the width of the first reading region R1. The additional shielding portion 112 may cover the region of the first reading region R1 where the excitation light from the second detection unit 31B is irradiated (including irradiation due to light leakage due to scattering, etc.). For example, in the scanning direction SC1, the additional shielding portion 112 covers at least the first reading region R1 at the position where the second photodetector 40B is provided. The linear edge 112a may be set to pass through the overlapping reading region RR on the extension line of the linear edge 110a. Also, for example, the linear edge 112a may be set in the overlapping reading region RR, inside the outer edge of the second reading region R2 and the outer edge of the first reading region R1. In other words, it is preferable but not essential that the width of the additional shielding portion 112 is the same as or larger than the width of the first reading region R1. It is sufficient that the irradiation region of the excitation light irradiated by the second detection unit 31B can be partially restricted by dividing it into sections with straight lines as boundaries.

When the holding unit 20 passes a position facing the second detection unit 31B, it is preferable that the additional shielding unit 112 is fixed as close to the holding unit 20 as possible, as long as the additional shielding unit 112 does not interfere with the fixed parts 22a, 22b, etc. of the holding unit 20.

By providing the additional shielding portion 112, as shown in FIG. 9, the boundary by the straight edge 112a appears as a clear line in the second image data DR2. This makes it possible to clearly define the boundary edge on the first reading region R1 side of the image read from the second reading region R2. A clear image can be obtained by combining the first image data DR1 and the second image data DR2 using the line as a reference. In particular, a clear image can be obtained by determining the corresponding positional relationship of the boundary edge by the straight edge 110a and the boundary edge by the straight edge 112a of the two images and combining the first image data DR1 and the second image data DR2. Note that the extension positions of the straight edge 110a and the straight edge 112a in the scanning direction SC1 are configured to form an extension line (straight line) by both, which is an important condition for preventing defects due to blurring or missing parts from occurring in the generation of the entire image data DR.

As in the second modified example shown in FIG. 10, the shielding portion 120 corresponding to the shielding portion 110 may be provided in the holding portion 20.

In the example shown in FIG. 10, a rectangular plate-shaped shielding portion 120 is provided at a position on the holding portion 20 that covers the second imaging plate 10B. The two opposite sides of the shielding portion 120 are linear edges 120a, 120b that are parallel to each other.

The shielding part 120 may be supported movably in the holding part 20 by a moving mechanism 126. The moving mechanism 126 may be a mechanism including a combination of a motor 127a, a ball screw mechanism including a screw shaft part 127b and a nut, and a guide part 128 that movably supports the shielding part 120, similar to the scanning mechanism 50 described above.

The above-mentioned moving mechanism 126 may support the shielding portion 120 so that it can move between a first shielding position (position shown by a solid line in FIG. 10) that covers the first reading region R1 and a second shielding position (position shown by a two-dot chain line in FIG. 10) that covers the second reading region R2 (see arrow Q). In the first shielding position, the linear edge 120a may be positioned so as to pass through the overlapping reading region RR. In the second shielding position, the linear edge 120b may be positioned so as to be in the same position as the linear edge 120a in the first shielding position.

In this second modified example, when the first detection unit 31A reads the first reading region R1, the shielding portion 120 is moved to the second shielding position by movement by the movement mechanism 126, and when the second detection unit 31B reads the second reading region R2, the shielding portion 120 is moved to the first shielding position by movement by the movement mechanism 126. This allows the shielding portion 120 located at the second shielding position to act as a shielding portion covering the second region, and the shielding portion 120 located at the first shielding position to act as an additional shielding portion covering the first region.

Therefore, the second variant can achieve the same effect as the first variant.

In addition, in this second modified example, when the second detection unit 31B reads the second reading region R2, it is not essential that the shielding portion 120 is positioned in the first shielding position. For example, the shielding portion 120 may be moved by the moving mechanism 126 to a position that does not cover the second imaging plate 10B.

As in the third modified example shown in FIG. 11, a mark 130 that can be read by the reading unit 30 may be formed in each of the areas of the second imaging plate 10B that belong to the first reading region R1 and the second reading region R2. In FIG. 11, the mark 130 is formed in the overlapping reading region RR that belongs to both the first reading region R1 and the second reading region R2.

Mark 130 may be any mark that can be distinguished from foreign matter, image noise, etc. that appears in the image data DR1, DR2, and that can identify the coordinates where mark 130 appears in the image data DR1, DR2. Mark 130 may be, for example, a letter, a symbol, a geometric shape, etc. In FIG. 11, mark 130 is, for example, a geometric shape of two short lines crossing vertically and horizontally.

The number of marks 130 is arbitrary. There may be one mark 130 or multiple marks 130. In FIG. 11, the marks 130 are provided at positions near one end and at positions near the other end of the overlapping reading region RR. However, it is preferable that the marks 130 are formed at positions that have the least effect on the subject image.

The mark 130 may be formed in any configuration as long as it can be read by the reading unit 30. For example, the mark 130 may be formed by forming the radiation image forming layer 11 of the second imaging plate 10B so as to avoid the area corresponding to the mark 130. The mark 130 may be formed by partially removing the radiation image forming layer 11. The mark 130 may also be formed by forming a light-shielding film that blocks at least one of the excitation light and the emission light so as to cover the surface of the radiation image forming layer 11 formed on the second imaging plate 10B. As a result, when the reading unit 30 detects the emission light due to the excitation light, the luminance value of the position corresponding to the position of the mark 130 becomes small. The area with the small luminance value is reflected in the first image data DR1 and the second image data DR2 as the presence area of the mark 130. The mark 130 may be formed by paint or the like.

The image processing unit 81 can perform image matching processing or the like on the first image data DR1 and the second image data DR2 to recognize the position of the mark 130 in the first image data DR1 and the position of the mark 130 in the second image data DR2. Then, the image processing unit 81 can combine the first image data DR1 and the second image data DR2 so that the position of the mark 130 in the first image data DR1 matches the position of the mark 130 in the second image data DR2.

It is not essential that the mark 130 is affixed to the overlapping reading region RR. Even in this case, for example, if the relationship between the position of the mark 130 in the first reading region R1 of the second imaging plate 10B and the position of the mark 130 in the second reading region R2 is known, the first image data DR1 and the second image data DR2 can be combined so that the position of the mark 130 recognized in the first image data DR1 and the position of the mark 130 recognized in the second image data DR2 have a known positional relationship.

This third variant improves the accuracy of combining the first image data DR1 and the second image data DR2.

In the first embodiment, an example in which the first detection unit 31A and the second detection unit 31B are arranged at different positions in the scanning direction SC1 has been described. However, as in the fourth modified example shown in FIG. 12, the first detection unit 141A corresponding to the first detection unit 31A and the second detection unit 141B corresponding to the second detection unit 31B may be arranged at the same position in the scanning direction SC1. In this case, it is preferable that the gap between the detection range by the first detection unit 141A and the detection range by the second detection unit 141B in the line scanning direction SC2 is as small as possible. A configuration in which the overlapping reading area RR is not set may also be used. When combining the first image data DR1 and the second image data DR2, the gap between the detection range by the first detection unit 141A and the detection range by the second detection unit 141B may be subjected to image complementation processing based on the peripheral image data of the gap.

In the first embodiment described above, an example was described in which the first reading region R1 is read by a first scan by the scanning mechanism 50, and the second reading region R2 is read by a second scan by the scanning mechanism 50. However, as in the fifth modified example shown in FIG. 13, the first reading region R1 and the second reading region R2 may be read by a single scan by the scanning mechanism 50. The first reading process and the second reading process being performed by a single scan means that the first reading process and the second reading process are performed during the period in which one scan is performed.

That is, as shown in FIG. 13, the operation of the reading device 1 is performed in step S12 instead of step S2 and step S3 in the flowchart shown in FIG. 7. In step S12, the scanning mechanism 50 performs one scan to move the holding part 20 further from the reading start position along the scanning direction SC1. As a result, when the second imaging plate 10B passes under the first photodetector 40A in the first detection unit 141A, the first photodetector 40A performs a first reading process to read the first reading region R1. When the second imaging plate 10B passes under the second photodetector 40B in the second detection unit 141B, the second photodetector 40B performs a second reading process to read the second reading region R2. The difference in the execution timing between the first reading process and the second reading process depends on the difference in the positions of the first photodetector 40A and the second photodetector 40B in the scanning direction SC1. As in the fourth modified example, when the first photodetector 40A of the first detection unit 141A and the second photodetector 40B of the second detection unit 141B are arranged at the same position in the scanning direction SC1, the first reading process and the second reading process are performed at the same time.

In this case, as described above, if the first photodetector 40A and the second photodetector 40B are positioned offset in the scanning direction SC1, the first photodetector 40A and the second photodetector 40B can perform reading while suppressing mutual influence. Also, in the line scanning direction SC2, it is easy to set the readable area by the first photodetector 40A and the readable area by the second photodetector 40B to overlap partially. In such a configuration, the first reading process and the second reading process are executed with a time lag. That is, for example, the second reading process is started a predetermined time after the start of the first reading process.

This fifth variant allows for faster reading processing.

In the sixth modified example, as shown in FIG. 14, the first detection unit 151A corresponding to the first detection unit 31A and the second detection unit 151B corresponding to the second detection unit 31B are configured to be separately movable by a unit scanning mechanism 159. With the configuration shown in the sixth modified example, the first reading process and the second reading process can be performed by one scan, as in the fifth modified example. The unit scanning mechanism 159 includes a guide portion 158 and a ball screw mechanism 157. The guide portion 158 is a guide rail or the like. The first detection unit 151A and the second detection unit 151B are separately supported by the guide portion 158 so as to be movable along the scanning direction SC1. The ball screw mechanism 157 is provided corresponding to each of the first detection unit 151A and the second detection unit 151B. Like the drive portion 52 in the scanning mechanism 50, the unit scanning mechanism 159 includes a motor 157a, a screw shaft portion 157b, and a nut (not shown). The screw shaft portion 157b is driven to rotate in a forward or reverse direction by the motor 157a. The screw shaft portion 157b extends along the scanning direction SC1, and a nut is screwed into the screw shaft portion 157b. The nut is fixed to the first detection unit 151A or the second detection unit 151B. The first detection unit 151A and the second detection unit 151B are provided so as to be located in different areas as viewed along the scanning direction SC1, so that they can pass each other along the scanning direction SC1, by driving the unit scanning mechanism 159. Then, with the holding portion 20 stopped at a predetermined position, the first detection unit 151A is moved to one side along the scanning direction SC1 (see arrow P1), and the second detection unit 151B is moved to the other side along the scanning direction SC1 (see arrow P2). This allows the first reading process and the second reading process to be executed by a single scan in which the scanning mechanism moves the first detection unit 151A and the second detection unit 151B in different directions (FIG. 14 illustrates a state in which the first detection unit 151A and the second detection unit 151B pass each other).
The first reading process and the second reading process can be performed in one scan by moving the holding portion 20 and by moving one of the first detection unit 151A and the second detection unit 151B.

In addition, when the first detection unit 151A and the second detection unit 151B are moved in the scanning direction SC1 by separate unit scanning mechanisms 159, as in the sixth modified example, it is possible that reading by the second detection unit 151B may start while reading by the first detection unit 151A is in progress.

Therefore, in a reading device equipped with a first detection unit and a second detection unit, the following three patterns can be assumed based on the relationship between the reading timing.

The first case is when the first detection unit and the second detection unit perform reading simultaneously. For example, this corresponds to the fourth modified example shown in FIG. 12 and the sixth modified example shown in FIG. 14, in which the reading timing of the first detection unit 151A and the second detection unit 151B are set to the same.

The second case is when the second detection unit starts reading after the first detection unit starts reading but before it finishes. For example, this corresponds to the case in the first embodiment described above and the sixth modified example shown in FIG. 14 where the second detection unit 151B starts reading after the first detection unit 151A starts reading but before it finishes.

The third case is when the first detection unit starts reading, and when the reading is completed, the second detection unit starts reading. For example, in the case of the first embodiment described above, when the distance between the reading position of the first detection unit 31A and the reading position of the second detection unit 31B is greater than the length of the long side of the second imaging plate 10B, or when the distance is not as large as described above, when the first detection unit 31A completes reading, the holder 20 moves to the reading start position of the second detection unit 31B, and then the second detection unit 31B starts reading. Also, for example, in the sixth modified example shown in FIG. 14, when the second detection unit 151B starts reading after the first detection unit 151A finishes reading, this case applies.

Here, the orientation of the first detection unit 31A and the second detection unit 31B is determined by the positions of the photodetectors 40A and 40B relative to the excitation light source 32. The orientation of the second detection unit 31B may be set to an orientation rotated 180 degrees from the orientation of the first detection unit 31A on a plane parallel to the directions SC1 and SC2. In other words, in the scanning direction SC1, the positional relationship between the excitation light source 32 and the photodetector 40A in the first detection unit 31A and the positional relationship between the excitation light source 32 and the photodetector 40B in the second detection unit 31B may be set to be reversed.

In this case, on the outbound path of scanning the imaging plate 10, the first detection unit 31A performs a first reading process to obtain the first image data DR1, and on the return path, the second detection unit 31B performs a second reading process to obtain the second image data DR2.

Then, for example, image processing can be performed to rotate the first image data DR1 or the second image data DR2 by half, and the first image data DR1 and the second image data DR2 can be combined to obtain the overall image data DR.

In this case, the positional relationship of the photodetectors 40A and 40B relative to the excitation light source 32 and the direction of movement of the imaging plate 10 are the same in the first and second reading processes, so the reading conditions for the first image data DR1 and the second image data DR2 are standardized. This is expected to unify the image quality of the combined overall image data DR as a whole, improving the image quality.

In addition, reading under standardized conditions can be achieved in one round trip, enabling rapid reading processing.

{Second embodiment}
A radiation image reading device 201 according to the second embodiment will be described. Figures 15 and 16 are partial schematic diagrams showing an example of the internal configuration of the device. In the description of the second embodiment, the same components as those described in the first embodiment are given the same reference numerals and their description will be omitted, and the description will focus on the differences from the first embodiment.

In the reading device 201 according to the second embodiment, the reading unit 230 corresponding to the reading unit 30 includes one detection unit 231. The detection unit 231 is a unit including an excitation light source 32 and a photodetector 40, similar to the detection unit 31A.

The reading device 201 includes an area-changing movement mechanism 220. The area-changing movement mechanism 220 is, for example, a mechanism that moves the reading unit 230 relative to the holding unit 20 along a line scanning direction SC2 that is perpendicular to the scanning direction SC1.

For example, the area change moving mechanism 220 may be configured to include a drive unit 222 and a guide unit 226, similar to the scanning mechanism 50. The guide unit 226 is, for example, a long member fixed along the line scanning direction SC2 and inserted into a guide hole formed in the detection unit 231. The guide unit 226 may be a rail that guides the detection unit 231. The drive unit 222 may be configured, for example, as a ball screw mechanism having a motor 222a, a screw shaft unit 222b, and a nut unit 222c, similar to the drive unit 52. The motor 222a is controlled, for example, by the drive control unit 83. The screw shaft unit 222b extends along the line scanning direction SC2 and is rotated by the motor 222a. The nut unit 222c is fixed to the detection unit 231 and is screwed into the screw shaft unit 222b. The screw shaft portion 222b rotates in the forward or reverse direction in response to the rotation of the motor 222a in the forward or reverse direction. The detection unit 231 can move along the line scanning direction SC2 in response to the rotation of the screw shaft portion 222b in the forward or reverse direction while being guided by the guide portion 226.

For example, the detection unit 231 can be located at a first position in the line scanning direction SC2 (see FIG. 15). The detection unit 231 can also be located at a second position in the line scanning direction SC2 that is different from the first position by moving along the line scanning direction SC2 by driving the area changing moving mechanism 220 (see FIG. 16). The first position and the second position are relative positions with respect to the second imaging plate 10B held by the holding unit 20, and in particular, are relative positions in the line scanning direction SC2. The first position is a position in the line scanning direction SC2 where the detection unit 231 can face the first reading region R1 of the second imaging plate 10B held by the holding unit 20. The second position is a position in the line scanning direction SC2 where the detection unit 231 can face the second reading region R2 of the second imaging plate 10B held by the holding unit 20.

As described in the first embodiment, the first reading region R1 and the second reading region R2 may overlap in the line scanning direction SC2. Therefore, in the line scanning direction SC2, the first position and the second position partially overlap. Note that the first reading region R1 and the second reading region R2 do not need to overlap. Therefore, the second position may be set on an extension of the first position along the line scanning direction SC2. In this case, it is preferable to set the gap between the first position and the second position as small as possible. A configuration in which an overlapping reading region RR is not set may also be used.

Figure 17 is a diagram showing a flowchart showing an example of the operation of the reading device 201. As shown in this flowchart, step S21 is executed between step S2 and step S3 in the flowchart shown in Figure 7.

In step S21, the area changing movement mechanism 220 moves the detection unit 231, which is located at the first position, to the second position. Therefore, in the first reading process in step S2 before step S21, the detection unit 231 can read the first reading region R1 of the second imaging plate 10B. Also, in the second reading process in step S3 after step S21, the detection unit 231 can read the second reading region R2 of the second imaging plate 10B.

The processing of steps S1, S2, S21, and S3 will be described as follows. Note that, prior to step S2, the detection unit 231 is assumed to be located in the first position as its initial position.

That is, in step S1, the scanning mechanism 50 moves the holding unit 20 to the reading start position under the control of the drive control unit 83.

Next, in step S2, the first reading process is executed. That is, the scanning mechanism 50 executes a first scan to move the holding portion 20 further from the reading start position along the scanning direction SC1. As a result, the first reading region R1 of the second imaging plate 10B passes under the photodetector 40 of the detection unit 231 located at the first position (see arrow P3 in FIG. 15). During this first scan, the photodetector 40 in the detection unit 231 reads the second imaging plate 10B in the first reading region R1. As a result, the first image data DR1 is obtained.

After the second imaging plate 10B passes under the photodetector 40 of the detection unit 231, in step S21, the area changing movement mechanism 220 moves the detection unit 231 to the second position.

After this, in step S3, the second reading process is executed. Here, the scanning mechanism 50 moves the holding part 20 until the second imaging plate 10B passes the detection unit 231, and then moves the holding part 20 along the scanning direction SC1 in the opposite direction to that in the first reading process. That is, the scanning mechanism 50 executes a second scan in which the holding part 20 is moved in the opposite direction to that of the first scan. This allows the second reading region R2 of the second imaging plate 10B to pass under the photodetector 40 in the detection unit 231 in the opposite direction to that of the first scan (see arrow P4 in FIG. 16). During this second scan, the photodetector 40 in the detection unit 231 reads the second imaging plate 10B in the second reading region R2. This obtains the second image data DR2.

According to steps S2, S21 and S3, the holding unit 20 is moved back and forth once. This enables a quick reading process. The second scan may be performed by moving the holding unit 20 in the return direction after the first scan, and then moving the holding unit 20 in the same forward direction as the first scan. In this case, the direction of movement of the second imaging plate 10B relative to the detection unit 231 is the same in the first reading process and the second reading process, so the reading conditions of the first image data DR1 and the second image data DR2 are common. This is expected to unify the image quality of the combined overall image data DR as a whole, improving the image quality.

In this way, once the first image data DR1 and the second image data DR2 are obtained, the processes from step S4 to step S7 are executed in the same manner as described in the first embodiment.

When reading the first imaging plate 10A, the above steps S21, S3, and S6 can be omitted.

According to this second embodiment, the same effects as those of the first embodiment can be obtained, except for the effect of using multiple detection units.

In addition, the first reading region R1 and the second reading region R2 can be read using the excitation light source 32 and the photodetector 40 in one detection unit 231. By reducing the number of detection units 231, the cost of the device 201 can be reduced. Furthermore, when the entire reading region R (see FIG. 5) of the second imaging plate 10B is read using a single detection unit 231, each reading region can be read by a detection unit 231 having the same reading characteristics, making it possible to read under the same conditions.

In addition, the reading of the first reading region R1 and the reading of the second reading region R2 are performed at mutually exclusive timing. This prevents, for example, the excitation light irradiated during one reading from affecting the other reading. This effect also applies to examples of conditions in other embodiments where reading is performed at mutually exclusive timing.

Here, the orientation of the detection unit 231 is determined by the position of the photodetector 40 relative to the excitation light source 32. When the detection unit 231 moves from the first position to the second position, the detection unit 231 may be rotated 180 degrees on a plane parallel to the directions SC1 and SC2. As a result, the orientation of the detection unit 231 at the second position may be set to an orientation rotated 180 degrees from the orientation of the detection unit 231 at the first position on a plane parallel to the directions SC1 and SC2. In other words, in the scanning direction SC1, the positional relationship between the excitation light source 32 and the photodetector 40 in the detection unit 231 at the first position may be set inversely to the positional relationship between the excitation light source 32 and the photodetector 40 in the detection unit 231 at the second position.

In this case, on the outbound path of scanning the imaging plate 10, the detection unit 231 at the first position performs a first reading process to obtain the first image data DR1, and on the return path, the detection unit 231 at the second position performs a second reading process to obtain the second image data DR2.

Then, for example, image processing can be performed to rotate the first image data DR1 or the second image data DR2 by half, and the first image data DR1 and the second image data DR2 can be combined to obtain the overall image data DR.

In this case, the positional relationship of the photodetector 40 with respect to the excitation light source 32 and the direction of movement of the imaging plate 10 are the same in the first and second reading processes, so the reading conditions of the first image data DR1 and the second image data DR2 are standardized. This is expected to unify the image quality of the combined overall image data DR as a whole, improving the image quality.

In addition, reading under standardized conditions can be achieved in one round trip, enabling rapid reading processing.

<Modification>
The various modifications already described in the first embodiment can also be applied to the second embodiment, unless inconsistent.

For example, the reading device 201 may include a shielding portion that shields at least a portion of the second reading region R2 when reading the first reading region R1, as described in the first or second modified example of the first embodiment. The shielding portion may be configured to be supported by the detection unit 231, as described in the first modified example, or may be configured to be movably supported by the holding portion 20, as described in the second modified example.

For example, the reading device 201 may include an additional shielding section that shields at least a portion of the first reading region R1 when reading the second reading region R2, as described in the first or second modified example of the first embodiment. The shielding section may be configured to be supported by the detection unit 231 separately from the shielding section, as described in the first modified example. Also, as described in the second modified example, the additional shielding section may be configured by moving a shielding section movably supported by the holding section 20.

In addition, in this second embodiment, the area-changing moving mechanism 220 does not need to move the detection unit 231. Instead of moving the detection unit, the area-changing moving mechanism may move the holding unit 20 along the line scanning direction SC2. For example, the scanning mechanism 50 may move the table along the scanning direction SC1, and the area-changing moving mechanism may move the holding unit 20 on the table along the line scanning direction SC2. The area-changing moving mechanism in this case may be configured using a motor and a ball screw mechanism, similar to the scanning mechanism 50, for example.

{Additional Note}
In the above first and second embodiments, the explanation has been centered mainly on an example in which the first reading region R1 and the second reading region R2 are set on the second imaging plate 10B. However, it is sufficient that the second imaging plate 10B has a plurality of reading regions set thereon that are shifted in a direction perpendicular to the scanning direction SC1, and the number of the plurality of reading regions does not have to be two. For example, in addition to the first reading region R1 and the second reading region R2, the second imaging plate 10B may have a third reading region or more set thereon.

For example, when the first to third reading areas are set, assuming the first embodiment, the three detection units may be arranged with a sequential shift in the line scanning direction. Assuming the second embodiment, three scans may be performed while the detection units are sequentially shifted in the line scanning direction.

If three or more reading areas are set on the second imaging plate 10B, the detection width of the detection unit can be made smaller, which can result in lower costs for each individual detection unit and potentially even lower costs for the entire device.

When three or more reading areas are set, a configuration in which the multiple reading areas are read by separate detection units as in the first embodiment may be combined with a configuration in which the detection unit is moved to read the multiple reading areas. For example, when three reading areas are set, one of the reading areas may be read by one detection unit, and the other two reading areas may be read by moving one detection unit.

In the above first and second embodiments, the description has been given on the assumption that the holding unit 20 moves in the horizontal direction. However, the holding unit 20 may move in a direction intersecting the horizontal direction. For example, the holding unit 20 may move in the vertical direction, or may move along a direction oblique to both the horizontal and vertical directions.

The configurations described in the above embodiments and modified examples can be combined as appropriate as long as they are not mutually contradictory. The direction of movement of the holding unit 20, the holding posture of the imaging plate 10 in the holding unit 20, and other directions and postures are not limited to those disclosed in the above examples. For example, the holding unit 20 may move along the up-down direction (vertical direction) or a direction tilted from the up-down direction. For example, the present invention can be implemented not only in the embodiment of the horizontal reading device 1 as shown in FIG. 1, but also in the embodiment of a vertical reading device.

This specification and drawings disclose the following aspects:

The first aspect is a radiation image reading device that reads a radiation image from an imaging plate, and includes a holding section that holds the imaging plate, a reading section that includes an excitation light source that irradiates the imaging plate held in the holding section with excitation light, and a photodetector that detects luminescence light from the imaging plate due to the excitation light, and a scanning mechanism that moves the holding section relative to the reading section along a scanning direction that is horizontal to the imaging plate held in the holding section, and the reading section detects the luminescence light from the imaging plate in a reading area that extends in the scanning direction and in a direction perpendicular to the scanning direction by scanning with the scanning mechanism, and is capable of setting a plurality of reading areas that are shifted in a direction perpendicular to the scanning direction as the reading area.

This radiation image reading device can set multiple reading areas that are offset in a direction perpendicular to the scanning direction, making it possible to read an imaging plate with a width larger than the detection width of the photodetector.

The second aspect is a radiation image reading device according to the first aspect, in which at least a first reading area and a second reading area that are shifted in a direction perpendicular to the scanning direction can be set as the reading area. This makes it possible to set at least a first reading area and a second reading area that are shifted in a direction perpendicular to the scanning direction, so that an imaging plate with a width larger than the detection width of the photodetector can be read.

A third aspect is a radiation image reading device according to the second aspect, in which the holding section can hold, as the imaging plates, a first imaging plate and a second imaging plate whose width in a direction perpendicular to the scanning direction is larger than that of the first imaging plate, and the detection width of the photodetector in the direction perpendicular to the scanning direction is larger than that of the first imaging plate and smaller than that of the second imaging plate. In this case, the first imaging plate can be read using one reading area. The second imaging plate, which is larger than the first imaging plate, can be read by reading the reading area multiple times.

A fourth aspect is a radiation image reading device according to the second or third aspect, in which the reading unit includes a first photodetector and a second photodetector as the photodetectors, the first photodetector and the second photodetector are positioned offset in a direction perpendicular to the scanning direction, the first photodetector reads the imaging plate in the first reading area, and the second photodetector reads the imaging plate in the second reading area. In this case, the imaging plate can be read by the first photodetector and the second photodetector having a detection width smaller than the width of the imaging plate.

In a fifth aspect, the radiation image reading device according to the fourth aspect is configured such that the scanning mechanism executes a first scan and a second scan, and during the first scan by the scanning mechanism, the first photodetector reads the imaging plate in the first reading area, and during the second scan by the scanning mechanism, the second photodetector reads the imaging plate in the second reading area. In this way, the first reading area and the second reading area are read during separate scans, so that the readings are less likely to affect each other.

The sixth aspect is a radiation image reading device according to the fourth aspect, in which the first photodetector reads the imaging plate in the first reading area and the second photodetector reads the imaging plate in the second reading area by one scan by the scanning mechanism. This enables rapid reading.

The seventh aspect is a radiation reading device according to any one of the fourth to sixth aspects, in which the first photodetector and the second photodetector are positioned offset in the scanning direction. This makes it easier to read while suppressing the first photodetector and the second photodetector from affecting each other.

The eighth aspect is a radiation image reading device according to the second aspect, in which the reading section includes a region changing movement mechanism that moves the photodetector relative to the holding section in a direction perpendicular to the scanning direction, and the scanning mechanism executes a first scan and a second scan, and during the first scan by the scanning mechanism, the photodetector is positioned at a first position relative to the holding section and reads the imaging plate in the first reading area, and during the second scan by the scanning mechanism, the photodetector is positioned at a second position relative to the holding section, which is different from the first position in the direction perpendicular to the scanning direction, and reads the imaging plate in the second reading area.

In this case, the first reading area and the second reading area can be read by one photodetector. By reducing the number of sensors, the cost of the device can be significantly reduced. In addition, for multiple areas that are read by the same photodetector, reading can be performed under conditions that eliminate individual differences between detectors.

The ninth aspect is a radiation image reading device according to any one of the second to eighth aspects, in which one excitation light source is integrated with one photodetector. This makes it easy to handle the photodetector and the excitation light source as a single unit.

A tenth aspect is a radiation image reading device according to any one of the second to ninth aspects, in which the first reading area and the second reading area partially overlap in a direction perpendicular to the scanning direction. This makes it difficult for a gap to occur between the image read from the first reading area and the image read from the second reading area.

The eleventh aspect is a radiation image reading device according to any one of the second to tenth aspects, which includes a shielding section that covers at least a portion of the second reading area when reading the first reading area. In this case, the excitation light is less likely to be irradiated onto the second area when reading the first area. This allows the second area to be read well, improving the accuracy of the generated image.

A twelfth aspect is a radiation image reading device according to the eleventh aspect, in which the boundary line of the shielding portion is set in the overlapping reading area of the first reading area and the second reading area. This makes it possible to clearly define the edge of the image read from the first reading area on the side of the second reading area. This improves the accuracy of combining multiple images and makes it difficult for brightness differences that are not due to latent images to occur at the boundary line, thereby improving the accuracy of the generated image.

A thirteenth aspect is a radiation image reading device according to the eleventh or twelfth aspect, which is provided with an additional shielding section that covers at least a part of the first reading area when reading the second reading area, and the boundary line of the additional shielding section is set in the overlapping reading area of the first reading area and the second reading area. In this case, the edge of the image read from the second reading area on the first reading area side can be made clear, which further improves the accuracy of the generated image.

A fourteenth aspect is a radiation image reading device according to any one of the second to thirteenth aspects, further comprising an image processing unit that generates image data by combining first image data based on data read from the first reading area and second image data based on data read from the second reading area. This makes it possible to provide the read image data as a single image for diagnosis, observation, etc.

The fifteenth aspect is a radiation image reading device according to the fourteenth aspect, in which a mark that can be read by the reading unit is formed in each of an area of the imaging plate that belongs to the first reading area and an area that belongs to the second reading area, and the image processing unit combines the first image data and the second image data based on the marks. This improves the accuracy of combining the first image data and the second image data.

The sixteenth aspect is a program for causing a computer that controls a radiation image reading device to execute the following processes: (a) a process in which the reading unit scans an imaging plate held by a holding unit along a scanning direction that is horizontal to the imaging plate so that reading can be performed on a plurality of reading areas including at least a first reading area and a second reading area that are shifted in a direction perpendicular to the scanning direction, and (b) a process in which image data is generated by combining first image data based on data read from the first reading area and second image data based on data read from the second reading area. This makes it possible to read an imaging plate with a width larger than the detection width of a photodetector.

The above description is illustrative in all respects and does not limit the present invention. It is understood that countless variations not illustrated can be envisioned without departing from the scope of the present invention.

1, 201 Radiation image reading device 10 Imaging plate (10A first imaging plate, 10B second imaging plate)
20 holding unit 30, 230 reading unit 31, 231 detection unit (31A, 141A, 151A first detection unit, 31B, 141B, 151B second detection unit)
32 Excitation light source 40 Photodetector (40A first photodetector, 40B second photodetector)
50 Scanning mechanism 80 Control unit 80a Processor 80b Memory unit 80bp Program 110, 120 Shielding unit 112 Additional shielding unit 126 Movement mechanism 159 Unit scanning mechanism 220 Area changing movement mechanism 222 Drive unit DR Whole image data DR1 First image data DR2 Second image data R Whole reading area R1 First reading area R2 Second reading area RR Overlapping reading area SC1 Scanning direction (predetermined direction)
SC2 Line scan direction

Claims (10)

A radiation image reading device for reading a radiation image from an imaging plate, comprising:
a holder for holding the imaging plate;
a reading unit including an excitation light source that irradiates the imaging plate held in the holding unit with excitation light, and a photodetector that detects luminescence from the imaging plate due to the excitation light;
a scanning mechanism that moves the holding unit relative to the reading unit along a scanning direction that is horizontal to the imaging plate held by the holding unit;
Equipped with
the reading unit detects emitted light from the imaging plate in a reading area extending in the scanning direction and a direction perpendicular to the scanning direction by scanning using the scanning mechanism;
As the reading area, at least a first reading area and a second reading area which are shifted in a direction perpendicular to the scanning direction can be set,
the holding section is capable of holding, as the imaging plate, a first imaging plate and a second imaging plate having a width in a direction perpendicular to the scanning direction larger than a width of the first imaging plate,
A radiation image reading device , wherein a detection width of the photodetector in a direction perpendicular to the scanning direction is larger than a width of the first imaging plate and smaller than a width of the second imaging plate . 2. The radiation image reading apparatus according to claim 1 ,
the reading unit includes a first photodetector and a second photodetector as the photodetectors,
a scanning direction of the imaging plate and a scanning area of the imaging plate; a scanning area of the imaging plate and a scanning area of the imaging plate; 3. The radiation image reading apparatus according to claim 2 ,
A radiation image reading device, wherein the first photodetector and the second photodetector are positioned offset from each other in the scanning direction. 4. The radiation image reading apparatus according to claim 1, further comprising:
the reading unit includes an area changing movement mechanism that moves the photodetector relative to the holding unit in a direction perpendicular to the scanning direction,
the scanning mechanism performs a first scan and a second scan;
During the first scan by the scanning mechanism, the photodetector is positioned at a first position relative to the holder and reads the imaging plate in the first reading area;
and during the second scan by the scanning mechanism, the photodetector is positioned at a second position relative to the holding portion, which is a position different from the first position in a direction perpendicular to the scanning direction, and reads the imaging plate in the second reading area. 5. The radiation image reading apparatus according to claim 1 ,
A radiation image reading device in which one excitation light source is integrated with one photodetector. 6. The radiation image reading apparatus according to claim 1 ,
A radiation image reading device, wherein the first reading area and the second reading area partially overlap in a direction perpendicular to the scanning direction. 7. The radiation image reading apparatus according to claim 1 ,
A radiation image reading device comprising: a shielding portion that covers at least a part of the second reading area when the first reading area is being read. 8. The radiation image reading apparatus according to claim 7 ,
A radiation image reading device, wherein a boundary line of the shielding portion is set in an overlapping reading area of the first reading area and the second reading area. 9. The radiation image reading apparatus according to claim 7 or 8 ,
an additional shielding portion that covers at least a part of the first reading area when reading the second reading area;
A radiation image reading device, wherein a boundary line of the additional shielding portion is set in an overlapping reading area between the first reading area and the second reading area. 10. The radiation image reading apparatus according to claim 1 ,
a radiation image reading device further comprising an image processing unit that generates image data by combining first image data based on data read from the first reading area and second image data based on data read from the second reading area.

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