JPH0434387A - Radiation image receiving apparatus and method - Google Patents

Abstract

PURPOSE:To minimize the generation of an error by fixing an objective region per one unit element during an image measuring period and substantially enhancing resolving power per a pixel. CONSTITUTION:In a radiation image receiving apparatus constituted of a radiation source 1 and a radiation detector 4 arranged within the plane vertical to the advance direction of a moving object 3 to be measured so as to hold the object 3 to be measured there between, the radiation detector 4 is moved in the same direction as the object 3 to be measured during an image measuring period to obtain image data. By this constitution, an objective region per one unit element is made substantially equal to the size of one unit element by moving the radiation detector 4 in the same direction as the object 3 to be measured at the time of the measurement of an image and the generation of an error due to the movement of the object to be measured can be minimized.

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial field of application Invention 1 Medical nails Conventional technology related to industrial radiation image receiving apparatuses and radiation image receiving methods Moving an object to be measured (hereinafter referred to as the object to be measured) Capturing absorption or reflection images of radiation by an object to be measured is frequently used in the medical and industrial fields.

This is a method in which radiation is irradiated onto an object to be measured that moves relative to a radiation detector, and the radiation detector detects changes in radiation absorption and reflection by the object to be measured, thereby inspecting and analyzing the object. Amoko's image reception method is used in industrial nondestructive testing (an X-ray source and a radiation detector are placed across the object to be measured placed on a conveyor line, and image measurements are performed at regular intervals. The radiation detectors that perform imaging are generally linear or planar ones.In the field of radiation image reception, technological improvements have also been remarkable.
Even though high-resolution radiation detectors have been developed, methods have also been developed to display images by arranging semiconductor detectors in an array to detect radiation quanta on a surface, and using the count value of the signal as the pixel density. Publication No. 59-100885). With this method, the dynamic range of each detection element is greatly improved, and high-precision images can be obtained.・The conventional radiation image receiving apparatus and radiation image receiving method will be explained below. as X
In the figure to explain an example using lines, 3 is the object to be measured 3a is the low absorption material ff1L 3b is the high absorption material portion 4 is the radiation detector Comparison between the position of the radiation detector 4 and the output signal To clarify the measured object 3
Assuming that the low-absorption material part 3a and the high-absorption material part 3b are clearly separated, the object to be measured 3 is fixed and the radiation detector 4 is Assuming that the radiation detector 4 has been moved, the horizontal axis shows the position of the radiation detector 4, and the vertical axis shows the output signal of the radiation detector 4.9 In such a configuration, when the radiation detector 4 is in the position shown in FIG. Since the irradiated X-rays directly enter the radiation detector 4, the output signal becomes Sl.A Next, when the radiation detector 4 moves rightward toward the page and the radiation detector 4 touches the edge of the object to be measured 3, Output begins to decrease. Radiation detector 4
When the radiation completely enters the low absorption material part 3a in the object to be measured 3, the output signal becomes S2.Furthermore, the radiation detector 4
When the radiation detector 4 moves to the right and hits the high absorption material section 3b, the output signal begins to decrease, and when the radiation detector 4 completely enters the high absorption material section 3b, the output signal becomes the lowest value Ss, which is the solution to the invention. However, in the conventional configuration described above, the radiation detector is fixed, and as the object to be measured moves, the target area per unit element is expanded, resulting in blurring of the image and measurement errors. For this reason, in precise analysis of minute parts, step feed is used to temporarily stop the object to be measured. The present invention solves the above-mentioned conventional problems, and it is difficult to perform step feeding due to the large inertia of the conveyor, making it impossible to measure with high precision. A radiation image receiving device that minimizes image blurring at the pixel edges caused by positional misalignment between the radiation detector and the object to be measured, and provides high-precision performance in precise analysis of minute areas. In order to achieve this object, the radiation image receiving apparatus of the present invention provides a means for solving the problem.
Located in a plane perpendicular to the direction of movement of the moving measured object,
A radiation image receiving device consisting of a radiation source and a radiation detector placed across an object to be measured is configured so that during image measurement, the radiation detector moves in the same direction as the object to be measured to obtain image information. This is what I did.

Effect With this configuration, by moving the radiation detector in the same direction as the object to be measured during image measurement, substantially 1
By setting the target area per unit element to the size of one unit element, it is possible to minimize errors caused by movement of the object to be measured.

EXAMPLE An example of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of a radiation image receiving device according to an embodiment of the present invention. FIG. 2 shows an example of the configuration of a radiation detector used in the radiation image receiving device of the present invention. FIG. 4 is a configuration doctor showing an example of the operation of the radiation detector used in the radiation image receiving apparatus of the present invention; FIG. Figure 6 (a) ~
(C) is a characteristic diagram showing the relationship between the radiation detector position and the output signal. In these diagrams, 1 is the radiation source, 2 is the irradiation aperture,
3 is an object to be measured; 4 is a radiation detector; 5 is a moving table on which the object to be measured 3 is mounted; 6 is a driver for driving the moving table 5; 7 is a case housing the radiation detector 4; 8 is a radiation detector. Number of peripheral circuits: 9 is the radiation detector fixed stand, 10
is a radiation detector drive, ii', 11 is a support stand, 12 is a signal cable nok, 13 is a drive control unit that controls the radiation detector 4, 14 is an input/output terminal, and 15 is a lattice structure, as described above. Regarding the configured radiation image receiving device,
The operation will be explained below in Figure 1. Even if only the necessary X-rays are extracted from the X-rays emitted from the radiation source 1 by the irradiation aperture 2, and even if these X-rays pass through the object to be measured 3 and are detected by the radiation detector 4, the object to be measured 3 moves. On the other hand, even if the radiation detector 4 is housed in the case 7 together with the radiation detector peripheral circuit 8, the case 7 is installed on the radiation detector fixing table 9. Even if the radiation detector fixing base 9 is movably installed on the support base 11, the radiation source l may be fixed (if the movement range of the measured object 3 is long). It is necessary to move the radiation detector 4 together with the radiation detector 4.Also, although a conveyor belt or the like is used as the moving stage 5, if a one-dimensional line sensor in which detection elements are arranged in one dimension is used as the radiation detector 4, the The line sensor is installed perpendicularly to the moving direction of the object to be measured 3. It scans and moves line by line to measure two-dimensional images.It also serves as a radiation detector 4, which is a two-dimensional surface with detection elements arranged in a planar shape. When a sensor is used, two-dimensional image measurement is performed by moving the radiation detector 4 by one pitch of pixels constituting the two-dimensional surface sensor.

FIG. 2 shows an embodiment of the radiation detector used in the radiation image receiving apparatus of the present invention. An external signal is supplied from the input/output terminal 14, and the signal enters the radiation detector drive source 10 from the drive control section 13 to control the radiation detector 4. On the other hand, the output from the radiation detector 4 is guided to the radiation detector peripheral circuit 8 by a signal cable 12 and taken out to the outside via an input/output terminal 14. The power shown in another embodiment (a grid-like structure 15 that shields radiation is installed in front of the radiation detector 4, and only the grid-like structure 15 is moved back and forth by the radiation detector driving source 10). Therefore, not only can the device be made smaller, but also the radiation detector 4 can be moved without having to move.
Electric wiring such as the signal cable 12 can be fixed, and a very reliable radiation detector can be realized.
The radiation image receiving device of the present invention also detects debris that is thicker than the sum of the distance that the image moves on the radiation detector 4 during one image measurement period and the aperture of the lattice-like structure that shields radiation. Vessel 4
Furthermore, although the movement of the grid structure 15 is important, as shown in FIG. 4, the position of the object to be measured 3 changes over time. When moving and returning, the number of image measurements can be increased by moving faster than when moving forward. Furthermore, as shown in FIG. 5, the radiation detector 4 can be moved forward and stopped or moved forward at a low speed repeatedly during a certain cycle or a certain distance along the movement of the object to be measured 3, thereby detecting the object to be measured 3 that is moving at high speed. Although highly accurate measurement is possible, the moving distance of the radiation detector 4 is the moving distance corresponding to one pixel of the measured object 3 per one image measurement period, and in high-definition images when using X-rays. 1 mm or less, and with a method in which an optical image is formed using a lens on a solid-state image sensor (one pixel pitch of a solid-state image sensor, that is, about 10 μm), the driving device of the radiation detector 4 has also become extremely small. The relationship between the radiation detector position and the output signal in the embodiments described above is as follows.
In this case, the output signal in an ideal case (6
As shown in Figure (a), it should appear clearly corresponding to each part of the object to be measured 3. Figure 2 (c) shows the output signal from the radiation image receiving device of the present invention. The present invention is applied to radiographic images and described above.
Although similar effects can be obtained in ordinary optical image capturing and reading, the present invention has advantages over and above the effects of the invention. It is possible to realize an excellent radiation image receiving device and radiation image receiving method that can substantially improve the image resolution and minimize the occurrence of errors due to the movement of the object to be measured. It is possible to improve the analysis accuracy of minute images such as X-ray images and optical images, and it will be a great contribution to medical measurement and industrial measurement.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a radiation image receiving apparatus according to an embodiment of the present invention. FIG. 2 is a configuration diagram showing an embodiment of a radiation detector used in the radiation image receiving apparatus of the present invention. Structure 8 showing another embodiment of the radiation detector used in the device. @ Fig. 4 is an operating doctor showing an example of the operation of the radiation detector used in the radiation image receiving apparatus of the present invention.
) to (c) are characteristic diagrams showing the relationship between the radiation detector position and the output signal. Figure 7 is a block diagram for explaining the conventional radiation image receiving device and radiation image receiving method.・Object to be measured (object to be measured), 4... Radiation detector 5... Moving color ) 4- Makiwa 1 Spring Detector 5- Neta-Kan e Agent's name Patent attorney Shigetaka Awano Haka 1 person (Figure 1) ↓ ↓ Teru Jli? To) direction♂u'rmine inspection】tsuLiiH PRei;"Shizukugo rags辷S】tsushii 1χ21 fig. time fig. time diagram! ! 1. Note

Claims (3)

[Claims] (1) A radiation source, a radiation detector placed opposite to the radiation source, and a moving table that passes through the space between the radiation source and the radiation detector, carries the object to be measured, and moves in a fixed direction. A radiation image receiving apparatus comprising: a mechanism that allows the radiation detector to move in the same direction as an object; (2) The radiation image receiving apparatus according to claim 1, wherein the radiation detector has radiation detection elements arranged in a planar or linear manner. (3) Claim 1 or 2, wherein the radiation detector has a lattice-like structure for shielding radiation in front of its radiation entrance surface, and the lattice-like structure can move in the same direction as the object to be measured. The radiation image receiving device (4) includes a radiation source, a radiation detector provided opposite to the radiation source, and a movable table that is placed between the radiation source and the radiation detector and carries an object to be measured and moves in a fixed direction. A radiation image receiving method that uses a radiation image receiving device equipped with a radiation detector and moves the radiation detector in the same direction as the object during image measurement.