JP3465700B2 - Panoramic X-ray equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dental X-ray diagnostic apparatus for panoramic X-ray photography.

[0002]

2. Description of the Related Art As a prior art of a panoramic X-ray photographing apparatus, there is a prior art of Japanese Patent Laid-Open No. 57-166144, in which an X-ray image sensor including a CCD or the like is used to perform electrical image processing and display a screen. It is written.

In Japanese Utility Model Publication No. 4-48169 and Japanese Patent Application Laid-Open No. 8-215191, a panorama X is realized by driving a CCD while sequentially changing a clock frequency during photographing.
The prior art for taking a line is described.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
No. 44, Japanese Utility Model Publication No. 4-48169, and Japanese Patent Laid-Open No. 8-48169.
Japanese Patent No. 215191 describes that only an X-ray image sensor including a CCD is used as an X-ray image receiving means.
No mention is made as to whether or not an X-ray image sensor including a CCD can be attached or detached, and whether or not photographing can be performed using a film in the photographing device. In actual use, there is absolutely no demand for film-based photography, and C
It is considered necessary to be able to easily switch between shooting using an X-ray image sensor including a CD and shooting using film.

Further, Japanese Utility Model Publication No. 4-48169, Japanese Patent Laid-Open No.
In JP-A 8-215191, the clock frequency is changed sequentially.
Although the CCD drive system to be used is described, it is actually used in the drive circuit.
Many clock frequencies required for panoramic X-ray photography of
The maximum clock frequency and the minimum clock frequency
The ratio is about 3: 1 and the maximum clock frequency and minimum clock frequency
Obtains slightly different clock frequencies between lock frequencies
As many clock frequency generators as possible
Set up or prepare one clock generator and set maximum clock
The ratio of frequency to minimum clock frequency is about 3: 1
And between the maximum clock frequency and the minimum clock frequency
Frequency divider circuit that can obtain different clock frequencies
It is difficult to actually realize the drive circuit
It will be difficult.

Further, the size of the film used in the conventional panoramic X-ray photography is 300 mm in width and 150 mm in length, and an image of the same size as the image obtained when the film is used in a panoramic X-ray photography apparatus using a CCD sensor. In order to obtain, it is necessary to prepare a long CCD sensor with a length of 150 mm or more.
Achieving a length of mm becomes very difficult in manufacturing.

In view of the above problems, the present invention makes it possible to easily switch between film-based shooting and CCD-based shooting by replacing the cassette without changing the conventional panoramic X-ray imaging apparatus. It is something to do.

Further, in the CCD driving circuit, the number of clock frequency transmitting elements for generating the clock frequency is one, and it is possible to perform panoramic X-ray photography without switching the clock frequency.

Further, a long sensor for panoramic X-ray photography can be easily realized.

[0010]

[0011]

[0012]

In order to achieve the above object, the first panoramic X-ray imaging apparatus of the present invention comprises a plurality of Cs.
The CD sensors are arranged vertically in a row along the secondary slits of the cassette mounting portion, and the effective pixels of the CCD sensors which are tilted in the same direction in the depth direction when the cassette mounting portion is viewed from the X-ray generator and vertically adjacent to each other The unit is provided with a long CCD sensor which is arranged so as to overlap the front and rear in the depth direction when the cassette mounting unit is viewed from the X-ray generation unit.

Also, in the second panoramic X-ray imaging apparatus of the present invention, a plurality of CCD sensors are arranged in a line vertically along the secondary slits of the cassette mounting section, and the cassette mounting section is viewed from the X-ray generation section. A long CCD sensor that is arranged so that every other effective pixel portion of the CCD sensor that is vertically shifted in the depth direction and vertically adjacent to each other overlaps in the depth direction from the X-ray generation portion to the cassette mounting portion in the depth direction. It is equipped with.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION With the panoramic X-ray photographing apparatus having the above-mentioned structure, it is possible to easily switch between photographing using a film and photographing using a CCD sensor.

Further, panoramic tomographic X-ray photography can be realized by a simple CCD sensor construction and an easy CCD drive circuit construction, and a long CCD sensor for panoramic X-ray photography can be easily obtained.

An embodiment of a panoramic X-ray imaging apparatus according to the present invention will be described below with reference to the drawings.

According to the present invention, the driving of the sensor can be easily controlled by creating and using the timing information regarding the photographing using an arbitrary photographing object.

Further, by using the timing information relating to the photographing of the photographing object and the constant reference signal together,
The drive signal control of the sensor can be performed more easily.

Embodiments of an imaging timing control apparatus and an X-ray imaging apparatus according to the present invention will be described below with reference to the drawings, taking a panoramic X-ray imaging apparatus for dentistry as an example.

FIG. 1 shows a panorama X showing the first embodiment.
It is a block diagram of a configuration of the radiographic apparatus. In FIG. 1, 1 is an X-ray generation unit that generates X-rays, 2 is a cassette mounting unit that mounts a sensor cassette into which a CCD sensor is inserted,
3 is a sensor cassette into which a CCD sensor is inserted, 4
Is a CCD sensor, 5 is an operation management unit that sends a reference signal and a drive start signal, 6 is a drive signal control circuit that sends a drive signal to the CCD sensor for photographing the target dentition, and 7 is C
A drive timing information output unit for outputting timing information for driving the CD sensor, 8 is a data processing circuit for processing captured image information, and 9 is a display unit for displaying the captured image.

2 (a), 2 (b) and 2 (c) are top views showing an outline of a panoramic X-ray imaging apparatus according to the present invention, respectively.
It is a side view and a top view. In FIG. 2, 10 is an X-ray irradiator that irradiates X-rays, and an X-ray generator is built in. 1
Reference numeral 1 denotes a person to be photographed, and the person to be photographed 11 is located between the X-ray irradiation unit 10 and a cassette mounting portion for mounting the sensor cassette 3 having the CCD sensor 4 inserted therein. Reference numeral 12 denotes a revolving arm that connects the X-ray irradiation unit and the cassette mounting unit, and is rotatably supported by a column 13. In the panoramic X-ray imaging apparatus configured as described above, the X-rays emitted from the X-ray irradiation unit 10 penetrate the person to be photographed 11 and are detected by the CCD sensor inserted in the sensor cassette 3 to perform X-ray imaging. Is performed, but FIG. 2 (c)
As shown in (3), the X-ray irradiator is also swung by the swivel arm 12 being swung while being supported by the support column 13, and a panoramic image can be captured.

FIG. 3 is a perspective view showing the shape and configuration of the sensor cassette 3 mounted on the cassette mounting portion. The sensor cassette 3 has a sensor unit in which the CCD sensor 4 is housed, and its position is when the sensor cassette 3 is mounted on the cassette mounting unit 2
The effective pixel portion of the CCD sensor 4 arranged inside the sensor cassette is overlapped with the secondary slit of the cassette mounting portion 2 when the cassette mounting portion 2 is viewed from above.

FIG. 4 is a schematic configuration diagram showing a first example of the long CCD sensor used in the embodiment of the present invention.
In this embodiment, the outer shape of the board is about 27 mm in length and about 21 in width.
mm, thickness about 4mm CCD sensor, effective pixel size is about 25mm in length, about 19mm in width
7 interline transfer CCD sensors are used.

Each CCD sensor is tilted in the depth direction when viewed from the X-ray generation unit 1 to the cassette mounting unit 2 so as to be tilted at an angle of about 10 degrees with respect to the vertical direction, and effective pixels are formed by vertically adjacent CCD sensors. Arrange them so that the overlap of the parts is 1 mm. This is because the CCD sensor has the elements of the sensor part mounted on the substrate, so the irradiated X-rays cannot be captured as an image only in the part of the substrate where the sensor element does not exist, so a continuous panorama. This is because the captured image cannot be obtained.

As a result, a long CCD sensor having a length of about 166 mm can be realized. Note that the outer shape of the CCD sensor, the size of the effective pixel portion, and the angle at which the CCD sensor is tilted are not limited to those used in this embodiment, and a long sensor composed of a plurality of CCD sensors is used as the sensor cassette 3. Anything that can be stored in

The overlapping of the effective pixel portions of the CCD sensors vertically adjacent to each other is not limited to 1 mm.
When the CCD sensor 4 is viewed from the line generation unit 1, it is sufficient that there is no gap between the lower end of the effective pixel portion of the CCD sensor above the adjacent CCD sensors and the upper end of the effective pixel of the lower CCD sensor.

FIG. 4 is a schematic view of the configuration of a long CCD sensor according to the second example used in the embodiment of the present invention.

In this embodiment, the external length of the base is approximately 27 m in length.
m, width 21 mm, thickness 4 mm, and 7 interline transfer CCD sensors with effective pixel size of 25 mm and width 19 mm.

Of the seven CCD sensors, the second, fourth, and sixth from the top are lowered by about 4.5 mm in the depth direction when looking at the cassette mounting portion 2 from the X-ray generation portion 1, and are also vertically adjacent. The CCD sensor is arranged so that the overlap of the effective pixel portions is 1 mm. As a result, a long CCD sensor having a length of about 169 mm can be realized.

The outer shape of the CCD sensor, the size of the effective pixel portion, and the angle at which the CCD sensor is tilted are not limited to those used in this embodiment, and a plurality of CCDs are used.
Any long sensor that can be housed in the sensor cassette 3 may be used.

The overlapping of the effective pixel portions of the CCD sensors vertically adjacent to each other is not limited to 1 mm.
When the CCD sensor 4 is viewed from the line generation unit 1, it is sufficient that there is no gap between the lower end of the effective pixel portion of the CCD sensor above the adjacent CCD sensors and the upper end of the effective pixel of the lower CCD sensor.

With respect to the panoramic X-ray imaging apparatus constructed as described above, the imaging procedure will be described below.

First, the sensor cassette 3 is mounted on the cassette mounting portion 2 and the person 11 to be photographed is positioned between the X-ray irradiation portion 10 and the sensor cassette 3.

Next, the dentition to be imaged is selected in the photographic device main body, and drive timing information corresponding to the dentition to be imaged selected in the photographic device main body is sent from the drive timing information output unit 7 to the drive signal control circuit 6. .

The drive timing information is derived through the process shown in FIG. The procedure for deriving the drive timing information will be described below with reference to the drawings.

FIG. 6A is a graph showing the change in the film feed speed V (t) according to the tooth row to be imaged selected in the image taking apparatus main body, where the horizontal axis is the elapsed time from the start of image taking and the vertical axis is the vertical axis. Is the film feed speed at each time. The curve of this graph shows, for example, that the dentist 11
Of the dentition is selected and an arbitrary curve that fits the dentition of the subject is selected from a plurality of samples.

FIG. 6 (b) shows the time required for the film to move a certain distance from the start of photographing from the film feed speed V (t) shown in FIG. 6 (a). The moving distance of the film from the start of shooting, and the vertical axis is the time from the start of shooting.

FIG. 6 (c) is a partially enlarged view of FIG. 6 (b). In the figure, a is the arrangement interval of pixels in the horizontal direction of the CCD sensor 4 in the state of being mounted in the sensor cassette 3, n is an integer of 0 or more, and t _n is the time required for the film to move the distance na from the start of shooting.

[0039] t _n a divided by the transmission time interval w of the reference signal T _n, a divided by the transmission interval time w of t n _{+ 1} the reference signal and _{T n + 1, T n +} 1 and T The difference of _n is obtained, and the first decimal place of the obtained difference is rounded off to obtain an integer w _n . A numerical sequence in which W _n obtained for each n of 0 or more is sequentially arranged becomes drive timing information according to the imaging target dentition.

FIG. 6D shows a graph in which the horizontal axis is n and the vertical axis is the value of W _n corresponding to each n.

Next, the drive signal control circuit 6 starts transmitting the drive signal to the CCD sensor 4 while controlling the transmission timing based on the drive timing information. CC
Driving of the D sensor will be described with reference to FIG. 7.

The photographing operation management unit 5 starts transmitting a reference signal, and this reference signal is input to the counter unit 17. Further, the photographing operation management unit 5 sends a drive start signal to the drive signal control circuit 6. The drive start signal is a signal for initializing the drive signal control circuit 6, and the operation of the drive signal control circuit 6 is started by receiving the drive start signal.

The reference register 16 is initialized by the drive start signal from the photographing operation management section 5, and the first drive timing information is written.

The drive timing information holding unit 14 receives and holds the drive timing information necessary for one photographing from the drive timing information output unit 7. As described above, the drive timing information is a sequence of numerical values representing the intervals at which the drive signal transmitter 17 transmits a series of drive signals.

For example, the number sequence is represented as {1, 5, 4, 3}. With this timing information, after first driving the CCD sensor 4, the CCD sensor 4 is driven at the timing of the fifth pulse output, and then the CCD sensor 4 is driven at the timing of the fourth pulse output,
Finally, at the timing when the third pulse appears after that, the CCD
This means driving the sensor 4.

Further, the next drive timing information is written in the reference register 15 by the photographing start signal transmitted from the data processing circuit 8 to the drive signal control circuit 6, and then the counter section 16 informs the drive signal transmission section 17 of the drive signal transmission start signal. Refer to the sequential drive timing information each time
Write in.

The counter section 16 sets the count number to 0 by the drive start signal from the photographing operation management section 5, and starts counting the reference signal transmitted by the photographing operation management section 5 at regular intervals. In addition, each time one counts, the count number is compared with the value written in the reference register 15, and when the count number becomes equal to the value written in the reference register 15, the drive signal transmission circuit 17 receives the drive signal. A transmission start signal is sent, and at the same time, the count number is reset to 0.

A drive signal is transmitted from the drive signal transmission unit 17 according to the value written in the reference register 15 and the count number of the counter unit 17. The drive signal control signal for controlling this drive signal is shown in FIG. An example is shown. In the reference register 15, as driving timing information, {1, 5, 4,
If the sequence 3} is written, first H
A signal is transmitted, and then H at the timing of the fifth transmission
A signal is emitted. The H signal is transmitted to the drive signal transmission unit 17, and the drive signal transmission unit receives the H signal to transmit a series of drive signals to the CCD sensor 4.

Further, in accordance with the drive signal transmitted from the drive signal transmitting section 13, the charge is transferred from the photodiode to the vertical register in the CCD sensor 4 and the charge for one stage is directed in the horizontal transfer register direction in the vertical register. And the charge in the horizontal transfer register is sent to the data processing circuit 8.

Further, the data processing circuit 8 sends a photographing start signal to the drive signal control circuit 6 after detecting a change in the image signal output from the CCD sensor 4 due to the start of X-ray irradiation, for example. This photographing signal is a signal for instructing to store the image information detected by the CCD sensor in the memory. A display image is generated based on the image information stored in this memory. After the drive signal is transmitted to the CCD sensor 4, the image signal output from the CCD sensor 4 to the data processing circuit 8 is started.

After the photographing, the display image generated by the data processing circuit 8 is displayed on the display means 9.

According to the present embodiment, by counting the reference signals based on the constant clock frequency, the CCD
By controlling the charge transfer inside the sensor, panoramic X-ray imaging can be easily realized with a simple circuit configuration.

Further, by deriving the drive timing information from the film feed speed corresponding to the tooth row to be imaged, the movement of the film and the movement of the charge in the vertical transfer register of the CCD can be easily synchronized and the tooth row to be imaged can be easily obtained. It is possible to perform panoramic X-ray photography according to the above.

As is clear from the above description, according to the panoramic X-ray imaging apparatus of the present embodiment, the cassette mounting portion is provided with the sensor cassette that can be detached at any time, and the CCD sensor is arranged in the sensor cassette, so that the film It is easy to switch between shooting using and CCD shooting.

Further, a long CCD sensor for panoramic X-ray photography can be easily realized by combining a plurality of small CCD sensors.

By controlling the charge transfer inside the CCD sensor by counting the reference signals based on a constant clock frequency, panoramic X-ray photography can be easily realized with a simple circuit configuration.

Further, by deriving the drive timing information from the film feed speed corresponding to the tooth row to be imaged, the movement of the film and the movement of the electric charge in the vertical transfer register of the CCD can be synchronized with each other and the tooth row to be imaged can be easily obtained. It is possible to perform panoramic X-ray photography according to the above.

[0058]

As is apparent from the above description, according to the long CCD sensor of the present invention, a long CCD sensor for panoramic X-ray photography can be easily realized by combining a plurality of small CCD sensors.

Further, according to the long sensor for panoramic X-ray photography of the present invention, the driving timing information is derived from the film feeding speed corresponding to the tooth row to be photographed, so that the movement of the film and the vertical transfer register of the CCD are stored. The panoramic X-ray imaging according to the imaging target tooth row can be easily performed by being synchronized with the movement of the electric charges.

[Brief description of drawings]

FIG. 1 is a functional block diagram of a panoramic X-ray imaging apparatus according to an embodiment of the present invention.

2A is a top view showing an overview of a panoramic X-ray imaging apparatus according to the present invention; FIG. 2B is a side view showing an overview of a panoramic X-ray imaging apparatus according to the present invention; FIG. 2C is a panorama according to the present invention; Top view of the X-ray imaging device

FIG. 3 is an external perspective view of a sensor cassette according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram of a long sensor according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram of a long sensor according to another embodiment of the present invention.

6A is a characteristic diagram showing the relationship between time and film feed speed in one embodiment of the present invention, and FIG. 6B is a time required for the film to move a certain distance from the start of shooting in one embodiment of the present invention. And (c) is a characteristic diagram showing a relation with a time required for the film to move a certain distance from the start of photographing in one embodiment of the present invention, and a characteristic diagram showing a part of the enlarged diagram (d) of the present invention. Characteristic diagram of one embodiment

FIG. 7 is a functional block diagram of a circuit that controls driving of a CCD according to an embodiment of the present invention.

FIG. 8 is a time chart showing a drive signal control signal of a CCD according to an embodiment of the present invention.

[Explanation of symbols]

1 X-ray generator 2 Cassette mounting section 3 sensor cassette 4 CCD sensor 5 Shooting operation management section 6 Drive signal control circuit 7 Drive timing information output section 8 Data processing circuit 9 Display device 10 Drive timing information holding unit 11 Reference register 12 Counter section 13 Drive signal transmitter

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-3-150487 (JP, A) JP-A-10-57367 (JP, A) JP-A-8-215190 (JP, A) JP-A-3- 189585 (JP, A) JP 3-102285 (JP, A) JP 8-313640 (JP, A) JP 61-45794 (JP, B2) International publication 96/007354 (WO, A1) International Publication 98/003011 (WO, A1) (58) Fields investigated (Int.Cl. ⁷ , DB name) A61B 6/00-6/14

Claims (2)

(57) [Claims] 1. A plurality of CCD sensors are arranged in a line vertically along a secondary slit of the cassette mounting section, and the cassette mounting section is viewed from the X-ray generating section in the same depth direction and tilted vertically. A panoramic X-ray imaging apparatus provided with a long CCD sensor in which effective pixel portions of adjacent CCD sensors are arranged so as to overlap with each other in the depth direction when the cassette mounting portion is viewed from the X-ray generation portion . 2. A plurality of CCD sensors are arranged in a line in a row along a secondary slit of the cassette mounting section, and the CCD mounting section is viewed from the X-ray generation section, and every other CCD sensor is shifted back and forth in the depth direction. A panoramic X-ray imaging apparatus provided with a long CCD sensor in which effective pixel portions of vertically adjacent CCD sensors are arranged so as to overlap with each other in the depth direction from the X-ray generation portion when viewed from the cassette mounting portion .