JP2003175022A - X-ray imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray imaging apparatus in which an optimum image quality adjustment is automatically conducted in accordance with an exposure object inside the X-ray imaging apparatus without requiring any complicated operation and any fine-adjustment of outputs of an X-ray exposure apparatus by automatically detecting the start/stop of X-ray exposure without any need for inputting/outputting oftrigger signals from the X-ray exposure apparatus, and to provide a recording medium in which a program therefor is stored. <P>SOLUTION: In the X-ray imaging apparatus, an image data output means receives X-rays and outputs image data containing a plurality of pixels and when a pixel value of a designated pixel in the image data is larger than a maximum pixel value of surrounding the designated pixel by a predetermined value or more, an abnormal data removing means judges the designated pixel as abnormal data and corrects these abnormal data. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray image device using a CCD sensor, and more particularly to an X-ray image device for displaying an image on a CRT or the like by digital processing without using a film. The X-ray imaging apparatus of the present invention is particularly useful for medical and dental diagnostic devices or industrial nondestructive inspection.

[0002]

2. Description of the Related Art In a conventional X-ray imaging apparatus, an X-ray film is used for recognizing an internal state of an object in a diagnosis or an inspection by an image. But,
In recent years, an X-ray image apparatus using a CCD sensor has been developed for the purpose of shortening the development time, easiness of data storage, deterioration prevention, and the like. This X-ray image device receives X-rays directly from a CCD sensor and converts the digitized data to C
The method of displaying on RT was used. A conventional X-ray image device is configured to receive light by a CCD sensor through a substance that converts X-rays that have passed through an affected area into light and display image data digitized pixel by pixel on an image display device.

As described above, the conventional X-ray imaging apparatus using the CCD sensor is the X-ray imaging apparatus in the conventional apparatus before this.
Compared with the method in which an X-ray is applied to a linear film to form an image, the labor for development is saved and the time taken to diagnose the affected area is shortened. In the conventional X-ray imaging apparatus using a CCD sensor, the image data is digitized, so that the image data is not deteriorated and is stored in a storage medium in a lump, which saves space for data storage. There was an advantage that it could be realized.

Further, such a conventional X-ray imaging apparatus is an effective auxiliary means for diagnosis and examination because it can freely adjust the brightness, contrast, enlargement of the affected area, etc. on the screen of the image display apparatus. . In particular, such an X-ray imaging apparatus is useful as a diagnostic aid in medical and dental fields due to digitization of image data. Further, such a conventional X-ray imaging apparatus is an apparatus that leads to an improvement in inspection efficiency when used in an industrial nondestructive inspection apparatus and can improve inspection accuracy.

The CCD sensor used in the conventional X-ray imaging apparatus is similar to that used in a video camera or the like, and the visible light received by the CCD sensor is converted into an analog signal in real time and output. It has a configuration to do. However, unlike a normal CCD sensor used in a video camera or the like, a CCD sensor used in an X-ray imaging apparatus has a phosphor (scintillator, for example, Gd ₂ ) that converts X-rays into visible light on the CCD surface of the CCD sensor. O
₂ S) are provided. In addition, instead of such a phosphor, a cadmium teralite detecting element (CdTe detecting element) that converts X-rays into electric charges is provided on the CCD surface so as to be connected to each pixel.

An X-ray image viewed by an examiner using an X-ray image device is usually a still image. Therefore, in the conventional X-ray imaging apparatus, the analog signal from the CCD sensor is converted into a digital signal by the A / D converter at the moment when the X-ray is irradiated, and is temporarily stored in the memory. Further, the image display device is configured to display the digitized image data as a still image on a CRT or the like. As described above, the conventional X-ray imaging device using the CCD sensor needs to receive a trigger signal from the X-ray irradiation device to notify the start and end of irradiation in order to capture the moment when the X-ray is irradiated. It was

Next, an example of a conventional X-ray imaging apparatus will be described with reference to the accompanying drawings. FIG. 23 is a block diagram showing the overall configuration of a conventional X-ray image device using a CCD sensor,
FIG. 24 is a flow chart showing a processing procedure from irradiation start to image display in the conventional X-ray imaging apparatus.

In FIG. 23, an X-ray irradiator 210 irradiates an affected area which is an irradiation target, and X-rays 2 which have passed through the irradiation target.
11 is received by the X-ray detection unit 201. The X-ray detection unit 201 includes a CCD element 212, an A / D converter 215,
It has a CCD drive circuit 216. X-ray detection unit 201
Outputs an image digital signal 217 corresponding to the X-ray 211 to the accumulating unit 205. The accumulating unit 205 to which the image digital signal 217 is input has a cumulative value calculating circuit 223 and a frame memory 225.

The X-ray irradiator 210 irradiates the X-ray 211 and simultaneously outputs an X-ray irradiation start trigger signal 241 to the accumulation start circuit 221 of the accumulation start unit 204. Further, the X-ray irradiation device 210 outputs the X-ray irradiation end trigger signal 242 to the accumulation stop circuit 230 of the accumulation stop unit 208 at the same time when the irradiation of the X-ray 211 is ended. At this time, the accumulation stop circuit 23
0 indicates that the cumulative stop instruction signal 231 is the cumulative value calculation circuit 223.
To the display instruction section 2 at the same time.
09 to the display instruction circuit 233. When the display instruction flag 232 is input, the display instruction circuit 233 outputs a display instruction signal 234 to the CPU 235 of the image display unit 238. When the display instruction signal 234 is input, the CPU 235 takes in the display digital image data 226 from the frame memory 225, and the image display device 237 such as a CRT.
To display. Further, the digital image data for storage 239 output from the CPU 235 is stored in the storage medium 240 as image data as needed.

In FIG. 23, arrows indicate the flow of X-rays 211 and signals, reference numeral 213 is an image analog signal, reference numeral 214 is a CCD drive signal, reference numeral 222 is a cumulative start instruction signal, and reference numeral 224 is a cumulative image digital signal. Reference numeral 236 indicates an image display signal. In FIG. 23, when the X-ray irradiator 210 irradiates the X-ray 211, the CCD element 212 outputs an image analog signal 213 corresponding to the image of the irradiation target to the A / D converter 215. The A / D converter 215 to which the image analog signal 213 is input outputs an image digital signal 217.

The X-ray irradiator 210 irradiates the X-ray 211 and simultaneously outputs an X-ray irradiation start trigger signal 241 to the accumulation start circuit 221. The accumulation start circuit 221 constantly monitors the input status of the X-ray irradiation start trigger signal 241.
FIG. 24 is a flowchart showing a processing procedure from X-ray irradiation to image display in the conventional X-ray imaging apparatus having the above-mentioned configuration. The accumulation start circuit 221 uses the STE in the flow shown in FIG.
Processing of P2 is being performed. If there is no input of the X-ray irradiation start trigger signal 241, the accumulation start circuit 221 proceeds to STEP.
The image data in 3 is not accumulated or accumulated.

On the other hand, the accumulation start circuit 2 of the accumulation start unit 204
When the X-ray irradiation start trigger signal 241 is input to 21, the accumulation of image data is started in STEP 4. At this time, the accumulation start circuit 221 of the accumulation start unit 204
Outputs the accumulation start instruction signal 222 to the accumulated value calculation circuit 223. When the accumulation start instruction signal 222 is input, the cumulative value calculation circuit 223 converts the image digital signal 217 periodically sent thereafter into the cumulative image digital signal 224 and stores it in the frame memory 225.

Next, referring to FIGS. 25 and 26, a method of A / D converting the image analog signal 213 which is the output signal from the CCD sensor having the CCD element and the image analog signal 213 in the A / D converter 215. Will be briefly described. FIG. 25 is a diagram conceptually showing a pixel configuration in the CCD sensor, and FIG. 26 is a diagram conceptually showing an A / D conversion method of the image analog signal 213 in the CCD sensor.

As shown in FIG. 25, the CCD element sensor has a predetermined number of pixels in the vertical and horizontal directions.
As shown in FIG. 26, the CCD sensor constantly outputs an image analog signal having image data for all pixels in the CCD sensor in a constant cycle. The image data for all the pixels is A / D converted by the A / D converter 215 every cycle.
It is converted to form the image digital signal 217. Further, the image digital signal 217 is accumulated and stored in the frame memory 225. The CPU 235 takes in display digital image data 226 which is an image digital signal stored from the frame memory 225, and the image data is displayed by an image display device 237 such as a CRT.

Next, the X-ray irradiation device 210 outputs the irradiation end trigger signal 242 to the accumulation stop circuit 230 at the same time when the irradiation of the X-ray 211 is ended. Accumulation stop circuit 230
Performs the processing of STEP5 of the flow shown in FIG. 24 and constantly monitors the input of the irradiation end trigger signal 242. If the irradiation end trigger signal 242 is not input, ST
The accumulation of the image data is continued in EP6.

On the other hand, when the accumulation stop circuit 230 receives the irradiation end trigger signal 242, the STE of FIG.
At P7, the accumulation of image data is stopped. At this time,
The accumulation stop circuit 230 outputs the accumulation stop instruction signal 231 to the accumulated value calculation circuit 223, and at the same time, the display instruction flag 232.
Is output to the display instruction circuit 233.

When the accumulation stop instruction signal 231 is input, the accumulation value calculation circuit 223 stops accumulation of the image digital signal 217 and storage processing for the frame memory 225.
When the display instruction flag 232 is input, the display instruction circuit 233 outputs the display instruction signal 234 to the CPU 235. When the display instruction signal 234 is input, the CPU 235 receives the display digital image data 226 from the frame memory 225 in STEP 8 and STEP 9 of FIG.
Is captured and displayed on the image display device 237 such as a CRT. Further, the image data is stored in the storage medium 240 as needed. A conventional X-ray imaging device using a CCD sensor is
Images are displayed and image data is stored by the above method.

[0018]

As a peculiar property of X-rays, there is a possibility that an irradiated area that should not be transmitted will be transmitted with a low probability, resulting in appearing as white dots on the screen. . For this reason, if the image data of the digital signal obtained by A / D converting the image analog signal from the CCD sensor is directly imaged, white spots will appear in places in whole, and when such image data is used, highly reliable diagnosis is possible. There was a problem that could not be done.

Further, in the conventional X-ray imaging apparatus, X
Since the input / output operations of the radiation irradiating device and the image display device are complicated, it is necessary to integrally form the X-ray irradiating device and the X-ray imaging device in consideration of operability. Therefore, there is a problem that the X-ray irradiator currently used for X-ray film cannot be used and is economically wasted. Also,
In order to obtain the optimum image quality, the output control on the side of the X-ray irradiator must be resorted to, and the conventional X-ray image apparatus also has a problem that it is difficult to adjust the image quality.

In the conventional X-ray imaging apparatus, since the intensity of X-rays is displayed as it is according to the difference in brightness and darkness, it is not sufficient as an image for the inspector to see, and density correction, etc. It was necessary to add the processing of. This is because it is better to display the dark part more finely than the light part and to widen the range of light and dark of the displayed image as much as possible in order to make the image that looks best visually. . However, it is difficult for the inspector to perform such density adjustment while viewing the image, because it is difficult to process many images in a short time in practice. Had become a big problem.

Further, since the image data is a digital value, the range that can be taken is finite, and if the X-ray irradiation dose is too large or too small beyond that range, the concentration cannot be adjusted and it is sufficient for diagnosis. There was a problem that it was not possible to obtain a good image. The CCD sensor used in the X-ray image device is superior to the film in terms of sensitivity, and is superior in certainty and accuracy that a sufficient image can be obtained with a small irradiation amount. However, the CCD sensor has a problem that it is very difficult to set conditions for adjusting the irradiation time setting and the irradiation distance setting to the sensitivity of the CCD sensor. For example, in dentistry, the X-ray transmittance differs depending on the difference between front teeth and molars, or the teeth of infants and teeth of adults, and the X-ray dose to be irradiated also differs. Therefore, the conventional X-ray image device using the CCD sensor needs test irradiation many times until an image is obtained under the optimum conditions, and it is necessary to perform unnecessary irradiation.

The present invention solves the above-mentioned problems, and eliminates the need for inputting / outputting a trigger signal from the X-ray irradiator, and automatically detects the start and end of X-ray irradiation, thereby performing a complicated operation. The purpose of the present invention is to obtain an X-ray imaging apparatus which is excellent in cost efficiency because it becomes possible to use the conventional X-ray irradiating device simply by removing it and removing the conventional X-ray film. Another object of the present invention is to obtain an X-ray image device in which the optimum image quality adjustment is automatically performed inside the X-ray image device according to the irradiation target without finely adjusting the output of the X-ray irradiation device. And

[0023]

In order to achieve the above object, an X-ray imaging apparatus according to the present invention has a plurality of pixels,
Image data output means for sequentially receiving, for each pixel, image data corresponding to the intensity of X-rays that have passed through the irradiation target, and image data of a designated pixel output from the image data output means and its periphery. The image data stored in the first image data storage unit is input from the first image data storage unit that temporarily stores the image data of the pixel, and the designated image data is input from the first image data storage unit. When the image data of the pixel is larger than the maximum value of the image data of the peripheral pixels by a predetermined value or more, the image data of the designated pixel is determined to be abnormal data, and the abnormal data removing unit corrects the abnormal data. And the image data sequentially input from the first image data storage unit and corrected by the abnormal data removal unit are sequentially stored, and the image data output unit And includes a second image data storing means for storing the image data of all the pixels that are the correction processing are sequentially outputted, from. Hereinafter, the term “pixel value” used in the present invention corresponds to the intensity of X-rays in a certain pixel, and an analog value such as electric charge or current corresponding to the luminance of the pixel in the CCD element, or such A digital value that corresponds to an analog value.

Therefore, in the X-ray imaging apparatus of the present invention, when the number of pixels of the designated pixel is larger than the value of the pixel having the maximum value by a predetermined value or more among the surrounding pixels, the designation is made. Since the pixel is determined to be abnormal data, the abnormal data can be surely determined, and the device is useful for image data correction processing.

In the X-ray imaging apparatus according to the present invention, when the abnormal data removing unit determines that the image data of the designated pixel is abnormal data, the image data of the designated pixel is converted into the surrounding pixels. Replace with the maximum value of the image data of. In the X-ray imaging apparatus according to the present invention, when the abnormal data removing unit determines that the image data of the designated pixel is abnormal data, the image data of the designated pixel is converted into the image data of the peripheral pixels. Replace with the average value of.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will be described below with reference to the accompanying drawings. << First Embodiment >> FIG. 1 shows a first embodiment X of the present invention.
It is a block diagram showing the whole line image device composition. In FIG. 1, X-rays 1 emitted from an X-ray irradiator 110 and passing through an irradiation target are CCD elements 2 serving as CCD sensors.
Entered in. CCD device 2 as image data output means
Converts the X-ray 1 into an image analog signal 3 having a size corresponding to the intensity, and outputs the image analog signal 3 to the A / D converter 4 of the image data capturing unit 11. The image analog signal 3 input to the A / D converter 4 is converted into an image digital signal and input to the line buffer 5. The line buffer 5 temporarily stores image data for two lines. Line buffer 5
The image data input to is input to the frame memory 7 via the filter 6, which is an abnormal data removing unit that removes white spot abnormal data. The frame memory 7 is a recording medium that stores all image data. In addition, the image data capturing unit 11 is a C that controls CCD driving and A / D conversion.
The PU 10 is provided, and the CCD element 2 is drive-controlled by the CCD drive signal 13.

The image display unit 12 connected to the image data fetching unit 11 has a CPU 8 for controlling image fetching and image display according to an external operation, and an image display device 9 for displaying image data. . The image data is C
It is configured to be recorded in the storage medium 14 based on a command from the PU 8.

The relationship between the lightness and darkness of an image and the pixel value which is the pixel data is such that the brighter the image, the larger the pixel value.
The pixel value indicates the substantial brightness of the pixel. Figure 2
FIG. 4 is an explanatory diagram showing the relationship between the brightness of an image and the size of pixel data. In the X-ray imaging apparatus according to the first embodiment, after the affected area to be irradiated is irradiated with X-rays 1, the CCD element 2 outputs a video analog signal 3 and the A / D converter 4 outputs each pixel. The pixel data is converted into digital data line by line.

The digital data sent from the A / D converter 4 is stored in the line buffer 5 as pixel data having pixels for up to two lines. Figure 3 shows the CCD
It is a figure which shows notionally some pixels in the element 2.
As shown in FIG. 3, the line buffer 5 transmits the pixel data for each pixel (target pixel data) and the eight pixel data around the pixel data to the white spot abnormality data removal filter 6.

FIG. 4 shows a filter 6 for removing white spot abnormal data.
3 is a flow showing a processing procedure in. The white spot abnormal data removing filter 6 performs the white spot abnormal data removing process according to the procedure shown in FIG. In STEP1 of the flow shown in FIG. 4, the target pixel data shown in FIG. 3 is input as X, and the maximum value (maximum peripheral pixel data) of the pixel data of eight peripheral pixels is input as Amax. In addition, a threshold value α that determines how much the target pixel data exceeds the peripheral pixel data is determined to be abnormal is set.

Next, in STEP 2 of FIG. 4, the target pixel data X is equal to or larger than the peripheral maximum pixel data Amax, and the difference between the target pixel data X and the peripheral maximum pixel data Amax is larger than the threshold value α, or If they are equal, that is, if the target pixel data X is larger than the sum of the maximum peripheral pixel data Amax and the threshold value α, in STEP 3, the target pixel data X is replaced with the value of the maximum peripheral pixel data Amax.

As described above, when the target pixel data X greatly exceeds the maximum peripheral pixel data Amax, it is determined that the target pixel is white spot abnormal data, and the target pixel data is set to the maximum value of the peripheral pixels. By replacing, white spot abnormal data is detected and corrected. As described above, the white spot abnormality data removal filter 6 processes each pixel,
The processed pixel data is sequentially stored in the frame memory 7.

In the first embodiment, the image data acquired by the CCD element 2 is converted into the white spot abnormal data removing filter 6.
The pixel data is converted into pixel data having no abnormal white point data in all pixel data by passing the pixel data, and the pixel data is stored in the frame memory 7 line by line. Therefore, the white spot abnormal data removing filter 6 can perform high-speed processing by causing the gate array to perform hardware processing.
All pixel data can be processed in a short time without spending time even through the white spot abnormality data removing filter 6.

Further, in the X-ray image apparatus of the first embodiment, the CPU 8 causes the image display device 9 to display the image data of the frame memory 7, and the storage medium 14 displays the corrected easy-to-see image data as necessary. Can be saved. Further, if necessary, the X-ray imaging apparatus of the first embodiment can easily adjust the brightness, contrast, enlargement of the affected area, etc. of the image on the image display apparatus by an external operation to the CPU 8 for diagnosis. The device has easy screen operation.

As described above, in the X-ray imaging apparatus of the first embodiment, when a certain pixel data of interest exceeds the maximum value of the eight pixel data around it by a predetermined threshold value or more, A white spot abnormality data removal filter 6 for correcting the pixel data of interest to a value within a predetermined range is provided. Therefore, a pixel having abnormal data that appears as a white dot in the X-ray image is detected from the peripheral pixel data of the pixel, and the abnormal white point pixel data is corrected to an appropriate value. In the X-ray image processing of the first embodiment of the present invention, by using the gate array and the high-speed CPU, the correction processing of the image data with almost no waiting time can be performed.

In the X-ray imaging apparatus according to the first embodiment, when the pixel data of interest X exceeds a predetermined value, the pixel data of interest X is replaced with the maximum pixel data Amax of the surroundings, but another embodiment. For example, instead of replacing the target pixel data X with the peripheral maximum pixel data Amax, instead of replacing it with the average value of eight pieces of peripheral pixel data, the same effect as in the above embodiment can be obtained.

<Second Embodiment> A second embodiment of the X-ray imaging apparatus of the present invention will be described below with reference to the accompanying drawings.
FIG. 5 is a block diagram showing the overall configuration of the X-ray imaging apparatus of the second embodiment. In FIG. 5, the X-rays 51 that have been irradiated from the X-ray irradiation device 110 and have passed through the affected area that is the irradiation target.
Is input to the CCD element 52. The CCD element 52, which is an image data output means, transmits the X-ray 51 to the image analog signal 5
It is converted to 9 and output to the A / D converter 53 of the image data capturing unit 60. The image analog signal 59 input to the A / D converter 53 is converted into an image digital signal, input to the frame memory 54, and recorded. The image data input to the frame memory 54 is corrected and rewritten by a white spot abnormal data removal filter 55 that removes white spot abnormal data.

Further, the image data fetching section 60 uses the CC
CPU that controls D drive, A / D conversion, data correction, etc.
56, a CCD element 52 by a CCD drive signal 62
Are driven and controlled. The image display unit 61 connected to the image data capturing unit 60 includes a CPU 57 that controls image capturing and image display according to an external operation, and an image display device 58 that displays image data. Further, the image data is configured to be recorded in the storage medium 63 based on a command from the CPU 57.

In the X-ray imaging system of the second embodiment, after the affected area to be irradiated is irradiated with X-ray 51, C
The video analog signal 59 output from the CD element 52 is A
In the / D converter 53, each pixel is digitized,
It is sequentially stored in the frame memory 54. When the storage of all pixel data is completed, the white spot abnormality data removal filter 55
The white spot abnormality data is corrected. FIG. 6 is a flowchart showing a procedure for correcting white spot abnormal data in the white spot abnormal data removing filter 55.

In STEP 1 of FIG. 6, first, the brightness distribution status of all pixel data in the frame memory 54 is recognized, and all the pixel addresses of the white spot abnormal data are acquired from the brightness distribution status. A method of obtaining the pixel address of the white spot abnormality data will be described with reference to FIGS. 7 to 9. FIG. 7 is a luminance distribution chart when there is no white spot abnormality data in all pixel data, and FIG. 8 is a luminance distribution chart when there is white spot abnormality data.

The luminance distribution shown in FIGS. 7 and 8 shows how each pixel is distributed in the entire luminance range in all pixel data, and white spot abnormal data is included in all pixel data. If not, the distribution curve becomes continuous as shown in FIG. However, if there is white spot abnormality data in all pixel data, as shown in FIG. 8, a continuous body curve (luminance distribution body portion) appears in a place where the luminance is bright.
There is a distribution curve (discontinuous portion) at a position a little away from. In FIG. 8, reference numeral a indicates a pixel value indicating the luminance at which the discontinuous portion starts, and reference numeral b indicates the luminance range between the luminance distribution main body portion and the discontinuous portion.

FIG. 9 shows a filter 55 for removing white spot abnormal data.
6 is a flow showing a pixel address acquisition procedure of white spot abnormality data in FIG. In STEP1 of the flow shown in FIG. 9, the brightness reference value is aconst and the discontinuous range reference value is bconst. Then, it is assumed that the brightness range of the discontinuous portion in the actual brightness distribution is b, and the pixel value indicating the brightness at which the discontinuity starts is a. The brightness range b of the brightness distribution and the pixel value a at which discontinuity starts are the same as the definition in the brightness distribution shown in FIG.

In STEP 2 shown in FIG. 9, the pixel value a
Is larger than a predetermined brightness reference value aconst, and the brightness range b of the discontinuous part is larger than a predetermined discontinuous range reference value bconst, all pixel addresses of the discontinuous part having a brightness higher than that of the main body of the brightness distribution are white dots. The pixel address is acquired as abnormal data.

As described above, after the pixel address is acquired as the white spot abnormality data, the process returns to the flow of FIG. 6 again and S of FIG.
In TEP2, the pixel data of white abnormal data (point of interest) is set to X, and eight peripheral pixel data around the pixel are set to A.
1 to A8. Peripheral pixel data A in STEP3
If all of 1 to A8 are normal data, the value of X is replaced with the average value of A1 to A8 in STEP 4 and stored in the frame memory 54. In this way, the average value replacement process is performed for all the white spot abnormality data when all the peripheral pixel data A1 to A8 are normal data. ST
The average value replacement process of EP3 and STEP4 is repeated until all pixels are completed.

Next, in STEP 5, the remaining white spot abnormal data is averaged for only the normal data out of the eight peripheral data, and this average value is set as new normal pixel data X of the target pixel. It is stored in the frame memory 54.

The correction processing of the above-mentioned white spot abnormality data is time consuming, but it is an effective correction method when there is a continuous abnormality in adjacent pixels. In this way, the white spot abnormality data in all pixel data is corrected, and the image data having no white spot abnormality data is stored in the frame memory 54. The CPU 57 of the image display unit 61 is the frame memory 5
The image data of No. 4 is displayed on the image display device 58, and the corrected easy-to-see image data is stored in the storage medium 63 as needed.

Further, in the X-ray imaging apparatus of the second embodiment, it is possible to easily adjust the brightness, contrast, enlargement of the affected area, etc. of the image data by an external operation, if necessary, and a screen that is easy to diagnose. It is a device with operation.

The X-ray imaging apparatus of the second embodiment is provided with the white spot abnormality data removal filter 55 to check the luminance distribution of all pixel data that have been taken in, and the luminance distribution is not continuous and is predetermined. When there is a luminance distribution that is more than a value apart, the pixel data having the discontinuous luminance distribution is changed to the average value of the surrounding data, and the pixel data in the frame memory is rewritten. Therefore, the X-ray imaging apparatus according to the second embodiment can detect pixels having abnormal data that appear as white dots from all pixel data and correct the abnormal white point pixel data to an appropriate value.

The correction processing of the X-ray image apparatus of the second embodiment enables the correction processing of image data with almost no waiting time by using the gate array and the high speed CPU. The second embodiment of the present invention is realized by a program, and the program is recorded on a recording medium such as a floppy disk (registered trademark, hereinafter referred to as a floppy disk) and transferred to another independent computer. It can be easily implemented in the system.

Next, a case where the correction process of the X-ray imaging apparatus of the second embodiment is carried out on a floppy disk will be described. FIG. 10 is an explanatory diagram for explaining a case where the correction process in the X-ray image apparatus is performed on a floppy disk. FIG. 10A is a diagram showing an example of the physical format of the floppy disk 70 which is the recording medium body. As shown in (a) of FIG. 10, the floppy disk 70 has concentric tracks formed from the outer circumference to the inner circumference, and is divided into 16 sector sectors. The program is recorded according to the divided storage areas.

FIG. 10B is a diagram for explaining a case for accommodating the floppy disk 70. From the left of FIG. 10B, a front view and a sectional view of the floppy disk case 71 and a front view of the floppy disk 70 are shown. Floppy disk 7
By storing 0 in the floppy disk case 71, the floppy disk 70 can be protected from dust and external shocks and safely transferred.

FIG. 10C is a diagram showing a computer system etc. for recording / reproducing a program on / from the floppy disk 70 shown in FIG. 10B. Figure 1
By connecting a floppy disk drive 73 to the computer system 72, as shown in (c) of 0, it is possible to record and reproduce the program on the floppy disk 70. The floppy disk 70 is inserted into and removed from the insertion slot 74 of the floppy disk drive 73, and the program is recorded and reproduced on the floppy disk 70.

When recording a program for correction processing of the X-ray image device, the floppy disk drive 7 is used.
3 reads the program from the floppy disk 70, and the read program is the computer system 7
2 is transferred.

In the X-ray image apparatus according to the second embodiment, the floppy disk 70 is used as the recording medium for the description, but an optical disk may be used. Further, the recording medium of the present invention is not limited to these, and as long as the program can be recorded such as an IC card and a ROM cassette, it can be carried out in the same manner as the above-mentioned embodiment.

In the second embodiment, the brightness distribution of all pixel data is acquired. However, the structure of acquiring the brightness distribution of pixel data in a specific range is the same as in the above embodiment. effective. Further, in the second embodiment, the pixel data of interest X is replaced with the average value of the normal data of the peripheral pixel data, but it may be replaced with the maximum value or the minimum value of the normal data.

<< Third Embodiment >> A third embodiment of the X-ray imaging apparatus of the present invention will be described below with reference to the accompanying drawings.
FIG. 11 is a block diagram showing the overall configuration of the X-ray imaging apparatus of the third embodiment. FIG. 12 is a flow showing a processing procedure from the irradiation start to the accumulation start in the third embodiment,
FIG. 13 is a flow chart showing a processing procedure from the start of accumulation to image display in the third embodiment.

In FIG. 11, X-rays 111 that have been irradiated from the X-ray irradiation device 110 and have passed through the affected area to be irradiated.
Is input to the CCD element 112 of the X-ray detection unit 101. The X-ray detector 101, which is an X-ray detector, has a CCD element 112, an A / D converter 115, and a CCD drive circuit 116. The X-ray detection unit 101 uses the image digital signal 11
7 and outputs the image digital signal 117. The accumulating unit 105, which is an accumulating unit, outputs the accumulated value calculating circuit 123.
And a frame memory 125.

CCD device 11 as image data output means
2 converts the X-ray 111 into an image analog signal 113,
Output to the A / D converter 115. A / D converter 115
Is an accumulator 1 that is an accumulator for accumulating the image digital signal 117.
05 to the pixel value detection circuit 118 of the pixel value detection unit 102 which is a cumulative value detection unit.
The output of the pixel value detection circuit 118 is input to the pixel number detection circuit 119 of the pixel number detection unit 103, which is the pixel number detection means, and the accumulation start circuit 121 of the accumulation start unit 104.
It is configured to be input to the cumulative value calculation circuit 123 via.

The accumulating unit 105 has a cumulative value calculating circuit 123 and a frame memory 125. Frame memory 1
The output of 25 is the cumulative detection circuit 12 of the cumulative value detection unit 106.
7 and then to the accumulation stop circuit 130 of the accumulation stop unit 108 via the accumulated pixel number detection circuit 128 of the accumulated pixel number detection unit 107. Cumulative pixel number detection circuit 128
Is output to the display instruction circuit 133 of the display instruction unit 109. The output of the display instruction circuit 133 is the image display unit 1.
38 to the CPU 135.

The image display section 138 connected to the display instructing section 109 has a CPU 135 for controlling image capturing and image display according to an external operation, and an image display device 137 for displaying image data. Further, the image data is configured to be recorded in the storage medium 140 based on a command from the CPU 135.

In FIG. 11, arrows indicate the flow of X-rays 111 and signals, and reference numeral 114 is a CCD drive signal.
Reference numeral 120 indicates a cumulative start flag, reference numeral 122 indicates a cumulative start instruction signal, reference numeral 124 indicates a cumulative image digital signal, reference numeral 12
Reference numeral 6 is digital image data for display, reference numeral 129 is a cumulative stop flag, reference numeral 131 is a cumulative stop instruction signal, reference numeral 132 is a display instruction flag, reference numeral 134 is a display instruction signal, reference numeral 13
Reference numeral 6 is an image display signal, and reference numeral 139 is digital image data for storage.

In the X-ray imaging system of the third embodiment,
The CCD element 112 is provided with a phosphor (scintillator, eg, Gd ₂ O ₂ S) that converts X-rays into visible light on the CCD surface. Alternatively, in the X-ray imaging apparatus of the present invention, a cadmium teralite detection element (CdTe detection element) electrically connected to each pixel may be provided on the CCD surface instead of the above phosphor. In addition, the cadmium teralite detection element (Cd
As a Te detection element), for example, Japanese Patent Laid-Open No. 6-50580
The element disclosed in Japanese Patent No. 0 is used.

Next, the operation of the X-ray imaging apparatus of the third embodiment will be described. First, when the X-ray irradiating device 110 irradiates the affected area or the like to be irradiated with X-rays 111, the CCD element 112 outputs an image analog signal 113 corresponding to an image to the A / D converter 115. The A / D converter 115, to which the image analog signal 113 is input, outputs the image digital signal 117 to the pixel value detecting unit 102 and the accumulating unit 10.
Output to 5.

FIG. 12 is a flow chart showing a processing procedure from the irradiation start to the accumulation start in the X-ray imaging system of the third embodiment. In the X-ray imaging apparatus of the third embodiment, in the pixel value detection circuit 118 of the pixel value detection unit 102, S of FIG.
As shown in TEP1, the pixel value reference value is set to a predetermined value valconst as an initial setting. This pixel value reference value serves as a reference for brightness for determining that X-ray irradiation has been performed. Further, in STEP 1, the pixel number reference value is set to a predetermined value numconst. This pixel number reference value serves as a reference for the number of pixels in the CCD sensor that determines that X-ray irradiation has been performed. A pixel number variable indicating the current count number of pixels is numx.

In STEP 2, the image data input standby state is entered, and in STEP 3, the image digital signal 11 is entered.
The number of pixels variable numx to capture the first pixel of 7
Is cleared to 0.

Next, in STEP 4, it is determined whether or not the pixel value of the pixel of interest at present is larger than the pixel value reference value valconst. If the pixel value of the pixel of interest is larger than the pixel value reference value valconst, STE
In P5, the pixel number variable numx is incremented by 1, and STE
Go to P6. On the other hand, the pixel value of the target pixel is the pixel value reference value v
If not larger than “alconst”, the process proceeds to STEP 6 with the pixel number variable numx as it is.

At STEP 6, it is judged whether the pixel values of all the pixels have been checked. If the pixel values of all pixels have not been checked, STEP7
In, the pixel of interest next to the image digital signal 117 is fetched and the loop to STEP 4 is repeated.

On the other hand, when it is determined in STEP 6 that the pixel values of all pixels have been checked, the process proceeds to STEP 8 and the process proceeds to the pixel number detection circuit 119 of the pixel number detection unit 103 shown in FIG. The pixel number detection circuit 119 of the pixel number detection unit 103 determines whether the pixel number variable numx is larger than the pixel number reference value numconst in STEP 8 of FIG.

In STEP 8, the pixel number variable numx
Is determined to be larger than the pixel number reference value numconst, the accumulation of image data is started in STEP 9. At this time, the pixel number detection circuit 119 outputs the accumulation start flag 120 to the accumulation start circuit 121 of FIG. On the other hand, if it is determined in STEP 8 that the pixel number variable numx is not larger than the pixel number reference value numconst, the process returns to STEP 2 and the loop is repeated.

The accumulation start circuit 121 of the accumulation start unit 104
Outputs the accumulation start instruction signal 122 to the accumulation value calculation circuit 123 when the accumulation start flag 120 is input. When the accumulation start instruction signal 122 is input, the accumulated value calculation circuit 123 periodically transmits the image digital signal 117 thereafter.
Is converted into a cumulative image digital signal 124 and stored in the frame memory 125. The output of the image analog signal of the CCD sensor having the CCD element and the method of A / D conversion in the third embodiment will be briefly described with reference to FIGS. 25 and 26 described above.

As shown in FIG. 25, the CCD sensor has a fixed number of pixels in the vertical and horizontal directions. CCD
As shown in FIG. 26, the sensor constantly outputs an image analog signal 113 having image data for all pixels of the CCD sensor in a constant cycle. The image data for all pixels is A / D converted in every cycle to obtain an image digital signal 117. The image digital signal 117 is accumulated and stored in the frame memory 125, and image data having an appropriate image quality is obtained.

As described above, when the accumulation of the image digital signal 117 is started, the accumulated value detection circuit 127 of the accumulated value detection unit 106 takes in the accumulated image digital signal 124 stored in the frame memory 125 to obtain the image data. The accumulation process of is started. FIG. 13 is a flow chart showing a processing procedure from the start of accumulation to image display in the X-ray imaging apparatus of the third embodiment.

As shown in FIG. 13, in STEP 10, the cumulative value reference value is set to a predetermined value sumva as an initial setting.
Set to lconst. The cumulative value reference value serves as a reference of brightness for making the X-ray image have an appropriate image quality. In addition, the cumulative pixel number reference value is set to a predetermined value sumnumc.
Set to onst. This cumulative pixel number reference value serves as a reference for the number of pixels in the CCD sensor for making the X-ray image have an appropriate image quality. The cumulative pixel number variable indicating the current count number of the accumulated pixel numbers is sumnumx
And

In STEP 11, the cumulative pixel number variable sumnumx is cleared to 0 in order to fetch the first target pixel of the cumulative image digital signal 124. Next, STE
In P12, the cumulative pixel value that is the currently focused cumulative pixel value is the cumulative pixel value reference value sumvalcon.
It is determined whether or not it is larger than st. If the cumulative pixel value of the pixel of interest is larger than the cumulative pixel value reference value sumvalconst, in STEP 13, the cumulative pixel number variable su
Increase mnumx by 1 and proceed to STEP 14.

On the other hand, if the cumulative pixel value of the target pixel is not larger than the cumulative pixel value reference value sumvalconst, the process directly proceeds to STEP14. In STEP 14,
It is determined whether the pixel values of all pixels have been checked. If the pixel values of all the pixels have not been checked, in STEP 15, it is set to fetch the next target pixel of the cumulative image digital signal 124, and S
Repeat the loop to TEP12.

On the other hand, when it is determined in STEP 14 that the pixel values of all the pixels have been checked,
The cumulative pixel number detection circuit 128 of the cumulative detection unit 106 (see FIG.
The process shifts to 1).

Accumulation pixel number detection circuit 1 of accumulation detection unit 106
28 is the cumulative pixel number variable sum in STEP 16
It is determined whether numx is larger than the cumulative pixel number reference value sumnumconst. In STEP16,
The cumulative pixel number variable sumnumx is the cumulative pixel number reference value su.
If it is smaller than mnumconst, in STEP 17, the accumulation of image data is continued, the process returns to STEP 12, and the above loop is repeated.

On the other hand, in STEP 16, the cumulative pixel number variable sumnumx is the pixel number reference value sumnumcon.
If it is larger than st, the accumulation of image data is stopped in STEP 18. At this time, the cumulative pixel number detection circuit 1
28 outputs the accumulation stop flag 129 to the accumulation stop circuit 130, and at the same time, displays the display instruction flag 132.
Output to 3. When the accumulation stop flag 129 is input, the accumulation stop circuit 130 outputs the accumulation stop instruction signal 131 to the accumulation value calculation circuit 123. When the cumulative stop instruction signal 131 is input, the cumulative value calculation circuit 123 stops the cumulative process of the image digital signal 117 and the process of storing it in the frame memory 125.

When the display instruction flag 132 is input from the cumulative pixel number detection circuit 128, the display instruction circuit 133 outputs a display instruction signal 134 to the CPU 135.
When the display instruction signal 134 is input, the CPU 135 fetches the display digital image data 126 from the frame memory 125 in STEP 19 of the flow shown in FIG. 13, and in STEP 20, the image display device 1 such as a CRT.
Display at 37. Further, the image data is saved in the storage medium 140 as needed.

As is clear from the above description, in the X-ray imaging apparatus according to the third embodiment of the present invention, the number of pixels having a pixel value larger than a predetermined value when X-ray is irradiated is a predetermined number. When the number is larger than the number, it is determined that X-ray irradiation has started, and the accumulation of image data is started. Further, the X-ray imaging apparatus of the third embodiment stops the accumulation when the number of pixels having the cumulative pixel value larger than the predetermined value is larger than the predetermined number. Therefore, in the X-ray imaging apparatus of the third embodiment, the optimum X-ray image can be automatically obtained without connecting the X-ray irradiation apparatus and the input / output unit regardless of the output control on the irradiation apparatus side.

<< Fourth Embodiment >> A fourth embodiment of the X-ray imaging apparatus of the present invention will be described below with reference to the accompanying drawings.
FIG. 14 is a block diagram showing the overall configuration of the X-ray imaging apparatus of the fourth embodiment. FIG. 15 is a flow chart showing a processing procedure from the irradiation start to the accumulation start in the X-ray imaging apparatus of the fourth embodiment. FIG. 16 is a flow chart showing the processing procedure from the accumulation start to the accumulation stop in the X-ray imaging apparatus of the fourth embodiment. FIG. 17 is a flow chart showing the processing procedure from the accumulation stop to the image display in the X-ray imaging apparatus of the fourth embodiment.

In FIG. 14, the X-ray 151 irradiated from the X-ray irradiation device 150 and passing through the affected area to be irradiated.
Is input to the CCD element 152 of the X-ray detection unit 141. The X-ray detection unit 141 has a CCD element 152, an A / D converter 155, and a CCD drive circuit 156. The X-ray detector 141 outputs an image digital signal 157, and the accumulator 182 to which the image digital signal 157 is input is an accumulator 181 and a plurality of frame memories 165a and 165.
b, 165c ... 165n.

CCD element 15 as image data output means
2 converts the X-ray 151 into an image analog signal 153 and outputs it to the A / D converter 155. A / D converter 15
The image digital signal 157 includes an accumulation circuit 181 of the accumulation unit 182 and a pixel value detection circuit 158 of the pixel value detection unit 142.
Output to. The output of the pixel value detection circuit 158 is input to the pixel number detection circuit 159 of the pixel number detection unit 143,
It is input to the accumulation circuit 181 via the accumulation start circuit 161 of the accumulation start unit 144. Also, the pixel number detection circuit 159
Outputs the accumulation stop flag 169 to the accumulation stop circuit 170 of the accumulation stop unit 148, and the accumulation stop circuit 170 outputs the accumulation stop instruction signal 171 to the accumulation circuit 181. The pixel number detection circuit 159 also outputs a display instruction flag 172 to the display instruction circuit 173 of the display instruction unit 149.

The output of the accumulator 182 is the image display unit 178.
Is input to the CPU 175. The image display unit 178 connected to the accumulating unit 182 includes a CPU 175 that controls image capturing and image display according to an external operation, and an image display device 177 that displays image data. Further, the image data is configured to be recorded in the storage medium 180 based on the instruction of the CPU 175.

In FIG. 14, arrows indicate the flow of X-rays 151 and signals, and reference numeral 154 is a CCD drive signal.
Reference numeral 160 is a cumulative start flag, reference numeral 162 is a cumulative start instruction signal, reference numeral 164 is a cumulative image digital signal, reference numeral 16
Reference numeral 6 is digital image data for display, reference numeral 169 is an accumulation stop flag, reference numeral 174 is a display instruction signal, reference numeral 176 is an image display signal, and reference numeral 179 is digital image data for storage.

Next, the operation of the X-ray imaging system of the fourth embodiment will be described. First, when the X-ray irradiator 150 irradiates the affected area or the like that is the irradiation target with the X-rays 151, the CCD element 152 outputs an image analog signal 153 corresponding to the image to the A / D converter 155. And
The A / D converter 155 outputs the image digital signal 157 to the accumulation circuit 181 of the accumulation unit 182 and the pixel value detection circuit 158 of the pixel value detection unit 142.

FIG. 15 is a flow chart showing the processing procedure from the irradiation start to the accumulation start in the X-ray imaging apparatus of the fourth embodiment. The pixel value detection circuit 158 sets the pixel value reference value to a predetermined value valconst as an initial setting in STEP1 of the flow shown in FIG. This pixel value reference value serves as a reference for brightness for determining that X-ray irradiation has been performed. In addition, the pixel number reference value is set to a predetermined value n
Set to umconst. This pixel number reference value serves as a reference for the number of pixels in the CCD sensor for determining that X-ray irradiation has been performed. The pixel number variable is numx.

Next, in STEP 2, the image data input standby state is entered, and in STEP 3, the pixel number variable nu for fetching the first pixel of the image digital signal 157.
Clear mx to 0.

Next, in STEP 4, it is determined whether or not the pixel value of the pixel of interest is greater than the pixel value reference value valconst. If the pixel value of the pixel of interest is larger than the pixel value reference value valconst, STEP
5, the pixel number variable numx is incremented by 1 and ST
Proceed to EP6. On the other hand, in STEP 4, if the pixel value of the target pixel is not larger than the pixel value reference value valconst, the process directly proceeds to STEP 6.

At STEP 6, it is determined whether the pixel values of all pixels have been checked. If it is determined that the pixel values of all pixels have not been checked, STE
In P7, the setting is made so that the pixel of interest next to the image digital signal 157 is taken in, the process returns to STEP3, and this loop is repeated. On the other hand, when it is determined in STEP 6 that the pixel values of all the pixels have been checked, the process by the pixel value detection circuit 158 (FIG. 14) ends, and the process proceeds to the process by the pixel number detection circuit 159 (FIG. 14). .

The pixel number detection circuit 159 determines in STEP8 in the flow of FIG. 15 whether the pixel number variable numx is larger than the pixel number reference value numconst. If the pixel number variable numx is the pixel number reference value numco
If it is larger than nst, in STEP 9, the image data accumulation process is started. At this time, the pixel number detection circuit 1
59 outputs the accumulation start flag 160 to the accumulation start circuit 161 (FIG. 14). On the other hand, if the pixel number variable numx is not larger than the pixel number reference value numconst, STEP
Returning to 2, this loop is repeated.

The accumulation start circuit 161 uses the accumulation start flag 1
When 60 is input, the accumulation start instruction signal 162 is output to the accumulation circuit 181. When the accumulation start instruction signal 162 is input, the accumulation circuit 181 converts the image digital signal 157 that is periodically sent thereafter into the accumulated image digital signal 164, and the number of times that the accumulated image digital signal 164 is accumulated. Depending on the frame memories 165a to 165
Store up to n separately. That is, when the image digital signal 157 is input only once, the frame memory 16
5a. Also, the image digital signal 157 is 2
When it is accumulated, it is stored in the frame memory 165b,
When accumulated three times, they are stored in the frame memory 165c and stored in separate memories, respectively, and when accumulated N times, they are stored in the frame memory 165n.

Therefore, it is necessary to prepare the frame memory for the maximum cumulative number of times, but the X-ray irradiation time is about 1 second at the longest, and one data acquisition of the frame memory is about 0.1 seconds. Therefore, it is sufficient that the number of frame memories to be prepared is about 10 to 20. Also, when the frame memory becomes insufficient, the contents of the last memory are updated.

As shown in FIGS. 25 and 26 described above,
The CCD sensor in the fourth embodiment is constructed,
The CCD sensor constantly outputs an image analog signal having image data for all pixels at a constant cycle. The image data for all pixels is A / D converted in every cycle to obtain an image digital signal 157. This image digital signal 1
57 is accumulated and stored in an appropriate frame memory, and image data having an appropriate image quality can be obtained. In addition, this C
The structure of the CD sensor is the same as that of the third embodiment. When the accumulation of the image digital signal 157 is started, the pixel value detection circuit 158 and the pixel number detection circuit 159 perform a process of determining whether or not the X-ray irradiation is completed according to the processing procedure of FIG.

FIG. 16 is a flow chart showing the processing procedure from the accumulation start to the accumulation stop in the X-ray imaging apparatus of the fourth embodiment. In the flow shown in FIG. 16, the processing from STEP10 to STEP16 is the same as STEP1 in FIG.
To STEP 7 are the same.

The pixel number detection circuit 159 is equivalent to the STE of FIG.
In P17, the pixel number variable numx is the pixel number reference value n
It is determined whether it is smaller than umconst. If the pixel number variable numx is smaller than the pixel number reference value numconst, the accumulation of image data is stopped in STEP 18. At this time, the pixel number detection circuit 159 outputs the accumulation stop flag 169 to the accumulation stop circuit 170 and simultaneously outputs the display instruction flag 172 to the display instruction circuit 173. On the other hand, in STEP 17, if the pixel number variable numx is larger than the pixel number reference value numconst, S is left unchanged.
The process proceeds to TEP 11 to wait for the input of image data to be input next.

Accumulation stop circuit 170 accumulates accumulation stop flag 16
When 9 is input, the accumulation stop instruction signal 171 is output to the accumulation circuit 181. The accumulation circuit 181 outputs the product stop instruction signal 1
When 71 is input, the storage of the cumulative image digital signal 164 in the frame memories 165a to 165n is stopped.

The display instruction circuit 173 uses the display instruction flag 17
When 2 is input, the display instruction signal 174 is output to the CPU 175. FIG. 17 is a flow chart showing the processing procedure from the accumulation stop to the image display in the X-ray imaging apparatus of the fourth embodiment. When the display instruction signal 174 is input, the CPU 175 acquires the designated value of the cumulative number of times determined by the external operation or the initial setting in STEP 19 in the flow shown in FIG. This numerical value is set based on the empirical knowledge of the operator, or is set at the time of initial installation due to the relationship with the X-ray irradiation device, and is always set to an appropriate value.

Next, in STEP 20 of FIG. 17, the display digital image data 166 is fetched from the memory in which the designated cumulative number of cumulative image data of the frame memories 165a to 165n are stored, and the image of the CRT or the like is read. It is displayed on the display device 177. Further, the image data is stored in the storage medium 180 as needed.

The X-ray imaging apparatus of the fourth embodiment uses the frame memory 16 in order to determine the designated value of the cumulative number.
Image data for all times stored in 5a to 165n are once displayed in parallel on an image display device such as a CRT, and the operator selects and determines the most appropriate image from them. Is also possible. Further, if the cumulative number of times for obtaining the optimum image quality can be determined in advance to one, the X-ray imaging apparatus of the fourth embodiment can be constructed by one frame memory, which is economically superior. It becomes a device.

As is clear from the above description, the X-ray imaging apparatus according to the fourth embodiment of the present invention has a predetermined number of pixels having a pixel value larger than a predetermined value when irradiated with X-rays. When the number is larger than the number, it is determined that the X-ray irradiation is started, the image data is started to be accumulated, the accumulated value is stored a plurality of times, and the number of pixels having a pixel value larger than the predetermined value is smaller than the predetermined number. It is configured to stop accumulating when it reaches. Therefore, the X-ray imaging apparatus of the fourth embodiment can obtain an optimum image quality regardless of the output control on the X-ray irradiation apparatus side, without connecting the X-ray irradiation apparatus to the input / output unit. .

<< Fifth Embodiment >> A fifth embodiment of the X-ray imaging apparatus of the present invention will be described below with reference to the accompanying drawings. FIG. 18 is a block diagram showing the overall configuration of the X-ray imaging apparatus according to the fifth embodiment of the present invention. FIG. 19 shows the fifth
6 is a flow showing a work procedure of the digital value conversion means in the X-ray image apparatus of the embodiment. FIG. 20 shows a pixel distribution of image digital values of all pixels, and FIG. 21 shows a pixel distribution after conversion of image digital values of all pixels when the pixel range is changed. FIG. 22 is a diagram showing conversion characteristics according to the display purpose or for making it easier to see visually.

In FIG. 18, the X-ray irradiator 301 is X-ray
The irradiation object 303 is irradiated by the line 302, and the irradiation object 30
The X-ray 304 that has passed 3 is input to the signal output unit 305. The signal output means 305 outputs the image analog signal 308 corresponding to the intensity of the input X-ray 304 to the signal amplifier 309.
Output to.

The signal output means 305 is a phosphor 306 (scintillator, for example, Gd ₂ O ₂ ) that converts X-rays into visible light.
S) and CCD sensor 30 that converts visible light into electric charge and transfers it
7 and outputs an image analog signal 308 formed in accordance with the amount of light received by each pixel of the CCD sensor 307 for all pixels. Thus, the signal output unit 305 causes the image analog signal 308 according to the intensity of the X-ray.
Is output to a signal amplifier 309 which is a signal amplifying means.

The X-ray image device of the present invention uses the phosphor 3
Instead of 06, a cadmium teralite detecting element (CdTe detecting element) electrically connected to each pixel of the CCD sensor may be provided on the CCD surface. The signal amplification means 309 A / D the input image analog signal 308.
The signal is amplified so as to have a level required for conversion, and the amplified image analog signal 310 is output to the A / D converter 11, which is the A / D conversion means 3.

In the A / D converter 311, the image analog signal 310 is converted into a digital value, and the image digital value 312 is output to the storage section 313 which is a storage means. A /
In the D converter 311, the X-ray 30 that has passed through the irradiation object
Image analog signal 310 output according to the irradiation amount of 4
Has been digitized. The image digital value 312 is stored in the storage unit 313. At this time, A /
The D converter 311 stores the data in the storage unit 313 while sequentially adding the data for each short time during X-ray irradiation. Storage unit 313
Has a capacity several times larger than the resolution of the A / D converter 311. Therefore, the storage unit 313 can hold image data having a large gradation.

The digital value converter 316, which is a digital value converting means, corrects the stored image digital value 317 and converts it into the display image digital value 318, and the storage unit 313.
Remember. Display image digital value 31 in storage unit 313
8 is input as a display digital value 314 to the display unit 315 which is a display unit. The display unit 315 outputs the image display signal 319 to the display device 320 such as a CRT and displays the image display signal 319.

Since the storage unit 313 having a capacity larger than the resolution of the A / D converter 311 holds the image data having a large gradation, the X-ray image apparatus of the fifth embodiment is capable of performing the X-ray irradiation. It is a device that can easily set conditions.

Next, the digital value converter 3 shown in FIG.
16 is a flow chart showing the work procedure of FIG. 19 and FIG.
An explanation will be given using a graph showing the pixel distribution of the image digital value of all pixels of 0. Further, FIG. 20 shows the state of the image density in the image data. ST of the flow shown in FIG.
In EP1, the digital value converter 316 includes the storage unit 3
The image digital value 317 of all the pixels once stored in 13 is taken out, and the number of pixels in the image digital value 317 is checked.

Next, in STEP 2, the pixel distribution state (density state) as shown in FIG. 20 is grasped from the checked image digital value 317. From this pixel distribution status (density status), an appropriate pixel distribution range of the image digital value 317 is determined. The appropriate pixel distribution range of the image digital value 317 is set in advance so that a predetermined number of upper and lower values in the pixel digital value 317 are removed or a predetermined rate is removed according to the application of the X-ray imaging apparatus. decide.

In STEP3 of the flow shown in FIG. 19, conversion of the image digital value 317 of all pixels is performed so that the pixel distribution range of the image digital value 317 determined in STEP2 becomes a wide range as shown in FIG. To do. Figure 2
1 is a graph showing an example of the image digital value 317 of all pixels changed to an appropriate pixel distribution range.

Next, an example of a conversion method for converting the maximum value and the minimum value of the image digital value 317 into the maximum value and the minimum value of the display image digital value 318 will be shown. The maximum value and the minimum value of the image digital value 317 that can be detected from the pixel distribution state are Bmax.
And Bmin. The maximum value and the minimum value of the display image digital value 318 are defined as Hmax and Hmin. When the image digital value 317 before conversion is Bdata and the display image digital value 318 after conversion is Hdata, the conversion of the image digital value 317 of all pixels is performed by the following equation. Hdata = ax
Bdata / b-c / b

[0113] However, a = Hmax-Hmin, b = Bmax−Bmin, c = Hmax × Bmin−Hmin × Bmax.

As shown in the above equation, it is feared that the resolution of the image may be deteriorated by performing the conversion for widening the pixel distribution range.
This can be solved by increasing the resolution of the converter 311.
Further, by increasing the capacity of the storage unit 313 and making the gradation of each pixel larger than the resolution of the A / D converter 311, it is possible to increase the margin until data saturation in the storage unit 313.

Next, a specific method of density correction will be described. FIG. 22 is a diagram showing conversion characteristics for making an image easier to see according to a display purpose. In STEP 4 of the flow shown in FIG. 19, the density correction is performed on the image digital values of all pixels according to the display purpose as shown in FIG. In the conversion characteristic shown in FIG. 22, changing the size of the image digital value and changing the image brightness, that is, the density are exactly the same operations.

When an inspector who views an X-ray image wants to see a bright portion, it is converted by the characteristic of γ1 which is close to a straight line. On the contrary, when he wants to see the dark portion in more detail, it is converted by the characteristic of γ2 which widens the range of the dark portion. To do. Next, in STEP 5, the converted display image digital value 318 is stored in the storage means 3.
In step 13, the original image digital value 317 is replaced with the original image digital value 317, and the image is again stored in the storage unit 313.

Further, the display unit 315 causes the storage unit 313 to operate.
The updated display digital value 314 is displayed as an image on the display device 320 such as a CRT. As described above, the X-ray imaging apparatus according to the fifth embodiment can widen the range of brightness of the displayed image, and the conversion characteristic according to the display purpose allows
It is possible to obtain a visually excellent image.

Further, the X-ray imaging system of the fifth embodiment is
There is no difficulty in setting the time and distance when irradiating a line,
The condition setting is easy and easy to use, and the storage unit having a capacity larger than the resolution of the A / D conversion unit holds the image data having a large gradation, which further enhances the ease of setting the condition. It is easy to set the conditions for irradiation.

<< Sixth Embodiment >> A sixth embodiment of the X-ray imaging apparatus of the present invention will be described below. The X-ray imaging apparatus of the sixth embodiment is a modification of the signal amplifier 309 which is the signal amplifying means in the X-ray imaging apparatus of the fifth embodiment described above.

The X-ray imaging apparatus according to the sixth embodiment of the present invention is
The signal amplifier 309 of the X-ray imaging apparatus of the fifth embodiment described above.
Is amplified so that the smaller the image analog signal is, the smaller the image analog signal is amplified. This amplifier has a conversion characteristic such as γ2 shown in FIG. 22, for example, and a smaller signal which X-rays are less likely to pass through is amplified more, and an image analog signal is output in a state where the dark portion has a wider density range. This image analog signal is A / D converted by the A / D conversion means and becomes a digital value, which is displayed on the display device 320 such as a CRT in the same manner as the X-ray image apparatus according to the fifth embodiment of the present invention.

X of the sixth embodiment constructed as described above
The line image device can more finely display the image in the dark portion than the image in the bright portion, and can obtain a visually excellent image. Further, the X-ray imaging apparatus of the sixth embodiment eliminates the difficulty of time setting and distance setting for X-ray irradiation, makes it easy to set conditions during X-ray irradiation, and is easy to use. The fact that the image data is held by the storage means having a capacity several times larger than the resolution of the / D conversion means further enhances the ease of setting conditions.

Since the X-ray imaging apparatus of the second embodiment detects abnormal data using the luminance distribution of a predetermined amount of pixels in the image data stored in the image data storage means, the abnormal data continues. Even in such a case, the correction process of the image data can be performed with high accuracy.

[0123]

As is apparent from the above description, the X-ray imaging apparatus of the present invention causes the designated pixel to be abnormal if the designated pixel is larger than the maximum value of the surrounding pixels by a predetermined value or more. Since the data is determined, the abnormal data can be reliably determined, and the image data correction process can be performed with high accuracy.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of an X-ray imaging apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an example of a relationship between the size of image data and brightness in the X-ray imaging apparatus of the first embodiment.

FIG. 3 is a diagram conceptually showing some pixels of the CCD sensor used in the description of the filter for removing white spot abnormal data in the X-ray imaging apparatus of the first embodiment.

FIG. 4 is a flowchart showing a processing procedure of a filter for removing white spot abnormal data in the X-ray imaging apparatus of the first embodiment.

FIG. 5 is a block diagram showing an overall configuration of an X-ray imaging apparatus according to a second embodiment of the present invention.

FIG. 6 is a flowchart showing a processing procedure of a filter for removing white spot abnormal data in the X-ray imaging apparatus of the second embodiment.

FIG. 7 is a graph showing a luminance distribution when there is no white spot abnormality data in the X-ray imaging apparatus of the second embodiment.

FIG. 8 is a graph showing a luminance distribution when there is white spot abnormality data in the X-ray imaging apparatus of the second embodiment.

FIG. 9 is a flowchart showing a processing procedure of a filter for removing white spot abnormal data in the X-ray imaging apparatus of the second embodiment.

FIG. 10 is a diagram showing a floppy disk, a floppy disk drive, and the like of the X-ray imaging apparatus of the second embodiment, and FIG. 10A is a diagram showing an example of a physical format of a floppy disk that is a storage medium body (B) is a diagram showing a floppy disc case for accommodating a floppy disc, and (c) is a diagram showing a floppy disc drive and the like for recording and reproducing a program by the floppy disc.

FIG. 11 is a block diagram showing an overall configuration of an X-ray imaging apparatus according to a third embodiment of the present invention.

FIG. 12 is a flowchart showing a processing procedure from irradiation start to accumulation start in the X-ray imaging apparatus of the third embodiment.

FIG. 13 is a flow chart showing a processing procedure from accumulation start to image display in the X-ray imaging apparatus of the third embodiment.

FIG. 14 is a block diagram showing an overall configuration of an X-ray imaging apparatus according to a fourth embodiment of the present invention.

FIG. 15 is a flowchart showing a processing procedure from irradiation start to accumulation start in the X-ray imaging apparatus of the fourth embodiment.

FIG. 16 is a flowchart showing a processing procedure from the accumulation start to the accumulation stop in the X-ray imaging apparatus of the fourth embodiment.

FIG. 17 is a flowchart showing a processing procedure from accumulation stop to image display in the X-ray imaging apparatus of the fourth embodiment.

FIG. 18 is a block diagram showing the overall configuration of an X-ray imaging apparatus according to a fifth embodiment of the present invention.

FIG. 19 is a flowchart showing the work procedure of the digital value converter in the X-ray imaging apparatus of the fifth embodiment.

FIG. 20 is a graph showing a pixel distribution of image digital values of all pixels in the X-ray imaging apparatus of the fifth embodiment.

FIG. 21 is a graph showing a pixel distribution after image digital value conversion of all pixels in the X-ray imaging apparatus of the fifth embodiment.

FIG. 22 is a graph showing conversion characteristics for forming an image that is easy to see or visually according to the display purpose in the X-ray imaging apparatus of the fifth embodiment.

FIG. 23 is a block diagram showing the overall configuration of a conventional X-ray imaging apparatus.

FIG. 24 is a flowchart showing a processing procedure from irradiation start to image display in the conventional X-ray imaging apparatus.

FIG. 25 is a diagram conceptually showing a pixel configuration of a CCD sensor.

FIG. 26 is a diagram conceptually showing an image analog signal output from the CCD sensor and an A / D conversion method.

[Explanation of symbols]

1 X-ray 2 CCD element 4 A / D converter 5 line buffer 6 White spot abnormal data removal filter 7 frame memory 8 CPU 9 Image display device 10 CPU 11 Image data acquisition unit 12 Image display section 14 storage media

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G06T 1/00 290 G06T 5/00 300 5C077 5/00 300 H04N 5/32 H04N 1/409 5/335 P 5/32 A61B 6/00 350Z 5/335 303F H04N 1/40 101C (72) Inventor Yasuo Omori 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Yasuhiko Maji Kadoma City Daiji 1006 Kadoma Matsushita Electric Industrial Co., Ltd. F term (reference) 2G001 AA01 BA11 CA01 DA09 HA07 HA13 JA13 KA03 LA01 2G088 EE01 EE30 FF02 GG19 GG20 GG21 JJ05 KK32 LL11 LL12 4C093 AA01 CA01 CA01 CA01 CA17 CA12 CA01 CA17 CA12 CA12 CA01 CA12 CA01 CA12 CA01 CA17 CA17 CA12 CA12 CA01 CA12 FD05 FD09 FD20 FF01 FF08 FH02 FH04 5B057 AA08 BA03 CA08 CA12 CA16 CB08 CB12 CB16 CC02 CE02 5C024 AX12 CX22 GY01 5C077 LL02 M P01 PP02 PP43 PP47 PP68 PQ12 PQ20 PQ25 SS06

Claims (3)

[Claims] 1. An image data output unit having a plurality of pixels, which receives X-rays passing through an irradiation target and sequentially outputs image data corresponding to the intensity of the X-rays for each pixel, and output from the image data output unit. First image data storage means for temporarily storing the image data of the designated pixel and the image data of the peripheral pixels, and the first image data storage means, When the stored image data is input and the image data of the designated pixel is larger than the maximum value of the image data of the peripheral pixels by a predetermined value or more, it is determined that the image data of the designated pixel is abnormal data. An abnormal data removing unit for correcting the abnormal data, and image data sequentially input from the first image data storage unit and corrected by the abnormal data removing unit in order. An X-ray image device including a second image data storage unit that stores the image data for all pixels, which is stored next and sequentially output from the image data output unit and subjected to the correction processing. 2. When the abnormal data removing means determines that the image data of the designated pixel is abnormal data, the image data of the designated pixel is replaced with the maximum value of the image data of the peripheral pixels. Item 1. The X-ray imaging apparatus according to Item 1. 3. When the abnormal data removing means determines that the image data of the designated pixel is abnormal data, the image data of the designated pixel is replaced with the average value of the image data of the peripheral pixels. Item 1. The X-ray imaging apparatus according to Item 1.