JPS6352760B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a portable X-ray generator that can be suitably used for medical purposes, for example.

BACKGROUND ART Conventionally, for example, when performing X-ray photography of tooth roots in dentistry, it is common to insert an X-ray film into the oral cavity and take a transmission image by irradiating X-rays from the outside. However, this method is inappropriate when observing the condition of tooth roots in real time using, for example, a cathode ray tube, or when transmitting images remotely. Therefore, when such a request is made, it is necessary to insert an X-ray tube that emits X-rays into the oral cavity and place an X-ray imaging device outside, but this can be done without causing pain to the patient. Moreover, it is quite difficult to insert an X-ray tube into the oral cavity while ensuring electrical safety.

In response to such demands, a medical X-ray generator 1 as shown in FIG. 1 has been known.
This device is composed of an X-ray tube section 2 that emits X-rays from the tip of a narrow diameter section, a high-voltage cable 3, a high-voltage power supply section 4, and a power supply cable 5. They are separated, and both are connected by a high voltage cable 3. This device 1 boosts and rectifies AC power supplied from a power cable 5 using a high-voltage transformer in a high-voltage power supply section 4 to supply the necessary high voltage to an X-ray tube section 2, and also supplies a filament power supply using a heater transformer. These power sources are supplied to the X-ray tube section 2 through a high-voltage cable 3.
In this case, each part to which high voltage is applied needs to be highly electrically insulated, and the high voltage power supply section 4
and the connection between the high voltage cable 3 and the high voltage cable 3.
The device itself and the connecting portion between the high-voltage cable 3 and the X-ray tube section 2 are necessarily large-sized. As described above, since the conventional device 1 has a structure in which the X-ray tube section 2 and the high-voltage power supply section 4 are separated, the high-voltage connection section is large and the
A thick high-voltage cable 3 must be connected to the rear of the X-ray tube section 2, making it difficult to move the X-ray tube section 2 to a convenient location for diagnosis. In addition, there are cases where there is a possibility of high voltage leakage accidents.
For example, when the X-ray tube section 2 is inserted into the oral cavity, there is a safety concern.

The purpose of the present invention is to provide a portable X-ray generator that can be safely used in such medical equipment, is small and easy to handle, and the gist thereof is to A glass X-ray tube has an electrically conductive target at the tip of its narrow diameter section and emits X-rays from the target, and includes a base section other than the narrow diameter section, a rechargeable battery, and an external energy supply. a charging circuit that receives energy from a source via an electrical insulator and charges the battery; a high-voltage power generation circuit that boosts the voltage supplied from the battery and applies it to the X-ray tube; and a high-voltage power generation circuit that can be remotely operated from the outside. The switch is integrally surrounded by an electrically insulating material, the entire circumference of the X-ray tube including the narrow diameter portion is completely covered with a conductive material, and the target is electrically connected to the conductive material. It is characterized by this.

The present invention will be explained in detail based on the embodiments shown in FIG. 2 and below.

FIG. 2 shows X which can be suitably used in the embodiment of the present invention.
It is a cross-sectional view of the wire tube 11, and 12 is a sealed tube made of glass, and is composed of a large diameter part 13 with a diameter of about 20 to 30 mm and a small diameter part 14 with a diameter of about 6 mm, for example. The inside is sealed with a vacuum or gas. A dot-shaped filament 15 for generating an electron beam is arranged inside the large diameter portion 13, and the filament 1
A current is applied to heat the 5 itself, and further e.g.
Lead wires 16a and 16b for supplying DC high voltage of about 60kV from the outside are connected, and the pipe body 12
being pulled out of the Further, a target 17 made of metal such as tungsten, copper, or platinum is arranged inside the tip of the narrow diameter portion 14 and converts the accelerated electron beam into X-rays. It is connected to the. Furthermore, the window 19 through which the X-rays emitted from the target 17 pass is made of a material such as glass, titanium, or copper that blocks soft X-rays, but may be made of beryllium or the like that transmits soft X-rays as necessary. It can also be made from materials. Further, one or more annular permanent magnets 20 are disposed around the narrow diameter section 14, and the position thereof can be appropriately moved and adjusted along the narrow diameter section 14. In addition, 21 is a power supply part, which includes a filament power supply 22 for heating the filament 15 and a high voltage power supply 23 for accelerating the electron beam generated from the filament 15.
It consists of

Therefore, in this X-ray tube 11, first, a current is supplied from the filament power source 22, and the filament 15 is supplied with current.
When heated, an electron beam is generated from the filament 15. Subsequently, by applying a high voltage from the high voltage power supply 23, the electron beam is accelerated and advances toward the target 17 in front. This electron beam will be attracted to the target 17 depending on the polarity of the target 17, and will collide with it.
cannot be concentrated in a very small area. Therefore, when the permanent magnet 20 is arranged around the narrow diameter portion 14, the electron beam can be moved along the central axis of the permanent magnet 20 by appropriately selecting the magnetic force and position of the permanent magnet 20. Target 1
It is possible to focus on a minute area portion of 7 and cause the collision to occur efficiently. The electron beam colliding with the target 17 generates X-rays, which pass through the window 19 of the tube body 12 and are scattered to the outside.

Note that an electrostatic lens may be provided in the large diameter portion 13 and used in combination to control the focusing of the electron beam.
It is desirable that the main control is performed by the permanent magnet 20 disposed around the narrow diameter portion 14. In this case, the permanent magnet 20 does not require an external power source, and, for example, the small diameter portion 14
Safety is guaranteed even when inserted into the oral cavity. Also,
Since the permanent magnet 20 is provided outside the narrow diameter portion 14, the electron beam can be easily focused on the target 17 by adjusting the position of the permanent magnet 20 after the tube body 21 is sealed. It also has advantages.

FIG. 3 shows an embodiment in which the narrow diameter portion 14 is bent as necessary and a permanent magnet 20 is arranged along the periphery of the bent portion 24. In this case as well, the electron beam is focused by the permanent magnet 20. bending part 2 while
4, and can collide with a small area portion of the target 17.

This X-ray tube 11 is made practical by applying approximately 60 kV as a high-voltage power supply and passing a filament current of approximately 1 mA, and is different from the conventional ordinary X-ray tube.
An output of about 1/1000, for example 0.1 to 0.3R, can be obtained. Even with such a small output X-ray tube 11, it is possible to obtain an X-ray transmitted image by arranging an imaging device with high multiplication, such as a channel plate, on the imaging side.

FIG. 4 shows an embodiment of a portable X-ray generator 30 according to the present invention using the X-ray tube 11 described above. Here, the basic part consisting of the large diameter part 13 of the X-ray tube 11 includes a rechargeable reversible battery 31, a high voltage generation circuit 32,
Together with the charging circuit 33, it is molded with, for example, a synthetic resin having high insulation properties. The periphery of this molded insulator 34 and the narrow diameter portion 14 of the X-ray tube 11
The surrounding area is covered with a case 35 made of a conductive material such as a metal plate and capable of electrostatic shielding.
The target 17 is grounded to the case 35.
The X-ray tube 11 uses a battery 31 as an energy supply source, but since the battery 31 itself has a low voltage, it is converted to alternating current by an oscillation circuit in a high voltage generation circuit 32, and then boosted by a transformer to be used as a high voltage power source. It's becoming like that.

What is important here is that this portable X-ray generator 30 has no external connection wiring, and it is impossible to connect the wiring at all, so the battery 31 can be replaced while still being sealed inside. It has become impossible to do so. This is done in consideration of human safety, and in order to use the battery 31 repeatedly, the battery 31 is charged without physical or electrical contact with an external energy supply source. For example, as shown in FIG. 5, in the charging circuit 33,
Using a core 37 around which a coil 36 is wound, a core 39 around which a coil 38 is similarly wound is connected from the outside by adjacent transformer coupling. That is, in this case, the charging circuit 33 uses a core 37 having a substantially C-shape with both ends facing outward, and a secondary coil 36 wound around the core 37.
When the cross-section of the core 39 through which a commercial alternating current is passed is fixed close to the secondary coil 36, a voltage is induced in the secondary coil 36, and the generated current is rectified by the rectifier circuits 40a and 40b in the charging circuit 33, and the battery 31 can be charged to. In this case, the case 35 needs to be made of a non-magnetic material such as aluminum or copper.

Furthermore, a switch is required to operate this X-ray generator 30, and this device 30 has a built-in switch 41 for heating the filament 15 and a switch 42 for applying high voltage to the filament 15. There is. These switches 4
If the filament 15 is turned on and the high voltage is supplied to it at the same time, only one 1 and 42 is required, but if high voltage is applied before the temperature of the filament 15 has risen sufficiently, it may cause damage to the human body. There is a problem that harmful soft X-rays are generated. Since it is a safety problem to draw out the internal wiring on the surface of the case 35, the switches 41 and 42 need to be buried in the molded insulator 34 and operated remotely from the outside. For example, a reed switch operated by applying a magnetic field or an optical switch 44 using an optical fiber 43 as shown in FIG. 6 can be used. In the case of this optical switch 44, if a hole 45 is made on the outer surface of the case 35, a conductive paint 46 that transmits light is embedded in the hole 45, and the end of the optical fiber 43 is buried inside the hole 45, it can be modulated from the outside. By supplying the light to the optical fiber 43, the internal optical switch 44 can be operated. switch 42 especially for high voltage supply
For example, it is preferable to use a switch that can selectively perform instantaneous operation, intermittent operation for time-lapse shooting, or continuous operation for only the necessary time for continuous irradiation. be.

In the above-described embodiment, the focusing control of the electron beam of the X-ray tube 11 was performed by the permanent magnet 20, but there is no problem if the focusing control is performed by an electrostatic lens in the large diameter portion 13. Further, for the mold insulator 34, insulating oil or the like can also be used instead of synthetic resin. Other methods of charging the battery 31 include storing the vibrational energy using ultrasonic waves, charging by irradiating light with a solar cell as a battery, and using a piezo transformer. It is also possible to use

In this X-ray generator 30, since the case 35 is at the ground potential of the target 17, etc.
5 does not become a high voltage, and there is no risk of shock to the patient due to high voltage leakage. Therefore, if the switches 41 and 42 are operated in such a state, X-rays are output from the target 17, making it possible to easily observe or photograph a transmitted image of the tooth root for dental treatment. In addition, since the battery is rechargeable, there is no need to provide a battery attachment/detachment mechanism, and the device configuration is simple. Also, since a non-contact charging method is adopted, the case 35 does not have electrode terminals, etc. Extremely safe. Note that the operating state of the switch and the charging state of the battery can also be confirmed using the LED provided in the device 30.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a conventional X-ray generator, Fig. 2 and the following show an embodiment of a portable X-ray generator according to the present invention, Fig. 2 is a cross-sectional view of an X-ray tube, and Fig. 3 4 is a configuration diagram of the X-ray generator, FIG. 5 is a configuration diagram for charging by transformer coupling, and FIG. 6 is a configuration diagram of an optical switch. . 11 is an X-ray tube, 12 is a tube body, 13 is a large diameter part, 14 is a small diameter part, 15 is a filament, 17 is a target, 20 is a permanent magnet, 21 is a power supply part, 2
2 is a filament power supply, 23 is a high voltage power supply, 30 is a portable X-ray generator, 31 is a battery, 32 is a high voltage generation circuit, 33 is a charging circuit, 34 is a molded insulator, 35 is a case, 36 is a coil, 37 is the core,
41, 42 are switches, 43 is an optical fiber, 44
is a light switch.

Claims (1)

[Scope of Claims] 1. A base body excluding the narrow diameter part of a glass X-ray tube that has a conductive target inside the tip of the narrow diameter part through which the electron beam passes and emits X-rays from the target. a rechargeable battery, a charging circuit that receives energy from an external energy source via an electrical insulator and charges the battery, and a high-voltage power source that boosts the voltage supplied from the battery and applies it to the X-ray tube. A generator circuit and a switch that can be operated remotely from the outside are integrally surrounded by an electrically insulating material, and the entire periphery of the X-ray tube, including the narrow diameter part, is completely covered with a conductive material, and the target is is electrically connected to the conductive material.
Line generator. 2. The portable device according to claim 1, wherein the charging circuit is provided with a core around which a secondary coil is wound, and the core around which the primary coil is wound and current is passed through is transformer-coupled in close proximity from the outside. X-ray generator. 3. The portable X-ray generator according to claim 1, wherein the switch is a reed switch and is activated by supplying a magnetic field from outside. 4. Claim 1, wherein the switch is a light switch, and is activated by receiving light from the outside through a conductive paint or an electrically insulating material.
The portable X-ray generator described in Section 1.